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 && 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 const char *res; 29 30 res = cbs->cb_call(cbs->private_data, insn); 31 if (res) 32 return res; 33 } 34 35 if (insn->src_reg == BPF_PSEUDO_CALL) 36 snprintf(buff, len, "%+d", insn->imm); 37 else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL) 38 snprintf(buff, len, "kernel-function"); 39 40 return buff; 41 } 42 43 static const char *__func_imm_name(const struct bpf_insn_cbs *cbs, 44 const struct bpf_insn *insn, 45 u64 full_imm, char *buff, size_t len) 46 { 47 if (cbs && cbs->cb_imm) 48 return cbs->cb_imm(cbs->private_data, insn, full_imm); 49 50 snprintf(buff, len, "0x%llx", (unsigned long long)full_imm); 51 return buff; 52 } 53 54 const char *func_id_name(int id) 55 { 56 if (id >= 0 && id < __BPF_FUNC_MAX_ID && func_id_str[id]) 57 return func_id_str[id]; 58 else 59 return "unknown"; 60 } 61 62 const char *const bpf_class_string[8] = { 63 [BPF_LD] = "ld", 64 [BPF_LDX] = "ldx", 65 [BPF_ST] = "st", 66 [BPF_STX] = "stx", 67 [BPF_ALU] = "alu", 68 [BPF_JMP] = "jmp", 69 [BPF_JMP32] = "jmp32", 70 [BPF_ALU64] = "alu64", 71 }; 72 73 const char *const bpf_alu_string[16] = { 74 [BPF_ADD >> 4] = "+=", 75 [BPF_SUB >> 4] = "-=", 76 [BPF_MUL >> 4] = "*=", 77 [BPF_DIV >> 4] = "/=", 78 [BPF_OR >> 4] = "|=", 79 [BPF_AND >> 4] = "&=", 80 [BPF_LSH >> 4] = "<<=", 81 [BPF_RSH >> 4] = ">>=", 82 [BPF_NEG >> 4] = "neg", 83 [BPF_MOD >> 4] = "%=", 84 [BPF_XOR >> 4] = "^=", 85 [BPF_MOV >> 4] = "=", 86 [BPF_ARSH >> 4] = "s>>=", 87 [BPF_END >> 4] = "endian", 88 }; 89 90 static const char *const bpf_atomic_alu_string[16] = { 91 [BPF_ADD >> 4] = "add", 92 [BPF_AND >> 4] = "and", 93 [BPF_OR >> 4] = "or", 94 [BPF_XOR >> 4] = "xor", 95 }; 96 97 static const char *const bpf_ldst_string[] = { 98 [BPF_W >> 3] = "u32", 99 [BPF_H >> 3] = "u16", 100 [BPF_B >> 3] = "u8", 101 [BPF_DW >> 3] = "u64", 102 }; 103 104 static const char *const bpf_jmp_string[16] = { 105 [BPF_JA >> 4] = "jmp", 106 [BPF_JEQ >> 4] = "==", 107 [BPF_JGT >> 4] = ">", 108 [BPF_JLT >> 4] = "<", 109 [BPF_JGE >> 4] = ">=", 110 [BPF_JLE >> 4] = "<=", 111 [BPF_JSET >> 4] = "&", 112 [BPF_JNE >> 4] = "!=", 113 [BPF_JSGT >> 4] = "s>", 114 [BPF_JSLT >> 4] = "s<", 115 [BPF_JSGE >> 4] = "s>=", 116 [BPF_JSLE >> 4] = "s<=", 117 [BPF_CALL >> 4] = "call", 118 [BPF_EXIT >> 4] = "exit", 119 }; 120 121 static void print_bpf_end_insn(bpf_insn_print_t verbose, 122 void *private_data, 123 const struct bpf_insn *insn) 124 { 125 verbose(private_data, "(%02x) r%d = %s%d r%d\n", 126 insn->code, insn->dst_reg, 127 BPF_SRC(insn->code) == BPF_TO_BE ? "be" : "le", 128 insn->imm, insn->dst_reg); 129 } 130 131 void print_bpf_insn(const struct bpf_insn_cbs *cbs, 132 const struct bpf_insn *insn, 133 bool allow_ptr_leaks) 134 { 135 const bpf_insn_print_t verbose = cbs->cb_print; 136 u8 class = BPF_CLASS(insn->code); 137 138 if (class == BPF_ALU || class == BPF_ALU64) { 139 if (BPF_OP(insn->code) == BPF_END) { 140 if (class == BPF_ALU64) 141 verbose(cbs->private_data, "BUG_alu64_%02x\n", insn->code); 142 else 143 print_bpf_end_insn(verbose, cbs->private_data, insn); 144 } else if (BPF_OP(insn->code) == BPF_NEG) { 145 verbose(cbs->private_data, "(%02x) %c%d = -%c%d\n", 146 insn->code, class == BPF_ALU ? 