This is a note to let you know that I've just added the patch titled dma-buf: cma_heap: Fix mutex locking section to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dma-buf-cma_heap-fix-mutex-locking-section.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2b557880b5c68916a65eb9f2c908842782dd6c0f Author: Weizhao Ouyang <o451686892@xxxxxxxxx> Date: Tue Jan 4 15:35:45 2022 +0800 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@xxxxxxxxx> Acked-by: John Stultz <john.stultz@xxxxxxxxxx> Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20220104073545.124244-1-o451686892@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c index 0c05b79870f96..83f02bd51dda6 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;