Most nouveau event handlers have storage in 'static' containers (structures with lifetimes nearly equivalent to the drm_device), but are dangerously reused via nouveau_event_get/_put. For example, if nouveau_event_get is called more than once for a given handler, the event handler list will be corrupted.
Migrate nouveau_event_get/_put from add/remove semantics to enable/disable semantics.
Signed-off-by: Peter Hurley peter@hurleysoftware.com --- drivers/gpu/drm/nouveau/core/core/event.c | 20 ++++++++++++-------- drivers/gpu/drm/nouveau/core/include/core/event.h | 4 ++++ drivers/gpu/drm/nouveau/nouveau_drm.c | 8 ++------ 3 files changed, 18 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/core/core/event.c b/drivers/gpu/drm/nouveau/core/core/event.c index 1a8d685..0a65ede 100644 --- a/drivers/gpu/drm/nouveau/core/core/event.c +++ b/drivers/gpu/drm/nouveau/core/core/event.c @@ -51,11 +51,13 @@ static void nouveau_event_put_locked(struct nouveau_event *event, int index, struct nouveau_eventh *handler) { - if (!--event->index[index].refs) { - if (event->disable) - event->disable(event, index); + if (__test_and_clear_bit(NVKM_EVENT_ENABLE, &handler->flags)) { + if (!--event->index[index].refs) { + if (event->disable) + event->disable(event, index); + } + list_del(&handler->head); } - list_del(&handler->head); }
void @@ -82,10 +84,12 @@ nouveau_event_get(struct nouveau_event *event, int index, return;
spin_lock_irqsave(&event->lock, flags); - list_add(&handler->head, &event->index[index].list); - if (!event->index[index].refs++) { - if (event->enable) - event->enable(event, index); + if (!__test_and_set_bit(NVKM_EVENT_ENABLE, &handler->flags)) { + list_add(&handler->head, &event->index[index].list); + if (!event->index[index].refs++) { + if (event->enable) + event->enable(event, index); + } } spin_unlock_irqrestore(&event->lock, flags); } diff --git a/drivers/gpu/drm/nouveau/core/include/core/event.h b/drivers/gpu/drm/nouveau/core/include/core/event.h index bdf1a0a..3e704d5 100644 --- a/drivers/gpu/drm/nouveau/core/include/core/event.h +++ b/drivers/gpu/drm/nouveau/core/include/core/event.h @@ -5,8 +5,12 @@ #define NVKM_EVENT_DROP 0 #define NVKM_EVENT_KEEP 1
+/* nouveau_eventh.flags bit #s */ +#define NVKM_EVENT_ENABLE 0 + struct nouveau_eventh { struct list_head head; + unsigned long flags; void *priv; int (*func)(struct nouveau_eventh *, int index); }; diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c index b29d04b..ccea2c4 100644 --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -88,7 +88,6 @@ nouveau_drm_vblank_enable(struct drm_device *dev, int head)
if (WARN_ON_ONCE(head > ARRAY_SIZE(drm->vblank))) return -EIO; - WARN_ON_ONCE(drm->vblank[head].func); drm->vblank[head].func = nouveau_drm_vblank_handler; nouveau_event_get(pdisp->vblank, head, &drm->vblank[head]); return 0; @@ -99,11 +98,8 @@ nouveau_drm_vblank_disable(struct drm_device *dev, int head) { struct nouveau_drm *drm = nouveau_drm(dev); struct nouveau_disp *pdisp = nouveau_disp(drm->device); - if (drm->vblank[head].func) - nouveau_event_put(pdisp->vblank, head, &drm->vblank[head]); - else - WARN_ON_ONCE(1); - drm->vblank[head].func = NULL; + + nouveau_event_put(pdisp->vblank, head, &drm->vblank[head]); }
static u64