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 <[email protected]>
  13  *      Alexei Starovoitov <[email protected]>
  14  *      Daniel Borkmann <[email protected]>
  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/bpf.h>
  26 #include <linux/btf.h>
  27 #include <linux/objtool.h>
  28 #include <linux/overflow.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 #include <linux/execmem.h>
  41
  42 #include <asm/barrier.h>
  43 #include <asm/unaligned.h>
  44
  45 /* Registers */
  46 #define BPF_R0  regs[BPF_REG_0]
  47 #define BPF_R1  regs[BPF_REG_1]
  48 #define BPF_R2  regs[BPF_REG_2]
  49 #define BPF_R3  regs[BPF_REG_3]
  50 #define BPF_R4  regs[BPF_REG_4]
  51 #define BPF_R5  regs[BPF_REG_5]
  52 #define BPF_R6  regs[BPF_REG_6]
  53 #define BPF_R7  regs[BPF_REG_7]
  54 #define BPF_R8  regs[BPF_REG_8]
  55 #define BPF_R9  regs[BPF_REG_9]
  56 #define BPF_R10 regs[BPF_REG_10]
  57
  58 /* Named registers */
  59 #define DST     regs[insn->dst_reg]
  60 #define SRC     regs[insn->src_reg]
  61 #define FP      regs[BPF_REG_FP]
  62 #define AX      regs[BPF_REG_AX]
  63 #define ARG1    regs[BPF_REG_ARG1]
  64 #define CTX     regs[BPF_REG_CTX]
  65 #define OFF     insn->off
  66 #define IMM     insn->imm
  67
  68 struct bpf_mem_alloc bpf_global_ma;
  69 bool bpf_global_ma_set;
  70
  71 /* No hurry in this branch
  72  *
  73  * Exported for the bpf jit load helper.
  74  */
  75 void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size)
  76 {
  77         u8 *ptr = NULL;
  78
  79         if (k >= SKF_NET_OFF) {
  80                 ptr = skb_network_header(skb) + k - SKF_NET_OFF;
  81         } else if (k >= SKF_LL_OFF) {
  82                 if (unlikely(!skb_mac_header_was_set(skb)))
  83                         return NULL;
  84                 ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
  85         }
  86         if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
  87                 return ptr;
  88
  89         return NULL;
  90 }
  91
  92 /* tell bpf programs that include vmlinux.h kernel's PAGE_SIZE */
  93 enum page_size_enum {
  94         __PAGE_SIZE = PAGE_SIZE
  95 };
  96
  97 struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flags)
  98 {
  99         gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
 100         struct bpf_prog_aux *aux;
 101         struct bpf_prog *fp;
 102
 103         size = round_up(size, __PAGE_SIZE);
 104         fp = __vmalloc(size, gfp_flags);
 105         if (fp == NULL)
 106                 return NULL;
 107
 108         aux = kzalloc(sizeof(*aux), bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
 109         if (aux == NULL) {
 110                 vfree(fp);
 111                 return NULL;
 112         }
 113         fp->active = alloc_percpu_gfp(int, bpf_memcg_flags(GFP_KERNEL | gfp_extra_flags));
 114         if (!fp->active) {
 115                 vfree(fp);
 116                 kfree(aux);
 117                 return NULL;
 118         }
 119
 120         fp->pages = size / PAGE_SIZE;
 121         fp->aux = aux;
 122         fp->aux->prog = fp;
 123         fp->jit_requested = ebpf_jit_enabled();
 124         fp->blinding_requested = bpf_jit_blinding_enabled(fp);
 125 #ifdef CONFIG_CGROUP_BPF
 126         aux->cgroup_atype = CGROUP_BPF_ATTACH_TYPE_INVALID;
 127 #endif
 128
 129         INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode);
 130 #ifdef CONFIG_FINEIBT
 131         INIT_LIST_HEAD_RCU(&fp->aux->ksym_prefix.lnode);
 132 #endif
 133         mutex_init(&fp->aux->used_maps_mutex);
 134         mutex_init(&fp->aux->dst_mutex);
 135
 136         return fp;
 137 }
 138
 139 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
 140 {
 141         gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
 142         struct bpf_prog *prog;
 143         int cpu;
 144
 145         prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
 146         if (!prog)
 147                 return NULL;
 148
 149         prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
 150         if (!prog->stats) {
 151                 free_percpu(prog->active);
 152                 kfree(prog->aux);
 153                 vfree(prog);
 154                 return NULL;
 155         }
 156
 157         for_each_possible_cpu(cpu) {
 158                 struct bpf_prog_stats *pstats;
 159
 160                 pstats = per_cpu_ptr(prog->stats, cpu);
 161                 u64_stats_init(&pstats->syncp);
 162         }
 163         return prog;
 164 }
 165 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
 166
 167 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
 168 {
 169         if (!prog->aux->nr_linfo || !prog->jit_requested)
 170                 return 0;
 171
 172         prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
 173                                           sizeof(*prog->aux->jited_linfo),
 174                                           bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN));
 175         if (!prog->aux->jited_linfo)
 176                 return -ENOMEM;
 177
 178         return 0;
 179 }
 180
 181 void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
 182 {
 183         if (prog->aux->jited_linfo &&
 184             (!prog->jited || !prog->aux->jited_linfo[0])) {
 185                 kvfree(prog->aux->jited_linfo);
 186                 prog->aux->jited_linfo = NULL;
 187         }
 188
 189         kfree(prog->aux->kfunc_tab);
 190         prog->aux->kfunc_tab = NULL;
 191 }
 192
 193 /* The jit engine is responsible to provide an array
 194  * for insn_off to the jited_off mapping (insn_to_jit_off).
 195  *
 196  * The idx to this array is the insn_off.  Hence, the insn_off
 197  * here is relative to the prog itself instead of the main prog.
 198  * This array has one entry for each xlated bpf insn.
 199  *
 200  * jited_off is the byte off to the end of the jited insn.
 201  *
 202  * Hence, with
 203  * insn_start:
 204  *      The first bpf insn off of the prog.  The insn off
 205  *      here is relative to the main prog.
 206  *      e.g. if prog is a subprog, insn_start > 0
 207  * linfo_idx:
 208  *      The prog's idx to prog->aux->linfo and jited_linfo
 209  *
 210  * jited_linfo[linfo_idx] = prog->bpf_func
 211  *
 212  * For i > linfo_idx,
 213  *
 214  * jited_linfo[i] = prog->bpf_func +
 215  *      insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
 216  */
 217 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
 218                                const u32 *insn_to_jit_off)
 219 {
 220         u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
 221         const struct bpf_line_info *linfo;
 222         void **jited_linfo;
 223
 224         if (!prog->aux->jited_linfo || prog->aux->func_idx > prog->aux->func_cnt)
 225                 /* Userspace did not provide linfo */
 226                 return;
 227
 228         linfo_idx = prog->aux->linfo_idx;
 229         linfo = &prog->aux->linfo[linfo_idx];
 230         insn_start = linfo[0].insn_off;
 231         insn_end = insn_start + prog->len;
 232
 233         jited_linfo = &prog->aux->jited_linfo[linfo_idx];
 234         jited_linfo[0] = prog->bpf_func;
 235
 236         nr_linfo = prog->aux->nr_linfo - linfo_idx;
 237
 238         for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
 239                 /* The verifier ensures that linfo[i].insn_off is
 240                  * strictly increasing
 241                  */
 242                 jited_linfo[i] = prog->bpf_func +
 243                         insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
 244 }
 245
 246 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 247                                   gfp_t gfp_extra_flags)
 248 {
 249         gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
 250         struct bpf_prog *fp;
 251         u32 pages;
 252
 253         size = round_up(size, PAGE_SIZE);
 254         pages = size / PAGE_SIZE;
 255         if (pages <= fp_old->pages)
 256                 return fp_old;
 257
 258         fp = __vmalloc(size, gfp_flags);
 259         if (fp) {
 260                 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
 261                 fp->pages = pages;
 262                 fp->aux->prog = fp;
 263
 264                 /* We keep fp->aux from fp_old around in the new
 265                  * reallocated structure.
 266                  */
 267                 fp_old->aux = NULL;
 268                 fp_old->stats = NULL;
 269                 fp_old->active = NULL;
 270                 __bpf_prog_free(fp_old);
 271         }
 272
 273         return fp;
 274 }
 275
 276 void __bpf_prog_free(struct bpf_prog *fp)
 277 {
 278         if (fp->aux) {
 279                 mutex_destroy(&fp->aux->used_maps_mutex);
 280                 mutex_destroy(&fp->aux->dst_mutex);
 281                 kfree(fp->aux->poke_tab);
 282                 kfree(fp->aux);
 283         }
 284         free_percpu(fp->stats);
 285         free_percpu(fp->active);
 286         vfree(fp);
 287 }
 288
 289 int bpf_prog_calc_tag(struct bpf_prog *fp)
 290 {
 291         const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
 292         u32 raw_size = bpf_prog_tag_scratch_size(fp);
 293         u32 digest[SHA1_DIGEST_WORDS];
 294         u32 ws[SHA1_WORKSPACE_WORDS];
 295         u32 i, bsize, psize, blocks;
 296         struct bpf_insn *dst;
 297         bool was_ld_map;
 298         u8 *raw, *todo;
 299         __be32 *result;
 300         __be64 *bits;
 301
 302         raw = vmalloc(raw_size);
 303         if (!raw)
 304                 return -ENOMEM;
 305
 306         sha1_init(digest);
 307         memset(ws, 0, sizeof(ws));
 308
 309         /* We need to take out the map fd for the digest calculation
 310          * since they are unstable from user space side.
 311          */
 312         dst = (void *)raw;
 313         for (i = 0, was_ld_map = false; i < fp->len; i++) {
 314                 dst[i] = fp->insnsi[i];
 315                 if (!was_ld_map &&
 316                     dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
 317                     (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
 318                      dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
 319                         was_ld_map = true;
 320                         dst[i].imm = 0;
 321                 } else if (was_ld_map &&
 322                            dst[i].code == 0 &&
 323                            dst[i].dst_reg == 0 &&
 324                            dst[i].src_reg == 0 &&
 325                            dst[i].off == 0) {
 326                         was_ld_map = false;
 327                         dst[i].imm = 0;
 328                 } else {
 329                         was_ld_map = false;
 330                 }
 331         }
 332
 333         psize = bpf_prog_insn_size(fp);
 334         memset(&raw[psize], 0, raw_size - psize);
 335         raw[psize++] = 0x80;
 336
 337         bsize  = round_up(psize, SHA1_BLOCK_SIZE);
 338         blocks = bsize / SHA1_BLOCK_SIZE;
 339         todo   = raw;
 340         if (bsize - psize >= sizeof(__be64)) {
 341                 bits = (__be64 *)(todo + bsize - sizeof(__be64));
 342         } else {
 343                 bits = (__be64 *)(todo + bsize + bits_offset);
 344                 blocks++;
 345         }
 346         *bits = cpu_to_be64((psize - 1) << 3);
 347
 348         while (blocks--) {
 349                 sha1_transform(digest, todo, ws);
 350                 todo += SHA1_BLOCK_SIZE;
 351         }
 352
 353         result = (__force __be32 *)digest;
 354         for (i = 0; i < SHA1_DIGEST_WORDS; i++)
 355                 result[i] = cpu_to_be32(digest[i]);
 356         memcpy(fp->tag, result, sizeof(fp->tag));
 357
 358         vfree(raw);
 359         return 0;
 360 }
 361
 362 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
 363                                 s32 end_new, s32 curr, const bool probe_pass)
 364 {
 365         const s64 imm_min = S32_MIN, imm_max = S32_MAX;
 366         s32 delta = end_new - end_old;
 367         s64 imm = insn->imm;
 368
 369         if (curr < pos && curr + imm + 1 >= end_old)
 370                 imm += delta;
 371         else if (curr >= end_new && curr + imm + 1 < end_new)
 372                 imm -= delta;
 373         if (imm < imm_min || imm > imm_max)
 374                 return -ERANGE;
 375         if (!probe_pass)
 376                 insn->imm = imm;
 377         return 0;
 378 }
 379
 380 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
 381                                 s32 end_new, s32 curr, const bool probe_pass)
 382 {
 383         s64 off_min, off_max, off;
 384         s32 delta = end_new - end_old;
 385
 386         if (insn->code == (BPF_JMP32 | BPF_JA)) {
 387                 off = insn->imm;
 388                 off_min = S32_MIN;
 389                 off_max = S32_MAX;
 390         } else {
 391                 off = insn->off;
 392                 off_min = S16_MIN;
 393                 off_max = S16_MAX;
 394         }
 395
 396         if (curr < pos && curr + off + 1 >= end_old)
 397                 off += delta;
 398         else if (curr >= end_new && curr + off + 1 < end_new)
 399                 off -= delta;
 400         if (off < off_min || off > off_max)
 401                 return -ERANGE;
 402         if (!probe_pass) {
 403                 if (insn->code == (BPF_JMP32 | BPF_JA))
 404                         insn->imm = off;
 405                 else
 406                         insn->off = off;
 407         }
 408         return 0;
 409 }
 410
 411 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
 412                             s32 end_new, const bool probe_pass)
 413 {
 414         u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
 415         struct bpf_insn *insn = prog->insnsi;
 416         int ret = 0;
 417
 418         for (i = 0; i < insn_cnt; i++, insn++) {
 419                 u8 code;
 420
 421                 /* In the probing pass we still operate on the original,
 422                  * unpatched image in order to check overflows before we
 423                  * do any other adjustments. Therefore skip the patchlet.
