net/core/sysctl_net_core.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* -*- linux-c -*-
   3  * sysctl_net_core.c: sysctl interface to net core subsystem.
   4  *
   5  * Begun April 1, 1996, Mike Shaver.
   6  * Added /proc/sys/net/core directory entry (empty =) ). [MS]
   7  */
   8
   9 #include <linux/filter.h>
  10 #include <linux/mm.h>
  11 #include <linux/sysctl.h>
  12 #include <linux/module.h>
  13 #include <linux/socket.h>
  14 #include <linux/netdevice.h>
  15 #include <linux/ratelimit.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/init.h>
  18 #include <linux/slab.h>
  19
  20 #include <net/ip.h>
  21 #include <net/sock.h>
  22 #include <net/net_ratelimit.h>
  23 #include <net/busy_poll.h>
  24 #include <net/pkt_sched.h>
  25
  26 static int two = 2;
  27 static int three = 3;
  28 static int int_3600 = 3600;
  29 static int min_sndbuf = SOCK_MIN_SNDBUF;
  30 static int min_rcvbuf = SOCK_MIN_RCVBUF;
  31 static int max_skb_frags = MAX_SKB_FRAGS;
  32 static long long_one __maybe_unused = 1;
  33 static long long_max __maybe_unused = LONG_MAX;
  34
  35 static int net_msg_warn;        /* Unused, but still a sysctl */
  36
  37 int sysctl_fb_tunnels_only_for_init_net __read_mostly = 0;
  38 EXPORT_SYMBOL(sysctl_fb_tunnels_only_for_init_net);
  39
  40 /* 0 - Keep current behavior:
  41  *     IPv4: inherit all current settings from init_net
  42  *     IPv6: reset all settings to default
  43  * 1 - Both inherit all current settings from init_net
  44  * 2 - Both reset all settings to default
  45  * 3 - Both inherit all settings from current netns
  46  */
  47 int sysctl_devconf_inherit_init_net __read_mostly;
  48 EXPORT_SYMBOL(sysctl_devconf_inherit_init_net);
  49
  50 #ifdef CONFIG_RPS
  51 static int rps_sock_flow_sysctl(struct ctl_table *table, int write,
  52                                 void *buffer, size_t *lenp, loff_t *ppos)
  53 {
  54         unsigned int orig_size, size;
  55         int ret, i;
  56         struct ctl_table tmp = {
  57                 .data = &size,
  58                 .maxlen = sizeof(size),
  59                 .mode = table->mode
  60         };
  61         struct rps_sock_flow_table *orig_sock_table, *sock_table;
  62         static DEFINE_MUTEX(sock_flow_mutex);
  63
  64         mutex_lock(&sock_flow_mutex);
  65
  66         orig_sock_table = rcu_dereference_protected(rps_sock_flow_table,
  67                                         lockdep_is_held(&sock_flow_mutex));
  68         size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0;
  69
  70         ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
  71
  72         if (write) {
  73                 if (size) {
  74                         if (size > 1<<29) {
  75                                 /* Enforce limit to prevent overflow */
  76                                 mutex_unlock(&sock_flow_mutex);
  77                                 return -EINVAL;
  78                         }
  79                         size = roundup_pow_of_two(size);
  80                         if (size != orig_size) {
  81                                 sock_table =
  82                                     vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
  83                                 if (!sock_table) {
  84                                         mutex_unlock(&sock_flow_mutex);
  85                                         return -ENOMEM;
  86                                 }
  87                                 rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1;
  88                                 sock_table->mask = size - 1;
  89                         } else
  90                                 sock_table = orig_sock_table;
  91
  92                         for (i = 0; i < size; i++)
  93                                 sock_table->ents[i] = RPS_NO_CPU;
  94                 } else
  95                         sock_table = NULL;
  96
  97                 if (sock_table != orig_sock_table) {
  98                         rcu_assign_pointer(rps_sock_flow_table, sock_table);
  99                         if (sock_table) {
 100                                 static_branch_inc(&rps_needed);
 101                                 static_branch_inc(&rfs_needed);
 102                         }
 103                         if (orig_sock_table) {
 104                                 static_branch_dec(&rps_needed);
 105                                 static_branch_dec(&rfs_needed);
