Messages in this thread | | | Date | Wed, 2 Sep 2020 12:05:44 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH v2] kprobes: Fix kill kprobe which has been marked as gone |
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Hi Ingo,
Could you merge this fix to -tip?
I can resend it with other kprobes fixes.
Hi Muchun,
We also need;
Cc: stable@vger.kernel.org
for bugfix so that the patch can be backported correctly after merged to upstream.
Thank you,
On Mon, 31 Aug 2020 10:59:19 +0800 Muchun Song <songmuchun@bytedance.com> wrote:
> Cc Andrew and Steven. > > Any other comments or someone can add this to the queue for the > merge window? It's worth fixing it. > > On Sat, Aug 22, 2020 at 11:01 AM Muchun Song <songmuchun@bytedance.com> wrote: > > > > If a kprobe is marked as gone, we should not kill it again. Otherwise, > > we can disarm the kprobe more than once. In that case, the statistics > > of kprobe_ftrace_enabled can unbalance which can lead to that kprobe > > do not work. > > > > Fixes: e8386a0cb22f ("kprobes: support probing module __exit function") > > Signed-off-by: Muchun Song <songmuchun@bytedance.com> > > Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com> > > Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> > > Acked-by: Masami Hiramatsu <mhiramat@kernel.org> > > --- > > changelogs in v2: > > 1. Add a WARN_ON_ONCE in the kill_kprobe() to catch incorrect use of it. > > 2. Update 'Fixes' tag in the commmit log. > > > > kernel/kprobes.c | 9 ++++++++- > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > > index d36e2b017588..9348b0c36ae0 100644 > > --- a/kernel/kprobes.c > > +++ b/kernel/kprobes.c > > @@ -2143,6 +2143,9 @@ static void kill_kprobe(struct kprobe *p) > > > > lockdep_assert_held(&kprobe_mutex); > > > > + if (WARN_ON_ONCE(kprobe_gone(p))) > > + return; > > + > > p->flags |= KPROBE_FLAG_GONE; > > if (kprobe_aggrprobe(p)) { > > /* > > @@ -2422,7 +2425,10 @@ static int kprobes_module_callback(struct notifier_block *nb, > > mutex_lock(&kprobe_mutex); > > for (i = 0; i < KPROBE_TABLE_SIZE; i++) { > > head = &kprobe_table[i]; > > - hlist_for_each_entry(p, head, hlist) > > + hlist_for_each_entry(p, head, hlist) { > > + if (kprobe_gone(p)) > > + continue; > > + > > if (within_module_init((unsigned long)p->addr, mod) || > > (checkcore && > > within_module_core((unsigned long)p->addr, mod))) { > > @@ -2439,6 +2445,7 @@ static int kprobes_module_callback(struct notifier_block *nb, > > */ > > kill_kprobe(p); > > } > > + } > > } > > if (val == MODULE_STATE_GOING) > > remove_module_kprobe_blacklist(mod); > > -- > > 2.11.0 > > > > > -- > Yours, > Muchun
-- Masami Hiramatsu <mhiramat@kernel.org>
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