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 <linux/bpf.h> 16 17 int bpf_jit_enable __read_mostly; 18 19 /* 20 * assembly code in arch/x86/net/bpf_jit.S 21 */ 22 extern u8 sk_load_word[], sk_load_half[], sk_load_byte[]; 23 extern u8 sk_load_word_positive_offset[], sk_load_half_positive_offset[]; 24 extern u8 sk_load_byte_positive_offset[]; 25 extern u8 sk_load_word_negative_offset[], sk_load_half_negative_offset[]; 26 extern u8 sk_load_byte_negative_offset[]; 27 28 static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len) 29 { 30 if (len == 1) 31 *ptr = bytes; 32 else if (len == 2) 33 *(u16 *)ptr = bytes; 34 else { 35 *(u32 *)ptr = bytes; 36 barrier(); 37 } 38 return ptr + len; 39 } 40 41 #define EMIT(bytes, len) \ 42 do { prog = emit_code(prog, bytes, len); cnt += len; } while (0) 43 44 #define EMIT1(b1) EMIT(b1, 1) 45 #define EMIT2(b1, b2) EMIT((b1) + ((b2) << 8), 2) 46 #define EMIT3(b1, b2, b3) EMIT((b1) + ((b2) << 8) + ((b3) << 16), 3) 47 #define EMIT4(b1, b2, b3, b4) EMIT((b1) + ((b2) << 8) + ((b3) << 16) + ((b4) << 24), 4) 48 #define EMIT1_off32(b1, off) \ 49 do {EMIT1(b1); EMIT(off, 4); } while (0) 50 #define EMIT2_off32(b1, b2, off) \ 51 do {EMIT2(b1, b2); EMIT(off, 4); } while (0) 52 #define EMIT3_off32(b1, b2, b3, off) \ 53 do {EMIT3(b1, b2, b3); EMIT(off, 4); } while (0) 54 #define EMIT4_off32(b1, b2, b3, b4, off) \ 55 do {EMIT4(b1, b2, b3, b4); EMIT(off, 4); } while (0) 56 57 static bool is_imm8(int value) 58 { 59 return value <= 127 && value >= -128; 60 } 61 62 static bool is_simm32(s64 value) 63 { 64 return value == (s64) (s32) value; 65 } 66 67 /* mov dst, src */ 68 #define EMIT_mov(DST, SRC) \ 69 do {if (DST != SRC) \ 70 EMIT3(add_2mod(0x48, DST, SRC), 0x89, add_2reg(0xC0, DST, SRC)); \ 71 } while (0) 72 73 static int bpf_size_to_x86_bytes(int bpf_size) 74 { 75 if (bpf_size == BPF_W) 76 return 4; 77 else if (bpf_size == BPF_H) 78 return 2; 79 else if (bpf_size == BPF_B) 80 return 1; 81 else if (bpf_size == BPF_DW) 82 return 4; /* imm32 */ 83 else 84 return 0; 85 } 86 87 /* list of x86 cond jumps opcodes (. + s8) 88 * Add 0x10 (and an extra 0x0f) to generate far jumps (. + s32) 89 */ 90 #define X86_JB 0x72 91 #define X86_JAE 0x73 92 #define X86_JE 0x74 93 #define X86_JNE 0x75 94 #define X86_JBE 0x76 95 #define X86_JA 0x77 96 #define X86_JGE 0x7D 97 #define X86_JG 0x7F 98 99 static void bpf_flush_icache(void *start, void *end) 100 { 101 mm_segment_t old_fs = get_fs(); 102 103 set_fs(KERNEL_DS); 104 smp_wmb(); 105 flush_icache_range((unsigned long)start, (unsigned long)end); 106 set_fs(old_fs); 107 } 108 109 #define CHOOSE_LOAD_FUNC(K, func) \ 110 ((int)K < 0 ? ((int)K >= SKF_LL_OFF ? func##_negative_offset : func) : func##_positive_offset) 111 112 /* pick a register outside of BPF range for JIT internal work */ 113 #define AUX_REG (MAX_BPF_JIT_REG + 1) 114 115 /* The following table maps BPF registers to x64 registers. 116 * 117 * x64 register r12 is unused, since if used as base address 118 * register in load/store instructions, it always needs an 119 * extra byte of encoding and is callee saved. 120 * 121 * r9 caches skb->len - skb->data_len 122 * r10 caches skb->data, and used for blinding (if enabled) 123 */ 124 static const int reg2hex[] = { 125 [BPF_REG_0] = 0, /* rax */ 126 [BPF_REG_1] = 7, /* rdi */ 127 [BPF_REG_2] = 6, /* rsi */ 128 [BPF_REG_3] = 2, /* rdx */ 129 [BPF_REG_4] = 1, /* rcx */ 130 [BPF_REG_5] = 0, /* r8 */ 131 [BPF_REG_6] = 3, /* rbx callee saved */ 132 [BPF_REG_7] = 5, /* r13 callee saved */ 133 [BPF_REG_8] = 6, /* r14 callee saved */ 134 [BPF_REG_9] = 7, /* r15 callee saved */ 135 [BPF_REG_FP] = 5, /* rbp readonly */ 136 [BPF_REG_AX] = 2, /* r10 temp register */ 137 [AUX_REG] = 3, /* r11 temp register */ 138 }; 139 140 /* is_ereg() == true if BPF register 'reg' maps to x64 r8..r15 141 * which need extra byte of encoding. 