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/prandom.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 <linux/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->ext_mutex);
 135         mutex_init(&fp->aux->dst_mutex);
 136
 137         return fp;
 138 }
 139
 140 struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
 141 {
 142         gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
 143         struct bpf_prog *prog;
 144         int cpu;
 145
 146         prog = bpf_prog_alloc_no_stats(size, gfp_extra_flags);
 147         if (!prog)
 148                 return NULL;
 149
 150         prog->stats = alloc_percpu_gfp(struct bpf_prog_stats, gfp_flags);
 151         if (!prog->stats) {
 152                 free_percpu(prog->active);
 153                 kfree(prog->aux);
 154                 vfree(prog);
 155                 return NULL;
 156         }
 157
 158         for_each_possible_cpu(cpu) {
 159                 struct bpf_prog_stats *pstats;
 160
 161                 pstats = per_cpu_ptr(prog->stats, cpu);
 162                 u64_stats_init(&pstats->syncp);
 163         }
 164         return prog;
 165 }
 166 EXPORT_SYMBOL_GPL(bpf_prog_alloc);
 167
 168 int bpf_prog_alloc_jited_linfo(struct bpf_prog *prog)
 169 {
 170         if (!prog->aux->nr_linfo || !prog->jit_requested)
 171                 return 0;
 172
 173         prog->aux->jited_linfo = kvcalloc(prog->aux->nr_linfo,
 174                                           sizeof(*prog->aux->jited_linfo),
 175                                           bpf_memcg_flags(GFP_KERNEL | __GFP_NOWARN));
 176         if (!prog->aux->jited_linfo)
 177                 return -ENOMEM;
 178
 179         return 0;
 180 }
 181
 182 void bpf_prog_jit_attempt_done(struct bpf_prog *prog)
 183 {
 184         if (prog->aux->jited_linfo &&
 185             (!prog->jited || !prog->aux->jited_linfo[0])) {
 186                 kvfree(prog->aux->jited_linfo);
 187                 prog->aux->jited_linfo = NULL;
 188         }
 189
 190         kfree(prog->aux->kfunc_tab);
 191         prog->aux->kfunc_tab = NULL;
 192 }
 193
 194 /* The jit engine is responsible to provide an array
 195  * for insn_off to the jited_off mapping (insn_to_jit_off).
 196  *
 197  * The idx to this array is the insn_off.  Hence, the insn_off
 198  * here is relative to the prog itself instead of the main prog.
 199  * This array has one entry for each xlated bpf insn.
 200  *
 201  * jited_off is the byte off to the end of the jited insn.
 202  *
 203  * Hence, with
 204  * insn_start:
 205  *      The first bpf insn off of the prog.  The insn off
 206  *      here is relative to the main prog.
 207  *      e.g. if prog is a subprog, insn_start > 0
 208  * linfo_idx:
 209  *      The prog's idx to prog->aux->linfo and jited_linfo
 210  *
 211  * jited_linfo[linfo_idx] = prog->bpf_func
 212  *
 213  * For i > linfo_idx,
 214  *
 215  * jited_linfo[i] = prog->bpf_func +
 216  *      insn_to_jit_off[linfo[i].insn_off - insn_start - 1]
 217  */
 218 void bpf_prog_fill_jited_linfo(struct bpf_prog *prog,
 219                                const u32 *insn_to_jit_off)
 220 {
 221         u32 linfo_idx, insn_start, insn_end, nr_linfo, i;
 222         const struct bpf_line_info *linfo;
 223         void **jited_linfo;
 224
 225         if (!prog->aux->jited_linfo || prog->aux->func_idx > prog->aux->func_cnt)
 226                 /* Userspace did not provide linfo */
 227                 return;
 228
 229         linfo_idx = prog->aux->linfo_idx;
 230         linfo = &prog->aux->linfo[linfo_idx];
 231         insn_start = linfo[0].insn_off;
 232         insn_end = insn_start + prog->len;
 233
 234         jited_linfo = &prog->aux->jited_linfo[linfo_idx];
 235         jited_linfo[0] = prog->bpf_func;
 236
 237         nr_linfo = prog->aux->nr_linfo - linfo_idx;
 238
 239         for (i = 1; i < nr_linfo && linfo[i].insn_off < insn_end; i++)
 240                 /* The verifier ensures that linfo[i].insn_off is
 241                  * strictly increasing
 242                  */
 243                 jited_linfo[i] = prog->bpf_func +
 244                         insn_to_jit_off[linfo[i].insn_off - insn_start - 1];
 245 }
 246
 247 struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 248                                   gfp_t gfp_extra_flags)
 249 {
 250         gfp_t gfp_flags = bpf_memcg_flags(GFP_KERNEL | __GFP_ZERO | gfp_extra_flags);
 251         struct bpf_prog *fp;
 252         u32 pages;
 253
 254         size = round_up(size, PAGE_SIZE);
 255         pages = size / PAGE_SIZE;
 256         if (pages <= fp_old->pages)
 257                 return fp_old;
 258
 259         fp = __vmalloc(size, gfp_flags);
 260         if (fp) {
 261                 memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
 262                 fp->pages = pages;
 263                 fp->aux->prog = fp;
 264
 265                 /* We keep fp->aux from fp_old around in the new
 266                  * reallocated structure.
 267                  */
 268                 fp_old->aux = NULL;
 269                 fp_old->stats = NULL;
 270                 fp_old->active = NULL;
 271                 __bpf_prog_free(fp_old);
 272         }
 273
 274         return fp;
 275 }
 276
 277 void __bpf_prog_free(struct bpf_prog *fp)
 278 {
 279         if (fp->aux) {
 280                 mutex_destroy(&fp->aux->used_maps_mutex);
 281                 mutex_destroy(&fp->aux->dst_mutex);
 282                 kfree(fp->aux->poke_tab);
 283                 kfree(fp->aux);
 284         }
 285         free_percpu(fp->stats);
 286         free_percpu(fp->active);
 287         vfree(fp);
 288 }
 289
 290 int bpf_prog_calc_tag(struct bpf_prog *fp)
 291 {
 292         const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
 293         u32 raw_size = bpf_prog_tag_scratch_size(fp);
 294         u32 digest[SHA1_DIGEST_WORDS];
 295         u32 ws[SHA1_WORKSPACE_WORDS];
 296         u32 i, bsize, psize, blocks;
 297         struct bpf_insn *dst;
 298         bool was_ld_map;
 299         u8 *raw, *todo;
 300         __be32 *result;
 301         __be64 *bits;
 302
 303         raw = vmalloc(raw_size);
 304         if (!raw)
 305                 return -ENOMEM;
 306
 307         sha1_init(digest);
 308         memset(ws, 0, sizeof(ws));
 309
 310         /* We need to take out the map fd for the digest calculation
 311          * since they are unstable from user space side.
 312          */
 313         dst = (void *)raw;
 314         for (i = 0, was_ld_map = false; i < fp->len; i++) {
 315                 dst[i] = fp->insnsi[i];
 316                 if (!was_ld_map &&
 317                     dst[i].code == (BPF_LD | BPF_IMM | BPF_DW) &&
 318                     (dst[i].src_reg == BPF_PSEUDO_MAP_FD ||
 319                      dst[i].src_reg == BPF_PSEUDO_MAP_VALUE)) {
 320                         was_ld_map = true;
 321                         dst[i].imm = 0;
 322                 } else if (was_ld_map &&
 323                            dst[i].code == 0 &&
 324                            dst[i].dst_reg == 0 &&
 325                            dst[i].src_reg == 0 &&
 326                            dst[i].off == 0) {
 327                         was_ld_map = false;
 328                         dst[i].imm = 0;
 329                 } else {
 330                         was_ld_map = false;
 331                 }
 332         }
 333
 334         psize = bpf_prog_insn_size(fp);
 335         memset(&raw[psize], 0, raw_size - psize);
 336         raw[psize++] = 0x80;
 337
 338         bsize  = round_up(psize, SHA1_BLOCK_SIZE);
 339         blocks = bsize / SHA1_BLOCK_SIZE;
 340         todo   = raw;
 341         if (bsize - psize >= sizeof(__be64)) {
 342                 bits = (__be64 *)(todo + bsize - sizeof(__be64));
 343         } else {
 344                 bits = (__be64 *)(todo + bsize + bits_offset);
 345                 blocks++;
 346         }
 347         *bits = cpu_to_be64((psize - 1) << 3);
 348
 349         while (blocks--) {
 350                 sha1_transform(digest, todo, ws);
 351                 todo += SHA1_BLOCK_SIZE;
 352         }
 353
 354         result = (__force __be32 *)digest;
 355         for (i = 0; i < SHA1_DIGEST_WORDS; i++)
 356                 result[i] = cpu_to_be32(digest[i]);
 357         memcpy(fp->tag, result, sizeof(fp->tag));
 358
 359         vfree(raw);
 360         return 0;
 361 }
 362
 363 static int bpf_adj_delta_to_imm(struct bpf_insn *insn, u32 pos, s32 end_old,
 364                                 s32 end_new, s32 curr, const bool probe_pass)
 365 {
 366         const s64 imm_min = S32_MIN, imm_max = S32_MAX;
 367         s32 delta = end_new - end_old;
 368         s64 imm = insn->imm;
 369
 370         if (curr < pos && curr + imm + 1 >= end_old)
 371                 imm += delta;
 372         else if (curr >= end_new && curr + imm + 1 < end_new)
 373                 imm -= delta;
 374         if (imm < imm_min || imm > imm_max)
 375                 return -ERANGE;
 376         if (!probe_pass)
 377                 insn->imm = imm;
 378         return 0;
 379 }
 380
 381 static int bpf_adj_delta_to_off(struct bpf_insn *insn, u32 pos, s32 end_old,
 382                                 s32 end_new, s32 curr, const bool probe_pass)
 383 {
 384         s64 off_min, off_max, off;
 385         s32 delta = end_new - end_old;
 386
 387         if (insn->code == (BPF_JMP32 | BPF_JA)) {
 388                 off = insn->imm;
 389                 off_min = S32_MIN;
 390                 off_max = S32_MAX;
 391         } else {
 392                 off = insn->off;
 393                 off_min = S16_MIN;
 394                 off_max = S16_MAX;
 395         }
 396
 397         if (curr < pos && curr + off + 1 >= end_old)
 398                 off += delta;
 399         else if (curr >= end_new && curr + off + 1 < end_new)
 400                 off -= delta;
 401         if (off < off_min || off > off_max)
 402                 return -ERANGE;
 403         if (!probe_pass) {
 404                 if (insn->code == (BPF_JMP32 | BPF_JA))
 405                         insn->imm = off;
 406                 else
 407                         insn->off = off;
 408         }
 409         return 0;
 410 }
 411
 412 static int bpf_adj_branches(struct bpf_prog *prog, u32 pos, s32 end_old,
 413                             s32 end_new, const bool probe_pass)
 414 {
 415         u32 i, insn_cnt = prog->len + (probe_pass ? end_new - end_old : 0);
 416         struct bpf_insn *insn = prog->insnsi;
 417         int ret = 0;
 418
 419         for (i = 0; i < insn_cnt; i++, insn++) {
 420                 u8 code;
 421
 422                 /* In the probing pass we still operate on the original,
 423                  * unpatched image in order to check overflows before we
 424                  * do any other adjustments. Therefore skip the patchlet.
 425                  */
 426                 if (probe_pass && i == pos) {
 427                         i = end_new;
 428                         insn = prog->insnsi + end_old;
 429                 }
 430                 if (bpf_pseudo_func(insn)) {
 431                         ret = bpf_adj_delta_to_imm(insn, pos, end_old,
 432                                                    end_new, i, probe_pass);
 433                         if (ret)
 434                                 return ret;
 435                         continue;
 436                 }
 437                 code = insn->code;
 438                 if ((BPF_CLASS(code) != BPF_JMP &&
 439                      BPF_CLASS(code) != BPF_JMP32) ||
 440                     BPF_OP(code) == BPF_EXIT)
 441                         continue;
 442                 /* Adjust offset of jmps if we cross patch boundaries. */
 443                 if (BPF_OP(code) == BPF_CALL) {
 444                         if (insn->src_reg != BPF_PSEUDO_CALL)
 445                                 continue;
 446                         ret = bpf_adj_delta_to_imm(insn, pos, end_old,
 447                                                    end_new, i, probe_pass);
 448                 } else {
 449                         ret = bpf_adj_delta_to_off(insn, pos, end_old,
 450                                                    end_new, i, probe_pass);
 451                 }
 452                 if (ret)
 453                         break;
 454         }
 455
 456         return ret;
 457 }
 458
 459 static void bpf_adj_linfo(struct bpf_prog *prog, u32 off, u32 delta)
 460 {
 461         struct bpf_line_info *linfo;
 462         u32 i, nr_linfo;
 463
 464         nr_linfo = prog->aux->nr_linfo;
 465         if (!nr_linfo || !delta)
 466                 return;
 467
 468         linfo = prog->aux->linfo;
 469
 470         for (i = 0; i < nr_linfo; i++)
 471                 if (off < linfo[i].insn_off)
 472                         break;
 473
 474         /* Push all off < linfo[i].insn_off by delta */
 475         for (; i < nr_linfo; i++)
 476                 linfo[i].insn_off += delta;
 477 }
 478
 479 struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off,
 480                                        const struct bpf_insn *patch, u32 len)
 481 {
 482         u32 insn_adj_cnt, insn_rest, insn_delta = len - 1;
 483         const u32 cnt_max = S16_MAX;
 484         struct bpf_prog *prog_adj;
 485         int err;
 486
 487         /* Since our patchlet doesn't expand the image, we're done. */
 488         if (insn_delta == 0) {
 489                 memcpy(prog->insnsi + off, patch, sizeof(*patch));
 490                 return prog;
 491         }
 492
 493         insn_adj_cnt = prog->len + insn_delta;
 494
 495         /* Reject anything that would potentially let the insn->off
 496          * target overflow when we have excessive program expansions.
 497          * We need to probe here before we do any reallocation where
 498          * we afterwards may not fail anymore.
 499          */
 500         if (insn_adj_cnt > cnt_max &&
 501             (err = bpf_adj_branches(prog, off, off + 1, off + len, true)))
 502                 return ERR_PTR(err);
 503
 504         /* Several new instructions need to be inserted. Make room
 505          * for them. Likely, there's no need for a new allocation as
 506          * last page could have large enough tailroom.
