Commit b8cdc051 authored Mar 09, 2016 by Alexei Starovoitov Committed by David S. Miller Mar 09, 2016

bpf: bpf_stackmap_copy depends on CONFIG_PERF_EVENTS



0-day bot reported build error:
kernel/built-in.o: In function `map_lookup_elem':
>> kernel/bpf/.tmp_syscall.o:(.text+0x329b3c): undefined reference to `bpf_stackmap_copy'
when CONFIG_BPF_SYSCALL is set and CONFIG_PERF_EVENTS is not.
Add weak definition to resolve it.
This code path in map_lookup_elem() is never taken
when CONFIG_PERF_EVENTS is not set.

Fixes: 557c0c6e ("bpf: convert stackmap to pre-allocation")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 3b8377dc

kernel/bpf/syscall.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -244,6 +244,11 @@ static void __user *u64_to_ptr(__u64 val)
		return (void __user *) (unsigned long) val;
		}

		int __weak bpf_stackmap_copy(struct bpf_map map, void key, void *value)
		{
		return -ENOTSUPP;
		}

		/* last field in 'union bpf_attr' used by this command */
		#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value

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