[PATCH bpf-next] bpf:syscall: Log error code on trampoline unlink failure

[xu.xin16]

From: xu xin <xu.xin16@xxxxxxxxxx>

Replace silent WARN_ON_ONCE with WARN_ONCE that prints the actual error
code from bpf_trampoline_unlink_prog(). This aids debugging of race
conditions during link teardown, while keeping the warning rate limited
to avoid log flooding.

Signed-off-by: xu xin <xu.xin16@xxxxxxxxxx>
---
 kernel/bpf/syscall.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 6db306d23b47..2348dc33abf4 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3626,10 +3626,13 @@ static void bpf_tracing_link_release(struct bpf_link *link)
 {
 	struct bpf_tracing_link *tr_link =
 		container_of(link, struct bpf_tracing_link, link.link);
+	int err;

-	WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link.node,
-						tr_link->trampoline,
-						tr_link->tgt_prog));
+	err = bpf_trampoline_unlink_prog(&tr_link->link.node,
+					tr_link->trampoline,
+					tr_link->tgt_prog);
+	if (err)
+		WARN_ONCE(err, "bpf_trampoline_unlink_prog returns error: %d\n", err);

 	bpf_trampoline_put(tr_link->trampoline);

-- 
2.25.1