kernel/bpf/helpers.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
   3  */
   4 #include <linux/bpf.h>
   5 #include <linux/rcupdate.h>
   6 #include <linux/random.h>
   7 #include <linux/smp.h>
   8 #include <linux/topology.h>
   9 #include <linux/ktime.h>
  10 #include <linux/sched.h>
  11 #include <linux/uidgid.h>
  12 #include <linux/filter.h>
  13 #include <linux/ctype.h>
  14 #include <linux/jiffies.h>
  15 #include <linux/pid_namespace.h>
  16 #include <linux/proc_ns.h>
  17
  18 #include "../../lib/kstrtox.h"
  19
  20 /* If kernel subsystem is allowing eBPF programs to call this function,
  21  * inside its own verifier_ops->get_func_proto() callback it should return
  22  * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
  23  *
  24  * Different map implementations will rely on rcu in map methods
  25  * lookup/update/delete, therefore eBPF programs must run under rcu lock
  26  * if program is allowed to access maps, so check rcu_read_lock_held in
  27  * all three functions.
  28  */
  29 BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key)
  30 {
  31         WARN_ON_ONCE(!rcu_read_lock_held());
  32         return (unsigned long) map->ops->map_lookup_elem(map, key);
  33 }
  34
  35 const struct bpf_func_proto bpf_map_lookup_elem_proto = {
  36         .func           = bpf_map_lookup_elem,
  37         .gpl_only       = false,
  38         .pkt_access     = true,
  39         .ret_type       = RET_PTR_TO_MAP_VALUE_OR_NULL,
  40         .arg1_type      = ARG_CONST_MAP_PTR,
  41         .arg2_type      = ARG_PTR_TO_MAP_KEY,
  42 };
  43
  44 BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
  45            void *, value, u64, flags)
  46 {
  47         WARN_ON_ONCE(!rcu_read_lock_held());
  48         return map->ops->map_update_elem(map, key, value, flags);
  49 }
  50
  51 const struct bpf_func_proto bpf_map_update_elem_proto = {
  52         .func           = bpf_map_update_elem,
  53         .gpl_only       = false,
  54         .pkt_access     = true,
  55         .ret_type       = RET_INTEGER,
  56         .arg1_type      = ARG_CONST_MAP_PTR,
  57         .arg2_type      = ARG_PTR_TO_MAP_KEY,
  58         .arg3_type      = ARG_PTR_TO_MAP_VALUE,
  59         .arg4_type      = ARG_ANYTHING,
  60 };
  61
  62 BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
  63 {
  64         WARN_ON_ONCE(!rcu_read_lock_held());
  65         return map->ops->map_delete_elem(map, key);
  66 }
  67
  68 const struct bpf_func_proto bpf_map_delete_elem_proto = {
  69         .func           = bpf_map_delete_elem,
  70         .gpl_only       = false,
  71         .pkt_access     = true,
  72         .ret_type       = RET_INTEGER,
  73         .arg1_type      = ARG_CONST_MAP_PTR,
  74         .arg2_type      = ARG_PTR_TO_MAP_KEY,
  75 };
  76
  77 BPF_CALL_3(bpf_map_push_elem, struct bpf_map *, map, void *, value, u64, flags)
  78 {
  79         return map->ops->map_push_elem(map, value, flags);
  80 }
  81
  82 const struct bpf_func_proto bpf_map_push_elem_proto = {
  83         .func           = bpf_map_push_elem,
  84         .gpl_only       = false,
  85         .pkt_access     = true,
  86         .ret_type       = RET_INTEGER,
  87         .arg1_type      = ARG_CONST_MAP_PTR,
  88         .arg2_type      = ARG_PTR_TO_MAP_VALUE,
  89         .arg3_type      = ARG_ANYTHING,
  90 };
  91
  92 BPF_CALL_2(bpf_map_pop_elem, struct bpf_map *, map, void *, value)
  93 {
  94         return map->ops->map_pop_elem(map, value);
  95 }
  96
  97 const struct bpf_func_proto bpf_map_pop_elem_proto = {
  98         .func           = bpf_map_pop_elem,
  99         .gpl_only       = false,
 100         .ret_type       = RET_INTEGER,
