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Groups > linux.kernel > #1640678
| From | "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC][PATCH 3/5] kprobes: Take get_online_cpus() before taking jump_label_lock() |
| Date | 2017-05-12 20:40 +0200 |
| Message-ID | <tGnDP-cz-3@gated-at.bofh.it> (permalink) |
| References | <tGmy5-7Uc-3@gated-at.bofh.it> <tGmy7-7Uc-57@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri, May 12, 2017 at 01:15:47PM -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
>
> jump_label_lock() is taken under get_online_cpus(). Make sure that kprobes
> follows suit.
>
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The remaining three (3/5 through 5/5) look straightforward. #4 appears
to be the one needing the recursive get_online_cpus().
Thanx, Paul
> ---
> kernel/kprobes.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index d733479a10ee..57cf73aef488 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -1294,13 +1294,13 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
> int ret = 0;
> struct kprobe *ap = orig_p;
>
> - /* For preparing optimization, jump_label_text_reserved() is called */
> - jump_label_lock();
> /*
> * Get online CPUs to avoid text_mutex deadlock.with stop machine,
> * which is invoked by unoptimize_kprobe() in add_new_kprobe()
> */
> get_online_cpus();
> + /* For preparing optimization, jump_label_text_reserved() is called */
> + jump_label_lock();
> mutex_lock(&text_mutex);
>
> if (!kprobe_aggrprobe(orig_p)) {
> @@ -1348,8 +1348,8 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
>
> out:
> mutex_unlock(&text_mutex);
> - put_online_cpus();
> jump_label_unlock();
> + put_online_cpus();
>
> if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) {
> ap->flags &= ~KPROBE_FLAG_DISABLED;
> --
> 2.10.2
>
>
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[RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Steven Rostedt <rostedt@goodmis.org> - 2017-05-12 19:30 +0200
[RFC][PATCH 5/5] perf: Grab event_mutex before taking get_online_cpus() Steven Rostedt <rostedt@goodmis.org> - 2017-05-12 19:30 +0200
[RFC][PATCH 3/5] kprobes: Take get_online_cpus() before taking jump_label_lock() Steven Rostedt <rostedt@goodmis.org> - 2017-05-12 19:30 +0200
Re: [RFC][PATCH 3/5] kprobes: Take get_online_cpus() before taking jump_label_lock() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-05-12 20:40 +0200
Re: [RFC][PATCH 3/5] kprobes: Take get_online_cpus() before taking jump_label_lock() Steven Rostedt <rostedt@goodmis.org> - 2017-05-12 20:50 +0200
Re: [RFC][PATCH 3/5] kprobes: Take get_online_cpus() before taking jump_label_lock() Masami Hiramatsu <mhiramat@kernel.org> - 2017-05-17 20:00 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-05-12 20:20 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Peter Zijlstra <peterz@infradead.org> - 2017-05-12 22:00 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Steven Rostedt <rostedt@goodmis.org> - 2017-05-12 22:20 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Steven Rostedt <rostedt@goodmis.org> - 2017-05-12 23:40 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-05-13 15:50 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Peter Zijlstra <peterz@infradead.org> - 2017-05-15 11:10 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-05-15 20:50 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Peter Zijlstra <peterz@infradead.org> - 2017-05-16 10:20 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-05-16 14:50 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-05-16 16:30 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Peter Zijlstra <peterz@infradead.org> - 2017-05-17 12:50 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-05-17 17:00 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-05-18 06:00 +0200
Re: [RFC][PATCH 0/5] perf/tracing/cpuhotplug: Fix locking order Steven Rostedt <rostedt@goodmis.org> - 2017-05-15 21:10 +0200
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