 424                  */
 425                 if (probe_pass && i == pos) {
 426                         i = end_new;
 427                         insn = prog->insnsi + end_old;
 428                 }
 429                 if (bpf_pseudo_func(insn)) {
 430                         ret = bpf_adj_delta_to_imm(insn, pos, end_old,
 431                                                    end_new, i, probe_pass);
 432                         if (ret)
 433                                 return ret;
 434                         continue;
 435                 }
 436                 code = insn->code;
 437                 if ((BPF_CLASS(code) != BPF_JMP &&
 438                      BPF_CLASS(code) != BPF_JMP32) ||
 439                     BPF_OP(code) == BPF_EXIT)
 440                         continue;
 441                 /* Adjust offset of jmps if we cross patch boundaries. */
 442                 if (BPF_OP(code) == BPF_CALL) {
 443                         if (insn->src_reg != BPF_PSEUDO_CALL)
 444                                 continue;
 445                         ret = bpf_adj_delta_to_imm(insn, pos, end_old,
 446                                                    end_new, i, probe_pass);
 447                 } else {
 448                         ret = bpf_adj_delta_to_off(insn, pos, end_old,
 449                                                    end_new, i, probe_pass);
 450                 }
 451                 if (ret)
 452                         break;
 453         }
 454
 455         return ret;
 456 }
 457
 458 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
 459 {
 460         struct bpf_line_info *linfo;
 461         u32 i, nr_linfo;
 462
 463         nr_linfo = prog->aux->nr_linfo;
 464         if (!nr_linfo || !delta)
 465                 return;
 466
 467         linfo = prog->aux->linfo;
 468
 469         for (i = 0; i < nr_linfo; i++)
 470                 if (off < linfo[i].insn_off)
 471                         break;
 472
 473         /* Push all off < linfo[i].insn_off by delta */
 474         for (; i < nr_linfo; i++)
 475                 linfo[i].insn_off += delta;
 476 }
 477
 478 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 479                                        const struct bpf_insn *patch, u32 len)
 480 {
 481         u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
 482         const u32 cnt_max = S16_MAX;
 483         struct bpf_prog *prog_adj;
 484         int err;
 485
 486         /* Since our patchlet doesn't expand the image, we're done. */
 487         if (insn_delta == 0) {
 488                 memcpy(prog->insnsi + off, patch, sizeof(*patch));
 489                 return prog;
 490         }
 491
 492         insn_adj_cnt = prog->len + insn_delta;
 493
 494         /* Reject anything that would potentially let the insn->off
 495          * target overflow when we have excessive program expansions.
 496          * We need to probe here before we do any reallocation where
 497          * we afterwards may not fail anymore.
 498          */
 499         if (insn_adj_cnt > cnt_max &&
 500             (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
 501                 return ERR_PTR(err);
 502
 503         /* Several new instructions need to be inserted. Make room
 504          * for them. Likely, there's no need for a new allocation as
 505          * last page could have large enough tailroom.
 506          */
 507         prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
 508                                     GFP_USER);
 509         if (!prog_adj)
 510                 return ERR_PTR(-ENOMEM);
 511
 512         prog_adj->len = insn_adj_cnt;
 513
 514         /* Patching happens in 3 steps:
 515          *
 516          * 1) Move over tail of insnsi from next instruction onwards,
 517          *    so we can patch the single target insn with one or more
 518          *    new ones (patching is always from 1 to n insns, n > 0).
 519          * 2) Inject new instructions at the target location.
 520          * 3) Adjust branch offsets if necessary.
 521          */
 522         insn_rest = insn_adj_cnt - off - len;
 523
 524         memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
 525                 sizeof(*patch) * insn_rest);
 526         memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
 527
 528         /* We are guaranteed to not fail at this point, otherwise
 529          * the ship has sailed to reverse to the original state. An
 530          * overflow cannot happen at this point.
 531          */
 532         BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
 533
 534         bpf_adj_linfo(prog_adj, off, insn_delta);
 535
 536         return prog_adj;
 537 }
 538
 539 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
 540 {
 541         /* Branch offsets can't overflow when program is shrinking, no need
 542          * to call bpf_adj_branches(..., true) here
 543          */
 544         memmove(prog->insnsi + off, prog->insnsi + off + cnt,
 545                 sizeof(struct bpf_insn) * (prog->len - off - cnt));
 546         prog->len -= cnt;
 547
 548         return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false));
 549 }
 550
 551 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
 552 {
 553         int i;
 554
 555         for (i = 0; i < fp->aux->real_func_cnt; i++)
 556                 bpf_prog_kallsyms_del(fp->aux->func[i]);
 557 }
 558
 559 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
 560 {
 561         bpf_prog_kallsyms_del_subprogs(fp);
 562         bpf_prog_kallsyms_del(fp);
 563 }
 564
 565 #ifdef CONFIG_BPF_JIT
 566 /* All BPF JIT sysctl knobs here. */
 567 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
 568 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
 569 int bpf_jit_harden   __read_mostly;
 570 long bpf_jit_limit   __read_mostly;
 571 long bpf_jit_limit_max __read_mostly;
 572
 573 static void
 574 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
 575 {
 576         WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
 577
 578         prog->aux->ksym.start = (unsigned long) prog->bpf_func;
 579         prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
 580 }
 581
 582 static void
 583 bpf_prog_ksym_set_name(struct bpf_prog *prog)
 584 {
 585         char *sym = prog->aux->ksym.name;
 586         const char *end = sym + KSYM_NAME_LEN;
 587         const struct btf_type *type;
 588         const char *func_name;
 589
 590         BUILD_BUG_ON(sizeof("bpf_prog_") +
 591                      sizeof(prog->tag) * 2 +
 592                      /* name has been null terminated.
 593                       * We should need +1 for the '_' preceding
 594                       * the name.  However, the null character
 595                       * is double counted between the name and the
 596                       * sizeof("bpf_prog_") above, so we omit
 597                       * the +1 here.
 598                       */
 599                      sizeof(prog->aux->name) > KSYM_NAME_LEN);
 600
 601         sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
 602         sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
 603
 604         /* prog->aux->name will be ignored if full btf name is available */
 605         if (prog->aux->func_info_cnt && prog->aux->func_idx < prog->aux->func_info_cnt) {
 606                 type = btf_type_by_id(prog->aux->btf,
 607                                       prog->aux->func_info[prog->aux->func_idx].type_id);
 608                 func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
 609                 snprintf(sym, (size_t)(end - sym), "_%s", func_name);
 610                 return;
 611         }
 612
 613         if (prog->aux->name[0])
 614                 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
 615         else
 616                 *sym = 0;
 617 }
 618
 619 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
 620 {
 621         return container_of(n, struct bpf_ksym, tnode)->start;
 622 }
 623
 624 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
 625                                           struct latch_tree_node *b)
 626 {
 627         return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
 628 }
 629
 630 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
 631 {
 632         unsigned long val = (unsigned long)key;
 633         const struct bpf_ksym *ksym;
 634
 635         ksym = container_of(n, struct bpf_ksym, tnode);
 636
 637         if (val < ksym->start)
 638                 return -1;
 639         /* Ensure that we detect return addresses as part of the program, when
 640          * the final instruction is a call for a program part of the stack
 641          * trace. Therefore, do val > ksym->end instead of val >= ksym->end.
 642          */
 643         if (val > ksym->end)
 644                 return  1;
 645
 646         return 0;
 647 }
 648
 649 static const struct latch_tree_ops bpf_tree_ops = {
 650         .less   = bpf_tree_less,
 651         .comp   = bpf_tree_comp,
 652 };
 653
 654 static DEFINE_SPINLOCK(bpf_lock);
 655 static LIST_HEAD(bpf_kallsyms);
 656 static struct latch_tree_root bpf_tree __cacheline_aligned;
 657
 658 void bpf_ksym_add(struct bpf_ksym *ksym)
 659 {
 660         spin_lock_bh(&bpf_lock);
 661         WARN_ON_ONCE(!list_empty(&ksym->lnode));
 662         list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
 663         latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
 664         spin_unlock_bh(&bpf_lock);
 665 }
 666
 667 static void __bpf_ksym_del(struct bpf_ksym *ksym)
 668 {
 669         if (list_empty(&ksym->lnode))
 670                 return;
 671
 672         latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
 673         list_del_rcu(&ksym->lnode);
 674 }
 675
 676 void bpf_ksym_del(struct bpf_ksym *ksym)
 677 {
 678         spin_lock_bh(&bpf_lock);
 679         __bpf_ksym_del(ksym);
 680         spin_unlock_bh(&bpf_lock);
 681 }
 682
 683 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
 684 {
 685         return fp->jited && !bpf_prog_was_classic(fp);
 686 }
 687
 688 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 689 {
 690         if (!bpf_prog_kallsyms_candidate(fp) ||
 691             !bpf_token_capable(fp->aux->token, CAP_BPF))
 692                 return;
 693
 694         bpf_prog_ksym_set_addr(fp);
 695         bpf_prog_ksym_set_name(fp);
 696         fp->aux->ksym.prog = true;
 697
 698         bpf_ksym_add(&fp->aux->ksym);
 699
 700 #ifdef CONFIG_FINEIBT
 701         /*
 702          * When FineIBT, code in the __cfi_foo() symbols can get executed
 703          * and hence unwinder needs help.
 704          */
 705         if (cfi_mode != CFI_FINEIBT)
 706                 return;
 707
 708         snprintf(fp->aux->ksym_prefix.name, KSYM_NAME_LEN,
 709                  "__cfi_%s", fp->aux->ksym.name);
 710
 711         fp->aux->ksym_prefix.start = (unsigned long) fp->bpf_func - 16;
 712         fp->aux->ksym_prefix.end   = (unsigned long) fp->bpf_func;
 713
 714         bpf_ksym_add(&fp->aux->ksym_prefix);
 715 #endif
 716 }
 717
 718 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 719 {
 720         if (!bpf_prog_kallsyms_candidate(fp))
 721                 return;
 722
 723         bpf_ksym_del(&fp->aux->ksym);
 724 #ifdef CONFIG_FINEIBT
 725         if (cfi_mode != CFI_FINEIBT)
 726                 return;
 727         bpf_ksym_del(&fp->aux->ksym_prefix);
 728 #endif
 729 }
 730
 731 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
 732 {
 733         struct latch_tree_node *n;
 734
 735         n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
 736         return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
 737 }
 738
 739 int __bpf_address_lookup(unsigned long addr, unsigned long *size,
 740                                  unsigned long *off, char *sym)
 741 {
 742         struct bpf_ksym *ksym;
 743         int ret = 0;
 744
 745         rcu_read_lock();
 746         ksym = bpf_ksym_find(addr);
 747         if (ksym) {
 748                 unsigned long symbol_start = ksym->start;
 749                 unsigned long symbol_end = ksym->end;
 750
 751                 ret = strscpy(sym, ksym->name, KSYM_NAME_LEN);
 752
 753                 if (size)
 754                         *size = symbol_end - symbol_start;
 755                 if (off)
 756                         *off  = addr - symbol_start;
 757         }
 758         rcu_read_unlock();
 759
 760         return ret;
 761 }
 762
 763 bool is_bpf_text_address(unsigned long addr)
 764 {
 765         bool ret;
 766
 767         rcu_read_lock();
 768         ret = bpf_ksym_find(addr) != NULL;
 769         rcu_read_unlock();
 770
 771         return ret;
 772 }
 773
 774 struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
 775 {
 776         struct bpf_ksym *ksym = bpf_ksym_find(addr);
 777
 778         return ksym && ksym->prog ?
