1 /* bpf_jit_comp.c : BPF JIT compiler 2 * 3 * Copyright (C) 2011-2013 Eric Dumazet (eric.dumazet@gmail.com) 4 * Internal BPF Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; version 2 9 * of the License. 10 */ 11 #include <linux/netdevice.h> 12 #include <linux/filter.h> 13 #include <linux/if_vlan.h> 14 #include <asm/cacheflush.h> 15 #include <asm/set_memory.h> 16 #include <linux/bpf.h> 17 18 int bpf_jit_enable __read_mostly; 19 20 /* 21 * assembly code in arch/x86/net/bpf_jit.S 22 */ 23 extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; 24 extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; 25 extern u8 sk_load_byte_positive_offset[]; 26 extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; 27 extern u8 sk_load_byte_negative_offset[]; 28 29 static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) 30 { 31 if (len == 1) 32 *ptr = bytes; 33 else if (len == 2) 34 *(u16 *)ptr = bytes; 35 else { 36 *(u32 *)ptr = bytes; 37 barrier(); 38 } 39 return ptr + len; 40 } 41 42 #define EMIT(bytes, len) \ 43 do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) 44 45 #define EMIT1(b1) EMIT(b1, 1) 46 #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) 47 #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) 48 #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) 49 #define EMIT1_off32(b1, off) \ 50 do {EMIT1(b1); EMIT(off, 4); } while (0) 51 #define EMIT2_off32(b1, b2, off) \ 52 do {EMIT2(b1, b2); EMIT(off, 4); } while (0) 53 #define EMIT3_off32(b1, b2, b3, off) \ 54 do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) 55 #define EMIT4_off32(b1, b2, b3, b4, off) \ 56 do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) 57 58 static bool is_imm8(int value) 59 { 60 return value <= 127 && value >= -128; 61 } 62 63 static bool is_simm32(s64 value) 64 { 65 return value == (s64) (s32) value; 66 } 67 68 /* mov dst, src */ 69 #define EMIT_mov(DST, SRC) \ 70 do {if (DST != SRC) \ 71 EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ 72 } while (0) 73 74 static int bpf_size_to_x86_bytes(int bpf_size) 75 { 76 if (bpf_size == BPF_W) 77 return 4; 78 else if (bpf_size == BPF_H) 79 return 2; 80 else if (bpf_size == BPF_B) 81 return 1; 82 else if (bpf_size == BPF_DW) 83 return 4; /* imm32 */ 84 else 85 return 0; 86 } 87 88 /* list of x86 cond jumps opcodes (. + s8) 89 * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) 90 */ 91 #define X86_JB 0x72 92 #define X86_JAE 0x73 93 #define X86_JE 0x74 94 #define X86_JNE 0x75 95 #define X86_JBE 0x76 96 #define X86_JA 0x77 97 #define X86_JGE 0x7D 98 #define X86_JG 0x7F 99 100 static void bpf_flush_icache(void *start, void *end) 101 { 102 mm_segment_t old_fs = get_fs(); 103 104 set_fs(KERNEL_DS); 105 smp_wmb(); 106 flush_icache_range((unsigned long)start, (unsigned long)end); 107 set_fs(old_fs); 108 } 109 110 #define CHOOSE_LOAD_FUNC(K, func) \ 111 ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) 112 113 /* pick a register outside of BPF range for JIT internal work */ 114 #define AUX_REG (MAX_BPF_JIT_REG + 1) 115 116 /* The following table maps BPF registers to x64 registers. 117 * 118 * x64 register r12 is unused, since if used as base address 119 * register in load/store instructions, it always needs an 120 * extra byte of encoding and is callee saved. 121 * 122 * r9 caches skb->len - skb->data_len 123 * r10 caches skb->data, and used for blinding (if enabled) 124 */ 125 static const int reg2hex[] = { 126 [BPF_REG_0] = 0, /* rax */ 127 [BPF_REG_1] = 7, /* rdi */ 128 [BPF_REG_2] = 6, /* rsi */ 129 [BPF_REG_3] = 2, /* rdx */ 130 [BPF_REG_4] = 1, /* rcx */ 131 [BPF_REG_5] = 0, /* r8 */ 132 [BPF_REG_6] = 3, /* rbx callee saved */ 133 [BPF_REG_7] = 5, /* r13 callee saved */ 134 [BPF_REG_8] = 6, /* r14 callee saved */ 135 [BPF_REG_9] = 7, /* r15 callee saved */ 136 [BPF_REG_FP] = 5, /* rbp readonly */ 137 [BPF_REG_AX] = 2, /* r10 temp register */ 138 [AUX_REG] = 3, /* r11 temp register */ 139 }; 140 141 /* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 142 * which need extra byte of encoding. 