142 * rax,rcx,...,rbp have simpler encoding 143 */ 144 static bool is_ereg(u32 reg) 145 { 146 return (1 << reg) & (BIT(BPF_REG_5) | 147 BIT(AUX_REG) | 148 BIT(BPF_REG_7) | 149 BIT(BPF_REG_8) | 150 BIT(BPF_REG_9) | 151 BIT(BPF_REG_AX)); 152 } 153 154 /* add modifiers if 'reg' maps to x64 registers r8..r15 */ 155 static u8 add_1mod(u8 byte, u32 reg) 156 { 157 if (is_ereg(reg)) 158 byte |= 1; 159 return byte; 160 } 161 162 static u8 add_2mod(u8 byte, u32 r1, u32 r2) 163 { 164 if (is_ereg(r1)) 165 byte |= 1; 166 if (is_ereg(r2)) 167 byte |= 4; 168 return byte; 169 } 170 171 /* encode 'dst_reg' register into x64 opcode 'byte' */ 172 static u8 add_1reg(u8 byte, u32 dst_reg) 173 { 174 return byte + reg2hex[dst_reg]; 175 } 176 177 /* encode 'dst_reg' and 'src_reg' registers into x64 opcode 'byte' */ 178 static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) 179 { 180 return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); 181 } 182 183 static void jit_fill_hole(void *area, unsigned int size) 184 { 185 /* fill whole space with int3 instructions */ 186 memset(area, 0xcc, size); 187 } 188 189 struct jit_context { 190 int cleanup_addr; /* epilogue code offset */ 191 bool seen_ld_abs; 192 bool seen_ax_reg; 193 }; 194 195 /* maximum number of bytes emitted while JITing one eBPF insn */ 196 #define BPF_MAX_INSN_SIZE 128 197 #define BPF_INSN_SAFETY 64 198 199 #define STACKSIZE \ 200 (MAX_BPF_STACK + \ 201 32 /* space for rbx, r13, r14, r15 */ + \ 202 8 /* space for skb_copy_bits() buffer */) 203 204 #define PROLOGUE_SIZE 48 205 206 /* 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) 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, STACKSIZE */ 218 EMIT3_off32(0x48, 0x81, 0xEC, STACKSIZE); 219 220 /* all classic BPF filters use R6(rbx) save it */ 221 222 /* mov qword ptr [rbp-X],rbx */ 223 EMIT3_off32(0x48, 0x89, 0x9D, -STACKSIZE); 224 225 /* bpf_convert_filter() maps classic BPF register X to R7 and uses R8 226 * as temporary, so all tcpdump filters need to spill/fill R7(r13) and 227 * R8(r14). R9(r15) spill could be made conditional, but there is only 228 * one 'bpf_error' return path out of helper functions inside bpf_jit.S 229 * The overhead of extra spill is negligible for any filter other 230 * than synthetic ones. Therefore not worth adding complexity. 231 */ 232 233 /* mov qword ptr [rbp-X],r13 */ 234 EMIT3_off32(0x4C, 0x89, 0xAD, -STACKSIZE + 8); 235 /* mov qword ptr [rbp-X],r14 */ 236 EMIT3_off32(0x4C, 0x89, 0xB5, -STACKSIZE + 16); 237 /* mov qword ptr [rbp-X],r15 */ 238 EMIT3_off32(0x4C, 0x89, 0xBD, -STACKSIZE + 24); 239 240 /* Clear the tail call counter (tail_call_cnt): for eBPF tail calls 241 * we need to reset the counter to 0. It's done in two instructions, 242 * resetting rax register to 0 (xor on eax gets 0 extended), and 243 * moving it to the counter location. 244 */ 245 246 /* xor eax, eax */ 247 EMIT2(0x31, 0xc0); 248 /* mov qword ptr [rbp-X], rax */ 249 EMIT3_off32(0x48, 0x89, 0x85, -STACKSIZE + 32); 250 251 BUILD_BUG_ON(cnt != PROLOGUE_SIZE); 252 *pprog = prog; 253 } 254 255 /* generate the following code: 256 * ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ... 257 * if (index >= array->map.max_entries) 258 * goto out; 259 * if (++tail_call_cnt > MAX_TAIL_CALL_CNT) 260 * goto out; 261 * prog = array->ptrs[index]; 262 * if (prog == NULL) 263 * goto out; 264 * goto *(prog->bpf_func + prologue_size); 265 * out: 266 */ 267 static void emit_bpf_tail_call(u8 **pprog) 268 { 269 u8 *prog = *pprog; 270 int label1, label2, label3; 271 int cnt = 0; 272 273 /* rdi - pointer to ctx 274 * rsi - pointer to bpf_array 275 * rdx - index in bpf_array 276 */ 277 278 /* if (index >= array->map.max_entries) 279 * goto out; 280 */ 281 EMIT4(0x48, 0x8B, 0x46, /* mov rax, qword ptr [rsi + 16] */ 282 offsetof(struct bpf_array, map.max_entries)); 283 EMIT3(0x48, 0x39, 0xD0); /* cmp rax, rdx */ 284 #define OFFSET1 47 /* number of bytes to jump */ 285 EMIT2(X86_JBE, OFFSET1); /* jbe out */ 286 label1 = cnt; 287 288 /* if (tail_call_cnt > MAX_TAIL_CALL_CNT) 289 * goto out; 290 */ 291 EMIT2_off32(0x8B, 0x85, -STACKSIZE + 36); /* mov eax, dword ptr [rbp - 516] */ 292 EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */ 293 #define OFFSET2 36 294 EMIT2(X86_JA, OFFSET2); /* ja out */ 295 label2 = cnt; 296 EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */ 297 EMIT2_off32(0x89, 0x85, -STACKSIZE + 36); /* mov dword ptr [rbp - 516], eax */ 298 299 /* prog = array->ptrs[index]; */ 300 