drm/i915: Skip pread/pwrite if size to copy is 0.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index dba8202..29e97c0 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -576,7 +576,7 @@
struct drm_i915_gem_pread *args = data;
struct drm_gem_object *obj;
struct drm_i915_gem_object *obj_priv;
- int ret;
+ int ret = 0;
obj = drm_gem_object_lookup(dev, file_priv, args->handle);
if (obj == NULL)
@@ -586,14 +586,17 @@
/* Bounds check source. */
if (args->offset > obj->size || args->size > obj->size - args->offset) {
ret = -EINVAL;
- goto err;
+ goto out;
}
+ if (args->size == 0)
+ goto out;
+
if (!access_ok(VERIFY_WRITE,
(char __user *)(uintptr_t)args->data_ptr,
args->size)) {
ret = -EFAULT;
- goto err;
+ goto out;
}
if (i915_gem_object_needs_bit17_swizzle(obj)) {
@@ -605,7 +608,7 @@
file_priv);
}
-err:
+out:
drm_gem_object_unreference_unlocked(obj);
return ret;
}
@@ -1059,14 +1062,17 @@
/* Bounds check destination. */
if (args->offset > obj->size || args->size > obj->size - args->offset) {
ret = -EINVAL;
- goto err;
+ goto out;
}
+ if (args->size == 0)
+ goto out;
+
if (!access_ok(VERIFY_READ,
(char __user *)(uintptr_t)args->data_ptr,
args->size)) {
ret = -EFAULT;
- goto err;
+ goto out;
}
/* We can only do the GTT pwrite on untiled buffers, as otherwise
@@ -1100,7 +1106,7 @@
DRM_INFO("pwrite failed %d\n", ret);
#endif
-err:
+out:
drm_gem_object_unreference_unlocked(obj);
return ret;
}