On 06/01/2016 07:17 PM, Dave Hansen wrote: > On 06/01/2016 05:11 PM, Michael Kerrisk (man-pages) wrote: >>>>>> >>>>>> If I read this right, it doesn't actually remove any pkey restrictions >>>>>> that may have been applied while the key was allocated. So there could be >>>>>> pages with that key assigned that might do surprising things if the key is >>>>>> reallocated for another use later, right? Is that how the API is intended >>>>>> to work? >>>> >>>> Yeah, that's how it works. >>>> >>>> It's not ideal. It would be _best_ if we during mm_pkey_free(), we >>>> ensured that no VMAs under that mm have that vma_pkey() set. But, that >>>> search would be potentially expensive (a walk over all VMAs), or would >>>> force us to keep a data structure with a count of all the VMAs with a >>>> given key. >>>> >>>> I should probably discuss this behavior in the manpages and address it >> s/probably// >> >> And, did I miss it. Was there an updated man-pages patch in the latest >> series? I did not notice it. > > There have been to changes to the patches that warranted updating the > manpages until now. I'll send the update immediately. Do those updated pages include discussion of the point noted above? I could not see it mentioned there. Just by the way, the above behavior seems to offer possibilities for users to shoot themselves in the foot, in a way that has security implications. (Or do I misunderstand?) Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- 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>