On 12/18/2015 08:04 AM, Andy Lutomirski wrote: > 1b. If the app malfunctions such that RSP points to pmem, the kernel > MUST NOT clobber the pmem space. I think that this basically mandates > that PKRU needs to have some safe state (i.e. definitely not the init > state) on signal delivery: the kernel is going to write a signal frame > at the address identified by RSP, and that address is in pmem, so > those writes need to fail.
The kernel is writing the signal frame using normal old copy_to_user(). Those are writing through mappings with _PAGE_USER set and should be subject to the PKRU state of the thread before the signal started to be delivered. We don't do the fpu__clear() until after this copy, so I think pkeys enforcement is being done properly for this today. -- 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/
