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x86/locking: Create stack frame in PV unlock

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The assembly PV_UNLOCK function is a callable non-leaf function which
doesn't honor CONFIG_FRAME_POINTER, which can result in bad stack
traces.

Create a stack frame when CONFIG_FRAME_POINTER is enabled.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hpe.com>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/6685a72ddbbd0ad3694337cca0af4b4ea09f5f40.1453405861.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Josh Poimboeuf 2016-01-21 16:49:32 -06:00 committed by Ingo Molnar
parent 5c1d5f283a
commit 16df4ff860
1 changed files with 4 additions and 0 deletions
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4
arch/x86/include/asm/qspinlock_paravirt.h
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@ -36,8 +36,10 @@ PV_CALLEE_SAVE_REGS_THUNK(__pv_queued_spin_unlock_slowpath);
*/
asm (".pushsection .text;"
".globl " PV_UNLOCK ";"
".type " PV_UNLOCK ", @function;"
".align 4,0x90;"
PV_UNLOCK ": "
FRAME_BEGIN
"push %rdx;"
"mov $0x1,%eax;"
"xor %edx,%edx;"
@ -45,6 +47,7 @@ asm (".pushsection .text;"
"cmp $0x1,%al;"
"jne .slowpath;"
"pop %rdx;"
FRAME_END
"ret;"
".slowpath: "
"push %rsi;"
@ -52,6 +55,7 @@ asm (".pushsection .text;"
"call " PV_UNLOCK_SLOWPATH ";"
"pop %rsi;"
"pop %rdx;"
FRAME_END
"ret;"
".size " PV_UNLOCK ", .-" PV_UNLOCK ";"
".popsection");