 779                container_of(ksym, struct bpf_prog_aux, ksym)->prog :
 780                NULL;
 781 }
 782
 783 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
 784 {
 785         const struct exception_table_entry *e = NULL;
 786         struct bpf_prog *prog;
 787
 788         rcu_read_lock();
 789         prog = bpf_prog_ksym_find(addr);
 790         if (!prog)
 791                 goto out;
 792         if (!prog->aux->num_exentries)
 793                 goto out;
 794
 795         e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
 796 out:
 797         rcu_read_unlock();
 798         return e;
 799 }
 800
 801 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 802                     char *sym)
 803 {
 804         struct bpf_ksym *ksym;
 805         unsigned int it = 0;
 806         int ret = -ERANGE;
 807
 808         if (!bpf_jit_kallsyms_enabled())
 809                 return ret;
 810
 811         rcu_read_lock();
 812         list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
 813                 if (it++ != symnum)
 814                         continue;
 815
 816                 strscpy(sym, ksym->name, KSYM_NAME_LEN);
 817
 818                 *value = ksym->start;
 819                 *type  = BPF_SYM_ELF_TYPE;
 820
 821                 ret = 0;
 822                 break;
 823         }
 824         rcu_read_unlock();
 825
 826         return ret;
 827 }
 828
 829 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
 830                                 struct bpf_jit_poke_descriptor *poke)
 831 {
 832         struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
 833         static const u32 poke_tab_max = 1024;
 834         u32 slot = prog->aux->size_poke_tab;
 835         u32 size = slot + 1;
 836
 837         if (size > poke_tab_max)
 838                 return -ENOSPC;
 839         if (poke->tailcall_target || poke->tailcall_target_stable ||
 840             poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
 841                 return -EINVAL;
 842
 843         switch (poke->reason) {
 844         case BPF_POKE_REASON_TAIL_CALL:
 845                 if (!poke->tail_call.map)
 846                         return -EINVAL;
 847                 break;
 848         default:
 849                 return -EINVAL;
 850         }
 851
 852         tab = krealloc_array(tab, size, sizeof(*poke), GFP_KERNEL);
 853         if (!tab)
 854                 return -ENOMEM;
 855
 856         memcpy(&tab[slot], poke, sizeof(*poke));
 857         prog->aux->size_poke_tab = size;
 858         prog->aux->poke_tab = tab;
 859
 860         return slot;
 861 }
 862
 863 /*
 864  * BPF program pack allocator.
 865  *
 866  * Most BPF programs are pretty small. Allocating a hole page for each
 867  * program is sometime a waste. Many small bpf program also adds pressure
 868  * to instruction TLB. To solve this issue, we introduce a BPF program pack
 869  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
 870  * to host BPF programs.
 871  */
 872 #define BPF_PROG_CHUNK_SHIFT    6
 873 #define BPF_PROG_CHUNK_SIZE     (1 << BPF_PROG_CHUNK_SHIFT)
 874 #define BPF_PROG_CHUNK_MASK     (~(BPF_PROG_CHUNK_SIZE - 1))
 875
 876 struct bpf_prog_pack {
 877         struct list_head list;
 878         void *ptr;
 879         unsigned long bitmap[];
 880 };
 881
 882 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
 883 {
 884         memset(area, 0, size);
 885 }
 886
 887 #define BPF_PROG_SIZE_TO_NBITS(size)    (round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
 888
 889 static DEFINE_MUTEX(pack_mutex);
 890 static LIST_HEAD(pack_list);
 891
 892 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
 893  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
 894  */
 895 #ifdef PMD_SIZE
 896 /* PMD_SIZE is really big for some archs. It doesn't make sense to
 897  * reserve too much memory in one allocation. Hardcode BPF_PROG_PACK_SIZE to
 898  * 2MiB * num_possible_nodes(). On most architectures PMD_SIZE will be
 899  * greater than or equal to 2MB.
 900  */
 901 #define BPF_PROG_PACK_SIZE (SZ_2M * num_possible_nodes())
 902 #else
 903 #define BPF_PROG_PACK_SIZE PAGE_SIZE
 904 #endif
 905
 906 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
 907
 908 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
 909 {
 910         struct bpf_prog_pack *pack;
 911         int err;
 912
 913         pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
 914                        GFP_KERNEL);
 915         if (!pack)
 916                 return NULL;
 917         pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE);
 918         if (!pack->ptr)
 919                 goto out;
 920         bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
 921         bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
 922
 923         set_vm_flush_reset_perms(pack->ptr);
 924         err = set_memory_rox((unsigned long)pack->ptr,
 925                              BPF_PROG_PACK_SIZE / PAGE_SIZE);
 926         if (err)
 927                 goto out;
 928         list_add_tail(&pack->list, &pack_list);
 929         return pack;
 930
 931 out:
 932         bpf_jit_free_exec(pack->ptr);
 933         kfree(pack);
 934         return NULL;
 935 }
 936
 937 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
 938 {
 939         unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
 940         struct bpf_prog_pack *pack;
 941         unsigned long pos;
 942         void *ptr = NULL;
 943
 944         mutex_lock(&pack_mutex);
 945         if (size > BPF_PROG_PACK_SIZE) {
 946                 size = round_up(size, PAGE_SIZE);
 947                 ptr = bpf_jit_alloc_exec(size);
 948                 if (ptr) {
 949                         int err;
 950
 951                         bpf_fill_ill_insns(ptr, size);
 952                         set_vm_flush_reset_perms(ptr);
 953                         err = set_memory_rox((unsigned long)ptr,
 954                                              size / PAGE_SIZE);
 955                         if (err) {
 956                                 bpf_jit_free_exec(ptr);
 957                                 ptr = NULL;
 958                         }
 959                 }
 960                 goto out;
 961         }
 962         list_for_each_entry(pack, &pack_list, list) {
 963                 pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
 964                                                  nbits, 0);
 965                 if (pos < BPF_PROG_CHUNK_COUNT)
 966                         goto found_free_area;
 967         }
 968
 969         pack = alloc_new_pack(bpf_fill_ill_insns);
 970         if (!pack)
 971                 goto out;
 972
 973         pos = 0;
 974
 975 found_free_area:
 976         bitmap_set(pack->bitmap, pos, nbits);
 977         ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
 978
 979 out:
 980         mutex_unlock(&pack_mutex);
 981         return ptr;
 982 }
 983
 984 void bpf_prog_pack_free(void *ptr, u32 size)
 985 {
 986         struct bpf_prog_pack *pack = NULL, *tmp;
 987         unsigned int nbits;
 988         unsigned long pos;
 989
 990         mutex_lock(&pack_mutex);
 991         if (size > BPF_PROG_PACK_SIZE) {
 992                 bpf_jit_free_exec(ptr);
 993                 goto out;
 994         }
 995
 996         list_for_each_entry(tmp, &pack_list, list) {
 997                 if (ptr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > ptr) {
 998                         pack = tmp;
 999                         break;
1000                 }
1001         }
1002
1003         if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
1004                 goto out;
1005
1006         nbits = BPF_PROG_SIZE_TO_NBITS(size);
1007         pos = ((unsigned long)ptr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
1008
1009         WARN_ONCE(bpf_arch_text_invalidate(ptr, size),
1010                   "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
1011
1012         bitmap_clear(pack->bitmap, pos, nbits);
1013         if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
1014                                        BPF_PROG_CHUNK_COUNT, 0) == 0) {
1015                 list_del(&pack->list);
1016                 bpf_jit_free_exec(pack->ptr);
1017                 kfree(pack);
1018         }
1019 out:
1020         mutex_unlock(&pack_mutex);
1021 }
1022
1023 static atomic_long_t bpf_jit_current;
1024
1025 /* Can be overridden by an arch's JIT compiler if it has a custom,
1026  * dedicated BPF backend memory area, or if neither of the two
1027  * below apply.
1028  */
1029 u64 __weak bpf_jit_alloc_exec_limit(void)
1030 {
1031 #if defined(MODULES_VADDR)
1032         return MODULES_END - MODULES_VADDR;
1033 #else
1034         return VMALLOC_END - VMALLOC_START;
1035 #endif
1036 }
1037
1038 static int __init bpf_jit_charge_init(void)
1039 {
1040         /* Only used as heuristic here to derive limit. */
1041         bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
1042         bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
1043                                             PAGE_SIZE), LONG_MAX);
1044         return 0;
1045 }
1046 pure_initcall(bpf_jit_charge_init);
1047
1048 int bpf_jit_charge_modmem(u32 size)
1049 {
1050         if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
1051                 if (!bpf_capable()) {
1052                         atomic_long_sub(size, &bpf_jit_current);
1053                         return -EPERM;
1054                 }
1055         }
1056
1057         return 0;
1058 }
1059
1060 void bpf_jit_uncharge_modmem(u32 size)
1061 {
1062         atomic_long_sub(size, &bpf_jit_current);
1063 }
1064
1065 void *__weak bpf_jit_alloc_exec(unsigned long size)
1066 {
1067         return execmem_alloc(EXECMEM_BPF, size);
1068 }
1069
1070 void __weak bpf_jit_free_exec(void *addr)
1071 {
1072         execmem_free(addr);
1073 }
1074
1075 struct bpf_binary_header *
1076 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1077                      unsigned int alignment,
1078                      bpf_jit_fill_hole_t bpf_fill_ill_insns)
1079 {
1080         struct bpf_binary_header *hdr;
1081         u32 size, hole, start;
1082
1083         WARN_ON_ONCE(!is_power_of_2(alignment) ||
1084                      alignment > BPF_IMAGE_ALIGNMENT);
1085
1086         /* Most of BPF filters are really small, but if some of them
1087          * fill a page, allow at least 128 extra bytes to insert a
1088          * random section of illegal instructions.
1089          */
1090         size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1091
1092         if (bpf_jit_charge_modmem(size))
1093                 return NULL;
1094         hdr = bpf_jit_alloc_exec(size);
1095         if (!hdr) {
1096                 bpf_jit_uncharge_modmem(size);
1097                 return NULL;
1098         }
1099
1100         /* Fill space with illegal/arch-dep instructions. */
1101         bpf_fill_ill_insns(hdr, size);
1102
1103         hdr->size = size;
1104         hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1105                      PAGE_SIZE - sizeof(*hdr));
1106         start = get_random_u32_below(hole) & ~(alignment - 1);
1107
1108         /* Leave a random number of instructions before BPF code. */
1109         *image_ptr = &hdr->image[start];
1110
1111         return hdr;
1112 }
1113
1114 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1115 {
1116         u32 size = hdr->size;
1117
1118         bpf_jit_free_exec(hdr);
1119         bpf_jit_uncharge_modmem(size);
1120 }
1121
1122 /* Allocate jit binary from bpf_prog_pack allocator.
1123  * Since the allocated memory is RO+X, the JIT engine cannot write directly
1124  * to the memory. To solve this problem, a RW buffer is also allocated at
1125  * as the same time. The JIT engine should calculate offsets based on the
1126  * RO memory address, but write JITed program to the RW buffer. Once the
1127  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1128  * the JITed program to the RO memory.
1129  */
1130 struct bpf_binary_header *
1131 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1132                           unsigned int alignment,
1133                           struct bpf_binary_header **rw_header,
1134                           u8 **rw_image,
1135                           bpf_jit_fill_hole_t bpf_fill_ill_insns)
1136 {
1137         struct bpf_binary_header *ro_header;
1138         u32 size, hole, start;
1139
1140         WARN_ON_ONCE(!is_power_of_2(alignment) ||
1141                      alignment > BPF_IMAGE_ALIGNMENT);
1142
1143         /* add 16 bytes for a random section of illegal instructions */
1144         size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1145
1146         if (bpf_jit_charge_modmem(size))
1147                 return NULL;
1148         ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1149         if (!ro_header) {
1150                 bpf_jit_uncharge_modmem(size);
1151                 return NULL;
1152         }
1153
1154         *rw_header = kvmalloc(size, GFP_KERNEL);
1155         if (!*rw_header) {
1156                 bpf_prog_pack_free(ro_header, size);
1157                 bpf_jit_uncharge_modmem(size);
1158                 return NULL;
1159         }
1160
1161         /* Fill space with illegal/arch-dep instructions. */
1162         bpf_fill_ill_insns(*rw_header, size);
1163         (*rw_header)->size = size;
1164
1165         hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1166                      BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1167         start = get_random_u32_below(hole) & ~(alignment - 1);
1168
1169         *image_ptr = &ro_header->image[start];
1170         *rw_image = &(*rw_header)->image[start];
1171
1172         return ro_header;
1173 }
1174
1175 /* Copy JITed text from rw_header to its final location, the ro_header. */
1176 int bpf_jit_binary_pack_finalize(struct bpf_binary_header *ro_header,
1177                                  struct bpf_binary_header *rw_header)
1178 {
1179         void *ptr;
1180
1181         ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1182
1183         kvfree(rw_header);
1184
1185         if (IS_ERR(ptr)) {
1186                 bpf_prog_pack_free(ro_header, ro_header->size);
1187                 return PTR_ERR(ptr);
1188         }
1189         return 0;
1190 }
1191
1192 /* bpf_jit_binary_pack_free is called in two different scenarios:
1193  *   1) when the program is freed after;
1194  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1195  * For case 2), we need to free both the RO memory and the RW buffer.
