dma-buf: cma_heap: Fix mutex locking section

[ Upstream commit 54329e6f7beea6af56c1230da293acc97d6a6ee7 ]

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>
Acked-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220104073545.124244-1-o451686892@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index 0c05b79..83f02bd 100644 (file)
--- 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;