On 06/03/2016 02:25 PM, Michael Kerrisk (man-pages) wrote: > On 06/03/2016 09:53 AM, Dave Hansen wrote: >> On 06/02/2016 05:25 PM, Michael Kerrisk (man-pages) wrote: >>> The convention for man-pages is that new sentences always start >>> of new source lines. (This makes subsequent patches less "noisy", >>> since the common unit of change in a text is a sentence.) >>> Could you fix this throughout please? >> >> Yep, I can do that, and I'll also integrate all of your comments, >> although I won't respond to all of them individually, I will integrate them. >> >>>> +no longer be used in any protection-key-related operations. >>>> +.PP >>>> +.RB ( pkey_alloc ()) >>>> +.I flags >>>> +may contain zero or more disable operations: >>> >>> Why "zero or more" rather than "zero or one"? I mean: >>> what sense could it make to OR together PKEY_DISABLE_ACCESS and >>> PKEY_DISABLE_WRITE? >> >> This is one of the attributes of the hardware that I carried up in to >> the interfaces. The hardware contains two bits: one to write-disable >> and one to access-disable. You're allowed to set both at the same time, >> even though the "access" bit overrules the "write" bit when set. >> >> So, it doesn't make a ton of logical sense with these two flags, but it >> might if we ever got an "execute disable" feature or some other feature >> that could be combined more arbitrarily. > > So, I have a suggestion. How about tightening the constraint here, so > that only one of these flags is allowed for now. (EINVAL if both > are specified.) That constraint could always be relaxed later , if > desired, and adding it now may allow some wriggle room later in terms > of modifying the API or allowing for different architectural choices. Another reason to give an error for this case: if the user does this, they were probably confused. An error let's them know they did something nonsensical... -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
