diff options
| author | Josh Poimboeuf <jpoimboe@redhat.com> | 2016-09-23 16:49:39 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-09-24 09:30:03 +0200 |
| commit | 317c2ce77d8ab73c24f4fb9c75e5bb441fbe3e30 (patch) | |
| tree | 343eb3fa3f0aa8a7fb11c136afa4281f0776fe16 /arch/m32r | |
| parent | 71f5443ebb1227c22e8decbcd28a1ea6deaf8257 (diff) | |
x86/alternatives: Add stack frame dependency to alternative_call_2()
Linus reported the following objtool warning:
kernel/signal.o: warning: objtool: .altinstr_replacement+0x54: call without frame pointer save/setup
The warning is valid. It's caused by the fact that gcc placed the call
instruction in alternative_call_2()'s inline asm before the frame
pointer setup, which breaks frame pointer convention and can result in a
bad stack trace.
Force a stack frame to be created before the call instruction by listing
the stack pointer as an output operand in the inline asm statement.
Reported-and-tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160923214939.j5o7c67nhepzmh3t@treble
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/m32r')
0 files changed, 0 insertions, 0 deletions