* [PATCH 0/5] Linux: Auxiliary vector parsing cleanups
@ 2022-01-11 18:43 Florian Weimer
2022-01-11 18:43 ` [PATCH 1/5] elf: Merge dl-sysdep.c into the Linux version Florian Weimer
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: Florian Weimer @ 2022-01-11 18:43 UTC (permalink / raw)
To: libc-alpha
This removes some support code for pre-2.4.0 kernels and Native Client.
The simplified version of _dl_sysdep_start has a higher chance to run on
CPUs with older ISA levels, which is the main motivation for this
cleanup.
Thanks,
Florian
Florian Weimer (5):
elf: Merge dl-sysdep.c into the Linux version
Linux: Remove HAVE_AUX_SECURE, HAVE_AUX_XID, HAVE_AUX_PAGESIZE
Linux: Remove DL_FIND_ARG_COMPONENTS
Linux: Assume that NEED_DL_SYSINFO_DSO is always defined
Linux: Consolidate auxiliary vector parsing
elf/dl-support.c | 80 +----
elf/dl-sysdep.c | 352 +------------------
sysdeps/unix/sysv/linux/alpha/dl-auxv.h | 18 +-
sysdeps/unix/sysv/linux/dl-parse_auxv.h | 61 ++++
sysdeps/unix/sysv/linux/dl-sysdep.c | 240 ++++++++++++-
sysdeps/unix/sysv/linux/ldsodefs.h | 12 -
sysdeps/unix/sysv/linux/m68k/sysdep.h | 4 +-
sysdeps/unix/sysv/linux/powerpc/dl-auxv.h | 14 +-
sysdeps/unix/sysv/linux/powerpc/dl-support.c | 4 +
9 files changed, 305 insertions(+), 480 deletions(-)
create mode 100644 sysdeps/unix/sysv/linux/dl-parse_auxv.h
create mode 100644 sysdeps/unix/sysv/linux/powerpc/dl-support.c
base-commit: 7e08db3359c86c94918feb33a1182cd0ff3bb10b
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/5] elf: Merge dl-sysdep.c into the Linux version
2022-01-11 18:43 [PATCH 0/5] Linux: Auxiliary vector parsing cleanups Florian Weimer
@ 2022-01-11 18:43 ` Florian Weimer
2022-01-11 18:43 ` [PATCH 2/5] Linux: Remove HAVE_AUX_SECURE, HAVE_AUX_XID, HAVE_AUX_PAGESIZE Florian Weimer
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Florian Weimer @ 2022-01-11 18:43 UTC (permalink / raw)
To: libc-alpha
The generic version is the de-facto Linux implementation. It
requires an auxiliary vector, so Hurd does not use it.
---
elf/dl-sysdep.c | 352 +---------------------------
sysdeps/unix/sysv/linux/dl-sysdep.c | 347 ++++++++++++++++++++++++++-
2 files changed, 337 insertions(+), 362 deletions(-)
diff --git a/elf/dl-sysdep.c b/elf/dl-sysdep.c
index f1dba8ef24..7aa90ad6ee 100644
--- a/elf/dl-sysdep.c
+++ b/elf/dl-sysdep.c
@@ -1,4 +1,4 @@
-/* Operating system support for run-time dynamic linker. Generic Unix version.
+/* Operating system support for run-time dynamic linker. Stub version.
Copyright (C) 1995-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -16,352 +16,4 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-/* We conditionalize the whole of this file rather than simply eliding it
- from the static build, because other sysdeps/ versions of this file
- might define things needed by a static build. */
-
-#ifdef SHARED
-
-#include <assert.h>
-#include <elf.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <libintl.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/mman.h>
-#include <ldsodefs.h>
-#include <_itoa.h>
-#include <fpu_control.h>
-
-#include <entry.h>
-#include <dl-machine.h>
-#include <dl-procinfo.h>
-#include <dl-osinfo.h>
-#include <libc-internal.h>
-#include <tls.h>
-
-#include <dl-tunables.h>
-#include <dl-auxv.h>
-#include <dl-hwcap-check.h>
-
-extern char **_environ attribute_hidden;
-extern char _end[] attribute_hidden;
-
-/* Protect SUID program against misuse of file descriptors. */
-extern void __libc_check_standard_fds (void);
-
-int __libc_enable_secure attribute_relro = 0;
-rtld_hidden_data_def (__libc_enable_secure)
-/* This variable contains the lowest stack address ever used. */
-void *__libc_stack_end attribute_relro = NULL;
-rtld_hidden_data_def(__libc_stack_end)
-void *_dl_random attribute_relro = NULL;
-
-#ifndef DL_FIND_ARG_COMPONENTS
-# define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp) \
- do { \
- void **_tmp; \
- (argc) = *(long int *) cookie; \
- (argv) = (char **) ((long int *) cookie + 1); \
- (envp) = (argv) + (argc) + 1; \
- for (_tmp = (void **) (envp); *_tmp; ++_tmp) \
- continue; \
- (auxp) = (void *) ++_tmp; \
- } while (0)
-#endif
-
-#ifndef DL_STACK_END
-# define DL_STACK_END(cookie) ((void *) (cookie))
-#endif
-
-ElfW(Addr)
-_dl_sysdep_start (void **start_argptr,
- void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
- ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv))
-{
- const ElfW(Phdr) *phdr = NULL;
- ElfW(Word) phnum = 0;
- ElfW(Addr) user_entry;
- ElfW(auxv_t) *av;
-#ifdef HAVE_AUX_SECURE
-# define set_seen(tag) (tag) /* Evaluate for the side effects. */
-# define set_seen_secure() ((void) 0)
-#else
- uid_t uid = 0;
- gid_t gid = 0;
- unsigned int seen = 0;
-# define set_seen_secure() (seen = -1)
-# ifdef HAVE_AUX_XID
-# define set_seen(tag) (tag) /* Evaluate for the side effects. */
-# else
-# define M(type) (1 << (type))
-# define set_seen(tag) seen |= M ((tag)->a_type)
-# endif
-#endif
-#ifdef NEED_DL_SYSINFO
- uintptr_t new_sysinfo = 0;
-#endif
-
- __libc_stack_end = DL_STACK_END (start_argptr);
- DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, _dl_argv, _environ,
- GLRO(dl_auxv));
-
- user_entry = (ElfW(Addr)) ENTRY_POINT;
- GLRO(dl_platform) = NULL; /* Default to nothing known about the platform. */
-
- /* NB: Default to a constant CONSTANT_MINSIGSTKSZ. */
- _Static_assert (__builtin_constant_p (CONSTANT_MINSIGSTKSZ),
- "CONSTANT_MINSIGSTKSZ is constant");
- GLRO(dl_minsigstacksize) = CONSTANT_MINSIGSTKSZ;
-
- for (av = GLRO(dl_auxv); av->a_type != AT_NULL; set_seen (av++))
- switch (av->a_type)
- {
- case AT_PHDR:
- phdr = (void *) av->a_un.a_val;
- break;
- case AT_PHNUM:
- phnum = av->a_un.a_val;
- break;
- case AT_PAGESZ:
- GLRO(dl_pagesize) = av->a_un.a_val;
- break;
- case AT_ENTRY:
- user_entry = av->a_un.a_val;
- break;
-#ifndef HAVE_AUX_SECURE
- case AT_UID:
- case AT_EUID:
- uid ^= av->a_un.a_val;
- break;
- case AT_GID:
- case AT_EGID:
- gid ^= av->a_un.a_val;
- break;
-#endif
- case AT_SECURE:
-#ifndef HAVE_AUX_SECURE
- seen = -1;
-#endif
- __libc_enable_secure = av->a_un.a_val;
- break;
- case AT_PLATFORM:
- GLRO(dl_platform) = (void *) av->a_un.a_val;
- break;
- case AT_HWCAP:
- GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
- break;
