From: Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>
To: libc-alpha@sourceware.org
Cc: Jakub Jelinek <jakub@redhat.com>,
gcc-patches@gcc.gnu.org, Jason Merrill <jason@redhat.com>
Subject: [PATCH 3/3] elf: Add _dl_find_eh_frame function
Date: Wed, 03 Nov 2021 17:28:02 +0100 [thread overview]
Message-ID: <ed580138ca8b4c467f84f1131cfe627729588212.1635954168.git.fweimer@redhat.com> (raw)
In-Reply-To: <cover.1635954168.git.fweimer@redhat.com>
This function is similar to __gnu_Unwind_Find_exidx as used on arm.
It can be used to speed up the libgcc unwinder.
---
NEWS | 4 +
bits/dlfcn_eh_frame.h | 33 +
dlfcn/Makefile | 2 +-
dlfcn/dlfcn.h | 2 +
elf/Makefile | 31 +-
elf/Versions | 3 +
elf/dl-close.c | 4 +
elf/dl-find_eh_frame.c | 864 ++++++++++++++++++
elf/dl-find_eh_frame.h | 90 ++
elf/dl-find_eh_frame_slow.h | 55 ++
elf/dl-libc_freeres.c | 2 +
elf/dl-open.c | 5 +
elf/rtld.c | 7 +
elf/tst-dl_find_eh_frame-mod1.c | 10 +
elf/tst-dl_find_eh_frame-mod2.c | 10 +
elf/tst-dl_find_eh_frame-mod3.c | 10 +
elf/tst-dl_find_eh_frame-mod4.c | 10 +
elf/tst-dl_find_eh_frame-mod5.c | 11 +
elf/tst-dl_find_eh_frame-mod6.c | 11 +
elf/tst-dl_find_eh_frame-mod7.c | 10 +
elf/tst-dl_find_eh_frame-mod8.c | 10 +
elf/tst-dl_find_eh_frame-mod9.c | 10 +
elf/tst-dl_find_eh_frame-threads.c | 237 +++++
elf/tst-dl_find_eh_frame.c | 179 ++++
include/atomic_wide_counter.h | 14 +
include/bits/dlfcn_eh_frame.h | 1 +
include/link.h | 3 +
manual/Makefile | 2 +-
manual/dynlink.texi | 69 ++
manual/libdl.texi | 10 -
manual/probes.texi | 2 +-
manual/threads.texi | 2 +-
sysdeps/i386/bits/dlfcn_eh_frame.h | 34 +
sysdeps/mach/hurd/i386/ld.abilist | 1 +
sysdeps/nios2/bits/dlfcn_eh_frame.h | 34 +
sysdeps/unix/sysv/linux/aarch64/ld.abilist | 1 +
sysdeps/unix/sysv/linux/alpha/ld.abilist | 1 +
sysdeps/unix/sysv/linux/arc/ld.abilist | 1 +
sysdeps/unix/sysv/linux/arm/be/ld.abilist | 1 +
sysdeps/unix/sysv/linux/arm/le/ld.abilist | 1 +
sysdeps/unix/sysv/linux/csky/ld.abilist | 1 +
sysdeps/unix/sysv/linux/hppa/ld.abilist | 1 +
sysdeps/unix/sysv/linux/i386/ld.abilist | 1 +
sysdeps/unix/sysv/linux/ia64/ld.abilist | 1 +
.../unix/sysv/linux/m68k/coldfire/ld.abilist | 1 +
.../unix/sysv/linux/m68k/m680x0/ld.abilist | 1 +
sysdeps/unix/sysv/linux/microblaze/ld.abilist | 1 +
.../unix/sysv/linux/mips/mips32/ld.abilist | 1 +
.../sysv/linux/mips/mips64/n32/ld.abilist | 1 +
.../sysv/linux/mips/mips64/n64/ld.abilist | 1 +
sysdeps/unix/sysv/linux/nios2/ld.abilist | 1 +
.../sysv/linux/powerpc/powerpc32/ld.abilist | 1 +
.../linux/powerpc/powerpc64/be/ld.abilist | 1 +
.../linux/powerpc/powerpc64/le/ld.abilist | 1 +
sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist | 1 +
sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist | 1 +
.../unix/sysv/linux/s390/s390-32/ld.abilist | 1 +
.../unix/sysv/linux/s390/s390-64/ld.abilist | 1 +
sysdeps/unix/sysv/linux/sh/be/ld.abilist | 1 +
sysdeps/unix/sysv/linux/sh/le/ld.abilist | 1 +
.../unix/sysv/linux/sparc/sparc32/ld.abilist | 1 +
.../unix/sysv/linux/sparc/sparc64/ld.abilist | 1 +
sysdeps/unix/sysv/linux/x86_64/64/ld.abilist | 1 +
sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist | 1 +
64 files changed, 1795 insertions(+), 16 deletions(-)
create mode 100644 bits/dlfcn_eh_frame.h
create mode 100644 elf/dl-find_eh_frame.c
create mode 100644 elf/dl-find_eh_frame.h
create mode 100644 elf/dl-find_eh_frame_slow.h
create mode 100644 elf/tst-dl_find_eh_frame-mod1.c
create mode 100644 elf/tst-dl_find_eh_frame-mod2.c
create mode 100644 elf/tst-dl_find_eh_frame-mod3.c
create mode 100644 elf/tst-dl_find_eh_frame-mod4.c
create mode 100644 elf/tst-dl_find_eh_frame-mod5.c
create mode 100644 elf/tst-dl_find_eh_frame-mod6.c
create mode 100644 elf/tst-dl_find_eh_frame-mod7.c
create mode 100644 elf/tst-dl_find_eh_frame-mod8.c
create mode 100644 elf/tst-dl_find_eh_frame-mod9.c
create mode 100644 elf/tst-dl_find_eh_frame-threads.c
create mode 100644 elf/tst-dl_find_eh_frame.c
create mode 100644 include/bits/dlfcn_eh_frame.h
create mode 100644 manual/dynlink.texi
delete mode 100644 manual/libdl.texi
create mode 100644 sysdeps/i386/bits/dlfcn_eh_frame.h
create mode 100644 sysdeps/nios2/bits/dlfcn_eh_frame.h
diff --git a/NEWS b/NEWS
index 82b7016aef..68c9c21458 100644
--- a/NEWS
+++ b/NEWS
@@ -64,6 +64,10 @@ Major new features:
to be used by compilers for optimizing usage of 'memcmp' when its
return value is only used for its boolean status.
+* The function _dl_find_eh_frame has been added. In-process unwinders
+ can use it to efficiently locate unwinding information for a code
+ address.
+
Deprecated and removed features, and other changes affecting compatibility:
* The r_version update in the debugger interface makes the glibc binary
diff --git a/bits/dlfcn_eh_frame.h b/bits/dlfcn_eh_frame.h
new file mode 100644
index 0000000000..fe4c6d6ad7
--- /dev/null
+++ b/bits/dlfcn_eh_frame.h
@@ -0,0 +1,33 @@
+/* System dependent definitions for find unwind information using ld.so.
+ 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; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef _DLFCN_H
+# error "Never use <bits/dlfcn_eh_frame.h> directly; include <dlfcn.h> instead."
+#endif
+
+/* This implementation does not use a DBASE pointer argument in
+ _dl_find_eh_frame. */
+#define DL_FIND_EH_FRAME_DBASE 0
+
+__BEGIN_DECLS
+/* If PC points into an object that has a PT_GNU_EH_FRAME segment,
+ return the pointer to the start of that segment in memory. If no
+ corresponding object exists or the object has no such segment,
+ returns NULL. */
+void *_dl_find_eh_frame (void *__pc) __THROW;
+__END_DECLS
diff --git a/dlfcn/Makefile b/dlfcn/Makefile
index 6bbfbb8344..fd6e2a30c5 100644
--- a/dlfcn/Makefile
+++ b/dlfcn/Makefile
@@ -19,7 +19,7 @@ subdir := dlfcn
include ../Makeconfig
-headers := bits/dlfcn.h dlfcn.h
+headers := bits/dlfcn.h bits/dlfcn_eh_frame.h dlfcn.h
extra-libs := libdl
libdl-routines := libdl-compat
routines = \
diff --git a/dlfcn/dlfcn.h b/dlfcn/dlfcn.h
index 4a3b870a48..d5355657c7 100644
--- a/dlfcn/dlfcn.h
+++ b/dlfcn/dlfcn.h
@@ -28,6 +28,8 @@
#ifdef __USE_GNU
+#include <bits/dlfcn_eh_frame.h>
+
/* If the first argument of `dlsym' or `dlvsym' is set to RTLD_NEXT
the run-time address of the symbol called NAME in the next shared
object is returned. The "next" relation is defined by the order
diff --git a/elf/Makefile b/elf/Makefile
index 1c768bdf47..49e35dd4ce 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -36,7 +36,7 @@ dl-routines = $(addprefix dl-,load lookup object reloc deps \
exception sort-maps lookup-direct \
call-libc-early-init write \
thread_gscope_wait tls_init_tp \
- debug-symbols)
+ debug-symbols find_eh_frame)
ifeq (yes,$(use-ldconfig))
