linux/kernel/bpf/syscall.c
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   1/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
   2 *
   3 * This program is free software; you can redistribute it and/or
   4 * modify it under the terms of version 2 of the GNU General Public
   5 * License as published by the Free Software Foundation.
   6 *
   7 * This program is distributed in the hope that it will be useful, but
   8 * WITHOUT ANY WARRANTY; without even the implied warranty of
   9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10 * General Public License for more details.
  11 */
  12#include <linux/bpf.h>
  13#include <linux/bpf_trace.h>
  14#include <linux/syscalls.h>
  15#include <linux/slab.h>
  16#include <linux/sched/signal.h>
  17#include <linux/vmalloc.h>
  18#include <linux/mmzone.h>
  19#include <linux/anon_inodes.h>
  20#include <linux/file.h>
  21#include <linux/license.h>
  22#include <linux/filter.h>
  23#include <linux/version.h>
  24#include <linux/kernel.h>
  25#include <linux/idr.h>
  26#include <linux/cred.h>
  27#include <linux/timekeeping.h>
  28#include <linux/ctype.h>
  29
  30#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
  31                           (map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
  32                           (map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
  33                           (map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
  34#define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
  35#define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map))
  36
  37#define BPF_OBJ_FLAG_MASK   (BPF_F_RDONLY | BPF_F_WRONLY)
  38
  39DEFINE_PER_CPU(int, bpf_prog_active);
  40static DEFINE_IDR(prog_idr);
  41static DEFINE_SPINLOCK(prog_idr_lock);
  42static DEFINE_IDR(map_idr);
  43static DEFINE_SPINLOCK(map_idr_lock);
  44
  45int sysctl_unprivileged_bpf_disabled __read_mostly;
  46
  47static const struct bpf_map_ops * const bpf_map_types[] = {
  48#define BPF_PROG_TYPE(_id, _ops)
  49#define BPF_MAP_TYPE(_id, _ops) \
  50        [_id] = &_ops,
  51#include <linux/bpf_types.h>
  52#undef BPF_PROG_TYPE
  53#undef BPF_MAP_TYPE
  54};
  55
  56/*
  57 * If we're handed a bigger struct than we know of, ensure all the unknown bits
  58 * are 0 - i.e. new user-space does not rely on any kernel feature extensions
  59 * we don't know about yet.
  60 *
  61 * There is a ToCToU between this function call and the following
  62 * copy_from_user() call. However, this is not a concern since this function is
  63 * meant to be a future-proofing of bits.
  64 */
  65static int check_uarg_tail_zero(void __user *uaddr,
  66                                size_t expected_size,
  67                                size_t actual_size)
  68{
  69        unsigned char __user *addr;
  70        unsigned char __user *end;
  71        unsigned char val;
  72        int err;
  73
  74        if (unlikely(actual_size > PAGE_SIZE))  /* silly large */
  75                return -E2BIG;
  76
  77        if (unlikely(!access_ok(VERIFY_READ, uaddr, actual_size)))
  78                return -EFAULT;
  79
  80        if (actual_size <= expected_size)
  81                return 0;
  82
  83        addr = uaddr + expected_size;
  84        end  = uaddr + actual_size;
  85
  86        for (; addr < end; addr++) {
  87                err = get_user(val, addr);
  88                if (err)
  89                        return err;
  90                if (val)
  91                        return -E2BIG;
  92        }
  93
  94        return 0;
  95}
  96
  97const struct bpf_map_ops bpf_map_offload_ops = {
  98        .map_alloc = bpf_map_offload_map_alloc,
  99        .map_free = bpf_map_offload_map_free,
 100};
 101
 102static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
 103{
 104        const struct bpf_map_ops *ops;
 105        struct bpf_map *map;
 106        int err;
 107
 108        if (attr->map_type >= ARRAY_SIZE(bpf_map_types))
 109                return ERR_PTR(-EINVAL);
 110        ops = bpf_map_types[attr->map_type];
 111        if (!ops)
 112                return ERR_PTR(-EINVAL);
 113
 114        if (ops->map_alloc_check) {
 115                err = ops->map_alloc_check(attr);
 116                if (err)
 117                        return ERR_PTR(err);
 118        }
 119        if (attr->map_ifindex)
 120                ops = &bpf_map_offload_ops;
 121        map = ops->map_alloc(attr);
 122        if (IS_ERR(map))
 123                return map;
 124        map->ops = ops;
 125        map->map_type = attr->map_type;
 126        return map;
 127}
 128
 129void *bpf_map_area_alloc(size_t size, int numa_node)
 130{
 131        /* We definitely need __GFP_NORETRY, so OOM killer doesn't
 132         * trigger under memory pressure as we really just want to
 133         * fail instead.
 134         */
 135        const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
 136        void *area;
 137
 138        if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
 139                area = kmalloc_node(size, GFP_USER | flags, numa_node);
 140                if (area != NULL)
 141                        return area;
 142        }
 143
 144        return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags,
 145                                           __builtin_return_address(0));
 146}
 147
 148void bpf_map_area_free(void *area)
 149{
 150        kvfree(area);
 151}
 152
 153void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
 154{
 155        map->map_type = attr->map_type;
 156        map->key_size = attr->key_size;
 157        map->value_size = attr->value_size;
 158        map->max_entries = attr->max_entries;
 159        map->map_flags = attr->map_flags;
 160        map->numa_node = bpf_map_attr_numa_node(attr);
 161}
 162
 163int bpf_map_precharge_memlock(u32 pages)
 164{
 165        struct user_struct *user = get_current_user();
 166        unsigned long memlock_limit, cur;
 167
 168        memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 169        cur = atomic_long_read(&user->locked_vm);
 170        free_uid(user);
 171        if (cur + pages > memlock_limit)
 172                return -EPERM;
 173        return 0;
 174}
 175
 176static int bpf_map_charge_memlock(struct bpf_map *map)
 177{
 178        struct user_struct *user = get_current_user();
 179        unsigned long memlock_limit;
 180
 181        memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 182
 183        atomic_long_add(map->pages, &user->locked_vm);
 184
 185        if (atomic_long_read(&user->locked_vm) > memlock_limit) {
 186                atomic_long_sub(map->pages, &user->locked_vm);
 187                free_uid(user);
 188                return -EPERM;
 189        }
 190        map->user = user;
 191        return 0;
 192}
 193
 194static void bpf_map_uncharge_memlock(struct bpf_map *map)
 195{
 196        struct user_struct *user = map->user;
 197
 198        atomic_long_sub(map->pages, &user->locked_vm);
 199        free_uid(user);
 200}
 201
 202static int bpf_map_alloc_id(struct bpf_map *map)
 203{
 204        int id;
 205
 206        spin_lock_bh(&map_idr_lock);
 207        id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
 208        if (id > 0)
 209                map->id = id;
 210        spin_unlock_bh(&map_idr_lock);
 211
 212        if (WARN_ON_ONCE(!id))
 213                return -ENOSPC;
 214
 215        return id > 0 ? 0 : id;
 216}
 217
 218void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
 219{
 220        unsigned long flags;
 221
 222        /* Offloaded maps are removed from the IDR store when their device
 223         * disappears - even if someone holds an fd to them they are unusable,
 224         * the memory is gone, all ops will fail; they are simply waiting for
 225         * refcnt to drop to be freed.