- case AT_HWCAP2:
- GLRO(dl_hwcap2) = (unsigned long int) av->a_un.a_val;
- break;
- case AT_CLKTCK:
- GLRO(dl_clktck) = av->a_un.a_val;
- break;
- case AT_FPUCW:
- GLRO(dl_fpu_control) = av->a_un.a_val;
- break;
-#ifdef NEED_DL_SYSINFO
- case AT_SYSINFO:
- new_sysinfo = av->a_un.a_val;
- break;
-#endif
-#ifdef NEED_DL_SYSINFO_DSO
- case AT_SYSINFO_EHDR:
- GLRO(dl_sysinfo_dso) = (void *) av->a_un.a_val;
- break;
-#endif
- case AT_RANDOM:
- _dl_random = (void *) av->a_un.a_val;
- break;
- case AT_MINSIGSTKSZ:
- GLRO(dl_minsigstacksize) = av->a_un.a_val;
- break;
- DL_PLATFORM_AUXV
- }
-
- dl_hwcap_check ();
-
-#ifndef HAVE_AUX_SECURE
- if (seen != -1)
- {
- /* Fill in the values we have not gotten from the kernel through the
- auxiliary vector. */
-# ifndef HAVE_AUX_XID
-# define SEE(UID, var, uid) \
- if ((seen & M (AT_##UID)) == 0) var ^= __get##uid ()
- SEE (UID, uid, uid);
- SEE (EUID, uid, euid);
- SEE (GID, gid, gid);
- SEE (EGID, gid, egid);
-# endif
-
- /* If one of the two pairs of IDs does not match this is a setuid
- or setgid run. */
- __libc_enable_secure = uid | gid;
- }
-#endif
-
-#ifndef HAVE_AUX_PAGESIZE
- if (GLRO(dl_pagesize) == 0)
- GLRO(dl_pagesize) = __getpagesize ();
-#endif
-
-#ifdef NEED_DL_SYSINFO
- if (new_sysinfo != 0)
- {
-# ifdef NEED_DL_SYSINFO_DSO
- /* Only set the sysinfo value if we also have the vsyscall DSO. */
- if (GLRO(dl_sysinfo_dso) != 0)
-# endif
- GLRO(dl_sysinfo) = new_sysinfo;
- }
-#endif
-
- __tunables_init (_environ);
-
- /* Initialize DSO sorting algorithm after tunables. */
- _dl_sort_maps_init ();
-
-#ifdef DL_SYSDEP_INIT
- DL_SYSDEP_INIT;
-#endif
-
-#ifdef DL_PLATFORM_INIT
- DL_PLATFORM_INIT;
-#endif
-
- /* Determine the length of the platform name. */
- if (GLRO(dl_platform) != NULL)
- GLRO(dl_platformlen) = strlen (GLRO(dl_platform));
-
- if (__sbrk (0) == _end)
- /* The dynamic linker was run as a program, and so the initial break
- starts just after our bss, at &_end. The malloc in dl-minimal.c
- will consume the rest of this page, so tell the kernel to move the
- break up that far. When the user program examines its break, it
- will see this new value and not clobber our data. */
- __sbrk (GLRO(dl_pagesize)
- - ((_end - (char *) 0) & (GLRO(dl_pagesize) - 1)));
-
- /* If this is a SUID program we make sure that FDs 0, 1, and 2 are
- allocated. If necessary we are doing it ourself. If it is not
- possible we stop the program. */
- if (__builtin_expect (__libc_enable_secure, 0))
- __libc_check_standard_fds ();
-
- (*dl_main) (phdr, phnum, &user_entry, GLRO(dl_auxv));
- return user_entry;
-}
-
-void
-_dl_sysdep_start_cleanup (void)
-{
-}
-
-void
-_dl_show_auxv (void)
-{
- char buf[64];
- ElfW(auxv_t) *av;
-
- /* Terminate string. */
- buf[63] = '\0';
-
- /* The following code assumes that the AT_* values are encoded
- starting from 0 with AT_NULL, 1 for AT_IGNORE, and all other values
- close by (otherwise the array will be too large). In case we have
- to support a platform where these requirements are not fulfilled
- some alternative implementation has to be used. */
- for (av = GLRO(dl_auxv); av->a_type != AT_NULL; ++av)
- {
- static const struct
- {
- const char label[22];
- enum { unknown = 0, dec, hex, str, ignore } form : 8;
- } auxvars[] =
- {
- [AT_EXECFD - 2] = { "EXECFD: ", dec },
- [AT_EXECFN - 2] = { "EXECFN: ", str },
- [AT_PHDR - 2] = { "PHDR: 0x", hex },
- [AT_PHENT - 2] = { "PHENT: ", dec },
- [AT_PHNUM - 2] = { "PHNUM: ", dec },
- [AT_PAGESZ - 2] = { "PAGESZ: ", dec },
- [AT_BASE - 2] = { "BASE: 0x", hex },
- [AT_FLAGS - 2] = { "FLAGS: 0x", hex },
- [AT_ENTRY - 2] = { "ENTRY: 0x", hex },
- [AT_NOTELF - 2] = { "NOTELF: ", hex },
- [AT_UID - 2] = { "UID: ", dec },
- [AT_EUID - 2] = { "EUID: ", dec },
- [AT_GID - 2] = { "GID: ", dec },
- [AT_EGID - 2] = { "EGID: ", dec },
- [AT_PLATFORM - 2] = { "PLATFORM: ", str },
- [AT_HWCAP - 2] = { "HWCAP: ", hex },
- [AT_CLKTCK - 2] = { "CLKTCK: ", dec },
- [AT_FPUCW - 2] = { "FPUCW: ", hex },
- [AT_DCACHEBSIZE - 2] = { "DCACHEBSIZE: 0x", hex },
- [AT_ICACHEBSIZE - 2] = { "ICACHEBSIZE: 0x", hex },
- [AT_UCACHEBSIZE - 2] = { "UCACHEBSIZE: 0x", hex },
- [AT_IGNOREPPC - 2] = { "IGNOREPPC", ignore },
- [AT_SECURE - 2] = { "SECURE: ", dec },
- [AT_BASE_PLATFORM - 2] = { "BASE_PLATFORM: ", str },
- [AT_SYSINFO - 2] = { "SYSINFO: 0x", hex },
- [AT_SYSINFO_EHDR - 2] = { "SYSINFO_EHDR: 0x", hex },
- [AT_RANDOM - 2] = { "RANDOM: 0x", hex },
- [AT_HWCAP2 - 2] = { "HWCAP2: 0x", hex },
- [AT_MINSIGSTKSZ - 2] = { "MINSIGSTKSZ: ", dec },
- [AT_L1I_CACHESIZE - 2] = { "L1I_CACHESIZE: ", dec },
- [AT_L1I_CACHEGEOMETRY - 2] = { "L1I_CACHEGEOMETRY: 0x", hex },
- [AT_L1D_CACHESIZE - 2] = { "L1D_CACHESIZE: ", dec },
- [AT_L1D_CACHEGEOMETRY - 2] = { "L1D_CACHEGEOMETRY: 0x", hex },
- [AT_L2_CACHESIZE - 2] = { "L2_CACHESIZE: ", dec },
- [AT_L2_CACHEGEOMETRY - 2] = { "L2_CACHEGEOMETRY: 0x", hex },
- [AT_L3_CACHESIZE - 2] = { "L3_CACHESIZE: ", dec },
- [AT_L3_CACHEGEOMETRY - 2] = { "L3_CACHEGEOMETRY: 0x", hex },
- };
- unsigned int idx = (unsigned int) (av->a_type - 2);
-
- if ((unsigned int) av->a_type < 2u
- || (idx < sizeof (auxvars) / sizeof (auxvars[0])
- && auxvars[idx].form == ignore))
- continue;
-
- assert (AT_NULL == 0);
- assert (AT_IGNORE == 1);
-
- /* Some entries are handled in a special way per platform. */
- if (_dl_procinfo (av->a_type, av->a_un.a_val) == 0)
- continue;
-
- if (idx < sizeof (auxvars) / sizeof (auxvars[0])
- && auxvars[idx].form != unknown)
- {
- const char *val = (char *) av->a_un.a_val;
-
- if (__builtin_expect (auxvars[idx].form, dec) == dec)
- val = _itoa ((unsigned long int) av->a_un.a_val,
- buf + sizeof buf - 1, 10, 0);
- else if (__builtin_expect (auxvars[idx].form, hex) == hex)
- val = _itoa ((unsigned long int) av->a_un.a_val,
- buf + sizeof buf - 1, 16, 0);
-
- _dl_printf ("AT_%s%s\n", auxvars[idx].label, val);
-
- continue;
- }
-
- /* Unknown value: print a generic line. */
- char buf2[17];
- buf2[sizeof (buf2) - 1] = '\0';
- const char *val2 = _itoa ((unsigned long int) av->a_un.a_val,
- buf2 + sizeof buf2 - 1, 16, 0);
- const char *val = _itoa ((unsigned long int) av->a_type,
- buf + sizeof buf - 1, 16, 0);
- _dl_printf ("AT_??? (0x%s): 0x%s\n", val, val2);
- }
-}
-
-#endif
+#error dl-sysdep support missing.
