* [PATCH 0/8] Remove malloc hooks
@ 2021-06-24 18:23 Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 1/8] Move glibc.malloc.check implementation into its own file Siddhesh Poyarekar
` (7 more replies)
0 siblings, 8 replies; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-24 18:23 UTC (permalink / raw)
To: libc-alpha; +Cc: dj, carlos, fweimer
This patchset removes the malloc hooks __malloc_hook, __free_hook,
__realloc_hook and __memalign_hook from the API and leaves compatibility
symbols so that existing applications can continue to link to them. The
reading and execution of the hooks has been moved to a DSO
libmalloc_compathooks.so, which can be preloaded for applications that
need it. By default these hooks no longer have any effect in the
library.
Further, the __morecore, __morecore_after_hook and __default_morecore
hooks have also been moved to compat symbols and removed from the API.
Existing applications will continue to link to them but they won't have
any effect on malloc behaviour.
To enable this, the MALLOC_CHECK_, mcheck() and mtrace() hooks have been
weaned away from hooks. In the process, some mcheck() failures have
been fixed and the overall behaviour is now simpler to follow.
This patchset depends on the mcheck testing infrastructure I've proposed
to expand coverage of tests:
https://sourceware.org/pipermail/libc-alpha/2021-June/127861.html
Siddhesh Poyarekar (8):
Move glibc.malloc.check implementation into its own file
malloc: Move malloc hook references to hooks.c
glibc.malloc.check: Wean away from malloc hooks
mcheck: Wean away from malloc hooks
mtrace: Wean away from malloc hooks
Remove malloc hooks
Remove __after_morecore_hook
Remove __morecore and __default_morecore
Makeconfig | 2 +-
NEWS | 14 +
include/malloc.h | 11 +-
include/stdlib.h | 3 -
malloc/Makefile | 19 +-
malloc/Versions | 3 +
malloc/arena.c | 26 +-
malloc/hooks.c | 542 +++++++-----------
malloc/malloc-check.c | 376 ++++++++++++
malloc/malloc-compathooks.c | 166 ++++++
malloc/malloc-internal.h | 6 +
malloc/malloc.c | 233 ++++----
malloc/malloc.h | 27 -
malloc/mcheck-hooks.c | 411 +++++++++++++
malloc/mcheck-init.c | 14 +-
malloc/mcheck.c | 369 +-----------
malloc/morecore.c | 15 +-
malloc/mtrace-hooks.c | 137 +++++
malloc/mtrace.c | 233 +-------
manual/memory.texi | 191 +-----
sysdeps/mach/hurd/i386/libc.abilist | 1 +
sysdeps/unix/sysv/linux/aarch64/libc.abilist | 1 +
sysdeps/unix/sysv/linux/alpha/libc.abilist | 1 +
sysdeps/unix/sysv/linux/arc/libc.abilist | 1 +
sysdeps/unix/sysv/linux/arm/be/libc.abilist | 1 +
sysdeps/unix/sysv/linux/arm/le/libc.abilist | 1 +
sysdeps/unix/sysv/linux/csky/libc.abilist | 1 +
sysdeps/unix/sysv/linux/hppa/libc.abilist | 1 +
sysdeps/unix/sysv/linux/i386/libc.abilist | 1 +
sysdeps/unix/sysv/linux/ia64/libc.abilist | 1 +
.../sysv/linux/m68k/coldfire/libc.abilist | 1 +
.../unix/sysv/linux/m68k/m680x0/libc.abilist | 1 +
.../sysv/linux/microblaze/be/libc.abilist | 1 +
.../sysv/linux/microblaze/le/libc.abilist | 1 +
.../sysv/linux/mips/mips32/fpu/libc.abilist | 1 +
.../sysv/linux/mips/mips32/nofpu/libc.abilist | 1 +
.../sysv/linux/mips/mips64/n32/libc.abilist | 1 +
.../sysv/linux/mips/mips64/n64/libc.abilist | 1 +
sysdeps/unix/sysv/linux/nios2/libc.abilist | 1 +
.../linux/powerpc/powerpc32/fpu/libc.abilist | 1 +
.../powerpc/powerpc32/nofpu/libc.abilist | 1 +
.../linux/powerpc/powerpc64/be/libc.abilist | 1 +
.../linux/powerpc/powerpc64/le/libc.abilist | 1 +
.../unix/sysv/linux/riscv/rv32/libc.abilist | 1 +
.../unix/sysv/linux/riscv/rv64/libc.abilist | 1 +
.../unix/sysv/linux/s390/s390-32/libc.abilist | 1 +
.../unix/sysv/linux/s390/s390-64/libc.abilist | 1 +
sysdeps/unix/sysv/linux/sh/be/libc.abilist | 1 +
sysdeps/unix/sysv/linux/sh/le/libc.abilist | 1 +
.../sysv/linux/sparc/sparc32/libc.abilist | 1 +
.../sysv/linux/sparc/sparc64/libc.abilist | 1 +
.../unix/sysv/linux/x86_64/64/libc.abilist | 1 +
.../unix/sysv/linux/x86_64/x32/libc.abilist | 1 +
53 files changed, 1526 insertions(+), 1305 deletions(-)
create mode 100644 malloc/malloc-check.c
create mode 100644 malloc/malloc-compathooks.c
create mode 100644 malloc/mcheck-hooks.c
create mode 100644 malloc/mtrace-hooks.c
--
2.31.1
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH 1/8] Move glibc.malloc.check implementation into its own file
2021-06-24 18:23 [PATCH 0/8] Remove malloc hooks Siddhesh Poyarekar
@ 2021-06-24 18:23 ` Siddhesh Poyarekar
2021-06-24 19:57 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 2/8] malloc: Move malloc hook references to hooks.c Siddhesh Poyarekar
` (6 subsequent siblings)
7 siblings, 1 reply; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-24 18:23 UTC (permalink / raw)
To: libc-alpha; +Cc: dj, carlos, fweimer
Separate the malloc check implementation from the malloc hooks. They
still use the hooks but are now maintained in a separate file.
---
malloc/hooks.c | 371 +---------------------------------------
malloc/malloc-check.c | 390 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 391 insertions(+), 370 deletions(-)
create mode 100644 malloc/malloc-check.c
diff --git a/malloc/hooks.c b/malloc/hooks.c
index 8080c3f40e..57a9b55788 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -49,376 +49,7 @@ memalign_hook_ini (size_t alignment, size_t sz, const void *caller)
return __libc_memalign (alignment, sz);
}
-/* Whether we are using malloc checking. */
-static int using_malloc_checking;
-
-/* Activate a standard set of debugging hooks. */
-void
-__malloc_check_init (void)
-{
- using_malloc_checking = 1;
- __malloc_hook = malloc_check;
- __free_hook = free_check;
- __realloc_hook = realloc_check;
- __memalign_hook = memalign_check;
-}
-
-/* When memory is tagged, the checking data is stored in the user part
- of the chunk. We can't rely on the user not having modified the
- tags, so fetch the tag at each location before dereferencing
- it. */
-#define SAFE_CHAR_OFFSET(p,offset) \
- ((unsigned char *) tag_at (((unsigned char *) p) + offset))
-
-/* A simple, standard set of debugging hooks. Overhead is `only' one
- byte per chunk; still this will catch most cases of double frees or
- overruns. The goal here is to avoid obscure crashes due to invalid
- usage, unlike in the MALLOC_DEBUG code. */
-
-static unsigned char
-magicbyte (const void *p)
-{
- unsigned char magic;
-
- magic = (((uintptr_t) p >> 3) ^ ((uintptr_t) p >> 11)) & 0xFF;
- /* Do not return 1. See the comment in mem2mem_check(). */
- if (magic == 1)
- ++magic;
- return magic;
-}
-
-/* Visualize the chunk as being partitioned into blocks of 255 bytes from the
- highest address of the chunk, downwards. The end of each block tells
- us the size of that block, up to the actual size of the requested
- memory. Our magic byte is right at the end of the requested size, so we
- must reach it with this iteration, otherwise we have witnessed a memory
- corruption. */
-static size_t
-malloc_check_get_size (mchunkptr p)
-{
- size_t size;
- unsigned char c;
- unsigned char magic = magicbyte (p);
-
- assert (using_malloc_checking == 1);
-
- for (size = CHUNK_HDR_SZ + memsize (p) - 1;
- (c = *SAFE_CHAR_OFFSET (p, size)) != magic;
- size -= c)
- {
- if (c <= 0 || size < (c + CHUNK_HDR_SZ))
- malloc_printerr ("malloc_check_get_size: memory corruption");
- }
-
- /* chunk2mem size. */
- return size - CHUNK_HDR_SZ;
-}
-
-/* Instrument a chunk with overrun detector byte(s) and convert it
- into a user pointer with requested size req_sz. */
-
-static void *
-mem2mem_check (void *ptr, size_t req_sz)
-{
- mchunkptr p;
- unsigned char *m_ptr = ptr;
- size_t max_sz, block_sz, i;
- unsigned char magic;
-
- if (!ptr)
- return ptr;
-
- p = mem2chunk (ptr);
- magic = magicbyte (p);
- max_sz = memsize (p);
-
- for (i = max_sz - 1; i > req_sz; i -= block_sz)
- {
- block_sz = MIN (i - req_sz, 0xff);
- /* Don't allow the magic byte to appear in the chain of length bytes.
- For the following to work, magicbyte cannot return 0x01. */
- if (block_sz == magic)
- --block_sz;
-
- *SAFE_CHAR_OFFSET (m_ptr, i) = block_sz;
- }
- *SAFE_CHAR_OFFSET (m_ptr, req_sz) = magic;
- return (void *) m_ptr;
-}
-
-/* Convert a pointer to be free()d or realloc()ed to a valid chunk
- pointer. If the provided pointer is not valid, return NULL. */
-
-static mchunkptr
-mem2chunk_check (void *mem, unsigned char **magic_p)
-{
- mchunkptr p;
- INTERNAL_SIZE_T sz, c;
- unsigned char magic;
-
- if (!aligned_OK (mem))
- return NULL;
-
- p = mem2chunk (mem);
- sz = chunksize (p);
- magic = magicbyte (p);
- if (!chunk_is_mmapped (p))
- {
- /* Must be a chunk in conventional heap memory. */
- int contig = contiguous (&main_arena);
- if ((contig &&
- ((char *) p < mp_.sbrk_base ||
- ((char *) p + sz) >= (mp_.sbrk_base + main_arena.system_mem))) ||
- sz < MINSIZE || sz & MALLOC_ALIGN_MASK || !inuse (p) ||
- (!prev_inuse (p) && ((prev_size (p) & MALLOC_ALIGN_MASK) != 0 ||
- (contig && (char *) prev_chunk (p) < mp_.sbrk_base) ||
- next_chunk (prev_chunk (p)) != p)))
- return NULL;
-
- for (sz = CHUNK_HDR_SZ + memsize (p) - 1;
- (c = *SAFE_CHAR_OFFSET (p, sz)) != magic;
- sz -= c)
- {
- if (c == 0 || sz < (c + CHUNK_HDR_SZ))
- return NULL;
- }
- }
- else
- {
- unsigned long offset, page_mask = GLRO (dl_pagesize) - 1;
-
- /* mmap()ed chunks have MALLOC_ALIGNMENT or higher power-of-two
- alignment relative to the beginning of a page. Check this
- first. */
- offset = (unsigned long) mem & page_mask;
- if ((offset != MALLOC_ALIGNMENT && offset != 0 && offset != 0x10 &&
- offset != 0x20 && offset != 0x40 && offset != 0x80 && offset != 0x100 &&
- offset != 0x200 && offset != 0x400 && offset != 0x800 && offset != 0x1000 &&
- offset < 0x2000) ||
- !chunk_is_mmapped (p) || prev_inuse (p) ||
- ((((unsigned long) p - prev_size (p)) & page_mask) != 0) ||
- ((prev_size (p) + sz) & page_mask) != 0)
- return NULL;
-
- for (sz = CHUNK_HDR_SZ + memsize (p) - 1;
- (c = *SAFE_CHAR_OFFSET (p, sz)) != magic;
- sz -= c)
- {
- if (c == 0 || sz < (c + CHUNK_HDR_SZ))
- return NULL;
- }
- }
-
- unsigned char* safe_p = SAFE_CHAR_OFFSET (p, sz);
- *safe_p ^= 0xFF;
- if (magic_p)
- *magic_p = safe_p;
- return p;
-}
-
-/* Check for corruption of the top chunk. */
-static void
-top_check (void)
-{
- mchunkptr t = top (&main_arena);
-
- if (t == initial_top (&main_arena) ||
- (!chunk_is_mmapped (t) &&
- chunksize (t) >= MINSIZE &&
- prev_inuse (t) &&
- (!contiguous (&main_arena) ||
- (char *) t + chunksize (t) == mp_.sbrk_base + main_arena.system_mem)))
- return;
-
- malloc_printerr ("malloc: top chunk is corrupt");
-}
-
-static void *
-malloc_check (size_t sz, const void *caller)
-{
- void *victim;
- size_t nb;
-
- if (__builtin_add_overflow (sz, 1, &nb))
- {
- __set_errno (ENOMEM);
- return NULL;
- }
-
- __libc_lock_lock (main_arena.mutex);
- top_check ();
- victim = _int_malloc (&main_arena, nb);
- __libc_lock_unlock (main_arena.mutex);
- return mem2mem_check (tag_new_usable (victim), sz);
-}
-
-static void
-free_check (void *mem, const void *caller)
-{
- mchunkptr p;
-
- if (!mem)
- return;
-
- int err = errno;
-
- /* Quickly check that the freed pointer matches the tag for the memory.
- This gives a useful double-free detection. */
- if (__glibc_unlikely (mtag_enabled))
- *(volatile char *)mem;
-
- __libc_lock_lock (main_arena.mutex);
- p = mem2chunk_check (mem, NULL);
- if (!p)
- malloc_printerr ("free(): invalid pointer");
- if (chunk_is_mmapped (p))
- {
- __libc_lock_unlock (main_arena.mutex);
- munmap_chunk (p);
- }
- else
- {
- /* Mark the chunk as belonging to the library again. */
- (void)tag_region (chunk2mem (p), memsize (p));
- _int_free (&main_arena, p, 1);
- __libc_lock_unlock (main_arena.mutex);
- }
- __set_errno (err);
-}
-
-static void *
-realloc_check (void *oldmem, size_t bytes, const void *caller)
-{
- INTERNAL_SIZE_T chnb;
- void *newmem = 0;
- unsigned char *magic_p;
- size_t rb;
-
- if (__builtin_add_overflow (bytes, 1, &rb))
- {
- __set_errno (ENOMEM);
- return NULL;
- }
- if (oldmem == 0)
- return malloc_check (bytes, NULL);
-
- if (bytes == 0)
- {
- free_check (oldmem, NULL);
- return NULL;
- }
-
- /* Quickly check that the freed pointer matches the tag for the memory.
- This gives a useful double-free detection. */
- if (__glibc_unlikely (mtag_enabled))
- *(volatile char *)oldmem;
-
- __libc_lock_lock (main_arena.mutex);
- const mchunkptr oldp = mem2chunk_check (oldmem, &magic_p);
- __libc_lock_unlock (main_arena.mutex);
- if (!oldp)
- malloc_printerr ("realloc(): invalid pointer");
- const INTERNAL_SIZE_T oldsize = chunksize (oldp);
-
- if (!checked_request2size (rb, &chnb))
- {
- __set_errno (ENOMEM);
- goto invert;
- }
-
- __libc_lock_lock (main_arena.mutex);
-
- if (chunk_is_mmapped (oldp))
- {
-#if HAVE_MREMAP
- mchunkptr newp = mremap_chunk (oldp, chnb);
- if (newp)
- newmem = chunk2mem_tag (newp);
- else
-#endif
- {
- /* Note the extra SIZE_SZ overhead. */
- if (oldsize - SIZE_SZ >= chnb)
- newmem = oldmem; /* do nothing */
- else
- {
- /* Must alloc, copy, free. */
- top_check ();
- newmem = _int_malloc (&main_arena, rb);
- if (newmem)
- {
- memcpy (newmem, oldmem, oldsize - CHUNK_HDR_SZ);
- munmap_chunk (oldp);
- }
- }
- }
- }
- else
- {
- top_check ();
- newmem = _int_realloc (&main_arena, oldp, oldsize, chnb);
- }
-
- DIAG_PUSH_NEEDS_COMMENT;
-#if __GNUC_PREREQ (7, 0)
- /* GCC 7 warns about magic_p may be used uninitialized. But we never
- reach here if magic_p is uninitialized. */
- DIAG_IGNORE_NEEDS_COMMENT (7, "-Wmaybe-uninitialized");
-#endif
- /* mem2chunk_check changed the magic byte in the old chunk.
- If newmem is NULL, then the old chunk will still be used though,
- so we need to invert that change here. */
-invert:
- if (newmem == NULL)
- *magic_p ^= 0xFF;
- DIAG_POP_NEEDS_COMMENT;
-
- __libc_lock_unlock (main_arena.mutex);
-
- return mem2mem_check (tag_new_usable (newmem), bytes);
-}
-
-static void *
-memalign_check (size_t alignment, size_t bytes, const void *caller)
-{
- void *mem;
-
- if (alignment <= MALLOC_ALIGNMENT)
- return malloc_check (bytes, NULL);
-
- if (alignment < MINSIZE)
- alignment = MINSIZE;
-
- /* If the alignment is greater than SIZE_MAX / 2 + 1 it cannot be a
- power of 2 and will cause overflow in the check below. */
- if (alignment > SIZE_MAX / 2 + 1)
- {
- __set_errno (EINVAL);
- return 0;
- }
-
- /* Check for overflow. */
- if (bytes > SIZE_MAX - alignment - MINSIZE)
- {
- __set_errno (ENOMEM);
- return 0;
- }
-
- /* Make sure alignment is power of 2. */
- if (!powerof2 (alignment))
- {
- size_t a = MALLOC_ALIGNMENT * 2;
- while (a < alignment)
- a <<= 1;
- alignment = a;
- }
-
- __libc_lock_lock (main_arena.mutex);
- top_check ();
- mem = _int_memalign (&main_arena, alignment, bytes + 1);
- __libc_lock_unlock (main_arena.mutex);
- return mem2mem_check (tag_new_usable (mem), bytes);
-}
+#include "malloc-check.c"
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_25)
diff --git a/malloc/malloc-check.c b/malloc/malloc-check.c
new file mode 100644
index 0000000000..dcab880510
--- /dev/null
+++ b/malloc/malloc-check.c
@@ -0,0 +1,390 @@
+/* glibc.malloc.check implementation.
+ Copyright (C) 2001-2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Wolfram Gloger <wg@malloc.de>, 2001.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If
+ not, see <https://www.gnu.org/licenses/>. */
+
+
+/* Whether we are using malloc checking. */
+static int using_malloc_checking;
+
+/* Activate a standard set of debugging hooks. */
+void
+__malloc_check_init (void)
+{
+ using_malloc_checking = 1;
+ __malloc_hook = malloc_check;
+ __free_hook = free_check;
+ __realloc_hook = realloc_check;
+ __memalign_hook = memalign_check;
+}
+
+/* When memory is tagged, the checking data is stored in the user part
+ of the chunk. We can't rely on the user not having modified the
+ tags, so fetch the tag at each location before dereferencing
+ it. */
+#define SAFE_CHAR_OFFSET(p,offset) \
+ ((unsigned char *) tag_at (((unsigned char *) p) + offset))
+
+/* A simple, standard set of debugging hooks. Overhead is `only' one
+ byte per chunk; still this will catch most cases of double frees or
+ overruns. The goal here is to avoid obscure crashes due to invalid
+ usage, unlike in the MALLOC_DEBUG code. */
+
+static unsigned char
+magicbyte (const void *p)
+{
+ unsigned char magic;
+
+ magic = (((uintptr_t) p >> 3) ^ ((uintptr_t) p >> 11)) & 0xFF;
+ /* Do not return 1. See the comment in mem2mem_check(). */
+ if (magic == 1)
+ ++magic;
+ return magic;
+}
+
+/* Visualize the chunk as being partitioned into blocks of 255 bytes from the
+ highest address of the chunk, downwards. The end of each block tells
+ us the size of that block, up to the actual size of the requested
+ memory. Our magic byte is right at the end of the requested size, so we
+ must reach it with this iteration, otherwise we have witnessed a memory
+ corruption. */
+static size_t
+malloc_check_get_size (mchunkptr p)
+{
+ size_t size;
+ unsigned char c;
+ unsigned char magic = magicbyte (p);
+
+ assert (using_malloc_checking == 1);
+
+ for (size = CHUNK_HDR_SZ + memsize (p) - 1;
+ (c = *SAFE_CHAR_OFFSET (p, size)) != magic;
+ size -= c)
+ {
+ if (c <= 0 || size < (c + CHUNK_HDR_SZ))
+ malloc_printerr ("malloc_check_get_size: memory corruption");
+ }
+
+ /* chunk2mem size. */
+ return size - CHUNK_HDR_SZ;
+}
+
+/* Instrument a chunk with overrun detector byte(s) and convert it
+ into a user pointer with requested size req_sz. */
+
+static void *
+mem2mem_check (void *ptr, size_t req_sz)
+{
+ mchunkptr p;
+ unsigned char *m_ptr = ptr;
+ size_t max_sz, block_sz, i;
+ unsigned char magic;
+
+ if (!ptr)
+ return ptr;
+
+ p = mem2chunk (ptr);
+ magic = magicbyte (p);
+ max_sz = memsize (p);
+
+ for (i = max_sz - 1; i > req_sz; i -= block_sz)
+ {
+ block_sz = MIN (i - req_sz, 0xff);
+ /* Don't allow the magic byte to appear in the chain of length bytes.
+ For the following to work, magicbyte cannot return 0x01. */
+ if (block_sz == magic)
+ --block_sz;
+
+ *SAFE_CHAR_OFFSET (m_ptr, i) = block_sz;
+ }
+ *SAFE_CHAR_OFFSET (m_ptr, req_sz) = magic;
+ return (void *) m_ptr;
+}
+
+/* Convert a pointer to be free()d or realloc()ed to a valid chunk
+ pointer. If the provided pointer is not valid, return NULL. */
+
+static mchunkptr
+mem2chunk_check (void *mem, unsigned char **magic_p)
+{
+ mchunkptr p;
+ INTERNAL_SIZE_T sz, c;
+ unsigned char magic;
+
+ if (!aligned_OK (mem))
+ return NULL;
+
+ p = mem2chunk (mem);
+ sz = chunksize (p);
+ magic = magicbyte (p);
+ if (!chunk_is_mmapped (p))
+ {
+ /* Must be a chunk in conventional heap memory. */
+ int contig = contiguous (&main_arena);
+ if ((contig &&
+ ((char *) p < mp_.sbrk_base ||
+ ((char *) p + sz) >= (mp_.sbrk_base + main_arena.system_mem))) ||
+ sz < MINSIZE || sz & MALLOC_ALIGN_MASK || !inuse (p) ||
+ (!prev_inuse (p) && ((prev_size (p) & MALLOC_ALIGN_MASK) != 0 ||
+ (contig && (char *) prev_chunk (p) < mp_.sbrk_base) ||
+ next_chunk (prev_chunk (p)) != p)))
+ return NULL;
+
+ for (sz = CHUNK_HDR_SZ + memsize (p) - 1;
+ (c = *SAFE_CHAR_OFFSET (p, sz)) != magic;
+ sz -= c)
+ {
+ if (c == 0 || sz < (c + CHUNK_HDR_SZ))
+ return NULL;
+ }
+ }
+ else
+ {
+ unsigned long offset, page_mask = GLRO (dl_pagesize) - 1;
+
+ /* mmap()ed chunks have MALLOC_ALIGNMENT or higher power-of-two
+ alignment relative to the beginning of a page. Check this
+ first. */
+ offset = (unsigned long) mem & page_mask;
+ if ((offset != MALLOC_ALIGNMENT && offset != 0 && offset != 0x10 &&
+ offset != 0x20 && offset != 0x40 && offset != 0x80 && offset != 0x100 &&
+ offset != 0x200 && offset != 0x400 && offset != 0x800 && offset != 0x1000 &&
+ offset < 0x2000) ||
+ !chunk_is_mmapped (p) || prev_inuse (p) ||
+ ((((unsigned long) p - prev_size (p)) & page_mask) != 0) ||
+ ((prev_size (p) + sz) & page_mask) != 0)
+ return NULL;
+
+ for (sz = CHUNK_HDR_SZ + memsize (p) - 1;
+ (c = *SAFE_CHAR_OFFSET (p, sz)) != magic;
+ sz -= c)
+ {
+ if (c == 0 || sz < (c + CHUNK_HDR_SZ))
+ return NULL;
+ }
+ }
+
+ unsigned char* safe_p = SAFE_CHAR_OFFSET (p, sz);
+ *safe_p ^= 0xFF;
+ if (magic_p)
+ *magic_p = safe_p;
+ return p;
+}
+
+/* Check for corruption of the top chunk. */
+static void
+top_check (void)
+{
+ mchunkptr t = top (&main_arena);
+
+ if (t == initial_top (&main_arena) ||
+ (!chunk_is_mmapped (t) &&
+ chunksize (t) >= MINSIZE &&
+ prev_inuse (t) &&
+ (!contiguous (&main_arena) ||
+ (char *) t + chunksize (t) == mp_.sbrk_base + main_arena.system_mem)))
+ return;
+
+ malloc_printerr ("malloc: top chunk is corrupt");
+}
+
+static void *
+malloc_check (size_t sz, const void *caller)
+{
+ void *victim;
+ size_t nb;
+
+ if (__builtin_add_overflow (sz, 1, &nb))
+ {
+ __set_errno (ENOMEM);
+ return NULL;
+ }
+
+ __libc_lock_lock (main_arena.mutex);
+ top_check ();
+ victim = _int_malloc (&main_arena, nb);
+ __libc_lock_unlock (main_arena.mutex);
+ return mem2mem_check (tag_new_usable (victim), sz);
+}
+
+static void
+free_check (void *mem, const void *caller)
+{
+ mchunkptr p;
+
+ if (!mem)
+ return;
+
+ int err = errno;
+
+ /* Quickly check that the freed pointer matches the tag for the memory.
+ This gives a useful double-free detection. */
+ if (__glibc_unlikely (mtag_enabled))
+ *(volatile char *)mem;
+
+ __libc_lock_lock (main_arena.mutex);
+ p = mem2chunk_check (mem, NULL);
+ if (!p)
+ malloc_printerr ("free(): invalid pointer");
+ if (chunk_is_mmapped (p))
+ {
+ __libc_lock_unlock (main_arena.mutex);
+ munmap_chunk (p);
+ }
+ else
+ {
+ /* Mark the chunk as belonging to the library again. */
+ (void)tag_region (chunk2mem (p), memsize (p));
+ _int_free (&main_arena, p, 1);
+ __libc_lock_unlock (main_arena.mutex);
+ }
+ __set_errno (err);
+}
+
+static void *
+realloc_check (void *oldmem, size_t bytes, const void *caller)
+{
+ INTERNAL_SIZE_T chnb;
+ void *newmem = 0;
+ unsigned char *magic_p;
+ size_t rb;
+
+ if (__builtin_add_overflow (bytes, 1, &rb))
+ {
+ __set_errno (ENOMEM);
+ return NULL;
+ }
+ if (oldmem == 0)
+ return malloc_check (bytes, NULL);
+
+ if (bytes == 0)
+ {
+ free_check (oldmem, NULL);
+ return NULL;
+ }
+
+ /* Quickly check that the freed pointer matches the tag for the memory.
+ This gives a useful double-free detection. */
+ if (__glibc_unlikely (mtag_enabled))
+ *(volatile char *)oldmem;
+
+ __libc_lock_lock (main_arena.mutex);
+ const mchunkptr oldp = mem2chunk_check (oldmem, &magic_p);
+ __libc_lock_unlock (main_arena.mutex);
+ if (!oldp)
+ malloc_printerr ("realloc(): invalid pointer");
+ const INTERNAL_SIZE_T oldsize = chunksize (oldp);
+
+ if (!checked_request2size (rb, &chnb))
+ {
+ __set_errno (ENOMEM);
+ goto invert;
+ }
+
+ __libc_lock_lock (main_arena.mutex);
+
+ if (chunk_is_mmapped (oldp))
+ {
+#if HAVE_MREMAP
+ mchunkptr newp = mremap_chunk (oldp, chnb);
+ if (newp)
+ newmem = chunk2mem_tag (newp);
+ else
+#endif
+ {
+ /* Note the extra SIZE_SZ overhead. */
+ if (oldsize - SIZE_SZ >= chnb)
+ newmem = oldmem; /* do nothing */
+ else
+ {
+ /* Must alloc, copy, free. */
+ top_check ();
+ newmem = _int_malloc (&main_arena, rb);
+ if (newmem)
+ {
+ memcpy (newmem, oldmem, oldsize - CHUNK_HDR_SZ);
+ munmap_chunk (oldp);
+ }
+ }
+ }
+ }
+ else
+ {
+ top_check ();
+ newmem = _int_realloc (&main_arena, oldp, oldsize, chnb);
+ }
+
+ DIAG_PUSH_NEEDS_COMMENT;
+#if __GNUC_PREREQ (7, 0)
+ /* GCC 7 warns about magic_p may be used uninitialized. But we never
+ reach here if magic_p is uninitialized. */
+ DIAG_IGNORE_NEEDS_COMMENT (7, "-Wmaybe-uninitialized");
+#endif
+ /* mem2chunk_check changed the magic byte in the old chunk.
+ If newmem is NULL, then the old chunk will still be used though,
+ so we need to invert that change here. */
+invert:
+ if (newmem == NULL)
+ *magic_p ^= 0xFF;
+ DIAG_POP_NEEDS_COMMENT;
+
+ __libc_lock_unlock (main_arena.mutex);
+
+ return mem2mem_check (tag_new_usable (newmem), bytes);
+}
+
+static void *
+memalign_check (size_t alignment, size_t bytes, const void *caller)
+{
+ void *mem;
+
+ if (alignment <= MALLOC_ALIGNMENT)
+ return malloc_check (bytes, NULL);
+
+ if (alignment < MINSIZE)
+ alignment = MINSIZE;
+
+ /* If the alignment is greater than SIZE_MAX / 2 + 1 it cannot be a
+ power of 2 and will cause overflow in the check below. */
+ if (alignment > SIZE_MAX / 2 + 1)
+ {
+ __set_errno (EINVAL);
+ return 0;
+ }
+
+ /* Check for overflow. */
+ if (bytes > SIZE_MAX - alignment - MINSIZE)
+ {
+ __set_errno (ENOMEM);
+ return 0;
+ }
+
+ /* Make sure alignment is power of 2. */
+ if (!powerof2 (alignment))
+ {
+ size_t a = MALLOC_ALIGNMENT * 2;
+ while (a < alignment)
+ a <<= 1;
+ alignment = a;
+ }
+
+ __libc_lock_lock (main_arena.mutex);
+ top_check ();
+ mem = _int_memalign (&main_arena, alignment, bytes + 1);
+ __libc_lock_unlock (main_arena.mutex);
+ return mem2mem_check (tag_new_usable (mem), bytes);
+}
--
2.31.1
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH 2/8] malloc: Move malloc hook references to hooks.c
2021-06-24 18:23 [PATCH 0/8] Remove malloc hooks Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 1/8] Move glibc.malloc.check implementation into its own file Siddhesh Poyarekar
@ 2021-06-24 18:23 ` Siddhesh Poyarekar
2021-06-24 21:10 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 3/8] glibc.malloc.check: Wean away from malloc hooks Siddhesh Poyarekar
` (5 subsequent siblings)
7 siblings, 1 reply; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-24 18:23 UTC (permalink / raw)
To: libc-alpha; +Cc: dj, carlos, fweimer
Make the core malloc code hooks free and instead only have entry
points for _*_debug_before inline functions.
This also introduces the first (albeit very constrained) breakage for
malloc hooks behaviour. The hook variables no longer call
ptmalloc_init, it is called directly on first invocation of an
allocator function. This breaks debugging hooks that may depend on
overriding the hook symbols with their own implementations due to
which ptmalloc_init is never called. In other words, it breaks hooks
users that use the malloc hooks to have their own implementation of
malloc that is conflicting with glibc malloc, which is not the
intended use of the hooks as documented.
None of the three debugging hooks in glibc depend on this behaviour
and hence continue to work as before. In any case, future patches
that move the hooks out into their own layer ought to bring back this
functionality. As a result, the breakage will not be visible to the
user in the end.
