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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.
62 lines
1.8 KiB
ArmAsm
62 lines
1.8 KiB
ArmAsm
/* Stack-aligning implementation of __tls_get_addr. x86-64 version.
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Copyright (C) 2017 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#ifdef SHARED
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# include <sysdep.h>
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# include "tlsdesc.h"
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# include "rtld-offsets.h"
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/* See __tls_get_addr and __tls_get_addr_slow in dl-tls.c. This function
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call __tls_get_addr_slow on both slow paths. It realigns the stack
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before the call to work around GCC PR58066. */
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ENTRY (__tls_get_addr)
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mov %fs:DTV_OFFSET, %RDX_LP
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mov GL_TLS_GENERATION_OFFSET+_rtld_local(%rip), %RAX_LP
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/* GL(dl_tls_generation) == dtv[0].counter */
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cmp %RAX_LP, (%rdx)
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jne 1f
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mov TI_MODULE_OFFSET(%rdi), %RAX_LP
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/* dtv[ti->ti_module] */
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# ifdef __LP64__
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salq $4, %rax
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movq (%rdx,%rax), %rax
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# else
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movl (%rdx,%rax, 8), %eax
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# endif
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cmp $-1, %RAX_LP
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je 1f
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add TI_OFFSET_OFFSET(%rdi), %RAX_LP
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ret
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1:
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/* On the slow path, align the stack. */
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pushq %rbp
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cfi_def_cfa_offset (16)
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cfi_offset (%rbp, -16)
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mov %RSP_LP, %RBP_LP
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cfi_def_cfa_register (%rbp)
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and $-16, %RSP_LP
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call __tls_get_addr_slow
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mov %RBP_LP, %RSP_LP
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popq %rbp
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cfi_def_cfa (%rsp, 8)
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ret
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END (__tls_get_addr)
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#endif /* SHARED */
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