[PATCH -tip 5/5] kprobes: Don't call BUG_ON if there is a kprobe in use on free list

From: Masami Hiramatsu
Date: Tue Aug 21 2018 - 05:40:23 EST


Instead of calling BUG_ON, if we find a kprobe in use on free kprobe
list, just remove it from the list and keep it on kprobe hash list
as same as other in-use kprobes.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
kernel/kprobes.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 63c342e5e6c3..e3420364b415 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -546,8 +546,14 @@ static void do_free_cleaned_kprobes(void)
struct optimized_kprobe *op, *tmp;

list_for_each_entry_safe(op, tmp, &freeing_list, list) {
- BUG_ON(!kprobe_unused(&op->kp));
list_del_init(&op->list);
+ if (!kprobe_unused(&op->kp)) {
+ /*
+ * This must not happen, but if there is a kprobe
+ * still in use, keep it on kprobes hash list.
+ */
+ continue;
+ }
free_aggr_kprobe(&op->kp);
}
}