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 const char *__bpf_address_lookup(unsigned long addr, unsigned long *size,
 740                                  unsigned long *off, char *sym)
 741 {
 742         struct bpf_ksym *ksym;
 743         char *ret = NULL;
 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                 strscpy(sym, ksym->name, KSYM_NAME_LEN);
 752
 753                 ret = sym;
 754                 if (size)
 755                         *size = symbol_end - symbol_start;
 756                 if (off)
 757                         *off  = addr - symbol_start;
 758         }
 759         rcu_read_unlock();
 760
 761         return ret;
 762 }
 763
 764 bool is_bpf_text_address(unsigned long addr)
 765 {
 766         bool ret;
 767
 768         rcu_read_lock();
 769         ret = bpf_ksym_find(addr) != NULL;
 770         rcu_read_unlock();
 771
 772         return ret;
 773 }
 774
 775 struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
 776 {
 777         struct bpf_ksym *ksym = bpf_ksym_find(addr);
 778
 779         return ksym && ksym->prog ?
 780                container_of(ksym, struct bpf_prog_aux, ksym)->prog :
 781                NULL;
 782 }
 783
 784 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
 785 {
 786         const struct exception_table_entry *e = NULL;
 787         struct bpf_prog *prog;
 788
 789         rcu_read_lock();
 790         prog = bpf_prog_ksym_find(addr);
 791         if (!prog)
 792                 goto out;
 793         if (!prog->aux->num_exentries)
 794                 goto out;
 795
 796         e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
 797 out:
 798         rcu_read_unlock();
 799         return e;
 800 }
 801
 802 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 803                     char *sym)
 804 {
 805         struct bpf_ksym *ksym;
 806         unsigned int it = 0;
 807         int ret = -ERANGE;
 808
 809         if (!bpf_jit_kallsyms_enabled())
 810                 return ret;
 811
 812         rcu_read_lock();
 813         list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
 814                 if (it++ != symnum)
 815                         continue;
 816
 817                 strscpy(sym, ksym->name, KSYM_NAME_LEN);
 818
 819                 *value = ksym->start;
 820                 *type  = BPF_SYM_ELF_TYPE;
 821
 822                 ret = 0;
 823                 break;
 824         }
 825         rcu_read_unlock();
 826
 827         return ret;
 828 }
 829
 830 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
 831                                 struct bpf_jit_poke_descriptor *poke)
 832 {
 833         struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
 834         static const u32 poke_tab_max = 1024;
 835         u32 slot = prog->aux->size_poke_tab;
 836         u32 size = slot + 1;
 837
 838         if (size > poke_tab_max)
 839                 return -ENOSPC;
 840         if (poke->tailcall_target || poke->tailcall_target_stable ||
 841             poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
 842                 return -EINVAL;
 843
 844         switch (poke->reason) {
 845         case BPF_POKE_REASON_TAIL_CALL:
 846                 if (!poke->tail_call.map)
 847                         return -EINVAL;
 848                 break;
 849         default:
 850                 return -EINVAL;
 851         }
 852
 853         tab = krealloc_array(tab, size, sizeof(*poke), GFP_KERNEL);
 854         if (!tab)
 855                 return -ENOMEM;
 856
 857         memcpy(&tab[slot], poke, sizeof(*poke));
 858         prog->aux->size_poke_tab = size;
 859         prog->aux->poke_tab = tab;
 860
 861         return slot;
 862 }
 863
 864 /*
 865  * BPF program pack allocator.
 866  *
 867  * Most BPF programs are pretty small. Allocating a hole page for each
 868  * program is sometime a waste. Many small bpf program also adds pressure
 869  * to instruction TLB. To solve this issue, we introduce a BPF program pack
 870  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
 871  * to host BPF programs.
 872  */
 873 #define BPF_PROG_CHUNK_SHIFT    6
 874 #define BPF_PROG_CHUNK_SIZE     (1 << BPF_PROG_CHUNK_SHIFT)
 875 #define BPF_PROG_CHUNK_MASK     (~(BPF_PROG_CHUNK_SIZE - 1))
 876
 877 struct bpf_prog_pack {
 878         struct list_head list;
 879         void *ptr;
 880         unsigned long bitmap[];
 881 };
 882
 883 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
 884 {
 885         memset(area, 0, size);
 886 }
 887
 888 #define BPF_PROG_SIZE_TO_NBITS(size)    (round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
 889
 890 static DEFINE_MUTEX(pack_mutex);
 891 static LIST_HEAD(pack_list);
 892
 893 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
 894  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
 895  */
 896 #ifdef PMD_SIZE
 897 /* PMD_SIZE is really big for some archs. It doesn't make sense to
 898  * reserve too much memory in one allocation. Hardcode BPF_PROG_PACK_SIZE to
 899  * 2MiB * num_possible_nodes(). On most architectures PMD_SIZE will be
 900  * greater than or equal to 2MB.
 901  */
 902 #define BPF_PROG_PACK_SIZE (SZ_2M * num_possible_nodes())
 903 #else
 904 #define BPF_PROG_PACK_SIZE PAGE_SIZE
 905 #endif
 906
 907 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
 908
 909 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
 910 {
 911         struct bpf_prog_pack *pack;
 912         int err;
 913
 914         pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
 915                        GFP_KERNEL);
 916         if (!pack)
 917                 return NULL;
 918         pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE);
 919         if (!pack->ptr)
 920                 goto out;
 921         bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
 922         bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
 923
 924         set_vm_flush_reset_perms(pack->ptr);
 925         err = set_memory_rox((unsigned long)pack->ptr,
 926                              BPF_PROG_PACK_SIZE / PAGE_SIZE);
 927         if (err)
 928                 goto out;
 929         list_add_tail(&pack->list, &pack_list);
 930         return pack;
 931
 932 out:
 933         bpf_jit_free_exec(pack->ptr);
 934         kfree(pack);
 935         return NULL;
 936 }
 937
 938 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
 939 {
 940         unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
 941         struct bpf_prog_pack *pack;
 942         unsigned long pos;
 943         void *ptr = NULL;
 944
 945         mutex_lock(&pack_mutex);
 946         if (size > BPF_PROG_PACK_SIZE) {
 947                 size = round_up(size, PAGE_SIZE);
 948                 ptr = bpf_jit_alloc_exec(size);
 949                 if (ptr) {
 950                         int err;
 951
 952                         bpf_fill_ill_insns(ptr, size);
 953                         set_vm_flush_reset_perms(ptr);
 954                         err = set_memory_rox((unsigned long)ptr,
 955                                              size / PAGE_SIZE);
 956                         if (err) {
 957                                 bpf_jit_free_exec(ptr);
 958                                 ptr = NULL;
 959                         }
 960                 }
 961                 goto out;
 962         }
 963         list_for_each_entry(pack, &pack_list, list) {
 964                 pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
 965                                                  nbits, 0);
 966                 if (pos < BPF_PROG_CHUNK_COUNT)
 967                         goto found_free_area;
 968         }
 969
 970         pack = alloc_new_pack(bpf_fill_ill_insns);
 971         if (!pack)
 972                 goto out;
 973
 974         pos = 0;
 975
 976 found_free_area:
 977         bitmap_set(pack->bitmap, pos, nbits);
 978         ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
 979
 980 out:
 981         mutex_unlock(&pack_mutex);
 982         return ptr;
 983 }
 984
 985 void bpf_prog_pack_free(void *ptr, u32 size)
 986 {
 987         struct bpf_prog_pack *pack = NULL, *tmp;
 988         unsigned int nbits;
 989         unsigned long pos;
 990
 991         mutex_lock(&pack_mutex);
 992         if (size > BPF_PROG_PACK_SIZE) {
 993                 bpf_jit_free_exec(ptr);
 994                 goto out;
 995         }
 996
 997         list_for_each_entry(tmp, &pack_list, list) {
 998                 if (ptr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > ptr) {
 999                         pack = tmp;
1000                         break;
1001                 }
1002         }
1003
1004         if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
1005                 goto out;
1006
1007         nbits = BPF_PROG_SIZE_TO_NBITS(size);
1008         pos = ((unsigned long)ptr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
1009
1010         WARN_ONCE(bpf_arch_text_invalidate(ptr, size),
1011                   "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
1012
1013         bitmap_clear(pack->bitmap, pos, nbits);
1014         if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
1015                                        BPF_PROG_CHUNK_COUNT, 0) == 0) {
1016                 list_del(&pack->list);
1017                 bpf_jit_free_exec(pack->ptr);
1018                 kfree(pack);
1019         }
1020 out:
1021         mutex_unlock(&pack_mutex);
1022 }
1023
1024 static atomic_long_t bpf_jit_current;
1025
1026 /* Can be overridden by an arch's JIT compiler if it has a custom,
1027  * dedicated BPF backend memory area, or if neither of the two
1028  * below apply.
1029  */
1030 u64 __weak bpf_jit_alloc_exec_limit(void)
1031 {
1032 #if defined(MODULES_VADDR)
1033         return MODULES_END - MODULES_VADDR;
1034 #else
1035         return VMALLOC_END - VMALLOC_START;
1036 #endif
1037 }
1038
1039 static int __init bpf_jit_charge_init(void)
1040 {
1041         /* Only used as heuristic here to derive limit. */
1042         bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
1043         bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
1044                                             PAGE_SIZE), LONG_MAX);
1045         return 0;
1046 }
1047 pure_initcall(bpf_jit_charge_init);
1048
1049 int bpf_jit_charge_modmem(u32 size)
1050 {
1051         if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
1052                 if (!bpf_capable()) {
1053                         atomic_long_sub(size, &bpf_jit_current);
1054                         return -EPERM;
1055                 }
1056         }
1057
1058         return 0;
1059 }
1060
1061 void bpf_jit_uncharge_modmem(u32 size)
1062 {
1063         atomic_long_sub(size, &bpf_jit_current);
1064 }
1065
1066 void *__weak bpf_jit_alloc_exec(unsigned long size)
1067 {
1068         return execmem_alloc(EXECMEM_BPF, size);
1069 }
1070
1071 void __weak bpf_jit_free_exec(void *addr)
1072 {
1073         execmem_free(addr);
1074 }
1075
1076 struct bpf_binary_header *
1077 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1078                      unsigned int alignment,
1079                      bpf_jit_fill_hole_t bpf_fill_ill_insns)
1080 {
1081         struct bpf_binary_header *hdr;
1082         u32 size, hole, start;
1083
1084         WARN_ON_ONCE(!is_power_of_2(alignment) ||
1085                      alignment > BPF_IMAGE_ALIGNMENT);
1086
1087         /* Most of BPF filters are really small, but if some of them
1088          * fill a page, allow at least 128 extra bytes to insert a
1089          * random section of illegal instructions.
