[PATCH 5.16 0975/1017] af_unix: Support POLLPRI for OOB.

Greg Kroah-Hartman
2022-04-05T10:28:40Z

From: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit d9a232d435dcc966738b0f414a86f7edf4f4c8c4 upstream.

The commit 314001f0bf92 ("af_unix: Add OOB support") introduced OOB for
AF_UNIX, but it lacks some changes for POLLPRI. Let's add the missing
piece.

In the selftest, normal datagrams are sent followed by OOB data, so this
commit replaces `POLLIN | POLLPRI` with just `POLLPRI` in the first test
case.

Fixes: 314001f0bf92 ("af_unix: Add OOB support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/unix/af_unix.c | 4 ++++
tools/testing/selftests/net/af_unix/test_unix_oob.c | 6 +++---
2 files changed, 7 insertions(+), 3 deletions(-)

--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -3049,6 +3049,10 @@ static __poll_t unix_poll(struct file *f
mask |= EPOLLIN | EPOLLRDNORM;
if (sk_is_readable(sk))
mask |= EPOLLIN | EPOLLRDNORM;
+#if IS_ENABLED(CONFIG_AF_UNIX_OOB)
+ if (READ_ONCE(unix_sk(sk)->oob_skb))
+ mask |= EPOLLPRI;
+#endif

/* Connection-based need to check for termination and startup */
if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&
--- a/tools/testing/selftests/net/af_unix/test_unix_oob.c
+++ b/tools/testing/selftests/net/af_unix/test_unix_oob.c
@@ -218,10 +218,10 @@ main(int argc, char **argv)

/* Test 1:
* veriyf that SIGURG is
- * delivered and 63 bytes are
- * read and oob is '@'
+ * delivered, 63 bytes are
+ * read, oob is '@', and POLLPRI works.
*/
- wait_for_data(pfd, POLLIN | POLLPRI);
+ wait_for_data(pfd, POLLPRI);
read_oob(pfd, &oob);
len = read_data(pfd, buf, 1024);
if (!signal_recvd || len != 63 || oob != '@') {