---
malloc/arena.c | 2 -
malloc/hooks.c | 110 ++++++++++++++++++++++++++++++++-------
malloc/malloc-internal.h | 1 +
malloc/malloc.c | 85 ++++++++++--------------------
4 files changed, 119 insertions(+), 79 deletions(-)
diff --git a/malloc/arena.c b/malloc/arena.c
index 7eb110445e..1861d20006 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -44,8 +44,6 @@
/***************************************************************************/
-#define top(ar_ptr) ((ar_ptr)->top)
-
/* A heap is a single contiguous memory region holding (coalesceable)
malloc_chunks. It is allocated with mmap() and always starts at an
address aligned to HEAP_MAX_SIZE. */
diff --git a/malloc/hooks.c b/malloc/hooks.c
index 57a9b55788..4960aafd08 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -21,35 +21,107 @@
corrupt pointer is detected: do nothing (0), print an error message
(1), or call abort() (2). */
-/* Hooks for debugging versions. The initial hooks just call the
- initialization routine, then do the normal work. */
+/* Define and initialize the hook variables. These weak definitions must
+ appear before any use of the variables in a function (arena.c uses one). */
+#ifndef weak_variable
+/* In GNU libc we want the hook variables to be weak definitions to
+ avoid a problem with Emacs. */
+# define weak_variable weak_function
+#endif
+
+/* Forward declarations. */
+
+#if HAVE_MALLOC_INIT_HOOK
+void (*__malloc_initialize_hook) (void) __attribute__ ((nocommon));
+compat_symbol (libc, __malloc_initialize_hook,
+ __malloc_initialize_hook, GLIBC_2_0);
+#endif
+
+void weak_variable (*__free_hook) (void *__ptr,
+ const void *) = NULL;
+void *weak_variable (*__malloc_hook)
+ (size_t __size, const void *) = NULL;
+void *weak_variable (*__realloc_hook)
+ (void *__ptr, size_t __size, const void *) = NULL;
+void *weak_variable (*__memalign_hook)
+ (size_t __alignment, size_t __size, const void *) = NULL;
+
+static void ptmalloc_init (void);
-static void *
-malloc_hook_ini (size_t sz, const void *caller)
+#include "malloc-check.c"
+
+static __always_inline bool
+_malloc_debug_before (size_t bytes, void **victimp, const void *address)
{
- __malloc_hook = NULL;
- ptmalloc_init ();
- return __libc_malloc (sz);
+ _Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
+ "PTRDIFF_MAX is not more than half of SIZE_MAX");
+
+ void *(*hook) (size_t, const void *)
+ = atomic_forced_read (__malloc_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ {
+ *victimp = (*hook)(bytes, address);
+ return true;
+ }
+ return false;
}
-static void *
-realloc_hook_ini (void *ptr, size_t sz, const void *caller)
+static __always_inline bool
+_free_debug_before (void *mem, const void *address)
{
- __malloc_hook = NULL;
- __realloc_hook = NULL;
- ptmalloc_init ();
- return __libc_realloc (ptr, sz);
+ void (*hook) (void *, const void *)
+ = atomic_forced_read (__free_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ {
+ (*hook)(mem, address);
+ return true;
+ }
+ return false;
}
-static void *
-memalign_hook_ini (size_t alignment, size_t sz, const void *caller)
+static __always_inline bool
+_realloc_debug_before (void *oldmem, size_t bytes, void **victimp,
+ const void *address)
{
- __memalign_hook = NULL;
- ptmalloc_init ();
- return __libc_memalign (alignment, sz);
+ void *(*hook) (void *, size_t, const void *) =
+ atomic_forced_read (__realloc_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ {
+ *victimp = (*hook)(oldmem, bytes, address);
+ return true;
+ }
+
+ return false;
}
-#include "malloc-check.c"
+static __always_inline bool
+_memalign_debug_before (size_t alignment, size_t bytes, void **victimp,
+ const void *address)
+{
+ void *(*hook) (size_t, size_t, const void *) =
+ atomic_forced_read (__memalign_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ {
+ *victimp = (*hook)(alignment, bytes, address);
+ return true;
+ }
+ return false;
+}
+
+static __always_inline bool
+_calloc_debug_before (size_t bytes, void **victimp, const void *address)
+{
+ void *(*hook) (size_t, const void *) =
+ atomic_forced_read (__malloc_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ {
+ *victimp = (*hook)(bytes, address);
+ if (*victimp != NULL)
+ memset (*victimp, 0, bytes);
+ return true;
+ }
+ return false;
+}
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_25)
diff --git a/malloc/malloc-internal.h b/malloc/malloc-internal.h
index 258f29584e..ee0f5697af 100644
--- a/malloc/malloc-internal.h
+++ b/malloc/malloc-internal.h
@@ -61,6 +61,7 @@
/* The corresponding bit mask value. */
#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1)
+#define top(ar_ptr) ((ar_ptr)->top)
/* Called in the parent process before a fork. */
void __malloc_fork_lock_parent (void) attribute_hidden;
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 0e2e1747e0..75ca6ec3f0 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -2013,30 +2013,6 @@ static void malloc_consolidate (mstate);
# define weak_variable weak_function
#endif
-/* Forward declarations. */
-static void *malloc_hook_ini (size_t sz,
- const void *caller) __THROW;
-static void *realloc_hook_ini (void *ptr, size_t sz,
- const void *caller) __THROW;
-static void *memalign_hook_ini (size_t alignment, size_t sz,
- const void *caller) __THROW;
-
-#if HAVE_MALLOC_INIT_HOOK
-void (*__malloc_initialize_hook) (void) __attribute__ ((nocommon));
-compat_symbol (libc, __malloc_initialize_hook,
- __malloc_initialize_hook, GLIBC_2_0);
-#endif
-
-void weak_variable (*__free_hook) (void *__ptr,
- const void *) = NULL;
-void *weak_variable (*__malloc_hook)
- (size_t __size, const void *) = malloc_hook_ini;
-void *weak_variable (*__realloc_hook)
- (void *__ptr, size_t __size, const void *)
- = realloc_hook_ini;
-void *weak_variable (*__memalign_hook)
- (size_t __alignment, size_t __size, const void *)
- = memalign_hook_ini;
void weak_variable (*__after_morecore_hook) (void) = NULL;
/* This function is called from the arena shutdown hook, to free the
@@ -2065,6 +2041,9 @@ free_perturb (char *p, size_t n)
#include <stap-probe.h>
+/* ----------------- Support for debugging hooks -------------------- */
+#include "hooks.c"
+
/* ------------------- Support for multiple arenas -------------------- */
#include "arena.c"
@@ -2425,10 +2404,6 @@ do_check_malloc_state (mstate av)
#endif
-/* ----------------- Support for debugging hooks -------------------- */
-#include "hooks.c"
-
-
/* ----------- Routines dealing with system allocation -------------- */
/*
@@ -3225,13 +3200,12 @@ __libc_malloc (size_t bytes)
mstate ar_ptr;
void *victim;
- _Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
- "PTRDIFF_MAX is not more than half of SIZE_MAX");
+ if (__malloc_initialized < 0)
+ ptmalloc_init ();
+
+ if (_malloc_debug_before (bytes, &victim, RETURN_ADDRESS (0)))
+ return victim;
- void *(*hook) (size_t, const void *)
- = atomic_forced_read (__malloc_hook);
- if (__builtin_expect (hook != NULL, 0))
- return (*hook)(bytes, RETURN_ADDRESS (0));
#if USE_TCACHE
/* int_free also calls request2size, be careful to not pad twice. */
size_t tbytes;
@@ -3292,13 +3266,11 @@ __libc_free (void *mem)
mstate ar_ptr;
mchunkptr p; /* chunk corresponding to mem */
- void (*hook) (void *, const void *)
- = atomic_forced_read (__free_hook);
- if (__builtin_expect (hook != NULL, 0))
- {
- (*hook)(mem, RETURN_ADDRESS (0));
- return;
- }
+ if (__malloc_initialized < 0)
+ ptmalloc_init ();
+
+ if (_free_debug_before (mem, RETURN_ADDRESS (0)))
+ return;
if (mem == 0) /* free(0) has no effect */
return;
@@ -3351,10 +3323,11 @@ __libc_realloc (void *oldmem, size_t bytes)
void *newp; /* chunk to return */
- void *(*hook) (void *, size_t, const void *) =
- atomic_forced_read (__realloc_hook);
- if (__builtin_expect (hook != NULL, 0))
- return (*hook)(oldmem, bytes, RETURN_ADDRESS (0));
+ if (__malloc_initialized < 0)
+ ptmalloc_init ();
+
+ if (_realloc_debug_before (oldmem, bytes, &newp, RETURN_ADDRESS (0)))
+ return newp;
#if REALLOC_ZERO_BYTES_FREES
if (bytes == 0 && oldmem != NULL)
@@ -3490,6 +3463,9 @@ void *
__libc_memalign (size_t alignment, size_t bytes)
{
void *address = RETURN_ADDRESS (0);
+ if (__malloc_initialized < 0)
+ ptmalloc_init ();
+
return _mid_memalign (alignment, bytes, address);
}
@@ -3499,10 +3475,8 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
mstate ar_ptr;
void *p;
- void *(*hook) (size_t, size_t, const void *) =
- atomic_forced_read (__memalign_hook);
- if (__builtin_expect (hook != NULL, 0))
- return (*hook)(alignment, bytes, address);
+ if (_memalign_debug_before (alignment, bytes, &p, address))
+ return p;
/* If we need less alignment than we give anyway, just relay to malloc. */
if (alignment <= MALLOC_ALIGNMENT)
@@ -3612,16 +3586,11 @@ __libc_calloc (size_t n, size_t elem_size)
sz = bytes;
- void *(*hook) (size_t, const void *) =
- atomic_forced_read (__malloc_hook);
- if (__builtin_expect (hook != NULL, 0))
- {
- mem = (*hook)(sz, RETURN_ADDRESS (0));
- if (mem == 0)
- return 0;
+ if (__malloc_initialized < 0)
+ ptmalloc_init ();
- return memset (mem, 0, sz);
- }
+ if (_calloc_debug_before (sz, &mem, RETURN_ADDRESS (0)))
+ return mem;
MAYBE_INIT_TCACHE ();
--
2.31.1
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH 3/8] glibc.malloc.check: Wean away from malloc hooks
2021-06-24 18:23 [PATCH 0/8] Remove malloc hooks Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 1/8] Move glibc.malloc.check implementation into its own file Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 2/8] malloc: Move malloc hook references to hooks.c Siddhesh Poyarekar
@ 2021-06-24 18:23 ` Siddhesh Poyarekar
2021-06-24 21:43 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 4/8] mcheck: " Siddhesh Poyarekar
` (4 subsequent siblings)
7 siblings, 1 reply; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-24 18:23 UTC (permalink / raw)
To: libc-alpha; +Cc: dj, carlos, fweimer
Set up a new internal debugging hooks flag variable and migrate
glibc.malloc.check to it so that it no longer uses the malloc hooks.
---
malloc/arena.c | 4 +--
malloc/hooks.c | 63 ++++++++++++++++++++++++++++++++++++++++++-
malloc/malloc-check.c | 30 ++++++---------------
malloc/malloc.c | 9 +------
4 files changed, 73 insertions(+), 33 deletions(-)
diff --git a/malloc/arena.c b/malloc/arena.c
index 1861d20006..357a3b0b30 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -210,7 +210,7 @@ TUNABLE_CALLBACK (set_mallopt_check) (tunable_val_t *valp)
{
int32_t value = (int32_t) valp->numval;
if (value != 0)
- __malloc_check_init ();
+ __malloc_debug_enable (MALLOC_CHECK_HOOK);
}
# define TUNABLE_CALLBACK_FNDECL(__name, __type) \
@@ -400,7 +400,7 @@ ptmalloc_init (void)
}
}
if (s && s[0] != '\0' && s[0] != '0')
- __malloc_check_init ();
+ __malloc_debug_enable (MALLOC_CHECK_HOOK);
#endif
#if HAVE_MALLOC_INIT_HOOK
diff --git a/malloc/hooks.c b/malloc/hooks.c
index 4960aafd08..77855801c8 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -21,6 +21,8 @@
corrupt pointer is detected: do nothing (0), print an error message
(1), or call abort() (2). */
+# include <stdbool.h>
+
/* Define and initialize the hook variables. These weak definitions must
appear before any use of the variables in a function (arena.c uses one). */
#ifndef weak_variable
@@ -29,6 +31,14 @@
# define weak_variable weak_function
#endif
+/* The internal malloc debugging hooks. */
+enum malloc_debug_hooks
+{
+ MALLOC_NONE_HOOK = 0,
+ MALLOC_CHECK_HOOK = 1 << 0, /* MALLOC_CHECK_ or glibc.malloc.check. */
+};
+static unsigned __malloc_debugging_hooks;
+
/* Forward declarations. */
#if HAVE_MALLOC_INIT_HOOK
@@ -48,6 +58,24 @@ void *weak_variable (*__memalign_hook)
static void ptmalloc_init (void);
+static __always_inline bool
+__is_malloc_debug_enabled (enum malloc_debug_hooks flag)
+{
+ return __malloc_debugging_hooks & flag;
+}
+
+static __always_inline void
+__malloc_debug_enable (enum malloc_debug_hooks flag)
+{
+ __malloc_debugging_hooks |= flag;
+}
+
+static __always_inline void
+__malloc_debug_disable (enum malloc_debug_hooks flag)
+{
+ __malloc_debugging_hooks &= ~flag;
+}
+
#include "malloc-check.c"
static __always_inline bool
@@ -63,6 +91,12 @@ _malloc_debug_before (size_t bytes, void **victimp, const void *address)
*victimp = (*hook)(bytes, address);
return true;
}
+
+ if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ {
+ *victimp = malloc_check (bytes);
+ return true;
+ }
return false;
}
@@ -76,6 +110,12 @@ _free_debug_before (void *mem, const void *address)
(*hook)(mem, address);
return true;
}
+
+ if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ {
+ free_check (mem);
+ return true;
+ }
return false;
}
@@ -91,6 +131,12 @@ _realloc_debug_before (void *oldmem, size_t bytes, void **victimp,
return true;
}
+ if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ {
+ *victimp = realloc_check (oldmem, bytes);
+ return true;
+ }
+
return false;
}
@@ -105,6 +151,13 @@ _memalign_debug_before (size_t alignment, size_t bytes, void **victimp,
*victimp = (*hook)(alignment, bytes, address);
return true;
}
+
+ if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ {
+ *victimp = memalign_check (alignment, bytes);
+ return true;
+ }
+
return false;
}
@@ -120,6 +173,14 @@ _calloc_debug_before (size_t bytes, void **victimp, const void *address)
memset (*victimp, 0, bytes);
return true;
}
+
+ if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ {
+ *victimp = malloc_check (bytes);
+ if (*victimp != NULL)
+ memset (*victimp, 0, bytes);
+ return true;
+ }
return false;
}
@@ -195,7 +256,7 @@ malloc_set_state (void *msptr)
__realloc_hook = NULL;
__free_hook = NULL;
__memalign_hook = NULL;
- using_malloc_checking = 0;
+ __malloc_debug_disable (MALLOC_CHECK_HOOK);
/* Patch the dumped heap. We no longer try to integrate into the
existing heap. Instead, we mark the existing chunks as mmapped.
diff --git a/malloc/malloc-check.c b/malloc/malloc-check.c
index dcab880510..a85e519498 100644
--- a/malloc/malloc-check.c
+++ b/malloc/malloc-check.c
@@ -18,20 +18,6 @@
not, see <https://www.gnu.org/licenses/>. */
-/* Whether we are using malloc checking. */
-static int using_malloc_checking;
-
-/* Activate a standard set of debugging hooks. */
-void
-__malloc_check_init (void)
-{
- using_malloc_checking = 1;
- __malloc_hook = malloc_check;
- __free_hook = free_check;
- __realloc_hook = realloc_check;
- __memalign_hook = memalign_check;
-}
-
/* When memory is tagged, the checking data is stored in the user part
of the chunk. We can't rely on the user not having modified the
tags, so fetch the tag at each location before dereferencing
@@ -69,7 +55,7 @@ malloc_check_get_size (mchunkptr p)
unsigned char c;
unsigned char magic = magicbyte (p);
- assert (using_malloc_checking == 1);
+ assert (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK));
for (size = CHUNK_HDR_SZ + memsize (p) - 1;
(c = *SAFE_CHAR_OFFSET (p, size)) != magic;
@@ -203,7 +189,7 @@ top_check (void)
}
static void *
-malloc_check (size_t sz, const void *caller)
+malloc_check (size_t sz)
{
void *victim;
size_t nb;
@@ -222,7 +208,7 @@ malloc_check (size_t sz, const void *caller)
}
static void
-free_check (void *mem, const void *caller)
+free_check (void *mem)
{
mchunkptr p;
@@ -256,7 +242,7 @@ free_check (void *mem, const void *caller)
}
static void *
-realloc_check (void *oldmem, size_t bytes, const void *caller)
+realloc_check (void *oldmem, size_t bytes)
{
INTERNAL_SIZE_T chnb;
void *newmem = 0;
@@ -269,11 +255,11 @@ realloc_check (void *oldmem, size_t bytes, const void *caller)
return NULL;
}
if (oldmem == 0)
- return malloc_check (bytes, NULL);
+ return malloc_check (bytes);
if (bytes == 0)
{
- free_check (oldmem, NULL);
+ free_check (oldmem);
return NULL;
}
@@ -348,12 +334,12 @@ invert:
}
static void *
-memalign_check (size_t alignment, size_t bytes, const void *caller)
+memalign_check (size_t alignment, size_t bytes)
{
void *mem;
if (alignment <= MALLOC_ALIGNMENT)
- return malloc_check (bytes, NULL);
+ return malloc_check (bytes);
if (alignment < MINSIZE)
alignment = MINSIZE;
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 75ca6ec3f0..60753446a1 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -1124,13 +1124,6 @@ static void munmap_chunk(mchunkptr p);
static mchunkptr mremap_chunk(mchunkptr p, size_t new_size);
#endif
-static void* malloc_check(size_t sz, const void *caller);
-static void free_check(void* mem, const void *caller);
-static void* realloc_check(void* oldmem, size_t bytes,
- const void *caller);
-static void* memalign_check(size_t alignment, size_t bytes,
- const void *caller);
-
/* ------------------ MMAP support ------------------ */
@@ -5078,7 +5071,7 @@ musable (void *mem)
p = mem2chunk (mem);
- if (__builtin_expect (using_malloc_checking == 1, 0))
+ if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
return malloc_check_get_size (p);
if (chunk_is_mmapped (p))
--
2.31.1
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH 4/8] mcheck: Wean away from malloc hooks
2021-06-24 18:23 [PATCH 0/8] Remove malloc hooks Siddhesh Poyarekar
` (2 preceding siblings ...)
2021-06-24 18:23 ` [PATCH 3/8] glibc.malloc.check: Wean away from malloc hooks Siddhesh Poyarekar
@ 2021-06-24 18:23 ` Siddhesh Poyarekar
2021-06-24 22:51 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 5/8] mtrace: " Siddhesh Poyarekar
` (3 subsequent siblings)
7 siblings, 1 reply; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-24 18:23 UTC (permalink / raw)
To: libc-alpha; +Cc: dj, carlos, fweimer
Split the mcheck implementation into the debugging hooks and the user
visible implementation so that the debugging hooks (in mcheck-hooks.c)
can be embedded like malloc-check.c.
Further, add *_debug_after debugging hooks into malloc so that mcheck
can then be adapted to using the debugging hooks instead of fiddling
with hooks variables. This adds an extra conditional branch at the
end of the allocator functions but it should have minimal effect in
the default use case.
Initialization using -lmcheck now depends on a new exported variable
__libc_lmcheck which is a const flag that mcheck-init can override.
While this simplifies the mcheck implementation, it still does not
make the interface thread safe as access to its internal structures is
still unprotected.
---
include/malloc.h | 10 +-
malloc/Makefile | 4 +-
malloc/Versions | 3 +
malloc/arena.c | 5 +
malloc/hooks.c | 132 ++++--
malloc/malloc.c | 113 +++--
malloc/mcheck-hooks.c | 411 ++++++++++++++++++
malloc/mcheck-init.c | 14 +-
malloc/mcheck.c | 369 +---------------
sysdeps/mach/hurd/i386/libc.abilist | 1 +
sysdeps/unix/sysv/linux/aarch64/libc.abilist | 1 +
sysdeps/unix/sysv/linux/alpha/libc.abilist | 1 +
sysdeps/unix/sysv/linux/arc/libc.abilist | 1 +
sysdeps/unix/sysv/linux/arm/be/libc.abilist | 1 +
sysdeps/unix/sysv/linux/arm/le/libc.abilist | 1 +
sysdeps/unix/sysv/linux/csky/libc.abilist | 1 +
sysdeps/unix/sysv/linux/hppa/libc.abilist | 1 +
sysdeps/unix/sysv/linux/i386/libc.abilist | 1 +
sysdeps/unix/sysv/linux/ia64/libc.abilist | 1 +
.../sysv/linux/m68k/coldfire/libc.abilist | 1 +
.../unix/sysv/linux/m68k/m680x0/libc.abilist | 1 +
.../sysv/linux/microblaze/be/libc.abilist | 1 +
.../sysv/linux/microblaze/le/libc.abilist | 1 +
.../sysv/linux/mips/mips32/fpu/libc.abilist | 1 +
.../sysv/linux/mips/mips32/nofpu/libc.abilist | 1 +
.../sysv/linux/mips/mips64/n32/libc.abilist | 1 +
.../sysv/linux/mips/mips64/n64/libc.abilist | 1 +
sysdeps/unix/sysv/linux/nios2/libc.abilist | 1 +
.../linux/powerpc/powerpc32/fpu/libc.abilist | 1 +
.../powerpc/powerpc32/nofpu/libc.abilist | 1 +
.../linux/powerpc/powerpc64/be/libc.abilist | 1 +
.../linux/powerpc/powerpc64/le/libc.abilist | 1 +
.../unix/sysv/linux/riscv/rv32/libc.abilist | 1 +
.../unix/sysv/linux/riscv/rv64/libc.abilist | 1 +
.../unix/sysv/linux/s390/s390-32/libc.abilist | 1 +
.../unix/sysv/linux/s390/s390-64/libc.abilist | 1 +
sysdeps/unix/sysv/linux/sh/be/libc.abilist | 1 +
sysdeps/unix/sysv/linux/sh/le/libc.abilist | 1 +
.../sysv/linux/sparc/sparc32/libc.abilist | 1 +
.../sysv/linux/sparc/sparc64/libc.abilist | 1 +
.../unix/sysv/linux/x86_64/64/libc.abilist | 1 +
.../unix/sysv/linux/x86_64/x32/libc.abilist | 1 +
42 files changed, 647 insertions(+), 447 deletions(-)
create mode 100644 malloc/mcheck-hooks.c
diff --git a/include/malloc.h b/include/malloc.h
index b77761f74d..bb1123d9d3 100644
--- a/include/malloc.h
+++ b/include/malloc.h
@@ -4,6 +4,11 @@
# ifndef _ISOMAC
# include <rtld-malloc.h>
+# include <stdbool.h>
+# include <mcheck.h>
+
+struct malloc_state;
+typedef struct malloc_state *mstate;
/* In the GNU libc we rename the global variable
`__malloc_initialized' to `__libc_malloc_initialized'. */
@@ -11,8 +16,9 @@
/* Nonzero if the malloc is already initialized. */
extern int __malloc_initialized attribute_hidden;
-struct malloc_state;
-typedef struct malloc_state *mstate;
+enum mcheck_status __mcheck_checkptr (const void *) attribute_hidden;
+extern int __mcheck_initialize (void (*) (enum mcheck_status), bool)
+ attribute_hidden;
# endif /* !_ISOMAC */
diff --git a/malloc/Makefile b/malloc/Makefile
index fd7f399250..f9433af880 100644
--- a/malloc/Makefile
+++ b/malloc/Makefile
@@ -90,9 +90,7 @@ tests-exclude-mcheck = tst-mallocstate \
tst-malloc-usable-static \
tst-malloc-usable-static-tunables \
tst-malloc-usable-tunables \
- tst-malloc_info \
- tst-memalign \
- tst-posix_memalign
+ tst-malloc_info
tests-mcheck = $(filter-out $(tests-exclude-mcheck), $(tests))
diff --git a/malloc/Versions b/malloc/Versions
index 62e4698a08..e138eaa24b 100644
--- a/malloc/Versions
+++ b/malloc/Versions
@@ -67,6 +67,9 @@ libc {
GLIBC_2.33 {
mallinfo2;
}
+ GLIBC_2.34 {
+ __libc_lmcheck;
+ }
GLIBC_PRIVATE {
# Internal startup hook for libpthread.
__libc_malloc_pthread_startup;
diff --git a/malloc/arena.c b/malloc/arena.c
index 357a3b0b30..a8500a25c9 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -403,6 +403,11 @@ ptmalloc_init (void)
__malloc_debug_enable (MALLOC_CHECK_HOOK);
#endif
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
+ if (__libc_lmcheck)
+ __mcheck_initialize (NULL, false);
+#endif
+
#if HAVE_MALLOC_INIT_HOOK
void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook);
if (hook != NULL)
diff --git a/malloc/hooks.c b/malloc/hooks.c
index 77855801c8..b517a98ea2 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -36,6 +36,7 @@ enum malloc_debug_hooks
{
MALLOC_NONE_HOOK = 0,
MALLOC_CHECK_HOOK = 1 << 0, /* MALLOC_CHECK_ or glibc.malloc.check. */
+ MALLOC_MCHECK_HOOK = 1 << 1, /* mcheck() */
};
static unsigned __malloc_debugging_hooks;
@@ -77,113 +78,180 @@ __malloc_debug_disable (enum malloc_debug_hooks flag)
}
#include "malloc-check.c"
+#include "mcheck-hooks.c"
static __always_inline bool
-_malloc_debug_before (size_t bytes, void **victimp, const void *address)
+_malloc_debug_before (size_t *bytesp, void **victimp, const void *address)
{
_Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
- "PTRDIFF_MAX is not more than half of SIZE_MAX");
+ "PTRDIFF_MAX is not more than half of SIZE_MAX");
void *(*hook) (size_t, const void *)
= atomic_forced_read (__malloc_hook);
if (__builtin_expect (hook != NULL, 0))
{
- *victimp = (*hook)(bytes, address);
+ *victimp = (*hook)(*bytesp, address);
return true;
}
- if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ if (__glibc_unlikely (__malloc_debugging_hooks))
{
- *victimp = malloc_check (bytes);
- return true;
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
+ && malloc_mcheck_before (bytesp, victimp))
+ return true;
+ if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
+ {
+ *victimp = malloc_check (*bytesp);
+ return true;
+ }
}
return false;
}
+static __always_inline void *
+_malloc_debug_after (void *mem, size_t bytes, const void *address)
+{
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
+ mem = malloc_mcheck_after (mem, bytes);
+ return mem;
+}
+
static __always_inline bool
-_free_debug_before (void *mem, const void *address)
+_free_debug_before (void **mem, const void *address)
{
void (*hook) (void *, const void *)
= atomic_forced_read (__free_hook);
if (__builtin_expect (hook != NULL, 0))
{
- (*hook)(mem, address);
+ (*hook)(*mem, address);
return true;
}
- if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ if (__glibc_unlikely (__malloc_debugging_hooks))
{
- free_check (mem);
- return true;
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
+ *mem = free_mcheck (*mem);
+ if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
+ {
+ free_check (*mem);
+ return true;
+ }
}
return false;
}
static __always_inline bool
-_realloc_debug_before (void *oldmem, size_t bytes, void **victimp,
- const void *address)
+_realloc_debug_before (void **oldmem, size_t *bytesp, size_t *oldsize,
+ void **victimp, const void *address)
{
void *(*hook) (void *, size_t, const void *) =
atomic_forced_read (__realloc_hook);
if (__builtin_expect (hook != NULL, 0))
{
- *victimp = (*hook)(oldmem, bytes, address);
+ *victimp = (*hook)(*oldmem, *bytesp, address);
return true;
}
- if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ if (__glibc_unlikely (__malloc_debugging_hooks))
{
- *victimp = realloc_check (oldmem, bytes);
- return true;
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
+ && realloc_mcheck_before (oldmem, bytesp, oldsize, victimp))
+ return true;
+ if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
+ {
+ *victimp = realloc_check (*oldmem, *bytesp);
+ return true;
+ }
}
return false;
}
+static __always_inline void *
+_realloc_debug_after (void *mem, void *oldmem, size_t bytes, size_t oldsize,
+ const void *address)
+{
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
+ mem = realloc_mcheck_after (mem, oldmem, bytes, oldsize);
+ return mem;
+}
+
static __always_inline bool
-_memalign_debug_before (size_t alignment, size_t bytes, void **victimp,
- const void *address)
+_memalign_debug_before (size_t alignment, size_t *bytesp, void **victimp,
+ const void *address)
{
void *(*hook) (size_t, size_t, const void *) =
atomic_forced_read (__memalign_hook);
if (__builtin_expect (hook != NULL, 0))
{
- *victimp = (*hook)(alignment, bytes, address);
+ *victimp = (*hook)(alignment, *bytesp, address);
return true;
}
-
- if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ if (__glibc_unlikely (__malloc_debugging_hooks))
{
- *victimp = memalign_check (alignment, bytes);
- return true;
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
+ && memalign_mcheck_before (alignment, bytesp, victimp))
+ return true;
+ if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
+ {
+ *victimp = memalign_check (alignment, *bytesp);
+ return true;
+ }
}
return false;
}
+static __always_inline void *
+_memalign_debug_after (void *mem, size_t alignment, size_t bytes,
+ const void *address)
+{
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
+ mem = memalign_mcheck_after (mem, alignment, bytes);
+ return mem;
+}
+
static __always_inline bool
-_calloc_debug_before (size_t bytes, void **victimp, const void *address)
+_calloc_debug_before (size_t *bytesp, void **victimp, const void *address)
{
void *(*hook) (size_t, const void *) =
atomic_forced_read (__malloc_hook);
if (__builtin_expect (hook != NULL, 0))
{
- *victimp = (*hook)(bytes, address);
+ *victimp = (*hook)(*bytesp, address);
+
if (*victimp != NULL)
- memset (*victimp, 0, bytes);
+ memset (*victimp, 0, *bytesp);
+
return true;
}
- if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
+ if (__glibc_unlikely (__malloc_debugging_hooks))
{
- *victimp = malloc_check (bytes);
- if (*victimp != NULL)
- memset (*victimp, 0, bytes);
- return true;
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
+ && malloc_mcheck_before (bytesp, victimp))
+ return true;
+ if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
+ {
+ *victimp = malloc_check (*bytesp);
+ return true;
+ }
}
return false;
}
+static __always_inline void *
+_calloc_debug_after (void *mem, size_t bytes, const void *address)
+{
+ if (__glibc_unlikely (__malloc_debugging_hooks) && mem != NULL)
+ {
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
+ mem = malloc_mcheck_after (mem, bytes);
+ memset (mem, 0, bytes);
+ }
+ return mem;
+}
+
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_25)
/* Support for restoring dumped heaps contained in historic Emacs
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 60753446a1..5ea12d1d3b 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -3192,12 +3192,13 @@ __libc_malloc (size_t bytes)
{
mstate ar_ptr;
void *victim;
+ size_t orig_bytes = bytes;
if (__malloc_initialized < 0)
ptmalloc_init ();
- if (_malloc_debug_before (bytes, &victim, RETURN_ADDRESS (0)))
- return victim;
+ if (_malloc_debug_before (&bytes, &victim, RETURN_ADDRESS (0)))
+ goto out;
#if USE_TCACHE
/* int_free also calls request2size, be careful to not pad twice. */
@@ -3205,7 +3206,8 @@ __libc_malloc (size_t bytes)
if (!checked_request2size (bytes, &tbytes))
{
__set_errno (ENOMEM);
- return NULL;
+ victim = NULL;
+ goto out;
}
size_t tc_idx = csize2tidx (tbytes);
@@ -3217,7 +3219,8 @@ __libc_malloc (size_t bytes)
&& tcache->counts[tc_idx] > 0)
{
victim = tcache_get (tc_idx);
- return tag_new_usable (victim);
+ victim = tag_new_usable (victim);
+ goto out;
}
DIAG_POP_NEEDS_COMMENT;
#endif
@@ -3227,7 +3230,7 @@ __libc_malloc (size_t bytes)
victim = tag_new_usable (_int_malloc (&main_arena, bytes));
assert (!victim || chunk_is_mmapped (mem2chunk (victim)) ||
&main_arena == arena_for_chunk (mem2chunk (victim)));
- return victim;
+ goto out;
}
arena_get (ar_ptr, bytes);
@@ -3249,7 +3252,9 @@ __libc_malloc (size_t bytes)
assert (!victim || chunk_is_mmapped (mem2chunk (victim)) ||
ar_ptr == arena_for_chunk (mem2chunk (victim)));
- return victim;
+
+out:
+ return _malloc_debug_after (victim, orig_bytes, RETURN_ADDRESS (0));
}
libc_hidden_def (__libc_malloc)
@@ -3262,7 +3267,7 @@ __libc_free (void *mem)
if (__malloc_initialized < 0)
ptmalloc_init ();
- if (_free_debug_before (mem, RETURN_ADDRESS (0)))
+ if (_free_debug_before (&mem, RETURN_ADDRESS (0)))
return;
if (mem == 0) /* free(0) has no effect */
@@ -3315,23 +3320,30 @@ __libc_realloc (void *oldmem, size_t bytes)
INTERNAL_SIZE_T nb; /* padded request size */
void *newp; /* chunk to return */
+ size_t orig_bytes = bytes, debug_osize = 0;
if (__malloc_initialized < 0)
ptmalloc_init ();
- if (_realloc_debug_before (oldmem, bytes, &newp, RETURN_ADDRESS (0)))
- return newp;
+ if (_realloc_debug_before (&oldmem, &bytes, &debug_osize, &newp,
+ RETURN_ADDRESS (0)))
+ goto out;
#if REALLOC_ZERO_BYTES_FREES
if (bytes == 0 && oldmem != NULL)
{
- __libc_free (oldmem); return 0;
+ __libc_free (oldmem);
+ newp = NULL;
+ goto out;
}
#endif
/* realloc of null is supposed to be same as malloc */
if (oldmem == 0)
- return __libc_malloc (bytes);
+ {
+ newp = __libc_malloc (bytes);
+ goto out;
+ }
/* Perform a quick check to ensure that the pointer's tag matches the
memory's tag. */
@@ -3365,7 +3377,8 @@ __libc_realloc (void *oldmem, size_t bytes)
if (!checked_request2size (bytes, &nb))
{
__set_errno (ENOMEM);
- return NULL;
+ newp = NULL;
+ goto out;
}
if (chunk_is_mmapped (oldp))
@@ -3377,7 +3390,10 @@ __libc_realloc (void *oldmem, size_t bytes)
/* Must alloc, copy, free. */
void *newmem = __libc_malloc (bytes);
if (newmem == 0)
- return NULL;
+ {
+ newp = NULL;
+ goto out;
+ }
/* Copy as many bytes as are available from the old chunk
and fit into the new size. NB: The overhead for faked
mmapped chunks is only SIZE_SZ, not CHUNK_HDR_SZ as for
@@ -3385,7 +3401,8 @@ __libc_realloc (void *oldmem, size_t bytes)
if (bytes > oldsize - SIZE_SZ)
bytes = oldsize - SIZE_SZ;
memcpy (newmem, oldmem, bytes);
- return newmem;
+ newp = newmem;
+ goto out;
}
void *newmem;
@@ -3400,21 +3417,29 @@ __libc_realloc (void *oldmem, size_t bytes)
reused. There's a performance hit for both us and the
caller for doing this, so we might want to
reconsider. */
- return tag_new_usable (newmem);
+ newp = tag_new_usable (newmem);
+ goto out;
}
#endif
/* Note the extra SIZE_SZ overhead. */
if (oldsize - SIZE_SZ >= nb)
- return oldmem; /* do nothing */
+ {
+ newp = oldmem; /* do nothing */
+ goto out;
+ }
/* Must alloc, copy, free. */
newmem = __libc_malloc (bytes);
if (newmem == 0)
- return 0; /* propagate failure */
+ {
+ newp = NULL; /* propagate failure */
+ goto out;
+ }
memcpy (newmem, oldmem, oldsize - CHUNK_HDR_SZ);
munmap_chunk (oldp);
- return newmem;
+ newp = newmem;
+ goto out;
}
if (SINGLE_THREAD_P)
@@ -3423,7 +3448,7 @@ __libc_realloc (void *oldmem, size_t bytes)
assert (!newp || chunk_is_mmapped (mem2chunk (newp)) ||
ar_ptr == arena_for_chunk (mem2chunk (newp)));
- return newp;
+ goto out;
}
__libc_lock_lock (ar_ptr->mutex);
@@ -3448,7 +3473,9 @@ __libc_realloc (void *oldmem, size_t bytes)
}
}
- return newp;
+out:
+ return _realloc_debug_after (newp, oldmem, orig_bytes, debug_osize,
+ RETURN_ADDRESS (0));
}
libc_hidden_def (__libc_realloc)
@@ -3467,13 +3494,17 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
{
mstate ar_ptr;
void *p;
+ size_t orig_bytes = bytes;
- if (_memalign_debug_before (alignment, bytes, &p, address))
- return p;
+ if (_memalign_debug_before (alignment, &bytes, &p, address))
+ goto out;
/* If we need less alignment than we give anyway, just relay to malloc. */
if (alignment <= MALLOC_ALIGNMENT)
- return __libc_malloc (bytes);
+ {
+ p = __libc_malloc (bytes);
+ goto out;
+ }
/* Otherwise, ensure that it is at least a minimum chunk size */
if (alignment < MINSIZE)
@@ -3484,7 +3515,8 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
if (alignment > SIZE_MAX / 2 + 1)
{
__set_errno (EINVAL);
- return 0;
+ p = NULL;
+ goto out;
}
@@ -3502,7 +3534,8 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
p = _int_memalign (&main_arena, alignment, bytes);
assert (!p || chunk_is_mmapped (mem2chunk (p)) ||
&main_arena == arena_for_chunk (mem2chunk (p)));
- return tag_new_usable (p);
+ p = tag_new_usable (p);
+ goto out;
}
arena_get (ar_ptr, bytes + alignment + MINSIZE);
@@ -3520,7 +3553,9 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
assert (!p || chunk_is_mmapped (mem2chunk (p)) ||
ar_ptr == arena_for_chunk (mem2chunk (p)));
- return tag_new_usable (p);
+ p = tag_new_usable (p);
+out:
+ return _memalign_debug_after (p, alignment, orig_bytes, RETURN_ADDRESS (0));
}
/* For ISO C11. */
weak_alias (__libc_memalign, aligned_alloc)
@@ -3582,8 +3617,8 @@ __libc_calloc (size_t n, size_t elem_size)
if (__malloc_initialized < 0)
ptmalloc_init ();
- if (_calloc_debug_before (sz, &mem, RETURN_ADDRESS (0)))
- return mem;
+ if (_calloc_debug_before (&sz, &mem, RETURN_ADDRESS (0)))
+ goto out;
MAYBE_INIT_TCACHE ();
@@ -3639,7 +3674,10 @@ __libc_calloc (size_t n, size_t elem_size)
/* Allocation failed even after a retry. */
if (mem == 0)
- return 0;
+ {
+ mem = NULL;
+ goto out;
+ }
mchunkptr p = mem2chunk (mem);
@@ -3647,7 +3685,10 @@ __libc_calloc (size_t n, size_t elem_size)
regardless of MORECORE_CLEARS, so we zero the whole block while
doing so. */
if (__glibc_unlikely (mtag_enabled))
- return tag_new_zero_region (mem, memsize (p));
+ {
+ mem = tag_new_zero_region (mem, memsize (p));
+ goto out;
+ }
INTERNAL_SIZE_T csz = chunksize (p);
@@ -3655,9 +3696,9 @@ __libc_calloc (size_t n, size_t elem_size)
if (chunk_is_mmapped (p))
{
if (__builtin_expect (perturb_byte, 0))
- return memset (mem, 0, sz);
+ memset (mem, 0, sz);
- return mem;
+ goto out;
}
#if MORECORE_CLEARS
@@ -3677,7 +3718,10 @@ __libc_calloc (size_t n, size_t elem_size)
assert (nclears >= 3);
if (nclears > 9)
- return memset (d, 0, clearsize);
+ {
+ memset (d, 0, clearsize);
+ goto out;
+ }
else
{
@@ -3701,7 +3745,8 @@ __libc_calloc (size_t n, size_t elem_size)
}
}
- return mem;
+out:
+ return _calloc_debug_after (mem, bytes, RETURN_ADDRESS (0));
}
/*
diff --git a/malloc/mcheck-hooks.c b/malloc/mcheck-hooks.c
new file mode 100644
index 0000000000..f3520c7659
--- /dev/null
+++ b/malloc/mcheck-hooks.c
@@ -0,0 +1,411 @@
+/* mcheck debugging hooks for malloc.