1090          */
1091         size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1092
1093         if (bpf_jit_charge_modmem(size))
1094                 return NULL;
1095         hdr = bpf_jit_alloc_exec(size);
1096         if (!hdr) {
1097                 bpf_jit_uncharge_modmem(size);
1098                 return NULL;
1099         }
1100
1101         /* Fill space with illegal/arch-dep instructions. */
1102         bpf_fill_ill_insns(hdr, size);
1103
1104         hdr->size = size;
1105         hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1106                      PAGE_SIZE - sizeof(*hdr));
1107         start = get_random_u32_below(hole) & ~(alignment - 1);
1108
1109         /* Leave a random number of instructions before BPF code. */
1110         *image_ptr = &hdr->image[start];
1111
1112         return hdr;
1113 }
1114
1115 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1116 {
1117         u32 size = hdr->size;
1118
1119         bpf_jit_free_exec(hdr);
1120         bpf_jit_uncharge_modmem(size);
1121 }
1122
1123 /* Allocate jit binary from bpf_prog_pack allocator.
1124  * Since the allocated memory is RO+X, the JIT engine cannot write directly
1125  * to the memory. To solve this problem, a RW buffer is also allocated at
1126  * as the same time. The JIT engine should calculate offsets based on the
1127  * RO memory address, but write JITed program to the RW buffer. Once the
1128  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1129  * the JITed program to the RO memory.
1130  */
1131 struct bpf_binary_header *
1132 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1133                           unsigned int alignment,
1134                           struct bpf_binary_header **rw_header,
1135                           u8 **rw_image,
1136                           bpf_jit_fill_hole_t bpf_fill_ill_insns)
1137 {
1138         struct bpf_binary_header *ro_header;
1139         u32 size, hole, start;
1140
1141         WARN_ON_ONCE(!is_power_of_2(alignment) ||
1142                      alignment > BPF_IMAGE_ALIGNMENT);
1143
1144         /* add 16 bytes for a random section of illegal instructions */
1145         size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1146
1147         if (bpf_jit_charge_modmem(size))
1148                 return NULL;
1149         ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1150         if (!ro_header) {
1151                 bpf_jit_uncharge_modmem(size);
1152                 return NULL;
1153         }
1154
1155         *rw_header = kvmalloc(size, GFP_KERNEL);
1156         if (!*rw_header) {
1157                 bpf_prog_pack_free(ro_header, size);
1158                 bpf_jit_uncharge_modmem(size);
1159                 return NULL;
1160         }
1161
1162         /* Fill space with illegal/arch-dep instructions. */
1163         bpf_fill_ill_insns(*rw_header, size);
1164         (*rw_header)->size = size;
1165
1166         hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1167                      BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1168         start = get_random_u32_below(hole) & ~(alignment - 1);
1169
1170         *image_ptr = &ro_header->image[start];
1171         *rw_image = &(*rw_header)->image[start];
1172
1173         return ro_header;
1174 }
1175
1176 /* Copy JITed text from rw_header to its final location, the ro_header. */
1177 int bpf_jit_binary_pack_finalize(struct bpf_prog *prog,
1178                                  struct bpf_binary_header *ro_header,
1179                                  struct bpf_binary_header *rw_header)
1180 {
1181         void *ptr;
1182
1183         ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1184
1185         kvfree(rw_header);
1186
1187         if (IS_ERR(ptr)) {
1188                 bpf_prog_pack_free(ro_header, ro_header->size);
1189                 return PTR_ERR(ptr);
1190         }
1191         return 0;
1192 }
1193
1194 /* bpf_jit_binary_pack_free is called in two different scenarios:
1195  *   1) when the program is freed after;
1196  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1197  * For case 2), we need to free both the RO memory and the RW buffer.
1198  *
1199  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1200  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1201  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1202  * bpf_arch_text_copy (when jit fails).
1203  */
1204 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1205                               struct bpf_binary_header *rw_header)
1206 {
1207         u32 size = ro_header->size;
1208
1209         bpf_prog_pack_free(ro_header, size);
1210         kvfree(rw_header);
1211         bpf_jit_uncharge_modmem(size);
1212 }
1213
1214 struct bpf_binary_header *
1215 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1216 {
1217         unsigned long real_start = (unsigned long)fp->bpf_func;
1218         unsigned long addr;
1219
1220         addr = real_start & BPF_PROG_CHUNK_MASK;
1221         return (void *)addr;
1222 }
1223
1224 static inline struct bpf_binary_header *
1225 bpf_jit_binary_hdr(const struct bpf_prog *fp)
1226 {
1227         unsigned long real_start = (unsigned long)fp->bpf_func;
1228         unsigned long addr;
1229
1230         addr = real_start & PAGE_MASK;
1231         return (void *)addr;
1232 }
1233
1234 /* This symbol is only overridden by archs that have different
1235  * requirements than the usual eBPF JITs, f.e. when they only
1236  * implement cBPF JIT, do not set images read-only, etc.
1237  */
1238 void __weak bpf_jit_free(struct bpf_prog *fp)
1239 {
1240         if (fp->jited) {
1241                 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1242
1243                 bpf_jit_binary_free(hdr);
1244                 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1245         }
1246
1247         bpf_prog_unlock_free(fp);
1248 }
1249
1250 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1251                           const struct bpf_insn *insn, bool extra_pass,
1252                           u64 *func_addr, bool *func_addr_fixed)
1253 {
1254         s16 off = insn->off;
1255         s32 imm = insn->imm;
1256         u8 *addr;
1257         int err;
1258
1259         *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1260         if (!*func_addr_fixed) {
1261                 /* Place-holder address till the last pass has collected
1262                  * all addresses for JITed subprograms in which case we
1263                  * can pick them up from prog->aux.
1264                  */
1265                 if (!extra_pass)
1266                         addr = NULL;
1267                 else if (prog->aux->func &&
1268                          off >= 0 && off < prog->aux->real_func_cnt)
1269                         addr = (u8 *)prog->aux->func[off]->bpf_func;
1270                 else
1271                         return -EINVAL;
1272         } else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1273                    bpf_jit_supports_far_kfunc_call()) {
1274                 err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1275                 if (err)
1276                         return err;
1277         } else {
1278                 /* Address of a BPF helper call. Since part of the core
1279                  * kernel, it's always at a fixed location. __bpf_call_base
1280                  * and the helper with imm relative to it are both in core
1281                  * kernel.
1282                  */
1283                 addr = (u8 *)__bpf_call_base + imm;
1284         }
1285
1286         *func_addr = (unsigned long)addr;
1287         return 0;
1288 }
1289
1290 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1291                               const struct bpf_insn *aux,
1292                               struct bpf_insn *to_buff,
1293                               bool emit_zext)
1294 {
1295         struct bpf_insn *to = to_buff;
1296         u32 imm_rnd = get_random_u32();
1297         s16 off;
1298
1299         BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1300         BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1301
1302         /* Constraints on AX register:
1303          *
1304          * AX register is inaccessible from user space. It is mapped in
1305          * all JITs, and used here for constant blinding rewrites. It is
1306          * typically "stateless" meaning its contents are only valid within
1307          * the executed instruction, but not across several instructions.
1308          * There are a few exceptions however which are further detailed
1309          * below.
1310          *
1311          * Constant blinding is only used by JITs, not in the interpreter.
1312          * The interpreter uses AX in some occasions as a local temporary
1313          * register e.g. in DIV or MOD instructions.
1314          *
1315          * In restricted circumstances, the verifier can also use the AX
1316          * register for rewrites as long as they do not interfere with
1317          * the above cases!
