[PATCH -tip v5 5/7] x86: fix kernel_trap_sp()

Masami Hiramatsu
2009-05-09T00:47:08Z

Use &regs->sp instead of regs for getting the top of stack in kernel mode.
(on x86-64, regs->sp always points the top of stack)

[ impact: Oprofile decodes only stack for backtracing on i386 ]

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jan Blunck <jblunck@suse.de>
---

arch/x86/include/asm/ptrace.h | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 5cdd19f..90b76b3 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -187,14 +187,14 @@ static inline int v8086_mode(struct pt_regs *regs)

/*
* X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
- * when it traps. So regs will be the current sp.
+ * when it traps. So &regs->sp will be the current sp.
*
* This is valid only for kernel mode traps.
*/
static inline unsigned long kernel_trap_sp(struct pt_regs *regs)
{
#ifdef CONFIG_X86_32
- return (unsigned long)regs;
+ return (unsigned long)&regs->sp;
#else
return regs->sp;
#endif