1196  *
1197  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1198  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1199  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1200  * bpf_arch_text_copy (when jit fails).
1201  */
1202 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1203                               struct bpf_binary_header *rw_header)
1204 {
1205         u32 size = ro_header->size;
1206
1207         bpf_prog_pack_free(ro_header, size);
1208         kvfree(rw_header);
1209         bpf_jit_uncharge_modmem(size);
1210 }
1211
1212 struct bpf_binary_header *
1213 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1214 {
1215         unsigned long real_start = (unsigned long)fp->bpf_func;
1216         unsigned long addr;
1217
1218         addr = real_start & BPF_PROG_CHUNK_MASK;
1219         return (void *)addr;
1220 }
1221
1222 static inline struct bpf_binary_header *
1223 bpf_jit_binary_hdr(const struct bpf_prog *fp)
1224 {
1225         unsigned long real_start = (unsigned long)fp->bpf_func;
1226         unsigned long addr;
1227
1228         addr = real_start & PAGE_MASK;
1229         return (void *)addr;
1230 }
1231
1232 /* This symbol is only overridden by archs that have different
1233  * requirements than the usual eBPF JITs, f.e. when they only
1234  * implement cBPF JIT, do not set images read-only, etc.
1235  */
1236 void __weak bpf_jit_free(struct bpf_prog *fp)
1237 {
1238         if (fp->jited) {
1239                 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1240
1241                 bpf_jit_binary_free(hdr);
1242                 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1243         }
1244
1245         bpf_prog_unlock_free(fp);
1246 }
1247
1248 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1249                           const struct bpf_insn *insn, bool extra_pass,
1250                           u64 *func_addr, bool *func_addr_fixed)
1251 {
1252         s16 off = insn->off;
1253         s32 imm = insn->imm;
1254         u8 *addr;
1255         int err;
1256
1257         *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1258         if (!*func_addr_fixed) {
1259                 /* Place-holder address till the last pass has collected
1260                  * all addresses for JITed subprograms in which case we
1261                  * can pick them up from prog->aux.
1262                  */
1263                 if (!extra_pass)
1264                         addr = NULL;
1265                 else if (prog->aux->func &&
1266                          off >= 0 && off < prog->aux->real_func_cnt)
1267                         addr = (u8 *)prog->aux->func[off]->bpf_func;
1268                 else
1269                         return -EINVAL;
1270         } else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1271                    bpf_jit_supports_far_kfunc_call()) {
1272                 err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1273                 if (err)
1274                         return err;
1275         } else {
1276                 /* Address of a BPF helper call. Since part of the core
1277                  * kernel, it's always at a fixed location. __bpf_call_base
1278                  * and the helper with imm relative to it are both in core
1279                  * kernel.
1280                  */
1281                 addr = (u8 *)__bpf_call_base + imm;
1282         }
1283
1284         *func_addr = (unsigned long)addr;
1285         return 0;
1286 }
1287
1288 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1289                               const struct bpf_insn *aux,
1290                               struct bpf_insn *to_buff,
1291                               bool emit_zext)
1292 {
1293         struct bpf_insn *to = to_buff;
1294         u32 imm_rnd = get_random_u32();
1295         s16 off;
1296
1297         BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1298         BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1299
1300         /* Constraints on AX register:
1301          *
1302          * AX register is inaccessible from user space. It is mapped in
1303          * all JITs, and used here for constant blinding rewrites. It is
1304          * typically "stateless" meaning its contents are only valid within
1305          * the executed instruction, but not across several instructions.
1306          * There are a few exceptions however which are further detailed
1307          * below.
1308          *
1309          * Constant blinding is only used by JITs, not in the interpreter.
1310          * The interpreter uses AX in some occasions as a local temporary
1311          * register e.g. in DIV or MOD instructions.
1312          *
1313          * In restricted circumstances, the verifier can also use the AX
1314          * register for rewrites as long as they do not interfere with
1315          * the above cases!
1316          */
1317         if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1318                 goto out;
1319
1320         if (from->imm == 0 &&
1321             (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1322              from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1323                 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1324                 goto out;
1325         }
1326
1327         switch (from->code) {
1328         case BPF_ALU | BPF_ADD | BPF_K:
1329         case BPF_ALU | BPF_SUB | BPF_K:
1330         case BPF_ALU | BPF_AND | BPF_K:
1331         case BPF_ALU | BPF_OR  | BPF_K:
1332         case BPF_ALU | BPF_XOR | BPF_K:
1333         case BPF_ALU | BPF_MUL | BPF_K:
1334         case BPF_ALU | BPF_MOV | BPF_K:
1335         case BPF_ALU | BPF_DIV | BPF_K:
1336         case BPF_ALU | BPF_MOD | BPF_K:
1337                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1338                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1339                 *to++ = BPF_ALU32_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1340                 break;
1341
1342         case BPF_ALU64 | BPF_ADD | BPF_K:
1343         case BPF_ALU64 | BPF_SUB | BPF_K:
1344         case BPF_ALU64 | BPF_AND | BPF_K:
1345         case BPF_ALU64 | BPF_OR  | BPF_K:
1346         case BPF_ALU64 | BPF_XOR | BPF_K:
1347         case BPF_ALU64 | BPF_MUL | BPF_K:
1348         case BPF_ALU64 | BPF_MOV | BPF_K:
1349         case BPF_ALU64 | BPF_DIV | BPF_K:
1350         case BPF_ALU64 | BPF_MOD | BPF_K:
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_ALU64_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1354                 break;
1355
1356         case BPF_JMP | BPF_JEQ  | BPF_K:
1357         case BPF_JMP | BPF_JNE  | BPF_K:
1358         case BPF_JMP | BPF_JGT  | BPF_K:
1359         case BPF_JMP | BPF_JLT  | BPF_K:
1360         case BPF_JMP | BPF_JGE  | BPF_K:
1361         case BPF_JMP | BPF_JLE  | BPF_K:
1362         case BPF_JMP | BPF_JSGT | BPF_K:
1363         case BPF_JMP | BPF_JSLT | BPF_K:
1364         case BPF_JMP | BPF_JSGE | BPF_K:
1365         case BPF_JMP | BPF_JSLE | BPF_K:
1366         case BPF_JMP | BPF_JSET | BPF_K:
1367                 /* Accommodate for extra offset in case of a backjump. */
1368                 off = from->off;
1369                 if (off < 0)
1370                         off -= 2;
1371                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1372                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1373                 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1374                 break;
1375
1376         case BPF_JMP32 | BPF_JEQ  | BPF_K:
1377         case BPF_JMP32 | BPF_JNE  | BPF_K:
1378         case BPF_JMP32 | BPF_JGT  | BPF_K:
1379         case BPF_JMP32 | BPF_JLT  | BPF_K:
1380         case BPF_JMP32 | BPF_JGE  | BPF_K:
1381         case BPF_JMP32 | BPF_JLE  | BPF_K:
1382         case BPF_JMP32 | BPF_JSGT | BPF_K:
1383         case BPF_JMP32 | BPF_JSLT | BPF_K:
1384         case BPF_JMP32 | BPF_JSGE | BPF_K:
1385         case BPF_JMP32 | BPF_JSLE | BPF_K:
1386         case BPF_JMP32 | BPF_JSET | BPF_K:
1387                 /* Accommodate for extra offset in case of a backjump. */
1388                 off = from->off;
1389                 if (off < 0)
1390                         off -= 2;
1391                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1392                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1393                 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1394                                       off);
1395                 break;
1396
1397         case BPF_LD | BPF_IMM | BPF_DW:
1398                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1399                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1400                 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1401                 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1402                 break;
1403         case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1404                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1405                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1406                 if (emit_zext)
1407                         *to++ = BPF_ZEXT_REG(BPF_REG_AX);
1408                 *to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1409                 break;
1410
1411         case BPF_ST | BPF_MEM | BPF_DW:
1412         case BPF_ST | BPF_MEM | BPF_W:
1413         case BPF_ST | BPF_MEM | BPF_H:
1414         case BPF_ST | BPF_MEM | BPF_B:
1415                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1416                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1417                 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1418                 break;
1419         }
1420 out:
1421         return to - to_buff;
1422 }
1423
1424 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1425                                               gfp_t gfp_extra_flags)
1426 {
1427         gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1428         struct bpf_prog *fp;
1429
1430         fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1431         if (fp != NULL) {
1432                 /* aux->prog still points to the fp_other one, so
1433                  * when promoting the clone to the real program,
1434                  * this still needs to be adapted.
1435                  */
1436                 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1437         }
1438
1439         return fp;
1440 }
1441
1442 static void bpf_prog_clone_free(struct bpf_prog *fp)
1443 {
1444         /* aux was stolen by the other clone, so we cannot free
1445          * it from this path! It will be freed eventually by the
1446          * other program on release.
1447          *
1448          * At this point, we don't need a deferred release since
1449          * clone is guaranteed to not be locked.
1450          */
1451         fp->aux = NULL;
1452         fp->stats = NULL;
1453         fp->active = NULL;
1454         __bpf_prog_free(fp);
1455 }
1456
1457 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1458 {
1459         /* We have to repoint aux->prog to self, as we don't
1460          * know whether fp here is the clone or the original.
1461          */
1462         fp->aux->prog = fp;
1463         bpf_prog_clone_free(fp_other);
1464 }
1465
1466 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1467 {
1468         struct bpf_insn insn_buff[16], aux[2];
1469         struct bpf_prog *clone, *tmp;
1470         int insn_delta, insn_cnt;
1471         struct bpf_insn *insn;
1472         int i, rewritten;
1473
1474         if (!prog->blinding_requested || prog->blinded)
1475                 return prog;
1476
1477         clone = bpf_prog_clone_create(prog, GFP_USER);
1478         if (!clone)
1479                 return ERR_PTR(-ENOMEM);
1480
1481         insn_cnt = clone->len;
1482         insn = clone->insnsi;
1483
1484         for (i = 0; i < insn_cnt; i++, insn++) {
1485                 if (bpf_pseudo_func(insn)) {
1486                         /* ld_imm64 with an address of bpf subprog is not
1487                          * a user controlled constant. Don't randomize it,
1488                          * since it will conflict with jit_subprogs() logic.
1489                          */
1490                         insn++;
1491                         i++;
1492                         continue;
1493                 }
1494
1495                 /* We temporarily need to hold the original ld64 insn
1496                  * so that we can still access the first part in the
1497                  * second blinding run.
1498                  */
1499                 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1500                     insn[1].code == 0)
1501                         memcpy(aux, insn, sizeof(aux));
1502
1503                 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1504                                                 clone->aux->verifier_zext);
1505                 if (!rewritten)
1506                         continue;
1507
1508                 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1509                 if (IS_ERR(tmp)) {
1510                         /* Patching may have repointed aux->prog during
1511                          * realloc from the original one, so we need to
1512                          * fix it up here on error.
1513                          */
1514                         bpf_jit_prog_release_other(prog, clone);
1515                         return tmp;
1516                 }
1517
1518                 clone = tmp;
1519                 insn_delta = rewritten - 1;
1520
1521                 /* Walk new program and skip insns we just inserted. */
1522                 insn = clone->insnsi + i + insn_delta;
1523                 insn_cnt += insn_delta;
1524                 i        += insn_delta;
1525         }
1526
1527         clone->blinded = 1;
1528         return clone;
1529 }
1530 #endif /* CONFIG_BPF_JIT */
1531
1532 /* Base function for offset calculation. Needs to go into .text section,
1533  * therefore keeping it non-static as well; will also be used by JITs
1534  * anyway later on, so do not let the compiler omit it. This also needs
1535  * to go into kallsyms for correlation from e.g. bpftool, so naming
1536  * must not change.