1318          */
1319         if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1320                 goto out;
1321
1322         if (from->imm == 0 &&
1323             (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1324              from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1325                 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1326                 goto out;
1327         }
1328
1329         switch (from->code) {
1330         case BPF_ALU | BPF_ADD | BPF_K:
1331         case BPF_ALU | BPF_SUB | BPF_K:
1332         case BPF_ALU | BPF_AND | BPF_K:
1333         case BPF_ALU | BPF_OR  | BPF_K:
1334         case BPF_ALU | BPF_XOR | BPF_K:
1335         case BPF_ALU | BPF_MUL | BPF_K:
1336         case BPF_ALU | BPF_MOV | BPF_K:
1337         case BPF_ALU | BPF_DIV | BPF_K:
1338         case BPF_ALU | BPF_MOD | BPF_K:
1339                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1340                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1341                 *to++ = BPF_ALU32_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1342                 break;
1343
1344         case BPF_ALU64 | BPF_ADD | BPF_K:
1345         case BPF_ALU64 | BPF_SUB | BPF_K:
1346         case BPF_ALU64 | BPF_AND | BPF_K:
1347         case BPF_ALU64 | BPF_OR  | BPF_K:
1348         case BPF_ALU64 | BPF_XOR | BPF_K:
1349         case BPF_ALU64 | BPF_MUL | BPF_K:
1350         case BPF_ALU64 | BPF_MOV | BPF_K:
1351         case BPF_ALU64 | BPF_DIV | BPF_K:
1352         case BPF_ALU64 | BPF_MOD | BPF_K:
1353                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1354                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1355                 *to++ = BPF_ALU64_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1356                 break;
1357
1358         case BPF_JMP | BPF_JEQ  | BPF_K:
1359         case BPF_JMP | BPF_JNE  | BPF_K:
1360         case BPF_JMP | BPF_JGT  | BPF_K:
1361         case BPF_JMP | BPF_JLT  | BPF_K:
1362         case BPF_JMP | BPF_JGE  | BPF_K:
1363         case BPF_JMP | BPF_JLE  | BPF_K:
1364         case BPF_JMP | BPF_JSGT | BPF_K:
1365         case BPF_JMP | BPF_JSLT | BPF_K:
1366         case BPF_JMP | BPF_JSGE | BPF_K:
1367         case BPF_JMP | BPF_JSLE | BPF_K:
1368         case BPF_JMP | BPF_JSET | BPF_K:
1369                 /* Accommodate for extra offset in case of a backjump. */
1370                 off = from->off;
1371                 if (off < 0)
1372                         off -= 2;
1373                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1374                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1375                 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1376                 break;
1377
1378         case BPF_JMP32 | BPF_JEQ  | BPF_K:
1379         case BPF_JMP32 | BPF_JNE  | BPF_K:
1380         case BPF_JMP32 | BPF_JGT  | BPF_K:
1381         case BPF_JMP32 | BPF_JLT  | BPF_K:
1382         case BPF_JMP32 | BPF_JGE  | BPF_K:
1383         case BPF_JMP32 | BPF_JLE  | BPF_K:
1384         case BPF_JMP32 | BPF_JSGT | BPF_K:
1385         case BPF_JMP32 | BPF_JSLT | BPF_K:
1386         case BPF_JMP32 | BPF_JSGE | BPF_K:
1387         case BPF_JMP32 | BPF_JSLE | BPF_K:
1388         case BPF_JMP32 | BPF_JSET | BPF_K:
1389                 /* Accommodate for extra offset in case of a backjump. */
1390                 off = from->off;
1391                 if (off < 0)
1392                         off -= 2;
1393                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1394                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1395                 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1396                                       off);
1397                 break;
1398
1399         case BPF_LD | BPF_IMM | BPF_DW:
1400                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1401                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1402                 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1403                 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1404                 break;
1405         case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1406                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1407                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1408                 if (emit_zext)
1409                         *to++ = BPF_ZEXT_REG(BPF_REG_AX);
1410                 *to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1411                 break;
1412
1413         case BPF_ST | BPF_MEM | BPF_DW:
1414         case BPF_ST | BPF_MEM | BPF_W:
1415         case BPF_ST | BPF_MEM | BPF_H:
1416         case BPF_ST | BPF_MEM | BPF_B:
1417                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1418                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1419                 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1420                 break;
1421         }
1422 out:
1423         return to - to_buff;
1424 }
1425
1426 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1427                                               gfp_t gfp_extra_flags)
1428 {
1429         gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1430         struct bpf_prog *fp;
1431
1432         fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1433         if (fp != NULL) {
1434                 /* aux->prog still points to the fp_other one, so
1435                  * when promoting the clone to the real program,
1436                  * this still needs to be adapted.
1437                  */
1438                 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1439         }
1440
1441         return fp;
1442 }
1443
1444 static void bpf_prog_clone_free(struct bpf_prog *fp)
1445 {
1446         /* aux was stolen by the other clone, so we cannot free
1447          * it from this path! It will be freed eventually by the
1448          * other program on release.
1449          *
1450          * At this point, we don't need a deferred release since
1451          * clone is guaranteed to not be locked.
1452          */
1453         fp->aux = NULL;
1454         fp->stats = NULL;
1455         fp->active = NULL;
1456         __bpf_prog_free(fp);
1457 }
1458
1459 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1460 {
1461         /* We have to repoint aux->prog to self, as we don't
1462          * know whether fp here is the clone or the original.
1463          */
1464         fp->aux->prog = fp;
1465         bpf_prog_clone_free(fp_other);
1466 }
1467
1468 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1469 {
1470         struct bpf_insn insn_buff[16], aux[2];
1471         struct bpf_prog *clone, *tmp;
1472         int insn_delta, insn_cnt;
1473         struct bpf_insn *insn;
1474         int i, rewritten;
1475
1476         if (!prog->blinding_requested || prog->blinded)
1477                 return prog;
1478
1479         clone = bpf_prog_clone_create(prog, GFP_USER);
1480         if (!clone)
1481                 return ERR_PTR(-ENOMEM);
1482
1483         insn_cnt = clone->len;
1484         insn = clone->insnsi;
1485
1486         for (i = 0; i < insn_cnt; i++, insn++) {
1487                 if (bpf_pseudo_func(insn)) {
1488                         /* ld_imm64 with an address of bpf subprog is not
1489                          * a user controlled constant. Don't randomize it,
1490                          * since it will conflict with jit_subprogs() logic.
1491                          */
1492                         insn++;
1493                         i++;
1494                         continue;
1495                 }
1496
1497                 /* We temporarily need to hold the original ld64 insn
1498                  * so that we can still access the first part in the
1499                  * second blinding run.
1500                  */
1501                 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1502                     insn[1].code == 0)
1503                         memcpy(aux, insn, sizeof(aux));
1504
1505                 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1506                                                 clone->aux->verifier_zext);
1507                 if (!rewritten)
1508                         continue;
1509
1510                 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1511                 if (IS_ERR(tmp)) {
1512                         /* Patching may have repointed aux->prog during
1513                          * realloc from the original one, so we need to
1514                          * fix it up here on error.
1515                          */
1516                         bpf_jit_prog_release_other(prog, clone);
1517                         return tmp;
1518                 }
1519
1520                 clone = tmp;
1521                 insn_delta = rewritten - 1;
1522
1523                 /* Walk new program and skip insns we just inserted. */
1524                 insn = clone->insnsi + i + insn_delta;
1525                 insn_cnt += insn_delta;
1526                 i        += insn_delta;
1527         }
1528
1529         clone->blinded = 1;
1530         return clone;
1531 }
1532 #endif /* CONFIG_BPF_JIT */
1533
1534 /* Base function for offset calculation. Needs to go into .text section,
1535  * therefore keeping it non-static as well; will also be used by JITs
1536  * anyway later on, so do not let the compiler omit it. This also needs
1537  * to go into kallsyms for correlation from e.g. bpftool, so naming
1538  * must not change.
1539  */
1540 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1541 {
1542         return 0;
1543 }
1544 EXPORT_SYMBOL_GPL(__bpf_call_base);
1545
1546 /* All UAPI available opcodes. */
1547 #define BPF_INSN_MAP(INSN_2, INSN_3)            \
1548         /* 32 bit ALU operations. */            \
1549         /*   Register based. */                 \
1550         INSN_3(ALU, ADD,  X),                   \
1551         INSN_3(ALU, SUB,  X),                   \
1552         INSN_3(ALU, AND,  X),                   \
1553         INSN_3(ALU, OR,   X),                   \
1554         INSN_3(ALU, LSH,  X),                   \
1555         INSN_3(ALU, RSH,  X),                   \
1556         INSN_3(ALU, XOR,  X),                   \
1557         INSN_3(ALU, MUL,  X),                   \
1558         INSN_3(ALU, MOV,  X),                   \
1559         INSN_3(ALU, ARSH, X),                   \
1560         INSN_3(ALU, DIV,  X),                   \
1561         INSN_3(ALU, MOD,  X),                   \
1562         INSN_2(ALU, NEG),                       \
1563         INSN_3(ALU, END, TO_BE),                \
1564         INSN_3(ALU, END, TO_LE),                \
1565         /*   Immediate based. */                \
1566         INSN_3(ALU, ADD,  K),                   \
1567         INSN_3(ALU, SUB,  K),                   \
1568         INSN_3(ALU, AND,  K),                   \
1569         INSN_3(ALU, OR,   K),                   \
1570         INSN_3(ALU, LSH,  K),                   \
1571         INSN_3(ALU, RSH,  K),                   \
1572         INSN_3(ALU, XOR,  K),                   \
1573         INSN_3(ALU, MUL,  K),                   \
1574         INSN_3(ALU, MOV,  K),                   \
1575         INSN_3(ALU, ARSH, K),                   \
1576         INSN_3(ALU, DIV,  K),                   \
1577         INSN_3(ALU, MOD,  K),                   \
1578         /* 64 bit ALU operations. */            \
1579         /*   Register based. */                 \
1580         INSN_3(ALU64, ADD,  X),                 \
1581         INSN_3(ALU64, SUB,  X),                 \
1582         INSN_3(ALU64, AND,  X),                 \
1583         INSN_3(ALU64, OR,   X),                 \
1584         INSN_3(ALU64, LSH,  X),                 \
1585         INSN_3(ALU64, RSH,  X),                 \
