From: Yonghong Song yhs@fb.com

[ Upstream commit 9eca5083757b679b37f210092c871916c2c222d0 ]

The bpf_map_lookup_elem is added in the bpf program. Without previous patch, the test change will trigger the following error: $ ./test_maps ... ; value_p = bpf_map_lookup_elem(map, &key); 20: (bf) r1 = r7 21: (bf) r2 = r8 22: (85) call bpf_map_lookup_elem#1 ; if (!value_p || *value_p != 123) 23: (15) if r0 == 0x0 goto pc+16 R0=map_value(id=2,off=0,ks=4,vs=4,imm=0) R6=inv1 R7=map_ptr(id=0,off=0,ks=4,vs=4,imm=0) R8=fp-8,call_-1 R10=fp0,call_-1 fp-8=mmmmmmmm ; if (!value_p || *value_p != 123) 24: (61) r1 = *(u32 *)(r0 +0) R0=map_value(id=2,off=0,ks=4,vs=4,imm=0) R6=inv1 R7=map_ptr(id=0,off=0,ks=4,vs=4,imm=0) R8=fp-8,call_-1 R10=fp0,call_-1 fp-8=mmmmmmmm bpf_spin_lock cannot be accessed directly by load/store

With the kernel fix in the previous commit, the error goes away.

Signed-off-by: Yonghong Song yhs@fb.com Acked-by: Andrii Nakryiko andriin@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/bpf/test_map_in_map.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_map_in_map.c b/tools/testing/selftests/bpf/test_map_in_map.c index ce923e67e08e..2985f262846e 100644 --- a/tools/testing/selftests/bpf/test_map_in_map.c +++ b/tools/testing/selftests/bpf/test_map_in_map.c @@ -27,6 +27,7 @@ SEC("xdp_mimtest") int xdp_mimtest0(struct xdp_md *ctx) { int value = 123; + int *value_p; int key = 0; void *map;

@@ -35,6 +36,9 @@ int xdp_mimtest0(struct xdp_md *ctx) return XDP_DROP;

bpf_map_update_elem(map, &key, &value, 0); + value_p = bpf_map_lookup_elem(map, &key); + if (!value_p || *value_p != 123) + return XDP_DROP;

map = bpf_map_lookup_elem(&mim_hash, &key); if (!map)