 101         .arg1_type      = ARG_CONST_MAP_PTR,
 102         .arg2_type      = ARG_PTR_TO_UNINIT_MAP_VALUE,
 103 };
 104
 105 BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value)
 106 {
 107         return map->ops->map_peek_elem(map, value);
 108 }
 109
 110 const struct bpf_func_proto bpf_map_peek_elem_proto = {
 111         .func           = bpf_map_pop_elem,
 112         .gpl_only       = false,
 113         .ret_type       = RET_INTEGER,
 114         .arg1_type      = ARG_CONST_MAP_PTR,
 115         .arg2_type      = ARG_PTR_TO_UNINIT_MAP_VALUE,
 116 };
 117
 118 const struct bpf_func_proto bpf_get_prandom_u32_proto = {
 119         .func           = bpf_user_rnd_u32,
 120         .gpl_only       = false,
 121         .ret_type       = RET_INTEGER,
 122 };
 123
 124 BPF_CALL_0(bpf_get_smp_processor_id)
 125 {
 126         return smp_processor_id();
 127 }
 128
 129 const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
 130         .func           = bpf_get_smp_processor_id,
 131         .gpl_only       = false,
 132         .ret_type       = RET_INTEGER,
 133 };
 134
 135 BPF_CALL_0(bpf_get_numa_node_id)
 136 {
 137         return numa_node_id();
 138 }
 139
 140 const struct bpf_func_proto bpf_get_numa_node_id_proto = {
 141         .func           = bpf_get_numa_node_id,
 142         .gpl_only       = false,
 143         .ret_type       = RET_INTEGER,
 144 };
 145
 146 BPF_CALL_0(bpf_ktime_get_ns)
 147 {
 148         /* NMI safe access to clock monotonic */
 149         return ktime_get_mono_fast_ns();
 150 }
 151
 152 const struct bpf_func_proto bpf_ktime_get_ns_proto = {
 153         .func           = bpf_ktime_get_ns,
 154         .gpl_only       = false,
 155         .ret_type       = RET_INTEGER,
 156 };
 157
 158 BPF_CALL_0(bpf_ktime_get_boot_ns)
 159 {
 160         /* NMI safe access to clock boottime */
 161         return ktime_get_boot_fast_ns();
 162 }
 163
 164 const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = {
 165         .func           = bpf_ktime_get_boot_ns,
 166         .gpl_only       = false,
 167         .ret_type       = RET_INTEGER,
 168 };
 169
 170 BPF_CALL_0(bpf_get_current_pid_tgid)
 171 {
 172         struct task_struct *task = current;
 173
 174         if (unlikely(!task))
 175                 return -EINVAL;
 176
 177         return (u64) task->tgid << 32 | task->pid;
 178 }
 179
 180 const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
 181         .func           = bpf_get_current_pid_tgid,
 182         .gpl_only       = false,
 183         .ret_type       = RET_INTEGER,
 184 };
 185
 186 BPF_CALL_0(bpf_get_current_uid_gid)
 187 {
 188         struct task_struct *task = current;
 189         kuid_t uid;
 190         kgid_t gid;
 191
 192         if (unlikely(!task))
 193                 return -EINVAL;
 194
 195         current_uid_gid(&uid, &gid);
 196         return (u64) from_kgid(&init_user_ns, gid) << 32 |
 197                      from_kuid(&init_user_ns, uid);
 198 }
 199
 200 const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
 201         .func           = bpf_get_current_uid_gid,
 202         .gpl_only       = false,
 203         .ret_type       = RET_INTEGER,
 204 };
 205
 206 BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size)
 207 {
 208         struct task_struct *task = current;
 209
 210         if (unlikely(!task))
 211                 goto err_clear;
 212
 213         strncpy(buf, task->comm, size);
 214
 215         /* Verifier guarantees that size > 0. For task->comm exceeding
 216          * size, guarantee that buf is %NUL-terminated. Unconditionally
 217          * done here to save the size test.