dl-routines += dl-cache
endif
@@ -230,7 +230,8 @@ tests-internal += loadtest unload unload2 circleload1 \
neededtest neededtest2 neededtest3 neededtest4 \
tst-tls3 tst-tls6 tst-tls7 tst-tls8 tst-dlmopen2 \
tst-ptrguard1 tst-stackguard1 \
- tst-create_format1 tst-tls-surplus tst-dl-hwcaps_split
+ tst-create_format1 tst-tls-surplus tst-dl-hwcaps_split \
+ tst-dl_find_eh_frame tst-dl_find_eh_frame-threads
tests-container += tst-pldd tst-dlopen-tlsmodid-container \
tst-dlopen-self-container tst-preload-pthread-libc
test-srcs = tst-pathopt
@@ -365,6 +366,11 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
tst-tls20mod-bad tst-tls21mod tst-dlmopen-dlerror-mod \
tst-auxvalmod \
tst-dlmopen-gethostbyname-mod tst-ro-dynamic-mod \
+ tst-dl_find_eh_frame-mod1 tst-dl_find_eh_frame-mod2 \
+ tst-dl_find_eh_frame-mod3 tst-dl_find_eh_frame-mod4 \
+ tst-dl_find_eh_frame-mod5 tst-dl_find_eh_frame-mod6 \
+ tst-dl_find_eh_frame-mod7 tst-dl_find_eh_frame-mod8 \
+ tst-dl_find_eh_frame-mod9 \
# Most modules build with _ISOMAC defined, but those filtered out
# depend on internal headers.
@@ -1957,3 +1963,24 @@ $(objpfx)tst-ro-dynamic-mod.so: $(objpfx)tst-ro-dynamic-mod.os \
$(LINK.o) -nostdlib -nostartfiles -shared -o $@ \
-Wl,--script=tst-ro-dynamic-mod.map \
$(objpfx)tst-ro-dynamic-mod.os
+
+$(objpfx)tst-dl_find_eh_frame.out: \
+ $(objpfx)tst-dl_find_eh_frame-mod1.so $(objpfx)tst-dl_find_eh_frame-mod2.so
+CFLAGS-tst-dl_find_eh_frame.c += -funwind-tables
+CFLAGS-tst-dl_find_eh_frame-mod1.c += -funwind-tables
+CFLAGS-tst-dl_find_eh_frame-mod2.c += -funwind-tables
+LDFLAGS-tst-dl_find_eh_frame-mod2.so += -Wl,--enable-new-dtags,-z,nodelete
+$(objpfx)tst-dl_find_eh_frame-threads: $(shared-thread-library)
+$(objpfx)tst-dl_find_eh_frame-threads.out: \
+ $(objpfx)tst-dl_find_eh_frame-mod1.so $(objpfx)tst-dl_find_eh_frame-mod2.so \
+ $(objpfx)tst-dl_find_eh_frame-mod3.so $(objpfx)tst-dl_find_eh_frame-mod4.so \
+ $(objpfx)tst-dl_find_eh_frame-mod5.so $(objpfx)tst-dl_find_eh_frame-mod6.so \
+ $(objpfx)tst-dl_find_eh_frame-mod7.so $(objpfx)tst-dl_find_eh_frame-mod8.so \
+ $(objpfx)tst-dl_find_eh_frame-mod9.so
+CFLAGS-tst-dl_find_eh_frame-mod3.c += -funwind-tables
+CFLAGS-tst-dl_find_eh_frame-mod4.c += -funwind-tables
+CFLAGS-tst-dl_find_eh_frame-mod5.c += -funwind-tables
+CFLAGS-tst-dl_find_eh_frame-mod6.c += -funwind-tables
+CFLAGS-tst-dl_find_eh_frame-mod7.c += -funwind-tables
+CFLAGS-tst-dl_find_eh_frame-mod8.c += -funwind-tables
+CFLAGS-tst-dl_find_eh_frame-mod9.c += -funwind-tables
diff --git a/elf/Versions b/elf/Versions
index 775aab62af..770a082886 100644
--- a/elf/Versions
+++ b/elf/Versions
@@ -48,6 +48,9 @@ ld {
# stack canary
__stack_chk_guard;
}
+ GLIBC_2.35 {
+ _dl_find_eh_frame;
+ }
GLIBC_PRIVATE {
# Those are in the dynamic linker, but used by libc.so.
__libc_enable_secure;
diff --git a/elf/dl-close.c b/elf/dl-close.c
index 4f5cfcc1c3..1249e964ee 100644
--- a/elf/dl-close.c
+++ b/elf/dl-close.c
@@ -32,6 +32,7 @@
#include <sysdep-cancel.h>
#include <tls.h>
#include <stap-probe.h>
+#include <dl-find_eh_frame.h>
#include <dl-unmap-segments.h>
@@ -718,6 +719,9 @@ _dl_close_worker (struct link_map *map, bool force)
if (imap->l_next != NULL)
imap->l_next->l_prev = imap->l_prev;
+ /* Update the data used by _dl_find_eh_frame. */
+ _dl_find_eh_frame_dlclose (imap);
+
free (imap->l_versions);
if (imap->l_origin != (char *) -1)
free ((char *) imap->l_origin);
diff --git a/elf/dl-find_eh_frame.c b/elf/dl-find_eh_frame.c
new file mode 100644
index 0000000000..c7313c122d
--- /dev/null
+++ b/elf/dl-find_eh_frame.c
@@ -0,0 +1,864 @@
+/* Locating DWARF unwind information using the dynamic loader.
+ 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; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <atomic_wide_counter.h>
+#include <dlfcn.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <dl-find_eh_frame_slow.h>
+
+/* Data for the main executable. There is usually a large gap between
+ the main executable and initially loaded shared objects. Record
+ the main executable separately, to increase the chance that the
+ range for the non-closeable mappings below covers only the shared
+ objects (and not also the gap between main executable and shared
+ objects). */
+static uintptr_t _dl_eh_main_map_start attribute_relro;
+static struct dl_eh_frame_info _dl_eh_main_info attribute_relro;
+
+/* Data for initally loaded shared objects that cannot be unlaoded.
+ The mapping base addresses are stored in address order in the
+ _dl_eh_nodelete_mappings_bases array (containing
+ _dl_eh_nodelete_mappings_size elements). The EH data for a base
+ address is stored in the parallel _dl_eh_nodelete_mappings_infos.
+ These arrays are not modified after initialization. */
+static uintptr_t _dl_eh_nodelete_mappings_end attribute_relro;
+static size_t _dl_eh_nodelete_mappings_size attribute_relro;
+static uintptr_t *_dl_eh_nodelete_mappings_bases attribute_relro;
+static struct dl_eh_frame_info *_dl_eh_nodelete_mappings_infos
+ attribute_relro;
+
+/* Mappings created by dlopen can go away with dlclose, so a data
+ dynamic data structure with some synchronization is needed.
+ Individual segments are similar to the _dl_eh_nodelete_mappings
+ above (two sorted arrays of the same length for bases/infos). The
+ previous segment contains lower addresses and is at most half as
+ long. Checking the address of the base address of the first
+ element during a lookup can therefore approximate a binary search
+ over all segments, even though the data is not stored in one
+ contiguous array.
+
+ During updates, the segments are overwritten in place, and a
+ software transactional memory construct (involving the
+ _dl_eh_loaded_mappings_version variable) is used to detect
+ concurrent modification and retry as necessary. The memory
+ allocations are never deallocated, but slots used for objects that
+ have been dlclose'd can be reused by dlopen. The memory can live
+ in the regular C malloc heap.
+
+ The segments are populated from the start of the list, with the
+ mappings with the highest address. Only if this segment is full,
+ previous segments are used for mappings at lower addresses. The
+ remaining segments are populated as needed, but after resizing,
+ some of the initial segments (at the end of the linked list) can be
+ empty (with size 0).
+
+ Adding new elements to this data structure is another source of
+ quadratic behavior for dlopen. If the other causes of quadratic
+ behavior are eliminated, a more complicated data structure will be
+ needed. */
+struct dl_eh_mappings_segment
+{
+ /* The previous segment has lower base addresses. */
+ struct dl_eh_mappings_segment *previous;
+
+ /* Used by __libc_freeres to deallocate malloc'ed memory. */
+ void *to_free;
+
+ /* Count of array elements in use and allocated. */
+ size_t size;
+ size_t allocated;
+ uintptr_t bases[]; /* infos array follows. */
+};
+
+/* To achieve async-signal-safety, two copies of the data structure
+ are used, so that a signal handler can still use this data even if
+ dlopen or dlclose modify the other copy. The the MSB in
+ _dl_eh_loaded_mappings_version determins which array element is the
+ currently active region. */
+static struct dl_eh_mappings_segment *_dl_eh_loaded_mappings[2];
+
+/* Returns the co-allocated struct dl_eh_frame_info array inside
+ *SEG. */
+static inline struct dl_eh_frame_info *
+_dl_eh_mappings_segment_infos (struct dl_eh_mappings_segment *seg)
+{
+ return (struct dl_eh_frame_info *) &seg->bases[seg->allocated];
+}
+
+/* Returns the number of actually used elements in all segements
+ starting at SEG. */
+static inline size_t
+_dl_eh_mappings_segment_count_used (struct dl_eh_mappings_segment *seg)
+{
+ size_t count = 0;
+ for (; seg != NULL && seg->size > 0; seg = seg->previous)
+ {
+ struct dl_eh_frame_info *infos = _dl_eh_mappings_segment_infos (seg);
+ for (size_t i = 0; i < seg->size; ++i)
+ /* Exclude elements which have been dlclose'd. */
+ count += infos[i].size > 0;
+ }
+ return count;
+}
+
+/* Compute the total number of available allocated segments linked
+ from SEG. */
+static inline size_t
+_dl_eh_mappings_segment_count_allocated (struct dl_eh_mappings_segment *seg)
+{
+ size_t count = 0;
+ for (; seg != NULL; seg = seg->previous)
+ count += seg->allocated;
+ return count;
+}
+
+/* This is essentially an arbitrary value. dlopen allocates plenty of
+ memory anyway, so over-allocated a bit does not hurt. Not having
+ many small-ish segments helps to avoid many small binary searches.
+ Not using a power of 2 means that we do not waste an extra page
+ just for the malloc header if a mapped allocation is used in the
+ glibc allocator. */
+enum { dl_eh_mappings_initial_segment_size = 63 };
+
+/* Allocate an empty segment. This used for the first ever
+ allocation. */
+static struct dl_eh_mappings_segment *
+_dl_eh_mappings_segment_allocate_unpadded (size_t size)
+{
+ if (size < dl_eh_mappings_initial_segment_size)
+ size = dl_eh_mappings_initial_segment_size;
+ /* No overflow checks here because the size is a mapping count, and
+ struct link_map is larger than what we allocate here. */
+ size_t to_allocate = (sizeof (struct dl_eh_mappings_segment)
+ + size * (sizeof (uintptr_t)
+ + sizeof (struct dl_eh_frame_info)));
+ struct dl_eh_mappings_segment *result = malloc (to_allocate);
+ if (result != NULL)
+ {
+ result->previous = NULL;
+ result->to_free = NULL; /* Minimal malloc memory cannot be freed. */
+ result->size = 0;
+ result->allocated = size;
+ }
+ return result;
+}
+
+/* Allocate an empty segment that is at least SIZE large. PREVIOUS */
+static struct dl_eh_mappings_segment *
+_dl_eh_mappings_segment_allocate (size_t size,
+ struct dl_eh_mappings_segment * previous)
+{
+ /* Exponential sizing policies, so that lookup approximates a binary
+ search. */
+ {
+ size_t minimum_growth;
+ if (previous == NULL)
+ minimum_growth = dl_eh_mappings_initial_segment_size;
+ else
+ minimum_growth = 2* previous->allocated;
+ if (size < minimum_growth)
+ size = minimum_growth;
+ }
+ enum { cache_line_size_estimate = 128 };
+ /* No overflow checks here because the size is a mapping count, and
+ struct link_map is larger than what we allocate here. */
+ size_t to_allocate = (sizeof (struct dl_eh_mappings_segment)
+ + size * (sizeof (uintptr_t)
+ + sizeof (struct dl_eh_frame_info))
+ + 2 * cache_line_size_estimate);
+ char *ptr = malloc (to_allocate);
+ if (ptr == NULL)
+ return NULL;
+ char *original_ptr = ptr;
+ /* Start and end at a (conservative) 128-byte cache line boundary.
+ Do not use memalign for compatibility with partially interposing
+ malloc implementations. */
+ char *end = PTR_ALIGN_DOWN (ptr + to_allocate, cache_line_size_estimate);
+ ptr = PTR_ALIGN_UP (ptr, cache_line_size_estimate);
+ struct dl_eh_mappings_segment *result
+ = (struct dl_eh_mappings_segment *) ptr;
+ result->previous = previous;
+ result->to_free = original_ptr;
+ result->size = 0;
+ /* We may have obtained slightly more space if malloc happened
+ to provide an over-aligned pointer. */
+ result->allocated = (((uintptr_t) (end - ptr)
+ - sizeof (struct dl_eh_mappings_segment))
+ / (sizeof (uintptr_t)
+ + sizeof (struct dl_eh_frame_info)));
+ assert (result->allocated >= size);
+ return result;
+}
+
+/* Monotonic counter for software transactional memory. The lowest
+ bit indicates which element of the _dl_eh_loaded_mappings contains
+ up-to-date data. */
+static __atomic_wide_counter _dl_eh_loaded_mappings_version;
+
+/* TM version at the start of the read operation. */
+static inline uint64_t
+_dl_eh_read_start_version (void)
+{
+ /* Acquire MO load synchronizes with the fences at the beginning and
+ end of the TM update region. */
+ return __atomic_wide_counter_load_acquire (&_dl_eh_loaded_mappings_version);
+}
+
+/* Optimized variant of _dl_eh_start_version which can be called when
+ the loader is write-locked. */
+static inline uint64_t
+_dl_eh_read_version_locked (void)
+{
+ return __atomic_wide_counter_load_relaxed (&_dl_eh_loaded_mappings_version);
+}
+
+/* Update the version to reflect that an update is happening. This
+ does not change the bit that controls the active segment chain.
