From: Carlos O'Donell <carlos@redhat.com>
To: libc-stable@sourceware.org
Subject: [PATCH 05/27] elf: Fix elf_get_dynamic_info() for bootstrap
Date: Tue, 12 Apr 2022 14:41:43 -0400 [thread overview]
Message-ID: <20220412184205.3343677-6-carlos@redhat.com> (raw)
In-Reply-To: <20220412184205.3343677-1-carlos@redhat.com>
From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
THe d6d89608ac8c broke powerpc for --enable-bind-now because it turned
out that different than patch assumption rtld elf_get_dynamic_info()
does require to handle RTLD_BOOTSTRAP to avoid DT_FLAGS and
DT_RUNPATH (more specially the GLRO usage which is not reallocate
yet).
This patch fixes by passing two arguments to elf_get_dynamic_info()
to inform that by rtld (bootstrap) or static pie initialization
(static_pie_bootstrap). I think using explicit argument is way more
clear and burried C preprocessor, and compiler should remove the
dead code.
I checked on x86_64 and i686 with default options, --enable-bind-now,
and --enable-bind-now and --enable--static-pie. I also check on
aarch64, armhf, powerpc64, and powerpc with default and
--enable-bind-now.
(cherry picked from commit 5118dcac68c4eadfd6304bb33adde63d062dc07f)
Resolved conflicts:
elf/rtld.c - Manual merge.
---
elf/dl-load.c | 2 +-
elf/dl-reloc-static-pie.c | 3 +-
elf/get-dynamic-info.h | 95 +++++++++++++++++++++++----------------
elf/rtld.c | 4 +-
elf/setup-vdso.h | 2 +-
5 files changed, 61 insertions(+), 45 deletions(-)
diff --git a/elf/dl-load.c b/elf/dl-load.c
index fb3da5aa56..a920b12a90 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -1296,7 +1296,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd,
if (l->l_ld != 0)
l->l_ld = (ElfW(Dyn) *) ((ElfW(Addr)) l->l_ld + l->l_addr);
- elf_get_dynamic_info (l);
+ elf_get_dynamic_info (l, false, false);
/* Make sure we are not dlopen'ing an object that has the
DF_1_NOOPEN flag set, or a PIE object. */
diff --git a/elf/dl-reloc-static-pie.c b/elf/dl-reloc-static-pie.c
index ababafcf98..757205affe 100644
--- a/elf/dl-reloc-static-pie.c
+++ b/elf/dl-reloc-static-pie.c
@@ -25,7 +25,6 @@
#include <dl-machine.h>
-#define STATIC_PIE_BOOTSTRAP
#define RESOLVE_MAP(map, scope, sym, version, flags) map
#include "dynamic-link.h"
#include "get-dynamic-info.h"
@@ -52,7 +51,7 @@ _dl_relocate_static_pie (void)
break;
}
- elf_get_dynamic_info (main_map);
+ elf_get_dynamic_info (main_map, false, true);
# ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
ELF_MACHINE_BEFORE_RTLD_RELOC (main_map, main_map->l_info);
diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h
index 1ac0663d1f..f63e07dc6d 100644
--- a/elf/get-dynamic-info.h
+++ b/elf/get-dynamic-info.h
@@ -26,7 +26,8 @@
#include <libc-diag.h>
static inline void __attribute__ ((unused, always_inline))
-elf_get_dynamic_info (struct link_map *l)
+elf_get_dynamic_info (struct link_map *l, bool bootstrap,
+ bool static_pie_bootstrap)
{
#if __ELF_NATIVE_CLASS == 32
typedef Elf32_Word d_tag_utype;
@@ -35,7 +36,7 @@ elf_get_dynamic_info (struct link_map *l)
#endif
#ifndef STATIC_PIE_BOOTSTRAP
- if (l->l_ld == NULL)
+ if (!bootstrap && l->l_ld == NULL)
return;
#endif
@@ -112,47 +113,63 @@ elf_get_dynamic_info (struct link_map *l)
if (info[DT_REL] != NULL)
assert (info[DT_RELENT]->d_un.d_val == sizeof (ElfW(Rel)));
#endif
-#ifdef STATIC_PIE_BOOTSTRAP
- assert (info[DT_RUNPATH] == NULL);
- assert (info[DT_RPATH] == NULL);
-#endif
- if (info[DT_FLAGS] != NULL)
+ if (bootstrap || static_pie_bootstrap)
{
- /* Flags are used. Translate to the old form where available.