1537  */
1538 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1539 {
1540         return 0;
1541 }
1542 EXPORT_SYMBOL_GPL(__bpf_call_base);
1543
1544 /* All UAPI available opcodes. */
1545 #define BPF_INSN_MAP(INSN_2, INSN_3)            \
1546         /* 32 bit ALU operations. */            \
1547         /*   Register based. */                 \
1548         INSN_3(ALU, ADD,  X),                   \
1549         INSN_3(ALU, SUB,  X),                   \
1550         INSN_3(ALU, AND,  X),                   \
1551         INSN_3(ALU, OR,   X),                   \
1552         INSN_3(ALU, LSH,  X),                   \
1553         INSN_3(ALU, RSH,  X),                   \
1554         INSN_3(ALU, XOR,  X),                   \
1555         INSN_3(ALU, MUL,  X),                   \
1556         INSN_3(ALU, MOV,  X),                   \
1557         INSN_3(ALU, ARSH, X),                   \
1558         INSN_3(ALU, DIV,  X),                   \
1559         INSN_3(ALU, MOD,  X),                   \
1560         INSN_2(ALU, NEG),                       \
1561         INSN_3(ALU, END, TO_BE),                \
1562         INSN_3(ALU, END, TO_LE),                \
1563         /*   Immediate based. */                \
1564         INSN_3(ALU, ADD,  K),                   \
1565         INSN_3(ALU, SUB,  K),                   \
1566         INSN_3(ALU, AND,  K),                   \
1567         INSN_3(ALU, OR,   K),                   \
1568         INSN_3(ALU, LSH,  K),                   \
1569         INSN_3(ALU, RSH,  K),                   \
1570         INSN_3(ALU, XOR,  K),                   \
1571         INSN_3(ALU, MUL,  K),                   \
1572         INSN_3(ALU, MOV,  K),                   \
1573         INSN_3(ALU, ARSH, K),                   \
1574         INSN_3(ALU, DIV,  K),                   \
1575         INSN_3(ALU, MOD,  K),                   \
1576         /* 64 bit ALU operations. */            \
1577         /*   Register based. */                 \
1578         INSN_3(ALU64, ADD,  X),                 \
1579         INSN_3(ALU64, SUB,  X),                 \
1580         INSN_3(ALU64, AND,  X),                 \
1581         INSN_3(ALU64, OR,   X),                 \
1582         INSN_3(ALU64, LSH,  X),                 \
1583         INSN_3(ALU64, RSH,  X),                 \
1584         INSN_3(ALU64, XOR,  X),                 \
1585         INSN_3(ALU64, MUL,  X),                 \
1586         INSN_3(ALU64, MOV,  X),                 \
1587         INSN_3(ALU64, ARSH, X),                 \
1588         INSN_3(ALU64, DIV,  X),                 \
1589         INSN_3(ALU64, MOD,  X),                 \
1590         INSN_2(ALU64, NEG),                     \
1591         INSN_3(ALU64, END, TO_LE),              \
1592         /*   Immediate based. */                \
1593         INSN_3(ALU64, ADD,  K),                 \
1594         INSN_3(ALU64, SUB,  K),                 \
1595         INSN_3(ALU64, AND,  K),                 \
1596         INSN_3(ALU64, OR,   K),                 \
1597         INSN_3(ALU64, LSH,  K),                 \
1598         INSN_3(ALU64, RSH,  K),                 \
1599         INSN_3(ALU64, XOR,  K),                 \
1600         INSN_3(ALU64, MUL,  K),                 \
1601         INSN_3(ALU64, MOV,  K),                 \
1602         INSN_3(ALU64, ARSH, K),                 \
1603         INSN_3(ALU64, DIV,  K),                 \
1604         INSN_3(ALU64, MOD,  K),                 \
1605         /* Call instruction. */                 \
1606         INSN_2(JMP, CALL),                      \
1607         /* Exit instruction. */                 \
1608         INSN_2(JMP, EXIT),                      \
1609         /* 32-bit Jump instructions. */         \
1610         /*   Register based. */                 \
1611         INSN_3(JMP32, JEQ,  X),                 \
1612         INSN_3(JMP32, JNE,  X),                 \
1613         INSN_3(JMP32, JGT,  X),                 \
1614         INSN_3(JMP32, JLT,  X),                 \
1615         INSN_3(JMP32, JGE,  X),                 \
1616         INSN_3(JMP32, JLE,  X),                 \
1617         INSN_3(JMP32, JSGT, X),                 \
1618         INSN_3(JMP32, JSLT, X),                 \
1619         INSN_3(JMP32, JSGE, X),                 \
1620         INSN_3(JMP32, JSLE, X),                 \
1621         INSN_3(JMP32, JSET, X),                 \
1622         /*   Immediate based. */                \
1623         INSN_3(JMP32, JEQ,  K),                 \
1624         INSN_3(JMP32, JNE,  K),                 \
1625         INSN_3(JMP32, JGT,  K),                 \
1626         INSN_3(JMP32, JLT,  K),                 \
1627         INSN_3(JMP32, JGE,  K),                 \
1628         INSN_3(JMP32, JLE,  K),                 \
1629         INSN_3(JMP32, JSGT, K),                 \
1630         INSN_3(JMP32, JSLT, K),                 \
1631         INSN_3(JMP32, JSGE, K),                 \
1632         INSN_3(JMP32, JSLE, K),                 \
1633         INSN_3(JMP32, JSET, K),                 \
1634         /* Jump instructions. */                \
1635         /*   Register based. */                 \
1636         INSN_3(JMP, JEQ,  X),                   \
1637         INSN_3(JMP, JNE,  X),                   \
1638         INSN_3(JMP, JGT,  X),                   \
1639         INSN_3(JMP, JLT,  X),                   \
1640         INSN_3(JMP, JGE,  X),                   \
1641         INSN_3(JMP, JLE,  X),                   \
1642         INSN_3(JMP, JSGT, X),                   \
1643         INSN_3(JMP, JSLT, X),                   \
1644         INSN_3(JMP, JSGE, X),                   \
1645         INSN_3(JMP, JSLE, X),                   \
1646         INSN_3(JMP, JSET, X),                   \
1647         /*   Immediate based. */                \
1648         INSN_3(JMP, JEQ,  K),                   \
1649         INSN_3(JMP, JNE,  K),                   \
1650         INSN_3(JMP, JGT,  K),                   \
1651         INSN_3(JMP, JLT,  K),                   \
1652         INSN_3(JMP, JGE,  K),                   \
1653         INSN_3(JMP, JLE,  K),                   \
1654         INSN_3(JMP, JSGT, K),                   \
1655         INSN_3(JMP, JSLT, K),                   \
1656         INSN_3(JMP, JSGE, K),                   \
1657         INSN_3(JMP, JSLE, K),                   \
1658         INSN_3(JMP, JSET, K),                   \
1659         INSN_2(JMP, JA),                        \
1660         INSN_2(JMP32, JA),                      \
1661         /* Store instructions. */               \
1662         /*   Register based. */                 \
1663         INSN_3(STX, MEM,  B),                   \
1664         INSN_3(STX, MEM,  H),                   \
1665         INSN_3(STX, MEM,  W),                   \
1666         INSN_3(STX, MEM,  DW),                  \
1667         INSN_3(STX, ATOMIC, W),                 \
1668         INSN_3(STX, ATOMIC, DW),                \
1669         /*   Immediate based. */                \
1670         INSN_3(ST, MEM, B),                     \
1671         INSN_3(ST, MEM, H),                     \
1672         INSN_3(ST, MEM, W),                     \
1673         INSN_3(ST, MEM, DW),                    \
1674         /* Load instructions. */                \
1675         /*   Register based. */                 \
1676         INSN_3(LDX, MEM, B),                    \
1677         INSN_3(LDX, MEM, H),                    \
1678         INSN_3(LDX, MEM, W),                    \
1679         INSN_3(LDX, MEM, DW),                   \
1680         INSN_3(LDX, MEMSX, B),                  \
1681         INSN_3(LDX, MEMSX, H),                  \
1682         INSN_3(LDX, MEMSX, W),                  \
1683         /*   Immediate based. */                \
1684         INSN_3(LD, IMM, DW)
1685
1686 bool bpf_opcode_in_insntable(u8 code)
1687 {
1688 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1689 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1690         static const bool public_insntable[256] = {
1691                 [0 ... 255] = false,
1692                 /* Now overwrite non-defaults ... */
1693                 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1694                 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1695                 [BPF_LD | BPF_ABS | BPF_B] = true,
1696                 [BPF_LD | BPF_ABS | BPF_H] = true,
1697                 [BPF_LD | BPF_ABS | BPF_W] = true,
1698                 [BPF_LD | BPF_IND | BPF_B] = true,
1699                 [BPF_LD | BPF_IND | BPF_H] = true,
1700                 [BPF_LD | BPF_IND | BPF_W] = true,
1701                 [BPF_JMP | BPF_JCOND] = true,
1702         };
1703 #undef BPF_INSN_3_TBL
1704 #undef BPF_INSN_2_TBL
1705         return public_insntable[code];
1706 }
1707
1708 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1709 /**
1710  *      ___bpf_prog_run - run eBPF program on a given context
1711  *      @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1712  *      @insn: is the array of eBPF instructions
1713  *
1714  * Decode and execute eBPF instructions.
1715  *
1716  * Return: whatever value is in %BPF_R0 at program exit
1717  */
1718 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1719 {
1720 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1721 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1722         static const void * const jumptable[256] __annotate_jump_table = {
1723                 [0 ... 255] = &&default_label,
1724                 /* Now overwrite non-defaults ... */
1725                 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1726                 /* Non-UAPI available opcodes. */
1727                 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1728                 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1729                 [BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1730                 [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1731                 [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1732                 [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1733                 [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1734                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B,
1735                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H,
1736                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W,
1737         };
1738 #undef BPF_INSN_3_LBL
1739 #undef BPF_INSN_2_LBL
1740         u32 tail_call_cnt = 0;
1741
1742 #define CONT     ({ insn++; goto select_insn; })
1743 #define CONT_JMP ({ insn++; goto select_insn; })
1744
1745 select_insn:
1746         goto *jumptable[insn->code];
1747
1748         /* Explicitly mask the register-based shift amounts with 63 or 31
1749          * to avoid undefined behavior. Normally this won't affect the
1750          * generated code, for example, in case of native 64 bit archs such
1751          * as x86-64 or arm64, the compiler is optimizing the AND away for
1752          * the interpreter. In case of JITs, each of the JIT backends compiles
1753          * the BPF shift operations to machine instructions which produce
1754          * implementation-defined results in such a case; the resulting
1755          * contents of the register may be arbitrary, but program behaviour
1756          * as a whole remains defined. In other words, in case of JIT backends,
1757          * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1758          */
1759         /* ALU (shifts) */
1760 #define SHT(OPCODE, OP)                                 \
1761         ALU64_##OPCODE##_X:                             \
1762                 DST = DST OP (SRC & 63);                \
1763                 CONT;                                   \
1764         ALU_##OPCODE##_X:                               \
1765                 DST = (u32) DST OP ((u32) SRC & 31);    \
1766                 CONT;                                   \
1767         ALU64_##OPCODE##_K:                             \
1768                 DST = DST OP IMM;                       \
1769                 CONT;                                   \
1770         ALU_##OPCODE##_K:                               \
1771                 DST = (u32) DST OP (u32) IMM;           \
1772                 CONT;
1773         /* ALU (rest) */
1774 #define ALU(OPCODE, OP)                                 \
1775         ALU64_##OPCODE##_X:                             \
1776                 DST = DST OP SRC;                       \
1777                 CONT;                                   \
1778         ALU_##OPCODE##_X:                               \
1779                 DST = (u32) DST OP (u32) SRC;           \
1780                 CONT;                                   \
1781         ALU64_##OPCODE##_K:                             \
1782                 DST = DST OP IMM;                       \
1783                 CONT;                                   \
1784         ALU_##OPCODE##_K:                               \
1785                 DST = (u32) DST OP (u32) IMM;           \
1786                 CONT;
1787         ALU(ADD,  +)
1788         ALU(SUB,  -)
1789         ALU(AND,  &)
1790         ALU(OR,   |)
1791         ALU(XOR,  ^)
1792         ALU(MUL,  *)
1793         SHT(LSH, <<)
1794         SHT(RSH, >>)
1795 #undef SHT
1796 #undef ALU
1797         ALU_NEG:
1798                 DST = (u32) -DST;
1799                 CONT;
1800         ALU64_NEG:
1801                 DST = -DST;
1802                 CONT;
1803         ALU_MOV_X:
1804                 switch (OFF) {
1805                 case 0:
1806                         DST = (u32) SRC;
1807                         break;
1808                 case 8:
1809                         DST = (u32)(s8) SRC;
1810                         break;
1811                 case 16:
1812                         DST = (u32)(s16) SRC;
1813                         break;
1814                 }
1815                 CONT;
1816         ALU_MOV_K:
1817                 DST = (u32) IMM;
1818                 CONT;
1819         ALU64_MOV_X:
1820                 switch (OFF) {
1821                 case 0:
1822                         DST = SRC;
1823                         break;
1824                 case 8:
1825                         DST = (s8) SRC;
1826                         break;
1827                 case 16:
1828                         DST = (s16) SRC;
1829                         break;
1830                 case 32:
1831                         DST = (s32) SRC;
1832                         break;
1833                 }
1834                 CONT;
1835         ALU64_MOV_K:
1836                 DST = IMM;
1837                 CONT;
1838         LD_IMM_DW:
1839                 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1840                 insn++;
1841                 CONT;
1842         ALU_ARSH_X:
1843                 DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1844                 CONT;
1845         ALU_ARSH_K:
1846                 DST = (u64) (u32) (((s32) DST) >> IMM);
1847                 CONT;
1848         ALU64_ARSH_X:
1849                 (*(s64 *) &DST) >>= (SRC & 63);
1850                 CONT;
1851         ALU64_ARSH_K:
1852                 (*(s64 *) &DST) >>= IMM;
1853                 CONT;
1854         ALU64_MOD_X:
1855                 switch (OFF) {
1856                 case 0:
1857                         div64_u64_rem(DST, SRC, &AX);
1858                         DST = AX;
1859                         break;
1860                 case 1:
1861                         AX = div64_s64(DST, SRC);
1862                         DST = DST - AX * SRC;
1863                         break;
1864                 }
1865                 CONT;
1866         ALU_MOD_X:
1867                 switch (OFF) {
1868                 case 0:
1869                         AX = (u32) DST;