 226         */
 227        if (!map->id)
 228                return;
 229
 230        if (do_idr_lock)
 231                spin_lock_irqsave(&map_idr_lock, flags);
 232        else
 233                __acquire(&map_idr_lock);
 234
 235        idr_remove(&map_idr, map->id);
 236        map->id = 0;
 237
 238        if (do_idr_lock)
 239                spin_unlock_irqrestore(&map_idr_lock, flags);
 240        else
 241                __release(&map_idr_lock);
 242}
 243
 244/* called from workqueue */
 245static void bpf_map_free_deferred(struct work_struct *work)
 246{
 247        struct bpf_map *map = container_of(work, struct bpf_map, work);
 248
 249        bpf_map_uncharge_memlock(map);
 250        security_bpf_map_free(map);
 251        /* implementation dependent freeing */
 252        map->ops->map_free(map);
 253}
 254
 255static void bpf_map_put_uref(struct bpf_map *map)
 256{
 257        if (atomic_dec_and_test(&map->usercnt)) {
 258                if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
 259                        bpf_fd_array_map_clear(map);
 260        }
 261}
 262
 263/* decrement map refcnt and schedule it for freeing via workqueue
 264 * (unrelying map implementation ops->map_free() might sleep)
 265 */
 266static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
 267{
 268        if (atomic_dec_and_test(&map->refcnt)) {
 269                /* bpf_map_free_id() must be called first */
 270                bpf_map_free_id(map, do_idr_lock);
 271                INIT_WORK(&map->work, bpf_map_free_deferred);
 272                schedule_work(&map->work);
 273        }
 274}
 275
 276void bpf_map_put(struct bpf_map *map)
 277{
 278        __bpf_map_put(map, true);
 279}
 280
 281void bpf_map_put_with_uref(struct bpf_map *map)
 282{
 283        bpf_map_put_uref(map);
 284        bpf_map_put(map);
 285}
 286
 287static int bpf_map_release(struct inode *inode, struct file *filp)
 288{
 289        struct bpf_map *map = filp->private_data;
 290
 291        if (map->ops->map_release)
 292                map->ops->map_release(map, filp);
 293
 294        bpf_map_put_with_uref(map);
 295        return 0;
 296}
 297
 298#ifdef CONFIG_PROC_FS
 299static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 300{
 301        const struct bpf_map *map = filp->private_data;
 302        const struct bpf_array *array;
 303        u32 owner_prog_type = 0;
 304        u32 owner_jited = 0;
 305
 306        if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
 307                array = container_of(map, struct bpf_array, map);
 308                owner_prog_type = array->owner_prog_type;
 309                owner_jited = array->owner_jited;
 310        }
 311
 312        seq_printf(m,
 313                   "map_type:\t%u\n"
 314                   "key_size:\t%u\n"
 315                   "value_size:\t%u\n"
 316                   "max_entries:\t%u\n"
 317                   "map_flags:\t%#x\n"
 318                   "memlock:\t%llu\n",
 319                   map->map_type,
 320                   map->key_size,
 321                   map->value_size,
 322                   map->max_entries,
 323                   map->map_flags,
 324                   map->pages * 1ULL << PAGE_SHIFT);
 325
 326        if (owner_prog_type) {
 327                seq_printf(m, "owner_prog_type:\t%u\n",
 328                           owner_prog_type);
 329                seq_printf(m, "owner_jited:\t%u\n",
 330                           owner_jited);
 331        }
 332}
 333#endif
 334
 335static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
 336                              loff_t *ppos)
 337{
 338        /* We need this handler such that alloc_file() enables
 339         * f_mode with FMODE_CAN_READ.
 340         */
 341        return -EINVAL;
 342}
 343
 344static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
 345                               size_t siz, loff_t *ppos)
 346{
 347        /* We need this handler such that alloc_file() enables
 348         * f_mode with FMODE_CAN_WRITE.
 349         */
 350        return -EINVAL;
 351}
 352
 353const struct file_operations bpf_map_fops = {
 354#ifdef CONFIG_PROC_FS
 355        .show_fdinfo    = bpf_map_show_fdinfo,
 356#endif
 357        .release        = bpf_map_release,
 358        .read           = bpf_dummy_read,
 359        .write          = bpf_dummy_write,
 360};
 361
 362int bpf_map_new_fd(struct bpf_map *map, int flags)
 363{
 364        int ret;
 365
 366        ret = security_bpf_map(map, OPEN_FMODE(flags));
 367        if (ret < 0)
 368                return ret;
 369
 370        return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
 371                                flags | O_CLOEXEC);
 372}
 373
 374int bpf_get_file_flag(int flags)
 375{
 376        if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
 377                return -EINVAL;
 378        if (flags & BPF_F_RDONLY)
 379                return O_RDONLY;
 380        if (flags & BPF_F_WRONLY)
 381                return O_WRONLY;
 382        return O_RDWR;
 383}
 384
 385/* helper macro to check that unused fields 'union bpf_attr' are zero */
 386#define CHECK_ATTR(CMD) \
 387        memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
 388                   sizeof(attr->CMD##_LAST_FIELD), 0, \
 389                   sizeof(*attr) - \
 390                   offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
 391                   sizeof(attr->CMD##_LAST_FIELD)) != NULL
 392
 393/* dst and src must have at least BPF_OBJ_NAME_LEN number of bytes.
 394 * Return 0 on success and < 0 on error.
 395 */
 396static int bpf_obj_name_cpy(char *dst, const char *src)
 397{
 398        const char *end = src + BPF_OBJ_NAME_LEN;
 399
 400        memset(dst, 0, BPF_OBJ_NAME_LEN);
 401
 402        /* Copy all isalnum() and '_' char */
 403        while (src < end && *src) {
 404                if (!isalnum(*src) && *src != '_')
 405                        return -EINVAL;
 406                *dst++ = *src++;
 407        }
 408
 409        /* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */
 410        if (src == end)
 411                return -EINVAL;
 412
 413        return 0;
 414}
 415
 416#define BPF_MAP_CREATE_LAST_FIELD map_ifindex
 417/* called via syscall */
 418static int map_create(union bpf_attr *attr)
 419{
 420        int numa_node = bpf_map_attr_numa_node(attr);
 421        struct bpf_map *map;
 422        int f_flags;
 423        int err;
 424
 425        err = CHECK_ATTR(BPF_MAP_CREATE);
 426        if (err)
 427                return -EINVAL;
 428
 429        f_flags = bpf_get_file_flag(attr->map_flags);
 430        if (f_flags < 0)
 431                return f_flags;
 432
 433        if (numa_node != NUMA_NO_NODE &&
 434            ((unsigned int)numa_node >= nr_node_ids ||
 435             !node_online(numa_node)))
 436                return -EINVAL;
 437
 438        /* find map type and init map: hashtable vs rbtree vs bloom vs ... */
 439        map = find_and_alloc_map(attr);
 440        if (IS_ERR(map))
 441                return PTR_ERR(map);
 442
 443        err = bpf_obj_name_cpy(map->name, attr->map_name);
 444        if (err)
 445                goto free_map_nouncharge;
 446
 447        atomic_set(&map->refcnt, 1);
 448        atomic_set(&map->usercnt, 1);
 449
 450        err = security_bpf_map_alloc(map);
 451        if (err)
 452                goto free_map_nouncharge;
 453
 454        err = bpf_map_charge_memlock(map);
 455        if (err)
 456                goto free_map_sec;
 457
 458        err = bpf_map_alloc_id(map);
 459        if (err)
 460                goto free_map;
 461
 462        err = bpf_map_new_fd(map, f_flags);
 463        if (err < 0) {
 464                /* failed to allocate fd.
