28 lines
840 B
C
28 lines
840 B
C
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{
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"BPF_ATOMIC bounds propagation, mem->reg",
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.insns = {
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/* a = 0; */
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/*
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* Note this is implemented with two separate instructions,
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* where you might think one would suffice:
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*
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* BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
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*
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* This is because BPF_ST_MEM doesn't seem to set the stack slot
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* type to 0 when storing an immediate.
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*/
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
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/* b = atomic_fetch_add(&a, 1); */
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BPF_MOV64_IMM(BPF_REG_1, 1),
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BPF_ATOMIC_OP(BPF_DW, BPF_ADD | BPF_FETCH, BPF_REG_10, BPF_REG_1, -8),
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/* Verifier should be able to tell that this infinite loop isn't reachable. */
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/* if (b) while (true) continue; */
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BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, -1),
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BPF_EXIT_INSN(),
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},
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.result = ACCEPT,
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.result_unpriv = REJECT,
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.errstr_unpriv = "back-edge",
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},
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