From 9bbeacf52f66d165739a4bbe9c018d17493a74b5 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 11 May 2011 13:06:13 +0200 Subject: [PATCH] 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 Acked-by: Masami Hiramatsu Link: http://lkml.kernel.org/r/20110511110613.GB2390@jolsa.brq.redhat.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/kprobes.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index c969fd9d1566..f1a6244d7d93 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)