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   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/signal.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/security.h>
  29 #include <linux/ctype.h>
  30 #include <linux/kmemcheck.h>
  31 #include <linux/fs.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/ratelimit.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/initrd.h>
  42 #include <linux/key.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/vmstat.h>
  48 #include <linux/nfs_fs.h>
  49 #include <linux/acpi.h>
  50 #include <linux/reboot.h>
  51 #include <linux/ftrace.h>
  52 #include <linux/slow-work.h>
  53 #include <linux/perf_event.h>
  54 #include <linux/kprobes.h>
  55
  56 #include <asm/uaccess.h>
  57 #include <asm/processor.h>
  58
  59 #ifdef CONFIG_X86
  60 #include <asm/nmi.h>
  61 #include <asm/stacktrace.h>
  62 #include <asm/io.h>
  63 #endif
  64
  65
  66 #if defined(CONFIG_SYSCTL)
  67
  68 /* External variables not in a header file. */
  69 extern int sysctl_overcommit_memory;
  70 extern int sysctl_overcommit_ratio;
  71 extern int sysctl_panic_on_oom;
  72 extern int sysctl_oom_kill_allocating_task;
  73 extern int sysctl_oom_dump_tasks;
  74 extern int max_threads;
  75 extern int core_uses_pid;
  76 extern int suid_dumpable;
  77 extern char core_pattern[];
  78 extern unsigned int core_pipe_limit;
  79 extern int pid_max;
  80 extern int min_free_kbytes;
  81 extern int pid_max_min, pid_max_max;
  82 extern int sysctl_drop_caches;
  83 extern int percpu_pagelist_fraction;
  84 extern int compat_log;
  85 extern int latencytop_enabled;
  86 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  87 #ifndef CONFIG_MMU
  88 extern int sysctl_nr_trim_pages;
  89 #endif
  90 #ifdef CONFIG_BLOCK
  91 extern int blk_iopoll_enabled;
  92 #endif
  93
  94 /* Constants used for minimum and  maximum */
  95 #ifdef CONFIG_DETECT_SOFTLOCKUP
  96 static int sixty = 60;
  97 static int neg_one = -1;
  98 #endif
  99
 100 static int zero;
 101 static int __maybe_unused one = 1;
 102 static int __maybe_unused two = 2;
 103 static unsigned long one_ul = 1;
 104 static int one_hundred = 100;
 105 #ifdef CONFIG_PRINTK
 106 static int ten_thousand = 10000;
 107 #endif
 108
 109 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 110 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 111
 112 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 113 static int maxolduid = 65535;
 114 static int minolduid;
 115 static int min_percpu_pagelist_fract = 8;
 116
 117 static int ngroups_max = NGROUPS_MAX;
 118
 119 #ifdef CONFIG_MODULES
 120 extern char modprobe_path[];
 121 extern int modules_disabled;
 122 #endif
 123 #ifdef CONFIG_CHR_DEV_SG
 124 extern int sg_big_buff;
 125 #endif
 126
 127 #ifdef CONFIG_SPARC
 128 #include <asm/system.h>
 129 #endif
 130
 131 #ifdef CONFIG_SPARC64
 132 extern int sysctl_tsb_ratio;
 133 #endif
 134
 135 #ifdef __hppa__
 136 extern int pwrsw_enabled;
 137 extern int unaligned_enabled;
 138 #endif
 139
 140 #ifdef CONFIG_S390
 141 #ifdef CONFIG_MATHEMU
 142 extern int sysctl_ieee_emulation_warnings;
 143 #endif
 144 extern int sysctl_userprocess_debug;
 145 extern int spin_retry;
 146 #endif
 147
 148 #ifdef CONFIG_BSD_PROCESS_ACCT
 149 extern int acct_parm[];
 150 #endif
 151
 152 #ifdef CONFIG_IA64
 153 extern int no_unaligned_warning;
 154 extern int unaligned_dump_stack;
 155 #endif
 156
 157 extern struct ratelimit_state printk_ratelimit_state;
 158
 159 #ifdef CONFIG_RT_MUTEXES
 160 extern int max_lock_depth;
 161 #endif
 162
 163 #ifdef CONFIG_PROC_SYSCTL
 164 static int proc_do_cad_pid(struct ctl_table *table, int write,
 165                   void __user *buffer, size_t *lenp, loff_t *ppos);
 166 static int proc_taint(struct ctl_table *table, int write,
 167                                void __user *buffer, size_t *lenp, loff_t *ppos);
 168 #endif
 169
 170 static struct ctl_table root_table[];
 171 static struct ctl_table_root sysctl_table_root;
 172 static struct ctl_table_header root_table_header = {
 173         .count = 1,
 174         .ctl_table = root_table,
 175         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 176         .root = &sysctl_table_root,
 177         .set = &sysctl_table_root.default_set,
 178 };
 179 static struct ctl_table_root sysctl_table_root = {
 180         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 181         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 182 };
 183
 184 static struct ctl_table kern_table[];
 185 static struct ctl_table vm_table[];
 186 static struct ctl_table fs_table[];
 187 static struct ctl_table debug_table[];
 188 static struct ctl_table dev_table[];
 189 extern struct ctl_table random_table[];
 190 #ifdef CONFIG_INOTIFY_USER
 191 extern struct ctl_table inotify_table[];
 192 #endif
 193 #ifdef CONFIG_EPOLL
 194 extern struct ctl_table epoll_table[];
 195 #endif
 196
 197 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 198 int sysctl_legacy_va_layout;
 199 #endif
 200
 201 extern int prove_locking;
 202 extern int lock_stat;
 203
 204 /* The default sysctl tables: */
 205
 206 static struct ctl_table root_table[] = {
 207         {
 208                 .procname       = "kernel",
 209                 .mode           = 0555,
 210                 .child          = kern_table,
 211         },
 212         {
 213                 .procname       = "vm",
 214                 .mode           = 0555,
 215                 .child          = vm_table,
 216         },
 217         {
 218                 .procname       = "fs",
 219                 .mode           = 0555,
 220                 .child          = fs_table,
 221         },
 222         {
 223                 .procname       = "debug",
 224                 .mode           = 0555,
 225                 .child          = debug_table,
 226         },
 227         {
 228                 .procname       = "dev",
 229                 .mode           = 0555,
 230                 .child          = dev_table,
 231         },
 232 /*
 233  * NOTE: do not add new entries to this table unless you have read
 234  * Documentation/sysctl/ctl_unnumbered.txt
 235  */
 236         { }
 237 };
 238
 239 #ifdef CONFIG_SCHED_DEBUG
 240 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 241 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 242 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 243 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 244 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 245 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 246 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
 247 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
 248 #endif
 249
 250 static struct ctl_table kern_table[] = {
 251         {
 252                 .procname       = "sched_child_runs_first",
 253                 .data           = &sysctl_sched_child_runs_first,
 254                 .maxlen         = sizeof(unsigned int),
 255                 .mode           = 0644,
 256                 .proc_handler   = proc_dointvec,
 257         },
 258 #ifdef CONFIG_SCHED_DEBUG
 259         {
 260                 .procname       = "sched_min_granularity_ns",
 261                 .data           = &sysctl_sched_min_granularity,
 262                 .maxlen         = sizeof(unsigned int),
 263                 .mode           = 0644,
 264                 .proc_handler   = sched_proc_update_handler,
 265                 .extra1         = &min_sched_granularity_ns,
 266                 .extra2         = &max_sched_granularity_ns,
 267         },
 268         {
 269                 .procname       = "sched_latency_ns",
 270                 .data           = &sysctl_sched_latency,
 271                 .maxlen         = sizeof(unsigned int),
 272                 .mode           = 0644,
 273                 .proc_handler   = sched_proc_update_handler,
 274                 .extra1         = &min_sched_granularity_ns,
 275                 .extra2         = &max_sched_granularity_ns,
 276         },
 277         {
 278                 .procname       = "sched_wakeup_granularity_ns",
 279                 .data           = &sysctl_sched_wakeup_granularity,
 280                 .maxlen         = sizeof(unsigned int),
 281                 .mode           = 0644,
 282                 .proc_handler   = sched_proc_update_handler,
 283                 .extra1         = &min_wakeup_granularity_ns,
 284                 .extra2         = &max_wakeup_granularity_ns,
 285         },
 286         {
 287                 .procname       = "sched_shares_ratelimit",
 288                 .data           = &sysctl_sched_shares_ratelimit,
 289                 .maxlen         = sizeof(unsigned int),
 290                 .mode           = 0644,
 291                 .proc_handler   = sched_proc_update_handler,
 292                 .extra1         = &min_sched_shares_ratelimit,
 293                 .extra2         = &max_sched_shares_ratelimit,
 294         },
 295         {
 296                 .procname       = "sched_tunable_scaling",
 297                 .data           = &sysctl_sched_tunable_scaling,
 298                 .maxlen         = sizeof(enum sched_tunable_scaling),
 299                 .mode           = 0644,
 300                 .proc_handler   = sched_proc_update_handler,
 301                 .extra1         = &min_sched_tunable_scaling,
 302                 .extra2         = &max_sched_tunable_scaling,
 303         },
 304         {
 305                 .procname       = "sched_shares_thresh",
 306                 .data           = &sysctl_sched_shares_thresh,
 307                 .maxlen         = sizeof(unsigned int),
 308                 .mode           = 0644,
 309                 .proc_handler   = proc_dointvec_minmax,
 310                 .extra1         = &zero,
 311         },
 312         {
 313                 .procname       = "sched_migration_cost",
 314                 .data           = &sysctl_sched_migration_cost,
 315                 .maxlen         = sizeof(unsigned int),
 316                 .mode           = 0644,
 317                 .proc_handler   = proc_dointvec,
 318         },
 319         {
 320                 .procname       = "sched_nr_migrate",
 321                 .data           = &sysctl_sched_nr_migrate,
 322                 .maxlen         = sizeof(unsigned int),
 323                 .mode           = 0644,
 324                 .proc_handler   = proc_dointvec,
 325         },
 326         {
 327                 .procname       = "sched_time_avg",
 328                 .data           = &sysctl_sched_time_avg,
 329                 .maxlen         = sizeof(unsigned int),
 330                 .mode           = 0644,
 331                 .proc_handler   = proc_dointvec,
 332         },
 333         {
 334                 .procname       = "timer_migration",
 335                 .data           = &sysctl_timer_migration,
 336                 .maxlen         = sizeof(unsigned int),
 337                 .mode           = 0644,
 338                 .proc_handler   = proc_dointvec_minmax,
 339                 .extra1         = &zero,
 340                 .extra2         = &one,
 341         },
 342 #endif
 343         {
 344                 .procname       = "sched_rt_period_us",
 345                 .data           = &sysctl_sched_rt_period,
 346                 .maxlen         = sizeof(unsigned int),
 347                 .mode           = 0644,
 348                 .proc_handler   = sched_rt_handler,
 349         },
 350         {
 351                 .procname       = "sched_rt_runtime_us",
 352                 .data           = &sysctl_sched_rt_runtime,
 353                 .maxlen         = sizeof(int),
 354                 .mode           = 0644,
 355                 .proc_handler   = sched_rt_handler,
 356         },
 357         {
 358                 .procname       = "sched_compat_yield",
 359                 .data           = &sysctl_sched_compat_yield,
 360                 .maxlen         = sizeof(unsigned int),
 361                 .mode           = 0644,
 362                 .proc_handler   = proc_dointvec,
 363         },
 364 #ifdef CONFIG_PROVE_LOCKING
 365         {
 366                 .procname       = "prove_locking",
 367                 .data           = &prove_locking,
 368                 .maxlen         = sizeof(int),
 369                 .mode           = 0644,
 370                 .proc_handler   = proc_dointvec,
 371         },
 372 #endif
 373 #ifdef CONFIG_LOCK_STAT
 374         {
 375                 .procname       = "lock_stat",