+ Copyright (C) 1990-2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Written May 1989 by Mike Haertel.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <mcheck.h>
+#include <libintl.h>
+
+/* Arbitrary magical numbers. */
+#define MAGICWORD 0xfedabeeb
+#define MAGICFREE 0xd8675309
+#define MAGICBYTE ((char) 0xd7)
+#define MALLOCFLOOD ((char) 0x93)
+#define FREEFLOOD ((char) 0x95)
+
+/* Function to call when something awful happens. */
+static void (*abortfunc) (enum mcheck_status);
+
+struct hdr
+{
+ size_t size; /* Exact size requested by user. */
+ unsigned long int magic; /* Magic number to check header integrity. */
+ struct hdr *prev;
+ struct hdr *next;
+ void *block; /* Real block allocated, for memalign. */
+ unsigned long int magic2; /* Extra, keeps us doubleword aligned. */
+};
+
+/* This is the beginning of the list of all memory blocks allocated.
+ It is only constructed if the pedantic testing is requested. */
+struct hdr *__mcheck_root;
+
+/* Nonzero if pedentic checking of all blocks is requested. */
+static bool pedantic;
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
+/* Flag to initialize mcheck on first malloc invocation through -lmcheck.
+ libmcheck.a overrides this with a strong symbol initialized to 1. The
+ symbol cannot be linked against directly during build. */
+const int __libc_lmcheck __attribute__ ((weak));
+compat_symbol (libc, __libc_lmcheck, __libc_lmcheck, GLIBC_2_34);
+#endif
+
+#if defined _LIBC || defined STDC_HEADERS || defined USG
+# include <string.h>
+# define flood memset
+#else
+static void flood (void *, int, size_t);
+static void
+flood (void *ptr, int val, size_t size)
+{
+ char *cp = ptr;
+ while (size--)
+ *cp++ = val;
+}
+#endif
+
+static enum mcheck_status
+checkhdr (const struct hdr *hdr)
+{
+ enum mcheck_status status;
+ bool mcheck_used = __is_malloc_debug_enabled (MALLOC_MCHECK_HOOK);
+
+ if (!mcheck_used)
+ /* Maybe the mcheck used is disabled? This happens when we find
+ an error and report it. */
+ return MCHECK_OK;
+
+ switch (hdr->magic ^ ((uintptr_t) hdr->prev + (uintptr_t) hdr->next))
+ {
+ default:
+ status = MCHECK_HEAD;
+ break;
+ case MAGICFREE:
+ status = MCHECK_FREE;
+ break;
+ case MAGICWORD:
+ if (((char *) &hdr[1])[hdr->size] != MAGICBYTE)
+ status = MCHECK_TAIL;
+ else if ((hdr->magic2 ^ (uintptr_t) hdr->block) != MAGICWORD)
+ status = MCHECK_HEAD;
+ else
+ status = MCHECK_OK;
+ break;
+ }
+ if (status != MCHECK_OK)
+ {
+ mcheck_used = 0;
+ (*abortfunc) (status);
+ mcheck_used = 1;
+ }
+ return status;
+}
+
+enum mcheck_status
+__mcheck_checkptr (const void *ptr)
+{
+ if (!__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
+ return MCHECK_DISABLED;
+
+ if (ptr != NULL)
+ return checkhdr (((struct hdr *) ptr) - 1);
+
+ /* Walk through all the active blocks and test whether they were tampered
+ with. */
+ struct hdr *runp = __mcheck_root;
+
+ /* Temporarily turn off the checks. */
+ pedantic = false;
+
+ while (runp != NULL)
+ {
+ (void) checkhdr (runp);
+
+ runp = runp->next;
+ }
+
+ /* Turn checks on again. */
+ pedantic = true;
+
+ return MCHECK_OK;
+}
+
+static void
+unlink_blk (struct hdr *ptr)
+{
+ if (ptr->next != NULL)
+ {
+ ptr->next->prev = ptr->prev;
+ ptr->next->magic = MAGICWORD ^ ((uintptr_t) ptr->next->prev
+ + (uintptr_t) ptr->next->next);
+ }
+ if (ptr->prev != NULL)
+ {
+ ptr->prev->next = ptr->next;
+ ptr->prev->magic = MAGICWORD ^ ((uintptr_t) ptr->prev->prev
+ + (uintptr_t) ptr->prev->next);
+ }
+ else
+ __mcheck_root = ptr->next;
+}
+
+static void
+link_blk (struct hdr *hdr)
+{
+ hdr->prev = NULL;
+ hdr->next = __mcheck_root;
+ __mcheck_root = hdr;
+ hdr->magic = MAGICWORD ^ (uintptr_t) hdr->next;
+
+ /* And the next block. */
+ if (hdr->next != NULL)
+ {
+ hdr->next->prev = hdr;
+ hdr->next->magic = MAGICWORD ^ ((uintptr_t) hdr
+ + (uintptr_t) hdr->next->next);
+ }
+}
+
+static void *
+free_mcheck (void *ptr)
+{
+ if (pedantic)
+ __mcheck_checkptr (NULL);
+ if (ptr)
+ {
+ struct hdr *hdr = ((struct hdr *) ptr) - 1;
+ checkhdr (hdr);
+ hdr->magic = MAGICFREE;
+ hdr->magic2 = MAGICFREE;
+ unlink_blk (hdr);
+ hdr->prev = hdr->next = NULL;
+ flood (ptr, FREEFLOOD, hdr->size);
+ ptr = hdr->block;
+ }
+ return ptr;
+}
+
+static bool
+malloc_mcheck_before (size_t *sizep, void **victimp)
+{
+ size_t size = *sizep;
+
+ if (pedantic)
+ __mcheck_checkptr (NULL);
+
+ if (size > ~((size_t) 0) - (sizeof (struct hdr) + 1))
+ {
+ __set_errno (ENOMEM);
+ *victimp = NULL;
+ return true;
+ }
+
+ *sizep = sizeof (struct hdr) + size + 1;
+ return false;
+}
+
+static void *
+malloc_mcheck_after (void *mem, size_t size)
+{
+ struct hdr *hdr = mem;
+
+ if (hdr == NULL)
+ return NULL;
+
+ hdr->size = size;
+ link_blk (hdr);
+ hdr->block = hdr;
+ hdr->magic2 = (uintptr_t) hdr ^ MAGICWORD;
+ ((char *) &hdr[1])[size] = MAGICBYTE;
+ flood ((void *) (hdr + 1), MALLOCFLOOD, size);
+ return (void *) (hdr + 1);
+}
+
+static bool
+memalign_mcheck_before (size_t alignment, size_t *sizep, void **victimp)
+{
+ struct hdr *hdr;
+ size_t slop, size = *sizep;
+
+ /* Punt to malloc to avoid double headers. */
+ if (alignment <= MALLOC_ALIGNMENT)
+ {
+ *victimp = __libc_malloc (size);
+ return true;
+ }
+
+ if (pedantic)
+ __mcheck_checkptr (NULL);
+
+ slop = (sizeof *hdr + alignment - 1) & - alignment;
+
+ if (size > ~((size_t) 0) - (slop + 1))
+ {
+ __set_errno (ENOMEM);
+ *victimp = NULL;
+ return true;
+ }
+
+ *sizep = slop + size + 1;
+ return false;
+}
+
+static void *
+memalign_mcheck_after (void *block, size_t alignment, size_t size)
+{
+ if (block == NULL)
+ return NULL;
+
+ /* This was served by __libc_malloc, so return as is. */
+ if (alignment <= MALLOC_ALIGNMENT)
+ return block;
+
+ size_t slop = (sizeof (struct hdr) + alignment - 1) & - alignment;
+ struct hdr *hdr = ((struct hdr *) (block + slop)) - 1;
+
+ hdr->size = size;
+ link_blk (hdr);
+ hdr->block = (void *) block;
+ hdr->magic2 = (uintptr_t) block ^ MAGICWORD;
+ ((char *) &hdr[1])[size] = MAGICBYTE;
+ flood ((void *) (hdr + 1), MALLOCFLOOD, size);
+ return (void *) (hdr + 1);
+}
+
+static bool
+realloc_mcheck_before (void **ptrp, size_t *sizep, size_t *oldsize,
+ void **victimp)
+{
+ size_t size = *sizep;
+ void *ptr = *ptrp;
+
+ /* Handle special cases to avoid adding multiple headers. */
+ if (size == 0)
+ {
+ __libc_free (ptr);
+ *victimp = NULL;
+ return true;
+ }
+
+ if (ptr == NULL)
+ {
+ *victimp = __libc_malloc (size);
+ *oldsize = 0;
+ return true;
+ }
+
+ if (size > ~((size_t) 0) - (sizeof (struct hdr) + 1))
+ {
+ __set_errno (ENOMEM);
+ *victimp = NULL;
+ *oldsize = 0;
+ return true;
+ }
+
+ if (pedantic)
+ __mcheck_checkptr (NULL);
+
+ struct hdr *hdr;
+ size_t osize;
+
+ /* Update the oldptr for glibc realloc. */
+ *ptrp = hdr = ((struct hdr *) ptr) - 1;
+
+ osize = hdr->size;
+
+ checkhdr (hdr);
+ unlink_blk (hdr);
+ if (size < osize)
+ flood ((char *) ptr + size, FREEFLOOD, osize - size);
+
+ *oldsize = osize;
+ *sizep = sizeof (struct hdr) + size + 1;
+ return false;
+}
+
+static void *
+realloc_mcheck_after (void *ptr, void *oldptr, size_t size, size_t osize)
+{
+ struct hdr *hdr = ptr;
+
+ if (hdr == NULL)
+ return NULL;
+
+ /* Malloc already added the header so don't tamper with it. */
+ if (oldptr == NULL)
+ return ptr;
+
+ hdr->size = size;
+ link_blk (hdr);
+ hdr->block = hdr;
+ hdr->magic2 = (uintptr_t) hdr ^ MAGICWORD;
+ ((char *) &hdr[1])[size] = MAGICBYTE;
+ if (size > osize)
+ flood ((char *) (hdr + 1) + osize, MALLOCFLOOD, size - osize);
+ return (void *) (hdr + 1);
+}
+
+__attribute__ ((noreturn))
+static void
+mabort (enum mcheck_status status)
+{
+ const char *msg;
+ switch (status)
+ {
+ case MCHECK_OK:
+ msg = _ ("memory is consistent, library is buggy\n");
+ break;
+ case MCHECK_HEAD:
+ msg = _ ("memory clobbered before allocated block\n");
+ break;
+ case MCHECK_TAIL:
+ msg = _ ("memory clobbered past end of allocated block\n");
+ break;
+ case MCHECK_FREE:
+ msg = _ ("block freed twice\n");
+ break;
+ default:
+ msg = _ ("bogus mcheck_status, library is buggy\n");
+ break;
+ }
+#ifdef _LIBC
+ __libc_fatal (msg);
+#else
+ fprintf (stderr, "mcheck: %s", msg);
+ fflush (stderr);
+ abort ();
+#endif
+}
+
+int
+__mcheck_initialize (void (*func) (enum mcheck_status), bool in_pedantic)
+{
+ abortfunc = (func != NULL) ? func : &mabort;
+
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
+ goto out;
+
+ switch (__malloc_initialized)
+ {
+ case -1:
+ ptmalloc_init ();
+ /* FALLTHROUGH */
+ case 0:
+ __malloc_debug_enable (MALLOC_MCHECK_HOOK);
+ break;
+ default:
+ break;
+ }
+
+ if (!__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
+ return -1;
+
+out:
+ pedantic = in_pedantic;
+ return 0;
+}
diff --git a/malloc/mcheck-init.c b/malloc/mcheck-init.c
index 9ee69ee5f8..e3d08ae05f 100644
--- a/malloc/mcheck-init.c
+++ b/malloc/mcheck-init.c
@@ -17,17 +17,7 @@
/* The object of this file should be installed as libmcheck.a,
so one can do -lmcheck to turn on mcheck. */
-
-#include <malloc.h>
-#include <mcheck.h>
#include <shlib-compat.h>
-static void
-turn_on_mcheck (void)
-{
- mcheck (NULL);
-}
-
-void (*__malloc_initialize_hook) (void) = turn_on_mcheck;
-compat_symbol_reference (libc, __malloc_initialize_hook,
- __malloc_initialize_hook, GLIBC_2_0);
+const int __libc_lmcheck = 1;
+compat_symbol_reference (libc, __libc_lmcheck, __libc_lmcheck, GLIBC_2_34);
diff --git a/malloc/mcheck.c b/malloc/mcheck.c
index 2a1fc645d4..f60766eded 100644
--- a/malloc/mcheck.c
+++ b/malloc/mcheck.c
@@ -1,4 +1,4 @@
-/* Standard debugging hooks for `malloc'.
+/* The mcheck() interface.
Copyright (C) 1990-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Written May 1989 by Mike Haertel.
@@ -23,378 +23,22 @@
# include <mcheck.h>
# include <stdint.h>
# include <stdio.h>
-# include <libintl.h>
# include <errno.h>
#endif
-/* Old hook values. */
-static void (*old_free_hook)(void *ptr, const void *);
-static void *(*old_malloc_hook) (size_t size, const void *);
-static void *(*old_memalign_hook) (size_t alignment, size_t size,
- const void *);
-static void *(*old_realloc_hook) (void *ptr, size_t size,
- const void *);
-
-/* Function to call when something awful happens. */
-static void (*abortfunc) (enum mcheck_status);
-
-/* Arbitrary magical numbers. */
-#define MAGICWORD 0xfedabeeb
-#define MAGICFREE 0xd8675309
-#define MAGICBYTE ((char) 0xd7)
-#define MALLOCFLOOD ((char) 0x93)
-#define FREEFLOOD ((char) 0x95)
-
-struct hdr
-{
- size_t size; /* Exact size requested by user. */
- unsigned long int magic; /* Magic number to check header integrity. */
- struct hdr *prev;
- struct hdr *next;
- void *block; /* Real block allocated, for memalign. */
- unsigned long int magic2; /* Extra, keeps us doubleword aligned. */
-};
-
-/* This is the beginning of the list of all memory blocks allocated.
- It is only constructed if the pedantic testing is requested. */
-static struct hdr *root;
-
-static int mcheck_used;
-
-/* Nonzero if pedentic checking of all blocks is requested. */
-static int pedantic;
-
-#if defined _LIBC || defined STDC_HEADERS || defined USG
-# include <string.h>
-# define flood memset
-#else
-static void flood (void *, int, size_t);
-static void
-flood (void *ptr, int val, size_t size)
-{
- char *cp = ptr;
- while (size--)
- *cp++ = val;
-}
-#endif
-
-static enum mcheck_status
-checkhdr (const struct hdr *hdr)
-{
- enum mcheck_status status;
-
- if (!mcheck_used)
- /* Maybe the mcheck used is disabled? This happens when we find
- an error and report it. */
- return MCHECK_OK;
-
- switch (hdr->magic ^ ((uintptr_t) hdr->prev + (uintptr_t) hdr->next))
- {
- default:
- status = MCHECK_HEAD;
- break;
- case MAGICFREE:
- status = MCHECK_FREE;
- break;
- case MAGICWORD:
- if (((char *) &hdr[1])[hdr->size] != MAGICBYTE)
- status = MCHECK_TAIL;
- else if ((hdr->magic2 ^ (uintptr_t) hdr->block) != MAGICWORD)
- status = MCHECK_HEAD;
- else
- status = MCHECK_OK;
- break;
- }
- if (status != MCHECK_OK)
- {
- mcheck_used = 0;
- (*abortfunc) (status);
- mcheck_used = 1;
- }
- return status;
-}
-
void
mcheck_check_all (void)
{
- /* Walk through all the active blocks and test whether they were tampered
- with. */
- struct hdr *runp = root;
-
- /* Temporarily turn off the checks. */
- pedantic = 0;
-
- while (runp != NULL)
- {
- (void) checkhdr (runp);
-
- runp = runp->next;
- }
-
- /* Turn checks on again. */
- pedantic = 1;
+ __mcheck_checkptr (NULL);
}
#ifdef _LIBC
libc_hidden_def (mcheck_check_all)
#endif
-static void
-unlink_blk (struct hdr *ptr)
-{
- if (ptr->next != NULL)
- {
- ptr->next->prev = ptr->prev;
- ptr->next->magic = MAGICWORD ^ ((uintptr_t) ptr->next->prev
- + (uintptr_t) ptr->next->next);
- }
- if (ptr->prev != NULL)
- {
- ptr->prev->next = ptr->next;
- ptr->prev->magic = MAGICWORD ^ ((uintptr_t) ptr->prev->prev
- + (uintptr_t) ptr->prev->next);
- }
- else
- root = ptr->next;
-}
-
-static void
-link_blk (struct hdr *hdr)
-{
- hdr->prev = NULL;
- hdr->next = root;
- root = hdr;
- hdr->magic = MAGICWORD ^ (uintptr_t) hdr->next;
-
- /* And the next block. */
- if (hdr->next != NULL)
- {
- hdr->next->prev = hdr;
- hdr->next->magic = MAGICWORD ^ ((uintptr_t) hdr
- + (uintptr_t) hdr->next->next);
- }
-}
-static void
-freehook (void *ptr, const void *caller)
-{
- if (pedantic)
- mcheck_check_all ();
- if (ptr)
- {
- struct hdr *hdr = ((struct hdr *) ptr) - 1;
- checkhdr (hdr);
- hdr->magic = MAGICFREE;
- hdr->magic2 = MAGICFREE;
- unlink_blk (hdr);
- hdr->prev = hdr->next = NULL;
- flood (ptr, FREEFLOOD, hdr->size);
- ptr = hdr->block;
- }
- __free_hook = old_free_hook;
- if (old_free_hook != NULL)
- (*old_free_hook)(ptr, caller);
- else
- free (ptr);
- __free_hook = freehook;
-}
-
-static void *
-mallochook (size_t size, const void *caller)
-{
- struct hdr *hdr;
-
- if (pedantic)
- mcheck_check_all ();
-
- if (size > ~((size_t) 0) - (sizeof (struct hdr) + 1))
- {
- __set_errno (ENOMEM);
- return NULL;
- }
-
- __malloc_hook = old_malloc_hook;
- if (old_malloc_hook != NULL)
- hdr = (struct hdr *) (*old_malloc_hook)(sizeof (struct hdr) + size + 1,
- caller);
- else
- hdr = (struct hdr *) malloc (sizeof (struct hdr) + size + 1);
- __malloc_hook = mallochook;
- if (hdr == NULL)
- return NULL;
-
- hdr->size = size;
- link_blk (hdr);
- hdr->block = hdr;
- hdr->magic2 = (uintptr_t) hdr ^ MAGICWORD;
- ((char *) &hdr[1])[size] = MAGICBYTE;
- flood ((void *) (hdr + 1), MALLOCFLOOD, size);
- return (void *) (hdr + 1);
-}
-
-static void *
-memalignhook (size_t alignment, size_t size,
- const void *caller)
-{
- struct hdr *hdr;
- size_t slop;
- char *block;
-
- if (pedantic)
- mcheck_check_all ();
-
- slop = (sizeof *hdr + alignment - 1) & - alignment;
-
- if (size > ~((size_t) 0) - (slop + 1))
- {
- __set_errno (ENOMEM);
- return NULL;
- }
-
- __memalign_hook = old_memalign_hook;
- if (old_memalign_hook != NULL)
- block = (*old_memalign_hook)(alignment, slop + size + 1, caller);
- else
- block = memalign (alignment, slop + size + 1);
- __memalign_hook = memalignhook;
- if (block == NULL)
- return NULL;
-
- hdr = ((struct hdr *) (block + slop)) - 1;
-
- hdr->size = size;
- link_blk (hdr);
- hdr->block = (void *) block;
- hdr->magic2 = (uintptr_t) block ^ MAGICWORD;
- ((char *) &hdr[1])[size] = MAGICBYTE;
- flood ((void *) (hdr + 1), MALLOCFLOOD, size);
- return (void *) (hdr + 1);
-}
-
-static void *
-reallochook (void *ptr, size_t size, const void *caller)
-{
- if (size == 0)
- {
- freehook (ptr, caller);
- return NULL;
- }
-
- struct hdr *hdr;
- size_t osize;
-
- if (pedantic)
- mcheck_check_all ();
-
- if (size > ~((size_t) 0) - (sizeof (struct hdr) + 1))
- {
- __set_errno (ENOMEM);
- return NULL;
- }
-
- if (ptr)
- {
- hdr = ((struct hdr *) ptr) - 1;
- osize = hdr->size;
-
- checkhdr (hdr);
- unlink_blk (hdr);
- if (size < osize)
- flood ((char *) ptr + size, FREEFLOOD, osize - size);
- }
- else
- {
- osize = 0;
- hdr = NULL;
- }
- __free_hook = old_free_hook;
- __malloc_hook = old_malloc_hook;
- __memalign_hook = old_memalign_hook;
- __realloc_hook = old_realloc_hook;
- if (old_realloc_hook != NULL)
- hdr = (struct hdr *) (*old_realloc_hook)((void *) hdr,
- sizeof (struct hdr) + size + 1,
- caller);
- else
- hdr = (struct hdr *) realloc ((void *) hdr,
- sizeof (struct hdr) + size + 1);
- __free_hook = freehook;
- __malloc_hook = mallochook;
- __memalign_hook = memalignhook;
- __realloc_hook = reallochook;
- if (hdr == NULL)
- return NULL;
-
- hdr->size = size;
- link_blk (hdr);
- hdr->block = hdr;
- hdr->magic2 = (uintptr_t) hdr ^ MAGICWORD;
- ((char *) &hdr[1])[size] = MAGICBYTE;
- if (size > osize)
- flood ((char *) (hdr + 1) + osize, MALLOCFLOOD, size - osize);
- return (void *) (hdr + 1);
-}
-
-__attribute__ ((noreturn))
-static void
-mabort (enum mcheck_status status)
-{
- const char *msg;
- switch (status)
- {
- case MCHECK_OK:
- msg = _ ("memory is consistent, library is buggy\n");
- break;
- case MCHECK_HEAD:
- msg = _ ("memory clobbered before allocated block\n");
- break;
- case MCHECK_TAIL:
- msg = _ ("memory clobbered past end of allocated block\n");
- break;
- case MCHECK_FREE:
- msg = _ ("block freed twice\n");
- break;
- default:
- msg = _ ("bogus mcheck_status, library is buggy\n");
- break;
- }
-#ifdef _LIBC
- __libc_fatal (msg);
-#else
- fprintf (stderr, "mcheck: %s", msg);
- fflush (stderr);
- abort ();
-#endif
-}
-
-/* Memory barrier so that GCC does not optimize out the argument. */
-#define malloc_opt_barrier(x) \
- ({ __typeof (x) __x = x; __asm ("" : "+m" (__x)); __x; })
-
int
mcheck (void (*func) (enum mcheck_status))
{
- abortfunc = (func != NULL) ? func : &mabort;
-
- /* These hooks may not be safely inserted if malloc is already in use. */
- if (__malloc_initialized <= 0 && !mcheck_used)
- {
- /* We call malloc() once here to ensure it is initialized. */
- void *p = malloc (0);
- /* GCC might optimize out the malloc/free pair without a barrier. */
- p = malloc_opt_barrier (p);
- free (p);
-
- old_free_hook = __free_hook;
- __free_hook = freehook;
- old_malloc_hook = __malloc_hook;
- __malloc_hook = mallochook;
- old_memalign_hook = __memalign_hook;
- __memalign_hook = memalignhook;
- old_realloc_hook = __realloc_hook;
- __realloc_hook = reallochook;
- mcheck_used = 1;
- }
-
- return mcheck_used ? 0 : -1;
+ return __mcheck_initialize (func, false);
}
#ifdef _LIBC
libc_hidden_def (mcheck)
@@ -403,14 +47,11 @@ libc_hidden_def (mcheck)
int
mcheck_pedantic (void (*func) (enum mcheck_status))
{
- int res = mcheck (func);
- if (res == 0)
- pedantic = 1;
- return res;
+ return __mcheck_initialize (func, true);
}
enum mcheck_status
mprobe (void *ptr)
{
- return mcheck_used ? checkhdr (((struct hdr *) ptr) - 1) : MCHECK_DISABLED;
+ return __mcheck_checkptr (ptr);
}
diff --git a/sysdeps/mach/hurd/i386/libc.abilist b/sysdeps/mach/hurd/i386/libc.abilist
index c3232ba32e..aaf9327015 100644
--- a/sysdeps/mach/hurd/i386/libc.abilist
+++ b/sysdeps/mach/hurd/i386/libc.abilist
@@ -2216,6 +2216,7 @@ GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
GLIBC_2.34 __isnanf128 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 _hurd_libc_proc_init F
GLIBC_2.34 dladdr F
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 42e240e284..fa3b7ec645 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2336,6 +2336,7 @@ GLIBC_2.33 mknod F
GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index fad54555dc..069767561d 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2429,6 +2429,7 @@ GLIBC_2.33 mknod F
GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/arc/libc.abilist b/sysdeps/unix/sysv/linux/arc/libc.abilist
index 907716ec39..88340442d5 100644
--- a/sysdeps/unix/sysv/linux/arc/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arc/libc.abilist
@@ -2095,6 +2095,7 @@ GLIBC_2.33 mknod F
GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
index 50f987a429..4164fef788 100644
--- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
@@ -219,6 +219,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/arm/le/libc.abilist b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
index bf9038af84..4de7bba9bc 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -216,6 +216,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/csky/libc.abilist b/sysdeps/unix/sysv/linux/csky/libc.abilist
index afb91f6f43..80b70542f1 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2308,6 +2308,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 125f8a269a..dfce047c08 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2262,6 +2262,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 517753bdd1..778392d7d1 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2446,6 +2446,7 @@ GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
GLIBC_2.34 __isnanf128 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index 23d0928360..6657a9377a 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -2269,6 +2269,7 @@ GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
GLIBC_2.34 __isnanf128 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index dd5fb50b18..50e975ec5c 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -220,6 +220,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index cb1d553361..b4b78fb34e 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2389,6 +2389,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
index 6a20a6fdf2..54f7e8fbfa 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2359,6 +2359,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
index 4c21cbb64d..81f1d89b1f 100644
--- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
@@ -2356,6 +2356,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index f83ba2f780..0956d06b3a 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2354,6 +2354,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index 347bbddb94..1a03772097 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -2352,6 +2352,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index 26b7ab529b..244154cc78 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2360,6 +2360,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index e667b0e553..0b26070aad 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2325,6 +2325,7 @@ GLIBC_2.33 mknod F
GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 89a1cc7da6..c4742882b9 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2398,6 +2398,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index f364c5219e..27ece00eb4 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -2416,6 +2416,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index f5bcc78afe..c4cf0ffeb4 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -2449,6 +2449,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
index 6032716053..a10c7b5f10 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2233,6 +2233,7 @@ GLIBC_2.33 mknod F
GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
index 8c5494e1dc..72a6ef2c1f 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2532,6 +2532,7 @@ GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
GLIBC_2.34 __isnanf128 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
index d7db279c1e..98ee166273 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc.abilist
@@ -2097,6 +2097,7 @@ GLIBC_2.33 wprintf F
GLIBC_2.33 write F
GLIBC_2.33 writev F
GLIBC_2.33 wscanf F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index ef03dc0f9e..ba5be3403a 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2297,6 +2297,7 @@ GLIBC_2.33 mknod F
GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index 9118cb68ec..69a3dab8bc 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2414,6 +2414,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index 66c01bd7e7..1cc22e808a 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2270,6 +2270,7 @@ GLIBC_2.33 mknod F
GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/sh/be/libc.abilist b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
index c40eb412c2..349794da3c 100644
--- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
@@ -2269,6 +2269,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/sh/le/libc.abilist b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
index 1412d33835..0fb54b1a62 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2266,6 +2266,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 7b55d34753..b2381d0717 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -2407,6 +2407,7 @@ GLIBC_2.34 __glob64_time64 F
GLIBC_2.34 __globfree64_time64 F
GLIBC_2.34 __gmtime64 F
GLIBC_2.34 __gmtime64_r F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __localtime64 F
GLIBC_2.34 __localtime64_r F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index cfd5f38864..b8bfd0a7fc 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2290,6 +2290,7 @@ GLIBC_2.33 mknod F
GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index 17be05f14f..793b73440d 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2248,6 +2248,7 @@ GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
GLIBC_2.34 __isnanf128 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index a9db18906b..1e7ff371d8 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2351,6 +2351,7 @@ GLIBC_2.33 mknodat F
GLIBC_2.33 stat F
GLIBC_2.33 stat64 F
GLIBC_2.34 __isnanf128 F
+GLIBC_2.34 __libc_lmcheck D 0x4
GLIBC_2.34 __libc_start_main F
GLIBC_2.34 __pthread_cleanup_routine F
GLIBC_2.34 __pthread_key_create F
--
2.31.1
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH 5/8] mtrace: Wean away from malloc hooks
2021-06-24 18:23 [PATCH 0/8] Remove malloc hooks Siddhesh Poyarekar
` (3 preceding siblings ...)
