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kprobes: fix kill kprobe which has been marked as gone 

[ Upstream commit b0399092cc ]

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: e8386a0cb2 ("kprobes: support probing module __exit function")
Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Song Liu <songliubraving@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20200822030055.32383-1-songmuchun@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5.4-rM2-2.2.x-imx-squashed
Muchun Song 2020-09-18 21:20:21 -07:00 committed by Greg Kroah-Hartman
parent 2906c6acda
commit e7b219bc7b
1 changed files with 8 additions and 1 deletions
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9
kernel/kprobes.c
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@ -2088,6 +2088,9 @@ static void kill_kprobe(struct kprobe *p)
{
struct kprobe *kp;
if (WARN_ON_ONCE(kprobe_gone(p)))
return;
p->flags |= KPROBE_FLAG_GONE;
if (kprobe_aggrprobe(p)) {
/*
@ -2270,7 +2273,10 @@ 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_rcu(p, head, hlist)
hlist_for_each_entry_rcu(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))) {
@ -2287,6 +2293,7 @@ static int kprobes_module_callback(struct notifier_block *nb,
*/
kill_kprobe(p);
}
}
}
mutex_unlock(&kprobe_mutex);
return NOTIFY_DONE;