I screwed up rebasing of my patch in
commit 43968d7b806d7a7e021261294c583a216fddf0e5 Author: Daniel Vetter daniel.vetter@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@chromium.org Cc: Michel Dänzer michel@daenzer.net Signed-off-by: Daniel Vetter daniel.vetter@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,