 376                 .data           = &lock_stat,
 377                 .maxlen         = sizeof(int),
 378                 .mode           = 0644,
 379                 .proc_handler   = proc_dointvec,
 380         },
 381 #endif
 382         {
 383                 .procname       = "panic",
 384                 .data           = &panic_timeout,
 385                 .maxlen         = sizeof(int),
 386                 .mode           = 0644,
 387                 .proc_handler   = proc_dointvec,
 388         },
 389         {
 390                 .procname       = "core_uses_pid",
 391                 .data           = &core_uses_pid,
 392                 .maxlen         = sizeof(int),
 393                 .mode           = 0644,
 394                 .proc_handler   = proc_dointvec,
 395         },
 396         {
 397                 .procname       = "core_pattern",
 398                 .data           = core_pattern,
 399                 .maxlen         = CORENAME_MAX_SIZE,
 400                 .mode           = 0644,
 401                 .proc_handler   = proc_dostring,
 402         },
 403         {
 404                 .procname       = "core_pipe_limit",
 405                 .data           = &core_pipe_limit,
 406                 .maxlen         = sizeof(unsigned int),
 407                 .mode           = 0644,
 408                 .proc_handler   = proc_dointvec,
 409         },
 410 #ifdef CONFIG_PROC_SYSCTL
 411         {
 412                 .procname       = "tainted",
 413                 .maxlen         = sizeof(long),
 414                 .mode           = 0644,
 415                 .proc_handler   = proc_taint,
 416         },
 417 #endif
 418 #ifdef CONFIG_LATENCYTOP
 419         {
 420                 .procname       = "latencytop",
 421                 .data           = &latencytop_enabled,
 422                 .maxlen         = sizeof(int),
 423                 .mode           = 0644,
 424                 .proc_handler   = proc_dointvec,
 425         },
 426 #endif
 427 #ifdef CONFIG_BLK_DEV_INITRD
 428         {
 429                 .procname       = "real-root-dev",
 430                 .data           = &real_root_dev,
 431                 .maxlen         = sizeof(int),
 432                 .mode           = 0644,
 433                 .proc_handler   = proc_dointvec,
 434         },
 435 #endif
 436         {
 437                 .procname       = "print-fatal-signals",
 438                 .data           = &print_fatal_signals,
 439                 .maxlen         = sizeof(int),
 440                 .mode           = 0644,
 441                 .proc_handler   = proc_dointvec,
 442         },
 443 #ifdef CONFIG_SPARC
 444         {
 445                 .procname       = "reboot-cmd",
 446                 .data           = reboot_command,
 447                 .maxlen         = 256,
 448                 .mode           = 0644,
 449                 .proc_handler   = proc_dostring,
 450         },
 451         {
 452                 .procname       = "stop-a",
 453                 .data           = &stop_a_enabled,
 454                 .maxlen         = sizeof (int),
 455                 .mode           = 0644,
 456                 .proc_handler   = proc_dointvec,
 457         },
 458         {
 459                 .procname       = "scons-poweroff",
 460                 .data           = &scons_pwroff,
 461                 .maxlen         = sizeof (int),
 462                 .mode           = 0644,
 463                 .proc_handler   = proc_dointvec,
 464         },
 465 #endif
 466 #ifdef CONFIG_SPARC64
 467         {
 468                 .procname       = "tsb-ratio",
 469                 .data           = &sysctl_tsb_ratio,
 470                 .maxlen         = sizeof (int),
 471                 .mode           = 0644,
 472                 .proc_handler   = proc_dointvec,
 473         },
 474 #endif
 475 #ifdef __hppa__
 476         {
 477                 .procname       = "soft-power",
 478                 .data           = &pwrsw_enabled,
 479                 .maxlen         = sizeof (int),
 480                 .mode           = 0644,
 481                 .proc_handler   = proc_dointvec,
 482         },
 483         {
 484                 .procname       = "unaligned-trap",
 485                 .data           = &unaligned_enabled,
 486                 .maxlen         = sizeof (int),
 487                 .mode           = 0644,
 488                 .proc_handler   = proc_dointvec,
 489         },
 490 #endif
 491         {
 492                 .procname       = "ctrl-alt-del",
 493                 .data           = &C_A_D,
 494                 .maxlen         = sizeof(int),
 495                 .mode           = 0644,
 496                 .proc_handler   = proc_dointvec,
 497         },
 498 #ifdef CONFIG_FUNCTION_TRACER
 499         {
 500                 .procname       = "ftrace_enabled",
 501                 .data           = &ftrace_enabled,
 502                 .maxlen         = sizeof(int),
 503                 .mode           = 0644,
 504                 .proc_handler   = ftrace_enable_sysctl,
 505         },
 506 #endif
 507 #ifdef CONFIG_STACK_TRACER
 508         {
 509                 .procname       = "stack_tracer_enabled",
 510                 .data           = &stack_tracer_enabled,
 511                 .maxlen         = sizeof(int),
 512                 .mode           = 0644,
 513                 .proc_handler   = stack_trace_sysctl,
 514         },
 515 #endif
 516 #ifdef CONFIG_TRACING
 517         {
 518                 .procname       = "ftrace_dump_on_oops",
 519                 .data           = &ftrace_dump_on_oops,
 520                 .maxlen         = sizeof(int),
 521                 .mode           = 0644,
 522                 .proc_handler   = proc_dointvec,
 523         },
 524 #endif
 525 #ifdef CONFIG_MODULES
 526         {
 527                 .procname       = "modprobe",
 528                 .data           = &modprobe_path,
 529                 .maxlen         = KMOD_PATH_LEN,
 530                 .mode           = 0644,
 531                 .proc_handler   = proc_dostring,
 532         },
 533         {
 534                 .procname       = "modules_disabled",
 535                 .data           = &modules_disabled,
 536                 .maxlen         = sizeof(int),
 537                 .mode           = 0644,
 538                 /* only handle a transition from default "0" to "1" */
 539                 .proc_handler   = proc_dointvec_minmax,
 540                 .extra1         = &one,
 541                 .extra2         = &one,
 542         },
 543 #endif
 544 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 545         {
 546                 .procname       = "hotplug",
 547                 .data           = &uevent_helper,
 548                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 549                 .mode           = 0644,
 550                 .proc_handler   = proc_dostring,
 551         },
 552 #endif
 553 #ifdef CONFIG_CHR_DEV_SG
 554         {
 555                 .procname       = "sg-big-buff",
 556                 .data           = &sg_big_buff,
 557                 .maxlen         = sizeof (int),
 558                 .mode           = 0444,
 559                 .proc_handler   = proc_dointvec,
 560         },
 561 #endif
 562 #ifdef CONFIG_BSD_PROCESS_ACCT
 563         {
 564                 .procname       = "acct",
 565                 .data           = &acct_parm,
 566                 .maxlen         = 3*sizeof(int),
 567                 .mode           = 0644,
 568                 .proc_handler   = proc_dointvec,
 569         },
 570 #endif
 571 #ifdef CONFIG_MAGIC_SYSRQ
 572         {
 573                 .procname       = "sysrq",
 574                 .data           = &__sysrq_enabled,
 575                 .maxlen         = sizeof (int),
 576                 .mode           = 0644,
 577                 .proc_handler   = proc_dointvec,
 578         },
 579 #endif
 580 #ifdef CONFIG_PROC_SYSCTL
 581         {
 582                 .procname       = "cad_pid",
 583                 .data           = NULL,
 584                 .maxlen         = sizeof (int),
 585                 .mode           = 0600,
 586                 .proc_handler   = proc_do_cad_pid,
 587         },
 588 #endif
 589         {
 590                 .procname       = "threads-max",
 591                 .data           = &max_threads,
 592                 .maxlen         = sizeof(int),
 593                 .mode           = 0644,
 594                 .proc_handler   = proc_dointvec,
 595         },
 596         {
 597                 .procname       = "random",
 598                 .mode           = 0555,
 599                 .child          = random_table,
 600         },
 601         {
 602                 .procname       = "overflowuid",
 603                 .data           = &overflowuid,
 604                 .maxlen         = sizeof(int),
 605                 .mode           = 0644,
 606                 .proc_handler   = proc_dointvec_minmax,
 607                 .extra1         = &minolduid,
 608                 .extra2         = &maxolduid,
 609         },
 610         {
 611                 .procname       = "overflowgid",
 612                 .data           = &overflowgid,
 613                 .maxlen         = sizeof(int),
 614                 .mode           = 0644,
 615                 .proc_handler   = proc_dointvec_minmax,
 616                 .extra1         = &minolduid,
 617                 .extra2         = &maxolduid,
 618         },
 619 #ifdef CONFIG_S390
 620 #ifdef CONFIG_MATHEMU
 621         {
 622                 .procname       = "ieee_emulation_warnings",
 623                 .data           = &sysctl_ieee_emulation_warnings,
 624                 .maxlen         = sizeof(int),
 625                 .mode           = 0644,
 626                 .proc_handler   = proc_dointvec,
 627         },
 628 #endif
 629         {
 630                 .procname       = "userprocess_debug",
 631                 .data           = &sysctl_userprocess_debug,
 632                 .maxlen         = sizeof(int),
 633                 .mode           = 0644,
 634                 .proc_handler   = proc_dointvec,
 635         },
 636 #endif
 637         {
 638                 .procname       = "pid_max",
 639                 .data           = &pid_max,
 640                 .maxlen         = sizeof (int),
 641                 .mode           = 0644,
 642                 .proc_handler   = proc_dointvec_minmax,
 643                 .extra1         = &pid_max_min,
 644                 .extra2         = &pid_max_max,
 645         },
 646         {
 647                 .procname       = "panic_on_oops",
 648                 .data           = &panic_on_oops,
 649                 .maxlen         = sizeof(int),
 650                 .mode           = 0644,
 651                 .proc_handler   = proc_dointvec,
 652         },
 653 #if defined CONFIG_PRINTK
 654         {
 655                 .procname       = "printk",
 656                 .data           = &console_loglevel,
 657                 .maxlen         = 4*sizeof(int),
 658                 .mode           = 0644,
 659                 .proc_handler   = proc_dointvec,
 660         },
 661         {
 662                 .procname       = "printk_ratelimit",
 663                 .data           = &printk_ratelimit_state.interval,
 664                 .maxlen         = sizeof(int),
 665                 .mode           = 0644,
 666                 .proc_handler   = proc_dointvec_jiffies,
 667         },
 668         {
 669                 .procname       = "printk_ratelimit_burst",
 670                 .data           = &printk_ratelimit_state.burst,
 671                 .maxlen         = sizeof(int),
 672                 .mode           = 0644,
 673                 .proc_handler   = proc_dointvec,
 674         },
 675         {
 676                 .procname       = "printk_delay",
 677                 .data           = &printk_delay_msec,
 678                 .maxlen         = sizeof(int),
 679                 .mode           = 0644,
 680                 .proc_handler   = proc_dointvec_minmax,
 681                 .extra1         = &zero,
 682                 .extra2         = &ten_thousand,
 683         },
 684 #endif
 685         {
 686                 .procname       = "ngroups_max",
 687                 .data           = &ngroups_max,
 688                 .maxlen         = sizeof (int),
 689                 .mode           = 0444,
