From: Vitaliy Makkoveev <mvs@openbsd.org>
Subject: Re: unlock socket close
To: Alexander Bluhm <bluhm@openbsd.org>
Cc: tech@openbsd.org
Date: Tue, 15 Jul 2025 03:01:02 +0300

On Tue, Jul 15, 2025 at 12:32:51AM +0200, Alexander Bluhm wrote:
> On Mon, Jul 14, 2025 at 08:18:07PM +0200, Alexander Bluhm wrote:
> > This diff is needed to run close(2) system call with shared netlock.
> 
> After parts have been commited, this is the remaining chunk that
> actually swiches soclose() and sofree() to shared netlock.
> 
> bluhm
>

Was OKed by me as a part of combined diff.

> Index: kern/uipc_socket.c
> ===================================================================
> RCS file: /data/mirror/openbsd/cvs/src/sys/kern/uipc_socket.c,v
> diff -u -p -r1.380 uipc_socket.c
> --- kern/uipc_socket.c	2 Jul 2025 16:44:40 -0000	1.380
> +++ kern/uipc_socket.c	14 Jul 2025 22:29:29 -0000
> @@ -213,10 +213,7 @@ socreate(int dom, struct socket **aso, i
>  	if (error) {
>  		so->so_state |= SS_NOFDREF;
>  		/* sofree() calls sounlock(). */
> -		soref(so);
> -		sofree(so, 1);
> -		sounlock_shared(so);
> -		sorele(so);
> +		sofree(so, 0);
>  		return (error);
>  	}
>  	sounlock_shared(so);
> @@ -304,7 +301,7 @@ sofree(struct socket *so, int keep_lock)
>  
>  	if (so->so_pcb || (so->so_state & SS_NOFDREF) == 0) {
>  		if (!keep_lock)
> -			sounlock(so);
> +			sounlock_shared(so);
>  		return;
>  	}
>  	if (so->so_head) {
> @@ -317,7 +314,7 @@ sofree(struct socket *so, int keep_lock)
>  		 */
>  		if (so->so_onq == &head->so_q) {
>  			if (!keep_lock)
> -				sounlock(so);
> +				sounlock_shared(so);
>  			return;
>  		}
>  
> @@ -344,7 +341,7 @@ sofree(struct socket *so, int keep_lock)
>  	}
>  
>  	if (!keep_lock)
> -		sounlock(so);
> +		sounlock_shared(so);
>  	sorele(so);
>  }
>  
> @@ -368,7 +365,7 @@ soclose(struct socket *so, int flags)
>  	struct socket *so2;
>  	int error = 0;
>  
> -	solock(so);
> +	solock_shared(so);
>  	/* Revoke async IO early. There is a final revocation in sofree(). */
>  	sigio_free(&so->so_sigio);
>  	if (so->so_state & SS_ISCONNECTED) {
> @@ -430,7 +427,7 @@ discard:
>  	if (so->so_sp) {
>  		struct socket *soback;
>  
> -		sounlock(so);
> +		sounlock_shared(so);
>  		/*
>  		 * Concurrent sounsplice() locks `sb_mtx' mutexes on
>  		 * both `so_snd' and `so_rcv' before unsplice sockets.
> @@ -477,7 +474,7 @@ notsplicedback:
>  		task_del(sosplice_taskq, &so->so_sp->ssp_task);
>  		taskq_barrier(sosplice_taskq);
>  
> -		solock(so);
> +		solock_shared(so);
>  	}
>  #endif /* SOCKET_SPLICE */
>  
>