On Thursday 06 December 2012 18:51:25 Chen Gang wrote: > Hello Greg Kroah-Hartman: > > in drivers/usb/core/message.c: > at line 943, status is kmalloc ( sizeof u16 ) > at line 952, assign the value of status to data > at line 953, free status. > > it is better to let "u16 status" instead of "u16 *status = kmalloc...". No, that would be a bug, because then we would do DMA on the stack. Doing DMA on the stack violates the DMA rules. Anything passed to usb_control_msg() as a buffer must be allocated from the heap, regardless of size. Regards Oliver -- 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