 465                 * bpf_map_put() is needed because the above
 466                 * bpf_map_alloc_id() has published the map
 467                 * to the userspace and the userspace may
 468                 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
 469                 */
 470                bpf_map_put(map);
 471                return err;
 472        }
 473
 474        trace_bpf_map_create(map, err);
 475        return err;
 476
 477free_map:
 478        bpf_map_uncharge_memlock(map);
 479free_map_sec:
 480        security_bpf_map_free(map);
 481free_map_nouncharge:
 482        map->ops->map_free(map);
 483        return err;
 484}
 485
 486/* if error is returned, fd is released.
 487 * On success caller should complete fd access with matching fdput()
 488 */
 489struct bpf_map *__bpf_map_get(struct fd f)
 490{
 491        if (!f.file)
 492                return ERR_PTR(-EBADF);
 493        if (f.file->f_op != &bpf_map_fops) {
 494                fdput(f);
 495                return ERR_PTR(-EINVAL);
 496        }
 497
 498        return f.file->private_data;
 499}
 500
 501/* prog's and map's refcnt limit */
 502#define BPF_MAX_REFCNT 32768
 503
 504struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
 505{
 506        if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
 507                atomic_dec(&map->refcnt);
 508                return ERR_PTR(-EBUSY);
 509        }
 510        if (uref)
 511                atomic_inc(&map->usercnt);
 512        return map;
 513}
 514
 515struct bpf_map *bpf_map_get_with_uref(u32 ufd)
 516{
 517        struct fd f = fdget(ufd);
 518        struct bpf_map *map;
 519
 520        map = __bpf_map_get(f);
 521        if (IS_ERR(map))
 522                return map;
 523
 524        map = bpf_map_inc(map, true);
 525        fdput(f);
 526
 527        return map;
 528}
 529
 530/* map_idr_lock should have been held */
 531static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map,
 532                                            bool uref)
 533{
 534        int refold;
 535
 536        refold = __atomic_add_unless(&map->refcnt, 1, 0);
 537
 538        if (refold >= BPF_MAX_REFCNT) {
 539                __bpf_map_put(map, false);
 540                return ERR_PTR(-EBUSY);
 541        }
 542
 543        if (!refold)
 544                return ERR_PTR(-ENOENT);
 545
 546        if (uref)
 547                atomic_inc(&map->usercnt);
 548
 549        return map;
 550}
 551
 552int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
 553{
 554        return -ENOTSUPP;
 555}
 556
 557/* last field in 'union bpf_attr' used by this command */
 558#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
 559
 560static int map_lookup_elem(union bpf_attr *attr)
 561{
 562        void __user *ukey = u64_to_user_ptr(attr->key);
 563        void __user *uvalue = u64_to_user_ptr(attr->value);
 564        int ufd = attr->map_fd;
 565        struct bpf_map *map;
 566        void *key, *value, *ptr;
 567        u32 value_size;
 568        struct fd f;
 569        int err;
 570
 571        if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
 572                return -EINVAL;
 573
 574        f = fdget(ufd);
 575        map = __bpf_map_get(f);
 576        if (IS_ERR(map))
 577                return PTR_ERR(map);
 578
 579        if (!(f.file->f_mode & FMODE_CAN_READ)) {
 580                err = -EPERM;
 581                goto err_put;
 582        }
 583
 584        key = memdup_user(ukey, map->key_size);
 585        if (IS_ERR(key)) {
 586                err = PTR_ERR(key);
 587                goto err_put;
 588        }
 589
 590        if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
 591            map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
 592            map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
 593                value_size = round_up(map->value_size, 8) * num_possible_cpus();
 594        else if (IS_FD_MAP(map))
 595                value_size = sizeof(u32);
 596        else
 597                value_size = map->value_size;
 598
 599        err = -ENOMEM;
 600        value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
 601        if (!value)
 602                goto free_key;
 603
 604        if (bpf_map_is_dev_bound(map)) {
 605                err = bpf_map_offload_lookup_elem(map, key, value);
 606        } else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
 607                   map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
 608                err = bpf_percpu_hash_copy(map, key, value);
 609        } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
 610                err = bpf_percpu_array_copy(map, key, value);
 611        } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
 612                err = bpf_stackmap_copy(map, key, value);
 613        } else if (IS_FD_ARRAY(map)) {
 614                err = bpf_fd_array_map_lookup_elem(map, key, value);
 615        } else if (IS_FD_HASH(map)) {
 616                err = bpf_fd_htab_map_lookup_elem(map, key, value);
 617        } else {
 618                rcu_read_lock();
 619                ptr = map->ops->map_lookup_elem(map, key);
 620                if (ptr)
 621                        memcpy(value, ptr, value_size);
 622                rcu_read_unlock();
 623                err = ptr ? 0 : -ENOENT;
 624        }
 625
 626        if (err)
 627                goto free_value;
 628
 629        err = -EFAULT;
 630        if (copy_to_user(uvalue, value, value_size) != 0)
 631                goto free_value;
 632
 633        trace_bpf_map_lookup_elem(map, ufd, key, value);
 634        err = 0;
 635
 636free_value:
 637        kfree(value);
 638free_key:
 639        kfree(key);
 640err_put:
 641        fdput(f);
 642        return err;
 643}
 644
 645#define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
 646
 647static int map_update_elem(union bpf_attr *attr)
 648{
 649        void __user *ukey = u64_to_user_ptr(attr->key);
 650        void __user *uvalue = u64_to_user_ptr(attr->value);
 651        int ufd = attr->map_fd;
 652        struct bpf_map *map;
 653        void *key, *value;
 654        u32 value_size;
 655        struct fd f;
 656        int err;
 657
 658        if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
 659                return -EINVAL;
 660
 661        f = fdget(ufd);
 662        map = __bpf_map_get(f);
 663        if (IS_ERR(map))
 664                return PTR_ERR(map);
 665
 666        if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
 667                err = -EPERM;
 668                goto err_put;
 669        }
 670
 671        key = memdup_user(ukey, map->key_size);
 672        if (IS_ERR(key)) {
 673                err = PTR_ERR(key);
 674                goto err_put;
 675        }
 676
 677        if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
 678            map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
 679            map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
 680                value_size = round_up(map->value_size, 8) * num_possible_cpus();
 681        else
 682                value_size = map->value_size;
 683
 684        err = -ENOMEM;
 685        value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
 686        if (!value)
 687                goto free_key;
 688
 689        err = -EFAULT;
 690        if (copy_from_user(value, uvalue, value_size) != 0)
 691                goto free_value;
 692
 693        /* Need to create a kthread, thus must support schedule */
 694        if (bpf_map_is_dev_bound(map)) {
 695                err = bpf_map_offload_update_elem(map, key, value, attr->flags);
 696                goto out;
 697        } else if (map->map_type == BPF_MAP_TYPE_CPUMAP) {
 698                err = map->ops->map_update_elem(map, key, value, attr->flags);
 699                goto out;
 700        }
 701
 702        /* must increment bpf_prog_active to avoid kprobe+bpf triggering from
 703         * inside bpf map update or delete otherwise deadlocks are possible
 704         */
 705        preempt_disable();
 706        __this_cpu_inc(bpf_prog_active);