+ Returns the index of the currently active segment chain. */
+static inline unsigned int
+_dl_eh_mappings_begin_update (void)
+{
+ unsigned int v
+ = __atomic_wide_counter_fetch_add_relaxed (&_dl_eh_loaded_mappings_version,
+ 2);
+ /* Subsequent stores to the TM data must not be reordered before the
+ store above with the version update. */
+ atomic_thread_fence_release ();
+ return v & 1;
+}
+
+/* Installs the just-updated version as the active version. */
+static inline void
+_dl_eh_mappings_end_update (void)
+{
+ /* The previous writes to the TM data must not be reordered after
+ the version update below. */
+ atomic_thread_fence_release ();
+ __atomic_wide_counter_fetch_add_relaxed (&_dl_eh_loaded_mappings_version,
+ 1);
+}
+/* Completes an in-place update without switching versions. */
+static inline void
+_dl_eh_mappings_end_update_no_switch (void)
+{
+ /* The previous writes to the TM data must not be reordered after
+ the version update below. */
+ atomic_thread_fence_release ();
+ __atomic_wide_counter_fetch_add_relaxed (&_dl_eh_loaded_mappings_version,
+ 2);
+}
+
+/* Return true if the read was successful, given the start
+ version. */
+static inline bool
+_dl_eh_read_success (uint64_t start_version)
+{
+ return _dl_eh_read_start_version () == start_version;
+}
+
+/* Returns the active segment identified by the specified start
+ version. */
+static struct dl_eh_mappings_segment *
+_dl_eh_mappings_active_segment (uint64_t start_version)
+{
+ return _dl_eh_loaded_mappings[start_version & 1];
+}
+
+/* Searches PC amoung the sorted array [FIRST, FIRST + SIZE). Returns
+ the index of the first element that is not less than PC, or SIZE if
+ there is no such element. */
+static inline size_t
+_dl_eh_find_lower_bound (uintptr_t pc, const uintptr_t *first1,
+ size_t size)
+{
+ const uintptr_t *first = first1;
+ while (size > 0)
+ {
+ size_t half = size >> 1;
+ const uintptr_t *middle = first + half;
+ if (*middle < pc)
+ {
+ first = middle + 1;
+ size -= half + 1;
+ }
+ else
+ size = half;
+ }
+ return first - first1;
+}
+
+void *
+_dl_find_eh_frame (void *pc1
+#if DL_FIND_EH_FRAME_DBASE
+ , void **dbase
+#endif
+ )
+{
+ uintptr_t pc = (uintptr_t) pc1;
+
+ if (_dl_eh_main_info.size == 0)
+ {
+ /* Not initialized. No locking is needed here because this can
+ only be called from audit modules, which cannot create
+ threads. */
+#if DL_FIND_EH_FRAME_DBASE
+ return _dl_find_eh_frame_slow (pc1, dbase);
+#else
+ return _dl_find_eh_frame_slow (pc1);
+#endif
+ }
+
+ /* Main executable. */
+ if (pc >= _dl_eh_main_map_start
+ && (pc - _dl_eh_main_map_start) < _dl_eh_main_info.size)
+ {
+#if DL_FIND_EH_FRAME_DBASE
+ *dbase = _dl_eh_main_info.dbase;
+#endif
+ return _dl_eh_main_info.eh_frame;
+ }
+
+ /* Other initially loaded objects. */
+ if (pc >= *_dl_eh_nodelete_mappings_bases
+ && pc < _dl_eh_nodelete_mappings_end)
+ {
+ size_t idx = _dl_eh_find_lower_bound (pc,
+ _dl_eh_nodelete_mappings_bases,
+ _dl_eh_nodelete_mappings_size);
+ const struct dl_eh_frame_info *info
+ = _dl_eh_nodelete_mappings_infos + idx;
+ bool match;
+ if (idx < _dl_eh_nodelete_mappings_size
+ && pc == _dl_eh_nodelete_mappings_bases[idx])
+ match = true;
+ else
+ {
+ /* PC might be in the previous mapping. */
+ --idx;
+ --info;
+ match = pc - _dl_eh_nodelete_mappings_bases[idx] < info->size;
+ }
+ if (match)
+ {
+#if DL_FIND_EH_FRAME_DBASE
+ *dbase = info->dbase;
+#endif
+ return info->eh_frame;
+ }
+ /* Fall through to the full search. The kernel may have mapped
+ the initial mappings with gaps that are later filled by
+ dlopen with other mappings. */
+ }
+
+ /* Handle audit modules, dlopen, dlopen objects. This uses software
+ transactional memory, with a retry loop in case the version
+ changes during execution. */
+ while (true)
+ {
+ retry:
+ ;
+ uint64_t start_version = _dl_eh_read_start_version ();
+
+ /* The read through seg->previous assumes that the CPU
+ recognizes the load dependency, so that no invalid size
+ values is read. Furthermore, the code assumes that no
+ out-of-thin-air value for seg->size is observed. Together,
+ this ensures that the observed seg->size value is always less
+ than seg->allocated, so that _dl_eh_mappings_index does not
+ read out-of-bounds. (This avoids intermediate TM version
+ verification. A concurrent version update will lead to
+ invalid lookup results, but not to out-of-memory access.)
+
+ Either seg == NULL or seg->size == 0 terminates the segment
+ list. _dl_eh_frame_frame_update does not bother to clear the
+ size on earlier unused segments. */
+ for (struct dl_eh_mappings_segment *seg
+ = _dl_eh_mappings_active_segment (start_version);
+ seg != NULL && seg->size > 0; seg = seg->previous)
+ if (pc >= seg->bases[0])
+ {
+ /* PC may lie within this segment. If it is less than the
+ segment start address, it can only lie in a previous
+ segment, due to the base address sorting. */
+ size_t idx = _dl_eh_find_lower_bound (pc, seg->bases, seg->size);
+ const struct dl_eh_frame_info *info
+ = _dl_eh_mappings_segment_infos (seg) + idx;
+ bool match;
+ if (idx < seg->size && pc == seg->bases[idx])
+ /* Check for dlcose. */
+ match = info->size > 0;
+ else
+ {
+ /* The match, if any, must be in the previous mapping. */
+ --idx;
+ --info;
+ match = pc - seg->bases[idx] < info->size;
+ }
+
+ if (match)
+ {
+ /* Found the right mapping. Copy out the data prior to
+ checking if the read transaction was successful. */
+ void *eh_frame_copy = info->eh_frame;
+#if DL_FIND_EH_FRAME_DBASE
+ void *dbase_copy = info->dbase;
+#endif
+ if (_dl_eh_read_success (start_version))
+ {
+#if DL_FIND_EH_FRAME_DBASE
+ *dbase = dbase_copy;
+#endif
+ return eh_frame_copy;
+ }
+ else
+ /* Read transaction failure. */
+ goto retry;
+ }
+ else
+ {
+ /* PC is not covered by this mapping. */
+ if (_dl_eh_read_success (start_version))
+ return NULL;
+ else
+ /* Read transaction failure. */
+ goto retry;
+ }
+ } /* if: PC might lie within the current seg. */
+
+ /* PC is not covered by any segment. */
+ if (_dl_eh_read_success (start_version))
+ return NULL;
+ } /* Transaction retry loop. */
+}
+
+/* _dl_eh_process_initial is called twice. First to compute the array
+ sizes from the initial loaded mappings. Second to fill in the
+ bases and infos arrays with the (still unsorted) data. Returns the
+ number of loaded (non-nodelete) mappings. */
+static size_t
+_dl_eh_process_initial (void)
+{
+ struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
+
+ size_t nodelete = 0;
+ if (!main_map->l_contiguous)
+ {
+ struct dl_eh_frame_info info;
+ _dl_get_eh_frame (main_map, &info);
+
+ /* PT_LOAD segments for a non-contiguous are added to the
+ non-closeable mappings. */
+ for (const ElfW(Phdr) *ph = main_map->l_phdr,
+ *ph_end = main_map->l_phdr + main_map->l_phnum;
+ ph < ph_end; ++ph)
+ if (ph->p_type == PT_LOAD)
+ {
+ if (_dl_eh_nodelete_mappings_bases != NULL)
+ {
+ /* Second pass only. */
+ _dl_eh_nodelete_mappings_bases[nodelete]
+ = ph->p_vaddr + main_map->l_addr;
+ _dl_eh_nodelete_mappings_infos[nodelete].size = ph->p_memsz;
+ _dl_eh_nodelete_mappings_infos[nodelete].eh_frame
+ = info.eh_frame;
+#if DL_FIND_EH_FRAME_DBASE
+ _dl_eh_nodelete_mappings_infos[nodelete].dbase = info.dbase;
+#endif
+ }
+ ++nodelete;
+ }
+ }
+
+ size_t loaded = 0;
+ for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
+ for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l != NULL;
+ l = l->l_next)
+ /* Skip the main map processed above, and proxy maps. */
+ if (l != main_map && l == l->l_real)
+ {
+ /* lt_library link maps are implicitly NODELETE. */
+ if (l->l_type == lt_library || l->l_nodelete_active)
+ {
+ if (_dl_eh_nodelete_mappings_bases != NULL)
+ {
+ /* Second pass only. */
+ _dl_eh_nodelete_mappings_bases[nodelete] = l->l_map_start;
+ _dl_get_eh_frame
+ (l, &_dl_eh_nodelete_mappings_infos[nodelete]);
+ }
+ ++nodelete;
+ }
+ else if (l->l_type == lt_loaded)
+ {
+ if (_dl_eh_loaded_mappings[0] != NULL)
+ {
+ /* Second pass only. */
+ _dl_eh_loaded_mappings[0]->bases[loaded] = l->l_map_start;
+ _dl_get_eh_frame (l, (_dl_eh_mappings_segment_infos
+ (_dl_eh_loaded_mappings[0])
+ + loaded));
+ }
+ ++loaded;
+ }
+ }
+
+ _dl_eh_nodelete_mappings_size = nodelete;
+ return loaded;
+}
+
+/* Selection sort based on mapping base address. The BASES and INFOS
+ arrays are updated at the same time. */
+void
+_dl_eh_sort_mappings (uintptr_t *bases, struct dl_eh_frame_info *infos,
+ size_t size)
+{
+ if (size < 2)
+ return;
+
+ for (size_t i = 0; i < size - 1; ++i)
+ {
+ /* Find minimum. */
+ size_t min_idx = i;
+ size_t min_val = bases[i];
+ for (size_t j = i + 1; j < size; ++j)
+ if (bases[j] < min_val)
+ {
+ min_idx = j;
+ min_val = bases[j];
+ }
+
+ /* Swap into place. */
+ bases[min_idx] = bases[i];
+ bases[i] = min_val;
+ struct dl_eh_frame_info tmp = infos[min_idx];
+ infos[min_idx] = infos[i];
+ infos[i] = tmp;
+ }
+}
+
+void
+_dl_find_eh_frame_init (void)
+{
+ /* Cover the main mapping. */
+ {
+ struct link_map *main_map = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
+
+ if (main_map->l_contiguous)
+ {
+ _dl_eh_main_map_start = main_map->l_map_start;
+ _dl_get_eh_frame (main_map, &_dl_eh_main_info);
+ }
+ else
+ {
+ /* Non-contiguous main maps are handled in
+ _dl_eh_process_initial. Mark as initialized, but not
+ coverying any valid PC. */
+ _dl_eh_main_map_start = -1;
+ _dl_eh_main_info.size = 1;
+ }
+ }
+
+ /* Allocate the data structures. */
+ size_t loaded_size = _dl_eh_process_initial ();
