From c32f0bd7d4838982c6724fca0da92353f27c6f88 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Thu, 16 Jan 2025 14:34:35 +0900 Subject: af_unix: Set drop reason in unix_release_sock(). unix_release_sock() is called when the last refcnt of struct file is released. Let's define a new drop reason SKB_DROP_REASON_SOCKET_CLOSE and set it for kfree_skb() in unix_release_sock(). # echo 1 > /sys/kernel/tracing/events/skb/kfree_skb/enable # python3 >>> from socket import * >>> s1, s2 = socketpair(AF_UNIX) >>> s1.send(b'hello world') >>> s2.close() # cat /sys/kernel/tracing/trace_pipe ... python3-280 ... kfree_skb: ... protocol=0 location=unix_release_sock+0x260/0x420 reason: SOCKET_CLOSE To be precise, unix_release_sock() is also called for a new child socket in unix_stream_connect() when something fails, but the new sk does not have skb in the recv queue then and no event is logged. Note that only tcp_inbound_ao_hash() uses a similar drop reason, SKB_DROP_REASON_TCP_CLOSE, and this can be generalised later. Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250116053441.5758-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- net/unix/af_unix.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net') diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 8f2b605ce5b3..a05d25cc5545 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -715,8 +715,8 @@ static void unix_release_sock(struct sock *sk, int embrion) if (state == TCP_LISTEN) unix_release_sock(skb->sk, 1); - /* passed fds are erased in the kfree_skb hook */ - kfree_skb(skb); + /* passed fds are erased in the kfree_skb hook */ + kfree_skb_reason(skb, SKB_DROP_REASON_SOCKET_CLOSE); } if (path.dentry) -- cgit v1.2.3