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