kernel/bpf/core.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Linux Socket Filter - Kernel level socket filtering
   4  *
   5  * Based on the design of the Berkeley Packet Filter. The new
   6  * internal format has been designed by PLUMgrid:
   7  *
   8  *      Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com
   9  *
  10  * Authors:
  11  *
  12  *      Jay Schulist <jschlst@samba.org>
  13  *      Alexei Starovoitov <ast@plumgrid.com>
  14  *      Daniel Borkmann <dborkman@redhat.com>
  15  *
  16  * Andi Kleen - Fix a few bad bugs and races.
  17  * Kris Katterjohn - Added many additional checks in bpf_check_classic()
  18  */
  19
  20 #include <uapi/linux/btf.h>
  21 #include <linux/filter.h>
  22 #include <linux/skbuff.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/random.h>
  25 #include <linux/moduleloader.h>
  26 #include <linux/bpf.h>
  27 #include <linux/btf.h>
  28 #include <linux/objtool.h>
  29 #include <linux/rbtree_latch.h>
  30 #include <linux/kallsyms.h>
  31 #include <linux/rcupdate.h>
  32 #include <linux/perf_event.h>
  33 #include <linux/extable.h>
  34 #include <linux/log2.h>
  35 #include <linux/bpf_verifier.h>
  36 #include <linux/nodemask.h>
  37 #include <linux/nospec.h>
  38 #include <linux/bpf_mem_alloc.h>
  39 #include <linux/memcontrol.h>
  40
  41 #include <asm/barrier.h>
  42 #include <asm/unaligned.h>
  43
  44 /* Registers */
  45 #define BPF_R0  regs[BPF_REG_0]
  46 #define BPF_R1  regs[BPF_REG_1]
  47 #define BPF_R2  regs[BPF_REG_2]
  48 #define BPF_R3  regs[BPF_REG_3]
  49 #define BPF_R4  regs[BPF_REG_4]
  50 #define BPF_R5  regs[BPF_REG_5]
  51 #define BPF_R6  regs[BPF_REG_6]
  52 #define BPF_R7  regs[BPF_REG_7]
  53 #define BPF_R8  regs[BPF_REG_8]
  54 #define BPF_R9  regs[BPF_REG_9]
  55 #define BPF_R10 regs[BPF_REG_10]
  56
  57 /* Named registers */
  58 #define DST     regs[insn->dst_reg]
  59 #define SRC     regs[insn->src_reg]
  60 #define FP      regs[BPF_REG_FP]
  61 #define AX      regs[BPF_REG_AX]
  62 #define ARG1    regs[BPF_REG_ARG1]
  63 #define CTX     regs[BPF_REG_CTX]
  64 #define OFF     insn->off
  65 #define IMM     insn->imm
  66
  67 struct bpf_mem_alloc bpf_global_ma;
  68 bool bpf_global_ma_set;
  69
  70 /* No hurry in this branch
  71  *
  72  * Exported for the bpf jit load helper.
  73  */
  74 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
  75 {
  76         u8 *ptr = NULL;
  77
  78         if (k >= SKF_NET_OFF) {
  79                 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
  80         } else if (k >= SKF_LL_OFF) {
  81                 if (unlikely(!skb_mac_header_was_set(skb)))
  82                         return NULL;
  83                 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
  84         }
  85         if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
  86                 return ptr;
  87
  88         return NULL;
  89 }
  90
  91 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
  92 {
  93         gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
  94         struct bpf_prog_aux *aux;
  95         struct bpf_prog *fp;
  96
  97         size = round_up(size, PAGE_SIZE);
  98         fp = __vmalloc(size, gfp_flags);
  99         if (fp == NULL)
 100                 return NULL;
 101
 102         aux = kzalloc(sizeof(*aux), bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
 103         if (aux == NULL) {
 104                 vfree(fp);
 105                 return NULL;
 106         }
 107         fp->active = alloc_percpu_gfp(int, bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
 108         if (!fp->active) {
 109                 vfree(fp);
 110                 kfree(aux);
 111                 return NULL;
 112         }
 113
 114         fp->pages = size / PAGE_SIZE;
 115         fp->aux = aux;
 116         fp->aux->prog = fp;
 117         fp->jit_requested = ebpf_jit_enabled();
 118         fp->blinding_requested = bpf_jit_blinding_enabled(fp);
 119 #ifdef CONFIG_CGROUP_BPF
 120         aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
 121 #endif
 122
 123         INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
 124         mutex_init(&fp->aux->used_maps_mutex);
 125         mutex_init(&fp->aux->dst_mutex);
 126
 127         return fp;
 128 }
 129
 130 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
 131 {
 132         gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
 133         struct bpf_prog *prog;
 134         int cpu;
 135
 136         prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
 137         if (!prog)
 138                 return NULL;
 139
 140         prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
 141         if (!prog->stats) {
 142                 free_percpu(prog->active);
 143                 kfree(prog->aux);
 144                 vfree(prog);
 145                 return NULL;
 146         }
 147
 148         for_each_possible_cpu(cpu) {
 149                 struct bpf_prog_stats *pstats;
 150
 151                 pstats = per_cpu_ptr(prog->stats, cpu);
 152                 u64_stats_init(&pstats->syncp);
 153         }
 154         return prog;
 155 }
 156 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
 157
 158 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
 159 {
 160         if (!prog->aux->nr_linfo || !prog->jit_requested)
 161                 return 0;
 162
 163         prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
 164                                           sizeof(*prog->aux->jited_linfo),
 165                                           bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN));
 166         if (!prog->aux->jited_linfo)
 167                 return -ENOMEM;
 168
 169         return 0;
 170 }
 171
 172 void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
 173 {
 174         if (prog->aux->jited_linfo &&
 175             (!prog->jited || !prog->aux->jited_linfo[0])) {
 176                 kvfree(prog->aux->jited_linfo);
 177                 prog->aux->jited_linfo = NULL;
 178         }
 179
 180         kfree(prog->aux->kfunc_tab);
 181         prog->aux->kfunc_tab = NULL;
 182 }
 183
 184 /* The jit engine is responsible to provide an array
 185  * for insn_off to the jited_off mapping (insn_to_jit_off).
 186  *
 187  * The idx to this array is the insn_off.  Hence, the insn_off
 188  * here is relative to the prog itself instead of the main prog.
 189  * This array has one entry for each xlated bpf insn.
 190  *
 191  * jited_off is the byte off to the end of the jited insn.
 192  *
 193  * Hence, with
 194  * insn_start:
 195  *      The first bpf insn off of the prog.  The insn off
 196  *      here is relative to the main prog.
 197  *      e.g. if prog is a subprog, insn_start > 0
 198  * linfo_idx:
 199  *      The prog's idx to prog->aux->linfo and jited_linfo
 200  *
 201  * jited_linfo[linfo_idx] = prog->bpf_func
 202  *
 203  * For i > linfo_idx,
 204  *
 205  * jited_linfo[i] = prog->bpf_func +
 206  *      insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
 207  */
 208 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
 209                                const u32 *insn_to_jit_off)
 210 {
 211         u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
 212         const struct bpf_line_info *linfo;
 213         void **jited_linfo;
 214
 215         if (!prog->aux->jited_linfo)
 216                 /* Userspace did not provide linfo */
 217                 return;
 218
 219         linfo_idx = prog->aux->linfo_idx;
 220         linfo = &prog->aux->linfo[linfo_idx];
 221         insn_start = linfo[0].insn_off;
 222         insn_end = insn_start + prog->len;
 223
 224         jited_linfo = &prog->aux->jited_linfo[linfo_idx];
 225         jited_linfo[0] = prog->bpf_func;
 226
 227         nr_linfo = prog->aux->nr_linfo - linfo_idx;
 228
 229         for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
 230                 /* The verifier ensures that linfo[i].insn_off is
 231                  * strictly increasing
 232                  */
 233                 jited_linfo[i] = prog->bpf_func +
 234                         insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
 235 }
 236
 237 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 238                                   gfp_t gfp_extra_flags)
 239 {
 240         gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
 241         struct bpf_prog *fp;
 242         u32 pages;
 243
 244         size = round_up(size, PAGE_SIZE);
 245         pages = size / PAGE_SIZE;
 246         if (pages <= fp_old->pages)
 247                 return fp_old;
 248
 249         fp = __vmalloc(size, gfp_flags);
 250         if (fp) {
 251                 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
 252                 fp->pages = pages;
 253                 fp->aux->prog = fp;
 254
 255                 /* We keep fp->aux from fp_old around in the new
 256                  * reallocated structure.
 257                  */
 258                 fp_old->aux = NULL;
 259                 fp_old->stats = NULL;
 260                 fp_old->active = NULL;
 261                 __bpf_prog_free(fp_old);
 262         }
 263
 264         return fp;
 265 }
 266
 267 void __bpf_prog_free(struct bpf_prog *fp)
 268 {
 269         if (fp->aux) {
 270                 mutex_destroy(&fp->aux->used_maps_mutex);
 271                 mutex_destroy(&fp->aux->dst_mutex);
 272                 kfree(fp->aux->poke_tab);
 273                 kfree(fp->aux);
 274         }
 275         free_percpu(fp->stats);
 276         free_percpu(fp->active);
 277         vfree(fp);
 278 }
 279
 280 int bpf_prog_calc_tag(struct bpf_prog *fp)
 281 {
 282         const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
 283         u32 raw_size = bpf_prog_tag_scratch_size(fp);
 284         u32 digest[SHA1_DIGEST_WORDS];
 285         u32 ws[SHA1_WORKSPACE_WORDS];
 286         u32 i, bsize, psize, blocks;
 287         struct bpf_insn *dst;
 288         bool was_ld_map;
 289         u8 *raw, *todo;
 290         __be32 *result;
 291         __be64 *bits;
 292
 293         raw = vmalloc(raw_size);
 294         if (!raw)
 295                 return -ENOMEM;
 296
 297         sha1_init(digest);
 298         memset(ws, 0, sizeof(ws));
 299
 300         /* We need to take out the map fd for the digest calculation
 301          * since they are unstable from user space side.
 302          */
 303         dst = (void *)raw;
 304         for (i = 0, was_ld_map = false; i < fp->len; i++) {
 305                 dst[i] = fp->insnsi[i];
 306                 if (!was_ld_map &&
 307                     dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
 308                     (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
 309                      dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
 310                         was_ld_map = true;
 311                         dst[i].imm = 0;
 312                 } else if (was_ld_map &&
 313                            dst[i].code == 0 &&
 314                            dst[i].dst_reg == 0 &&
 315                            dst[i].src_reg == 0 &&
 316                            dst[i].off == 0) {
 317                         was_ld_map = false;
 318                         dst[i].imm = 0;
 319                 } else {
 320                         was_ld_map = false;
 321                 }
 322         }
 323
 324         psize = bpf_prog_insn_size(fp);
 325         memset(&raw[psize], 0, raw_size - psize);
 326         raw[psize++] = 0x80;
 327
 328         bsize  = round_up(psize, SHA1_BLOCK_SIZE);
 329         blocks = bsize / SHA1_BLOCK_SIZE;
 330         todo   = raw;
 331         if (bsize - psize >= sizeof(__be64)) {
 332                 bits = (__be64 *)(todo + bsize - sizeof(__be64));
 333         } else {
 334                 bits = (__be64 *)(todo + bsize + bits_offset);
 335                 blocks++;
 336         }
 337         *bits = cpu_to_be64((psize - 1) << 3);
 338
 339         while (blocks--) {
 340                 sha1_transform(digest, todo, ws);
 341                 todo += SHA1_BLOCK_SIZE;
 342         }
 343
 344         result = (__force __be32 *)digest;
 345         for (i = 0; i < SHA1_DIGEST_WORDS; i++)
 346                 result[i] = cpu_to_be32(digest[i]);
 347         memcpy(fp->tag, result, sizeof(fp->tag));
 348
 349         vfree(raw);
 350         return 0;
 351 }
 352
 353 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
 354                                 s32 end_new, s32 curr, const bool probe_pass)
 355 {
 356         const s64 imm_min = S32_MIN, imm_max = S32_MAX;
 357         s32 delta = end_new - end_old;
 358         s64 imm = insn->imm;
 359
 360         if (curr < pos && curr + imm + 1 >= end_old)
 361                 imm += delta;
 362         else if (curr >= end_new && curr + imm + 1 < end_new)
 363                 imm -= delta;
 364         if (imm < imm_min || imm > imm_max)
 365                 return -ERANGE;
 366         if (!probe_pass)
 367                 insn->imm = imm;
 368         return 0;
 369 }
 370
 371 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
 372                                 s32 end_new, s32 curr, const bool probe_pass)
 373 {
 374         const s32 off_min = S16_MIN, off_max = S16_MAX;
 375         s32 delta = end_new - end_old;
 376         s32 off = insn->off;
 377
 378         if (curr < pos && curr + off + 1 >= end_old)
 379                 off += delta;
 380         else if (curr >= end_new && curr + off + 1 < end_new)
 381                 off -= delta;
 382         if (off < off_min || off > off_max)
 383                 return -ERANGE;
 384         if (!probe_pass)
 385                 insn->off = off;
 386         return 0;
 387 }
 388
 389 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
 390                             s32 end_new, const bool probe_pass)
 391 {
 392         u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
 393         struct bpf_insn *insn = prog->insnsi;
 394         int ret = 0;
 395
 396         for (i = 0; i < insn_cnt; i++, insn++) {
 397                 u8 code;
 398
 399                 /* In the probing pass we still operate on the original,
 400                  * unpatched image in order to check overflows before we
 401                  * do any other adjustments. Therefore skip the patchlet.
