kernel/sysctl.c

   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/printk.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/security.h>
  30 #include <linux/ctype.h>
  31 #include <linux/kmemcheck.h>
  32 #include <linux/fs.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/ratelimit.h>
  41 #include <linux/compaction.h>
  42 #include <linux/hugetlb.h>
  43 #include <linux/initrd.h>
  44 #include <linux/key.h>
  45 #include <linux/times.h>
  46 #include <linux/limits.h>
  47 #include <linux/dcache.h>
  48 #include <linux/dnotify.h>
  49 #include <linux/syscalls.h>
  50 #include <linux/vmstat.h>
  51 #include <linux/nfs_fs.h>
  52 #include <linux/acpi.h>
  53 #include <linux/reboot.h>
  54 #include <linux/ftrace.h>
  55 #include <linux/perf_event.h>
  56 #include <linux/kprobes.h>
  57 #include <linux/pipe_fs_i.h>
  58 #include <linux/oom.h>
  59 #include <linux/kmod.h>
  60
  61 #include <asm/uaccess.h>
  62 #include <asm/processor.h>
  63
  64 #ifdef CONFIG_X86
  65 #include <asm/nmi.h>
  66 #include <asm/stacktrace.h>
  67 #include <asm/io.h>
  68 #endif
  69 #ifdef CONFIG_BSD_PROCESS_ACCT
  70 #include <linux/acct.h>
  71 #endif
  72 #ifdef CONFIG_RT_MUTEXES
  73 #include <linux/rtmutex.h>
  74 #endif
  75 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
  76 #include <linux/lockdep.h>
  77 #endif
  78 #ifdef CONFIG_CHR_DEV_SG
  79 #include <scsi/sg.h>
  80 #endif
  81
  82 #ifdef CONFIG_LOCKUP_DETECTOR
  83 #include <linux/nmi.h>
  84 #endif
  85
  86
  87 #if defined(CONFIG_SYSCTL)
  88
  89 /* External variables not in a header file. */
  90 extern int sysctl_overcommit_memory;
  91 extern int sysctl_overcommit_ratio;
  92 extern int max_threads;
  93 extern int core_uses_pid;
  94 extern int suid_dumpable;
  95 extern char core_pattern[];
  96 extern unsigned int core_pipe_limit;
  97 extern int pid_max;
  98 extern int min_free_kbytes;
  99 extern int pid_max_min, pid_max_max;
 100 extern int sysctl_drop_caches;
 101 extern int percpu_pagelist_fraction;
 102 extern int compat_log;
 103 extern int latencytop_enabled;
 104 extern int sysctl_nr_open_min, sysctl_nr_open_max;
 105 #ifndef CONFIG_MMU
 106 extern int sysctl_nr_trim_pages;
 107 #endif
 108 #ifdef CONFIG_BLOCK
 109 extern int blk_iopoll_enabled;
 110 #endif
 111
 112 /* Constants used for minimum and  maximum */
 113 #ifdef CONFIG_LOCKUP_DETECTOR
 114 static int sixty = 60;
 115 static int neg_one = -1;
 116 #endif
 117
 118 static int zero;
 119 static int __maybe_unused one = 1;
 120 static int __maybe_unused two = 2;
 121 static int __maybe_unused three = 3;
 122 static unsigned long one_ul = 1;
 123 static int one_hundred = 100;
 124 #ifdef CONFIG_PRINTK
 125 static int ten_thousand = 10000;
 126 #endif
 127
 128 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 129 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 130
 131 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 132 static int maxolduid = 65535;
 133 static int minolduid;
 134 static int min_percpu_pagelist_fract = 8;
 135
 136 static int ngroups_max = NGROUPS_MAX;
 137
 138 #ifdef CONFIG_INOTIFY_USER
 139 #include <linux/inotify.h>
 140 #endif
 141 #ifdef CONFIG_SPARC
 142 #include <asm/system.h>
 143 #endif
 144
 145 #ifdef CONFIG_SPARC64
 146 extern int sysctl_tsb_ratio;
 147 #endif
 148
 149 #ifdef __hppa__
 150 extern int pwrsw_enabled;
 151 extern int unaligned_enabled;
 152 #endif
 153
 154 #ifdef CONFIG_S390
 155 #ifdef CONFIG_MATHEMU
 156 extern int sysctl_ieee_emulation_warnings;
 157 #endif
 158 extern int sysctl_userprocess_debug;
 159 extern int spin_retry;
 160 #endif
 161
 162 #ifdef CONFIG_IA64
 163 extern int no_unaligned_warning;
 164 extern int unaligned_dump_stack;
 165 #endif
 166
 167 #ifdef CONFIG_PROC_SYSCTL
 168 static int proc_do_cad_pid(struct ctl_table *table, int write,
 169                   void __user *buffer, size_t *lenp, loff_t *ppos);
 170 static int proc_taint(struct ctl_table *table, int write,
 171                                void __user *buffer, size_t *lenp, loff_t *ppos);
 172 #endif
 173
 174 #ifdef CONFIG_PRINTK
 175 static int proc_dmesg_restrict(struct ctl_table *table, int write,
 176                                 void __user *buffer, size_t *lenp, loff_t *ppos);
 177 #endif
 178
 179 #ifdef CONFIG_MAGIC_SYSRQ
 180 /* Note: sysrq code uses it's own private copy */
 181 static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
 182
 183 static int sysrq_sysctl_handler(ctl_table *table, int write,
 184                                 void __user *buffer, size_t *lenp,
 185                                 loff_t *ppos)
 186 {
 187         int error;
 188
 189         error = proc_dointvec(table, write, buffer, lenp, ppos);
 190         if (error)
 191                 return error;
 192
 193         if (write)
 194                 sysrq_toggle_support(__sysrq_enabled);
 195
 196         return 0;
 197 }
 198
 199 #endif
 200
 201 static struct ctl_table root_table[];
 202 static struct ctl_table_root sysctl_table_root;
 203 static struct ctl_table_header root_table_header = {
 204         {{.count = 1,
 205         .ctl_table = root_table,
 206         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
 207         .root = &sysctl_table_root,
 208         .set = &sysctl_table_root.default_set,
 209 };
 210 static struct ctl_table_root sysctl_table_root = {
 211         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 212         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 213 };
 214
 215 static struct ctl_table kern_table[];
 216 static struct ctl_table vm_table[];
 217 static struct ctl_table fs_table[];
 218 static struct ctl_table debug_table[];
 219 static struct ctl_table dev_table[];
 220 extern struct ctl_table random_table[];
 221 #ifdef CONFIG_EPOLL
 222 extern struct ctl_table epoll_table[];
 223 #endif
 224
 225 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 226 int sysctl_legacy_va_layout;
 227 #endif
 228
 229 /* The default sysctl tables: */
 230
 231 static struct ctl_table root_table[] = {
 232         {
 233                 .procname       = "kernel",
 234                 .mode           = 0555,
 235                 .child          = kern_table,
 236         },
 237         {
 238                 .procname       = "vm",
 239                 .mode           = 0555,
 240                 .child          = vm_table,
 241         },
 242         {
 243                 .procname       = "fs",
 244                 .mode           = 0555,
 245                 .child          = fs_table,
 246         },
 247         {
 248                 .procname       = "debug",
 249                 .mode           = 0555,
 250                 .child          = debug_table,
 251         },
 252         {
 253                 .procname       = "dev",
 254                 .mode           = 0555,
 255                 .child          = dev_table,
 256         },
 257         { }
 258 };
 259
 260 #ifdef CONFIG_SCHED_DEBUG
 261 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 262 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 263 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 264 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 265 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 266 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 267 #endif
 268
 269 #ifdef CONFIG_COMPACTION
 270 static int min_extfrag_threshold;
 271 static int max_extfrag_threshold = 1000;
 272 #endif
 273
 274 static struct ctl_table kern_table[] = {
 275         {
 276                 .procname       = "sched_child_runs_first",
 277                 .data           = &sysctl_sched_child_runs_first,
 278                 .maxlen         = sizeof(unsigned int),
 279                 .mode           = 0644,
 280                 .proc_handler   = proc_dointvec,
 281         },
 282 #ifdef CONFIG_SCHED_DEBUG
 283         {
 284                 .procname       = "sched_min_granularity_ns",
 285                 .data           = &sysctl_sched_min_granularity,
 286                 .maxlen         = sizeof(unsigned int),
 287                 .mode           = 0644,
 288                 .proc_handler   = sched_proc_update_handler,
 289                 .extra1         = &min_sched_granularity_ns,
 290                 .extra2         = &max_sched_granularity_ns,
 291         },
 292         {
 293                 .procname       = "sched_latency_ns",
 294                 .data           = &sysctl_sched_latency,
 295                 .maxlen         = sizeof(unsigned int),
 296                 .mode           = 0644,
 297                 .proc_handler   = sched_proc_update_handler,
 298                 .extra1         = &min_sched_granularity_ns,
 299                 .extra2         = &max_sched_granularity_ns,
 300         },
 301         {
