Re: [PATCH] opensm/osm_torus.c: Fix crash in torus_update_osm_vlarb

["Jim Schutt" <jaschut-4OHPYypu0djtX7QSmKvirg@public.gmane.org>]

On 12/03/2012 08:26 AM, Hal Rosenstock wrote:
>
> Signed-off-by: Alex Netes<alexne-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Signed-off-by: Hal Rosenstock<hal-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> ---
>   opensm/osm_torus.c |    2 +-
>   1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/opensm/osm_torus.c b/opensm/osm_torus.c
> index c06f8d4..075f84a 100644
> --- a/opensm/osm_torus.c
> +++ b/opensm/osm_torus.c
> @@ -8089,7 +8089,7 @@ void torus_update_osm_vlarb(void *context, osm_physp_t *osm_phys_port,
>   	 * So, leave VL 0 alone, remap VL 4 to VL 1, zero out the rest,
>   	 * and compress out the zero entries to the end.
>   	 */
> -	if (!sw || !port_num ||
> +	if (!sw || !port_num || sw->port[port_num] ||
>   	    sw->port[port_num]->pgrp->port_grp != 2 * TORUS_MAX_DIM)
>   		return;
>

With the patch as-is, if torus_update_osm_vlarb() returns early
for any non-NULL switch port, it will never do any updates.

If the crash was that sw->port[port_num] was NULL,
shouldn't the check be !sw->port[port_num] ?

Can you tell me more about the test case that leads to the crash?

Is it that there's a switch with a port that's not connected
to anything, and torus_update_osm_vlarb() was called for it?

Testing for a non-NULL sw->port[port_num] is definitely the right
thing to do to handle that case, and I'm sorry I missed it earlier.

If not, then something else is likely broken, and we need to find
and fix that.

-- Jim

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