On 10/03/2015 12:27 AM, Ingo Molnar wrote: > - I'd also suggest providing an initial value with the 'alloc' call. It's true > that user-space can do this itself in assembly, OTOH there's no reason not to > provide a C interface for this. You mean an initial value for the rights register (PKRU), correct? So init_val would be something like PKEY_DENY_ACCESS PKEY_DENY_WRITE and it would refer only to the key that was allocated. > - Along similar considerations, also add a sys_pkey_query() system call to query > the mapping of a specific pkey. (returns -EBADF or so if the key is not mapped > at the moment.) This too could be vDSO accelerated in the future. Do you mean whether the key is being used on a mapping (VMA) or rather whether the key is currently allocated (has been returned from sys_pkey_alloc() in the past)? > I.e. something like: > > unsigned long sys_pkey_alloc (unsigned long flags, unsigned long init_val) > unsigned long sys_pkey_set (int pkey, unsigned long new_val) > unsigned long sys_pkey_get (int pkey) > unsigned long sys_pkey_free (int pkey) > > Optional suggestion: > > - _Maybe_ also allow the 'remote managed' setup of pkeys: of non-local tasks - > but I'm not sure about that: it looks expensive and complex, and a TID argument > can always be added later if there's some real need. Yeah, let's see how the stuff above looks first. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>