 302                 .procname       = "sched_wakeup_granularity_ns",
 303                 .data           = &sysctl_sched_wakeup_granularity,
 304                 .maxlen         = sizeof(unsigned int),
 305                 .mode           = 0644,
 306                 .proc_handler   = sched_proc_update_handler,
 307                 .extra1         = &min_wakeup_granularity_ns,
 308                 .extra2         = &max_wakeup_granularity_ns,
 309         },
 310         {
 311                 .procname       = "sched_tunable_scaling",
 312                 .data           = &sysctl_sched_tunable_scaling,
 313                 .maxlen         = sizeof(enum sched_tunable_scaling),
 314                 .mode           = 0644,
 315                 .proc_handler   = sched_proc_update_handler,
 316                 .extra1         = &min_sched_tunable_scaling,
 317                 .extra2         = &max_sched_tunable_scaling,
 318         },
 319         {
 320                 .procname       = "sched_migration_cost",
 321                 .data           = &sysctl_sched_migration_cost,
 322                 .maxlen         = sizeof(unsigned int),
 323                 .mode           = 0644,
 324                 .proc_handler   = proc_dointvec,
 325         },
 326         {
 327                 .procname       = "sched_nr_migrate",
 328                 .data           = &sysctl_sched_nr_migrate,
 329                 .maxlen         = sizeof(unsigned int),
 330                 .mode           = 0644,
 331                 .proc_handler   = proc_dointvec,
 332         },
 333         {
 334                 .procname       = "sched_time_avg",
 335                 .data           = &sysctl_sched_time_avg,
 336                 .maxlen         = sizeof(unsigned int),
 337                 .mode           = 0644,
 338                 .proc_handler   = proc_dointvec,
 339         },
 340         {
 341                 .procname       = "sched_shares_window",
 342                 .data           = &sysctl_sched_shares_window,
 343                 .maxlen         = sizeof(unsigned int),
 344                 .mode           = 0644,
 345                 .proc_handler   = proc_dointvec,
 346         },
 347         {
 348                 .procname       = "timer_migration",
 349                 .data           = &sysctl_timer_migration,
 350                 .maxlen         = sizeof(unsigned int),
 351                 .mode           = 0644,
 352                 .proc_handler   = proc_dointvec_minmax,
 353                 .extra1         = &zero,
 354                 .extra2         = &one,
 355         },
 356 #endif
 357         {
 358                 .procname       = "sched_rt_period_us",
 359                 .data           = &sysctl_sched_rt_period,
 360                 .maxlen         = sizeof(unsigned int),
 361                 .mode           = 0644,
 362                 .proc_handler   = sched_rt_handler,
 363         },
 364         {
 365                 .procname       = "sched_rt_runtime_us",
 366                 .data           = &sysctl_sched_rt_runtime,
 367                 .maxlen         = sizeof(int),
 368                 .mode           = 0644,
 369                 .proc_handler   = sched_rt_handler,
 370         },
 371 #ifdef CONFIG_SCHED_AUTOGROUP
 372         {
 373                 .procname       = "sched_autogroup_enabled",
 374                 .data           = &sysctl_sched_autogroup_enabled,
 375                 .maxlen         = sizeof(unsigned int),
 376                 .mode           = 0644,
 377                 .proc_handler   = proc_dointvec_minmax,
 378                 .extra1         = &zero,
 379                 .extra2         = &one,
 380         },
 381 #endif
 382 #ifdef CONFIG_PROVE_LOCKING
 383         {
 384                 .procname       = "prove_locking",
 385                 .data           = &prove_locking,
 386                 .maxlen         = sizeof(int),
 387                 .mode           = 0644,
 388                 .proc_handler   = proc_dointvec,
 389         },
 390 #endif
 391 #ifdef CONFIG_LOCK_STAT
 392         {
 393                 .procname       = "lock_stat",
 394                 .data           = &lock_stat,
 395                 .maxlen         = sizeof(int),
 396                 .mode           = 0644,
 397                 .proc_handler   = proc_dointvec,
 398         },
 399 #endif
 400         {
 401                 .procname       = "panic",
 402                 .data           = &panic_timeout,
 403                 .maxlen         = sizeof(int),
 404                 .mode           = 0644,
 405                 .proc_handler   = proc_dointvec,
 406         },
 407         {
 408                 .procname       = "core_uses_pid",
 409                 .data           = &core_uses_pid,
 410                 .maxlen         = sizeof(int),
 411                 .mode           = 0644,
 412                 .proc_handler   = proc_dointvec,
 413         },
 414         {
 415                 .procname       = "core_pattern",
 416                 .data           = core_pattern,
 417                 .maxlen         = CORENAME_MAX_SIZE,
 418                 .mode           = 0644,
 419                 .proc_handler   = proc_dostring,
 420         },
 421         {
 422                 .procname       = "core_pipe_limit",
 423                 .data           = &core_pipe_limit,
 424                 .maxlen         = sizeof(unsigned int),
 425                 .mode           = 0644,
 426                 .proc_handler   = proc_dointvec,
 427         },
 428 #ifdef CONFIG_PROC_SYSCTL
 429         {
 430                 .procname       = "tainted",
 431                 .maxlen         = sizeof(long),
 432                 .mode           = 0644,
 433                 .proc_handler   = proc_taint,
 434         },
 435 #endif
 436 #ifdef CONFIG_LATENCYTOP
 437         {
 438                 .procname       = "latencytop",
 439                 .data           = &latencytop_enabled,
 440                 .maxlen         = sizeof(int),
 441                 .mode           = 0644,
 442                 .proc_handler   = proc_dointvec,
 443         },
 444 #endif
 445 #ifdef CONFIG_BLK_DEV_INITRD
 446         {
 447                 .procname       = "real-root-dev",
 448                 .data           = &real_root_dev,
 449                 .maxlen         = sizeof(int),
 450                 .mode           = 0644,
 451                 .proc_handler   = proc_dointvec,
 452         },
 453 #endif
 454         {
 455                 .procname       = "print-fatal-signals",
 456                 .data           = &print_fatal_signals,
 457                 .maxlen         = sizeof(int),
 458                 .mode           = 0644,
 459                 .proc_handler   = proc_dointvec,
 460         },
 461 #ifdef CONFIG_SPARC
 462         {
 463                 .procname       = "reboot-cmd",
 464                 .data           = reboot_command,
 465                 .maxlen         = 256,
 466                 .mode           = 0644,
 467                 .proc_handler   = proc_dostring,
 468         },
 469         {
 470                 .procname       = "stop-a",
 471                 .data           = &stop_a_enabled,
 472                 .maxlen         = sizeof (int),
 473                 .mode           = 0644,
 474                 .proc_handler   = proc_dointvec,
 475         },
 476         {
 477                 .procname       = "scons-poweroff",
 478                 .data           = &scons_pwroff,
 479                 .maxlen         = sizeof (int),
 480                 .mode           = 0644,
 481                 .proc_handler   = proc_dointvec,
 482         },
 483 #endif
 484 #ifdef CONFIG_SPARC64
 485         {
 486                 .procname       = "tsb-ratio",
 487                 .data           = &sysctl_tsb_ratio,
 488                 .maxlen         = sizeof (int),
 489                 .mode           = 0644,
 490                 .proc_handler   = proc_dointvec,
 491         },
 492 #endif
 493 #ifdef __hppa__
 494         {
 495                 .procname       = "soft-power",
 496                 .data           = &pwrsw_enabled,
 497                 .maxlen         = sizeof (int),
 498                 .mode           = 0644,
 499                 .proc_handler   = proc_dointvec,
 500         },
 501         {
 502                 .procname       = "unaligned-trap",
 503                 .data           = &unaligned_enabled,
 504                 .maxlen         = sizeof (int),
 505                 .mode           = 0644,
 506                 .proc_handler   = proc_dointvec,
 507         },
 508 #endif
 509         {
 510                 .procname       = "ctrl-alt-del",
 511                 .data           = &C_A_D,
 512                 .maxlen         = sizeof(int),
