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author | Nick Alcock <nick.alcock@oracle.com> | 2016-12-26 10:08:57 +0100 |
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committer | Florian Weimer <fweimer@redhat.com> | 2016-12-26 10:11:05 +0100 |
commit | 524a8ef2ad76af8ac049293d993a1856b0d888fb (patch) | |
tree | ff9d41f1c2c7c1a2361e3f46a8376a23b96faf17 /sysdeps | |
parent | 66a704c43cfec810fea67a6959f2d1c94f4d594f (diff) | |
download | glibc-524a8ef2ad76af8ac049293d993a1856b0d888fb.zip glibc-524a8ef2ad76af8ac049293d993a1856b0d888fb.tar.gz glibc-524a8ef2ad76af8ac049293d993a1856b0d888fb.tar.bz2 |
PLT avoidance for __stack_chk_fail [BZ #7065]
Add a hidden __stack_chk_fail_local alias to libc.so,
and make sure that on targets which use __stack_chk_fail,
this does not introduce a local PLT reference into libc.so.
Diffstat (limited to 'sysdeps')
-rw-r--r-- | sysdeps/generic/symbol-hacks.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/sysdeps/generic/symbol-hacks.h b/sysdeps/generic/symbol-hacks.h index ce576c9..d614c09 100644 --- a/sysdeps/generic/symbol-hacks.h +++ b/sysdeps/generic/symbol-hacks.h @@ -4,4 +4,16 @@ asm ("memmove = __GI_memmove"); asm ("memset = __GI_memset"); asm ("memcpy = __GI_memcpy"); + +/* Some targets do not use __stack_chk_fail_local. In libc.so, + redirect __stack_chk_fail to a hidden reference + __stack_chk_fail_local, to avoid the PLT reference. + __stack_chk_fail itself is a global symbol, exported from libc.so, + and cannot be made hidden. */ + +# if IS_IN (libc) && defined SHARED && \ + defined STACK_PROTECTOR_LEVEL && STACK_PROTECTOR_LEVEL > 0 +asm (".hidden __stack_chk_fail_local\n" + "__stack_chk_fail = __stack_chk_fail_local"); +# endif #endif |