143 * rax,rcx,...,rbp have simpler encoding 144 */ 145 static bool is_ereg(u32 reg) 146 { 147 return (1 << reg) & (BIT(BPF_REG_5) | 148 BIT(AUX_REG) | 149 BIT(BPF_REG_7) | 150 BIT(BPF_REG_8) | 151 BIT(BPF_REG_9) | 152 BIT(BPF_REG_AX)); 153 } 154 155 /* add modifiers if 'reg' maps to x64 registers r8..r15 */ 156 static u8 add_1mod(u8 byte, u32 reg) 157 { 158 if (is_ereg(reg)) 159 byte |= 1; 160 return byte; 161 } 162 163 static u8 add_2mod(u8 byte, u32 r1, u32 r2) 164 { 165 if (is_ereg(r1)) 166 byte |= 1; 167 if (is_ereg(r2)) 168 byte |= 4; 169 return byte; 170 } 171 172 /* encode 'dst_reg' register into x64 opcode 'byte' */ 173 static u8 add_1reg(u8 byte, u32 dst_reg) 174 { 175 return byte + reg2hex[dst_reg]; 176 } 177 178 /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ 179 static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) 180 { 181 return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); 182 } 183 184 static void jit_fill_hole(void *area, unsigned int size) 185 { 186 /* fill whole space with int3 instructions */ 187 memset(area, 0xcc, size); 188 } 189 190 struct jit_context { 191 int cleanup_addr; /* epilogue code offset */ 192 bool seen_ld_abs; 193 bool seen_ax_reg; 194 }; 195 196 /* maximum number of bytes emitted while JITing one eBPF insn */ 197 #define BPF_MAX_INSN_SIZE 128 198 #define BPF_INSN_SAFETY 64 199 200 #define AUX_STACK_SPACE \ 201 (32 /* space for rbx, r13, r14, r15 */ + \ 202 8 /* space for skb_copy_bits() buffer */) 203 204 #define PROLOGUE_SIZE 37 205 206 /* emit x64 prologue code for BPF program and check it's size. 207 * bpf_tail_call helper will skip it while jumping into another program 208 */ 209 static void emit_prologue(u8 **pprog, u32 stack_depth) 210 { 211 u8 *prog = *pprog; 212 int cnt = 0; 213 214 EMIT1(0x55); /* push rbp */ 215 EMIT3(0x48, 0x89, 0xE5); /* mov rbp,rsp */ 216 217 /* sub rsp, rounded_stack_depth + AUX_STACK_SPACE */ 218 EMIT3_off32(0x48, 0x81, 0xEC, 219 round_up(stack_depth, 8) + AUX_STACK_SPACE); 220 221 /* sub rbp, AUX_STACK_SPACE */ 222 EMIT4(0x48, 0x83, 0xED, AUX_STACK_SPACE); 223 224 /* all classic BPF filters use R6(rbx) save it */ 225 226 /* mov qword ptr [rbp+0],rbx */ 227 EMIT4(0x48, 0x89, 0x5D, 0); 228 229 /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 230 * as temporary, so all tcpdump filters need to spill/fill R7(r13) and 231 * R8(r14). R9(r15) spill could be made conditional, but there is only 232 * one 'bpf_error' return path out of helper functions inside bpf_jit.S 233 * The overhead of extra spill is negligible for any filter other 234 * than synthetic ones. Therefore not worth adding complexity. 235 */ 236 237 /* mov qword ptr [rbp+8],r13 */ 238 EMIT4(0x4C, 0x89, 0x6D, 8); 239 /* mov qword ptr [rbp+16],r14 */ 240 EMIT4(0x4C, 0x89, 0x75, 16); 241 /* mov qword ptr [rbp+24],r15 */ 242 EMIT4(0x4C, 0x89, 0x7D, 24); 243 244 /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls 245 * we need to reset the counter to 0. It's done in two instructions, 246 * resetting rax register to 0 (xor on eax gets 0 extended), and 247 * moving it to the counter location. 248 */ 249 250 /* xor eax, eax */ 251 EMIT2(0x31, 0xc0); 252 /* mov qword ptr [rbp+32], rax */ 253 EMIT4(0x48, 0x89, 0x45, 32); 254 255 BUILD_BUG_ON(cnt != PROLOGUE_SIZE); 256 *pprog = prog; 257 } 258 259 /* generate the following code: 260 * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... 261 * if (index >= array->map.max_entries) 262 * goto out; 263 * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) 264 * goto out; 265 * prog = array->ptrs[index]; 266 * if (prog == NULL) 267 * goto out; 268 * goto *(prog->bpf_func + prologue_size); 269 * out: 270 */ 271 static void emit_bpf_tail_call(u8 **pprog) 272 { 273 u8 *prog = *pprog; 274 int label1, label2, label3; 275 int cnt = 0; 276 277 /* rdi - pointer to ctx 278 * rsi - pointer to bpf_array 279 * rdx - index in bpf_array 280 */ 281 282 /* if (index >= array->map.max_entries) 283 * goto out; 284 */ 285 EMIT4(0x48, 0x8B, 0x46, /* mov rax, qword ptr [rsi + 16] */ 286 offsetof(struct bpf_array, map.max_entries)); 287 EMIT3(0x48, 0x39, 0xD0); /* cmp rax, rdx */ 288 #define OFFSET1 47 /* number of bytes to jump */ 289 EMIT2(X86_JBE, OFFSET1); /* jbe out */ 290 label1 = cnt; 291 292 /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) 