 707        if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
 708            map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
 709                err = bpf_percpu_hash_update(map, key, value, attr->flags);
 710        } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
 711                err = bpf_percpu_array_update(map, key, value, attr->flags);
 712        } else if (IS_FD_ARRAY(map)) {
 713                rcu_read_lock();
 714                err = bpf_fd_array_map_update_elem(map, f.file, key, value,
 715                                                   attr->flags);
 716                rcu_read_unlock();
 717        } else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
 718                rcu_read_lock();
 719                err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
 720                                                  attr->flags);
 721                rcu_read_unlock();
 722        } else {
 723                rcu_read_lock();
 724                err = map->ops->map_update_elem(map, key, value, attr->flags);
 725                rcu_read_unlock();
 726        }
 727        __this_cpu_dec(bpf_prog_active);
 728        preempt_enable();
 729out:
 730        if (!err)
 731                trace_bpf_map_update_elem(map, ufd, key, value);
 732free_value:
 733        kfree(value);
 734free_key:
 735        kfree(key);
 736err_put:
 737        fdput(f);
 738        return err;
 739}
 740
 741#define BPF_MAP_DELETE_ELEM_LAST_FIELD key
 742
 743static int map_delete_elem(union bpf_attr *attr)
 744{
 745        void __user *ukey = u64_to_user_ptr(attr->key);
 746        int ufd = attr->map_fd;
 747        struct bpf_map *map;
 748        struct fd f;
 749        void *key;
 750        int err;
 751
 752        if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
 753                return -EINVAL;
 754
 755        f = fdget(ufd);
 756        map = __bpf_map_get(f);
 757        if (IS_ERR(map))
 758                return PTR_ERR(map);
 759
 760        if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
 761                err = -EPERM;
 762                goto err_put;
 763        }
 764
 765        key = memdup_user(ukey, map->key_size);
 766        if (IS_ERR(key)) {
 767                err = PTR_ERR(key);
 768                goto err_put;
 769        }
 770
 771        if (bpf_map_is_dev_bound(map)) {
 772                err = bpf_map_offload_delete_elem(map, key);
 773                goto out;
 774        }
 775
 776        preempt_disable();
 777        __this_cpu_inc(bpf_prog_active);
 778        rcu_read_lock();
 779        err = map->ops->map_delete_elem(map, key);
 780        rcu_read_unlock();
 781        __this_cpu_dec(bpf_prog_active);
 782        preempt_enable();
 783out:
 784        if (!err)
 785                trace_bpf_map_delete_elem(map, ufd, key);
 786        kfree(key);
 787err_put:
 788        fdput(f);
 789        return err;
 790}
 791
 792/* last field in 'union bpf_attr' used by this command */
 793#define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
 794
 795static int map_get_next_key(union bpf_attr *attr)
 796{
 797        void __user *ukey = u64_to_user_ptr(attr->key);
 798        void __user *unext_key = u64_to_user_ptr(attr->next_key);
 799        int ufd = attr->map_fd;
 800        struct bpf_map *map;
 801        void *key, *next_key;
 802        struct fd f;
 803        int err;
 804
 805        if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
 806                return -EINVAL;
 807
 808        f = fdget(ufd);
 809        map = __bpf_map_get(f);
 810        if (IS_ERR(map))
 811                return PTR_ERR(map);
 812
 813        if (!(f.file->f_mode & FMODE_CAN_READ)) {
 814                err = -EPERM;
 815                goto err_put;
 816        }
 817
 818        if (ukey) {
 819                key = memdup_user(ukey, map->key_size);
 820                if (IS_ERR(key)) {
 821                        err = PTR_ERR(key);
 822                        goto err_put;
 823                }
 824        } else {
 825                key = NULL;
 826        }
 827
 828        err = -ENOMEM;
 829        next_key = kmalloc(map->key_size, GFP_USER);
 830        if (!next_key)
 831                goto free_key;
 832
 833        if (bpf_map_is_dev_bound(map)) {
 834                err = bpf_map_offload_get_next_key(map, key, next_key);
 835                goto out;
 836        }
 837
 838        rcu_read_lock();
 839        err = map->ops->map_get_next_key(map, key, next_key);
 840        rcu_read_unlock();
 841out:
 842        if (err)
 843                goto free_next_key;
 844
 845        err = -EFAULT;
 846        if (copy_to_user(unext_key, next_key, map->key_size) != 0)
 847                goto free_next_key;
 848
 849        trace_bpf_map_next_key(map, ufd, key, next_key);
 850        err = 0;
 851
 852free_next_key:
 853        kfree(next_key);
 854free_key:
 855        kfree(key);
 856err_put:
 857        fdput(f);
 858        return err;
 859}
 860
 861static const struct bpf_prog_ops * const bpf_prog_types[] = {
 862#define BPF_PROG_TYPE(_id, _name) \
 863        [_id] = & _name ## _prog_ops,
 864#define BPF_MAP_TYPE(_id, _ops)
 865#include <linux/bpf_types.h>
 866#undef BPF_PROG_TYPE
 867#undef BPF_MAP_TYPE
 868};
 869
 870static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
 871{
 872        if (type >= ARRAY_SIZE(bpf_prog_types) || !bpf_prog_types[type])
 873                return -EINVAL;
 874
 875        if (!bpf_prog_is_dev_bound(prog->aux))
 876                prog->aux->ops = bpf_prog_types[type];
 877        else
 878                prog->aux->ops = &bpf_offload_prog_ops;
 879        prog->type = type;
 880        return 0;
 881}
 882
 883/* drop refcnt on maps used by eBPF program and free auxilary data */
 884static void free_used_maps(struct bpf_prog_aux *aux)
 885{
 886        int i;
 887
 888        for (i = 0; i < aux->used_map_cnt; i++)
 889                bpf_map_put(aux->used_maps[i]);
 890
 891        kfree(aux->used_maps);
 892}
 893
 894int __bpf_prog_charge(struct user_struct *user, u32 pages)
 895{
 896        unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
 897        unsigned long user_bufs;
 898
 899        if (user) {
 900                user_bufs = atomic_long_add_return(pages, &user->locked_vm);
 901                if (user_bufs > memlock_limit) {
 902                        atomic_long_sub(pages, &user->locked_vm);
 903                        return -EPERM;
 904                }
 905        }
 906
 907        return 0;
 908}
 909
 910void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
 911{
 912        if (user)
 913                atomic_long_sub(pages, &user->locked_vm);
 914}
 915
 916static int bpf_prog_charge_memlock(struct bpf_prog *prog)
 917{
 918        struct user_struct *user = get_current_user();
 919        int ret;
 920
 921        ret = __bpf_prog_charge(user, prog->pages);
 922        if (ret) {
 923                free_uid(user);
 924                return ret;
 925        }
 926
 927        prog->aux->user = user;
 928        return 0;
 929}
 930
 931static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
 932{
 933        struct user_struct *user = prog->aux->user;
 934
 935        __bpf_prog_uncharge(user, prog->pages);
 936        free_uid(user);
 937}
 938
 939static int bpf_prog_alloc_id(struct bpf_prog *prog)
 940{
 941        int id;
 942
 943        spin_lock_bh(&prog_idr_lock);
 944        id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
 945        if (id > 0)
 946                prog->aux->id = id;
 947        spin_unlock_bh(&prog_idr_lock);
 948
 949        /* id is in [1, INT_MAX) */
 950        if (WARN_ON_ONCE(!id))
 951                return -ENOSPC;
 952
 953        return id > 0 ? 0 : id;
 954}
 955
 956void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
 957{
 958        /* cBPF to eBPF migrations are currently not in the idr store.
 959         * Offloaded programs are removed from the store when their device
 960         * disappears - even if someone grabs an fd to them they are unusable,
 961         * simply waiting for refcnt to drop to be freed.
