On Fri, 4 May 2018 14:45:07 -0700 Ram Pai <linux...@us.ibm.com> wrote:
> On Fri, May 04, 2018 at 02:31:10PM -0700, Dave Hansen wrote: > > On 05/04/2018 02:26 PM, Michal Suchánek wrote: > > > If it is not ok to change permissions of pkey 0 is it ok to free > > > it? > > > > It's pretty much never OK to free it on x86 or ppc. But, we're not > > going to put code in to keep userspace from shooting itself in the > > foot, at least on x86. > > and on powerpc aswell. But once it's free it can be re-allocated. So you are moving the special-casing from free code to code dealing with allocation. If you want something like allocate_exec_only_pkey then the function (either in kernel or in userspace) needs to make sure it is not getting/requesting key 0 on powerpc. Thanks Michal
