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| author | Fedor Pchelkin <pchelkin@ispras.ru> | 2024-05-04 14:47:01 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-12 12:39:46 +0300 |
| commit | 54a66f249c86dd1cdba9cd22c9c1ceb43e04f9cd (patch) | |
| tree | 718e59a78aeb60d173c0e0bb4c2fe60efbd0b416 | |
| parent | 4cbe4df46b7ebc43a6d40cc38b2d04e80a10aaa3 (diff) | |
| download | linux-54a66f249c86dd1cdba9cd22c9c1ceb43e04f9cd.tar.xz | |
dma-mapping: benchmark: fix up kthread-related error handling
[ Upstream commit bb9025f4432f8c158322cf2c04c2b492f23eb511 ]
kthread creation failure is invalidly handled inside do_map_benchmark().
The put_task_struct() calls on the error path are supposed to balance the
get_task_struct() calls which only happen after all the kthreads are
successfully created. Rollback using kthread_stop() for already created
kthreads in case of such failure.
In normal situation call kthread_stop_put() to gracefully stop kthreads
and put their task refcounts. This should be done for all started
kthreads.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 65789daa8087 ("dma-mapping: add benchmark support for streaming DMA APIs")
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/dma/map_benchmark.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c index 02205ab53b7e..2478957cf9f8 100644 --- a/kernel/dma/map_benchmark.c +++ b/kernel/dma/map_benchmark.c @@ -118,6 +118,8 @@ static int do_map_benchmark(struct map_benchmark_data *map) if (IS_ERR(tsk[i])) { pr_err("create dma_map thread failed\n"); ret = PTR_ERR(tsk[i]); + while (--i >= 0) + kthread_stop(tsk[i]); goto out; } @@ -139,13 +141,17 @@ static int do_map_benchmark(struct map_benchmark_data *map) msleep_interruptible(map->bparam.seconds * 1000); - /* wait for the completion of benchmark threads */ + /* wait for the completion of all started benchmark threads */ for (i = 0; i < threads; i++) { - ret = kthread_stop(tsk[i]); - if (ret) - goto out; + int kthread_ret = kthread_stop_put(tsk[i]); + + if (kthread_ret) + ret = kthread_ret; } + if (ret) + goto out; + loops = atomic64_read(&map->loops); if (likely(loops > 0)) { u64 map_variance, unmap_variance; @@ -170,8 +176,6 @@ static int do_map_benchmark(struct map_benchmark_data *map) } out: - for (i = 0; i < threads; i++) - put_task_struct(tsk[i]); put_device(map->dev); kfree(tsk); return ret; |