linux-kernel - Re: [PATCH v2 7/8] powerpc/pgtable: remove _PAGE_BIT_SWAP

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: <3272510e-ff5c-8694-c45c-7be9eaed4b42@redhat.com>
Date:   Wed, 30 Mar 2022 08:58:32 +0200
From:   David Hildenbrand <david@...hat.com>
To:     Christophe Leroy <christophe.leroy@...roup.eu>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Cc:     "x86@...nel.org" <x86@...nel.org>, Jan Kara <jack@...e.cz>,
        Catalin Marinas <catalin.marinas@....com>,
        Yang Shi <shy828301@...il.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Peter Xu <peterx@...hat.com>, Michal Hocko <mhocko@...nel.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        Donald Dutile <ddutile@...hat.com>,
        Liang Zhang <zhangliang5@...wei.com>,
        Borislav Petkov <bp@...en8.de>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        Will Deacon <will@...nel.org>, Christoph Hellwig <hch@....de>,
        Paul Mackerras <paulus@...ba.org>,
        Andrea Arcangeli <aarcange@...hat.com>,
        "linux-s390@...r.kernel.org" <linux-s390@...r.kernel.org>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Rik van Riel <riel@...riel.com>,
        Hugh Dickins <hughd@...gle.com>,
        Matthew Wilcox <willy@...radead.org>,
        Mike Rapoport <rppt@...ux.ibm.com>,
        Ingo Molnar <mingo@...hat.com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        Jason Gunthorpe <jgg@...dia.com>,
        David Rientjes <rientjes@...gle.com>,
        Gerald Schaefer <gerald.schaefer@...ux.ibm.com>,
        Pedro Gomes <pedrodemargomes@...il.com>,
        Jann Horn <jannh@...gle.com>,
        John Hubbard <jhubbard@...dia.com>,
        Heiko Carstens <hca@...ux.ibm.com>,
        Shakeel Butt <shakeelb@...gle.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Vlastimil Babka <vbabka@...e.cz>,
        Oded Gabbay <oded.gabbay@...il.com>,
        "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>,
        Oleg Nesterov <oleg@...hat.com>, Nadav Amit <namit@...are.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Roman Gushchin <guro@...com>,
        "Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
        Mike Kravetz <mike.kravetz@...cle.com>
Subject: Re: [PATCH v2 7/8] powerpc/pgtable: remove _PAGE_BIT_SWAP_TYPE for
 book3s

On 30.03.22 08:07, Christophe Leroy wrote:
> 
> 
> Le 29/03/2022 à 18:43, David Hildenbrand a écrit :
>> The swap type is simply stored in bits 0x1f of the swap pte. Let's
>> simplify by just getting rid of _PAGE_BIT_SWAP_TYPE. It's not like that
>> we can simply change it: _PAGE_SWP_SOFT_DIRTY would suddenly fall into
>> _RPAGE_RSV1, which isn't possible and would make the
>> BUILD_BUG_ON(_PAGE_HPTEFLAGS & _PAGE_SWP_SOFT_DIRTY) angry.
>>
>> While at it, make it clearer which bit we're actually using for
>> _PAGE_SWP_SOFT_DIRTY by just using the proper define and introduce and
>> use SWP_TYPE_MASK.
>>
>> Signed-off-by: David Hildenbrand <david@...hat.com>
>> ---
>>   arch/powerpc/include/asm/book3s/64/pgtable.h | 12 +++++-------
> 
> Why only BOOK3S ? Why not BOOK3E as well ?

Hi Cristophe,

I'm focusing on the most relevant enterprise architectures for now. I
don't have the capacity to convert each and every architecture at this
point (especially, I don't to waste my time in case this doesn't get
merged, and book3e didn't look straight forward to me).

Once this series hits upstream, I can look into other architectures --
and I'll be happy if other people jump in that have more familiarity
with the architecture-specific swp pte layouts.

Thanks

-- 
Thanks,

David / dhildenb