 402                  */
 403                 if (probe_pass && i == pos) {
 404                         i = end_new;
 405                         insn = prog->insnsi + end_old;
 406                 }
 407                 if (bpf_pseudo_func(insn)) {
 408                         ret = bpf_adj_delta_to_imm(insn, pos, end_old,
 409                                                    end_new, i, probe_pass);
 410                         if (ret)
 411                                 return ret;
 412                         continue;
 413                 }
 414                 code = insn->code;
 415                 if ((BPF_CLASS(code) != BPF_JMP &&
 416                      BPF_CLASS(code) != BPF_JMP32) ||
 417                     BPF_OP(code) == BPF_EXIT)
 418                         continue;
 419                 /* Adjust offset of jmps if we cross patch boundaries. */
 420                 if (BPF_OP(code) == BPF_CALL) {
 421                         if (insn->src_reg != BPF_PSEUDO_CALL)
 422                                 continue;
 423                         ret = bpf_adj_delta_to_imm(insn, pos, end_old,
 424                                                    end_new, i, probe_pass);
 425                 } else {
 426                         ret = bpf_adj_delta_to_off(insn, pos, end_old,
 427                                                    end_new, i, probe_pass);
 428                 }
 429                 if (ret)
 430                         break;
 431         }
 432
 433         return ret;
 434 }
 435
 436 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
 437 {
 438         struct bpf_line_info *linfo;
 439         u32 i, nr_linfo;
 440
 441         nr_linfo = prog->aux->nr_linfo;
 442         if (!nr_linfo || !delta)
 443                 return;
 444
 445         linfo = prog->aux->linfo;
 446
 447         for (i = 0; i < nr_linfo; i++)
 448                 if (off < linfo[i].insn_off)
 449                         break;
 450
 451         /* Push all off < linfo[i].insn_off by delta */
 452         for (; i < nr_linfo; i++)
 453                 linfo[i].insn_off += delta;
 454 }
 455
 456 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 457                                        const struct bpf_insn *patch, u32 len)
 458 {
 459         u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
 460         const u32 cnt_max = S16_MAX;
 461         struct bpf_prog *prog_adj;
 462         int err;
 463
 464         /* Since our patchlet doesn't expand the image, we're done. */
 465         if (insn_delta == 0) {
 466                 memcpy(prog->insnsi + off, patch, sizeof(*patch));
 467                 return prog;
 468         }
 469
 470         insn_adj_cnt = prog->len + insn_delta;
 471
 472         /* Reject anything that would potentially let the insn->off
 473          * target overflow when we have excessive program expansions.
 474          * We need to probe here before we do any reallocation where
 475          * we afterwards may not fail anymore.
 476          */
 477         if (insn_adj_cnt > cnt_max &&
 478             (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
 479                 return ERR_PTR(err);
 480
 481         /* Several new instructions need to be inserted. Make room
 482          * for them. Likely, there's no need for a new allocation as
 483          * last page could have large enough tailroom.
 484          */
 485         prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
 486                                     GFP_USER);
 487         if (!prog_adj)
 488                 return ERR_PTR(-ENOMEM);
 489
 490         prog_adj->len = insn_adj_cnt;
 491
 492         /* Patching happens in 3 steps:
 493          *
 494          * 1) Move over tail of insnsi from next instruction onwards,
 495          *    so we can patch the single target insn with one or more
 496          *    new ones (patching is always from 1 to n insns, n > 0).
 497          * 2) Inject new instructions at the target location.
 498          * 3) Adjust branch offsets if necessary.
 499          */
 500         insn_rest = insn_adj_cnt - off - len;
 501
 502         memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
 503                 sizeof(*patch) * insn_rest);
 504         memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
 505
 506         /* We are guaranteed to not fail at this point, otherwise
 507          * the ship has sailed to reverse to the original state. An
 508          * overflow cannot happen at this point.
 509          */
 510         BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
 511
 512         bpf_adj_linfo(prog_adj, off, insn_delta);
 513
 514         return prog_adj;
 515 }
 516
 517 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
 518 {
 519         /* Branch offsets can't overflow when program is shrinking, no need
 520          * to call bpf_adj_branches(..., true) here
 521          */
 522         memmove(prog->insnsi + off, prog->insnsi + off + cnt,
 523                 sizeof(struct bpf_insn) * (prog->len - off - cnt));
 524         prog->len -= cnt;
 525
 526         return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
 527 }
 528
 529 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
 530 {
 531         int i;
 532
 533         for (i = 0; i < fp->aux->func_cnt; i++)
 534                 bpf_prog_kallsyms_del(fp->aux->func[i]);
 535 }
 536
 537 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
 538 {
 539         bpf_prog_kallsyms_del_subprogs(fp);
 540         bpf_prog_kallsyms_del(fp);
 541 }
 542
 543 #ifdef CONFIG_BPF_JIT
 544 /* All BPF JIT sysctl knobs here. */
 545 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
 546 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
 547 int bpf_jit_harden   __read_mostly;
 548 long bpf_jit_limit   __read_mostly;
 549 long bpf_jit_limit_max __read_mostly;
 550
 551 static void
 552 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
 553 {
 554         WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
 555
 556         prog->aux->ksym.start = (unsigned long) prog->bpf_func;
 557         prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
 558 }
 559
 560 static void
 561 bpf_prog_ksym_set_name(struct bpf_prog *prog)
 562 {
 563         char *sym = prog->aux->ksym.name;
 564         const char *end = sym + KSYM_NAME_LEN;
 565         const struct btf_type *type;
 566         const char *func_name;
 567
 568         BUILD_BUG_ON(sizeof("bpf_prog_") +
 569                      sizeof(prog->tag) * 2 +
 570                      /* name has been null terminated.
 571                       * We should need +1 for the '_' preceding
 572                       * the name.  However, the null character
 573                       * is double counted between the name and the
 574                       * sizeof("bpf_prog_") above, so we omit
 575                       * the +1 here.
 576                       */
 577                      sizeof(prog->aux->name) > KSYM_NAME_LEN);
 578
 579         sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
 580         sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
 581
 582         /* prog->aux->name will be ignored if full btf name is available */
 583         if (prog->aux->func_info_cnt) {
 584                 type = btf_type_by_id(prog->aux->btf,
 585                                       prog->aux->func_info[prog->aux->func_idx].type_id);
 586                 func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
 587                 snprintf(sym, (size_t)(end - sym), "_%s", func_name);
 588                 return;
 589         }
 590
 591         if (prog->aux->name[0])
 592                 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
 593         else
 594                 *sym = 0;
 595 }
 596
 597 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
 598 {
 599         return container_of(n, struct bpf_ksym, tnode)->start;
 600 }
 601
 602 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
 603                                           struct latch_tree_node *b)
 604 {
 605         return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
 606 }
 607
 608 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
 609 {
 610         unsigned long val = (unsigned long)key;
 611         const struct bpf_ksym *ksym;
 612
 613         ksym = container_of(n, struct bpf_ksym, tnode);
 614
 615         if (val < ksym->start)
 616                 return -1;
 617         if (val >= ksym->end)
 618                 return  1;
 619
 620         return 0;
 621 }
 622
 623 static const struct latch_tree_ops bpf_tree_ops = {
 624         .less   = bpf_tree_less,
 625         .comp   = bpf_tree_comp,
 626 };
 627
 628 static DEFINE_SPINLOCK(bpf_lock);
 629 static LIST_HEAD(bpf_kallsyms);
 630 static struct latch_tree_root bpf_tree __cacheline_aligned;
 631
 632 void bpf_ksym_add(struct bpf_ksym *ksym)
 633 {
 634         spin_lock_bh(&bpf_lock);
 635         WARN_ON_ONCE(!list_empty(&ksym->lnode));
 636         list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
 637         latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
 638         spin_unlock_bh(&bpf_lock);
 639 }
 640
 641 static void __bpf_ksym_del(struct bpf_ksym *ksym)
 642 {
 643         if (list_empty(&ksym->lnode))
 644                 return;
 645
 646         latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
 647         list_del_rcu(&ksym->lnode);
 648 }
 649
 650 void bpf_ksym_del(struct bpf_ksym *ksym)
 651 {
 652         spin_lock_bh(&bpf_lock);
 653         __bpf_ksym_del(ksym);
 654         spin_unlock_bh(&bpf_lock);
 655 }
 656
 657 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
 658 {
 659         return fp->jited && !bpf_prog_was_classic(fp);
 660 }
 661
 662 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 663 {
 664         if (!bpf_prog_kallsyms_candidate(fp) ||
 665             !bpf_capable())
 666                 return;
 667
 668         bpf_prog_ksym_set_addr(fp);
 669         bpf_prog_ksym_set_name(fp);
 670         fp->aux->ksym.prog = true;
 671
 672         bpf_ksym_add(&fp->aux->ksym);
 673 }
 674
 675 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 676 {
 677         if (!bpf_prog_kallsyms_candidate(fp))
 678                 return;
 679
 680         bpf_ksym_del(&fp->aux->ksym);
 681 }
 682
 683 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
 684 {
 685         struct latch_tree_node *n;
 686
 687         n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
 688         return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
 689 }
 690
 691 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
 692                                  unsigned long *off, char *sym)
 693 {
 694         struct bpf_ksym *ksym;
 695         char *ret = NULL;
 696
 697         rcu_read_lock();
 698         ksym = bpf_ksym_find(addr);
 699         if (ksym) {
 700                 unsigned long symbol_start = ksym->start;
 701                 unsigned long symbol_end = ksym->end;
 702
 703                 strncpy(sym, ksym->name, KSYM_NAME_LEN);
 704
 705                 ret = sym;
 706                 if (size)
 707                         *size = symbol_end - symbol_start;
 708                 if (off)
 709                         *off  = addr - symbol_start;
 710         }
 711         rcu_read_unlock();
 712
 713         return ret;
 714 }
 715
 716 bool is_bpf_text_address(unsigned long addr)
 717 {
 718         bool ret;
 719
 720         rcu_read_lock();
 721         ret = bpf_ksym_find(addr) != NULL;
 722         rcu_read_unlock();
 723
 724         return ret;
 725 }
 726
 727 static struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
 728 {
 729         struct bpf_ksym *ksym = bpf_ksym_find(addr);
 730
 731         return ksym && ksym->prog ?