293 * goto out; 294 */ 295 EMIT2_off32(0x8B, 0x85, 36); /* mov eax, dword ptr [rbp + 36] */ 296 EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ 297 #define OFFSET2 36 298 EMIT2(X86_JA, OFFSET2); /* ja out */ 299 label2 = cnt; 300 EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ 301 EMIT2_off32(0x89, 0x85, 36); /* mov dword ptr [rbp + 36], eax */ 302 303 /* prog = array->ptrs[index]; */ 304 EMIT4_off32(0x48, 0x8D, 0x84, 0xD6, /* lea rax, [rsi + rdx * 8 + offsetof(...)] */ 305 offsetof(struct bpf_array, ptrs)); 306 EMIT3(0x48, 0x8B, 0x00); /* mov rax, qword ptr [rax] */ 307 308 /* if (prog == NULL) 309 * goto out; 310 */ 311 EMIT4(0x48, 0x83, 0xF8, 0x00); /* cmp rax, 0 */ 312 #define OFFSET3 10 313 EMIT2(X86_JE, OFFSET3); /* je out */ 314 label3 = cnt; 315 316 /* goto *(prog->bpf_func + prologue_size); */ 317 EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ 318 offsetof(struct bpf_prog, bpf_func)); 319 EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ 320 321 /* now we're ready to jump into next BPF program 322 * rdi == ctx (1st arg) 323 * rax == prog->bpf_func + prologue_size 324 */ 325 EMIT2(0xFF, 0xE0); /* jmp rax */ 326 327 /* out: */ 328 BUILD_BUG_ON(cnt - label1 != OFFSET1); 329 BUILD_BUG_ON(cnt - label2 != OFFSET2); 330 BUILD_BUG_ON(cnt - label3 != OFFSET3); 331 *pprog = prog; 332 } 333 334 335 static void emit_load_skb_data_hlen(u8 **pprog) 336 { 337 u8 *prog = *pprog; 338 int cnt = 0; 339 340 /* r9d = skb->len - skb->data_len (headlen) 341 * r10 = skb->data 342 */ 343 /* mov %r9d, off32(%rdi) */ 344 EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); 345 346 /* sub %r9d, off32(%rdi) */ 347 EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); 348 349 /* mov %r10, off32(%rdi) */ 350 EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); 351 *pprog = prog; 352 } 353 354 static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, 355 int oldproglen, struct jit_context *ctx) 356 { 357 struct bpf_insn *insn = bpf_prog->insnsi; 358 int insn_cnt = bpf_prog->len; 359 bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); 360 bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); 361 bool seen_exit = false; 362 u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; 363 int i, cnt = 0; 364 int proglen = 0; 365 u8 *prog = temp; 366 367 emit_prologue(&prog, bpf_prog->aux->stack_depth); 368 369 if (seen_ld_abs) 370 emit_load_skb_data_hlen(&prog); 371 372 for (i = 0; i < insn_cnt; i++, insn++) { 373 const s32 imm32 = insn->imm; 374 u32 dst_reg = insn->dst_reg; 375 u32 src_reg = insn->src_reg; 376 u8 b1 = 0, b2 = 0, b3 = 0; 377 s64 jmp_offset; 378 u8 jmp_cond; 379 bool reload_skb_data; 380 int ilen; 381 u8 *func; 382 383 if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) 384 ctx->seen_ax_reg = seen_ax_reg = true; 385 386 switch (insn->code) { 387 /* ALU */ 388 case BPF_ALU | BPF_ADD | BPF_X: 389 case BPF_ALU | BPF_SUB | BPF_X: 390 case BPF_ALU | BPF_AND | BPF_X: 391 case BPF_ALU | BPF_OR | BPF_X: 392 case BPF_ALU | BPF_XOR | BPF_X: 393 case BPF_ALU64 | BPF_ADD | BPF_X: 394 case BPF_ALU64 | BPF_SUB | BPF_X: 395 case BPF_ALU64 | BPF_AND | BPF_X: 396 case BPF_ALU64 | BPF_OR | BPF_X: 397 case BPF_ALU64 | BPF_XOR | BPF_X: 398 switch (BPF_OP(insn->code)) { 399 case BPF_ADD: b2 = 0x01; break; 400 case BPF_SUB: b2 = 0x29; break; 401 case BPF_AND: b2 = 0x21; break; 402 case BPF_OR: b2 = 0x09; break; 403 case BPF_XOR: b2 = 0x31; break; 404 } 405 if (BPF_CLASS(insn->code) == BPF_ALU64) 406 EMIT1(add_2mod(0x48, dst_reg, src_reg)); 407 else if (is_ereg(dst_reg) || is_ereg(src_reg)) 408 EMIT1(add_2mod(0x40, dst_reg, src_reg)); 409 EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); 410 break; 411 412 /* mov dst, src */ 413 case BPF_ALU64 | BPF_MOV | BPF_X: 414 EMIT_mov(dst_reg, src_reg); 415 break; 416 417 /* mov32 dst, src */ 418 case BPF_ALU | BPF_MOV | BPF_X: 419 if (is_ereg(dst_reg) || is_ereg(src_reg)) 420 EMIT1(add_2mod(0x40, dst_reg, src_reg)); 421 EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); 422 break; 423 424 /* neg dst */ 425 case BPF_ALU | BPF_NEG: 426 case BPF_ALU64 | BPF_NEG: 427 if (BPF_CLASS(insn->code) == BPF_ALU64) 428 EMIT1(add_1mod(0x48, dst_reg)); 