+ _dl_eh_nodelete_mappings_bases
+ = malloc (_dl_eh_nodelete_mappings_size
+ * sizeof (*_dl_eh_nodelete_mappings_bases));
+ _dl_eh_nodelete_mappings_infos
+ = malloc (_dl_eh_nodelete_mappings_size
+ * sizeof (*_dl_eh_nodelete_mappings_infos));
+ if (loaded_size > 0)
+ _dl_eh_loaded_mappings[0] = (_dl_eh_mappings_segment_allocate_unpadded
+ (loaded_size));
+ if (_dl_eh_nodelete_mappings_bases == NULL
+ || _dl_eh_nodelete_mappings_infos == NULL
+ || (loaded_size > 0 && _dl_eh_loaded_mappings[0] == NULL))
+ _dl_fatal_printf ("\
+Fatal glibc error: cannot allocate memory for DWARF EH frame data\n");
+ /* Fill in the data with the second call. */
+ _dl_eh_nodelete_mappings_size = 0;
+ _dl_eh_process_initial ();
+
+ /* Sort both arrays. */
+ if (_dl_eh_nodelete_mappings_size > 0)
+ {
+ _dl_eh_sort_mappings (_dl_eh_nodelete_mappings_bases,
+ _dl_eh_nodelete_mappings_infos,
+ _dl_eh_nodelete_mappings_size);
+ size_t last_idx = _dl_eh_nodelete_mappings_size - 1;
+ _dl_eh_nodelete_mappings_end
+ = (_dl_eh_nodelete_mappings_bases[last_idx]
+ + _dl_eh_nodelete_mappings_infos[last_idx].size);
+ }
+ if (loaded_size > 0)
+ _dl_eh_sort_mappings
+ (_dl_eh_loaded_mappings[0]->bases,
+ _dl_eh_mappings_segment_infos (_dl_eh_loaded_mappings[0]),
+ _dl_eh_loaded_mappings[0]->size);
+}
+
+static void
+_dl_eh_frame_link_map_sort (struct link_map **loaded, size_t size)
+{
+ /* Selection sort based on map_start. */
+ if (size < 2)
+ return;
+ for (size_t i = 0; i < size - 1; ++i)
+ {
+ /* Find minimum. */
+ size_t min_idx = i;
+ ElfW(Addr) min_val = loaded[i]->l_map_start;
+ for (size_t j = i + 1; j < size; ++j)
+ if (loaded[j]->l_map_start < min_val)
+ {
+ min_idx = j;
+ min_val = loaded[j]->l_map_start;
+ }
+
+ /* Swap into place. */
+ struct link_map *tmp = loaded[min_idx];
+ loaded[min_idx] = loaded[i];
+ loaded[i] = tmp;
+ }
+}
+
+/* Initializes the segment for writing. Returns the target write
+ index (plus 1) in this segment. The index is chosen so that a
+ partially filled segment still has data at index 0. */
+static inline size_t
+_dl_eh_frame_update_init_seg (struct dl_eh_mappings_segment *seg,
+ size_t remaining_to_add)
+{
+ if (remaining_to_add < seg->allocated)
+ /* Partially filled segment. */
+ seg->size = remaining_to_add;
+ else
+ seg->size = seg->allocated;
+ return seg->size;
+}
+
+/* Invoked from _dl_eh_frame_frame after sorting. */
+static bool
+_dl_find_eh_frame_update_1 (struct link_map **loaded, size_t count)
+{
+ int active_idx = _dl_eh_mappings_begin_update ();
+
+ struct dl_eh_mappings_segment *current_seg
+ = _dl_eh_loaded_mappings[active_idx];
+ size_t current_used = _dl_eh_mappings_segment_count_used (current_seg);
+
+ struct dl_eh_mappings_segment *target_seg
+ = _dl_eh_loaded_mappings[!active_idx];
+ size_t remaining_to_add = current_used + count;
+
+ /* Ensure that the new segment chain has enough space. */
+ {
+ size_t new_allocated
+ = _dl_eh_mappings_segment_count_allocated (target_seg);
+ if (new_allocated < remaining_to_add)
+ {
+ size_t more = remaining_to_add - new_allocated;
+ target_seg = _dl_eh_mappings_segment_allocate (more, target_seg);
+ if (target_seg == NULL)
+ /* Out of memory. */
+ return false;
+ /* The barrier ensures that a concurrent TM read or fork does
+ not see a partially initialized segment. */
+ atomic_store_release (&_dl_eh_loaded_mappings[!active_idx], target_seg);
+ }
+ }
+ size_t target_seg_index1 = _dl_eh_frame_update_init_seg (target_seg,
+ remaining_to_add);
+
+ /* Merge the current_seg segment list with the loaded array into the
+ target_set. Merging occurs backwards, in decreasing l_map_start
+ order. */
+ size_t loaded_index1 = count;
+ size_t current_seg_index1;
+ if (current_seg == NULL)
+ current_seg_index1 = 0;
+ else
+ current_seg_index1 = current_seg->size;
+ while (true)
+ {
+ if (current_seg_index1 == 0)
+ {
+ /* Switch to the previous segment. */
+ if (current_seg != NULL)
+ current_seg = current_seg->previous;
+ if (current_seg != NULL)
+ {
+ current_seg_index1 = current_seg->size;
+ if (current_seg_index1 == 0)
+ /* No more data in previous segments. */
+ current_seg = NULL;
+ }
+ }
+
+ if (current_seg != NULL
+ && (_dl_eh_mappings_segment_infos (current_seg)
+ [current_seg_index1 - 1]).size == 0)
+ {
+ /* This mapping has been dlclose'd. Do not copy it. */
+ --current_seg_index1;
+ continue;
+ }
+
+ if (loaded_index1 == 0 && current_seg == NULL)
+ /* No more data in either source. */
+ break;
+
+ /* Make room for another mapping. */
+ assert (remaining_to_add > 0);
+ if (target_seg_index1 == 0)
+ {
+ /* Switch segments and set the size of the segment. */
+ target_seg = target_seg->previous;
+ target_seg_index1 = _dl_eh_frame_update_init_seg (target_seg,
+ remaining_to_add);
+ }
+
+ /* Determine where to store the data. */
+ uintptr_t *pbase = &target_seg->bases[target_seg_index1 - 1];
+ struct dl_eh_frame_info *pinfo
+ = _dl_eh_mappings_segment_infos (target_seg) + target_seg_index1 - 1;
+
+ if (loaded_index1 == 0
+ || (current_seg != NULL
+ && (loaded[loaded_index1 - 1]->l_map_start
+ < current_seg->bases[current_seg_index1 - 1])))
+ {
+ /* Prefer mapping in current_seg. */
+ assert (current_seg_index1 > 0);
+ *pbase = current_seg->bases[current_seg_index1 - 1];
+ *pinfo = (_dl_eh_mappings_segment_infos (current_seg)
+ [current_seg_index1 - 1]);
+ --current_seg_index1;
+ }
+ else
+ {
+ /* Prefer newly loaded linkmap. */
+ assert (loaded_index1 > 0);
+ struct link_map *l = loaded[loaded_index1 - 1];
+ *pbase = l->l_map_start;
+ _dl_get_eh_frame (l, pinfo);
+ l->l_eh_frame_processed = 1;
+ --loaded_index1;
+ }
+
+ /* Consume space in target segment. */
+ --target_seg_index1;
+
+ --remaining_to_add;
+ }
+
+ /* Everything has been added. */
+ assert (remaining_to_add == 0);
+
+ /* The segment must have been filled up to the beginning. */
+ assert (target_seg_index1 == 0);
+
+ /* Prevent searching further into unused segments. */
+ if (target_seg->previous != NULL)
+ target_seg->previous->size = 0;
+
+ _dl_eh_mappings_end_update ();
+ return true;
+}
+
+bool
+_dl_find_eh_frame_update (struct link_map *new_map)
+{
+ /* Copy the newly-loaded link maps into an array for sorting. */
+ size_t count = 0;
+ for (struct link_map *l = new_map; l != NULL; l = l->l_next)
+ count += !l->l_eh_frame_processed;
+ struct link_map **map_array = malloc (count * sizeof (*map_array));
+ if (map_array == NULL)
+ return false;
+ {
+ size_t i = 0;
+ for (struct link_map *l = new_map; l != NULL; l = l->l_next)
+ if (!l->l_eh_frame_processed)
+ map_array[i++] = l;
+ }
+ if (count == 0)
+ return true;
+
+ _dl_eh_frame_link_map_sort (map_array, count);
+ bool ok = _dl_find_eh_frame_update_1 (map_array, count);
+ free (map_array);
+ return ok;
+}
+
+void
+_dl_find_eh_frame_dlclose (struct link_map *map)
+{
+ uint64_t start_version = _dl_eh_read_version_locked ();
+ uintptr_t map_start = map->l_map_start;
+
+
+ /* Directly patch the size information in the mapping to mark it as
+ unused. See the parallel lookup logic in _dl_find_eh_frame. Do
+ not check for previous dlclose at the same mapping address
+ because that cannot happen (there would have to be an
+ intermediate dlopen, which drops size-zero mappings). */
+ for (struct dl_eh_mappings_segment *seg
+ = _dl_eh_mappings_active_segment (start_version);
+ seg != NULL && seg->size > 0; seg = seg->previous)
+ if (map_start >= seg->bases[0])
+ {
+ size_t idx = _dl_eh_find_lower_bound (map_start, seg->bases, seg->size);
+ struct dl_eh_frame_info *info
+ = _dl_eh_mappings_segment_infos (seg) + idx;
+ if (idx == seg->size || map_start != seg->bases[idx])
+ /* Ignore missing link maps because of potential shutdown
+ issues around __libc_freeres. */
+ return;
+
+ /* The update happens in-place, but given that we do not use
+ atomic accesses on the read side, update the version around
+ the update to trigger re-validation in concurrent
+ readers. */
+ _dl_eh_mappings_begin_update ();
+
+ /* Mark as closed. */
+ info->size = 0;
+
+ _dl_eh_mappings_end_update_no_switch ();
+ }
+}
+
+void
+_dl_find_eh_frame_freeres (void)
+{
+ for (int idx = 0; idx < 2; ++idx)
+ {
+ for (struct dl_eh_mappings_segment *seg = _dl_eh_loaded_mappings[idx];
+ seg != NULL; )
+ {
+ struct dl_eh_mappings_segment *previous = seg->previous;
+ free (seg->to_free);
+ seg = previous;
+ }
+ /* Stop searching in shared objects. */
+ _dl_eh_loaded_mappings[idx] = 0;
+ }
+}
diff --git a/elf/dl-find_eh_frame.h b/elf/dl-find_eh_frame.h
new file mode 100644
index 0000000000..4bde9b14db
--- /dev/null
+++ b/elf/dl-find_eh_frame.h
@@ -0,0 +1,90 @@
+/* Declarations for finding DWARF EH frame information.
+ 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; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef _DL_FIND_EH_FRAME_H
+#define _DL_FIND_EH_FRAME_H
+
+#include <assert.h>
+#include <dlfcn.h>
+#include <ldsodefs.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+/* Exception handling information for a mapping (shared object or load
+ segment). The base address is stored separately to increase cache
+ utilization. */
+struct dl_eh_frame_info
+{
+ /* Size of the mapping. dlclose sets this to zero without removing
+ the array element. */
+ uintptr_t size;
+ void *eh_frame; /* Corresponding PT_GNU_EH_FRAME. */
+#if DL_FIND_EH_FRAME_DBASE
+ void *dbase;
+#endif
+
+ /* Note: During the initialization phase, size is used for the base
+ address and eh_frame for a pointer to the link map.