 732                container_of(ksym, struct bpf_prog_aux, ksym)->prog :
 733                NULL;
 734 }
 735
 736 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
 737 {
 738         const struct exception_table_entry *e = NULL;
 739         struct bpf_prog *prog;
 740
 741         rcu_read_lock();
 742         prog = bpf_prog_ksym_find(addr);
 743         if (!prog)
 744                 goto out;
 745         if (!prog->aux->num_exentries)
 746                 goto out;
 747
 748         e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
 749 out:
 750         rcu_read_unlock();
 751         return e;
 752 }
 753
 754 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 755                     char *sym)
 756 {
 757         struct bpf_ksym *ksym;
 758         unsigned int it = 0;
 759         int ret = -ERANGE;
 760
 761         if (!bpf_jit_kallsyms_enabled())
 762                 return ret;
 763
 764         rcu_read_lock();
 765         list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
 766                 if (it++ != symnum)
 767                         continue;
 768
 769                 strncpy(sym, ksym->name, KSYM_NAME_LEN);
 770
 771                 *value = ksym->start;
 772                 *type  = BPF_SYM_ELF_TYPE;
 773
 774                 ret = 0;
 775                 break;
 776         }
 777         rcu_read_unlock();
 778
 779         return ret;
 780 }
 781
 782 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
 783                                 struct bpf_jit_poke_descriptor *poke)
 784 {
 785         struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
 786         static const u32 poke_tab_max = 1024;
 787         u32 slot = prog->aux->size_poke_tab;
 788         u32 size = slot + 1;
 789
 790         if (size > poke_tab_max)
 791                 return -ENOSPC;
 792         if (poke->tailcall_target || poke->tailcall_target_stable ||
 793             poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
 794                 return -EINVAL;
 795
 796         switch (poke->reason) {
 797         case BPF_POKE_REASON_TAIL_CALL:
 798                 if (!poke->tail_call.map)
 799                         return -EINVAL;
 800                 break;
 801         default:
 802                 return -EINVAL;
 803         }
 804
 805         tab = krealloc(tab, size * sizeof(*poke), GFP_KERNEL);
 806         if (!tab)
 807                 return -ENOMEM;
 808
 809         memcpy(&tab[slot], poke, sizeof(*poke));
 810         prog->aux->size_poke_tab = size;
 811         prog->aux->poke_tab = tab;
 812
 813         return slot;
 814 }
 815
 816 /*
 817  * BPF program pack allocator.
 818  *
 819  * Most BPF programs are pretty small. Allocating a hole page for each
 820  * program is sometime a waste. Many small bpf program also adds pressure
 821  * to instruction TLB. To solve this issue, we introduce a BPF program pack
 822  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
 823  * to host BPF programs.
 824  */
 825 #define BPF_PROG_CHUNK_SHIFT    6
 826 #define BPF_PROG_CHUNK_SIZE     (1 << BPF_PROG_CHUNK_SHIFT)
 827 #define BPF_PROG_CHUNK_MASK     (~(BPF_PROG_CHUNK_SIZE - 1))
 828
 829 struct bpf_prog_pack {
 830         struct list_head list;
 831         void *ptr;
 832         unsigned long bitmap[];
 833 };
 834
 835 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
 836 {
 837         memset(area, 0, size);
 838 }
 839
 840 #define BPF_PROG_SIZE_TO_NBITS(size)    (round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
 841
 842 static DEFINE_MUTEX(pack_mutex);
 843 static LIST_HEAD(pack_list);
 844
 845 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
 846  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
 847  */
 848 #ifdef PMD_SIZE
 849 #define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
 850 #else
 851 #define BPF_PROG_PACK_SIZE PAGE_SIZE
 852 #endif
 853
 854 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
 855
 856 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
 857 {
 858         struct bpf_prog_pack *pack;
 859
 860         pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
 861                        GFP_KERNEL);
 862         if (!pack)
 863                 return NULL;
 864         pack->ptr = module_alloc(BPF_PROG_PACK_SIZE);
 865         if (!pack->ptr) {
 866                 kfree(pack);
 867                 return NULL;
 868         }
 869         bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
 870         bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
 871         list_add_tail(&pack->list, &pack_list);
 872
 873         set_vm_flush_reset_perms(pack->ptr);
 874         set_memory_rox((unsigned long)pack->ptr, BPF_PROG_PACK_SIZE / PAGE_SIZE);
 875         return pack;
 876 }
 877
 878 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
 879 {
 880         unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
 881         struct bpf_prog_pack *pack;
 882         unsigned long pos;
 883         void *ptr = NULL;
 884
 885         mutex_lock(&pack_mutex);
 886         if (size > BPF_PROG_PACK_SIZE) {
 887                 size = round_up(size, PAGE_SIZE);
 888                 ptr = module_alloc(size);
 889                 if (ptr) {
 890                         bpf_fill_ill_insns(ptr, size);
 891                         set_vm_flush_reset_perms(ptr);
 892                         set_memory_rox((unsigned long)ptr, size / PAGE_SIZE);
 893                 }
 894                 goto out;
 895         }
 896         list_for_each_entry(pack, &pack_list, list) {
 897                 pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
 898                                                  nbits, 0);
 899                 if (pos < BPF_PROG_CHUNK_COUNT)
 900                         goto found_free_area;
 901         }
 902
 903         pack = alloc_new_pack(bpf_fill_ill_insns);
 904         if (!pack)
 905                 goto out;
 906
 907         pos = 0;
 908
 909 found_free_area:
 910         bitmap_set(pack->bitmap, pos, nbits);
 911         ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
 912
 913 out:
 914         mutex_unlock(&pack_mutex);
 915         return ptr;
 916 }
 917
 918 void bpf_prog_pack_free(struct bpf_binary_header *hdr)
 919 {
 920         struct bpf_prog_pack *pack = NULL, *tmp;
 921         unsigned int nbits;
 922         unsigned long pos;
 923
 924         mutex_lock(&pack_mutex);
 925         if (hdr->size > BPF_PROG_PACK_SIZE) {
 926                 module_memfree(hdr);
 927                 goto out;
 928         }
 929
 930         list_for_each_entry(tmp, &pack_list, list) {
 931                 if ((void *)hdr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > (void *)hdr) {
 932                         pack = tmp;
 933                         break;
 934                 }
 935         }
 936
 937         if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
 938                 goto out;
 939
 940         nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size);
 941         pos = ((unsigned long)hdr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
 942
 943         WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size),
 944                   "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
 945
 946         bitmap_clear(pack->bitmap, pos, nbits);
 947         if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
 948                                        BPF_PROG_CHUNK_COUNT, 0) == 0) {
 949                 list_del(&pack->list);
 950                 module_memfree(pack->ptr);
 951                 kfree(pack);
 952         }
 953 out:
 954         mutex_unlock(&pack_mutex);
 955 }
 956
 957 static atomic_long_t bpf_jit_current;
 958
 959 /* Can be overridden by an arch's JIT compiler if it has a custom,
 960  * dedicated BPF backend memory area, or if neither of the two
 961  * below apply.
 962  */
 963 u64 __weak bpf_jit_alloc_exec_limit(void)
 964 {
 965 #if defined(MODULES_VADDR)
 966         return MODULES_END - MODULES_VADDR;
 967 #else
 968         return VMALLOC_END - VMALLOC_START;
 969 #endif
 970 }
 971
 972 static int __init bpf_jit_charge_init(void)
 973 {
 974         /* Only used as heuristic here to derive limit. */
 975         bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
 976         bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
 977                                             PAGE_SIZE), LONG_MAX);
 978         return 0;
 979 }
 980 pure_initcall(bpf_jit_charge_init);
 981
 982 int bpf_jit_charge_modmem(u32 size)
 983 {
 984         if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
 985                 if (!bpf_capable()) {
 986                         atomic_long_sub(size, &bpf_jit_current);
 987                         return -EPERM;
 988                 }
 989         }
 990
 991         return 0;
 992 }
 993
 994 void bpf_jit_uncharge_modmem(u32 size)
 995 {
 996         atomic_long_sub(size, &bpf_jit_current);
 997 }
 998
 999 void *__weak bpf_jit_alloc_exec(unsigned long size)
1000 {
1001         return module_alloc(size);
1002 }
1003
1004 void __weak bpf_jit_free_exec(void *addr)
1005 {
1006         module_memfree(addr);
1007 }
1008
1009 struct bpf_binary_header *
1010 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1011                      unsigned int alignment,
1012                      bpf_jit_fill_hole_t bpf_fill_ill_insns)
1013 {
1014         struct bpf_binary_header *hdr;
1015         u32 size, hole, start;
1016
1017         WARN_ON_ONCE(!is_power_of_2(alignment) ||
1018                      alignment > BPF_IMAGE_ALIGNMENT);
1019
1020         /* Most of BPF filters are really small, but if some of them
1021          * fill a page, allow at least 128 extra bytes to insert a
1022          * random section of illegal instructions.
1023          */
1024         size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1025
1026         if (bpf_jit_charge_modmem(size))
1027                 return NULL;
1028         hdr = bpf_jit_alloc_exec(size);
1029         if (!hdr) {
1030                 bpf_jit_uncharge_modmem(size);
1031                 return NULL;
1032         }
1033
1034         /* Fill space with illegal/arch-dep instructions. */
1035         bpf_fill_ill_insns(hdr, size);
1036
1037         hdr->size = size;
1038         hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1039                      PAGE_SIZE - sizeof(*hdr));
1040         start = get_random_u32_below(hole) & ~(alignment - 1);
1041
1042         /* Leave a random number of instructions before BPF code. */
1043         *image_ptr = &hdr->image[start];
1044
1045         return hdr;
1046 }
1047
1048 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1049 {
1050         u32 size = hdr->size;
1051
1052         bpf_jit_free_exec(hdr);
1053         bpf_jit_uncharge_modmem(size);
1054 }
1055
1056 /* Allocate jit binary from bpf_prog_pack allocator.
1057  * Since the allocated memory is RO+X, the JIT engine cannot write directly
1058  * to the memory. To solve this problem, a RW buffer is also allocated at
1059  * as the same time. The JIT engine should calculate offsets based on the
1060  * RO memory address, but write JITed program to the RW buffer. Once the
1061  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1062  * the JITed program to the RO memory.
1063  */
1064 struct bpf_binary_header *
1065 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1066                           unsigned int alignment,
1067                           struct bpf_binary_header **rw_header,
1068                           u8 **rw_image,
1069                           bpf_jit_fill_hole_t bpf_fill_ill_insns)
1070 {
1071         struct bpf_binary_header *ro_header;
1072         u32 size, hole, start;
1073
1074         WARN_ON_ONCE(!is_power_of_2(alignment) ||
1075                      alignment > BPF_IMAGE_ALIGNMENT);
1076
1077         /* add 16 bytes for a random section of illegal instructions */
1078         size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1079
1080         if (bpf_jit_charge_modmem(size))
1081                 return NULL;
1082         ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1083         if (!ro_header) {
1084                 bpf_jit_uncharge_modmem(size);
1085                 return NULL;
1086         }
1087
1088         *rw_header = kvmalloc(size, GFP_KERNEL);
1089         if (!*rw_header) {
1090                 bpf_arch_text_copy(&ro_header->size, &size, sizeof(size));
1091                 bpf_prog_pack_free(ro_header);
1092                 bpf_jit_uncharge_modmem(size);
1093                 return NULL;
1094         }
1095
1096         /* Fill space with illegal/arch-dep instructions. */
1097         bpf_fill_ill_insns(*rw_header, size);
1098         (*rw_header)->size = size;
1099
1100         hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1101                      BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1102         start = get_random_u32_below(hole) & ~(alignment - 1);
1103
1104         *image_ptr = &ro_header->image[start];
1105         *rw_image = &(*rw_header)->image[start];
1106
1107         return ro_header;
1108 }
1109
1110 /* Copy JITed text from rw_header to its final location, the ro_header. */
1111 int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
1112                                  struct bpf_binary_header *ro_header,
1113                                  struct bpf_binary_header *rw_header)
1114 {
1115         void *ptr;
1116
1117         ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1118
1119         kvfree(rw_header);
1120
1121         if (IS_ERR(ptr)) {
1122                 bpf_prog_pack_free(ro_header);
1123                 return PTR_ERR(ptr);
1124         }
1125         return 0;
1126 }
1127
1128 /* bpf_jit_binary_pack_free is called in two different scenarios:
1129  *   1) when the program is freed after;
1130  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1131  * For case 2), we need to free both the RO memory and the RW buffer.