2021-06-24 18:23 ` [PATCH 4/8] mcheck: " Siddhesh Poyarekar
@ 2021-06-24 18:23 ` Siddhesh Poyarekar
2021-06-24 23:13 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 6/8] Remove " Siddhesh Poyarekar
` (2 subsequent siblings)
7 siblings, 1 reply; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-24 18:23 UTC (permalink / raw)
To: libc-alpha; +Cc: dj, carlos, fweimer
Split mtrace hooks into before and after and adapt to the new internal
debugging hooks infrastructure. With this, the malloc hooks are
unused internally and can be removed from the main library.
This also eliminates the only use of memalign through a PLT in the
library, so checklocalplt data needs to be updated to reflect that.
---
include/malloc.h | 1 +
malloc/hooks.c | 38 ++-
malloc/mtrace-hooks.c | 137 ++++++++++
malloc/mtrace.c | 233 +-----------------
sysdeps/generic/localplt.data | 1 -
sysdeps/mach/hurd/i386/localplt.data | 1 -
sysdeps/unix/sysv/linux/aarch64/localplt.data | 1 -
sysdeps/unix/sysv/linux/alpha/localplt.data | 1 -
sysdeps/unix/sysv/linux/arc/localplt.data | 1 -
sysdeps/unix/sysv/linux/arm/localplt.data | 1 -
sysdeps/unix/sysv/linux/csky/localplt.data | 1 -
sysdeps/unix/sysv/linux/hppa/localplt.data | 1 -
sysdeps/unix/sysv/linux/i386/localplt.data | 1 -
sysdeps/unix/sysv/linux/ia64/localplt.data | 1 -
.../sysv/linux/m68k/coldfire/localplt.data | 1 -
.../unix/sysv/linux/m68k/m680x0/localplt.data | 1 -
.../unix/sysv/linux/microblaze/localplt.data | 1 -
sysdeps/unix/sysv/linux/nios2/localplt.data | 1 -
.../linux/powerpc/powerpc32/fpu/localplt.data | 1 -
.../powerpc/powerpc32/nofpu/localplt.data | 1 -
.../linux/powerpc/powerpc64/localplt.data | 1 -
sysdeps/unix/sysv/linux/riscv/localplt.data | 1 -
sysdeps/unix/sysv/linux/s390/localplt.data | 1 -
sysdeps/unix/sysv/linux/sh/localplt.data | 1 -
.../sysv/linux/sparc/sparc32/localplt.data | 1 -
.../sysv/linux/sparc/sparc64/localplt.data | 1 -
sysdeps/x86_64/localplt.data | 1 -
27 files changed, 180 insertions(+), 252 deletions(-)
create mode 100644 malloc/mtrace-hooks.c
diff --git a/include/malloc.h b/include/malloc.h
index bb1123d9d3..6169d486f5 100644
--- a/include/malloc.h
+++ b/include/malloc.h
@@ -15,6 +15,7 @@ typedef struct malloc_state *mstate;
#define __malloc_initialized __libc_malloc_initialized
/* Nonzero if the malloc is already initialized. */
extern int __malloc_initialized attribute_hidden;
+extern FILE *__mtrace_mallstream attribute_hidden;
enum mcheck_status __mcheck_checkptr (const void *) attribute_hidden;
extern int __mcheck_initialize (void (*) (enum mcheck_status), bool)
diff --git a/malloc/hooks.c b/malloc/hooks.c
index b517a98ea2..492e9aac63 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -37,6 +37,7 @@ enum malloc_debug_hooks
MALLOC_NONE_HOOK = 0,
MALLOC_CHECK_HOOK = 1 << 0, /* MALLOC_CHECK_ or glibc.malloc.check. */
MALLOC_MCHECK_HOOK = 1 << 1, /* mcheck() */
+ MALLOC_MTRACE_HOOK = 1 << 2, /* mtrace() */
};
static unsigned __malloc_debugging_hooks;
@@ -79,6 +80,7 @@ __malloc_debug_disable (enum malloc_debug_hooks flag)
#include "malloc-check.c"
#include "mcheck-hooks.c"
+#include "mtrace-hooks.c"
static __always_inline bool
_malloc_debug_before (size_t *bytesp, void **victimp, const void *address)
@@ -111,8 +113,13 @@ _malloc_debug_before (size_t *bytesp, void **victimp, const void *address)
static __always_inline void *
_malloc_debug_after (void *mem, size_t bytes, const void *address)
{
- if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
- mem = malloc_mcheck_after (mem, bytes);
+ if (__glibc_unlikely (__malloc_debugging_hooks))
+ {
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
+ mem = malloc_mcheck_after (mem, bytes);
+ if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
+ mem = malloc_mtrace_after (mem, bytes, address);
+ }
return mem;
}
@@ -129,6 +136,8 @@ _free_debug_before (void **mem, const void *address)
if (__glibc_unlikely (__malloc_debugging_hooks))
{
+ if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
+ free_mtrace (mem, address);
if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
*mem = free_mcheck (*mem);
if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
@@ -171,8 +180,13 @@ static __always_inline void *
_realloc_debug_after (void *mem, void *oldmem, size_t bytes, size_t oldsize,
const void *address)
{
- if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
- mem = realloc_mcheck_after (mem, oldmem, bytes, oldsize);
+ if (__glibc_unlikely (__malloc_debugging_hooks))
+ {
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
+ mem = realloc_mcheck_after (mem, oldmem, bytes, oldsize);
+ if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
+ mem = realloc_mtrace_after (mem, oldmem, bytes, address);
+ }
return mem;
}
@@ -206,8 +220,13 @@ static __always_inline void *
_memalign_debug_after (void *mem, size_t alignment, size_t bytes,
const void *address)
{
- if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
- mem = memalign_mcheck_after (mem, alignment, bytes);
+ if (__glibc_unlikely (__malloc_debugging_hooks))
+ {
+ if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
+ mem = memalign_mcheck_after (mem, alignment, bytes);
+ if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
+ mem = memalign_mtrace_after (mem, bytes, address);
+ }
return mem;
}
@@ -243,11 +262,14 @@ _calloc_debug_before (size_t *bytesp, void **victimp, const void *address)
static __always_inline void *
_calloc_debug_after (void *mem, size_t bytes, const void *address)
{
- if (__glibc_unlikely (__malloc_debugging_hooks) && mem != NULL)
+ if (__glibc_unlikely (__malloc_debugging_hooks))
{
if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
mem = malloc_mcheck_after (mem, bytes);
- memset (mem, 0, bytes);
+ if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
+ mem = malloc_mtrace_after (mem, bytes, address);
+ else if (mem != NULL)
+ memset (mem, 0, bytes);
}
return mem;
}
diff --git a/malloc/mtrace-hooks.c b/malloc/mtrace-hooks.c
new file mode 100644
index 0000000000..c1c6d6a6e9
--- /dev/null
+++ b/malloc/mtrace-hooks.c
@@ -0,0 +1,137 @@
+
+# include <libc-lock.h>
+
+#include <kernel-features.h>
+
+FILE *__mtrace_mallstream;
+
+__libc_lock_define_initialized (static, lock);
+
+static void
+tr_where (const void *caller, Dl_info *info)
+{
+ if (caller != NULL)
+ {
+ if (info != NULL)
+ {
+ char *buf = (char *) "";
+ if (info->dli_sname != NULL)
+ {
+ size_t len = strlen (info->dli_sname);
+ buf = alloca (len + 6 + 2 * sizeof (void *));
+
+ buf[0] = '(';
+ __stpcpy (_fitoa (caller >= (const void *) info->dli_saddr
+ ? caller - (const void *) info->dli_saddr
+ : (const void *) info->dli_saddr - caller,
+ __stpcpy (__mempcpy (buf + 1, info->dli_sname,
+ len),
+ caller >= (void *) info->dli_saddr
+ ? "+0x" : "-0x"),
+ 16, 0),
+ ")");
+ }
+
+ fprintf (__mtrace_mallstream, "@ %s%s%s[%p] ",
+ info->dli_fname ? : "", info->dli_fname ? ":" : "",
+ buf, caller);
+ }
+ else
+ fprintf (__mtrace_mallstream, "@ [%p] ", caller);
+ }
+}
+
+static Dl_info *
+lock_and_info (const void *caller, Dl_info *mem)
+{
+ if (caller == NULL)
+ return NULL;
+
+ Dl_info *res = _dl_addr (caller, mem, NULL, NULL) ? mem : NULL;
+
+ __libc_lock_lock (lock);
+
+ return res;
+}
+
+static bool
+free_mtrace (void *ptr, const void *caller)
+{
+ if (ptr == NULL)
+ return true;
+
+ Dl_info mem;
+ Dl_info *info = lock_and_info (caller, &mem);
+ tr_where (caller, info);
+ /* Be sure to print it first. */
+ fprintf (__mtrace_mallstream, "- %p\n", ptr);
+ __libc_lock_unlock (lock);
+
+ /* Continue on to free. */
+ return false;
+}
+
+static void *
+malloc_mtrace_after (void *block, size_t size, const void *caller)
+{
+ Dl_info mem;
+ Dl_info *info = lock_and_info (caller, &mem);
+
+ tr_where (caller, info);
+ /* We could be printing a NULL here; that's OK. */
+ fprintf (__mtrace_mallstream, "+ %p %#lx\n", block,
+ (unsigned long int) size);
+
+ __libc_lock_unlock (lock);
+
+ return block;
+}
+
+static void *
+realloc_mtrace_after (void *block, const void *oldptr, size_t size,
+ const void *caller)
+{
+ Dl_info mem;
+ Dl_info *info = lock_and_info (caller, &mem);
+
+ tr_where (caller, info);
+ if (block == NULL)
+ {
+ if (size != 0)
+ /* Failed realloc. */
+ fprintf (__mtrace_mallstream, "! %p %#lx\n", oldptr,
+ (unsigned long int) size);
+ else
+ fprintf (__mtrace_mallstream, "- %p\n", oldptr);
+ }
+ else if (oldptr == NULL)
+ fprintf (__mtrace_mallstream, "+ %p %#lx\n", block,
+ (unsigned long int) size);
+ else
+ {
+ fprintf (__mtrace_mallstream, "< %p\n", oldptr);
+ tr_where (caller, info);
+ fprintf (__mtrace_mallstream, "> %p %#lx\n", block,
+ (unsigned long int) size);
+ }
+
+ __libc_lock_unlock (lock);
+
+ return block;
+}
+
+static void *
+memalign_mtrace_after (void *block, size_t size, const void *caller)
+{
+ Dl_info mem;
+ Dl_info *info = lock_and_info (caller, &mem);
+
+ tr_where (caller, info);
+ /* We could be printing a NULL here; that's OK. */
+ fprintf (__mtrace_mallstream, "+ %p %#lx\n", block,
+ (unsigned long int) size);
+
+ __libc_lock_unlock (lock);
+
+ return block;
+}
diff --git a/malloc/mtrace.c b/malloc/mtrace.c
index 6c2c58b706..2cc4507e25 100644
--- a/malloc/mtrace.c
+++ b/malloc/mtrace.c
@@ -22,7 +22,6 @@
# define _MALLOC_INTERNAL
# include <malloc.h>
# include <mcheck.h>
-# include <libc-lock.h>
#endif
#include <dlfcn.h>
@@ -35,20 +34,14 @@
#include <libc-internal.h>
#include <dso_handle.h>
-
#include <libio/iolibio.h>
#define setvbuf(s, b, f, l) _IO_setvbuf (s, b, f, l)
#define fwrite(buf, size, count, fp) _IO_fwrite (buf, size, count, fp)
-#include <kernel-features.h>
-
#define TRACE_BUFFER_SIZE 512
-static FILE *mallstream;
-static const char mallenv[] = "MALLOC_TRACE";
static char *malloc_trace_buffer;
-
-__libc_lock_define_initialized (static, lock);
+static const char mallenv[] = "MALLOC_TRACE";
#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
/* Compatibility symbols that were introduced to help break at allocation sites
@@ -69,204 +62,6 @@ tr_break (void)
compat_symbol (libc, tr_break, tr_break, GLIBC_2_0);
#endif
-
-/* Old hook values. */
-static void (*tr_old_free_hook) (void *ptr, const void *);
-static void *(*tr_old_malloc_hook) (size_t size, const void *);
-static void *(*tr_old_realloc_hook) (void *ptr, size_t size,
- const void *);
-static void *(*tr_old_memalign_hook) (size_t __alignment, size_t __size,
- const void *);
-
-static void
-tr_where (const void *caller, Dl_info *info)
-{
- if (caller != NULL)
- {
- if (info != NULL)
- {
- char *buf = (char *) "";
- if (info->dli_sname != NULL)
- {
- size_t len = strlen (info->dli_sname);
- buf = alloca (len + 6 + 2 * sizeof (void *));
-
- buf[0] = '(';
- __stpcpy (_fitoa (caller >= (const void *) info->dli_saddr
- ? caller - (const void *) info->dli_saddr
- : (const void *) info->dli_saddr - caller,
- __stpcpy (__mempcpy (buf + 1, info->dli_sname,
- len),
- caller >= (void *) info->dli_saddr
- ? "+0x" : "-0x"),
- 16, 0),
- ")");
- }
-
- fprintf (mallstream, "@ %s%s%s[%p] ",
- info->dli_fname ? : "", info->dli_fname ? ":" : "",
- buf, caller);
- }
- else
- fprintf (mallstream, "@ [%p] ", caller);
- }
-}
-
-static Dl_info *
-lock_and_info (const void *caller, Dl_info *mem)
-{
- if (caller == NULL)
- return NULL;
-
- Dl_info *res = _dl_addr (caller, mem, NULL, NULL) ? mem : NULL;
-
- __libc_lock_lock (lock);
-
- return res;
-}
-
-static void tr_freehook (void *, const void *);
-static void * tr_mallochook (size_t, const void *);
-static void * tr_reallochook (void *, size_t, const void *);
-static void * tr_memalignhook (size_t, size_t, const void *);
-
-/* Set all the default non-trace hooks. */
-static __always_inline void
-set_default_hooks (void)
-{
- __free_hook = tr_old_free_hook;
- __malloc_hook = tr_old_malloc_hook;
- __realloc_hook = tr_old_realloc_hook;
- __memalign_hook = tr_old_memalign_hook;
-}
-
-/* Set all of the tracing hooks used for mtrace. */
-static __always_inline void
-set_trace_hooks (void)
-{
- __free_hook = tr_freehook;
- __malloc_hook = tr_mallochook;
- __realloc_hook = tr_reallochook;
- __memalign_hook = tr_memalignhook;
-}
-
-/* Save the current set of hooks as the default hooks. */
-static __always_inline void
-save_default_hooks (void)
-{
- tr_old_free_hook = __free_hook;
- tr_old_malloc_hook = __malloc_hook;
- tr_old_realloc_hook = __realloc_hook;
- tr_old_memalign_hook = __memalign_hook;
-}
-
-static void
-tr_freehook (void *ptr, const void *caller)
-{
- if (ptr == NULL)
- return;
-
- Dl_info mem;
- Dl_info *info = lock_and_info (caller, &mem);
- tr_where (caller, info);
- /* Be sure to print it first. */
- fprintf (mallstream, "- %p\n", ptr);
- set_default_hooks ();
- if (tr_old_free_hook != NULL)
- (*tr_old_free_hook)(ptr, caller);
- else
- free (ptr);
- set_trace_hooks ();
- __libc_lock_unlock (lock);
-}
-
-static void *
-tr_mallochook (size_t size, const void *caller)
-{
- void *hdr;
-
- Dl_info mem;
- Dl_info *info = lock_and_info (caller, &mem);
-
- set_default_hooks ();
- if (tr_old_malloc_hook != NULL)
- hdr = (void *) (*tr_old_malloc_hook)(size, caller);
- else
- hdr = (void *) malloc (size);
- set_trace_hooks ();
-
- tr_where (caller, info);
- /* We could be printing a NULL here; that's OK. */
- fprintf (mallstream, "+ %p %#lx\n", hdr, (unsigned long int) size);
-
- __libc_lock_unlock (lock);
-
- return hdr;
-}
-
-static void *
-tr_reallochook (void *ptr, size_t size, const void *caller)
-{
- void *hdr;
-
- Dl_info mem;
- Dl_info *info = lock_and_info (caller, &mem);
-
- set_default_hooks ();
- if (tr_old_realloc_hook != NULL)
- hdr = (void *) (*tr_old_realloc_hook)(ptr, size, caller);
- else
- hdr = (void *) realloc (ptr, size);
- set_trace_hooks ();
-
- tr_where (caller, info);
- if (hdr == NULL)
- {
- if (size != 0)
- /* Failed realloc. */
- fprintf (mallstream, "! %p %#lx\n", ptr, (unsigned long int) size);
- else
- fprintf (mallstream, "- %p\n", ptr);
- }
- else if (ptr == NULL)
- fprintf (mallstream, "+ %p %#lx\n", hdr, (unsigned long int) size);
- else
- {
- fprintf (mallstream, "< %p\n", ptr);
- tr_where (caller, info);
- fprintf (mallstream, "> %p %#lx\n", hdr, (unsigned long int) size);
- }
-
- __libc_lock_unlock (lock);
-
- return hdr;
-}
-
-static void *
-tr_memalignhook (size_t alignment, size_t size, const void *caller)
-{
- void *hdr;
-
- Dl_info mem;
- Dl_info *info = lock_and_info (caller, &mem);
-
- set_default_hooks ();
- if (tr_old_memalign_hook != NULL)
- hdr = (void *) (*tr_old_memalign_hook)(alignment, size, caller);
- else
- hdr = (void *) memalign (alignment, size);
- set_trace_hooks ();
-
- tr_where (caller, info);
- /* We could be printing a NULL here; that's OK. */
- fprintf (mallstream, "+ %p %#lx\n", hdr, (unsigned long int) size);
-
- __libc_lock_unlock (lock);
-
- return hdr;
-}
-
-
#ifdef _LIBC
/* This function gets called to make sure all memory the library
@@ -276,7 +71,7 @@ static void __libc_freeres_fn_section
release_libc_mem (void)
{
/* Only call the free function if we still are running in mtrace mode. */
- if (mallstream != NULL)
+ if (__mtrace_mallstream != NULL)
__libc_freeres ();
}
#endif
@@ -293,7 +88,7 @@ mtrace (void)
char *mallfile;
/* Don't panic if we're called more than once. */
- if (mallstream != NULL)
+ if (__mtrace_mallstream != NULL)
return;
#ifdef _LIBC
@@ -310,15 +105,15 @@ mtrace (void)
if (mtb == NULL)
return;
- mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "wce");
- if (mallstream != NULL)
+ __mtrace_mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null",
+ "wce");
+ if (__mtrace_mallstream != NULL)
{
/* Be sure it doesn't malloc its buffer! */
malloc_trace_buffer = mtb;
- setvbuf (mallstream, malloc_trace_buffer, _IOFBF, TRACE_BUFFER_SIZE);
- fprintf (mallstream, "= Start\n");
- save_default_hooks ();
- set_trace_hooks ();
+ setvbuf (__mtrace_mallstream, malloc_trace_buffer, _IOFBF,
+ TRACE_BUFFER_SIZE);
+ fprintf (__mtrace_mallstream, "= Start\n");
#ifdef _LIBC
if (!added_atexit_handler)
{
@@ -336,15 +131,11 @@ mtrace (void)
void
muntrace (void)
{
- if (mallstream == NULL)
+ if (__mtrace_mallstream == NULL)
return;
- /* Do the reverse of what done in mtrace: first reset the hooks and
- MALLSTREAM, and only after that write the trailer and close the
- file. */
- FILE *f = mallstream;
- mallstream = NULL;
- set_default_hooks ();
+ FILE *f = __mtrace_mallstream;
+ __mtrace_mallstream = NULL;
fprintf (f, "= End\n");
fclose (f);
diff --git a/sysdeps/generic/localplt.data b/sysdeps/generic/localplt.data
index e2083c0ce6..9b4f35786a 100644
--- a/sysdeps/generic/localplt.data
+++ b/sysdeps/generic/localplt.data
@@ -4,7 +4,6 @@
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/mach/hurd/i386/localplt.data b/sysdeps/mach/hurd/i386/localplt.data
index 94064ecbc5..47fbe1e2a7 100644
--- a/sysdeps/mach/hurd/i386/localplt.data
+++ b/sysdeps/mach/hurd/i386/localplt.data
@@ -6,7 +6,6 @@
libc.so: calloc + REL R_386_GLOB_DAT
libc.so: free + REL R_386_GLOB_DAT
libc.so: malloc + REL R_386_GLOB_DAT
-libc.so: memalign + REL R_386_GLOB_DAT
libc.so: realloc + REL R_386_GLOB_DAT
libm.so: matherr + REL R_386_GLOB_DAT
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/aarch64/localplt.data b/sysdeps/unix/sysv/linux/aarch64/localplt.data
index 2c14b652ef..348b3f3793 100644
--- a/sysdeps/unix/sysv/linux/aarch64/localplt.data
+++ b/sysdeps/unix/sysv/linux/aarch64/localplt.data
@@ -4,7 +4,6 @@
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# If outline atomics are used, libgcc (built outside of glibc) may
diff --git a/sysdeps/unix/sysv/linux/alpha/localplt.data b/sysdeps/unix/sysv/linux/alpha/localplt.data
index 43f6fdaea1..44bf36f4f1 100644
--- a/sysdeps/unix/sysv/linux/alpha/localplt.data
+++ b/sysdeps/unix/sysv/linux/alpha/localplt.data
@@ -18,7 +18,6 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc + RELA R_ALPHA_GLOB_DAT
libc.so: free + RELA R_ALPHA_GLOB_DAT
libc.so: malloc + RELA R_ALPHA_GLOB_DAT
-libc.so: memalign + RELA R_ALPHA_GLOB_DAT
libc.so: realloc + RELA R_ALPHA_GLOB_DAT
libm.so: matherr + RELA R_ALPHA_GLOB_DAT
# We used to offer inline functions that used this, so it must be exported.
diff --git a/sysdeps/unix/sysv/linux/arc/localplt.data b/sysdeps/unix/sysv/linux/arc/localplt.data
index 4479e8ee8a..ac5332caf7 100644
--- a/sysdeps/unix/sysv/linux/arc/localplt.data
+++ b/sysdeps/unix/sysv/linux/arc/localplt.data
@@ -1,6 +1,5 @@
libc.so: realloc
libc.so: malloc
-libc.so: memalign
libc.so: calloc
libc.so: free
# At -Os, a struct assignment in libgcc-static pulls this in
diff --git a/sysdeps/unix/sysv/linux/arm/localplt.data b/sysdeps/unix/sysv/linux/arm/localplt.data
index eb315da2f1..78896444c6 100644
--- a/sysdeps/unix/sysv/linux/arm/localplt.data
+++ b/sysdeps/unix/sysv/linux/arm/localplt.data
@@ -1,7 +1,6 @@
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: raise
libc.so: realloc
libm.so: matherr
diff --git a/sysdeps/unix/sysv/linux/csky/localplt.data b/sysdeps/unix/sysv/linux/csky/localplt.data
index 0ed8650b65..817ab2659a 100644
--- a/sysdeps/unix/sysv/linux/csky/localplt.data
+++ b/sysdeps/unix/sysv/linux/csky/localplt.data
@@ -4,7 +4,6 @@
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
# The TLS-enabled version of these functions is interposed from libc.so.
ld.so: _dl_signal_error
diff --git a/sysdeps/unix/sysv/linux/hppa/localplt.data b/sysdeps/unix/sysv/linux/hppa/localplt.data
index 09893d4dcf..baf857a750 100644
--- a/sysdeps/unix/sysv/linux/hppa/localplt.data
+++ b/sysdeps/unix/sysv/linux/hppa/localplt.data
@@ -4,7 +4,6 @@
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libc.so: __sigsetjmp
libc.so: _IO_funlockfile
diff --git a/sysdeps/unix/sysv/linux/i386/localplt.data b/sysdeps/unix/sysv/linux/i386/localplt.data
index 5334875b4b..f9bf7fb410 100644
--- a/sysdeps/unix/sysv/linux/i386/localplt.data
+++ b/sysdeps/unix/sysv/linux/i386/localplt.data
@@ -4,7 +4,6 @@ libc.so: _Unwind_Find_FDE + REL R_386_GLOB_DAT
libc.so: calloc + REL R_386_GLOB_DAT
libc.so: free + REL R_386_GLOB_DAT
libc.so: malloc + REL R_386_GLOB_DAT
-libc.so: memalign + REL R_386_GLOB_DAT
libc.so: realloc + REL R_386_GLOB_DAT
libm.so: matherr + REL R_386_GLOB_DAT
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/ia64/localplt.data b/sysdeps/unix/sysv/linux/ia64/localplt.data
index 1c566a503e..174fb88128 100644
--- a/sysdeps/unix/sysv/linux/ia64/localplt.data
+++ b/sysdeps/unix/sysv/linux/ia64/localplt.data
@@ -1,7 +1,6 @@
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
libm.so: matherrf
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/localplt.data b/sysdeps/unix/sysv/linux/m68k/coldfire/localplt.data
index 3c5efb7204..42fa90508c 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/localplt.data
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/localplt.data
@@ -2,7 +2,6 @@ libc.so: __m68k_read_tp
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/localplt.data b/sysdeps/unix/sysv/linux/m68k/m680x0/localplt.data
index 843f4e25f2..34bd4c1aca 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/localplt.data
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/localplt.data
@@ -3,7 +3,6 @@ libc.so: __m68k_read_tp
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/microblaze/localplt.data b/sysdeps/unix/sysv/linux/microblaze/localplt.data
index 0e98d5251e..c3801314c9 100644
--- a/sysdeps/unix/sysv/linux/microblaze/localplt.data
+++ b/sysdeps/unix/sysv/linux/microblaze/localplt.data
@@ -2,7 +2,6 @@ libc.so: __errno_location
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# The dynamic loader needs __tls_get_addr for TLS.
diff --git a/sysdeps/unix/sysv/linux/nios2/localplt.data b/sysdeps/unix/sysv/linux/nios2/localplt.data
index b37987c7c0..17fcfdd4db 100644
--- a/sysdeps/unix/sysv/linux/nios2/localplt.data
+++ b/sysdeps/unix/sysv/linux/nios2/localplt.data
@@ -6,7 +6,6 @@ libc.so: __gedf2
libc.so: malloc
libc.so: __gtsf2 ?
libc.so: __nesf2
-libc.so: memalign
libc.so: __mulsf3
libc.so: __floatunsisf
libc.so: __addsf3
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data
index a02dd5cc24..c0af84eef7 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data
@@ -2,7 +2,6 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
index d8072597b7..581e54b95c 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
@@ -30,7 +30,6 @@ libc.so: abort ?
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: memset ?
libc.so: realloc
libm.so: copysignl ?
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data
index bb498fbe3a..d69b7ae646 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data
@@ -1,7 +1,6 @@
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/riscv/localplt.data b/sysdeps/unix/sysv/linux/riscv/localplt.data
index 0a235592c3..e6d5330d5b 100644
--- a/sysdeps/unix/sysv/linux/riscv/localplt.data
+++ b/sysdeps/unix/sysv/linux/riscv/localplt.data
@@ -4,7 +4,6 @@
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: memset ?
libc.so: realloc
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/s390/localplt.data b/sysdeps/unix/sysv/linux/s390/localplt.data
index a02dd5cc24..c0af84eef7 100644
--- a/sysdeps/unix/sysv/linux/s390/localplt.data
+++ b/sysdeps/unix/sysv/linux/s390/localplt.data
@@ -2,7 +2,6 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/sh/localplt.data b/sysdeps/unix/sysv/linux/sh/localplt.data
index 3225177c50..6491b9e37b 100644
--- a/sysdeps/unix/sysv/linux/sh/localplt.data
+++ b/sysdeps/unix/sysv/linux/sh/localplt.data
@@ -4,7 +4,6 @@
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libc.so: _Unwind_Find_FDE
libc.so: _exit
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data b/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data
index be51efd566..38309a1393 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data
@@ -16,7 +16,6 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data b/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data
index 809062d46c..6a216f3a5a 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data
@@ -15,7 +15,6 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc
libc.so: free
libc.so: malloc
-libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/x86_64/localplt.data b/sysdeps/x86_64/localplt.data
index 8f41e92870..d1f2e26612 100644
--- a/sysdeps/x86_64/localplt.data
+++ b/sysdeps/x86_64/localplt.data
@@ -6,7 +6,6 @@
libc.so: calloc + RELA R_X86_64_GLOB_DAT
libc.so: free + RELA R_X86_64_GLOB_DAT
libc.so: malloc + RELA R_X86_64_GLOB_DAT
-libc.so: memalign + RELA R_X86_64_GLOB_DAT
libc.so: realloc + RELA R_X86_64_GLOB_DAT
libm.so: matherr + RELA R_X86_64_GLOB_DAT
# The TLS-enabled version of these functions is interposed from libc.so.
--
2.31.1
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH 6/8] Remove malloc hooks
2021-06-24 18:23 [PATCH 0/8] Remove malloc hooks Siddhesh Poyarekar
` (4 preceding siblings ...)
2021-06-24 18:23 ` [PATCH 5/8] mtrace: " Siddhesh Poyarekar
@ 2021-06-24 18:23 ` Siddhesh Poyarekar
2021-06-24 23:31 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 7/8] Remove __after_morecore_hook Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 8/8] Remove __morecore and __default_morecore Siddhesh Poyarekar
7 siblings, 1 reply; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-24 18:23 UTC (permalink / raw)
To: libc-alpha; +Cc: dj, carlos, fweimer
Make malloc hooks symbols compat-only so that new applications cannot
link against them and remove the declarations from the API. The
existing hooks variables are not used in the library anymore.
Legacy applications that need hooks functionality need to preload a
new DSO libmalloc_compathooks.so, which interposes the libc malloc
functions to execute hooks if they exist.
Also remove all references to the malloc hooks in the manual. Mention
the removal in NEWS and also warn that libmalloc_compathooks.so is a
temporary measure and may be removed in a future version of glibc.
memalign makes a comeback as a PLT reference since the initialization
hooks use them. tst-mallocstate now needs libmalloc_compathooks.so
since it uses __malloc_initialize_hook to set up initial heap state to
emumate emacs.
---
Makeconfig | 2 +-
NEWS | 9 +
malloc/Makefile | 15 +-
malloc/arena.c | 5 -
malloc/hooks.c | 114 ++++++-----
malloc/malloc-compathooks.c | 166 +++++++++++++++
malloc/malloc.c | 10 -
malloc/malloc.h | 14 --
manual/memory.texi | 191 +-----------------
sysdeps/generic/localplt.data | 1 +
sysdeps/mach/hurd/i386/localplt.data | 1 +
sysdeps/unix/sysv/linux/aarch64/localplt.data | 1 +
sysdeps/unix/sysv/linux/alpha/localplt.data | 1 +
sysdeps/unix/sysv/linux/arc/localplt.data | 1 +
sysdeps/unix/sysv/linux/arm/localplt.data | 1 +
sysdeps/unix/sysv/linux/csky/localplt.data | 1 +
sysdeps/unix/sysv/linux/hppa/localplt.data | 1 +
sysdeps/unix/sysv/linux/i386/localplt.data | 1 +
sysdeps/unix/sysv/linux/ia64/localplt.data | 1 +
.../sysv/linux/m68k/coldfire/localplt.data | 1 +
.../unix/sysv/linux/m68k/m680x0/localplt.data | 1 +
.../unix/sysv/linux/microblaze/localplt.data | 1 +
sysdeps/unix/sysv/linux/nios2/localplt.data | 1 +
.../linux/powerpc/powerpc32/fpu/localplt.data | 1 +
.../powerpc/powerpc32/nofpu/localplt.data | 1 +
.../linux/powerpc/powerpc64/localplt.data | 1 +
sysdeps/unix/sysv/linux/riscv/localplt.data | 1 +
sysdeps/unix/sysv/linux/s390/localplt.data | 1 +
sysdeps/unix/sysv/linux/sh/localplt.data | 1 +
.../sysv/linux/sparc/sparc32/localplt.data | 1 +
.../sysv/linux/sparc/sparc64/localplt.data | 1 +
sysdeps/x86_64/localplt.data | 1 +
32 files changed, 284 insertions(+), 265 deletions(-)
create mode 100644 malloc/malloc-compathooks.c
diff --git a/Makeconfig b/Makeconfig
index 407df9e6a1..991d6d3e99 100644
--- a/Makeconfig
+++ b/Makeconfig
@@ -951,7 +951,7 @@ libio-include = -I$(..)libio
built-modules = iconvprogs iconvdata ldconfig lddlibc4 libmemusage \
libSegFault libpcprofile librpcsvc locale-programs \
memusagestat nonlib nscd extramodules libnldbl libsupport \
- testsuite
+ testsuite libmalloc_compathooks
in-module = $(subst -,_,$(firstword $(libof-$(basename $(@F))) \
$(libof-$(<F)) \
diff --git a/NEWS b/NEWS
index 536e80721a..8a7226aef2 100644
--- a/NEWS
+++ b/NEWS
@@ -68,6 +68,15 @@ Deprecated and removed features, and other changes affecting compatibility:
mtrace. Similar functionality can be achieved by using conditional
breakpoints within mtrace functions from within gdb.