 106                                 synchronize_rcu();
 107                                 vfree(orig_sock_table);
 108                         }
 109                 }
 110         }
 111
 112         mutex_unlock(&sock_flow_mutex);
 113
 114         return ret;
 115 }
 116 #endif /* CONFIG_RPS */
 117
 118 #ifdef CONFIG_NET_FLOW_LIMIT
 119 static DEFINE_MUTEX(flow_limit_update_mutex);
 120
 121 static int flow_limit_cpu_sysctl(struct ctl_table *table, int write,
 122                                  void *buffer, size_t *lenp, loff_t *ppos)
 123 {
 124         struct sd_flow_limit *cur;
 125         struct softnet_data *sd;
 126         cpumask_var_t mask;
 127         int i, len, ret = 0;
 128
 129         if (!alloc_cpumask_var(&mask, GFP_KERNEL))
 130                 return -ENOMEM;
 131
 132         if (write) {
 133                 ret = cpumask_parse(buffer, mask);
 134                 if (ret)
 135                         goto done;
 136
 137                 mutex_lock(&flow_limit_update_mutex);
 138                 len = sizeof(*cur) + netdev_flow_limit_table_len;
 139                 for_each_possible_cpu(i) {
 140                         sd = &per_cpu(softnet_data, i);
 141                         cur = rcu_dereference_protected(sd->flow_limit,
 142                                      lockdep_is_held(&flow_limit_update_mutex));
 143                         if (cur && !cpumask_test_cpu(i, mask)) {
 144                                 RCU_INIT_POINTER(sd->flow_limit, NULL);
 145                                 synchronize_rcu();
 146                                 kfree(cur);
 147                         } else if (!cur && cpumask_test_cpu(i, mask)) {
 148                                 cur = kzalloc_node(len, GFP_KERNEL,
 149                                                    cpu_to_node(i));
 150                                 if (!cur) {
 151                                         /* not unwinding previous changes */
 152                                         ret = -ENOMEM;
 153                                         goto write_unlock;
 154                                 }
 155                                 cur->num_buckets = netdev_flow_limit_table_len;
 156                                 rcu_assign_pointer(sd->flow_limit, cur);
 157                         }
 158                 }
 159 write_unlock:
 160                 mutex_unlock(&flow_limit_update_mutex);
 161         } else {
 162                 char kbuf[128];
 163
 164                 if (*ppos || !*lenp) {
 165                         *lenp = 0;
 166                         goto done;
 167                 }
 168
 169                 cpumask_clear(mask);
 170                 rcu_read_lock();
 171                 for_each_possible_cpu(i) {
 172                         sd = &per_cpu(softnet_data, i);
 173                         if (rcu_dereference(sd->flow_limit))
 174                                 cpumask_set_cpu(i, mask);
 175                 }
 176                 rcu_read_unlock();
 177
 178                 len = min(sizeof(kbuf) - 1, *lenp);
 179                 len = scnprintf(kbuf, len, "%*pb", cpumask_pr_args(mask));
 180                 if (!len) {
 181                         *lenp = 0;
 182                         goto done;
 183                 }
 184                 if (len < *lenp)
 185                         kbuf[len++] = '\n';
 186                 memcpy(buffer, kbuf, len);
 187                 *lenp = len;
 188                 *ppos += len;
 189         }
 190
 191 done:
 192         free_cpumask_var(mask);
 193         return ret;
 194 }
 195
 196 static int flow_limit_table_len_sysctl(struct ctl_table *table, int write,
 197                                        void *buffer, size_t *lenp, loff_t *ppos)
 198 {
 199         unsigned int old, *ptr;
 200         int ret;
 201
 202         mutex_lock(&flow_limit_update_mutex);
 203
 204         ptr = table->data;
 205         old = *ptr;
 206         ret = proc_dointvec(table, write, buffer, lenp, ppos);
 207         if (!ret && write && !is_power_of_2(*ptr)) {
 208                 *ptr = old;
 209                 ret = -EINVAL;
 210         }
 211
 212         mutex_unlock(&flow_limit_update_mutex);
 213         return ret;
 214 }
 215 #endif /* CONFIG_NET_FLOW_LIMIT */
 216
 217 #ifdef CONFIG_NET_SCHED
 218 static int set_default_qdisc(struct ctl_table *table, int write,
 219                              void *buffer, size_t *lenp, loff_t *ppos)