1132  *
1133  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1134  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1135  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1136  * bpf_arch_text_copy (when jit fails).
1137  */
1138 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1139                               struct bpf_binary_header *rw_header)
1140 {
1141         u32 size = ro_header->size;
1142
1143         bpf_prog_pack_free(ro_header);
1144         kvfree(rw_header);
1145         bpf_jit_uncharge_modmem(size);
1146 }
1147
1148 struct bpf_binary_header *
1149 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1150 {
1151         unsigned long real_start = (unsigned long)fp->bpf_func;
1152         unsigned long addr;
1153
1154         addr = real_start & BPF_PROG_CHUNK_MASK;
1155         return (void *)addr;
1156 }
1157
1158 static inline struct bpf_binary_header *
1159 bpf_jit_binary_hdr(const struct bpf_prog *fp)
1160 {
1161         unsigned long real_start = (unsigned long)fp->bpf_func;
1162         unsigned long addr;
1163
1164         addr = real_start & PAGE_MASK;
1165         return (void *)addr;
1166 }
1167
1168 /* This symbol is only overridden by archs that have different
1169  * requirements than the usual eBPF JITs, f.e. when they only
1170  * implement cBPF JIT, do not set images read-only, etc.
1171  */
1172 void __weak bpf_jit_free(struct bpf_prog *fp)
1173 {
1174         if (fp->jited) {
1175                 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1176
1177                 bpf_jit_binary_free(hdr);
1178                 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1179         }
1180
1181         bpf_prog_unlock_free(fp);
1182 }
1183
1184 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1185                           const struct bpf_insn *insn, bool extra_pass,
1186                           u64 *func_addr, bool *func_addr_fixed)
1187 {
1188         s16 off = insn->off;
1189         s32 imm = insn->imm;
1190         u8 *addr;
1191         int err;
1192
1193         *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1194         if (!*func_addr_fixed) {
1195                 /* Place-holder address till the last pass has collected
1196                  * all addresses for JITed subprograms in which case we
1197                  * can pick them up from prog->aux.
1198                  */
1199                 if (!extra_pass)
1200                         addr = NULL;
1201                 else if (prog->aux->func &&
1202                          off >= 0 && off < prog->aux->func_cnt)
1203                         addr = (u8 *)prog->aux->func[off]->bpf_func;
1204                 else
1205                         return -EINVAL;
1206         } else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1207                    bpf_jit_supports_far_kfunc_call()) {
1208                 err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1209                 if (err)
1210                         return err;
1211         } else {
1212                 /* Address of a BPF helper call. Since part of the core
1213                  * kernel, it's always at a fixed location. __bpf_call_base
1214                  * and the helper with imm relative to it are both in core
1215                  * kernel.
1216                  */
1217                 addr = (u8 *)__bpf_call_base + imm;
1218         }
1219
1220         *func_addr = (unsigned long)addr;
1221         return 0;
1222 }
1223
1224 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1225                               const struct bpf_insn *aux,
1226                               struct bpf_insn *to_buff,
1227                               bool emit_zext)
1228 {
1229         struct bpf_insn *to = to_buff;
1230         u32 imm_rnd = get_random_u32();
1231         s16 off;
1232
1233         BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1234         BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1235
1236         /* Constraints on AX register:
1237          *
1238          * AX register is inaccessible from user space. It is mapped in
1239          * all JITs, and used here for constant blinding rewrites. It is
1240          * typically "stateless" meaning its contents are only valid within
1241          * the executed instruction, but not across several instructions.
1242          * There are a few exceptions however which are further detailed
1243          * below.
1244          *
1245          * Constant blinding is only used by JITs, not in the interpreter.
1246          * The interpreter uses AX in some occasions as a local temporary
1247          * register e.g. in DIV or MOD instructions.
1248          *
1249          * In restricted circumstances, the verifier can also use the AX
1250          * register for rewrites as long as they do not interfere with
1251          * the above cases!
1252          */
1253         if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1254                 goto out;
1255
1256         if (from->imm == 0 &&
1257             (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1258              from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1259                 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1260                 goto out;
1261         }
1262
1263         switch (from->code) {
1264         case BPF_ALU | BPF_ADD | BPF_K:
1265         case BPF_ALU | BPF_SUB | BPF_K:
1266         case BPF_ALU | BPF_AND | BPF_K:
1267         case BPF_ALU | BPF_OR  | BPF_K:
1268         case BPF_ALU | BPF_XOR | BPF_K:
1269         case BPF_ALU | BPF_MUL | BPF_K:
1270         case BPF_ALU | BPF_MOV | BPF_K:
1271         case BPF_ALU | BPF_DIV | BPF_K:
1272         case BPF_ALU | BPF_MOD | BPF_K:
1273                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1274                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1275                 *to++ = BPF_ALU32_REG(from->code, from->dst_reg, BPF_REG_AX);
1276                 break;
1277
1278         case BPF_ALU64 | BPF_ADD | BPF_K:
1279         case BPF_ALU64 | BPF_SUB | BPF_K:
1280         case BPF_ALU64 | BPF_AND | BPF_K:
1281         case BPF_ALU64 | BPF_OR  | BPF_K:
1282         case BPF_ALU64 | BPF_XOR | BPF_K:
1283         case BPF_ALU64 | BPF_MUL | BPF_K:
1284         case BPF_ALU64 | BPF_MOV | BPF_K:
1285         case BPF_ALU64 | BPF_DIV | BPF_K:
1286         case BPF_ALU64 | BPF_MOD | BPF_K:
1287                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1288                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1289                 *to++ = BPF_ALU64_REG(from->code, from->dst_reg, BPF_REG_AX);
1290                 break;
1291
1292         case BPF_JMP | BPF_JEQ  | BPF_K:
1293         case BPF_JMP | BPF_JNE  | BPF_K:
1294         case BPF_JMP | BPF_JGT  | BPF_K:
1295         case BPF_JMP | BPF_JLT  | BPF_K:
1296         case BPF_JMP | BPF_JGE  | BPF_K:
1297         case BPF_JMP | BPF_JLE  | BPF_K:
1298         case BPF_JMP | BPF_JSGT | BPF_K:
1299         case BPF_JMP | BPF_JSLT | BPF_K:
1300         case BPF_JMP | BPF_JSGE | BPF_K:
1301         case BPF_JMP | BPF_JSLE | BPF_K:
1302         case BPF_JMP | BPF_JSET | BPF_K:
1303                 /* Accommodate for extra offset in case of a backjump. */
1304                 off = from->off;
1305                 if (off < 0)
1306                         off -= 2;
1307                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1308                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1309                 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1310                 break;
1311
1312         case BPF_JMP32 | BPF_JEQ  | BPF_K:
1313         case BPF_JMP32 | BPF_JNE  | BPF_K:
1314         case BPF_JMP32 | BPF_JGT  | BPF_K:
1315         case BPF_JMP32 | BPF_JLT  | BPF_K:
1316         case BPF_JMP32 | BPF_JGE  | BPF_K:
1317         case BPF_JMP32 | BPF_JLE  | BPF_K:
1318         case BPF_JMP32 | BPF_JSGT | BPF_K:
1319         case BPF_JMP32 | BPF_JSLT | BPF_K:
1320         case BPF_JMP32 | BPF_JSGE | BPF_K:
1321         case BPF_JMP32 | BPF_JSLE | BPF_K:
1322         case BPF_JMP32 | BPF_JSET | BPF_K:
1323                 /* Accommodate for extra offset in case of a backjump. */
1324                 off = from->off;
1325                 if (off < 0)
1326                         off -= 2;
1327                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1328                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1329                 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1330                                       off);
1331                 break;
1332
1333         case BPF_LD | BPF_IMM | BPF_DW:
1334                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1335                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1336                 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1337                 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1338                 break;
1339         case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1340                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1341                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1342                 if (emit_zext)
1343                         *to++ = BPF_ZEXT_REG(BPF_REG_AX);
1344                 *to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1345                 break;
1346
1347         case BPF_ST | BPF_MEM | BPF_DW:
1348         case BPF_ST | BPF_MEM | BPF_W:
1349         case BPF_ST | BPF_MEM | BPF_H:
1350         case BPF_ST | BPF_MEM | BPF_B:
1351                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1352                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1353                 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1354                 break;
1355         }
1356 out:
1357         return to - to_buff;
1358 }
1359
1360 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1361                                               gfp_t gfp_extra_flags)
1362 {
1363         gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1364         struct bpf_prog *fp;
1365
1366         fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1367         if (fp != NULL) {
1368                 /* aux->prog still points to the fp_other one, so
1369                  * when promoting the clone to the real program,
1370                  * this still needs to be adapted.
1371                  */
1372                 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1373         }
1374
1375         return fp;
1376 }
1377
1378 static void bpf_prog_clone_free(struct bpf_prog *fp)
1379 {
1380         /* aux was stolen by the other clone, so we cannot free
1381          * it from this path! It will be freed eventually by the
1382          * other program on release.
1383          *
1384          * At this point, we don't need a deferred release since
1385          * clone is guaranteed to not be locked.
1386          */
1387         fp->aux = NULL;
1388         fp->stats = NULL;
1389         fp->active = NULL;
1390         __bpf_prog_free(fp);
1391 }
1392
1393 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1394 {
1395         /* We have to repoint aux->prog to self, as we don't
1396          * know whether fp here is the clone or the original.
1397          */
1398         fp->aux->prog = fp;
1399         bpf_prog_clone_free(fp_other);
1400 }
1401
1402 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1403 {
1404         struct bpf_insn insn_buff[16], aux[2];
1405         struct bpf_prog *clone, *tmp;
1406         int insn_delta, insn_cnt;
1407         struct bpf_insn *insn;
1408         int i, rewritten;
1409
1410         if (!prog->blinding_requested || prog->blinded)
1411                 return prog;
1412
1413         clone = bpf_prog_clone_create(prog, GFP_USER);
1414         if (!clone)
1415                 return ERR_PTR(-ENOMEM);
1416
1417         insn_cnt = clone->len;
1418         insn = clone->insnsi;
1419
1420         for (i = 0; i < insn_cnt; i++, insn++) {
1421                 if (bpf_pseudo_func(insn)) {
1422                         /* ld_imm64 with an address of bpf subprog is not
1423                          * a user controlled constant. Don't randomize it,
1424                          * since it will conflict with jit_subprogs() logic.
1425                          */
1426                         insn++;
1427                         i++;
1428                         continue;
1429                 }
1430
1431                 /* We temporarily need to hold the original ld64 insn
1432                  * so that we can still access the first part in the
1433                  * second blinding run.
1434                  */
1435                 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1436                     insn[1].code == 0)
1437                         memcpy(aux, insn, sizeof(aux));
1438
1439                 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1440                                                 clone->aux->verifier_zext);
1441                 if (!rewritten)
1442                         continue;
1443
1444                 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1445                 if (IS_ERR(tmp)) {
1446                         /* Patching may have repointed aux->prog during
1447                          * realloc from the original one, so we need to
1448                          * fix it up here on error.
