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 <chris@xxxxxxxxxxxxxxxxxx>
---
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
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
