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| author | Boris Brezillon <boris.brezillon@collabora.com> | 2021-09-03 14:05:54 +0200 |
|---|---|---|
| committer | Boris Brezillon <boris.brezillon@collabora.com> | 2021-09-07 09:58:26 +0200 |
| commit | d4c16733e7960aa50d6d3bc4a03ee1578baaa47b (patch) | |
| tree | 018f5f404e035d49e67ed13829cd4b878555eaa4 /drivers/gpu/drm/scheduler | |
| parent | 5bd785a8140333f9162438d0075edd1e432e7ef8 (diff) | |
| download | linux-d4c16733e7960aa50d6d3bc4a03ee1578baaa47b.tar.bz2 | |
drm/sched: Fix drm_sched_fence_free() so it can be passed an uninitialized fence
drm_sched_job_cleanup() will pass an uninitialized fence to
drm_sched_fence_free(), which will cause to_drm_sched_fence() to return
a NULL fence object, causing a NULL pointer deref when this NULL object
is passed to kmem_cache_free().
Let's create a new drm_sched_fence_free() function that takes a
drm_sched_fence pointer and suffix the old function with _rcu. While at
it, complain if drm_sched_fence_free() is passed an initialized fence
or if drm_sched_fence_free_rcu() is passed an uninitialized fence.
Fixes: dbe48d030b28 ("drm/sched: Split drm_sched_job_init")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210903120554.444101-1-boris.brezillon@collabora.com
Diffstat (limited to 'drivers/gpu/drm/scheduler')
| -rw-r--r-- | drivers/gpu/drm/scheduler/sched_fence.c | 27 | ||||
| -rw-r--r-- | drivers/gpu/drm/scheduler/sched_main.c | 2 |
2 files changed, 19 insertions, 10 deletions
diff --git a/drivers/gpu/drm/scheduler/sched_fence.c b/drivers/gpu/drm/scheduler/sched_fence.c index db3fd1303fc4..7fd869520ef2 100644 --- a/drivers/gpu/drm/scheduler/sched_fence.c +++ b/drivers/gpu/drm/scheduler/sched_fence.c @@ -69,19 +69,28 @@ static const char *drm_sched_fence_get_timeline_name(struct dma_fence *f) return (const char *)fence->sched->name; } +static void drm_sched_fence_free_rcu(struct rcu_head *rcu) +{ + struct dma_fence *f = container_of(rcu, struct dma_fence, rcu); + struct drm_sched_fence *fence = to_drm_sched_fence(f); + + if (!WARN_ON_ONCE(!fence)) + kmem_cache_free(sched_fence_slab, fence); +} + /** - * drm_sched_fence_free - free up the fence memory + * drm_sched_fence_free - free up an uninitialized fence * - * @rcu: RCU callback head + * @fence: fence to free * - * Free up the fence memory after the RCU grace period. + * Free up the fence memory. Should only be used if drm_sched_fence_init() + * has not been called yet. */ -void drm_sched_fence_free(struct rcu_head *rcu) +void drm_sched_fence_free(struct drm_sched_fence *fence) { - struct dma_fence *f = container_of(rcu, struct dma_fence, rcu); - struct drm_sched_fence *fence = to_drm_sched_fence(f); - - kmem_cache_free(sched_fence_slab, fence); + /* This function should not be called if the fence has been initialized. */ + if (!WARN_ON_ONCE(fence->sched)) + kmem_cache_free(sched_fence_slab, fence); } /** @@ -97,7 +106,7 @@ static void drm_sched_fence_release_scheduled(struct dma_fence *f) struct drm_sched_fence *fence = to_drm_sched_fence(f); dma_fence_put(fence->parent); - call_rcu(&fence->finished.rcu, drm_sched_fence_free); + call_rcu(&fence->finished.rcu, drm_sched_fence_free_rcu); } /** diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index fbbd3b03902f..6987d412a946 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -750,7 +750,7 @@ void drm_sched_job_cleanup(struct drm_sched_job *job) dma_fence_put(&job->s_fence->finished); } else { /* aborted job before committing to run it */ - drm_sched_fence_free(&job->s_fence->finished.rcu); + drm_sched_fence_free(job->s_fence); } job->s_fence = NULL; |