+* The deprecated memory allocation hooks __malloc_hook, __realloc_hook,
+ __memalign_hook and __free_hook are now removed from the API. Compatibility
+ symbols are present to support legacy programs but new applications can no
+ longer link to these symbols. Further, the hooks no longer have any effect
+ on glibc functionality. A compatibility DSO libmalloc_compathooks.so has
+ been provided as a transitional measure to get hook functionality back for
+ legacy programs until they are updated to remove references to the memory
+ allocation hooks.
+
Changes to build and runtime requirements:
* On Linux, the shm_open, sem_open, and related functions now expect the
diff --git a/malloc/Makefile b/malloc/Makefile
index f9433af880..7d07b94a03 100644
--- a/malloc/Makefile
+++ b/malloc/Makefile
@@ -41,6 +41,7 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
tst-malloc-stats-cancellation \
tst-tcfree1 tst-tcfree2 tst-tcfree3 \
tst-safe-linking \
+ tst-compathooks-off tst-compathooks-on
tests-static := \
tst-interpose-static-nothread \
@@ -112,8 +113,8 @@ routines = malloc morecore mcheck mtrace obstack reallocarray \
install-lib := libmcheck.a
non-lib.a := libmcheck.a
-# Additional library.
-extra-libs = libmemusage
+# Additional libraries.
+extra-libs = libmemusage libmalloc_compathooks
extra-libs-others = $(extra-libs)
# Helper objects for some tests.
@@ -128,6 +129,9 @@ test-extras = \
libmemusage-routines = memusage
libmemusage-inhibit-o = $(filter-out .os,$(object-suffixes))
+libmalloc_compathooks-routines = malloc-compathooks
+libmalloc_compathooks-inhibit-o = $(filter-out .os,$(object-suffixes))
+
$(objpfx)tst-malloc-backtrace: $(shared-thread-library)
$(objpfx)tst-malloc-thread-exit: $(shared-thread-library)
$(objpfx)tst-malloc-thread-fail: $(shared-thread-library)
@@ -313,3 +317,10 @@ $(objpfx)tst-mallocfork2-mcheck: $(shared-thread-library)
$(objpfx)tst-malloc-tcache-leak-malloc-check: $(shared-thread-library)
$(objpfx)tst-malloc_info-malloc-check: $(shared-thread-library)
$(objpfx)tst-mallocfork2-malloc-check: $(shared-thread-library)
+
+tst-compathooks-on-ENV = LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
+tst-compathooks-on-mcheck-ENV = LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
+tst-compathooks-on-malloc-check-ENV = \
+ LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
+tst-mallocstate-ENV = LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
+tst-mallocstate-malloc-check-ENV = LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
diff --git a/malloc/arena.c b/malloc/arena.c
index a8500a25c9..8591c8ea56 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -408,11 +408,6 @@ ptmalloc_init (void)
__mcheck_initialize (NULL, false);
#endif
-#if HAVE_MALLOC_INIT_HOOK
- void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook);
- if (hook != NULL)
- (*hook)();
-#endif
__malloc_initialized = 1;
}
diff --git a/malloc/hooks.c b/malloc/hooks.c
index 492e9aac63..cc9ffc8b63 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -42,23 +42,84 @@ enum malloc_debug_hooks
static unsigned __malloc_debugging_hooks;
/* Forward declarations. */
+static void ptmalloc_init (void);
-#if HAVE_MALLOC_INIT_HOOK
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
void (*__malloc_initialize_hook) (void) __attribute__ ((nocommon));
compat_symbol (libc, __malloc_initialize_hook,
__malloc_initialize_hook, GLIBC_2_0);
+
+# define MALLOC_INIT_HOOK() ({ \
+ void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook); \
+ if (hook != NULL) \
+ (*hook)(); \
+})
+#else
+# define MALLOC_INIT_HOOK()
#endif
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
+
+static void *malloc_hook_ini (size_t, const void *) __THROW;
+static void *realloc_hook_ini (void *, size_t, const void *) __THROW;
+static void *memalign_hook_ini (size_t, size_t, const void *) __THROW;
+
void weak_variable (*__free_hook) (void *__ptr,
const void *) = NULL;
void *weak_variable (*__malloc_hook)
- (size_t __size, const void *) = NULL;
+ (size_t __size, const void *) = malloc_hook_ini;
void *weak_variable (*__realloc_hook)
- (void *__ptr, size_t __size, const void *) = NULL;
+ (void *__ptr, size_t __size, const void *) = realloc_hook_ini;
void *weak_variable (*__memalign_hook)
- (size_t __alignment, size_t __size, const void *) = NULL;
+ (size_t __alignment, size_t __size, const void *) = memalign_hook_ini;
-static void ptmalloc_init (void);
+compat_symbol (libc, __free_hook, __free_hook, GLIBC_2_0);
+compat_symbol (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
+compat_symbol (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
+compat_symbol (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
+
+/* These hooks will get executed only through the interposed allocator
+ functions in libmalloc_compathooks. This means that the calls to malloc,
+ realloc, etc. will lead back into the interposed functions, which is what we
+ want.
+
+ These initial hooks are assumed to be called in a single-threaded context,
+ so it is safe to reset all hooks at once upon initialization. */
+
+static void
+generic_hook_ini (void)
+{
+ __malloc_hook = NULL;
+ __realloc_hook = NULL;
+ __memalign_hook = NULL;
+ if (__malloc_initialized < 0)
+ {
+ ptmalloc_init ();
+ MALLOC_INIT_HOOK ();
+ }
+}
+
+static void *
+malloc_hook_ini (size_t sz, const void *caller)
+{
+ generic_hook_ini ();
+ return malloc (sz);
+}
+
+static void *
+realloc_hook_ini (void *ptr, size_t sz, const void *caller)
+{
+ generic_hook_ini ();
+ return realloc (ptr, sz);
+}
+
+static void *
+memalign_hook_ini (size_t alignment, size_t sz, const void *caller)
+{
+ generic_hook_ini ();
+ return memalign (alignment, sz);
+}
+#endif
static __always_inline bool
__is_malloc_debug_enabled (enum malloc_debug_hooks flag)
@@ -88,14 +149,6 @@ _malloc_debug_before (size_t *bytesp, void **victimp, const void *address)
_Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
"PTRDIFF_MAX is not more than half of SIZE_MAX");
- void *(*hook) (size_t, const void *)
- = atomic_forced_read (__malloc_hook);
- if (__builtin_expect (hook != NULL, 0))
- {
- *victimp = (*hook)(*bytesp, address);
- return true;
- }
-
if (__glibc_unlikely (__malloc_debugging_hooks))
{
if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
@@ -126,14 +179,6 @@ _malloc_debug_after (void *mem, size_t bytes, const void *address)
static __always_inline bool
_free_debug_before (void **mem, const void *address)
{
- void (*hook) (void *, const void *)
- = atomic_forced_read (__free_hook);
- if (__builtin_expect (hook != NULL, 0))
- {
- (*hook)(*mem, address);
- return true;
- }
-
if (__glibc_unlikely (__malloc_debugging_hooks))
{
if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
@@ -153,14 +198,6 @@ static __always_inline bool
_realloc_debug_before (void **oldmem, size_t *bytesp, size_t *oldsize,
void **victimp, const void *address)
{
- void *(*hook) (void *, size_t, const void *) =
- atomic_forced_read (__realloc_hook);
- if (__builtin_expect (hook != NULL, 0))
- {
- *victimp = (*hook)(*oldmem, *bytesp, address);
- return true;
- }
-
if (__glibc_unlikely (__malloc_debugging_hooks))
{
if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
@@ -194,13 +231,6 @@ static __always_inline bool
_memalign_debug_before (size_t alignment, size_t *bytesp, void **victimp,
const void *address)
{
- void *(*hook) (size_t, size_t, const void *) =
- atomic_forced_read (__memalign_hook);
- if (__builtin_expect (hook != NULL, 0))
- {
- *victimp = (*hook)(alignment, *bytesp, address);
- return true;
- }
if (__glibc_unlikely (__malloc_debugging_hooks))
{
if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
@@ -233,18 +263,6 @@ _memalign_debug_after (void *mem, size_t alignment, size_t bytes,
static __always_inline bool
_calloc_debug_before (size_t *bytesp, void **victimp, const void *address)
{
- void *(*hook) (size_t, const void *) =
- atomic_forced_read (__malloc_hook);
- if (__builtin_expect (hook != NULL, 0))
- {
- *victimp = (*hook)(*bytesp, address);
-
- if (*victimp != NULL)
- memset (*victimp, 0, *bytesp);
-
- return true;
- }
-
if (__glibc_unlikely (__malloc_debugging_hooks))
{
if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
diff --git a/malloc/malloc-compathooks.c b/malloc/malloc-compathooks.c
new file mode 100644
index 0000000000..6d1eaab774
--- /dev/null
+++ b/malloc/malloc-compathooks.c
@@ -0,0 +1,166 @@
+/* Malloc hooks compatibility DSO.
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If
+ not, see <https://www.gnu.org/licenses/>. */
+
+#include <atomic.h>
+#include <libc-symbols.h>
+#include <shlib-compat.h>
+#include <string.h>
+#include <unistd.h>
+
+extern void (*__free_hook) (void *__ptr, const void *);
+compat_symbol_reference (libc, __free_hook, __free_hook, GLIBC_2_0);
+extern void * (*__malloc_hook) (size_t __size, const void *);
+compat_symbol_reference (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
+extern void * (*__realloc_hook)
+ (void *__ptr, size_t __size, const void *);
+compat_symbol_reference (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
+extern void * (*__memalign_hook)
+ (size_t __alignment, size_t __size, const void *);
+compat_symbol_reference (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
+
+/* Support only the glibc allocators. */
+extern void *__libc_malloc (size_t);
+extern void __libc_free (void *);
+extern void *__libc_realloc (void *, size_t);
+extern void *__libc_memalign (size_t, size_t);
+extern void *__libc_valloc (size_t);
+extern void *__libc_pvalloc (size_t);
+extern void *__libc_calloc (size_t, size_t);
+
+static size_t pagesize;
+
+/* The allocator functions. */
+
+static void *
+__compathook_malloc (size_t bytes)
+{
+ void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ return (*hook)(bytes, RETURN_ADDRESS (0));
+
+ return __libc_malloc (bytes);
+}
+strong_alias (__compathook_malloc, malloc)
+
+static void
+__compathook_free (void *mem)
+{
+ void (*hook) (void *, const void *) = atomic_forced_read (__free_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ {
+ (*hook)(mem, RETURN_ADDRESS (0));
+ return;
+ }
+ __libc_free (mem);
+}
+strong_alias (__compathook_free, free)
+
+static void *
+__compathook_realloc (void *oldmem, size_t bytes)
+{
+ void *(*hook) (void *, size_t, const void *) =
+ atomic_forced_read (__realloc_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ return (*hook)(oldmem, bytes, RETURN_ADDRESS (0));
+
+ return __libc_realloc (oldmem, bytes);
+}
+strong_alias (__compathook_realloc, realloc)
+
+static void *
+__compathook_memalign (size_t alignment, size_t bytes)
+{
+ void *(*hook) (size_t, size_t, const void *) =
+ atomic_forced_read (__memalign_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ return (*hook)(alignment, bytes, RETURN_ADDRESS (0));
+
+ return __libc_memalign (alignment, bytes);
+}
+strong_alias (__compathook_memalign, memalign)
+
+static void *
+__compathook_pvalloc (size_t bytes)
+{
+ void *(*hook) (size_t, size_t, const void *) =
+ atomic_forced_read (__memalign_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ {
+ size_t rounded_bytes;
+
+ if (!pagesize)
+ pagesize = sysconf (_SC_PAGESIZE);
+
+ /* ALIGN_UP with overflow check. */
+ if (__glibc_unlikely (__builtin_add_overflow (bytes,
+ pagesize - 1,
+ &rounded_bytes)))
+ {
+ errno = ENOMEM;
+ return NULL;
+ }
+ rounded_bytes = rounded_bytes & -(pagesize - 1);
+ return (*hook)(pagesize, rounded_bytes, RETURN_ADDRESS (0));
+ }
+
+ return __libc_pvalloc (bytes);
+}
+strong_alias (__compathook_pvalloc, pvalloc)
+
+static void *
+__compathook_valloc (size_t bytes)
+{
+ void *(*hook) (size_t, size_t, const void *) =
+ atomic_forced_read (__memalign_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ {
+ if (!pagesize)
+ pagesize = sysconf (_SC_PAGESIZE);
+
+ return (*hook)(pagesize, bytes, RETURN_ADDRESS (0));
+ }
+
+ return __libc_valloc (bytes);
+}
+strong_alias (__compathook_valloc, valloc)
+
+static void *
+__compathook_calloc (size_t nmemb, size_t size)
+{
+ void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook);
+ if (__builtin_expect (hook != NULL, 0))
+ {
+ size_t bytes;
+
+ if (__glibc_unlikely (__builtin_mul_overflow (nmemb, size, &bytes)))
+ {
+ errno = ENOMEM;
+ return NULL;
+ }
+
+ void *mem = (*hook)(bytes, RETURN_ADDRESS (0));
+
+ if (mem != NULL)
+ memset (mem, 0, bytes);
+
+ return mem;
+ }
+
+ return __libc_calloc (nmemb, size);
+}
+strong_alias (__compathook_calloc, calloc)
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 5ea12d1d3b..16ad933c66 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -570,16 +570,6 @@ tag_at (void *ptr)
#define HAVE_MREMAP 0
#endif
-/* We may need to support __malloc_initialize_hook for backwards
- compatibility. */
-
-#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
-# define HAVE_MALLOC_INIT_HOOK 1
-#else
-# define HAVE_MALLOC_INIT_HOOK 0
-#endif
-
-
/*
This version of malloc supports the standard SVID/XPG mallinfo
routine that returns a struct containing usage properties and
diff --git a/malloc/malloc.h b/malloc/malloc.h
index c1c0896d29..709fa454b5 100644
--- a/malloc/malloc.h
+++ b/malloc/malloc.h
@@ -165,20 +165,6 @@ extern void malloc_stats (void) __THROW;
extern int malloc_info (int __options, FILE *__fp) __THROW;
/* Hooks for debugging and user-defined versions. */
-extern void (*__MALLOC_HOOK_VOLATILE __free_hook) (void *__ptr,
- const void *)
-__MALLOC_DEPRECATED;
-extern void *(*__MALLOC_HOOK_VOLATILE __malloc_hook)(size_t __size,
- const void *)
-__MALLOC_DEPRECATED;
-extern void *(*__MALLOC_HOOK_VOLATILE __realloc_hook)(void *__ptr,
- size_t __size,
- const void *)
-__MALLOC_DEPRECATED;
-extern void *(*__MALLOC_HOOK_VOLATILE __memalign_hook)(size_t __alignment,
- size_t __size,
- const void *)
-__MALLOC_DEPRECATED;
extern void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void)
__MALLOC_DEPRECATED;
diff --git a/manual/memory.texi b/manual/memory.texi
index 28ec2e4e63..e66ecd582d 100644
--- a/manual/memory.texi
+++ b/manual/memory.texi
@@ -328,8 +328,6 @@ any time (or never).
* Malloc Tunable Parameters:: Use @code{mallopt} to adjust allocation
parameters.
* Heap Consistency Checking:: Automatic checking for errors.
-* Hooks for Malloc:: You can use these hooks for debugging
- programs that use @code{malloc}.
* Statistics of Malloc:: Getting information about how much
memory your program is using.
* Summary of Malloc:: Summary of @code{malloc} and related functions.
@@ -1388,170 +1386,6 @@ compatibility. Both @code{MALLOC_CHECK_} and @samp{-lmcheck} should
uncover the same bugs - but using @code{MALLOC_CHECK_} you don't need to
recompile your application.
-@node Hooks for Malloc
-@subsubsection Memory Allocation Hooks
-@cindex allocation hooks, for @code{malloc}
-
-@Theglibc{} lets you modify the behavior of @code{malloc},
-@code{realloc}, and @code{free} by specifying appropriate hook
-functions. You can use these hooks to help you debug programs that use
-dynamic memory allocation, for example.
-
-The hook variables are declared in @file{malloc.h}.
-@pindex malloc.h
-
-@defvar __malloc_hook
-@standards{GNU, malloc.h}
-The value of this variable is a pointer to the function that
-@code{malloc} uses whenever it is called. You should define this
-function to look like @code{malloc}; that is, like:
-
-@smallexample
-void *@var{function} (size_t @var{size}, const void *@var{caller})
-@end smallexample
-
-The value of @var{caller} is the return address found on the stack when
-the @code{malloc} function was called. This value allows you to trace
-the memory consumption of the program.
-@end defvar
-
-@defvar __realloc_hook
-@standards{GNU, malloc.h}
-The value of this variable is a pointer to function that @code{realloc}
-uses whenever it is called. You should define this function to look
-like @code{realloc}; that is, like:
-
-@smallexample
-void *@var{function} (void *@var{ptr}, size_t @var{size}, const void *@var{caller})
-@end smallexample
-
-The value of @var{caller} is the return address found on the stack when
-the @code{realloc} function was called. This value allows you to trace the
-memory consumption of the program.
-@end defvar
-
-@defvar __free_hook
-@standards{GNU, malloc.h}
-The value of this variable is a pointer to function that @code{free}
-uses whenever it is called. You should define this function to look
-like @code{free}; that is, like:
-
-@smallexample
-void @var{function} (void *@var{ptr}, const void *@var{caller})
-@end smallexample
-
-The value of @var{caller} is the return address found on the stack when
-the @code{free} function was called. This value allows you to trace the
-memory consumption of the program.
-@end defvar
-
-@defvar __memalign_hook
-@standards{GNU, malloc.h}
-The value of this variable is a pointer to function that @code{aligned_alloc},
-@code{memalign}, @code{posix_memalign} and @code{valloc} use whenever they
-are called. You should define this function to look like @code{aligned_alloc};
-that is, like:
-
-@smallexample
-void *@var{function} (size_t @var{alignment}, size_t @var{size}, const void *@var{caller})
-@end smallexample
-
-The value of @var{caller} is the return address found on the stack when
-the @code{aligned_alloc}, @code{memalign}, @code{posix_memalign} or
-@code{valloc} functions are called. This value allows you to trace the
-memory consumption of the program.
-@end defvar
-
-You must make sure that the function you install as a hook for one of
-these functions does not call that function recursively without restoring
-the old value of the hook first! Otherwise, your program will get stuck
-in an infinite recursion. Before calling the function recursively, one
-should make sure to restore all the hooks to their previous value. When
-coming back from the recursive call, all the hooks should be resaved
-since a hook might modify itself.
-
-An issue to look out for is the time at which the hook functions
-can be safely installed. If the hook functions call the @code{malloc}-related
-functions recursively, it is necessary that @code{malloc} has already properly
-initialized itself at the time when @code{__malloc_hook} etc. is
-assigned to. On the other hand, if the hook functions provide a
-complete @code{malloc} implementation of their own, it is vital that the hooks
-are assigned to @emph{before} the very first @code{malloc} call has
-completed, because otherwise a chunk obtained from the ordinary,
-un-hooked @code{malloc} may later be handed to @code{__free_hook}, for example.
-
-Here is an example showing how to use @code{__malloc_hook} and
-@code{__free_hook} properly. It installs a function that prints out
-information every time @code{malloc} or @code{free} is called. We just
-assume here that @code{realloc} and @code{memalign} are not used in our
-program.
-
-@smallexample
-/* Prototypes for __malloc_hook, __free_hook */
-#include <malloc.h>
-
-/* Prototypes for our hooks. */
-static void my_init_hook (void);
-static void *my_malloc_hook (size_t, const void *);
-static void my_free_hook (void*, const void *);
-
-static void
-my_init (void)
-@{
- old_malloc_hook = __malloc_hook;
- old_free_hook = __free_hook;
- __malloc_hook = my_malloc_hook;
- __free_hook = my_free_hook;
-@}
-
-static void *
-my_malloc_hook (size_t size, const void *caller)
-@{
- void *result;
- /* Restore all old hooks */
- __malloc_hook = old_malloc_hook;
- __free_hook = old_free_hook;
- /* Call recursively */
- result = malloc (size);
- /* Save underlying hooks */
- old_malloc_hook = __malloc_hook;
- old_free_hook = __free_hook;
- /* @r{@code{printf} might call @code{malloc}, so protect it too.} */
- printf ("malloc (%u) returns %p\n", (unsigned int) size, result);
- /* Restore our own hooks */
- __malloc_hook = my_malloc_hook;
- __free_hook = my_free_hook;
- return result;
-@}
-
-static void
-my_free_hook (void *ptr, const void *caller)
-@{
- /* Restore all old hooks */
- __malloc_hook = old_malloc_hook;
- __free_hook = old_free_hook;
- /* Call recursively */
- free (ptr);
- /* Save underlying hooks */
- old_malloc_hook = __malloc_hook;
- old_free_hook = __free_hook;
- /* @r{@code{printf} might call @code{free}, so protect it too.} */
- printf ("freed pointer %p\n", ptr);
- /* Restore our own hooks */
- __malloc_hook = my_malloc_hook;
- __free_hook = my_free_hook;
-@}
-
-main ()
-@{
- my_init ();
- @dots{}
-@}
-@end smallexample
-
-The @code{mcheck} function (@pxref{Heap Consistency Checking}) works by
-installing such hooks.
-
@c __morecore, __after_morecore_hook are undocumented
@c It's not clear whether to document them.
@@ -1686,19 +1520,6 @@ Tell @code{malloc} to perform occasional consistency checks on
dynamically allocated memory, and to call @var{abortfn} when an
inconsistency is found. @xref{Heap Consistency Checking}.
-@item void *(*__malloc_hook) (size_t @var{size}, const void *@var{caller})
-A pointer to a function that @code{malloc} uses whenever it is called.
-
-@item void *(*__realloc_hook) (void *@var{ptr}, size_t @var{size}, const void *@var{caller})
-A pointer to a function that @code{realloc} uses whenever it is called.
-
-@item void (*__free_hook) (void *@var{ptr}, const void *@var{caller})
-A pointer to a function that @code{free} uses whenever it is called.
-
-@item void (*__memalign_hook) (size_t @var{size}, size_t @var{alignment}, const void *@var{caller})
-A pointer to a function that @code{aligned_alloc}, @code{memalign},
-@code{posix_memalign} and @code{valloc} use whenever they are called.
-
@item struct mallinfo2 mallinfo2 (void)
Return information about the current dynamic memory usage.
@xref{Statistics of Malloc}.
@@ -1733,7 +1554,7 @@ penalties for the program if the debugging mode is not enabled.
@deftypefun void mtrace (void)
@standards{GNU, mcheck.h}
-@safety{@prelim{}@mtunsafe{@mtsenv{} @mtasurace{:mtrace} @mtasuconst{:malloc_hooks} @mtuinit{}}@asunsafe{@asuinit{} @ascuheap{} @asucorrupt{} @asulock{}}@acunsafe{@acuinit{} @acucorrupt{} @aculock{} @acsfd{} @acsmem{}}}
+@safety{@prelim{}@mtunsafe{@mtsenv{} @mtasurace{:mtrace} @mtuinit{}}@asunsafe{@asuinit{} @ascuheap{} @asucorrupt{} @asulock{}}@acunsafe{@acuinit{} @acucorrupt{} @aculock{} @acsfd{} @acsmem{}}}
@c Like the mcheck hooks, these are not designed with thread safety in
@c mind, because the hook pointers are temporarily modified without
@c regard to other threads, signals or cancellation.
@@ -1758,10 +1579,10 @@ with the SUID or SGID bit set.
If the named file is successfully opened, @code{mtrace} installs special
handlers for the functions @code{malloc}, @code{realloc}, and
-@code{free} (@pxref{Hooks for Malloc}). From then on, all uses of these
-functions are traced and protocolled into the file. There is now of
-course a speed penalty for all calls to the traced functions so tracing
-should not be enabled during normal use.
+@code{free}. From then on, all uses of these functions are traced and
+protocolled into the file. There is now of course a speed penalty for all
+calls to the traced functions so tracing should not be enabled during normal
+use.
This function is a GNU extension and generally not available on other
systems. The prototype can be found in @file{mcheck.h}.
@@ -1769,7 +1590,7 @@ systems. The prototype can be found in @file{mcheck.h}.
@deftypefun void muntrace (void)
@standards{GNU, mcheck.h}
-@safety{@prelim{}@mtunsafe{@mtasurace{:mtrace} @mtasuconst{:malloc_hooks} @mtslocale{}}@asunsafe{@asucorrupt{} @ascuheap{}}@acunsafe{@acucorrupt{} @acsmem{} @aculock{} @acsfd{}}}
+@safety{@prelim{}@mtunsafe{@mtasurace{:mtrace} @mtslocale{}}@asunsafe{@asucorrupt{} @ascuheap{}}@acunsafe{@acucorrupt{} @acsmem{} @aculock{} @acsfd{}}}
@c muntrace @mtasurace:mtrace @mtslocale @asucorrupt @ascuheap @acucorrupt @acsmem @aculock @acsfd
@c fprintf (fputs) dup @mtslocale @asucorrupt @ascuheap @acsmem @aculock @acucorrupt
diff --git a/sysdeps/generic/localplt.data b/sysdeps/generic/localplt.data
index 9b4f35786a..e2083c0ce6 100644
--- a/sysdeps/generic/localplt.data
+++ b/sysdeps/generic/localplt.data
@@ -4,6 +4,7 @@
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/mach/hurd/i386/localplt.data b/sysdeps/mach/hurd/i386/localplt.data
index 47fbe1e2a7..94064ecbc5 100644
--- a/sysdeps/mach/hurd/i386/localplt.data
+++ b/sysdeps/mach/hurd/i386/localplt.data
@@ -6,6 +6,7 @@
libc.so: calloc + REL R_386_GLOB_DAT
libc.so: free + REL R_386_GLOB_DAT
libc.so: malloc + REL R_386_GLOB_DAT
+libc.so: memalign + REL R_386_GLOB_DAT
libc.so: realloc + REL R_386_GLOB_DAT
libm.so: matherr + REL R_386_GLOB_DAT
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/aarch64/localplt.data b/sysdeps/unix/sysv/linux/aarch64/localplt.data
index 348b3f3793..2c14b652ef 100644
--- a/sysdeps/unix/sysv/linux/aarch64/localplt.data
+++ b/sysdeps/unix/sysv/linux/aarch64/localplt.data
@@ -4,6 +4,7 @@
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# If outline atomics are used, libgcc (built outside of glibc) may
diff --git a/sysdeps/unix/sysv/linux/alpha/localplt.data b/sysdeps/unix/sysv/linux/alpha/localplt.data
index 44bf36f4f1..43f6fdaea1 100644
--- a/sysdeps/unix/sysv/linux/alpha/localplt.data
+++ b/sysdeps/unix/sysv/linux/alpha/localplt.data
@@ -18,6 +18,7 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc + RELA R_ALPHA_GLOB_DAT
libc.so: free + RELA R_ALPHA_GLOB_DAT
libc.so: malloc + RELA R_ALPHA_GLOB_DAT
+libc.so: memalign + RELA R_ALPHA_GLOB_DAT
libc.so: realloc + RELA R_ALPHA_GLOB_DAT
libm.so: matherr + RELA R_ALPHA_GLOB_DAT
# We used to offer inline functions that used this, so it must be exported.
diff --git a/sysdeps/unix/sysv/linux/arc/localplt.data b/sysdeps/unix/sysv/linux/arc/localplt.data
index ac5332caf7..4479e8ee8a 100644
--- a/sysdeps/unix/sysv/linux/arc/localplt.data
+++ b/sysdeps/unix/sysv/linux/arc/localplt.data
@@ -1,5 +1,6 @@
libc.so: realloc
libc.so: malloc
+libc.so: memalign
libc.so: calloc
libc.so: free
# At -Os, a struct assignment in libgcc-static pulls this in
diff --git a/sysdeps/unix/sysv/linux/arm/localplt.data b/sysdeps/unix/sysv/linux/arm/localplt.data
index 78896444c6..eb315da2f1 100644
--- a/sysdeps/unix/sysv/linux/arm/localplt.data
+++ b/sysdeps/unix/sysv/linux/arm/localplt.data
@@ -1,6 +1,7 @@
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: raise
libc.so: realloc
libm.so: matherr
diff --git a/sysdeps/unix/sysv/linux/csky/localplt.data b/sysdeps/unix/sysv/linux/csky/localplt.data
index 817ab2659a..0ed8650b65 100644
--- a/sysdeps/unix/sysv/linux/csky/localplt.data
+++ b/sysdeps/unix/sysv/linux/csky/localplt.data
@@ -4,6 +4,7 @@
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
# The TLS-enabled version of these functions is interposed from libc.so.
ld.so: _dl_signal_error
diff --git a/sysdeps/unix/sysv/linux/hppa/localplt.data b/sysdeps/unix/sysv/linux/hppa/localplt.data
index baf857a750..09893d4dcf 100644
--- a/sysdeps/unix/sysv/linux/hppa/localplt.data
+++ b/sysdeps/unix/sysv/linux/hppa/localplt.data
@@ -4,6 +4,7 @@
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libc.so: __sigsetjmp
libc.so: _IO_funlockfile
diff --git a/sysdeps/unix/sysv/linux/i386/localplt.data b/sysdeps/unix/sysv/linux/i386/localplt.data
index f9bf7fb410..5334875b4b 100644
--- a/sysdeps/unix/sysv/linux/i386/localplt.data
+++ b/sysdeps/unix/sysv/linux/i386/localplt.data
@@ -4,6 +4,7 @@ libc.so: _Unwind_Find_FDE + REL R_386_GLOB_DAT
libc.so: calloc + REL R_386_GLOB_DAT
libc.so: free + REL R_386_GLOB_DAT
libc.so: malloc + REL R_386_GLOB_DAT
+libc.so: memalign + REL R_386_GLOB_DAT
libc.so: realloc + REL R_386_GLOB_DAT
libm.so: matherr + REL R_386_GLOB_DAT
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/ia64/localplt.data b/sysdeps/unix/sysv/linux/ia64/localplt.data
index 174fb88128..1c566a503e 100644
--- a/sysdeps/unix/sysv/linux/ia64/localplt.data
+++ b/sysdeps/unix/sysv/linux/ia64/localplt.data
@@ -1,6 +1,7 @@
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
libm.so: matherrf
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/localplt.data b/sysdeps/unix/sysv/linux/m68k/coldfire/localplt.data
index 42fa90508c..3c5efb7204 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/localplt.data
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/localplt.data
@@ -2,6 +2,7 @@ libc.so: __m68k_read_tp
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/localplt.data b/sysdeps/unix/sysv/linux/m68k/m680x0/localplt.data
index 34bd4c1aca..843f4e25f2 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/localplt.data
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/localplt.data
@@ -3,6 +3,7 @@ libc.so: __m68k_read_tp
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/microblaze/localplt.data b/sysdeps/unix/sysv/linux/microblaze/localplt.data
index c3801314c9..0e98d5251e 100644
--- a/sysdeps/unix/sysv/linux/microblaze/localplt.data
+++ b/sysdeps/unix/sysv/linux/microblaze/localplt.data
@@ -2,6 +2,7 @@ libc.so: __errno_location
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# The dynamic loader needs __tls_get_addr for TLS.
diff --git a/sysdeps/unix/sysv/linux/nios2/localplt.data b/sysdeps/unix/sysv/linux/nios2/localplt.data
index 17fcfdd4db..b37987c7c0 100644
--- a/sysdeps/unix/sysv/linux/nios2/localplt.data
+++ b/sysdeps/unix/sysv/linux/nios2/localplt.data
@@ -6,6 +6,7 @@ libc.so: __gedf2
libc.so: malloc
libc.so: __gtsf2 ?
libc.so: __nesf2
+libc.so: memalign
libc.so: __mulsf3
libc.so: __floatunsisf
libc.so: __addsf3
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data
index c0af84eef7..a02dd5cc24 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/localplt.data
@@ -2,6 +2,7 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
index 581e54b95c..d8072597b7 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/localplt.data
@@ -30,6 +30,7 @@ libc.so: abort ?
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: memset ?
libc.so: realloc
libm.so: copysignl ?
