Messages in this thread Patch in this message | | | Date | Wed, 11 May 2011 13:10:01 GMT | From | tip-bot for Jiri Olsa <> | Subject | [tip:perf/urgent] kprobes, x86: Disable irqs during optimized callback |
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Commit-ID: 9bbeacf52f66d165739a4bbe9c018d17493a74b5 Gitweb: http://git.kernel.org/tip/9bbeacf52f66d165739a4bbe9c018d17493a74b5 Author: Jiri Olsa <jolsa@redhat.com> AuthorDate: Wed, 11 May 2011 13:06:13 +0200 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Wed, 11 May 2011 13:21:23 +0200
kprobes, x86: Disable irqs during optimized callback
Disable irqs during optimized callback, so we dont miss any in-irq kprobes.
The following commands:
# cd /debug/tracing/ # echo "p mutex_unlock" >> kprobe_events # echo "p _raw_spin_lock" >> kprobe_events # echo "p smp_apic_timer_interrupt" >> ./kprobe_events # echo 1 > events/enable
Cause the optimized kprobes to be missed. None is missed with the fix applied.
Signed-off-by: Jiri Olsa <jolsa@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Link: http://lkml.kernel.org/r/20110511110613.GB2390@jolsa.brq.redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu> --- arch/x86/kernel/kprobes.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index c969fd9..f1a6244 100644 --- a/arch/x86/kernel/kprobes.c +++ b/arch/x86/kernel/kprobes.c @@ -1183,12 +1183,13 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + unsigned long flags; /* This is possible if op is under delayed unoptimizing */ if (kprobe_disabled(&op->kp)) return; - preempt_disable(); + local_irq_save(flags); if (kprobe_running()) { kprobes_inc_nmissed_count(&op->kp); } else { @@ -1207,7 +1208,7 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op, opt_pre_handler(&op->kp, regs); __this_cpu_write(current_kprobe, NULL); } - preempt_enable_no_resched(); + local_irq_restore(flags); } static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src)
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