1586         INSN_3(ALU64, XOR,  X),                 \
1587         INSN_3(ALU64, MUL,  X),                 \
1588         INSN_3(ALU64, MOV,  X),                 \
1589         INSN_3(ALU64, ARSH, X),                 \
1590         INSN_3(ALU64, DIV,  X),                 \
1591         INSN_3(ALU64, MOD,  X),                 \
1592         INSN_2(ALU64, NEG),                     \
1593         INSN_3(ALU64, END, TO_LE),              \
1594         /*   Immediate based. */                \
1595         INSN_3(ALU64, ADD,  K),                 \
1596         INSN_3(ALU64, SUB,  K),                 \
1597         INSN_3(ALU64, AND,  K),                 \
1598         INSN_3(ALU64, OR,   K),                 \
1599         INSN_3(ALU64, LSH,  K),                 \
1600         INSN_3(ALU64, RSH,  K),                 \
1601         INSN_3(ALU64, XOR,  K),                 \
1602         INSN_3(ALU64, MUL,  K),                 \
1603         INSN_3(ALU64, MOV,  K),                 \
1604         INSN_3(ALU64, ARSH, K),                 \
1605         INSN_3(ALU64, DIV,  K),                 \
1606         INSN_3(ALU64, MOD,  K),                 \
1607         /* Call instruction. */                 \
1608         INSN_2(JMP, CALL),                      \
1609         /* Exit instruction. */                 \
1610         INSN_2(JMP, EXIT),                      \
1611         /* 32-bit Jump instructions. */         \
1612         /*   Register based. */                 \
1613         INSN_3(JMP32, JEQ,  X),                 \
1614         INSN_3(JMP32, JNE,  X),                 \
1615         INSN_3(JMP32, JGT,  X),                 \
1616         INSN_3(JMP32, JLT,  X),                 \
1617         INSN_3(JMP32, JGE,  X),                 \
1618         INSN_3(JMP32, JLE,  X),                 \
1619         INSN_3(JMP32, JSGT, X),                 \
1620         INSN_3(JMP32, JSLT, X),                 \
1621         INSN_3(JMP32, JSGE, X),                 \
1622         INSN_3(JMP32, JSLE, X),                 \
1623         INSN_3(JMP32, JSET, X),                 \
1624         /*   Immediate based. */                \
1625         INSN_3(JMP32, JEQ,  K),                 \
1626         INSN_3(JMP32, JNE,  K),                 \
1627         INSN_3(JMP32, JGT,  K),                 \
1628         INSN_3(JMP32, JLT,  K),                 \
1629         INSN_3(JMP32, JGE,  K),                 \
1630         INSN_3(JMP32, JLE,  K),                 \
1631         INSN_3(JMP32, JSGT, K),                 \
1632         INSN_3(JMP32, JSLT, K),                 \
1633         INSN_3(JMP32, JSGE, K),                 \
1634         INSN_3(JMP32, JSLE, K),                 \
1635         INSN_3(JMP32, JSET, K),                 \
1636         /* Jump instructions. */                \
1637         /*   Register based. */                 \
1638         INSN_3(JMP, JEQ,  X),                   \
1639         INSN_3(JMP, JNE,  X),                   \
1640         INSN_3(JMP, JGT,  X),                   \
1641         INSN_3(JMP, JLT,  X),                   \
1642         INSN_3(JMP, JGE,  X),                   \
1643         INSN_3(JMP, JLE,  X),                   \
1644         INSN_3(JMP, JSGT, X),                   \
1645         INSN_3(JMP, JSLT, X),                   \
1646         INSN_3(JMP, JSGE, X),                   \
1647         INSN_3(JMP, JSLE, X),                   \
1648         INSN_3(JMP, JSET, X),                   \
1649         /*   Immediate based. */                \
1650         INSN_3(JMP, JEQ,  K),                   \
1651         INSN_3(JMP, JNE,  K),                   \
1652         INSN_3(JMP, JGT,  K),                   \
1653         INSN_3(JMP, JLT,  K),                   \
1654         INSN_3(JMP, JGE,  K),                   \
1655         INSN_3(JMP, JLE,  K),                   \
1656         INSN_3(JMP, JSGT, K),                   \
1657         INSN_3(JMP, JSLT, K),                   \
1658         INSN_3(JMP, JSGE, K),                   \
1659         INSN_3(JMP, JSLE, K),                   \
1660         INSN_3(JMP, JSET, K),                   \
1661         INSN_2(JMP, JA),                        \
1662         INSN_2(JMP32, JA),                      \
1663         /* Store instructions. */               \
1664         /*   Register based. */                 \
1665         INSN_3(STX, MEM,  B),                   \
1666         INSN_3(STX, MEM,  H),                   \
1667         INSN_3(STX, MEM,  W),                   \
1668         INSN_3(STX, MEM,  DW),                  \
1669         INSN_3(STX, ATOMIC, W),                 \
1670         INSN_3(STX, ATOMIC, DW),                \
1671         /*   Immediate based. */                \
1672         INSN_3(ST, MEM, B),                     \
1673         INSN_3(ST, MEM, H),                     \
1674         INSN_3(ST, MEM, W),                     \
1675         INSN_3(ST, MEM, DW),                    \
1676         /* Load instructions. */                \
1677         /*   Register based. */                 \
1678         INSN_3(LDX, MEM, B),                    \
1679         INSN_3(LDX, MEM, H),                    \
1680         INSN_3(LDX, MEM, W),                    \
1681         INSN_3(LDX, MEM, DW),                   \
1682         INSN_3(LDX, MEMSX, B),                  \
1683         INSN_3(LDX, MEMSX, H),                  \
1684         INSN_3(LDX, MEMSX, W),                  \
1685         /*   Immediate based. */                \
1686         INSN_3(LD, IMM, DW)
1687
1688 bool bpf_opcode_in_insntable(u8 code)
1689 {
1690 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1691 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1692         static const bool public_insntable[256] = {
1693                 [0 ... 255] = false,
1694                 /* Now overwrite non-defaults ... */
1695                 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1696                 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1697                 [BPF_LD | BPF_ABS | BPF_B] = true,
1698                 [BPF_LD | BPF_ABS | BPF_H] = true,
1699                 [BPF_LD | BPF_ABS | BPF_W] = true,
1700                 [BPF_LD | BPF_IND | BPF_B] = true,
1701                 [BPF_LD | BPF_IND | BPF_H] = true,
1702                 [BPF_LD | BPF_IND | BPF_W] = true,
1703                 [BPF_JMP | BPF_JCOND] = true,
1704         };
1705 #undef BPF_INSN_3_TBL
1706 #undef BPF_INSN_2_TBL
1707         return public_insntable[code];
1708 }
1709
1710 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1711 /**
1712  *      ___bpf_prog_run - run eBPF program on a given context
1713  *      @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1714  *      @insn: is the array of eBPF instructions
1715  *
1716  * Decode and execute eBPF instructions.
1717  *
1718  * Return: whatever value is in %BPF_R0 at program exit
1719  */
1720 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1721 {
1722 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1723 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1724         static const void * const jumptable[256] __annotate_jump_table = {
1725                 [0 ... 255] = &&default_label,
1726                 /* Now overwrite non-defaults ... */
1727                 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1728                 /* Non-UAPI available opcodes. */
1729                 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1730                 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1731                 [BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1732                 [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1733                 [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1734                 [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1735                 [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1736                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B,
1737                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H,
1738                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W,
1739         };
1740 #undef BPF_INSN_3_LBL
1741 #undef BPF_INSN_2_LBL
1742         u32 tail_call_cnt = 0;
1743
1744 #define CONT     ({ insn++; goto select_insn; })
1745 #define CONT_JMP ({ insn++; goto select_insn; })
1746
1747 select_insn:
1748         goto *jumptable[insn->code];
1749
1750         /* Explicitly mask the register-based shift amounts with 63 or 31
1751          * to avoid undefined behavior. Normally this won't affect the
1752          * generated code, for example, in case of native 64 bit archs such
1753          * as x86-64 or arm64, the compiler is optimizing the AND away for
1754          * the interpreter. In case of JITs, each of the JIT backends compiles
1755          * the BPF shift operations to machine instructions which produce
1756          * implementation-defined results in such a case; the resulting
1757          * contents of the register may be arbitrary, but program behaviour
1758          * as a whole remains defined. In other words, in case of JIT backends,
1759          * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1760          */
1761         /* ALU (shifts) */
1762 #define SHT(OPCODE, OP)                                 \
1763         ALU64_##OPCODE##_X:                             \
1764                 DST = DST OP (SRC & 63);                \
1765                 CONT;                                   \
1766         ALU_##OPCODE##_X:                               \
1767                 DST = (u32) DST OP ((u32) SRC & 31);    \
1768                 CONT;                                   \
1769         ALU64_##OPCODE##_K:                             \
1770                 DST = DST OP IMM;                       \
1771                 CONT;                                   \
1772         ALU_##OPCODE##_K:                               \
1773                 DST = (u32) DST OP (u32) IMM;           \
1774                 CONT;
1775         /* ALU (rest) */
1776 #define ALU(OPCODE, OP)                                 \
1777         ALU64_##OPCODE##_X:                             \
1778                 DST = DST OP SRC;                       \
1779                 CONT;                                   \
1780         ALU_##OPCODE##_X:                               \
1781                 DST = (u32) DST OP (u32) SRC;           \
1782                 CONT;                                   \
1783         ALU64_##OPCODE##_K:                             \
1784                 DST = DST OP IMM;                       \
1785                 CONT;                                   \
1786         ALU_##OPCODE##_K:                               \
1787                 DST = (u32) DST OP (u32) IMM;           \
1788                 CONT;
1789         ALU(ADD,  +)
1790         ALU(SUB,  -)
1791         ALU(AND,  &)
1792         ALU(OR,   |)
1793         ALU(XOR,  ^)
1794         ALU(MUL,  *)
1795         SHT(LSH, <<)
1796         SHT(RSH, >>)
1797 #undef SHT
1798 #undef ALU
1799         ALU_NEG:
1800                 DST = (u32) -DST;
1801                 CONT;
1802         ALU64_NEG:
1803                 DST = -DST;
1804                 CONT;
1805         ALU_MOV_X:
1806                 switch (OFF) {
1807                 case 0:
1808                         DST = (u32) SRC;
1809                         break;
1810                 case 8:
1811                         DST = (u32)(s8) SRC;
1812                         break;
1813                 case 16:
1814                         DST = (u32)(s16) SRC;
1815                         break;
1816                 }
1817                 CONT;
1818         ALU_MOV_K:
1819                 DST = (u32) IMM;
1820                 CONT;
1821         ALU64_MOV_X:
1822                 switch (OFF) {
1823                 case 0:
1824                         DST = SRC;
1825                         break;