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data b/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data
index d69b7ae646..bb498fbe3a 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/localplt.data
@@ -1,6 +1,7 @@
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/riscv/localplt.data b/sysdeps/unix/sysv/linux/riscv/localplt.data
index e6d5330d5b..0a235592c3 100644
--- a/sysdeps/unix/sysv/linux/riscv/localplt.data
+++ b/sysdeps/unix/sysv/linux/riscv/localplt.data
@@ -4,6 +4,7 @@
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: memset ?
libc.so: realloc
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/s390/localplt.data b/sysdeps/unix/sysv/linux/s390/localplt.data
index c0af84eef7..a02dd5cc24 100644
--- a/sysdeps/unix/sysv/linux/s390/localplt.data
+++ b/sysdeps/unix/sysv/linux/s390/localplt.data
@@ -2,6 +2,7 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/sh/localplt.data b/sysdeps/unix/sysv/linux/sh/localplt.data
index 6491b9e37b..3225177c50 100644
--- a/sysdeps/unix/sysv/linux/sh/localplt.data
+++ b/sysdeps/unix/sysv/linux/sh/localplt.data
@@ -4,6 +4,7 @@
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libc.so: _Unwind_Find_FDE
libc.so: _exit
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data b/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data
index 38309a1393..be51efd566 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/localplt.data
@@ -16,6 +16,7 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data b/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data
index 6a216f3a5a..809062d46c 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data
@@ -15,6 +15,7 @@ libc.so: _Unwind_Find_FDE
libc.so: calloc
libc.so: free
libc.so: malloc
+libc.so: memalign
libc.so: realloc
libm.so: matherr
# The TLS-enabled version of these functions is interposed from libc.so.
diff --git a/sysdeps/x86_64/localplt.data b/sysdeps/x86_64/localplt.data
index d1f2e26612..8f41e92870 100644
--- a/sysdeps/x86_64/localplt.data
+++ b/sysdeps/x86_64/localplt.data
@@ -6,6 +6,7 @@
libc.so: calloc + RELA R_X86_64_GLOB_DAT
libc.so: free + RELA R_X86_64_GLOB_DAT
libc.so: malloc + RELA R_X86_64_GLOB_DAT
+libc.so: memalign + RELA R_X86_64_GLOB_DAT
libc.so: realloc + RELA R_X86_64_GLOB_DAT
libm.so: matherr + RELA R_X86_64_GLOB_DAT
# The TLS-enabled version of these functions is interposed from libc.so.
--
2.31.1
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH 7/8] Remove __after_morecore_hook
2021-06-24 18:23 [PATCH 0/8] Remove malloc hooks Siddhesh Poyarekar
` (5 preceding siblings ...)
2021-06-24 18:23 ` [PATCH 6/8] Remove " Siddhesh Poyarekar
@ 2021-06-24 18:23 ` Siddhesh Poyarekar
2021-06-24 23:33 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 8/8] Remove __morecore and __default_morecore Siddhesh Poyarekar
7 siblings, 1 reply; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-24 18:23 UTC (permalink / raw)
To: libc-alpha; +Cc: dj, carlos, fweimer
Remove __after_morecore_hook from the API and finalize the symbol so
that it can no longer be used in new applications. Old applications
using __after_morecore_hook will find that their hook is no longer
called.
---
malloc/hooks.c | 3 +++
malloc/malloc.c | 30 +-----------------------------
malloc/malloc.h | 5 -----
3 files changed, 4 insertions(+), 34 deletions(-)
diff --git a/malloc/hooks.c b/malloc/hooks.c
index cc9ffc8b63..fa6b3f4c16 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -78,6 +78,9 @@ compat_symbol (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
compat_symbol (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
compat_symbol (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
+void weak_variable (*__after_morecore_hook) (void) = NULL;
+compat_symbol (libc, __after_morecore_hook, __after_morecore_hook, GLIBC_2_0);
+
/* These hooks will get executed only through the interposed allocator
functions in libmalloc_compathooks. This means that the calls to malloc,
realloc, etc. will lead back into the interposed functions, which is what we
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 16ad933c66..51970105b5 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -1988,16 +1988,6 @@ static void malloc_consolidate (mstate);
/* -------------- Early definitions for debugging hooks ---------------- */
-/* Define and initialize the hook variables. These weak definitions must
- appear before any use of the variables in a function (arena.c uses one). */
-#ifndef weak_variable
-/* In GNU libc we want the hook variables to be weak definitions to
- avoid a problem with Emacs. */
-# define weak_variable weak_function
-#endif
-
-void weak_variable (*__after_morecore_hook) (void) = NULL;
-
/* This function is called from the arena shutdown hook, to free the
thread cache (if it exists). */
static void tcache_thread_shutdown (void);
@@ -2622,14 +2612,7 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
LIBC_PROBE (memory_sbrk_more, 2, brk, size);
}
- if (brk != (char *) (MORECORE_FAILURE))
- {
- /* Call the `morecore' hook if necessary. */
- void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
- if (__builtin_expect (hook != NULL, 0))
- (*hook)();
- }
- else
+ if (brk == (char *) (MORECORE_FAILURE))
{
/*
If have mmap, try using it as a backup when MORECORE fails or
@@ -2768,13 +2751,6 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
correction = 0;
snd_brk = (char *) (MORECORE (0));
}
- else
- {
- /* Call the `morecore' hook if necessary. */
- void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
- if (__builtin_expect (hook != NULL, 0))
- (*hook)();
- }
}
/* handle non-contiguous cases */
@@ -2933,10 +2909,6 @@ systrim (size_t pad, mstate av)
*/
MORECORE (-extra);
- /* Call the `morecore' hook if necessary. */
- void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
- if (__builtin_expect (hook != NULL, 0))
- (*hook)();
new_brk = (char *) (MORECORE (0));
LIBC_PROBE (memory_sbrk_less, 2, new_brk, extra);
diff --git a/malloc/malloc.h b/malloc/malloc.h
index 709fa454b5..d066a05d82 100644
--- a/malloc/malloc.h
+++ b/malloc/malloc.h
@@ -164,10 +164,5 @@ extern void malloc_stats (void) __THROW;
/* Output information about state of allocator to stream FP. */
extern int malloc_info (int __options, FILE *__fp) __THROW;
-/* Hooks for debugging and user-defined versions. */
-extern void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void)
- __MALLOC_DEPRECATED;
-
-
__END_DECLS
#endif /* malloc.h */
--
2.31.1
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH 8/8] Remove __morecore and __default_morecore
2021-06-24 18:23 [PATCH 0/8] Remove malloc hooks Siddhesh Poyarekar
` (6 preceding siblings ...)
2021-06-24 18:23 ` [PATCH 7/8] Remove __after_morecore_hook Siddhesh Poyarekar
@ 2021-06-24 18:23 ` Siddhesh Poyarekar
2021-06-24 23:38 ` DJ Delorie
7 siblings, 1 reply; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-24 18:23 UTC (permalink / raw)
To: libc-alpha; +Cc: dj, carlos, fweimer
Make the __morecore and __default_morecore symbols compat-only and
remove their declarations from the API.
---
NEWS | 5 +++++
include/stdlib.h | 3 ---
malloc/arena.c | 12 ++----------
malloc/hooks.c | 3 +++
malloc/malloc-internal.h | 5 +++++
malloc/malloc.c | 4 +---
malloc/malloc.h | 8 --------
malloc/morecore.c | 15 +++++++++++++--
8 files changed, 29 insertions(+), 26 deletions(-)
diff --git a/NEWS b/NEWS
index 8a7226aef2..3596593a2a 100644
--- a/NEWS
+++ b/NEWS
@@ -77,6 +77,11 @@ Deprecated and removed features, and other changes affecting compatibility:
legacy programs until they are updated to remove references to the memory
allocation hooks.
+* The __morecore and __after_morecore_hook malloc hooks and the default
+ implementation __default_morecore have been removed from the API. Existing
+ applications will continue to link against these symbols but the interfaces
+ no longer have any effect on malloc.
+
Changes to build and runtime requirements:
* On Linux, the shm_open, sem_open, and related functions now expect the
diff --git a/include/stdlib.h b/include/stdlib.h
index e2453c1896..c5cccce85c 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -300,9 +300,6 @@ libc_hidden_proto (__qfcvt_r)
# define MB_CUR_MAX (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MB_CUR_MAX))
# endif
-extern void *__default_morecore (ptrdiff_t) __THROW;
-libc_hidden_proto (__default_morecore)
-
struct abort_msg_s
{
unsigned int size;
diff --git a/malloc/arena.c b/malloc/arena.c
index 8591c8ea56..00e8b5a32f 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -272,14 +272,6 @@ next_env_entry (char ***position)
#endif
-#if defined(SHARED) || defined(USE_MTAG)
-static void *
-__failing_morecore (ptrdiff_t d)
-{
- return (void *) MORECORE_FAILURE;
-}
-#endif
-
#ifdef SHARED
extern struct dl_open_hook *_dl_open_hook;
libc_hidden_proto (_dl_open_hook);
@@ -300,7 +292,7 @@ ptmalloc_init (void)
and that morecore does not support tagged regions, then
disable it. */
if (__MTAG_SBRK_UNTAGGED)
- __morecore = __failing_morecore;
+ __always_fail_morecore = true;
mtag_enabled = true;
mtag_mmap_flags = __MTAG_MMAP_FLAGS;
@@ -313,7 +305,7 @@ ptmalloc_init (void)
generic sbrk implementation also enforces this, but it is not
used on Hurd. */
if (!__libc_initial)
- __morecore = __failing_morecore;
+ __always_fail_morecore = true;
#endif
thread_arena = &main_arena;
diff --git a/malloc/hooks.c b/malloc/hooks.c
index fa6b3f4c16..934b6f90d0 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -81,6 +81,9 @@ compat_symbol (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
void weak_variable (*__after_morecore_hook) (void) = NULL;
compat_symbol (libc, __after_morecore_hook, __after_morecore_hook, GLIBC_2_0);
+void *(*__morecore)(ptrdiff_t);
+compat_symbol (libc, __morecore, __morecore, GLIBC_2_0);
+
/* These hooks will get executed only through the interposed allocator
functions in libmalloc_compathooks. This means that the calls to malloc,
realloc, etc. will lead back into the interposed functions, which is what we
diff --git a/malloc/malloc-internal.h b/malloc/malloc-internal.h
index ee0f5697af..b104f7cdbf 100644
--- a/malloc/malloc-internal.h
+++ b/malloc/malloc-internal.h
@@ -21,6 +21,7 @@
#include <malloc-machine.h>
#include <malloc-sysdep.h>
+#include <stdbool.h>
/* INTERNAL_SIZE_T is the word-size used for internal bookkeeping of
chunk sizes.
@@ -63,6 +64,8 @@
#define top(ar_ptr) ((ar_ptr)->top)
+extern bool __always_fail_morecore attribute_hidden;
+
/* Called in the parent process before a fork. */
void __malloc_fork_lock_parent (void) attribute_hidden;
@@ -78,4 +81,6 @@ void __malloc_arena_thread_freeres (void) attribute_hidden;
/* Activate a standard set of debugging hooks. */
void __malloc_check_init (void) attribute_hidden;
+extern void *__glibc_morecore (ptrdiff_t) attribute_hidden;
+
#endif /* _MALLOC_INTERNAL_H */
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 51970105b5..f5058f0f0c 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -382,10 +382,8 @@ __malloc_assert (const char *assertion, const char *file, unsigned int line,
/* Definition for getting more memory from the OS. */
-#define MORECORE (*__morecore)
+#define MORECORE (*__glibc_morecore)
#define MORECORE_FAILURE 0
-void * __default_morecore (ptrdiff_t);
-void *(*__morecore)(ptrdiff_t) = __default_morecore;
/* Memory tagging. */
diff --git a/malloc/malloc.h b/malloc/malloc.h
index d066a05d82..2df0b38050 100644
--- a/malloc/malloc.h
+++ b/malloc/malloc.h
@@ -76,14 +76,6 @@ extern void *valloc (size_t __size) __THROW __attribute_malloc__
extern void *pvalloc (size_t __size) __THROW __attribute_malloc__
__wur __attr_dealloc_free;
-/* Underlying allocation function; successive calls should return
- contiguous pieces of memory. */
-extern void *(*__morecore) (ptrdiff_t __size) __MALLOC_DEPRECATED;
-
-/* Default value of `__morecore'. */
-extern void *__default_morecore (ptrdiff_t __size)
-__THROW __attribute_malloc__ __MALLOC_DEPRECATED;
-
/* SVID2/XPG mallinfo structure */
struct mallinfo
diff --git a/malloc/morecore.c b/malloc/morecore.c
index 047228779b..c85a85c0eb 100644
--- a/malloc/morecore.c
+++ b/malloc/morecore.c
@@ -38,16 +38,27 @@ libc_hidden_proto (__sbrk)
# define NULL 0
#endif
+#if defined(SHARED) || defined(USE_MTAG)
+bool __always_fail_morecore = false;
+#endif
+
/* Allocate INCREMENT more bytes of data space,
and return the start of data space, or NULL on errors.
If INCREMENT is negative, shrink data space. */
void *
-__default_morecore (ptrdiff_t increment)
+__glibc_morecore (ptrdiff_t increment)
{
+#if defined(SHARED) || defined(USE_MTAG)
+ if (__always_fail_morecore)
+ return NULL;
+#endif
+
void *result = (void *) __sbrk (increment);
if (result == (void *) -1)
return NULL;
return result;
}
-libc_hidden_def (__default_morecore)
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
+compat_symbol (libc, __glibc_morecore, __default_morecore, GLIBC_2_0);
+#endif
--
2.31.1
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 1/8] Move glibc.malloc.check implementation into its own file
2021-06-24 18:23 ` [PATCH 1/8] Move glibc.malloc.check implementation into its own file Siddhesh Poyarekar
@ 2021-06-24 19:57 ` DJ Delorie
2021-06-28 4:34 ` Siddhesh Poyarekar
0 siblings, 1 reply; 21+ messages in thread
From: DJ Delorie @ 2021-06-24 19:57 UTC (permalink / raw)
To: Siddhesh Poyarekar; +Cc: libc-alpha, carlos, fweimer
Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> Separate the malloc check implementation from the malloc hooks. They
> still use the hooks but are now maintained in a separate file.
Missing Makefile dependency. Otherwise, it's just a block code move,
which is fine.
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 2/8] malloc: Move malloc hook references to hooks.c
2021-06-24 18:23 ` [PATCH 2/8] malloc: Move malloc hook references to hooks.c Siddhesh Poyarekar
@ 2021-06-24 21:10 ` DJ Delorie
0 siblings, 0 replies; 21+ messages in thread
From: DJ Delorie @ 2021-06-24 21:10 UTC (permalink / raw)
To: Siddhesh Poyarekar; +Cc: libc-alpha, carlos, fweimer
Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> Make the core malloc code hooks free and instead only have entry
> points for _*_debug_before inline functions.
> diff --git a/malloc/arena.c b/malloc/arena.c
> index 7eb110445e..1861d20006 100644
> --- a/malloc/arena.c
> +++ b/malloc/arena.c
> @@ -44,8 +44,6 @@
>
> /***************************************************************************/
>
> -#define top(ar_ptr) ((ar_ptr)->top)
> -
Moved to malloc-internal.h; ok
> diff --git a/malloc/hooks.c b/malloc/hooks.c
> index 57a9b55788..4960aafd08 100644
> --- a/malloc/hooks.c
> +++ b/malloc/hooks.c
> @@ -21,35 +21,107 @@
> corrupt pointer is detected: do nothing (0), print an error message
> (1), or call abort() (2). */
>
> -/* Hooks for debugging versions. The initial hooks just call the
> - initialization routine, then do the normal work. */
> +/* Define and initialize the hook variables. These weak definitions must
> + appear before any use of the variables in a function (arena.c uses one). */
> +#ifndef weak_variable
> +/* In GNU libc we want the hook variables to be weak definitions to
> + avoid a problem with Emacs. */
> +# define weak_variable weak_function
> +#endif
> +
> +/* Forward declarations. */
> +
> +#if HAVE_MALLOC_INIT_HOOK
> +void (*__malloc_initialize_hook) (void) __attribute__ ((nocommon));
> +compat_symbol (libc, __malloc_initialize_hook,
> + __malloc_initialize_hook, GLIBC_2_0);
> +#endif
> +
> +void weak_variable (*__free_hook) (void *__ptr,
> + const void *) = NULL;
> +void *weak_variable (*__malloc_hook)
> + (size_t __size, const void *) = NULL;
> +void *weak_variable (*__realloc_hook)
> + (void *__ptr, size_t __size, const void *) = NULL;
> +void *weak_variable (*__memalign_hook)
> + (size_t __alignment, size_t __size, const void *) = NULL;
> +
> +static void ptmalloc_init (void);
ok.
> -static void *
> -malloc_hook_ini (size_t sz, const void *caller)
> +#include "malloc-check.c"
Moved from later, ok.
> +static __always_inline bool
> +_malloc_debug_before (size_t bytes, void **victimp, const void *address)
> {
> - __malloc_hook = NULL;
> - ptmalloc_init ();
> - return __libc_malloc (sz);
> + _Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
> + "PTRDIFF_MAX is not more than half of SIZE_MAX");
> +
> + void *(*hook) (size_t, const void *)
> + = atomic_forced_read (__malloc_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + {
> + *victimp = (*hook)(bytes, address);
> + return true;
> + }
> + return false;
> }
Ok.
> -static void *
> -realloc_hook_ini (void *ptr, size_t sz, const void *caller)
> +static __always_inline bool
> +_free_debug_before (void *mem, const void *address)
> {
> - __malloc_hook = NULL;
> - __realloc_hook = NULL;
> - ptmalloc_init ();
> - return __libc_realloc (ptr, sz);
> + void (*hook) (void *, const void *)
> + = atomic_forced_read (__free_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + {
> + (*hook)(mem, address);
> + return true;
> + }
> + return false;
> }
Ok.
> -static void *
> -memalign_hook_ini (size_t alignment, size_t sz, const void *caller)
> +static __always_inline bool
> +_realloc_debug_before (void *oldmem, size_t bytes, void **victimp,
> + const void *address)
> {
> - __memalign_hook = NULL;
> - ptmalloc_init ();
> - return __libc_memalign (alignment, sz);
> + void *(*hook) (void *, size_t, const void *) =
> + atomic_forced_read (__realloc_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + {
> + *victimp = (*hook)(oldmem, bytes, address);
> + return true;
> + }
> +
> + return false;
> }
Ok.
> -#include "malloc-check.c"
Ok.
> +static __always_inline bool
> +_memalign_debug_before (size_t alignment, size_t bytes, void **victimp,
> + const void *address)
> +{
> + void *(*hook) (size_t, size_t, const void *) =
> + atomic_forced_read (__memalign_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + {
> + *victimp = (*hook)(alignment, bytes, address);
> + return true;
> + }
> + return false;
> +}
Ok.
> +static __always_inline bool
> +_calloc_debug_before (size_t bytes, void **victimp, const void *address)
> +{
> + void *(*hook) (size_t, const void *) =
> + atomic_forced_read (__malloc_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + {
> + *victimp = (*hook)(bytes, address);
> + if (*victimp != NULL)
> + memset (*victimp, 0, bytes);
> + return true;
> + }
> + return false;
> +}
Ok.
> diff --git a/malloc/malloc-internal.h b/malloc/malloc-internal.h
> index 258f29584e..ee0f5697af 100644
> --- a/malloc/malloc-internal.h
> +++ b/malloc/malloc-internal.h
> @@ -61,6 +61,7 @@
> /* The corresponding bit mask value. */
> #define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1)
>
> +#define top(ar_ptr) ((ar_ptr)->top)
Ok.
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index 0e2e1747e0..75ca6ec3f0 100644
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -2013,30 +2013,6 @@ static void malloc_consolidate (mstate);
> # define weak_variable weak_function
> #endif
>
> -/* Forward declarations. */
> -static void *malloc_hook_ini (size_t sz,
> - const void *caller) __THROW;
> -static void *realloc_hook_ini (void *ptr, size_t sz,
> - const void *caller) __THROW;
> -static void *memalign_hook_ini (size_t alignment, size_t sz,
> - const void *caller) __THROW;
> -
> -#if HAVE_MALLOC_INIT_HOOK
> -void (*__malloc_initialize_hook) (void) __attribute__ ((nocommon));
> -compat_symbol (libc, __malloc_initialize_hook,
> - __malloc_initialize_hook, GLIBC_2_0);
> -#endif
> -
> -void weak_variable (*__free_hook) (void *__ptr,
> - const void *) = NULL;
> -void *weak_variable (*__malloc_hook)
> - (size_t __size, const void *) = malloc_hook_ini;
> -void *weak_variable (*__realloc_hook)
> - (void *__ptr, size_t __size, const void *)
> - = realloc_hook_ini;
> -void *weak_variable (*__memalign_hook)
> - (size_t __alignment, size_t __size, const void *)
> - = memalign_hook_ini;
> void weak_variable (*__after_morecore_hook) (void) = NULL;
Moved, ok.
> @@ -2065,6 +2041,9 @@ free_perturb (char *p, size_t n)
>
> #include <stap-probe.h>
>
> +/* ----------------- Support for debugging hooks -------------------- */
> +#include "hooks.c"
> +
> /* ------------------- Support for multiple arenas -------------------- */
> #include "arena.c"
>
> @@ -2425,10 +2404,6 @@ do_check_malloc_state (mstate av)
> #endif
>
>
> -/* ----------------- Support for debugging hooks -------------------- */
> -#include "hooks.c"
> -
> -
> /* ----------- Routines dealing with system allocation -------------- */
Ok.
> @@ -3225,13 +3200,12 @@ __libc_malloc (size_t bytes)
> mstate ar_ptr;
> void *victim;
>
> - _Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
> - "PTRDIFF_MAX is not more than half of SIZE_MAX");
> + if (__malloc_initialized < 0)
> + ptmalloc_init ();
> +
> + if (_malloc_debug_before (bytes, &victim, RETURN_ADDRESS (0)))
> + return victim;
>
> - void *(*hook) (size_t, const void *)
> - = atomic_forced_read (__malloc_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - return (*hook)(bytes, RETURN_ADDRESS (0));
Ok.
> @@ -3292,13 +3266,11 @@ __libc_free (void *mem)
> mstate ar_ptr;
> mchunkptr p; /* chunk corresponding to mem */
>
> - void (*hook) (void *, const void *)
> - = atomic_forced_read (__free_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - {
> - (*hook)(mem, RETURN_ADDRESS (0));
> - return;
> - }
> + if (__malloc_initialized < 0)
> + ptmalloc_init ();
> +
> + if (_free_debug_before (mem, RETURN_ADDRESS (0)))
> + return;
Ok.
> @@ -3351,10 +3323,11 @@ __libc_realloc (void *oldmem, size_t bytes)
>
> void *newp; /* chunk to return */
>
> - void *(*hook) (void *, size_t, const void *) =
> - atomic_forced_read (__realloc_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - return (*hook)(oldmem, bytes, RETURN_ADDRESS (0));
> + if (__malloc_initialized < 0)
> + ptmalloc_init ();
> +
> + if (_realloc_debug_before (oldmem, bytes, &newp, RETURN_ADDRESS (0)))
> + return newp;
Ok.
> @@ -3490,6 +3463,9 @@ void *
> __libc_memalign (size_t alignment, size_t bytes)
> {
> void *address = RETURN_ADDRESS (0);
> + if (__malloc_initialized < 0)
> + ptmalloc_init ();
> +
> return _mid_memalign (alignment, bytes, address);
> }
Ok.
> @@ -3499,10 +3475,8 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
> mstate ar_ptr;
> void *p;
>
> - void *(*hook) (size_t, size_t, const void *) =
> - atomic_forced_read (__memalign_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - return (*hook)(alignment, bytes, address);
> + if (_memalign_debug_before (alignment, bytes, &p, address))
> + return p;
Ok.
> @@ -3612,16 +3586,11 @@ __libc_calloc (size_t n, size_t elem_size)
>
> sz = bytes;
>
> - void *(*hook) (size_t, const void *) =
> - atomic_forced_read (__malloc_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - {
> - mem = (*hook)(sz, RETURN_ADDRESS (0));
> - if (mem == 0)
> - return 0;
> + if (__malloc_initialized < 0)
> + ptmalloc_init ();
>
> - return memset (mem, 0, sz);
> - }
> + if (_calloc_debug_before (sz, &mem, RETURN_ADDRESS (0)))
> + return mem;
Ok.
LGTM
Reviewed-by: DJ Delorie <dj@redhat.com>
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 3/8] glibc.malloc.check: Wean away from malloc hooks
2021-06-24 18:23 ` [PATCH 3/8] glibc.malloc.check: Wean away from malloc hooks Siddhesh Poyarekar
@ 2021-06-24 21:43 ` DJ Delorie
0 siblings, 0 replies; 21+ messages in thread
From: DJ Delorie @ 2021-06-24 21:43 UTC (permalink / raw)
To: Siddhesh Poyarekar; +Cc: libc-alpha, carlos, fweimer
Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> Set up a new internal debugging hooks flag variable and migrate
> glibc.malloc.check to it so that it no longer uses the malloc hooks.
> diff --git a/malloc/hooks.c b/malloc/hooks.c
> index 4960aafd08..77855801c8 100644
> --- a/malloc/hooks.c
> +++ b/malloc/hooks.c
> @@ -21,6 +21,8 @@
> corrupt pointer is detected: do nothing (0), print an error message
> (1), or call abort() (2). */
>
> +# include <stdbool.h>
> +
Ok.
> @@ -29,6 +31,14 @@
> # define weak_variable weak_function
> #endif
>
> +/* The internal malloc debugging hooks. */
> +enum malloc_debug_hooks
> +{
> + MALLOC_NONE_HOOK = 0,
> + MALLOC_CHECK_HOOK = 1 << 0, /* MALLOC_CHECK_ or glibc.malloc.check. */
> +};
> +static unsigned __malloc_debugging_hooks;
> +
Ok.
> @@ -48,6 +58,24 @@ void *weak_variable (*__memalign_hook)
>
> static void ptmalloc_init (void);
>
> +static __always_inline bool
> +__is_malloc_debug_enabled (enum malloc_debug_hooks flag)
> +{
> + return __malloc_debugging_hooks & flag;
> +}
> +
> +static __always_inline void
> +__malloc_debug_enable (enum malloc_debug_hooks flag)
> +{
> + __malloc_debugging_hooks |= flag;
> +}
> +
> +static __always_inline void
> +__malloc_debug_disable (enum malloc_debug_hooks flag)
> +{
> + __malloc_debugging_hooks &= ~flag;
> +}
> +
Ok.
> @@ -63,6 +91,12 @@ _malloc_debug_before (size_t bytes, void **victimp, const void *address)
> *victimp = (*hook)(bytes, address);
> return true;
> }
> +
> + if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + {
> + *victimp = malloc_check (bytes);
> + return true;
> + }
> return false;
> }
Ok. Too bad there isn't a way to tag the *function* as likely/unlikely,
rather than the *calls*.
> @@ -76,6 +110,12 @@ _free_debug_before (void *mem, const void *address)
> (*hook)(mem, address);
> return true;
> }
> +
> + if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + {
> + free_check (mem);
> + return true;
> + }
> return false;
> }
Ok.
> @@ -91,6 +131,12 @@ _realloc_debug_before (void *oldmem, size_t bytes, void **victimp,
> return true;
> }
>
> + if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + {
> + *victimp = realloc_check (oldmem, bytes);
> + return true;
> + }
> +
> return false;
> }
Ok.
> @@ -105,6 +151,13 @@ _memalign_debug_before (size_t alignment, size_t bytes, void **victimp,
> *victimp = (*hook)(alignment, bytes, address);
> return true;
> }
> +
> + if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + {
> + *victimp = memalign_check (alignment, bytes);
> + return true;
> + }
> +
> return false;
> }
Ok.
> @@ -120,6 +173,14 @@ _calloc_debug_before (size_t bytes, void **victimp, const void *address)
> memset (*victimp, 0, bytes);
> return true;
> }
> +
> + if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + {
> + *victimp = malloc_check (bytes);
> + if (*victimp != NULL)
> + memset (*victimp, 0, bytes);
> + return true;
> + }
> return false;
> }
Ok.
> @@ -195,7 +256,7 @@ malloc_set_state (void *msptr)
> __realloc_hook = NULL;
> __free_hook = NULL;
> __memalign_hook = NULL;
> - using_malloc_checking = 0;
> + __malloc_debug_disable (MALLOC_CHECK_HOOK);
Ok.
> diff --git a/malloc/malloc-check.c b/malloc/malloc-check.c
> index dcab880510..a85e519498 100644
> --- a/malloc/malloc-check.c
> +++ b/malloc/malloc-check.c
> @@ -18,20 +18,6 @@
> not, see <https://www.gnu.org/licenses/>. */
>
>
> -/* Whether we are using malloc checking. */
> -static int using_malloc_checking;
> -
> -/* Activate a standard set of debugging hooks. */
> -void
> -__malloc_check_init (void)
> -{
> - using_malloc_checking = 1;
> - __malloc_hook = malloc_check;
> - __free_hook = free_check;
> - __realloc_hook = realloc_check;
> - __memalign_hook = memalign_check;
> -}
> -
Ok.
> @@ -69,7 +55,7 @@ malloc_check_get_size (mchunkptr p)
> unsigned char c;
> unsigned char magic = magicbyte (p);
>
> - assert (using_malloc_checking == 1);
> + assert (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK));
Ok.
> @@ -203,7 +189,7 @@ top_check (void)
> }
>
> static void *
> -malloc_check (size_t sz, const void *caller)
> +malloc_check (size_t sz)
Ok.
> @@ -222,7 +208,7 @@ malloc_check (size_t sz, const void *caller)
> }
>
> static void
> -free_check (void *mem, const void *caller)
> +free_check (void *mem)
Ok.
> @@ -256,7 +242,7 @@ free_check (void *mem, const void *caller)
> }
>
> static void *
> -realloc_check (void *oldmem, size_t bytes, const void *caller)
> +realloc_check (void *oldmem, size_t bytes)
Ok.
> @@ -269,11 +255,11 @@ realloc_check (void *oldmem, size_t bytes, const void *caller)
> return NULL;
> }
> if (oldmem == 0)
> - return malloc_check (bytes, NULL);
> + return malloc_check (bytes);
Ok.
> if (bytes == 0)
> {
> - free_check (oldmem, NULL);
> + free_check (oldmem);
Ok.
> @@ -348,12 +334,12 @@ invert:
> }
>
> static void *
> -memalign_check (size_t alignment, size_t bytes, const void *caller)
> +memalign_check (size_t alignment, size_t bytes)
> {
> void *mem;
>
> if (alignment <= MALLOC_ALIGNMENT)
> - return malloc_check (bytes, NULL);
> + return malloc_check (bytes);
Ok
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index 75ca6ec3f0..60753446a1 100644
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -1124,13 +1124,6 @@ static void munmap_chunk(mchunkptr p);
> static mchunkptr mremap_chunk(mchunkptr p, size_t new_size);
> #endif
>
> -static void* malloc_check(size_t sz, const void *caller);
> -static void free_check(void* mem, const void *caller);
> -static void* realloc_check(void* oldmem, size_t bytes,
> - const void *caller);
> -static void* memalign_check(size_t alignment, size_t bytes,
> - const void *caller);
Ok.
> @@ -5078,7 +5071,7 @@ musable (void *mem)
>
> p = mem2chunk (mem);
>
> - if (__builtin_expect (using_malloc_checking == 1, 0))
> + if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> return malloc_check_get_size (p);
Ok.
> if (chunk_is_mmapped (p))
> diff --git a/malloc/arena.c b/malloc/arena.c
> index 1861d20006..357a3b0b30 100644
> --- a/malloc/arena.c
> +++ b/malloc/arena.c
> @@ -210,7 +210,7 @@ TUNABLE_CALLBACK (set_mallopt_check) (tunable_val_t *valp)
> {
> int32_t value = (int32_t) valp->numval;
> if (value != 0)
> - __malloc_check_init ();
> + __malloc_debug_enable (MALLOC_CHECK_HOOK);
> }
Ok.
> # define TUNABLE_CALLBACK_FNDECL(__name, __type) \
> @@ -400,7 +400,7 @@ ptmalloc_init (void)
> }
> }
> if (s && s[0] != '\0' && s[0] != '0')
> - __malloc_check_init ();
> + __malloc_debug_enable (MALLOC_CHECK_HOOK);
> #endif
Ok.
LGTM
Reviewed-by: DJ Delorie <dj@redhat.com>
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 4/8] mcheck: Wean away from malloc hooks
2021-06-24 18:23 ` [PATCH 4/8] mcheck: " Siddhesh Poyarekar
@ 2021-06-24 22:51 ` DJ Delorie
2021-06-28 6:22 ` Siddhesh Poyarekar
0 siblings, 1 reply; 21+ messages in thread
From: DJ Delorie @ 2021-06-24 22:51 UTC (permalink / raw)
To: Siddhesh Poyarekar; +Cc: libc-alpha, carlos, fweimer
Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> Initialization using -lmcheck now depends on a new exported variable
> __libc_lmcheck which is a const flag that mcheck-init can override.
I wonder if we should bite the bullet and add an official malloc_ioctl()
or something. Oh wait, we have mallopt() already. Can we hijack this
instead of adding an ABI?
mallopt (MALLOC_INTERNAL_GET_VER, 0) returns malloc_version + 1000
(or returns 0 or 1, for "not supported")
mallopt (MALLOC_INTERNAL_SET_DEBUG, debug_flags)
This could be done in a .ctor/.init; I wonder if that would be early
enough.
(and yes, this is why I initially did all this in a separate library
that overrode the libc symbols - linking means you get the new functions
right away)
> diff --git a/include/malloc.h b/include/malloc.h
> index b77761f74d..bb1123d9d3 100644
> --- a/include/malloc.h
> +++ b/include/malloc.h
> @@ -4,6 +4,11 @@
>
> # ifndef _ISOMAC
> # include <rtld-malloc.h>
> +# include <stdbool.h>
> +# include <mcheck.h>
> +
> +struct malloc_state;
> +typedef struct malloc_state *mstate;
Moved from below, ok.
