On 7/16/19 12:13 AM, Alexei Starovoitov wrote: > On Thu, Jul 4, 2019 at 1:53 AM Ilya Leoshkevich <iii@xxxxxxxxxxxxx> wrote: >> >> 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@xxxxxxxxxxxxx> >> --- >> >> v1->v2: >> - use __BYTE_ORDER instead of __BYTE_ORDER__. >> >> 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..e5940c4e8b8f 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 == __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 > > I think tests should be arch and endian independent where possible. > In this case test_val.index is 4 byte and 4 byte load should work just as well. Yes, agree, this should be fixed with BPF_W as load. Thanks, Daniel
