[PATCH bpf-next] selftests/bpf: fix "alu with different scalars 1" on s390

[Ilya Leoshkevich <iii@linux.ibm.com>]

BPF_LDX_MEM is used to load the least significant byte of the retrieved
test_val.index, however, on big-endian machines it ends up retrieving
the most significant byte.

Use the correct least significant byte offset on big-endian machines.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 tools/testing/selftests/bpf/verifier/value_ptr_arith.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/selftests/bpf/verifier/value_ptr_arith.c b/tools/testing/selftests/bpf/verifier/value_ptr_arith.c
index c3de1a2c9dc5..3b221bb4b317 100644
--- a/tools/testing/selftests/bpf/verifier/value_ptr_arith.c
+++ b/tools/testing/selftests/bpf/verifier/value_ptr_arith.c
@@ -183,7 +183,11 @@
 	BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
 	BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
 	BPF_EXIT_INSN(),
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 	BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),
+#else
+	BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, sizeof(int) - 1),
+#endif
 	BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),
 	BPF_MOV64_IMM(BPF_REG_2, 0),
 	BPF_MOV64_IMM(BPF_REG_3, 0x100000),
-- 
2.21.0