 962         */
 963        if (!prog->aux->id)
 964                return;
 965
 966        if (do_idr_lock)
 967                spin_lock_bh(&prog_idr_lock);
 968        else
 969                __acquire(&prog_idr_lock);
 970
 971        idr_remove(&prog_idr, prog->aux->id);
 972        prog->aux->id = 0;
 973
 974        if (do_idr_lock)
 975                spin_unlock_bh(&prog_idr_lock);
 976        else
 977                __release(&prog_idr_lock);
 978}
 979
 980static void __bpf_prog_put_rcu(struct rcu_head *rcu)
 981{
 982        struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
 983
 984        free_used_maps(aux);
 985        bpf_prog_uncharge_memlock(aux->prog);
 986        security_bpf_prog_free(aux);
 987        bpf_prog_free(aux->prog);
 988}
 989
 990static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
 991{
 992        if (atomic_dec_and_test(&prog->aux->refcnt)) {
 993                int i;
 994
 995                trace_bpf_prog_put_rcu(prog);
 996                /* bpf_prog_free_id() must be called first */
 997                bpf_prog_free_id(prog, do_idr_lock);
 998
 999                for (i = 0; i < prog->aux->func_cnt; i++)
1000                        bpf_prog_kallsyms_del(prog->aux->func[i]);
1001                bpf_prog_kallsyms_del(prog);
1002
1003                call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
1004        }
1005}
1006
1007void bpf_prog_put(struct bpf_prog *prog)
1008{
1009        __bpf_prog_put(prog, true);
1010}
1011EXPORT_SYMBOL_GPL(bpf_prog_put);
1012
1013static int bpf_prog_release(struct inode *inode, struct file *filp)
1014{
1015        struct bpf_prog *prog = filp->private_data;
1016
1017        bpf_prog_put(prog);
1018        return 0;
1019}
1020
1021#ifdef CONFIG_PROC_FS
1022static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
1023{
1024        const struct bpf_prog *prog = filp->private_data;
1025        char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
1026
1027        bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
1028        seq_printf(m,
1029                   "prog_type:\t%u\n"
1030                   "prog_jited:\t%u\n"
1031                   "prog_tag:\t%s\n"
1032                   "memlock:\t%llu\n",
1033                   prog->type,
1034                   prog->jited,
1035                   prog_tag,
1036                   prog->pages * 1ULL << PAGE_SHIFT);
1037}
1038#endif
1039
1040const struct file_operations bpf_prog_fops = {
1041#ifdef CONFIG_PROC_FS
1042        .show_fdinfo    = bpf_prog_show_fdinfo,
1043#endif
1044        .release        = bpf_prog_release,
1045        .read           = bpf_dummy_read,
1046        .write          = bpf_dummy_write,
1047};
1048
1049int bpf_prog_new_fd(struct bpf_prog *prog)
1050{
1051        int ret;
1052
1053        ret = security_bpf_prog(prog);
1054        if (ret < 0)
1055                return ret;
1056
1057        return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
1058                                O_RDWR | O_CLOEXEC);
1059}
1060
1061static struct bpf_prog *____bpf_prog_get(struct fd f)
1062{
1063        if (!f.file)
1064                return ERR_PTR(-EBADF);
1065        if (f.file->f_op != &bpf_prog_fops) {
1066                fdput(f);
1067                return ERR_PTR(-EINVAL);
1068        }
1069
1070        return f.file->private_data;
1071}
1072
1073struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
1074{
1075        if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
1076                atomic_sub(i, &prog->aux->refcnt);
1077                return ERR_PTR(-EBUSY);
1078        }
1079        return prog;
1080}
1081EXPORT_SYMBOL_GPL(bpf_prog_add);
1082
1083void bpf_prog_sub(struct bpf_prog *prog, int i)
1084{
1085        /* Only to be used for undoing previous bpf_prog_add() in some
1086         * error path. We still know that another entity in our call
1087         * path holds a reference to the program, thus atomic_sub() can
1088         * be safely used in such cases!
1089         */
1090        WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
1091}
1092EXPORT_SYMBOL_GPL(bpf_prog_sub);
1093
1094struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
1095{
1096        return bpf_prog_add(prog, 1);
1097}
1098EXPORT_SYMBOL_GPL(bpf_prog_inc);
1099
1100/* prog_idr_lock should have been held */
1101struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
1102{
1103        int refold;
1104
1105        refold = __atomic_add_unless(&prog->aux->refcnt, 1, 0);
1106
1107        if (refold >= BPF_MAX_REFCNT) {
1108                __bpf_prog_put(prog, false);
1109                return ERR_PTR(-EBUSY);
1110        }
1111
1112        if (!refold)
1113                return ERR_PTR(-ENOENT);
1114
1115        return prog;
1116}
1117EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
1118
1119bool bpf_prog_get_ok(struct bpf_prog *prog,
1120                            enum bpf_prog_type *attach_type, bool attach_drv)
1121{
1122        /* not an attachment, just a refcount inc, always allow */
1123        if (!attach_type)
1124                return true;
1125
1126        if (prog->type != *attach_type)
1127                return false;
1128        if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
1129                return false;
1130
1131        return true;
1132}
1133
1134static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
1135                                       bool attach_drv)
1136{
1137        struct fd f = fdget(ufd);
1138        struct bpf_prog *prog;
1139
1140        prog = ____bpf_prog_get(f);
1141        if (IS_ERR(prog))
1142                return prog;
1143        if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
1144                prog = ERR_PTR(-EINVAL);
1145                goto out;
1146        }
1147
1148        prog = bpf_prog_inc(prog);
1149out:
1150        fdput(f);
1151        return prog;
1152}
1153
1154struct bpf_prog *bpf_prog_get(u32 ufd)
1155{
1156        return __bpf_prog_get(ufd, NULL, false);
1157}
1158
1159struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
1160                                       bool attach_drv)
1161{
1162        struct bpf_prog *prog = __bpf_prog_get(ufd, &type, attach_drv);
1163
1164        if (!IS_ERR(prog))
1165                trace_bpf_prog_get_type(prog);
1166        return prog;
1167}
1168EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
1169
1170/* last field in 'union bpf_attr' used by this command */
1171#define BPF_PROG_LOAD_LAST_FIELD prog_ifindex
1172
1173static int bpf_prog_load(union bpf_attr *attr)
1174{
1175        enum bpf_prog_type type = attr->prog_type;
1176        struct bpf_prog *prog;
1177        int err;
1178        char license[128];
1179        bool is_gpl;
1180
1181        if (CHECK_ATTR(BPF_PROG_LOAD))
1182                return -EINVAL;
1183
1184        if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT)
1185                return -EINVAL;
1186
1187        /* copy eBPF program license from user space */
1188        if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
1189                              sizeof(license) - 1) < 0)
1190                return -EFAULT;
1191        license[sizeof(license) - 1] = 0;
1192
1193        /* eBPF programs must be GPL compatible to use GPL-ed functions */
1194        is_gpl = license_is_gpl_compatible(license);
1195
1196        if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS)
1197                return -E2BIG;
1198
1199        if (type == BPF_PROG_TYPE_KPROBE &&
1200            attr->kern_version != LINUX_VERSION_CODE)
1201                return -EINVAL;
1202
1203        if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
1204            type != BPF_PROG_TYPE_CGROUP_SKB &&
1205            !capable(CAP_SYS_ADMIN))
1206                return -EPERM;
1207
1208        /* plain bpf_prog allocation */
1209        prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
1210        if (!prog)
1211                return -ENOMEM;
1212
1213        prog->aux->offload_requested = !!attr->prog_ifindex;
1214
1215        err = security_bpf_prog_alloc(prog->aux);
1216        if (err)
1217                goto free_prog_nouncharge;
1218
1219        err = bpf_prog_charge_memlock(prog);
1220        if (err)
1221                goto free_prog_sec;
1222
1223        prog->len = attr->insn_cnt;
1224
1225        err = -EFAULT;
1226        if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
1227                           bpf_prog_insn_size(prog)) != 0)
1228                goto free_prog;
1229
1230        prog->orig_prog = NULL;
1231        prog->jited = 0;
1232
1233        atomic_set(&prog->aux->refcnt, 1);
1234        prog->gpl_compatible = is_gpl ? 1 : 0;
1235
1236        if (bpf_prog_is_dev_bound(prog->aux)) {
1237                err = bpf_prog_offload_init(prog, attr);
1238                if (err)
1239                        goto free_prog;
1240        }
1241
1242        /* find program type: socket_filter vs tracing_filter */
1243        err = find_prog_type(type, prog);
1244        if (err < 0)
1245                goto free_prog;
1246
1247        prog->aux->load_time = ktime_get_boot_ns();
1248        err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name);
1249        if (err)
1250                goto free_prog;
1251
1252        /* run eBPF verifier */
1253        err = bpf_check(&prog, attr);
1254        if (err < 0)
1255                goto free_used_maps;
1256
1257        /* eBPF program is ready to be JITed */
1258        if (!prog->bpf_func)
1259                prog = bpf_prog_select_runtime(prog, &err);
1260        if (err < 0)
1261                goto free_used_maps;
1262
1263        err = bpf_prog_alloc_id(prog);
1264        if (err)
1265                goto free_used_maps;
1266
1267        err = bpf_prog_new_fd(prog);
1268        if (err < 0) {
1269                /* failed to allocate fd.