> /* In the GNU libc we rename the global variable
> `__malloc_initialized' to `__libc_malloc_initialized'. */
> @@ -11,8 +16,9 @@
> /* Nonzero if the malloc is already initialized. */
> extern int __malloc_initialized attribute_hidden;
>
> -struct malloc_state;
> -typedef struct malloc_state *mstate;
> +enum mcheck_status __mcheck_checkptr (const void *) attribute_hidden;
> +extern int __mcheck_initialize (void (*) (enum mcheck_status), bool)
> + attribute_hidden;
Ok.
> diff --git a/malloc/Makefile b/malloc/Makefile
> index fd7f399250..f9433af880 100644
> --- a/malloc/Makefile
> +++ b/malloc/Makefile
> @@ -90,9 +90,7 @@ tests-exclude-mcheck = tst-mallocstate \
> tst-malloc-usable-static \
> tst-malloc-usable-static-tunables \
> tst-malloc-usable-tunables \
> - tst-malloc_info \
> - tst-memalign \
> - tst-posix_memalign
> + tst-malloc_info
Ok.
> diff --git a/malloc/hooks.c b/malloc/hooks.c
> index 77855801c8..b517a98ea2 100644
> --- a/malloc/hooks.c
> +++ b/malloc/hooks.c
> @@ -36,6 +36,7 @@ enum malloc_debug_hooks
> {
> MALLOC_NONE_HOOK = 0,
> MALLOC_CHECK_HOOK = 1 << 0, /* MALLOC_CHECK_ or glibc.malloc.check. */
> + MALLOC_MCHECK_HOOK = 1 << 1, /* mcheck() */
> };
> static unsigned __malloc_debugging_hooks;
Ok.
> @@ -77,113 +78,180 @@ __malloc_debug_disable (enum malloc_debug_hooks flag)
> }
>
> #include "malloc-check.c"
> +#include "mcheck-hooks.c"
>
> static __always_inline bool
> -_malloc_debug_before (size_t bytes, void **victimp, const void *address)
> +_malloc_debug_before (size_t *bytesp, void **victimp, const void *address)
> {
> _Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
> - "PTRDIFF_MAX is not more than half of SIZE_MAX");
> + "PTRDIFF_MAX is not more than half of SIZE_MAX");
Ok.
> - *victimp = (*hook)(bytes, address);
> + *victimp = (*hook)(*bytesp, address);
Ok.
> }
>
> - if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + if (__glibc_unlikely (__malloc_debugging_hooks))
Ok. Updated for "any flag set"
> - *victimp = malloc_check (bytes);
> - return true;
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
> + && malloc_mcheck_before (bytesp, victimp))
> + return true;
> + if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
> + {
> + *victimp = malloc_check (*bytesp);
> + return true;
> + }
> }
> return false;
> }
Ok.
> +static __always_inline void *
> +_malloc_debug_after (void *mem, size_t bytes, const void *address)
> +{
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
> + mem = malloc_mcheck_after (mem, bytes);
> + return mem;
> +}
ok.
> static __always_inline bool
> -_free_debug_before (void *mem, const void *address)
> +_free_debug_before (void **mem, const void *address)
Ok.
> - (*hook)(mem, address);
> + (*hook)(*mem, address);
Ok.
> - if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + if (__glibc_unlikely (__malloc_debugging_hooks))
> {
> - free_check (mem);
> - return true;
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
> + *mem = free_mcheck (*mem);
> + if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
> + {
> + free_check (*mem);
> + return true;
> + }
> }
> return false;
> }
Ok.
> static __always_inline bool
> -_realloc_debug_before (void *oldmem, size_t bytes, void **victimp,
> - const void *address)
> +_realloc_debug_before (void **oldmem, size_t *bytesp, size_t *oldsize,
> + void **victimp, const void *address)
Ok.
> - *victimp = (*hook)(oldmem, bytes, address);
> + *victimp = (*hook)(*oldmem, *bytesp, address);
Ok.
> - if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + if (__glibc_unlikely (__malloc_debugging_hooks))
> {
> - *victimp = realloc_check (oldmem, bytes);
> - return true;
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
> + && realloc_mcheck_before (oldmem, bytesp, oldsize, victimp))
> + return true;
> + if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
> + {
> + *victimp = realloc_check (*oldmem, *bytesp);
> + return true;
> + }
> }
Ok.
> +static __always_inline void *
> +_realloc_debug_after (void *mem, void *oldmem, size_t bytes, size_t oldsize,
> + const void *address)
> +{
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
> + mem = realloc_mcheck_after (mem, oldmem, bytes, oldsize);
> + return mem;
> +}
Ok.
> static __always_inline bool
> -_memalign_debug_before (size_t alignment, size_t bytes, void **victimp,
> - const void *address)
> +_memalign_debug_before (size_t alignment, size_t *bytesp, void **victimp,
> + const void *address)
Ok.
> - *victimp = (*hook)(alignment, bytes, address);
> + *victimp = (*hook)(alignment, *bytesp, address);
Ok.
> -
> - if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + if (__glibc_unlikely (__malloc_debugging_hooks))
> {
> - *victimp = memalign_check (alignment, bytes);
> - return true;
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
> + && memalign_mcheck_before (alignment, bytesp, victimp))
> + return true;
> + if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
> + {
> + *victimp = memalign_check (alignment, *bytesp);
> + return true;
> + }
> }
Ok.
> +static __always_inline void *
> +_memalign_debug_after (void *mem, size_t alignment, size_t bytes,
> + const void *address)
> +{
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
> + mem = memalign_mcheck_after (mem, alignment, bytes);
> + return mem;
> +}
Ok.
> static __always_inline bool
> -_calloc_debug_before (size_t bytes, void **victimp, const void *address)
> +_calloc_debug_before (size_t *bytesp, void **victimp, const void *address)
Ok
> void *(*hook) (size_t, const void *) =
> atomic_forced_read (__malloc_hook);
> if (__builtin_expect (hook != NULL, 0))
> {
> - *victimp = (*hook)(bytes, address);
> + *victimp = (*hook)(*bytesp, address);
> +
> if (*victimp != NULL)
> - memset (*victimp, 0, bytes);
> + memset (*victimp, 0, *bytesp);
> +
> return true;
> }
Ok.
> - if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
> + if (__glibc_unlikely (__malloc_debugging_hooks))
> {
> - *victimp = malloc_check (bytes);
> - if (*victimp != NULL)
> - memset (*victimp, 0, bytes);
> - return true;
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
> + && malloc_mcheck_before (bytesp, victimp))
> + return true;
> + if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
> + {
> + *victimp = malloc_check (*bytesp);
> + return true;
memset missing? no, moved to below... A comment would help here.
> +static __always_inline void *
> +_calloc_debug_after (void *mem, size_t bytes, const void *address)
> +{
> + if (__glibc_unlikely (__malloc_debugging_hooks) && mem != NULL)
> + {
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
> + mem = malloc_mcheck_after (mem, bytes);
> + memset (mem, 0, bytes);
> + }
> + return mem;
> +}
So we memset if *any* hook is called, ok.
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index 60753446a1..5ea12d1d3b 100644
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -3192,12 +3192,13 @@ __libc_malloc (size_t bytes)
> {
> mstate ar_ptr;
> void *victim;
> + size_t orig_bytes = bytes;
Do we need to initialize victim to NULL here?
> if (__malloc_initialized < 0)
> ptmalloc_init ();
>
> - if (_malloc_debug_before (bytes, &victim, RETURN_ADDRESS (0)))
> - return victim;
> + if (_malloc_debug_before (&bytes, &victim, RETURN_ADDRESS (0)))
> + goto out;
Ok.
> @@ -3205,7 +3206,8 @@ __libc_malloc (size_t bytes)
> if (!checked_request2size (bytes, &tbytes))
> {
> __set_errno (ENOMEM);
> - return NULL;
> + victim = NULL;
> + goto out;
Ok.
> @@ -3217,7 +3219,8 @@ __libc_malloc (size_t bytes)
> && tcache->counts[tc_idx] > 0)
> {
> victim = tcache_get (tc_idx);
> - return tag_new_usable (victim);
> + victim = tag_new_usable (victim);
> + goto out;
Ok.
> @@ -3227,7 +3230,7 @@ __libc_malloc (size_t bytes)
> victim = tag_new_usable (_int_malloc (&main_arena, bytes));
> assert (!victim || chunk_is_mmapped (mem2chunk (victim)) ||
> &main_arena == arena_for_chunk (mem2chunk (victim)));
> - return victim;
> + goto out;
Ok.
> @@ -3249,7 +3252,9 @@ __libc_malloc (size_t bytes)
>
> assert (!victim || chunk_is_mmapped (mem2chunk (victim)) ||
> ar_ptr == arena_for_chunk (mem2chunk (victim)));
> - return victim;
> +
> +out:
> + return _malloc_debug_after (victim, orig_bytes, RETURN_ADDRESS (0));
> }
This handles both NULL and non-NULL cases, so ok.
> @@ -3262,7 +3267,7 @@ __libc_free (void *mem)
> if (__malloc_initialized < 0)
> ptmalloc_init ();
>
> - if (_free_debug_before (mem, RETURN_ADDRESS (0)))
> + if (_free_debug_before (&mem, RETURN_ADDRESS (0)))
> return;
Ok.
> @@ -3315,23 +3320,30 @@ __libc_realloc (void *oldmem, size_t bytes)
> INTERNAL_SIZE_T nb; /* padded request size */
>
> void *newp; /* chunk to return */
> + size_t orig_bytes = bytes, debug_osize = 0;
Ok.
> - if (_realloc_debug_before (oldmem, bytes, &newp, RETURN_ADDRESS (0)))
> - return newp;
> + if (_realloc_debug_before (&oldmem, &bytes, &debug_osize, &newp,
> + RETURN_ADDRESS (0)))
> + goto out;
Ok.
> #if REALLOC_ZERO_BYTES_FREES
> if (bytes == 0 && oldmem != NULL)
> {
> - __libc_free (oldmem); return 0;
> + __libc_free (oldmem);
> + newp = NULL;
> + goto out;
> }
> #endif
Ok.
> /* realloc of null is supposed to be same as malloc */
> if (oldmem == 0)
> - return __libc_malloc (bytes);
> + {
> + newp = __libc_malloc (bytes);
> + goto out;
> + }
Ok.
> @@ -3365,7 +3377,8 @@ __libc_realloc (void *oldmem, size_t bytes)
> if (!checked_request2size (bytes, &nb))
> {
> __set_errno (ENOMEM);
> - return NULL;
> + newp = NULL;
> + goto out;
> }
Ok.
> @@ -3377,7 +3390,10 @@ __libc_realloc (void *oldmem, size_t bytes)
> /* Must alloc, copy, free. */
> void *newmem = __libc_malloc (bytes);
> if (newmem == 0)
> - return NULL;
> + {
> + newp = NULL;
> + goto out;
> + }
Ok.
> @@ -3385,7 +3401,8 @@ __libc_realloc (void *oldmem, size_t bytes)
> if (bytes > oldsize - SIZE_SZ)
> bytes = oldsize - SIZE_SZ;
> memcpy (newmem, oldmem, bytes);
> - return newmem;
> + newp = newmem;
> + goto out;
Ok.
> @@ -3400,21 +3417,29 @@ __libc_realloc (void *oldmem, size_t bytes)
> reused. There's a performance hit for both us and the
> caller for doing this, so we might want to
> reconsider. */
> - return tag_new_usable (newmem);
> + newp = tag_new_usable (newmem);
> + goto out;
Ok.
> #endif
> /* Note the extra SIZE_SZ overhead. */
> if (oldsize - SIZE_SZ >= nb)
> - return oldmem; /* do nothing */
> + {
> + newp = oldmem; /* do nothing */
> + goto out;
> + }
Ok.
> /* Must alloc, copy, free. */
> newmem = __libc_malloc (bytes);
> if (newmem == 0)
> - return 0; /* propagate failure */
> + {
> + newp = NULL; /* propagate failure */
> + goto out;
> + }
Ok.
> memcpy (newmem, oldmem, oldsize - CHUNK_HDR_SZ);
> munmap_chunk (oldp);
> - return newmem;
> + newp = newmem;
> + goto out;
> }
Ok.
> @@ -3423,7 +3448,7 @@ __libc_realloc (void *oldmem, size_t bytes)
> assert (!newp || chunk_is_mmapped (mem2chunk (newp)) ||
> ar_ptr == arena_for_chunk (mem2chunk (newp)));
>
> - return newp;
> + goto out;
Ok.
> @@ -3448,7 +3473,9 @@ __libc_realloc (void *oldmem, size_t bytes)
> }
> }
>
> - return newp;
> +out:
> + return _realloc_debug_after (newp, oldmem, orig_bytes, debug_osize,
> + RETURN_ADDRESS (0));
> }
Ok.
> @@ -3467,13 +3494,17 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
> {
> mstate ar_ptr;
> void *p;
> + size_t orig_bytes = bytes;
>
> - if (_memalign_debug_before (alignment, bytes, &p, address))
> - return p;
> + if (_memalign_debug_before (alignment, &bytes, &p, address))
> + goto out;
Ok.
> /* If we need less alignment than we give anyway, just relay to malloc. */
> if (alignment <= MALLOC_ALIGNMENT)
> - return __libc_malloc (bytes);
> + {
> + p = __libc_malloc (bytes);
> + goto out;
> + }
Ok.
> @@ -3484,7 +3515,8 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
> if (alignment > SIZE_MAX / 2 + 1)
> {
> __set_errno (EINVAL);
> - return 0;
> + p = NULL;
> + goto out;
> }
Ok.
> @@ -3502,7 +3534,8 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
> p = _int_memalign (&main_arena, alignment, bytes);
> assert (!p || chunk_is_mmapped (mem2chunk (p)) ||
> &main_arena == arena_for_chunk (mem2chunk (p)));
> - return tag_new_usable (p);
> + p = tag_new_usable (p);
> + goto out;
> }
Ok.
> @@ -3520,7 +3553,9 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
>
> assert (!p || chunk_is_mmapped (mem2chunk (p)) ||
> ar_ptr == arena_for_chunk (mem2chunk (p)));
> - return tag_new_usable (p);
> + p = tag_new_usable (p);
> +out:
> + return _memalign_debug_after (p, alignment, orig_bytes, RETURN_ADDRESS (0));
> }
Ok.
> @@ -3582,8 +3617,8 @@ __libc_calloc (size_t n, size_t elem_size)
> if (__malloc_initialized < 0)
> ptmalloc_init ();
>
> - if (_calloc_debug_before (sz, &mem, RETURN_ADDRESS (0)))
> - return mem;
> + if (_calloc_debug_before (&sz, &mem, RETURN_ADDRESS (0)))
> + goto out;
Ok.
> @@ -3639,7 +3674,10 @@ __libc_calloc (size_t n, size_t elem_size)
>
> /* Allocation failed even after a retry. */
> if (mem == 0)
> - return 0;
> + {
> + mem = NULL;
> + goto out;
> + }
Ok.
> @@ -3647,7 +3685,10 @@ __libc_calloc (size_t n, size_t elem_size)
> regardless of MORECORE_CLEARS, so we zero the whole block while
> doing so. */
> if (__glibc_unlikely (mtag_enabled))
> - return tag_new_zero_region (mem, memsize (p));
> + {
> + mem = tag_new_zero_region (mem, memsize (p));
> + goto out;
> + }
Ok.
> @@ -3655,9 +3696,9 @@ __libc_calloc (size_t n, size_t elem_size)
> if (chunk_is_mmapped (p))
> {
> if (__builtin_expect (perturb_byte, 0))
> - return memset (mem, 0, sz);
> + memset (mem, 0, sz);
>
> - return mem;
> + goto out;
> }
Ok.
> @@ -3677,7 +3718,10 @@ __libc_calloc (size_t n, size_t elem_size)
> assert (nclears >= 3);
>
> if (nclears > 9)
> - return memset (d, 0, clearsize);
> + {
> + memset (d, 0, clearsize);
> + goto out;
> + }
Ok; d is a copy of mem set before the patch text.
> @@ -3701,7 +3745,8 @@ __libc_calloc (size_t n, size_t elem_size)
> }
> }
>
> - return mem;
> +out:
> + return _calloc_debug_after (mem, bytes, RETURN_ADDRESS (0));
> }
Ok.
> diff --git a/malloc/mcheck-hooks.c b/malloc/mcheck-hooks.c
> new file mode 100644
> index 0000000000..f3520c7659
> --- /dev/null
> +++ b/malloc/mcheck-hooks.c
> @@ -0,0 +1,411 @@
Ok.
> diff --git a/malloc/mcheck.c b/malloc/mcheck.c
> index 2a1fc645d4..f60766eded 100644
> --- a/malloc/mcheck.c
> +++ b/malloc/mcheck.c
> @@ -1,4 +1,4 @@
> -/* Standard debugging hooks for `malloc'.
> +/* The mcheck() interface.
> Copyright (C) 1990-2021 Free Software Foundation, Inc.
> This file is part of the GNU C Library.
> Written May 1989 by Mike Haertel.
> @@ -23,378 +23,22 @@
> # include <mcheck.h>
> # include <stdint.h>
> # include <stdio.h>
> -# include <libintl.h>
> # include <errno.h>
> #endif
>
> -/* Old hook values. */
> -static void (*old_free_hook)(void *ptr, const void *);
> -static void *(*old_malloc_hook) (size_t size, const void *);
> -static void *(*old_memalign_hook) (size_t alignment, size_t size,
> - const void *);
> . . .
> - }
> -
> - return mcheck_used ? 0 : -1;
> + return __mcheck_initialize (func, false);
> }
Ok.
> @@ -403,14 +47,11 @@ libc_hidden_def (mcheck)
> int
> mcheck_pedantic (void (*func) (enum mcheck_status))
> {
> - int res = mcheck (func);
> - if (res == 0)
> - pedantic = 1;
> - return res;
> + return __mcheck_initialize (func, true);
> }
Ok.
> enum mcheck_status
> mprobe (void *ptr)
> {
> - return mcheck_used ? checkhdr (((struct hdr *) ptr) - 1) : MCHECK_DISABLED;
> + return __mcheck_checkptr (ptr);
> }
Ok.
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 5/8] mtrace: Wean away from malloc hooks
2021-06-24 18:23 ` [PATCH 5/8] mtrace: " Siddhesh Poyarekar
@ 2021-06-24 23:13 ` DJ Delorie
2021-06-28 6:25 ` Siddhesh Poyarekar
0 siblings, 1 reply; 21+ messages in thread
From: DJ Delorie @ 2021-06-24 23:13 UTC (permalink / raw)
To: Siddhesh Poyarekar; +Cc: libc-alpha, carlos, fweimer
Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> Split mtrace hooks into before and after and adapt to the new internal
> debugging hooks infrastructure. With this, the malloc hooks are
> unused internally and can be removed from the main library.
>
> This also eliminates the only use of memalign through a PLT in the
> library, so checklocalplt data needs to be updated to reflect that.
> diff --git a/include/malloc.h b/include/malloc.h
> index bb1123d9d3..6169d486f5 100644
> --- a/include/malloc.h
> +++ b/include/malloc.h
> @@ -15,6 +15,7 @@ typedef struct malloc_state *mstate;
> #define __malloc_initialized __libc_malloc_initialized
> /* Nonzero if the malloc is already initialized. */
> extern int __malloc_initialized attribute_hidden;
> +extern FILE *__mtrace_mallstream attribute_hidden;
Ok.
> diff --git a/malloc/hooks.c b/malloc/hooks.c
> index b517a98ea2..492e9aac63 100644
> --- a/malloc/hooks.c
> +++ b/malloc/hooks.c
> @@ -37,6 +37,7 @@ enum malloc_debug_hooks
> MALLOC_NONE_HOOK = 0,
> MALLOC_CHECK_HOOK = 1 << 0, /* MALLOC_CHECK_ or glibc.malloc.check. */
> MALLOC_MCHECK_HOOK = 1 << 1, /* mcheck() */
> + MALLOC_MTRACE_HOOK = 1 << 2, /* mtrace() */
> };
> static unsigned __malloc_debugging_hooks;
Ok.
> @@ -111,8 +113,13 @@ _malloc_debug_before (size_t *bytesp, void **victimp, const void *address)
> static __always_inline void *
> _malloc_debug_after (void *mem, size_t bytes, const void *address)
> {
> - if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
> - mem = malloc_mcheck_after (mem, bytes);
> + if (__glibc_unlikely (__malloc_debugging_hooks))
> + {
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
> + mem = malloc_mcheck_after (mem, bytes);
> + if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
> + mem = malloc_mtrace_after (mem, bytes, address);
> + }
> return mem;
> }
I suspect this should have been in part 4, but ok.
> @@ -129,6 +136,8 @@ _free_debug_before (void **mem, const void *address)
>
> if (__glibc_unlikely (__malloc_debugging_hooks))
> {
> + if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
> + free_mtrace (mem, address);
> if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
> *mem = free_mcheck (*mem);
> if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
Ok.
> @@ -171,8 +180,13 @@ static __always_inline void *
> _realloc_debug_after (void *mem, void *oldmem, size_t bytes, size_t oldsize,
> const void *address)
> {
> - if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
> - mem = realloc_mcheck_after (mem, oldmem, bytes, oldsize);
> + if (__glibc_unlikely (__malloc_debugging_hooks))
> + {
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
> + mem = realloc_mcheck_after (mem, oldmem, bytes, oldsize);
> + if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
> + mem = realloc_mtrace_after (mem, oldmem, bytes, address);
> + }
> return mem;
> }
Part 4, but ok.
> @@ -206,8 +220,13 @@ static __always_inline void *
> _memalign_debug_after (void *mem, size_t alignment, size_t bytes,
> const void *address)
> {
> - if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
> - mem = memalign_mcheck_after (mem, alignment, bytes);
> + if (__glibc_unlikely (__malloc_debugging_hooks))
> + {
> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK) && mem != NULL)
> + mem = memalign_mcheck_after (mem, alignment, bytes);
> + if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
> + mem = memalign_mtrace_after (mem, bytes, address);
> + }
> return mem;
> }
Likewise. Ok.
> @@ -243,11 +262,14 @@ _calloc_debug_before (size_t *bytesp, void **victimp, const void *address)
> static __always_inline void *
> _calloc_debug_after (void *mem, size_t bytes, const void *address)
> {
> - if (__glibc_unlikely (__malloc_debugging_hooks) && mem != NULL)
> + if (__glibc_unlikely (__malloc_debugging_hooks))
> {
> if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
> mem = malloc_mcheck_after (mem, bytes);
> - memset (mem, 0, bytes);
> + if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
> + mem = malloc_mtrace_after (mem, bytes, address);
> + else if (mem != NULL)
> + memset (mem, 0, bytes);
> }
Why "else memset" ? We don't zero memory when tracing? Or it's zero'd
elsewhere? What if we have both hooks set?
Regardless, deserves a comment here.
> diff --git a/malloc/mtrace-hooks.c b/malloc/mtrace-hooks.c
> new file mode 100644
> index 0000000000..c1c6d6a6e9
> --- /dev/null
> +++ b/malloc/mtrace-hooks.c
Still missing makefile dependency.
Mostly just a copy-paste from mtrace.c, so OK.
> diff --git a/malloc/mtrace.c b/malloc/mtrace.c
> index 6c2c58b706..2cc4507e25 100644
> --- a/malloc/mtrace.c
> +++ b/malloc/mtrace.c
> @@ -22,7 +22,6 @@
> # define _MALLOC_INTERNAL
> # include <malloc.h>
> # include <mcheck.h>
> -# include <libc-lock.h>
> #endif
Lots of deletions moved to mtrace-hooks.c, ok.
> @@ -276,7 +71,7 @@ static void __libc_freeres_fn_section
> release_libc_mem (void)
> {
> /* Only call the free function if we still are running in mtrace mode. */
> - if (mallstream != NULL)
> + if (__mtrace_mallstream != NULL)
> __libc_freeres ();
> }
Ok.
> @@ -293,7 +88,7 @@ mtrace (void)
> char *mallfile;
>
> /* Don't panic if we're called more than once. */
> - if (mallstream != NULL)
> + if (__mtrace_mallstream != NULL)
> return;
Ok.
> #ifdef _LIBC
> @@ -310,15 +105,15 @@ mtrace (void)
> if (mtb == NULL)
> return;
>
> - mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null", "wce");
> - if (mallstream != NULL)
> + __mtrace_mallstream = fopen (mallfile != NULL ? mallfile : "/dev/null",
> + "wce");
> + if (__mtrace_mallstream != NULL)
Ok.
> {
> /* Be sure it doesn't malloc its buffer! */
> malloc_trace_buffer = mtb;
> - setvbuf (mallstream, malloc_trace_buffer, _IOFBF, TRACE_BUFFER_SIZE);
> - fprintf (mallstream, "= Start\n");
> - save_default_hooks ();
> - set_trace_hooks ();
> + setvbuf (__mtrace_mallstream, malloc_trace_buffer, _IOFBF,
> + TRACE_BUFFER_SIZE);
> + fprintf (__mtrace_mallstream, "= Start\n");
Ok.
> @@ -336,15 +131,11 @@ mtrace (void)
> void
> muntrace (void)
> {
> - if (mallstream == NULL)
> + if (__mtrace_mallstream == NULL)
> return;
Ok.
> - /* Do the reverse of what done in mtrace: first reset the hooks and
> - MALLSTREAM, and only after that write the trailer and close the
> - file. */
> - FILE *f = mallstream;
> - mallstream = NULL;
> - set_default_hooks ();
> + FILE *f = __mtrace_mallstream;
> + __mtrace_mallstream = NULL;
>
> fprintf (f, "= End\n");
> fclose (f);
Ok.
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 6/8] Remove malloc hooks
2021-06-24 18:23 ` [PATCH 6/8] Remove " Siddhesh Poyarekar
@ 2021-06-24 23:31 ` DJ Delorie
2021-06-28 6:37 ` Siddhesh Poyarekar
0 siblings, 1 reply; 21+ messages in thread
From: DJ Delorie @ 2021-06-24 23:31 UTC (permalink / raw)
To: Siddhesh Poyarekar; +Cc: libc-alpha, carlos, fweimer
Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> Make malloc hooks symbols compat-only so that new applications cannot
> link against them and remove the declarations from the API. The
> existing hooks variables are not used in the library anymore.
>
> Legacy applications that need hooks functionality need to preload a
> new DSO libmalloc_compathooks.so, which interposes the libc malloc
> functions to execute hooks if they exist.
>
> Also remove all references to the malloc hooks in the manual. Mention
> the removal in NEWS and also warn that libmalloc_compathooks.so is a
> temporary measure and may be removed in a future version of glibc.
>
> memalign makes a comeback as a PLT reference since the initialization
> hooks use them. tst-mallocstate now needs libmalloc_compathooks.so
> since it uses __malloc_initialize_hook to set up initial heap state to
> emumate emacs.
> diff --git a/Makeconfig b/Makeconfig
> index 407df9e6a1..991d6d3e99 100644
> --- a/Makeconfig
> +++ b/Makeconfig
> @@ -951,7 +951,7 @@ libio-include = -I$(..)libio
> built-modules = iconvprogs iconvdata ldconfig lddlibc4 libmemusage \
> libSegFault libpcprofile librpcsvc locale-programs \
> memusagestat nonlib nscd extramodules libnldbl libsupport \
> - testsuite
> + testsuite libmalloc_compathooks
New library, ok.
> diff --git a/NEWS b/NEWS
> index 536e80721a..8a7226aef2 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -68,6 +68,15 @@ Deprecated and removed features, and other changes affecting compatibility:
> mtrace. Similar functionality can be achieved by using conditional
> breakpoints within mtrace functions from within gdb.
>
> +* The deprecated memory allocation hooks __malloc_hook, __realloc_hook,
> + __memalign_hook and __free_hook are now removed from the API. Compatibility
> + symbols are present to support legacy programs but new applications can no
> + longer link to these symbols. Further, the hooks no longer have any effect
> + on glibc functionality. A compatibility DSO libmalloc_compathooks.so has
> + been provided as a transitional measure to get hook functionality back for
> + legacy programs until they are updated to remove references to the memory
> + allocation hooks.
> +
Ok.
> diff --git a/malloc/Makefile b/malloc/Makefile
> index f9433af880..7d07b94a03 100644
> --- a/malloc/Makefile
> +++ b/malloc/Makefile
> @@ -41,6 +41,7 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
> tst-malloc-stats-cancellation \
> tst-tcfree1 tst-tcfree2 tst-tcfree3 \
> tst-safe-linking \
> + tst-compathooks-off tst-compathooks-on
Ok.
> -# Additional library.
> -extra-libs = libmemusage
> +# Additional libraries.
> +extra-libs = libmemusage libmalloc_compathooks
> extra-libs-others = $(extra-libs)
Ok.
> @@ -128,6 +129,9 @@ test-extras = \
> libmemusage-routines = memusage
> libmemusage-inhibit-o = $(filter-out .os,$(object-suffixes))
>
> +libmalloc_compathooks-routines = malloc-compathooks
> +libmalloc_compathooks-inhibit-o = $(filter-out .os,$(object-suffixes))
Ok.
> @@ -313,3 +317,10 @@ $(objpfx)tst-mallocfork2-mcheck: $(shared-thread-library)
> $(objpfx)tst-malloc-tcache-leak-malloc-check: $(shared-thread-library)
> $(objpfx)tst-malloc_info-malloc-check: $(shared-thread-library)
> $(objpfx)tst-mallocfork2-malloc-check: $(shared-thread-library)
> +
> +tst-compathooks-on-ENV = LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
> +tst-compathooks-on-mcheck-ENV = LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
> +tst-compathooks-on-malloc-check-ENV = \
> + LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
> +tst-mallocstate-ENV = LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
> +tst-mallocstate-malloc-check-ENV = LD_PRELOAD=$(objpfx)libmalloc_compathooks.so
Ok.
> diff --git a/malloc/arena.c b/malloc/arena.c
> index a8500a25c9..8591c8ea56 100644
> --- a/malloc/arena.c
> +++ b/malloc/arena.c
> @@ -408,11 +408,6 @@ ptmalloc_init (void)
> __mcheck_initialize (NULL, false);
> #endif
>
> -#if HAVE_MALLOC_INIT_HOOK
> - void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook);
> - if (hook != NULL)
> - (*hook)();
> -#endif
> __malloc_initialized = 1;
> }
Ok.
> diff --git a/malloc/hooks.c b/malloc/hooks.c
> index 492e9aac63..cc9ffc8b63 100644
> --- a/malloc/hooks.c
> +++ b/malloc/hooks.c
> @@ -42,23 +42,84 @@ enum malloc_debug_hooks
> static unsigned __malloc_debugging_hooks;
>
> /* Forward declarations. */
> +static void ptmalloc_init (void);
>
> -#if HAVE_MALLOC_INIT_HOOK
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
2_24? Not 2_34?
> void (*__malloc_initialize_hook) (void) __attribute__ ((nocommon));
> compat_symbol (libc, __malloc_initialize_hook,
> __malloc_initialize_hook, GLIBC_2_0);
> +
> +# define MALLOC_INIT_HOOK() ({ \
> + void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook); \
> + if (hook != NULL) \
> + (*hook)(); \
> +})
> +#else
> +# define MALLOC_INIT_HOOK()
> #endif
Ok.
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
> +
> +static void *malloc_hook_ini (size_t, const void *) __THROW;
> +static void *realloc_hook_ini (void *, size_t, const void *) __THROW;
> +static void *memalign_hook_ini (size_t, size_t, const void *) __THROW;
> +
> void weak_variable (*__free_hook) (void *__ptr,
> const void *) = NULL;
> void *weak_variable (*__malloc_hook)
> - (size_t __size, const void *) = NULL;
> + (size_t __size, const void *) = malloc_hook_ini;
> void *weak_variable (*__realloc_hook)
> - (void *__ptr, size_t __size, const void *) = NULL;
> + (void *__ptr, size_t __size, const void *) = realloc_hook_ini;
> void *weak_variable (*__memalign_hook)
> - (size_t __alignment, size_t __size, const void *) = NULL;
> + (size_t __alignment, size_t __size, const void *) = memalign_hook_ini;
>
> -static void ptmalloc_init (void);
> +compat_symbol (libc, __free_hook, __free_hook, GLIBC_2_0);
> +compat_symbol (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
> +compat_symbol (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
> +compat_symbol (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
> +
> +/* These hooks will get executed only through the interposed allocator
> + functions in libmalloc_compathooks. This means that the calls to malloc,
> + realloc, etc. will lead back into the interposed functions, which is what we
> + want.
> +
> + These initial hooks are assumed to be called in a single-threaded context,
> + so it is safe to reset all hooks at once upon initialization. */
> +
> +static void
> +generic_hook_ini (void)
> +{
> + __malloc_hook = NULL;
> + __realloc_hook = NULL;
> + __memalign_hook = NULL;
> + if (__malloc_initialized < 0)
> + {
> + ptmalloc_init ();
> + MALLOC_INIT_HOOK ();
> + }
> +}
> +
> +static void *
> +malloc_hook_ini (size_t sz, const void *caller)
> +{
> + generic_hook_ini ();
> + return malloc (sz);
> +}
> +
> +static void *
> +realloc_hook_ini (void *ptr, size_t sz, const void *caller)
> +{
> + generic_hook_ini ();
> + return realloc (ptr, sz);
> +}
> +
> +static void *
> +memalign_hook_ini (size_t alignment, size_t sz, const void *caller)
> +{
> + generic_hook_ini ();
> + return memalign (alignment, sz);
> +}
> +#endif
Ok. Why not free_hook?
