@@ -635,9 +635,9 @@ i915_gem_execbuffer_relocate_slow(struct drm_device *dev,
* relocations were valid.
*/
for (j = 0; j < exec[i].relocation_count; j++) {
- if (copy_to_user(&user_relocs[j].presumed_offset,
- &invalid_offset,
- sizeof(invalid_offset))) {
+ if (__copy_to_user(&user_relocs[j].presumed_offset,
+ &invalid_offset,
+ sizeof(invalid_offset))) {
ret = -EFAULT;
mutex_lock(&dev->struct_mutex);
goto err;
@@ -1161,18 +1161,21 @@ i915_gem_execbuffer(struct drm_device *dev, void *data,
ret = i915_gem_do_execbuffer(dev, data, file, &exec2, exec2_list);
if (!ret) {
+ struct drm_i915_gem_exec_object __user *user_exec_list =
+ to_user_ptr(args->buffers_ptr);
+
/* Copy the new buffer offsets back to the user's exec list. */
- for (i = 0; i < args->buffer_count; i++)
- exec_list[i].offset = exec2_list[i].offset;
- /* ... and back out to userspace */
- ret = copy_to_user(to_user_ptr(args->buffers_ptr),
- exec_list,
- sizeof(*exec_list) * args->buffer_count);
- if (ret) {
- ret = -EFAULT;
- DRM_DEBUG("failed to copy %d exec entries "
- "back to user (%d)\n",
- args->buffer_count, ret);
+ for (i = 0; i < args->buffer_count; i++) {
+ ret = __copy_to_user(&user_exec_list[i].offset,
+ &exec2_list[i].offset,
+ sizeof(user_exec_list[i].offset));
+ if (ret) {
+ ret = -EFAULT;
+ DRM_DEBUG("failed to copy %d exec entries "
+ "back to user (%d)\n",
+ args->buffer_count, ret);
+ break;
+ }
}
}
@@ -1218,14 +1221,21 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data,
ret = i915_gem_do_execbuffer(dev, data, file, args, exec2_list);
if (!ret) {
/* Copy the new buffer offsets back to the user's exec list. */
- ret = copy_to_user(to_user_ptr(args->buffers_ptr),
- exec2_list,
- sizeof(*exec2_list) * args->buffer_count);
- if (ret) {
- ret = -EFAULT;
- DRM_DEBUG("failed to copy %d exec entries "
- "back to user (%d)\n",
- args->buffer_count, ret);
+ struct drm_i915_gem_exec_object2 *user_exec_list =
+ to_user_ptr(args->buffers_ptr);
+ int i;
+
+ for (i = 0; i < args->buffer_count; i++) {
+ ret = __copy_to_user(&user_exec_list[i].offset,
+ &exec2_list[i].offset,
+ sizeof(user_exec_list[i].offset));
+ if (ret) {
+ ret = -EFAULT;
+ DRM_DEBUG("failed to copy %d exec entries "
+ "back to user\n",
+ args->buffer_count);
+ break;
+ }
}
}
This is a note to let you know that I have just added a patch titled drm/i915: Only copy back the modified fields to userspace from execbuffer to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From e55086d0a61c09affe4bbfee27607b13b3ec3d22 Mon Sep 17 00:00:00 2001 From: Chris Wilson <chris@chris-wilson.co.uk> Date: Fri, 23 May 2014 10:45:52 +0100 Subject: drm/i915: Only copy back the modified fields to userspace from execbuffer commit 9aab8bff7aa3bee567213ad3c1fdfb217bb980a2 upstream. We only want to modifiy a single field in the userspace view of the execbuffer command buffer, so explicitly change that rather than copy everything back again. This serves two purposes: 1. The single fields are much cheaper to copy (constant size so the copy uses special case code) and much smaller than the whole array. 2. We modify the array for internal use that need to be masked from the user. Note: We need this backported since without it the next bugfix will blow up when userspace recycles batchbuffers and relocations. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/gpu/drm/i915/i915_gem_execbuffer.c | 54 ++++++++++++++++++------------ 1 file changed, 32 insertions(+), 22 deletions(-) -- 1.9.1