WSL2-Linux-Kernel/drivers/dma-buf
Charan Teja Reddy 8ff10b430c dma-buf: WARN on dmabuf release with pending attachments
[ Upstream commit f492283b15 ]

It is expected from the clients to follow the below steps on an imported
dmabuf fd:
a) dmabuf = dma_buf_get(fd) // Get the dmabuf from fd
b) dma_buf_attach(dmabuf); // Clients attach to the dmabuf
   o Here the kernel does some slab allocations, say for
dma_buf_attachment and may be some other slab allocation in the
dmabuf->ops->attach().
c) Client may need to do dma_buf_map_attachment().
d) Accordingly dma_buf_unmap_attachment() should be called.
e) dma_buf_detach () // Clients detach to the dmabuf.
   o Here the slab allocations made in b) are freed.
f) dma_buf_put(dmabuf) // Can free the dmabuf if it is the last
reference.

Now say an erroneous client failed at step c) above thus it directly
called dma_buf_put(), step f) above. Considering that it may be the last
reference to the dmabuf, buffer will be freed with pending attachments
left to the dmabuf which can show up as the 'memory leak'. This should
at least be reported as the WARN().

Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1627043468-16381-1-git-send-email-charante@codeaurora.org
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-18 19:16:08 +01:00
..
heaps drm-misc-next for 5.13: 2021-03-16 17:08:46 +10:00
Kconfig dma-buf: DMABUF_SYSFS_STATS should depend on DMA_SHARED_BUFFER 2021-09-07 12:42:21 +05:30
Makefile dmabuf: Add the capability to expose DMA-BUF stats in sysfs 2021-06-15 11:50:24 +02:00
dma-buf-sysfs-stats.c dma-buf: Delete the DMA-BUF attachment sysfs statistics 2021-07-20 11:06:59 +02:00
dma-buf-sysfs-stats.h dma-buf: Delete the DMA-BUF attachment sysfs statistics 2021-07-20 11:06:59 +02:00
dma-buf.c dma-buf: WARN on dmabuf release with pending attachments 2021-11-18 19:16:08 +01:00
dma-fence-array.c
dma-fence-chain.c dma-buf: some dma_fence_chain improvements 2021-06-14 19:33:16 +02:00
dma-fence.c drm/syncobj: use newly allocated stub fences 2021-04-08 12:21:13 +02:00
dma-heap.c dma-buf: dma-heap: Provide accessor to get heap name 2021-02-25 18:28:24 +05:30
dma-resv.c dma-buf: fix dma_resv_test_signaled test_all handling v2 2021-07-08 14:59:08 +02:00
selftest.c
selftest.h
selftests.h
seqno-fence.c
st-dma-fence-chain.c dma-buf: add dma_fence_chain_alloc/free v3 2021-06-14 19:38:34 +02:00
st-dma-fence.c dma-buf: Avoid comma separated statements 2021-02-09 17:14:11 +01:00
sw_sync.c
sync_debug.c
sync_debug.h
sync_file.c dma-buf/sync_file: Don't leak fences on merge failure 2021-07-12 13:34:49 +02:00
sync_trace.h
udmabuf.c udmabuf: fix general protection fault in udmabuf_create 2021-08-12 09:27:22 +02:00