> __is_malloc_debug_enabled (enum malloc_debug_hooks flag)
> @@ -88,14 +149,6 @@ _malloc_debug_before (size_t *bytesp, void **victimp, const void *address)
> _Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
> "PTRDIFF_MAX is not more than half of SIZE_MAX");
>
> - void *(*hook) (size_t, const void *)
> - = atomic_forced_read (__malloc_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - {
> - *victimp = (*hook)(*bytesp, address);
> - return true;
> - }
> -
Yay! Ok.
> @@ -126,14 +179,6 @@ _malloc_debug_after (void *mem, size_t bytes, const void *address)
> static __always_inline bool
> _free_debug_before (void **mem, const void *address)
> {
> - void (*hook) (void *, const void *)
> - = atomic_forced_read (__free_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - {
> - (*hook)(*mem, address);
> - return true;
> - }
> -
Ok.
> @@ -153,14 +198,6 @@ static __always_inline bool
> _realloc_debug_before (void **oldmem, size_t *bytesp, size_t *oldsize,
> void **victimp, const void *address)
> {
> - void *(*hook) (void *, size_t, const void *) =
> - atomic_forced_read (__realloc_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - {
> - *victimp = (*hook)(*oldmem, *bytesp, address);
> - return true;
> - }
> -
Ok.
> @@ -194,13 +231,6 @@ static __always_inline bool
> _memalign_debug_before (size_t alignment, size_t *bytesp, void **victimp,
> const void *address)
> {
> - void *(*hook) (size_t, size_t, const void *) =
> - atomic_forced_read (__memalign_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - {
> - *victimp = (*hook)(alignment, *bytesp, address);
> - return true;
> - }
Ok.
> if (__glibc_unlikely (__malloc_debugging_hooks))
> {
> if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
> @@ -233,18 +263,6 @@ _memalign_debug_after (void *mem, size_t alignment, size_t bytes,
> static __always_inline bool
> _calloc_debug_before (size_t *bytesp, void **victimp, const void *address)
> {
> - void *(*hook) (size_t, const void *) =
> - atomic_forced_read (__malloc_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - {
> - *victimp = (*hook)(*bytesp, address);
> -
> - if (*victimp != NULL)
> - memset (*victimp, 0, *bytesp);
> -
> - return true;
> - }
> -
Ok.
> diff --git a/malloc/malloc-compathooks.c b/malloc/malloc-compathooks.c
> new file mode 100644
> index 0000000000..6d1eaab774
> --- /dev/null
> +++ b/malloc/malloc-compathooks.c
> @@ -0,0 +1,166 @@
> +/* Malloc hooks compatibility DSO.
> + Copyright (C) 2021 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public License as
> + published by the Free Software Foundation; either version 2.1 of the
> + License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; see the file COPYING.LIB. If
> + not, see <https://www.gnu.org/licenses/>. */
> +
> +#include <atomic.h>
> +#include <libc-symbols.h>
> +#include <shlib-compat.h>
> +#include <string.h>
> +#include <unistd.h>
> +
> +extern void (*__free_hook) (void *__ptr, const void *);
> +compat_symbol_reference (libc, __free_hook, __free_hook, GLIBC_2_0);
> +extern void * (*__malloc_hook) (size_t __size, const void *);
> +compat_symbol_reference (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
> +extern void * (*__realloc_hook)
> + (void *__ptr, size_t __size, const void *);
> +compat_symbol_reference (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
> +extern void * (*__memalign_hook)
> + (size_t __alignment, size_t __size, const void *);
> +compat_symbol_reference (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
> +
> +/* Support only the glibc allocators. */
> +extern void *__libc_malloc (size_t);
> +extern void __libc_free (void *);
> +extern void *__libc_realloc (void *, size_t);
> +extern void *__libc_memalign (size_t, size_t);
> +extern void *__libc_valloc (size_t);
> +extern void *__libc_pvalloc (size_t);
> +extern void *__libc_calloc (size_t, size_t);
Ok.
> +static size_t pagesize;
Ok.
> +/* The allocator functions. */
> +
> +static void *
> +__compathook_malloc (size_t bytes)
> +{
> + void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + return (*hook)(bytes, RETURN_ADDRESS (0));
> +
> + return __libc_malloc (bytes);
> +}
> +strong_alias (__compathook_malloc, malloc)
Ok.
> +static void
> +__compathook_free (void *mem)
> +{
> + void (*hook) (void *, const void *) = atomic_forced_read (__free_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + {
> + (*hook)(mem, RETURN_ADDRESS (0));
> + return;
> + }
> + __libc_free (mem);
> +}
> +strong_alias (__compathook_free, free)
Ok.
> +static void *
> +__compathook_realloc (void *oldmem, size_t bytes)
> +{
> + void *(*hook) (void *, size_t, const void *) =
> + atomic_forced_read (__realloc_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + return (*hook)(oldmem, bytes, RETURN_ADDRESS (0));
> +
> + return __libc_realloc (oldmem, bytes);
> +}
> +strong_alias (__compathook_realloc, realloc)
Ok.
> +static void *
> +__compathook_memalign (size_t alignment, size_t bytes)
> +{
> + void *(*hook) (size_t, size_t, const void *) =
> + atomic_forced_read (__memalign_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + return (*hook)(alignment, bytes, RETURN_ADDRESS (0));
> +
> + return __libc_memalign (alignment, bytes);
> +}
> +strong_alias (__compathook_memalign, memalign)
Ok.
> +static void *
> +__compathook_pvalloc (size_t bytes)
> +{
> + void *(*hook) (size_t, size_t, const void *) =
> + atomic_forced_read (__memalign_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + {
> + size_t rounded_bytes;
> +
> + if (!pagesize)
> + pagesize = sysconf (_SC_PAGESIZE);
> +
> + /* ALIGN_UP with overflow check. */
> + if (__glibc_unlikely (__builtin_add_overflow (bytes,
> + pagesize - 1,
> + &rounded_bytes)))
> + {
> + errno = ENOMEM;
> + return NULL;
> + }
> + rounded_bytes = rounded_bytes & -(pagesize - 1);
> + return (*hook)(pagesize, rounded_bytes, RETURN_ADDRESS (0));
> + }
> +
> + return __libc_pvalloc (bytes);
> +}
> +strong_alias (__compathook_pvalloc, pvalloc)
Ok.
> +static void *
> +__compathook_valloc (size_t bytes)
> +{
> + void *(*hook) (size_t, size_t, const void *) =
> + atomic_forced_read (__memalign_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + {
> + if (!pagesize)
> + pagesize = sysconf (_SC_PAGESIZE);
> +
> + return (*hook)(pagesize, bytes, RETURN_ADDRESS (0));
> + }
> +
> + return __libc_valloc (bytes);
> +}
> +strong_alias (__compathook_valloc, valloc)
Ok.
> +static void *
> +__compathook_calloc (size_t nmemb, size_t size)
> +{
> + void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook);
> + if (__builtin_expect (hook != NULL, 0))
> + {
> + size_t bytes;
> +
> + if (__glibc_unlikely (__builtin_mul_overflow (nmemb, size, &bytes)))
> + {
> + errno = ENOMEM;
> + return NULL;
> + }
> +
> + void *mem = (*hook)(bytes, RETURN_ADDRESS (0));
> +
> + if (mem != NULL)
> + memset (mem, 0, bytes);
> +
> + return mem;
> + }
> +
> + return __libc_calloc (nmemb, size);
> +}
> +strong_alias (__compathook_calloc, calloc)
Ok.
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index 5ea12d1d3b..16ad933c66 100644
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -570,16 +570,6 @@ tag_at (void *ptr)
> #define HAVE_MREMAP 0
> #endif
>
> -/* We may need to support __malloc_initialize_hook for backwards
> - compatibility. */
> -
> -#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
> -# define HAVE_MALLOC_INIT_HOOK 1
> -#else
> -# define HAVE_MALLOC_INIT_HOOK 0
> -#endif
> -
> -
Ok.
> diff --git a/malloc/malloc.h b/malloc/malloc.h
> index c1c0896d29..709fa454b5 100644
> --- a/malloc/malloc.h
> +++ b/malloc/malloc.h
> @@ -165,20 +165,6 @@ extern void malloc_stats (void) __THROW;
> extern int malloc_info (int __options, FILE *__fp) __THROW;
>
> /* Hooks for debugging and user-defined versions. */
> -extern void (*__MALLOC_HOOK_VOLATILE __free_hook) (void *__ptr,
> - const void *)
> -__MALLOC_DEPRECATED;
> -extern void *(*__MALLOC_HOOK_VOLATILE __malloc_hook)(size_t __size,
> - const void *)
> -__MALLOC_DEPRECATED;
> -extern void *(*__MALLOC_HOOK_VOLATILE __realloc_hook)(void *__ptr,
> - size_t __size,
> - const void *)
> -__MALLOC_DEPRECATED;
> -extern void *(*__MALLOC_HOOK_VOLATILE __memalign_hook)(size_t __alignment,
> - size_t __size,
> - const void *)
> -__MALLOC_DEPRECATED;
> extern void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void)
> __MALLOC_DEPRECATED;
Ok.
> diff --git a/manual/memory.texi b/manual/memory.texi
> index 28ec2e4e63..e66ecd582d 100644
> --- a/manual/memory.texi
> +++ b/manual/memory.texi
> @@ -328,8 +328,6 @@ any time (or never).
> * Malloc Tunable Parameters:: Use @code{mallopt} to adjust allocation
> parameters.
> * Heap Consistency Checking:: Automatic checking for errors.
> -* Hooks for Malloc:: You can use these hooks for debugging
> - programs that use @code{malloc}.
> * Statistics of Malloc:: Getting information about how much
> memory your program is using.
> * Summary of Malloc:: Summary of @code{malloc} and related functions.
> @@ -1388,170 +1386,6 @@ compatibility. Both @code{MALLOC_CHECK_} and @samp{-lmcheck} should
> uncover the same bugs - but using @code{MALLOC_CHECK_} you don't need to
> recompile your application.
>
> -@node Hooks for Malloc
> -@subsubsection Memory Allocation Hooks
> -@cindex allocation hooks, for @code{malloc}
> -
> . . .
> -The @code{mcheck} function (@pxref{Heap Consistency Checking}) works by
> -installing such hooks.
> -
Ok.
> @@ -1686,19 +1520,6 @@ Tell @code{malloc} to perform occasional consistency checks on
> dynamically allocated memory, and to call @var{abortfn} when an
> inconsistency is found. @xref{Heap Consistency Checking}.
>
> -@item void *(*__malloc_hook) (size_t @var{size}, const void *@var{caller})
> -A pointer to a function that @code{malloc} uses whenever it is called.
> -
> -@item void *(*__realloc_hook) (void *@var{ptr}, size_t @var{size}, const void *@var{caller})
> -A pointer to a function that @code{realloc} uses whenever it is called.
> -
> -@item void (*__free_hook) (void *@var{ptr}, const void *@var{caller})
> -A pointer to a function that @code{free} uses whenever it is called.
> -
> -@item void (*__memalign_hook) (size_t @var{size}, size_t @var{alignment}, const void *@var{caller})
> -A pointer to a function that @code{aligned_alloc}, @code{memalign},
> -@code{posix_memalign} and @code{valloc} use whenever they are called.
> -
Ok.
> @@ -1733,7 +1554,7 @@ penalties for the program if the debugging mode is not enabled.
>
> @deftypefun void mtrace (void)
> @standards{GNU, mcheck.h}
> -@safety{@prelim{}@mtunsafe{@mtsenv{} @mtasurace{:mtrace} @mtasuconst{:malloc_hooks} @mtuinit{}}@asunsafe{@asuinit{} @ascuheap{} @asucorrupt{} @asulock{}}@acunsafe{@acuinit{} @acucorrupt{} @aculock{} @acsfd{} @acsmem{}}}
> +@safety{@prelim{}@mtunsafe{@mtsenv{} @mtasurace{:mtrace} @mtuinit{}}@asunsafe{@asuinit{} @ascuheap{} @asucorrupt{} @asulock{}}@acunsafe{@acuinit{} @acucorrupt{} @aculock{} @acsfd{} @acsmem{}}}
Ok.
> @@ -1758,10 +1579,10 @@ with the SUID or SGID bit set.
>
> If the named file is successfully opened, @code{mtrace} installs special
> handlers for the functions @code{malloc}, @code{realloc}, and
> -@code{free} (@pxref{Hooks for Malloc}). From then on, all uses of these
> -functions are traced and protocolled into the file. There is now of
> -course a speed penalty for all calls to the traced functions so tracing
> -should not be enabled during normal use.
> +@code{free}. From then on, all uses of these functions are traced and
> +protocolled into the file. There is now of course a speed penalty for all
> +calls to the traced functions so tracing should not be enabled during normal
> +use.
Ok.
> @@ -1769,7 +1590,7 @@ systems. The prototype can be found in @file{mcheck.h}.
>
> @deftypefun void muntrace (void)
> @standards{GNU, mcheck.h}
> -@safety{@prelim{}@mtunsafe{@mtasurace{:mtrace} @mtasuconst{:malloc_hooks} @mtslocale{}}@asunsafe{@asucorrupt{} @ascuheap{}}@acunsafe{@acucorrupt{} @acsmem{} @aculock{} @acsfd{}}}
> +@safety{@prelim{}@mtunsafe{@mtasurace{:mtrace} @mtslocale{}}@asunsafe{@asucorrupt{} @ascuheap{}}@acunsafe{@acucorrupt{} @acsmem{} @aculock{} @acsfd{}}}
Ok.
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 7/8] Remove __after_morecore_hook
2021-06-24 18:23 ` [PATCH 7/8] Remove __after_morecore_hook Siddhesh Poyarekar
@ 2021-06-24 23:33 ` DJ Delorie
0 siblings, 0 replies; 21+ messages in thread
From: DJ Delorie @ 2021-06-24 23:33 UTC (permalink / raw)
To: Siddhesh Poyarekar; +Cc: libc-alpha, carlos, fweimer
Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> Remove __after_morecore_hook from the API and finalize the symbol so
> that it can no longer be used in new applications. Old applications
> using __after_morecore_hook will find that their hook is no longer
> called.
> diff --git a/malloc/hooks.c b/malloc/hooks.c
> index cc9ffc8b63..fa6b3f4c16 100644
> --- a/malloc/hooks.c
> +++ b/malloc/hooks.c
> @@ -78,6 +78,9 @@ compat_symbol (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
> compat_symbol (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
> compat_symbol (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
>
> +void weak_variable (*__after_morecore_hook) (void) = NULL;
> +compat_symbol (libc, __after_morecore_hook, __after_morecore_hook, GLIBC_2_0);
> +
Ok.
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index 16ad933c66..51970105b5 100644
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -1988,16 +1988,6 @@ static void malloc_consolidate (mstate);
>
> /* -------------- Early definitions for debugging hooks ---------------- */
>
> -/* Define and initialize the hook variables. These weak definitions must
> - appear before any use of the variables in a function (arena.c uses one). */
> -#ifndef weak_variable
> -/* In GNU libc we want the hook variables to be weak definitions to
> - avoid a problem with Emacs. */
> -# define weak_variable weak_function
> -#endif
> -
> -void weak_variable (*__after_morecore_hook) (void) = NULL;
> -
Ok.
> @@ -2622,14 +2612,7 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
> LIBC_PROBE (memory_sbrk_more, 2, brk, size);
> }
>
> - if (brk != (char *) (MORECORE_FAILURE))
> - {
> - /* Call the `morecore' hook if necessary. */
> - void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - (*hook)();
> - }
> - else
> + if (brk == (char *) (MORECORE_FAILURE))
Ok.
> @@ -2768,13 +2751,6 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
> correction = 0;
> snd_brk = (char *) (MORECORE (0));
> }
> - else
> - {
> - /* Call the `morecore' hook if necessary. */
> - void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - (*hook)();
> - }
Ok.
> @@ -2933,10 +2909,6 @@ systrim (size_t pad, mstate av)
> */
>
> MORECORE (-extra);
> - /* Call the `morecore' hook if necessary. */
> - void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
> - if (__builtin_expect (hook != NULL, 0))
> - (*hook)();
> new_brk = (char *) (MORECORE (0));
Ok.
> diff --git a/malloc/malloc.h b/malloc/malloc.h
> index 709fa454b5..d066a05d82 100644
> --- a/malloc/malloc.h
> +++ b/malloc/malloc.h
> @@ -164,10 +164,5 @@ extern void malloc_stats (void) __THROW;
> /* Output information about state of allocator to stream FP. */
> extern int malloc_info (int __options, FILE *__fp) __THROW;
>
> -/* Hooks for debugging and user-defined versions. */
> -extern void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void)
> - __MALLOC_DEPRECATED;
> -
> -
> __END_DECLS
> #endif /* malloc.h */
Ok.
LGTM
Reviewed-by: DJ Delorie <dj@redhat.com>
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 8/8] Remove __morecore and __default_morecore
2021-06-24 18:23 ` [PATCH 8/8] Remove __morecore and __default_morecore Siddhesh Poyarekar
@ 2021-06-24 23:38 ` DJ Delorie
0 siblings, 0 replies; 21+ messages in thread
From: DJ Delorie @ 2021-06-24 23:38 UTC (permalink / raw)
To: Siddhesh Poyarekar; +Cc: libc-alpha, carlos, fweimer
Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
> Make the __morecore and __default_morecore symbols compat-only and
> remove their declarations from the API.
> diff --git a/NEWS b/NEWS
>
> +* The __morecore and __after_morecore_hook malloc hooks and the default
> + implementation __default_morecore have been removed from the API. Existing
> + applications will continue to link against these symbols but the interfaces
> + no longer have any effect on malloc.
> +
Ok.
> diff --git a/include/stdlib.h b/include/stdlib.h
> index e2453c1896..c5cccce85c 100644
> --- a/include/stdlib.h
> +++ b/include/stdlib.h
> @@ -300,9 +300,6 @@ libc_hidden_proto (__qfcvt_r)
> # define MB_CUR_MAX (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MB_CUR_MAX))
> # endif
>
> -extern void *__default_morecore (ptrdiff_t) __THROW;
> -libc_hidden_proto (__default_morecore)
> -
Ok.
> diff --git a/malloc/arena.c b/malloc/arena.c
> -#if defined(SHARED) || defined(USE_MTAG)
> -static void *
> -__failing_morecore (ptrdiff_t d)
> -{
> - return (void *) MORECORE_FAILURE;
> -}
> -#endif
> -
Ok.
> @@ -300,7 +292,7 @@ ptmalloc_init (void)
> and that morecore does not support tagged regions, then
> disable it. */
> if (__MTAG_SBRK_UNTAGGED)
> - __morecore = __failing_morecore;
> + __always_fail_morecore = true;
Ok.
> @@ -313,7 +305,7 @@ ptmalloc_init (void)
> generic sbrk implementation also enforces this, but it is not
> used on Hurd. */
> if (!__libc_initial)
> - __morecore = __failing_morecore;
> + __always_fail_morecore = true;
> #endif
Ok.
> diff --git a/malloc/hooks.c b/malloc/hooks.c
>
> +void *(*__morecore)(ptrdiff_t);
> +compat_symbol (libc, __morecore, __morecore, GLIBC_2_0);
Ok.
> diff --git a/malloc/malloc-internal.h b/malloc/malloc-internal.h
>
> #include <malloc-machine.h>
> #include <malloc-sysdep.h>
> +#include <stdbool.h>
Ok.
> @@ -63,6 +64,8 @@
>
> #define top(ar_ptr) ((ar_ptr)->top)
>
> +extern bool __always_fail_morecore attribute_hidden;
> +
Ok
> @@ -78,4 +81,6 @@ void __malloc_arena_thread_freeres (void) attribute_hidden;
> /* Activate a standard set of debugging hooks. */
> void __malloc_check_init (void) attribute_hidden;
>
> +extern void *__glibc_morecore (ptrdiff_t) attribute_hidden;
> +
Ok.
> diff --git a/malloc/malloc.c b/malloc/malloc.c
>
>
> /* Definition for getting more memory from the OS. */
> -#define MORECORE (*__morecore)
> +#define MORECORE (*__glibc_morecore)
> #define MORECORE_FAILURE 0
> -void * __default_morecore (ptrdiff_t);
> -void *(*__morecore)(ptrdiff_t) = __default_morecore;
Ok.
> diff --git a/malloc/malloc.h b/malloc/malloc.h
> @@ -76,14 +76,6 @@ extern void *valloc (size_t __size) __THROW __attribute_malloc__
> extern void *pvalloc (size_t __size) __THROW __attribute_malloc__
> __wur __attr_dealloc_free;
>
> -/* Underlying allocation function; successive calls should return
> - contiguous pieces of memory. */
> -extern void *(*__morecore) (ptrdiff_t __size) __MALLOC_DEPRECATED;
> -
> -/* Default value of `__morecore'. */
> -extern void *__default_morecore (ptrdiff_t __size)
> -__THROW __attribute_malloc__ __MALLOC_DEPRECATED;
> -
Ok.
> diff --git a/malloc/morecore.c b/malloc/morecore.c
> index 047228779b..c85a85c0eb 100644
> --- a/malloc/morecore.c
> +++ b/malloc/morecore.c
> @@ -38,16 +38,27 @@ libc_hidden_proto (__sbrk)
> # define NULL 0
> #endif
>
> +#if defined(SHARED) || defined(USE_MTAG)
> +bool __always_fail_morecore = false;
> +#endif
> +
Ok.
> /* Allocate INCREMENT more bytes of data space,
> and return the start of data space, or NULL on errors.
> If INCREMENT is negative, shrink data space. */
> void *
> -__default_morecore (ptrdiff_t increment)
> +__glibc_morecore (ptrdiff_t increment)
> {
> +#if defined(SHARED) || defined(USE_MTAG)
> + if (__always_fail_morecore)
> + return NULL;
> +#endif
> +
> void *result = (void *) __sbrk (increment);
> if (result == (void *) -1)
> return NULL;
>
> return result;
> }
> -libc_hidden_def (__default_morecore)
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
> +compat_symbol (libc, __glibc_morecore, __default_morecore, GLIBC_2_0);
> +#endif
Ok.
LGTM
Reviewed-by: DJ Delorie <dj@redhat.com>
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 1/8] Move glibc.malloc.check implementation into its own file
2021-06-24 19:57 ` DJ Delorie
@ 2021-06-28 4:34 ` Siddhesh Poyarekar
0 siblings, 0 replies; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-28 4:34 UTC (permalink / raw)
To: libc-alpha
On 6/25/21 1:27 AM, DJ Delorie via Libc-alpha wrote:
> Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
>> Separate the malloc check implementation from the malloc hooks. They
>> still use the hooks but are now maintained in a separate file.
>
> Missing Makefile dependency. Otherwise, it's just a block code move,
> which is fine.
>
Fixed, I'll send the updated patchset. I'll also include the mcheck
tests addition and the tr_break deprecation in the next set.
Siddhesh
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 4/8] mcheck: Wean away from malloc hooks
2021-06-24 22:51 ` DJ Delorie
@ 2021-06-28 6:22 ` Siddhesh Poyarekar
0 siblings, 0 replies; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-28 6:22 UTC (permalink / raw)
To: DJ Delorie; +Cc: fweimer, libc-alpha
On 6/25/21 4:21 AM, DJ Delorie via Libc-alpha wrote:
>
> Siddhesh Poyarekar <siddhesh@sourceware.org> writes:
>> Initialization using -lmcheck now depends on a new exported variable
>> __libc_lmcheck which is a const flag that mcheck-init can override.
>
> I wonder if we should bite the bullet and add an official malloc_ioctl()
> or something. Oh wait, we have mallopt() already. Can we hijack this
> instead of adding an ABI?
>
> mallopt (MALLOC_INTERNAL_GET_VER, 0) returns malloc_version + 1000
> (or returns 0 or 1, for "not supported")
>
> mallopt (MALLOC_INTERNAL_SET_DEBUG, debug_flags)
>
> This could be done in a .ctor/.init; I wonder if that would be early
> enough.
It won't be; it is likely that a ctor preceding the DSO that was linked
with -lmcheck could call malloc and hence result in ptmalloc_init being
called before the ctor mallopt is called.
I reckon it has to be an ELF hack. An exported symbol like
__libc_lmcheck seems like the cleanest way to do it.
We could add an ELF note, but typically notes don't impact execution so
that seems like a bad idea.
We could add a specially named segment (e.g. .glibc.lmcheck) with no
contents (or a single nop word) that ld.so reads to decide if mcheck
should be enabled. However that's not too different from __libc_lmcheck
in terms of ABI impact (we don't add a symbol version but its absence
will have the same effect) with the added complexity in the dynamic linker.
>> - if (__glibc_unlikely (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK)))
>> + if (__glibc_unlikely (__malloc_debugging_hooks))
>> {
>> - *victimp = malloc_check (bytes);
>> - if (*victimp != NULL)
>> - memset (*victimp, 0, bytes);
>> - return true;
>> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK)
>> + && malloc_mcheck_before (bytesp, victimp))
>> + return true;
>> + if (__is_malloc_debug_enabled (MALLOC_CHECK_HOOK))
>> + {
>> + *victimp = malloc_check (*bytesp);
>> + return true;
>
> memset missing? no, moved to below... A comment would help here.
Added comment.
>> +static __always_inline void *
>> +_calloc_debug_after (void *mem, size_t bytes, const void *address)
>> +{
>> + if (__glibc_unlikely (__malloc_debugging_hooks) && mem != NULL)
>> + {
>> + if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
>> + mem = malloc_mcheck_after (mem, bytes);
>> + memset (mem, 0, bytes);
>> + }
>> + return mem;
>> +}
>
> So we memset if *any* hook is called, ok.
>
>> diff --git a/malloc/malloc.c b/malloc/malloc.c
>> index 60753446a1..5ea12d1d3b 100644
>> --- a/malloc/malloc.c
>> +++ b/malloc/malloc.c
>> @@ -3192,12 +3192,13 @@ __libc_malloc (size_t bytes)
>> {
>> mstate ar_ptr;
>> void *victim;
>> + size_t orig_bytes = bytes;
>
> Do we need to initialize victim to NULL here?
All paths initialize victim, but I've initialized it anyway and left it
to the compiler to optimize it away.
Thanks,
Siddhesh
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 5/8] mtrace: Wean away from malloc hooks
2021-06-24 23:13 ` DJ Delorie
@ 2021-06-28 6:25 ` Siddhesh Poyarekar
0 siblings, 0 replies; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-28 6:25 UTC (permalink / raw)
To: DJ Delorie; +Cc: fweimer, libc-alpha
On 6/25/21 4:43 AM, DJ Delorie via Libc-alpha wrote:
>> @@ -243,11 +262,14 @@ _calloc_debug_before (size_t *bytesp, void **victimp, const void *address)
>> static __always_inline void *
>> _calloc_debug_after (void *mem, size_t bytes, const void *address)
>> {
>> - if (__glibc_unlikely (__malloc_debugging_hooks) && mem != NULL)
>> + if (__glibc_unlikely (__malloc_debugging_hooks))
>> {
>> if (__is_malloc_debug_enabled (MALLOC_MCHECK_HOOK))
>> mem = malloc_mcheck_after (mem, bytes);
>> - memset (mem, 0, bytes);
>> + if (__is_malloc_debug_enabled (MALLOC_MTRACE_HOOK))
>> + mem = malloc_mtrace_after (mem, bytes, address);
>> + else if (mem != NULL)
>> + memset (mem, 0, bytes);
>> }
>
> Why "else memset" ? We don't zero memory when tracing? Or it's zero'd
> elsewhere? What if we have both hooks set?
>
> Regardless, deserves a comment here.
Ahh yes, that will break if mtrace hook is enabled along with another
hook. Mtrace itself does not need zeroing because it defers allocation
and zeroing to glibc malloc.
I'll fix it up and also add a comment.
>> diff --git a/malloc/mtrace-hooks.c b/malloc/mtrace-hooks.c
>> new file mode 100644
>> index 0000000000..c1c6d6a6e9
>> --- /dev/null
>> +++ b/malloc/mtrace-hooks.c
>
> Still missing makefile dependency.
>
> Mostly just a copy-paste from mtrace.c, so OK.
>
Fixed.
Thanks,
Siddhesh
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 6/8] Remove malloc hooks
2021-06-24 23:31 ` DJ Delorie
@ 2021-06-28 6:37 ` Siddhesh Poyarekar
0 siblings, 0 replies; 21+ messages in thread
From: Siddhesh Poyarekar @ 2021-06-28 6:37 UTC (permalink / raw)
To: DJ Delorie; +Cc: fweimer, libc-alpha
On 6/25/21 5:01 AM, DJ Delorie via Libc-alpha wrote:
>> diff --git a/malloc/hooks.c b/malloc/hooks.c
>> index 492e9aac63..cc9ffc8b63 100644
>> --- a/malloc/hooks.c
>> +++ b/malloc/hooks.c
>> @@ -42,23 +42,84 @@ enum malloc_debug_hooks
>> static unsigned __malloc_debugging_hooks;
>>
>> /* Forward declarations. */
>> +static void ptmalloc_init (void);
>>
>> -#if HAVE_MALLOC_INIT_HOOK
>> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
>
> 2_24? Not 2_34?
__malloc_initialize_hook was made compat in 2.24.
>> void (*__malloc_initialize_hook) (void) __attribute__ ((nocommon));
>> compat_symbol (libc, __malloc_initialize_hook,
>> __malloc_initialize_hook, GLIBC_2_0);
>> +
>> +# define MALLOC_INIT_HOOK() ({ \
>> + void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook); \
>> + if (hook != NULL) \
>> + (*hook)(); \
>> +})
>> +#else
>> +# define MALLOC_INIT_HOOK()
>> #endif
>
> Ok.
>
>> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
>> +
>> +static void *malloc_hook_ini (size_t, const void *) __THROW;
>> +static void *realloc_hook_ini (void *, size_t, const void *) __THROW;
>> +static void *memalign_hook_ini (size_t, size_t, const void *) __THROW;
>> +
>> void weak_variable (*__free_hook) (void *__ptr,
>> const void *) = NULL;
>> void *weak_variable (*__malloc_hook)
>> - (size_t __size, const void *) = NULL;
>> + (size_t __size, const void *) = malloc_hook_ini;
>> void *weak_variable (*__realloc_hook)
>> - (void *__ptr, size_t __size, const void *) = NULL;
>> + (void *__ptr, size_t __size, const void *) = realloc_hook_ini;
>> void *weak_variable (*__memalign_hook)
>> - (size_t __alignment, size_t __size, const void *) = NULL;
>> + (size_t __alignment, size_t __size, const void *) = memalign_hook_ini;
>>
>> -static void ptmalloc_init (void);
>> +compat_symbol (libc, __free_hook, __free_hook, GLIBC_2_0);
>> +compat_symbol (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
>> +compat_symbol (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
>> +compat_symbol (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
>> +
>> +/* These hooks will get executed only through the interposed allocator
>> + functions in libmalloc_compathooks. This means that the calls to malloc,
>> + realloc, etc. will lead back into the interposed functions, which is what we
>> + want.
>> +
>> + These initial hooks are assumed to be called in a single-threaded context,
>> + so it is safe to reset all hooks at once upon initialization. */
>> +
>> +static void
>> +generic_hook_ini (void)
>> +{
>> + __malloc_hook = NULL;
>> + __realloc_hook = NULL;
>> + __memalign_hook = NULL;
>> + if (__malloc_initialized < 0)
>> + {
>> + ptmalloc_init ();
>> + MALLOC_INIT_HOOK ();
>> + }
>> +}
>> +
>> +static void *
>> +malloc_hook_ini (size_t sz, const void *caller)
>> +{
>> + generic_hook_ini ();
>> + return malloc (sz);
>> +}
>> +
>> +static void *
>> +realloc_hook_ini (void *ptr, size_t sz, const void *caller)
>> +{
>> + generic_hook_ini ();
>> + return realloc (ptr, sz);
>> +}
>> +
>> +static void *
>> +memalign_hook_ini (size_t alignment, size_t sz, const void *caller)
>> +{
>> + generic_hook_ini ();
>> + return memalign (alignment, sz);
>> +}
>> +#endif
>
> Ok. Why not free_hook?
free_hook started out as NULL, so there's no need to reset it. It also
cannot legitimately be the first malloc function to be called (except
with NULL, which is a nop anyway)
Siddhesh
^ permalink raw reply [flat|nested] 21+ messages in thread
end of thread, other threads:[~2021-06-28 6:37 UTC | newest]
Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
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2021-06-24 18:23 [PATCH 0/8] Remove malloc hooks Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 1/8] Move glibc.malloc.check implementation into its own file Siddhesh Poyarekar
2021-06-24 19:57 ` DJ Delorie
2021-06-28 4:34 ` Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 2/8] malloc: Move malloc hook references to hooks.c Siddhesh Poyarekar
2021-06-24 21:10 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 3/8] glibc.malloc.check: Wean away from malloc hooks Siddhesh Poyarekar
2021-06-24 21:43 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 4/8] mcheck: " Siddhesh Poyarekar
2021-06-24 22:51 ` DJ Delorie
2021-06-28 6:22 ` Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 5/8] mtrace: " Siddhesh Poyarekar
2021-06-24 23:13 ` DJ Delorie
2021-06-28 6:25 ` Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 6/8] Remove " Siddhesh Poyarekar
2021-06-24 23:31 ` DJ Delorie
2021-06-28 6:37 ` Siddhesh Poyarekar
2021-06-24 18:23 ` [PATCH 7/8] Remove __after_morecore_hook Siddhesh Poyarekar
2021-06-24 23:33 ` DJ Delorie
2021-06-24 18:23 ` [PATCH 8/8] Remove __morecore and __default_morecore Siddhesh Poyarekar
2021-06-24 23:38 ` DJ Delorie
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