1270                 * bpf_prog_put() is needed because the above
1271                 * bpf_prog_alloc_id() has published the prog
1272                 * to the userspace and the userspace may
1273                 * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
1274                 */
1275                bpf_prog_put(prog);
1276                return err;
1277        }
1278
1279        bpf_prog_kallsyms_add(prog);
1280        trace_bpf_prog_load(prog, err);
1281        return err;
1282
1283free_used_maps:
1284        free_used_maps(prog->aux);
1285free_prog:
1286        bpf_prog_uncharge_memlock(prog);
1287free_prog_sec:
1288        security_bpf_prog_free(prog->aux);
1289free_prog_nouncharge:
1290        bpf_prog_free(prog);
1291        return err;
1292}
1293
1294#define BPF_OBJ_LAST_FIELD file_flags
1295
1296static int bpf_obj_pin(const union bpf_attr *attr)
1297{
1298        if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
1299                return -EINVAL;
1300
1301        return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
1302}
1303
1304static int bpf_obj_get(const union bpf_attr *attr)
1305{
1306        if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
1307            attr->file_flags & ~BPF_OBJ_FLAG_MASK)
1308                return -EINVAL;
1309
1310        return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
1311                                attr->file_flags);
1312}
1313
1314#ifdef CONFIG_CGROUP_BPF
1315
1316#define BPF_PROG_ATTACH_LAST_FIELD attach_flags
1317
1318static int sockmap_get_from_fd(const union bpf_attr *attr, bool attach)
1319{
1320        struct bpf_prog *prog = NULL;
1321        int ufd = attr->target_fd;
1322        struct bpf_map *map;
1323        struct fd f;
1324        int err;
1325
1326        f = fdget(ufd);
1327        map = __bpf_map_get(f);
1328        if (IS_ERR(map))
1329                return PTR_ERR(map);
1330
1331        if (attach) {
1332                prog = bpf_prog_get_type(attr->attach_bpf_fd,
1333                                         BPF_PROG_TYPE_SK_SKB);
1334                if (IS_ERR(prog)) {
1335                        fdput(f);
1336                        return PTR_ERR(prog);
1337                }
1338        }
1339
1340        err = sock_map_prog(map, prog, attr->attach_type);
1341        if (err) {
1342                fdput(f);
1343                if (prog)
1344                        bpf_prog_put(prog);
1345                return err;
1346        }
1347
1348        fdput(f);
1349        return 0;
1350}
1351
1352#define BPF_F_ATTACH_MASK \
1353        (BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)
1354
1355static int bpf_prog_attach(const union bpf_attr *attr)
1356{
1357        enum bpf_prog_type ptype;
1358        struct bpf_prog *prog;
1359        struct cgroup *cgrp;
1360        int ret;
1361
1362        if (!capable(CAP_NET_ADMIN))
1363                return -EPERM;
1364
1365        if (CHECK_ATTR(BPF_PROG_ATTACH))
1366                return -EINVAL;
1367
1368        if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
1369                return -EINVAL;
1370
1371        switch (attr->attach_type) {
1372        case BPF_CGROUP_INET_INGRESS:
1373        case BPF_CGROUP_INET_EGRESS:
1374                ptype = BPF_PROG_TYPE_CGROUP_SKB;
1375                break;
1376        case BPF_CGROUP_INET_SOCK_CREATE:
1377                ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1378                break;
1379        case BPF_CGROUP_SOCK_OPS:
1380                ptype = BPF_PROG_TYPE_SOCK_OPS;
1381                break;
1382        case BPF_CGROUP_DEVICE:
1383                ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1384                break;
1385        case BPF_SK_SKB_STREAM_PARSER:
1386        case BPF_SK_SKB_STREAM_VERDICT:
1387                return sockmap_get_from_fd(attr, true);
1388        default:
1389                return -EINVAL;
1390        }
1391
1392        prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1393        if (IS_ERR(prog))
1394                return PTR_ERR(prog);
1395
1396        cgrp = cgroup_get_from_fd(attr->target_fd);
1397        if (IS_ERR(cgrp)) {
1398                bpf_prog_put(prog);
1399                return PTR_ERR(cgrp);
1400        }
1401
1402        ret = cgroup_bpf_attach(cgrp, prog, attr->attach_type,
1403                                attr->attach_flags);
1404        if (ret)
1405                bpf_prog_put(prog);
1406        cgroup_put(cgrp);
1407
1408        return ret;
1409}
1410
1411#define BPF_PROG_DETACH_LAST_FIELD attach_type
1412
1413static int bpf_prog_detach(const union bpf_attr *attr)
1414{
1415        enum bpf_prog_type ptype;
1416        struct bpf_prog *prog;
1417        struct cgroup *cgrp;
1418        int ret;
1419
1420        if (!capable(CAP_NET_ADMIN))
1421                return -EPERM;
1422
1423        if (CHECK_ATTR(BPF_PROG_DETACH))
1424                return -EINVAL;
1425
1426        switch (attr->attach_type) {
1427        case BPF_CGROUP_INET_INGRESS:
1428        case BPF_CGROUP_INET_EGRESS:
1429                ptype = BPF_PROG_TYPE_CGROUP_SKB;
1430                break;
1431        case BPF_CGROUP_INET_SOCK_CREATE:
1432                ptype = BPF_PROG_TYPE_CGROUP_SOCK;
1433                break;
1434        case BPF_CGROUP_SOCK_OPS:
1435                ptype = BPF_PROG_TYPE_SOCK_OPS;
1436                break;
1437        case BPF_CGROUP_DEVICE:
1438                ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
1439                break;
1440        case BPF_SK_SKB_STREAM_PARSER:
1441        case BPF_SK_SKB_STREAM_VERDICT:
1442                return sockmap_get_from_fd(attr, false);
1443        default:
1444                return -EINVAL;
1445        }
1446
1447        cgrp = cgroup_get_from_fd(attr->target_fd);
1448        if (IS_ERR(cgrp))
1449                return PTR_ERR(cgrp);
1450
1451        prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
1452        if (IS_ERR(prog))
1453                prog = NULL;
1454
1455        ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, 0);
1456        if (prog)
1457                bpf_prog_put(prog);
1458        cgroup_put(cgrp);
1459        return ret;
1460}
1461
1462#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
1463
1464static int bpf_prog_query(const union bpf_attr *attr,
1465                          union bpf_attr __user *uattr)
1466{
1467        struct cgroup *cgrp;
1468        int ret;
1469
1470        if (!capable(CAP_NET_ADMIN))
1471                return -EPERM;
1472        if (CHECK_ATTR(BPF_PROG_QUERY))
1473                return -EINVAL;
1474        if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
1475                return -EINVAL;
1476
1477        switch (attr->query.attach_type) {
1478        case BPF_CGROUP_INET_INGRESS:
1479        case BPF_CGROUP_INET_EGRESS:
1480        case BPF_CGROUP_INET_SOCK_CREATE:
1481        case BPF_CGROUP_SOCK_OPS:
1482        case BPF_CGROUP_DEVICE:
1483                break;
1484        default:
1485                return -EINVAL;
1486        }
1487        cgrp = cgroup_get_from_fd(attr->query.target_fd);
1488        if (IS_ERR(cgrp))
1489                return PTR_ERR(cgrp);
1490        ret = cgroup_bpf_query(cgrp, attr, uattr);
1491        cgroup_put(cgrp);
1492        return ret;
1493}
1494#endif /* CONFIG_CGROUP_BPF */
1495
1496#define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
1497
1498static int bpf_prog_test_run(const union bpf_attr *attr,
1499                             union bpf_attr __user *uattr)
1500{
1501        struct bpf_prog *prog;
1502        int ret = -ENOTSUPP;
1503
1504        if (!capable(CAP_SYS_ADMIN))
1505                return -EPERM;
1506        if (CHECK_ATTR(BPF_PROG_TEST_RUN))
1507                return -EINVAL;
1508
1509        prog = bpf_prog_get(attr->test.prog_fd);
1510        if (IS_ERR(prog))
1511                return PTR_ERR(prog);
1512
1513        if (prog->aux->ops->test_run)
1514                ret = prog->aux->ops->test_run(prog, attr, uattr);
1515
1516        bpf_prog_put(prog);
1517        return ret;
1518}
1519
1520#define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
1521
1522static int bpf_obj_get_next_id(const union bpf_attr *attr,
