glibc/glibc-RHEL-36148-1.patch
Patsy Griffin 666f2b55d3 - elf: Clarify and invert second argument of _dl_allocate_tls_init
- elf: Avoid re-initializing already allocated TLS in dlopen

Resolves: RHEL-36148
2024-08-28 15:23:03 -04:00

89 lines
3.7 KiB
Diff

commit fe06fb313bddf7e4530056897d4a706606e49377
Author: Florian Weimer <fweimer@redhat.com>
Date: Thu Aug 1 23:31:23 2024 +0200
elf: Clarify and invert second argument of _dl_allocate_tls_init
Also remove an outdated comment: _dl_allocate_tls_init is
called as part of pthread_create.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
diff -Nrup a/elf/dl-tls.c b/elf/dl-tls.c
--- a/elf/dl-tls.c 2024-08-27 22:51:44.720953314 -0400
+++ b/elf/dl-tls.c 2024-08-27 22:51:07.686759191 -0400
@@ -558,9 +558,14 @@ _dl_resize_dtv (dtv_t *dtv, size_t max_m
/* Allocate initial TLS. RESULT should be a non-NULL pointer to storage
for the TLS space. The DTV may be resized, and so this function may
call malloc to allocate that space. The loader's GL(dl_load_tls_lock)
- is taken when manipulating global TLS-related data in the loader. */
+ is taken when manipulating global TLS-related data in the loader.
+
+ If MAIN_THREAD, this is the first call during process
+ initialization. In this case, TLS initialization for secondary
+ (audit) namespaces is skipped because that has already been handled
+ by dlopen. */
void *
-_dl_allocate_tls_init (void *result, bool init_tls)
+_dl_allocate_tls_init (void *result, bool main_thread)
{
if (result == NULL)
/* The memory allocation failed. */
@@ -639,7 +644,7 @@ _dl_allocate_tls_init (void *result, boo
because it would already be set by the audit setup. However,
subsequent thread creation would need to follow the default
behaviour. */
- if (map->l_ns != LM_ID_BASE && !init_tls)
+ if (map->l_ns != LM_ID_BASE && main_thread)
continue;
memset (__mempcpy (dest, map->l_tls_initimage,
map->l_tls_initimage_size), '\0',
@@ -667,7 +672,7 @@ _dl_allocate_tls (void *mem)
{
return _dl_allocate_tls_init (mem == NULL
? _dl_allocate_tls_storage ()
- : allocate_dtv (mem), true);
+ : allocate_dtv (mem), false);
}
rtld_hidden_def (_dl_allocate_tls)
diff -Nrup a/elf/rtld.c b/elf/rtld.c
--- a/elf/rtld.c 2024-08-27 22:51:44.720953314 -0400
+++ b/elf/rtld.c 2024-08-27 22:54:51.136930475 -0400
@@ -2485,7 +2485,7 @@ dl_main (const ElfW(Phdr) *phdr,
into the main thread's TLS area, which we allocated above.
Note: thread-local variables must only be accessed after completing
the next step. */
- _dl_allocate_tls_init (tcbp, false);
+ _dl_allocate_tls_init (tcbp, true);
/* And finally install it for the main thread. */
if (! tls_init_tp_called)
diff -Nrup a/nptl/allocatestack.c b/nptl/allocatestack.c
--- a/nptl/allocatestack.c 2024-08-27 22:51:43.922949131 -0400
+++ b/nptl/allocatestack.c 2024-08-27 22:51:07.687759197 -0400
@@ -137,7 +137,7 @@ get_cached_stack (size_t *sizep, void **
memset (dtv, '\0', (dtv[-1].counter + 1) * sizeof (dtv_t));
/* Re-initialize the TLS. */
- _dl_allocate_tls_init (TLS_TPADJ (result), true);
+ _dl_allocate_tls_init (TLS_TPADJ (result), false);
return result;
}
diff -Nrup a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
--- a/sysdeps/generic/ldsodefs.h 2024-08-27 22:51:44.720953314 -0400
+++ b/sysdeps/generic/ldsodefs.h 2024-08-27 22:56:44.425524320 -0400
@@ -1258,10 +1258,8 @@ extern void _dl_get_tls_static_info (siz
extern void _dl_allocate_static_tls (struct link_map *map) attribute_hidden;
-/* These are internal entry points to the two halves of _dl_allocate_tls,
- only used within rtld.c itself at startup time. */
extern void *_dl_allocate_tls_storage (void) attribute_hidden;
-extern void *_dl_allocate_tls_init (void *, bool);
+extern void *_dl_allocate_tls_init (void *result, bool main_thread);
rtld_hidden_proto (_dl_allocate_tls_init)
/* Deallocate memory allocated with _dl_allocate_tls. */