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 <gratins...@ispras.ru>
---
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
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