1// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) 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) 11static const char * const func_id_str[] = { 12 __BPF_FUNC_MAPPER(__BPF_FUNC_STR_FN) 13}; 14#undef __BPF_FUNC_STR_FN 15 16static 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 43static 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 54const 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 62const 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 73const 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 90static const char *const bpf_alu_sign_string[16] = { 91 [BPF_DIV >> 4] = "s/=", 92 [BPF_MOD >> 4] = "s%=", 93}; 94 95static const char *const bpf_movsx_string[4] = { 96 [0] = "(s8)", 97 [1] = "(s16)", 98 [3] = "(s32)", 99}; 100 101static const char *const bpf_atomic_alu_string[16] = { 102 [BPF_ADD >> 4] = "add", 103 [BPF_AND >> 4] = "and", 104 [BPF_OR >> 4] = "or", 105 [BPF_XOR >> 4] = "xor", 106}; 107 108static const char *const bpf_ldst_string[] = { 109 [BPF_W >> 3] = "u32", 110 [BPF_H >> 3] = "u16", 111 [BPF_B >> 3] = "u8", 112 [BPF_DW >> 3] = "u64", 113}; 114 115static const char *const bpf_ldsx_string[] = { 116 [BPF_W >> 3] = "s32", 117 [BPF_H >> 3] = "s16", 118 [BPF_B >> 3] = "s8", 119}; 120 121static const char *const bpf_jmp_string[16] = { 122 [BPF_JA >> 4] = "jmp", 123 [BPF_JEQ >> 4] = "==", 124 [BPF_JGT >> 4] = ">", 125 [BPF_JLT >> 4] = "<", 126 [BPF_JGE >> 4] = ">=", 127 [BPF_JLE >> 4] = "<=", 128 [BPF_JSET >> 4] = "&", 129 [BPF_JNE >> 4] = "!=", 130 [BPF_JSGT >> 4] = "s>", 131 [BPF_JSLT >> 4] = "s<", 132 [BPF_JSGE >> 4] = "s>=", 133 [BPF_JSLE >> 4] = "s<=", 134 [BPF_CALL >> 4] = "call", 135 [BPF_EXIT >> 4] = "exit", 136}; 137 138static void print_bpf_end_insn(bpf_insn_print_t verbose, 139 void *private_data, 140 const struct bpf_insn *insn) 141{ 142 verbose(private_data, "(%02x) r%d = %s%d r%d\n", 143 insn->code, insn->dst_reg, 144 BPF_SRC(insn->code) == BPF_TO_BE ? "be" : "le", 145 insn->imm, insn->dst_reg); 146} 147 148static void print_bpf_bswap_insn(bpf_insn_print_t verbose, 149 void *private_data, 150 const struct bpf_insn *insn) 151{ 152 verbose(private_data, "(%02x) r%d = bswap%d r%d\n", 153 insn->code, insn->dst_reg, 154 insn->imm, insn->dst_reg); 155} 156 157static bool is_sdiv_smod(const struct bpf_insn *insn) 158{ 159 return (BPF_OP(insn->code) == BPF_DIV || BPF_OP(insn->code) == BPF_MOD) && 160 insn->off == 1; 161} 162 163static bool is_movsx(const struct bpf_insn *insn) 164{ 165 return BPF_OP(insn->code) == BPF_MOV && 166 (insn->off == 8 || insn->off == 16 || insn->off == 32); 167} 168 169static bool is_addr_space_cast(const struct bpf_insn *insn) 170{ 171 return insn->code == (BPF_ALU64 | BPF_MOV | BPF_X) && 172 insn->off == BPF_ADDR_SPACE_CAST; 173} 174 175void print_bpf_insn(const struct bpf_insn_cbs *cbs, 176 const struct bpf_insn *insn, 177 bool allow_ptr_leaks) 178{ 179 const bpf_insn_print_t verbose = cbs->cb_print; 180 u8 class = BPF_CLASS(insn->code); 181 182 if (class == BPF_ALU || class == BPF_ALU64) { 183 if (BPF_OP(insn->code) == BPF_END) { 184 if (class == BPF_ALU64) 185 print_bpf_bswap_insn(verbose, cbs->private_data, insn); 186 else 187 print_bpf_end_insn(verbose, cbs->private_data, insn); 188 } else if (BPF_OP(insn->code) == BPF_NEG) { 189 verbose(cbs->private_data, "(%02x) %c%d = -%c%d\n", 190 insn->code, class == BPF_ALU ? 