bpf: test_verifier: sanitation: alu with different scalars

[Yauheni Kaliuta]

Hi!

I'm wondering, how the sanitaion tests (#903 5.2-rc6 for example)
are supposed to work on BE arches:

{
        "sanitation: alu with different scalars 1",
        .insns = {
        BPF_MOV64_IMM(BPF_REG_0, 1),
        BPF_LD_MAP_FD(BPF_REG_ARG1, 0),
        BPF_MOV64_REG(BPF_REG_ARG2, BPF_REG_FP),
        BPF_ALU64_IMM(BPF_ADD, BPF_REG_ARG2, -16),
        BPF_ST_MEM(BPF_DW, BPF_REG_FP, -16, 0),
        BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
        BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
        BPF_EXIT_INSN(),
        BPF_LDX_MEM(BPF_B, BPF_REG_1, BPF_REG_0, 0),

reads one byte 0 on BE and 28 on LE (from ->index) since

        struct test_val {
                unsigned int index;
                int foo[MAX_ENTRIES];
        };

        struct test_val value = {
                .index = (6 + 1) * sizeof(int),
                .foo[6] = 0xabcdef12,
        };

        BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3),

So different branches are taken depending of the endianness.

        BPF_MOV64_IMM(BPF_REG_2, 0),
        BPF_MOV64_IMM(BPF_REG_3, 0x100000),
        BPF_JMP_A(2),
        BPF_MOV64_IMM(BPF_REG_2, 42),
        BPF_MOV64_IMM(BPF_REG_3, 0x100001),
        BPF_ALU64_REG(BPF_ADD, BPF_REG_2, BPF_REG_3),
        BPF_MOV64_REG(BPF_REG_0, BPF_REG_2),
        BPF_EXIT_INSN(),
        },
        .fixup_map_array_48b = { 1 },
        .result = ACCEPT,
        .retval = 0x100000,
},



-- 
WBR,
Yauheni Kaliuta