429 else if (is_ereg(dst_reg)) 430 EMIT1(add_1mod(0x40, dst_reg)); 431 EMIT2(0xF7, add_1reg(0xD8, dst_reg)); 432 break; 433 434 case BPF_ALU | BPF_ADD | BPF_K: 435 case BPF_ALU | BPF_SUB | BPF_K: 436 case BPF_ALU | BPF_AND | BPF_K: 437 case BPF_ALU | BPF_OR | BPF_K: 438 case BPF_ALU | BPF_XOR | BPF_K: 439 case BPF_ALU64 | BPF_ADD | BPF_K: 440 case BPF_ALU64 | BPF_SUB | BPF_K: 441 case BPF_ALU64 | BPF_AND | BPF_K: 442 case BPF_ALU64 | BPF_OR | BPF_K: 443 case BPF_ALU64 | BPF_XOR | BPF_K: 444 if (BPF_CLASS(insn->code) == BPF_ALU64) 445 EMIT1(add_1mod(0x48, dst_reg)); 446 else if (is_ereg(dst_reg)) 447 EMIT1(add_1mod(0x40, dst_reg)); 448 449 switch (BPF_OP(insn->code)) { 450 case BPF_ADD: b3 = 0xC0; break; 451 case BPF_SUB: b3 = 0xE8; break; 452 case BPF_AND: b3 = 0xE0; break; 453 case BPF_OR: b3 = 0xC8; break; 454 case BPF_XOR: b3 = 0xF0; break; 455 } 456 457 if (is_imm8(imm32)) 458 EMIT3(0x83, add_1reg(b3, dst_reg), imm32); 459 else 460 EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); 461 break; 462 463 case BPF_ALU64 | BPF_MOV | BPF_K: 464 /* optimization: if imm32 is positive, 465 * use 'mov eax, imm32' (which zero-extends imm32) 466 * to save 2 bytes 467 */ 468 if (imm32 < 0) { 469 /* 'mov rax, imm32' sign extends imm32 */ 470 b1 = add_1mod(0x48, dst_reg); 471 b2 = 0xC7; 472 b3 = 0xC0; 473 EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); 474 break; 475 } 476 477 case BPF_ALU | BPF_MOV | BPF_K: 478 /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' 479 * to save 3 bytes. 480 */ 481 if (imm32 == 0) { 482 if (is_ereg(dst_reg)) 483 EMIT1(add_2mod(0x40, dst_reg, dst_reg)); 484 b2 = 0x31; /* xor */ 485 b3 = 0xC0; 486 EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); 487 break; 488 } 489 490 /* mov %eax, imm32 */ 491 if (is_ereg(dst_reg)) 492 EMIT1(add_1mod(0x40, dst_reg)); 493 EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); 494 break; 495 496 case BPF_LD | BPF_IMM | BPF_DW: 497 /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' 498 * to save 7 bytes. 499 */ 500 if (insn[0].imm == 0 && insn[1].imm == 0) { 501 b1 = add_2mod(0x48, dst_reg, dst_reg); 502 b2 = 0x31; /* xor */ 503 b3 = 0xC0; 504 EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); 505 506 insn++; 507 i++; 508 break; 509 } 510 511 /* movabsq %rax, imm64 */ 512 EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); 513 EMIT(insn[0].imm, 4); 514 EMIT(insn[1].imm, 4); 515 516 insn++; 517 i++; 518 break; 519 520 /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ 521 case BPF_ALU | BPF_MOD | BPF_X: 522 case BPF_ALU | BPF_DIV | BPF_X: 523 case BPF_ALU | BPF_MOD | BPF_K: 524 case BPF_ALU | BPF_DIV | BPF_K: 525 case BPF_ALU64 | BPF_MOD | BPF_X: 526 case BPF_ALU64 | BPF_DIV | BPF_X: 527 case BPF_ALU64 | BPF_MOD | BPF_K: 528 case BPF_ALU64 | BPF_DIV | BPF_K: 529 EMIT1(0x50); /* push rax */ 530 EMIT1(0x52); /* push rdx */ 531 532 if (BPF_SRC(insn->code) == BPF_X) 533 /* mov r11, src_reg */ 534 EMIT_mov(AUX_REG, src_reg); 535 else 536 /* mov r11, imm32 */ 537 EMIT3_off32(0x49, 0xC7, 0xC3, imm32); 538 539 /* mov rax, dst_reg */ 540 EMIT_mov(BPF_REG_0, dst_reg); 541 542 /* xor edx, edx 543 * equivalent to 'xor rdx, rdx', but one byte less 544 */ 545 EMIT2(0x31, 0xd2); 546 547 if (BPF_SRC(insn->code) == BPF_X) { 548 /* if (src_reg == 0) return 0 */ 549 550 /* cmp r11, 0 */ 551 EMIT4(0x49, 0x83, 0xFB, 0x00); 552 553 /* jne .+9 (skip over pop, pop, xor and jmp) */ 554 EMIT2(X86_JNE, 1 + 1 + 2 + 5); 555 EMIT1(0x5A); /* pop rdx */ 556 EMIT1(0x58); /* pop rax */ 557 EMIT2(0x31, 0xc0); /* xor eax, eax */ 558 559 /* jmp cleanup_addr 560 * addrs[i] - 11, because there are 11 bytes 561 * after this insn: div, mov, pop, pop, mov 562 */ 563 jmp_offset = ctx->cleanup_addr - (addrs[i] - 11); 564 EMIT1_off32(0xE9, jmp_offset); 565 } 566 567 if (BPF_CLASS(insn->code) == BPF_ALU64) 568 /* div r11 */ 569 EMIT3(0x49, 0xF7, 0xF3); 570 else 571 /* div r11d */ 572 EMIT3(0x41, 0xF7, 0xF3); 573 574 if (BPF_OP(insn->code) == BPF_MOD) 575 /* mov r11, rdx */ 576 EMIT3(0x49, 0x89, 0xD3); 577 else 578 /* mov r11, rax */ 579 EMIT3(0x49, 0x89, 0xC3); 580 581 EMIT1(0x5A); /* pop rdx */ 582 EMIT1(0x58); /* pop rax */ 583 584 /* mov dst_reg, r11 */ 585 EMIT_mov(dst_reg, AUX_REG); 586 break; 587 588 case BPF_ALU | BPF_MUL | BPF_K: 589 case BPF_ALU | BPF_MUL | BPF_X: 590 case BPF_ALU64 | BPF_MUL | BPF_K: 591 case BPF_ALU64 | BPF_MUL | BPF_X: 592 EMIT1(0x50); /* push rax */ 593 EMIT1(0x52); /* push rdx */ 594 595 /* mov r11, dst_reg */ 596 EMIT_mov(AUX_REG, dst_reg); 597 598 if (BPF_SRC(insn->code) == BPF_X) 599 /* mov rax, src_reg */ 600 EMIT_mov(BPF_REG_0, src_reg); 601 else 602 /* mov rax, imm32 */ 603 EMIT3_off32(0x48, 0xC7, 0xC0, imm32); 604 605 if (BPF_CLASS(insn->code) == BPF_ALU64) 606 EMIT1(add_1mod(0x48, AUX_REG)); 607 else if (is_ereg(AUX_REG)) 608 EMIT1(add_1mod(0x40, AUX_REG)); 609 /* mul(q) r11 */ 610 EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); 611 612 /* mov r11, rax */ 613 EMIT_mov(AUX_REG, BPF_REG_0); 614 615 EMIT1(0x5A); /* pop rdx */ 616 EMIT1(0x58); /* pop rax */ 617 618 /* mov dst_reg, r11 */ 619 EMIT_mov(dst_reg, AUX_REG); 620 break; 621 622 /* shifts */ 623 case BPF_ALU | BPF_LSH | BPF_K: 624 case BPF_ALU | BPF_RSH | BPF_K: 625 case BPF_ALU | BPF_ARSH | BPF_K: 626 case BPF_ALU64 | BPF_LSH | BPF_K: 627 case BPF_ALU64 | BPF_RSH | BPF_K: 628 case BPF_ALU64 | BPF_ARSH | BPF_K: 629 if (BPF_CLASS(insn->code) == BPF_ALU64) 630 EMIT1(add_1mod(0x48, dst_reg)); 631 else if (is_ereg(dst_reg)) 632 EMIT1(add_1mod(0x40, dst_reg)); 633 634 switch (BPF_OP(insn->code)) { 635 case BPF_LSH: b3 = 0xE0; break; 636 case BPF_RSH: b3 = 0xE8; break; 637 case BPF_ARSH: b3 = 0xF8; break; 638 } 639 EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); 640 break; 641 642 case BPF_ALU | BPF_LSH | BPF_X: 643 case BPF_ALU | BPF_RSH | BPF_X: 644 case BPF_ALU | BPF_ARSH | BPF_X: 645 case BPF_ALU64 | BPF_LSH | BPF_X: 646 case BPF_ALU64 | BPF_RSH | BPF_X: 647 case BPF_ALU64 | BPF_ARSH | BPF_X: 648 649 /* check for bad case when dst_reg == rcx */ 650 if (dst_reg == BPF_REG_4) { 651 /* mov r11, dst_reg */ 652 EMIT_mov(AUX_REG, dst_reg); 653 dst_reg = AUX_REG; 654 } 655 656 if (src_reg != BPF_REG_4) { /* common case */ 657 EMIT1(0x51); /* push rcx */ 658 659 /* mov rcx, src_reg */ 660 EMIT_mov(BPF_REG_4, src_reg); 661 } 662 663 /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ 664 if (BPF_CLASS(insn->code) == BPF_ALU64) 665 EMIT1(add_1mod(0x48, dst_reg)); 666 else if (is_ereg(dst_reg)) 667 EMIT1(add_1mod(0x40, dst_reg)); 668 669 switch (BPF_OP(insn->code)) { 670 case BPF_LSH: b3 = 0xE0; break; 671 case BPF_RSH: b3 = 0xE8; break; 672 case BPF_ARSH: b3 = 0xF8; break; 673 } 674 EMIT2(0xD3, add_1reg(b3, dst_reg)); 675 676 if (src_reg != BPF_REG_4) 677 EMIT1(0x59); /* pop rcx */ 678 679 if (insn->dst_reg == BPF_REG_4) 680 /* mov dst_reg, r11 */ 681 EMIT_mov(insn->dst_reg, AUX_REG); 682 break; 683 684 case BPF_ALU | BPF_END | BPF_FROM_BE: 685 switch (imm32) { 686 case 16: 687 /* emit 'ror %ax, 8' to swap lower 2 bytes */ 688 EMIT1(0x66); 689 if (is_ereg(dst_reg)) 690 EMIT1(0x41); 691 EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); 692 693 /* emit 'movzwl eax, ax' */ 694 if (is_ereg(dst_reg)) 695 EMIT3(0x45, 0x0F, 0xB7); 696 else 697 EMIT2(0x0F, 0xB7); 698 EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 699 break; 700 case 32: 701 /* emit 'bswap eax' to swap lower 4 bytes */ 702 if (is_ereg(dst_reg)) 703 EMIT2(0x41, 0x0F); 704 else 705 EMIT1(0x0F); 706 EMIT1(add_1reg(0xC8, dst_reg)); 707 break; 708 case 64: 709 /* emit 'bswap rax' to swap 8 bytes */ 710 EMIT3(add_1mod(0x48, dst_reg), 0x0F, 711 add_1reg(0xC8, dst_reg)); 712 break; 713 } 714 break; 715 716 case BPF_ALU | BPF_END | BPF_FROM_LE: 717 switch (imm32) { 718 case 16: 719 /* emit 'movzwl eax, ax' to zero extend 16-bit 720 * into 64 bit 721 */ 722 if (is_ereg(dst_reg)) 723 EMIT3(0x45, 0x0F, 0xB7); 724 else 725 EMIT2(0x0F, 0xB7); 726 EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 727 break; 728 case 32: 729 /* emit 'mov eax, eax' to clear upper 32-bits */ 730 if (is_ereg(dst_reg)) 731 EMIT1(0x45); 732 EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); 733 break; 734 case 64: 735 /* nop */ 736 break; 737 } 738 break; 739 740 /* ST: *(u8*)(dst_reg + off) = imm */ 741 case BPF_ST | BPF_MEM | BPF_B: 742 if (is_ereg(dst_reg)) 743 EMIT2(0x41, 