Messages in this thread | | | Date | Sat, 17 Mar 2018 10:12:15 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH 1/3] x86, pkeys: do not special case protection key 0 |
| |
On Fri, 16 Mar 2018, Dave Hansen wrote:
> > From: Dave Hansen <dave.hansen@linux.intel.com> > > mm_pkey_is_allocated() treats pkey 0 as unallocated. That is > inconsistent with the manpages, and also inconsistent with > mm->context.pkey_allocation_map. Stop special casing it and only > disallow values that are actually bad (< 0). > > The end-user visible effect of this is that you can now use > mprotect_pkey() to set pkey=0. > > This is a bit nicer than what Ram proposed because it is simpler > and removes special-casing for pkey 0. On the other hand, it does > allow applciations to pkey_free() pkey-0, but that's just a silly > thing to do, so we are not going to protect against it.
What's the consequence of that? Application crashing and burning itself or something more subtle?
Thanks,
tglx
| |