 513                 .mode           = 0644,
 514                 .proc_handler   = proc_dointvec,
 515         },
 516 #ifdef CONFIG_FUNCTION_TRACER
 517         {
 518                 .procname       = "ftrace_enabled",
 519                 .data           = &ftrace_enabled,
 520                 .maxlen         = sizeof(int),
 521                 .mode           = 0644,
 522                 .proc_handler   = ftrace_enable_sysctl,
 523         },
 524 #endif
 525 #ifdef CONFIG_STACK_TRACER
 526         {
 527                 .procname       = "stack_tracer_enabled",
 528                 .data           = &stack_tracer_enabled,
 529                 .maxlen         = sizeof(int),
 530                 .mode           = 0644,
 531                 .proc_handler   = stack_trace_sysctl,
 532         },
 533 #endif
 534 #ifdef CONFIG_TRACING
 535         {
 536                 .procname       = "ftrace_dump_on_oops",
 537                 .data           = &ftrace_dump_on_oops,
 538                 .maxlen         = sizeof(int),
 539                 .mode           = 0644,
 540                 .proc_handler   = proc_dointvec,
 541         },
 542 #endif
 543 #ifdef CONFIG_MODULES
 544         {
 545                 .procname       = "modprobe",
 546                 .data           = &modprobe_path,
 547                 .maxlen         = KMOD_PATH_LEN,
 548                 .mode           = 0644,
 549                 .proc_handler   = proc_dostring,
 550         },
 551         {
 552                 .procname       = "modules_disabled",
 553                 .data           = &modules_disabled,
 554                 .maxlen         = sizeof(int),
 555                 .mode           = 0644,
 556                 /* only handle a transition from default "0" to "1" */
 557                 .proc_handler   = proc_dointvec_minmax,
 558                 .extra1         = &one,
 559                 .extra2         = &one,
 560         },
 561 #endif
 562 #ifdef CONFIG_HOTPLUG
 563         {
 564                 .procname       = "hotplug",
 565                 .data           = &uevent_helper,
 566                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 567                 .mode           = 0644,
 568                 .proc_handler   = proc_dostring,
 569         },
 570 #endif
 571 #ifdef CONFIG_CHR_DEV_SG
 572         {
 573                 .procname       = "sg-big-buff",
 574                 .data           = &sg_big_buff,
 575                 .maxlen         = sizeof (int),
 576                 .mode           = 0444,
 577                 .proc_handler   = proc_dointvec,
 578         },
 579 #endif
 580 #ifdef CONFIG_BSD_PROCESS_ACCT
 581         {
 582                 .procname       = "acct",
 583                 .data           = &acct_parm,
 584                 .maxlen         = 3*sizeof(int),
 585                 .mode           = 0644,
 586                 .proc_handler   = proc_dointvec,
 587         },
 588 #endif
 589 #ifdef CONFIG_MAGIC_SYSRQ
 590         {
 591                 .procname       = "sysrq",
 592                 .data           = &__sysrq_enabled,
 593                 .maxlen         = sizeof (int),
 594                 .mode           = 0644,
 595                 .proc_handler   = sysrq_sysctl_handler,
 596         },
 597 #endif
 598 #ifdef CONFIG_PROC_SYSCTL
 599         {
 600                 .procname       = "cad_pid",
 601                 .data           = NULL,
 602                 .maxlen         = sizeof (int),
 603                 .mode           = 0600,
 604                 .proc_handler   = proc_do_cad_pid,
 605         },
 606 #endif
 607         {
 608                 .procname       = "threads-max",
 609                 .data           = &max_threads,
 610                 .maxlen         = sizeof(int),
 611                 .mode           = 0644,
 612                 .proc_handler   = proc_dointvec,
 613         },
 614         {
 615                 .procname       = "random",
 616                 .mode           = 0555,
 617                 .child          = random_table,
 618         },
 619         {
 620                 .procname       = "usermodehelper",
 621                 .mode           = 0555,
 622                 .child          = usermodehelper_table,
 623         },
 624         {
 625                 .procname       = "overflowuid",
 626                 .data           = &overflowuid,
 627                 .maxlen         = sizeof(int),
 628                 .mode           = 0644,
 629                 .proc_handler   = proc_dointvec_minmax,
 630                 .extra1         = &minolduid,
 631                 .extra2         = &maxolduid,
 632         },
 633         {
 634                 .procname       = "overflowgid",
 635                 .data           = &overflowgid,
 636                 .maxlen         = sizeof(int),
 637                 .mode           = 0644,
 638                 .proc_handler   = proc_dointvec_minmax,
 639                 .extra1         = &minolduid,
 640                 .extra2         = &maxolduid,
 641         },
 642 #ifdef CONFIG_S390
 643 #ifdef CONFIG_MATHEMU
 644         {
 645                 .procname       = "ieee_emulation_warnings",
 646                 .data           = &sysctl_ieee_emulation_warnings,
 647                 .maxlen         = sizeof(int),
 648                 .mode           = 0644,
 649                 .proc_handler   = proc_dointvec,
 650         },
 651 #endif
 652         {
 653                 .procname       = "userprocess_debug",
 654                 .data           = &show_unhandled_signals,
 655                 .maxlen         = sizeof(int),
 656                 .mode           = 0644,
 657                 .proc_handler   = proc_dointvec,
 658         },
 659 #endif
 660         {
 661                 .procname       = "pid_max",
 662                 .data           = &pid_max,
 663                 .maxlen         = sizeof (int),
 664                 .mode           = 0644,
 665                 .proc_handler   = proc_dointvec_minmax,
 666                 .extra1         = &pid_max_min,
 667                 .extra2         = &pid_max_max,
 668         },
 669         {
 670                 .procname       = "panic_on_oops",
 671                 .data           = &panic_on_oops,
 672                 .maxlen         = sizeof(int),
 673                 .mode           = 0644,
 674                 .proc_handler   = proc_dointvec,
 675         },
 676 #if defined CONFIG_PRINTK
 677         {
 678                 .procname       = "printk",
 679                 .data           = &console_loglevel,
 680                 .maxlen         = 4*sizeof(int),
 681                 .mode           = 0644,
 682                 .proc_handler   = proc_dointvec,
 683         },
 684         {
 685                 .procname       = "printk_ratelimit",
 686                 .data           = &printk_ratelimit_state.interval,
 687                 .maxlen         = sizeof(int),
 688                 .mode           = 0644,
 689                 .proc_handler   = proc_dointvec_jiffies,
 690         },
 691         {
 692                 .procname       = "printk_ratelimit_burst",
 693                 .data           = &printk_ratelimit_state.burst,
 694                 .maxlen         = sizeof(int),
 695                 .mode           = 0644,
 696                 .proc_handler   = proc_dointvec,
 697         },
 698         {
 699                 .procname       = "printk_delay",
 700                 .data           = &printk_delay_msec,
 701                 .maxlen         = sizeof(int),
 702                 .mode           = 0644,
 703                 .proc_handler   = proc_dointvec_minmax,
 704                 .extra1         = &zero,
 705                 .extra2         = &ten_thousand,
 706         },
 707         {
 708                 .procname       = "dmesg_restrict",
 709                 .data           = &dmesg_restrict,
 710                 .maxlen         = sizeof(int),
 711                 .mode           = 0644,
 712                 .proc_handler   = proc_dointvec_minmax,
 713                 .extra1         = &zero,
 714                 .extra2         = &one,
 715         },
 716         {
 717                 .procname       = "kptr_restrict",
 718                 .data           = &kptr_restrict,
 719                 .maxlen         = sizeof(int),
 720                 .mode           = 0644,
 721                 .proc_handler   = proc_dmesg_restrict,
 722                 .extra1         = &zero,
 723                 .extra2         = &two,
 724         },
 725 #endif
 726         {
 727                 .procname       = "ngroups_max",
 728                 .data           = &ngroups_max,
 729                 .maxlen         = sizeof (int),
 730                 .mode           = 0444,