0xC6); 744 else 745 EMIT1(0xC6); 746 goto st; 747 case BPF_ST | BPF_MEM | BPF_H: 748 if (is_ereg(dst_reg)) 749 EMIT3(0x66, 0x41, 0xC7); 750 else 751 EMIT2(0x66, 0xC7); 752 goto st; 753 case BPF_ST | BPF_MEM | BPF_W: 754 if (is_ereg(dst_reg)) 755 EMIT2(0x41, 0xC7); 756 else 757 EMIT1(0xC7); 758 goto st; 759 case BPF_ST | BPF_MEM | BPF_DW: 760 EMIT2(add_1mod(0x48, dst_reg), 0xC7); 761 762 st: if (is_imm8(insn->off)) 763 EMIT2(add_1reg(0x40, dst_reg), insn->off); 764 else 765 EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); 766 767 EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); 768 break; 769 770 /* STX: *(u8*)(dst_reg + off) = src_reg */ 771 case BPF_STX | BPF_MEM | BPF_B: 772 /* emit 'mov byte ptr [rax + off], al' */ 773 if (is_ereg(dst_reg) || is_ereg(src_reg) || 774 /* have to add extra byte for x86 SIL, DIL regs */ 775 src_reg == BPF_REG_1 || src_reg == BPF_REG_2) 776 EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); 777 else 778 EMIT1(0x88); 779 goto stx; 780 case BPF_STX | BPF_MEM | BPF_H: 781 if (is_ereg(dst_reg) || is_ereg(src_reg)) 782 EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); 783 else 784 EMIT2(0x66, 0x89); 785 goto stx; 786 case BPF_STX | BPF_MEM | BPF_W: 787 if (is_ereg(dst_reg) || is_ereg(src_reg)) 788 EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); 789 else 790 EMIT1(0x89); 791 goto stx; 792 case BPF_STX | BPF_MEM | BPF_DW: 793 EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); 794 stx: if (is_imm8(insn->off)) 795 EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); 796 else 797 EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), 798 insn->off); 799 break; 800 801 /* LDX: dst_reg = *(u8*)(src_reg + off) */ 802 case BPF_LDX | BPF_MEM | BPF_B: 803 /* emit 'movzx rax, byte ptr [rax + off]' */ 804 EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); 805 goto ldx; 806 case BPF_LDX | BPF_MEM | BPF_H: 807 /* emit 'movzx rax, word ptr [rax + off]' */ 808 EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); 809 goto ldx; 810 case BPF_LDX | BPF_MEM | BPF_W: 811 /* emit 'mov eax, dword ptr [rax+0x14]' */ 812 if (is_ereg(dst_reg) || is_ereg(src_reg)) 813 EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); 814 else 815 EMIT1(0x8B); 816 goto ldx; 817 case BPF_LDX | BPF_MEM | BPF_DW: 818 /* emit 'mov rax, qword ptr [rax+0x14]' */ 819 EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); 820 ldx: /* if insn->off == 0 we can save one extra byte, but 821 * special case of x86 r13 which always needs an offset 822 * is not worth the hassle 823 */ 824 if (is_imm8(insn->off)) 825 EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); 826 else 827 EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), 828 insn->off); 829 break; 830 831 /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ 832 case BPF_STX | BPF_XADD | BPF_W: 833 /* emit 'lock add dword ptr [rax + off], eax' */ 834 if (is_ereg(dst_reg) || is_ereg(src_reg)) 835 EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); 836 else 837 EMIT2(0xF0, 0x01); 838 goto xadd; 839 case BPF_STX | BPF_XADD | BPF_DW: 840 EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); 841 xadd: if (is_imm8(insn->off)) 842 EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); 843 else 844 EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), 845 insn->off); 846 break; 847 848 /* call */ 849 case BPF_JMP | BPF_CALL: 850 func = (u8 *) __bpf_call_base + imm32; 851 jmp_offset = func - (image + addrs[i]); 852 if (seen_ld_abs) { 853 reload_skb_data = bpf_helper_changes_pkt_data(func); 854 if (reload_skb_data) { 855 EMIT1(0x57); /* push %rdi */ 856 jmp_offset += 22; /* pop, mov, sub, mov */ 857 } else { 858 EMIT2(0x41, 0x52); /* push %r10 */ 859 EMIT2(0x41, 0x51); /* push %r9 */ 860 /* need to adjust jmp offset, since 861 * pop %r9, pop %r10 take 4 bytes after call insn 862 */ 863 jmp_offset += 4; 864 } 865 } 866 if (!imm32 || !is_simm32(jmp_offset)) { 867 pr_err("unsupported bpf func %d addr %p image %p\n", 868 imm32, func, image); 869 return -EINVAL; 870 } 871 EMIT1_off32(0xE8, jmp_offset); 872 if (seen_ld_abs) { 873 if (reload_skb_data) { 874 EMIT1(0x5F); /* pop %rdi */ 875 