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 <songmuc...@bytedance.com>
Co-developed-by: Chengming Zhou <zhouchengm...@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengm...@bytedance.com>
Acked-by: Masami Hiramatsu <mhira...@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
