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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Wim Van Sebroeck <wim@iguana.be>,
	Linux Watchdog Mailing List <linux-watchdog@vger.kernel.org>
Subject: Re: [RFC] watchdog ->release() races
Date: Tue, 7 May 2013 22:17:22 +0100	[thread overview]
Message-ID: <20130507211722.GS25399@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CA+55aFwxBj-+r3z_1JgAG4Tv5p3NF-WTaYedYNGq9jDq+riOaw@mail.gmail.com>

On Tue, May 07, 2013 at 02:00:02PM -0700, Linus Torvalds wrote:
> On Tue, May 7, 2013 at 1:10 PM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > It's obviously racy; I'm not sure if we care about that race, but if we
> > do, there's about 80 drivers that need to be fixed...
> 
> I suspect the "we don't really care" is the correct answer here. It's
> not like you can really screw things up by mistake, and if you try to
> screw this up on purpose, you need to be root anyway to open
> /dev/watchdog etc.

I'm not sure...  It's obviously not a "the sky is falling" kind of thing,
but in a situation when task B kills task A, then spins trying to open
until open() succeeds...  Hell knows; it might be triggerable by somebody
not trying to trigger the race on purpose.  I really don't know what does
the userland side of that thing look like, thus the Cc to linux-wtchdog...

  reply	other threads:[~2013-05-07 21:17 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-07 20:10 [RFC] watchdog ->release() races Al Viro
2013-05-07 21:00 ` Linus Torvalds
2013-05-07 21:17   ` Al Viro [this message]
2013-05-08  0:30 ` Guenter Roeck

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