From: Ralf Baechle <ralf@linux-mips.org>
To: David Daney <ddaney@avtrex.com>
Cc: Kaz Kylheku <kaz@zeugmasystems.com>, linux-mips@linux-mips.org
Subject: Re: futex_wake_op deadlock?
Date: Tue, 20 Nov 2007 19:00:41 +0000 [thread overview]
Message-ID: <20071120190041.GA18138@linux-mips.org> (raw)
In-Reply-To: <4743279B.7070402@avtrex.com>
On Tue, Nov 20, 2007 at 10:29:47AM -0800, David Daney wrote:
>> Notice the branch at the end of the fixup code, it goes back to the
>> SC instruction. The SC instruction took an exception so it will not have
>> changed $1 so the loop will continue endless unless by coincidence the
>> value to be stored from $1 happened to be zero.
>>
>> Obviously this one was MIPS specific and may hit all supported ABIs. So
>> my initial suspicion this might be the issue David Miller recently
>> discovered in the binary compat code isn't true. And it's a local DoS
>> probably for all of 2.6.16 and up.
>>
>
> I mostly similar code is in 2.6.15, so I think it is effected as well.
> 2.6.12 on the other hand doesn't seem to have futex.h
It originally appeared in the lmo kernel for 2.6.14-rc1 and a little
after the 2.6.14 release in kernel.org.
If I say 2.6.16 then it's simply that I don't ever look at anything that
doesn't have a -stable branch.
Ralf
prev parent reply other threads:[~2007-11-20 19:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-16 23:52 futex_wake_op deadlock? Kaz Kylheku
2007-11-16 23:52 ` Kaz Kylheku
2007-11-19 18:48 ` Ralf Baechle
2007-11-19 21:27 ` Kaz Kylheku
2007-11-19 21:27 ` Kaz Kylheku
2007-11-19 21:42 ` Kaz Kylheku
2007-11-19 21:42 ` Kaz Kylheku
2007-11-20 11:21 ` Ralf Baechle
2007-11-20 18:06 ` Kaz Kylheku
2007-11-20 18:06 ` Kaz Kylheku
2007-11-20 18:16 ` Ralf Baechle
2007-11-20 18:24 ` Kaz Kylheku
2007-11-20 18:24 ` Kaz Kylheku
2007-11-20 18:29 ` David Daney
2007-11-20 19:00 ` Ralf Baechle [this message]
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