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Subjectbpf: test_verifier: sanitation: alu with different scalars
Date
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

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