Remove debug/stack_chk_fail_local.c [BZ #21740]
Commit Message
Since
commit 524a8ef2ad76af8ac049293d993a1856b0d888fb
Author: Nick Alcock <nick.alcock@oracle.com>
Date: Mon Dec 26 10:08:57 2016 +0100
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.
added
strong_alias (__stack_chk_fail, __stack_chk_fail_local)
to debug/stack_chk_fail.c, debug/stack_chk_fail_local.c should be
removed.
OK for master?
H.J.
---
* [BZ #21740]
* debug/Makefile (static-only-routines): Remove
stack_chk_fail_local.
* debug/stack_chk_fail_local.c: Removed.
---
debug/Makefile | 2 +-
debug/stack_chk_fail_local.c | 46 --------------------------------------------
2 files changed, 1 insertion(+), 47 deletions(-)
delete mode 100644 debug/stack_chk_fail_local.c
Comments
On 9 Jul 2017, H. J. Lu verbalised:
> Since
>
> commit 524a8ef2ad76af8ac049293d993a1856b0d888fb
> Author: Nick Alcock <nick.alcock@oracle.com>
> Date: Mon Dec 26 10:08:57 2016 +0100
>
> 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.
>
> added
>
> strong_alias (__stack_chk_fail, __stack_chk_fail_local)
>
> to debug/stack_chk_fail.c, debug/stack_chk_fail_local.c should be
> removed.
>
> OK for master?
If it passes a test build with --enable-stack-protector=all without
pulling junk into ld.so and exploding at ld.so link time, sure. (That's
what happened every time I tried to remove this stuff before, but I may
have failed to notice that this may not be necessary any more.)
> -/* On some architectures, this helps needless PIC pointer setup
> - that would be needed just for the __stack_chk_fail call. */
Does anyone know what architectures these might be? Presumably x86-32...
@@ -51,7 +51,7 @@ routines = backtrace backtracesyms backtracesymsfd noophooks \
explicit_bzero_chk \
stack_chk_fail fortify_fail \
$(static-only-routines)
-static-only-routines := warning-nop stack_chk_fail_local
+static-only-routines := warning-nop
# Building the stack-protector failure routines with stack protection
# makes no sense.
deleted file mode 100644
@@ -1,46 +0,0 @@
-/* Copyright (C) 2005-2017 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.
-
- In addition to the permissions in the GNU Lesser General Public
- License, the Free Software Foundation gives you unlimited
- permission to link the compiled version of this file with other
- programs, and to distribute those programs without any restriction
- coming from the use of this file. (The GNU Lesser General Public
- License restrictions do apply in other respects; for example, they
- cover modification of the file, and distribution when not linked
- into another program.)
-
- Note that people who make modified versions of this file are not
- obligated to grant this special exception for their modified
- versions; it is their choice whether to do so. The GNU Lesser
- General Public License gives permission to release a modified
- version without this exception; this exception also makes it
- possible to release a modified version which carries forward this
- exception.
-
- 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/>. */
-
-#include <sys/cdefs.h>
-
-extern void __stack_chk_fail (void) __attribute__ ((noreturn));
-
-/* On some architectures, this helps needless PIC pointer setup
- that would be needed just for the __stack_chk_fail call. */
-
-void __attribute__ ((noreturn)) attribute_hidden
-__stack_chk_fail_local (void)
-{
- __stack_chk_fail ();
-}