EMIT4_off32(0x48, 0x8D, 0x84, 0xD6, /* lea rax, [rsi + rdx * 8 + offsetof(...)] */ 301 offsetof(struct bpf_array, ptrs)); 302 EMIT3(0x48, 0x8B, 0x00); /* mov rax, qword ptr [rax] */ 303 304 /* if (prog == NULL) 305 * goto out; 306 */ 307 EMIT4(0x48, 0x83, 0xF8, 0x00); /* cmp rax, 0 */ 308 #define OFFSET3 10 309 EMIT2(X86_JE, OFFSET3); /* je out */ 310 label3 = cnt; 311 312 /* goto *(prog->bpf_func + prologue_size); */ 313 EMIT4(0x48, 0x8B, 0x40, /* mov rax, qword ptr [rax + 32] */ 314 offsetof(struct bpf_prog, bpf_func)); 315 EMIT4(0x48, 0x83, 0xC0, PROLOGUE_SIZE); /* add rax, prologue_size */ 316 317 /* now we're ready to jump into next BPF program 318 * rdi == ctx (1st arg) 319 * rax == prog->bpf_func + prologue_size 320 */ 321 EMIT2(0xFF, 0xE0); /* jmp rax */ 322 323 /* out: */ 324 BUILD_BUG_ON(cnt - label1 != OFFSET1); 325 BUILD_BUG_ON(cnt - label2 != OFFSET2); 326 BUILD_BUG_ON(cnt - label3 != OFFSET3); 327 *pprog = prog; 328 } 329 330 331 static void emit_load_skb_data_hlen(u8 **pprog) 332 { 333 u8 *prog = *pprog; 334 int cnt = 0; 335 336 /* r9d = skb->len - skb->data_len (headlen) 337 * r10 = skb->data 338 */ 339 /* mov %r9d, off32(%rdi) */ 340 EMIT3_off32(0x44, 0x8b, 0x8f, offsetof(struct sk_buff, len)); 341 342 /* sub %r9d, off32(%rdi) */ 343 EMIT3_off32(0x44, 0x2b, 0x8f, offsetof(struct sk_buff, data_len)); 344 345 /* mov %r10, off32(%rdi) */ 346 EMIT3_off32(0x4c, 0x8b, 0x97, offsetof(struct sk_buff, data)); 347 *pprog = prog; 348 } 349 350 static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, 351 int oldproglen, struct jit_context *ctx) 352 { 353 struct bpf_insn *insn = bpf_prog->insnsi; 354 int insn_cnt = bpf_prog->len; 355 bool seen_ld_abs = ctx->seen_ld_abs | (oldproglen == 0); 356 bool seen_ax_reg = ctx->seen_ax_reg | (oldproglen == 0); 357 bool seen_exit = false; 358 u8 temp[BPF_MAX_INSN_SIZE + BPF_INSN_SAFETY]; 359 int i, cnt = 0; 360 int proglen = 0; 361 u8 *prog = temp; 362 363 emit_prologue(&prog); 364 365 if (seen_ld_abs) 366 emit_load_skb_data_hlen(&prog); 367 368 for (i = 0; i < insn_cnt; i++, insn++) { 369 const s32 imm32 = insn->imm; 370 u32 dst_reg = insn->dst_reg; 371 u32 src_reg = insn->src_reg; 372 u8 b1 = 0, b2 = 0, b3 = 0; 373 s64 jmp_offset; 374 u8 jmp_cond; 375 bool reload_skb_data; 376 int ilen; 377 u8 *func; 378 379 if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX) 380 ctx->seen_ax_reg = seen_ax_reg = true; 381 382 switch (insn->code) { 383 /* ALU */ 384 case BPF_ALU | BPF_ADD | BPF_X: 385 case BPF_ALU | BPF_SUB | BPF_X: 386 case BPF_ALU | BPF_AND | BPF_X: 387 case BPF_ALU | BPF_OR | BPF_X: 388 case BPF_ALU | BPF_XOR | BPF_X: 389 case BPF_ALU64 | BPF_ADD | BPF_X: 390 case BPF_ALU64 | BPF_SUB | BPF_X: 391 case BPF_ALU64 | BPF_AND | BPF_X: 392 case BPF_ALU64 | BPF_OR | BPF_X: 393 case BPF_ALU64 | BPF_XOR | BPF_X: 394 switch (BPF_OP(insn->code)) { 395 case BPF_ADD: b2 = 0x01; break; 396 case BPF_SUB: b2 = 0x29; break; 397 case BPF_AND: b2 = 0x21; break; 398 case BPF_OR: b2 = 0x09; break; 399 case BPF_XOR: b2 = 0x31; break; 400 } 401 if (BPF_CLASS(insn->code) == BPF_ALU64) 402 EMIT1(add_2mod(0x48, dst_reg, src_reg)); 403 else if (is_ereg(dst_reg) || is_ereg(src_reg)) 404 EMIT1(add_2mod(0x40, dst_reg, src_reg)); 405 EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); 406 break; 407 408 /* mov dst, src */ 409 case BPF_ALU64 | BPF_MOV | BPF_X: 410 EMIT_mov(dst_reg, src_reg); 411 break; 412 413 /* mov32 dst, src */ 414 case BPF_ALU | BPF_MOV | BPF_X: 415 if (is_ereg(dst_reg) || is_ereg(src_reg)) 416 EMIT1(add_2mod(0x40, dst_reg, src_reg)); 417 EMIT2(0x89, add_2reg(0xC0, dst_reg, src_reg)); 418 break; 419 420 /* neg dst */ 421 case BPF_ALU | BPF_NEG: 422 case BPF_ALU64 | BPF_NEG: 423 if (BPF_CLASS(insn->code) == BPF_ALU64) 424 EMIT1(add_1mod(0x48, dst_reg)); 425 else if (is_ereg(dst_reg)) 426 EMIT1(add_1mod(0x40, dst_reg)); 427 EMIT2(0xF7, add_1reg(0xD8, dst_reg)); 428 break; 429 430 case BPF_ALU | BPF_ADD | BPF_K: 431 case BPF_ALU | BPF_SUB | BPF_K: 432 case BPF_ALU | BPF_AND | BPF_K: 433 case BPF_ALU | BPF_OR | BPF_K: 434 case BPF_ALU | BPF_XOR | BPF_K: 435 case BPF_ALU64 | BPF_ADD | BPF_K: 436 case BPF_ALU64 | BPF_SUB | BPF_K: 437 case BPF_ALU64 | BPF_AND | BPF_K: 438 case BPF_ALU64 | BPF_OR | BPF_K: 439 case BPF_ALU64 | BPF_XOR | BPF_K: 440 if (BPF_CLASS(insn->code) == BPF_ALU64) 441 EMIT1(add_1mod(0x48, dst_reg)); 442 else if (is_ereg(dst_reg)) 443 EMIT1(add_1mod(0x40, dst_reg)); 444 445 switch (BPF_OP(insn->code)) { 446 case BPF_ADD: b3 = 0xC0; break; 447 case BPF_SUB: b3 = 0xE8; break; 448 case BPF_AND: b3 = 0xE0; break; 449 case BPF_OR: b3 = 0xC8; break; 450 case BPF_XOR: b3 = 0xF0; break; 451 } 452 453 if (is_imm8(imm32)) 454 EMIT3(0x83, add_1reg(b3, dst_reg), imm32); 455 else 456 EMIT2_off32(0x81, add_1reg(b3, dst_reg), imm32); 457 break; 458 459 case BPF_ALU64 | BPF_MOV | BPF_K: 460 /* optimization: if imm32 is positive, 461 * use 'mov eax, imm32' (which zero-extends imm32) 462 * to save 2 bytes 463 */ 464 if (imm32 < 0) { 465 /* 'mov rax, imm32' sign extends imm32 */ 466 b1 = add_1mod(0x48, dst_reg); 467 b2 = 0xC7; 468 b3 = 0xC0; 469 EMIT3_off32(b1, b2, add_1reg(b3, dst_reg), imm32); 470 break; 471 } 472 473 case BPF_ALU | BPF_MOV | BPF_K: 474 /* optimization: if imm32 is zero, use 'xor <dst>,<dst>' 475 * to save 3 bytes. 476 */ 477 if (imm32 == 0) { 478 if (is_ereg(dst_reg)) 479 EMIT1(add_2mod(0x40, dst_reg, dst_reg)); 480 b2 = 0x31; /* xor */ 481 b3 = 0xC0; 482 EMIT2(b2, add_2reg(b3, dst_reg, dst_reg)); 483 break; 484 } 485 486 /* mov %eax, imm32 */ 487 if (is_ereg(dst_reg)) 488 EMIT1(add_1mod(0x40, dst_reg)); 489 EMIT1_off32(add_1reg(0xB8, dst_reg), imm32); 490 break; 491 492 case BPF_LD | BPF_IMM | BPF_DW: 493 if (insn[1].code != 0 || insn[1].src_reg != 0 || 494 insn[1].dst_reg != 0 || insn[1].off != 0) { 495 /* verifier must catch invalid insns */ 496 pr_err("invalid BPF_LD_IMM64 insn\n"); 497 return -EINVAL; 498 } 499 500 /* optimization: if imm64 is zero, use 'xor <dst>,<dst>' 501 * to save 7 bytes. 502 */ 503 if (insn[0].imm == 0 && insn[1].imm == 0) { 504 b1 = add_2mod(0x48, dst_reg, dst_reg); 505 b2 = 0x31; /* xor */ 506 b3 = 0xC0; 507 EMIT3(b1, b2, add_2reg(b3, dst_reg, dst_reg)); 508 509 insn++; 510 i++; 511 break; 512 } 513 514 /* movabsq %rax, imm64 */ 515 EMIT2(add_1mod(0x48, dst_reg), add_1reg(0xB8, dst_reg)); 516 EMIT(insn[0].imm, 4); 517 EMIT(insn[1].imm, 4); 518 519 insn++; 520 i++; 521 break; 522 523 /* dst %= src, dst /= src, dst %= imm32, dst /= imm32 */ 524 case BPF_ALU | BPF_MOD | BPF_X: 525 case BPF_ALU | BPF_DIV | BPF_X: 526 case BPF_ALU | BPF_MOD | BPF_K: 527 case BPF_ALU | BPF_DIV | BPF_K: 528 case BPF_ALU64 | BPF_MOD | BPF_X: 529 case BPF_ALU64 | BPF_DIV | BPF_X: 530 case BPF_ALU64 | BPF_MOD | BPF_K: 531 case BPF_ALU64 | BPF_DIV | BPF_K: 532 EMIT1(0x50); /* push rax */ 533 EMIT1(0x52); /* push rdx */ 534 535 if (BPF_SRC(insn->code) == BPF_X) 536 /* mov r11, src_reg */ 537 EMIT_mov(AUX_REG, src_reg); 538 else 539 /* mov r11, imm32 */ 540 EMIT3_off32(0x49, 0xC7, 0xC3, imm32); 541 542 /* mov rax, dst_reg */ 543 EMIT_mov(BPF_REG_0, dst_reg); 544 545 /* xor edx, edx 546 * equivalent to 'xor rdx, rdx', but one byte less 547 */ 548 EMIT2(0x31, 0xd2); 549 550 if (BPF_SRC(insn->code) == BPF_X) { 551 /* if (src_reg == 0) return 0 */ 552 553 /* cmp r11, 0 */ 554 EMIT4(0x49, 0x83, 0xFB, 0x00); 555 556 /* jne .+9 (skip over pop, pop, xor and jmp) */ 557 EMIT2(X86_JNE, 1 + 1 + 2 + 5); 558 EMIT1(0x5A); /* pop rdx */ 559 EMIT1(0x58); /* pop rax */ 560 EMIT2(0x31, 0xc0); /* xor eax, eax */ 561 562 /* jmp cleanup_addr 563 * addrs[i] - 11, because there are 11 bytes 564 * after this insn: div, mov, pop, pop, mov 565 */ 566 jmp_offset = ctx->cleanup_addr - (addrs[i] - 11); 567 EMIT1_off32(0xE9, jmp_offset); 568 } 569 570 if (BPF_CLASS(insn->code) == BPF_ALU64) 571 /* div r11 */ 572 EMIT3(0x49, 0xF7, 0xF3); 573 else 574 /* div r11d */ 575 EMIT3(0x41, 0xF7, 0xF3); 576 577 if (BPF_OP(insn->code) == BPF_MOD) 578 /* mov r11, rdx */ 579 EMIT3(0x49, 0x89, 0xD3); 580 else 581 /* mov r11, rax */ 582 EMIT3(0x49, 0x89, 0xC3); 583 584 EMIT1(0x5A); /* pop rdx */ 585 EMIT1(0x58); /* pop rax */ 586 587 /* mov dst_reg, r11 */ 588 EMIT_mov(dst_reg, AUX_REG); 589 break; 590 591 case BPF_ALU | BPF_MUL | BPF_K: 592 case BPF_ALU | BPF_MUL | BPF_X: 593 case BPF_ALU64 | BPF_MUL | BPF_K: 594 case BPF_ALU64 | BPF_MUL | BPF_X: 595 