Messages in this thread | | | Date | Fri, 12 May 2017 11:39:11 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [RFC][PATCH 3/5] kprobes: Take get_online_cpus() before taking jump_label_lock() |
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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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