1826                 case 8:
1827                         DST = (s8) SRC;
1828                         break;
1829                 case 16:
1830                         DST = (s16) SRC;
1831                         break;
1832                 case 32:
1833                         DST = (s32) SRC;
1834                         break;
1835                 }
1836                 CONT;
1837         ALU64_MOV_K:
1838                 DST = IMM;
1839                 CONT;
1840         LD_IMM_DW:
1841                 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1842                 insn++;
1843                 CONT;
1844         ALU_ARSH_X:
1845                 DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1846                 CONT;
1847         ALU_ARSH_K:
1848                 DST = (u64) (u32) (((s32) DST) >> IMM);
1849                 CONT;
1850         ALU64_ARSH_X:
1851                 (*(s64 *) &DST) >>= (SRC & 63);
1852                 CONT;
1853         ALU64_ARSH_K:
1854                 (*(s64 *) &DST) >>= IMM;
1855                 CONT;
1856         ALU64_MOD_X:
1857                 switch (OFF) {
1858                 case 0:
1859                         div64_u64_rem(DST, SRC, &AX);
1860                         DST = AX;
1861                         break;
1862                 case 1:
1863                         AX = div64_s64(DST, SRC);
1864                         DST = DST - AX * SRC;
1865                         break;
1866                 }
1867                 CONT;
1868         ALU_MOD_X:
1869                 switch (OFF) {
1870                 case 0:
1871                         AX = (u32) DST;
1872                         DST = do_div(AX, (u32) SRC);
1873                         break;
1874                 case 1:
1875                         AX = abs((s32)DST);
1876                         AX = do_div(AX, abs((s32)SRC));
1877                         if ((s32)DST < 0)
1878                                 DST = (u32)-AX;
1879                         else
1880                                 DST = (u32)AX;
1881                         break;
1882                 }
1883                 CONT;
1884         ALU64_MOD_K:
1885                 switch (OFF) {
1886                 case 0:
1887                         div64_u64_rem(DST, IMM, &AX);
1888                         DST = AX;
1889                         break;
1890                 case 1:
1891                         AX = div64_s64(DST, IMM);
1892                         DST = DST - AX * IMM;
1893                         break;
1894                 }
1895                 CONT;
1896         ALU_MOD_K:
1897                 switch (OFF) {
1898                 case 0:
1899                         AX = (u32) DST;
1900                         DST = do_div(AX, (u32) IMM);
1901                         break;
1902                 case 1:
1903                         AX = abs((s32)DST);
1904                         AX = do_div(AX, abs((s32)IMM));
1905                         if ((s32)DST < 0)
1906                                 DST = (u32)-AX;
1907                         else
1908                                 DST = (u32)AX;
1909                         break;
1910                 }
1911                 CONT;
1912         ALU64_DIV_X:
1913                 switch (OFF) {
1914                 case 0:
1915                         DST = div64_u64(DST, SRC);
1916                         break;
1917                 case 1:
1918                         DST = div64_s64(DST, SRC);
1919                         break;
1920                 }
1921                 CONT;
1922         ALU_DIV_X:
1923                 switch (OFF) {
1924                 case 0:
1925                         AX = (u32) DST;
1926                         do_div(AX, (u32) SRC);
1927                         DST = (u32) AX;
1928                         break;
1929                 case 1:
1930                         AX = abs((s32)DST);
1931                         do_div(AX, abs((s32)SRC));
1932                         if (((s32)DST < 0) == ((s32)SRC < 0))
1933                                 DST = (u32)AX;
1934                         else
1935                                 DST = (u32)-AX;
1936                         break;
1937                 }
1938                 CONT;
1939         ALU64_DIV_K:
1940                 switch (OFF) {
1941                 case 0:
1942                         DST = div64_u64(DST, IMM);
1943                         break;
1944                 case 1:
1945                         DST = div64_s64(DST, IMM);
1946                         break;
1947                 }
1948                 CONT;
1949         ALU_DIV_K:
1950                 switch (OFF) {
1951                 case 0:
1952                         AX = (u32) DST;
1953                         do_div(AX, (u32) IMM);
1954                         DST = (u32) AX;
1955                         break;
1956                 case 1:
1957                         AX = abs((s32)DST);
1958                         do_div(AX, abs((s32)IMM));
1959                         if (((s32)DST < 0) == ((s32)IMM < 0))
1960                                 DST = (u32)AX;
1961                         else
1962                                 DST = (u32)-AX;
1963                         break;
1964                 }
1965                 CONT;
1966         ALU_END_TO_BE:
1967                 switch (IMM) {
1968                 case 16:
1969                         DST = (__force u16) cpu_to_be16(DST);
1970                         break;
1971                 case 32:
1972                         DST = (__force u32) cpu_to_be32(DST);
1973                         break;
1974                 case 64:
1975                         DST = (__force u64) cpu_to_be64(DST);
1976                         break;
1977                 }
1978                 CONT;
1979         ALU_END_TO_LE:
1980                 switch (IMM) {
1981                 case 16:
1982                         DST = (__force u16) cpu_to_le16(DST);
1983                         break;
1984                 case 32:
1985                         DST = (__force u32) cpu_to_le32(DST);
1986                         break;
1987                 case 64:
1988                         DST = (__force u64) cpu_to_le64(DST);
1989                         break;
1990                 }
1991                 CONT;
1992         ALU64_END_TO_LE:
1993                 switch (IMM) {
1994                 case 16:
1995                         DST = (__force u16) __swab16(DST);
1996                         break;
1997                 case 32:
1998                         DST = (__force u32) __swab32(DST);
1999                         break;
2000                 case 64:
2001                         DST = (__force u64) __swab64(DST);
2002                         break;
2003                 }
2004                 CONT;
2005
2006         /* CALL */
2007         JMP_CALL:
2008                 /* Function call scratches BPF_R1-BPF_R5 registers,
2009                  * preserves BPF_R6-BPF_R9, and stores return value
2010                  * into BPF_R0.
2011                  */
2012                 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
2013                                                        BPF_R4, BPF_R5);
2014                 CONT;
2015
2016         JMP_CALL_ARGS:
2017                 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
2018                                                             BPF_R3, BPF_R4,
2019                                                             BPF_R5,
2020                                                             insn + insn->off + 1);
2021                 CONT;
2022
2023         JMP_TAIL_CALL: {
2024                 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
2025                 struct bpf_array *array = container_of(map, struct bpf_array, map);
2026                 struct bpf_prog *prog;
2027                 u32 index = BPF_R3;
2028
2029                 if (unlikely(index >= array->map.max_entries))
2030                         goto out;
2031
2032                 if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
2033                         goto out;
2034
2035                 tail_call_cnt++;
2036
2037                 prog = READ_ONCE(array->ptrs[index]);
2038                 if (!prog)
2039                         goto out;
2040
2041                 /* ARG1 at this point is guaranteed to point to CTX from
2042                  * the verifier side due to the fact that the tail call is
2043                  * handled like a helper, that is, bpf_tail_call_proto,
2044                  * where arg1_type is ARG_PTR_TO_CTX.
2045                  */
2046                 insn = prog->insnsi;
2047                 goto select_insn;
2048 out:
2049                 CONT;
2050         }
2051         JMP_JA:
2052                 insn += insn->off;
2053                 CONT;
2054         JMP32_JA:
2055                 insn += insn->imm;
2056                 CONT;
2057         JMP_EXIT:
2058                 return BPF_R0;
2059         /* JMP */
2060 #define COND_JMP(SIGN, OPCODE, CMP_OP)                          \
2061         JMP_##OPCODE##_X:                                       \
2062                 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {     \
2063                         insn += insn->off;                      \
2064                         CONT_JMP;                               \
2065                 }                                               \
2066                 CONT;                                           \
2067         JMP32_##OPCODE##_X:                                     \
2068                 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {     \
2069                         insn += insn->off;                      \
2070                         CONT_JMP;                               \
2071                 }                                               \
2072                 CONT;                                           \
2073         JMP_##OPCODE##_K:                                       \
2074                 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {     \
2075                         insn += insn->off;                      \
2076                         CONT_JMP;                               \
2077                 }                                               \
2078                 CONT;                                           \
2079         JMP32_##OPCODE##_K:                                     \
2080                 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {     \
2081                         insn += insn->off;                      \
2082                         CONT_JMP;                               \
2083                 }                                               \
2084                 CONT;
2085         COND_JMP(u, JEQ, ==)
2086         COND_JMP(u, JNE, !=)
2087         COND_JMP(u, JGT, >)
2088         COND_JMP(u, JLT, <)
2089         COND_JMP(u, JGE, >=)
2090         COND_JMP(u, JLE, <=)
2091         COND_JMP(u, JSET, &)
2092         COND_JMP(s, JSGT, >)
2093         COND_JMP(s, JSLT, <)
2094         COND_JMP(s, JSGE, >=)
2095         COND_JMP(s, JSLE, <=)
2096 #undef COND_JMP
2097         /* ST, STX and LDX*/
2098         ST_NOSPEC:
2099                 /* Speculation barrier for mitigating Speculative Store Bypass.
2100                  * In case of arm64, we rely on the firmware mitigation as
2101                  * controlled via the ssbd kernel parameter. Whenever the
2102                  * mitigation is enabled, it works for all of the kernel code
2103                  * with no need to provide any additional instructions here.
2104                  * In case of x86, we use 'lfence' insn for mitigation. We
2105                  * reuse preexisting logic from Spectre v1 mitigation that
2106                  * happens to produce the required code on x86 for v4 as well.