emit_load_skb_data_hlen(&prog); 876 } else { 877 EMIT2(0x41, 0x59); /* pop %r9 */ 878 EMIT2(0x41, 0x5A); /* pop %r10 */ 879 } 880 } 881 break; 882 883 case BPF_JMP | BPF_TAIL_CALL: 884 emit_bpf_tail_call(&prog); 885 break; 886 887 /* cond jump */ 888 case BPF_JMP | BPF_JEQ | BPF_X: 889 case BPF_JMP | BPF_JNE | BPF_X: 890 case BPF_JMP | BPF_JGT | BPF_X: 891 case BPF_JMP | BPF_JGE | BPF_X: 892 case BPF_JMP | BPF_JSGT | BPF_X: 893 case BPF_JMP | BPF_JSGE | BPF_X: 894 /* cmp dst_reg, src_reg */ 895 EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, 896 add_2reg(0xC0, dst_reg, src_reg)); 897 goto emit_cond_jmp; 898 899 case BPF_JMP | BPF_JSET | BPF_X: 900 /* test dst_reg, src_reg */ 901 EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, 902 add_2reg(0xC0, dst_reg, src_reg)); 903 goto emit_cond_jmp; 904 905 case BPF_JMP | BPF_JSET | BPF_K: 906 /* test dst_reg, imm32 */ 907 EMIT1(add_1mod(0x48, dst_reg)); 908 EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); 909 goto emit_cond_jmp; 910 911 case BPF_JMP | BPF_JEQ | BPF_K: 912 case BPF_JMP | BPF_JNE | BPF_K: 913 case BPF_JMP | BPF_JGT | BPF_K: 914 case BPF_JMP | BPF_JGE | BPF_K: 915 case BPF_JMP | BPF_JSGT | BPF_K: 916 case BPF_JMP | BPF_JSGE | BPF_K: 917 /* cmp dst_reg, imm8/32 */ 918 EMIT1(add_1mod(0x48, dst_reg)); 919 920 if (is_imm8(imm32)) 921 EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); 922 else 923 EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); 924 925 emit_cond_jmp: /* convert BPF opcode to x86 */ 926 switch (BPF_OP(insn->code)) { 927 case BPF_JEQ: 928 jmp_cond = X86_JE; 929 break; 930 case BPF_JSET: 931 case BPF_JNE: 932 jmp_cond = X86_JNE; 933 break; 934 case BPF_JGT: 935 /* GT is unsigned '>', JA in x86 */ 936 jmp_cond = X86_JA; 937 break; 938 case BPF_JGE: 939 /* GE is unsigned '>=', JAE in x86 */ 940 jmp_cond = X86_JAE; 941 break; 942 case BPF_JSGT: 943 /* signed '>', GT in x86 */ 944 jmp_cond = X86_JG; 945 break; 946 case BPF_JSGE: 947 /* signed '>=', GE in x86 */ 948 jmp_cond = X86_JGE; 949 break; 950 default: /* to silence gcc warning */ 951 return -EFAULT; 952 } 953 jmp_offset = addrs[i + insn->off] - addrs[i]; 954 if (is_imm8(jmp_offset)) { 955 EMIT2(jmp_cond, jmp_offset); 956 } else if (is_simm32(jmp_offset)) { 957 EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); 958 } else { 959 pr_err("cond_jmp gen bug %llx\n", jmp_offset); 960 return -EFAULT; 961 } 962 963 break; 964 965 case BPF_JMP | BPF_JA: 966 jmp_offset = addrs[i + insn->off] - addrs[i]; 967 if (!jmp_offset) 968 /* optimize out nop jumps */ 969 break; 970 emit_jmp: 971 if (is_imm8(jmp_offset)) { 972 EMIT2(0xEB, jmp_offset); 973 } else if (is_simm32(jmp_offset)) { 974 EMIT1_off32(0xE9, jmp_offset); 975 } else { 976 pr_err("jmp gen bug %llx\n", jmp_offset); 977 return -EFAULT; 978 } 979 break; 980 981 case BPF_LD | BPF_IND | BPF_W: 982 func = sk_load_word; 983 goto common_load; 984 case BPF_LD | BPF_ABS | BPF_W: 985 func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); 986 common_load: 987 ctx->seen_ld_abs = seen_ld_abs = true; 988 jmp_offset = func - (image + addrs[i]); 989 if (!func || !is_simm32(jmp_offset)) { 990 pr_err("unsupported bpf func %d addr %p image %p\n", 991 imm32, func, image); 992 return -EINVAL; 993 } 994 if (BPF_MODE(insn->code) == BPF_ABS) { 995 /* mov %esi, imm32 */ 996 EMIT1_off32(0xBE, imm32); 997 } else { 998 /* mov %rsi, src_reg */ 999 EMIT_mov(BPF_REG_2, src_reg); 1000 if (imm32) { 1001 if (is_imm8(imm32)) 1002 /* add %esi, imm8 */ 1003 EMIT3(0x83, 0xC6, imm32); 1004 else 1005 /* add %esi, imm32 */ 1006 EMIT2_off32(0x81, 0xC6, imm32); 1007 } 1008 } 1009 /* skb pointer is in R6 (%rbx), it will be copied into 1010 * %rdi if skb_copy_bits() call is necessary. 