mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 12:41:05 +00:00
031e519c95
This change forces realignment of the stack pointer in __tls_get_addr, so that binaries compiled by GCCs older than GCC 4.9: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 continue to work even if vector instructions are used in glibc which require the ABI stack realignment. __tls_get_addr_slow is added to handle the slow paths in the default implementation of__tls_get_addr in elf/dl-tls.c. The new __tls_get_addr calls __tls_get_addr_slow after realigning the stack. Internal calls within ld.so go directly to the default implementation of __tls_get_addr because they do not need stack realignment. [BZ #21609] * sysdeps/x86_64/Makefile (sysdep-dl-routines): Add tls_get_addr. (gen-as-const-headers): Add rtld-offsets.sym. * sysdeps/x86_64/dl-tls.c: New file. * sysdeps/x86_64/rtld-offsets.sym: Likwise. * sysdeps/x86_64/tls_get_addr.S: Likewise. * sysdeps/x86_64/dl-tls.h: Add multiple inclusion guards. * sysdeps/x86_64/tlsdesc.sym (TI_MODULE_OFFSET): New. (TI_OFFSET_OFFSET): Likwise.
54 lines
1.7 KiB
C
54 lines
1.7 KiB
C
/* Thread-local storage handling in the ELF dynamic linker. x86-64 version.
|
|
Copyright (C) 2017 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
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#ifdef SHARED
|
|
/* Work around GCC PR58066, due to which __tls_get_addr may be called
|
|
with an unaligned stack. The compat implementation is in
|
|
tls_get_addr-compat.S. */
|
|
|
|
# include <dl-tls.h>
|
|
|
|
/* Define __tls_get_addr within elf/dl-tls.c under a different
|
|
name. */
|
|
extern __typeof__ (__tls_get_addr) ___tls_get_addr;
|
|
|
|
# define __tls_get_addr ___tls_get_addr
|
|
# include <elf/dl-tls.c>
|
|
# undef __tls_get_addr
|
|
|
|
hidden_ver (___tls_get_addr, __tls_get_addr)
|
|
|
|
/* Only handle slow paths for __tls_get_addr. */
|
|
attribute_hidden
|
|
void *
|
|
__tls_get_addr_slow (GET_ADDR_ARGS)
|
|
{
|
|
dtv_t *dtv = THREAD_DTV ();
|
|
|
|
if (__glibc_unlikely (dtv[0].counter != GL(dl_tls_generation)))
|
|
return update_get_addr (GET_ADDR_PARAM);
|
|
|
|
return tls_get_addr_tail (GET_ADDR_PARAM, dtv, NULL);
|
|
}
|
|
#else
|
|
|
|
/* No compatibility symbol needed. */
|
|
# include <elf/dl-tls.c>
|
|
|
|
#endif
|