drm/nouveau/pm: prevent freeing the wrong engine context

This fixes a crash when multiple PM engine contexts are created.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Martin Peres <martin.peres@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c
index 2006c445938d9493773ef2dbf9bb07d045a67b96..274457ca3fef798d62b955d02a70cbd91e287cb0 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/pm/base.c
@@ -332,9 +332,12 @@ static void
 nvkm_perfctx_dtor(struct nvkm_object *object)
 {
        struct nvkm_pm *ppm = (void *)object->engine;
+       struct nvkm_perfctx *ctx = (void *)object;
+
        mutex_lock(&nv_subdev(ppm)->mutex);
-       nvkm_engctx_destroy(&ppm->context->base);
-       ppm->context = NULL;
+       nvkm_engctx_destroy(&ctx->base);
+       if (ppm->context == ctx)
+               ppm->context = NULL;
        mutex_unlock(&nv_subdev(ppm)->mutex);
 }