linux-kernel - Re: scsi-mq V2

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:	Thu, 10 Jul 2014 21:59:36 +0200
From:	Jens Axboe <axboe@...nel.dk>
To:	Jeff Moyer <jmoyer@...hat.com>, Benjamin LaHaise <bcrl@...ck.org>
CC:	"Elliott\, Robert \(Server Storage\)" <Elliott@...com>,
	Christoph Hellwig <hch@...radead.org>,
	"dgilbert@...erlog.com" <dgilbert@...erlog.com>,
	James Bottomley <James.Bottomley@...senPartnership.com>,
	Bart Van Assche <bvanassche@...ionio.com>,
	"linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: scsi-mq V2

On 2014-07-10 17:11, Jeff Moyer wrote:
> Benjamin LaHaise <bcrl@...ck.org> writes:
>
>>>
>>> [  186.339064] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>> [  186.339065] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>> [  186.339067] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>> [  186.339068] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>> [  186.339069] ioctx_alloc: nr_events=-2 aio_max_nr=65536
>>
>> Something is horribly wrong here.  There is no way that value for nr_events
>> should be passed in to ioctx_alloc().  This implies that userland is calling
>> io_setup() with an impossibly large value for nr_events.  Can you post the
>> actual diff for your fs/aio.c relative to linus' tree?
>>
>
> fio does exactly this!  it passes INT_MAX.

That's correct, I had actually forgotten about this. It was a change 
made a few years back, in correlation with the aio optimizations posted 
then, basically telling aio to ignore that silly (and broken) user ring.

-- 
Jens Axboe

--
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/