From 524a8ef2ad76af8ac049293d993a1856b0d888fb Mon Sep 17 00:00:00 2001 From: Nick Alcock Date: Mon, 26 Dec 2016 10:08:57 +0100 Subject: 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. --- sysdeps/generic/symbol-hacks.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'sysdeps/generic') diff --git a/sysdeps/generic/symbol-hacks.h b/sysdeps/generic/symbol-hacks.h index ce576c9fd2..d614c099c9 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 -- cgit 1.4.1