1870                         DST = do_div(AX, (u32) SRC);
1871                         break;
1872                 case 1:
1873                         AX = abs((s32)DST);
1874                         AX = do_div(AX, abs((s32)SRC));
1875                         if ((s32)DST < 0)
1876                                 DST = (u32)-AX;
1877                         else
1878                                 DST = (u32)AX;
1879                         break;
1880                 }
1881                 CONT;
1882         ALU64_MOD_K:
1883                 switch (OFF) {
1884                 case 0:
1885                         div64_u64_rem(DST, IMM, &AX);
1886                         DST = AX;
1887                         break;
1888                 case 1:
1889                         AX = div64_s64(DST, IMM);
1890                         DST = DST - AX * IMM;
1891                         break;
1892                 }
1893                 CONT;
1894         ALU_MOD_K:
1895                 switch (OFF) {
1896                 case 0:
1897                         AX = (u32) DST;
1898                         DST = do_div(AX, (u32) IMM);
1899                         break;
1900                 case 1:
1901                         AX = abs((s32)DST);
1902                         AX = do_div(AX, abs((s32)IMM));
1903                         if ((s32)DST < 0)
1904                                 DST = (u32)-AX;
1905                         else
1906                                 DST = (u32)AX;
1907                         break;
1908                 }
1909                 CONT;
1910         ALU64_DIV_X:
1911                 switch (OFF) {
1912                 case 0:
1913                         DST = div64_u64(DST, SRC);
1914                         break;
1915                 case 1:
1916                         DST = div64_s64(DST, SRC);
1917                         break;
1918                 }
1919                 CONT;
1920         ALU_DIV_X:
1921                 switch (OFF) {
1922                 case 0:
1923                         AX = (u32) DST;
1924                         do_div(AX, (u32) SRC);
1925                         DST = (u32) AX;
1926                         break;
1927                 case 1:
1928                         AX = abs((s32)DST);
1929                         do_div(AX, abs((s32)SRC));
1930                         if (((s32)DST < 0) == ((s32)SRC < 0))
1931                                 DST = (u32)AX;
1932                         else
1933                                 DST = (u32)-AX;
1934                         break;
1935                 }
1936                 CONT;
1937         ALU64_DIV_K:
1938                 switch (OFF) {
1939                 case 0:
1940                         DST = div64_u64(DST, IMM);
1941                         break;
1942                 case 1:
1943                         DST = div64_s64(DST, IMM);
1944                         break;
1945                 }
1946                 CONT;
1947         ALU_DIV_K:
1948                 switch (OFF) {
1949                 case 0:
1950                         AX = (u32) DST;
1951                         do_div(AX, (u32) IMM);
1952                         DST = (u32) AX;
1953                         break;
1954                 case 1:
1955                         AX = abs((s32)DST);
1956                         do_div(AX, abs((s32)IMM));
1957                         if (((s32)DST < 0) == ((s32)IMM < 0))
1958                                 DST = (u32)AX;
1959                         else
1960                                 DST = (u32)-AX;
1961                         break;
1962                 }
1963                 CONT;
1964         ALU_END_TO_BE:
1965                 switch (IMM) {
1966                 case 16:
1967                         DST = (__force u16) cpu_to_be16(DST);
1968                         break;
1969                 case 32:
1970                         DST = (__force u32) cpu_to_be32(DST);
1971                         break;
1972                 case 64:
1973                         DST = (__force u64) cpu_to_be64(DST);
1974                         break;
1975                 }
1976                 CONT;
1977         ALU_END_TO_LE:
1978                 switch (IMM) {
1979                 case 16:
1980                         DST = (__force u16) cpu_to_le16(DST);
1981                         break;
1982                 case 32:
1983                         DST = (__force u32) cpu_to_le32(DST);
1984                         break;
1985                 case 64:
1986                         DST = (__force u64) cpu_to_le64(DST);
1987                         break;
1988                 }
1989                 CONT;
1990         ALU64_END_TO_LE:
1991                 switch (IMM) {
1992                 case 16:
1993                         DST = (__force u16) __swab16(DST);
1994                         break;
1995                 case 32:
1996                         DST = (__force u32) __swab32(DST);
1997                         break;
1998                 case 64:
1999                         DST = (__force u64) __swab64(DST);
2000                         break;
2001                 }
2002                 CONT;
2003
2004         /* CALL */
2005         JMP_CALL:
2006                 /* Function call scratches BPF_R1-BPF_R5 registers,
2007                  * preserves BPF_R6-BPF_R9, and stores return value
2008                  * into BPF_R0.
2009                  */
2010                 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
2011                                                        BPF_R4, BPF_R5);
2012                 CONT;
2013
2014         JMP_CALL_ARGS:
2015                 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
2016                                                             BPF_R3, BPF_R4,
2017                                                             BPF_R5,
2018                                                             insn + insn->off + 1);
2019                 CONT;
2020
2021         JMP_TAIL_CALL: {
2022                 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
2023                 struct bpf_array *array = container_of(map, struct bpf_array, map);
2024                 struct bpf_prog *prog;
2025                 u32 index = BPF_R3;
2026
2027                 if (unlikely(index >= array->map.max_entries))
2028                         goto out;
2029
2030                 if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
2031                         goto out;
2032
2033                 tail_call_cnt++;
2034
2035                 prog = READ_ONCE(array->ptrs[index]);
2036                 if (!prog)
2037                         goto out;
2038
2039                 /* ARG1 at this point is guaranteed to point to CTX from
2040                  * the verifier side due to the fact that the tail call is
2041                  * handled like a helper, that is, bpf_tail_call_proto,
2042                  * where arg1_type is ARG_PTR_TO_CTX.
2043                  */
2044                 insn = prog->insnsi;
2045                 goto select_insn;
2046 out:
2047                 CONT;
2048         }
2049         JMP_JA:
2050                 insn += insn->off;
2051                 CONT;
2052         JMP32_JA:
2053                 insn += insn->imm;
2054                 CONT;
2055         JMP_EXIT:
2056                 return BPF_R0;
2057         /* JMP */
2058 #define COND_JMP(SIGN, OPCODE, CMP_OP)                          \
2059         JMP_##OPCODE##_X:                                       \
2060                 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {     \
2061                         insn += insn->off;                      \
2062                         CONT_JMP;                               \
2063                 }                                               \
2064                 CONT;                                           \
2065         JMP32_##OPCODE##_X:                                     \
2066                 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {     \
2067                         insn += insn->off;                      \
2068                         CONT_JMP;                               \
2069                 }                                               \
2070                 CONT;                                           \
2071         JMP_##OPCODE##_K:                                       \
2072                 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {     \
2073                         insn += insn->off;                      \
2074                         CONT_JMP;                               \
2075                 }                                               \
2076                 CONT;                                           \
2077         JMP32_##OPCODE##_K:                                     \
2078                 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {     \
2079                         insn += insn->off;                      \
2080                         CONT_JMP;                               \
2081                 }                                               \
2082                 CONT;
2083         COND_JMP(u, JEQ, ==)
2084         COND_JMP(u, JNE, !=)
2085         COND_JMP(u, JGT, >)
2086         COND_JMP(u, JLT, <)
2087         COND_JMP(u, JGE, >=)
2088         COND_JMP(u, JLE, <=)
2089         COND_JMP(u, JSET, &)
2090         COND_JMP(s, JSGT, >)
2091         COND_JMP(s, JSLT, <)
2092         COND_JMP(s, JSGE, >=)
2093         COND_JMP(s, JSLE, <=)
2094 #undef COND_JMP
2095         /* ST, STX and LDX*/
2096         ST_NOSPEC:
2097                 /* Speculation barrier for mitigating Speculative Store Bypass.
2098                  * In case of arm64, we rely on the firmware mitigation as
2099                  * controlled via the ssbd kernel parameter. Whenever the
2100                  * mitigation is enabled, it works for all of the kernel code
2101                  * with no need to provide any additional instructions here.
2102                  * In case of x86, we use 'lfence' insn for mitigation. We
2103                  * reuse preexisting logic from Spectre v1 mitigation that
2104                  * happens to produce the required code on x86 for v4 as well.
2105                  */
2106                 barrier_nospec();
2107                 CONT;
2108 #define LDST(SIZEOP, SIZE)                                              \
2109         STX_MEM_##SIZEOP:                                               \
2110                 *(SIZE *)(unsigned long) (DST + insn->off) = SRC;       \
2111                 CONT;                                                   \
2112         ST_MEM_##SIZEOP:                                                \
2113                 *(SIZE *)(unsigned long) (DST + insn->off) = IMM;       \
2114                 CONT;                                                   \
2115         LDX_MEM_##SIZEOP:                                               \
2116                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
2117                 CONT;                                                   \
2118         LDX_PROBE_MEM_##SIZEOP:                                         \
2119                 bpf_probe_read_kernel_common(&DST, sizeof(SIZE),        \
2120                               (const void *)(long) (SRC + insn->off));  \
2121                 DST = *((SIZE *)&DST);                                  \
2122                 CONT;
2123
2124         LDST(B,   u8)
2125         LDST(H,  u16)
2126         LDST(W,  u32)
2127         LDST(DW, u64)
2128 #undef LDST
2129
2130 #define LDSX(SIZEOP, SIZE)                                              \
2131         LDX_MEMSX_##SIZEOP:                                             \
2132                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
2133                 CONT;                                                   \
2134         LDX_PROBE_MEMSX_##SIZEOP:                                       \
2135                 bpf_probe_read_kernel_common(&DST, sizeof(SIZE),                \
2136                                       (const void *)(long) (SRC + insn->off));  \
2137                 DST = *((SIZE *)&DST);                                  \
2138                 CONT;
2139
2140         LDSX(B,   s8)
2141         LDSX(H,  s16)
2142         LDSX(W,  s32)
2143 #undef LDSX
2144
2145 #define ATOMIC_ALU_OP(BOP, KOP)                                         \
2146                 case BOP:                                               \
2147                         if (BPF_SIZE(insn->code) == BPF_W)              \
2148                                 atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
2149                                              (DST + insn->off));        \
2150                         else                                            \
2151                                 atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
2152                                                (DST + insn->off));      \
2153                         break;                                          \
2154                 case BOP | BPF_FETCH:                                   \
2155                         if (BPF_SIZE(insn->code) == BPF_W)              \
2156                                 SRC = (u32) atomic_fetch_##KOP(         \
2157                                         (u32) SRC,                      \
2158                                         (atomic_t *)(unsigned long) (DST + insn->off)); \
2159                         else                                            \
2160                                 SRC = (u64) atomic64_fetch_##KOP(       \
2161                                         (u64) SRC,                      \
2162                                         (atomic64_t *)(unsigned long) (DST + insn->off)); \
2163                         break;
2164
2165         STX_ATOMIC_DW:
2166         STX_ATOMIC_W:
2167                 switch (IMM) {
2168                 ATOMIC_ALU_OP(BPF_ADD, add)
2169                 ATOMIC_ALU_OP(BPF_AND, and)
2170                 ATOMIC_ALU_OP(BPF_OR, or)
2171                 ATOMIC_ALU_OP(BPF_XOR, xor)
2172 #undef ATOMIC_ALU_OP
2173
2174                 case BPF_XCHG:
2175                         if (BPF_SIZE(insn->code) == BPF_W)
2176                                 SRC = (u32) atomic_xchg(
2177                                         (atomic_t *)(unsigned long) (DST + insn->off),
2178                                         (u32) SRC);
2179                         else
2180                                 SRC = (u64) atomic64_xchg(
2181                                         (atomic64_t *)(unsigned long) (DST + insn->off),
2182                                         (u64) SRC);
2183                         break;
2184                 case BPF_CMPXCHG:
2185                         if (BPF_SIZE(insn->code) == BPF_W)
2186                                 BPF_R0 = (u32) atomic_cmpxchg(
2187                                         (atomic_t *)(unsigned long) (DST + insn->off),
2188                                         (u32) BPF_R0, (u32) SRC);
2189                         else
2190                                 BPF_R0 = (u64) atomic64_cmpxchg(
2191                                         (atomic64_t *)(unsigned long) (DST + insn->off),
2192                                         (u64) BPF_R0, (u64) SRC);
2193                         break;
2194
2195                 default:
2196                         goto default_label;
2197                 }
2198                 CONT;
2199
2200         default_label:
2201                 /* If we ever reach this, we have a bug somewhere. Die hard here
2202                  * instead of just returning 0; we could be somewhere in a subprog,
2203                  * so execution could continue otherwise which we do /not/ want.
