On Thu, 2015-03-19 at 10:38 +0100, Pavel Machek wrote: > On Thu 2015-03-19 10:14:21, Oliver Neukum wrote: > > On Mon, 2015-03-16 at 22:37 +0100, Jiri Kosina wrote: > > > Are you sure CONFIG_DMA_API_DEBUG wouldn't warn here? > > > > As far as I can tell, it will not warn. The problem is not in the > > mapping itself. That is usually legitimate. The problem arises > > because the buffer doesn't have a cacheline of its own. Thus the > > memory corruption happens after the IO operation has started. > > Nasty. Would WARN_ON(buffer & CACHELINE_SIZE-1) do at least part of No. It is perfectly legitimate to put your buffer at an offset or to combine buffers provided you don't use them at the same time. > the trick? Alternatively, could we call ksize() on the object, and > fail if it is not big enough? What object? We have a pointer to a memory location. > Alternatively, we could create "allocate_for_usb" function, and only > take pointers allocated by that function in usb functions. That would > also teach people the problem exists... No, this problem is not limited to USB. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
