| Message ID | 1421722311-30455-1-git-send-email-wangnan0@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
(2015/01/20 11:51), Wang Nan wrote: > debugfs/kprobes/enabled doesn't work correctly on optimized kprobes. > Masami Hiramatsu has a test report on x86_64 platform: > > https://lkml.org/lkml/2015/1/19/274 > > This patch forces it to unoptimize kprobe if kprobes_all_disarmed > is set. It also checks the flag in unregistering path for skipping > unneeded disarming process when kprobes globally disarmed. > OK, here is the test result. ---- [root@localhost tracing]# echo p do_fork+5 > kprobe_events [root@localhost tracing]# echo $$ > set_ftrace_pid [root@localhost tracing]# echo 1 > events/kprobes/p_do_fork_5/enable [root@localhost tracing]# cat trace # tracer: nop # # entries-in-buffer/entries-written: 1/1 #P:8 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | bash-11466 [004] d... 4548.420463: p_do_fork_5: (do_fork+0x5/0x360) [root@localhost tracing]# cat ../kprobes/list ffffffff810bc1c5 k do_fork+0x5 [OPTIMIZED] [root@localhost tracing]# echo 0 > ../kprobes/enabled # kprobes globally disabled [root@localhost tracing]# echo > trace # clear trace buffer [root@localhost tracing]# cat trace # tracer: nop # # entries-in-buffer/entries-written: 0/0 #P:8 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | # No event traced! [root@localhost tracing]# echo 0 > events/kprobes/p_do_fork_5/enable [root@localhost tracing]# echo > kprobe_events [root@localhost tracing]# cat ../kprobes/list [root@localhost tracing]# # And we can safely remove the probe ----- Now it looks good to me :) Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Ingo, Could you pull this patch to your -tip tree? Thank you, > Signed-off-by: Wang Nan <wangnan0@huawei.com> > --- > kernel/kprobes.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 9471710..fb995ef 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -869,7 +869,8 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt) > { > struct kprobe *_p; > > - unoptimize_kprobe(p, false); /* Try to unoptimize */ > + /* Try to unoptimize */ > + unoptimize_kprobe(p, kprobes_all_disarmed); > > if (!kprobe_queued(p)) { > arch_disarm_kprobe(p); > @@ -1571,7 +1572,13 @@ static struct kprobe *__disable_kprobe(struct kprobe *p) > > /* Try to disarm and disable this/parent probe */ > if (p == orig_p || aggr_kprobe_disabled(orig_p)) { > - disarm_kprobe(orig_p, true); > + /* > + * If kprobes_all_disarmed is set, orig_p > + * should have already been disarmed, so > + * skip unneed disarming process. > + */ > + if (!kprobes_all_disarmed) > + disarm_kprobe(orig_p, true); > orig_p->flags |= KPROBE_FLAG_DISABLED; > } > } >
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 9471710..fb995ef 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -869,7 +869,8 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt) { struct kprobe *_p; - unoptimize_kprobe(p, false); /* Try to unoptimize */ + /* Try to unoptimize */ + unoptimize_kprobe(p, kprobes_all_disarmed); if (!kprobe_queued(p)) { arch_disarm_kprobe(p); @@ -1571,7 +1572,13 @@ static struct kprobe *__disable_kprobe(struct kprobe *p) /* Try to disarm and disable this/parent probe */ if (p == orig_p || aggr_kprobe_disabled(orig_p)) { - disarm_kprobe(orig_p, true); + /* + * If kprobes_all_disarmed is set, orig_p + * should have already been disarmed, so + * skip unneed disarming process. + */ + if (!kprobes_all_disarmed) + disarm_kprobe(orig_p, true); orig_p->flags |= KPROBE_FLAG_DISABLED; } }
debugfs/kprobes/enabled doesn't work correctly on optimized kprobes. Masami Hiramatsu has a test report on x86_64 platform: https://lkml.org/lkml/2015/1/19/274 This patch forces it to unoptimize kprobe if kprobes_all_disarmed is set. It also checks the flag in unregistering path for skipping unneeded disarming process when kprobes globally disarmed. Signed-off-by: Wang Nan <wangnan0@huawei.com> --- kernel/kprobes.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)