Messages in this thread Patch in this message | | | From | "Shi, Alex" <> | Date | Tue, 13 Oct 2009 13:35:41 +0800 | Subject | RE: [tip:x86/urgent] x86: fix kernel panic on 32 bits when profiling |
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Yes, it seems better than mine.
BRG Alex
-----Original Message----- From: tip tree robot [mailto:bounces.tip@hpa.at.zytor.com] On Behalf Of tip-bot for H. Peter Anvin Sent: 2009年10月13日 2:58 To: linux-tip-commits@vger.kernel.org Cc: Chen, Tim C; hpa@zytor.com; mingo@redhat.com; akpm@linux-foundation.org; Shi, Alex; tglx@linutronix.de; rjw@sisk.pl Subject: [tip:x86/urgent] x86: fix kernel panic on 32 bits when profiling
Commit-ID: d1705c558c95418378b11a0be963fe1b3e2fa381 Gitweb: http://git.kernel.org/tip/d1705c558c95418378b11a0be963fe1b3e2fa381 Author: H. Peter Anvin <hpa@zytor.com> AuthorDate: Mon, 12 Oct 2009 11:32:31 -0700 Committer: H. Peter Anvin <hpa@zytor.com> CommitDate: Mon, 12 Oct 2009 11:53:51 -0700
x86: fix kernel panic on 32 bits when profiling
Latest kernel has a kernel panic in booting on i386 machine when profile=2 setting in cmdline. It is due to 'sp' being incorrect in profile_pc().
BUG: unable to handle kernel NULL pointer dereference at 00000246 IP: [<c01288b6>] profile_pc+0x2a/0x48 *pde = 00000000 Oops: 0000 [#1] SMP
This differs from the original version by Alex Shi in that we use the kernel_stack_pointer() inline already defined in <asm/ptrace.h> for this purpose, instead of #ifdef.
Originally-by: Alex Shi <alex.shi@intel.com> Cc: "Chen, Tim C" <tim.c.chen@intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com> --- arch/x86/kernel/time.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c index dcb00d2..be25734 100644 --- a/arch/x86/kernel/time.c +++ b/arch/x86/kernel/time.c @@ -38,7 +38,8 @@ unsigned long profile_pc(struct pt_regs *regs) #ifdef CONFIG_FRAME_POINTER return *(unsigned long *)(regs->bp + sizeof(long)); #else - unsigned long *sp = (unsigned long *)regs->sp; + unsigned long *sp = + (unsigned long *)kernel_stack_pointer(regs); /* * Return address is either directly at stack pointer * or above a saved flags. Eflags has bits 22-31 zero, | |