staging: vcsm-cma: Fix memory leak from not detaching dmabuf

When importing there was a missing call to detach the buffer,
so each import leaked the sg table entry.

Actually the release process for both locally allocated and
imported buffers is identical, so fix them to both use the same
function.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

diff --git a/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c b/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c
index 40ce67f..88c4df8 100644 (file)
--- a/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c
+++ b/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c
@@ -237,6 +237,7 @@ static void vc_sm_add_resource(struct vc_sm_privdata_t *privdata,
 
 /*
  * Cleans up imported dmabuf.
+ * Should be called with mutex held.
  */
 static void vc_sm_clean_up_dmabuf(struct vc_sm_buffer *buffer)
 {
@@ -244,7 +245,6 @@ static void vc_sm_clean_up_dmabuf(struct vc_sm_buffer *buffer)
                return;
 
        /* Handle cleaning up imported dmabufs */
-       mutex_lock(&buffer->lock);
        if (buffer->import.sgt) {
                dma_buf_unmap_attachment(buffer->import.attach,
                                         buffer->import.sgt,
@@ -255,7 +255,6 @@ static void vc_sm_clean_up_dmabuf(struct vc_sm_buffer *buffer)
                dma_buf_detach(buffer->dma_buf, buffer->import.attach);
                buffer->import.attach = NULL;
        }
-       mutex_unlock(&buffer->lock);
 }
 
 /*
@@ -673,23 +672,6 @@ int vc_sm_import_dmabuf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
 }
 
 static
-void vc_sm_import_dma_buf_release(struct dma_buf *dmabuf)
-{
-       struct vc_sm_buffer *buf = dmabuf->priv;
-
-       pr_debug("%s: Relasing dma_buf %p\n", __func__, dmabuf);
-       mutex_lock(&buf->lock);
-       if (!buf->imported)
-               return;
-
-       buf->in_use = 0;
-
-       vc_sm_vpu_free(buf);
-
-       vc_sm_release_resource(buf);
-}
-
-static
 int vc_sm_import_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
                                          enum dma_data_direction direction)
 {
@@ -717,7 +699,7 @@ static const struct dma_buf_ops dma_buf_import_ops = {
        .map_dma_buf = vc_sm_import_map_dma_buf,
        .unmap_dma_buf = vc_sm_import_unmap_dma_buf,
        .mmap = vc_sm_import_dmabuf_mmap,
-       .release = vc_sm_import_dma_buf_release,
+       .release = vc_sm_dma_buf_release,
        .attach = vc_sm_import_dma_buf_attach,
        .detach = vc_sm_import_dma_buf_detatch,
        .begin_cpu_access = vc_sm_import_dma_buf_begin_cpu_access,