 507          */
 508         prog_adj = bpf_prog_realloc(prog, bpf_prog_size(insn_adj_cnt),
 509                                     GFP_USER);
 510         if (!prog_adj)
 511                 return ERR_PTR(-ENOMEM);
 512
 513         prog_adj->len = insn_adj_cnt;
 514
 515         /* Patching happens in 3 steps:
 516          *
 517          * 1) Move over tail of insnsi from next instruction onwards,
 518          *    so we can patch the single target insn with one or more
 519          *    new ones (patching is always from 1 to n insns, n > 0).
 520          * 2) Inject new instructions at the target location.
 521          * 3) Adjust branch offsets if necessary.
 522          */
 523         insn_rest = insn_adj_cnt - off - len;
 524
 525         memmove(prog_adj->insnsi + off + len, prog_adj->insnsi + off + 1,
 526                 sizeof(*patch) * insn_rest);
 527         memcpy(prog_adj->insnsi + off, patch, sizeof(*patch) * len);
 528
 529         /* We are guaranteed to not fail at this point, otherwise
 530          * the ship has sailed to reverse to the original state. An
 531          * overflow cannot happen at this point.
 532          */
 533         BUG_ON(bpf_adj_branches(prog_adj, off, off + 1, off + len, false));
 534
 535         bpf_adj_linfo(prog_adj, off, insn_delta);
 536
 537         return prog_adj;
 538 }
 539
 540 int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt)
 541 {
 542         int err;
 543
 544         /* Branch offsets can't overflow when program is shrinking, no need
 545          * to call bpf_adj_branches(..., true) here
 546          */
 547         memmove(prog->insnsi + off, prog->insnsi + off + cnt,
 548                 sizeof(struct bpf_insn) * (prog->len - off - cnt));
 549         prog->len -= cnt;
 550
 551         err = bpf_adj_branches(prog, off, off + cnt, off, false);
 552         WARN_ON_ONCE(err);
 553         return err;
 554 }
 555
 556 static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp)
 557 {
 558         int i;
 559
 560         for (i = 0; i < fp->aux->real_func_cnt; i++)
 561                 bpf_prog_kallsyms_del(fp->aux->func[i]);
 562 }
 563
 564 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
 565 {
 566         bpf_prog_kallsyms_del_subprogs(fp);
 567         bpf_prog_kallsyms_del(fp);
 568 }
 569
 570 #ifdef CONFIG_BPF_JIT
 571 /* All BPF JIT sysctl knobs here. */
 572 int bpf_jit_enable   __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
 573 int bpf_jit_kallsyms __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_DEFAULT_ON);
 574 int bpf_jit_harden   __read_mostly;
 575 long bpf_jit_limit   __read_mostly;
 576 long bpf_jit_limit_max __read_mostly;
 577
 578 static void
 579 bpf_prog_ksym_set_addr(struct bpf_prog *prog)
 580 {
 581         WARN_ON_ONCE(!bpf_prog_ebpf_jited(prog));
 582
 583         prog->aux->ksym.start = (unsigned long) prog->bpf_func;
 584         prog->aux->ksym.end   = prog->aux->ksym.start + prog->jited_len;
 585 }
 586
 587 static void
 588 bpf_prog_ksym_set_name(struct bpf_prog *prog)
 589 {
 590         char *sym = prog->aux->ksym.name;
 591         const char *end = sym + KSYM_NAME_LEN;
 592         const struct btf_type *type;
 593         const char *func_name;
 594
 595         BUILD_BUG_ON(sizeof("bpf_prog_") +
 596                      sizeof(prog->tag) * 2 +
 597                      /* name has been null terminated.
 598                       * We should need +1 for the '_' preceding
 599                       * the name.  However, the null character
 600                       * is double counted between the name and the
 601                       * sizeof("bpf_prog_") above, so we omit
 602                       * the +1 here.
 603                       */
 604                      sizeof(prog->aux->name) > KSYM_NAME_LEN);
 605
 606         sym += snprintf(sym, KSYM_NAME_LEN, "bpf_prog_");
 607         sym  = bin2hex(sym, prog->tag, sizeof(prog->tag));
 608
 609         /* prog->aux->name will be ignored if full btf name is available */
 610         if (prog->aux->func_info_cnt && prog->aux->func_idx < prog->aux->func_info_cnt) {
 611                 type = btf_type_by_id(prog->aux->btf,
 612                                       prog->aux->func_info[prog->aux->func_idx].type_id);
 613                 func_name = btf_name_by_offset(prog->aux->btf, type->name_off);
 614                 snprintf(sym, (size_t)(end - sym), "_%s", func_name);
 615                 return;
 616         }
 617
 618         if (prog->aux->name[0])
 619                 snprintf(sym, (size_t)(end - sym), "_%s", prog->aux->name);
 620         else
 621                 *sym = 0;
 622 }
 623
 624 static unsigned long bpf_get_ksym_start(struct latch_tree_node *n)
 625 {
 626         return container_of(n, struct bpf_ksym, tnode)->start;
 627 }
 628
 629 static __always_inline bool bpf_tree_less(struct latch_tree_node *a,
 630                                           struct latch_tree_node *b)
 631 {
 632         return bpf_get_ksym_start(a) < bpf_get_ksym_start(b);
 633 }
 634
 635 static __always_inline int bpf_tree_comp(void *key, struct latch_tree_node *n)
 636 {
 637         unsigned long val = (unsigned long)key;
 638         const struct bpf_ksym *ksym;
 639
 640         ksym = container_of(n, struct bpf_ksym, tnode);
 641
 642         if (val < ksym->start)
 643                 return -1;
 644         /* Ensure that we detect return addresses as part of the program, when
 645          * the final instruction is a call for a program part of the stack
 646          * trace. Therefore, do val > ksym->end instead of val >= ksym->end.
 647          */
 648         if (val > ksym->end)
 649                 return  1;
 650
 651         return 0;
 652 }
 653
 654 static const struct latch_tree_ops bpf_tree_ops = {
 655         .less   = bpf_tree_less,
 656         .comp   = bpf_tree_comp,
 657 };
 658
 659 static DEFINE_SPINLOCK(bpf_lock);
 660 static LIST_HEAD(bpf_kallsyms);
 661 static struct latch_tree_root bpf_tree __cacheline_aligned;
 662
 663 void bpf_ksym_add(struct bpf_ksym *ksym)
 664 {
 665         spin_lock_bh(&bpf_lock);
 666         WARN_ON_ONCE(!list_empty(&ksym->lnode));
 667         list_add_tail_rcu(&ksym->lnode, &bpf_kallsyms);
 668         latch_tree_insert(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
 669         spin_unlock_bh(&bpf_lock);
 670 }
 671
 672 static void __bpf_ksym_del(struct bpf_ksym *ksym)
 673 {
 674         if (list_empty(&ksym->lnode))
 675                 return;
 676
 677         latch_tree_erase(&ksym->tnode, &bpf_tree, &bpf_tree_ops);
 678         list_del_rcu(&ksym->lnode);
 679 }
 680
 681 void bpf_ksym_del(struct bpf_ksym *ksym)
 682 {
 683         spin_lock_bh(&bpf_lock);
 684         __bpf_ksym_del(ksym);
 685         spin_unlock_bh(&bpf_lock);
 686 }
 687
 688 static bool bpf_prog_kallsyms_candidate(const struct bpf_prog *fp)
 689 {
 690         return fp->jited && !bpf_prog_was_classic(fp);
 691 }
 692
 693 void bpf_prog_kallsyms_add(struct bpf_prog *fp)
 694 {
 695         if (!bpf_prog_kallsyms_candidate(fp) ||
 696             !bpf_token_capable(fp->aux->token, CAP_BPF))
 697                 return;
 698
 699         bpf_prog_ksym_set_addr(fp);
 700         bpf_prog_ksym_set_name(fp);
 701         fp->aux->ksym.prog = true;
 702
 703         bpf_ksym_add(&fp->aux->ksym);
 704
 705 #ifdef CONFIG_FINEIBT
 706         /*
 707          * When FineIBT, code in the __cfi_foo() symbols can get executed
 708          * and hence unwinder needs help.
 709          */
 710         if (cfi_mode != CFI_FINEIBT)
 711                 return;
 712
 713         snprintf(fp->aux->ksym_prefix.name, KSYM_NAME_LEN,
 714                  "__cfi_%s", fp->aux->ksym.name);
 715
 716         fp->aux->ksym_prefix.start = (unsigned long) fp->bpf_func - 16;
 717         fp->aux->ksym_prefix.end   = (unsigned long) fp->bpf_func;
 718
 719         bpf_ksym_add(&fp->aux->ksym_prefix);
 720 #endif
 721 }
 722
 723 void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 724 {
 725         if (!bpf_prog_kallsyms_candidate(fp))
 726                 return;
 727
 728         bpf_ksym_del(&fp->aux->ksym);
 729 #ifdef CONFIG_FINEIBT
 730         if (cfi_mode != CFI_FINEIBT)
 731                 return;
 732         bpf_ksym_del(&fp->aux->ksym_prefix);
 733 #endif
 734 }
 735
 736 static struct bpf_ksym *bpf_ksym_find(unsigned long addr)
 737 {
 738         struct latch_tree_node *n;
 739
 740         n = latch_tree_find((void *)addr, &bpf_tree, &bpf_tree_ops);
 741         return n ? container_of(n, struct bpf_ksym, tnode) : NULL;
 742 }
 743
 744 int __bpf_address_lookup(unsigned long addr, unsigned long *size,
 745                                  unsigned long *off, char *sym)
 746 {
 747         struct bpf_ksym *ksym;
 748         int ret = 0;
 749
 750         rcu_read_lock();
 751         ksym = bpf_ksym_find(addr);
 752         if (ksym) {
 753                 unsigned long symbol_start = ksym->start;
 754                 unsigned long symbol_end = ksym->end;
 755
 756                 ret = strscpy(sym, ksym->name, KSYM_NAME_LEN);
 757
 758                 if (size)
 759                         *size = symbol_end - symbol_start;
 760                 if (off)
 761                         *off  = addr - symbol_start;
 762         }
 763         rcu_read_unlock();
 764
 765         return ret;
 766 }
 767
 768 bool is_bpf_text_address(unsigned long addr)
 769 {
 770         bool ret;
 771
 772         rcu_read_lock();
 773         ret = bpf_ksym_find(addr) != NULL;
 774         rcu_read_unlock();
 775
 776         return ret;
 777 }
 778
 779 struct bpf_prog *bpf_prog_ksym_find(unsigned long addr)
 780 {
 781         struct bpf_ksym *ksym = bpf_ksym_find(addr);
 782
 783         return ksym && ksym->prog ?
 784                container_of(ksym, struct bpf_prog_aux, ksym)->prog :
 785                NULL;
 786 }
 787
 788 const struct exception_table_entry *search_bpf_extables(unsigned long addr)
 789 {
 790         const struct exception_table_entry *e = NULL;
 791         struct bpf_prog *prog;
 792
 793         rcu_read_lock();
 794         prog = bpf_prog_ksym_find(addr);
 795         if (!prog)
 796                 goto out;
 797         if (!prog->aux->num_exentries)
 798                 goto out;
 799
 800         e = search_extable(prog->aux->extable, prog->aux->num_exentries, addr);
 801 out:
 802         rcu_read_unlock();
 803         return e;
 804 }
 805
 806 int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
 807                     char *sym)
 808 {
 809         struct bpf_ksym *ksym;
 810         unsigned int it = 0;
 811         int ret = -ERANGE;
 812
 813         if (!bpf_jit_kallsyms_enabled())
 814                 return ret;
 815
 816         rcu_read_lock();
 817         list_for_each_entry_rcu(ksym, &bpf_kallsyms, lnode) {
 818                 if (it++ != symnum)
 819                         continue;
 820
 821                 strscpy(sym, ksym->name, KSYM_NAME_LEN);
 822
 823                 *value = ksym->start;
 824                 *type  = BPF_SYM_ELF_TYPE;
 825
 826                 ret = 0;
 827                 break;
 828         }
 829         rcu_read_unlock();
 830
 831         return ret;
 832 }
 833
 834 int bpf_jit_add_poke_descriptor(struct bpf_prog *prog,
 835                                 struct bpf_jit_poke_descriptor *poke)
 836 {
 837         struct bpf_jit_poke_descriptor *tab = prog->aux->poke_tab;
 838         static const u32 poke_tab_max = 1024;
 839         u32 slot = prog->aux->size_poke_tab;
 840         u32 size = slot + 1;
 841
 842         if (size > poke_tab_max)
 843                 return -ENOSPC;
 844         if (poke->tailcall_target || poke->tailcall_target_stable ||
 845             poke->tailcall_bypass || poke->adj_off || poke->bypass_addr)
 846                 return -EINVAL;
 847
 848         switch (poke->reason) {
 849         case BPF_POKE_REASON_TAIL_CALL:
 850                 if (!poke->tail_call.map)
 851                         return -EINVAL;
 852                 break;
 853         default:
 854                 return -EINVAL;
 855         }
 856
 857         tab = krealloc_array(tab, size, sizeof(*poke), GFP_KERNEL);
 858         if (!tab)
 859                 return -ENOMEM;
 860
 861         memcpy(&tab[slot], poke, sizeof(*poke));
 862         prog->aux->size_poke_tab = size;
 863         prog->aux->poke_tab = tab;
 864
 865         return slot;
 866 }
 867
 868 /*
 869  * BPF program pack allocator.
 870  *
 871  * Most BPF programs are pretty small. Allocating a hole page for each
 872  * program is sometime a waste. Many small bpf program also adds pressure
 873  * to instruction TLB. To solve this issue, we introduce a BPF program pack
 874  * allocator. The prog_pack allocator uses HPAGE_PMD_SIZE page (2MB on x86)
 875  * to host BPF programs.
 876  */
 877 #define BPF_PROG_CHUNK_SHIFT    6
 878 #define BPF_PROG_CHUNK_SIZE     (1 << BPF_PROG_CHUNK_SHIFT)
 879 #define BPF_PROG_CHUNK_MASK     (~(BPF_PROG_CHUNK_SIZE - 1))
 880
 881 struct bpf_prog_pack {
 882         struct list_head list;
 883         void *ptr;
 884         unsigned long bitmap[];
 885 };
 886
 887 void bpf_jit_fill_hole_with_zero(void *area, unsigned int size)
 888 {
 889         memset(area, 0, size);
 890 }
 891
 892 #define BPF_PROG_SIZE_TO_NBITS(size)    (round_up(size, BPF_PROG_CHUNK_SIZE) / BPF_PROG_CHUNK_SIZE)
 893
 894 static DEFINE_MUTEX(pack_mutex);
 895 static LIST_HEAD(pack_list);
 896
 897 /* PMD_SIZE is not available in some special config, e.g. ARCH=arm with
 898  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
 899  */
 900 #ifdef PMD_SIZE
 901 /* PMD_SIZE is really big for some archs. It doesn't make sense to
 902  * reserve too much memory in one allocation. Hardcode BPF_PROG_PACK_SIZE to
 903  * 2MiB * num_possible_nodes(). On most architectures PMD_SIZE will be
 904  * greater than or equal to 2MB.
