linux-kernel - Re: [PATCH v9 3/8] mm: Move set/get_pcppage

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]

Date:   Mon, 9 Sep 2019 12:56:08 +0300
From:   "Kirill A. Shutemov" <kirill@...temov.name>
To:     Alexander Duyck <alexander.duyck@...il.com>
Cc:     virtio-dev@...ts.oasis-open.org, kvm@...r.kernel.org,
        mst@...hat.com, catalin.marinas@....com, david@...hat.com,
        dave.hansen@...el.com, linux-kernel@...r.kernel.org,
        willy@...radead.org, mhocko@...nel.org, linux-mm@...ck.org,
        akpm@...ux-foundation.org, will@...nel.org,
        linux-arm-kernel@...ts.infradead.org, osalvador@...e.de,
        yang.zhang.wz@...il.com, pagupta@...hat.com,
        konrad.wilk@...cle.com, nitesh@...hat.com, riel@...riel.com,
        lcapitulino@...hat.com, wei.w.wang@...el.com, aarcange@...hat.com,
        ying.huang@...el.com, pbonzini@...hat.com,
        dan.j.williams@...el.com, fengguang.wu@...el.com,
        alexander.h.duyck@...ux.intel.com, kirill.shutemov@...ux.intel.com
Subject: Re: [PATCH v9 3/8] mm: Move set/get_pcppage_migratetype to mmzone.h

On Sat, Sep 07, 2019 at 10:25:28AM -0700, Alexander Duyck wrote:
> From: Alexander Duyck <alexander.h.duyck@...ux.intel.com>
> 
> In order to support page reporting it will be necessary to store and
> retrieve the migratetype of a page. To enable that I am moving the set and
> get operations for pcppage_migratetype into the mm/internal.h header so
> that they can be used outside of the page_alloc.c file.
> 
> Reviewed-by: Dan Williams <dan.j.williams@...el.com>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@...ux.intel.com>

I'm not sure that it's great idea to export this functionality beyond
mm/page_alloc.c without any additional safeguards. How would we avoid to
messing with ->index when the page is not in the right state of its
life-cycle. Can we add some VM_BUG_ON()s here?

-- 
 Kirill A. Shutemov