2204                  *
2205                  * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2206                  */
2207                 pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2208                         insn->code, insn->imm);
2209                 BUG_ON(1);
2210                 return 0;
2211 }
2212
2213 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2214 #define DEFINE_BPF_PROG_RUN(stack_size) \
2215 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2216 { \
2217         u64 stack[stack_size / sizeof(u64)]; \
2218         u64 regs[MAX_BPF_EXT_REG] = {}; \
2219 \
2220         kmsan_unpoison_memory(stack, sizeof(stack)); \
2221         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2222         ARG1 = (u64) (unsigned long) ctx; \
2223         return ___bpf_prog_run(regs, insn); \
2224 }
2225
2226 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2227 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2228 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2229                                       const struct bpf_insn *insn) \
2230 { \
2231         u64 stack[stack_size / sizeof(u64)]; \
2232         u64 regs[MAX_BPF_EXT_REG]; \
2233 \
2234         kmsan_unpoison_memory(stack, sizeof(stack)); \
2235         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2236         BPF_R1 = r1; \
2237         BPF_R2 = r2; \
2238         BPF_R3 = r3; \
2239         BPF_R4 = r4; \
2240         BPF_R5 = r5; \
2241         return ___bpf_prog_run(regs, insn); \
2242 }
2243
2244 #define EVAL1(FN, X) FN(X)
2245 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2246 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2247 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2248 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2249 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2250
2251 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2252 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2253 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2254
2255 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2256 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2257 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2258
2259 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2260
2261 static unsigned int (*interpreters[])(const void *ctx,
2262                                       const struct bpf_insn *insn) = {
2263 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2264 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2265 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2266 };
2267 #undef PROG_NAME_LIST
2268 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2269 static __maybe_unused
2270 u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2271                            const struct bpf_insn *insn) = {
2272 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2273 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2274 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2275 };
2276 #undef PROG_NAME_LIST
2277
2278 #ifdef CONFIG_BPF_SYSCALL
2279 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2280 {
2281         stack_depth = max_t(u32, stack_depth, 1);
2282         insn->off = (s16) insn->imm;
2283         insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2284                 __bpf_call_base_args;
2285         insn->code = BPF_JMP | BPF_CALL_ARGS;
2286 }
2287 #endif
2288 #else
2289 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2290                                          const struct bpf_insn *insn)
2291 {
2292         /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2293          * is not working properly, so warn about it!
2294          */
2295         WARN_ON_ONCE(1);
2296         return 0;
2297 }
2298 #endif
2299
2300 bool bpf_prog_map_compatible(struct bpf_map *map,
2301                              const struct bpf_prog *fp)
2302 {
2303         enum bpf_prog_type prog_type = resolve_prog_type(fp);
2304         bool ret;
2305         struct bpf_prog_aux *aux = fp->aux;
2306
2307         if (fp->kprobe_override)
2308                 return false;
2309
2310         /* XDP programs inserted into maps are not guaranteed to run on
2311          * a particular netdev (and can run outside driver context entirely
2312          * in the case of devmap and cpumap). Until device checks
2313          * are implemented, prohibit adding dev-bound programs to program maps.
2314          */
2315         if (bpf_prog_is_dev_bound(aux))
2316                 return false;
2317
2318         spin_lock(&map->owner.lock);
2319         if (!map->owner.type) {
2320                 /* There's no owner yet where we could check for
2321                  * compatibility.
2322                  */
2323                 map->owner.type  = prog_type;
2324                 map->owner.jited = fp->jited;
2325                 map->owner.xdp_has_frags = aux->xdp_has_frags;
2326                 map->owner.attach_func_proto = aux->attach_func_proto;
2327                 ret = true;
2328         } else {
2329                 ret = map->owner.type  == prog_type &&
2330                       map->owner.jited == fp->jited &&
2331                       map->owner.xdp_has_frags == aux->xdp_has_frags;
2332                 if (ret &&
2333                     map->owner.attach_func_proto != aux->attach_func_proto) {
2334                         switch (prog_type) {
2335                         case BPF_PROG_TYPE_TRACING:
2336                         case BPF_PROG_TYPE_LSM:
2337                         case BPF_PROG_TYPE_EXT:
2338                         case BPF_PROG_TYPE_STRUCT_OPS:
2339                                 ret = false;
2340                                 break;
2341                         default:
2342                                 break;
2343                         }
2344                 }
2345         }
2346         spin_unlock(&map->owner.lock);
2347
2348         return ret;
2349 }
2350
2351 static int bpf_check_tail_call(const struct bpf_prog *fp)
2352 {
2353         struct bpf_prog_aux *aux = fp->aux;
2354         int i, ret = 0;
2355
2356         mutex_lock(&aux->used_maps_mutex);
2357         for (i = 0; i < aux->used_map_cnt; i++) {
2358                 struct bpf_map *map = aux->used_maps[i];
2359
2360                 if (!map_type_contains_progs(map))
2361                         continue;
2362
2363                 if (!bpf_prog_map_compatible(map, fp)) {
2364                         ret = -EINVAL;
2365                         goto out;
2366                 }
2367         }
2368
2369 out:
2370         mutex_unlock(&aux->used_maps_mutex);
2371         return ret;
2372 }
2373
2374 static void bpf_prog_select_func(struct bpf_prog *fp)
2375 {
2376 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2377         u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2378
2379         fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2380 #else
2381         fp->bpf_func = __bpf_prog_ret0_warn;
2382 #endif
2383 }
2384
2385 /**
2386  *      bpf_prog_select_runtime - select exec runtime for BPF program
2387  *      @fp: bpf_prog populated with BPF program
2388  *      @err: pointer to error variable
2389  *
2390  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2391  * The BPF program will be executed via bpf_prog_run() function.
2392  *
2393  * Return: the &fp argument along with &err set to 0 for success or
2394  * a negative errno code on failure
2395  */
2396 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2397 {
2398         /* In case of BPF to BPF calls, verifier did all the prep
2399          * work with regards to JITing, etc.
2400          */
2401         bool jit_needed = false;
2402
2403         if (fp->bpf_func)
2404                 goto finalize;
2405
2406         if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2407             bpf_prog_has_kfunc_call(fp))
2408                 jit_needed = true;
2409
2410         bpf_prog_select_func(fp);
2411
2412         /* eBPF JITs can rewrite the program in case constant
2413          * blinding is active. However, in case of error during
2414          * blinding, bpf_int_jit_compile() must always return a
2415          * valid program, which in this case would simply not
2416          * be JITed, but falls back to the interpreter.
2417          */
2418         if (!bpf_prog_is_offloaded(fp->aux)) {
2419                 *err = bpf_prog_alloc_jited_linfo(fp);
2420                 if (*err)
2421                         return fp;
2422
2423                 fp = bpf_int_jit_compile(fp);
2424                 bpf_prog_jit_attempt_done(fp);
2425                 if (!fp->jited && jit_needed) {
2426                         *err = -ENOTSUPP;
2427                         return fp;
2428                 }
2429         } else {
2430                 *err = bpf_prog_offload_compile(fp);
2431                 if (*err)
2432                         return fp;
2433         }
2434
2435 finalize:
2436         *err = bpf_prog_lock_ro(fp);
2437         if (*err)
2438                 return fp;
2439
2440         /* The tail call compatibility check can only be done at
2441          * this late stage as we need to determine, if we deal
2442          * with JITed or non JITed program concatenations and not
2443          * all eBPF JITs might immediately support all features.
2444          */
2445         *err = bpf_check_tail_call(fp);
2446
2447         return fp;
2448 }
2449 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2450
2451 static unsigned int __bpf_prog_ret1(const void *ctx,
2452                                     const struct bpf_insn *insn)
2453 {
2454         return 1;
2455 }
2456
2457 static struct bpf_prog_dummy {
2458         struct bpf_prog prog;
2459 } dummy_bpf_prog = {
2460         .prog = {
2461                 .bpf_func = __bpf_prog_ret1,
2462         },
2463 };
2464
2465 struct bpf_empty_prog_array bpf_empty_prog_array = {
2466         .null_prog = NULL,
2467 };
2468 EXPORT_SYMBOL(bpf_empty_prog_array);
2469
2470 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2471 {
2472         struct bpf_prog_array *p;
2473
2474         if (prog_cnt)
2475                 p = kzalloc(struct_size(p, items, prog_cnt + 1), flags);
2476         else
2477                 p = &bpf_empty_prog_array.hdr;
2478
2479         return p;
2480 }
2481
2482 void bpf_prog_array_free(struct bpf_prog_array *progs)
2483 {
2484         if (!progs || progs == &bpf_empty_prog_array.hdr)
2485                 return;
2486         kfree_rcu(progs, rcu);
2487 }
2488
2489 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2490 {
2491         struct bpf_prog_array *progs;
2492
2493         /* If RCU Tasks Trace grace period implies RCU grace period, there is
2494          * no need to call kfree_rcu(), just call kfree() directly.
2495          */
2496         progs = container_of(rcu, struct bpf_prog_array, rcu);
2497         if (rcu_trace_implies_rcu_gp())
2498                 kfree(progs);
2499         else
2500                 kfree_rcu(progs, rcu);
2501 }
2502
2503 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2504 {
2505         if (!progs || progs == &bpf_empty_prog_array.hdr)
2506                 return;
2507         call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2508 }
2509
2510 int bpf_prog_array_length(struct bpf_prog_array *array)
2511 {
2512         struct bpf_prog_array_item *item;
2513         u32 cnt = 0;
2514
2515         for (item = array->items; item->prog; item++)
2516                 if (item->prog != &dummy_bpf_prog.prog)
2517                         cnt++;
2518         return cnt;
2519 }
2520
2521 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2522 {
2523         struct bpf_prog_array_item *item;
2524
2525         for (item = array->items; item->prog; item++)
2526                 if (item->prog != &dummy_bpf_prog.prog)
2527                         return false;
2528         return true;
2529 }
2530
2531 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2532                                      u32 *prog_ids,
2533                                      u32 request_cnt)
2534 {
2535         struct bpf_prog_array_item *item;
2536         int i = 0;
2537
2538         for (item = array->items; item->prog; item++) {
2539                 if (item->prog == &dummy_bpf_prog.prog)
2540                         continue;
2541                 prog_ids[i] = item->prog->aux->id;
2542                 if (++i == request_cnt) {
2543                         item++;
2544                         break;
2545                 }
2546         }
2547
2548         return !!(item->prog);
2549 }
2550
2551 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2552                                 __u32 __user *prog_ids, u32 cnt)
2553 {
2554         unsigned long err = 0;
2555         bool nospc;
2556         u32 *ids;
2557
2558         /* users of this function are doing:
2559          * cnt = bpf_prog_array_length();
2560          * if (cnt > 0)
2561          *     bpf_prog_array_copy_to_user(..., cnt);
2562          * so below kcalloc doesn't need extra cnt > 0 check.
2563          */
2564         ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2565         if (!ids)
2566                 return -ENOMEM;
2567         nospc = bpf_prog_array_copy_core(array, ids, cnt);
2568         err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2569         kfree(ids);
2570         if (err)
2571                 return -EFAULT;
2572         if (nospc)
2573                 return -ENOSPC;
2574         return 0;
2575 }
2576
2577 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2578                                 struct bpf_prog *old_prog)
2579 {
2580         struct bpf_prog_array_item *item;
2581
2582         for (item = array->items; item->prog; item++)
2583                 if (item->prog == old_prog) {
2584                         WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2585                         break;
2586                 }
2587 }
2588
2589 /**
2590  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2591  *                                   index into the program array with
2592  *                                   a dummy no-op program.
2593  * @array: a bpf_prog_array
2594  * @index: the index of the program to replace
2595  *
2596  * Skips over dummy programs, by not counting them, when calculating
2597  * the position of the program to replace.
2598  *
2599  * Return:
2600  * * 0          - Success
2601  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
2602  * * -ENOENT    - Index out of range
2603  */
2604 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2605 {
2606         return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2607 }
2608
2609 /**
2610  * bpf_prog_array_update_at() - Updates the program at the given index
2611  *                              into the program array.
2612  * @array: a bpf_prog_array
2613  * @index: the index of the program to update
2614  * @prog: the program to insert into the array
2615  *
2616  * Skips over dummy programs, by not counting them, when calculating
2617  * the position of the program to update.