 905  */
 906 #define BPF_PROG_PACK_SIZE (SZ_2M * num_possible_nodes())
 907 #else
 908 #define BPF_PROG_PACK_SIZE PAGE_SIZE
 909 #endif
 910
 911 #define BPF_PROG_CHUNK_COUNT (BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE)
 912
 913 static struct bpf_prog_pack *alloc_new_pack(bpf_jit_fill_hole_t bpf_fill_ill_insns)
 914 {
 915         struct bpf_prog_pack *pack;
 916         int err;
 917
 918         pack = kzalloc(struct_size(pack, bitmap, BITS_TO_LONGS(BPF_PROG_CHUNK_COUNT)),
 919                        GFP_KERNEL);
 920         if (!pack)
 921                 return NULL;
 922         pack->ptr = bpf_jit_alloc_exec(BPF_PROG_PACK_SIZE);
 923         if (!pack->ptr)
 924                 goto out;
 925         bpf_fill_ill_insns(pack->ptr, BPF_PROG_PACK_SIZE);
 926         bitmap_zero(pack->bitmap, BPF_PROG_PACK_SIZE / BPF_PROG_CHUNK_SIZE);
 927
 928         set_vm_flush_reset_perms(pack->ptr);
 929         err = set_memory_rox((unsigned long)pack->ptr,
 930                              BPF_PROG_PACK_SIZE / PAGE_SIZE);
 931         if (err)
 932                 goto out;
 933         list_add_tail(&pack->list, &pack_list);
 934         return pack;
 935
 936 out:
 937         bpf_jit_free_exec(pack->ptr);
 938         kfree(pack);
 939         return NULL;
 940 }
 941
 942 void *bpf_prog_pack_alloc(u32 size, bpf_jit_fill_hole_t bpf_fill_ill_insns)
 943 {
 944         unsigned int nbits = BPF_PROG_SIZE_TO_NBITS(size);
 945         struct bpf_prog_pack *pack;
 946         unsigned long pos;
 947         void *ptr = NULL;
 948
 949         mutex_lock(&pack_mutex);
 950         if (size > BPF_PROG_PACK_SIZE) {
 951                 size = round_up(size, PAGE_SIZE);
 952                 ptr = bpf_jit_alloc_exec(size);
 953                 if (ptr) {
 954                         int err;
 955
 956                         bpf_fill_ill_insns(ptr, size);
 957                         set_vm_flush_reset_perms(ptr);
 958                         err = set_memory_rox((unsigned long)ptr,
 959                                              size / PAGE_SIZE);
 960                         if (err) {
 961                                 bpf_jit_free_exec(ptr);
 962                                 ptr = NULL;
 963                         }
 964                 }
 965                 goto out;
 966         }
 967         list_for_each_entry(pack, &pack_list, list) {
 968                 pos = bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
 969                                                  nbits, 0);
 970                 if (pos < BPF_PROG_CHUNK_COUNT)
 971                         goto found_free_area;
 972         }
 973
 974         pack = alloc_new_pack(bpf_fill_ill_insns);
 975         if (!pack)
 976                 goto out;
 977
 978         pos = 0;
 979
 980 found_free_area:
 981         bitmap_set(pack->bitmap, pos, nbits);
 982         ptr = (void *)(pack->ptr) + (pos << BPF_PROG_CHUNK_SHIFT);
 983
 984 out:
 985         mutex_unlock(&pack_mutex);
 986         return ptr;
 987 }
 988
 989 void bpf_prog_pack_free(void *ptr, u32 size)
 990 {
 991         struct bpf_prog_pack *pack = NULL, *tmp;
 992         unsigned int nbits;
 993         unsigned long pos;
 994
 995         mutex_lock(&pack_mutex);
 996         if (size > BPF_PROG_PACK_SIZE) {
 997                 bpf_jit_free_exec(ptr);
 998                 goto out;
 999         }
1000
1001         list_for_each_entry(tmp, &pack_list, list) {
1002                 if (ptr >= tmp->ptr && (tmp->ptr + BPF_PROG_PACK_SIZE) > ptr) {
1003                         pack = tmp;
1004                         break;
1005                 }
1006         }
1007
1008         if (WARN_ONCE(!pack, "bpf_prog_pack bug\n"))
1009                 goto out;
1010
1011         nbits = BPF_PROG_SIZE_TO_NBITS(size);
1012         pos = ((unsigned long)ptr - (unsigned long)pack->ptr) >> BPF_PROG_CHUNK_SHIFT;
1013
1014         WARN_ONCE(bpf_arch_text_invalidate(ptr, size),
1015                   "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n");
1016
1017         bitmap_clear(pack->bitmap, pos, nbits);
1018         if (bitmap_find_next_zero_area(pack->bitmap, BPF_PROG_CHUNK_COUNT, 0,
1019                                        BPF_PROG_CHUNK_COUNT, 0) == 0) {
1020                 list_del(&pack->list);
1021                 bpf_jit_free_exec(pack->ptr);
1022                 kfree(pack);
1023         }
1024 out:
1025         mutex_unlock(&pack_mutex);
1026 }
1027
1028 static atomic_long_t bpf_jit_current;
1029
1030 /* Can be overridden by an arch's JIT compiler if it has a custom,
1031  * dedicated BPF backend memory area, or if neither of the two
1032  * below apply.
1033  */
1034 u64 __weak bpf_jit_alloc_exec_limit(void)
1035 {
1036 #if defined(MODULES_VADDR)
1037         return MODULES_END - MODULES_VADDR;
1038 #else
1039         return VMALLOC_END - VMALLOC_START;
1040 #endif
1041 }
1042
1043 static int __init bpf_jit_charge_init(void)
1044 {
1045         /* Only used as heuristic here to derive limit. */
1046         bpf_jit_limit_max = bpf_jit_alloc_exec_limit();
1047         bpf_jit_limit = min_t(u64, round_up(bpf_jit_limit_max >> 1,
1048                                             PAGE_SIZE), LONG_MAX);
1049         return 0;
1050 }
1051 pure_initcall(bpf_jit_charge_init);
1052
1053 int bpf_jit_charge_modmem(u32 size)
1054 {
1055         if (atomic_long_add_return(size, &bpf_jit_current) > READ_ONCE(bpf_jit_limit)) {
1056                 if (!bpf_capable()) {
1057                         atomic_long_sub(size, &bpf_jit_current);
1058                         return -EPERM;
1059                 }
1060         }
1061
1062         return 0;
1063 }
1064
1065 void bpf_jit_uncharge_modmem(u32 size)
1066 {
1067         atomic_long_sub(size, &bpf_jit_current);
1068 }
1069
1070 void *__weak bpf_jit_alloc_exec(unsigned long size)
1071 {
1072         return execmem_alloc(EXECMEM_BPF, size);
1073 }
1074
1075 void __weak bpf_jit_free_exec(void *addr)
1076 {
1077         execmem_free(addr);
1078 }
1079
1080 struct bpf_binary_header *
1081 bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
1082                      unsigned int alignment,
1083                      bpf_jit_fill_hole_t bpf_fill_ill_insns)
1084 {
1085         struct bpf_binary_header *hdr;
1086         u32 size, hole, start;
1087
1088         WARN_ON_ONCE(!is_power_of_2(alignment) ||
1089                      alignment > BPF_IMAGE_ALIGNMENT);
1090
1091         /* Most of BPF filters are really small, but if some of them
1092          * fill a page, allow at least 128 extra bytes to insert a
1093          * random section of illegal instructions.
1094          */
1095         size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
1096
1097         if (bpf_jit_charge_modmem(size))
1098                 return NULL;
1099         hdr = bpf_jit_alloc_exec(size);
1100         if (!hdr) {
1101                 bpf_jit_uncharge_modmem(size);
1102                 return NULL;
1103         }
1104
1105         /* Fill space with illegal/arch-dep instructions. */
1106         bpf_fill_ill_insns(hdr, size);
1107
1108         hdr->size = size;
1109         hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
1110                      PAGE_SIZE - sizeof(*hdr));
1111         start = get_random_u32_below(hole) & ~(alignment - 1);
1112
1113         /* Leave a random number of instructions before BPF code. */
1114         *image_ptr = &hdr->image[start];
1115
1116         return hdr;
1117 }
1118
1119 void bpf_jit_binary_free(struct bpf_binary_header *hdr)
1120 {
1121         u32 size = hdr->size;
1122
1123         bpf_jit_free_exec(hdr);
1124         bpf_jit_uncharge_modmem(size);
1125 }
1126
1127 /* Allocate jit binary from bpf_prog_pack allocator.
1128  * Since the allocated memory is RO+X, the JIT engine cannot write directly
1129  * to the memory. To solve this problem, a RW buffer is also allocated at
1130  * as the same time. The JIT engine should calculate offsets based on the
1131  * RO memory address, but write JITed program to the RW buffer. Once the
1132  * JIT engine finishes, it calls bpf_jit_binary_pack_finalize, which copies
1133  * the JITed program to the RO memory.
1134  */
1135 struct bpf_binary_header *
1136 bpf_jit_binary_pack_alloc(unsigned int proglen, u8 **image_ptr,
1137                           unsigned int alignment,
1138                           struct bpf_binary_header **rw_header,
1139                           u8 **rw_image,
1140                           bpf_jit_fill_hole_t bpf_fill_ill_insns)
1141 {
1142         struct bpf_binary_header *ro_header;
1143         u32 size, hole, start;
1144
1145         WARN_ON_ONCE(!is_power_of_2(alignment) ||
1146                      alignment > BPF_IMAGE_ALIGNMENT);
1147
1148         /* add 16 bytes for a random section of illegal instructions */
1149         size = round_up(proglen + sizeof(*ro_header) + 16, BPF_PROG_CHUNK_SIZE);
1150
1151         if (bpf_jit_charge_modmem(size))
1152                 return NULL;
1153         ro_header = bpf_prog_pack_alloc(size, bpf_fill_ill_insns);
1154         if (!ro_header) {
1155                 bpf_jit_uncharge_modmem(size);
1156                 return NULL;
1157         }
1158
1159         *rw_header = kvmalloc(size, GFP_KERNEL);
1160         if (!*rw_header) {
1161                 bpf_prog_pack_free(ro_header, size);
1162                 bpf_jit_uncharge_modmem(size);
1163                 return NULL;
1164         }
1165
1166         /* Fill space with illegal/arch-dep instructions. */
1167         bpf_fill_ill_insns(*rw_header, size);
1168         (*rw_header)->size = size;
1169
1170         hole = min_t(unsigned int, size - (proglen + sizeof(*ro_header)),
1171                      BPF_PROG_CHUNK_SIZE - sizeof(*ro_header));
1172         start = get_random_u32_below(hole) & ~(alignment - 1);
1173
1174         *image_ptr = &ro_header->image[start];
1175         *rw_image = &(*rw_header)->image[start];
1176
1177         return ro_header;
1178 }
1179
1180 /* Copy JITed text from rw_header to its final location, the ro_header. */
1181 int bpf_jit_binary_pack_finalize(struct bpf_binary_header *ro_header,
1182                                  struct bpf_binary_header *rw_header)
1183 {
1184         void *ptr;
1185
1186         ptr = bpf_arch_text_copy(ro_header, rw_header, rw_header->size);
1187
1188         kvfree(rw_header);
1189
1190         if (IS_ERR(ptr)) {
1191                 bpf_prog_pack_free(ro_header, ro_header->size);
1192                 return PTR_ERR(ptr);
1193         }
1194         return 0;
1195 }
1196
1197 /* bpf_jit_binary_pack_free is called in two different scenarios:
1198  *   1) when the program is freed after;
1199  *   2) when the JIT engine fails (before bpf_jit_binary_pack_finalize).
1200  * For case 2), we need to free both the RO memory and the RW buffer.
1201  *
1202  * bpf_jit_binary_pack_free requires proper ro_header->size. However,
1203  * bpf_jit_binary_pack_alloc does not set it. Therefore, ro_header->size
1204  * must be set with either bpf_jit_binary_pack_finalize (normal path) or
1205  * bpf_arch_text_copy (when jit fails).
1206  */
1207 void bpf_jit_binary_pack_free(struct bpf_binary_header *ro_header,
1208                               struct bpf_binary_header *rw_header)
1209 {
1210         u32 size = ro_header->size;
1211
1212         bpf_prog_pack_free(ro_header, size);
1213         kvfree(rw_header);
1214         bpf_jit_uncharge_modmem(size);
1215 }
1216
1217 struct bpf_binary_header *
1218 bpf_jit_binary_pack_hdr(const struct bpf_prog *fp)
1219 {
1220         unsigned long real_start = (unsigned long)fp->bpf_func;
1221         unsigned long addr;
1222
1223         addr = real_start & BPF_PROG_CHUNK_MASK;
1224         return (void *)addr;
1225 }
1226
1227 static inline struct bpf_binary_header *
1228 bpf_jit_binary_hdr(const struct bpf_prog *fp)
1229 {
1230         unsigned long real_start = (unsigned long)fp->bpf_func;
1231         unsigned long addr;
1232
1233         addr = real_start & PAGE_MASK;
1234         return (void *)addr;
1235 }
1236
1237 /* This symbol is only overridden by archs that have different
1238  * requirements than the usual eBPF JITs, f.e. when they only
1239  * implement cBPF JIT, do not set images read-only, etc.
1240  */
1241 void __weak bpf_jit_free(struct bpf_prog *fp)
1242 {
1243         if (fp->jited) {
1244                 struct bpf_binary_header *hdr = bpf_jit_binary_hdr(fp);
1245
1246                 bpf_jit_binary_free(hdr);
1247                 WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
1248         }
1249
1250         bpf_prog_unlock_free(fp);
1251 }
1252
1253 int bpf_jit_get_func_addr(const struct bpf_prog *prog,
1254                           const struct bpf_insn *insn, bool extra_pass,
1255                           u64 *func_addr, bool *func_addr_fixed)
1256 {
1257         s16 off = insn->off;
1258         s32 imm = insn->imm;
1259         u8 *addr;
1260         int err;
1261
1262         *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
1263         if (!*func_addr_fixed) {
1264                 /* Place-holder address till the last pass has collected
1265                  * all addresses for JITed subprograms in which case we
1266                  * can pick them up from prog->aux.
