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Commit c0e7b4aa authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Paul Mackerras
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[POWERPC] spusched: Fix null pointer dereference in find_victim 



find_victim can dereference a NULL pointer when iterating over the list
of victim spus because list_mutex only guarantees spu->ct to be stable,
but of course not to be non-NULL.

Also fix find_victim to not call spu_unbind_context without list_mutex
because that violates the above guarantee.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: default avatarJeremy Kerr <jk@ozlabs.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent c2f82897

arch/powerpc/platforms/cell/spufs/sched.c

+2 −2
Original line number Diff line number Diff line
@@ -579,7 +579,7 @@ static struct spu *find_victim(struct spu_context *ctx) 
		list_for_each_entry(spu, &cbe_spu_info[node].spus, cbe_list) {

			struct spu_context *tmp = spu->ctx;



			if (tmp->prio > ctx->prio &&

			if (tmp && tmp->prio > ctx->prio &&

			    (!victim || tmp->prio > victim->prio))

				victim = spu->ctx;

		}
@@ -611,9 +611,9 @@ static struct spu *find_victim(struct spu_context *ctx) 


			mutex_lock(&cbe_spu_info[node].list_mutex);

			cbe_spu_info[node].nr_active--;

			spu_unbind_context(spu, victim);

			mutex_unlock(&cbe_spu_info[node].list_mutex);



			spu_unbind_context(spu, victim);

			victim->stats.invol_ctx_switch++;

			spu->stats.invol_ctx_switch++;

			mutex_unlock(&victim->state_mutex);