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Message-ID: <4B41D42A.9040008@xenontk.org>
Date: Mon, 04 Jan 2010 17:12:34 +0530
From: David John <davidjon@xenontk.org>
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To: Rusty Russell <rusty@rustcorp.com.au>
CC: jbarnes@virtuousgeek.org, andreas.herrmann3@amd.com, rjw@sisk.pl,
       linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] Check the node argument passed to cpumask_of_node
References: <201001012255.28094.rjw@sisk.pl> <1262412947-3890-1-BlackWidow-davidjon@xenontk.org> <201001041458.24145.rusty@rustcorp.com.au>
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On 01/04/2010 09:58 AM, Rusty Russell wrote:
> On Sat, 2 Jan 2010 04:45:47 pm David John wrote:
>> Commit e0cd516 "PCI: derive nearby CPUs from device's instead of bus' NUMA information"
>> causes an null pointer dereference when reading from the sysfs attributes local_cpu*
>> on Intel machines with no ACPI NUMA proximity info, since dev->numa_node gets set to -1
>> for all PCI devices, which then gets passed to cpumask_of_node.
>>
>> Ensure that the node value is valid.
> 
> This only works for x86, and only for !CONFIG_DEBUG_PER_CPU_MAPS.
> 
> I suggest fixing the callers introduced in e0cd516 for the moment,
> then if you feel enthused, change the semantics of cpumask_of_node and
> remove the checks from the various callers.

Okay, I'll do as you suggested.

Regards,
David.