From: Tvrtko Ursulin tvrtko.ursulin@intel.com

We have to reject unknown flags for uAPI considerations, and also because the curent implementation limits their i915 storage space to two bits.

v2: (Chris Wilson) * Fix fail in ABI check. * Added unknown flags and BUILD_BUG_ON.

v3: * Use ARCH_KMALLOC_MINALIGN instead of alignof. (Chris Wilson)

Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Fixes: cf6e7bac6357 ("drm/i915: Add support for drm syncobjs") Cc: Jason Ekstrand jason@jlekstrand.net Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Jani Nikula jani.nikula@linux.intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: Rodrigo Vivi rodrigo.vivi@intel.com Cc: David Airlie airlied@linux.ie Cc: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 8 ++++++++ include/uapi/drm/i915_drm.h | 1 + 2 files changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 3d7190764f10..a53be7d01055 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -2100,6 +2100,11 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args, goto err; }

+ if (fence.flags & __I915_EXEC_FENCE_UNKNOWN_FLAGS) { + err = -EINVAL; + goto err; + } + syncobj = drm_syncobj_find(file, fence.handle); if (!syncobj) { DRM_DEBUG("Invalid syncobj handle provided\n"); @@ -2107,6 +2112,9 @@ get_fence_array(struct drm_i915_gem_execbuffer2 *args, goto err; }

+ BUILD_BUG_ON(~(ARCH_KMALLOC_MINALIGN - 1) & + ~__I915_EXEC_FENCE_UNKNOWN_FLAGS); + fences[n] = ptr_pack_bits(syncobj, fence.flags, 2); }

diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h index 125bde7d9504..ac3c6503ca27 100644 --- a/include/uapi/drm/i915_drm.h +++ b/include/uapi/drm/i915_drm.h @@ -839,6 +839,7 @@ struct drm_i915_gem_exec_fence {

#define I915_EXEC_FENCE_WAIT (1<<0) #define I915_EXEC_FENCE_SIGNAL (1<<1) +#define __I915_EXEC_FENCE_UNKNOWN_FLAGS (-(I915_EXEC_FENCE_SIGNAL << 1)) __u32 flags; };