netdev - Re: [dm-devel] [PATCH v5] fault-injection: introduce kvmalloc fallback options

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: <20180426214011-mutt-send-email-mst@kernel.org>
Date:   Thu, 26 Apr 2018 21:49:19 +0300
From:   "Michael S. Tsirkin" <mst@...hat.com>
To:     Mikulas Patocka <mpatocka@...hat.com>
Cc:     James Bottomley <James.Bottomley@...senPartnership.com>,
        Michal Hocko <mhocko@...nel.org>,
        David Rientjes <rientjes@...gle.com>, dm-devel@...hat.com,
        eric.dumazet@...il.com, netdev@...r.kernel.org,
        jasowang@...hat.com, Randy Dunlap <rdunlap@...radead.org>,
        linux-kernel@...r.kernel.org, Matthew Wilcox <willy@...radead.org>,
        linux-mm@...ck.org, edumazet@...gle.com,
        Andrew Morton <akpm@...ux-foundation.org>,
        virtualization@...ts.linux-foundation.org,
        David Miller <davem@...emloft.net>,
        Vlastimil Babka <vbabka@...e.cz>
Subject: Re: [dm-devel] [PATCH v5] fault-injection: introduce kvmalloc
 fallback options

On Thu, Apr 26, 2018 at 12:07:25PM -0400, Mikulas Patocka wrote:
> > IIUC debug kernels mainly exist so people who experience e.g. memory
> > corruption can try and debug the failure. In this case, CONFIG_DEBUG_SG
> > will *already* catch a failure early. Nothing special needs to be done.
> 
> The patch helps people debug such memory coprruptions (such as using DMA 
> API on the result of kvmalloc).

That's my point.  I don't think your patch helps debug any memory
corruptions.  With CONFIG_DEBUG_SG using DMA API already causes a
BUG_ON, that's before any memory can get corrupted.

-- 
MST