From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alex Deucher Subject: [ 06/26] drm/radeon: prevent crash in the ring space allocation Date: Thu, 7 Feb 2013 16:57:34 -0800 Message-Id: <20130208004628.320326689@linuxfoundation.org> In-Reply-To: <20130208004627.258272404@linuxfoundation.org> References: <20130208004627.258272404@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Deucher commit fd5d93a0015ce1a7db881382022b2fcdfdc61760 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/radeon/radeon_ring.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/gpu/drm/radeon/radeon_ring.c +++ b/drivers/gpu/drm/radeon/radeon_ring.c @@ -311,6 +311,9 @@ int radeon_ring_alloc(struct radeon_devi { 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;