2618  *
2619  * Return:
2620  * * 0          - Success
2621  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
2622  * * -ENOENT    - Index out of range
2623  */
2624 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2625                              struct bpf_prog *prog)
2626 {
2627         struct bpf_prog_array_item *item;
2628
2629         if (unlikely(index < 0))
2630                 return -EINVAL;
2631
2632         for (item = array->items; item->prog; item++) {
2633                 if (item->prog == &dummy_bpf_prog.prog)
2634                         continue;
2635                 if (!index) {
2636                         WRITE_ONCE(item->prog, prog);
2637                         return 0;
2638                 }
2639                 index--;
2640         }
2641         return -ENOENT;
2642 }
2643
2644 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2645                         struct bpf_prog *exclude_prog,
2646                         struct bpf_prog *include_prog,
2647                         u64 bpf_cookie,
2648                         struct bpf_prog_array **new_array)
2649 {
2650         int new_prog_cnt, carry_prog_cnt = 0;
2651         struct bpf_prog_array_item *existing, *new;
2652         struct bpf_prog_array *array;
2653         bool found_exclude = false;
2654
2655         /* Figure out how many existing progs we need to carry over to
2656          * the new array.
2657          */
2658         if (old_array) {
2659                 existing = old_array->items;
2660                 for (; existing->prog; existing++) {
2661                         if (existing->prog == exclude_prog) {
2662                                 found_exclude = true;
2663                                 continue;
2664                         }
2665                         if (existing->prog != &dummy_bpf_prog.prog)
2666                                 carry_prog_cnt++;
2667                         if (existing->prog == include_prog)
2668                                 return -EEXIST;
2669                 }
2670         }
2671
2672         if (exclude_prog && !found_exclude)
2673                 return -ENOENT;
2674
2675         /* How many progs (not NULL) will be in the new array? */
2676         new_prog_cnt = carry_prog_cnt;
2677         if (include_prog)
2678                 new_prog_cnt += 1;
2679
2680         /* Do we have any prog (not NULL) in the new array? */
2681         if (!new_prog_cnt) {
2682                 *new_array = NULL;
2683                 return 0;
2684         }
2685
2686         /* +1 as the end of prog_array is marked with NULL */
2687         array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2688         if (!array)
2689                 return -ENOMEM;
2690         new = array->items;
2691
2692         /* Fill in the new prog array */
2693         if (carry_prog_cnt) {
2694                 existing = old_array->items;
2695                 for (; existing->prog; existing++) {
2696                         if (existing->prog == exclude_prog ||
2697                             existing->prog == &dummy_bpf_prog.prog)
2698                                 continue;
2699
2700                         new->prog = existing->prog;
2701                         new->bpf_cookie = existing->bpf_cookie;
2702                         new++;
2703                 }
2704         }
2705         if (include_prog) {
2706                 new->prog = include_prog;
2707                 new->bpf_cookie = bpf_cookie;
2708                 new++;
2709         }
2710         new->prog = NULL;
2711         *new_array = array;
2712         return 0;
2713 }
2714
2715 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2716                              u32 *prog_ids, u32 request_cnt,
2717                              u32 *prog_cnt)
2718 {
2719         u32 cnt = 0;
2720
2721         if (array)
2722                 cnt = bpf_prog_array_length(array);
2723
2724         *prog_cnt = cnt;
2725
2726         /* return early if user requested only program count or nothing to copy */
2727         if (!request_cnt || !cnt)
2728                 return 0;
2729
2730         /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2731         return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2732                                                                      : 0;
2733 }
2734
2735 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2736                           struct bpf_map **used_maps, u32 len)
2737 {
2738         struct bpf_map *map;
2739         bool sleepable;
2740         u32 i;
2741
2742         sleepable = aux->prog->sleepable;
2743         for (i = 0; i < len; i++) {
2744                 map = used_maps[i];
2745                 if (map->ops->map_poke_untrack)
2746                         map->ops->map_poke_untrack(map, aux);
2747                 if (sleepable)
2748                         atomic64_dec(&map->sleepable_refcnt);
2749                 bpf_map_put(map);
2750         }
2751 }
2752
2753 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2754 {
2755         __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2756         kfree(aux->used_maps);
2757 }
2758
2759 void __bpf_free_used_btfs(struct btf_mod_pair *used_btfs, u32 len)
2760 {
2761 #ifdef CONFIG_BPF_SYSCALL
2762         struct btf_mod_pair *btf_mod;
2763         u32 i;
2764
2765         for (i = 0; i < len; i++) {
2766                 btf_mod = &used_btfs[i];
2767                 if (btf_mod->module)
2768                         module_put(btf_mod->module);
2769                 btf_put(btf_mod->btf);
2770         }
2771 #endif
2772 }
2773
2774 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2775 {
2776         __bpf_free_used_btfs(aux->used_btfs, aux->used_btf_cnt);
2777         kfree(aux->used_btfs);
2778 }
2779
2780 static void bpf_prog_free_deferred(struct work_struct *work)
2781 {
2782         struct bpf_prog_aux *aux;
2783         int i;
2784
2785         aux = container_of(work, struct bpf_prog_aux, work);
2786 #ifdef CONFIG_BPF_SYSCALL
2787         bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2788 #endif
2789 #ifdef CONFIG_CGROUP_BPF
2790         if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2791                 bpf_cgroup_atype_put(aux->cgroup_atype);
2792 #endif
2793         bpf_free_used_maps(aux);
2794         bpf_free_used_btfs(aux);
2795         if (bpf_prog_is_dev_bound(aux))
2796                 bpf_prog_dev_bound_destroy(aux->prog);
2797 #ifdef CONFIG_PERF_EVENTS
2798         if (aux->prog->has_callchain_buf)
2799                 put_callchain_buffers();
2800 #endif
2801         if (aux->dst_trampoline)
2802                 bpf_trampoline_put(aux->dst_trampoline);
2803         for (i = 0; i < aux->real_func_cnt; i++) {
2804                 /* We can just unlink the subprog poke descriptor table as
2805                  * it was originally linked to the main program and is also
2806                  * released along with it.
2807                  */
2808                 aux->func[i]->aux->poke_tab = NULL;
2809                 bpf_jit_free(aux->func[i]);
2810         }
2811         if (aux->real_func_cnt) {
2812                 kfree(aux->func);
2813                 bpf_prog_unlock_free(aux->prog);
2814         } else {
2815                 bpf_jit_free(aux->prog);
2816         }
2817 }
2818
2819 void bpf_prog_free(struct bpf_prog *fp)
2820 {
2821         struct bpf_prog_aux *aux = fp->aux;
2822
2823         if (aux->dst_prog)
2824                 bpf_prog_put(aux->dst_prog);
2825         bpf_token_put(aux->token);
2826         INIT_WORK(&aux->work, bpf_prog_free_deferred);
2827         schedule_work(&aux->work);
2828 }
2829 EXPORT_SYMBOL_GPL(bpf_prog_free);
2830
2831 /* RNG for unprivileged user space with separated state from prandom_u32(). */
2832 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2833
2834 void bpf_user_rnd_init_once(void)
2835 {
2836         prandom_init_once(&bpf_user_rnd_state);
2837 }
2838
2839 BPF_CALL_0(bpf_user_rnd_u32)
2840 {
2841         /* Should someone ever have the rather unwise idea to use some
2842          * of the registers passed into this function, then note that
2843          * this function is called from native eBPF and classic-to-eBPF
2844          * transformations. Register assignments from both sides are
2845          * different, f.e. classic always sets fn(ctx, A, X) here.
2846          */
2847         struct rnd_state *state;
2848         u32 res;
2849
2850         state = &get_cpu_var(bpf_user_rnd_state);
2851         res = prandom_u32_state(state);
2852         put_cpu_var(bpf_user_rnd_state);
2853
2854         return res;
2855 }
2856
2857 BPF_CALL_0(bpf_get_raw_cpu_id)
2858 {
2859         return raw_smp_processor_id();
2860 }
2861
2862 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2863 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2864 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2865 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2866 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2867 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2868 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2869 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2870 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2871 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2872 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2873
2874 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2875 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2876 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2877 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2878 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2879 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2880 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2881
2882 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2883 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2884 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2885 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2886 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2887 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2888 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2889 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2890 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2891 const struct bpf_func_proto bpf_set_retval_proto __weak;
2892 const struct bpf_func_proto bpf_get_retval_proto __weak;
2893
2894 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2895 {
2896         return NULL;
2897 }
2898
2899 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2900 {
2901         return NULL;
2902 }
2903
2904 u64 __weak
2905 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2906                  void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2907 {
2908         return -ENOTSUPP;
2909 }
2910 EXPORT_SYMBOL_GPL(bpf_event_output);
2911
2912 /* Always built-in helper functions. */
2913 const struct bpf_func_proto bpf_tail_call_proto = {
2914         .func           = NULL,
2915         .gpl_only       = false,
2916         .ret_type       = RET_VOID,
2917         .arg1_type      = ARG_PTR_TO_CTX,
2918         .arg2_type      = ARG_CONST_MAP_PTR,
2919         .arg3_type      = ARG_ANYTHING,
2920 };
2921
2922 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2923  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2924  * eBPF and implicitly also cBPF can get JITed!
2925  */
2926 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2927 {
2928         return prog;
2929 }
2930
2931 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2932  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2933  */
2934 void __weak bpf_jit_compile(struct bpf_prog *prog)
2935 {
2936 }
2937
2938 bool __weak bpf_helper_changes_pkt_data(void *func)
2939 {
2940         return false;
2941 }
2942
2943 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2944  * analysis code and wants explicit zero extension inserted by verifier.
2945  * Otherwise, return FALSE.
2946  *
2947  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2948  * you don't override this. JITs that don't want these extra insns can detect
2949  * them using insn_is_zext.
2950  */
2951 bool __weak bpf_jit_needs_zext(void)
2952 {
2953         return false;
2954 }
2955
2956 /* Return true if the JIT inlines the call to the helper corresponding to
2957  * the imm.
2958  *
2959  * The verifier will not patch the insn->imm for the call to the helper if
2960  * this returns true.
2961  */
2962 bool __weak bpf_jit_inlines_helper_call(s32 imm)
2963 {
2964         return false;
2965 }
2966
2967 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2968 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2969 {
2970         return false;
2971 }
2972
2973 bool __weak bpf_jit_supports_percpu_insn(void)
2974 {
2975         return false;
2976 }
2977
2978 bool __weak bpf_jit_supports_kfunc_call(void)
2979 {
2980         return false;
2981 }
2982
2983 bool __weak bpf_jit_supports_far_kfunc_call(void)
2984 {
2985         return false;
2986 }
2987
2988 bool __weak bpf_jit_supports_arena(void)
2989 {
2990         return false;
2991 }
2992
2993 bool __weak bpf_jit_supports_insn(struct bpf_insn *insn, bool in_arena)
2994 {
2995         return false;
2996 }
2997
2998 u64 __weak bpf_arch_uaddress_limit(void)
2999 {
3000 #if defined(CONFIG_64BIT) && defined(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE)
3001         return TASK_SIZE;
3002 #else
3003         return 0;
3004 #endif
3005 }
3006
3007 /* Return TRUE if the JIT backend satisfies the following two conditions:
3008  * 1) JIT backend supports atomic_xchg() on pointer-sized words.
3009  * 2) Under the specific arch, the implementation of xchg() is the same
3010  *    as atomic_xchg() on pointer-sized words.
3011  */
3012 bool __weak bpf_jit_supports_ptr_xchg(void)
3013 {
3014         return false;
3015 }
3016
3017 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
3018  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
3019  */
3020 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
3021                          int len)
3022 {
3023         return -EFAULT;
3024 }
3025
3026 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
3027                               void *addr1, void *addr2)
3028 {
3029         return -ENOTSUPP;
3030 }
3031
3032 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
3033 {
3034         return ERR_PTR(-ENOTSUPP);
3035 }
3036
3037 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
3038 {
3039         return -ENOTSUPP;
3040 }
3041
3042 bool __weak bpf_jit_supports_exceptions(void)
3043 {
3044         return false;
3045 }
3046
3047 void __weak arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), void *cookie)
3048 {
3049 }
3050
3051 /* for configs without MMU or 32-bit */
3052 __weak const struct bpf_map_ops arena_map_ops;
3053 __weak u64 bpf_arena_get_user_vm_start(struct bpf_arena *arena)
3054 {
3055         return 0;
3056 }
3057 __weak u64 bpf_arena_get_kern_vm_start(struct bpf_arena *arena)
3058 {
3059         return 0;
3060 }
3061
3062 #ifdef CONFIG_BPF_SYSCALL
3063 static int __init bpf_global_ma_init(void)
3064 {
3065         int ret;
3066
3067         ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
3068         bpf_global_ma_set = !ret;
3069         return ret;
3070 }
3071 late_initcall(bpf_global_ma_init);
3072 #endif
3073
3074 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
3075 EXPORT_SYMBOL(bpf_stats_enabled_key);
3076
3077 /* All definitions of tracepoints related to BPF. */
3078 #define CREATE_TRACE_POINTS
3079 #include <linux/bpf_trace.h>
3080
3081 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
3082 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);