Re: [PATCH] powerpc/hotplug-mem: Fix aa_index match bug for hotplug

From: Michael Ellerman
Date: Wed May 31 2017 - 00:03:29 EST


Nathan Fontenot <nfont@xxxxxxxxxxxxxxxxxx> writes:
> On 05/30/2017 06:41 AM, Michael Ellerman wrote:
>> Michael Bringmann <mwb@xxxxxxxxxxxxxxxxxx> writes:
>>> When adding or removing memory, the aa_index (affinity value) for the
>>> memblock must also be converted to match the endianness of the rest
>>> of the 'ibm,dynamic-memory' property. Otherwise, subsequent retrieval
>>> of the attribute will likely lead to non-existent nodes, followed by
>>> using the default node in the code inappropriately.
>>>
>>> Signed-off-by: Michael Bringmann <mwb@xxxxxxxxxxxxxxxxxx>
>>>
>>> diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
>>> index e104c71..1fb162b 100644
>>> --- a/arch/powerpc/platforms/pseries/hotplug-memory.c
>>> +++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
>>> @@ -124,6 +124,7 @@ static struct property *dlpar_clone_drconf_property(struct device_node *dn)
>>> for (i = 0; i < num_lmbs; i++) {
>>> lmbs[i].base_addr = be64_to_cpu(lmbs[i].base_addr);
>>> lmbs[i].drc_index = be32_to_cpu(lmbs[i].drc_index);
>>> + lmbs[i].aa_index = be32_to_cpu(lmbs[i].aa_index);
>>> lmbs[i].flags = be32_to_cpu(lmbs[i].flags);
>>> }
>>>
>>
>> AFAICS this code was added in commit 5f97b2a0d176 ("powerpc/pseries:
>> Implement memory hotplug add in the kernel").
>>
>> So this should probably be marked:
>>
>> Fixes: 5f97b2a0d176 ("powerpc/pseries: Implement memory hotplug add in the kernel")
>>
>> And it seems like a bug we'd want fixed in stable, so:
>>
>> Cc: stable@xxxxxxxxxxxxxxx # v4.1+
>>
>> Am I right?
>
> Yes, that is correct.

Thanks.

cheers