1011 * sk_load_* helpers also use %r10 and %r9d. 1012 * See bpf_jit.S 1013 */ 1014 if (seen_ax_reg) 1015 /* r10 = skb->data, mov %r10, off32(%rbx) */ 1016 EMIT3_off32(0x4c, 0x8b, 0x93, 1017 offsetof(struct sk_buff, data)); 1018 EMIT1_off32(0xE8, jmp_offset); /* call */ 1019 break; 1020 1021 case BPF_LD | BPF_IND | BPF_H: 1022 func = sk_load_half; 1023 goto common_load; 1024 case BPF_LD | BPF_ABS | BPF_H: 1025 func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); 1026 goto common_load; 1027 case BPF_LD | BPF_IND | BPF_B: 1028 func = sk_load_byte; 1029 goto common_load; 1030 case BPF_LD | BPF_ABS | BPF_B: 1031 func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); 1032 goto common_load; 1033 1034 case BPF_JMP | BPF_EXIT: 1035 if (seen_exit) { 1036 jmp_offset = ctx->cleanup_addr - addrs[i]; 1037 goto emit_jmp; 1038 } 1039 seen_exit = true; 1040 /* update cleanup_addr */ 1041 ctx->cleanup_addr = proglen; 1042 /* mov rbx, qword ptr [rbp+0] */ 1043 EMIT4(0x48, 0x8B, 0x5D, 0); 1044 /* mov r13, qword ptr [rbp+8] */ 1045 EMIT4(0x4C, 0x8B, 0x6D, 8); 1046 /* mov r14, qword ptr [rbp+16] */ 1047 EMIT4(0x4C, 0x8B, 0x75, 16); 1048 /* mov r15, qword ptr [rbp+24] */ 1049 EMIT4(0x4C, 0x8B, 0x7D, 24); 1050 1051 /* add rbp, AUX_STACK_SPACE */ 1052 EMIT4(0x48, 0x83, 0xC5, AUX_STACK_SPACE); 1053 EMIT1(0xC9); /* leave */ 1054 EMIT1(0xC3); /* ret */ 1055 break; 1056 1057 default: 1058 /* By design x64 JIT should support all BPF instructions 1059 * This error will be seen if new instruction was added 1060 * to interpreter, but not to JIT 1061 * or if there is junk in bpf_prog 1062 */ 1063 pr_err("bpf_jit: unknown opcode %02x\n", insn->code); 1064 return -EINVAL; 1065 } 1066 1067 ilen = prog - temp; 1068 if (ilen > BPF_MAX_INSN_SIZE) { 1069 pr_err("bpf_jit: fatal insn size error\n"); 1070 return -EFAULT; 1071 } 1072 1073 if (image) { 1074 if (unlikely(proglen + ilen > oldproglen)) { 1075 pr_err("bpf_jit: fatal error\n"); 1076 return -EFAULT; 1077 } 1078 memcpy(image + proglen, temp, ilen); 1079 } 1080 proglen += ilen; 1081 addrs[i] = proglen; 1082 prog = temp; 1083 } 1084 return proglen; 1085 } 1086 1087 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) 1088 { 1089 struct bpf_binary_header *header = NULL; 1090 struct bpf_prog *tmp, *orig_prog = prog; 1091 int proglen, oldproglen = 0; 1092 struct jit_context ctx = {}; 1093 bool tmp_blinded = false; 1094 u8 *image = NULL; 1095 int *addrs; 1096 int pass; 1097 int i; 1098 1099 if (!bpf_jit_enable) 1100 return orig_prog; 1101 1102 tmp = bpf_jit_blind_constants(prog); 1103 /* If blinding was requested and we failed during blinding, 1104 * we must fall back to the interpreter. 1105 */ 1106 if (IS_ERR(tmp)) 1107 return orig_prog; 1108 if (tmp != prog) { 1109 tmp_blinded = true; 1110 prog = tmp; 1111 } 1112 1113 addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); 1114 if (!addrs) { 1115 prog = orig_prog; 1116 goto out; 1117 } 1118 1119 /* Before first pass, make a rough estimation of addrs[] 1120 * each bpf instruction is translated to less than 64 bytes 1121 */ 1122 for (proglen = 0, i = 0; i < prog->len; i++) { 1123 proglen += 64; 1124 addrs[i] = proglen; 1125 } 1126 ctx.cleanup_addr = proglen; 1127 1128 /* JITed image shrinks with every pass and the loop iterates 1129 * until the image stops shrinking. Very large bpf programs 1130 * may converge on the last pass. In such case do one more 1131 * pass to emit the final image 1132 */ 1133 for (pass = 0; pass < 10 || image; pass++) { 1134 proglen = do_jit(prog, addrs, image, oldproglen, &ctx); 1135 if (proglen <= 0) { 1136 image = NULL; 1137 if (header) 1138 bpf_jit_binary_free(header); 1139 prog = orig_prog; 1140 goto out_addrs; 1141 } 1142 if (image) { 1143 if (proglen != oldproglen) { 1144 pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", 1145 proglen, oldproglen); 1146 prog = orig_prog; 1147 goto out_addrs; 1148 } 1149 break; 1150 } 1151 if (proglen == oldproglen) { 1152 header = bpf_jit_binary_alloc(proglen, &image, 1153 1, jit_fill_hole); 1154 if (!header) { 1155 prog = orig_prog; 1156 goto out_addrs; 1157 } 1158 } 1159 oldproglen = proglen; 1160 } 1161 1162 if (bpf_jit_enable > 1) 1163 bpf_jit_dump(prog->len, proglen, pass + 1, image); 1164 1165 if (image) { 1166 bpf_flush_icache(header, image + proglen); 1167 bpf_jit_binary_lock_ro(header); 1168 prog->bpf_func = (void *)image; 1169 prog->jited = 1; 1170 prog->jited_len = proglen; 1171 } else { 1172 prog = orig_prog; 1173 } 1174 1175 out_addrs: 1176 kfree(addrs); 1177 out: 1178 if (tmp_blinded) 1179 bpf_jit_prog_release_other(prog, prog == orig_prog ? 1180 tmp : orig_prog); 1181 return prog; 1182 } 1183