 731                 .proc_handler   = proc_dointvec,
 732         },
 733 #if defined(CONFIG_LOCKUP_DETECTOR)
 734         {
 735                 .procname       = "watchdog",
 736                 .data           = &watchdog_enabled,
 737                 .maxlen         = sizeof (int),
 738                 .mode           = 0644,
 739                 .proc_handler   = proc_dowatchdog,
 740                 .extra1         = &zero,
 741                 .extra2         = &one,
 742         },
 743         {
 744                 .procname       = "watchdog_thresh",
 745                 .data           = &watchdog_thresh,
 746                 .maxlen         = sizeof(int),
 747                 .mode           = 0644,
 748                 .proc_handler   = proc_dowatchdog,
 749                 .extra1         = &neg_one,
 750                 .extra2         = &sixty,
 751         },
 752         {
 753                 .procname       = "softlockup_panic",
 754                 .data           = &softlockup_panic,
 755                 .maxlen         = sizeof(int),
 756                 .mode           = 0644,
 757                 .proc_handler   = proc_dointvec_minmax,
 758                 .extra1         = &zero,
 759                 .extra2         = &one,
 760         },
 761         {
 762                 .procname       = "nmi_watchdog",
 763                 .data           = &watchdog_enabled,
 764                 .maxlen         = sizeof (int),
 765                 .mode           = 0644,
 766                 .proc_handler   = proc_dowatchdog,
 767                 .extra1         = &zero,
 768                 .extra2         = &one,
 769         },
 770 #endif
 771 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 772         {
 773                 .procname       = "unknown_nmi_panic",
 774                 .data           = &unknown_nmi_panic,
 775                 .maxlen         = sizeof (int),
 776                 .mode           = 0644,
 777                 .proc_handler   = proc_dointvec,
 778         },
 779 #endif
 780 #if defined(CONFIG_X86)
 781         {
 782                 .procname       = "panic_on_unrecovered_nmi",
 783                 .data           = &panic_on_unrecovered_nmi,
 784                 .maxlen         = sizeof(int),
 785                 .mode           = 0644,
 786                 .proc_handler   = proc_dointvec,
 787         },
 788         {
 789                 .procname       = "panic_on_io_nmi",
 790                 .data           = &panic_on_io_nmi,
 791                 .maxlen         = sizeof(int),
 792                 .mode           = 0644,
 793                 .proc_handler   = proc_dointvec,
 794         },
 795         {
 796                 .procname       = "bootloader_type",
 797                 .data           = &bootloader_type,
 798                 .maxlen         = sizeof (int),
 799                 .mode           = 0444,
 800                 .proc_handler   = proc_dointvec,
 801         },
 802         {
 803                 .procname       = "bootloader_version",
 804                 .data           = &bootloader_version,
 805                 .maxlen         = sizeof (int),
 806                 .mode           = 0444,
 807                 .proc_handler   = proc_dointvec,
 808         },
 809         {
 810                 .procname       = "kstack_depth_to_print",
 811                 .data           = &kstack_depth_to_print,
 812                 .maxlen         = sizeof(int),
 813                 .mode           = 0644,
 814                 .proc_handler   = proc_dointvec,
 815         },
 816         {
 817                 .procname       = "io_delay_type",
 818                 .data           = &io_delay_type,
 819                 .maxlen         = sizeof(int),
 820                 .mode           = 0644,
 821                 .proc_handler   = proc_dointvec,
 822         },
 823 #endif
 824 #if defined(CONFIG_MMU)
 825         {
 826                 .procname       = "randomize_va_space",
 827                 .data           = &randomize_va_space,
 828                 .maxlen         = sizeof(int),
 829                 .mode           = 0644,
 830                 .proc_handler   = proc_dointvec,
 831         },
 832 #endif
 833 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 834         {
 835                 .procname       = "spin_retry",
 836                 .data           = &spin_retry,
 837                 .maxlen         = sizeof (int),
 838                 .mode           = 0644,
 839                 .proc_handler   = proc_dointvec,
 840         },
 841 #endif
 842 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 843         {
 844                 .procname       = "acpi_video_flags",
 845                 .data           = &acpi_realmode_flags,
 846                 .maxlen         = sizeof (unsigned long),
 847                 .mode           = 0644,
 848                 .proc_handler   = proc_doulongvec_minmax,
 849         },
 850 #endif
 851 #ifdef CONFIG_IA64
 852         {
 853                 .procname       = "ignore-unaligned-usertrap",
 854                 .data           = &no_unaligned_warning,
 855                 .maxlen         = sizeof (int),
 856                 .mode           = 0644,
 857                 .proc_handler   = proc_dointvec,
 858         },
 859         {
 860                 .procname       = "unaligned-dump-stack",
 861                 .data           = &unaligned_dump_stack,
 862                 .maxlen         = sizeof (int),
 863                 .mode           = 0644,
 864                 .proc_handler   = proc_dointvec,
 865         },
 866 #endif
 867 #ifdef CONFIG_DETECT_HUNG_TASK
 868         {
 869                 .procname       = "hung_task_panic",
 870                 .data           = &sysctl_hung_task_panic,
 871                 .maxlen         = sizeof(int),
 872                 .mode           = 0644,
 873                 .proc_handler   = proc_dointvec_minmax,
 874                 .extra1         = &zero,
 875                 .extra2         = &one,
 876         },
 877         {
 878                 .procname       = "hung_task_check_count",
 879                 .data           = &sysctl_hung_task_check_count,
 880                 .maxlen         = sizeof(unsigned long),
 881                 .mode           = 0644,
 882                 .proc_handler   = proc_doulongvec_minmax,
 883         },
 884         {
 885                 .procname       = "hung_task_timeout_secs",
 886                 .data           = &sysctl_hung_task_timeout_secs,
 887                 .maxlen         = sizeof(unsigned long),
 888                 .mode           = 0644,
 889                 .proc_handler   = proc_dohung_task_timeout_secs,
 890         },
 891         {
 892                 .procname       = "hung_task_warnings",
 893                 .data           = &sysctl_hung_task_warnings,
 894                 .maxlen         = sizeof(unsigned long),
 895                 .mode           = 0644,
 896                 .proc_handler   = proc_doulongvec_minmax,
 897         },
 898 #endif
 899 #ifdef CONFIG_COMPAT
 900         {
 901                 .procname       = "compat-log",
 902                 .data           = &compat_log,
 903                 .maxlen         = sizeof (int),
 904                 .mode           = 0644,
 905                 .proc_handler   = proc_dointvec,
 906         },
 907 #endif
 908 #ifdef CONFIG_RT_MUTEXES
 909         {
 910                 .procname       = "max_lock_depth",
 911                 .data           = &max_lock_depth,
 912                 .maxlen         = sizeof(int),
 913                 .mode           = 0644,
 914                 .proc_handler   = proc_dointvec,
 915         },
 916 #endif
 917         {
 918                 .procname       = "poweroff_cmd",
 919                 .data           = &poweroff_cmd,
 920                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 921                 .mode           = 0644,
 922                 .proc_handler   = proc_dostring,
 923         },
 924 #ifdef CONFIG_KEYS
 925         {
 926                 .procname       = "keys",
 927                 .mode           = 0555,
 928                 .child          = key_sysctls,
 929         },
 930 #endif
 931 #ifdef CONFIG_RCU_TORTURE_TEST
 932         {
 933                 .procname       = "rcutorture_runnable",
 934                 .data           = &rcutorture_runnable,
 935                 .maxlen         = sizeof(int),
 936                 .mode           = 0644,
 937                 .proc_handler   = proc_dointvec,
 938         },
 939 #endif
 940 #ifdef CONFIG_PERF_EVENTS
 941         /*
 942          * User-space scripts rely on the existence of this file
 943          * as a feature check for perf_events being enabled.
