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drm/nouveau/core: Allow asymmetric nouveau_event_get/_put

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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: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
This commit is contained in:
Peter Hurley
2013-08-27 16:12:57 -04:00
committed by Ben Skeggs
parent 019255797d
commit ac51bb0983
3 changed files with 18 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
drivers/gpu/drm/nouveau/core/core/event.c
View File

@@ -27,11 +27,13 @@ static void
nouveau_event_put_locked(struct nouveau_event *event, int index, nouveau_event_put_locked(struct nouveau_event *event, int index,
struct nouveau_eventh *handler) struct nouveau_eventh *handler)
{ {
if (!--event->index[index].refs) { if (__test_and_clear_bit(NVKM_EVENT_ENABLE, &handler->flags)) {
if (event->disable) if (!--event->index[index].refs) {
event->disable(event, index); if (event->disable)
event->disable(event, index);
}
list_del(&handler->head);
} }
list_del(&handler->head);
} }
void void
@@ -58,10 +60,12 @@ nouveau_event_get(struct nouveau_event *event, int index,
return; return;
spin_lock_irqsave(&event->lock, flags); spin_lock_irqsave(&event->lock, flags);
list_add(&handler->head, &event->index[index].list); if (!__test_and_set_bit(NVKM_EVENT_ENABLE, &handler->flags)) {
if (!event->index[index].refs++) { list_add(&handler->head, &event->index[index].list);
if (event->enable) if (!event->index[index].refs++) {
event->enable(event, index); if (event->enable)
event->enable(event, index);
}
} }
spin_unlock_irqrestore(&event->lock, flags); spin_unlock_irqrestore(&event->lock, flags);
} }

4
drivers/gpu/drm/nouveau/core/include/core/event.h
View File

@@ -5,8 +5,12 @@
#define NVKM_EVENT_DROP 0 #define NVKM_EVENT_DROP 0
#define NVKM_EVENT_KEEP 1 #define NVKM_EVENT_KEEP 1
/* nouveau_eventh.flags bit #s */
#define NVKM_EVENT_ENABLE 0
struct nouveau_eventh { struct nouveau_eventh {
struct list_head head; struct list_head head;
unsigned long flags;
void *priv; void *priv;
int (*func)(struct nouveau_eventh *, int index); int (*func)(struct nouveau_eventh *, int index);
}; };

8
drivers/gpu/drm/nouveau/nouveau_drm.c
View File

@@ -95,7 +95,6 @@ nouveau_drm_vblank_enable(struct drm_device *dev, int head)
if (WARN_ON_ONCE(head >= ARRAY_SIZE(drm->vblank))) if (WARN_ON_ONCE(head >= ARRAY_SIZE(drm->vblank)))
return -EIO; return -EIO;
WARN_ON_ONCE(drm->vblank[head].func);
drm->vblank[head].func = nouveau_drm_vblank_handler; drm->vblank[head].func = nouveau_drm_vblank_handler;
nouveau_event_get(pdisp->vblank, head, &drm->vblank[head]); nouveau_event_get(pdisp->vblank, head, &drm->vblank[head]);
return 0; 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_drm *drm = nouveau_drm(dev);
struct nouveau_disp *pdisp = nouveau_disp(drm->device); struct nouveau_disp *pdisp = nouveau_disp(drm->device);
if (drm->vblank[head].func)
nouveau_event_put(pdisp->vblank, head, &drm->vblank[head]); nouveau_event_put(pdisp->vblank, head, &drm->vblank[head]);
else
WARN_ON_ONCE(1);
drm->vblank[head].func = NULL;
} }
static u64 static u64