diff --git a/sysdeps/unix/sysv/linux/dl-sysdep.c b/sysdeps/unix/sysv/linux/dl-sysdep.c
index 66ba489cd3..4f60cecf98 100644
--- a/sysdeps/unix/sysv/linux/dl-sysdep.c
+++ b/sysdeps/unix/sysv/linux/dl-sysdep.c
@@ -16,29 +16,352 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-/* Linux needs some special initialization, but otherwise uses
- the generic dynamic linker system interface code. */
-
-#include <string.h>
+#include <_itoa.h>
+#include <assert.h>
+#include <dl-auxv.h>
+#include <dl-hwcap-check.h>
+#include <dl-osinfo.h>
+#include <dl-procinfo.h>
+#include <dl-tunables.h>
+#include <elf.h>
+#include <entry.h>
+#include <errno.h>
#include <fcntl.h>
-#include <unistd.h>
-#include <sys/param.h>
-#include <sys/utsname.h>
+#include <fpu_control.h>
#include <ldsodefs.h>
+#include <libc-internal.h>
+#include <libintl.h>
#include <not-cancel.h>
+#include <stdlib.h>
+#include <string.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/utsname.h>
+#include <tls.h>
+#include <unistd.h>
+
+#include <dl-machine.h>
#ifdef SHARED
-# define DL_SYSDEP_INIT frob_brk ()
+extern char **_environ attribute_hidden;
+extern char _end[] attribute_hidden;
+
+/* Protect SUID program against misuse of file descriptors. */
+extern void __libc_check_standard_fds (void);
-static inline void
-frob_brk (void)
+int __libc_enable_secure attribute_relro = 0;
+rtld_hidden_data_def (__libc_enable_secure)
+/* This variable contains the lowest stack address ever used. */
+void *__libc_stack_end attribute_relro = NULL;
+rtld_hidden_data_def(__libc_stack_end)
+void *_dl_random attribute_relro = NULL;
+
+#ifndef DL_FIND_ARG_COMPONENTS
+# define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp) \
+ do { \
+ void **_tmp; \
+ (argc) = *(long int *) cookie; \
+ (argv) = (char **) ((long int *) cookie + 1); \
+ (envp) = (argv) + (argc) + 1; \
+ for (_tmp = (void **) (envp); *_tmp; ++_tmp) \
+ continue; \
+ (auxp) = (void *) ++_tmp; \
+ } while (0)
+#endif
+
+#ifndef DL_STACK_END
+# define DL_STACK_END(cookie) ((void *) (cookie))
+#endif
+
+ElfW(Addr)
+_dl_sysdep_start (void **start_argptr,
+ void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
+ ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv))
{
+ const ElfW(Phdr) *phdr = NULL;
+ ElfW(Word) phnum = 0;
+ ElfW(Addr) user_entry;
+ ElfW(auxv_t) *av;
+#ifdef HAVE_AUX_SECURE
+# define set_seen(tag) (tag) /* Evaluate for the side effects. */
+# define set_seen_secure() ((void) 0)
+#else
+ uid_t uid = 0;
+ gid_t gid = 0;
+ unsigned int seen = 0;
+# define set_seen_secure() (seen = -1)
+# ifdef HAVE_AUX_XID
+# define set_seen(tag) (tag) /* Evaluate for the side effects. */
+# else
+# define M(type) (1 << (type))
+# define set_seen(tag) seen |= M ((tag)->a_type)
+# endif
+#endif
+#ifdef NEED_DL_SYSINFO
+ uintptr_t new_sysinfo = 0;
+#endif
+
+ __libc_stack_end = DL_STACK_END (start_argptr);
+ DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, _dl_argv, _environ,
+ GLRO(dl_auxv));
+
+ user_entry = (ElfW(Addr)) ENTRY_POINT;
+ GLRO(dl_platform) = NULL; /* Default to nothing known about the platform. */
+
+ /* NB: Default to a constant CONSTANT_MINSIGSTKSZ. */
+ _Static_assert (__builtin_constant_p (CONSTANT_MINSIGSTKSZ),
+ "CONSTANT_MINSIGSTKSZ is constant");
+ GLRO(dl_minsigstacksize) = CONSTANT_MINSIGSTKSZ;
+
+ for (av = GLRO(dl_auxv); av->a_type != AT_NULL; set_seen (av++))
+ switch (av->a_type)
+ {
+ case AT_PHDR:
+ phdr = (void *) av->a_un.a_val;
+ break;
+ case AT_PHNUM:
+ phnum = av->a_un.a_val;
+ break;
+ case AT_PAGESZ:
+ GLRO(dl_pagesize) = av->a_un.a_val;
+ break;
+ case AT_ENTRY:
+ user_entry = av->a_un.a_val;
+ break;
+#ifndef HAVE_AUX_SECURE
+ case AT_UID:
+ case AT_EUID:
+ uid ^= av->a_un.a_val;
+ break;
+ case AT_GID:
+ case AT_EGID:
+ gid ^= av->a_un.a_val;
+ break;
+#endif
+ case AT_SECURE:
+#ifndef HAVE_AUX_SECURE
+ seen = -1;
+#endif
+ __libc_enable_secure = av->a_un.a_val;
+ break;
+ case AT_PLATFORM:
+ GLRO(dl_platform) = (void *) av->a_un.a_val;
+ break;
+ case AT_HWCAP:
+ GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
+ break;
+ case AT_HWCAP2:
+ GLRO(dl_hwcap2) = (unsigned long int) av->a_un.a_val;
+ break;
+ case AT_CLKTCK:
+ GLRO(dl_clktck) = av->a_un.a_val;
+ break;
+ case AT_FPUCW:
+ GLRO(dl_fpu_control) = av->a_un.a_val;
+ break;
+#ifdef NEED_DL_SYSINFO
+ case AT_SYSINFO:
+ new_sysinfo = av->a_un.a_val;
+ break;
+#endif
+#ifdef NEED_DL_SYSINFO_DSO
+ case AT_SYSINFO_EHDR:
+ GLRO(dl_sysinfo_dso) = (void *) av->a_un.a_val;
+ break;
+#endif
+ case AT_RANDOM:
+ _dl_random = (void *) av->a_un.a_val;
+ break;
+ case AT_MINSIGSTKSZ:
+ GLRO(dl_minsigstacksize) = av->a_un.a_val;
+ break;
+ DL_PLATFORM_AUXV
+ }
+
+ dl_hwcap_check ();
+
+#ifndef HAVE_AUX_SECURE
+ if (seen != -1)
+ {
+ /* Fill in the values we have not gotten from the kernel through the
+ auxiliary vector. */
+# ifndef HAVE_AUX_XID
+# define SEE(UID, var, uid) \
+ if ((seen & M (AT_##UID)) == 0) var ^= __get##uid ()
+ SEE (UID, uid, uid);
+ SEE (EUID, uid, euid);
+ SEE (GID, gid, gid);
+ SEE (EGID, gid, egid);
+# endif
+
+ /* If one of the two pairs of IDs does not match this is a setuid
+ or setgid run. */
+ __libc_enable_secure = uid | gid;
+ }
+#endif
+
+#ifndef HAVE_AUX_PAGESIZE
+ if (GLRO(dl_pagesize) == 0)
+ GLRO(dl_pagesize) = __getpagesize ();
+#endif
+
+#ifdef NEED_DL_SYSINFO
+ if (new_sysinfo != 0)
+ {
+# ifdef NEED_DL_SYSINFO_DSO
+ /* Only set the sysinfo value if we also have the vsyscall DSO. */
+ if (GLRO(dl_sysinfo_dso) != 0)