 944          *
 945          * So it's an ABI, do not remove!
 946          */
 947         {
 948                 .procname       = "perf_event_paranoid",
 949                 .data           = &sysctl_perf_event_paranoid,
 950                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 951                 .mode           = 0644,
 952                 .proc_handler   = proc_dointvec,
 953         },
 954         {
 955                 .procname       = "perf_event_mlock_kb",
 956                 .data           = &sysctl_perf_event_mlock,
 957                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 958                 .mode           = 0644,
 959                 .proc_handler   = proc_dointvec,
 960         },
 961         {
 962                 .procname       = "perf_event_max_sample_rate",
 963                 .data           = &sysctl_perf_event_sample_rate,
 964                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
 965                 .mode           = 0644,
 966                 .proc_handler   = perf_proc_update_handler,
 967         },
 968 #endif
 969 #ifdef CONFIG_KMEMCHECK
 970         {
 971                 .procname       = "kmemcheck",
 972                 .data           = &kmemcheck_enabled,
 973                 .maxlen         = sizeof(int),
 974                 .mode           = 0644,
 975                 .proc_handler   = proc_dointvec,
 976         },
 977 #endif
 978 #ifdef CONFIG_BLOCK
 979         {
 980                 .procname       = "blk_iopoll",
 981                 .data           = &blk_iopoll_enabled,
 982                 .maxlen         = sizeof(int),
 983                 .mode           = 0644,
 984                 .proc_handler   = proc_dointvec,
 985         },
 986 #endif
 987         { }
 988 };
 989
 990 static struct ctl_table vm_table[] = {
 991         {
 992                 .procname       = "overcommit_memory",
 993                 .data           = &sysctl_overcommit_memory,
 994                 .maxlen         = sizeof(sysctl_overcommit_memory),
 995                 .mode           = 0644,
 996                 .proc_handler   = proc_dointvec_minmax,
 997                 .extra1         = &zero,
 998                 .extra2         = &two,
 999         },
1000         {
1001                 .procname       = "panic_on_oom",
1002                 .data           = &sysctl_panic_on_oom,
1003                 .maxlen         = sizeof(sysctl_panic_on_oom),
1004                 .mode           = 0644,
1005                 .proc_handler   = proc_dointvec_minmax,
1006                 .extra1         = &zero,
1007                 .extra2         = &two,
1008         },
1009         {
1010                 .procname       = "oom_kill_allocating_task",
1011                 .data           = &sysctl_oom_kill_allocating_task,
1012                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1013                 .mode           = 0644,
1014                 .proc_handler   = proc_dointvec,
1015         },
1016         {
1017                 .procname       = "oom_dump_tasks",
1018                 .data           = &sysctl_oom_dump_tasks,
1019                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1020                 .mode           = 0644,
1021                 .proc_handler   = proc_dointvec,
1022         },
1023         {
1024                 .procname       = "overcommit_ratio",
1025                 .data           = &sysctl_overcommit_ratio,
1026                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1027                 .mode           = 0644,
1028                 .proc_handler   = proc_dointvec,
1029         },
1030         {
1031                 .procname       = "page-cluster",
1032                 .data           = &page_cluster,
1033                 .maxlen         = sizeof(int),
1034                 .mode           = 0644,
1035                 .proc_handler   = proc_dointvec_minmax,
1036                 .extra1         = &zero,
1037         },
1038         {
1039                 .procname       = "dirty_background_ratio",
1040                 .data           = &dirty_background_ratio,
1041                 .maxlen         = sizeof(dirty_background_ratio),
1042                 .mode           = 0644,
1043                 .proc_handler   = dirty_background_ratio_handler,
1044                 .extra1         = &zero,
1045                 .extra2         = &one_hundred,
1046         },
1047         {
1048                 .procname       = "dirty_background_bytes",
1049                 .data           = &dirty_background_bytes,
1050                 .maxlen         = sizeof(dirty_background_bytes),
1051                 .mode           = 0644,
1052                 .proc_handler   = dirty_background_bytes_handler,
1053                 .extra1         = &one_ul,
1054         },
1055         {
1056                 .procname       = "dirty_ratio",
1057                 .data           = &vm_dirty_ratio,
1058                 .maxlen         = sizeof(vm_dirty_ratio),
1059                 .mode           = 0644,
1060                 .proc_handler   = dirty_ratio_handler,
1061                 .extra1         = &zero,
1062                 .extra2         = &one_hundred,
1063         },
1064         {
1065                 .procname       = "dirty_bytes",
1066                 .data           = &vm_dirty_bytes,
1067                 .maxlen         = sizeof(vm_dirty_bytes),
1068                 .mode           = 0644,
1069                 .proc_handler   = dirty_bytes_handler,
1070                 .extra1         = &dirty_bytes_min,
1071         },
1072         {
1073                 .procname       = "dirty_writeback_centisecs",
1074                 .data           = &dirty_writeback_interval,
1075                 .maxlen         = sizeof(dirty_writeback_interval),
1076                 .mode           = 0644,
1077                 .proc_handler   = dirty_writeback_centisecs_handler,
1078         },
1079         {
1080                 .procname       = "dirty_expire_centisecs",
1081                 .data           = &dirty_expire_interval,
1082                 .maxlen         = sizeof(dirty_expire_interval),
1083                 .mode           = 0644,
1084                 .proc_handler   = proc_dointvec_minmax,
1085                 .extra1         = &zero,
1086         },
1087         {
1088                 .procname       = "nr_pdflush_threads",
1089                 .data           = &nr_pdflush_threads,
1090                 .maxlen         = sizeof nr_pdflush_threads,
1091                 .mode           = 0444 /* read-only*/,
1092                 .proc_handler   = proc_dointvec,
1093         },
1094         {
1095                 .procname       = "swappiness",
1096                 .data           = &vm_swappiness,
1097                 .maxlen         = sizeof(vm_swappiness),
1098                 .mode           = 0644,
1099                 .proc_handler   = proc_dointvec_minmax,
1100                 .extra1         = &zero,
1101                 .extra2         = &one_hundred,
1102         },
1103 #ifdef CONFIG_HUGETLB_PAGE
1104         {
1105                 .procname       = "nr_hugepages",
1106                 .data           = NULL,
1107                 .maxlen         = sizeof(unsigned long),
1108                 .mode           = 0644,
1109                 .proc_handler   = hugetlb_sysctl_handler,
1110                 .extra1         = (void *)&hugetlb_zero,
1111                 .extra2         = (void *)&hugetlb_infinity,
1112         },
1113 #ifdef CONFIG_NUMA
1114         {
1115                 .procname       = "nr_hugepages_mempolicy",
1116                 .data           = NULL,
1117                 .maxlen         = sizeof(unsigned long),
1118                 .mode           = 0644,
1119                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1120                 .extra1         = (void *)&hugetlb_zero,
1121                 .extra2         = (void *)&hugetlb_infinity,
1122         },
1123 #endif
1124          {
1125                 .procname       = "hugetlb_shm_group",
1126                 .data           = &sysctl_hugetlb_shm_group,
1127                 .maxlen         = sizeof(gid_t),
1128                 .mode           = 0644,
1129                 .proc_handler   = proc_dointvec,
1130          },
1131          {
1132                 .procname       = "hugepages_treat_as_movable",
1133                 .data           = &hugepages_treat_as_movable,
1134                 .maxlen         = sizeof(int),
1135                 .mode           = 0644,
1136                 .proc_handler   = hugetlb_treat_movable_handler,
1137         },
1138         {
1139                 .procname       = "nr_overcommit_hugepages",
1140                 .data           = NULL,
1141                 .maxlen         = sizeof(unsigned long),
1142                 .mode           = 0644,
1143                 .proc_handler   = hugetlb_overcommit_handler,
