[PATCH] dma-buf: cma_heap: Fix mutex locking section

Weizhao Ouyang
2022-01-04T07:36:17Z

Fix cma_heap_buffer mutex locking critical section to protect vmap_cnt
and vaddr.

Fixes: a5d2d29e24be ("dma-buf: heaps: Move heap-helper logic into the cma_heap implementation")
Signed-off-by: Weizhao Ouyang <o451686892@gmail.com>
---
drivers/dma-buf/heaps/cma_heap.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index 0c05b79870f9..83f02bd51dda 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -124,10 +124,11 @@ static int cma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
struct cma_heap_buffer *buffer = dmabuf->priv;
struct dma_heap_attachment *a;

+ mutex_lock(&buffer->lock);
+
if (buffer->vmap_cnt)
invalidate_kernel_vmap_range(buffer->vaddr, buffer->len);

- mutex_lock(&buffer->lock);
list_for_each_entry(a, &buffer->attachments, list) {
if (!a->mapped)
continue;
@@ -144,10 +145,11 @@ static int cma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
struct cma_heap_buffer *buffer = dmabuf->priv;
struct dma_heap_attachment *a;

+ mutex_lock(&buffer->lock);
+
if (buffer->vmap_cnt)
flush_kernel_vmap_range(buffer->vaddr, buffer->len);

- mutex_lock(&buffer->lock);
list_for_each_entry(a, &buffer->attachments, list) {
if (!a->mapped)
continue;
--
2.32.0