This just allows the compiler to pessimise callers who try to abuse the ioctl in the hope of making the correct users faster.
Signed-off-by: Chris Wilson <[email protected]> --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 36 +++++++++++++----------------- 1 file changed, 15 insertions(+), 21 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c index 4304d8b9e17c..0ba1e7bbd09d 100644 --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c @@ -870,41 +870,38 @@ i915_gem_execbuffer_move_to_gpu(struct intel_engine_cs *ring, return intel_ring_invalidate_all_caches(ring); } -static bool -i915_gem_check_execbuffer(struct drm_i915_gem_execbuffer2 *exec) -{ - if (exec->flags & __I915_EXEC_UNKNOWN_FLAGS) - return false; - - return ((exec->batch_start_offset | exec->batch_len) & 0x7) == 0; -} - static int validate_exec_list(struct drm_device *dev, - struct drm_i915_gem_exec_object2 *exec, - int count) + const struct drm_i915_gem_execbuffer2 *args, + const struct drm_i915_gem_exec_object2 *exec) { unsigned relocs_total = 0; unsigned relocs_max = UINT_MAX / sizeof(struct drm_i915_gem_relocation_entry); unsigned invalid_flags; int i; + if (unlikely(args->flags & __I915_EXEC_UNKNOWN_FLAGS)) + return -EINVAL; + + if (unlikely((args->batch_start_offset | args->batch_len) & 0x7)) + return -EINVAL; + invalid_flags = __EXEC_OBJECT_UNKNOWN_FLAGS; if (USES_FULL_PPGTT(dev)) invalid_flags |= EXEC_OBJECT_NEEDS_GTT; - for (i = 0; i < count; i++) { + for (i = 0; i < args->buffer_count; i++) { char __user *ptr = to_user_ptr(exec[i].relocs_ptr); int length; /* limited by fault_in_pages_readable() */ - if (exec[i].flags & invalid_flags) + if (unlikely(exec[i].flags & invalid_flags)) return -EINVAL; /* First check for malicious input causing overflow in * the worst case where we need to allocate the entire * relocation tree as a single array. */ - if (exec[i].relocation_count > relocs_max - relocs_total) + if (unlikely(exec[i].relocation_count > relocs_max - relocs_total)) return -EINVAL; relocs_total += exec[i].relocation_count; @@ -915,11 +912,11 @@ validate_exec_list(struct drm_device *dev, * to read, but since we may need to update the presumed * offsets during execution, check for full write access. */ - if (!access_ok(VERIFY_WRITE, ptr, length)) + if (unlikely(!access_ok(VERIFY_WRITE, ptr, length))) return -EFAULT; if (likely(!i915.prefault_disable)) { - if (fault_in_multipages_readable(ptr, length)) + if (unlikely(fault_in_multipages_readable(ptr, length))) return -EFAULT; } } @@ -1256,11 +1253,8 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data, int ret; bool need_relocs; - if (!i915_gem_check_execbuffer(args)) - return -EINVAL; - - ret = validate_exec_list(dev, exec, args->buffer_count); - if (ret) + ret = validate_exec_list(dev, args, exec); + if (unlikely(ret)) return ret; flags = 0; -- 2.1.0.rc1 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