+ _dl_eh_mappings_segment_finish computes the final data for a
+ segment after sorting by base address. */
+};
+
+/* Extract the exception handling data from a link map and writes it
+ to *INFO. If no such data is available INFO->eh_frame will be
+ NULL. */
+static void __attribute__ ((unused))
+_dl_get_eh_frame (const struct link_map *l, struct dl_eh_frame_info *info)
+{
+ info->size = l->l_map_end - l->l_map_start;
+#if DL_FIND_EH_FRAME_DBASE
+ info->dbase = (void *) l->l_info[DT_PLTGOT];
+#endif
+
+ for (const ElfW(Phdr) *ph = l->l_phdr, *ph_end = l->l_phdr + l->l_phnum;
+ ph < ph_end; ++ph)
+ if (ph->p_type == PT_GNU_EH_FRAME)
+ {
+ info->eh_frame = (void *) (ph->p_vaddr + l->l_addr);
+ return;
+ }
+
+ /* Object has no PT_GNU_EH_FRAME. */
+ info->eh_frame = NULL;
+}
+
+
+/* Called by the dynamic linker to set up the data structures for the
+ initially loaded objects. This creates a few persistent
+ allocations, so it should be called with the minimal malloc. */
+void _dl_find_eh_frame_init (void) attribute_hidden;
+
+/* Called by dlopen/dlmopen to add new objects to the DWARF EH frame
+ data structures. NEW_MAP is the dlopen'ed link map. Link maps on
+ the l_next list are added if l_eh_frame_processed is 0. Needs to
+ be protected by loader write lock. Returns true on success, false
+ on malloc failure. */
+bool _dl_find_eh_frame_update (struct link_map *new_map) attribute_hidden;
+
+/* Called by dlclose to remove the link map from the DWARF EH frame
+ data structures. Needs to be protected by loader write lock. */
+void _dl_find_eh_frame_dlclose (struct link_map *l) attribute_hidden;
+
+/* Called from __libc_freeres to deallocate malloc'ed memory. */
+void _dl_find_eh_frame_freeres (void) attribute_hidden;
+
+#endif /* _DL_FIND_EH_FRAME_H */
diff --git a/elf/dl-find_eh_frame_slow.h b/elf/dl-find_eh_frame_slow.h
new file mode 100644
index 0000000000..355351ce28
--- /dev/null
+++ b/elf/dl-find_eh_frame_slow.h
@@ -0,0 +1,55 @@
+/* Locating DWARF unwind information using the dynamic loader. Slow version.
+ 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; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <assert.h>
+#include <dlfcn.h>
+#include <ldsodefs.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <elf/dl-find_eh_frame.h>
+
+/* This function is similar to _dl_find_eh_frame, but travers the link
+ maps directly. It is used from audit modules before
+ _dl_find_eh_frame_init has been called, and for testing. */
+static void *
+_dl_find_eh_frame_slow (void *pc
+#if DL_FIND_EH_FRAME_DBASE
+ , void **dbase
+#endif
+ )
+{
+ ElfW(Addr) addr = (ElfW(Addr)) pc;
+ for (Lmid_t ns = 0; ns < GL(dl_nns); ++ns)
+ for (struct link_map *l = GL(dl_ns)[ns]._ns_loaded; l != NULL;
+ l = l->l_next)
+ if (addr >= l->l_map_start && addr < l->l_map_end
+ && (l->l_contiguous || _dl_addr_inside_object (l, addr)))
+ {
+ assert (ns == l->l_ns);
+ struct dl_eh_frame_info info;
+ _dl_get_eh_frame (l, &info);
+#if DL_FIND_EH_FRAME_DBASE
+ *dbase = info.dbase;
+#endif
+ return info.eh_frame;
+ }
+
+ /* Object not found. */
+ return NULL;
+}
diff --git a/elf/dl-libc_freeres.c b/elf/dl-libc_freeres.c
index 68f305a6f9..7822730e7d 100644
--- a/elf/dl-libc_freeres.c
+++ b/elf/dl-libc_freeres.c
@@ -17,8 +17,10 @@
<https://www.gnu.org/licenses/>. */
#include <ldsodefs.h>
+#include <dl-find_eh_frame.h>
void
__rtld_libc_freeres (void)
{
+ _dl_find_eh_frame_freeres ();
}
diff --git a/elf/dl-open.c b/elf/dl-open.c
index 6ea5dd2457..c889cc5c54 100644
--- a/elf/dl-open.c
+++ b/elf/dl-open.c
@@ -36,6 +36,7 @@
#include <array_length.h>
#include <libc-early-init.h>
#include <gnu/lib-names.h>
+#include <dl-find_eh_frame.h>
#include <dl-dst.h>
#include <dl-prop.h>
@@ -749,6 +750,10 @@ dl_open_worker_begin (void *a)
objects. */
update_scopes (new);
+ if (!_dl_find_eh_frame_update (new))
+ _dl_signal_error (ENOMEM, new->l_libname->name, NULL,
+ N_ ("cannot allocate EH frame data"));
+
/* FIXME: It is unclear whether the order here is correct.
Shouldn't new objects be made available for binding (and thus
execution) only after there TLS data has been set up fully?
diff --git a/elf/rtld.c b/elf/rtld.c
index 847141e21d..c379da29cc 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -50,6 +50,7 @@
#include <gnu/lib-names.h>
#include <dl-tunables.h>
#include <get-dynamic-info.h>
+#include <dl-find_eh_frame.h>
#include <assert.h>
@@ -2331,6 +2332,9 @@ dl_main (const ElfW(Phdr) *phdr,
rtld_timer_stop (&relocate_time, start);
}
+ /* Set up the EH frame lookup structures. */
+ _dl_find_eh_frame_init ();
+
/* The library defining malloc has already been relocated due to
prelinking. Resolve the malloc symbols for the dynamic
loader. */
@@ -2439,6 +2443,9 @@ dl_main (const ElfW(Phdr) *phdr,
re-relocation, we might call a user-supplied function
(e.g. calloc from _dl_relocate_object) that uses TLS data. */
+ /* Set up the EH frame lookup structures. */
+ _dl_find_eh_frame_init ();
+
/* The malloc implementation has been relocated, so resolving
its symbols (and potentially calling IFUNC resolvers) is safe
at this point. */
diff --git a/elf/tst-dl_find_eh_frame-mod1.c b/elf/tst-dl_find_eh_frame-mod1.c
new file mode 100644
index 0000000000..d33ef56efd
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-mod1.c
@@ -0,0 +1,10 @@
+char mod1_data;
+
+void
+mod1_function (void (*f) (void))
+{
+ /* Make sure this is not a tail call and unwind information is
+ therefore needed. */
+ f ();
+ f ();
+}
diff --git a/elf/tst-dl_find_eh_frame-mod2.c b/elf/tst-dl_find_eh_frame-mod2.c
new file mode 100644
index 0000000000..7feccf9f57
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-mod2.c
@@ -0,0 +1,10 @@
+char mod2_data;
+
+void
+mod2_function (void (*f) (void))
+{
+ /* Make sure this is not a tail call and unwind information is
+ therefore needed. */
+ f ();
+ f ();
+}
diff --git a/elf/tst-dl_find_eh_frame-mod3.c b/elf/tst-dl_find_eh_frame-mod3.c
new file mode 100644
index 0000000000..c1fc20ff9c
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-mod3.c
@@ -0,0 +1,10 @@
+char mod3_data[4096];
+
+void
+mod3_function (void (*f) (void))
+{
+ /* Make sure this is not a tail call and unwind information is
+ therefore needed. */
+ f ();
+ f ();
+}
diff --git a/elf/tst-dl_find_eh_frame-mod4.c b/elf/tst-dl_find_eh_frame-mod4.c
new file mode 100644
index 0000000000..27934e6011
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-mod4.c
@@ -0,0 +1,10 @@
+char mod4_data;
+
+void
+mod4_function (void (*f) (void))
+{
+ /* Make sure this is not a tail call and unwind information is
+ therefore needed. */
+ f ();
+ f ();
+}
diff --git a/elf/tst-dl_find_eh_frame-mod5.c b/elf/tst-dl_find_eh_frame-mod5.c
new file mode 100644
index 0000000000..3bdbda8ccd
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-mod5.c
@@ -0,0 +1,11 @@
+/* Slightly larger to get different layouts. */
+char mod5_data[4096];
+
+void
+mod5_function (void (*f) (void))
+{
+ /* Make sure this is not a tail call and unwind information is
+ therefore needed. */
+ f ();
+ f ();
+}
diff --git a/elf/tst-dl_find_eh_frame-mod6.c b/elf/tst-dl_find_eh_frame-mod6.c
new file mode 100644
index 0000000000..f78acffb9e
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-mod6.c
@@ -0,0 +1,11 @@
+/* Large to get different layouts. */
+char mod6_data[4096];
+
+void
+mod6_function (void (*f) (void))
+{
+ /* Make sure this is not a tail call and unwind information is
+ therefore needed. */
+ f ();
+ f ();
+}
diff --git a/elf/tst-dl_find_eh_frame-mod7.c b/elf/tst-dl_find_eh_frame-mod7.c
new file mode 100644
index 0000000000..71353880da
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-mod7.c
@@ -0,0 +1,10 @@
+char mod7_data;
+
+void
+mod7_function (void (*f) (void))
+{
+ /* Make sure this is not a tail call and unwind information is
+ therefore needed. */
+ f ();
+ f ();
+}
diff --git a/elf/tst-dl_find_eh_frame-mod8.c b/elf/tst-dl_find_eh_frame-mod8.c
new file mode 100644
index 0000000000..41f8f1ea09
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-mod8.c
@@ -0,0 +1,10 @@
+char mod8_data;
+
+void
+mod8_function (void (*f) (void))
+{
+ /* Make sure this is not a tail call and unwind information is
+ therefore needed. */
+ f ();
+ f ();
+}
diff --git a/elf/tst-dl_find_eh_frame-mod9.c b/elf/tst-dl_find_eh_frame-mod9.c
new file mode 100644
index 0000000000..dc2e7a20cb
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-mod9.c
@@ -0,0 +1,10 @@
+char mod9_data;
+
+void
+mod9_function (void (*f) (void))
+{
+ /* Make sure this is not a tail call and unwind information is
+ therefore needed. */
+ f ();
+ f ();
+}
diff --git a/elf/tst-dl_find_eh_frame-threads.c b/elf/tst-dl_find_eh_frame-threads.c
new file mode 100644
index 0000000000..355241a354
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame-threads.c
@@ -0,0 +1,237 @@
+/* _dl_find_eh_frame test with parallelism.
