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author | H.J. Lu <hjl.tools@gmail.com> | 2016-02-19 15:43:45 -0800 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2016-02-19 15:45:09 -0800 |
commit | 8d9c92017d85f23ba6a2b3614b2f2bcf1820d6f0 (patch) | |
tree | d1e153725deb1ed9714f982bd94585a45a6ca8a2 /.gitignore | |
parent | eab5028860f8e20c543bccb2d7cc100d167ead34 (diff) | |
download | glibc-8d9c92017d85f23ba6a2b3614b2f2bcf1820d6f0.tar.gz glibc-8d9c92017d85f23ba6a2b3614b2f2bcf1820d6f0.tar.xz glibc-8d9c92017d85f23ba6a2b3614b2f2bcf1820d6f0.zip |
[x86_64] Set DL_RUNTIME_UNALIGNED_VEC_SIZE to 8
Due to GCC bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58066 __tls_get_addr may be called with 8-byte stack alignment. Although this bug has been fixed in GCC 4.9.4, 5.3 and 6, we can't assume that stack will be always aligned at 16 bytes. Since SSE optimized memory/string functions with aligned SSE register load and store are used in the dynamic linker, we must set DL_RUNTIME_UNALIGNED_VEC_SIZE to 8 so that _dl_runtime_resolve_sse will align the stack before calling _dl_fixup: Dump of assembler code for function _dl_runtime_resolve_sse: 0x00007ffff7deea90 <+0>: push %rbx 0x00007ffff7deea91 <+1>: mov %rsp,%rbx 0x00007ffff7deea94 <+4>: and $0xfffffffffffffff0,%rsp ^^^^^^^^^^^ Align stack to 16 bytes 0x00007ffff7deea98 <+8>: sub $0x100,%rsp 0x00007ffff7deea9f <+15>: mov %rax,0xc0(%rsp) 0x00007ffff7deeaa7 <+23>: mov %rcx,0xc8(%rsp) 0x00007ffff7deeaaf <+31>: mov %rdx,0xd0(%rsp) 0x00007ffff7deeab7 <+39>: mov %rsi,0xd8(%rsp) 0x00007ffff7deeabf <+47>: mov %rdi,0xe0(%rsp) 0x00007ffff7deeac7 <+55>: mov %r8,0xe8(%rsp) 0x00007ffff7deeacf <+63>: mov %r9,0xf0(%rsp) 0x00007ffff7deead7 <+71>: movaps %xmm0,(%rsp) 0x00007ffff7deeadb <+75>: movaps %xmm1,0x10(%rsp) 0x00007ffff7deeae0 <+80>: movaps %xmm2,0x20(%rsp) 0x00007ffff7deeae5 <+85>: movaps %xmm3,0x30(%rsp) 0x00007ffff7deeaea <+90>: movaps %xmm4,0x40(%rsp) 0x00007ffff7deeaef <+95>: movaps %xmm5,0x50(%rsp) 0x00007ffff7deeaf4 <+100>: movaps %xmm6,0x60(%rsp) 0x00007ffff7deeaf9 <+105>: movaps %xmm7,0x70(%rsp) [BZ #19679] * sysdeps/x86_64/dl-trampoline.S (DL_RUNIME_UNALIGNED_VEC_SIZE): Renamed to ... (DL_RUNTIME_UNALIGNED_VEC_SIZE): This. Set to 8. (DL_RUNIME_RESOLVE_REALIGN_STACK): Renamed to ... (DL_RUNTIME_RESOLVE_REALIGN_STACK): This. Updated. (DL_RUNIME_RESOLVE_REALIGN_STACK): Renamed to ... (DL_RUNTIME_RESOLVE_REALIGN_STACK): This. * sysdeps/x86_64/dl-trampoline.h (DL_RUNIME_RESOLVE_REALIGN_STACK): Renamed to ... (DL_RUNTIME_RESOLVE_REALIGN_STACK): This.
Diffstat (limited to '.gitignore')
0 files changed, 0 insertions, 0 deletions