2107                  */
2108                 barrier_nospec();
2109                 CONT;
2110 #define LDST(SIZEOP, SIZE)                                              \
2111         STX_MEM_##SIZEOP:                                               \
2112                 *(SIZE *)(unsigned long) (DST + insn->off) = SRC;       \
2113                 CONT;                                                   \
2114         ST_MEM_##SIZEOP:                                                \
2115                 *(SIZE *)(unsigned long) (DST + insn->off) = IMM;       \
2116                 CONT;                                                   \
2117         LDX_MEM_##SIZEOP:                                               \
2118                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
2119                 CONT;                                                   \
2120         LDX_PROBE_MEM_##SIZEOP:                                         \
2121                 bpf_probe_read_kernel_common(&DST, sizeof(SIZE),        \
2122                               (const void *)(long) (SRC + insn->off));  \
2123                 DST = *((SIZE *)&DST);                                  \
2124                 CONT;
2125
2126         LDST(B,   u8)
2127         LDST(H,  u16)
2128         LDST(W,  u32)
2129         LDST(DW, u64)
2130 #undef LDST
2131
2132 #define LDSX(SIZEOP, SIZE)                                              \
2133         LDX_MEMSX_##SIZEOP:                                             \
2134                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
2135                 CONT;                                                   \
2136         LDX_PROBE_MEMSX_##SIZEOP:                                       \
2137                 bpf_probe_read_kernel_common(&DST, sizeof(SIZE),                \
2138                                       (const void *)(long) (SRC + insn->off));  \
2139                 DST = *((SIZE *)&DST);                                  \
2140                 CONT;
2141
2142         LDSX(B,   s8)
2143         LDSX(H,  s16)
2144         LDSX(W,  s32)
2145 #undef LDSX
2146
2147 #define ATOMIC_ALU_OP(BOP, KOP)                                         \
2148                 case BOP:                                               \
2149                         if (BPF_SIZE(insn->code) == BPF_W)              \
2150                                 atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
2151                                              (DST + insn->off));        \
2152                         else                                            \
2153                                 atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
2154                                                (DST + insn->off));      \
2155                         break;                                          \
2156                 case BOP | BPF_FETCH:                                   \
2157                         if (BPF_SIZE(insn->code) == BPF_W)              \
2158                                 SRC = (u32) atomic_fetch_##KOP(         \
2159                                         (u32) SRC,                      \
2160                                         (atomic_t *)(unsigned long) (DST + insn->off)); \
2161                         else                                            \
2162                                 SRC = (u64) atomic64_fetch_##KOP(       \
2163                                         (u64) SRC,                      \
2164                                         (atomic64_t *)(unsigned long) (DST + insn->off)); \
2165                         break;
2166
2167         STX_ATOMIC_DW:
2168         STX_ATOMIC_W:
2169                 switch (IMM) {
2170                 ATOMIC_ALU_OP(BPF_ADD, add)
2171                 ATOMIC_ALU_OP(BPF_AND, and)
2172                 ATOMIC_ALU_OP(BPF_OR, or)
2173                 ATOMIC_ALU_OP(BPF_XOR, xor)
2174 #undef ATOMIC_ALU_OP
2175
2176                 case BPF_XCHG:
2177                         if (BPF_SIZE(insn->code) == BPF_W)
2178                                 SRC = (u32) atomic_xchg(
2179                                         (atomic_t *)(unsigned long) (DST + insn->off),
2180                                         (u32) SRC);
2181                         else
2182                                 SRC = (u64) atomic64_xchg(
2183                                         (atomic64_t *)(unsigned long) (DST + insn->off),
2184                                         (u64) SRC);
2185                         break;
2186                 case BPF_CMPXCHG:
2187                         if (BPF_SIZE(insn->code) == BPF_W)
2188                                 BPF_R0 = (u32) atomic_cmpxchg(
2189                                         (atomic_t *)(unsigned long) (DST + insn->off),
2190                                         (u32) BPF_R0, (u32) SRC);
2191                         else
2192                                 BPF_R0 = (u64) atomic64_cmpxchg(
2193                                         (atomic64_t *)(unsigned long) (DST + insn->off),
2194                                         (u64) BPF_R0, (u64) SRC);
2195                         break;
2196
2197                 default:
2198                         goto default_label;
2199                 }
2200                 CONT;
2201
2202         default_label:
2203                 /* If we ever reach this, we have a bug somewhere. Die hard here
2204                  * instead of just returning 0; we could be somewhere in a subprog,
2205                  * so execution could continue otherwise which we do /not/ want.
2206                  *
2207                  * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2208                  */
2209                 pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2210                         insn->code, insn->imm);
2211                 BUG_ON(1);
2212                 return 0;
2213 }
2214
2215 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2216 #define DEFINE_BPF_PROG_RUN(stack_size) \
2217 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2218 { \
2219         u64 stack[stack_size / sizeof(u64)]; \
2220         u64 regs[MAX_BPF_EXT_REG] = {}; \
2221 \
2222         kmsan_unpoison_memory(stack, sizeof(stack)); \
2223         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2224         ARG1 = (u64) (unsigned long) ctx; \
2225         return ___bpf_prog_run(regs, insn); \
2226 }
2227
2228 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2229 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2230 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2231                                       const struct bpf_insn *insn) \
2232 { \
2233         u64 stack[stack_size / sizeof(u64)]; \
2234         u64 regs[MAX_BPF_EXT_REG]; \
2235 \
2236         kmsan_unpoison_memory(stack, sizeof(stack)); \
2237         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2238         BPF_R1 = r1; \
2239         BPF_R2 = r2; \
2240         BPF_R3 = r3; \
2241         BPF_R4 = r4; \
2242         BPF_R5 = r5; \
2243         return ___bpf_prog_run(regs, insn); \
2244 }
2245
2246 #define EVAL1(FN, X) FN(X)
2247 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2248 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2249 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2250 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2251 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2252
2253 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2254 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2255 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2256
2257 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2258 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2259 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2260
2261 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2262
2263 static unsigned int (*interpreters[])(const void *ctx,
2264                                       const struct bpf_insn *insn) = {
2265 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2266 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2267 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2268 };
2269 #undef PROG_NAME_LIST
2270 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2271 static __maybe_unused
2272 u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2273                            const struct bpf_insn *insn) = {
2274 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2275 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2276 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2277 };
2278 #undef PROG_NAME_LIST
2279
2280 #ifdef CONFIG_BPF_SYSCALL
2281 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2282 {
2283         stack_depth = max_t(u32, stack_depth, 1);
2284         insn->off = (s16) insn->imm;
2285         insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2286                 __bpf_call_base_args;
2287         insn->code = BPF_JMP | BPF_CALL_ARGS;
2288 }
2289 #endif
2290 #else
2291 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2292                                          const struct bpf_insn *insn)
2293 {
2294         /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2295          * is not working properly, so warn about it!
2296          */
2297         WARN_ON_ONCE(1);
2298         return 0;
2299 }
2300 #endif
2301
2302 bool bpf_prog_map_compatible(struct bpf_map *map,
2303                              const struct bpf_prog *fp)
2304 {
2305         enum bpf_prog_type prog_type = resolve_prog_type(fp);
2306         bool ret;
2307
2308         if (fp->kprobe_override)
2309                 return false;
2310
2311         /* XDP programs inserted into maps are not guaranteed to run on
2312          * a particular netdev (and can run outside driver context entirely
2313          * in the case of devmap and cpumap). Until device checks
2314          * are implemented, prohibit adding dev-bound programs to program maps.
2315          */
2316         if (bpf_prog_is_dev_bound(fp->aux))
2317                 return false;
2318
2319         spin_lock(&map->owner.lock);
2320         if (!map->owner.type) {
2321                 /* There's no owner yet where we could check for
2322                  * compatibility.
2323                  */
2324                 map->owner.type  = prog_type;
2325                 map->owner.jited = fp->jited;
2326                 map->owner.xdp_has_frags = fp->aux->xdp_has_frags;
2327                 ret = true;
2328         } else {
2329                 ret = map->owner.type  == prog_type &&
2330                       map->owner.jited == fp->jited &&
2331                       map->owner.xdp_has_frags == fp->aux->xdp_has_frags;
2332         }
2333         spin_unlock(&map->owner.lock);
2334
2335         return ret;
2336 }
2337
2338 static int bpf_check_tail_call(const struct bpf_prog *fp)
2339 {
2340         struct bpf_prog_aux *aux = fp->aux;
2341         int i, ret = 0;
2342
2343         mutex_lock(&aux->used_maps_mutex);
2344         for (i = 0; i < aux->used_map_cnt; i++) {
2345                 struct bpf_map *map = aux->used_maps[i];
2346
2347                 if (!map_type_contains_progs(map))
2348                         continue;
2349
2350                 if (!bpf_prog_map_compatible(map, fp)) {
2351                         ret = -EINVAL;
2352                         goto out;
2353                 }
2354         }
2355
2356 out:
2357         mutex_unlock(&aux->used_maps_mutex);
2358         return ret;
2359 }
2360
2361 static void bpf_prog_select_func(struct bpf_prog *fp)
2362 {
2363 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2364         u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2365
2366         fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2367 #else
2368         fp->bpf_func = __bpf_prog_ret0_warn;
2369 #endif
2370 }
2371
2372 /**
2373  *      bpf_prog_select_runtime - select exec runtime for BPF program
2374  *      @fp: bpf_prog populated with BPF program
2375  *      @err: pointer to error variable
2376  *
2377  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2378  * The BPF program will be executed via bpf_prog_run() function.
2379  *
2380  * Return: the &fp argument along with &err set to 0 for success or
2381  * a negative errno code on failure
2382  */
2383 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2384 {
2385         /* In case of BPF to BPF calls, verifier did all the prep
2386          * work with regards to JITing, etc.