 220 {
 221         char id[IFNAMSIZ];
 222         struct ctl_table tbl = {
 223                 .data = id,
 224                 .maxlen = IFNAMSIZ,
 225         };
 226         int ret;
 227
 228         qdisc_get_default(id, IFNAMSIZ);
 229
 230         ret = proc_dostring(&tbl, write, buffer, lenp, ppos);
 231         if (write && ret == 0)
 232                 ret = qdisc_set_default(id);
 233         return ret;
 234 }
 235 #endif
 236
 237 static int proc_do_dev_weight(struct ctl_table *table, int write,
 238                            void *buffer, size_t *lenp, loff_t *ppos)
 239 {
 240         int ret;
 241
 242         ret = proc_dointvec(table, write, buffer, lenp, ppos);
 243         if (ret != 0)
 244                 return ret;
 245
 246         dev_rx_weight = weight_p * dev_weight_rx_bias;
 247         dev_tx_weight = weight_p * dev_weight_tx_bias;
 248
 249         return ret;
 250 }
 251
 252 static int proc_do_rss_key(struct ctl_table *table, int write,
 253                            void *buffer, size_t *lenp, loff_t *ppos)
 254 {
 255         struct ctl_table fake_table;
 256         char buf[NETDEV_RSS_KEY_LEN * 3];
 257
 258         snprintf(buf, sizeof(buf), "%*phC", NETDEV_RSS_KEY_LEN, netdev_rss_key);
 259         fake_table.data = buf;
 260         fake_table.maxlen = sizeof(buf);
 261         return proc_dostring(&fake_table, write, buffer, lenp, ppos);
 262 }
 263
 264 #ifdef CONFIG_BPF_JIT
 265 static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
 266                                            void *buffer, size_t *lenp,
 267                                            loff_t *ppos)
 268 {
 269         int ret, jit_enable = *(int *)table->data;
 270         struct ctl_table tmp = *table;
 271
 272         if (write && !capable(CAP_SYS_ADMIN))
 273                 return -EPERM;
 274
 275         tmp.data = &jit_enable;
 276         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
 277         if (write && !ret) {
 278                 if (jit_enable < 2 ||
 279                     (jit_enable == 2 && bpf_dump_raw_ok(current_cred()))) {
 280                         *(int *)table->data = jit_enable;
 281                         if (jit_enable == 2)
 282                                 pr_warn("bpf_jit_enable = 2 was set! NEVER use this in production, only for JIT debugging!\n");
 283                 } else {
 284                         ret = -EPERM;
 285                 }
 286         }
 287         return ret;
 288 }
 289
 290 # ifdef CONFIG_HAVE_EBPF_JIT
 291 static int
 292 proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
 293                                     void *buffer, size_t *lenp, loff_t *ppos)
 294 {
 295         if (!capable(CAP_SYS_ADMIN))
 296                 return -EPERM;
 297
 298         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
 299 }
 300 # endif /* CONFIG_HAVE_EBPF_JIT */
 301
 302 static int
 303 proc_dolongvec_minmax_bpf_restricted(struct ctl_table *table, int write,
 304                                      void *buffer, size_t *lenp, loff_t *ppos)
 305 {
 306         if (!capable(CAP_SYS_ADMIN))
 307                 return -EPERM;
 308
 309         return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 310 }
 311 #endif
 312
 313 static struct ctl_table net_core_table[] = {
 314         {
 315                 .procname       = "wmem_max",
 316                 .data           = &sysctl_wmem_max,
 317                 .maxlen         = sizeof(int),
 318                 .mode           = 0644,
 319                 .proc_handler   = proc_dointvec_minmax,
 320                 .extra1         = &min_sndbuf,
 321         },
 322         {
 323                 .procname       = "rmem_max",
 324                 .data           = &sysctl_rmem_max,
 325                 .maxlen         = sizeof(int),
 326                 .mode           = 0644,
 327                 .proc_handler   = proc_dointvec_minmax,
 328                 .extra1         = &min_rcvbuf,
 329         },
 330         {
 331                 .procname       = "wmem_default",
 332                 .data           = &sysctl_wmem_default,
 333                 .maxlen         = sizeof(int),
 334                 .mode           = 0644,
 335                 .proc_handler   = proc_dointvec_minmax,
 336                 .extra1         = &min_sndbuf,
 337         },
 338         {
 339                 .procname       = "rmem_default",