 690                 .proc_handler   = proc_dointvec,
 691         },
 692 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 693         {
 694                 .procname       = "unknown_nmi_panic",
 695                 .data           = &unknown_nmi_panic,
 696                 .maxlen         = sizeof (int),
 697                 .mode           = 0644,
 698                 .proc_handler   = proc_dointvec,
 699         },
 700         {
 701                 .procname       = "nmi_watchdog",
 702                 .data           = &nmi_watchdog_enabled,
 703                 .maxlen         = sizeof (int),
 704                 .mode           = 0644,
 705                 .proc_handler   = proc_nmi_enabled,
 706         },
 707 #endif
 708 #if defined(CONFIG_X86)
 709         {
 710                 .procname       = "panic_on_unrecovered_nmi",
 711                 .data           = &panic_on_unrecovered_nmi,
 712                 .maxlen         = sizeof(int),
 713                 .mode           = 0644,
 714                 .proc_handler   = proc_dointvec,
 715         },
 716         {
 717                 .procname       = "panic_on_io_nmi",
 718                 .data           = &panic_on_io_nmi,
 719                 .maxlen         = sizeof(int),
 720                 .mode           = 0644,
 721                 .proc_handler   = proc_dointvec,
 722         },
 723         {
 724                 .procname       = "bootloader_type",
 725                 .data           = &bootloader_type,
 726                 .maxlen         = sizeof (int),
 727                 .mode           = 0444,
 728                 .proc_handler   = proc_dointvec,
 729         },
 730         {
 731                 .procname       = "bootloader_version",
 732                 .data           = &bootloader_version,
 733                 .maxlen         = sizeof (int),
 734                 .mode           = 0444,
 735                 .proc_handler   = proc_dointvec,
 736         },
 737         {
 738                 .procname       = "kstack_depth_to_print",
 739                 .data           = &kstack_depth_to_print,
 740                 .maxlen         = sizeof(int),
 741                 .mode           = 0644,
 742                 .proc_handler   = proc_dointvec,
 743         },
 744         {
 745                 .procname       = "io_delay_type",
 746                 .data           = &io_delay_type,
 747                 .maxlen         = sizeof(int),
 748                 .mode           = 0644,
 749                 .proc_handler   = proc_dointvec,
 750         },
 751 #endif
 752 #if defined(CONFIG_MMU)
 753         {
 754                 .procname       = "randomize_va_space",
 755                 .data           = &randomize_va_space,
 756                 .maxlen         = sizeof(int),
 757                 .mode           = 0644,
 758                 .proc_handler   = proc_dointvec,
 759         },
 760 #endif
 761 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 762         {
 763                 .procname       = "spin_retry",
 764                 .data           = &spin_retry,
 765                 .maxlen         = sizeof (int),
 766                 .mode           = 0644,
 767                 .proc_handler   = proc_dointvec,
 768         },
 769 #endif
 770 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 771         {
 772                 .procname       = "acpi_video_flags",
 773                 .data           = &acpi_realmode_flags,
 774                 .maxlen         = sizeof (unsigned long),
 775                 .mode           = 0644,
 776                 .proc_handler   = proc_doulongvec_minmax,
 777         },
 778 #endif
 779 #ifdef CONFIG_IA64
 780         {
 781                 .procname       = "ignore-unaligned-usertrap",
 782                 .data           = &no_unaligned_warning,
 783                 .maxlen         = sizeof (int),
 784                 .mode           = 0644,
 785                 .proc_handler   = proc_dointvec,
 786         },
 787         {
 788                 .procname       = "unaligned-dump-stack",
 789                 .data           = &unaligned_dump_stack,
 790                 .maxlen         = sizeof (int),
 791                 .mode           = 0644,
 792                 .proc_handler   = proc_dointvec,
 793         },
 794 #endif
 795 #ifdef CONFIG_DETECT_SOFTLOCKUP
 796         {
 797                 .procname       = "softlockup_panic",
 798                 .data           = &softlockup_panic,
 799                 .maxlen         = sizeof(int),
 800                 .mode           = 0644,
 801                 .proc_handler   = proc_dointvec_minmax,
 802                 .extra1         = &zero,
 803                 .extra2         = &one,
 804         },
 805         {
 806                 .procname       = "softlockup_thresh",
 807                 .data           = &softlockup_thresh,
 808                 .maxlen         = sizeof(int),
 809                 .mode           = 0644,
 810                 .proc_handler   = proc_dosoftlockup_thresh,
 811                 .extra1         = &neg_one,
 812                 .extra2         = &sixty,
 813         },
 814 #endif
 815 #ifdef CONFIG_DETECT_HUNG_TASK
 816         {
 817                 .procname       = "hung_task_panic",
 818                 .data           = &sysctl_hung_task_panic,
 819                 .maxlen         = sizeof(int),
 820                 .mode           = 0644,
 821                 .proc_handler   = proc_dointvec_minmax,
 822                 .extra1         = &zero,
 823                 .extra2         = &one,
 824         },
 825         {
 826                 .procname       = "hung_task_check_count",
 827                 .data           = &sysctl_hung_task_check_count,
 828                 .maxlen         = sizeof(unsigned long),
 829                 .mode           = 0644,
 830                 .proc_handler   = proc_doulongvec_minmax,
 831         },
 832         {
 833                 .procname       = "hung_task_timeout_secs",
 834                 .data           = &sysctl_hung_task_timeout_secs,
 835                 .maxlen         = sizeof(unsigned long),
 836                 .mode           = 0644,
 837                 .proc_handler   = proc_dohung_task_timeout_secs,
 838         },
 839         {
 840                 .procname       = "hung_task_warnings",
 841                 .data           = &sysctl_hung_task_warnings,
 842                 .maxlen         = sizeof(unsigned long),
 843                 .mode           = 0644,
 844                 .proc_handler   = proc_doulongvec_minmax,
 845         },
 846 #endif
 847 #ifdef CONFIG_COMPAT
 848         {
 849                 .procname       = "compat-log",
 850                 .data           = &compat_log,
 851                 .maxlen         = sizeof (int),
 852                 .mode           = 0644,
 853                 .proc_handler   = proc_dointvec,
 854         },
 855 #endif
 856 #ifdef CONFIG_RT_MUTEXES
 857         {
 858                 .procname       = "max_lock_depth",
 859                 .data           = &max_lock_depth,
 860                 .maxlen         = sizeof(int),
 861                 .mode           = 0644,
 862                 .proc_handler   = proc_dointvec,
 863         },
 864 #endif
 865         {
 866                 .procname       = "poweroff_cmd",
 867                 .data           = &poweroff_cmd,
 868                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 869                 .mode           = 0644,
 870                 .proc_handler   = proc_dostring,
 871         },
 872 #ifdef CONFIG_KEYS
 873         {
 874                 .procname       = "keys",
 875                 .mode           = 0555,
 876                 .child          = key_sysctls,
 877         },
 878 #endif
 879 #ifdef CONFIG_RCU_TORTURE_TEST
 880         {
 881                 .procname       = "rcutorture_runnable",
 882                 .data           = &rcutorture_runnable,
 883                 .maxlen         = sizeof(int),
 884                 .mode           = 0644,
 885                 .proc_handler   = proc_dointvec,
 886         },
 887 #endif
 888 #ifdef CONFIG_SLOW_WORK
 889         {
 890                 .procname       = "slow-work",
 891                 .mode           = 0555,
 892                 .child          = slow_work_sysctls,
 893         },
 894 #endif
 895 #ifdef CONFIG_PERF_EVENTS
 896         {
 897                 .procname       = "perf_event_paranoid",
 898                 .data           = &sysctl_perf_event_paranoid,
 899                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 900                 .mode           = 0644,
 901                 .proc_handler   = proc_dointvec,
 902         },
 903         {
 904                 .procname       = "perf_event_mlock_kb",
 905                 .data           = &sysctl_perf_event_mlock,
 906                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 907                 .mode           = 0644,
 908                 .proc_handler   = proc_dointvec,
 909         },
 910         {
 911                 .procname       = "perf_event_max_sample_rate",
 912                 .data           = &sysctl_perf_event_sample_rate,
 913                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
 914                 .mode           = 0644,
 915                 .proc_handler   = proc_dointvec,
 916         },
 917 #endif
 918 #ifdef CONFIG_KMEMCHECK
 919         {
 920                 .procname       = "kmemcheck",
 921                 .data           = &kmemcheck_enabled,
 922                 .maxlen         = sizeof(int),
 923                 .mode           = 0644,
 924                 .proc_handler   = proc_dointvec,
 925         },
 926 #endif
 927 #ifdef CONFIG_BLOCK
 928         {
 929                 .procname       = "blk_iopoll",
 930                 .data           = &blk_iopoll_enabled,
 931                 .maxlen         = sizeof(int),
 932                 .mode           = 0644,
 933                 .proc_handler   = proc_dointvec,
 934         },
 935 #endif
 936 /*
 937  * NOTE: do not add new entries to this table unless you have read
 938  * Documentation/sysctl/ctl_unnumbered.txt
 939  */
 940         { }
 941 };
 942
 943 static struct ctl_table vm_table[] = {
 944         {
 945                 .procname       = "overcommit_memory",
 946                 .data           = &sysctl_overcommit_memory,
 947                 .maxlen         = sizeof(sysctl_overcommit_memory),
 948                 .mode           = 0644,
 949                 .proc_handler   = proc_dointvec,
 950         },
 951         {
 952                 .procname       = "panic_on_oom",
 953                 .data           = &sysctl_panic_on_oom,
 954                 .maxlen         = sizeof(sysctl_panic_on_oom),
 955                 .mode           = 0644,
 956                 .proc_handler   = proc_dointvec,
 957         },
 958         {
 959                 .procname       = "oom_kill_allocating_task",
 960                 .data           = &sysctl_oom_kill_allocating_task,
 961                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 962                 .mode           = 0644,
 963                 .proc_handler   = proc_dointvec,
 964         },
 965         {
 966                 .procname       = "oom_dump_tasks",
 967                 .data           = &sysctl_oom_dump_tasks,
 968                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
 969                 .mode           = 0644,
 970                 .proc_handler   = proc_dointvec,
 971         },
 972         {
 973                 .procname       = "overcommit_ratio",
 974                 .data           = &sysctl_overcommit_ratio,
 975                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 976                 .mode           = 0644,
 977                 .proc_handler   = proc_dointvec,
 978         },
 979         {
 980                 .procname       = "page-cluster",
 981                 .data           = &page_cluster,
 982                 .maxlen         = sizeof(int),
 983                 .mode           = 0644,
 984                 .proc_handler   = proc_dointvec,
 985         },
 986         {
 987                 .procname       = "dirty_background_ratio",
 988                 .data           = &dirty_background_ratio,
 989                 .maxlen         = sizeof(dirty_background_ratio),
 990                 .mode           = 0644,
 991                 .proc_handler   = dirty_background_ratio_handler,
