Commit 680753dd authored by Christian König's avatar Christian König
Browse files

dma-buf: fix inconsistent debug print v2 



Drop the whole rcu handling since we are holding the resv lock anyway.

v2: drop all rcu handling instead.

Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210602140359.272601-1-christian.koenig@amd.com
parent 610d9c31

drivers/dma-buf/dma-buf.c

+9 −18
Original line number Diff line number Diff line
@@ -1349,15 +1349,14 @@ EXPORT_SYMBOL_GPL(dma_buf_vunmap); 
#ifdef CONFIG_DEBUG_FS

static int dma_buf_debug_show(struct seq_file *s, void *unused)

{

	int ret;

	struct dma_buf *buf_obj;

	struct dma_buf_attachment *attach_obj;

	struct dma_resv *robj;

	struct dma_resv_list *fobj;

	struct dma_fence *fence;

	unsigned seq;

	int count = 0, attach_count, shared_count, i;

	size_t size = 0;

	int ret;



	ret = mutex_lock_interruptible(&db_list.lock);
@@ -1383,33 +1382,25 @@ static int dma_buf_debug_show(struct seq_file *s, void *unused) 
				buf_obj->name ?: "");



		robj = buf_obj->resv;

		while (true) {

			seq = read_seqcount_begin(&robj->seq);

			rcu_read_lock();

			fobj = rcu_dereference(robj->fence);

			shared_count = fobj ? fobj->shared_count : 0;

			fence = rcu_dereference(robj->fence_excl);

			if (!read_seqcount_retry(&robj->seq, seq))

				break;

			rcu_read_unlock();

		}



		fence = rcu_dereference_protected(robj->fence_excl,

						  dma_resv_held(robj));

		if (fence)

			seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n",

				   fence->ops->get_driver_name(fence),

				   fence->ops->get_timeline_name(fence),

				   dma_fence_is_signaled(fence) ? "" : "un");



		fobj = rcu_dereference_protected(robj->fence,

						 dma_resv_held(robj));

		shared_count = fobj ? fobj->shared_count : 0;

		for (i = 0; i < shared_count; i++) {

			fence = rcu_dereference(fobj->shared[i]);

			if (!dma_fence_get_rcu(fence))

				continue;

			fence = rcu_dereference_protected(fobj->shared[i],

							  dma_resv_held(robj));

			seq_printf(s, "\tShared fence: %s %s %ssignalled\n",

				   fence->ops->get_driver_name(fence),

				   fence->ops->get_timeline_name(fence),

				   dma_fence_is_signaled(fence) ? "" : "un");

			dma_fence_put(fence);

		}

		rcu_read_unlock();



		seq_puts(s, "\tAttached Devices:\n");

		attach_count = 0;