+ 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; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <array_length.h>
+#include <dlfcn.h>
+#include <elf/dl-find_eh_frame.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <support/support.h>
+#include <support/xdlfcn.h>
+#include <support/xthread.h>
+#include <support/xunistd.h>
+
+struct find_result
+{
+ void *eh_frame;
+#if DL_FIND_EH_FRAME_DBASE
+ void *dbase;
+#endif
+};
+
+/* _dl_find_eh_frame with uniform calling convetion. */
+static struct find_result
+find (void *pc)
+{
+ struct find_result result;
+#if DL_FIND_EH_FRAME_DBASE
+ result.eh_frame = _dl_find_eh_frame (pc, &result.dbase);
+#else
+ result.eh_frame = _dl_find_eh_frame (pc);
+#endif
+ return result;
+}
+
+/* Returns the soname for the test object NUMBER. */
+static char *
+soname (int number)
+{
+ return xasprintf ("tst-dl_find_eh_frame-mod%d.so", number);
+}
+
+/* Returns the data symbol name for the test object NUMBER. */
+static char *
+symbol (int number)
+{
+ return xasprintf ("mod%d_data", number);
+}
+
+struct verify_data
+{
+ char *soname;
+ struct link_map *link_map;
+ void *address; /* Address in the shared object. */
+ void *map_start; /* Minimum covered address. */
+ void *map_end; /* Maximum covered address. */
+ struct dl_eh_frame_info info;
+ pthread_t thr;
+};
+
+/* Compare _dl_find_eh_frame result with struct dl_eh_frame_info. */
+static void
+check (struct find_result actual, struct verify_data *expected)
+{
+ if (actual.eh_frame != expected->info.eh_frame)
+ {
+ support_record_failure ();
+ printf ("%s: error: %s EH frame is %p, expected %p\n",
+ __FILE__, expected->soname, actual.eh_frame,
+ expected->info.eh_frame);
+ }
+ if (actual.eh_frame == NULL)
+ /* No result to check. */
+ return;
+#if DL_FIND_EH_FRAME_DBASE
+ if (actual.dbase != expected->info.dbase)
+ {
+ support_record_failure ();
+ printf ("%s: error: %s data base is %p, expected %p\n",
+ __FILE__, expected->soname, actual.dbase, expected->info.dbase);
+ }
+#endif
+}
+
+/* Request process termination after 3 seconds. */
+static bool exit_requested;
+static void *
+exit_thread (void *ignored)
+{
+ usleep (3 * 100 * 1000);
+ __atomic_store_n (&exit_requested, true, __ATOMIC_RELAXED);
+ return NULL;
+}
+
+static void *
+verify_thread (void *closure)
+{
+ struct verify_data *data = closure;
+
+ while (!__atomic_load_n (&exit_requested, __ATOMIC_RELAXED))
+ {
+ check (find (data->address), data);
+ check (find (data->map_start), data);
+ check (find (data->map_end), data);
+ }
+
+ return NULL;
+}
+
+/* Sets up the verification data, dlopen'ing shared object NUMBER, and
+ launches a verification thread. */
+static void
+start_verify (int number, struct verify_data *data)
+{
+ data->soname = soname (number);
+ data->link_map = xdlopen (data->soname, RTLD_NOW);
+ _dl_get_eh_frame (data->link_map, &data->info);
+ char *sym = symbol (number);
+ data->address = xdlsym (data->link_map, sym);
+ data->map_start = (void *) data->link_map->l_map_start;
+ data->map_end = (void *) (data->link_map->l_map_end - 1);
+ free (sym);
+ data->thr = xpthread_create (NULL, verify_thread, data);
+}
+
+
+static int
+do_test (void)
+{
+ struct verify_data data_mod2;
+ struct verify_data data_mod4;
+ struct verify_data data_mod7;
+
+ /* Load the modules with gaps. */
+ {
+ void *mod1 = xdlopen ("tst-dl_find_eh_frame-mod1.so", RTLD_NOW);
+ start_verify (2, &data_mod2);
+ void *mod3 = xdlopen ("tst-dl_find_eh_frame-mod3.so", RTLD_NOW);
+ start_verify (4, &data_mod4);
+ void *mod5 = xdlopen ("tst-dl_find_eh_frame-mod5.so", RTLD_NOW);
+ void *mod6 = xdlopen ("tst-dl_find_eh_frame-mod6.so", RTLD_NOW);
+ start_verify (7, &data_mod7);
+ xdlclose (mod6);
+ xdlclose (mod5);
+ xdlclose (mod3);
+ xdlclose (mod1);
+ }
+
+ /* Objects that continuously opened and closed. */
+ struct temp_object
+ {
+ char *soname;
+ char *symbol;
+ struct link_map *link_map;
+ void *address;
+ void *eh_frame;
+ } temp_objects[] =
+ {
+ { soname (1), symbol (1), },
+ { soname (3), symbol (3), },
+ { soname (5), symbol (5), },
+ { soname (6), symbol (6), },
+ { soname (8), symbol (8), },
+ { soname (9), symbol (9), },
+ };
+
+ pthread_t exit_thr = xpthread_create (NULL, exit_thread, NULL);
+
+ struct drand48_data state;
+ srand48_r (1, &state);
+ while (!__atomic_load_n (&exit_requested, __ATOMIC_RELAXED))
+ {
+ long int idx;
+ lrand48_r (&state, &idx);
+ idx %= array_length (temp_objects);
+ if (temp_objects[idx].link_map == NULL)
+ {
+ temp_objects[idx].link_map = xdlopen (temp_objects[idx].soname,
+ RTLD_NOW);
+ temp_objects[idx].address = xdlsym (temp_objects[idx].link_map,
+ temp_objects[idx].symbol);
+ temp_objects[idx].eh_frame
+ = find (temp_objects[idx].address).eh_frame;
+ }
+ else
+ {
+ xdlclose (temp_objects[idx].link_map);
+ temp_objects[idx].link_map = NULL;
+ void *eh_frame = find (temp_objects[idx].address).eh_frame;
+ if (eh_frame != NULL)
+ {
+ support_record_failure ();
+ printf ("%s: error: %s EH frame is %p after dclose, was %p\n",
+ __FILE__, temp_objects[idx].soname, eh_frame,
+ temp_objects[idx].eh_frame);
+ }
+ }
+ }
+
+ xpthread_join (data_mod2.thr);
+ xpthread_join (data_mod4.thr);
+ xpthread_join (data_mod7.thr);
+ xpthread_join (exit_thr);
+
+ for (size_t i = 0; i < array_length (temp_objects); ++i)
+ {
+ free (temp_objects[i].soname);
+ free (temp_objects[i].symbol);
+ if (temp_objects[i].link_map != NULL)
+ xdlclose (temp_objects[i].link_map);
+ }
+
+ free (data_mod2.soname);
+ free (data_mod4.soname);
+ xdlclose (data_mod4.link_map);
+ free (data_mod7.soname);
+ xdlclose (data_mod7.link_map);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/elf/tst-dl_find_eh_frame.c b/elf/tst-dl_find_eh_frame.c
new file mode 100644
index 0000000000..a532db6cda
--- /dev/null
+++ b/elf/tst-dl_find_eh_frame.c
@@ -0,0 +1,179 @@
+/* Basic tests for _dl_find_eh_frame.
+ 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; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <dl-find_eh_frame.h>
+#include <dlfcn.h>
+#include <gnu/lib-names.h>
+#include <ldsodefs.h>
+#include <link.h>
+#include <stdio.h>
+#include <support/check.h>
+#include <support/xdlfcn.h>
+
+/* Use data objects for testing, so that it is not necessary to decode
+ function descriptors on architectures that have them. */
+static char main_program_data;
+
+struct find_result
+{
+ void *eh_frame;
+#if DL_FIND_EH_FRAME_DBASE
+ void *dbase;
+#endif
+};
+
+/* _dl_find_eh_frame with uniform calling convetion. */
+static struct find_result
+find (void *pc)
+{
+ struct find_result result;
+#if DL_FIND_EH_FRAME_DBASE
+ result.eh_frame = _dl_find_eh_frame (pc, &result.dbase);
+#else
+ result.eh_frame = _dl_find_eh_frame (pc);
+#endif
+ return result;
+}
+
+/* Compare _dl_find_eh_frame result with struct dl_eh_frame_info. */
+static void
+check (struct find_result actual, struct dl_eh_frame_info expected, int line)
+{
+ if (actual.eh_frame != expected.eh_frame)
+ {
+ support_record_failure ();
+ printf ("%s:%d: error: EH frame is %p, expected %p\n",
+ __FILE__, line, actual.eh_frame, expected.eh_frame);
+ }
+ if (actual.eh_frame == NULL)
+ /* No result to check. */
+ return;
+#if DL_FIND_EH_FRAME_DBASE
+ if (actual.dbase != expected.dbase)
+ {
+ support_record_failure ();
+ printf ("%s:%d: error: data base is %p, expected %p\n",
+ __FILE__, line, actual.dbase, expected.dbase);
+ }
+#endif
+}
+
+/* Check that unwind data for the main executable and the dynamic
+ linker can be found. */
+static void
+check_initial (void)
+{
+ /* Avoid direct reference, which could lead to copy relocations. */
+ struct r_debug *debug = xdlsym (NULL, "_r_debug");
+ TEST_VERIFY_EXIT (debug != NULL);
+ char **tzname = xdlsym (NULL, "tzname");
+
+ /* The main executable has an unnamed link map. */
+ struct link_map *main_map = (struct link_map *) debug->r_map;
+ TEST_COMPARE_STRING (main_map->l_name, "");
+
+ /* The link map of the dynamic linker. */
+ struct link_map *rtld_map = xdlopen (LD_SO, RTLD_LAZY | RTLD_NOLOAD);
+ TEST_VERIFY_EXIT (rtld_map != NULL);
+
+ /* The link map of libc.so. */
+ struct link_map *libc_map = xdlopen (LIBC_SO, RTLD_LAZY | RTLD_NOLOAD);
+ TEST_VERIFY_EXIT (libc_map != NULL);
+
+ struct dl_eh_frame_info expected;
+
+ /* Data in the main program. */
+ _dl_get_eh_frame (main_map, &expected);
+ check (find (&main_program_data), expected, __LINE__);
+ /* Corner cases for the mapping. */
+ check (find ((void *) main_map->l_map_start), expected, __LINE__);
+ check (find ((void *) (main_map->l_map_end - 1)), expected, __LINE__);
+
+ /* Data in the dynamic loader. */
+ _dl_get_eh_frame (rtld_map, &expected);
+ check (find (debug), expected, __LINE__);
+ check (find ((void *) rtld_map->l_map_start), expected, __LINE__);
+ check (find ((void *) (rtld_map->l_map_end - 1)), expected, __LINE__);
+
+ /* Data in libc. */
+ _dl_get_eh_frame (libc_map, &expected);
+ check (find (tzname), expected, __LINE__);
+ check (find ((void *) libc_map->l_map_start), expected, __LINE__);
+ check (find ((void *) (libc_map->l_map_end - 1)), expected, __LINE__);
+}
+
+static int
+do_test (void)
+{
+ printf ("info: main program unwind data: %p\n",
+ find (&main_program_data).eh_frame);
+
+ check_initial ();
+
+ /* dlopen-based test. First an object that can be dlclosed. */
+ struct link_map *mod1 = xdlopen ("tst-dl_find_eh_frame-mod1.so", RTLD_NOW);
+ void *mod1_data = xdlsym (mod1, "mod1_data");
+ void *map_start = (void *) mod1->l_map_start;
+ void *map_end = (void *) (mod1->l_map_end - 1);