1144                 .extra1         = (void *)&hugetlb_zero,
1145                 .extra2         = (void *)&hugetlb_infinity,
1146         },
1147 #endif
1148         {
1149                 .procname       = "lowmem_reserve_ratio",
1150                 .data           = &sysctl_lowmem_reserve_ratio,
1151                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1152                 .mode           = 0644,
1153                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1154         },
1155         {
1156                 .procname       = "drop_caches",
1157                 .data           = &sysctl_drop_caches,
1158                 .maxlen         = sizeof(int),
1159                 .mode           = 0644,
1160                 .proc_handler   = drop_caches_sysctl_handler,
1161                 .extra1         = &one,
1162                 .extra2         = &three,
1163         },
1164 #ifdef CONFIG_COMPACTION
1165         {
1166                 .procname       = "compact_memory",
1167                 .data           = &sysctl_compact_memory,
1168                 .maxlen         = sizeof(int),
1169                 .mode           = 0200,
1170                 .proc_handler   = sysctl_compaction_handler,
1171         },
1172         {
1173                 .procname       = "extfrag_threshold",
1174                 .data           = &sysctl_extfrag_threshold,
1175                 .maxlen         = sizeof(int),
1176                 .mode           = 0644,
1177                 .proc_handler   = sysctl_extfrag_handler,
1178                 .extra1         = &min_extfrag_threshold,
1179                 .extra2         = &max_extfrag_threshold,
1180         },
1181
1182 #endif /* CONFIG_COMPACTION */
1183         {
1184                 .procname       = "min_free_kbytes",
1185                 .data           = &min_free_kbytes,
1186                 .maxlen         = sizeof(min_free_kbytes),
1187                 .mode           = 0644,
1188                 .proc_handler   = min_free_kbytes_sysctl_handler,
1189                 .extra1         = &zero,
1190         },
1191         {
1192                 .procname       = "percpu_pagelist_fraction",
1193                 .data           = &percpu_pagelist_fraction,
1194                 .maxlen         = sizeof(percpu_pagelist_fraction),
1195                 .mode           = 0644,
1196                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1197                 .extra1         = &min_percpu_pagelist_fract,
1198         },
1199 #ifdef CONFIG_MMU
1200         {
1201                 .procname       = "max_map_count",
1202                 .data           = &sysctl_max_map_count,
1203                 .maxlen         = sizeof(sysctl_max_map_count),
1204                 .mode           = 0644,
1205                 .proc_handler   = proc_dointvec_minmax,
1206                 .extra1         = &zero,
1207         },
1208 #else
1209         {
1210                 .procname       = "nr_trim_pages",
1211                 .data           = &sysctl_nr_trim_pages,
1212                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1213                 .mode           = 0644,
1214                 .proc_handler   = proc_dointvec_minmax,
1215                 .extra1         = &zero,
1216         },
1217 #endif
1218         {
1219                 .procname       = "laptop_mode",
1220                 .data           = &laptop_mode,
1221                 .maxlen         = sizeof(laptop_mode),
1222                 .mode           = 0644,
1223                 .proc_handler   = proc_dointvec_jiffies,
1224         },
1225         {
1226                 .procname       = "block_dump",
1227                 .data           = &block_dump,
1228                 .maxlen         = sizeof(block_dump),
1229                 .mode           = 0644,
1230                 .proc_handler   = proc_dointvec,
1231                 .extra1         = &zero,
1232         },
1233         {
1234                 .procname       = "vfs_cache_pressure",
1235                 .data           = &sysctl_vfs_cache_pressure,
1236                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1237                 .mode           = 0644,
1238                 .proc_handler   = proc_dointvec,
1239                 .extra1         = &zero,
1240         },
1241 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1242         {
1243                 .procname       = "legacy_va_layout",
1244                 .data           = &sysctl_legacy_va_layout,
1245                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1246                 .mode           = 0644,
1247                 .proc_handler   = proc_dointvec,
1248                 .extra1         = &zero,
1249         },
1250 #endif
1251 #ifdef CONFIG_NUMA
1252         {
1253                 .procname       = "zone_reclaim_mode",
1254                 .data           = &zone_reclaim_mode,
1255                 .maxlen         = sizeof(zone_reclaim_mode),
1256                 .mode           = 0644,
1257                 .proc_handler   = proc_dointvec,
1258                 .extra1         = &zero,
1259         },
1260         {
1261                 .procname       = "min_unmapped_ratio",
1262                 .data           = &sysctl_min_unmapped_ratio,
1263                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1264                 .mode           = 0644,
1265                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1266                 .extra1         = &zero,
1267                 .extra2         = &one_hundred,
1268         },
1269         {
1270                 .procname       = "min_slab_ratio",
1271                 .data           = &sysctl_min_slab_ratio,
1272                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1273                 .mode           = 0644,
1274                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1275                 .extra1         = &zero,
1276                 .extra2         = &one_hundred,
1277         },
1278 #endif
1279 #ifdef CONFIG_SMP
1280         {
1281                 .procname       = "stat_interval",
1282                 .data           = &sysctl_stat_interval,
1283                 .maxlen         = sizeof(sysctl_stat_interval),
1284                 .mode           = 0644,
1285                 .proc_handler   = proc_dointvec_jiffies,
1286         },
1287 #endif
1288 #ifdef CONFIG_MMU
1289         {
1290                 .procname       = "mmap_min_addr",
1291                 .data           = &dac_mmap_min_addr,
1292                 .maxlen         = sizeof(unsigned long),
1293                 .mode           = 0644,
1294                 .proc_handler   = mmap_min_addr_handler,
1295         },
1296 #endif
1297 #ifdef CONFIG_NUMA
1298         {
1299                 .procname       = "numa_zonelist_order",
1300                 .data           = &numa_zonelist_order,
1301                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1302                 .mode           = 0644,
1303                 .proc_handler   = numa_zonelist_order_handler,
1304         },
1305 #endif
1306 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1307    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1308         {
1309                 .procname       = "vdso_enabled",
1310                 .data           = &vdso_enabled,
1311                 .maxlen         = sizeof(vdso_enabled),
1312                 .mode           = 0644,
1313                 .proc_handler   = proc_dointvec,
1314                 .extra1         = &zero,
1315         },
1316 #endif
1317 #ifdef CONFIG_HIGHMEM
1318         {
1319                 .procname       = "highmem_is_dirtyable",
1320                 .data           = &vm_highmem_is_dirtyable,
1321                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1322                 .mode           = 0644,
1323                 .proc_handler   = proc_dointvec_minmax,
1324                 .extra1         = &zero,
1325                 .extra2         = &one,
1326         },
1327 #endif
1328         {
1329                 .procname       = "scan_unevictable_pages",
1330                 .data           = &scan_unevictable_pages,
1331                 .maxlen         = sizeof(scan_unevictable_pages),
1332                 .mode           = 0644,
1333                 .proc_handler   = scan_unevictable_handler,
1334         },
1335 #ifdef CONFIG_MEMORY_FAILURE
1336         {
1337                 .procname       = "memory_failure_early_kill",
1338                 .data           = &sysctl_memory_failure_early_kill,
1339                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1340                 .mode           = 0644,
1341                 .proc_handler   = proc_dointvec_minmax,
1342                 .extra1         = &zero,
1343                 .extra2         = &one,
1344         },
1345         {
1346                 .procname       = "memory_failure_recovery",