'w' : 'r', 147 insn->dst_reg, class == BPF_ALU ? 'w' : 'r', 148 insn->dst_reg); 149 } else if (BPF_SRC(insn->code) == BPF_X) { 150 verbose(cbs->private_data, "(%02x) %c%d %s %c%d\n", 151 insn->code, class == BPF_ALU ? 'w' : 'r', 152 insn->dst_reg, 153 bpf_alu_string[BPF_OP(insn->code) >> 4], 154 class == BPF_ALU ? 'w' : 'r', 155 insn->src_reg); 156 } else { 157 verbose(cbs->private_data, "(%02x) %c%d %s %d\n", 158 insn->code, class == BPF_ALU ? 'w' : 'r', 159 insn->dst_reg, 160 bpf_alu_string[BPF_OP(insn->code) >> 4], 161 insn->imm); 162 } 163 } else if (class == BPF_STX) { 164 if (BPF_MODE(insn->code) == BPF_MEM) 165 verbose(cbs->private_data, "(%02x) *(%s *)(r%d %+d) = r%d\n", 166 insn->code, 167 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 168 insn->dst_reg, 169 insn->off, insn->src_reg); 170 else if (BPF_MODE(insn->code) == BPF_ATOMIC && 171 (insn->imm == BPF_ADD || insn->imm == BPF_AND || 172 insn->imm == BPF_OR || insn->imm == BPF_XOR)) { 173 verbose(cbs->private_data, "(%02x) lock *(%s *)(r%d %+d) %s r%d\n", 174 insn->code, 175 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 176 insn->dst_reg, insn->off, 177 bpf_alu_string[BPF_OP(insn->imm) >> 4], 178 insn->src_reg); 179 } else if (BPF_MODE(insn->code) == BPF_ATOMIC && 180 (insn->imm == (BPF_ADD | BPF_FETCH) || 181 insn->imm == (BPF_AND | BPF_FETCH) || 182 insn->imm == (BPF_OR | BPF_FETCH) || 183 insn->imm == (BPF_XOR | BPF_FETCH))) { 184 verbose(cbs->private_data, "(%02x) r%d = atomic%s_fetch_%s((%s *)(r%d %+d), r%d)\n", 185 insn->code, insn->src_reg, 186 BPF_SIZE(insn->code) == BPF_DW ? "64" : "", 187 bpf_atomic_alu_string[BPF_OP(insn->imm) >> 4], 188 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 189 insn->dst_reg, insn->off, insn->src_reg); 190 } else if (BPF_MODE(insn->code) == BPF_ATOMIC && 191 insn->imm == BPF_CMPXCHG) { 192 verbose(cbs->private_data, "(%02x) r0 = atomic%s_cmpxchg((%s *)(r%d %+d), r0, r%d)\n", 193 insn->code, 194 BPF_SIZE(insn->code) == BPF_DW ? "64" : "", 195 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 196 insn->dst_reg, insn->off, 197 insn->src_reg); 198 } else if (BPF_MODE(insn->code) == BPF_ATOMIC && 199 insn->imm == BPF_XCHG) { 200 verbose(cbs->private_data, "(%02x) r%d = atomic%s_xchg((%s *)(r%d %+d), r%d)\n", 201 insn->code, insn->src_reg, 202 BPF_SIZE(insn->code) == BPF_DW ? "64" : "", 203 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 204 insn->dst_reg, insn->off, insn->src_reg); 205 } else { 206 verbose(cbs->private_data, "BUG_%02x\n", insn->code); 207 } 208 } else if (class == BPF_ST) { 209 if (BPF_MODE(insn->code) != BPF_MEM) { 210 verbose(cbs->private_data, "BUG_st_%02x\n", insn->code); 211 return; 212 } 213 verbose(cbs->private_data, "(%02x) *(%s *)(r%d %+d) = %d\n", 214 insn->code, 215 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 216 insn->dst_reg, 217 insn->off, insn->imm); 218 } else if (class == BPF_LDX) { 219 if (BPF_MODE(insn->code) != BPF_MEM) { 220 verbose(cbs->private_data, "BUG_ldx_%02x\n", insn->code); 221 return; 222 } 223 verbose(cbs->private_data, "(%02x) r%d = *(%s *)(r%d %+d)\n", 224 insn->code, insn->dst_reg, 225 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 226 insn->src_reg, insn->off); 227 } else if (class == BPF_LD) { 228 if (BPF_MODE(insn->code) == BPF_ABS) { 229 verbose(cbs->private_data, "(%02x) r0 = *(%s *)skb[%d]\n", 230 insn->code, 231 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 232 insn->imm); 233 } else if (BPF_MODE(insn->code) == BPF_IND) { 234 verbose(cbs->private_data, "(%02x) r0 = *(%s *)skb[r%d + %d]\n", 235 insn->code, 236 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 237 insn->src_reg, insn->imm); 238 } else if (BPF_MODE(insn->code) == BPF_IMM && 239 BPF_SIZE(insn->code) == BPF_DW) { 240 /* At this point, we already made sure that the second 241 * part of the ldimm64 insn is accessible. 242 */ 243 u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm; 244 bool is_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD || 245 insn->src_reg == BPF_PSEUDO_MAP_VALUE; 246 char tmp[64]; 247 248 if (is_ptr && !allow_ptr_leaks) 249 imm = 0; 250 251 verbose(cbs->private_data, "(%02x) r%d = %s\n", 252 insn->code, insn->dst_reg, 253 __func_imm_name(cbs, insn, imm, 254 tmp, sizeof(tmp))); 255 } else { 256 verbose(cbs->private_data, "BUG_ld_%02x\n", insn->code); 257 return; 258 } 259 } else if (class == BPF_JMP32 || class == BPF_JMP) { 260 u8 opcode = BPF_OP(insn->code); 261 262 if (opcode == BPF_CALL) { 263 char tmp[64]; 264 265 if (insn->src_reg == BPF_PSEUDO_CALL) { 266 verbose(cbs->private_data, "(%02x) call pc%s\n", 267 insn->code, 268 __func_get_name(cbs, insn, 269 tmp, sizeof(tmp))); 270 } else { 271 strcpy(tmp, "unknown"); 272 verbose(cbs->private_data, "(%02x) call %s#%d\n", insn->code, 273 __func_get_name(cbs, insn, 274 tmp, sizeof(tmp)), 275 insn->imm); 276 } 277 } else if (insn->code == (BPF_JMP | BPF_JA)) { 278 verbose(cbs->private_data, "(%02x) goto pc%+d\n", 279 insn->code, insn->off); 280 } else if (insn->code == (BPF_JMP | BPF_EXIT)) { 281 verbose(cbs->private_data, "(%02x) exit\n", insn->code); 282 } else if (BPF_SRC(insn->code) == BPF_X) { 283 verbose(cbs->private_data, 284 "(%02x) if %c%d %s %c%d goto pc%+d\n", 285 insn->code, class == BPF_JMP32 ? 'w' : 'r', 286 insn->dst_reg, 287 bpf_jmp_string[BPF_OP(insn->code) >> 4], 288 class == BPF_JMP32 ? 'w' : 'r', 289 insn->src_reg, insn->off); 290 } else { 291 verbose(cbs->private_data, 292 "(%02x) if %c%d %s 0x%x goto pc%+d\n", 293 insn->code, class == BPF_JMP32 ? 'w' : 'r', 294 insn->dst_reg, 295 bpf_jmp_string[BPF_OP(insn->code) >> 4], 296 insn->imm, insn->off); 297 } 298 } else { 299 verbose(cbs->private_data, "(%02x) %s\n", 300 insn->code, bpf_class_string[class]); 301 } 302 } 303