drm/i915: Skip pread/pwrite if size to copy is 0.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This commit is contained in:
Chris Wilson 2010-09-26 20:23:38 +01:00
parent df6d075a4d
commit 35b62a89b0
1 changed files with 13 additions and 7 deletions

View File

@ -576,7 +576,7 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
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 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
/* 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 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data,
file_priv);
}
err:
out:
drm_gem_object_unreference_unlocked(obj);
return ret;
}
@ -1059,14 +1062,17 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
/* 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 @@ i915_gem_pwrite_ioctl(struct drm_device *dev, void *data,
DRM_INFO("pwrite failed %d\n", ret);
#endif
err:
out:
drm_gem_object_unreference_unlocked(obj);
return ret;
}