1449                          */
1450                         bpf_jit_prog_release_other(prog, clone);
1451                         return tmp;
1452                 }
1453
1454                 clone = tmp;
1455                 insn_delta = rewritten - 1;
1456
1457                 /* Walk new program and skip insns we just inserted. */
1458                 insn = clone->insnsi + i + insn_delta;
1459                 insn_cnt += insn_delta;
1460                 i        += insn_delta;
1461         }
1462
1463         clone->blinded = 1;
1464         return clone;
1465 }
1466 #endif /* CONFIG_BPF_JIT */
1467
1468 /* Base function for offset calculation. Needs to go into .text section,
1469  * therefore keeping it non-static as well; will also be used by JITs
1470  * anyway later on, so do not let the compiler omit it. This also needs
1471  * to go into kallsyms for correlation from e.g. bpftool, so naming
1472  * must not change.
1473  */
1474 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1475 {
1476         return 0;
1477 }
1478 EXPORT_SYMBOL_GPL(__bpf_call_base);
1479
1480 /* All UAPI available opcodes. */
1481 #define BPF_INSN_MAP(INSN_2, INSN_3)            \
1482         /* 32 bit ALU operations. */            \
1483         /*   Register based. */                 \
1484         INSN_3(ALU, ADD,  X),                   \
1485         INSN_3(ALU, SUB,  X),                   \
1486         INSN_3(ALU, AND,  X),                   \
1487         INSN_3(ALU, OR,   X),                   \
1488         INSN_3(ALU, LSH,  X),                   \
1489         INSN_3(ALU, RSH,  X),                   \
1490         INSN_3(ALU, XOR,  X),                   \
1491         INSN_3(ALU, MUL,  X),                   \
1492         INSN_3(ALU, MOV,  X),                   \
1493         INSN_3(ALU, ARSH, X),                   \
1494         INSN_3(ALU, DIV,  X),                   \
1495         INSN_3(ALU, MOD,  X),                   \
1496         INSN_2(ALU, NEG),                       \
1497         INSN_3(ALU, END, TO_BE),                \
1498         INSN_3(ALU, END, TO_LE),                \
1499         /*   Immediate based. */                \
1500         INSN_3(ALU, ADD,  K),                   \
1501         INSN_3(ALU, SUB,  K),                   \
1502         INSN_3(ALU, AND,  K),                   \
1503         INSN_3(ALU, OR,   K),                   \
1504         INSN_3(ALU, LSH,  K),                   \
1505         INSN_3(ALU, RSH,  K),                   \
1506         INSN_3(ALU, XOR,  K),                   \
1507         INSN_3(ALU, MUL,  K),                   \
1508         INSN_3(ALU, MOV,  K),                   \
1509         INSN_3(ALU, ARSH, K),                   \
1510         INSN_3(ALU, DIV,  K),                   \
1511         INSN_3(ALU, MOD,  K),                   \
1512         /* 64 bit ALU operations. */            \
1513         /*   Register based. */                 \
1514         INSN_3(ALU64, ADD,  X),                 \
1515         INSN_3(ALU64, SUB,  X),                 \
1516         INSN_3(ALU64, AND,  X),                 \
1517         INSN_3(ALU64, OR,   X),                 \
1518         INSN_3(ALU64, LSH,  X),                 \
1519         INSN_3(ALU64, RSH,  X),                 \
1520         INSN_3(ALU64, XOR,  X),                 \
1521         INSN_3(ALU64, MUL,  X),                 \
1522         INSN_3(ALU64, MOV,  X),                 \
1523         INSN_3(ALU64, ARSH, X),                 \
1524         INSN_3(ALU64, DIV,  X),                 \
1525         INSN_3(ALU64, MOD,  X),                 \
1526         INSN_2(ALU64, NEG),                     \
1527         INSN_3(ALU64, END, TO_LE),              \
1528         /*   Immediate based. */                \
1529         INSN_3(ALU64, ADD,  K),                 \
1530         INSN_3(ALU64, SUB,  K),                 \
1531         INSN_3(ALU64, AND,  K),                 \
1532         INSN_3(ALU64, OR,   K),                 \
1533         INSN_3(ALU64, LSH,  K),                 \
1534         INSN_3(ALU64, RSH,  K),                 \
1535         INSN_3(ALU64, XOR,  K),                 \
1536         INSN_3(ALU64, MUL,  K),                 \
1537         INSN_3(ALU64, MOV,  K),                 \
1538         INSN_3(ALU64, ARSH, K),                 \
1539         INSN_3(ALU64, DIV,  K),                 \
1540         INSN_3(ALU64, MOD,  K),                 \
1541         /* Call instruction. */                 \
1542         INSN_2(JMP, CALL),                      \
1543         /* Exit instruction. */                 \
1544         INSN_2(JMP, EXIT),                      \
1545         /* 32-bit Jump instructions. */         \
1546         /*   Register based. */                 \
1547         INSN_3(JMP32, JEQ,  X),                 \
1548         INSN_3(JMP32, JNE,  X),                 \
1549         INSN_3(JMP32, JGT,  X),                 \
1550         INSN_3(JMP32, JLT,  X),                 \
1551         INSN_3(JMP32, JGE,  X),                 \
1552         INSN_3(JMP32, JLE,  X),                 \
1553         INSN_3(JMP32, JSGT, X),                 \
1554         INSN_3(JMP32, JSLT, X),                 \
1555         INSN_3(JMP32, JSGE, X),                 \
1556         INSN_3(JMP32, JSLE, X),                 \
1557         INSN_3(JMP32, JSET, X),                 \
1558         /*   Immediate based. */                \
1559         INSN_3(JMP32, JEQ,  K),                 \
1560         INSN_3(JMP32, JNE,  K),                 \
1561         INSN_3(JMP32, JGT,  K),                 \
1562         INSN_3(JMP32, JLT,  K),                 \
1563         INSN_3(JMP32, JGE,  K),                 \
1564         INSN_3(JMP32, JLE,  K),                 \
1565         INSN_3(JMP32, JSGT, K),                 \
1566         INSN_3(JMP32, JSLT, K),                 \
1567         INSN_3(JMP32, JSGE, K),                 \
1568         INSN_3(JMP32, JSLE, K),                 \
1569         INSN_3(JMP32, JSET, K),                 \
1570         /* Jump instructions. */                \
1571         /*   Register based. */                 \
1572         INSN_3(JMP, JEQ,  X),                   \
1573         INSN_3(JMP, JNE,  X),                   \
1574         INSN_3(JMP, JGT,  X),                   \
1575         INSN_3(JMP, JLT,  X),                   \
1576         INSN_3(JMP, JGE,  X),                   \
1577         INSN_3(JMP, JLE,  X),                   \
1578         INSN_3(JMP, JSGT, X),                   \
1579         INSN_3(JMP, JSLT, X),                   \
1580         INSN_3(JMP, JSGE, X),                   \
1581         INSN_3(JMP, JSLE, X),                   \
1582         INSN_3(JMP, JSET, X),                   \
1583         /*   Immediate based. */                \
1584         INSN_3(JMP, JEQ,  K),                   \
1585         INSN_3(JMP, JNE,  K),                   \
1586         INSN_3(JMP, JGT,  K),                   \
1587         INSN_3(JMP, JLT,  K),                   \
1588         INSN_3(JMP, JGE,  K),                   \
1589         INSN_3(JMP, JLE,  K),                   \
1590         INSN_3(JMP, JSGT, K),                   \
1591         INSN_3(JMP, JSLT, K),                   \
1592         INSN_3(JMP, JSGE, K),                   \
1593         INSN_3(JMP, JSLE, K),                   \
1594         INSN_3(JMP, JSET, K),                   \
1595         INSN_2(JMP, JA),                        \
1596         /* Store instructions. */               \
1597         /*   Register based. */                 \
1598         INSN_3(STX, MEM,  B),                   \
1599         INSN_3(STX, MEM,  H),                   \
1600         INSN_3(STX, MEM,  W),                   \
1601         INSN_3(STX, MEM,  DW),                  \
1602         INSN_3(STX, ATOMIC, W),                 \
1603         INSN_3(STX, ATOMIC, DW),                \
1604         /*   Immediate based. */                \
1605         INSN_3(ST, MEM, B),                     \
1606         INSN_3(ST, MEM, H),                     \
1607         INSN_3(ST, MEM, W),                     \
1608         INSN_3(ST, MEM, DW),                    \
1609         /* Load instructions. */                \
1610         /*   Register based. */                 \
1611         INSN_3(LDX, MEM, B),                    \
1612         INSN_3(LDX, MEM, H),                    \
1613         INSN_3(LDX, MEM, W),                    \
1614         INSN_3(LDX, MEM, DW),                   \
1615         INSN_3(LDX, MEMSX, B),                  \
1616         INSN_3(LDX, MEMSX, H),                  \
1617         INSN_3(LDX, MEMSX, W),                  \
1618         /*   Immediate based. */                \
1619         INSN_3(LD, IMM, DW)
1620
1621 bool bpf_opcode_in_insntable(u8 code)
1622 {
1623 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1624 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1625         static const bool public_insntable[256] = {
1626                 [0 ... 255] = false,
1627                 /* Now overwrite non-defaults ... */
1628                 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1629                 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1630                 [BPF_LD | BPF_ABS | BPF_B] = true,
1631                 [BPF_LD | BPF_ABS | BPF_H] = true,
1632                 [BPF_LD | BPF_ABS | BPF_W] = true,
1633                 [BPF_LD | BPF_IND | BPF_B] = true,
1634                 [BPF_LD | BPF_IND | BPF_H] = true,
1635                 [BPF_LD | BPF_IND | BPF_W] = true,
1636         };
1637 #undef BPF_INSN_3_TBL
1638 #undef BPF_INSN_2_TBL
1639         return public_insntable[code];
1640 }
1641
1642 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1643 u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr)
1644 {
1645         memset(dst, 0, size);
1646         return -EFAULT;
1647 }
1648
1649 /**
1650  *      ___bpf_prog_run - run eBPF program on a given context
1651  *      @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1652  *      @insn: is the array of eBPF instructions
1653  *
1654  * Decode and execute eBPF instructions.