1267                  */
1268                 if (!extra_pass)
1269                         addr = NULL;
1270                 else if (prog->aux->func &&
1271                          off >= 0 && off < prog->aux->real_func_cnt)
1272                         addr = (u8 *)prog->aux->func[off]->bpf_func;
1273                 else
1274                         return -EINVAL;
1275         } else if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL &&
1276                    bpf_jit_supports_far_kfunc_call()) {
1277                 err = bpf_get_kfunc_addr(prog, insn->imm, insn->off, &addr);
1278                 if (err)
1279                         return err;
1280         } else {
1281                 /* Address of a BPF helper call. Since part of the core
1282                  * kernel, it's always at a fixed location. __bpf_call_base
1283                  * and the helper with imm relative to it are both in core
1284                  * kernel.
1285                  */
1286                 addr = (u8 *)__bpf_call_base + imm;
1287         }
1288
1289         *func_addr = (unsigned long)addr;
1290         return 0;
1291 }
1292
1293 static int bpf_jit_blind_insn(const struct bpf_insn *from,
1294                               const struct bpf_insn *aux,
1295                               struct bpf_insn *to_buff,
1296                               bool emit_zext)
1297 {
1298         struct bpf_insn *to = to_buff;
1299         u32 imm_rnd = get_random_u32();
1300         s16 off;
1301
1302         BUILD_BUG_ON(BPF_REG_AX  + 1 != MAX_BPF_JIT_REG);
1303         BUILD_BUG_ON(MAX_BPF_REG + 1 != MAX_BPF_JIT_REG);
1304
1305         /* Constraints on AX register:
1306          *
1307          * AX register is inaccessible from user space. It is mapped in
1308          * all JITs, and used here for constant blinding rewrites. It is
1309          * typically "stateless" meaning its contents are only valid within
1310          * the executed instruction, but not across several instructions.
1311          * There are a few exceptions however which are further detailed
1312          * below.
1313          *
1314          * Constant blinding is only used by JITs, not in the interpreter.
1315          * The interpreter uses AX in some occasions as a local temporary
1316          * register e.g. in DIV or MOD instructions.
1317          *
1318          * In restricted circumstances, the verifier can also use the AX
1319          * register for rewrites as long as they do not interfere with
1320          * the above cases!
1321          */
1322         if (from->dst_reg == BPF_REG_AX || from->src_reg == BPF_REG_AX)
1323                 goto out;
1324
1325         if (from->imm == 0 &&
1326             (from->code == (BPF_ALU   | BPF_MOV | BPF_K) ||
1327              from->code == (BPF_ALU64 | BPF_MOV | BPF_K))) {
1328                 *to++ = BPF_ALU64_REG(BPF_XOR, from->dst_reg, from->dst_reg);
1329                 goto out;
1330         }
1331
1332         switch (from->code) {
1333         case BPF_ALU | BPF_ADD | BPF_K:
1334         case BPF_ALU | BPF_SUB | BPF_K:
1335         case BPF_ALU | BPF_AND | BPF_K:
1336         case BPF_ALU | BPF_OR  | BPF_K:
1337         case BPF_ALU | BPF_XOR | BPF_K:
1338         case BPF_ALU | BPF_MUL | BPF_K:
1339         case BPF_ALU | BPF_MOV | BPF_K:
1340         case BPF_ALU | BPF_DIV | BPF_K:
1341         case BPF_ALU | BPF_MOD | BPF_K:
1342                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1343                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1344                 *to++ = BPF_ALU32_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1345                 break;
1346
1347         case BPF_ALU64 | BPF_ADD | BPF_K:
1348         case BPF_ALU64 | BPF_SUB | BPF_K:
1349         case BPF_ALU64 | BPF_AND | BPF_K:
1350         case BPF_ALU64 | BPF_OR  | BPF_K:
1351         case BPF_ALU64 | BPF_XOR | BPF_K:
1352         case BPF_ALU64 | BPF_MUL | BPF_K:
1353         case BPF_ALU64 | BPF_MOV | BPF_K:
1354         case BPF_ALU64 | BPF_DIV | BPF_K:
1355         case BPF_ALU64 | BPF_MOD | BPF_K:
1356                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1357                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1358                 *to++ = BPF_ALU64_REG_OFF(from->code, from->dst_reg, BPF_REG_AX, from->off);
1359                 break;
1360
1361         case BPF_JMP | BPF_JEQ  | BPF_K:
1362         case BPF_JMP | BPF_JNE  | BPF_K:
1363         case BPF_JMP | BPF_JGT  | BPF_K:
1364         case BPF_JMP | BPF_JLT  | BPF_K:
1365         case BPF_JMP | BPF_JGE  | BPF_K:
1366         case BPF_JMP | BPF_JLE  | BPF_K:
1367         case BPF_JMP | BPF_JSGT | BPF_K:
1368         case BPF_JMP | BPF_JSLT | BPF_K:
1369         case BPF_JMP | BPF_JSGE | BPF_K:
1370         case BPF_JMP | BPF_JSLE | BPF_K:
1371         case BPF_JMP | BPF_JSET | BPF_K:
1372                 /* Accommodate for extra offset in case of a backjump. */
1373                 off = from->off;
1374                 if (off < 0)
1375                         off -= 2;
1376                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1377                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1378                 *to++ = BPF_JMP_REG(from->code, from->dst_reg, BPF_REG_AX, off);
1379                 break;
1380
1381         case BPF_JMP32 | BPF_JEQ  | BPF_K:
1382         case BPF_JMP32 | BPF_JNE  | BPF_K:
1383         case BPF_JMP32 | BPF_JGT  | BPF_K:
1384         case BPF_JMP32 | BPF_JLT  | BPF_K:
1385         case BPF_JMP32 | BPF_JGE  | BPF_K:
1386         case BPF_JMP32 | BPF_JLE  | BPF_K:
1387         case BPF_JMP32 | BPF_JSGT | BPF_K:
1388         case BPF_JMP32 | BPF_JSLT | BPF_K:
1389         case BPF_JMP32 | BPF_JSGE | BPF_K:
1390         case BPF_JMP32 | BPF_JSLE | BPF_K:
1391         case BPF_JMP32 | BPF_JSET | BPF_K:
1392                 /* Accommodate for extra offset in case of a backjump. */
1393                 off = from->off;
1394                 if (off < 0)
1395                         off -= 2;
1396                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1397                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1398                 *to++ = BPF_JMP32_REG(from->code, from->dst_reg, BPF_REG_AX,
1399                                       off);
1400                 break;
1401
1402         case BPF_LD | BPF_IMM | BPF_DW:
1403                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[1].imm);
1404                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1405                 *to++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_AX, 32);
1406                 *to++ = BPF_ALU64_REG(BPF_MOV, aux[0].dst_reg, BPF_REG_AX);
1407                 break;
1408         case 0: /* Part 2 of BPF_LD | BPF_IMM | BPF_DW. */
1409                 *to++ = BPF_ALU32_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ aux[0].imm);
1410                 *to++ = BPF_ALU32_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1411                 if (emit_zext)
1412                         *to++ = BPF_ZEXT_REG(BPF_REG_AX);
1413                 *to++ = BPF_ALU64_REG(BPF_OR,  aux[0].dst_reg, BPF_REG_AX);
1414                 break;
1415
1416         case BPF_ST | BPF_MEM | BPF_DW:
1417         case BPF_ST | BPF_MEM | BPF_W:
1418         case BPF_ST | BPF_MEM | BPF_H:
1419         case BPF_ST | BPF_MEM | BPF_B:
1420                 *to++ = BPF_ALU64_IMM(BPF_MOV, BPF_REG_AX, imm_rnd ^ from->imm);
1421                 *to++ = BPF_ALU64_IMM(BPF_XOR, BPF_REG_AX, imm_rnd);
1422                 *to++ = BPF_STX_MEM(from->code, from->dst_reg, BPF_REG_AX, from->off);
1423                 break;
1424         }
1425 out:
1426         return to - to_buff;
1427 }
1428
1429 static struct bpf_prog *bpf_prog_clone_create(struct bpf_prog *fp_other,
1430                                               gfp_t gfp_extra_flags)
1431 {
1432         gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | gfp_extra_flags;
1433         struct bpf_prog *fp;
1434
1435         fp = __vmalloc(fp_other->pages * PAGE_SIZE, gfp_flags);
1436         if (fp != NULL) {
1437                 /* aux->prog still points to the fp_other one, so
1438                  * when promoting the clone to the real program,
1439                  * this still needs to be adapted.
1440                  */
1441                 memcpy(fp, fp_other, fp_other->pages * PAGE_SIZE);
1442         }
1443
1444         return fp;
1445 }
1446
1447 static void bpf_prog_clone_free(struct bpf_prog *fp)
1448 {
1449         /* aux was stolen by the other clone, so we cannot free
1450          * it from this path! It will be freed eventually by the
1451          * other program on release.
1452          *
1453          * At this point, we don't need a deferred release since
1454          * clone is guaranteed to not be locked.
1455          */
1456         fp->aux = NULL;
1457         fp->stats = NULL;
1458         fp->active = NULL;
1459         __bpf_prog_free(fp);
1460 }
1461
1462 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other)
1463 {
1464         /* We have to repoint aux->prog to self, as we don't
1465          * know whether fp here is the clone or the original.
1466          */
1467         fp->aux->prog = fp;
1468         bpf_prog_clone_free(fp_other);
1469 }
1470
1471 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *prog)
1472 {
1473         struct bpf_insn insn_buff[16], aux[2];
1474         struct bpf_prog *clone, *tmp;
1475         int insn_delta, insn_cnt;
1476         struct bpf_insn *insn;
1477         int i, rewritten;
1478
1479         if (!prog->blinding_requested || prog->blinded)
1480                 return prog;
1481
1482         clone = bpf_prog_clone_create(prog, GFP_USER);
1483         if (!clone)
1484                 return ERR_PTR(-ENOMEM);
1485
1486         insn_cnt = clone->len;
1487         insn = clone->insnsi;
1488
1489         for (i = 0; i < insn_cnt; i++, insn++) {
1490                 if (bpf_pseudo_func(insn)) {
1491                         /* ld_imm64 with an address of bpf subprog is not
1492                          * a user controlled constant. Don't randomize it,
1493                          * since it will conflict with jit_subprogs() logic.
1494                          */
1495                         insn++;
1496                         i++;
1497                         continue;
1498                 }
1499
1500                 /* We temporarily need to hold the original ld64 insn
1501                  * so that we can still access the first part in the
1502                  * second blinding run.
1503                  */
1504                 if (insn[0].code == (BPF_LD | BPF_IMM | BPF_DW) &&
1505                     insn[1].code == 0)
1506                         memcpy(aux, insn, sizeof(aux));
1507
1508                 rewritten = bpf_jit_blind_insn(insn, aux, insn_buff,
1509                                                 clone->aux->verifier_zext);
1510                 if (!rewritten)
1511                         continue;
1512
1513                 tmp = bpf_patch_insn_single(clone, i, insn_buff, rewritten);
1514                 if (IS_ERR(tmp)) {
1515                         /* Patching may have repointed aux->prog during
1516                          * realloc from the original one, so we need to
1517                          * fix it up here on error.
1518                          */
1519                         bpf_jit_prog_release_other(prog, clone);
1520                         return tmp;
1521                 }
1522
1523                 clone = tmp;
1524                 insn_delta = rewritten - 1;
1525
1526                 /* Walk new program and skip insns we just inserted. */
1527                 insn = clone->insnsi + i + insn_delta;
1528                 insn_cnt += insn_delta;
1529                 i        += insn_delta;
1530         }
1531
1532         clone->blinded = 1;
1533         return clone;
1534 }
1535 #endif /* CONFIG_BPF_JIT */
1536
1537 /* Base function for offset calculation. Needs to go into .text section,
1538  * therefore keeping it non-static as well; will also be used by JITs
1539  * anyway later on, so do not let the compiler omit it. This also needs
1540  * to go into kallsyms for correlation from e.g. bpftool, so naming
1541  * must not change.