+# endif
+ GLRO(dl_sysinfo) = new_sysinfo;
+ }
+#endif
+
+ __tunables_init (_environ);
+
+ /* Initialize DSO sorting algorithm after tunables. */
+ _dl_sort_maps_init ();
+
__brk (0); /* Initialize the break. */
-}
-# include <elf/dl-sysdep.c>
+#ifdef DL_PLATFORM_INIT
+ DL_PLATFORM_INIT;
#endif
+ /* Determine the length of the platform name. */
+ if (GLRO(dl_platform) != NULL)
+ GLRO(dl_platformlen) = strlen (GLRO(dl_platform));
+
+ if (__sbrk (0) == _end)
+ /* The dynamic linker was run as a program, and so the initial break
+ starts just after our bss, at &_end. The malloc in dl-minimal.c
+ will consume the rest of this page, so tell the kernel to move the
+ break up that far. When the user program examines its break, it
+ will see this new value and not clobber our data. */
+ __sbrk (GLRO(dl_pagesize)
+ - ((_end - (char *) 0) & (GLRO(dl_pagesize) - 1)));
+
+ /* If this is a SUID program we make sure that FDs 0, 1, and 2 are
+ allocated. If necessary we are doing it ourself. If it is not
+ possible we stop the program. */
+ if (__builtin_expect (__libc_enable_secure, 0))
+ __libc_check_standard_fds ();
+
+ (*dl_main) (phdr, phnum, &user_entry, GLRO(dl_auxv));
+ return user_entry;
+}
+
+void
+_dl_sysdep_start_cleanup (void)
+{
+}
+
+void
+_dl_show_auxv (void)
+{
+ char buf[64];
+ ElfW(auxv_t) *av;
+
+ /* Terminate string. */
+ buf[63] = '\0';
+
+ /* The following code assumes that the AT_* values are encoded
+ starting from 0 with AT_NULL, 1 for AT_IGNORE, and all other values
+ close by (otherwise the array will be too large). In case we have
+ to support a platform where these requirements are not fulfilled
+ some alternative implementation has to be used. */
+ for (av = GLRO(dl_auxv); av->a_type != AT_NULL; ++av)
+ {
+ static const struct
+ {
+ const char label[22];
+ enum { unknown = 0, dec, hex, str, ignore } form : 8;
+ } auxvars[] =
+ {
+ [AT_EXECFD - 2] = { "EXECFD: ", dec },
+ [AT_EXECFN - 2] = { "EXECFN: ", str },
+ [AT_PHDR - 2] = { "PHDR: 0x", hex },
+ [AT_PHENT - 2] = { "PHENT: ", dec },
+ [AT_PHNUM - 2] = { "PHNUM: ", dec },
+ [AT_PAGESZ - 2] = { "PAGESZ: ", dec },
+ [AT_BASE - 2] = { "BASE: 0x", hex },
+ [AT_FLAGS - 2] = { "FLAGS: 0x", hex },
+ [AT_ENTRY - 2] = { "ENTRY: 0x", hex },
+ [AT_NOTELF - 2] = { "NOTELF: ", hex },
+ [AT_UID - 2] = { "UID: ", dec },
+ [AT_EUID - 2] = { "EUID: ", dec },
+ [AT_GID - 2] = { "GID: ", dec },
+ [AT_EGID - 2] = { "EGID: ", dec },
+ [AT_PLATFORM - 2] = { "PLATFORM: ", str },
+ [AT_HWCAP - 2] = { "HWCAP: ", hex },
+ [AT_CLKTCK - 2] = { "CLKTCK: ", dec },
+ [AT_FPUCW - 2] = { "FPUCW: ", hex },
+ [AT_DCACHEBSIZE - 2] = { "DCACHEBSIZE: 0x", hex },
+ [AT_ICACHEBSIZE - 2] = { "ICACHEBSIZE: 0x", hex },
+ [AT_UCACHEBSIZE - 2] = { "UCACHEBSIZE: 0x", hex },
+ [AT_IGNOREPPC - 2] = { "IGNOREPPC", ignore },
+ [AT_SECURE - 2] = { "SECURE: ", dec },
+ [AT_BASE_PLATFORM - 2] = { "BASE_PLATFORM: ", str },
+ [AT_SYSINFO - 2] = { "SYSINFO: 0x", hex },
+ [AT_SYSINFO_EHDR - 2] = { "SYSINFO_EHDR: 0x", hex },
+ [AT_RANDOM - 2] = { "RANDOM: 0x", hex },
+ [AT_HWCAP2 - 2] = { "HWCAP2: 0x", hex },
+ [AT_MINSIGSTKSZ - 2] = { "MINSIGSTKSZ: ", dec },
+ [AT_L1I_CACHESIZE - 2] = { "L1I_CACHESIZE: ", dec },
+ [AT_L1I_CACHEGEOMETRY - 2] = { "L1I_CACHEGEOMETRY: 0x", hex },
+ [AT_L1D_CACHESIZE - 2] = { "L1D_CACHESIZE: ", dec },
+ [AT_L1D_CACHEGEOMETRY - 2] = { "L1D_CACHEGEOMETRY: 0x", hex },
+ [AT_L2_CACHESIZE - 2] = { "L2_CACHESIZE: ", dec },
+ [AT_L2_CACHEGEOMETRY - 2] = { "L2_CACHEGEOMETRY: 0x", hex },
+ [AT_L3_CACHESIZE - 2] = { "L3_CACHESIZE: ", dec },
+ [AT_L3_CACHEGEOMETRY - 2] = { "L3_CACHEGEOMETRY: 0x", hex },
+ };
+ unsigned int idx = (unsigned int) (av->a_type - 2);
+
+ if ((unsigned int) av->a_type < 2u
+ || (idx < sizeof (auxvars) / sizeof (auxvars[0])
+ && auxvars[idx].form == ignore))
+ continue;
+
+ assert (AT_NULL == 0);
+ assert (AT_IGNORE == 1);
+
+ /* Some entries are handled in a special way per platform. */
+ if (_dl_procinfo (av->a_type, av->a_un.a_val) == 0)
+ continue;
+
+ if (idx < sizeof (auxvars) / sizeof (auxvars[0])
+ && auxvars[idx].form != unknown)
+ {
+ const char *val = (char *) av->a_un.a_val;
+
+ if (__builtin_expect (auxvars[idx].form, dec) == dec)
+ val = _itoa ((unsigned long int) av->a_un.a_val,
+ buf + sizeof buf - 1, 10, 0);
+ else if (__builtin_expect (auxvars[idx].form, hex) == hex)
+ val = _itoa ((unsigned long int) av->a_un.a_val,
+ buf + sizeof buf - 1, 16, 0);
+
+ _dl_printf ("AT_%s%s\n", auxvars[idx].label, val);
+
+ continue;
+ }
+
+ /* Unknown value: print a generic line. */
+ char buf2[17];
+ buf2[sizeof (buf2) - 1] = '\0';
+ const char *val2 = _itoa ((unsigned long int) av->a_un.a_val,
+ buf2 + sizeof buf2 - 1, 16, 0);
+ const char *val = _itoa ((unsigned long int) av->a_type,
+ buf + sizeof buf - 1, 16, 0);
+ _dl_printf ("AT_??? (0x%s): 0x%s\n", val, val2);
+ }
+}
+
+#endif /* SHARED */
+
int
attribute_hidden
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/5] Linux: Remove HAVE_AUX_SECURE, HAVE_AUX_XID, HAVE_AUX_PAGESIZE
2022-01-11 18:43 [PATCH 0/5] Linux: Auxiliary vector parsing cleanups Florian Weimer
2022-01-11 18:43 ` [PATCH 1/5] elf: Merge dl-sysdep.c into the Linux version Florian Weimer
@ 2022-01-11 18:43 ` Florian Weimer
2022-01-11 18:43 ` [PATCH 3/5] Linux: Remove DL_FIND_ARG_COMPONENTS Florian Weimer
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Florian Weimer @ 2022-01-11 18:43 UTC (permalink / raw)
To: libc-alpha
They are always defined.
