From: David Daney <david.daney@xxxxxxxxxx> 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@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@xxxxxxxxxx> Signed-off-by: David Daney <david.daney@xxxxxxxxxx> --- drivers/of/of_numa.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c index f63d4b0d..a53982a 100644 --- a/drivers/of/of_numa.c +++ b/drivers/of/of_numa.c @@ -176,7 +176,12 @@ int of_node_to_nid(struct device_node *device) np->name); of_node_put(np); - if (!r) + /* + * If numa=off passed on command line, or with a defective + * device tree, the nid may not be in the set of possible + * nodes. Check for this case and return NUMA_NO_NODE. + */ + if (!r && nid < MAX_NUMNODES && node_possible(nid)) return nid; return NUMA_NO_NODE; -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html