 992                 .extra1         = &zero,
 993                 .extra2         = &one_hundred,
 994         },
 995         {
 996                 .procname       = "dirty_background_bytes",
 997                 .data           = &dirty_background_bytes,
 998                 .maxlen         = sizeof(dirty_background_bytes),
 999                 .mode           = 0644,
1000                 .proc_handler   = dirty_background_bytes_handler,
1001                 .extra1         = &one_ul,
1002         },
1003         {
1004                 .procname       = "dirty_ratio",
1005                 .data           = &vm_dirty_ratio,
1006                 .maxlen         = sizeof(vm_dirty_ratio),
1007                 .mode           = 0644,
1008                 .proc_handler   = dirty_ratio_handler,
1009                 .extra1         = &zero,
1010                 .extra2         = &one_hundred,
1011         },
1012         {
1013                 .procname       = "dirty_bytes",
1014                 .data           = &vm_dirty_bytes,
1015                 .maxlen         = sizeof(vm_dirty_bytes),
1016                 .mode           = 0644,
1017                 .proc_handler   = dirty_bytes_handler,
1018                 .extra1         = &dirty_bytes_min,
1019         },
1020         {
1021                 .procname       = "dirty_writeback_centisecs",
1022                 .data           = &dirty_writeback_interval,
1023                 .maxlen         = sizeof(dirty_writeback_interval),
1024                 .mode           = 0644,
1025                 .proc_handler   = dirty_writeback_centisecs_handler,
1026         },
1027         {
1028                 .procname       = "dirty_expire_centisecs",
1029                 .data           = &dirty_expire_interval,
1030                 .maxlen         = sizeof(dirty_expire_interval),
1031                 .mode           = 0644,
1032                 .proc_handler   = proc_dointvec,
1033         },
1034         {
1035                 .procname       = "nr_pdflush_threads",
1036                 .data           = &nr_pdflush_threads,
1037                 .maxlen         = sizeof nr_pdflush_threads,
1038                 .mode           = 0444 /* read-only*/,
1039                 .proc_handler   = proc_dointvec,
1040         },
1041         {
1042                 .procname       = "swappiness",
1043                 .data           = &vm_swappiness,
1044                 .maxlen         = sizeof(vm_swappiness),
1045                 .mode           = 0644,
1046                 .proc_handler   = proc_dointvec_minmax,
1047                 .extra1         = &zero,
1048                 .extra2         = &one_hundred,
1049         },
1050 #ifdef CONFIG_HUGETLB_PAGE
1051         {
1052                 .procname       = "nr_hugepages",
1053                 .data           = NULL,
1054                 .maxlen         = sizeof(unsigned long),
1055                 .mode           = 0644,
1056                 .proc_handler   = hugetlb_sysctl_handler,
1057                 .extra1         = (void *)&hugetlb_zero,
1058                 .extra2         = (void *)&hugetlb_infinity,
1059         },
1060 #ifdef CONFIG_NUMA
1061         {
1062                 .procname       = "nr_hugepages_mempolicy",
1063                 .data           = NULL,
1064                 .maxlen         = sizeof(unsigned long),
1065                 .mode           = 0644,
1066                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1067                 .extra1         = (void *)&hugetlb_zero,
1068                 .extra2         = (void *)&hugetlb_infinity,
1069         },
1070 #endif
1071          {
1072                 .procname       = "hugetlb_shm_group",
1073                 .data           = &sysctl_hugetlb_shm_group,
1074                 .maxlen         = sizeof(gid_t),
1075                 .mode           = 0644,
1076                 .proc_handler   = proc_dointvec,
1077          },
1078          {
1079                 .procname       = "hugepages_treat_as_movable",
1080                 .data           = &hugepages_treat_as_movable,
1081                 .maxlen         = sizeof(int),
1082                 .mode           = 0644,
1083                 .proc_handler   = hugetlb_treat_movable_handler,
1084         },
1085         {
1086                 .procname       = "nr_overcommit_hugepages",
1087                 .data           = NULL,
1088                 .maxlen         = sizeof(unsigned long),
1089                 .mode           = 0644,
1090                 .proc_handler   = hugetlb_overcommit_handler,
1091                 .extra1         = (void *)&hugetlb_zero,
1092                 .extra2         = (void *)&hugetlb_infinity,
1093         },
1094 #endif
1095         {
1096                 .procname       = "lowmem_reserve_ratio",
1097                 .data           = &sysctl_lowmem_reserve_ratio,
1098                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1099                 .mode           = 0644,
1100                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1101         },
1102         {
1103                 .procname       = "drop_caches",
1104                 .data           = &sysctl_drop_caches,
1105                 .maxlen         = sizeof(int),
1106                 .mode           = 0644,
1107                 .proc_handler   = drop_caches_sysctl_handler,
1108         },
1109         {
1110                 .procname       = "min_free_kbytes",
1111                 .data           = &min_free_kbytes,
1112                 .maxlen         = sizeof(min_free_kbytes),
1113                 .mode           = 0644,
1114                 .proc_handler   = min_free_kbytes_sysctl_handler,
1115                 .extra1         = &zero,
1116         },
1117         {
1118                 .procname       = "percpu_pagelist_fraction",
1119                 .data           = &percpu_pagelist_fraction,
1120                 .maxlen         = sizeof(percpu_pagelist_fraction),
1121                 .mode           = 0644,
1122                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1123                 .extra1         = &min_percpu_pagelist_fract,
1124         },
1125 #ifdef CONFIG_MMU
1126         {
1127                 .procname       = "max_map_count",
1128                 .data           = &sysctl_max_map_count,
1129                 .maxlen         = sizeof(sysctl_max_map_count),
1130                 .mode           = 0644,
1131                 .proc_handler   = proc_dointvec_minmax,
1132                 .extra1         = &zero,
1133         },
1134 #else
1135         {
1136                 .procname       = "nr_trim_pages",
1137                 .data           = &sysctl_nr_trim_pages,
1138                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1139                 .mode           = 0644,
1140                 .proc_handler   = proc_dointvec_minmax,
1141                 .extra1         = &zero,
1142         },
1143 #endif
1144         {
1145                 .procname       = "laptop_mode",
1146                 .data           = &laptop_mode,
1147                 .maxlen         = sizeof(laptop_mode),
1148                 .mode           = 0644,
1149                 .proc_handler   = proc_dointvec_jiffies,
1150         },
1151         {
1152                 .procname       = "block_dump",
1153                 .data           = &block_dump,
1154                 .maxlen         = sizeof(block_dump),
1155                 .mode           = 0644,
1156                 .proc_handler   = proc_dointvec,
1157                 .extra1         = &zero,
1158         },
1159         {
1160                 .procname       = "vfs_cache_pressure",
1161                 .data           = &sysctl_vfs_cache_pressure,
1162                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1163                 .mode           = 0644,
1164                 .proc_handler   = proc_dointvec,
1165                 .extra1         = &zero,
1166         },
1167 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1168         {
1169                 .procname       = "legacy_va_layout",
1170                 .data           = &sysctl_legacy_va_layout,
1171                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1172                 .mode           = 0644,
1173                 .proc_handler   = proc_dointvec,
1174                 .extra1         = &zero,
1175         },
1176 #endif
1177 #ifdef CONFIG_NUMA
1178         {
1179                 .procname       = "zone_reclaim_mode",
1180                 .data           = &zone_reclaim_mode,
1181                 .maxlen         = sizeof(zone_reclaim_mode),
1182                 .mode           = 0644,
1183                 .proc_handler   = proc_dointvec,
1184                 .extra1         = &zero,
1185         },
1186         {
1187                 .procname       = "min_unmapped_ratio",
1188                 .data           = &sysctl_min_unmapped_ratio,
1189                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1190                 .mode           = 0644,
1191                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1192                 .extra1         = &zero,
1193                 .extra2         = &one_hundred,
1194         },
1195         {
1196                 .procname       = "min_slab_ratio",
1197                 .data           = &sysctl_min_slab_ratio,
1198                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1199                 .mode           = 0644,
1200                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1201                 .extra1         = &zero,
1202                 .extra2         = &one_hundred,
1203         },
1204 #endif
1205 #ifdef CONFIG_SMP
1206         {
1207                 .procname       = "stat_interval",
1208                 .data           = &sysctl_stat_interval,
1209                 .maxlen         = sizeof(sysctl_stat_interval),
1210                 .mode           = 0644,
1211                 .proc_handler   = proc_dointvec_jiffies,
1212         },
1213 #endif
1214 #ifdef CONFIG_MMU
1215         {
1216                 .procname       = "mmap_min_addr",
1217                 .data           = &dac_mmap_min_addr,
1218                 .maxlen         = sizeof(unsigned long),
1219                 .mode           = 0644,
1220                 .proc_handler   = mmap_min_addr_handler,
1221         },
1222 #endif
1223 #ifdef CONFIG_NUMA
1224         {
1225                 .procname       = "numa_zonelist_order",
1226                 .data           = &numa_zonelist_order,
1227                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1228                 .mode           = 0644,
1229                 .proc_handler   = numa_zonelist_order_handler,
1230         },
1231 #endif
1232 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1233    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1234         {
1235                 .procname       = "vdso_enabled",
1236                 .data           = &vdso_enabled,
1237                 .maxlen         = sizeof(vdso_enabled),
1238                 .mode           = 0644,
1239                 .proc_handler   = proc_dointvec,
1240                 .extra1         = &zero,
1241         },
1242 #endif
1243 #ifdef CONFIG_HIGHMEM
1244         {
1245                 .procname       = "highmem_is_dirtyable",
1246                 .data           = &vm_highmem_is_dirtyable,
1247                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1248                 .mode           = 0644,
1249                 .proc_handler   = proc_dointvec_minmax,
1250                 .extra1         = &zero,
1251                 .extra2         = &one,
1252         },
1253 #endif
1254         {
1255                 .procname       = "scan_unevictable_pages",
1256                 .data           = &scan_unevictable_pages,
1257                 .maxlen         = sizeof(scan_unevictable_pages),
1258                 .mode           = 0644,
1259                 .proc_handler   = scan_unevictable_handler,
1260         },
1261 #ifdef CONFIG_MEMORY_FAILURE
1262         {
1263                 .procname       = "memory_failure_early_kill",
1264                 .data           = &sysctl_memory_failure_early_kill,
1265                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1266                 .mode           = 0644,
1267                 .proc_handler   = proc_dointvec_minmax,
1268                 .extra1         = &zero,
1269                 .extra2         = &one,
1270         },
1271         {
