| Message ID | 20250410092418.135258-3-phasta@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | [1/3] drm/nouveau: Prevent signaled fences in pending list | expand |
diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c index 7cc84472cece..33535987d8ed 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fence.c +++ b/drivers/gpu/drm/nouveau/nouveau_fence.c @@ -274,7 +274,7 @@ nouveau_fence_done(struct nouveau_fence *fence) nvif_event_block(&fctx->event); spin_unlock_irqrestore(&fctx->lock, flags); } - return dma_fence_is_signaled(&fence->base); + return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->base.flags); } static long
Nouveau currently relies on the assumption that dma_fences will only ever get signaled through nouveau_fence_signal(), which takes care of removing a signaled fence from the list nouveau_fence_chan.pending. This self-imposed rule is violated in nouveau_fence_done(), where dma_fence_is_signaled() (somewhat surprisingly, considering its name) can signal the fence without removing it from the list. This enables accesses to already signaled fences through the list, which is a bug. In particular, it can race with nouveau_fence_context_kill(), which would then attempt to set an error code on an already signaled fence, which is illegal. In nouveau_fence_done(), the call to nouveau_fence_update() already ensures to signal all ready fences. Thus, the signaling potentially performed by dma_fence_is_signaled() is actually not necessary. Replace the call to dma_fence_is_signaled() with nouveau_fence_base_is_signaled(). Cc: <stable@vger.kernel.org> # 4.10+, precise commit not to be determined Signed-off-by: Philipp Stanner <phasta@kernel.org> --- drivers/gpu/drm/nouveau/nouveau_fence.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)