svn commit: r363308 - head/sys/net

[Konstantin Belousov]

On Sat, Jul 18, 2020 at 12:43:11PM +0000, Kristof Provost wrote:
> Author: kp
> Date: Sat Jul 18 12:43:11 2020
> New Revision: 363308
> URL: https://svnweb.freebsd.org/changeset/base/363308
> 
> Log:
>   bridge: Don't sleep during epoch
>   
>   While it doesn't trigger INVARIANTS or WITNESS on head it does in stable/12.
>   There's also no reason for it, as we can easily report the out of memory error
>   to the caller (i.e. userspace). All of these can already fail.
This makes syscalls (ioctl) fail randomly.  Can you pre-allocate the buffers
before entering epoch, instead ?

>   
>   PR:		248046
>   MFC after:	3 days
> 
> Modified:
>   head/sys/net/if_bridge.c
> 
> Modified: head/sys/net/if_bridge.c
> ==============================================================================
> --- head/sys/net/if_bridge.c	Sat Jul 18 12:21:08 2020	(r363307)
> +++ head/sys/net/if_bridge.c	Sat Jul 18 12:43:11 2020	(r363308)
> @@ -1393,9 +1393,9 @@ bridge_ioctl_gifs(struct bridge_softc *sc, void *arg)
>  		bifc->ifbic_len = buflen;
>  		return (0);
>  	}
> -	BRIDGE_UNLOCK(sc);
> -	outbuf = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
> -	BRIDGE_LOCK(sc);
> +	outbuf = malloc(buflen, M_TEMP, M_NOWAIT | M_ZERO);
> +	if (outbuf == NULL)
> +		return (ENOMEM);
>  
>  	count = 0;
>  	buf = outbuf;
> @@ -1455,9 +1455,9 @@ bridge_ioctl_rts(struct bridge_softc *sc, void *arg)
>  		count++;
>  	buflen = sizeof(bareq) * count;
>  
> -	BRIDGE_UNLOCK(sc);
> -	outbuf = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
> -	BRIDGE_LOCK(sc);
> +	outbuf = malloc(buflen, M_TEMP, M_NOWAIT | M_ZERO);
> +	if (outbuf == NULL)
> +		return (ENOMEM);
>  
>  	count = 0;
>  	buf = outbuf;
> @@ -1783,9 +1783,9 @@ bridge_ioctl_gifsstp(struct bridge_softc *sc, void *ar
>  		return (0);
>  	}
>  
> -	BRIDGE_UNLOCK(sc);
> -	outbuf = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
> -	BRIDGE_LOCK(sc);
> +	outbuf = malloc(buflen, M_TEMP, M_NOWAIT | M_ZERO);
> +	if (outbuf == NULL)
> +		return (ENOMEM);
>  
>  	count = 0;
>  	buf = outbuf;