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

[Kuniyuki Iwashima <kuniyu@amazon.com>]

> [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@gmail.com>
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@gmail.com>
> ---
>  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