1523                               union bpf_attr __user *uattr,
1524                               struct idr *idr,
1525                               spinlock_t *lock)
1526{
1527        u32 next_id = attr->start_id;
1528        int err = 0;
1529
1530        if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
1531                return -EINVAL;
1532
1533        if (!capable(CAP_SYS_ADMIN))
1534                return -EPERM;
1535
1536        next_id++;
1537        spin_lock_bh(lock);
1538        if (!idr_get_next(idr, &next_id))
1539                err = -ENOENT;
1540        spin_unlock_bh(lock);
1541
1542        if (!err)
1543                err = put_user(next_id, &uattr->next_id);
1544
1545        return err;
1546}
1547
1548#define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
1549
1550static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
1551{
1552        struct bpf_prog *prog;
1553        u32 id = attr->prog_id;
1554        int fd;
1555
1556        if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
1557                return -EINVAL;
1558
1559        if (!capable(CAP_SYS_ADMIN))
1560                return -EPERM;
1561
1562        spin_lock_bh(&prog_idr_lock);
1563        prog = idr_find(&prog_idr, id);
1564        if (prog)
1565                prog = bpf_prog_inc_not_zero(prog);
1566        else
1567                prog = ERR_PTR(-ENOENT);
1568        spin_unlock_bh(&prog_idr_lock);
1569
1570        if (IS_ERR(prog))
1571                return PTR_ERR(prog);
1572
1573        fd = bpf_prog_new_fd(prog);
1574        if (fd < 0)
1575                bpf_prog_put(prog);
1576
1577        return fd;
1578}
1579
1580#define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
1581
1582static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
1583{
1584        struct bpf_map *map;
1585        u32 id = attr->map_id;
1586        int f_flags;
1587        int fd;
1588
1589        if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
1590            attr->open_flags & ~BPF_OBJ_FLAG_MASK)
1591                return -EINVAL;
1592
1593        if (!capable(CAP_SYS_ADMIN))
1594                return -EPERM;
1595
1596        f_flags = bpf_get_file_flag(attr->open_flags);
1597        if (f_flags < 0)
1598                return f_flags;
1599
1600        spin_lock_bh(&map_idr_lock);
1601        map = idr_find(&map_idr, id);
1602        if (map)
1603                map = bpf_map_inc_not_zero(map, true);
1604        else
1605                map = ERR_PTR(-ENOENT);
1606        spin_unlock_bh(&map_idr_lock);
1607
1608        if (IS_ERR(map))
1609                return PTR_ERR(map);
1610
1611        fd = bpf_map_new_fd(map, f_flags);
1612        if (fd < 0)
1613                bpf_map_put(map);
1614
1615        return fd;
1616}
1617
1618static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
1619                                              unsigned long addr)
1620{
1621        int i;
1622
1623        for (i = 0; i < prog->aux->used_map_cnt; i++)
1624                if (prog->aux->used_maps[i] == (void *)addr)
1625                        return prog->aux->used_maps[i];
1626        return NULL;
1627}
1628
1629static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
1630{
1631        const struct bpf_map *map;
1632        struct bpf_insn *insns;
1633        u64 imm;
1634        int i;
1635
1636        insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
1637                        GFP_USER);
1638        if (!insns)
1639                return insns;
1640
1641        for (i = 0; i < prog->len; i++) {
1642                if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) {
1643                        insns[i].code = BPF_JMP | BPF_CALL;
1644                        insns[i].imm = BPF_FUNC_tail_call;
1645                        /* fall-through */
1646                }
1647                if (insns[i].code == (BPF_JMP | BPF_CALL) ||
1648                    insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) {
1649                        if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS))
1650                                insns[i].code = BPF_JMP | BPF_CALL;
1651                        if (!bpf_dump_raw_ok())
1652                                insns[i].imm = 0;
1653                        continue;
1654                }
1655
1656                if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW))
1657                        continue;
1658
1659                imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
1660                map = bpf_map_from_imm(prog, imm);
1661                if (map) {
1662                        insns[i].src_reg = BPF_PSEUDO_MAP_FD;
1663                        insns[i].imm = map->id;
1664                        insns[i + 1].imm = 0;
1665                        continue;
1666                }
1667
1668                if (!bpf_dump_raw_ok() &&
1669                    imm == (unsigned long)prog->aux) {
1670                        insns[i].imm = 0;
1671                        insns[i + 1].imm = 0;
1672                        continue;
1673                }
1674        }
1675
1676        return insns;
1677}
1678
1679static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
1680                                   const union bpf_attr *attr,
1681                                   union bpf_attr __user *uattr)
1682{
1683        struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1684        struct bpf_prog_info info = {};
1685        u32 info_len = attr->info.info_len;
1686        char __user *uinsns;
1687        u32 ulen;
1688        int err;
1689
1690        err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1691        if (err)
1692                return err;
1693        info_len = min_t(u32, sizeof(info), info_len);
1694
1695        if (copy_from_user(&info, uinfo, info_len))
1696                return -EFAULT;
1697
1698        info.type = prog->type;
1699        info.id = prog->aux->id;
1700        info.load_time = prog->aux->load_time;
1701        info.created_by_uid = from_kuid_munged(current_user_ns(),
1702                                               prog->aux->user->uid);
1703
1704        memcpy(info.tag, prog->tag, sizeof(prog->tag));
1705        memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
1706
1707        ulen = info.nr_map_ids;
1708        info.nr_map_ids = prog->aux->used_map_cnt;
1709        ulen = min_t(u32, info.nr_map_ids, ulen);
1710        if (ulen) {
1711                u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
1712                u32 i;
1713
1714                for (i = 0; i < ulen; i++)
1715                        if (put_user(prog->aux->used_maps[i]->id,
1716                                     &user_map_ids[i]))
1717                                return -EFAULT;
1718        }
1719
1720        if (!capable(CAP_SYS_ADMIN)) {
1721                info.jited_prog_len = 0;
1722                info.xlated_prog_len = 0;
1723                goto done;
1724        }
1725
1726        ulen = info.xlated_prog_len;
1727        info.xlated_prog_len = bpf_prog_insn_size(prog);
1728        if (info.xlated_prog_len && ulen) {
1729                struct bpf_insn *insns_sanitized;
1730                bool fault;
1731
1732                if (prog->blinded && !bpf_dump_raw_ok()) {
1733                        info.xlated_prog_insns = 0;
1734                        goto done;
1735                }
1736                insns_sanitized = bpf_insn_prepare_dump(prog);
1737                if (!insns_sanitized)
1738                        return -ENOMEM;
1739                uinsns = u64_to_user_ptr(info.xlated_prog_insns);
1740                ulen = min_t(u32, info.xlated_prog_len, ulen);
1741                fault = copy_to_user(uinsns, insns_sanitized, ulen);
1742                kfree(insns_sanitized);
1743                if (fault)
1744                        return -EFAULT;
1745        }
1746
1747        if (bpf_prog_is_dev_bound(prog->aux)) {
1748                err = bpf_prog_offload_info_fill(&info, prog);
1749                if (err)
1750                        return err;
1751                goto done;
1752        }
1753
1754        /* NOTE: the following code is supposed to be skipped for offload.