1272                 .procname       = "memory_failure_recovery",
1273                 .data           = &sysctl_memory_failure_recovery,
1274                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1275                 .mode           = 0644,
1276                 .proc_handler   = proc_dointvec_minmax,
1277                 .extra1         = &zero,
1278                 .extra2         = &one,
1279         },
1280 #endif
1281
1282 /*
1283  * NOTE: do not add new entries to this table unless you have read
1284  * Documentation/sysctl/ctl_unnumbered.txt
1285  */
1286         { }
1287 };
1288
1289 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1290 static struct ctl_table binfmt_misc_table[] = {
1291         { }
1292 };
1293 #endif
1294
1295 static struct ctl_table fs_table[] = {
1296         {
1297                 .procname       = "inode-nr",
1298                 .data           = &inodes_stat,
1299                 .maxlen         = 2*sizeof(int),
1300                 .mode           = 0444,
1301                 .proc_handler   = proc_dointvec,
1302         },
1303         {
1304                 .procname       = "inode-state",
1305                 .data           = &inodes_stat,
1306                 .maxlen         = 7*sizeof(int),
1307                 .mode           = 0444,
1308                 .proc_handler   = proc_dointvec,
1309         },
1310         {
1311                 .procname       = "file-nr",
1312                 .data           = &files_stat,
1313                 .maxlen         = 3*sizeof(int),
1314                 .mode           = 0444,
1315                 .proc_handler   = proc_nr_files,
1316         },
1317         {
1318                 .procname       = "file-max",
1319                 .data           = &files_stat.max_files,
1320                 .maxlen         = sizeof(int),
1321                 .mode           = 0644,
1322                 .proc_handler   = proc_dointvec,
1323         },
1324         {
1325                 .procname       = "nr_open",
1326                 .data           = &sysctl_nr_open,
1327                 .maxlen         = sizeof(int),
1328                 .mode           = 0644,
1329                 .proc_handler   = proc_dointvec_minmax,
1330                 .extra1         = &sysctl_nr_open_min,
1331                 .extra2         = &sysctl_nr_open_max,
1332         },
1333         {
1334                 .procname       = "dentry-state",
1335                 .data           = &dentry_stat,
1336                 .maxlen         = 6*sizeof(int),
1337                 .mode           = 0444,
1338                 .proc_handler   = proc_dointvec,
1339         },
1340         {
1341                 .procname       = "overflowuid",
1342                 .data           = &fs_overflowuid,
1343                 .maxlen         = sizeof(int),
1344                 .mode           = 0644,
1345                 .proc_handler   = proc_dointvec_minmax,
1346                 .extra1         = &minolduid,
1347                 .extra2         = &maxolduid,
1348         },
1349         {
1350                 .procname       = "overflowgid",
1351                 .data           = &fs_overflowgid,
1352                 .maxlen         = sizeof(int),
1353                 .mode           = 0644,
1354                 .proc_handler   = proc_dointvec_minmax,
1355                 .extra1         = &minolduid,
1356                 .extra2         = &maxolduid,
1357         },
1358 #ifdef CONFIG_FILE_LOCKING
1359         {
1360                 .procname       = "leases-enable",
1361                 .data           = &leases_enable,
1362                 .maxlen         = sizeof(int),
1363                 .mode           = 0644,
1364                 .proc_handler   = proc_dointvec,
1365         },
1366 #endif
1367 #ifdef CONFIG_DNOTIFY
1368         {
1369                 .procname       = "dir-notify-enable",
1370                 .data           = &dir_notify_enable,
1371                 .maxlen         = sizeof(int),
1372                 .mode           = 0644,
1373                 .proc_handler   = proc_dointvec,
1374         },
1375 #endif
1376 #ifdef CONFIG_MMU
1377 #ifdef CONFIG_FILE_LOCKING
1378         {
1379                 .procname       = "lease-break-time",
1380                 .data           = &lease_break_time,
1381                 .maxlen         = sizeof(int),
1382                 .mode           = 0644,
1383                 .proc_handler   = proc_dointvec,
1384         },
1385 #endif
1386 #ifdef CONFIG_AIO
1387         {
1388                 .procname       = "aio-nr",
1389                 .data           = &aio_nr,
1390                 .maxlen         = sizeof(aio_nr),
1391                 .mode           = 0444,
1392                 .proc_handler   = proc_doulongvec_minmax,
1393         },
1394         {
1395                 .procname       = "aio-max-nr",
1396                 .data           = &aio_max_nr,
1397                 .maxlen         = sizeof(aio_max_nr),
1398                 .mode           = 0644,
1399                 .proc_handler   = proc_doulongvec_minmax,
1400         },
1401 #endif /* CONFIG_AIO */
1402 #ifdef CONFIG_INOTIFY_USER
1403         {
1404                 .procname       = "inotify",
1405                 .mode           = 0555,
1406                 .child          = inotify_table,
1407         },
1408 #endif
1409 #ifdef CONFIG_EPOLL
1410         {
1411                 .procname       = "epoll",
1412                 .mode           = 0555,
1413                 .child          = epoll_table,
1414         },
1415 #endif
1416 #endif
1417         {
1418                 .procname       = "suid_dumpable",
1419                 .data           = &suid_dumpable,
1420                 .maxlen         = sizeof(int),
1421                 .mode           = 0644,
1422                 .proc_handler   = proc_dointvec_minmax,
1423                 .extra1         = &zero,
1424                 .extra2         = &two,
1425         },
1426 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1427         {
1428                 .procname       = "binfmt_misc",
1429                 .mode           = 0555,
1430                 .child          = binfmt_misc_table,
1431         },
1432 #endif
1433 /*
1434  * NOTE: do not add new entries to this table unless you have read
1435  * Documentation/sysctl/ctl_unnumbered.txt
1436  */
1437         { }
1438 };
1439
1440 static struct ctl_table debug_table[] = {
1441 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC)
1442         {
1443                 .procname       = "exception-trace",
1444                 .data           = &show_unhandled_signals,
1445                 .maxlen         = sizeof(int),
1446                 .mode           = 0644,
1447                 .proc_handler   = proc_dointvec
1448         },
1449 #endif
1450 #if defined(CONFIG_OPTPROBES)
1451         {
1452                 .procname       = "kprobes-optimization",
1453                 .data           = &sysctl_kprobes_optimization,
1454                 .maxlen         = sizeof(int),
1455                 .mode           = 0644,
1456                 .proc_handler   = proc_kprobes_optimization_handler,
1457                 .extra1         = &zero,
1458                 .extra2         = &one,
1459         },
1460 #endif
1461         { }
1462 };
1463
1464 static struct ctl_table dev_table[] = {
1465         { }
1466 };
1467
1468 static DEFINE_SPINLOCK(sysctl_lock);
1469
1470 /* called under sysctl_lock */
1471 static int use_table(struct ctl_table_header *p)
1472 {
1473         if (unlikely(p->unregistering))
1474                 return 0;
1475         p->used++;
1476         return 1;
1477 }
1478
1479 /* called under sysctl_lock */
1480 static void unuse_table(struct ctl_table_header *p)
1481 {
1482         if (!--p->used)
1483                 if (unlikely(p->unregistering))
1484                         complete(p->unregistering);
1485 }
1486
1487 /* called under sysctl_lock, will reacquire if has to wait */
1488 static void start_unregistering(struct ctl_table_header *p)
1489 {
1490         /*
1491          * if p->used is 0, nobody will ever touch that entry again;
1492          * we'll eliminate all paths to it before dropping sysctl_lock
1493          */
1494         if (unlikely(p->used)) {
1495                 struct completion wait;
1496                 init_completion(&wait);
1497                 p->unregistering = &wait;
1498                 spin_unlock(&sysctl_lock);
1499                 wait_for_completion(&wait);
1500                 spin_lock(&sysctl_lock);
1501         } else {
1502                 /* anything non-NULL; we'll never dereference it */
1503                 p->unregistering = ERR_PTR(-EINVAL);
1504         }
1505         /*
1506          * do not remove from the list until nobody holds it; walking the
1507          * list in do_sysctl() relies on that.
1508          */
1509         list_del_init(&p->ctl_entry);
1510 }
1511
1512 void sysctl_head_get(struct ctl_table_header *head)
1513 {
1514         spin_lock(&sysctl_lock);
1515         head->count++;
1516         spin_unlock(&sysctl_lock);
1517 }
1518
1519 void sysctl_head_put(struct ctl_table_header *head)
1520 {
1521         spin_lock(&sysctl_lock);
1522         if (!--head->count)
1523                 kfree(head);
1524         spin_unlock(&sysctl_lock);
1525 }
1526
1527 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1528 {
1529         if (!head)
1530                 BUG();
1531         spin_lock(&sysctl_lock);
1532         if (!use_table(head))
1533                 head = ERR_PTR(-ENOENT);
1534         spin_unlock(&sysctl_lock);
1535         return head;
1536 }
1537
1538 void sysctl_head_finish(struct ctl_table_header *head)
1539 {
1540         if (!head)
1541                 return;
1542         spin_lock(&sysctl_lock);
1543         unuse_table(head);
1544         spin_unlock(&sysctl_lock);
1545 }
1546
1547 static struct ctl_table_set *
1548 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1549 {
1550         struct ctl_table_set *set = &root->default_set;
1551         if (root->lookup)
1552                 set = root->lookup(root, namespaces);
1553         return set;
1554 }
1555
1556 static struct list_head *
1557 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1558 {
1559         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1560         return &set->list;
1561 }
1562
1563 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1564                                             struct ctl_table_header *prev)
1565 {
1566         struct ctl_table_root *root;
1567         struct list_head *header_list;
1568         struct ctl_table_header *head;
1569         struct list_head *tmp;
1570
1571         spin_lock(&sysctl_lock);
1572         if (prev) {
1573                 head = prev;
1574                 tmp = &prev->ctl_entry;
1575                 unuse_table(prev);
1576                 goto next;
1577         }
1578         tmp = &root_table_header.ctl_entry;
1579         for (;;) {
1580                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1581
1582                 if (!use_table(head))
1583                         goto next;
1584                 spin_unlock(&sysctl_lock);
1585                 return head;
1586         next:
1587                 root = head->root;
1588                 tmp = tmp->next;
1589                 header_list = lookup_header_list(root, namespaces);
1590                 if (tmp != header_list)
1591                         continue;
1592
1593                 do {
1594                         root = list_entry(root->root_list.next,
1595                                         struct ctl_table_root, root_list);
1596                         if (root == &sysctl_table_root)
1597                                 goto out;
1598                         header_list = lookup_header_list(root, namespaces);
1599                 } while (list_empty(header_list));
1600                 tmp = header_list->next;
1601         }
1602 out:
1603         spin_unlock(&sysctl_lock);
1604         return NULL;
1605 }
1606
1607 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1608 {
1609         return __sysctl_head_next(current->nsproxy, prev);
1610 }
1611
1612 void register_sysctl_root(struct ctl_table_root *root)
1613 {
1614         spin_lock(&sysctl_lock);
1615         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1616         spin_unlock(&sysctl_lock);
1617 }
1618
1619 /*
1620  * sysctl_perm does NOT grant the superuser all rights automatically, because
1621  * some sysctl variables are readonly even to root.