'w' : 'r', 191 insn->dst_reg, class == BPF_ALU ? 'w' : 'r', 192 insn->dst_reg); 193 } else if (is_addr_space_cast(insn)) { 194 verbose(cbs->private_data, "(%02x) r%d = addr_space_cast(r%d, %d, %d)\n", 195 insn->code, insn->dst_reg, 196 insn->src_reg, ((u32)insn->imm) >> 16, (u16)insn->imm); 197 } else if (BPF_SRC(insn->code) == BPF_X) { 198 verbose(cbs->private_data, "(%02x) %c%d %s %s%c%d\n", 199 insn->code, class == BPF_ALU ? 'w' : 'r', 200 insn->dst_reg, 201 is_sdiv_smod(insn) ? bpf_alu_sign_string[BPF_OP(insn->code) >> 4] 202 : bpf_alu_string[BPF_OP(insn->code) >> 4], 203 is_movsx(insn) ? bpf_movsx_string[(insn->off >> 3) - 1] : "", 204 class == BPF_ALU ? 'w' : 'r', 205 insn->src_reg); 206 } else { 207 verbose(cbs->private_data, "(%02x) %c%d %s %d\n", 208 insn->code, class == BPF_ALU ? 'w' : 'r', 209 insn->dst_reg, 210 is_sdiv_smod(insn) ? bpf_alu_sign_string[BPF_OP(insn->code) >> 4] 211 : bpf_alu_string[BPF_OP(insn->code) >> 4], 212 insn->imm); 213 } 214 } else if (class == BPF_STX) { 215 if (BPF_MODE(insn->code) == BPF_MEM) 216 verbose(cbs->private_data, "(%02x) *(%s *)(r%d %+d) = r%d\n", 217 insn->code, 218 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 219 insn->dst_reg, 220 insn->off, insn->src_reg); 221 else if (BPF_MODE(insn->code) == BPF_ATOMIC && 222 (insn->imm == BPF_ADD || insn->imm == BPF_AND || 223 insn->imm == BPF_OR || insn->imm == BPF_XOR)) { 224 verbose(cbs->private_data, "(%02x) lock *(%s *)(r%d %+d) %s r%d\n", 225 insn->code, 226 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 227 insn->dst_reg, insn->off, 228 bpf_alu_string[BPF_OP(insn->imm) >> 4], 229 insn->src_reg); 230 } else if (BPF_MODE(insn->code) == BPF_ATOMIC && 231 (insn->imm == (BPF_ADD | BPF_FETCH) || 232 insn->imm == (BPF_AND | BPF_FETCH) || 233 insn->imm == (BPF_OR | BPF_FETCH) || 234 insn->imm == (BPF_XOR | BPF_FETCH))) { 235 verbose(cbs->private_data, "(%02x) r%d = atomic%s_fetch_%s((%s *)(r%d %+d), r%d)\n", 236 insn->code, insn->src_reg, 237 BPF_SIZE(insn->code) == BPF_DW ? "64" : "", 238 bpf_atomic_alu_string[BPF_OP(insn->imm) >> 4], 239 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 240 insn->dst_reg, insn->off, insn->src_reg); 241 } else if (BPF_MODE(insn->code) == BPF_ATOMIC && 242 insn->imm == BPF_CMPXCHG) { 243 verbose(cbs->private_data, "(%02x) r0 = atomic%s_cmpxchg((%s *)(r%d %+d), r0, r%d)\n", 244 insn->code, 245 BPF_SIZE(insn->code) == BPF_DW ? "64" : "", 246 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 247 insn->dst_reg, insn->off, 248 insn->src_reg); 249 } else if (BPF_MODE(insn->code) == BPF_ATOMIC && 250 insn->imm == BPF_XCHG) { 251 verbose(cbs->private_data, "(%02x) r%d = atomic%s_xchg((%s *)(r%d %+d), r%d)\n", 252 insn->code, insn->src_reg, 253 BPF_SIZE(insn->code) == BPF_DW ? "64" : "", 254 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 255 insn->dst_reg, insn->off, insn->src_reg); 256 } else { 257 verbose(cbs->private_data, "BUG_%02x\n", insn->code); 258 } 259 } else if (class == BPF_ST) { 260 if (BPF_MODE(insn->code) == BPF_MEM) { 261 verbose(cbs->private_data, "(%02x) *(%s *)(r%d %+d) = %d\n", 262 insn->code, 263 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 264 insn->dst_reg, 265 insn->off, insn->imm); 266 } else if (BPF_MODE(insn->code) == 0xc0 /* BPF_NOSPEC, no UAPI */) { 267 verbose(cbs->private_data, "(%02x) nospec\n", insn->code); 268 } else { 269 verbose(cbs->private_data, "BUG_st_%02x\n", insn->code); 270 } 271 } else if (class == BPF_LDX) { 272 if (BPF_MODE(insn->code) != BPF_MEM && BPF_MODE(insn->code) != BPF_MEMSX) { 273 verbose(cbs->private_data, "BUG_ldx_%02x\n", insn->code); 274 return; 275 } 276 verbose(cbs->private_data, "(%02x) r%d = *(%s *)(r%d %+d)\n", 277 insn->code, insn->dst_reg, 278 BPF_MODE(insn->code) == BPF_MEM ? 