 340                 .data           = &sysctl_rmem_default,
 341                 .maxlen         = sizeof(int),
 342                 .mode           = 0644,
 343                 .proc_handler   = proc_dointvec_minmax,
 344                 .extra1         = &min_rcvbuf,
 345         },
 346         {
 347                 .procname       = "dev_weight",
 348                 .data           = &weight_p,
 349                 .maxlen         = sizeof(int),
 350                 .mode           = 0644,
 351                 .proc_handler   = proc_do_dev_weight,
 352         },
 353         {
 354                 .procname       = "dev_weight_rx_bias",
 355                 .data           = &dev_weight_rx_bias,
 356                 .maxlen         = sizeof(int),
 357                 .mode           = 0644,
 358                 .proc_handler   = proc_do_dev_weight,
 359         },
 360         {
 361                 .procname       = "dev_weight_tx_bias",
 362                 .data           = &dev_weight_tx_bias,
 363                 .maxlen         = sizeof(int),
 364                 .mode           = 0644,
 365                 .proc_handler   = proc_do_dev_weight,
 366         },
 367         {
 368                 .procname       = "netdev_max_backlog",
 369                 .data           = &netdev_max_backlog,
 370                 .maxlen         = sizeof(int),
 371                 .mode           = 0644,
 372                 .proc_handler   = proc_dointvec
 373         },
 374         {
 375                 .procname       = "netdev_rss_key",
 376                 .data           = &netdev_rss_key,
 377                 .maxlen         = sizeof(int),
 378                 .mode           = 0444,
 379                 .proc_handler   = proc_do_rss_key,
 380         },
 381 #ifdef CONFIG_BPF_JIT
 382         {
 383                 .procname       = "bpf_jit_enable",
 384                 .data           = &bpf_jit_enable,
 385                 .maxlen         = sizeof(int),
 386                 .mode           = 0644,
 387                 .proc_handler   = proc_dointvec_minmax_bpf_enable,
 388 # ifdef CONFIG_BPF_JIT_ALWAYS_ON
 389                 .extra1         = SYSCTL_ONE,
 390                 .extra2         = SYSCTL_ONE,
 391 # else
 392                 .extra1         = SYSCTL_ZERO,
 393                 .extra2         = &two,
 394 # endif
 395         },
 396 # ifdef CONFIG_HAVE_EBPF_JIT
 397         {
 398                 .procname       = "bpf_jit_harden",
 399                 .data           = &bpf_jit_harden,
 400                 .maxlen         = sizeof(int),
 401                 .mode           = 0600,
 402                 .proc_handler   = proc_dointvec_minmax_bpf_restricted,
 403                 .extra1         = SYSCTL_ZERO,
 404                 .extra2         = &two,
 405         },
 406         {
 407                 .procname       = "bpf_jit_kallsyms",
 408                 .data           = &bpf_jit_kallsyms,
 409                 .maxlen         = sizeof(int),
 410                 .mode           = 0600,
 411                 .proc_handler   = proc_dointvec_minmax_bpf_restricted,
 412                 .extra1         = SYSCTL_ZERO,
 413                 .extra2         = SYSCTL_ONE,
 414         },
 415 # endif
 416         {
 417                 .procname       = "bpf_jit_limit",
 418                 .data           = &bpf_jit_limit,
 419                 .maxlen         = sizeof(long),
 420                 .mode           = 0600,
 421                 .proc_handler   = proc_dolongvec_minmax_bpf_restricted,
 422                 .extra1         = &long_one,
 423                 .extra2         = &bpf_jit_limit_max,
 424         },
 425 #endif
 426         {
 427                 .procname       = "netdev_tstamp_prequeue",
 428                 .data           = &netdev_tstamp_prequeue,
 429                 .maxlen         = sizeof(int),
 430                 .mode           = 0644,
 431                 .proc_handler   = proc_dointvec
 432         },
 433         {
 434                 .procname       = "message_cost",
 435                 .data           = &net_ratelimit_state.interval,
 436                 .maxlen         = sizeof(int),
 437                 .mode           = 0644,
 438                 .proc_handler   = proc_dointvec_jiffies,
 439         },
 440         {
 441                 .procname       = "message_burst",
 442                 .data           = &net_ratelimit_state.burst,