---
sysdeps/unix/sysv/linux/dl-sysdep.c | 55 +----------------------------
sysdeps/unix/sysv/linux/ldsodefs.h | 12 -------
2 files changed, 1 insertion(+), 66 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/dl-sysdep.c b/sysdeps/unix/sysv/linux/dl-sysdep.c
index 4f60cecf98..72aa109f2f 100644
--- a/sysdeps/unix/sysv/linux/dl-sysdep.c
+++ b/sysdeps/unix/sysv/linux/dl-sysdep.c
@@ -85,21 +85,6 @@ _dl_sysdep_start (void **start_argptr,
ElfW(Word) phnum = 0;
ElfW(Addr) user_entry;
ElfW(auxv_t) *av;
-#ifdef HAVE_AUX_SECURE
-# define set_seen(tag) (tag) /* Evaluate for the side effects. */
-# define set_seen_secure() ((void) 0)
-#else
- uid_t uid = 0;
- gid_t gid = 0;
- unsigned int seen = 0;
-# define set_seen_secure() (seen = -1)
-# ifdef HAVE_AUX_XID
-# define set_seen(tag) (tag) /* Evaluate for the side effects. */
-# else
-# define M(type) (1 << (type))
-# define set_seen(tag) seen |= M ((tag)->a_type)
-# endif
-#endif
#ifdef NEED_DL_SYSINFO
uintptr_t new_sysinfo = 0;
#endif
@@ -116,7 +101,7 @@ _dl_sysdep_start (void **start_argptr,
"CONSTANT_MINSIGSTKSZ is constant");
GLRO(dl_minsigstacksize) = CONSTANT_MINSIGSTKSZ;
- for (av = GLRO(dl_auxv); av->a_type != AT_NULL; set_seen (av++))
+ for (av = GLRO(dl_auxv); av->a_type != AT_NULL; av++)
switch (av->a_type)
{
case AT_PHDR:
@@ -131,20 +116,7 @@ _dl_sysdep_start (void **start_argptr,
case AT_ENTRY:
user_entry = av->a_un.a_val;
break;
-#ifndef HAVE_AUX_SECURE
- case AT_UID:
- case AT_EUID:
- uid ^= av->a_un.a_val;
- break;
- case AT_GID:
- case AT_EGID:
- gid ^= av->a_un.a_val;
- break;
-#endif
case AT_SECURE:
-#ifndef HAVE_AUX_SECURE
- seen = -1;
-#endif
__libc_enable_secure = av->a_un.a_val;
break;
case AT_PLATFORM:
@@ -183,31 +155,6 @@ _dl_sysdep_start (void **start_argptr,
dl_hwcap_check ();
-#ifndef HAVE_AUX_SECURE
- if (seen != -1)
- {
- /* Fill in the values we have not gotten from the kernel through the
- auxiliary vector. */
-# ifndef HAVE_AUX_XID
-# define SEE(UID, var, uid) \
- if ((seen & M (AT_##UID)) == 0) var ^= __get##uid ()
- SEE (UID, uid, uid);
- SEE (EUID, uid, euid);
- SEE (GID, gid, gid);
- SEE (EGID, gid, egid);
-# endif
-
- /* If one of the two pairs of IDs does not match this is a setuid
- or setgid run. */
- __libc_enable_secure = uid | gid;
- }
-#endif
-
-#ifndef HAVE_AUX_PAGESIZE
- if (GLRO(dl_pagesize) == 0)
- GLRO(dl_pagesize) = __getpagesize ();
-#endif
-
#ifdef NEED_DL_SYSINFO
if (new_sysinfo != 0)
{
diff --git a/sysdeps/unix/sysv/linux/ldsodefs.h b/sysdeps/unix/sysv/linux/ldsodefs.h
index 011756ddc1..af108991f0 100644
--- a/sysdeps/unix/sysv/linux/ldsodefs.h
+++ b/sysdeps/unix/sysv/linux/ldsodefs.h
@@ -24,16 +24,4 @@
/* Get the real definitions. */
#include_next <ldsodefs.h>
-/* We can assume that the kernel always provides the AT_UID, AT_EUID,
- AT_GID, and AT_EGID values in the auxiliary vector from 2.4.0 or so on. */
-#define HAVE_AUX_XID
-
-/* We can assume that the kernel always provides the AT_SECURE value
- in the auxiliary vector from 2.5.74 or so on. */
-#define HAVE_AUX_SECURE
-
-/* Starting with one of the 2.4.0 pre-releases the Linux kernel passes
- up the page size information. */
-#define HAVE_AUX_PAGESIZE
-
#endif /* ldsodefs.h */
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 3/5] Linux: Remove DL_FIND_ARG_COMPONENTS
2022-01-11 18:43 [PATCH 0/5] Linux: Auxiliary vector parsing cleanups Florian Weimer
2022-01-11 18:43 ` [PATCH 1/5] elf: Merge dl-sysdep.c into the Linux version Florian Weimer
2022-01-11 18:43 ` [PATCH 2/5] Linux: Remove HAVE_AUX_SECURE, HAVE_AUX_XID, HAVE_AUX_PAGESIZE Florian Weimer
@ 2022-01-11 18:43 ` Florian Weimer
2022-01-11 18:44 ` [PATCH 4/5] Linux: Assume that NEED_DL_SYSINFO_DSO is always defined Florian Weimer
2022-01-11 18:44 ` [PATCH 5/5] Linux: Consolidate auxiliary vector parsing Florian Weimer
4 siblings, 0 replies; 6+ messages in thread
From: Florian Weimer @ 2022-01-11 18:43 UTC (permalink / raw)
To: libc-alpha
The generic definition is always used since the Native Client
port has been removed.
