Commit ac51bb09 authored by Peter Hurley's avatar Peter Hurley Committed by Ben Skeggs

drm/nouveau/core: Allow asymmetric nouveau_event_get/_put

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.
Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
parent 01925579
......@@ -27,11 +27,13 @@ static void
nouveau_event_put_locked(struct nouveau_event *event, int index,
struct nouveau_eventh *handler)
{
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);
}
}
void
......@@ -58,11 +60,13 @@ nouveau_event_get(struct nouveau_event *event, int index,
return;
spin_lock_irqsave(&event->lock, flags);
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);
}
......
......@@ -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);
};
......
......@@ -95,7 +95,6 @@ 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;
......@@ -106,11 +105,8 @@ 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;
}
static u64
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment