linux-kernel - Re: [PATCH] video4linux: Push down the BKL

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: <20080523163956.6e93746c@core>
Date:	Fri, 23 May 2008 16:39:56 +0100
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	corbet@....net (Jonathan Corbet)
Cc:	video4linux-list@...hat.com, linux-kernel@...r.kernel.org,
	mchehab@...radead.org
Subject: Re: [PATCH] video4linux: Push down the BKL

> On the other hand, the next level of BKL pushdown would be painful as
> all hell, given the massive number of callbacks in the V4L2 API.  So I'm
> thinking it might be justified to create a video_ioctl2_locked() for
> V4L2 drivers which are not yet known to be safe in the absence of the
> BKL.  The amount of extra code would be quite small, and it would let
> safe drivers operate BKL-free.

The problem is that currently they are almost all unsafe - I did a quick
survey as part of the changes. Pushing it down to the video2_ioctl is a
starting point, but the v4l layer is going to need a lot of love and its
own gradual migration.

Right now we've gone from BKL buried in fs to BKL at top of v4l layer
which is indeed only a starting point. I'd assumed the same as you are
think a new video_ioctl2 and switching drivers one by one (I was assuming
adding video2_ioctl_unlocked())

Alan
--
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/