[PATCH 1/2] dma-buf: fix inconsistent debug print v2
Christian König
ckoenig.leichtzumerken at gmail.com
Wed Jun 2 14:03:58 UTC 2021
Drop the whole rcu handling since we are holding the resv lock anyway.
v2: drop all rcu handling instead.
Signed-off-by: Christian König <christian.koenig at amd.com>
---
drivers/dma-buf/dma-buf.c | 27 +++++++++------------------
1 file changed, 9 insertions(+), 18 deletions(-)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index eadd1eaa2fb5..ee04fb442015 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -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;
--
2.25.1
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