1655  *
1656  * Return: whatever value is in %BPF_R0 at program exit
1657  */
1658 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1659 {
1660 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1661 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1662         static const void * const jumptable[256] __annotate_jump_table = {
1663                 [0 ... 255] = &&default_label,
1664                 /* Now overwrite non-defaults ... */
1665                 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1666                 /* Non-UAPI available opcodes. */
1667                 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1668                 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1669                 [BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1670                 [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1671                 [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1672                 [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1673                 [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1674                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B,
1675                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H,
1676                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W,
1677         };
1678 #undef BPF_INSN_3_LBL
1679 #undef BPF_INSN_2_LBL
1680         u32 tail_call_cnt = 0;
1681
1682 #define CONT     ({ insn++; goto select_insn; })
1683 #define CONT_JMP ({ insn++; goto select_insn; })
1684
1685 select_insn:
1686         goto *jumptable[insn->code];
1687
1688         /* Explicitly mask the register-based shift amounts with 63 or 31
1689          * to avoid undefined behavior. Normally this won't affect the
1690          * generated code, for example, in case of native 64 bit archs such
1691          * as x86-64 or arm64, the compiler is optimizing the AND away for
1692          * the interpreter. In case of JITs, each of the JIT backends compiles
1693          * the BPF shift operations to machine instructions which produce
1694          * implementation-defined results in such a case; the resulting
1695          * contents of the register may be arbitrary, but program behaviour
1696          * as a whole remains defined. In other words, in case of JIT backends,
1697          * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1698          */
1699         /* ALU (shifts) */
1700 #define SHT(OPCODE, OP)                                 \
1701         ALU64_##OPCODE##_X:                             \
1702                 DST = DST OP (SRC & 63);                \
1703                 CONT;                                   \
1704         ALU_##OPCODE##_X:                               \
1705                 DST = (u32) DST OP ((u32) SRC & 31);    \
1706                 CONT;                                   \
1707         ALU64_##OPCODE##_K:                             \
1708                 DST = DST OP IMM;                       \
1709                 CONT;                                   \
1710         ALU_##OPCODE##_K:                               \
1711                 DST = (u32) DST OP (u32) IMM;           \
1712                 CONT;
1713         /* ALU (rest) */
1714 #define ALU(OPCODE, OP)                                 \
1715         ALU64_##OPCODE##_X:                             \
1716                 DST = DST OP SRC;                       \
1717                 CONT;                                   \
1718         ALU_##OPCODE##_X:                               \
1719                 DST = (u32) DST OP (u32) SRC;           \
1720                 CONT;                                   \
1721         ALU64_##OPCODE##_K:                             \
1722                 DST = DST OP IMM;                       \
1723                 CONT;                                   \
1724         ALU_##OPCODE##_K:                               \
1725                 DST = (u32) DST OP (u32) IMM;           \
1726                 CONT;
1727         ALU(ADD,  +)
1728         ALU(SUB,  -)
1729         ALU(AND,  &)
1730         ALU(OR,   |)
1731         ALU(XOR,  ^)
1732         ALU(MUL,  *)
1733         SHT(LSH, <<)
1734         SHT(RSH, >>)
1735 #undef SHT
1736 #undef ALU
1737         ALU_NEG:
1738                 DST = (u32) -DST;
1739                 CONT;
1740         ALU64_NEG:
1741                 DST = -DST;
1742                 CONT;
1743         ALU_MOV_X:
1744                 switch (OFF) {
1745                 case 0:
1746                         DST = (u32) SRC;
1747                         break;
1748                 case 8:
1749                         DST = (u32)(s8) SRC;
1750                         break;
1751                 case 16:
1752                         DST = (u32)(s16) SRC;
1753                         break;
1754                 }
1755                 CONT;
1756         ALU_MOV_K:
1757                 DST = (u32) IMM;
1758                 CONT;
1759         ALU64_MOV_X:
1760                 switch (OFF) {
1761                 case 0:
1762                         DST = SRC;
1763                         break;
1764                 case 8:
1765                         DST = (s8) SRC;
1766                         break;
1767                 case 16:
1768                         DST = (s16) SRC;
1769                         break;
1770                 case 32:
1771                         DST = (s32) SRC;
1772                         break;
1773                 }
1774                 CONT;
1775         ALU64_MOV_K:
1776                 DST = IMM;
1777                 CONT;
1778         LD_IMM_DW:
1779                 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1780                 insn++;
1781                 CONT;
1782         ALU_ARSH_X:
1783                 DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1784                 CONT;
1785         ALU_ARSH_K:
1786                 DST = (u64) (u32) (((s32) DST) >> IMM);
1787                 CONT;
1788         ALU64_ARSH_X:
1789                 (*(s64 *) &DST) >>= (SRC & 63);
1790                 CONT;
1791         ALU64_ARSH_K:
1792                 (*(s64 *) &DST) >>= IMM;
1793                 CONT;
1794         ALU64_MOD_X:
1795                 div64_u64_rem(DST, SRC, &AX);
1796                 DST = AX;
1797                 CONT;
1798         ALU_MOD_X:
1799                 AX = (u32) DST;
1800                 DST = do_div(AX, (u32) SRC);
1801                 CONT;
1802         ALU64_MOD_K:
1803                 div64_u64_rem(DST, IMM, &AX);
1804                 DST = AX;
1805                 CONT;
1806         ALU_MOD_K:
1807                 AX = (u32) DST;
1808                 DST = do_div(AX, (u32) IMM);
1809                 CONT;
1810         ALU64_DIV_X:
1811                 DST = div64_u64(DST, SRC);
1812                 CONT;
1813         ALU_DIV_X:
1814                 AX = (u32) DST;
1815                 do_div(AX, (u32) SRC);
1816                 DST = (u32) AX;
1817                 CONT;
1818         ALU64_DIV_K:
1819                 DST = div64_u64(DST, IMM);
1820                 CONT;
1821         ALU_DIV_K:
1822                 AX = (u32) DST;
1823                 do_div(AX, (u32) IMM);
1824                 DST = (u32) AX;
1825                 CONT;
1826         ALU_END_TO_BE:
1827                 switch (IMM) {
1828                 case 16:
1829                         DST = (__force u16) cpu_to_be16(DST);
1830                         break;
1831                 case 32:
1832                         DST = (__force u32) cpu_to_be32(DST);
1833                         break;
1834                 case 64:
1835                         DST = (__force u64) cpu_to_be64(DST);
1836                         break;
1837                 }
1838                 CONT;
1839         ALU_END_TO_LE:
1840                 switch (IMM) {
1841                 case 16:
1842                         DST = (__force u16) cpu_to_le16(DST);
1843                         break;
1844                 case 32:
1845                         DST = (__force u32) cpu_to_le32(DST);
1846                         break;
1847                 case 64:
1848                         DST = (__force u64) cpu_to_le64(DST);
1849                         break;
1850                 }
1851                 CONT;
1852         ALU64_END_TO_LE:
1853                 switch (IMM) {
1854                 case 16:
1855                         DST = (__force u16) __swab16(DST);
1856                         break;
1857                 case 32:
1858                         DST = (__force u32) __swab32(DST);
1859                         break;
1860                 case 64:
1861                         DST = (__force u64) __swab64(DST);
1862                         break;
1863                 }
1864                 CONT;
1865
1866         /* CALL */
1867         JMP_CALL:
1868                 /* Function call scratches BPF_R1-BPF_R5 registers,
1869                  * preserves BPF_R6-BPF_R9, and stores return value
1870                  * into BPF_R0.
1871                  */
1872                 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
1873                                                        BPF_R4, BPF_R5);
1874                 CONT;
1875
1876         JMP_CALL_ARGS:
1877                 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
1878                                                             BPF_R3, BPF_R4,
1879                                                             BPF_R5,
1880                                                             insn + insn->off + 1);
1881                 CONT;
1882
1883         JMP_TAIL_CALL: {
1884                 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
1885                 struct bpf_array *array = container_of(map, struct bpf_array, map);
1886                 struct bpf_prog *prog;
1887                 u32 index = BPF_R3;
1888
1889                 if (unlikely(index >= array->map.max_entries))
1890                         goto out;
1891
1892                 if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
1893                         goto out;
1894
1895                 tail_call_cnt++;
1896
1897                 prog = READ_ONCE(array->ptrs[index]);
1898                 if (!prog)
1899                         goto out;
1900
1901                 /* ARG1 at this point is guaranteed to point to CTX from
1902                  * the verifier side due to the fact that the tail call is
1903                  * handled like a helper, that is, bpf_tail_call_proto,
1904                  * where arg1_type is ARG_PTR_TO_CTX.
1905                  */
1906                 insn = prog->insnsi;
1907                 goto select_insn;
1908 out:
1909                 CONT;
1910         }
1911         JMP_JA:
1912                 insn += insn->off;
1913                 CONT;
1914         JMP_EXIT:
1915                 return BPF_R0;
1916         /* JMP */
1917 #define COND_JMP(SIGN, OPCODE, CMP_OP)                          \
1918         JMP_##OPCODE##_X:                                       \
1919                 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {     \
1920                         insn += insn->off;                      \
1921                         CONT_JMP;                               \
1922                 }                                               \
1923                 CONT;                                           \
1924         JMP32_##OPCODE##_X:                                     \
1925                 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {     \
1926                         insn += insn->off;                      \
1927                         CONT_JMP;                               \
1928                 }                                               \
1929                 CONT;                                           \
1930         JMP_##OPCODE##_K:                                       \
1931                 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {     \
1932                         insn += insn->off;                      \
1933                         CONT_JMP;                               \
1934                 }                                               \
1935                 CONT;                                           \
1936         JMP32_##OPCODE##_K:                                     \
1937                 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {     \
1938                         insn += insn->off;                      \
1939                         CONT_JMP;                               \
1940                 }                                               \
1941                 CONT;
1942         COND_JMP(u, JEQ, ==)
1943         COND_JMP(u, JNE, !=)
1944         COND_JMP(u, JGT, >)
1945         COND_JMP(u, JLT, <)
1946         COND_JMP(u, JGE, >=)
1947         COND_JMP(u, JLE, <=)
1948         COND_JMP(u, JSET, &)
1949         COND_JMP(s, JSGT, >)
1950         COND_JMP(s, JSLT, <)
1951         COND_JMP(s, JSGE, >=)
1952         COND_JMP(s, JSLE, <=)
1953 #undef COND_JMP
1954         /* ST, STX and LDX*/
1955         ST_NOSPEC:
1956                 /* Speculation barrier for mitigating Speculative Store Bypass.
1957                  * In case of arm64, we rely on the firmware mitigation as
1958                  * controlled via the ssbd kernel parameter. Whenever the
1959                  * mitigation is enabled, it works for all of the kernel code
1960                  * with no need to provide any additional instructions here.
1961                  * In case of x86, we use 'lfence' insn for mitigation. We
1962                  * reuse preexisting logic from Spectre v1 mitigation that
1963                  * happens to produce the required code on x86 for v4 as well.
1964                  */
1965                 barrier_nospec();
1966                 CONT;
1967 #define LDST(SIZEOP, SIZE)                                              \
1968         STX_MEM_##SIZEOP:                                               \
1969                 *(SIZE *)(unsigned long) (DST + insn->off) = SRC;       \
1970                 CONT;                                                   \
1971         ST_MEM_##SIZEOP:                                                \
1972                 *(SIZE *)(unsigned long) (DST + insn->off) = IMM;       \
1973                 CONT;                                                   \
1974         LDX_MEM_##SIZEOP:                                               \
1975                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
1976                 CONT;                                                   \
1977         LDX_PROBE_MEM_##SIZEOP:                                         \
1978                 bpf_probe_read_kernel(&DST, sizeof(SIZE),               \
1979                                       (const void *)(long) (SRC + insn->off));  \
1980                 DST = *((SIZE *)&DST);                                  \
1981                 CONT;
1982
1983         LDST(B,   u8)
1984         LDST(H,  u16)
1985         LDST(W,  u32)
1986         LDST(DW, u64)
1987 #undef LDST
1988
1989 #define LDSX(SIZEOP, SIZE)                                              \
1990         LDX_MEMSX_##SIZEOP:                                             \
1991                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
1992                 CONT;                                                   \
1993         LDX_PROBE_MEMSX_##SIZEOP:                                       \
1994                 bpf_probe_read_kernel(&DST, sizeof(SIZE),               \
1995                                       (const void *)(long) (SRC + insn->off));  \
1996                 DST = *((SIZE *)&DST);                                  \
1997                 CONT;
1998
1999         LDSX(B,   s8)
2000         LDSX(H,  s16)
2001         LDSX(W,  s32)
2002 #undef LDSX
2003
2004 #define ATOMIC_ALU_OP(BOP, KOP)                                         \
2005                 case BOP:                                               \
2006                         if (BPF_SIZE(insn->code) == BPF_W)              \
2007                                 atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
2008                                              (DST + insn->off));        \
2009                         else                                            \
2010                                 atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
2011                                                (DST + insn->off));      \
2012                         break;                                          \
2013                 case BOP | BPF_FETCH:                                   \
2014                         if (BPF_SIZE(insn->code) == BPF_W)              \
2015                                 SRC = (u32) atomic_fetch_##KOP(         \
2016                                         (u32) SRC,                      \
2017                                         (atomic_t *)(unsigned long) (DST + insn->off)); \
2018                         else                                            \
2019                                 SRC = (u64) atomic64_fetch_##KOP(       \
2020                                         (u64) SRC,                      \
2021                                         (atomic64_t *)(unsigned long) (DST + insn->off)); \
2022                         break;
2023
2024         STX_ATOMIC_DW:
2025         STX_ATOMIC_W:
2026                 switch (IMM) {
2027                 ATOMIC_ALU_OP(BPF_ADD, add)
2028                 ATOMIC_ALU_OP(BPF_AND, and)
2029                 ATOMIC_ALU_OP(BPF_OR, or)
2030                 ATOMIC_ALU_OP(BPF_XOR, xor)
2031 #undef ATOMIC_ALU_OP
2032
2033                 case BPF_XCHG:
2034                         if (BPF_SIZE(insn->code) == BPF_W)
2035                                 SRC = (u32) atomic_xchg(
2036                                         (atomic_t *)(unsigned long) (DST + insn->off),
2037                                         (u32) SRC);
2038                         else
2039                                 SRC = (u64) atomic64_xchg(
2040                                         (atomic64_t *)(unsigned long) (DST + insn->off),
2041                                         (u64) SRC);
2042                         break;
2043                 case BPF_CMPXCHG:
2044                         if (BPF_SIZE(insn->code) == BPF_W)
2045                                 BPF_R0 = (u32) atomic_cmpxchg(
2046                                         (atomic_t *)(unsigned long) (DST + insn->off),
2047                                         (u32) BPF_R0, (u32) SRC);
2048                         else
2049                                 BPF_R0 = (u64) atomic64_cmpxchg(
2050                                         (atomic64_t *)(unsigned long) (DST + insn->off),
2051                                         (u64) BPF_R0, (u64) SRC);
2052                         break;
2053
2054                 default:
2055                         goto default_label;
2056                 }
2057                 CONT;
2058
2059         default_label:
2060                 /* If we ever reach this, we have a bug somewhere. Die hard here
2061                  * instead of just returning 0; we could be somewhere in a subprog,
2062                  * so execution could continue otherwise which we do /not/ want.