1347                 .data           = &sysctl_memory_failure_recovery,
1348                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1349                 .mode           = 0644,
1350                 .proc_handler   = proc_dointvec_minmax,
1351                 .extra1         = &zero,
1352                 .extra2         = &one,
1353         },
1354 #endif
1355         { }
1356 };
1357
1358 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1359 static struct ctl_table binfmt_misc_table[] = {
1360         { }
1361 };
1362 #endif
1363
1364 static struct ctl_table fs_table[] = {
1365         {
1366                 .procname       = "inode-nr",
1367                 .data           = &inodes_stat,
1368                 .maxlen         = 2*sizeof(int),
1369                 .mode           = 0444,
1370                 .proc_handler   = proc_nr_inodes,
1371         },
1372         {
1373                 .procname       = "inode-state",
1374                 .data           = &inodes_stat,
1375                 .maxlen         = 7*sizeof(int),
1376                 .mode           = 0444,
1377                 .proc_handler   = proc_nr_inodes,
1378         },
1379         {
1380                 .procname       = "file-nr",
1381                 .data           = &files_stat,
1382                 .maxlen         = sizeof(files_stat),
1383                 .mode           = 0444,
1384                 .proc_handler   = proc_nr_files,
1385         },
1386         {
1387                 .procname       = "file-max",
1388                 .data           = &files_stat.max_files,
1389                 .maxlen         = sizeof(files_stat.max_files),
1390                 .mode           = 0644,
1391                 .proc_handler   = proc_doulongvec_minmax,
1392         },
1393         {
1394                 .procname       = "nr_open",
1395                 .data           = &sysctl_nr_open,
1396                 .maxlen         = sizeof(int),
1397                 .mode           = 0644,
1398                 .proc_handler   = proc_dointvec_minmax,
1399                 .extra1         = &sysctl_nr_open_min,
1400                 .extra2         = &sysctl_nr_open_max,
1401         },
1402         {
1403                 .procname       = "dentry-state",
1404                 .data           = &dentry_stat,
1405                 .maxlen         = 6*sizeof(int),
1406                 .mode           = 0444,
1407                 .proc_handler   = proc_nr_dentry,
1408         },
1409         {
1410                 .procname       = "overflowuid",
1411                 .data           = &fs_overflowuid,
1412                 .maxlen         = sizeof(int),
1413                 .mode           = 0644,
1414                 .proc_handler   = proc_dointvec_minmax,
1415                 .extra1         = &minolduid,
1416                 .extra2         = &maxolduid,
1417         },
1418         {
1419                 .procname       = "overflowgid",
1420                 .data           = &fs_overflowgid,
1421                 .maxlen         = sizeof(int),
1422                 .mode           = 0644,
1423                 .proc_handler   = proc_dointvec_minmax,
1424                 .extra1         = &minolduid,
1425                 .extra2         = &maxolduid,
1426         },
1427 #ifdef CONFIG_FILE_LOCKING
1428         {
1429                 .procname       = "leases-enable",
1430                 .data           = &leases_enable,
1431                 .maxlen         = sizeof(int),
1432                 .mode           = 0644,
1433                 .proc_handler   = proc_dointvec,
1434         },
1435 #endif
1436 #ifdef CONFIG_DNOTIFY
1437         {
1438                 .procname       = "dir-notify-enable",
1439                 .data           = &dir_notify_enable,
1440                 .maxlen         = sizeof(int),
1441                 .mode           = 0644,
1442                 .proc_handler   = proc_dointvec,
1443         },
1444 #endif
1445 #ifdef CONFIG_MMU
1446 #ifdef CONFIG_FILE_LOCKING
1447         {
1448                 .procname       = "lease-break-time",
1449                 .data           = &lease_break_time,
1450                 .maxlen         = sizeof(int),
1451                 .mode           = 0644,
1452                 .proc_handler   = proc_dointvec,
1453         },
1454 #endif
1455 #ifdef CONFIG_AIO
1456         {
1457                 .procname       = "aio-nr",
1458                 .data           = &aio_nr,
1459                 .maxlen         = sizeof(aio_nr),
1460                 .mode           = 0444,
1461                 .proc_handler   = proc_doulongvec_minmax,
1462         },
1463         {
1464                 .procname       = "aio-max-nr",
1465                 .data           = &aio_max_nr,
1466                 .maxlen         = sizeof(aio_max_nr),
1467                 .mode           = 0644,
1468                 .proc_handler   = proc_doulongvec_minmax,
1469         },
1470 #endif /* CONFIG_AIO */
1471 #ifdef CONFIG_INOTIFY_USER
1472         {
1473                 .procname       = "inotify",
1474                 .mode           = 0555,
1475                 .child          = inotify_table,
1476         },
1477 #endif
1478 #ifdef CONFIG_EPOLL
1479         {
1480                 .procname       = "epoll",
1481                 .mode           = 0555,
1482                 .child          = epoll_table,
1483         },
1484 #endif
1485 #endif
1486         {
1487                 .procname       = "suid_dumpable",
1488                 .data           = &suid_dumpable,
1489                 .maxlen         = sizeof(int),
1490                 .mode           = 0644,
1491                 .proc_handler   = proc_dointvec_minmax,
1492                 .extra1         = &zero,
1493                 .extra2         = &two,
1494         },
1495 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1496         {
1497                 .procname       = "binfmt_misc",
1498                 .mode           = 0555,
1499                 .child          = binfmt_misc_table,
1500         },
1501 #endif
1502         {
1503                 .procname       = "pipe-max-size",
1504                 .data           = &pipe_max_size,
1505                 .maxlen         = sizeof(int),
1506                 .mode           = 0644,
1507                 .proc_handler   = &pipe_proc_fn,
1508                 .extra1         = &pipe_min_size,
1509         },
1510         { }
1511 };
1512
1513 static struct ctl_table debug_table[] = {
1514 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1515     defined(CONFIG_S390) || defined(CONFIG_TILE)
1516         {
1517                 .procname       = "exception-trace",
1518                 .data           = &show_unhandled_signals,
1519                 .maxlen         = sizeof(int),
1520                 .mode           = 0644,
1521                 .proc_handler   = proc_dointvec
1522         },
1523 #endif
1524 #if defined(CONFIG_OPTPROBES)
1525         {
1526                 .procname       = "kprobes-optimization",
1527                 .data           = &sysctl_kprobes_optimization,
1528                 .maxlen         = sizeof(int),
1529                 .mode           = 0644,
1530                 .proc_handler   = proc_kprobes_optimization_handler,
1531                 .extra1         = &zero,
1532                 .extra2         = &one,
1533         },
1534 #endif
1535         { }
1536 };
1537
1538 static struct ctl_table dev_table[] = {
1539         { }
1540 };
1541
1542 static DEFINE_SPINLOCK(sysctl_lock);
1543
1544 /* called under sysctl_lock */
1545 static int use_table(struct ctl_table_header *p)
1546 {
1547         if (unlikely(p->unregistering))
1548                 return 0;
1549         p->used++;
1550         return 1;
1551 }
1552
1553 /* called under sysctl_lock */
1554 static void unuse_table(struct ctl_table_header *p)
1555 {
1556         if (!--p->used)
1557                 if (unlikely(p->unregistering))
1558                         complete(p->unregistering);
1559 }
1560
1561 /* called under sysctl_lock, will reacquire if has to wait */
1562 static void start_unregistering(struct ctl_table_header *p)
1563 {
1564         /*
1565          * if p->used is 0, nobody will ever touch that entry again;
1566          * we'll eliminate all paths to it before dropping sysctl_lock
1567          */
1568         if (unlikely(p->used)) {
1569                 struct completion wait;
1570                 init_completion(&wait);
1571                 p->unregistering = &wait;
1572                 spin_unlock(&sysctl_lock);
1573                 wait_for_completion(&wait);
1574                 spin_lock(&sysctl_lock);
1575         } else {
1576                 /* anything non-NULL; we'll never dereference it */
1577                 p->unregistering = ERR_PTR(-EINVAL);
1578         }
1579         /*
1580          * do not remove from the list until nobody holds it; walking the
1581          * list in do_sysctl() relies on that.