---
sysdeps/unix/sysv/linux/dl-sysdep.c | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/dl-sysdep.c b/sysdeps/unix/sysv/linux/dl-sysdep.c
index 72aa109f2f..a13e0ea7ad 100644
--- a/sysdeps/unix/sysv/linux/dl-sysdep.c
+++ b/sysdeps/unix/sysv/linux/dl-sysdep.c
@@ -59,19 +59,6 @@ void *__libc_stack_end attribute_relro = NULL;
rtld_hidden_data_def(__libc_stack_end)
void *_dl_random attribute_relro = NULL;
-#ifndef DL_FIND_ARG_COMPONENTS
-# define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp) \
- do { \
- void **_tmp; \
- (argc) = *(long int *) cookie; \
- (argv) = (char **) ((long int *) cookie + 1); \
- (envp) = (argv) + (argc) + 1; \
- for (_tmp = (void **) (envp); *_tmp; ++_tmp) \
- continue; \
- (auxp) = (void *) ++_tmp; \
- } while (0)
-#endif
-
#ifndef DL_STACK_END
# define DL_STACK_END(cookie) ((void *) (cookie))
#endif
@@ -90,8 +77,16 @@ _dl_sysdep_start (void **start_argptr,
#endif
__libc_stack_end = DL_STACK_END (start_argptr);
- DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, _dl_argv, _environ,
- GLRO(dl_auxv));
+ _dl_argc = (intptr_t) *start_argptr;
+ _dl_argv = (char **) (start_argptr + 1); /* Necessary aliasing violation. */
+ _environ = _dl_argv + _dl_argc + 1;
+ for (char **tmp = _environ + 1; ; ++tmp)
+ if (*tmp == NULL)
+ {
+ /* Another necessary aliasing violation. */
+ GLRO(dl_auxv) = (ElfW(auxv_t) *) (tmp + 1);
+ break;
+ }
user_entry = (ElfW(Addr)) ENTRY_POINT;
GLRO(dl_platform) = NULL; /* Default to nothing known about the platform. */
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 4/5] Linux: Assume that NEED_DL_SYSINFO_DSO is always defined
2022-01-11 18:43 [PATCH 0/5] Linux: Auxiliary vector parsing cleanups Florian Weimer
` (2 preceding siblings ...)
2022-01-11 18:43 ` [PATCH 3/5] Linux: Remove DL_FIND_ARG_COMPONENTS Florian Weimer
@ 2022-01-11 18:44 ` Florian Weimer
2022-01-11 18:44 ` [PATCH 5/5] Linux: Consolidate auxiliary vector parsing Florian Weimer
4 siblings, 0 replies; 6+ messages in thread
From: Florian Weimer @ 2022-01-11 18:44 UTC (permalink / raw)
To: libc-alpha
The definition itself is still needed for generic code.
---
sysdeps/unix/sysv/linux/dl-sysdep.c | 8 ++------
sysdeps/unix/sysv/linux/m68k/sysdep.h | 4 +---
2 files changed, 3 insertions(+), 9 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/dl-sysdep.c b/sysdeps/unix/sysv/linux/dl-sysdep.c
index a13e0ea7ad..2bda76b820 100644
--- a/sysdeps/unix/sysv/linux/dl-sysdep.c
+++ b/sysdeps/unix/sysv/linux/dl-sysdep.c
@@ -134,11 +134,9 @@ _dl_sysdep_start (void **start_argptr,
new_sysinfo = av->a_un.a_val;
break;
#endif
-#ifdef NEED_DL_SYSINFO_DSO
case AT_SYSINFO_EHDR:
GLRO(dl_sysinfo_dso) = (void *) av->a_un.a_val;
break;
-#endif
case AT_RANDOM:
_dl_random = (void *) av->a_un.a_val;
break;
@@ -153,10 +151,8 @@ _dl_sysdep_start (void **start_argptr,
#ifdef NEED_DL_SYSINFO
if (new_sysinfo != 0)
{
-# ifdef NEED_DL_SYSINFO_DSO
/* Only set the sysinfo value if we also have the vsyscall DSO. */
if (GLRO(dl_sysinfo_dso) != 0)
-# endif
GLRO(dl_sysinfo) = new_sysinfo;
}
#endif
@@ -309,7 +305,7 @@ int
attribute_hidden
_dl_discover_osversion (void)
{
-#if defined NEED_DL_SYSINFO_DSO && defined SHARED
+#ifdef SHARED
if (GLRO(dl_sysinfo_map) != NULL)
{
/* If the kernel-supplied DSO contains a note indicating the kernel's
@@ -340,7 +336,7 @@ _dl_discover_osversion (void)
}
}
}
-#endif
+#endif /* SHARED */
char bufmem[64];
char *buf = bufmem;
diff --git a/sysdeps/unix/sysv/linux/m68k/sysdep.h b/sysdeps/unix/sysv/linux/m68k/sysdep.h
index 628e1be835..d87892a377 100644
--- a/sysdeps/unix/sysv/linux/m68k/sysdep.h
+++ b/sysdeps/unix/sysv/linux/m68k/sysdep.h
@@ -299,8 +299,6 @@ SYSCALL_ERROR_LABEL: \
#define PTR_MANGLE(var) (void) (var)
#define PTR_DEMANGLE(var) (void) (var)
-#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
/* M68K needs system-supplied DSO to access TLS helpers
even when statically linked. */
-# define NEED_STATIC_SYSINFO_DSO 1
-#endif
+#define NEED_STATIC_SYSINFO_DSO 1
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 5/5] Linux: Consolidate auxiliary vector parsing
2022-01-11 18:43 [PATCH 0/5] Linux: Auxiliary vector parsing cleanups Florian Weimer
` (3 preceding siblings ...)
2022-01-11 18:44 ` [PATCH 4/5] Linux: Assume that NEED_DL_SYSINFO_DSO is always defined Florian Weimer
@ 2022-01-11 18:44 ` Florian Weimer
4 siblings, 0 replies; 6+ messages in thread
From: Florian Weimer @ 2022-01-11 18:44 UTC (permalink / raw)
To: libc-alpha
And optimize it slightly.