1755         * bpf_prog_offload_info_fill() is the place to fill similar fields
1756         * for offload.
1757         */
1758        ulen = info.jited_prog_len;
1759        info.jited_prog_len = prog->jited_len;
1760        if (info.jited_prog_len && ulen) {
1761                if (bpf_dump_raw_ok()) {
1762                        uinsns = u64_to_user_ptr(info.jited_prog_insns);
1763                        ulen = min_t(u32, info.jited_prog_len, ulen);
1764                        if (copy_to_user(uinsns, prog->bpf_func, ulen))
1765                                return -EFAULT;
1766                } else {
1767                        info.jited_prog_insns = 0;
1768                }
1769        }
1770
1771done:
1772        if (copy_to_user(uinfo, &info, info_len) ||
1773            put_user(info_len, &uattr->info.info_len))
1774                return -EFAULT;
1775
1776        return 0;
1777}
1778
1779static int bpf_map_get_info_by_fd(struct bpf_map *map,
1780                                  const union bpf_attr *attr,
1781                                  union bpf_attr __user *uattr)
1782{
1783        struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
1784        struct bpf_map_info info = {};
1785        u32 info_len = attr->info.info_len;
1786        int err;
1787
1788        err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
1789        if (err)
1790                return err;
1791        info_len = min_t(u32, sizeof(info), info_len);
1792
1793        info.type = map->map_type;
1794        info.id = map->id;
1795        info.key_size = map->key_size;
1796        info.value_size = map->value_size;
1797        info.max_entries = map->max_entries;
1798        info.map_flags = map->map_flags;
1799        memcpy(info.name, map->name, sizeof(map->name));
1800
1801        if (bpf_map_is_dev_bound(map)) {
1802                err = bpf_map_offload_info_fill(&info, map);
1803                if (err)
1804                        return err;
1805        }
1806
1807        if (copy_to_user(uinfo, &info, info_len) ||
1808            put_user(info_len, &uattr->info.info_len))
1809                return -EFAULT;
1810
1811        return 0;
1812}
1813
1814#define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
1815
1816static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
1817                                  union bpf_attr __user *uattr)
1818{
1819        int ufd = attr->info.bpf_fd;
1820        struct fd f;
1821        int err;
1822
1823        if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
1824                return -EINVAL;
1825
1826        f = fdget(ufd);
1827        if (!f.file)
1828                return -EBADFD;
1829
1830        if (f.file->f_op == &bpf_prog_fops)
1831                err = bpf_prog_get_info_by_fd(f.file->private_data, attr,
1832                                              uattr);
1833        else if (f.file->f_op == &bpf_map_fops)
1834                err = bpf_map_get_info_by_fd(f.file->private_data, attr,
1835                                             uattr);
1836        else
1837                err = -EINVAL;
1838
1839        fdput(f);
1840        return err;
1841}
1842
1843SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
1844{
1845        union bpf_attr attr = {};
1846        int err;
1847
1848        if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN))
1849                return -EPERM;
1850
1851        err = check_uarg_tail_zero(uattr, sizeof(attr), size);
1852        if (err)
1853                return err;
1854        size = min_t(u32, size, sizeof(attr));
1855
1856        /* copy attributes from user space, may be less than sizeof(bpf_attr) */
1857        if (copy_from_user(&attr, uattr, size) != 0)
1858                return -EFAULT;
1859
1860        err = security_bpf(cmd, &attr, size);
1861        if (err < 0)
1862                return err;
1863
1864        switch (cmd) {
1865        case BPF_MAP_CREATE:
1866                err = map_create(&attr);
1867                break;
1868        case BPF_MAP_LOOKUP_ELEM:
1869                err = map_lookup_elem(&attr);
1870                break;
1871        case BPF_MAP_UPDATE_ELEM:
1872                err = map_update_elem(&attr);
1873                break;
1874        case BPF_MAP_DELETE_ELEM:
1875                err = map_delete_elem(&attr);
1876                break;
1877        case BPF_MAP_GET_NEXT_KEY:
1878                err = map_get_next_key(&attr);
1879                break;
1880        case BPF_PROG_LOAD:
1881                err = bpf_prog_load(&attr);
1882                break;
1883        case BPF_OBJ_PIN:
1884                err = bpf_obj_pin(&attr);
1885                break;
1886        case BPF_OBJ_GET:
1887                err = bpf_obj_get(&attr);
1888                break;
1889#ifdef CONFIG_CGROUP_BPF
1890        case BPF_PROG_ATTACH:
1891                err = bpf_prog_attach(&attr);
1892                break;
1893        case BPF_PROG_DETACH:
1894                err = bpf_prog_detach(&attr);
1895                break;
1896        case BPF_PROG_QUERY:
1897                err = bpf_prog_query(&attr, uattr);
1898                break;
1899#endif
1900        case BPF_PROG_TEST_RUN:
1901                err = bpf_prog_test_run(&attr, uattr);
1902                break;
1903        case BPF_PROG_GET_NEXT_ID:
1904                err = bpf_obj_get_next_id(&attr, uattr,
1905                                          &prog_idr, &prog_idr_lock);
1906                break;
1907        case BPF_MAP_GET_NEXT_ID:
1908                err = bpf_obj_get_next_id(&attr, uattr,
1909                                          &map_idr, &map_idr_lock);
1910                break;
1911        case BPF_PROG_GET_FD_BY_ID:
1912                err = bpf_prog_get_fd_by_id(&attr);
1913                break;
1914        case BPF_MAP_GET_FD_BY_ID:
1915                err = bpf_map_get_fd_by_id(&attr);
1916                break;
1917        case BPF_OBJ_GET_INFO_BY_FD:
1918                err = bpf_obj_get_info_by_fd(&attr, uattr);
1919                break;
1920        default:
1921                err = -EINVAL;
1922                break;
1923        }
1924
1925        return err;
1926}
1927