279 bpf_ldst_string[BPF_SIZE(insn->code) >> 3] : 280 bpf_ldsx_string[BPF_SIZE(insn->code) >> 3], 281 insn->src_reg, insn->off); 282 } else if (class == BPF_LD) { 283 if (BPF_MODE(insn->code) == BPF_ABS) { 284 verbose(cbs->private_data, "(%02x) r0 = *(%s *)skb[%d]\n", 285 insn->code, 286 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 287 insn->imm); 288 } else if (BPF_MODE(insn->code) == BPF_IND) { 289 verbose(cbs->private_data, "(%02x) r0 = *(%s *)skb[r%d + %d]\n", 290 insn->code, 291 bpf_ldst_string[BPF_SIZE(insn->code) >> 3], 292 insn->src_reg, insn->imm); 293 } else if (BPF_MODE(insn->code) == BPF_IMM && 294 BPF_SIZE(insn->code) == BPF_DW) { 295 /* At this point, we already made sure that the second 296 * part of the ldimm64 insn is accessible. 297 */ 298 u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm; 299 bool is_ptr = insn->src_reg == BPF_PSEUDO_MAP_FD || 300 insn->src_reg == BPF_PSEUDO_MAP_VALUE; 301 char tmp[64]; 302 303 if (is_ptr && !allow_ptr_leaks) 304 imm = 0; 305 306 verbose(cbs->private_data, "(%02x) r%d = %s\n", 307 insn->code, insn->dst_reg, 308 __func_imm_name(cbs, insn, imm, 309 tmp, sizeof(tmp))); 310 } else { 311 verbose(cbs->private_data, "BUG_ld_%02x\n", insn->code); 312 return; 313 } 314 } else if (class == BPF_JMP32 || class == BPF_JMP) { 315 u8 opcode = BPF_OP(insn->code); 316 317 if (opcode == BPF_CALL) { 318 char tmp[64]; 319 320 if (insn->src_reg == BPF_PSEUDO_CALL) { 321 verbose(cbs->private_data, "(%02x) call pc%s\n", 322 insn->code, 323 __func_get_name(cbs, insn, 324 tmp, sizeof(tmp))); 325 } else { 326 strcpy(tmp, "unknown"); 327 verbose(cbs->private_data, "(%02x) call %s#%d\n", insn->code, 328 __func_get_name(cbs, insn, 329 tmp, sizeof(tmp)), 330 insn->imm); 331 } 332 } else if (insn->code == (BPF_JMP | BPF_JA)) { 333 verbose(cbs->private_data, "(%02x) goto pc%+d\n", 334 insn->code, insn->off); 335 } else if (insn->code == (BPF_JMP | BPF_JCOND) && 336 insn->src_reg == BPF_MAY_GOTO) { 337 verbose(cbs->private_data, "(%02x) may_goto pc%+d\n", 338 insn->code, insn->off); 339 } else if (insn->code == (BPF_JMP32 | BPF_JA)) { 340 verbose(cbs->private_data, "(%02x) gotol pc%+d\n", 341 insn->code, insn->imm); 342 } else if (insn->code == (BPF_JMP | BPF_EXIT)) { 343 verbose(cbs->private_data, "(%02x) exit\n", insn->code); 344 } else if (BPF_SRC(insn->code) == BPF_X) { 345 verbose(cbs->private_data, 346 "(%02x) if %c%d %s %c%d goto pc%+d\n", 347 insn->code, class == BPF_JMP32 ? 'w' : 'r', 348 insn->dst_reg, 349 bpf_jmp_string[BPF_OP(insn->code) >> 4], 350 class == BPF_JMP32 ? 'w' : 'r', 351 insn->src_reg, insn->off); 352 } else { 353 verbose(cbs->private_data, 354 "(%02x) if %c%d %s 0x%x goto pc%+d\n", 355 insn->code, class == BPF_JMP32 ? 'w' : 'r', 356 insn->dst_reg, 357 bpf_jmp_string[BPF_OP(insn->code) >> 4], 358 insn->imm, insn->off); 359 } 360 } else { 361 verbose(cbs->private_data, "(%02x) %s\n", 362 insn->code, bpf_class_string[class]); 363 } 364} 365