 218          */
 219         buf[size - 1] = 0;
 220         return 0;
 221 err_clear:
 222         memset(buf, 0, size);
 223         return -EINVAL;
 224 }
 225
 226 const struct bpf_func_proto bpf_get_current_comm_proto = {
 227         .func           = bpf_get_current_comm,
 228         .gpl_only       = false,
 229         .ret_type       = RET_INTEGER,
 230         .arg1_type      = ARG_PTR_TO_UNINIT_MEM,
 231         .arg2_type      = ARG_CONST_SIZE,
 232 };
 233
 234 #if defined(CONFIG_QUEUED_SPINLOCKS) || defined(CONFIG_BPF_ARCH_SPINLOCK)
 235
 236 static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
 237 {
 238         arch_spinlock_t *l = (void *)lock;
 239         union {
 240                 __u32 val;
 241                 arch_spinlock_t lock;
 242         } u = { .lock = __ARCH_SPIN_LOCK_UNLOCKED };
 243
 244         compiletime_assert(u.val == 0, "__ARCH_SPIN_LOCK_UNLOCKED not 0");
 245         BUILD_BUG_ON(sizeof(*l) != sizeof(__u32));
 246         BUILD_BUG_ON(sizeof(*lock) != sizeof(__u32));
 247         arch_spin_lock(l);
 248 }
 249
 250 static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
 251 {
 252         arch_spinlock_t *l = (void *)lock;
 253
 254         arch_spin_unlock(l);
 255 }
 256
 257 #else
 258
 259 static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
 260 {
 261         atomic_t *l = (void *)lock;
 262
 263         BUILD_BUG_ON(sizeof(*l) != sizeof(*lock));
 264         do {
 265                 atomic_cond_read_relaxed(l, !VAL);
 266         } while (atomic_xchg(l, 1));
 267 }
 268
 269 static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
 270 {
 271         atomic_t *l = (void *)lock;
 272
 273         atomic_set_release(l, 0);
 274 }
 275
 276 #endif
 277
 278 static DEFINE_PER_CPU(unsigned long, irqsave_flags);
 279
 280 notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
 281 {
 282         unsigned long flags;
 283
 284         local_irq_save(flags);
 285         __bpf_spin_lock(lock);
 286         __this_cpu_write(irqsave_flags, flags);
 287         return 0;
 288 }
 289
 290 const struct bpf_func_proto bpf_spin_lock_proto = {
 291         .func           = bpf_spin_lock,
 292         .gpl_only       = false,
 293         .ret_type       = RET_VOID,
 294         .arg1_type      = ARG_PTR_TO_SPIN_LOCK,
 295 };
 296
 297 notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
 298 {
 299         unsigned long flags;
 300
 301         flags = __this_cpu_read(irqsave_flags);
 302         __bpf_spin_unlock(lock);
 303         local_irq_restore(flags);
 304         return 0;
 305 }
 306
 307 const struct bpf_func_proto bpf_spin_unlock_proto = {
 308         .func           = bpf_spin_unlock,
 309         .gpl_only       = false,
 310         .ret_type       = RET_VOID,
 311         .arg1_type      = ARG_PTR_TO_SPIN_LOCK,
 312 };
 313
 314 void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
 315                            bool lock_src)
 316 {
 317         struct bpf_spin_lock *lock;
 318
 319         if (lock_src)
 320                 lock = src + map->spin_lock_off;
 321         else
 322                 lock = dst + map->spin_lock_off;
 323         preempt_disable();
 324         ____bpf_spin_lock(lock);
 325         copy_map_value(map, dst, src);
 326         ____bpf_spin_unlock(lock);
 327         preempt_enable();
 328 }
 329
 330 BPF_CALL_0(bpf_jiffies64)
 331 {
 332         return get_jiffies_64();
 333 }
 334
 335 const struct bpf_func_proto bpf_jiffies64_proto = {
 336         .func           = bpf_jiffies64,
 337         .gpl_only       = false,
 338         .ret_type       = RET_INTEGER,
 339 };
 340
 341 #ifdef CONFIG_CGROUPS
 342 BPF_CALL_0(bpf_get_current_cgroup_id)
 343 {
 344         struct cgroup *cgrp = task_dfl_cgroup(current);
 345
 346         return cgroup_id(cgrp);
 347 }
 348
 349 const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
 350         .func           = bpf_get_current_cgroup_id,
 351         .gpl_only       = false,
 352         .ret_type       = RET_INTEGER,
 353 };
 354
 355 BPF_CALL_1(bpf_get_current_ancestor_cgroup_id, int, ancestor_level)
 356 {
 357         struct cgroup *cgrp = task_dfl_cgroup(current);
 358         struct cgroup *ancestor;
 359
 360         ancestor = cgroup_ancestor(cgrp, ancestor_level);
 361         if (!ancestor)
 362                 return 0;
 363         return cgroup_id(ancestor);
 364 }
 365
 366 const struct bpf_func_proto bpf_get_current_ancestor_cgroup_id_proto = {
 367         .func           = bpf_get_current_ancestor_cgroup_id,
 368         .gpl_only       = false,
 369         .ret_type       = RET_INTEGER,
 370         .arg1_type      = ARG_ANYTHING,
 371 };
 372
 373 #ifdef CONFIG_CGROUP_BPF
 374 DECLARE_PER_CPU(struct bpf_cgroup_storage*,
 375                 bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
 376
 377 BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
 378 {
 379         /* flags argument is not used now,
 380          * but provides an ability to extend the API.
