On 07/22/2012 05:14 AM, Jiri Olsa wrote: > Adding copy_from_user_nmi_nochk that provides the best effort > copy regardless the requesting size crossing the task boundary. > > This is going to be useful for stack dump we need in post > DWARF CFI based unwind, where we have predefined size of > the user stack to dump, and we need to store the most of > the requested dump size, regardless this size is crossing > the task boundary.
Huh? This is a TASK_SIZE check, which makes sure that the request doesn't cross into kernel land. Otherwise userspace could presumably read kernel memory by setting bogus values of sp. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
