linux-kernel - Re: [PATCH v3] x86: treat pkey-0 special

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <f5ef79ef-122a-e0a3-9b8e-d49c33f4a417@intel.com>
Date:   Thu, 15 Mar 2018 08:55:31 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     Thomas Gleixner <tglx@...utronix.de>, Ram Pai <linuxram@...ibm.com>
Cc:     mingo@...hat.com, mpe@...erman.id.au,
        linuxppc-dev@...ts.ozlabs.org, linux-mm@...ck.org, x86@...nel.org,
        linux-arch@...r.kernel.org, linux-kernel@...r.kernel.org,
        akpm@...ux-foundation.org, benh@...nel.crashing.org,
        paulus@...ba.org, khandual@...ux.vnet.ibm.com,
        aneesh.kumar@...ux.vnet.ibm.com, bsingharora@...il.com,
        hbabu@...ibm.com, mhocko@...nel.org, bauerman@...ux.vnet.ibm.com,
        ebiederm@...ssion.com, corbet@....net, arnd@...db.de,
        fweimer@...hat.com, msuchanek@...e.com, Ulrich.Weigand@...ibm.com
Subject: Re: [PATCH v3] x86: treat pkey-0 special

On 03/15/2018 02:46 AM, Thomas Gleixner wrote:
>> +	if (!pkey || !mm_pkey_is_allocated(mm, pkey))
> Why this extra check? mm_pkey_is_allocated(mm, 0) should not return true
> ever. If it does, then this wants to be fixed.

I was thinking that we _do_ actually want it to seem allocated.  It just
get "allocated" implicitly when an mm is created.  I think that will
simplify the code if we avoid treating it specially in as many places as
possible.