2387          */
2388         bool jit_needed = false;
2389
2390         if (fp->bpf_func)
2391                 goto finalize;
2392
2393         if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2394             bpf_prog_has_kfunc_call(fp))
2395                 jit_needed = true;
2396
2397         bpf_prog_select_func(fp);
2398
2399         /* eBPF JITs can rewrite the program in case constant
2400          * blinding is active. However, in case of error during
2401          * blinding, bpf_int_jit_compile() must always return a
2402          * valid program, which in this case would simply not
2403          * be JITed, but falls back to the interpreter.
2404          */
2405         if (!bpf_prog_is_offloaded(fp->aux)) {
2406                 *err = bpf_prog_alloc_jited_linfo(fp);
2407                 if (*err)
2408                         return fp;
2409
2410                 fp = bpf_int_jit_compile(fp);
2411                 bpf_prog_jit_attempt_done(fp);
2412                 if (!fp->jited && jit_needed) {
2413                         *err = -ENOTSUPP;
2414                         return fp;
2415                 }
2416         } else {
2417                 *err = bpf_prog_offload_compile(fp);
2418                 if (*err)
2419                         return fp;
2420         }
2421
2422 finalize:
2423         *err = bpf_prog_lock_ro(fp);
2424         if (*err)
2425                 return fp;
2426
2427         /* The tail call compatibility check can only be done at
2428          * this late stage as we need to determine, if we deal
2429          * with JITed or non JITed program concatenations and not
2430          * all eBPF JITs might immediately support all features.
2431          */
2432         *err = bpf_check_tail_call(fp);
2433
2434         return fp;
2435 }
2436 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2437
2438 static unsigned int __bpf_prog_ret1(const void *ctx,
2439                                     const struct bpf_insn *insn)
2440 {
2441         return 1;
2442 }
2443
2444 static struct bpf_prog_dummy {
2445         struct bpf_prog prog;
2446 } dummy_bpf_prog = {
2447         .prog = {
2448                 .bpf_func = __bpf_prog_ret1,
2449         },
2450 };
2451
2452 struct bpf_empty_prog_array bpf_empty_prog_array = {
2453         .null_prog = NULL,
2454 };
2455 EXPORT_SYMBOL(bpf_empty_prog_array);
2456
2457 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2458 {
2459         struct bpf_prog_array *p;
2460
2461         if (prog_cnt)
2462                 p = kzalloc(struct_size(p, items, prog_cnt + 1), flags);
2463         else
2464                 p = &bpf_empty_prog_array.hdr;
2465
2466         return p;
2467 }
2468
2469 void bpf_prog_array_free(struct bpf_prog_array *progs)
2470 {
2471         if (!progs || progs == &bpf_empty_prog_array.hdr)
2472                 return;
2473         kfree_rcu(progs, rcu);
2474 }
2475
2476 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2477 {
2478         struct bpf_prog_array *progs;
2479
2480         /* If RCU Tasks Trace grace period implies RCU grace period, there is
2481          * no need to call kfree_rcu(), just call kfree() directly.
2482          */
2483         progs = container_of(rcu, struct bpf_prog_array, rcu);
2484         if (rcu_trace_implies_rcu_gp())
2485                 kfree(progs);
2486         else
2487                 kfree_rcu(progs, rcu);
2488 }
2489
2490 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2491 {
2492         if (!progs || progs == &bpf_empty_prog_array.hdr)
2493                 return;
2494         call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2495 }
2496
2497 int bpf_prog_array_length(struct bpf_prog_array *array)
2498 {
2499         struct bpf_prog_array_item *item;
2500         u32 cnt = 0;
2501
2502         for (item = array->items; item->prog; item++)
2503                 if (item->prog != &dummy_bpf_prog.prog)
2504                         cnt++;
2505         return cnt;
2506 }
2507
2508 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2509 {
2510         struct bpf_prog_array_item *item;
2511
2512         for (item = array->items; item->prog; item++)
2513                 if (item->prog != &dummy_bpf_prog.prog)
2514                         return false;
2515         return true;
2516 }
2517
2518 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2519                                      u32 *prog_ids,
2520                                      u32 request_cnt)
2521 {
2522         struct bpf_prog_array_item *item;
2523         int i = 0;
2524
2525         for (item = array->items; item->prog; item++) {
2526                 if (item->prog == &dummy_bpf_prog.prog)
2527                         continue;
2528                 prog_ids[i] = item->prog->aux->id;
2529                 if (++i == request_cnt) {
2530                         item++;
2531                         break;
2532                 }
2533         }
2534
2535         return !!(item->prog);
2536 }
2537
2538 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2539                                 __u32 __user *prog_ids, u32 cnt)
2540 {
2541         unsigned long err = 0;
2542         bool nospc;
2543         u32 *ids;
2544
2545         /* users of this function are doing:
2546          * cnt = bpf_prog_array_length();
2547          * if (cnt > 0)
2548          *     bpf_prog_array_copy_to_user(..., cnt);
2549          * so below kcalloc doesn't need extra cnt > 0 check.
2550          */
2551         ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2552         if (!ids)
2553                 return -ENOMEM;
2554         nospc = bpf_prog_array_copy_core(array, ids, cnt);
2555         err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2556         kfree(ids);
2557         if (err)
2558                 return -EFAULT;
2559         if (nospc)
2560                 return -ENOSPC;
2561         return 0;
2562 }
2563
2564 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2565                                 struct bpf_prog *old_prog)
2566 {
2567         struct bpf_prog_array_item *item;
2568
2569         for (item = array->items; item->prog; item++)
2570                 if (item->prog == old_prog) {
2571                         WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2572                         break;
2573                 }
2574 }
2575
2576 /**
2577  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2578  *                                   index into the program array with
2579  *                                   a dummy no-op program.
2580  * @array: a bpf_prog_array
2581  * @index: the index of the program to replace
2582  *
2583  * Skips over dummy programs, by not counting them, when calculating
2584  * the position of the program to replace.
2585  *
2586  * Return:
2587  * * 0          - Success
2588  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
2589  * * -ENOENT    - Index out of range
2590  */
2591 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2592 {
2593         return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2594 }
2595
2596 /**
2597  * bpf_prog_array_update_at() - Updates the program at the given index
2598  *                              into the program array.
2599  * @array: a bpf_prog_array
2600  * @index: the index of the program to update
2601  * @prog: the program to insert into the array
2602  *
2603  * Skips over dummy programs, by not counting them, when calculating
2604  * the position of the program to update.
2605  *
2606  * Return:
2607  * * 0          - Success
2608  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
2609  * * -ENOENT    - Index out of range
2610  */
2611 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2612                              struct bpf_prog *prog)
2613 {
2614         struct bpf_prog_array_item *item;
2615
2616         if (unlikely(index < 0))
2617                 return -EINVAL;
2618
2619         for (item = array->items; item->prog; item++) {
2620                 if (item->prog == &dummy_bpf_prog.prog)
2621                         continue;
2622                 if (!index) {
2623                         WRITE_ONCE(item->prog, prog);
2624                         return 0;
2625                 }
2626                 index--;
2627         }
2628         return -ENOENT;
2629 }
2630
2631 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2632                         struct bpf_prog *exclude_prog,
2633                         struct bpf_prog *include_prog,
2634                         u64 bpf_cookie,
2635                         struct bpf_prog_array **new_array)
2636 {
2637         int new_prog_cnt, carry_prog_cnt = 0;
2638         struct bpf_prog_array_item *existing, *new;
2639         struct bpf_prog_array *array;
2640         bool found_exclude = false;
2641
2642         /* Figure out how many existing progs we need to carry over to
2643          * the new array.
