linux-kernel - Re: [PATCH 2/2] mm: verify compound order when freeing a 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>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <543DACFB.2060405@oracle.com>
Date:	Tue, 14 Oct 2014 19:08:43 -0400
From:	Sasha Levin <sasha.levin@...cle.com>
To:	David Cohen <david.a.cohen@...ux.intel.com>,
	Yu Zhao <yuzhao@...gle.com>
CC:	Andrew Morton <akpm@...ux-foundation.org>,
	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
	Mel Gorman <mgorman@...e.de>, Rik van Riel <riel@...hat.com>,
	Ingo Molnar <mingo@...nel.org>,
	Hugh Dickins <hughd@...gle.com>, Bob Liu <lliubbo@...il.com>,
	Johannes Weiner <hannes@...xchg.org>,
	David Rientjes <rientjes@...gle.com>,
	Vlastimil Babka <vbabka@...e.cz>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/2] mm: verify compound order when freeing a page

On 10/14/2014 04:29 PM, David Cohen wrote:
>> +	VM_BUG_ON(PageTail(page));
>> > +	VM_BUG_ON(PageHead(page) && compound_order(page) != order);
> It may be too severe. AFAIU we're not talking about a fatal error.
> How about VM_WARN_ON()?

VM_BUG_ON() should catch anything which is not "supposed" to happen,
and not just the severe stuff. Unlike BUG_ON, VM_BUG_ON only gets
hit with mm debugging enabled.


Thanks,
Sasha
--
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/