1542  */
1543 noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
1544 {
1545         return 0;
1546 }
1547 EXPORT_SYMBOL_GPL(__bpf_call_base);
1548
1549 /* All UAPI available opcodes. */
1550 #define BPF_INSN_MAP(INSN_2, INSN_3)            \
1551         /* 32 bit ALU operations. */            \
1552         /*   Register based. */                 \
1553         INSN_3(ALU, ADD,  X),                   \
1554         INSN_3(ALU, SUB,  X),                   \
1555         INSN_3(ALU, AND,  X),                   \
1556         INSN_3(ALU, OR,   X),                   \
1557         INSN_3(ALU, LSH,  X),                   \
1558         INSN_3(ALU, RSH,  X),                   \
1559         INSN_3(ALU, XOR,  X),                   \
1560         INSN_3(ALU, MUL,  X),                   \
1561         INSN_3(ALU, MOV,  X),                   \
1562         INSN_3(ALU, ARSH, X),                   \
1563         INSN_3(ALU, DIV,  X),                   \
1564         INSN_3(ALU, MOD,  X),                   \
1565         INSN_2(ALU, NEG),                       \
1566         INSN_3(ALU, END, TO_BE),                \
1567         INSN_3(ALU, END, TO_LE),                \
1568         /*   Immediate based. */                \
1569         INSN_3(ALU, ADD,  K),                   \
1570         INSN_3(ALU, SUB,  K),                   \
1571         INSN_3(ALU, AND,  K),                   \
1572         INSN_3(ALU, OR,   K),                   \
1573         INSN_3(ALU, LSH,  K),                   \
1574         INSN_3(ALU, RSH,  K),                   \
1575         INSN_3(ALU, XOR,  K),                   \
1576         INSN_3(ALU, MUL,  K),                   \
1577         INSN_3(ALU, MOV,  K),                   \
1578         INSN_3(ALU, ARSH, K),                   \
1579         INSN_3(ALU, DIV,  K),                   \
1580         INSN_3(ALU, MOD,  K),                   \
1581         /* 64 bit ALU operations. */            \
1582         /*   Register based. */                 \
1583         INSN_3(ALU64, ADD,  X),                 \
1584         INSN_3(ALU64, SUB,  X),                 \
1585         INSN_3(ALU64, AND,  X),                 \
1586         INSN_3(ALU64, OR,   X),                 \
1587         INSN_3(ALU64, LSH,  X),                 \
1588         INSN_3(ALU64, RSH,  X),                 \
1589         INSN_3(ALU64, XOR,  X),                 \
1590         INSN_3(ALU64, MUL,  X),                 \
1591         INSN_3(ALU64, MOV,  X),                 \
1592         INSN_3(ALU64, ARSH, X),                 \
1593         INSN_3(ALU64, DIV,  X),                 \
1594         INSN_3(ALU64, MOD,  X),                 \
1595         INSN_2(ALU64, NEG),                     \
1596         INSN_3(ALU64, END, TO_LE),              \
1597         /*   Immediate based. */                \
1598         INSN_3(ALU64, ADD,  K),                 \
1599         INSN_3(ALU64, SUB,  K),                 \
1600         INSN_3(ALU64, AND,  K),                 \
1601         INSN_3(ALU64, OR,   K),                 \
1602         INSN_3(ALU64, LSH,  K),                 \
1603         INSN_3(ALU64, RSH,  K),                 \
1604         INSN_3(ALU64, XOR,  K),                 \
1605         INSN_3(ALU64, MUL,  K),                 \
1606         INSN_3(ALU64, MOV,  K),                 \
1607         INSN_3(ALU64, ARSH, K),                 \
1608         INSN_3(ALU64, DIV,  K),                 \
1609         INSN_3(ALU64, MOD,  K),                 \
1610         /* Call instruction. */                 \
1611         INSN_2(JMP, CALL),                      \
1612         /* Exit instruction. */                 \
1613         INSN_2(JMP, EXIT),                      \
1614         /* 32-bit Jump instructions. */         \
1615         /*   Register based. */                 \
1616         INSN_3(JMP32, JEQ,  X),                 \
1617         INSN_3(JMP32, JNE,  X),                 \
1618         INSN_3(JMP32, JGT,  X),                 \
1619         INSN_3(JMP32, JLT,  X),                 \
1620         INSN_3(JMP32, JGE,  X),                 \
1621         INSN_3(JMP32, JLE,  X),                 \
1622         INSN_3(JMP32, JSGT, X),                 \
1623         INSN_3(JMP32, JSLT, X),                 \
1624         INSN_3(JMP32, JSGE, X),                 \
1625         INSN_3(JMP32, JSLE, X),                 \
1626         INSN_3(JMP32, JSET, X),                 \
1627         /*   Immediate based. */                \
1628         INSN_3(JMP32, JEQ,  K),                 \
1629         INSN_3(JMP32, JNE,  K),                 \
1630         INSN_3(JMP32, JGT,  K),                 \
1631         INSN_3(JMP32, JLT,  K),                 \
1632         INSN_3(JMP32, JGE,  K),                 \
1633         INSN_3(JMP32, JLE,  K),                 \
1634         INSN_3(JMP32, JSGT, K),                 \
1635         INSN_3(JMP32, JSLT, K),                 \
1636         INSN_3(JMP32, JSGE, K),                 \
1637         INSN_3(JMP32, JSLE, K),                 \
1638         INSN_3(JMP32, JSET, K),                 \
1639         /* Jump instructions. */                \
1640         /*   Register based. */                 \
1641         INSN_3(JMP, JEQ,  X),                   \
1642         INSN_3(JMP, JNE,  X),                   \
1643         INSN_3(JMP, JGT,  X),                   \
1644         INSN_3(JMP, JLT,  X),                   \
1645         INSN_3(JMP, JGE,  X),                   \
1646         INSN_3(JMP, JLE,  X),                   \
1647         INSN_3(JMP, JSGT, X),                   \
1648         INSN_3(JMP, JSLT, X),                   \
1649         INSN_3(JMP, JSGE, X),                   \
1650         INSN_3(JMP, JSLE, X),                   \
1651         INSN_3(JMP, JSET, X),                   \
1652         /*   Immediate based. */                \
1653         INSN_3(JMP, JEQ,  K),                   \
1654         INSN_3(JMP, JNE,  K),                   \
1655         INSN_3(JMP, JGT,  K),                   \
1656         INSN_3(JMP, JLT,  K),                   \
1657         INSN_3(JMP, JGE,  K),                   \
1658         INSN_3(JMP, JLE,  K),                   \
1659         INSN_3(JMP, JSGT, K),                   \
1660         INSN_3(JMP, JSLT, K),                   \
1661         INSN_3(JMP, JSGE, K),                   \
1662         INSN_3(JMP, JSLE, K),                   \
1663         INSN_3(JMP, JSET, K),                   \
1664         INSN_2(JMP, JA),                        \
1665         INSN_2(JMP32, JA),                      \
1666         /* Store instructions. */               \
1667         /*   Register based. */                 \
1668         INSN_3(STX, MEM,  B),                   \
1669         INSN_3(STX, MEM,  H),                   \
1670         INSN_3(STX, MEM,  W),                   \
1671         INSN_3(STX, MEM,  DW),                  \
1672         INSN_3(STX, ATOMIC, W),                 \
1673         INSN_3(STX, ATOMIC, DW),                \
1674         /*   Immediate based. */                \
1675         INSN_3(ST, MEM, B),                     \
1676         INSN_3(ST, MEM, H),                     \
1677         INSN_3(ST, MEM, W),                     \
1678         INSN_3(ST, MEM, DW),                    \
1679         /* Load instructions. */                \
1680         /*   Register based. */                 \
1681         INSN_3(LDX, MEM, B),                    \
1682         INSN_3(LDX, MEM, H),                    \
1683         INSN_3(LDX, MEM, W),                    \
1684         INSN_3(LDX, MEM, DW),                   \
1685         INSN_3(LDX, MEMSX, B),                  \
1686         INSN_3(LDX, MEMSX, H),                  \
1687         INSN_3(LDX, MEMSX, W),                  \
1688         /*   Immediate based. */                \
1689         INSN_3(LD, IMM, DW)
1690
1691 bool bpf_opcode_in_insntable(u8 code)
1692 {
1693 #define BPF_INSN_2_TBL(x, y)    [BPF_##x | BPF_##y] = true
1694 #define BPF_INSN_3_TBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = true
1695         static const bool public_insntable[256] = {
1696                 [0 ... 255] = false,
1697                 /* Now overwrite non-defaults ... */
1698                 BPF_INSN_MAP(BPF_INSN_2_TBL, BPF_INSN_3_TBL),
1699                 /* UAPI exposed, but rewritten opcodes. cBPF carry-over. */
1700                 [BPF_LD | BPF_ABS | BPF_B] = true,
1701                 [BPF_LD | BPF_ABS | BPF_H] = true,
1702                 [BPF_LD | BPF_ABS | BPF_W] = true,
1703                 [BPF_LD | BPF_IND | BPF_B] = true,
1704                 [BPF_LD | BPF_IND | BPF_H] = true,
1705                 [BPF_LD | BPF_IND | BPF_W] = true,
1706                 [BPF_JMP | BPF_JCOND] = true,
1707         };
1708 #undef BPF_INSN_3_TBL
1709 #undef BPF_INSN_2_TBL
1710         return public_insntable[code];
1711 }
1712
1713 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
1714 /**
1715  *      ___bpf_prog_run - run eBPF program on a given context
1716  *      @regs: is the array of MAX_BPF_EXT_REG eBPF pseudo-registers
1717  *      @insn: is the array of eBPF instructions
1718  *
1719  * Decode and execute eBPF instructions.
1720  *
1721  * Return: whatever value is in %BPF_R0 at program exit
1722  */
1723 static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn)
1724 {
1725 #define BPF_INSN_2_LBL(x, y)    [BPF_##x | BPF_##y] = &&x##_##y
1726 #define BPF_INSN_3_LBL(x, y, z) [BPF_##x | BPF_##y | BPF_##z] = &&x##_##y##_##z
1727         static const void * const jumptable[256] __annotate_jump_table = {
1728                 [0 ... 255] = &&default_label,
1729                 /* Now overwrite non-defaults ... */
1730                 BPF_INSN_MAP(BPF_INSN_2_LBL, BPF_INSN_3_LBL),
1731                 /* Non-UAPI available opcodes. */
1732                 [BPF_JMP | BPF_CALL_ARGS] = &&JMP_CALL_ARGS,
1733                 [BPF_JMP | BPF_TAIL_CALL] = &&JMP_TAIL_CALL,
1734                 [BPF_ST  | BPF_NOSPEC] = &&ST_NOSPEC,
1735                 [BPF_LDX | BPF_PROBE_MEM | BPF_B] = &&LDX_PROBE_MEM_B,
1736                 [BPF_LDX | BPF_PROBE_MEM | BPF_H] = &&LDX_PROBE_MEM_H,
1737                 [BPF_LDX | BPF_PROBE_MEM | BPF_W] = &&LDX_PROBE_MEM_W,
1738                 [BPF_LDX | BPF_PROBE_MEM | BPF_DW] = &&LDX_PROBE_MEM_DW,
1739                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_B] = &&LDX_PROBE_MEMSX_B,
1740                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_H] = &&LDX_PROBE_MEMSX_H,
1741                 [BPF_LDX | BPF_PROBE_MEMSX | BPF_W] = &&LDX_PROBE_MEMSX_W,
1742         };
1743 #undef BPF_INSN_3_LBL
1744 #undef BPF_INSN_2_LBL
1745         u32 tail_call_cnt = 0;
1746
1747 #define CONT     ({ insn++; goto select_insn; })
1748 #define CONT_JMP ({ insn++; goto select_insn; })
1749
1750 select_insn:
1751         goto *jumptable[insn->code];
1752
1753         /* Explicitly mask the register-based shift amounts with 63 or 31
1754          * to avoid undefined behavior. Normally this won't affect the
1755          * generated code, for example, in case of native 64 bit archs such
1756          * as x86-64 or arm64, the compiler is optimizing the AND away for
1757          * the interpreter. In case of JITs, each of the JIT backends compiles
1758          * the BPF shift operations to machine instructions which produce
1759          * implementation-defined results in such a case; the resulting
1760          * contents of the register may be arbitrary, but program behaviour
1761          * as a whole remains defined. In other words, in case of JIT backends,
1762          * the AND must /not/ be added to the emitted LSH/RSH/ARSH translation.
1763          */
1764         /* ALU (shifts) */
1765 #define SHT(OPCODE, OP)                                 \
1766         ALU64_##OPCODE##_X:                             \
1767                 DST = DST OP (SRC & 63);                \
1768                 CONT;                                   \
1769         ALU_##OPCODE##_X:                               \
1770                 DST = (u32) DST OP ((u32) SRC & 31);    \
1771                 CONT;                                   \
1772         ALU64_##OPCODE##_K:                             \
1773                 DST = DST OP IMM;                       \
1774                 CONT;                                   \
1775         ALU_##OPCODE##_K:                               \
1776                 DST = (u32) DST OP (u32) IMM;           \
1777                 CONT;
1778         /* ALU (rest) */
1779 #define ALU(OPCODE, OP)                                 \
1780         ALU64_##OPCODE##_X:                             \
1781                 DST = DST OP SRC;                       \
1782                 CONT;                                   \
1783         ALU_##OPCODE##_X:                               \
1784                 DST = (u32) DST OP (u32) SRC;           \
1785                 CONT;                                   \
1786         ALU64_##OPCODE##_K:                             \
1787                 DST = DST OP IMM;                       \
1788                 CONT;                                   \
1789         ALU_##OPCODE##_K:                               \
1790                 DST = (u32) DST OP (u32) IMM;           \
1791                 CONT;
1792         ALU(ADD,  +)
1793         ALU(SUB,  -)
1794         ALU(AND,  &)
1795         ALU(OR,   |)
1796         ALU(XOR,  ^)
1797         ALU(MUL,  *)
1798         SHT(LSH, <<)
1799         SHT(RSH, >>)
1800 #undef SHT
1801 #undef ALU
1802         ALU_NEG:
1803                 DST = (u32) -DST;
1804                 CONT;
1805         ALU64_NEG:
1806                 DST = -DST;
1807                 CONT;
1808         ALU_MOV_X:
1809                 switch (OFF) {
1810                 case 0:
1811                         DST = (u32) SRC;
1812                         break;
1813                 case 8:
1814                         DST = (u32)(s8) SRC;
1815                         break;
1816                 case 16:
1817                         DST = (u32)(s16) SRC;
1818                         break;
1819                 }
1820                 CONT;
1821         ALU_MOV_K:
1822                 DST = (u32) IMM;
1823                 CONT;
1824         ALU64_MOV_X:
1825                 switch (OFF) {
1826                 case 0:
1827                         DST = SRC;
1828                         break;
1829                 case 8:
1830                         DST = (s8) SRC;
1831                         break;
1832                 case 16:
1833                         DST = (s16) SRC;
1834                         break;
1835                 case 32:
1836                         DST = (s32) SRC;
1837                         break;
1838                 }
1839                 CONT;
1840         ALU64_MOV_K:
1841                 DST = IMM;
1842                 CONT;
1843         LD_IMM_DW:
1844                 DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32;
1845                 insn++;
1846                 CONT;
1847         ALU_ARSH_X:
1848                 DST = (u64) (u32) (((s32) DST) >> (SRC & 31));
1849                 CONT;
1850         ALU_ARSH_K:
1851                 DST = (u64) (u32) (((s32) DST) >> IMM);
1852                 CONT;
1853         ALU64_ARSH_X:
1854                 (*(s64 *) &DST) >>= (SRC & 63);
1855                 CONT;
1856         ALU64_ARSH_K:
1857                 (*(s64 *) &DST) >>= IMM;
1858                 CONT;
1859         ALU64_MOD_X:
1860                 switch (OFF) {
1861                 case 0:
1862                         div64_u64_rem(DST, SRC, &AX);
1863                         DST = AX;
1864                         break;
1865                 case 1:
1866                         AX = div64_s64(DST, SRC);
1867                         DST = DST - AX * SRC;
1868                         break;
1869                 }
1870                 CONT;
1871         ALU_MOD_X:
1872                 switch (OFF) {
1873                 case 0:
1874                         AX = (u32) DST;
1875                         DST = do_div(AX, (u32) SRC);
1876                         break;
1877                 case 1:
1878                         AX = abs((s32)DST);
1879                         AX = do_div(AX, abs((s32)SRC));
1880                         if ((s32)DST < 0)
1881                                 DST = (u32)-AX;
1882                         else
1883                                 DST = (u32)AX;
1884                         break;
1885                 }
1886                 CONT;
1887         ALU64_MOD_K:
1888                 switch (OFF) {
1889                 case 0:
1890                         div64_u64_rem(DST, IMM, &AX);
1891                         DST = AX;
1892                         break;
1893                 case 1:
1894                         AX = div64_s64(DST, IMM);
1895                         DST = DST - AX * IMM;
1896                         break;
1897                 }
1898                 CONT;
1899         ALU_MOD_K:
1900                 switch (OFF) {
1901                 case 0:
1902                         AX = (u32) DST;
1903                         DST = do_div(AX, (u32) IMM);
1904                         break;
1905                 case 1:
1906                         AX = abs((s32)DST);
1907                         AX = do_div(AX, abs((s32)IMM));
1908                         if ((s32)DST < 0)
1909                                 DST = (u32)-AX;
1910                         else
1911                                 DST = (u32)AX;
1912                         break;
1913                 }
1914                 CONT;
1915         ALU64_DIV_X:
1916                 switch (OFF) {
1917                 case 0:
1918                         DST = div64_u64(DST, SRC);
1919                         break;
1920                 case 1:
1921                         DST = div64_s64(DST, SRC);
1922                         break;
1923                 }
1924                 CONT;
1925         ALU_DIV_X:
1926                 switch (OFF) {
1927                 case 0:
1928                         AX = (u32) DST;
1929                         do_div(AX, (u32) SRC);
1930                         DST = (u32) AX;
1931                         break;
1932                 case 1:
1933                         AX = abs((s32)DST);
1934                         do_div(AX, abs((s32)SRC));
1935                         if (((s32)DST < 0) == ((s32)SRC < 0))
1936                                 DST = (u32)AX;
1937                         else
1938                                 DST = (u32)-AX;
1939                         break;
1940                 }
1941                 CONT;
1942         ALU64_DIV_K:
1943                 switch (OFF) {
1944                 case 0:
1945                         DST = div64_u64(DST, IMM);
1946                         break;
1947                 case 1:
1948                         DST = div64_s64(DST, IMM);
1949                         break;
1950                 }
1951                 CONT;
1952         ALU_DIV_K:
1953                 switch (OFF) {
1954                 case 0:
1955                         AX = (u32) DST;
1956                         do_div(AX, (u32) IMM);
1957                         DST = (u32) AX;
1958                         break;
1959                 case 1:
1960                         AX = abs((s32)DST);
1961                         do_div(AX, abs((s32)IMM));
1962                         if (((s32)DST < 0) == ((s32)IMM < 0))
1963                                 DST = (u32)AX;
1964                         else
1965                                 DST = (u32)-AX;
1966                         break;
1967                 }
1968                 CONT;
1969         ALU_END_TO_BE:
1970                 switch (IMM) {
1971                 case 16:
1972                         DST = (__force u16) cpu_to_be16(DST);
1973                         break;
1974                 case 32:
1975                         DST = (__force u32) cpu_to_be32(DST);
1976                         break;
1977                 case 64:
1978                         DST = (__force u64) cpu_to_be64(DST);
1979                         break;
1980                 }
1981                 CONT;
1982         ALU_END_TO_LE:
1983                 switch (IMM) {
1984                 case 16:
1985                         DST = (__force u16) cpu_to_le16(DST);
1986                         break;
1987                 case 32:
1988                         DST = (__force u32) cpu_to_le32(DST);
1989                         break;
1990                 case 64:
1991                         DST = (__force u64) cpu_to_le64(DST);
1992                         break;
1993                 }
1994                 CONT;
1995         ALU64_END_TO_LE:
1996                 switch (IMM) {
1997                 case 16:
1998                         DST = (__force u16) __swab16(DST);
1999                         break;
2000                 case 32:
2001                         DST = (__force u32) __swab32(DST);
2002                         break;
2003                 case 64:
2004                         DST = (__force u64) __swab64(DST);
2005                         break;
2006                 }
2007                 CONT;
2008
2009         /* CALL */
2010         JMP_CALL:
2011                 /* Function call scratches BPF_R1-BPF_R5 registers,
2012                  * preserves BPF_R6-BPF_R9, and stores return value
2013                  * into BPF_R0.
