FROMLIST: dma-buf: heaps: Fix the name used when exporting dmabufs to be the actual heap name

By default dma_buf_export() sets the exporter name to be
KBUILD_MODNAME. Unfortunately this may not be identical to the
string used as the heap name (ie: "system" vs "system_heap").

This can cause some minor confusion with tooling, and there is
the future potential where multiple heap types may be exported
by the same module (but would all have the same name).

So to avoid all this, set the exporter exp_name to the heap name.

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Liam Mark <lmark@codeaurora.org>
Cc: Chris Goldsworthy <cgoldswo@codeaurora.org>
Cc: Laura Abbott <labbott@kernel.org>
Cc: Brian Starkey <Brian.Starkey@arm.com>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sandeep Patil <sspatil@google.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: Ørjan Eide <orjan.eide@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Ezequiel Garcia <ezequiel@collabora.com>
Cc: Simon Ser <contact@emersion.fr>
Cc: James Jones <jajones@nvidia.com>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
Link: https://lore.kernel.org/lkml/20210209194818.2459062-2-john.stultz@linaro.org/
Bug: 167709539
Change-Id: I618f0c5bd2cdf32ed966b25e7efbdbe280cf1c24
Signed-off-by: Hridya Valsaraju <hridya@google.com>
(cherry picked from commit b2336b34be868f6eca115fcef79ed361e19b5020)
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

drivers/dma-buf/heaps/cma_heap.c

@@ -339,6 +339,7 @@ static struct dma_buf *cma_heap_allocate(struct dma_heap *heap,
 	buffer->pagecount = pagecount;
 
 	/* create the dmabuf */
+	exp_info.exp_name = dma_heap_get_name(heap);
 	exp_info.ops = &cma_heap_buf_ops;
 	exp_info.size = buffer->len;
 	exp_info.flags = fd_flags;

drivers/dma-buf/heaps/system_heap.c

@@ -415,6 +415,7 @@ static struct dma_buf *system_heap_do_allocate(struct dma_heap *heap,
 	}
 
 	/* create the dmabuf */
+	exp_info.exp_name = dma_heap_get_name(heap);
 	exp_info.ops = &system_heap_buf_ops;
 	exp_info.size = buffer->len;
 	exp_info.flags = fd_flags;