EMIT1(0x50); /* push rax */ 596 EMIT1(0x52); /* push rdx */ 597 598 /* mov r11, dst_reg */ 599 EMIT_mov(AUX_REG, dst_reg); 600 601 if (BPF_SRC(insn->code) == BPF_X) 602 /* mov rax, src_reg */ 603 EMIT_mov(BPF_REG_0, src_reg); 604 else 605 /* mov rax, imm32 */ 606 EMIT3_off32(0x48, 0xC7, 0xC0, imm32); 607 608 if (BPF_CLASS(insn->code) == BPF_ALU64) 609 EMIT1(add_1mod(0x48, AUX_REG)); 610 else if (is_ereg(AUX_REG)) 611 EMIT1(add_1mod(0x40, AUX_REG)); 612 /* mul(q) r11 */ 613 EMIT2(0xF7, add_1reg(0xE0, AUX_REG)); 614 615 /* mov r11, rax */ 616 EMIT_mov(AUX_REG, BPF_REG_0); 617 618 EMIT1(0x5A); /* pop rdx */ 619 EMIT1(0x58); /* pop rax */ 620 621 /* mov dst_reg, r11 */ 622 EMIT_mov(dst_reg, AUX_REG); 623 break; 624 625 /* shifts */ 626 case BPF_ALU | BPF_LSH | BPF_K: 627 case BPF_ALU | BPF_RSH | BPF_K: 628 case BPF_ALU | BPF_ARSH | BPF_K: 629 case BPF_ALU64 | BPF_LSH | BPF_K: 630 case BPF_ALU64 | BPF_RSH | BPF_K: 631 case BPF_ALU64 | BPF_ARSH | BPF_K: 632 if (BPF_CLASS(insn->code) == BPF_ALU64) 633 EMIT1(add_1mod(0x48, dst_reg)); 634 else if (is_ereg(dst_reg)) 635 EMIT1(add_1mod(0x40, dst_reg)); 636 637 switch (BPF_OP(insn->code)) { 638 case BPF_LSH: b3 = 0xE0; break; 639 case BPF_RSH: b3 = 0xE8; break; 640 case BPF_ARSH: b3 = 0xF8; break; 641 } 642 EMIT3(0xC1, add_1reg(b3, dst_reg), imm32); 643 break; 644 645 case BPF_ALU | BPF_LSH | BPF_X: 646 case BPF_ALU | BPF_RSH | BPF_X: 647 case BPF_ALU | BPF_ARSH | BPF_X: 648 case BPF_ALU64 | BPF_LSH | BPF_X: 649 case BPF_ALU64 | BPF_RSH | BPF_X: 650 case BPF_ALU64 | BPF_ARSH | BPF_X: 651 652 /* check for bad case when dst_reg == rcx */ 653 if (dst_reg == BPF_REG_4) { 654 /* mov r11, dst_reg */ 655 EMIT_mov(AUX_REG, dst_reg); 656 dst_reg = AUX_REG; 657 } 658 659 if (src_reg != BPF_REG_4) { /* common case */ 660 EMIT1(0x51); /* push rcx */ 661 662 /* mov rcx, src_reg */ 663 EMIT_mov(BPF_REG_4, src_reg); 664 } 665 666 /* shl %rax, %cl | shr %rax, %cl | sar %rax, %cl */ 667 if (BPF_CLASS(insn->code) == BPF_ALU64) 668 EMIT1(add_1mod(0x48, dst_reg)); 669 else if (is_ereg(dst_reg)) 670 EMIT1(add_1mod(0x40, dst_reg)); 671 672 switch (BPF_OP(insn->code)) { 673 case BPF_LSH: b3 = 0xE0; break; 674 case BPF_RSH: b3 = 0xE8; break; 675 case BPF_ARSH: b3 = 0xF8; break; 676 } 677 EMIT2(0xD3, add_1reg(b3, dst_reg)); 678 679 if (src_reg != BPF_REG_4) 680 EMIT1(0x59); /* pop rcx */ 681 682 if (insn->dst_reg == BPF_REG_4) 683 /* mov dst_reg, r11 */ 684 EMIT_mov(insn->dst_reg, AUX_REG); 685 break; 686 687 case BPF_ALU | BPF_END | BPF_FROM_BE: 688 switch (imm32) { 689 case 16: 690 /* emit 'ror %ax, 8' to swap lower 2 bytes */ 691 EMIT1(0x66); 692 if (is_ereg(dst_reg)) 693 EMIT1(0x41); 694 EMIT3(0xC1, add_1reg(0xC8, dst_reg), 8); 695 696 /* emit 'movzwl eax, ax' */ 697 if (is_ereg(dst_reg)) 698 EMIT3(0x45, 0x0F, 0xB7); 699 else 700 EMIT2(0x0F, 0xB7); 701 EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 702 break; 703 case 32: 704 /* emit 'bswap eax' to swap lower 4 bytes */ 705 if (is_ereg(dst_reg)) 706 EMIT2(0x41, 0x0F); 707 else 708 EMIT1(0x0F); 709 EMIT1(add_1reg(0xC8, dst_reg)); 710 break; 711 case 64: 712 /* emit 'bswap rax' to swap 8 bytes */ 713 EMIT3(add_1mod(0x48, dst_reg), 0x0F, 714 add_1reg(0xC8, dst_reg)); 715 break; 716 } 717 break; 718 719 case BPF_ALU | BPF_END | BPF_FROM_LE: 720 switch (imm32) { 721 case 16: 722 /* emit 'movzwl eax, ax' to zero extend 16-bit 723 * into 64 bit 724 */ 725 if (is_ereg(dst_reg)) 726 EMIT3(0x45, 0x0F, 0xB7); 727 else 728 EMIT2(0x0F, 0xB7); 729 EMIT1(add_2reg(0xC0, dst_reg, dst_reg)); 730 break; 731 case 32: 732 /* emit 'mov eax, eax' to clear upper 32-bits */ 733 if (is_ereg(dst_reg)) 734 EMIT1(0x45); 735 EMIT2(0x89, add_2reg(0xC0, dst_reg, dst_reg)); 736 break; 737 case 64: 738 /* nop */ 739 break; 740 } 741 break; 742 743 /* ST: *(u8*)(dst_reg + off) = imm */ 744 case BPF_ST | BPF_MEM | BPF_B: 745 if (is_ereg(dst_reg)) 746 EMIT2(0x41, 0xC6); 747 else 748 EMIT1(0xC6); 749 goto st; 750 case BPF_ST | BPF_MEM | BPF_H: 751 if (is_ereg(dst_reg)) 752 EMIT3(0x66, 0x41, 0xC7); 753 else 754 EMIT2(0x66, 0xC7); 755 goto st; 756 case BPF_ST | BPF_MEM | BPF_W: 757 if (is_ereg(dst_reg)) 758 EMIT2(0x41, 0xC7); 759 else 760 EMIT1(0xC7); 761 goto