 381          * verifier checks that its value is correct.
 382          */
 383         enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
 384         struct bpf_cgroup_storage *storage;
 385         void *ptr;
 386
 387         storage = this_cpu_read(bpf_cgroup_storage[stype]);
 388
 389         if (stype == BPF_CGROUP_STORAGE_SHARED)
 390                 ptr = &READ_ONCE(storage->buf)->data[0];
 391         else
 392                 ptr = this_cpu_ptr(storage->percpu_buf);
 393
 394         return (unsigned long)ptr;
 395 }
 396
 397 const struct bpf_func_proto bpf_get_local_storage_proto = {
 398         .func           = bpf_get_local_storage,
 399         .gpl_only       = false,
 400         .ret_type       = RET_PTR_TO_MAP_VALUE,
 401         .arg1_type      = ARG_CONST_MAP_PTR,
 402         .arg2_type      = ARG_ANYTHING,
 403 };
 404 #endif
 405
 406 #define BPF_STRTOX_BASE_MASK 0x1F
 407
 408 static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
 409                           unsigned long long *res, bool *is_negative)
 410 {
 411         unsigned int base = flags & BPF_STRTOX_BASE_MASK;
 412         const char *cur_buf = buf;
 413         size_t cur_len = buf_len;
 414         unsigned int consumed;
 415         size_t val_len;
 416         char str[64];
 417
 418         if (!buf || !buf_len || !res || !is_negative)
 419                 return -EINVAL;
 420
 421         if (base != 0 && base != 8 && base != 10 && base != 16)
 422                 return -EINVAL;
 423
 424         if (flags & ~BPF_STRTOX_BASE_MASK)
 425                 return -EINVAL;
 426
 427         while (cur_buf < buf + buf_len && isspace(*cur_buf))
 428                 ++cur_buf;
 429
 430         *is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
 431         if (*is_negative)
 432                 ++cur_buf;
 433
 434         consumed = cur_buf - buf;
 435         cur_len -= consumed;
 436         if (!cur_len)
 437                 return -EINVAL;
 438
 439         cur_len = min(cur_len, sizeof(str) - 1);
 440         memcpy(str, cur_buf, cur_len);
 441         str[cur_len] = '\0';
 442         cur_buf = str;
 443
 444         cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
 445         val_len = _parse_integer(cur_buf, base, res);
 446
 447         if (val_len & KSTRTOX_OVERFLOW)
 448                 return -ERANGE;
 449
 450         if (val_len == 0)
 451                 return -EINVAL;
 452
 453         cur_buf += val_len;
 454         consumed += cur_buf - str;
 455
 456         return consumed;
 457 }
 458
 459 static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
 460                          long long *res)
 461 {
 462         unsigned long long _res;
 463         bool is_negative;
 464         int err;
 465
 466         err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
 467         if (err < 0)
 468                 return err;
 469         if (is_negative) {
 470                 if ((long long)-_res > 0)
 471                         return -ERANGE;
 472                 *res = -_res;
 473         } else {
 474                 if ((long long)_res < 0)
 475                         return -ERANGE;
 476                 *res = _res;
 477         }
 478         return err;
 479 }
 480
 481 BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
 482            long *, res)
 483 {
 484         long long _res;
 485         int err;
 486
 487         err = __bpf_strtoll(buf, buf_len, flags, &_res);
 488         if (err < 0)
 489                 return err;
 490         if (_res != (long)_res)
 491                 return -ERANGE;
 492         *res = _res;
 493         return err;
