36 lines
1.1 KiB
C
36 lines
1.1 KiB
C
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{
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"raw_tracepoint_writable: reject variable offset",
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.insns = {
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/* r6 is our tp buffer */
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BPF_LDX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0),
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BPF_LD_MAP_FD(BPF_REG_1, 0),
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/* move the key (== 0) to r10-8 */
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BPF_MOV32_IMM(BPF_REG_0, 0),
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BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
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BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
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BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_0, 0),
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/* lookup in the map */
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BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
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BPF_FUNC_map_lookup_elem),
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/* exit clean if null */
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BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
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BPF_EXIT_INSN(),
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/* shift the buffer pointer to a variable location */
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BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0),
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BPF_ALU64_REG(BPF_ADD, BPF_REG_6, BPF_REG_0),
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/* clobber whatever's there */
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BPF_MOV64_IMM(BPF_REG_7, 4242),
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BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_7, 0),
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BPF_MOV64_IMM(BPF_REG_0, 0),
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BPF_EXIT_INSN(),
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},
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.fixup_map_hash_8b = { 1, },
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.prog_type = BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
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.errstr = "R6 invalid variable buffer offset: off=0, var_off=(0x0; 0xffffffff)",
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.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
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},
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