st; 762 case BPF_ST | BPF_MEM | BPF_DW: 763 EMIT2(add_1mod(0x48, dst_reg), 0xC7); 764 765 st: if (is_imm8(insn->off)) 766 EMIT2(add_1reg(0x40, dst_reg), insn->off); 767 else 768 EMIT1_off32(add_1reg(0x80, dst_reg), insn->off); 769 770 EMIT(imm32, bpf_size_to_x86_bytes(BPF_SIZE(insn->code))); 771 break; 772 773 /* STX: *(u8*)(dst_reg + off) = src_reg */ 774 case BPF_STX | BPF_MEM | BPF_B: 775 /* emit 'mov byte ptr [rax + off], al' */ 776 if (is_ereg(dst_reg) || is_ereg(src_reg) || 777 /* have to add extra byte for x86 SIL, DIL regs */ 778 src_reg == BPF_REG_1 || src_reg == BPF_REG_2) 779 EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x88); 780 else 781 EMIT1(0x88); 782 goto stx; 783 case BPF_STX | BPF_MEM | BPF_H: 784 if (is_ereg(dst_reg) || is_ereg(src_reg)) 785 EMIT3(0x66, add_2mod(0x40, dst_reg, src_reg), 0x89); 786 else 787 EMIT2(0x66, 0x89); 788 goto stx; 789 case BPF_STX | BPF_MEM | BPF_W: 790 if (is_ereg(dst_reg) || is_ereg(src_reg)) 791 EMIT2(add_2mod(0x40, dst_reg, src_reg), 0x89); 792 else 793 EMIT1(0x89); 794 goto stx; 795 case BPF_STX | BPF_MEM | BPF_DW: 796 EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); 797 stx: if (is_imm8(insn->off)) 798 EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); 799 else 800 EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), 801 insn->off); 802 break; 803 804 /* LDX: dst_reg = *(u8*)(src_reg + off) */ 805 case BPF_LDX | BPF_MEM | BPF_B: 806 /* emit 'movzx rax, byte ptr [rax + off]' */ 807 EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB6); 808 goto ldx; 809 case BPF_LDX | BPF_MEM | BPF_H: 810 /* emit 'movzx rax, word ptr [rax + off]' */ 811 EMIT3(add_2mod(0x48, src_reg, dst_reg), 0x0F, 0xB7); 812 goto ldx; 813 case BPF_LDX | BPF_MEM | BPF_W: 814 /* emit 'mov eax, dword ptr [rax+0x14]' */ 815 if (is_ereg(dst_reg) || is_ereg(src_reg)) 816 EMIT2(add_2mod(0x40, src_reg, dst_reg), 0x8B); 817 else 818 EMIT1(0x8B); 819 goto ldx; 820 case BPF_LDX | BPF_MEM | BPF_DW: 821 /* emit 'mov rax, qword ptr [rax+0x14]' */ 822 EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); 823 ldx: /* if insn->off == 0 we can save one extra byte, but 824 * special case of x86 r13 which always needs an offset 825 * is not worth the hassle 826 */ 827 if (is_imm8(insn->off)) 828 EMIT2(add_2reg(0x40, src_reg, dst_reg), insn->off); 829 else 830 EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), 831 insn->off); 832 break; 833 834 /* STX XADD: lock *(u32*)(dst_reg + off) += src_reg */ 835 case BPF_STX | BPF_XADD | BPF_W: 836 /* emit 'lock add dword ptr [rax + off], eax' */ 837 if (is_ereg(dst_reg) || is_ereg(src_reg)) 838 EMIT3(0xF0, add_2mod(0x40, dst_reg, src_reg), 0x01); 839 else 840 EMIT2(0xF0, 0x01); 841 goto xadd; 842 case BPF_STX | BPF_XADD | BPF_DW: 843 EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); 844 xadd: if (is_imm8(insn->off)) 845 EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); 846 else 847 EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), 848 insn->off); 849 break; 850 851 /* call */ 852 case BPF_JMP | BPF_CALL: 853 func = (u8 *) __bpf_call_base + imm32; 854 jmp_offset = func - (image + addrs[i]); 855 if (seen_ld_abs) { 856 reload_skb_data = bpf_helper_changes_skb_data(func); 857 if (reload_skb_data) { 858 EMIT1(0x57); /* push %rdi */ 859 jmp_offset += 22; /* pop, mov, sub, mov */ 860 } else { 861 EMIT2(0x41, 0x52); /* push %r10 */ 862 EMIT2(0x41, 0x51); /* push %r9 */ 863 /* need to adjust jmp offset, since 864 * pop %r9, pop %r10 take 4 bytes after call insn 865 */ 866 jmp_offset += 4; 867 } 868 } 869 if (!imm32 || !is_simm32(jmp_offset)) { 870 pr_err("unsupported bpf func %d addr %p image %p\n", 871 imm32, func, image); 872 return -EINVAL; 873 } 874 EMIT1_off32(0xE8, jmp_offset); 875 if (seen_ld_abs) { 876 if (reload_skb_data) { 877 EMIT1(0x5F); /* pop %rdi */ 878 emit_load_skb_data_hlen(&prog); 879 } else { 880 EMIT2(0x41, 0x59); /* pop %r9 */ 881 EMIT2(0x41, 0x5A); /* pop %r10 */ 882 } 883 } 884 break; 885 886 case BPF_JMP | BPF_CALL | BPF_X: 887 emit_bpf_tail_call(&prog); 888 break; 889 890 /* cond jump */ 891 case BPF_JMP | BPF_JEQ | BPF_X: 892 case BPF_JMP | BPF_JNE | BPF_X: 893 case BPF_JMP | BPF_JGT | BPF_X: 894 case BPF_JMP | BPF_JGE | BPF_X: 895 case BPF_JMP | BPF_JSGT | BPF_X: 896 case BPF_JMP | BPF_JSGE | BPF_X: 897 /* cmp dst_reg, src_reg */ 898 EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x39, 899 add_2reg(0xC0, dst_reg, src_reg)); 900 goto emit_cond_jmp; 901 902 case BPF_JMP | BPF_JSET | BPF_X: 903 /* test dst_reg, src_reg */ 904 EMIT3(add_2mod(0x48, dst_reg, src_reg), 0x85, 905 add_2reg(0xC0, dst_reg, src_reg)); 906 goto emit_cond_jmp; 907 908 case BPF_JMP | BPF_JSET | BPF_K: 909 /* test dst_reg, imm32 */ 910 EMIT1(add_1mod(0x48, dst_reg)); 911 EMIT2_off32(0xF7, add_1reg(0xC0, dst_reg), imm32); 912 goto emit_cond_jmp; 913 914 case BPF_JMP | BPF_JEQ | BPF_K: 915 case BPF_JMP | BPF_JNE | BPF_K: 916 case BPF_JMP | BPF_JGT | BPF_K: 917 case BPF_JMP | BPF_JGE | BPF_K: 918 case BPF_JMP | BPF_JSGT | BPF_K: 919 case BPF_JMP | BPF_JSGE | BPF_K: 920 /* cmp dst_reg, imm8/32 */ 921 EMIT1(add_1mod(0x48, dst_reg)); 922 923 if (is_imm8(imm32)) 924 EMIT3(0x83, add_1reg(0xF8, dst_reg), imm32); 925 else 926 EMIT2_off32(0x81, add_1reg(0xF8, dst_reg), imm32); 927 928 emit_cond_jmp: /* convert BPF opcode to x86 */ 929 switch (BPF_OP(insn->code)) { 930 case BPF_JEQ: 931 jmp_cond = X86_JE; 932 break; 933 case BPF_JSET: 934 case BPF_JNE: 935 jmp_cond = X86_JNE; 936 break; 937 case BPF_JGT: 938 /* GT is unsigned '>', JA in x86 */ 939 jmp_cond = X86_JA; 940 break; 941 case BPF_JGE: 942 /* GE is unsigned '>=', JAE in x86 */ 943 jmp_cond = X86_JAE; 944 break; 945 case BPF_JSGT: 946 /* signed '>', GT in x86 */ 947 jmp_cond = X86_JG; 948 break; 949 case BPF_JSGE: 950 /* signed '>=', GE in x86 */ 951 jmp_cond = X86_JGE; 952 break; 953 default: /* to silence gcc warning */ 954 return -EFAULT; 955 } 956 jmp_offset = addrs[i + insn->off] - addrs[i]; 957 if (is_imm8(jmp_offset)) { 958 EMIT2(jmp_cond, jmp_offset); 959 } else if (is_simm32(jmp_offset)) { 960 EMIT2_off32(0x0F, jmp_cond + 0x10, jmp_offset); 961 } else { 962 pr_err("cond_jmp gen bug %llx\n", jmp_offset); 963 return -EFAULT; 964 } 965 966 break; 967 968 case BPF_JMP | BPF_JA: 969 jmp_offset = addrs[i + insn->off] - addrs[i]; 970 if (!jmp_offset) 971 /* optimize out nop jumps */ 972 break; 973 emit_jmp: 974 if (is_imm8(jmp_offset)) { 975 EMIT2(0xEB, jmp_offset); 976 } else if (is_simm32(jmp_offset)) { 977 EMIT1_off32(0xE9, jmp_offset); 978 } else { 979 pr_err("jmp gen bug %llx\n", jmp_offset); 980 return -EFAULT; 981 } 982 break; 983 984 case BPF_LD | BPF_IND | BPF_W: 985 func = sk_load_word; 986 goto common_load; 987 case BPF_LD | BPF_ABS | BPF_W: 988 func = CHOOSE_LOAD_FUNC(imm32, sk_load_word); 989 common_load: 990 ctx->seen_ld_abs = seen_ld_abs = true; 991 jmp_offset = func - (image + addrs[i]); 992 if (!func || !is_simm32(jmp_offset)) { 993 pr_err("unsupported bpf func %d addr %p image %p\n", 994 imm32, func, image); 995 return -EINVAL; 996 } 997 if (BPF_MODE(insn->code) == BPF_ABS) { 998 /* mov %esi, imm32 */ 999 EMIT1_off32(0xBE, imm32); 1000 } else { 1001 /* mov %rsi, src_reg */ 1002 EMIT_mov(BPF_REG_2, src_reg); 1003 if (imm32) { 1004 if (is_imm8(imm32)) 1005 /* add %esi, imm8 */ 1006 EMIT3(0x83, 0xC6, imm32); 1007 else 1008 /* add %esi, imm32 */ 1009 EMIT2_off32(0x81, 0xC6, imm32); 1010 } 1011 } 1012 /* skb pointer is in R6 (%rbx), it will be copied into 1013 * %rdi if skb_copy_bits() call is necessary. 1014 * sk_load_* helpers also use %r10 and %r9d. 1015 * See bpf_jit.S 1016 */ 1017 if (seen_ax_reg) 1018 /* r10 = skb->data, mov %r10, off32(%rbx) */ 1019 EMIT3_off32(0x4c, 0x8b, 0x93, 1020 offsetof(struct sk_buff, data)); 1021 EMIT1_off32(0xE8, jmp_offset); /* call */ 1022 break; 1023 1024 case BPF_LD | BPF_IND | BPF_H: 1025 func = sk_load_half; 1026 goto common_load; 1027 case BPF_LD | BPF_ABS | BPF_H: 1028 func = CHOOSE_LOAD_FUNC(imm32, sk_load_half); 1029 goto common_load; 1030 case BPF_LD | BPF_IND | BPF_B: 1031 func = sk_load_byte; 1032 goto common_load; 1033 case BPF_LD | BPF_ABS | BPF_B: 1034 func = CHOOSE_LOAD_FUNC(imm32, sk_load_byte); 1035 goto common_load; 1036 1037 case BPF_JMP | BPF_EXIT: 1038 if (seen_exit) { 1039 jmp_offset = ctx->cleanup_addr - addrs[i]; 1040 goto emit_jmp; 1041 } 1042 seen_exit = true; 