On Mar 19, 2013 9:55 AM, "Rob Clark" robdclark@gmail.com wrote:
On Mon, Mar 18, 2013 at 8:00 PM, YoungJun Cho yj44.cho@samsung.com
wrote:
On Mar 19, 2013 3:01 AM, "Rob Clark" robdclark@gmail.com wrote:
Btw, what is the hw response to invalid input (ie. bottom>top, invalid size, etc)?
Unfortunately the IOMMU page fault is happened. So we need some codes
for
protecting kernel.
hmm, a page fault is not necessarily a problem.. do you have some way to know which userspace client the the fault is associated with (I assume so, unless you have some way to have multiple contexts active at one time), and some sane way to recover?
When IOMMU page fault is occured, kernel oops is generated now because it is unrecoverable.
I only ask this because, for an xorg/exa perspective, you can have a large # of blits that effect a small # of pixels, so minimizing per-blit overhead can be important for performance. (otoh, if you already have to do some cmdstream checking in the kernel to ensure security, maybe it doesn't add much overhead for a few extra checks. Depends on whether it can all be done in one pass and without additional load (LDR) instructions from the cmdstream buffer (which is presumably not in a cached buffer)
Right, performance is important. We already have checked all command lists for buffer addresses security and it is done in one pass. And this patch gathers additional data for HW restriction during previous checking routine.
Thank you Best regards YJ
BR, -R
Thank you~ Best regards YJ
Ie. if it will just ignore the blit or raise an error irq which can be handled sanely, it could be ok to avoid the overhead of the cmdstream checking in the kernel. The kernel part really just needs to ensure that userspace can't cause security problems (read/write access to non-gfx-buffers, or lock up the system, that sort of thing). It doesn't need to guarantee that the results are sensible.
BR, -R
On Wed, Mar 13, 2013 at 5:03 AM, Inki Dae inki.dae@samsung.com wrote:
This patch set checks the contents of g2d command list from user is valid or not according to G2D hardware restrictions. For now, G2D driver wasn't considered for them properly.
For this, this patch set includes relevant code cleaups, fixups and adds a new function to get buffer size to the gem to be accessed by G2D dma.
Inki Dae (1): drm/exynos: Add a new function to get gem buffer size
YoungJun Cho (6): drm/exynos: Fix error routine to getting dma addr. drm/exynos: clear node object type at gem unmap drm/exynos: Fix G2D core mulfunctioning issue drm/exynos: Clean up some G2D codes for readability drm/exynos: Deal with g2d buffer info more efficiently drm/exynos: Check g2d cmd list for g2d restrictions
drivers/gpu/drm/exynos/exynos_drm_g2d.c | 381 ++++++++++++++++++++++++++----- drivers/gpu/drm/exynos/exynos_drm_gem.c | 21 ++ drivers/gpu/drm/exynos/exynos_drm_gem.h | 5 + 3 files changed, 349 insertions(+), 58 deletions(-)
-- 1.7.4.1
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