From: Bob Paauwe <[email protected]> 3.4.107-rc1 review patch. If anyone has any objections, please let me know.
------------------ commit af1a7301c7cf8912dca03065d448c4437c5c239f upstream. When creating a fence for a tiled object, only fence the area that makes up the actual tiles. The object may be larger than the tiled area and if we allow those extra addresses to be fenced, they'll get converted to addresses beyond where the object is mapped. This opens up the possiblity of writes beyond the end of object. To prevent this, we adjust the size of the fence to only encompass the area that makes up the actual tiles. The extra space is considered un-tiled and now behaves as if it was a linear object. Testcase: igt/gem_tiled_fence_overflow Reported-by: Dan Hettena <[email protected]> Signed-off-by: Bob Paauwe <[email protected]> Reviewed-by: Daniel Vetter <[email protected]> Signed-off-by: Jani Nikula <[email protected]> [lizf: Backported to 3.4: - adjust context - adjust indentation - make the same change to both sandybridge_write_fence_reg() and i965_write_fence_reg()] Signed-off-by: Zefan Li <[email protected]> --- drivers/gpu/drm/i915/i915_gem.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 2ac4ded..b1f1d10 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2193,6 +2193,13 @@ static int sandybridge_write_fence_reg(struct drm_i915_gem_object *obj, int regnum = obj->fence_reg; uint64_t val; + /* Adjust fence size to match tiled area */ + if (obj->tiling_mode != I915_TILING_NONE) { + uint32_t row_size = obj->stride * + (obj->tiling_mode == I915_TILING_Y ? 32 : 8); + size = (size / row_size) * row_size; + } + val = (uint64_t)((obj->gtt_offset + size - 4096) & 0xfffff000) << 32; val |= obj->gtt_offset & 0xfffff000; @@ -2230,6 +2237,13 @@ static int i965_write_fence_reg(struct drm_i915_gem_object *obj, int regnum = obj->fence_reg; uint64_t val; + /* Adjust fence size to match tiled area */ + if (obj->tiling_mode != I915_TILING_NONE) { + uint32_t row_size = obj->stride * + (obj->tiling_mode == I915_TILING_Y ? 32 : 8); + size = (size / row_size) * row_size; + } + val = (uint64_t)((obj->gtt_offset + size - 4096) & 0xfffff000) << 32; val |= obj->gtt_offset & 0xfffff000; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