2063                  *
2064                  * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2065                  */
2066                 pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2067                         insn->code, insn->imm);
2068                 BUG_ON(1);
2069                 return 0;
2070 }
2071
2072 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2073 #define DEFINE_BPF_PROG_RUN(stack_size) \
2074 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2075 { \
2076         u64 stack[stack_size / sizeof(u64)]; \
2077         u64 regs[MAX_BPF_EXT_REG] = {}; \
2078 \
2079         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2080         ARG1 = (u64) (unsigned long) ctx; \
2081         return ___bpf_prog_run(regs, insn); \
2082 }
2083
2084 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2085 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2086 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2087                                       const struct bpf_insn *insn) \
2088 { \
2089         u64 stack[stack_size / sizeof(u64)]; \
2090         u64 regs[MAX_BPF_EXT_REG]; \
2091 \
2092         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2093         BPF_R1 = r1; \
2094         BPF_R2 = r2; \
2095         BPF_R3 = r3; \
2096         BPF_R4 = r4; \
2097         BPF_R5 = r5; \
2098         return ___bpf_prog_run(regs, insn); \
2099 }
2100
2101 #define EVAL1(FN, X) FN(X)
2102 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2103 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2104 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2105 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2106 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2107
2108 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2109 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2110 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2111
2112 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2113 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2114 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2115
2116 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2117
2118 static unsigned int (*interpreters[])(const void *ctx,
2119                                       const struct bpf_insn *insn) = {
2120 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2121 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2122 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2123 };
2124 #undef PROG_NAME_LIST
2125 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2126 static __maybe_unused
2127 u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2128                            const struct bpf_insn *insn) = {
2129 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2130 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2131 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2132 };
2133 #undef PROG_NAME_LIST
2134
2135 #ifdef CONFIG_BPF_SYSCALL
2136 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2137 {
2138         stack_depth = max_t(u32, stack_depth, 1);
2139         insn->off = (s16) insn->imm;
2140         insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2141                 __bpf_call_base_args;
2142         insn->code = BPF_JMP | BPF_CALL_ARGS;
2143 }
2144 #endif
2145 #else
2146 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2147                                          const struct bpf_insn *insn)
2148 {
2149         /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2150          * is not working properly, so warn about it!
2151          */
2152         WARN_ON_ONCE(1);
2153         return 0;
2154 }
2155 #endif
2156
2157 bool bpf_prog_map_compatible(struct bpf_map *map,
2158                              const struct bpf_prog *fp)
2159 {
2160         enum bpf_prog_type prog_type = resolve_prog_type(fp);
2161         bool ret;
2162
2163         if (fp->kprobe_override)
2164                 return false;
2165
2166         /* XDP programs inserted into maps are not guaranteed to run on
2167          * a particular netdev (and can run outside driver context entirely
2168          * in the case of devmap and cpumap). Until device checks
2169          * are implemented, prohibit adding dev-bound programs to program maps.
2170          */
2171         if (bpf_prog_is_dev_bound(fp->aux))
2172                 return false;
2173
2174         spin_lock(&map->owner.lock);
2175         if (!map->owner.type) {
2176                 /* There's no owner yet where we could check for
2177                  * compatibility.
2178                  */
2179                 map->owner.type  = prog_type;
2180                 map->owner.jited = fp->jited;
2181                 map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
2182                 ret = true;
2183         } else {
2184                 ret = map->owner.type  == prog_type &&
2185                       map->owner.jited == fp->jited &&
2186                       map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
2187         }
2188         spin_unlock(&map->owner.lock);
2189
2190         return ret;
2191 }
2192
2193 static int bpf_check_tail_call(const struct bpf_prog *fp)
2194 {
2195         struct bpf_prog_aux *aux = fp->aux;
2196         int i, ret = 0;
2197
2198         mutex_lock(&aux->used_maps_mutex);
2199         for (i = 0; i < aux->used_map_cnt; i++) {
2200                 struct bpf_map *map = aux->used_maps[i];
2201
2202                 if (!map_type_contains_progs(map))
2203                         continue;
2204
2205                 if (!bpf_prog_map_compatible(map, fp)) {
2206                         ret = -EINVAL;
2207                         goto out;
2208                 }
2209         }
2210
2211 out:
2212         mutex_unlock(&aux->used_maps_mutex);
2213         return ret;
2214 }
2215
2216 static void bpf_prog_select_func(struct bpf_prog *fp)
2217 {
2218 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2219         u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2220
2221         fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2222 #else
2223         fp->bpf_func = __bpf_prog_ret0_warn;
2224 #endif
2225 }
2226
2227 /**
2228  *      bpf_prog_select_runtime - select exec runtime for BPF program
2229  *      @fp: bpf_prog populated with BPF program
2230  *      @err: pointer to error variable
2231  *
2232  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2233  * The BPF program will be executed via bpf_prog_run() function.
2234  *
2235  * Return: the &fp argument along with &err set to 0 for success or
2236  * a negative errno code on failure
2237  */
2238 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2239 {
2240         /* In case of BPF to BPF calls, verifier did all the prep
2241          * work with regards to JITing, etc.
2242          */
2243         bool jit_needed = false;
2244
2245         if (fp->bpf_func)
2246                 goto finalize;
2247
2248         if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2249             bpf_prog_has_kfunc_call(fp))
2250                 jit_needed = true;
2251
2252         bpf_prog_select_func(fp);
2253
2254         /* eBPF JITs can rewrite the program in case constant
2255          * blinding is active. However, in case of error during
2256          * blinding, bpf_int_jit_compile() must always return a
2257          * valid program, which in this case would simply not
2258          * be JITed, but falls back to the interpreter.
2259          */
2260         if (!bpf_prog_is_offloaded(fp->aux)) {
2261                 *err = bpf_prog_alloc_jited_linfo(fp);
2262                 if (*err)
2263                         return fp;
2264
2265                 fp = bpf_int_jit_compile(fp);
2266                 bpf_prog_jit_attempt_done(fp);
2267                 if (!fp->jited && jit_needed) {
2268                         *err = -ENOTSUPP;
2269                         return fp;
2270                 }
2271         } else {
2272                 *err = bpf_prog_offload_compile(fp);
2273                 if (*err)
2274                         return fp;
2275         }
2276
2277 finalize:
2278         bpf_prog_lock_ro(fp);
2279
2280         /* The tail call compatibility check can only be done at
2281          * this late stage as we need to determine, if we deal
2282          * with JITed or non JITed program concatenations and not
2283          * all eBPF JITs might immediately support all features.
2284          */
2285         *err = bpf_check_tail_call(fp);
2286
2287         return fp;
2288 }
2289 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2290
2291 static unsigned int __bpf_prog_ret1(const void *ctx,
2292                                     const struct bpf_insn *insn)
2293 {
2294         return 1;
2295 }
2296
2297 static struct bpf_prog_dummy {
2298         struct bpf_prog prog;
2299 } dummy_bpf_prog = {
2300         .prog = {
2301                 .bpf_func = __bpf_prog_ret1,
2302         },
2303 };
2304
2305 struct bpf_empty_prog_array bpf_empty_prog_array = {
2306         .null_prog = NULL,
2307 };
2308 EXPORT_SYMBOL(bpf_empty_prog_array);
2309
2310 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2311 {
2312         if (prog_cnt)
2313                 return kzalloc(sizeof(struct bpf_prog_array) +
2314                                sizeof(struct bpf_prog_array_item) *
2315                                (prog_cnt + 1),
2316                                flags);
2317
2318         return &bpf_empty_prog_array.hdr;
2319 }
2320
2321 void bpf_prog_array_free(struct bpf_prog_array *progs)
2322 {
2323         if (!progs || progs == &bpf_empty_prog_array.hdr)
2324                 return;
2325         kfree_rcu(progs, rcu);
2326 }
2327
2328 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2329 {
2330         struct bpf_prog_array *progs;
2331
2332         /* If RCU Tasks Trace grace period implies RCU grace period, there is
2333          * no need to call kfree_rcu(), just call kfree() directly.
2334          */
2335         progs = container_of(rcu, struct bpf_prog_array, rcu);
2336         if (rcu_trace_implies_rcu_gp())
2337                 kfree(progs);
2338         else
2339                 kfree_rcu(progs, rcu);
2340 }
2341
2342 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2343 {
2344         if (!progs || progs == &bpf_empty_prog_array.hdr)
2345                 return;
2346         call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2347 }
2348
2349 int bpf_prog_array_length(struct bpf_prog_array *array)
2350 {
2351         struct bpf_prog_array_item *item;
2352         u32 cnt = 0;
2353
2354         for (item = array->items; item->prog; item++)
2355                 if (item->prog != &dummy_bpf_prog.prog)
2356                         cnt++;
2357         return cnt;
2358 }
2359
2360 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2361 {
2362         struct bpf_prog_array_item *item;
2363
2364         for (item = array->items; item->prog; item++)
2365                 if (item->prog != &dummy_bpf_prog.prog)
2366                         return false;
2367         return true;
2368 }
2369
2370 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2371                                      u32 *prog_ids,
2372                                      u32 request_cnt)
2373 {
2374         struct bpf_prog_array_item *item;
2375         int i = 0;
2376
2377         for (item = array->items; item->prog; item++) {
2378                 if (item->prog == &dummy_bpf_prog.prog)
2379                         continue;
2380                 prog_ids[i] = item->prog->aux->id;
2381                 if (++i == request_cnt) {
2382                         item++;
2383                         break;
2384                 }
2385         }
2386
2387         return !!(item->prog);
2388 }
2389
2390 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2391                                 __u32 __user *prog_ids, u32 cnt)
2392 {
2393         unsigned long err = 0;
2394         bool nospc;
2395         u32 *ids;
2396
2397         /* users of this function are doing:
2398          * cnt = bpf_prog_array_length();
2399          * if (cnt > 0)
2400          *     bpf_prog_array_copy_to_user(..., cnt);
2401          * so below kcalloc doesn't need extra cnt > 0 check.
2402          */
2403         ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2404         if (!ids)
2405                 return -ENOMEM;
2406         nospc = bpf_prog_array_copy_core(array, ids, cnt);
2407         err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2408         kfree(ids);
2409         if (err)
2410                 return -EFAULT;
2411         if (nospc)
2412                 return -ENOSPC;
2413         return 0;
2414 }
2415
2416 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2417                                 struct bpf_prog *old_prog)
2418 {
2419         struct bpf_prog_array_item *item;
2420
2421         for (item = array->items; item->prog; item++)
2422                 if (item->prog == old_prog) {
2423                         WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2424                         break;
2425                 }
2426 }
2427
2428 /**
2429  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2430  *                                   index into the program array with
2431  *                                   a dummy no-op program.
