1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 3 * Copyright (c) 2016 Facebook 4 */ 5 6 #include <linux/bpf.h> 7 8 #include "disasm.h" 9 10 #define __BPF_FUNC_STR_FN(x) [BPF_FUNC_ ## x] = __stringify(bpf_ ## x) 11 static const char * const func_id_str[] = { 12 __BPF_FUNC_MAPPER(__BPF_FUNC_STR_FN) 13 }; 14 #undef __BPF_FUNC_STR_FN 15 16 static const char *__func_get_name(const struct bpf_insn_cbs *cbs, 17 const struct bpf_insn *insn, 18 char *buff, size_t len) 19 { 20 BUILD_BUG_ON(ARRAY_SIZE(func_id_str) != __BPF_FUNC_MAX_ID); 21 22 if (insn->src_reg != BPF_PSEUDO_CALL && 23 insn->imm >= 0 && insn->imm < __BPF_FUNC_MAX_ID && 24 func_id_str[insn->imm]) 25 return func_id_str[insn->imm]; 26 27 if (cbs && cbs->cb_call) 28 return cbs->cb_call(cbs->private_data, insn); 29 30 if (insn->src_reg == BPF_PSEUDO_CALL) 31 snprintf(buff, len, "%+d", insn->imm); 32 33 return buff; 34 } 35 36 static const char *__func_imm_name(const struct bpf_insn_cbs *cbs, 37 const struct bpf_insn *insn, 38 u64 full_imm, char *buff, size_t len) 39 { 40 if (cbs && cbs->cb_imm) 41 return cbs->cb_imm(cbs->private_data, insn, full_imm); 42 43 snprintf(buff, len, "0x%llx", (unsigned long long)full_imm); 44 return buff; 45 } 46 47 const char *func_id_name(int id) 48 { 49 if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id]) 50 return func_id_str[id]; 51 else 52 return "unknown"; 53 } 54 55 const char *const bpf_class_string[8] = { 56 [BPF_LD] = "ld", 57 [BPF_LDX] = "ldx", 58 [BPF_ST] = "st", 59 [BPF_STX] = "stx", 60 [BPF_ALU] = "alu", 61 [BPF_JMP] = "jmp", 62 [BPF_JMP32] = "jmp32", 63 [BPF_ALU64] = "alu64", 64 }; 65 66 const char *const bpf_alu_string[16] = { 67 [BPF_ADD >> 4] = "+=", 68 [BPF_SUB >> 4] = "-=", 69 [BPF_MUL >> 4] = "*=", 70 [BPF_DIV >> 4] = "/=", 71 [BPF_OR >> 4] = "|=", 72 [BPF_AND >> 4] = "&=", 73 [BPF_LSH >> 4] = "<<=", 74 [BPF_RSH >> 4] = ">>=", 75 [BPF_NEG >> 4] = "neg", 76 [BPF_MOD >> 4] = "%=", 77 [BPF_XOR >> 4] = "^=", 78 [BPF_MOV >> 4] = "=", 79 [BPF_ARSH >> 4] = "s>>=", 80 [BPF_END >> 4] = "endian", 81 }; 82 83 static const char *const bpf_atomic_alu_string[16] = { 84 [BPF_ADD >> 4] = "add", 85 [BPF_AND >> 4] = "and", 86 [BPF_OR >> 4] = "or", 87 [BPF_XOR >> 4] = "or", 88 }; 89 90 static const char *const bpf_ldst_string[] = { 91 [BPF_W >> 3] = "u32", 92 [BPF_H >> 3] = "u16", 93 [BPF_B >> 3] = "u8", 94 [BPF_DW >> 3] = "u64", 95 }; 96 97 static const char *const bpf_jmp_string[16] = { 98 [BPF_JA >> 4] = "jmp", 99 [BPF_JEQ >> 4] = "==", 100 [BPF_JGT >> 4] = ">", 101 [BPF_JLT >> 4] = "<", 102 [BPF_JGE >> 4] = ">=", 103 [BPF_JLE >> 4] = "<=", 104 [BPF_JSET >> 4] = "&", 105 [BPF_JNE >> 4] = "!=", 106 [BPF_JSGT >> 4] = "s>", 107 [BPF_JSLT >> 4] = "s<", 108 [BPF_JSGE >> 4] = "s>=", 109 [BPF_JSLE >> 4] = "s<=", 110 [BPF_CALL >> 4] = "call", 111 [BPF_EXIT >> 4] = "exit", 112 }; 113 114 static void print_bpf_end_insn(bpf_insn_print_t verbose, 115 void *private_data, 116 const struct bpf_insn *insn) 117 { 118 verbose(private_data, "(%02x) r%d = %s%d r%d\n", 119 insn->code, insn->dst_reg, 120 BPF_SRC(insn->code) == BPF_TO_BE ? "be" : "le", 121 insn->imm, insn->dst_reg); 122 } 123 124 void print_bpf_insn(const