From fd5d93a0015ce1a7db881382022b2fcdfdc61760 Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Wed, 30 Jan 2013 14:24:09 -0500 Subject: [PATCH] drm/radeon: prevent crash in the ring space allocation If the requested number of DWs on the ring is larger than the size of the ring itself, return an error. In testing with large VM updates, we've seen crashes when we try and allocate more space on the ring than the total size of the ring without checking. This prevents the crash but for large VM updates or bo moves of very large buffers, we will need to break the transaction down into multiple batches. I have patches to use IBs for the next kernel. Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org --- drivers/gpu/drm/radeon/radeon_ring.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c index 2430d80b1871..cd72062d5a91 100644 --- a/drivers/gpu/drm/radeon/radeon_ring.c +++ b/drivers/gpu/drm/radeon/radeon_ring.c @@ -377,6 +377,9 @@ int radeon_ring_alloc(struct radeon_device *rdev, struct radeon_ring *ring, unsi { int r; + /* make sure we aren't trying to allocate more space than there is on the ring */ + if (ndw > (ring->ring_size / 4)) + return -ENOMEM; /* Align requested size with padding so unlock_commit can * pad safely */ ndw = (ndw + ring->align_mask) & ~ring->align_mask; -- GitLab