linux-kernel - Re: [PATCH] NVMe: Avoid interrupt disable during queue init.

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:	Fri, 22 May 2015 20:21:27 +0530
From:	Parav Pandit <parav.pandit@...gotech.com>
To:	Keith Busch <keith.busch@...el.com>
Cc:	linux-nvme@...ts.infradead.org,
	Matthew Wilcox <willy@...ux.intel.com>,
	Jens Axboe <axboe@...nel.dk>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] NVMe: Avoid interrupt disable during queue init.

On Fri, May 22, 2015 at 8:18 PM, Keith Busch <keith.busch@...el.com> wrote:
> On Thu, 21 May 2015, Parav Pandit wrote:
>>
>> On Fri, May 22, 2015 at 1:04 AM, Keith Busch <keith.busch@...el.com>
>> wrote:
>>>
>>> The q_lock is held to protect polling from reading inconsistent data.
>>
>>
>> ah, yes. I can see the nvme_kthread can poll the CQ while its getting
>> created through the nvme_resume().
>> I think this opens up other issue.
>>
>> nvme_kthread() should,
>>
>> Instead of,
>> struct nvme_queue *nvmeq = dev->queues[i];
>>
>> it should do,
>> struct nvme_queue *nvmeq = rcu_dereference(dev->queues[i]);
>
>
> The rcu protection on nvme queues was removed with the blk-mq conversion
> as we rely on that layer for h/w access.

o.k. But above is at level where data I/Os are not even active. Its
between nvme_kthread and nvme_resume() from power management
subsystem.
I must be missing something.
--
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/