+ check_initial ();
+
+ struct dl_eh_frame_info expected;
+ _dl_get_eh_frame (mod1, &expected);
+ check (find (mod1_data), expected, __LINE__);
+ check (find (map_start), expected, __LINE__);
+ check (find (map_end), expected, __LINE__);
+
+ /* Unloading must make the unwinding data unavailable. */
+ xdlclose (mod1);
+ check_initial ();
+ expected.eh_frame = NULL;
+ check (find (mod1_data), expected, __LINE__);
+ check (find (map_start), expected, __LINE__);
+ check (find (map_end), expected, __LINE__);
+
+ /* Now try a NODELETE load. */
+ struct link_map *mod2 = xdlopen ("tst-dl_find_eh_frame-mod2.so", RTLD_NOW);
+ void *mod2_data = xdlsym (mod1, "mod2_data");
+ map_start = (void *) mod2->l_map_start;
+ map_end = (void *) (mod2->l_map_end - 1);
+ check_initial ();
+ _dl_get_eh_frame (mod2, &expected);
+ check (find (mod2_data), expected, __LINE__);
+ check (find (map_start), expected, __LINE__);
+ check (find (map_end), expected, __LINE__);
+ dlclose (mod2); /* Does nothing due to NODELETE. */
+ check_initial ();
+ check (find (mod2_data), expected, __LINE__);
+ check (find (map_start), expected, __LINE__);
+ check (find (map_end), expected, __LINE__);
+
+ /* Now load again the first module. */
+ mod1 = xdlopen ("tst-dl_find_eh_frame-mod1.so", RTLD_NOW);
+ mod1_data = xdlsym (mod1, "mod1_data");
+ map_start = (void *) mod1->l_map_start;
+ map_end = (void *) (mod1->l_map_end - 1);
+ check_initial ();
+ _dl_get_eh_frame (mod1, &expected);
+ check (find (mod1_data), expected, __LINE__);
+ check (find (map_start), expected, __LINE__);
+ check (find (map_end), expected, __LINE__);
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/include/atomic_wide_counter.h b/include/atomic_wide_counter.h
index 31f009d5e6..d1c40cd85f 100644
--- a/include/atomic_wide_counter.h
+++ b/include/atomic_wide_counter.h
@@ -30,6 +30,12 @@ __atomic_wide_counter_load_relaxed (__atomic_wide_counter *c)
return atomic_load_relaxed (&c->__value64);
}
+static inline uint64_t
+__atomic_wide_counter_load_acquire (__atomic_wide_counter *c)
+{
+ return atomic_load_acquire (&c->__value64);
+}
+
static inline uint64_t
__atomic_wide_counter_fetch_add_relaxed (__atomic_wide_counter *c,
unsigned int val)
@@ -64,6 +70,14 @@ __atomic_wide_counter_fetch_xor_release (__atomic_wide_counter *c,
uint64_t __atomic_wide_counter_load_relaxed (__atomic_wide_counter *c)
attribute_hidden;
+static inline uint64_t
+__atomic_wide_counter_load_acquire (__atomic_wide_counter *c)
+{
+ uint64_t r = __atomic_wide_counter_load_relaxed (c);
+ atomic_thread_fence_acquire ();
+ return r;
+}
+
uint64_t __atomic_wide_counter_fetch_add_relaxed (__atomic_wide_counter *c,
unsigned int op)
attribute_hidden;
diff --git a/include/bits/dlfcn_eh_frame.h b/include/bits/dlfcn_eh_frame.h
new file mode 100644
index 0000000000..3f694c45bc
--- /dev/null
+++ b/include/bits/dlfcn_eh_frame.h
@@ -0,0 +1 @@
+#include_next <bits/dlfcn_eh_frame.h>
diff --git a/include/link.h b/include/link.h
index c1c382ccfa..fa2ecc2f4a 100644
--- a/include/link.h
+++ b/include/link.h
@@ -211,6 +211,9 @@ struct link_map
freed, ie. not allocated with
the dummy malloc in ld.so. */
unsigned int l_ld_readonly:1; /* Nonzero if dynamic section is readonly. */
+ unsigned int l_eh_frame_processed:1; /* Zero if _dl_eh_frame_update
+ needs to process this
+ lt_library map. */
/* NODELETE status of the map. Only valid for maps of type
lt_loaded. Lazy binding sets l_nodelete_active directly,
diff --git a/manual/Makefile b/manual/Makefile
index e83444341e..31678681ef 100644
--- a/manual/Makefile
+++ b/manual/Makefile
@@ -39,7 +39,7 @@ chapters = $(addsuffix .texi, \
pipe socket terminal syslog math arith time \
resource setjmp signal startup process ipc job \
nss users sysinfo conf crypt debug threads \
- probes tunables)
+ dynlink probes tunables)
appendices = lang.texi header.texi install.texi maint.texi platform.texi \
contrib.texi
licenses = freemanuals.texi lgpl-2.1.texi fdl-1.3.texi
diff --git a/manual/dynlink.texi b/manual/dynlink.texi
new file mode 100644
index 0000000000..8969a8029d
--- /dev/null
+++ b/manual/dynlink.texi
@@ -0,0 +1,69 @@
+@node Dynamic Linker
+@c @node Dynamic Linker, Internal Probes, Threads, Top
+@c %MENU% Loading programs and shared objects.
+@chapter Dynamic Linker
+@cindex dynamic linker
+@cindex dynamic loader
+
+The @dfn{dynamic linker} is responsible for loading dynamically linked
+programs and their dependencies (in the form of shared objects). The
+dynamic linker in @theglibc{} also supports loading shared objects (such
+as plugins) later at run time.
+
+Dynamic linkers are sometimes called @dfn{dynamic loaders}.
+
+@menu
+* Dynamic Linker Introspection:: Interfaces for querying mapping information.
+@end menu
+
+@node Dynamic Linker Introspection
+@section Dynamic Linker Introspection
+
+@Theglibc{} provides various functions for querying information from the
+dynamic linker.
+
+@deftypefun {void *} _dl_find_eh_frame (void *@var{pc})
+@standards{GNU, dlfcn.h}
+@safety{@mtsafe{}@assafe{}@acsafe{}}
+This function returns a pointer to the unwinding information for the
+object that contains the program coder @var{pc}. If the platform uses
+DWARF unwinding information, this is the in-memory address of the
+@code{PT_GNU_EH_FRAME} segment.
+
+In case @var{pc} resides in an object that lacks unwinding information,
+the function returns @code{NULL}. If no object matches @var{pc},
+@code{NULL} is returned as well.
+
+@code{_dl_find_eh_frame} itself is thread-safe. However, if the
+application invokes @code{dlclose} for the object that contains @var{pc}
+concurrently with @code{_dl_find_eh_frame} or after the call returns,
+accessing the unwinding data for that object is not safe. Therefore,
+the application needs to ensure by other means (e.g., by convention)
+that @var{pc} remains a valid code address while the unwinding
+information is processed.
+
+This function is a GNU extension.
+@end deftypefun
+
+@deftypevr Macro int DL_FIND_EH_FRAME_DBASE
+@standards{GNU, dlfcn.h}
+On most targets, this macro is defined as @code{0}. If it is defined to
+@code{1}, the @code{_dl_find_eh_frame} function expects a second
+argument of type @code{void **}. In this case, a pointer to a
+@code{void *} object must be passed, and if @code{_dl_find_eh_frame}
+finds any unwinding information, it writes the base address for
+@code{DW_EH_PE_datarel} DWARF encodings to this location.
+
+This macro is a GNU extension.
+@end deftypevr
+
+@c FIXME these are undocumented:
+@c dladdr
+@c dladdr1
+@c dlclose
+@c dlerror
+@c dlinfo
+@c dlmopen
+@c dlopen
+@c dlsym
+@c dlvsym
diff --git a/manual/libdl.texi b/manual/libdl.texi
deleted file mode 100644
index e3fe0452d9..0000000000
--- a/manual/libdl.texi
+++ /dev/null
@@ -1,10 +0,0 @@
-@c FIXME these are undocumented:
-@c dladdr
-@c dladdr1
-@c dlclose
-@c dlerror
-@c dlinfo
-@c dlmopen
-@c dlopen
-@c dlsym
-@c dlvsym
diff --git a/manual/probes.texi b/manual/probes.texi
index 4aae76b819..ee019e6517 100644
--- a/manual/probes.texi
+++ b/manual/probes.texi
@@ -1,5 +1,5 @@
@node Internal Probes
-@c @node Internal Probes, Tunables, Threads, Top
+@c @node Internal Probes, Tunables, Dynamic Linker, Top
@c %MENU% Probes to monitor libc internal behavior
@chapter Internal probes
diff --git a/manual/threads.texi b/manual/threads.texi
index 06b6b277a1..7f166bfa87 100644
--- a/manual/threads.texi
+++ b/manual/threads.texi
@@ -1,5 +1,5 @@
@node Threads
-@c @node Threads, Internal Probes, Debugging Support, Top
+@c @node Threads, Dynamic Linker, Debugging Support, Top
@c %MENU% Functions, constants, and data types for working with threads
@chapter Threads
@cindex threads
diff --git a/sysdeps/i386/bits/dlfcn_eh_frame.h b/sysdeps/i386/bits/dlfcn_eh_frame.h
new file mode 100644
index 0000000000..98f6b37029
--- /dev/null
+++ b/sysdeps/i386/bits/dlfcn_eh_frame.h
@@ -0,0 +1,34 @@
+/* i386 definitions for find unwind information using ld.so.
+ 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; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef _DLFCN_H
+# error "Never use <bits/dlfcn_eh_frame.h> directly; include <dlfcn.h> instead."
+#endif
+
+/* This implementation uses a DBASE pointer argument in
+ _dl_find_eh_frame. */
+#define DL_FIND_EH_FRAME_DBASE 1
+
+__BEGIN_DECLS
+/* If PC points into an object that has a PT_GNU_EH_FRAME segment,
+ return the pointer to the start of that segment in memory, and
+ *DBASE is updated with the base address for DW_EH_PE_datarel DWARF
+ encodings. If no corresponding object exists or the object has no
+ such segment, returns NULL. */
+void *_dl_find_eh_frame (void *__pc, void **__dbase) __THROW __nonnull ((2));
+__END_DECLS
diff --git a/sysdeps/mach/hurd/i386/ld.abilist b/sysdeps/mach/hurd/i386/ld.abilist
index 7e20c5e7ce..786cd93810 100644
--- a/sysdeps/mach/hurd/i386/ld.abilist
+++ b/sysdeps/mach/hurd/i386/ld.abilist
@@ -16,3 +16,4 @@ GLIBC_2.2.6 _r_debug D 0x14
GLIBC_2.2.6 abort F
GLIBC_2.3 ___tls_get_addr F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/nios2/bits/dlfcn_eh_frame.h b/sysdeps/nios2/bits/dlfcn_eh_frame.h
new file mode 100644
index 0000000000..3acc741c6e
--- /dev/null
+++ b/sysdeps/nios2/bits/dlfcn_eh_frame.h
@@ -0,0 +1,34 @@
+/* nios2 definitions for find unwind information using ld.so.
+ 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; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef _DLFCN_H
+# error "Never use <bits/dlfcn_eh_frame.h> directly; include <dlfcn.h> instead."
