linux-kernel - Re: [PATCH v3] mm/page_owner: use kvmalloc instead of kmalloc

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: <1540975637.10275.10.camel@mtkswgap22>
Date:   Wed, 31 Oct 2018 16:47:17 +0800
From:   Miles Chen <miles.chen@...iatek.com>
To:     Michal Hocko <mhocko@...nel.org>
CC:     Andrew Morton <akpm@...ux-foundation.org>,
        Joe Perches <joe@...ches.com>,
        Matthew Wilcox <willy@...radead.org>, <linux-mm@...ck.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>, <wsd_upstream@...iatek.com>
Subject: Re: [PATCH v3] mm/page_owner: use kvmalloc instead of kmalloc

On Tue, 2018-10-30 at 09:15 +0100, Michal Hocko wrote:
> On Tue 30-10-18 14:55:51, Miles Chen wrote:
> [...]
> > It's a real problem when using page_owner.
> > I found this issue recently: I'm not able to read page_owner information
> > during a overnight test. (error: read failed: Out of memory). I replace
> > kmalloc() with vmalloc() and it worked well.
> 
> Is this with trimming the allocation to a single page and doing shorter
> than requested reads?


I printed out the allocate count on my device the request count is <=
4096. So I tested this scenario by trimming the count to from 4096 to
1024 bytes and it works fine. 

count = count > 1024? 1024: count;

It tested it on both 32bit and 64bit kernel.