Calling memory allocation function from the context of interrupt: request_irq(udc->irq, mv_udc_irq, IRQF_SHARED, driver_name, udc); Function mv_udc_irq(..) calls: irq_process_tr_complete(..) that calls: handle_setup_packet(..) that calls: ch9setaddress(..) that calls: udc_prime_status(..) that calls: req_to_dtd(..) that calls: build_dtd(..) that calls: dma_pool_alloc(udc->dtd_pool, GFP_KERNEL, dma). In the case of GFP_KERNEL flag, function execution can be preempted, because a greater number of operations to find and allocate memory blocks is executed. The patch change GFP_KERNEL flag to GFP_ATOMIC. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Vladimir Gratinskiy <gratinskiy@xxxxxxxxx> --- drivers/usb/gadget/mv_udc_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/gadget/mv_udc_core.c b/drivers/usb/gadget/mv_udc_core.c index 75db2c3..ba91f7c 100644 --- a/drivers/usb/gadget/mv_udc_core.c +++ b/drivers/usb/gadget/mv_udc_core.c @@ -375,7 +375,7 @@ static struct mv_dtd *build_dtd(struct mv_req *req, unsigned *length, * Be careful that no _GFP_HIGHMEM is set, * or we can not use dma_to_virt */ - dtd = dma_pool_alloc(udc->dtd_pool, GFP_KERNEL, dma); + dtd = dma_pool_alloc(udc->dtd_pool, GFP_ATOMIC, dma); if (dtd == NULL) return dtd; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
