linux-kernel - Re: [PATCH 1/3] mm/pagewalk.c: fix end address calculation in walk_page

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>] [day] [month] [year] [list]

Message-ID: <20140227212034.GA6106@node.dhcp.inet.fi>
Date:	Thu, 27 Feb 2014 23:20:34 +0200
From:	"Kirill A. Shutemov" <kirill@...temov.name>
To:	Naoya Horiguchi <n-horiguchi@...jp.nec.com>
Cc:	akpm@...ux-foundation.org, sasha.levin@...cle.com,
	linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/3] mm/pagewalk.c: fix end address calculation in
 walk_page_range()

On Thu, Feb 27, 2014 at 04:19:01PM -0500, Naoya Horiguchi wrote:
> On Thu, Feb 27, 2014 at 01:03:23PM -0800, Andrew Morton wrote:
> > On Wed, 26 Feb 2014 23:39:35 -0500 Naoya Horiguchi <n-horiguchi@...jp.nec.com> wrote:
> > 
> > > When we try to walk over inside a vma, walk_page_range() tries to walk
> > > until vma->vm_end even if a given end is before that point.
> > > So this patch takes the smaller one as an end address.
> > > 
> > > ...
> > >
> > > --- next-20140220.orig/mm/pagewalk.c
> > > +++ next-20140220/mm/pagewalk.c
> > > @@ -321,8 +321,9 @@ int walk_page_range(unsigned long start, unsigned long end,
> > >  			next = vma->vm_start;
> > >  		} else { /* inside the found vma */
> > >  			walk->vma = vma;
> > > -			next = vma->vm_end;
> > > -			err = walk_page_test(start, end, walk);
> > > +			next = min_t(unsigned long, end, vma->vm_end);
> > 
> > min_t is unneeded, isn't it?  Everything here has type unsigned long.
> 
> Yes, so simply (end < vma->vm_end ? end: vma->vm_end) is enough.
> # I just considered min_t as simple minimum getter without thinking type check.

We have non-typed min() for that.

-- 
 Kirill A. Shutemov
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/