 443                 .maxlen         = sizeof(int),
 444                 .mode           = 0644,
 445                 .proc_handler   = proc_dointvec,
 446         },
 447         {
 448                 .procname       = "optmem_max",
 449                 .data           = &sysctl_optmem_max,
 450                 .maxlen         = sizeof(int),
 451                 .mode           = 0644,
 452                 .proc_handler   = proc_dointvec
 453         },
 454         {
 455                 .procname       = "tstamp_allow_data",
 456                 .data           = &sysctl_tstamp_allow_data,
 457                 .maxlen         = sizeof(int),
 458                 .mode           = 0644,
 459                 .proc_handler   = proc_dointvec_minmax,
 460                 .extra1         = SYSCTL_ZERO,
 461                 .extra2         = SYSCTL_ONE
 462         },
 463 #ifdef CONFIG_RPS
 464         {
 465                 .procname       = "rps_sock_flow_entries",
 466                 .maxlen         = sizeof(int),
 467                 .mode           = 0644,
 468                 .proc_handler   = rps_sock_flow_sysctl
 469         },
 470 #endif
 471 #ifdef CONFIG_NET_FLOW_LIMIT
 472         {
 473                 .procname       = "flow_limit_cpu_bitmap",
 474                 .mode           = 0644,
 475                 .proc_handler   = flow_limit_cpu_sysctl
 476         },
 477         {
 478                 .procname       = "flow_limit_table_len",
 479                 .data           = &netdev_flow_limit_table_len,
 480                 .maxlen         = sizeof(int),
 481                 .mode           = 0644,
 482                 .proc_handler   = flow_limit_table_len_sysctl
 483         },
 484 #endif /* CONFIG_NET_FLOW_LIMIT */
 485 #ifdef CONFIG_NET_RX_BUSY_POLL
 486         {
 487                 .procname       = "busy_poll",
 488                 .data           = &sysctl_net_busy_poll,
 489                 .maxlen         = sizeof(unsigned int),
 490                 .mode           = 0644,
 491                 .proc_handler   = proc_dointvec_minmax,
 492                 .extra1         = SYSCTL_ZERO,
 493         },
 494         {
 495                 .procname       = "busy_read",
 496                 .data           = &sysctl_net_busy_read,
 497                 .maxlen         = sizeof(unsigned int),
 498                 .mode           = 0644,
 499                 .proc_handler   = proc_dointvec_minmax,
 500                 .extra1         = SYSCTL_ZERO,
 501         },
 502 #endif
 503 #ifdef CONFIG_NET_SCHED
 504         {
 505                 .procname       = "default_qdisc",
 506                 .mode           = 0644,
 507                 .maxlen         = IFNAMSIZ,
 508                 .proc_handler   = set_default_qdisc
 509         },
 510 #endif
 511         {
 512                 .procname       = "netdev_budget",
 513                 .data           = &netdev_budget,
 514                 .maxlen         = sizeof(int),
 515                 .mode           = 0644,
 516                 .proc_handler   = proc_dointvec
 517         },
 518         {
 519                 .procname       = "warnings",
 520                 .data           = &net_msg_warn,
 521                 .maxlen         = sizeof(int),
 522                 .mode           = 0644,
 523                 .proc_handler   = proc_dointvec
 524         },
 525         {
 526                 .procname       = "max_skb_frags",
 527                 .data           = &sysctl_max_skb_frags,
 528                 .maxlen         = sizeof(int),
 529                 .mode           = 0644,
 530                 .proc_handler   = proc_dointvec_minmax,
 531                 .extra1         = SYSCTL_ONE,
 532                 .extra2         = &max_skb_frags,
 533         },
 534         {
 535                 .procname       = "netdev_budget_usecs",
 536                 .data           = &netdev_budget_usecs,
 537                 .maxlen         = sizeof(unsigned int),
 538                 .mode           = 0644,
 539                 .proc_handler   = proc_dointvec_minmax,
 540                 .extra1         = SYSCTL_ZERO,
 541         },
 542         {
 543                 .procname       = "fb_tunnels_only_for_init_net",
 544                 .data           = &sysctl_fb_tunnels_only_for_init_net,
 545                 .maxlen         = sizeof(int),
 546                 .mode           = 0644,