2014                  */
2015                 BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3,
2016                                                        BPF_R4, BPF_R5);
2017                 CONT;
2018
2019         JMP_CALL_ARGS:
2020                 BPF_R0 = (__bpf_call_base_args + insn->imm)(BPF_R1, BPF_R2,
2021                                                             BPF_R3, BPF_R4,
2022                                                             BPF_R5,
2023                                                             insn + insn->off + 1);
2024                 CONT;
2025
2026         JMP_TAIL_CALL: {
2027                 struct bpf_map *map = (struct bpf_map *) (unsigned long) BPF_R2;
2028                 struct bpf_array *array = container_of(map, struct bpf_array, map);
2029                 struct bpf_prog *prog;
2030                 u32 index = BPF_R3;
2031
2032                 if (unlikely(index >= array->map.max_entries))
2033                         goto out;
2034
2035                 if (unlikely(tail_call_cnt >= MAX_TAIL_CALL_CNT))
2036                         goto out;
2037
2038                 tail_call_cnt++;
2039
2040                 prog = READ_ONCE(array->ptrs[index]);
2041                 if (!prog)
2042                         goto out;
2043
2044                 /* ARG1 at this point is guaranteed to point to CTX from
2045                  * the verifier side due to the fact that the tail call is
2046                  * handled like a helper, that is, bpf_tail_call_proto,
2047                  * where arg1_type is ARG_PTR_TO_CTX.
2048                  */
2049                 insn = prog->insnsi;
2050                 goto select_insn;
2051 out:
2052                 CONT;
2053         }
2054         JMP_JA:
2055                 insn += insn->off;
2056                 CONT;
2057         JMP32_JA:
2058                 insn += insn->imm;
2059                 CONT;
2060         JMP_EXIT:
2061                 return BPF_R0;
2062         /* JMP */
2063 #define COND_JMP(SIGN, OPCODE, CMP_OP)                          \
2064         JMP_##OPCODE##_X:                                       \
2065                 if ((SIGN##64) DST CMP_OP (SIGN##64) SRC) {     \
2066                         insn += insn->off;                      \
2067                         CONT_JMP;                               \
2068                 }                                               \
2069                 CONT;                                           \
2070         JMP32_##OPCODE##_X:                                     \
2071                 if ((SIGN##32) DST CMP_OP (SIGN##32) SRC) {     \
2072                         insn += insn->off;                      \
2073                         CONT_JMP;                               \
2074                 }                                               \
2075                 CONT;                                           \
2076         JMP_##OPCODE##_K:                                       \
2077                 if ((SIGN##64) DST CMP_OP (SIGN##64) IMM) {     \
2078                         insn += insn->off;                      \
2079                         CONT_JMP;                               \
2080                 }                                               \
2081                 CONT;                                           \
2082         JMP32_##OPCODE##_K:                                     \
2083                 if ((SIGN##32) DST CMP_OP (SIGN##32) IMM) {     \
2084                         insn += insn->off;                      \
2085                         CONT_JMP;                               \
2086                 }                                               \
2087                 CONT;
2088         COND_JMP(u, JEQ, ==)
2089         COND_JMP(u, JNE, !=)
2090         COND_JMP(u, JGT, >)
2091         COND_JMP(u, JLT, <)
2092         COND_JMP(u, JGE, >=)
2093         COND_JMP(u, JLE, <=)
2094         COND_JMP(u, JSET, &)
2095         COND_JMP(s, JSGT, >)
2096         COND_JMP(s, JSLT, <)
2097         COND_JMP(s, JSGE, >=)
2098         COND_JMP(s, JSLE, <=)
2099 #undef COND_JMP
2100         /* ST, STX and LDX*/
2101         ST_NOSPEC:
2102                 /* Speculation barrier for mitigating Speculative Store Bypass.
2103                  * In case of arm64, we rely on the firmware mitigation as
2104                  * controlled via the ssbd kernel parameter. Whenever the
2105                  * mitigation is enabled, it works for all of the kernel code
2106                  * with no need to provide any additional instructions here.
2107                  * In case of x86, we use 'lfence' insn for mitigation. We
2108                  * reuse preexisting logic from Spectre v1 mitigation that
2109                  * happens to produce the required code on x86 for v4 as well.
2110                  */
2111                 barrier_nospec();
2112                 CONT;
2113 #define LDST(SIZEOP, SIZE)                                              \
2114         STX_MEM_##SIZEOP:                                               \
2115                 *(SIZE *)(unsigned long) (DST + insn->off) = SRC;       \
2116                 CONT;                                                   \
2117         ST_MEM_##SIZEOP:                                                \
2118                 *(SIZE *)(unsigned long) (DST + insn->off) = IMM;       \
2119                 CONT;                                                   \
2120         LDX_MEM_##SIZEOP:                                               \
2121                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
2122                 CONT;                                                   \
2123         LDX_PROBE_MEM_##SIZEOP:                                         \
2124                 bpf_probe_read_kernel_common(&DST, sizeof(SIZE),        \
2125                               (const void *)(long) (SRC + insn->off));  \
2126                 DST = *((SIZE *)&DST);                                  \
2127                 CONT;
2128
2129         LDST(B,   u8)
2130         LDST(H,  u16)
2131         LDST(W,  u32)
2132         LDST(DW, u64)
2133 #undef LDST
2134
2135 #define LDSX(SIZEOP, SIZE)                                              \
2136         LDX_MEMSX_##SIZEOP:                                             \
2137                 DST = *(SIZE *)(unsigned long) (SRC + insn->off);       \
2138                 CONT;                                                   \
2139         LDX_PROBE_MEMSX_##SIZEOP:                                       \
2140                 bpf_probe_read_kernel_common(&DST, sizeof(SIZE),                \
2141                                       (const void *)(long) (SRC + insn->off));  \
2142                 DST = *((SIZE *)&DST);                                  \
2143                 CONT;
2144
2145         LDSX(B,   s8)
2146         LDSX(H,  s16)
2147         LDSX(W,  s32)
2148 #undef LDSX
2149
2150 #define ATOMIC_ALU_OP(BOP, KOP)                                         \
2151                 case BOP:                                               \
2152                         if (BPF_SIZE(insn->code) == BPF_W)              \
2153                                 atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \
2154                                              (DST + insn->off));        \
2155                         else                                            \
2156                                 atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \
2157                                                (DST + insn->off));      \
2158                         break;                                          \
2159                 case BOP | BPF_FETCH:                                   \
2160                         if (BPF_SIZE(insn->code) == BPF_W)              \
2161                                 SRC = (u32) atomic_fetch_##KOP(         \
2162                                         (u32) SRC,                      \
2163                                         (atomic_t *)(unsigned long) (DST + insn->off)); \
2164                         else                                            \
2165                                 SRC = (u64) atomic64_fetch_##KOP(       \
2166                                         (u64) SRC,                      \
2167                                         (atomic64_t *)(unsigned long) (DST + insn->off)); \
2168                         break;
2169
2170         STX_ATOMIC_DW:
2171         STX_ATOMIC_W:
2172                 switch (IMM) {
2173                 ATOMIC_ALU_OP(BPF_ADD, add)
2174                 ATOMIC_ALU_OP(BPF_AND, and)
2175                 ATOMIC_ALU_OP(BPF_OR, or)
2176                 ATOMIC_ALU_OP(BPF_XOR, xor)
2177 #undef ATOMIC_ALU_OP
2178
2179                 case BPF_XCHG:
2180                         if (BPF_SIZE(insn->code) == BPF_W)
2181                                 SRC = (u32) atomic_xchg(
2182                                         (atomic_t *)(unsigned long) (DST + insn->off),
2183                                         (u32) SRC);
2184                         else
2185                                 SRC = (u64) atomic64_xchg(
2186                                         (atomic64_t *)(unsigned long) (DST + insn->off),
2187                                         (u64) SRC);
2188                         break;
2189                 case BPF_CMPXCHG:
2190                         if (BPF_SIZE(insn->code) == BPF_W)
2191                                 BPF_R0 = (u32) atomic_cmpxchg(
2192                                         (atomic_t *)(unsigned long) (DST + insn->off),
2193                                         (u32) BPF_R0, (u32) SRC);
2194                         else
2195                                 BPF_R0 = (u64) atomic64_cmpxchg(
2196                                         (atomic64_t *)(unsigned long) (DST + insn->off),
2197                                         (u64) BPF_R0, (u64) SRC);
2198                         break;
2199
2200                 default:
2201                         goto default_label;
2202                 }
2203                 CONT;
2204
2205         default_label:
2206                 /* If we ever reach this, we have a bug somewhere. Die hard here
2207                  * instead of just returning 0; we could be somewhere in a subprog,
2208                  * so execution could continue otherwise which we do /not/ want.
2209                  *
2210                  * Note, verifier whitelists all opcodes in bpf_opcode_in_insntable().
2211                  */
2212                 pr_warn("BPF interpreter: unknown opcode %02x (imm: 0x%x)\n",
2213                         insn->code, insn->imm);
2214                 BUG_ON(1);
2215                 return 0;
2216 }
2217
2218 #define PROG_NAME(stack_size) __bpf_prog_run##stack_size
2219 #define DEFINE_BPF_PROG_RUN(stack_size) \
2220 static unsigned int PROG_NAME(stack_size)(const void *ctx, const struct bpf_insn *insn) \
2221 { \
2222         u64 stack[stack_size / sizeof(u64)]; \
2223         u64 regs[MAX_BPF_EXT_REG] = {}; \
2224 \
2225         kmsan_unpoison_memory(stack, sizeof(stack)); \
2226         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2227         ARG1 = (u64) (unsigned long) ctx; \
2228         return ___bpf_prog_run(regs, insn); \
2229 }
2230
2231 #define PROG_NAME_ARGS(stack_size) __bpf_prog_run_args##stack_size
2232 #define DEFINE_BPF_PROG_RUN_ARGS(stack_size) \
2233 static u64 PROG_NAME_ARGS(stack_size)(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5, \
2234                                       const struct bpf_insn *insn) \
2235 { \
2236         u64 stack[stack_size / sizeof(u64)]; \
2237         u64 regs[MAX_BPF_EXT_REG]; \
2238 \
2239         kmsan_unpoison_memory(stack, sizeof(stack)); \
2240         FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; \
2241         BPF_R1 = r1; \
2242         BPF_R2 = r2; \
2243         BPF_R3 = r3; \
2244         BPF_R4 = r4; \
2245         BPF_R5 = r5; \
2246         return ___bpf_prog_run(regs, insn); \
2247 }
2248
2249 #define EVAL1(FN, X) FN(X)
2250 #define EVAL2(FN, X, Y...) FN(X) EVAL1(FN, Y)
2251 #define EVAL3(FN, X, Y...) FN(X) EVAL2(FN, Y)
2252 #define EVAL4(FN, X, Y...) FN(X) EVAL3(FN, Y)
2253 #define EVAL5(FN, X, Y...) FN(X) EVAL4(FN, Y)
2254 #define EVAL6(FN, X, Y...) FN(X) EVAL5(FN, Y)
2255
2256 EVAL6(DEFINE_BPF_PROG_RUN, 32, 64, 96, 128, 160, 192);
2257 EVAL6(DEFINE_BPF_PROG_RUN, 224, 256, 288, 320, 352, 384);
2258 EVAL4(DEFINE_BPF_PROG_RUN, 416, 448, 480, 512);
2259
2260 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 32, 64, 96, 128, 160, 192);
2261 EVAL6(DEFINE_BPF_PROG_RUN_ARGS, 224, 256, 288, 320, 352, 384);
2262 EVAL4(DEFINE_BPF_PROG_RUN_ARGS, 416, 448, 480, 512);
2263
2264 #define PROG_NAME_LIST(stack_size) PROG_NAME(stack_size),
2265
2266 static unsigned int (*interpreters[])(const void *ctx,
2267                                       const struct bpf_insn *insn) = {
2268 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2269 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2270 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2271 };
2272 #undef PROG_NAME_LIST
2273 #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size),
2274 static __maybe_unused
2275 u64 (*interpreters_args[])(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5,
2276                            const struct bpf_insn *insn) = {
2277 EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192)
2278 EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384)
2279 EVAL4(PROG_NAME_LIST, 416, 448, 480, 512)
2280 };
2281 #undef PROG_NAME_LIST
2282
2283 #ifdef CONFIG_BPF_SYSCALL
2284 void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth)
2285 {
2286         stack_depth = max_t(u32, stack_depth, 1);
2287         insn->off = (s16) insn->imm;
2288         insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] -
2289                 __bpf_call_base_args;
2290         insn->code = BPF_JMP | BPF_CALL_ARGS;
2291 }
2292 #endif
2293 #else
2294 static unsigned int __bpf_prog_ret0_warn(const void *ctx,
2295                                          const struct bpf_insn *insn)
2296 {
2297         /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON
2298          * is not working properly, so warn about it!
