[PATCH v2] of, numa: Return NUMA_NO_NODE from disable of_node_to_nid() if nid not possible.

[Rob Herring]

On Thu, Nov 3, 2016 at 10:11 AM, David Daney <ddaney at caviumnetworks.com> wrote:
> On 11/02/2016 08:37 PM, Rob Herring wrote:
>>
>> On Fri, Oct 28, 2016 at 4:15 PM, David Daney <ddaney.cavm at gmail.com>
>> wrote:
>>>
>>> From: David Daney <david.daney at cavium.com>
>>>
>>> On arm64 NUMA kernels we can pass "numa=off" on the command line to
>>> disable NUMA.  A side effect of this is that kmalloc_node() calls to
>>> non-zero nodes will crash the system with an OOPS:
>>>
>>> [    0.000000] ITS at 0x0000901000020000: allocated 2097152 Devices
>>> @10002000000 (flat, esz 8, psz 64K, shr 1)
>>> [    0.000000] Unable to handle kernel NULL pointer dereference at
>>> virtual address 00001680
>>> [    0.000000] pgd = fffffc0009470000
>>> [    0.000000] [00001680] *pgd=0000010ffff90003, *pud=0000010ffff90003,
>>> *pmd=0000010ffff90003, *pte=0000000000000000
>>> [    0.000000] Internal error: Oops: 96000006 [#1] SMP
>>> .
>>> .
>>> .
>>> [    0.000000] [<fffffc00081c8950>] __alloc_pages_nodemask+0xa4/0xe68
>>> [    0.000000] [<fffffc000821fa70>] new_slab+0xd0/0x564
>>> [    0.000000] [<fffffc0008221e24>] ___slab_alloc+0x2e4/0x514
>>> [    0.000000] [<fffffc0008239498>] __slab_alloc+0x48/0x58
>>> [    0.000000] [<fffffc0008222c20>] __kmalloc_node+0xd0/0x2dc
>>> [    0.000000] [<fffffc0008115374>] __irq_domain_add+0x7c/0x164
>>> [    0.000000] [<fffffc0008b461dc>] its_probe+0x784/0x81c
>>> [    0.000000] [<fffffc0008b462bc>] its_init+0x48/0x1b0
>>> [    0.000000] [<fffffc0008b4543c>] gic_init_bases+0x228/0x360
>>> [    0.000000] [<fffffc0008b456bc>] gic_of_init+0x148/0x1cc
>>> [    0.000000] [<fffffc0008b5aec8>] of_irq_init+0x184/0x298
>>> [    0.000000] [<fffffc0008b43f9c>] irqchip_init+0x14/0x38
>>> [    0.000000] [<fffffc0008b12d60>] init_IRQ+0xc/0x30
>>> [    0.000000] [<fffffc0008b10a3c>] start_kernel+0x240/0x3b8
>>> [    0.000000] [<fffffc0008b101c4>] __primary_switched+0x30/0x6c
>>> [    0.000000] Code: 912ec2a0 b9403809 0a0902fb 37b007db (f9400300)
>>> .
>>> .
>>> .
>>>
>>> This is caused by code like this in kernel/irq/irqdomain.c
>>>
>>>     domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) *
>>> size),
>>>                   GFP_KERNEL, of_node_to_nid(of_node));
>>>
>>> When NUMA is disabled, the concept of a node is really undefined, so
>>> of_node_to_nid() should unconditionally return NUMA_NO_NODE.
>>>
>>> Fix by returning NUMA_NO_NODE when the nid is not in the set of
>>> possible nodes.
>>>
>>> Reported-by: Gilbert Netzer <noname at pdc.kth.se>
>>> Signed-off-by: David Daney <david.daney at cavium.com>
>>
>>
>> Does this need to go in 4.9?
>
>
> That would be my preference.

Given how late this is now, my having nothing else for 4.9 and that
his has never worked, I've applied for 4.10, but I did tag for stable.

Rob