 494 }
 495
 496 const struct bpf_func_proto bpf_strtol_proto = {
 497         .func           = bpf_strtol,
 498         .gpl_only       = false,
 499         .ret_type       = RET_INTEGER,
 500         .arg1_type      = ARG_PTR_TO_MEM,
 501         .arg2_type      = ARG_CONST_SIZE,
 502         .arg3_type      = ARG_ANYTHING,
 503         .arg4_type      = ARG_PTR_TO_LONG,
 504 };
 505
 506 BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
 507            unsigned long *, res)
 508 {
 509         unsigned long long _res;
 510         bool is_negative;
 511         int err;
 512
 513         err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
 514         if (err < 0)
 515                 return err;
 516         if (is_negative)
 517                 return -EINVAL;
 518         if (_res != (unsigned long)_res)
 519                 return -ERANGE;
 520         *res = _res;
 521         return err;
 522 }
 523
 524 const struct bpf_func_proto bpf_strtoul_proto = {
 525         .func           = bpf_strtoul,
 526         .gpl_only       = false,
 527         .ret_type       = RET_INTEGER,
 528         .arg1_type      = ARG_PTR_TO_MEM,
 529         .arg2_type      = ARG_CONST_SIZE,
 530         .arg3_type      = ARG_ANYTHING,
 531         .arg4_type      = ARG_PTR_TO_LONG,
 532 };
 533 #endif
 534
 535 BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
 536            struct bpf_pidns_info *, nsdata, u32, size)
 537 {
 538         struct task_struct *task = current;
 539         struct pid_namespace *pidns;
 540         int err = -EINVAL;
 541
 542         if (unlikely(size != sizeof(struct bpf_pidns_info)))
 543                 goto clear;
 544
 545         if (unlikely((u64)(dev_t)dev != dev))
 546                 goto clear;
 547
 548         if (unlikely(!task))
 549                 goto clear;
 550
 551         pidns = task_active_pid_ns(task);
 552         if (unlikely(!pidns)) {
 553                 err = -ENOENT;
 554                 goto clear;
 555         }
 556
 557         if (!ns_match(&pidns->ns, (dev_t)dev, ino))
 558                 goto clear;
 559
 560         nsdata->pid = task_pid_nr_ns(task, pidns);
 561         nsdata->tgid = task_tgid_nr_ns(task, pidns);
 562         return 0;
 563 clear:
 564         memset((void *)nsdata, 0, (size_t) size);
 565         return err;
 566 }
 567
 568 const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
 569         .func           = bpf_get_ns_current_pid_tgid,
 570         .gpl_only       = false,
 571         .ret_type       = RET_INTEGER,
 572         .arg1_type      = ARG_ANYTHING,
 573         .arg2_type      = ARG_ANYTHING,
 574         .arg3_type      = ARG_PTR_TO_UNINIT_MEM,
 575         .arg4_type      = ARG_CONST_SIZE,
 576 };
 577
 578 static const struct bpf_func_proto bpf_get_raw_smp_processor_id_proto = {
 579         .func           = bpf_get_raw_cpu_id,
 580         .gpl_only       = false,
 581         .ret_type       = RET_INTEGER,
 582 };
 583
 584 BPF_CALL_5(bpf_event_output_data, void *, ctx, struct bpf_map *, map,
 585            u64, flags, void *, data, u64, size)
 586 {
 587         if (unlikely(flags & ~(BPF_F_INDEX_MASK)))
 588                 return -EINVAL;
 589
 590         return bpf_event_output(map, flags, data, size, NULL, 0, NULL);
 591 }
 592
 593 const struct bpf_func_proto bpf_event_output_data_proto =  {
 594         .func           = bpf_event_output_data,
 595         .gpl_only       = true,
 596         .ret_type       = RET_INTEGER,
 597         .arg1_type      = ARG_PTR_TO_CTX,
 598         .arg2_type      = ARG_CONST_MAP_PTR,
 599         .arg3_type      = ARG_ANYTHING,
