The sync_pt were not adding themselves atomically to the timeline lists, corruption imminent. Only a single list is required to track the unsignaled sync_pt, so reduce it and rename the lock more appropriately along with using idiomatic names to distinguish a list from links along it.
v2: Prevent spinlock recursion on free during create (next patch) and fixup crossref in kerneldoc
Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Sean Paul seanpaul@chromium.org Cc: Gustavo Padovan gustavo@padovan.org --- drivers/dma-buf/sw_sync.c | 48 ++++++++++++++++++-------------------------- drivers/dma-buf/sync_debug.c | 9 ++++----- drivers/dma-buf/sync_debug.h | 21 ++++++++----------- 3 files changed, 31 insertions(+), 47 deletions(-)
diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c index 6effa1ce010e..f20d18c421a3 100644 --- a/drivers/dma-buf/sw_sync.c +++ b/drivers/dma-buf/sw_sync.c @@ -96,9 +96,8 @@ static struct sync_timeline *sync_timeline_create(const char *name) obj->context = dma_fence_context_alloc(1); strlcpy(obj->name, name, sizeof(obj->name));
- INIT_LIST_HEAD(&obj->child_list_head); - INIT_LIST_HEAD(&obj->active_list_head); - spin_lock_init(&obj->child_list_lock); + INIT_LIST_HEAD(&obj->pt_list); + spin_lock_init(&obj->lock);
sync_timeline_debug_add(obj);
@@ -139,17 +138,15 @@ static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc)
trace_sync_timeline(obj);
- spin_lock_irq(&obj->child_list_lock); + spin_lock_irq(&obj->lock);
obj->value += inc;
- list_for_each_entry_safe(pt, next, &obj->active_list_head, - active_list) { + list_for_each_entry_safe(pt, next, &obj->pt_list, link) if (dma_fence_is_signaled_locked(&pt->base)) - list_del_init(&pt->active_list); - } + list_del_init(&pt->link);
- spin_unlock_irq(&obj->child_list_lock); + spin_unlock_irq(&obj->lock); }
/** @@ -171,15 +168,15 @@ static struct sync_pt *sync_pt_create(struct sync_timeline *obj, if (!pt) return NULL;
- spin_lock_irq(&obj->child_list_lock); - sync_timeline_get(obj); - dma_fence_init(&pt->base, &timeline_fence_ops, &obj->child_list_lock, + dma_fence_init(&pt->base, &timeline_fence_ops, &obj->lock, obj->context, value); - list_add_tail(&pt->child_list, &obj->child_list_head); - INIT_LIST_HEAD(&pt->active_list); + INIT_LIST_HEAD(&pt->link);
- spin_unlock_irq(&obj->child_list_lock); + spin_lock_irq(&obj->lock); + if (!dma_fence_is_signaled_locked(&pt->base)) + list_add_tail(&pt->link, &obj->pt_list); + spin_unlock_irq(&obj->lock);
return pt; } @@ -200,15 +197,15 @@ static void timeline_fence_release(struct dma_fence *fence) { struct sync_pt *pt = dma_fence_to_sync_pt(fence); struct sync_timeline *parent = dma_fence_parent(fence); - unsigned long flags;
- spin_lock_irqsave(fence->lock, flags); + if (!list_empty(&pt->link)) { + unsigned long flags;
- list_del(&pt->child_list); - if (!list_empty(&pt->active_list)) - list_del(&pt->active_list); - - spin_unlock_irqrestore(fence->lock, flags); + spin_lock_irqsave(fence->lock, flags); + if (!list_empty(&pt->link)) + list_del(&pt->link); + spin_unlock_irqrestore(fence->lock, flags); + }
sync_timeline_put(parent); dma_fence_free(fence); @@ -223,13 +220,6 @@ static bool timeline_fence_signaled(struct dma_fence *fence)
static bool timeline_fence_enable_signaling(struct dma_fence *fence) { - struct sync_pt *pt = dma_fence_to_sync_pt(fence); - struct sync_timeline *parent = dma_fence_parent(fence); - - if (timeline_fence_signaled(fence)) - return false; - - list_add_tail(&pt->active_list, &parent->active_list_head); return true; }
diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c index 0e91632248ba..2264a075f6a9 100644 --- a/drivers/dma-buf/sync_debug.c +++ b/drivers/dma-buf/sync_debug.c @@ -119,13 +119,12 @@ static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
seq_printf(s, "%s: %d\n", obj->name, obj->value);
- spin_lock_irq(&obj->child_list_lock); - list_for_each(pos, &obj->child_list_head) { - struct sync_pt *pt = - container_of(pos, struct sync_pt, child_list); + spin_lock_irq(&obj->lock); + list_for_each(pos, &obj->pt_list) { + struct sync_pt *pt = container_of(pos, struct sync_pt, link); sync_print_fence(s, &pt->base, false); } - spin_unlock_irq(&obj->child_list_lock); + spin_unlock_irq(&obj->lock); }
static void sync_print_sync_file(struct seq_file *s, diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h index 26fe8b9907b3..6a2a8e69a7d0 100644 --- a/drivers/dma-buf/sync_debug.h +++ b/drivers/dma-buf/sync_debug.h @@ -24,42 +24,37 @@ * struct sync_timeline - sync object * @kref: reference count on fence. * @name: name of the sync_timeline. Useful for debugging - * @child_list_head: list of children sync_pts for this sync_timeline - * @child_list_lock: lock protecting @child_list_head and fence.status - * @active_list_head: list of active (unsignaled/errored) sync_pts + * @lock: lock protecting @pt_list and @value + * @pt_list: list of active (unsignaled/errored) sync_pts * @sync_timeline_list: membership in global sync_timeline_list */ struct sync_timeline { struct kref kref; char name[32];
- /* protected by child_list_lock */ + /* protected by lock */ u64 context; int value;
- struct list_head child_list_head; - spinlock_t child_list_lock; - - struct list_head active_list_head; + struct list_head pt_list; + spinlock_t lock;
struct list_head sync_timeline_list; };
static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence) { - return container_of(fence->lock, struct sync_timeline, child_list_lock); + return container_of(fence->lock, struct sync_timeline, lock); }
/** * struct sync_pt - sync_pt object * @base: base fence object - * @child_list: sync timeline child's list - * @active_list: sync timeline active child's list + * @link: link on the sync timeline's list */ struct sync_pt { struct dma_fence base; - struct list_head child_list; - struct list_head active_list; + struct list_head link; };
#ifdef CONFIG_SW_SYNC