[PATCH 5.15 157/207] drm/msm: Restore error return on invalid fence

Greg Kroah-Hartman
2021-12-06T15:43:29Z

From: Rob Clark <robdclark@chromium.org>

[ Upstream commit 067ecab9eef620d41040715669e5fcdc2f8ff963 ]

When converting to use an idr to map userspace fence seqno values back
to a dma_fence, we lost the error return when userspace passes seqno
that is larger than the last submitted fence. Restore this check.

Reported-by: Akhil P Oommen <akhilpo@codeaurora.org>
Fixes: a61acbbe9cf8 ("drm/msm: Track "seqno" fences by idr")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Akhil P Oommen <akhilpo@codeaurora.org>
Link: https://lore.kernel.org/r/20211111192457.747899-3-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/msm/msm_drv.c | 6 ++++++
drivers/gpu/drm/msm/msm_gem_submit.c | 1 +
drivers/gpu/drm/msm/msm_gpu.h | 3 +++
3 files changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 4c5661f38dd26..27f737a253c77 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -944,6 +944,12 @@ static int wait_fence(struct msm_gpu_submitqueue *queue, uint32_t fence_id,
struct dma_fence *fence;
int ret;

+ if (fence_id > queue->last_fence) {
+ DRM_ERROR_RATELIMITED("waiting on invalid fence: %u (of %u)\n",
+ fence_id, queue->last_fence);
+ return -EINVAL;
+ }
+
/*
* Map submitqueue scoped "seqno" (which is actually an idr key)
* back to underlying dma-fence
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index 151d19e4453cd..a38f23be497d8 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -911,6 +911,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data,
drm_sched_entity_push_job(&submit->base, queue->entity);

args->fence = submit->fence_id;
+ queue->last_fence = submit->fence_id;

msm_reset_syncobjs(syncobjs_to_reset, args->nr_in_syncobjs);
msm_process_post_deps(post_deps, args->nr_out_syncobjs,
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index ee25d556c8a10..2e2424066e701 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -352,6 +352,8 @@ static inline int msm_gpu_convert_priority(struct msm_gpu *gpu, int prio,
* @ring_nr: the ringbuffer used by this submitqueue, which is determined
* by the submitqueue's priority
* @faults: the number of GPU hangs associated with this submitqueue
+ * @last_fence: the sequence number of the last allocated fence (for error
+ * checking)
* @ctx: the per-drm_file context associated with the submitqueue (ie.
* which set of pgtables do submits jobs associated with the
* submitqueue use)
@@ -367,6 +369,7 @@ struct msm_gpu_submitqueue {
u32 flags;
u32 ring_nr;
int faults;
+ uint32_t last_fence;
struct msm_file_private *ctx;
struct list_head node;
struct idr fence_idr;
--
2.33.0