Re: [PATCH] net: unix: Fix undefined 'other' error

From: Kuniyuki Iwashima
Date: Sun Feb 09 2025 - 19:27:02 EST



> [PATCH] net: unix: Fix undefined 'other' error

Please add net-next after PATCH and start with af_unix: as with
other commits when you post v2.

[PATCH net-next v2]: af_unix: ...


From: Purva Yeshi <purvayeshi550@xxxxxxxxx>
Date: Mon, 10 Feb 2025 00:13:55 +0530
> Fix issue detected by smatch tool:
> An "undefined 'other'" error occur in __releases() annotation.
>
> The issue occurs because __releases(&unix_sk(other)->lock) is placed
> at the function signature level, where other is not yet in scope.
>
> Fix this by replacing it with __releases(&u->lock), using u, a local
> variable, which is properly defined inside the function.

Tweaking an annotation with a comment for a static analyzer to fix
a warning for yet another static analyzer is too much.

Please remove sparse annotation instead.

Here's the only place where sparse is used in AF_UNIX code, and we
don't use sparse even for /proc/net/unix.


>
> Signed-off-by: Purva Yeshi <purvayeshi550@xxxxxxxxx>
> ---
> net/unix/af_unix.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
> index 34945de1f..37b01605a 100644
> --- a/net/unix/af_unix.c
> +++ b/net/unix/af_unix.c
> @@ -1508,7 +1508,10 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
> }
>
> static long unix_wait_for_peer(struct sock *other, long timeo)
> - __releases(&unix_sk(other)->lock)
> + /*
> + * Use local variable instead of function parameter
> + */
> + __releases(&u->lock)
> {
> struct unix_sock *u = unix_sk(other);
> int sched;
> --
> 2.34.1