2644          */
2645         if (old_array) {
2646                 existing = old_array->items;
2647                 for (; existing->prog; existing++) {
2648                         if (existing->prog == exclude_prog) {
2649                                 found_exclude = true;
2650                                 continue;
2651                         }
2652                         if (existing->prog != &dummy_bpf_prog.prog)
2653                                 carry_prog_cnt++;
2654                         if (existing->prog == include_prog)
2655                                 return -EEXIST;
2656                 }
2657         }
2658
2659         if (exclude_prog && !found_exclude)
2660                 return -ENOENT;
2661
2662         /* How many progs (not NULL) will be in the new array? */
2663         new_prog_cnt = carry_prog_cnt;
2664         if (include_prog)
2665                 new_prog_cnt += 1;
2666
2667         /* Do we have any prog (not NULL) in the new array? */
2668         if (!new_prog_cnt) {
2669                 *new_array = NULL;
2670                 return 0;
2671         }
2672
2673         /* +1 as the end of prog_array is marked with NULL */
2674         array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2675         if (!array)
2676                 return -ENOMEM;
2677         new = array->items;
2678
2679         /* Fill in the new prog array */
2680         if (carry_prog_cnt) {
2681                 existing = old_array->items;
2682                 for (; existing->prog; existing++) {
2683                         if (existing->prog == exclude_prog ||
2684                             existing->prog == &dummy_bpf_prog.prog)
2685                                 continue;
2686
2687                         new->prog = existing->prog;
2688                         new->bpf_cookie = existing->bpf_cookie;
2689                         new++;
2690                 }
2691         }
2692         if (include_prog) {
2693                 new->prog = include_prog;
2694                 new->bpf_cookie = bpf_cookie;
2695                 new++;
2696         }
2697         new->prog = NULL;
2698         *new_array = array;
2699         return 0;
2700 }
2701
2702 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2703                              u32 *prog_ids, u32 request_cnt,
2704                              u32 *prog_cnt)
2705 {
2706         u32 cnt = 0;
2707
2708         if (array)
2709                 cnt = bpf_prog_array_length(array);
2710
2711         *prog_cnt = cnt;
2712
2713         /* return early if user requested only program count or nothing to copy */
2714         if (!request_cnt || !cnt)
2715                 return 0;
2716
2717         /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2718         return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2719                                                                      : 0;
2720 }
2721
2722 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2723                           struct bpf_map **used_maps, u32 len)
2724 {
2725         struct bpf_map *map;
2726         bool sleepable;
2727         u32 i;
2728
2729         sleepable = aux->prog->sleepable;
2730         for (i = 0; i < len; i++) {
2731                 map = used_maps[i];
2732                 if (map->ops->map_poke_untrack)
2733                         map->ops->map_poke_untrack(map, aux);
2734                 if (sleepable)
2735                         atomic64_dec(&map->sleepable_refcnt);
2736                 bpf_map_put(map);
2737         }
2738 }
2739
2740 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2741 {
2742         __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2743         kfree(aux->used_maps);
2744 }
2745
2746 void __bpf_free_used_btfs(struct bpf_prog_aux *aux,
2747                           struct btf_mod_pair *used_btfs, u32 len)
2748 {
2749 #ifdef CONFIG_BPF_SYSCALL
2750         struct btf_mod_pair *btf_mod;
2751         u32 i;
2752
2753         for (i = 0; i < len; i++) {
2754                 btf_mod = &used_btfs[i];
2755                 if (btf_mod->module)
2756                         module_put(btf_mod->module);
2757                 btf_put(btf_mod->btf);
2758         }
2759 #endif
2760 }
2761
2762 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2763 {
2764         __bpf_free_used_btfs(aux, aux->used_btfs, aux->used_btf_cnt);
2765         kfree(aux->used_btfs);
2766 }
2767
2768 static void bpf_prog_free_deferred(struct work_struct *work)
2769 {
2770         struct bpf_prog_aux *aux;
2771         int i;
2772
2773         aux = container_of(work, struct bpf_prog_aux, work);
2774 #ifdef CONFIG_BPF_SYSCALL
2775         bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2776 #endif
2777 #ifdef CONFIG_CGROUP_BPF
2778         if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2779                 bpf_cgroup_atype_put(aux->cgroup_atype);
2780 #endif
2781         bpf_free_used_maps(aux);
2782         bpf_free_used_btfs(aux);
2783         if (bpf_prog_is_dev_bound(aux))
2784                 bpf_prog_dev_bound_destroy(aux->prog);
2785 #ifdef CONFIG_PERF_EVENTS
2786         if (aux->prog->has_callchain_buf)
2787                 put_callchain_buffers();
2788 #endif
2789         if (aux->dst_trampoline)
2790                 bpf_trampoline_put(aux->dst_trampoline);
2791         for (i = 0; i < aux->real_func_cnt; i++) {
2792                 /* We can just unlink the subprog poke descriptor table as
2793                  * it was originally linked to the main program and is also
2794                  * released along with it.
2795                  */
2796                 aux->func[i]->aux->poke_tab = NULL;
2797                 bpf_jit_free(aux->func[i]);
2798         }
2799         if (aux->real_func_cnt) {
2800                 kfree(aux->func);
2801                 bpf_prog_unlock_free(aux->prog);
2802         } else {
2803                 bpf_jit_free(aux->prog);
2804         }
2805 }
2806
2807 void bpf_prog_free(struct bpf_prog *fp)
2808 {
2809         struct bpf_prog_aux *aux = fp->aux;
2810
2811         if (aux->dst_prog)
2812                 bpf_prog_put(aux->dst_prog);
2813         bpf_token_put(aux->token);
2814         INIT_WORK(&aux->work, bpf_prog_free_deferred);
2815         schedule_work(&aux->work);
2816 }
2817 EXPORT_SYMBOL_GPL(bpf_prog_free);
2818
2819 /* RNG for unprivileged user space with separated state from prandom_u32(). */
2820 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2821
2822 void bpf_user_rnd_init_once(void)
2823 {
2824         prandom_init_once(&bpf_user_rnd_state);
2825 }
2826
2827 BPF_CALL_0(bpf_user_rnd_u32)
2828 {
2829         /* Should someone ever have the rather unwise idea to use some
2830          * of the registers passed into this function, then note that
2831          * this function is called from native eBPF and classic-to-eBPF
2832          * transformations. Register assignments from both sides are
2833          * different, f.e. classic always sets fn(ctx, A, X) here.
2834          */
2835         struct rnd_state *state;
2836         u32 res;
2837
2838         state = &get_cpu_var(bpf_user_rnd_state);
2839         res = prandom_u32_state(state);
2840         put_cpu_var(bpf_user_rnd_state);
2841
2842         return res;
2843 }
2844
2845 BPF_CALL_0(bpf_get_raw_cpu_id)
2846 {
2847         return raw_smp_processor_id();
2848 }
2849
2850 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2851 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2852 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2853 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2854 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2855 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2856 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2857 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2858 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2859 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2860 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2861
2862 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2863 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2864 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2865 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2866 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2867 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2868 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2869
2870 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2871 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2872 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2873 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2874 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2875 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2876 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2877 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2878 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2879 const struct bpf_func_proto bpf_set_retval_proto __weak;
2880 const struct bpf_func_proto bpf_get_retval_proto __weak;
2881
2882 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2883 {
2884         return NULL;
2885 }
2886
2887 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2888 {
2889         return NULL;
2890 }
2891
2892 u64 __weak
2893 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2894                  void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2895 {
2896         return -ENOTSUPP;
2897 }
2898 EXPORT_SYMBOL_GPL(bpf_event_output);
2899
2900 /* Always built-in helper functions. */
2901 const struct bpf_func_proto bpf_tail_call_proto = {
2902         .func           = NULL,
2903         .gpl_only       = false,
2904         .ret_type       = RET_VOID,
2905         .arg1_type      = ARG_PTR_TO_CTX,
2906         .arg2_type      = ARG_CONST_MAP_PTR,
2907         .arg3_type      = ARG_ANYTHING,
2908 };
2909
2910 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2911  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2912  * eBPF and implicitly also cBPF can get JITed!
2913  */
2914 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2915 {
2916         return prog;
2917 }
2918
2919 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2920  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2921  */
2922 void __weak bpf_jit_compile(struct bpf_prog *prog)
2923 {
2924 }
2925
2926 bool __weak bpf_helper_changes_pkt_data(void *func)
2927 {
2928         return false;
2929 }
2930
2931 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2932  * analysis code and wants explicit zero extension inserted by verifier.
2933  * Otherwise, return FALSE.
2934  *
2935  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2936  * you don't override this. JITs that don't want these extra insns can detect
2937  * them using insn_is_zext.
2938  */
2939 bool __weak bpf_jit_needs_zext(void)
2940 {
2941         return false;
2942 }
2943
2944 /* Return true if the JIT inlines the call to the helper corresponding to
2945  * the imm.
2946  *
2947  * The verifier will not patch the insn->imm for the call to the helper if
2948  * this returns true.
2949  */
2950 bool __weak bpf_jit_inlines_helper_call(s32 imm)
2951 {
2952         return false;
2953 }
2954
2955 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2956 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2957 {
2958         return false;
2959 }
2960
2961 bool __weak bpf_jit_supports_percpu_insn(void)
2962 {
2963         return false;
2964 }
2965
2966 bool __weak bpf_jit_supports_kfunc_call(void)
2967 {
2968         return false;
2969 }
2970
2971 bool __weak bpf_jit_supports_far_kfunc_call(void)
2972 {
2973         return false;
2974 }
2975
2976 bool __weak bpf_jit_supports_arena(void)
2977 {
2978         return false;
2979 }
2980
2981 bool __weak bpf_jit_supports_insn(struct bpf_insn *insn, bool in_arena)
2982 {
2983         return false;
2984 }
2985
2986 u64 __weak bpf_arch_uaddress_limit(void)
2987 {
2988 #if defined(CONFIG_64BIT) && defined(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE)
2989         return TASK_SIZE;
2990 #else
2991         return 0;
2992 #endif
2993 }
2994
2995 /* Return TRUE if the JIT backend satisfies the following two conditions:
2996  * 1) JIT backend supports atomic_xchg() on pointer-sized words.
2997  * 2) Under the specific arch, the implementation of xchg() is the same
2998  *    as atomic_xchg() on pointer-sized words.
2999  */
3000 bool __weak bpf_jit_supports_ptr_xchg(void)
3001 {
3002         return false;
3003 }
3004
3005 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
3006  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
3007  */
3008 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
3009                          int len)
3010 {
3011         return -EFAULT;
3012 }
3013
3014 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
3015                               void *addr1, void *addr2)
3016 {
3017         return -ENOTSUPP;
3018 }
3019
3020 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
3021 {
3022         return ERR_PTR(-ENOTSUPP);
3023 }
3024
3025 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
3026 {
3027         return -ENOTSUPP;
3028 }
3029
3030 bool __weak bpf_jit_supports_exceptions(void)
3031 {
3032         return false;
3033 }
3034
3035 void __weak arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), void *cookie)
3036 {
3037 }
3038
3039 /* for configs without MMU or 32-bit */
3040 __weak const struct bpf_map_ops arena_map_ops;
3041 __weak u64 bpf_arena_get_user_vm_start(struct bpf_arena *arena)
3042 {
3043         return 0;
3044 }
3045 __weak u64 bpf_arena_get_kern_vm_start(struct bpf_arena *arena)
3046 {
3047         return 0;
3048 }
3049
3050 #ifdef CONFIG_BPF_SYSCALL
3051 static int __init bpf_global_ma_init(void)
3052 {
3053         int ret;
3054
3055         ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
3056         bpf_global_ma_set = !ret;
3057         return ret;
3058 }
3059 late_initcall(bpf_global_ma_init);
3060 #endif
3061
3062 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
3063 EXPORT_SYMBOL(bpf_stats_enabled_key);
3064
3065 /* All definitions of tracepoints related to BPF. */
3066 #define CREATE_TRACE_POINTS
3067 #include <linux/bpf_trace.h>
3068
3069 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
3070 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);