From: Christoph Hellwig <hch@infradead.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>, linux-block@vger.kernel.org
Subject: Re: [PATCH 3/6] blk-mq: embed blk_mq_ops directly in the request queue
Date: Wed, 14 Nov 2018 07:39:48 -0800 [thread overview]
Message-ID: <20181114153948.GA22811@infradead.org> (raw)
In-Reply-To: <130070cd-e0d1-e75e-4341-7c1b26d1531e@kernel.dk>
On Wed, Nov 14, 2018 at 08:33:06AM -0700, Jens Axboe wrote:
> It's measurable. It doesn't defeat the const at all, the mq_ops
> is still const and is never modified outside of when the queue
> is allocated. The only difference is of course that it is no
> longer residing in a read only mapped section, which is a shame.
And the separate section is very much the point of the const.
Without it attackers can easily overwrite the function pointer and
use it for exploits, as the C const attribute by itself doesn't
protect from that in any way. But once it is in a read-only section
it can't easily be modified.
next prev parent reply other threads:[~2018-11-14 15:39 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-10 15:13 [PATCHSET 0/6] Various block optimizations Jens Axboe
2018-11-10 15:13 ` [PATCH 1/6] nvme: don't disable local ints for polled queue Jens Axboe
2018-11-14 8:43 ` Christoph Hellwig
2018-11-14 15:31 ` Jens Axboe
2018-11-14 15:37 ` Keith Busch
2018-11-14 10:18 ` Max Gurtovoy
2018-11-10 15:13 ` [PATCH 2/6] block: add queue_is_mq() helper Jens Axboe
2018-11-10 15:13 ` [PATCH 3/6] blk-mq: embed blk_mq_ops directly in the request queue Jens Axboe
2018-11-14 15:20 ` Christoph Hellwig
2018-11-14 15:33 ` Jens Axboe
2018-11-14 15:39 ` Christoph Hellwig [this message]
2018-11-14 15:47 ` Jens Axboe
2018-11-14 15:58 ` Christoph Hellwig
2018-11-10 15:13 ` [PATCH 4/6] block: avoid ordered task state change for polled IO Jens Axboe
2018-11-12 9:35 ` jianchao.wang
2018-11-12 16:26 ` Jens Axboe
2018-11-12 16:26 ` Jens Axboe
2018-11-13 2:02 ` jianchao.wang
2018-11-10 15:13 ` [PATCH 5/6] blk-rq-qos: inline check for q->rq_qos functions Jens Axboe
2018-11-14 15:21 ` Christoph Hellwig
2018-11-14 15:33 ` Jens Axboe
2018-11-14 15:40 ` Christoph Hellwig
2018-11-14 17:16 ` Jens Axboe
2018-11-10 15:13 ` [PATCH 6/6] block: add polled wakeup task helper Jens Axboe
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