 547                 .proc_handler   = proc_dointvec_minmax,
 548                 .extra1         = SYSCTL_ZERO,
 549                 .extra2         = &two,
 550         },
 551         {
 552                 .procname       = "devconf_inherit_init_net",
 553                 .data           = &sysctl_devconf_inherit_init_net,
 554                 .maxlen         = sizeof(int),
 555                 .mode           = 0644,
 556                 .proc_handler   = proc_dointvec_minmax,
 557                 .extra1         = SYSCTL_ZERO,
 558                 .extra2         = &three,
 559         },
 560         {
 561                 .procname       = "high_order_alloc_disable",
 562                 .data           = &net_high_order_alloc_disable_key.key,
 563                 .maxlen         = sizeof(net_high_order_alloc_disable_key),
 564                 .mode           = 0644,
 565                 .proc_handler   = proc_do_static_key,
 566         },
 567         {
 568                 .procname       = "gro_normal_batch",
 569                 .data           = &gro_normal_batch,
 570                 .maxlen         = sizeof(unsigned int),
 571                 .mode           = 0644,
 572                 .proc_handler   = proc_dointvec_minmax,
 573                 .extra1         = SYSCTL_ONE,
 574         },
 575         {
 576                 .procname       = "netdev_unregister_timeout_secs",
 577                 .data           = &netdev_unregister_timeout_secs,
 578                 .maxlen         = sizeof(unsigned int),
 579                 .mode           = 0644,
 580                 .proc_handler   = proc_dointvec_minmax,
 581                 .extra1         = SYSCTL_ONE,
 582                 .extra2         = &int_3600,
 583         },
 584         { }
 585 };
 586
 587 static struct ctl_table netns_core_table[] = {
 588         {
 589                 .procname       = "somaxconn",
 590                 .data           = &init_net.core.sysctl_somaxconn,
 591                 .maxlen         = sizeof(int),
 592                 .mode           = 0644,
 593                 .extra1         = SYSCTL_ZERO,
 594                 .proc_handler   = proc_dointvec_minmax
 595         },
 596         { }
 597 };
 598
 599 static int __init fb_tunnels_only_for_init_net_sysctl_setup(char *str)
 600 {
 601         /* fallback tunnels for initns only */
 602         if (!strncmp(str, "initns", 6))
 603                 sysctl_fb_tunnels_only_for_init_net = 1;
 604         /* no fallback tunnels anywhere */
 605         else if (!strncmp(str, "none", 4))
 606                 sysctl_fb_tunnels_only_for_init_net = 2;
 607
 608         return 1;
 609 }
 610 __setup("fb_tunnels=", fb_tunnels_only_for_init_net_sysctl_setup);
 611
 612 static __net_init int sysctl_core_net_init(struct net *net)
 613 {
 614         struct ctl_table *tbl;
 615
 616         tbl = netns_core_table;
 617         if (!net_eq(net, &init_net)) {
 618                 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
 619                 if (tbl == NULL)
 620                         goto err_dup;
 621
 622                 tbl[0].data = &net->core.sysctl_somaxconn;
 623
 624                 /* Don't export any sysctls to unprivileged users */
 625                 if (net->user_ns != &init_user_ns) {
 626                         tbl[0].procname = NULL;
 627                 }
 628         }
 629
 630         net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl);
 631         if (net->core.sysctl_hdr == NULL)
 632                 goto err_reg;
 633
 634         return 0;
 635
 636 err_reg:
 637         if (tbl != netns_core_table)
 638                 kfree(tbl);
 639 err_dup:
 640         return -ENOMEM;
 641 }
 642
 643 static __net_exit void sysctl_core_net_exit(struct net *net)
 644 {
 645         struct ctl_table *tbl;
 646
 647         tbl = net->core.sysctl_hdr->ctl_table_arg;
 648         unregister_net_sysctl_table(net->core.sysctl_hdr);
 649         BUG_ON(tbl == netns_core_table);
 650         kfree(tbl);
 651 }
 652
 653 static __net_initdata struct pernet_operations sysctl_core_ops = {
 654         .init = sysctl_core_net_init,
 655         .exit = sysctl_core_net_exit,
 656 };
 657
 658 static __init int sysctl_core_init(void)
 659 {
 660         register_net_sysctl(&init_net, "net/core", net_core_table);
 661         return register_pernet_subsys(&sysctl_core_ops);
 662 }
 663
 664 fs_initcall(sysctl_core_init);