2432  * @array: a bpf_prog_array
2433  * @index: the index of the program to replace
2434  *
2435  * Skips over dummy programs, by not counting them, when calculating
2436  * the position of the program to replace.
2437  *
2438  * Return:
2439  * * 0          - Success
2440  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
2441  * * -ENOENT    - Index out of range
2442  */
2443 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2444 {
2445         return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2446 }
2447
2448 /**
2449  * bpf_prog_array_update_at() - Updates the program at the given index
2450  *                              into the program array.
2451  * @array: a bpf_prog_array
2452  * @index: the index of the program to update
2453  * @prog: the program to insert into the array
2454  *
2455  * Skips over dummy programs, by not counting them, when calculating
2456  * the position of the program to update.
2457  *
2458  * Return:
2459  * * 0          - Success
2460  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
2461  * * -ENOENT    - Index out of range
2462  */
2463 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2464                              struct bpf_prog *prog)
2465 {
2466         struct bpf_prog_array_item *item;
2467
2468         if (unlikely(index < 0))
2469                 return -EINVAL;
2470
2471         for (item = array->items; item->prog; item++) {
2472                 if (item->prog == &dummy_bpf_prog.prog)
2473                         continue;
2474                 if (!index) {
2475                         WRITE_ONCE(item->prog, prog);
2476                         return 0;
2477                 }
2478                 index--;
2479         }
2480         return -ENOENT;
2481 }
2482
2483 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2484                         struct bpf_prog *exclude_prog,
2485                         struct bpf_prog *include_prog,
2486                         u64 bpf_cookie,
2487                         struct bpf_prog_array **new_array)
2488 {
2489         int new_prog_cnt, carry_prog_cnt = 0;
2490         struct bpf_prog_array_item *existing, *new;
2491         struct bpf_prog_array *array;
2492         bool found_exclude = false;
2493
2494         /* Figure out how many existing progs we need to carry over to
2495          * the new array.
2496          */
2497         if (old_array) {
2498                 existing = old_array->items;
2499                 for (; existing->prog; existing++) {
2500                         if (existing->prog == exclude_prog) {
2501                                 found_exclude = true;
2502                                 continue;
2503                         }
2504                         if (existing->prog != &dummy_bpf_prog.prog)
2505                                 carry_prog_cnt++;
2506                         if (existing->prog == include_prog)
2507                                 return -EEXIST;
2508                 }
2509         }
2510
2511         if (exclude_prog && !found_exclude)
2512                 return -ENOENT;
2513
2514         /* How many progs (not NULL) will be in the new array? */
2515         new_prog_cnt = carry_prog_cnt;
2516         if (include_prog)
2517                 new_prog_cnt += 1;
2518
2519         /* Do we have any prog (not NULL) in the new array? */
2520         if (!new_prog_cnt) {
2521                 *new_array = NULL;
2522                 return 0;
2523         }
2524
2525         /* +1 as the end of prog_array is marked with NULL */
2526         array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2527         if (!array)
2528                 return -ENOMEM;
2529         new = array->items;
2530
2531         /* Fill in the new prog array */
2532         if (carry_prog_cnt) {
2533                 existing = old_array->items;
2534                 for (; existing->prog; existing++) {
2535                         if (existing->prog == exclude_prog ||
2536                             existing->prog == &dummy_bpf_prog.prog)
2537                                 continue;
2538
2539                         new->prog = existing->prog;
2540                         new->bpf_cookie = existing->bpf_cookie;
2541                         new++;
2542                 }
2543         }
2544         if (include_prog) {
2545                 new->prog = include_prog;
2546                 new->bpf_cookie = bpf_cookie;
2547                 new++;
2548         }
2549         new->prog = NULL;
2550         *new_array = array;
2551         return 0;
2552 }
2553
2554 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2555                              u32 *prog_ids, u32 request_cnt,
2556                              u32 *prog_cnt)
2557 {
2558         u32 cnt = 0;
2559
2560         if (array)
2561                 cnt = bpf_prog_array_length(array);
2562
2563         *prog_cnt = cnt;
2564
2565         /* return early if user requested only program count or nothing to copy */
2566         if (!request_cnt || !cnt)
2567                 return 0;
2568
2569         /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2570         return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2571                                                                      : 0;
2572 }
2573
2574 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2575                           struct bpf_map **used_maps, u32 len)
2576 {
2577         struct bpf_map *map;
2578         u32 i;
2579
2580         for (i = 0; i < len; i++) {
2581                 map = used_maps[i];
2582                 if (map->ops->map_poke_untrack)
2583                         map->ops->map_poke_untrack(map, aux);
2584                 bpf_map_put(map);
2585         }
2586 }
2587
2588 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2589 {
2590         __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2591         kfree(aux->used_maps);
2592 }
2593
2594 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2595                           struct btf_mod_pair *used_btfs, u32 len)
2596 {
2597 #ifdef CONFIG_BPF_SYSCALL
2598         struct btf_mod_pair *btf_mod;
2599         u32 i;
2600
2601         for (i = 0; i < len; i++) {
2602                 btf_mod = &used_btfs[i];
2603                 if (btf_mod->module)
2604                         module_put(btf_mod->module);
2605                 btf_put(btf_mod->btf);
2606         }
2607 #endif
2608 }
2609
2610 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2611 {
2612         __bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2613         kfree(aux->used_btfs);
2614 }
2615
2616 static void bpf_prog_free_deferred(struct work_struct *work)
2617 {
2618         struct bpf_prog_aux *aux;
2619         int i;
2620
2621         aux = container_of(work, struct bpf_prog_aux, work);
2622 #ifdef CONFIG_BPF_SYSCALL
2623         bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2624 #endif
2625 #ifdef CONFIG_CGROUP_BPF
2626         if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2627                 bpf_cgroup_atype_put(aux->cgroup_atype);
2628 #endif
2629         bpf_free_used_maps(aux);
2630         bpf_free_used_btfs(aux);
2631         if (bpf_prog_is_dev_bound(aux))
2632                 bpf_prog_dev_bound_destroy(aux->prog);
2633 #ifdef CONFIG_PERF_EVENTS
2634         if (aux->prog->has_callchain_buf)
2635                 put_callchain_buffers();
2636 #endif
2637         if (aux->dst_trampoline)
2638                 bpf_trampoline_put(aux->dst_trampoline);
2639         for (i = 0; i < aux->func_cnt; i++) {
2640                 /* We can just unlink the subprog poke descriptor table as
2641                  * it was originally linked to the main program and is also
2642                  * released along with it.
2643                  */
2644                 aux->func[i]->aux->poke_tab = NULL;
2645                 bpf_jit_free(aux->func[i]);
2646         }
2647         if (aux->func_cnt) {
2648                 kfree(aux->func);
2649                 bpf_prog_unlock_free(aux->prog);
2650         } else {
2651                 bpf_jit_free(aux->prog);
2652         }
2653 }
2654
2655 void bpf_prog_free(struct bpf_prog *fp)
2656 {
2657         struct bpf_prog_aux *aux = fp->aux;
2658
2659         if (aux->dst_prog)
2660                 bpf_prog_put(aux->dst_prog);
2661         INIT_WORK(&aux->work, bpf_prog_free_deferred);
2662         schedule_work(&aux->work);
2663 }
2664 EXPORT_SYMBOL_GPL(bpf_prog_free);
2665
2666 /* RNG for unpriviledged user space with separated state from prandom_u32(). */
2667 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2668
2669 void bpf_user_rnd_init_once(void)
2670 {
2671         prandom_init_once(&bpf_user_rnd_state);
2672 }
2673
2674 BPF_CALL_0(bpf_user_rnd_u32)
2675 {
2676         /* Should someone ever have the rather unwise idea to use some
2677          * of the registers passed into this function, then note that
2678          * this function is called from native eBPF and classic-to-eBPF
2679          * transformations. Register assignments from both sides are
2680          * different, f.e. classic always sets fn(ctx, A, X) here.
2681          */
2682         struct rnd_state *state;
2683         u32 res;
2684
2685         state = &get_cpu_var(bpf_user_rnd_state);
2686         res = prandom_u32_state(state);
2687         put_cpu_var(bpf_user_rnd_state);
2688
2689         return res;
2690 }
2691
2692 BPF_CALL_0(bpf_get_raw_cpu_id)
2693 {
2694         return raw_smp_processor_id();
2695 }
2696
2697 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2698 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2699 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2700 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2701 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2702 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2703 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2704 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2705 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2706 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2707 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2708
2709 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2710 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2711 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2712 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2713 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2714 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2715 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2716
2717 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2718 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2719 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2720 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2721 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2722 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2723 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2724 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2725 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2726 const struct bpf_func_proto bpf_set_retval_proto __weak;
2727 const struct bpf_func_proto bpf_get_retval_proto __weak;
2728
2729 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2730 {
2731         return NULL;
2732 }
2733
2734 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2735 {
2736         return NULL;
2737 }
2738
2739 u64 __weak
2740 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2741                  void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2742 {
2743         return -ENOTSUPP;
2744 }
2745 EXPORT_SYMBOL_GPL(bpf_event_output);
2746
2747 /* Always built-in helper functions. */
2748 const struct bpf_func_proto bpf_tail_call_proto = {
2749         .func           = NULL,
2750         .gpl_only       = false,
2751         .ret_type       = RET_VOID,
2752         .arg1_type      = ARG_PTR_TO_CTX,
2753         .arg2_type      = ARG_CONST_MAP_PTR,
2754         .arg3_type      = ARG_ANYTHING,
2755 };
2756
2757 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2758  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2759  * eBPF and implicitly also cBPF can get JITed!
2760  */
2761 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2762 {
2763         return prog;
2764 }
2765
2766 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2767  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2768  */
2769 void __weak bpf_jit_compile(struct bpf_prog *prog)
2770 {
2771 }
2772
2773 bool __weak bpf_helper_changes_pkt_data(void *func)
2774 {
2775         return false;
2776 }
2777
2778 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2779  * analysis code and wants explicit zero extension inserted by verifier.
2780  * Otherwise, return FALSE.
2781  *
2782  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2783  * you don't override this. JITs that don't want these extra insns can detect
2784  * them using insn_is_zext.
2785  */
2786 bool __weak bpf_jit_needs_zext(void)
2787 {
2788         return false;
2789 }
2790
2791 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2792 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2793 {
2794         return false;
2795 }
2796
2797 bool __weak bpf_jit_supports_kfunc_call(void)
2798 {
2799         return false;
2800 }
2801
2802 bool __weak bpf_jit_supports_far_kfunc_call(void)
2803 {
2804         return false;
2805 }
2806
2807 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
2808  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
2809  */
2810 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
2811                          int len)
2812 {
2813         return -EFAULT;
2814 }
2815
2816 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
2817                               void *addr1, void *addr2)
2818 {
2819         return -ENOTSUPP;
2820 }
2821
2822 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
2823 {
2824         return ERR_PTR(-ENOTSUPP);
2825 }
2826
2827 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
2828 {
2829         return -ENOTSUPP;
2830 }
2831
2832 #ifdef CONFIG_BPF_SYSCALL
2833 static int __init bpf_global_ma_init(void)
2834 {
2835         int ret;
2836
2837         ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
2838         bpf_global_ma_set = !ret;
2839         return ret;
2840 }
2841 late_initcall(bpf_global_ma_init);
2842 #endif
2843
2844 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
2845 EXPORT_SYMBOL(bpf_stats_enabled_key);
2846
2847 /* All definitions of tracepoints related to BPF. */
2848 #define CREATE_TRACE_POINTS
2849 #include <linux/bpf_trace.h>
2850
2851 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
2852 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);