1043 /* update cleanup_addr */ 1044 ctx->cleanup_addr = proglen; 1045 /* mov rbx, qword ptr [rbp-X] */ 1046 EMIT3_off32(0x48, 0x8B, 0x9D, -STACKSIZE); 1047 /* mov r13, qword ptr [rbp-X] */ 1048 EMIT3_off32(0x4C, 0x8B, 0xAD, -STACKSIZE + 8); 1049 /* mov r14, qword ptr [rbp-X] */ 1050 EMIT3_off32(0x4C, 0x8B, 0xB5, -STACKSIZE + 16); 1051 /* mov r15, qword ptr [rbp-X] */ 1052 EMIT3_off32(0x4C, 0x8B, 0xBD, -STACKSIZE + 24); 1053 1054 EMIT1(0xC9); /* leave */ 1055 EMIT1(0xC3); /* ret */ 1056 break; 1057 1058 default: 1059 /* By design x64 JIT should support all BPF instructions 1060 * This error will be seen if new instruction was added 1061 * to interpreter, but not to JIT 1062 * or if there is junk in bpf_prog 1063 */ 1064 pr_err("bpf_jit: unknown opcode %02x\n", insn->code); 1065 return -EINVAL; 1066 } 1067 1068 ilen = prog - temp; 1069 if (ilen > BPF_MAX_INSN_SIZE) { 1070 pr_err("bpf_jit_compile fatal insn size error\n"); 1071 return -EFAULT; 1072 } 1073 1074 if (image) { 1075 if (unlikely(proglen + ilen > oldproglen)) { 1076 pr_err("bpf_jit_compile fatal error\n"); 1077 return -EFAULT; 1078 } 1079 memcpy(image + proglen, temp, ilen); 1080 } 1081 proglen += ilen; 1082 addrs[i] = proglen; 1083 prog = temp; 1084 } 1085 return proglen; 1086 } 1087 1088 void bpf_jit_compile(struct bpf_prog *prog) 1089 { 1090 } 1091 1092 struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) 1093 { 1094 struct bpf_binary_header *header = NULL; 1095 struct bpf_prog *tmp, *orig_prog = prog; 1096 int proglen, oldproglen = 0; 1097 struct jit_context ctx = {}; 1098 bool tmp_blinded = false; 1099 u8 *image = NULL; 1100 int *addrs; 1101 int pass; 1102 int i; 1103 1104 if (!bpf_jit_enable) 1105 return orig_prog; 1106 1107 tmp = bpf_jit_blind_constants(prog); 1108 /* If blinding was requested and we failed during blinding, 1109 * we must fall back to the interpreter. 1110 */ 1111 if (IS_ERR(tmp)) 1112 return orig_prog; 1113 if (tmp != prog) { 1114 tmp_blinded = true; 1115 prog = tmp; 1116 } 1117 1118 addrs = kmalloc(prog->len * sizeof(*addrs), GFP_KERNEL); 1119 if (!addrs) { 1120 prog = orig_prog; 1121 goto out; 1122 } 1123 1124 /* Before first pass, make a rough estimation of addrs[] 1125 * each bpf instruction is translated to less than 64 bytes 1126 */ 1127 for (proglen = 0, i = 0; i < prog->len; i++) { 1128 proglen += 64; 1129 addrs[i] = proglen; 1130 } 1131 ctx.cleanup_addr = proglen; 1132 1133 /* JITed image shrinks with every pass and the loop iterates 1134 * until the image stops shrinking. Very large bpf programs 1135 * may converge on the last pass. In such case do one more 1136 * pass to emit the final image 1137 */ 1138 for (pass = 0; pass < 10 || image; pass++) { 1139 proglen = do_jit(prog, addrs, image, oldproglen, &ctx); 1140 if (proglen <= 0) { 1141 image = NULL; 1142 if (header) 1143 bpf_jit_binary_free(header); 1144 prog = orig_prog; 1145 goto out_addrs; 1146 } 1147 if (image) { 1148 if (proglen != oldproglen) { 1149 pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", 1150 proglen, oldproglen); 1151 prog = orig_prog; 1152 goto out_addrs; 1153 } 1154 break; 1155 } 1156 if (proglen == oldproglen) { 1157 header = bpf_jit_binary_alloc(proglen, &image, 1158 1, jit_fill_hole); 1159 if (!header) { 1160 prog = orig_prog; 1161 goto out_addrs; 1162 } 1163 } 1164 oldproglen = proglen; 1165 } 1166 1167 if (bpf_jit_enable > 1) 1168 bpf_jit_dump(prog->len, proglen, pass + 1, image); 1169 1170 if (image) { 1171 bpf_flush_icache(header, image + proglen); 1172 set_memory_ro((unsigned long)header, header->pages); 1173 prog->bpf_func = (void *)image; 1174 prog->jited = 1; 1175 } 1176 1177 out_addrs: 1178 kfree(addrs); 1179 out: 1180 if (tmp_blinded) 1181 bpf_jit_prog_release_other(prog, prog == orig_prog ? 1182 tmp : orig_prog); 1183 return prog; 1184 } 1185 1186 void bpf_jit_free(struct bpf_prog *fp) 1187 { 1188 unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; 1189 struct bpf_binary_header *header = (void *)addr; 1190 1191 if (!fp->jited) 1192 goto free_filter; 1193 1194 set_memory_rw(addr, header->pages); 1195 bpf_jit_binary_free(header); 1196 1197 free_filter: 1198 bpf_prog_unlock_free(fp); 1199 } 1200