From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Carsten Emde <C.Emde@osadl.org>
Cc: Fernando Lopez-Lezcano <nando@ccrma.Stanford.EDU>,
linux-rt-users <linux-rt-users@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: 3.10.20-rt17, BUG and Oops
Date: Mon, 02 Dec 2013 09:27:41 +0100 [thread overview]
Message-ID: <529C447D.6010306@linutronix.de> (raw)
In-Reply-To: <529A6AFD.9020308@osadl.org>
On 11/30/2013 11:47 PM, Carsten Emde wrote:
> Sebastian,
Hi Carsten,
>> index a06d983..d3add07 100644
>> --- a/drivers/acpi/ec.c
>> +++ b/drivers/acpi/ec.c
>> @@ -175,16 +175,19 @@ static void start_transaction(struct acpi_ec *ec)
>> static void advance_transaction(struct acpi_ec *ec, u8 status)
>> {
>> unsigned long flags;
>
>> - struct transaction *t = ec->curr;
>> + struct transaction *t;
>>
>> spin_lock_irqsave(&ec->lock, flags);
>> + t = ec->curr;
> Looks like a race - did you find a place where ec->curr->wdata could be
> overwritten? The small size of the potential race window may explain why
> it took a couple of days to trigger it.
The pointer is assigned under a lock but here it is dereferenced before
taking the lock. It looks racy this might be the bug.
> Will apply the fix and the warning - let's see.
>
> Thanks.
> -Carsten.
Sebastian
next prev parent reply other threads:[~2013-12-02 8:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-30 7:56 3.10.20-rt17, BUG and Oops Fernando Lopez-Lezcano
2013-11-30 16:40 ` Carsten Emde
2013-11-30 20:39 ` Sebastian Andrzej Siewior
2013-11-30 22:47 ` Carsten Emde
2013-12-02 8:27 ` Sebastian Andrzej Siewior [this message]
2013-12-15 14:53 ` Sebastian Andrzej Siewior
2013-12-15 23:50 ` Carsten Emde
2013-12-16 8:09 ` Sebastian Andrzej Siewior
2013-12-21 21:23 ` Carsten Emde
2013-12-17 19:40 ` Fernando Lopez-Lezcano
2013-12-17 19:42 ` Sebastian Andrzej Siewior
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