2299          */
2300         WARN_ON_ONCE(1);
2301         return 0;
2302 }
2303 #endif
2304
2305 bool bpf_prog_map_compatible(struct bpf_map *map,
2306                              const struct bpf_prog *fp)
2307 {
2308         enum bpf_prog_type prog_type = resolve_prog_type(fp);
2309         bool ret;
2310         struct bpf_prog_aux *aux = fp->aux;
2311
2312         if (fp->kprobe_override)
2313                 return false;
2314
2315         /* XDP programs inserted into maps are not guaranteed to run on
2316          * a particular netdev (and can run outside driver context entirely
2317          * in the case of devmap and cpumap). Until device checks
2318          * are implemented, prohibit adding dev-bound programs to program maps.
2319          */
2320         if (bpf_prog_is_dev_bound(aux))
2321                 return false;
2322
2323         spin_lock(&map->owner.lock);
2324         if (!map->owner.type) {
2325                 /* There's no owner yet where we could check for
2326                  * compatibility.
2327                  */
2328                 map->owner.type  = prog_type;
2329                 map->owner.jited = fp->jited;
2330                 map->owner.xdp_has_frags = aux->xdp_has_frags;
2331                 map->owner.attach_func_proto = aux->attach_func_proto;
2332                 ret = true;
2333         } else {
2334                 ret = map->owner.type  == prog_type &&
2335                       map->owner.jited == fp->jited &&
2336                       map->owner.xdp_has_frags == aux->xdp_has_frags;
2337                 if (ret &&
2338                     map->owner.attach_func_proto != aux->attach_func_proto) {
2339                         switch (prog_type) {
2340                         case BPF_PROG_TYPE_TRACING:
2341                         case BPF_PROG_TYPE_LSM:
2342                         case BPF_PROG_TYPE_EXT:
2343                         case BPF_PROG_TYPE_STRUCT_OPS:
2344                                 ret = false;
2345                                 break;
2346                         default:
2347                                 break;
2348                         }
2349                 }
2350         }
2351         spin_unlock(&map->owner.lock);
2352
2353         return ret;
2354 }
2355
2356 static int bpf_check_tail_call(const struct bpf_prog *fp)
2357 {
2358         struct bpf_prog_aux *aux = fp->aux;
2359         int i, ret = 0;
2360
2361         mutex_lock(&aux->used_maps_mutex);
2362         for (i = 0; i < aux->used_map_cnt; i++) {
2363                 struct bpf_map *map = aux->used_maps[i];
2364
2365                 if (!map_type_contains_progs(map))
2366                         continue;
2367
2368                 if (!bpf_prog_map_compatible(map, fp)) {
2369                         ret = -EINVAL;
2370                         goto out;
2371                 }
2372         }
2373
2374 out:
2375         mutex_unlock(&aux->used_maps_mutex);
2376         return ret;
2377 }
2378
2379 static void bpf_prog_select_func(struct bpf_prog *fp)
2380 {
2381 #ifndef CONFIG_BPF_JIT_ALWAYS_ON
2382         u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1);
2383
2384         fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1];
2385 #else
2386         fp->bpf_func = __bpf_prog_ret0_warn;
2387 #endif
2388 }
2389
2390 /**
2391  *      bpf_prog_select_runtime - select exec runtime for BPF program
2392  *      @fp: bpf_prog populated with BPF program
2393  *      @err: pointer to error variable
2394  *
2395  * Try to JIT eBPF program, if JIT is not available, use interpreter.
2396  * The BPF program will be executed via bpf_prog_run() function.
2397  *
2398  * Return: the &fp argument along with &err set to 0 for success or
2399  * a negative errno code on failure
2400  */
2401 struct bpf_prog *bpf_prog_select_runtime(struct bpf_prog *fp, int *err)
2402 {
2403         /* In case of BPF to BPF calls, verifier did all the prep
2404          * work with regards to JITing, etc.
2405          */
2406         bool jit_needed = false;
2407
2408         if (fp->bpf_func)
2409                 goto finalize;
2410
2411         if (IS_ENABLED(CONFIG_BPF_JIT_ALWAYS_ON) ||
2412             bpf_prog_has_kfunc_call(fp))
2413                 jit_needed = true;
2414
2415         bpf_prog_select_func(fp);
2416
2417         /* eBPF JITs can rewrite the program in case constant
2418          * blinding is active. However, in case of error during
2419          * blinding, bpf_int_jit_compile() must always return a
2420          * valid program, which in this case would simply not
2421          * be JITed, but falls back to the interpreter.
2422          */
2423         if (!bpf_prog_is_offloaded(fp->aux)) {
2424                 *err = bpf_prog_alloc_jited_linfo(fp);
2425                 if (*err)
2426                         return fp;
2427
2428                 fp = bpf_int_jit_compile(fp);
2429                 bpf_prog_jit_attempt_done(fp);
2430                 if (!fp->jited && jit_needed) {
2431                         *err = -ENOTSUPP;
2432                         return fp;
2433                 }
2434         } else {
2435                 *err = bpf_prog_offload_compile(fp);
2436                 if (*err)
2437                         return fp;
2438         }
2439
2440 finalize:
2441         *err = bpf_prog_lock_ro(fp);
2442         if (*err)
2443                 return fp;
2444
2445         /* The tail call compatibility check can only be done at
2446          * this late stage as we need to determine, if we deal
2447          * with JITed or non JITed program concatenations and not
2448          * all eBPF JITs might immediately support all features.
2449          */
2450         *err = bpf_check_tail_call(fp);
2451
2452         return fp;
2453 }
2454 EXPORT_SYMBOL_GPL(bpf_prog_select_runtime);
2455
2456 static unsigned int __bpf_prog_ret1(const void *ctx,
2457                                     const struct bpf_insn *insn)
2458 {
2459         return 1;
2460 }
2461
2462 static struct bpf_prog_dummy {
2463         struct bpf_prog prog;
2464 } dummy_bpf_prog = {
2465         .prog = {
2466                 .bpf_func = __bpf_prog_ret1,
2467         },
2468 };
2469
2470 struct bpf_empty_prog_array bpf_empty_prog_array = {
2471         .null_prog = NULL,
2472 };
2473 EXPORT_SYMBOL(bpf_empty_prog_array);
2474
2475 struct bpf_prog_array *bpf_prog_array_alloc(u32 prog_cnt, gfp_t flags)
2476 {
2477         struct bpf_prog_array *p;
2478
2479         if (prog_cnt)
2480                 p = kzalloc(struct_size(p, items, prog_cnt + 1), flags);
2481         else
2482                 p = &bpf_empty_prog_array.hdr;
2483
2484         return p;
2485 }
2486
2487 void bpf_prog_array_free(struct bpf_prog_array *progs)
2488 {
2489         if (!progs || progs == &bpf_empty_prog_array.hdr)
2490                 return;
2491         kfree_rcu(progs, rcu);
2492 }
2493
2494 static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
2495 {
2496         struct bpf_prog_array *progs;
2497
2498         /* If RCU Tasks Trace grace period implies RCU grace period, there is
2499          * no need to call kfree_rcu(), just call kfree() directly.
2500          */
2501         progs = container_of(rcu, struct bpf_prog_array, rcu);
2502         if (rcu_trace_implies_rcu_gp())
2503                 kfree(progs);
2504         else
2505                 kfree_rcu(progs, rcu);
2506 }
2507
2508 void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
2509 {
2510         if (!progs || progs == &bpf_empty_prog_array.hdr)
2511                 return;
2512         call_rcu_tasks_trace(&progs->rcu, __bpf_prog_array_free_sleepable_cb);
2513 }
2514
2515 int bpf_prog_array_length(struct bpf_prog_array *array)
2516 {
2517         struct bpf_prog_array_item *item;
2518         u32 cnt = 0;
2519
2520         for (item = array->items; item->prog; item++)
2521                 if (item->prog != &dummy_bpf_prog.prog)
2522                         cnt++;
2523         return cnt;
2524 }
2525
2526 bool bpf_prog_array_is_empty(struct bpf_prog_array *array)
2527 {
2528         struct bpf_prog_array_item *item;
2529
2530         for (item = array->items; item->prog; item++)
2531                 if (item->prog != &dummy_bpf_prog.prog)
2532                         return false;
2533         return true;
2534 }
2535
2536 static bool bpf_prog_array_copy_core(struct bpf_prog_array *array,
2537                                      u32 *prog_ids,
2538                                      u32 request_cnt)
2539 {
2540         struct bpf_prog_array_item *item;
2541         int i = 0;
2542
2543         for (item = array->items; item->prog; item++) {
2544                 if (item->prog == &dummy_bpf_prog.prog)
2545                         continue;
2546                 prog_ids[i] = item->prog->aux->id;
2547                 if (++i == request_cnt) {
2548                         item++;
2549                         break;
2550                 }
2551         }
2552
2553         return !!(item->prog);
2554 }
2555
2556 int bpf_prog_array_copy_to_user(struct bpf_prog_array *array,
2557                                 __u32 __user *prog_ids, u32 cnt)
2558 {
2559         unsigned long err = 0;
2560         bool nospc;
2561         u32 *ids;
2562
2563         /* users of this function are doing:
2564          * cnt = bpf_prog_array_length();
2565          * if (cnt > 0)
2566          *     bpf_prog_array_copy_to_user(..., cnt);
2567          * so below kcalloc doesn't need extra cnt > 0 check.
2568          */
2569         ids = kcalloc(cnt, sizeof(u32), GFP_USER | __GFP_NOWARN);
2570         if (!ids)
2571                 return -ENOMEM;
2572         nospc = bpf_prog_array_copy_core(array, ids, cnt);
2573         err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
2574         kfree(ids);
2575         if (err)
2576                 return -EFAULT;
2577         if (nospc)
2578                 return -ENOSPC;
2579         return 0;
2580 }
2581
2582 void bpf_prog_array_delete_safe(struct bpf_prog_array *array,
2583                                 struct bpf_prog *old_prog)
2584 {
2585         struct bpf_prog_array_item *item;
2586
2587         for (item = array->items; item->prog; item++)
2588                 if (item->prog == old_prog) {
2589                         WRITE_ONCE(item->prog, &dummy_bpf_prog.prog);
2590                         break;
2591                 }
2592 }
2593
2594 /**
2595  * bpf_prog_array_delete_safe_at() - Replaces the program at the given
2596  *                                   index into the program array with
2597  *                                   a dummy no-op program.
2598  * @array: a bpf_prog_array
2599  * @index: the index of the program to replace
2600  *
2601  * Skips over dummy programs, by not counting them, when calculating
2602  * the position of the program to replace.
2603  *
2604  * Return:
2605  * * 0          - Success
2606  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
2607  * * -ENOENT    - Index out of range
2608  */
2609 int bpf_prog_array_delete_safe_at(struct bpf_prog_array *array, int index)
2610 {
2611         return bpf_prog_array_update_at(array, index, &dummy_bpf_prog.prog);
2612 }
2613
2614 /**
2615  * bpf_prog_array_update_at() - Updates the program at the given index
2616  *                              into the program array.
2617  * @array: a bpf_prog_array
2618  * @index: the index of the program to update
2619  * @prog: the program to insert into the array
2620  *
2621  * Skips over dummy programs, by not counting them, when calculating
2622  * the position of the program to update.
2623  *
2624  * Return:
2625  * * 0          - Success
2626  * * -EINVAL    - Invalid index value. Must be a non-negative integer.
2627  * * -ENOENT    - Index out of range
2628  */
2629 int bpf_prog_array_update_at(struct bpf_prog_array *array, int index,
2630                              struct bpf_prog *prog)
2631 {
2632         struct bpf_prog_array_item *item;
2633
2634         if (unlikely(index < 0))
2635                 return -EINVAL;
2636
2637         for (item = array->items; item->prog; item++) {
2638                 if (item->prog == &dummy_bpf_prog.prog)
2639                         continue;
2640                 if (!index) {
2641                         WRITE_ONCE(item->prog, prog);
2642                         return 0;
2643                 }
2644                 index--;
2645         }
2646         return -ENOENT;
2647 }
2648
2649 int bpf_prog_array_copy(struct bpf_prog_array *old_array,
2650                         struct bpf_prog *exclude_prog,
2651                         struct bpf_prog *include_prog,
2652                         u64 bpf_cookie,
2653                         struct bpf_prog_array **new_array)
2654 {
2655         int new_prog_cnt, carry_prog_cnt = 0;
2656         struct bpf_prog_array_item *existing, *new;
2657         struct bpf_prog_array *array;
2658         bool found_exclude = false;
2659
2660         /* Figure out how many existing progs we need to carry over to
2661          * the new array.