The large switch statement in _dl_sysdep_start can be replaced with
a large array. This reduces source code and binary size. On
i686-linux-gnu:
Before:
text data bss dec hex filename
7791 12 0 7803 1e7b elf/dl-sysdep.os
After:
text data bss dec hex filename
7135 12 0 7147 1beb elf/dl-sysdep.os
---
elf/dl-support.c | 80 +------------
sysdeps/unix/sysv/linux/alpha/dl-auxv.h | 18 +--
sysdeps/unix/sysv/linux/dl-parse_auxv.h | 61 ++++++++++
sysdeps/unix/sysv/linux/dl-sysdep.c | 111 ++++++-------------
sysdeps/unix/sysv/linux/powerpc/dl-auxv.h | 14 +--
sysdeps/unix/sysv/linux/powerpc/dl-support.c | 4 +
6 files changed, 107 insertions(+), 181 deletions(-)
create mode 100644 sysdeps/unix/sysv/linux/dl-parse_auxv.h
create mode 100644 sysdeps/unix/sysv/linux/powerpc/dl-support.c
diff --git a/elf/dl-support.c b/elf/dl-support.c
index fb64765537..0fff62064a 100644
--- a/elf/dl-support.c
+++ b/elf/dl-support.c
@@ -241,93 +241,21 @@ __rtld_lock_define_initialized_recursive (, _dl_load_tls_lock)
#ifdef HAVE_AUX_VECTOR
+#include <dl-parse_auxv.h>
+
int _dl_clktck;
void
_dl_aux_init (ElfW(auxv_t) *av)
{
- int seen = 0;
- uid_t uid = 0;
- gid_t gid = 0;
-
#ifdef NEED_DL_SYSINFO
/* NB: Avoid RELATIVE relocation in static PIE. */
GL(dl_sysinfo) = DL_SYSINFO_DEFAULT;
#endif
_dl_auxv = av;
- for (; av->a_type != AT_NULL; ++av)
- switch (av->a_type)
- {
- case AT_PAGESZ:
- if (av->a_un.a_val != 0)
- GLRO(dl_pagesize) = av->a_un.a_val;
- break;
- case AT_CLKTCK:
- GLRO(dl_clktck) = av->a_un.a_val;
- break;
- case AT_PHDR:
- GL(dl_phdr) = (const void *) av->a_un.a_val;
- break;
- case AT_PHNUM:
- GL(dl_phnum) = av->a_un.a_val;
- break;
- case AT_PLATFORM:
- GLRO(dl_platform) = (void *) av->a_un.a_val;
- break;
- case AT_HWCAP:
- GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
- break;
- case AT_HWCAP2:
- GLRO(dl_hwcap2) = (unsigned long int) av->a_un.a_val;
- break;
- case AT_FPUCW:
- GLRO(dl_fpu_control) = av->a_un.a_val;
- break;
-#ifdef NEED_DL_SYSINFO
- case AT_SYSINFO:
- GL(dl_sysinfo) = av->a_un.a_val;
- break;
-#endif
-#ifdef NEED_DL_SYSINFO_DSO
- case AT_SYSINFO_EHDR:
- GL(dl_sysinfo_dso) = (void *) av->a_un.a_val;
- break;
-#endif
- case AT_UID:
- uid ^= av->a_un.a_val;
- seen |= 1;
- break;
- case AT_EUID:
- uid ^= av->a_un.a_val;
- seen |= 2;
- break;
- case AT_GID:
- gid ^= av->a_un.a_val;
- seen |= 4;
- break;
- case AT_EGID:
- gid ^= av->a_un.a_val;
- seen |= 8;
- break;
- case AT_SECURE:
- seen = -1;
- __libc_enable_secure = av->a_un.a_val;
- __libc_enable_secure_decided = 1;
- break;
- case AT_RANDOM:
- _dl_random = (void *) av->a_un.a_val;
- break;
- case AT_MINSIGSTKSZ:
- _dl_minsigstacksize = av->a_un.a_val;
- break;
- DL_PLATFORM_AUXV
- }
- if (seen == 0xf)
- {
- __libc_enable_secure = uid != 0 || gid != 0;
- __libc_enable_secure_decided = 1;
- }
+ dl_parse_auxv_t auxv_values = { 0, };
+ _dl_parse_auxv (av, auxv_values);
}
#endif
diff --git a/sysdeps/unix/sysv/linux/alpha/dl-auxv.h b/sysdeps/unix/sysv/linux/alpha/dl-auxv.h
index 81d90da095..fcec743239 100644
--- a/sysdeps/unix/sysv/linux/alpha/dl-auxv.h
+++ b/sysdeps/unix/sysv/linux/alpha/dl-auxv.h
@@ -20,16 +20,8 @@
extern long __libc_alpha_cache_shape[4];
-#define DL_PLATFORM_AUXV \
- case AT_L1I_CACHESHAPE: \
- __libc_alpha_cache_shape[0] = av->a_un.a_val; \
- break; \
- case AT_L1D_CACHESHAPE: \
- __libc_alpha_cache_shape[1] = av->a_un.a_val; \
- break; \
- case AT_L2_CACHESHAPE: \
- __libc_alpha_cache_shape[2] = av->a_un.a_val; \
- break; \
- case AT_L3_CACHESHAPE: \
- __libc_alpha_cache_shape[3] = av->a_un.a_val; \
- break;
+#define DL_PLATFORM_AUXV \
+ __libc_alpha_cache_shape[0] = auxv_values[AT_L1I_CACHESHAPE]; \
+ __libc_alpha_cache_shape[1] = auxv_values[AT_L1D_CACHESHAPE]; \
+ __libc_alpha_cache_shape[2] = auxv_values[AT_L2_CACHESHAPE]; \
+ __libc_alpha_cache_shape[3] = auxv_values[AT_L3_CACHESHAPE];
diff --git a/sysdeps/unix/sysv/linux/dl-parse_auxv.h b/sysdeps/unix/sysv/linux/dl-parse_auxv.h
new file mode 100644
index 0000000000..f450c6c5ce
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/dl-parse_auxv.h
@@ -0,0 +1,61 @@
+/* Parse the Linux auxiliary vector.
+ Copyright (C) 1995-2022 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; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <elf.h>
+#include <entry.h>
+#include <fpu_control.h>
+#include <ldsodefs.h>
+#include <link.h>
+
+typedef ElfW(Addr) dl_parse_auxv_t[AT_MINSIGSTKSZ + 1];
+
+/* Copy the auxiliary vector into AUX_VALUES and set up GLRO
+ variables. */
+static inline
+void _dl_parse_auxv (ElfW(auxv_t) *av, dl_parse_auxv_t auxv_values)
+{
+ auxv_values[AT_ENTRY] = (ElfW(Addr)) ENTRY_POINT;
+ auxv_values[AT_PAGESZ] = EXEC_PAGESIZE;
+ auxv_values[AT_FPUCW] = _FPU_DEFAULT;
+
+ /* NB: Default to a constant CONSTANT_MINSIGSTKSZ. */
+ _Static_assert (__builtin_constant_p (CONSTANT_MINSIGSTKSZ),
+ "CONSTANT_MINSIGSTKSZ is constant");
+ auxv_values[AT_MINSIGSTKSZ] = CONSTANT_MINSIGSTKSZ;
+
+ for (; av->a_type != AT_NULL; av++)
+ if (av->a_type <= AT_MINSIGSTKSZ)
+ auxv_values[av->a_type] = av->a_un.a_val;
+
+ GLRO(dl_pagesize) = auxv_values[AT_PAGESZ];
+ __libc_enable_secure = auxv_values[AT_SECURE];
+ GLRO(dl_platform) = (void *) auxv_values[AT_PLATFORM];
+ GLRO(dl_hwcap) = auxv_values[AT_HWCAP];
+ GLRO(dl_hwcap2) = auxv_values[AT_HWCAP2];
+ GLRO(dl_clktck) = auxv_values[AT_CLKTCK];
+ GLRO(dl_fpu_control) = auxv_values[AT_FPUCW];
+ _dl_random = (void *) auxv_values[AT_RANDOM];
+ GLRO(dl_minsigstacksize) = auxv_values[AT_MINSIGSTKSZ];
+ GLRO(dl_sysinfo_dso) = (void *) auxv_values[AT_SYSINFO_EHDR];
+#ifdef NEED_DL_SYSINFO
+ if (GLRO(dl_sysinfo_dso) != NULL)
+ GLRO(dl_sysinfo) = auxv_values[AT_SYSINFO];
+#endif
+
+ DL_PLATFORM_AUXV
+}
diff --git a/sysdeps/unix/sysv/linux/dl-sysdep.c b/sysdeps/unix/sysv/linux/dl-sysdep.c
index 2bda76b820..71cf1968b5 100644
--- a/sysdeps/unix/sysv/linux/dl-sysdep.c
+++ b/sysdeps/unix/sysv/linux/dl-sysdep.c
@@ -21,13 +21,12 @@
#include <dl-auxv.h>
#include <dl-hwcap-check.h>
