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Subject[PATCH v12 19/21] x86/asm: Create stack frames in rwsem functions
Date
rwsem.S has several callable non-leaf functions which don't honor
CONFIG_FRAME_POINTER, which can result in bad stack traces.

Create stack frames for them when CONFIG_FRAME_POINTER is enabled.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
arch/x86/lib/rwsem.S | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/x86/lib/rwsem.S b/arch/x86/lib/rwsem.S
index 40027db..be110ef 100644
--- a/arch/x86/lib/rwsem.S
+++ b/arch/x86/lib/rwsem.S
@@ -15,6 +15,7 @@

#include <linux/linkage.h>
#include <asm/alternative-asm.h>
+#include <asm/frame.h>

#define __ASM_HALF_REG(reg) __ASM_SEL(reg, e##reg)
#define __ASM_HALF_SIZE(inst) __ASM_SEL(inst##w, inst##l)
@@ -84,24 +85,29 @@

/* Fix up special calling conventions */
ENTRY(call_rwsem_down_read_failed)
+ FRAME_BEGIN
save_common_regs
__ASM_SIZE(push,) %__ASM_REG(dx)
movq %rax,%rdi
call rwsem_down_read_failed
__ASM_SIZE(pop,) %__ASM_REG(dx)
restore_common_regs
+ FRAME_END
ret
ENDPROC(call_rwsem_down_read_failed)

ENTRY(call_rwsem_down_write_failed)
+ FRAME_BEGIN
save_common_regs
movq %rax,%rdi
call rwsem_down_write_failed
restore_common_regs
+ FRAME_END
ret
ENDPROC(call_rwsem_down_write_failed)

ENTRY(call_rwsem_wake)
+ FRAME_BEGIN
/* do nothing if still outstanding active readers */
__ASM_HALF_SIZE(dec) %__ASM_HALF_REG(dx)
jnz 1f
@@ -109,15 +115,18 @@ ENTRY(call_rwsem_wake)
movq %rax,%rdi
call rwsem_wake
restore_common_regs
-1: ret
+1: FRAME_END
+ ret
ENDPROC(call_rwsem_wake)

ENTRY(call_rwsem_downgrade_wake)
+ FRAME_BEGIN
save_common_regs
__ASM_SIZE(push,) %__ASM_REG(dx)
movq %rax,%rdi
call rwsem_downgrade_wake
__ASM_SIZE(pop,) %__ASM_REG(dx)
restore_common_regs
+ FRAME_END
ret
ENDPROC(call_rwsem_downgrade_wake)
--
2.4.3


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