struct bpf_insn_cbs *cbs, 125 const struct bpf_insn *insn, 126 bool allow_ptr_leaks) 127 { 128 const bpf_insn_print_t verbose = cbs->cb_print; 129 u8 class = BPF_CLASS(insn->code); 130 131 if (class == BPF_ALU || class == BPF_ALU64) { 132 if (BPF_OP(insn->code) == BPF_END) { 133 if (class == BPF_ALU64) 134 verbose(cbs->private_data, "BUG_alu64_%02x\n", insn->code); 135 else 136 print_bpf_end_insn(verbose, cbs->private_data, insn); 137 } else if (BPF_OP(insn->code) == BPF_NEG) { 138 verbose(cbs->private_data, "(%02x) %c%d = -%c%d\n", 139 insn->code, class == BPF_ALU ? 'w' : 'r', 140 insn->dst_reg, class == BPF_ALU ? 'w' : 'r', 141 insn->dst_reg); 142 } else if (BPF_SRC(insn->code) == BPF_X) { 143 verbose(cbs->private_data, "(%02x) %c%d %s %c%d\n", 144 insn->code, class == BPF_ALU ? 'w' : 'r', 145 insn->dst_reg, 146 bpf_alu_string[BPF_OP(insn->code) >> 4], 147 class == BPF_ALU ? 'w' : 'r', 148 insn->src_reg); 149 } else { 150 verbose(cbs->private_data, "(%02x) %c%d %s %d\n", 151 insn->code, class == BPF_ALU ? 'w' : 'r', 152 insn->dst_reg, 153 bpf_alu_string[BPF_OP(insn->code) >> 4], 154 insn->imm); 155 } 156 } else if (class == BPF_STX) { 157 if (BPF_MODE(insn->code) == BPF_MEM) 158 verbose(cbs->private_data, "(%02x) *(%s *)(r%d %+d) = r%d\n", 159 insn->code, 160 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 161 insn->dst_reg, 162 insn->off, insn->src_reg); 163 else if (BPF_MODE(insn->code) == BPF_ATOMIC && 164 (insn->imm == BPF_ADD || insn->imm == BPF_AND || 165 insn->imm == BPF_OR || insn->imm == BPF_XOR)) { 166 verbose(cbs->private_data, "(%02x) lock *(%s *)(r%d %+d) %s r%d\n", 167 insn->code, 168 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 169 insn->dst_reg, insn->off, 170 bpf_alu_string[BPF_OP(insn->imm) >> 4], 171 insn->src_reg); 172 } else if (BPF_MODE(insn->code) == BPF_ATOMIC && 173 (insn->imm == (BPF_ADD | BPF_FETCH) || 174 insn->imm == (BPF_AND | BPF_FETCH) || 175 insn->imm == (BPF_OR | BPF_FETCH) || 176 insn->imm == (BPF_XOR | BPF_FETCH))) { 177 verbose(cbs->private_data, "(%02x) r%d = atomic%s_fetch_%s((%s *)(r%d %+d), r%d)\n", 178 insn->code, insn->src_reg, 179 BPF_SIZE(insn->code) == BPF_DW ? "64" : "", 180 bpf_atomic_alu_string[BPF_OP(insn->imm) >> 4], 181 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 182 insn->dst_reg, insn->off, insn->src_reg); 183 } else if (BPF_MODE(insn->code) == BPF_ATOMIC && 184 insn->imm == BPF_CMPXCHG) { 185 verbose(cbs->private_data, "(%02x) r0 = atomic%s_cmpxchg((%s *)(r%d %+d), r0, r%d)\n", 186 insn->code, 187 BPF_SIZE(insn->code) == BPF_DW ? "64" : "", 188 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 189 insn->dst_reg, insn->off, 190 insn->src_reg); 191 } else if (BPF_MODE(insn->code) == BPF_ATOMIC && 192 insn->imm == BPF_XCHG) { 193 verbose(cbs->private_data, "(%02x) r%d = atomic%s_xchg((%s *)(r%d %+d), r%d)\n", 194 insn->code, insn->src_reg, 195 BPF_SIZE(insn->code) == BPF_DW ? "64" : "", 196 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 197 insn->dst_reg, insn->off, insn->src_reg); 198 } else { 199 verbose(cbs->private_data, "BUG_%02x\n", insn->code); 200 } 201 } else if (class == BPF_ST) { 202 if (BPF_MODE(insn->code) != BPF_MEM) { 