1622  */
1623
1624 static int test_perm(int mode, int op)
1625 {
1626         if (!current_euid())
1627                 mode >>= 6;
1628         else if (in_egroup_p(0))
1629                 mode >>= 3;
1630         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1631                 return 0;
1632         return -EACCES;
1633 }
1634
1635 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1636 {
1637         int error;
1638         int mode;
1639
1640         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1641         if (error)
1642                 return error;
1643
1644         if (root->permissions)
1645                 mode = root->permissions(root, current->nsproxy, table);
1646         else
1647                 mode = table->mode;
1648
1649         return test_perm(mode, op);
1650 }
1651
1652 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1653 {
1654         for (; table->procname; table++) {
1655                 table->parent = parent;
1656                 if (table->child)
1657                         sysctl_set_parent(table, table->child);
1658         }
1659 }
1660
1661 static __init int sysctl_init(void)
1662 {
1663         sysctl_set_parent(NULL, root_table);
1664 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1665         {
1666                 int err;
1667                 err = sysctl_check_table(current->nsproxy, root_table);
1668         }
1669 #endif
1670         return 0;
1671 }
1672
1673 core_initcall(sysctl_init);
1674
1675 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1676                                       struct ctl_table *table)
1677 {
1678         struct ctl_table *p;
1679         const char *s = branch->procname;
1680
1681         /* branch should have named subdirectory as its first element */
1682         if (!s || !branch->child)
1683                 return NULL;
1684
1685         /* ... and nothing else */
1686         if (branch[1].procname)
1687                 return NULL;
1688
1689         /* table should contain subdirectory with the same name */
1690         for (p = table; p->procname; p++) {
1691                 if (!p->child)
1692                         continue;
1693                 if (p->procname && strcmp(p->procname, s) == 0)
1694                         return p;
1695         }
1696         return NULL;
1697 }
1698
1699 /* see if attaching q to p would be an improvement */
1700 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1701 {
1702         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1703         struct ctl_table *next;
1704         int is_better = 0;
1705         int not_in_parent = !p->attached_by;
1706
1707         while ((next = is_branch_in(by, to)) != NULL) {
1708                 if (by == q->attached_by)
1709                         is_better = 1;
1710                 if (to == p->attached_by)
1711                         not_in_parent = 1;
1712                 by = by->child;
1713                 to = next->child;
1714         }
1715
1716         if (is_better && not_in_parent) {
1717                 q->attached_by = by;
1718                 q->attached_to = to;
1719                 q->parent = p;
1720         }
1721 }
1722
1723 /**
1724  * __register_sysctl_paths - register a sysctl hierarchy
1725  * @root: List of sysctl headers to register on
1726  * @namespaces: Data to compute which lists of sysctl entries are visible
1727  * @path: The path to the directory the sysctl table is in.
1728  * @table: the top-level table structure
1729  *
1730  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1731  * array. A completely 0 filled entry terminates the table.
1732  *
1733  * The members of the &struct ctl_table structure are used as follows:
1734  *
1735  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1736  *            enter a sysctl file
1737  *
1738  * data - a pointer to data for use by proc_handler
1739  *
1740  * maxlen - the maximum size in bytes of the data
1741  *
1742  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1743  *
1744  * child - a pointer to the child sysctl table if this entry is a directory, or
1745  *         %NULL.
1746  *
1747  * proc_handler - the text handler routine (described below)
1748  *
1749  * de - for internal use by the sysctl routines
1750  *
1751  * extra1, extra2 - extra pointers usable by the proc handler routines
1752  *
1753  * Leaf nodes in the sysctl tree will be represented by a single file
1754  * under /proc; non-leaf nodes will be represented by directories.
1755  *
1756  * sysctl(2) can automatically manage read and write requests through
1757  * the sysctl table.  The data and maxlen fields of the ctl_table
1758  * struct enable minimal validation of the values being written to be
1759  * performed, and the mode field allows minimal authentication.
1760  *
1761  * There must be a proc_handler routine for any terminal nodes
1762  * mirrored under /proc/sys (non-terminals are handled by a built-in
1763  * directory handler).  Several default handlers are available to
1764  * cover common cases -
1765  *
1766  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1767  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1768  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1769  *
1770  * It is the handler's job to read the input buffer from user memory
1771  * and process it. The handler should return 0 on success.
1772  *
1773  * This routine returns %NULL on a failure to register, and a pointer
1774  * to the table header on success.
1775  */
1776 struct ctl_table_header *__register_sysctl_paths(
1777         struct ctl_table_root *root,
1778         struct nsproxy *namespaces,
1779         const struct ctl_path *path, struct ctl_table *table)
1780 {
1781         struct ctl_table_header *header;
1782         struct ctl_table *new, **prevp;
1783         unsigned int n, npath;
1784         struct ctl_table_set *set;
1785
1786         /* Count the path components */
1787         for (npath = 0; path[npath].procname; ++npath)
1788                 ;
1789
1790         /*
1791          * For each path component, allocate a 2-element ctl_table array.
1792          * The first array element will be filled with the sysctl entry
1793          * for this, the second will be the sentinel (procname == 0).
1794          *
1795          * We allocate everything in one go so that we don't have to
1796          * worry about freeing additional memory in unregister_sysctl_table.
1797          */
1798         header = kzalloc(sizeof(struct ctl_table_header) +
1799                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1800         if (!header)
1801                 return NULL;
1802
1803         new = (struct ctl_table *) (header + 1);
1804
1805         /* Now connect the dots */
1806         prevp = &header->ctl_table;
1807         for (n = 0; n < npath; ++n, ++path) {
1808                 /* Copy the procname */
1809                 new->procname = path->procname;
1810                 new->mode     = 0555;
1811
1812                 *prevp = new;
1813                 prevp = &new->child;
1814
1815                 new += 2;
1816         }
1817         *prevp = table;
1818         header->ctl_table_arg = table;
1819
1820         INIT_LIST_HEAD(&header->ctl_entry);
1821         header->used = 0;
1822         header->unregistering = NULL;
1823         header->root = root;
1824         sysctl_set_parent(NULL, header->ctl_table);
1825         header->count = 1;
1826 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1827         if (sysctl_check_table(namespaces, header->ctl_table)) {
1828                 kfree(header);
1829                 return NULL;
1830         }
1831 #endif
1832         spin_lock(&sysctl_lock);
1833         header->set = lookup_header_set(root, namespaces);
1834         header->attached_by = header->ctl_table;
1835         header->attached_to = root_table;
1836         header->parent = &root_table_header;
1837         for (set = header->set; set; set = set->parent) {
1838                 struct ctl_table_header *p;
1839                 list_for_each_entry(p, &set->list, ctl_entry) {
1840                         if (p->unregistering)
1841                                 continue;
1842                         try_attach(p, header);
1843                 }
1844         }
1845         header->parent->count++;
1846         list_add_tail(&header->ctl_entry, &header->set->list);
1847         spin_unlock(&sysctl_lock);
1848
1849         return header;
1850 }
1851
1852 /**
1853  * register_sysctl_table_path - register a sysctl table hierarchy
1854  * @path: The path to the directory the sysctl table is in.
1855  * @table: the top-level table structure
1856  *
1857  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1858  * array. A completely 0 filled entry terminates the table.
1859  *
1860  * See __register_sysctl_paths for more details.
1861  */
1862 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1863                                                 struct ctl_table *table)
1864 {
1865         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1866                                         path, table);
1867 }
1868
1869 /**
1870  * register_sysctl_table - register a sysctl table hierarchy
1871  * @table: the top-level table structure
1872  *
1873  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1874  * array. A completely 0 filled entry terminates the table.
1875  *
1876  * See register_sysctl_paths for more details.
1877  */
1878 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1879 {
1880         static const struct ctl_path null_path[] = { {} };
1881
1882         return register_sysctl_paths(null_path, table);
1883 }
1884
1885 /**
1886  * unregister_sysctl_table - unregister a sysctl table hierarchy
1887  * @header: the header returned from register_sysctl_table
1888  *
1889  * Unregisters the sysctl table and all children. proc entries may not
1890  * actually be removed until they are no longer used by anyone.
