I screwed up rebasing of my patch in
commit 43968d7b806d7a7e021261294c583a216fddf0e5
Author: Daniel Vetter <daniel.vetter at ffwll.ch>
Date: Wed Sep 21 10:59:24 2016 +0200
drm: Extract drm_plane.[hc]
which meant on error paths drm_crtc_vblank_put could be called without
a get, leading to an underrun of the refcount.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98020
Cc: Sean Paul <seanpaul at chromium.org>
Cc: Michel Dänzer <michel at daenzer.net>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
drivers/gpu/drm/drm_plane.c | 81 ++++++++++++++++++++++-----------------------
1 file changed, 39 insertions(+), 42 deletions(-)
diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 783aef8acab7..249c0ae52c6d 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -783,6 +783,45 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
if (!crtc)
return -ENOENT;
+ if (crtc->funcs->page_flip_target) {
+ u32 current_vblank;
+ int r;
+
+ r = drm_crtc_vblank_get(crtc);
+ if (r)
+ return r;
+
+ current_vblank = drm_crtc_vblank_count(crtc);
+
+ switch (page_flip->flags & DRM_MODE_PAGE_FLIP_TARGET) {
+ case DRM_MODE_PAGE_FLIP_TARGET_ABSOLUTE:
+ if ((int)(target_vblank - current_vblank) > 1) {
+ DRM_DEBUG("Invalid absolute flip target %u, "
+ "must be <= %u\n", target_vblank,
+ current_vblank + 1);
+ drm_crtc_vblank_put(crtc);
+ return -EINVAL;
+ }
+ break;
+ case DRM_MODE_PAGE_FLIP_TARGET_RELATIVE:
+ if (target_vblank != 0 && target_vblank != 1) {
+ DRM_DEBUG("Invalid relative flip target %u, "
+ "must be 0 or 1\n", target_vblank);
+ drm_crtc_vblank_put(crtc);
+ return -EINVAL;
+ }
+ target_vblank += current_vblank;
+ break;
+ default:
+ target_vblank = current_vblank +
+ !(page_flip->flags & DRM_MODE_PAGE_FLIP_ASYNC);
+ break;
+ }
+ } else if (crtc->funcs->page_flip == NULL ||
+ (page_flip->flags & DRM_MODE_PAGE_FLIP_TARGET)) {
+ return -EINVAL;
+ }
+
drm_modeset_lock_crtc(crtc, crtc->primary);
if (crtc->primary->fb == NULL) {
/* The framebuffer is currently unbound, presumably
@@ -793,9 +832,6 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
goto out;
}
- if (crtc->funcs->page_flip == NULL)
- goto out;
-
fb = drm_framebuffer_lookup(dev, page_flip->fb_id);
if (!fb) {
ret = -ENOENT;
@@ -839,45 +875,6 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
}
crtc->primary->old_fb = crtc->primary->fb;
- if (crtc->funcs->page_flip_target) {
- u32 current_vblank;
- int r;
-
- r = drm_crtc_vblank_get(crtc);
- if (r)
- return r;
-
- current_vblank = drm_crtc_vblank_count(crtc);
-
- switch (page_flip->flags & DRM_MODE_PAGE_FLIP_TARGET) {
- case DRM_MODE_PAGE_FLIP_TARGET_ABSOLUTE:
- if ((int)(target_vblank - current_vblank) > 1) {
- DRM_DEBUG("Invalid absolute flip target %u, "
- "must be <= %u\n", target_vblank,
- current_vblank + 1);
- drm_crtc_vblank_put(crtc);
- return -EINVAL;
- }
- break;
- case DRM_MODE_PAGE_FLIP_TARGET_RELATIVE:
- if (target_vblank != 0 && target_vblank != 1) {
- DRM_DEBUG("Invalid relative flip target %u, "
- "must be 0 or 1\n", target_vblank);
- drm_crtc_vblank_put(crtc);
- return -EINVAL;
- }
- target_vblank += current_vblank;
- break;
- default:
- target_vblank = current_vblank +
- !(page_flip->flags & DRM_MODE_PAGE_FLIP_ASYNC);
- break;
- }
- } else if (crtc->funcs->page_flip == NULL ||
- (page_flip->flags & DRM_MODE_PAGE_FLIP_TARGET)) {
- return -EINVAL;
- }
-
if (crtc->funcs->page_flip_target)
ret = crtc->funcs->page_flip_target(crtc, fb, e,
page_flip->flags,
--
2.9.3