- Since these l_info entries are only tested for NULL pointers it
- is ok if they point to the DT_FLAGS entry. */
- l->l_flags = info[DT_FLAGS]->d_un.d_val;
-
- if (l->l_flags & DF_SYMBOLIC)
- info[DT_SYMBOLIC] = info[DT_FLAGS];
- if (l->l_flags & DF_TEXTREL)
- info[DT_TEXTREL] = info[DT_FLAGS];
- if (l->l_flags & DF_BIND_NOW)
- info[DT_BIND_NOW] = info[DT_FLAGS];
+ assert (info[DT_RUNPATH] == NULL);
+ assert (info[DT_RPATH] == NULL);
}
- if (info[VERSYMIDX (DT_FLAGS_1)] != NULL)
+ if (bootstrap)
{
- l->l_flags_1 = info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val;
- if (l->l_flags_1 & DF_1_NODELETE)
- l->l_nodelete_pending = true;
-
- /* Only DT_1_SUPPORTED_MASK bits are supported, and we would like
- to assert this, but we can't. Users have been setting
- unsupported DF_1_* flags for a long time and glibc has ignored
- them. Therefore to avoid breaking existing applications the
- best we can do is add a warning during debugging with the
- intent of notifying the user of the problem. */
- if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
- && l->l_flags_1 & ~DT_1_SUPPORTED_MASK)
- _dl_debug_printf ("\nWARNING: Unsupported flag value(s) of 0x%x in DT_FLAGS_1.\n",
- l->l_flags_1 & ~DT_1_SUPPORTED_MASK);
-
- if (l->l_flags_1 & DF_1_NOW)
- info[DT_BIND_NOW] = info[VERSYMIDX (DT_FLAGS_1)];
+ /* Only the bind now flags are allowed. */
+ assert (info[VERSYMIDX (DT_FLAGS_1)] == NULL
+ || (info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val & ~DF_1_NOW) == 0);
+ /* Flags must not be set for ld.so. */
+ assert (info[DT_FLAGS] == NULL
+ || (info[DT_FLAGS]->d_un.d_val & ~DF_BIND_NOW) == 0);
}
- if (info[DT_RUNPATH] != NULL)
- /* If both RUNPATH and RPATH are given, the latter is ignored. */
- info[DT_RPATH] = NULL;
+ else
+ {
+ if (info[DT_FLAGS] != NULL)
+ {
+ /* Flags are used. Translate to the old form where available.
+ Since these l_info entries are only tested for NULL pointers it
+ is ok if they point to the DT_FLAGS entry. */
+ l->l_flags = info[DT_FLAGS]->d_un.d_val;
+
+ if (l->l_flags & DF_SYMBOLIC)
+ info[DT_SYMBOLIC] = info[DT_FLAGS];
+ if (l->l_flags & DF_TEXTREL)
+ info[DT_TEXTREL] = info[DT_FLAGS];
+ if (l->l_flags & DF_BIND_NOW)
+ info[DT_BIND_NOW] = info[DT_FLAGS];
+ }
+
+ if (info[VERSYMIDX (DT_FLAGS_1)] != NULL)
+ {
+ l->l_flags_1 = info[VERSYMIDX (DT_FLAGS_1)]->d_un.d_val;
+ if (l->l_flags_1 & DF_1_NODELETE)
+ l->l_nodelete_pending = true;
+
+ /* Only DT_1_SUPPORTED_MASK bits are supported, and we would like
+ to assert this, but we can't. Users have been setting
+ unsupported DF_1_* flags for a long time and glibc has ignored
+ them. Therefore to avoid breaking existing applications the
+ best we can do is add a warning during debugging with the
+ intent of notifying the user of the problem. */
+ if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_FILES, 0)
+ && l->l_flags_1 & ~DT_1_SUPPORTED_MASK)
+ _dl_debug_printf ("\nWARNING: Unsupported flag value(s) of 0x%x "
+ "in DT_FLAGS_1.\n",
+ l->l_flags_1 & ~DT_1_SUPPORTED_MASK);
+
+ if (l->l_flags_1 & DF_1_NOW)
+ info[DT_BIND_NOW] = info[VERSYMIDX (DT_FLAGS_1)];
+ }
+
+ if (info[DT_RUNPATH] != NULL)
+ /* If both RUNPATH and RPATH are given, the latter is ignored. */
+ info[DT_RPATH] = NULL;
+ }
}
#endif
diff --git a/elf/rtld.c b/elf/rtld.c
index 0a4c3d4fed..e52e9cd66e 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -548,7 +548,7 @@ _dl_start (void *arg)
/* Read our own dynamic section and fill in the info array. */
bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
bootstrap_map.l_ld_readonly = DL_RO_DYN_SECTION;
- elf_get_dynamic_info (&bootstrap_map);
+ elf_get_dynamic_info (&bootstrap_map, true, false);