2662          */
2663         if (old_array) {
2664                 existing = old_array->items;
2665                 for (; existing->prog; existing++) {
2666                         if (existing->prog == exclude_prog) {
2667                                 found_exclude = true;
2668                                 continue;
2669                         }
2670                         if (existing->prog != &dummy_bpf_prog.prog)
2671                                 carry_prog_cnt++;
2672                         if (existing->prog == include_prog)
2673                                 return -EEXIST;
2674                 }
2675         }
2676
2677         if (exclude_prog && !found_exclude)
2678                 return -ENOENT;
2679
2680         /* How many progs (not NULL) will be in the new array? */
2681         new_prog_cnt = carry_prog_cnt;
2682         if (include_prog)
2683                 new_prog_cnt += 1;
2684
2685         /* Do we have any prog (not NULL) in the new array? */
2686         if (!new_prog_cnt) {
2687                 *new_array = NULL;
2688                 return 0;
2689         }
2690
2691         /* +1 as the end of prog_array is marked with NULL */
2692         array = bpf_prog_array_alloc(new_prog_cnt + 1, GFP_KERNEL);
2693         if (!array)
2694                 return -ENOMEM;
2695         new = array->items;
2696
2697         /* Fill in the new prog array */
2698         if (carry_prog_cnt) {
2699                 existing = old_array->items;
2700                 for (; existing->prog; existing++) {
2701                         if (existing->prog == exclude_prog ||
2702                             existing->prog == &dummy_bpf_prog.prog)
2703                                 continue;
2704
2705                         new->prog = existing->prog;
2706                         new->bpf_cookie = existing->bpf_cookie;
2707                         new++;
2708                 }
2709         }
2710         if (include_prog) {
2711                 new->prog = include_prog;
2712                 new->bpf_cookie = bpf_cookie;
2713                 new++;
2714         }
2715         new->prog = NULL;
2716         *new_array = array;
2717         return 0;
2718 }
2719
2720 int bpf_prog_array_copy_info(struct bpf_prog_array *array,
2721                              u32 *prog_ids, u32 request_cnt,
2722                              u32 *prog_cnt)
2723 {
2724         u32 cnt = 0;
2725
2726         if (array)
2727                 cnt = bpf_prog_array_length(array);
2728
2729         *prog_cnt = cnt;
2730
2731         /* return early if user requested only program count or nothing to copy */
2732         if (!request_cnt || !cnt)
2733                 return 0;
2734
2735         /* this function is called under trace/bpf_trace.c: bpf_event_mutex */
2736         return bpf_prog_array_copy_core(array, prog_ids, request_cnt) ? -ENOSPC
2737                                                                      : 0;
2738 }
2739
2740 void __bpf_free_used_maps(struct bpf_prog_aux *aux,
2741                           struct bpf_map **used_maps, u32 len)
2742 {
2743         struct bpf_map *map;
2744         bool sleepable;
2745         u32 i;
2746
2747         sleepable = aux->prog->sleepable;
2748         for (i = 0; i < len; i++) {
2749                 map = used_maps[i];
2750                 if (map->ops->map_poke_untrack)
2751                         map->ops->map_poke_untrack(map, aux);
2752                 if (sleepable)
2753                         atomic64_dec(&map->sleepable_refcnt);
2754                 bpf_map_put(map);
2755         }
2756 }
2757
2758 static void bpf_free_used_maps(struct bpf_prog_aux *aux)
2759 {
2760         __bpf_free_used_maps(aux, aux->used_maps, aux->used_map_cnt);
2761         kfree(aux->used_maps);
2762 }
2763
2764 void __bpf_free_used_btfs(struct btf_mod_pair *used_btfs, u32 len)
2765 {
2766 #ifdef CONFIG_BPF_SYSCALL
2767         struct btf_mod_pair *btf_mod;
2768         u32 i;
2769
2770         for (i = 0; i < len; i++) {
2771                 btf_mod = &used_btfs[i];
2772                 if (btf_mod->module)
2773                         module_put(btf_mod->module);
2774                 btf_put(btf_mod->btf);
2775         }
2776 #endif
2777 }
2778
2779 static void bpf_free_used_btfs(struct bpf_prog_aux *aux)
2780 {
2781         __bpf_free_used_btfs(aux->used_btfs, aux->used_btf_cnt);
2782         kfree(aux->used_btfs);
2783 }
2784
2785 static void bpf_prog_free_deferred(struct work_struct *work)
2786 {
2787         struct bpf_prog_aux *aux;
2788         int i;
2789
2790         aux = container_of(work, struct bpf_prog_aux, work);
2791 #ifdef CONFIG_BPF_SYSCALL
2792         bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab);
2793 #endif
2794 #ifdef CONFIG_CGROUP_BPF
2795         if (aux->cgroup_atype != CGROUP_BPF_ATTACH_TYPE_INVALID)
2796                 bpf_cgroup_atype_put(aux->cgroup_atype);
2797 #endif
2798         bpf_free_used_maps(aux);
2799         bpf_free_used_btfs(aux);
2800         if (bpf_prog_is_dev_bound(aux))
2801                 bpf_prog_dev_bound_destroy(aux->prog);
2802 #ifdef CONFIG_PERF_EVENTS
2803         if (aux->prog->has_callchain_buf)
2804                 put_callchain_buffers();
2805 #endif
2806         if (aux->dst_trampoline)
2807                 bpf_trampoline_put(aux->dst_trampoline);
2808         for (i = 0; i < aux->real_func_cnt; i++) {
2809                 /* We can just unlink the subprog poke descriptor table as
2810                  * it was originally linked to the main program and is also
2811                  * released along with it.
2812                  */
2813                 aux->func[i]->aux->poke_tab = NULL;
2814                 bpf_jit_free(aux->func[i]);
2815         }
2816         if (aux->real_func_cnt) {
2817                 kfree(aux->func);
2818                 bpf_prog_unlock_free(aux->prog);
2819         } else {
2820                 bpf_jit_free(aux->prog);
2821         }
2822 }
2823
2824 void bpf_prog_free(struct bpf_prog *fp)
2825 {
2826         struct bpf_prog_aux *aux = fp->aux;
2827
2828         if (aux->dst_prog)
2829                 bpf_prog_put(aux->dst_prog);
2830         bpf_token_put(aux->token);
2831         INIT_WORK(&aux->work, bpf_prog_free_deferred);
2832         schedule_work(&aux->work);
2833 }
2834 EXPORT_SYMBOL_GPL(bpf_prog_free);
2835
2836 /* RNG for unprivileged user space with separated state from prandom_u32(). */
2837 static DEFINE_PER_CPU(struct rnd_state, bpf_user_rnd_state);
2838
2839 void bpf_user_rnd_init_once(void)
2840 {
2841         prandom_init_once(&bpf_user_rnd_state);
2842 }
2843
2844 BPF_CALL_0(bpf_user_rnd_u32)
2845 {
2846         /* Should someone ever have the rather unwise idea to use some
2847          * of the registers passed into this function, then note that
2848          * this function is called from native eBPF and classic-to-eBPF
2849          * transformations. Register assignments from both sides are
2850          * different, f.e. classic always sets fn(ctx, A, X) here.
2851          */
2852         struct rnd_state *state;
2853         u32 res;
2854
2855         state = &get_cpu_var(bpf_user_rnd_state);
2856         res = prandom_u32_state(state);
2857         put_cpu_var(bpf_user_rnd_state);
2858
2859         return res;
2860 }
2861
2862 BPF_CALL_0(bpf_get_raw_cpu_id)
2863 {
2864         return raw_smp_processor_id();
2865 }
2866
2867 /* Weak definitions of helper functions in case we don't have bpf syscall. */
2868 const struct bpf_func_proto bpf_map_lookup_elem_proto __weak;
2869 const struct bpf_func_proto bpf_map_update_elem_proto __weak;
2870 const struct bpf_func_proto bpf_map_delete_elem_proto __weak;
2871 const struct bpf_func_proto bpf_map_push_elem_proto __weak;
2872 const struct bpf_func_proto bpf_map_pop_elem_proto __weak;
2873 const struct bpf_func_proto bpf_map_peek_elem_proto __weak;
2874 const struct bpf_func_proto bpf_map_lookup_percpu_elem_proto __weak;
2875 const struct bpf_func_proto bpf_spin_lock_proto __weak;
2876 const struct bpf_func_proto bpf_spin_unlock_proto __weak;
2877 const struct bpf_func_proto bpf_jiffies64_proto __weak;
2878
2879 const struct bpf_func_proto bpf_get_prandom_u32_proto __weak;
2880 const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak;
2881 const struct bpf_func_proto bpf_get_numa_node_id_proto __weak;
2882 const struct bpf_func_proto bpf_ktime_get_ns_proto __weak;
2883 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak;
2884 const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak;
2885 const struct bpf_func_proto bpf_ktime_get_tai_ns_proto __weak;
2886
2887 const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak;
2888 const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
2889 const struct bpf_func_proto bpf_get_current_comm_proto __weak;
2890 const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
2891 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto __weak;
2892 const struct bpf_func_proto bpf_get_local_storage_proto __weak;
2893 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
2894 const struct bpf_func_proto bpf_snprintf_btf_proto __weak;
2895 const struct bpf_func_proto bpf_seq_printf_btf_proto __weak;
2896 const struct bpf_func_proto bpf_set_retval_proto __weak;
2897 const struct bpf_func_proto bpf_get_retval_proto __weak;
2898
2899 const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
2900 {
2901         return NULL;
2902 }
2903
2904 const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
2905 {
2906         return NULL;
2907 }
2908
2909 u64 __weak
2910 bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
2911                  void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
2912 {
2913         return -ENOTSUPP;
2914 }
2915 EXPORT_SYMBOL_GPL(bpf_event_output);
2916
2917 /* Always built-in helper functions. */
2918 const struct bpf_func_proto bpf_tail_call_proto = {
2919         .func           = NULL,
2920         .gpl_only       = false,
2921         .ret_type       = RET_VOID,
2922         .arg1_type      = ARG_PTR_TO_CTX,
2923         .arg2_type      = ARG_CONST_MAP_PTR,
2924         .arg3_type      = ARG_ANYTHING,
2925 };
2926
2927 /* Stub for JITs that only support cBPF. eBPF programs are interpreted.
2928  * It is encouraged to implement bpf_int_jit_compile() instead, so that
2929  * eBPF and implicitly also cBPF can get JITed!
2930  */
2931 struct bpf_prog * __weak bpf_int_jit_compile(struct bpf_prog *prog)
2932 {
2933         return prog;
2934 }
2935
2936 /* Stub for JITs that support eBPF. All cBPF code gets transformed into
2937  * eBPF by the kernel and is later compiled by bpf_int_jit_compile().
2938  */
2939 void __weak bpf_jit_compile(struct bpf_prog *prog)
2940 {
2941 }
2942
2943 bool __weak bpf_helper_changes_pkt_data(enum bpf_func_id func_id)
2944 {
2945         return false;
2946 }
2947
2948 /* Return TRUE if the JIT backend wants verifier to enable sub-register usage
2949  * analysis code and wants explicit zero extension inserted by verifier.
2950  * Otherwise, return FALSE.
2951  *
2952  * The verifier inserts an explicit zero extension after BPF_CMPXCHGs even if
2953  * you don't override this. JITs that don't want these extra insns can detect
2954  * them using insn_is_zext.
2955  */
2956 bool __weak bpf_jit_needs_zext(void)
2957 {
2958         return false;
2959 }
2960
2961 /* Return true if the JIT inlines the call to the helper corresponding to
2962  * the imm.
2963  *
2964  * The verifier will not patch the insn->imm for the call to the helper if
2965  * this returns true.
2966  */
2967 bool __weak bpf_jit_inlines_helper_call(s32 imm)
2968 {
2969         return false;
2970 }
2971
2972 /* Return TRUE if the JIT backend supports mixing bpf2bpf and tailcalls. */
2973 bool __weak bpf_jit_supports_subprog_tailcalls(void)
2974 {
2975         return false;
2976 }
2977
2978 bool __weak bpf_jit_supports_percpu_insn(void)
2979 {
2980         return false;
2981 }
2982
2983 bool __weak bpf_jit_supports_kfunc_call(void)
2984 {
2985         return false;
2986 }
2987
2988 bool __weak bpf_jit_supports_far_kfunc_call(void)
2989 {
2990         return false;
2991 }
2992
2993 bool __weak bpf_jit_supports_arena(void)
2994 {
2995         return false;
2996 }
2997
2998 bool __weak bpf_jit_supports_insn(struct bpf_insn *insn, bool in_arena)
2999 {
3000         return false;
3001 }
3002
3003 u64 __weak bpf_arch_uaddress_limit(void)
3004 {
3005 #if defined(CONFIG_64BIT) && defined(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE)
3006         return TASK_SIZE;
3007 #else
3008         return 0;
3009 #endif
3010 }
3011
3012 /* Return TRUE if the JIT backend satisfies the following two conditions:
3013  * 1) JIT backend supports atomic_xchg() on pointer-sized words.
3014  * 2) Under the specific arch, the implementation of xchg() is the same
3015  *    as atomic_xchg() on pointer-sized words.
3016  */
3017 bool __weak bpf_jit_supports_ptr_xchg(void)
3018 {
3019         return false;
3020 }
3021
3022 /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call
3023  * skb_copy_bits(), so provide a weak definition of it for NET-less config.
3024  */
3025 int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to,
3026                          int len)
3027 {
3028         return -EFAULT;
3029 }
3030
3031 int __weak bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
3032                               void *addr1, void *addr2)
3033 {
3034         return -ENOTSUPP;
3035 }
3036
3037 void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len)
3038 {
3039         return ERR_PTR(-ENOTSUPP);
3040 }
3041
3042 int __weak bpf_arch_text_invalidate(void *dst, size_t len)
3043 {
3044         return -ENOTSUPP;
3045 }
3046
3047 bool __weak bpf_jit_supports_exceptions(void)
3048 {
3049         return false;
3050 }
3051
3052 bool __weak bpf_jit_supports_private_stack(void)
3053 {
3054         return false;
3055 }
3056
3057 void __weak arch_bpf_stack_walk(bool (*consume_fn)(void *cookie, u64 ip, u64 sp, u64 bp), void *cookie)
3058 {
3059 }
3060
3061 /* for configs without MMU or 32-bit */
3062 __weak const struct bpf_map_ops arena_map_ops;
3063 __weak u64 bpf_arena_get_user_vm_start(struct bpf_arena *arena)
3064 {
3065         return 0;
3066 }
3067 __weak u64 bpf_arena_get_kern_vm_start(struct bpf_arena *arena)
3068 {
3069         return 0;
3070 }
3071
3072 #ifdef CONFIG_BPF_SYSCALL
3073 static int __init bpf_global_ma_init(void)
3074 {
3075         int ret;
3076
3077         ret = bpf_mem_alloc_init(&bpf_global_ma, 0, false);
3078         bpf_global_ma_set = !ret;
3079         return ret;
3080 }
3081 late_initcall(bpf_global_ma_init);
3082 #endif
3083
3084 DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
3085 EXPORT_SYMBOL(bpf_stats_enabled_key);
3086
3087 /* All definitions of tracepoints related to BPF. */
3088 #define CREATE_TRACE_POINTS
3089 #include <linux/bpf_trace.h>
3090
3091 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_exception);
3092 EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);