Commit-ID: 9bbeacf52f66d165739a4bbe9c018d17493a74b5
Gitweb: http://git.kernel.org/tip/9bbeacf52f66d165739a4bbe9c018d17493a74b5
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Wed, 11 May 2011 13:06:13 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
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@xxxxxxxxxx>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20110511110613.GB2390@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
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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