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kprobes, x86: Disable irqs during optimized callback

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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>
This commit is contained in:
Jiri Olsa 2011-05-11 13:06:13 +02:00 committed by Ingo Molnar
parent 693d92a1bb
commit 9bbeacf52f
1 changed files with 3 additions and 2 deletions
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5
arch/x86/kernel/kprobes.c
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@ -1183,12 +1183,13 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op,
struct pt_regs *regs) struct pt_regs *regs)
{ {
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
unsigned long flags;
/* This is possible if op is under delayed unoptimizing */ /* This is possible if op is under delayed unoptimizing */
if (kprobe_disabled(&op->kp)) if (kprobe_disabled(&op->kp))
return; return;
preempt_disable(); local_irq_save(flags);
if (kprobe_running()) { if (kprobe_running()) {
kprobes_inc_nmissed_count(&op->kp); kprobes_inc_nmissed_count(&op->kp);
} else { } else {
@ -1207,7 +1208,7 @@ static void __kprobes optimized_callback(struct optimized_kprobe *op,
opt_pre_handler(&op->kp, regs); opt_pre_handler(&op->kp, regs);
__this_cpu_write(current_kprobe, NULL); __this_cpu_write(current_kprobe, NULL);
} }
preempt_enable_no_resched(); local_irq_restore(flags);
} }
static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src) static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src)