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| author | Alexander Kochetkov <al.kochet@gmail.com> | 2017-10-04 14:37:23 +0300 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2017-10-20 11:46:45 +0530 |
| commit | e588710311ee5bece284871d613418831d56f2bd (patch) | |
| tree | 62d76603c0ce97d6d1b1cdfeb07fc5aa066cd733 /fs/binfmt_elf_fdpic.c | |
| parent | 2bd6bf03f4c1c59381d62c61d03f6cc3fe71f66e (diff) | |
| download | lwn-e588710311ee5bece284871d613418831d56f2bd.tar.gz lwn-e588710311ee5bece284871d613418831d56f2bd.zip | |
dmaengine: pl330: fix descriptor allocation fail
If two concurrent threads call pl330_get_desc() when DMAC descriptor
pool is empty it is possible that allocation for one of threads will fail
with message:
kernel: dma-pl330 20078000.dma-controller: pl330_get_desc:2469 ALERT!
Here how that can happen. Thread A calls pl330_get_desc() to get
descriptor. If DMAC descriptor pool is empty pl330_get_desc() allocates
new descriptor on shared pool using add_desc() and then get newly
allocated descriptor using pluck_desc(). At the same time thread B calls
pluck_desc() and take newly allocated descriptor. In that case descriptor
allocation for thread A will fail.
Using on-stack pool for new descriptor allow avoid the issue described.
The patch modify pl330_get_desc() to use on-stack pool for allocation
new descriptors.
Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'fs/binfmt_elf_fdpic.c')
0 files changed, 0 insertions, 0 deletions