dmatest: Fix NULL pointer dereference on ioat (944ea4dd) · Commits · 戴 / test

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> Reviewed-by:

Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by:

Vinod Koul <vinod.koul@linux.intel.com>

drivers/dma/dmatest.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -536,7 +536,7 @@ 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);
		@@ -561,7 +561,7 @@ 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);
		}

include/linux/dmaengine.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -608,7 +608,10 @@ static inline int dmaengine_device_control(struct dma_chan *chan,
		enum dma_ctrl_cmd cmd,
		unsigned long 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,

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