+#endif
+
+/* This implementation uses a DBASE pointer argument in
+ _dl_find_eh_frame. */
+#define DL_FIND_EH_FRAME_DBASE 1
+
+__BEGIN_DECLS
+/* If PC points into an object that has a PT_GNU_EH_FRAME segment,
+ return the pointer to the start of that segment in memory, and
+ *DBASE is updated with the base address for DW_EH_PE_datarel DWARF
+ encodings. If no corresponding object exists or the object has no
+ such segment, returns NULL. */
+void *_dl_find_eh_frame (void *__pc, void **__dbase) __THROW __nonnull ((2));
+__END_DECLS
diff --git a/sysdeps/unix/sysv/linux/aarch64/ld.abilist b/sysdeps/unix/sysv/linux/aarch64/ld.abilist
index 80b2fe6725..4655d8d00f 100644
--- a/sysdeps/unix/sysv/linux/aarch64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/ld.abilist
@@ -3,3 +3,4 @@ GLIBC_2.17 __stack_chk_guard D 0x8
GLIBC_2.17 __tls_get_addr F
GLIBC_2.17 _dl_mcount F
GLIBC_2.17 _r_debug D 0x28
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/alpha/ld.abilist b/sysdeps/unix/sysv/linux/alpha/ld.abilist
index 98a03f611f..21f873600a 100644
--- a/sysdeps/unix/sysv/linux/alpha/ld.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/ld.abilist
@@ -2,4 +2,5 @@ GLIBC_2.0 _r_debug D 0x28
GLIBC_2.1 __libc_stack_end D 0x8
GLIBC_2.1 _dl_mcount F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __stack_chk_guard D 0x8
diff --git a/sysdeps/unix/sysv/linux/arc/ld.abilist b/sysdeps/unix/sysv/linux/arc/ld.abilist
index 048f17c848..b1b719ca61 100644
--- a/sysdeps/unix/sysv/linux/arc/ld.abilist
+++ b/sysdeps/unix/sysv/linux/arc/ld.abilist
@@ -3,3 +3,4 @@ GLIBC_2.32 __stack_chk_guard D 0x4
GLIBC_2.32 __tls_get_addr F
GLIBC_2.32 _dl_mcount F
GLIBC_2.32 _r_debug D 0x14
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/arm/be/ld.abilist b/sysdeps/unix/sysv/linux/arm/be/ld.abilist
index cc8825c3bc..973f414c35 100644
--- a/sysdeps/unix/sysv/linux/arm/be/ld.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/ld.abilist
@@ -1,3 +1,4 @@
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __libc_stack_end D 0x4
GLIBC_2.4 __stack_chk_guard D 0x4
GLIBC_2.4 __tls_get_addr F
diff --git a/sysdeps/unix/sysv/linux/arm/le/ld.abilist b/sysdeps/unix/sysv/linux/arm/le/ld.abilist
index cc8825c3bc..973f414c35 100644
--- a/sysdeps/unix/sysv/linux/arm/le/ld.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/ld.abilist
@@ -1,3 +1,4 @@
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __libc_stack_end D 0x4
GLIBC_2.4 __stack_chk_guard D 0x4
GLIBC_2.4 __tls_get_addr F
diff --git a/sysdeps/unix/sysv/linux/csky/ld.abilist b/sysdeps/unix/sysv/linux/csky/ld.abilist
index 564ac09737..bba19877b0 100644
--- a/sysdeps/unix/sysv/linux/csky/ld.abilist
+++ b/sysdeps/unix/sysv/linux/csky/ld.abilist
@@ -3,3 +3,4 @@ GLIBC_2.29 __stack_chk_guard D 0x4
GLIBC_2.29 __tls_get_addr F
GLIBC_2.29 _dl_mcount F
GLIBC_2.29 _r_debug D 0x14
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/hppa/ld.abilist b/sysdeps/unix/sysv/linux/hppa/ld.abilist
index d155a59843..dcee0ece2a 100644
--- a/sysdeps/unix/sysv/linux/hppa/ld.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/ld.abilist
@@ -2,4 +2,5 @@ GLIBC_2.2 __libc_stack_end D 0x4
GLIBC_2.2 _dl_mcount F
GLIBC_2.2 _r_debug D 0x14
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/i386/ld.abilist b/sysdeps/unix/sysv/linux/i386/ld.abilist
index 0478e22071..0c4c02d18e 100644
--- a/sysdeps/unix/sysv/linux/i386/ld.abilist
+++ b/sysdeps/unix/sysv/linux/i386/ld.abilist
@@ -3,3 +3,4 @@ GLIBC_2.1 __libc_stack_end D 0x4
GLIBC_2.1 _dl_mcount F
GLIBC_2.3 ___tls_get_addr F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/ia64/ld.abilist b/sysdeps/unix/sysv/linux/ia64/ld.abilist
index 33f91199bf..6ae0cb97b4 100644
--- a/sysdeps/unix/sysv/linux/ia64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/ld.abilist
@@ -2,3 +2,4 @@ GLIBC_2.2 __libc_stack_end D 0x8
GLIBC_2.2 _dl_mcount F
GLIBC_2.2 _r_debug D 0x28
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist
index cc8825c3bc..973f414c35 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist
@@ -1,3 +1,4 @@
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __libc_stack_end D 0x4
GLIBC_2.4 __stack_chk_guard D 0x4
GLIBC_2.4 __tls_get_addr F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist
index 3ba474c27f..1719c1bff0 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist
@@ -2,4 +2,5 @@ GLIBC_2.0 _r_debug D 0x14
GLIBC_2.1 __libc_stack_end D 0x4
GLIBC_2.1 _dl_mcount F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/microblaze/ld.abilist b/sysdeps/unix/sysv/linux/microblaze/ld.abilist
index a4933c3541..b915864bd6 100644
--- a/sysdeps/unix/sysv/linux/microblaze/ld.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/ld.abilist
@@ -3,3 +3,4 @@ GLIBC_2.18 __stack_chk_guard D 0x4
GLIBC_2.18 __tls_get_addr F
GLIBC_2.18 _dl_mcount F
GLIBC_2.18 _r_debug D 0x14
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist b/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist
index be09641a48..6f85418bc8 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist
@@ -2,4 +2,5 @@ GLIBC_2.0 _r_debug D 0x14
GLIBC_2.2 __libc_stack_end D 0x4
GLIBC_2.2 _dl_mcount F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist
index be09641a48..6f85418bc8 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist
@@ -2,4 +2,5 @@ GLIBC_2.0 _r_debug D 0x14
GLIBC_2.2 __libc_stack_end D 0x4
GLIBC_2.2 _dl_mcount F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist
index 1ea36e13f2..b2621aad3b 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist
@@ -2,4 +2,5 @@ GLIBC_2.0 _r_debug D 0x28
GLIBC_2.2 __libc_stack_end D 0x8
GLIBC_2.2 _dl_mcount F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __stack_chk_guard D 0x8
diff --git a/sysdeps/unix/sysv/linux/nios2/ld.abilist b/sysdeps/unix/sysv/linux/nios2/ld.abilist
index 52178802dd..7a8bd00445 100644
--- a/sysdeps/unix/sysv/linux/nios2/ld.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/ld.abilist
@@ -3,3 +3,4 @@ GLIBC_2.21 __stack_chk_guard D 0x4
GLIBC_2.21 __tls_get_addr F
GLIBC_2.21 _dl_mcount F
GLIBC_2.21 _r_debug D 0x14
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
index 4bbfba7a61..f3a533cbdb 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
@@ -4,3 +4,4 @@ GLIBC_2.1 _dl_mcount F
GLIBC_2.22 __tls_get_addr_opt F
GLIBC_2.23 __parse_hwcap_and_convert_at_platform F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist
index 283fb4510b..63ab18b70f 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist
@@ -4,3 +4,4 @@ GLIBC_2.3 __libc_stack_end D 0x8
GLIBC_2.3 __tls_get_addr F
GLIBC_2.3 _dl_mcount F
GLIBC_2.3 _r_debug D 0x28
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist
index b1f313c7cd..1fec480d9d 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist
@@ -4,3 +4,4 @@ GLIBC_2.17 _dl_mcount F
GLIBC_2.17 _r_debug D 0x28
GLIBC_2.22 __tls_get_addr_opt F
GLIBC_2.23 __parse_hwcap_and_convert_at_platform F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist
index 94ca64c43d..7cec190630 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist
@@ -3,3 +3,4 @@ GLIBC_2.33 __stack_chk_guard D 0x4
GLIBC_2.33 __tls_get_addr F
GLIBC_2.33 _dl_mcount F
GLIBC_2.33 _r_debug D 0x14
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist
index 845f356c3c..81795b588d 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist
@@ -3,3 +3,4 @@ GLIBC_2.27 __stack_chk_guard D 0x8
GLIBC_2.27 __tls_get_addr F
GLIBC_2.27 _dl_mcount F
GLIBC_2.27 _r_debug D 0x28
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist
index b56f005beb..34d9165bdb 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist
@@ -2,3 +2,4 @@ GLIBC_2.0 _r_debug D 0x14
GLIBC_2.1 __libc_stack_end D 0x4
GLIBC_2.1 _dl_mcount F
GLIBC_2.3 __tls_get_offset F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist
index 6f788a086d..1175537ca3 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist
@@ -2,3 +2,4 @@ GLIBC_2.2 __libc_stack_end D 0x8
GLIBC_2.2 _dl_mcount F
GLIBC_2.2 _r_debug D 0x28
GLIBC_2.3 __tls_get_offset F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/sh/be/ld.abilist b/sysdeps/unix/sysv/linux/sh/be/ld.abilist
index d155a59843..dcee0ece2a 100644
--- a/sysdeps/unix/sysv/linux/sh/be/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/ld.abilist
@@ -2,4 +2,5 @@ GLIBC_2.2 __libc_stack_end D 0x4
GLIBC_2.2 _dl_mcount F
GLIBC_2.2 _r_debug D 0x14
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/sh/le/ld.abilist b/sysdeps/unix/sysv/linux/sh/le/ld.abilist
index d155a59843..dcee0ece2a 100644
--- a/sysdeps/unix/sysv/linux/sh/le/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/ld.abilist
@@ -2,4 +2,5 @@ GLIBC_2.2 __libc_stack_end D 0x4
GLIBC_2.2 _dl_mcount F
GLIBC_2.2 _r_debug D 0x14
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist
index 0c6610e3c2..21bd7308c0 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist
@@ -2,3 +2,4 @@ GLIBC_2.0 _r_debug D 0x14
GLIBC_2.1 __libc_stack_end D 0x4
GLIBC_2.1 _dl_mcount F
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist
index 33f91199bf..6ae0cb97b4 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist
@@ -2,3 +2,4 @@ GLIBC_2.2 __libc_stack_end D 0x8
GLIBC_2.2 _dl_mcount F
GLIBC_2.2 _r_debug D 0x28
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist b/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
index d3cdf7611e..8a8a9e4bb3 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
@@ -2,3 +2,4 @@ GLIBC_2.2.5 __libc_stack_end D 0x8
GLIBC_2.2.5 _dl_mcount F
GLIBC_2.2.5 _r_debug D 0x28
GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 _dl_find_eh_frame F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
index c70bccf782..99bd4f5197 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
@@ -2,3 +2,4 @@ GLIBC_2.16 __libc_stack_end D 0x4
GLIBC_2.16 __tls_get_addr F
GLIBC_2.16 _dl_mcount F
GLIBC_2.16 _r_debug D 0x14
+GLIBC_2.35 _dl_find_eh_frame F
--
2.31.1
next prev parent reply other threads:[~2021-11-03 16:34 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-03 16:27 [PATCH 0/3] Add _dl_find_eh_frame function for unwinder optimization Florian Weimer via Libc-alpha
2021-11-03 16:27 ` [PATCH 1/3] nptl: Extract <bits/atomic_wide_counter.h> from pthread_cond_common.c Florian Weimer via Libc-alpha
2021-11-15 19:24 ` Adhemerval Zanella via Libc-alpha
2021-11-18 13:19 ` Jakub Jelinek via Libc-alpha
2021-11-18 13:23 ` Florian Weimer via Libc-alpha
2021-11-03 16:27 ` [PATCH 2/3] elf: Introduce GLRO (dl_libc_freeres), called from __libc_freeres Florian Weimer via Libc-alpha
2021-11-15 19:28 ` Adhemerval Zanella via Libc-alpha
2021-11-03 16:28 ` Florian Weimer via Libc-alpha [this message]
2021-11-16 12:42 ` [PATCH 3/3] elf: Add _dl_find_eh_frame function Adhemerval Zanella via Libc-alpha
2021-11-17 13:40 ` Florian Weimer via Libc-alpha
2021-11-23 16:52 ` Adhemerval Zanella via Libc-alpha
2021-11-18 13:43 ` Jakub Jelinek via Libc-alpha
2021-11-18 14:09 ` Florian Weimer via Libc-alpha
2021-11-18 15:37 ` Jakub Jelinek via Libc-alpha
2021-11-18 16:28 ` Florian Weimer via Libc-alpha
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