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