#include <dl-osinfo.h>
+#include <dl-parse_auxv.h>
#include <dl-procinfo.h>
#include <dl-tunables.h>
#include <elf.h>
-#include <entry.h>
#include <errno.h>
#include <fcntl.h>
-#include <fpu_control.h>
#include <ldsodefs.h>
#include <libc-internal.h>
#include <libintl.h>
@@ -63,24 +62,24 @@ void *_dl_random attribute_relro = NULL;
# define DL_STACK_END(cookie) ((void *) (cookie))
#endif
-ElfW(Addr)
-_dl_sysdep_start (void **start_argptr,
- void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
- ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv))
+/* Arguments passed to dl_main. */
+struct dl_main_arguments
{
- const ElfW(Phdr) *phdr = NULL;
- ElfW(Word) phnum = 0;
+ const ElfW(Phdr) *phdr;
+ ElfW(Word) phnum;
ElfW(Addr) user_entry;
- ElfW(auxv_t) *av;
-#ifdef NEED_DL_SYSINFO
- uintptr_t new_sysinfo = 0;
-#endif
+};
- __libc_stack_end = DL_STACK_END (start_argptr);
+/* Separate function, so that dl_main can be called without the large
+ array on the stack. */
+static void
+_dl_sysdep_parse_arguments (void **start_argptr,
+ struct dl_main_arguments *args)
+{
_dl_argc = (intptr_t) *start_argptr;
_dl_argv = (char **) (start_argptr + 1); /* Necessary aliasing violation. */
_environ = _dl_argv + _dl_argc + 1;
- for (char **tmp = _environ + 1; ; ++tmp)
+ for (char **tmp = _environ; ; ++tmp)
if (*tmp == NULL)
{
/* Another necessary aliasing violation. */
@@ -88,74 +87,25 @@ _dl_sysdep_start (void **start_argptr,
break;
}
- user_entry = (ElfW(Addr)) ENTRY_POINT;
- GLRO(dl_platform) = NULL; /* Default to nothing known about the platform. */
+ dl_parse_auxv_t auxv_values = { 0, };
+ _dl_parse_auxv (GLRO(dl_auxv), auxv_values);
- /* NB: Default to a constant CONSTANT_MINSIGSTKSZ. */
- _Static_assert (__builtin_constant_p (CONSTANT_MINSIGSTKSZ),
- "CONSTANT_MINSIGSTKSZ is constant");
- GLRO(dl_minsigstacksize) = CONSTANT_MINSIGSTKSZ;
+ args->phdr = (const ElfW(Phdr) *) auxv_values[AT_PHDR];
+ args->phnum = auxv_values[AT_PHNUM];
+ args->user_entry = auxv_values[AT_ENTRY];
+}
- for (av = GLRO(dl_auxv); av->a_type != AT_NULL; av++)
- switch (av->a_type)
- {
- case AT_PHDR:
- phdr = (void *) av->a_un.a_val;
- break;
- case AT_PHNUM:
- phnum = av->a_un.a_val;
- break;
- case AT_PAGESZ:
- GLRO(dl_pagesize) = av->a_un.a_val;
- break;
- case AT_ENTRY:
- user_entry = av->a_un.a_val;
- break;
- case AT_SECURE:
- __libc_enable_secure = av->a_un.a_val;
- break;
- case AT_PLATFORM:
- GLRO(dl_platform) = (void *) av->a_un.a_val;
- break;
- case AT_HWCAP:
- GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
- break;
- case AT_HWCAP2:
- GLRO(dl_hwcap2) = (unsigned long int) av->a_un.a_val;
- break;
- case AT_CLKTCK:
- GLRO(dl_clktck) = av->a_un.a_val;
- break;
- case AT_FPUCW:
- GLRO(dl_fpu_control) = av->a_un.a_val;
- break;
-#ifdef NEED_DL_SYSINFO
- case AT_SYSINFO:
- new_sysinfo = av->a_un.a_val;
- break;
-#endif
- case AT_SYSINFO_EHDR:
- GLRO(dl_sysinfo_dso) = (void *) av->a_un.a_val;
- break;
- case AT_RANDOM:
- _dl_random = (void *) av->a_un.a_val;
- break;
- case AT_MINSIGSTKSZ:
- GLRO(dl_minsigstacksize) = av->a_un.a_val;
- break;
- DL_PLATFORM_AUXV
- }
+ElfW(Addr)
+_dl_sysdep_start (void **start_argptr,
+ void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
+ ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv))
+{
+ __libc_stack_end = DL_STACK_END (start_argptr);
- dl_hwcap_check ();
+ struct dl_main_arguments dl_main_args;
+ _dl_sysdep_parse_arguments (start_argptr, &dl_main_args);
-#ifdef NEED_DL_SYSINFO
- if (new_sysinfo != 0)
- {
- /* Only set the sysinfo value if we also have the vsyscall DSO. */
- if (GLRO(dl_sysinfo_dso) != 0)
- GLRO(dl_sysinfo) = new_sysinfo;
- }
-#endif
+ dl_hwcap_check ();
__tunables_init (_environ);
@@ -187,8 +137,9 @@ _dl_sysdep_start (void **start_argptr,
if (__builtin_expect (__libc_enable_secure, 0))
__libc_check_standard_fds ();
- (*dl_main) (phdr, phnum, &user_entry, GLRO(dl_auxv));
- return user_entry;
+ (*dl_main) (dl_main_args.phdr, dl_main_args.phnum,
+ &dl_main_args.user_entry, GLRO(dl_auxv));
+ return dl_main_args.user_entry;
}
void
diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h b/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
index 594371940a..ce2281cf11 100644
--- a/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
+++ b/sysdeps/unix/sysv/linux/powerpc/dl-auxv.h
@@ -16,15 +16,5 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
-#include <ldsodefs.h>
-
-#if IS_IN (libc) && !defined SHARED
-int GLRO(dl_cache_line_size);
-#endif
-
-/* Scan the Aux Vector for the "Data Cache Block Size" entry and assign it
- to dl_cache_line_size. */
-#define DL_PLATFORM_AUXV \
- case AT_DCACHEBSIZE: \
- GLRO(dl_cache_line_size) = av->a_un.a_val; \
- break;
+#define DL_PLATFORM_AUXV \
+ GLRO(dl_cache_line_size) = auxv_values[AT_DCACHEBSIZE];
diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-support.c b/sysdeps/unix/sysv/linux/powerpc/dl-support.c
new file mode 100644
index 0000000000..abe68a7049
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/dl-support.c
@@ -0,0 +1,4 @@
+#include <elf/dl-support.c>
+
+/* Populated from the auxiliary vector. */
+int _dl_cache_line_size;
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-01-11 18:44 UTC | newest]
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-- links below jump to the message on this page --
2022-01-11 18:43 [PATCH 0/5] Linux: Auxiliary vector parsing cleanups Florian Weimer
2022-01-11 18:43 ` [PATCH 1/5] elf: Merge dl-sysdep.c into the Linux version Florian Weimer
2022-01-11 18:43 ` [PATCH 2/5] Linux: Remove HAVE_AUX_SECURE, HAVE_AUX_XID, HAVE_AUX_PAGESIZE Florian Weimer
2022-01-11 18:43 ` [PATCH 3/5] Linux: Remove DL_FIND_ARG_COMPONENTS Florian Weimer
2022-01-11 18:44 ` [PATCH 4/5] Linux: Assume that NEED_DL_SYSINFO_DSO is always defined Florian Weimer
2022-01-11 18:44 ` [PATCH 5/5] Linux: Consolidate auxiliary vector parsing Florian Weimer
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