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[PATCH -tip v5 5/7] x86: fix kernel_trap_sp()
- From: Masami Hiramatsu <mhiramat at redhat dot com>
- To: Ingo Molnar<mingo at elte dot hu>, Steven Rostedt <rostedt at goodmis dot org>, lkml<linux-kernel at vger dot kernel dot org>
- Cc: systemtap<systemtap at sources dot redhat dot com>, kvm<kvm at vger dot kernel dot org>, Masami Hiramatsu <mhiramat at redhat dot com>, Harvey Harrison <harvey dot harrison at gmail dot com>, Ingo Molnar <mingo at elte dot hu>, Thomas Gleixner <tglx at linutronix dot de>, Jan Blunck <jblunck at suse dot de>
- Date: Fri, 08 May 2009 20:49:04 -0400
- Subject: [PATCH -tip v5 5/7] x86: fix kernel_trap_sp()
- References: <20090509004829.5505.38720.stgit@localhost.localdomain>
Use ®s->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 ®s->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)®s->sp;
#else
return regs->sp;
#endif
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division
e-mail: mhiramat@redhat.com