 600         .arg4_type      = ARG_PTR_TO_MEM,
 601         .arg5_type      = ARG_CONST_SIZE_OR_ZERO,
 602 };
 603
 604 const struct bpf_func_proto bpf_get_current_task_proto __weak;
 605 const struct bpf_func_proto bpf_probe_read_user_proto __weak;
 606 const struct bpf_func_proto bpf_probe_read_user_str_proto __weak;
 607 const struct bpf_func_proto bpf_probe_read_kernel_proto __weak;
 608 const struct bpf_func_proto bpf_probe_read_kernel_str_proto __weak;
 609
 610 const struct bpf_func_proto *
 611 bpf_base_func_proto(enum bpf_func_id func_id)
 612 {
 613         switch (func_id) {
 614         case BPF_FUNC_map_lookup_elem:
 615                 return &bpf_map_lookup_elem_proto;
 616         case BPF_FUNC_map_update_elem:
 617                 return &bpf_map_update_elem_proto;
 618         case BPF_FUNC_map_delete_elem:
 619                 return &bpf_map_delete_elem_proto;
 620         case BPF_FUNC_map_push_elem:
 621                 return &bpf_map_push_elem_proto;
 622         case BPF_FUNC_map_pop_elem:
 623                 return &bpf_map_pop_elem_proto;
 624         case BPF_FUNC_map_peek_elem:
 625                 return &bpf_map_peek_elem_proto;
 626         case BPF_FUNC_get_prandom_u32:
 627                 return &bpf_get_prandom_u32_proto;
 628         case BPF_FUNC_get_smp_processor_id:
 629                 return &bpf_get_raw_smp_processor_id_proto;
 630         case BPF_FUNC_get_numa_node_id:
 631                 return &bpf_get_numa_node_id_proto;
 632         case BPF_FUNC_tail_call:
 633                 return &bpf_tail_call_proto;
 634         case BPF_FUNC_ktime_get_ns:
 635                 return &bpf_ktime_get_ns_proto;
 636         case BPF_FUNC_ktime_get_boot_ns:
 637                 return &bpf_ktime_get_boot_ns_proto;
 638         case BPF_FUNC_ringbuf_output:
 639                 return &bpf_ringbuf_output_proto;
 640         case BPF_FUNC_ringbuf_reserve:
 641                 return &bpf_ringbuf_reserve_proto;
 642         case BPF_FUNC_ringbuf_submit:
 643                 return &bpf_ringbuf_submit_proto;
 644         case BPF_FUNC_ringbuf_discard:
 645                 return &bpf_ringbuf_discard_proto;
 646         case BPF_FUNC_ringbuf_query:
 647                 return &bpf_ringbuf_query_proto;
 648         default:
 649                 break;
 650         }
 651
 652         if (!bpf_capable())
 653                 return NULL;
 654
 655         switch (func_id) {
 656         case BPF_FUNC_spin_lock:
 657                 return &bpf_spin_lock_proto;
 658         case BPF_FUNC_spin_unlock:
 659                 return &bpf_spin_unlock_proto;
 660         case BPF_FUNC_trace_printk:
 661                 if (!perfmon_capable())
 662                         return NULL;
 663                 return bpf_get_trace_printk_proto();
 664         case BPF_FUNC_jiffies64:
 665                 return &bpf_jiffies64_proto;
 666         default:
 667                 break;
 668         }
 669
 670         if (!perfmon_capable())
 671                 return NULL;
 672
 673         switch (func_id) {
 674         case BPF_FUNC_get_current_task:
 675                 return &bpf_get_current_task_proto;
 676         case BPF_FUNC_probe_read_user:
 677                 return &bpf_probe_read_user_proto;
 678         case BPF_FUNC_probe_read_kernel:
 679                 return &bpf_probe_read_kernel_proto;
 680         case BPF_FUNC_probe_read_user_str:
 681                 return &bpf_probe_read_user_str_proto;
 682         case BPF_FUNC_probe_read_kernel_str:
 683                 return &bpf_probe_read_kernel_str_proto;
 684         default:
 685                 return NULL;
 686         }
 687 }