Messages in this thread Patch in this message | | | From | Jon Mason <> | Subject | [PATCH v2] dmatest: Fix NULL pointer dereference on ioat | Date | Sun, 11 Nov 2012 16:03:20 -0700 |
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device_control is an optional and not implemented in all DMA drivers. Any calls to these will result in a NULL pointer dereference. dmatest makes two of these calls when completing the kernel thread and removing the module. These are corrected by calling the dmaengine_device_control wrapper and checking for a non-existant device_control function pointer there.
Signed-off-by: Jon Mason <jon.mason@intel.com> CC: Vinod Koul <vinod.koul@intel.com> CC: Dan Williams <djbw@fb.com> --- drivers/dma/dmatest.c | 4 ++-- include/linux/dmaengine.h | 5 ++++- 2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c index 24225f0..6ef9465 100644 --- a/drivers/dma/dmatest.c +++ b/drivers/dma/dmatest.c @@ -499,7 +499,7 @@ err_srcs: thread_name, total_tests, failed_tests, ret); /* terminate all transfers on specified channels */ - chan->device->device_control(chan, DMA_TERMINATE_ALL, 0); + dmaengine_terminate_all(chan); if (iterations > 0) while (!kthread_should_stop()) { DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wait_dmatest_exit); @@ -524,7 +524,7 @@ static void dmatest_cleanup_channel(struct dmatest_chan *dtc) } /* terminate all transfers on specified channels */ - dtc->chan->device->device_control(dtc->chan, DMA_TERMINATE_ALL, 0); + dmaengine_terminate_all(dtc->chan); kfree(dtc); } diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index d3201e4..cf94e5f 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -608,7 +608,10 @@ static inline int dmaengine_device_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned long arg) { - return chan->device->device_control(chan, cmd, arg); + if (chan->device->device_control) + return chan->device->device_control(chan, cmd, arg); + else + return -ENOSYS; } static inline int dmaengine_slave_config(struct dma_chan *chan, -- 1.7.9.5
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