#if NO_TLS_OFFSET != 0
bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
@@ -1616,7 +1616,7 @@ dl_main (const ElfW(Phdr) *phdr,
if (! rtld_is_main)
{
/* Extract the contents of the dynamic section for easy access. */
- elf_get_dynamic_info (main_map);
+ elf_get_dynamic_info (main_map, false, false);
/* If the main map is libc.so, update the base namespace to
refer to this map. If libc.so is loaded later, this happens
diff --git a/elf/setup-vdso.h b/elf/setup-vdso.h
index f44748bc98..3f20578046 100644
--- a/elf/setup-vdso.h
+++ b/elf/setup-vdso.h
@@ -64,7 +64,7 @@ setup_vdso (struct link_map *main_map __attribute__ ((unused)),
l->l_map_end += l->l_addr;
l->l_text_end += l->l_addr;
l->l_ld = (void *) ((ElfW(Addr)) l->l_ld + l->l_addr);
- elf_get_dynamic_info (l);
+ elf_get_dynamic_info (l, false, false);
_dl_setup_hash (l);
l->l_relocated = 1;
--
2.35.1
next prev parent reply other threads:[~2022-04-12 18:42 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-12 18:41 [PATCH 00/27] Improve LD_AUDIT support in glibc 2.34 Carlos O'Donell
2022-04-12 18:41 ` [PATCH 01/27] powerpc: Delete unneeded ELF_MACHINE_BEFORE_RTLD_RELOC Carlos O'Donell
2022-04-12 18:41 ` [PATCH 02/27] elf: Avoid nested functions in the loader [BZ #27220] Carlos O'Donell
2022-04-12 18:41 ` [PATCH 03/27] elf: Fix elf_get_dynamic_info definition Carlos O'Donell
2022-04-12 18:41 ` [PATCH 04/27] elf: Fix dynamic-link.h usage on rtld.c Carlos O'Donell
2022-04-12 18:41 ` Carlos O'Donell [this message]
2022-04-12 18:41 ` [PATCH 06/27] elf: Move LAV_CURRENT to link_lavcurrent.h Carlos O'Donell
2022-04-12 18:41 ` [PATCH 07/27] elf: Move la_activity (LA_ACT_ADD) after _dl_add_to_namespace_list() (BZ #28062) Carlos O'Donell
2022-04-12 18:41 ` [PATCH 08/27] elf: Add _dl_audit_objopen Carlos O'Donell
2022-04-12 18:41 ` [PATCH 09/27] elf: Add _dl_audit_activity_map and _dl_audit_activity_nsid Carlos O'Donell
2022-04-12 18:41 ` [PATCH 10/27] elf: Add _dl_audit_objsearch Carlos O'Donell
2022-04-12 18:41 ` [PATCH 11/27] elf: Add _dl_audit_objclose Carlos O'Donell
2022-04-12 18:41 ` [PATCH 12/27] elf: Add _dl_audit_symbind_alt and _dl_audit_symbind Carlos O'Donell
2022-04-12 18:41 ` [PATCH 13/27] elf: Add _dl_audit_preinit Carlos O'Donell
2022-04-12 18:41 ` [PATCH 14/27] elf: Add _dl_audit_pltenter Carlos O'Donell
2022-04-12 18:41 ` [PATCH 15/27] elf: Add _dl_audit_pltexit Carlos O'Donell
2022-04-12 18:41 ` [PATCH 16/27] elf: Avoid unnecessary slowdown from profiling with audit (BZ#15533) Carlos O'Donell
2022-04-12 18:41 ` [PATCH 17/27] elf: Add audit tests for modules with TLSDESC Carlos O'Donell
2022-04-12 18:41 ` [PATCH 18/27] elf: Issue audit la_objopen for vDSO Carlos O'Donell
2022-04-12 18:41 ` [PATCH 19/27] elf: Do not fail for failed dlmopen on audit modules (BZ #28061) Carlos O'Donell
2022-04-12 18:41 ` [PATCH 20/27] elf: Add la_activity during application exit Carlos O'Donell
2022-04-12 18:41 ` [PATCH 21/27] elf: Fix initial-exec TLS access on audit modules (BZ #28096) Carlos O'Donell
2022-04-12 18:42 ` [PATCH 22/27] elf: Issue la_symbind for bind-now (BZ #23734) Carlos O'Donell
2022-04-12 18:42 ` [PATCH 23/27] elf: Fix runtime linker auditing on aarch64 (BZ #26643) Carlos O'Donell
2022-04-12 18:42 ` [PATCH 24/27] Fix elf/tst-audit25a with default bind now toolchains Carlos O'Donell
2022-04-12 18:42 ` [PATCH 25/27] elf: Replace tst-audit24bmod2.so with tst-audit24bmod2 Carlos O'Donell
2022-04-12 18:42 ` [PATCH 26/27] hppa: Fix bind-now audit (BZ #28857) Carlos O'Donell
2022-04-12 18:42 ` [PATCH 27/27] NEWS: Update fixed bug list for LD_AUDIT backports Carlos O'Donell
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