gpu: ion: Incrememnt user refcount during vma_open/vma_close
Ion allows multiple mmaps of the same buffers. This means that
incrementing the usermap count in mmap and decrementing it in
release is not sufficient as release will only ever be called
once. Fix this by only doing the reference count change in the
vma_open and close which are called whenever mmap is called.
Change-Id: I6d17c0f563d0b90481d8e092c1e206f2b33c8e00
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
diff --git a/drivers/gpu/ion/ion.c b/drivers/gpu/ion/ion.c
index e6a1b86..4591ad0 100644
--- a/drivers/gpu/ion/ion.c
+++ b/drivers/gpu/ion/ion.c
@@ -1147,9 +1147,6 @@
struct ion_buffer *buffer = file->private_data;
pr_debug("%s: %d\n", __func__, __LINE__);
- mutex_lock(&buffer->lock);
- buffer->umap_cnt--;
- mutex_unlock(&buffer->lock);
/* drop the reference to the buffer -- this prevents the
buffer from going away because the client holding it exited
while it was being passed */
@@ -1172,6 +1169,9 @@
vma->vm_private_data = NULL;
return;
}
+ mutex_lock(&buffer->lock);
+ buffer->umap_cnt++;
+ mutex_unlock(&buffer->lock);
pr_debug("%s: %d client_cnt %d handle_cnt %d alloc_cnt %d\n",
__func__, __LINE__,
atomic_read(&client->ref.refcount),
@@ -1190,6 +1190,9 @@
if (!handle)
return;
client = handle->client;
+ mutex_lock(&buffer->lock);
+ buffer->umap_cnt--;
+ mutex_unlock(&buffer->lock);
pr_debug("%s: %d client_cnt %d handle_cnt %d alloc_cnt %d\n",
__func__, __LINE__,
atomic_read(&client->ref.refcount),
@@ -1265,7 +1268,6 @@
/* now map it to userspace */
ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma,
flags);
- buffer->umap_cnt++;
mutex_unlock(&buffer->lock);
if (ret) {
pr_err("%s: failure mapping buffer to userspace\n",