linux-kernel - Re: [PATCH v4 06/11] mm: thp: check pmd migration entry in common path

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:   Fri, 24 Mar 2017 19:50:14 +0300
From:   "Kirill A. Shutemov" <kirill@...temov.name>
To:     Zi Yan <zi.yan@...rutgers.edu>
Cc:     Zi Yan <zi.yan@...t.com>, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, kirill.shutemov@...ux.intel.com,
        akpm@...ux-foundation.org, minchan@...nel.org, vbabka@...e.cz,
        mgorman@...hsingularity.net, mhocko@...nel.org,
        n-horiguchi@...jp.nec.com, khandual@...ux.vnet.ibm.com,
        dnellans@...dia.com
Subject: Re: [PATCH v4 06/11] mm: thp: check pmd migration entry in common
 path

On Fri, Mar 24, 2017 at 11:09:25AM -0500, Zi Yan wrote:
> Kirill A. Shutemov wrote:
> > On Mon, Mar 13, 2017 at 11:45:02AM -0400, Zi Yan wrote:
> > Again. That's doesn't look right..
> 
> It will be changed:
> 
>  	ptl = pmd_lock(mm, pmd);
> +retry_locked:
> +	if (unlikely(!pmd_present(*pmd))) {
> +		if (likely(!(flags & FOLL_MIGRATION))) {
> +			spin_unlock(ptl);
> +			return no_page_table(vma, flags);
> +		}
> +		pmd_migration_entry_wait(mm, pmd);
> +		goto retry_locked;

Nope. pmd_migration_entry_wait() unlocks the ptl.

-- 
 Kirill A. Shutemov