bpf: Avoid allocing memory on memoryless numa node

In architecture like powerpc, we can have cpus without any local memory
attached to it. In such cases the node does not have real memory.

Use local_memory_node(), which is guaranteed to have memory.
local_memory_node is a noop in other architectures that does not support
memoryless nodes.

Signed-off-by: Xianting Tian <[email protected]>

Author: Xianting Tian

kernel/bpf/cpumap.c

@@ -420,7 +420,7 @@ __cpu_map_entry_alloc(struct bpf_cpumap_val *value, u32 cpu, int map_id)
 	struct xdp_bulk_queue *bq;
 
 	/* Have map->numa_node, but choose node of redirect target CPU */
-	numa = cpu_to_node(cpu);
+	numa = local_memory_node(cpu_to_node(cpu));
 
 	rcpu = kzalloc_node(sizeof(*rcpu), gfp, numa);
 	if (!rcpu)