203 verbose(cbs->private_data, "BUG_st_%02x\n", insn->code); 204 return; 205 } 206 verbose(cbs->private_data, "(%02x) *(%s *)(r%d %+d) = %d\n", 207 insn->code, 208 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 209 insn->dst_reg, 210 insn->off, insn->imm); 211 } else if (class == BPF_LDX) { 212 if (BPF_MODE(insn->code) != BPF_MEM) { 213 verbose(cbs->private_data, "BUG_ldx_%02x\n", insn->code); 214 return; 215 } 216 verbose(cbs->private_data, "(%02x) r%d = *(%s *)(r%d %+d)\n", 217 insn->code, insn->dst_reg, 218 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 219 insn->src_reg, insn->off); 220 } else if (class == BPF_LD) { 221 if (BPF_MODE(insn->code) == BPF_ABS) { 222 verbose(cbs->private_data, "(%02x) r0 = *(%s *)skb[%d]\n", 223 insn->code, 224 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 225 insn->imm); 226 } else if (BPF_MODE(insn->code) == BPF_IND) { 227 verbose(cbs->private_data, "(%02x) r0 = *(%s *)skb[r%d + %d]\n", 228 insn->code, 229 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 230 insn->src_reg, insn->imm); 231 } else if (BPF_MODE(insn->code) == BPF_IMM && 232 BPF_SIZE(insn->code) == BPF_DW) { 233 /* At this point, we already made sure that the second 234 * part of the ldimm64 insn is accessible. 235 */ 236 u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm; 237 bool is_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD || 238 insn->src_reg == BPF_PSEUDO_MAP_VALUE; 239 char tmp[64]; 240 241 if (is_ptr && !allow_ptr_leaks) 242 imm = 0; 243 244 verbose(cbs->private_data, "(%02x) r%d = %s\n", 245 insn->code, insn->dst_reg, 246 __func_imm_name(cbs, insn, imm, 247 tmp, sizeof(tmp))); 248 } else { 249 verbose(cbs->private_data, "BUG_ld_%02x\n", insn->code); 250 return; 251 } 252 } else if (class == BPF_JMP32 || class == BPF_JMP) { 253 u8 opcode = BPF_OP(insn->code); 254 255 if (opcode == BPF_CALL) { 256 char tmp[64]; 257 258 if (insn->src_reg == BPF_PSEUDO_CALL) { 259 verbose(cbs->private_data, "(%02x) call pc%s\n", 260 insn->code, 261 __func_get_name(cbs, insn, 262 tmp, sizeof(tmp))); 263 } else { 264 strcpy(tmp, "unknown"); 265 verbose(cbs->private_data, "(%02x) call %s#%d\n", insn->code, 266 __func_get_name(cbs, insn, 267 tmp, sizeof(tmp)), 268 insn->imm); 269 } 270 } else if (insn->code == (BPF_JMP | BPF_JA)) { 271 verbose(cbs->private_data, "(%02x) goto pc%+d\n", 272 insn->code, insn->off); 273 } else if (insn->code == (BPF_JMP | BPF_EXIT)) { 274 verbose(cbs->private_data, "(%02x) exit\n", insn->code); 275 } else if (BPF_SRC(insn->code) == BPF_X) { 276 verbose(cbs->private_data, 277 "(%02x) if %c%d %s %c%d goto pc%+d\n", 278 insn->code, class == BPF_JMP32 ? 'w' : 'r', 279 insn->dst_reg, 280 bpf_jmp_string[BPF_OP(insn->code) >> 4], 281 class == BPF_JMP32 ? 'w' : 'r', 282 insn->src_reg, insn->off); 283 } else { 284 verbose(cbs->private_data, 285 "(%02x) if %c%d %s 0x%x goto pc%+d\n", 286 insn->code, class == BPF_JMP32 ? 'w' : 'r', 287 insn->dst_reg, 288 bpf_jmp_string[BPF_OP(insn->code) >> 4], 289 insn->imm, insn->off); 290 } 291 } else { 292 verbose(cbs->private_data, "(%02x) %s\n", 293 insn->code, bpf_class_string[class]); 294 } 295 } 296