1891  */
1892 void unregister_sysctl_table(struct ctl_table_header * header)
1893 {
1894         might_sleep();
1895
1896         if (header == NULL)
1897                 return;
1898
1899         spin_lock(&sysctl_lock);
1900         start_unregistering(header);
1901         if (!--header->parent->count) {
1902                 WARN_ON(1);
1903                 kfree(header->parent);
1904         }
1905         if (!--header->count)
1906                 kfree(header);
1907         spin_unlock(&sysctl_lock);
1908 }
1909
1910 int sysctl_is_seen(struct ctl_table_header *p)
1911 {
1912         struct ctl_table_set *set = p->set;
1913         int res;
1914         spin_lock(&sysctl_lock);
1915         if (p->unregistering)
1916                 res = 0;
1917         else if (!set->is_seen)
1918                 res = 1;
1919         else
1920                 res = set->is_seen(set);
1921         spin_unlock(&sysctl_lock);
1922         return res;
1923 }
1924
1925 void setup_sysctl_set(struct ctl_table_set *p,
1926         struct ctl_table_set *parent,
1927         int (*is_seen)(struct ctl_table_set *))
1928 {
1929         INIT_LIST_HEAD(&p->list);
1930         p->parent = parent ? parent : &sysctl_table_root.default_set;
1931         p->is_seen = is_seen;
1932 }
1933
1934 #else /* !CONFIG_SYSCTL */
1935 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1936 {
1937         return NULL;
1938 }
1939
1940 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1941                                                     struct ctl_table *table)
1942 {
1943         return NULL;
1944 }
1945
1946 void unregister_sysctl_table(struct ctl_table_header * table)
1947 {
1948 }
1949
1950 void setup_sysctl_set(struct ctl_table_set *p,
1951         struct ctl_table_set *parent,
1952         int (*is_seen)(struct ctl_table_set *))
1953 {
1954 }
1955
1956 void sysctl_head_put(struct ctl_table_header *head)
1957 {
1958 }
1959
1960 #endif /* CONFIG_SYSCTL */
1961
1962 /*
1963  * /proc/sys support
1964  */
1965
1966 #ifdef CONFIG_PROC_SYSCTL
1967
1968 static int _proc_do_string(void* data, int maxlen, int write,
1969                            void __user *buffer,
1970                            size_t *lenp, loff_t *ppos)
1971 {
1972         size_t len;
1973         char __user *p;
1974         char c;
1975
1976         if (!data || !maxlen || !*lenp) {
1977                 *lenp = 0;
1978                 return 0;
1979         }
1980
1981         if (write) {
1982                 len = 0;
1983                 p = buffer;
1984                 while (len < *lenp) {
1985                         if (get_user(c, p++))
1986                                 return -EFAULT;
1987                         if (c == 0 || c == '\n')
1988                                 break;
1989                         len++;
1990                 }
1991                 if (len >= maxlen)
1992                         len = maxlen-1;
1993                 if(copy_from_user(data, buffer, len))
1994                         return -EFAULT;
1995                 ((char *) data)[len] = 0;
1996                 *ppos += *lenp;
1997         } else {
1998                 len = strlen(data);
1999                 if (len > maxlen)
2000                         len = maxlen;
2001
2002                 if (*ppos > len) {
2003                         *lenp = 0;
2004                         return 0;
2005                 }
2006
2007                 data += *ppos;
2008                 len  -= *ppos;
2009
2010                 if (len > *lenp)
2011                         len = *lenp;
2012                 if (len)
2013                         if(copy_to_user(buffer, data, len))
2014                                 return -EFAULT;
2015                 if (len < *lenp) {
2016                         if(put_user('\n', ((char __user *) buffer) + len))
2017                                 return -EFAULT;
2018                         len++;
2019                 }
2020                 *lenp = len;
2021                 *ppos += len;
2022         }
2023         return 0;
2024 }
2025
2026 /**
2027  * proc_dostring - read a string sysctl
2028  * @table: the sysctl table
2029  * @write: %TRUE if this is a write to the sysctl file
2030  * @buffer: the user buffer
2031  * @lenp: the size of the user buffer
2032  * @ppos: file position
2033  *
2034  * Reads/writes a string from/to the user buffer. If the kernel
2035  * buffer provided is not large enough to hold the string, the
2036  * string is truncated. The copied string is %NULL-terminated.
2037  * If the string is being read by the user process, it is copied
2038  * and a newline '\n' is added. It is truncated if the buffer is
2039  * not large enough.
2040  *
2041  * Returns 0 on success.
2042  */
2043 int proc_dostring(struct ctl_table *table, int write,
2044                   void __user *buffer, size_t *lenp, loff_t *ppos)
2045 {
2046         return _proc_do_string(table->data, table->maxlen, write,
2047                                buffer, lenp, ppos);
2048 }
2049
2050
2051 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2052                                  int *valp,
2053                                  int write, void *data)
2054 {
2055         if (write) {
2056                 *valp = *negp ? -*lvalp : *lvalp;
2057         } else {
2058                 int val = *valp;
2059                 if (val < 0) {
2060                         *negp = -1;
2061                         *lvalp = (unsigned long)-val;
2062                 } else {
2063                         *negp = 0;
2064                         *lvalp = (unsigned long)val;
2065                 }
2066         }
2067         return 0;
2068 }
2069
2070 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2071                   int write, void __user *buffer,
2072                   size_t *lenp, loff_t *ppos,
2073                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2074                               int write, void *data),
2075                   void *data)
2076 {
2077 #define TMPBUFLEN 21
2078         int *i, vleft, first = 1, neg;
2079         unsigned long lval;
2080         size_t left, len;
2081
2082         char buf[TMPBUFLEN], *p;
2083         char __user *s = buffer;
2084
2085         if (!tbl_data || !table->maxlen || !*lenp ||
2086             (*ppos && !write)) {
2087                 *lenp = 0;
2088                 return 0;
2089         }
2090
2091         i = (int *) tbl_data;
2092         vleft = table->maxlen / sizeof(*i);
2093         left = *lenp;
2094
2095         if (!conv)
2096                 conv = do_proc_dointvec_conv;
2097
2098         for (; left && vleft--; i++, first=0) {
2099                 if (write) {
2100                         while (left) {
2101                                 char c;
2102                                 if (get_user(c, s))
2103                                         return -EFAULT;
2104                                 if (!isspace(c))
2105                                         break;
2106                                 left--;
2107                                 s++;
2108                         }
2109                         if (!left)
2110                                 break;
2111                         neg = 0;
2112                         len = left;
2113                         if (len > sizeof(buf) - 1)
2114                                 len = sizeof(buf) - 1;
2115                         if (copy_from_user(buf, s, len))
2116                                 return -EFAULT;
2117                         buf[len] = 0;
2118                         p = buf;
2119                         if (*p == '-' && left > 1) {
2120                                 neg = 1;
2121                                 p++;
2122                         }
2123                         if (*p < '0' || *p > '9')
2124                                 break;
2125
2126                         lval = simple_strtoul(p, &p, 0);
2127
2128                         len = p-buf;
2129                         if ((len < left) && *p && !isspace(*p))
2130                                 break;
2131                         s += len;
2132                         left -= len;
2133
2134                         if (conv(&neg, &lval, i, 1, data))
2135                                 break;
2136                 } else {
2137                         p = buf;
2138                         if (!first)
2139                                 *p++ = '\t';
2140
2141                         if (conv(&neg, &lval, i, 0, data))
2142                                 break;
2143
2144                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2145                         len = strlen(buf);
2146                         if (len > left)
2147                                 len = left;
2148                         if(copy_to_user(s, buf, len))
2149                                 return -EFAULT;
2150                         left -= len;
2151                         s += len;
2152                 }
2153         }
2154
2155         if (!write && !first && left) {
2156                 if(put_user('\n', s))
2157                         return -EFAULT;
2158                 left--, s++;
2159         }
2160         if (write) {
2161                 while (left) {
2162                         char c;
2163                         if (get_user(c, s++))
2164                                 return -EFAULT;
2165                         if (!isspace(c))
2166                                 break;
2167                         left--;
2168                 }
2169         }
2170         if (write && first)
2171                 return -EINVAL;
2172         *lenp -= left;
2173         *ppos += *lenp;
2174         return 0;
2175 #undef TMPBUFLEN
2176 }
2177
2178 static int do_proc_dointvec(struct ctl_table *table, int write,
2179                   void __user *buffer, size_t *lenp, loff_t *ppos,
2180                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2181                               int write, void *data),
2182                   void *data)
2183 {
2184         return __do_proc_dointvec(table->data, table, write,
2185                         buffer, lenp, ppos, conv, data);
2186 }
2187
2188 /**
2189  * proc_dointvec - read a vector of integers
2190  * @table: the sysctl table
2191  * @write: %TRUE if this is a write to the sysctl file
2192  * @buffer: the user buffer
2193  * @lenp: the size of the user buffer
2194  * @ppos: file position
2195  *
2196  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2197  * values from/to the user buffer, treated as an ASCII string.
2198  *
2199  * Returns 0 on success.
2200  */
2201 int proc_dointvec(struct ctl_table *table, int write,
2202                      void __user *buffer, size_t *lenp, loff_t *ppos)
2203 {
2204     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2205                             NULL,NULL);
2206 }
2207
2208 /*
2209  * Taint values can only be increased
2210  * This means we can safely use a temporary.
2211  */
2212 static int proc_taint(struct ctl_table *table, int write,
2213                                void __user *buffer, size_t *lenp, loff_t *ppos)
2214 {
2215         struct ctl_table t;
2216         unsigned long tmptaint = get_taint();
2217         int err;
2218
2219         if (write && !capable(CAP_SYS_ADMIN))
2220                 return -EPERM;
2221
2222         t = *table;
2223         t.data = &tmptaint;
2224         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2225         if (err < 0)
2226                 return err;
2227
2228         if (write) {
2229                 /*
2230                  * Poor man's atomic or. Not worth adding a primitive
2231                  * to everyone's atomic.h for this
2232                  */
2233                 int i;
2234                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2235                         if ((tmptaint >> i) & 1)
2236                                 add_taint(i);
2237                 }
2238         }
2239
2240         return err;
2241 }
2242
2243 struct do_proc_dointvec_minmax_conv_param {
2244         int *min;
2245         int *max;
2246 };
2247
2248 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2249                                         int *valp,
2250                                         int write, void *data)
2251 {
2252         struct do_proc_dointvec_minmax_conv_param *param = data;
2253         if (write) {
2254                 int val = *negp ? -*lvalp : *lvalp;
2255                 if ((param->min && *param->min > val) ||
2256                     (param->max && *param->max < val))
2257                         return -EINVAL;
2258                 *valp = val;
2259         } else {
2260                 int val = *valp;
2261                 if (val < 0) {
2262                         *negp = -1;
2263                         *lvalp = (unsigned long)-val;
2264                 } else {
2265                         *negp = 0;
2266                         *lvalp = (unsigned long)val;
2267                 }
2268         }
2269         return 0;
2270 }
2271
2272 /**
2273  * proc_dointvec_minmax - read a vector of integers with min/max values
2274  * @table: the sysctl table
2275  * @write: %TRUE if this is a write to the sysctl file
2276  * @buffer: the user buffer
2277  * @lenp: the size of the user buffer
2278  * @ppos: file position
2279  *
2280  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2281  * values from/to the user buffer, treated as an ASCII string.
2282  *
2283  * This routine will ensure the values are within the range specified by
2284  * table->extra1 (min) and table->extra2 (max).
2285  *
2286  * Returns 0 on success.
2287  */
2288 int proc_dointvec_minmax(struct ctl_table *table, int write,
2289                   void __user *buffer, size_t *lenp, loff_t *ppos)
2290 {
2291         struct do_proc_dointvec_minmax_conv_param param = {
2292                 .min = (int *) table->extra1,
2293                 .max = (int *) table->extra2,
2294         };
2295         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2296                                 do_proc_dointvec_minmax_conv, &param);
2297 }
2298
2299 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2300                                      void __user *buffer,
2301                                      size_t *lenp, loff_t *ppos,
2302                                      unsigned long convmul,
2303                                      unsigned long convdiv)
2304 {
2305 #define TMPBUFLEN 21
2306         unsigned long *i, *min, *max, val;
2307         int vleft, first=1, neg;
2308         size_t len, left;
2309         char buf[TMPBUFLEN], *p;
2310         char __user *s = buffer;
2311
2312         if (!data || !table->maxlen || !*lenp ||
2313             (*ppos && !write)) {
2314                 *lenp = 0;
2315                 return 0;
2316         }
2317
2318         i = (unsigned long *) data;
2319         min = (unsigned long *) table->extra1;
2320         max = (unsigned long *) table->extra2;
2321         vleft = table->maxlen / sizeof(unsigned long);
2322         left = *lenp;
2323
2324         for (; left && vleft--; i++, min++, max++, first=0) {
2325                 if (write) {
2326                         while (left) {
2327                                 char c;
2328                                 if (get_user(c, s))
2329                                         return -EFAULT;
2330                                 if (!isspace(c))
2331                                         break;
2332                                 left--;
2333                                 s++;
2334                         }
2335                         if (!left)
2336                                 break;
2337                         neg = 0;
2338                         len = left;
2339                         if (len > TMPBUFLEN-1)
2340                                 len = TMPBUFLEN-1;
2341                         if (copy_from_user(buf, s, len))
2342                                 return -EFAULT;
2343                         buf[len] = 0;
2344                         p = buf;
2345                         if (*p == '-' && left > 1) {
2346                                 neg = 1;
2347                                 p++;
2348                         }
2349                         if (*p < '0' || *p > '9')
2350                                 break;
2351                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2352                         len = p-buf;
2353                         if ((len < left) && *p && !isspace(*p))
2354                                 break;
2355                         if (neg)
2356                                 val = -val;
2357                         s += len;
2358                         left -= len;
2359
2360                         if(neg)
2361                                 continue;
2362                         if ((min && val < *min) || (max && val > *max))
2363                                 continue;
2364                         *i = val;
2365                 } else {
2366                         p = buf;
2367                         if (!first)
2368                                 *p++ = '\t';
2369                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2370                         len = strlen(buf);
2371                         if (len > left)
2372                                 len = left;
2373                         if(copy_to_user(s, buf, len))
2374                                 return -EFAULT;
2375                         left -= len;
2376                         s += len;
2377                 }
2378         }
2379
2380         if (!write && !first && left) {
2381                 if(put_user('\n', s))
2382                         return -EFAULT;
2383                 left--, s++;
2384         }
2385         if (write) {
2386                 while (left) {
2387                         char c;
2388                         if (get_user(c, s++))
2389                                 return -EFAULT;
2390                         if (!isspace(c))
2391                                 break;
2392                         left--;
2393                 }
2394         }
2395         if (write && first)
2396                 return -EINVAL;
2397         *lenp -= left;
2398         *ppos += *lenp;
2399         return 0;
2400 #undef TMPBUFLEN
2401 }
2402
2403 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2404                                      void __user *buffer,
2405                                      size_t *lenp, loff_t *ppos,
2406                                      unsigned long convmul,
2407                                      unsigned long convdiv)
2408 {
2409         return __do_proc_doulongvec_minmax(table->data, table, write,
2410                         buffer, lenp, ppos, convmul, convdiv);
2411 }
2412
2413 /**
2414  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2415  * @table: the sysctl table
2416  * @write: %TRUE if this is a write to the sysctl file
2417  * @buffer: the user buffer
2418  * @lenp: the size of the user buffer
2419  * @ppos: file position
2420  *
2421  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2422  * values from/to the user buffer, treated as an ASCII string.
2423  *
2424  * This routine will ensure the values are within the range specified by
2425  * table->extra1 (min) and table->extra2 (max).
2426  *
2427  * Returns 0 on success.
2428  */
2429 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2430                            void __user *buffer, size_t *lenp, loff_t *ppos)
2431 {
2432     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2433 }
2434
2435 /**
2436  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2437  * @table: the sysctl table
2438  * @write: %TRUE if this is a write to the sysctl file
2439  * @buffer: the user buffer
2440  * @lenp: the size of the user buffer
2441  * @ppos: file position
2442  *
2443  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2444  * values from/to the user buffer, treated as an ASCII string. The values
2445  * are treated as milliseconds, and converted to jiffies when they are stored.
2446  *
2447  * This routine will ensure the values are within the range specified by
2448  * table->extra1 (min) and table->extra2 (max).
2449  *
2450  * Returns 0 on success.
2451  */
2452 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2453                                       void __user *buffer,
2454                                       size_t *lenp, loff_t *ppos)
2455 {
2456     return do_proc_doulongvec_minmax(table, write, buffer,
2457                                      lenp, ppos, HZ, 1000l);
2458 }
2459
2460
2461 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2462                                          int *valp,
2463                                          int write, void *data)
2464 {
2465         if (write) {
2466                 if (*lvalp > LONG_MAX / HZ)
2467                         return 1;
2468                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2469         } else {
2470                 int val = *valp;
2471                 unsigned long lval;
2472                 if (val < 0) {
2473                         *negp = -1;
2474                         lval = (unsigned long)-val;
2475                 } else {
2476                         *negp = 0;
2477                         lval = (unsigned long)val;
2478                 }
2479                 *lvalp = lval / HZ;
2480         }
2481         return 0;
2482 }
2483
2484 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2485                                                 int *valp,
2486                                                 int write, void *data)
2487 {
2488         if (write) {
2489                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2490                         return 1;
2491                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2492         } else {
2493                 int val = *valp;
2494                 unsigned long lval;
2495                 if (val < 0) {
2496                         *negp = -1;
2497                         lval = (unsigned long)-val;
2498                 } else {
2499                         *negp = 0;
2500                         lval = (unsigned long)val;
2501                 }
2502                 *lvalp = jiffies_to_clock_t(lval);
2503         }
2504         return 0;
2505 }
2506
2507 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2508                                             int *valp,
2509                                             int write, void *data)
2510 {
2511         if (write) {
2512                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2513         } else {
2514                 int val = *valp;
2515                 unsigned long lval;
2516                 if (val < 0) {
2517                         *negp = -1;
2518                         lval = (unsigned long)-val;
2519                 } else {
2520                         *negp = 0;
2521                         lval = (unsigned long)val;
2522                 }
2523                 *lvalp = jiffies_to_msecs(lval);
2524         }
2525         return 0;
2526 }
2527
2528 /**
2529  * proc_dointvec_jiffies - read a vector of integers as seconds
2530  * @table: the sysctl table
2531  * @write: %TRUE if this is a write to the sysctl file
2532  * @buffer: the user buffer
2533  * @lenp: the size of the user buffer
2534  * @ppos: file position
2535  *
2536  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2537  * values from/to the user buffer, treated as an ASCII string.
2538  * The values read are assumed to be in seconds, and are converted into
2539  * jiffies.
2540  *
2541  * Returns 0 on success.
2542  */
2543 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2544                           void __user *buffer, size_t *lenp, loff_t *ppos)
2545 {
2546     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2547                             do_proc_dointvec_jiffies_conv,NULL);
2548 }
2549
2550 /**
2551  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2552  * @table: the sysctl table
2553  * @write: %TRUE if this is a write to the sysctl file
2554  * @buffer: the user buffer
2555  * @lenp: the size of the user buffer
2556  * @ppos: pointer to the file position
2557  *
2558  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2559  * values from/to the user buffer, treated as an ASCII string.
2560  * The values read are assumed to be in 1/USER_HZ seconds, and
2561  * are converted into jiffies.
2562  *
2563  * Returns 0 on success.
2564  */
2565 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2566                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2567 {
2568     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2569                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2570 }
2571
2572 /**
2573  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2574  * @table: the sysctl table
2575  * @write: %TRUE if this is a write to the sysctl file
2576  * @buffer: the user buffer
2577  * @lenp: the size of the user buffer
2578  * @ppos: file position
2579  * @ppos: the current position in the file
2580  *
2581  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2582  * values from/to the user buffer, treated as an ASCII string.
2583  * The values read are assumed to be in 1/1000 seconds, and
2584  * are converted into jiffies.
2585  *
2586  * Returns 0 on success.
2587  */
2588 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2589                              void __user *buffer, size_t *lenp, loff_t *ppos)
2590 {
2591         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2592                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2593 }
2594
2595 static int proc_do_cad_pid(struct ctl_table *table, int write,
2596                            void __user *buffer, size_t *lenp, loff_t *ppos)
2597 {
2598         struct pid *new_pid;
2599         pid_t tmp;
2600         int r;
2601
2602         tmp = pid_vnr(cad_pid);
2603
2604         r = __do_proc_dointvec(&tmp, table, write, buffer,
2605                                lenp, ppos, NULL, NULL);
2606         if (r || !write)
2607                 return r;
2608
2609         new_pid = find_get_pid(tmp);
2610         if (!new_pid)
2611                 return -ESRCH;
2612
2613         put_pid(xchg(&cad_pid, new_pid));
2614         return 0;
2615 }
2616
2617 #else /* CONFIG_PROC_FS */
2618
2619 int proc_dostring(struct ctl_table *table, int write,
2620                   void __user *buffer, size_t *lenp, loff_t *ppos)
2621 {
2622         return -ENOSYS;
2623 }
2624
2625 int proc_dointvec(struct ctl_table *table, int write,
2626                   void __user *buffer, size_t *lenp, loff_t *ppos)
2627 {
2628         return -ENOSYS;
2629 }
2630
2631 int proc_dointvec_minmax(struct ctl_table *table, int write,
2632                     void __user *buffer, size_t *lenp, loff_t *ppos)
2633 {
2634         return -ENOSYS;
2635 }
2636
2637 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2638                     void __user *buffer, size_t *lenp, loff_t *ppos)
2639 {
2640         return -ENOSYS;
2641 }
2642
2643 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2644                     void __user *buffer, size_t *lenp, loff_t *ppos)
2645 {
2646         return -ENOSYS;
2647 }
2648
2649 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2650                              void __user *buffer, size_t *lenp, loff_t *ppos)
2651 {
2652         return -ENOSYS;
2653 }
2654
2655 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2656                     void __user *buffer, size_t *lenp, loff_t *ppos)
2657 {
2658         return -ENOSYS;
2659 }
2660
2661 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2662                                       void __user *buffer,
2663                                       size_t *lenp, loff_t *ppos)
2664 {
2665     return -ENOSYS;
2666 }
2667
2668
2669 #endif /* CONFIG_PROC_FS */
2670
2671 /*
2672  * No sense putting this after each symbol definition, twice,
2673  * exception granted :-)
2674  */
2675 EXPORT_SYMBOL(proc_dointvec);
2676 EXPORT_SYMBOL(proc_dointvec_jiffies);
2677 EXPORT_SYMBOL(proc_dointvec_minmax);
2678 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2679 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2680 EXPORT_SYMBOL(proc_dostring);
2681 EXPORT_SYMBOL(proc_doulongvec_minmax);
2682 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2683 EXPORT_SYMBOL(register_sysctl_table);
2684 EXPORT_SYMBOL(register_sysctl_paths);
2685 EXPORT_SYMBOL(unregister_sysctl_table);