1582          */
1583         list_del_init(&p->ctl_entry);
1584 }
1585
1586 void sysctl_head_get(struct ctl_table_header *head)
1587 {
1588         spin_lock(&sysctl_lock);
1589         head->count++;
1590         spin_unlock(&sysctl_lock);
1591 }
1592
1593 void sysctl_head_put(struct ctl_table_header *head)
1594 {
1595         spin_lock(&sysctl_lock);
1596         if (!--head->count)
1597                 kfree_rcu(head, rcu);
1598         spin_unlock(&sysctl_lock);
1599 }
1600
1601 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1602 {
1603         if (!head)
1604                 BUG();
1605         spin_lock(&sysctl_lock);
1606         if (!use_table(head))
1607                 head = ERR_PTR(-ENOENT);
1608         spin_unlock(&sysctl_lock);
1609         return head;
1610 }
1611
1612 void sysctl_head_finish(struct ctl_table_header *head)
1613 {
1614         if (!head)
1615                 return;
1616         spin_lock(&sysctl_lock);
1617         unuse_table(head);
1618         spin_unlock(&sysctl_lock);
1619 }
1620
1621 static struct ctl_table_set *
1622 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1623 {
1624         struct ctl_table_set *set = &root->default_set;
1625         if (root->lookup)
1626                 set = root->lookup(root, namespaces);
1627         return set;
1628 }
1629
1630 static struct list_head *
1631 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1632 {
1633         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1634         return &set->list;
1635 }
1636
1637 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1638                                             struct ctl_table_header *prev)
1639 {
1640         struct ctl_table_root *root;
1641         struct list_head *header_list;
1642         struct ctl_table_header *head;
1643         struct list_head *tmp;
1644
1645         spin_lock(&sysctl_lock);
1646         if (prev) {
1647                 head = prev;
1648                 tmp = &prev->ctl_entry;
1649                 unuse_table(prev);
1650                 goto next;
1651         }
1652         tmp = &root_table_header.ctl_entry;
1653         for (;;) {
1654                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1655
1656                 if (!use_table(head))
1657                         goto next;
1658                 spin_unlock(&sysctl_lock);
1659                 return head;
1660         next:
1661                 root = head->root;
1662                 tmp = tmp->next;
1663                 header_list = lookup_header_list(root, namespaces);
1664                 if (tmp != header_list)
1665                         continue;
1666
1667                 do {
1668                         root = list_entry(root->root_list.next,
1669                                         struct ctl_table_root, root_list);
1670                         if (root == &sysctl_table_root)
1671                                 goto out;
1672                         header_list = lookup_header_list(root, namespaces);
1673                 } while (list_empty(header_list));
1674                 tmp = header_list->next;
1675         }
1676 out:
1677         spin_unlock(&sysctl_lock);
1678         return NULL;
1679 }
1680
1681 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1682 {
1683         return __sysctl_head_next(current->nsproxy, prev);
1684 }
1685
1686 void register_sysctl_root(struct ctl_table_root *root)
1687 {
1688         spin_lock(&sysctl_lock);
1689         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1690         spin_unlock(&sysctl_lock);
1691 }
1692
1693 /*
1694  * sysctl_perm does NOT grant the superuser all rights automatically, because
1695  * some sysctl variables are readonly even to root.
1696  */
1697
1698 static int test_perm(int mode, int op)
1699 {
1700         if (!current_euid())
1701                 mode >>= 6;
1702         else if (in_egroup_p(0))
1703                 mode >>= 3;
1704         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1705                 return 0;
1706         return -EACCES;
1707 }
1708
1709 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1710 {
1711         int mode;
1712
1713         if (root->permissions)
1714                 mode = root->permissions(root, current->nsproxy, table);
1715         else
1716                 mode = table->mode;
1717
1718         return test_perm(mode, op);
1719 }
1720
1721 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1722 {
1723         for (; table->procname; table++) {
1724                 table->parent = parent;
1725                 if (table->child)
1726                         sysctl_set_parent(table, table->child);
1727         }
1728 }
1729
1730 static __init int sysctl_init(void)
1731 {
1732         sysctl_set_parent(NULL, root_table);
1733 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1734         sysctl_check_table(current->nsproxy, root_table);
1735 #endif
1736         return 0;
1737 }
1738
1739 core_initcall(sysctl_init);
1740
1741 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1742                                       struct ctl_table *table)
1743 {
1744         struct ctl_table *p;
1745         const char *s = branch->procname;
1746
1747         /* branch should have named subdirectory as its first element */
1748         if (!s || !branch->child)
1749                 return NULL;
1750
1751         /* ... and nothing else */
1752         if (branch[1].procname)
1753                 return NULL;
1754
1755         /* table should contain subdirectory with the same name */
1756         for (p = table; p->procname; p++) {
1757                 if (!p->child)
1758                         continue;
1759                 if (p->procname && strcmp(p->procname, s) == 0)
1760                         return p;
1761         }
1762         return NULL;
1763 }
1764
1765 /* see if attaching q to p would be an improvement */
1766 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1767 {
1768         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1769         struct ctl_table *next;
1770         int is_better = 0;
1771         int not_in_parent = !p->attached_by;
1772
1773         while ((next = is_branch_in(by, to)) != NULL) {
1774                 if (by == q->attached_by)
1775                         is_better = 1;
1776                 if (to == p->attached_by)
1777                         not_in_parent = 1;
1778                 by = by->child;
1779                 to = next->child;
1780         }
1781
1782         if (is_better && not_in_parent) {
1783                 q->attached_by = by;
1784                 q->attached_to = to;
1785                 q->parent = p;
1786         }
1787 }
1788
1789 /**
1790  * __register_sysctl_paths - register a sysctl hierarchy
1791  * @root: List of sysctl headers to register on
1792  * @namespaces: Data to compute which lists of sysctl entries are visible
1793  * @path: The path to the directory the sysctl table is in.
1794  * @table: the top-level table structure
1795  *
1796  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1797  * array. A completely 0 filled entry terminates the table.
1798  *
1799  * The members of the &struct ctl_table structure are used as follows:
1800  *
1801  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1802  *            enter a sysctl file
1803  *
1804  * data - a pointer to data for use by proc_handler
1805  *
1806  * maxlen - the maximum size in bytes of the data
1807  *
1808  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1809  *
1810  * child - a pointer to the child sysctl table if this entry is a directory, or
1811  *         %NULL.
1812  *
1813  * proc_handler - the text handler routine (described below)
1814  *
1815  * de - for internal use by the sysctl routines
1816  *
1817  * extra1, extra2 - extra pointers usable by the proc handler routines
1818  *
1819  * Leaf nodes in the sysctl tree will be represented by a single file
1820  * under /proc; non-leaf nodes will be represented by directories.
1821  *
1822  * sysctl(2) can automatically manage read and write requests through
1823  * the sysctl table.  The data and maxlen fields of the ctl_table
1824  * struct enable minimal validation of the values being written to be
1825  * performed, and the mode field allows minimal authentication.
1826  *
1827  * There must be a proc_handler routine for any terminal nodes
1828  * mirrored under /proc/sys (non-terminals are handled by a built-in
1829  * directory handler).  Several default handlers are available to
1830  * cover common cases -
1831  *
1832  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1833  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1834  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1835  *
1836  * It is the handler's job to read the input buffer from user memory
1837  * and process it. The handler should return 0 on success.
1838  *
1839  * This routine returns %NULL on a failure to register, and a pointer
1840  * to the table header on success.
1841  */
1842 struct ctl_table_header *__register_sysctl_paths(
1843         struct ctl_table_root *root,
1844         struct nsproxy *namespaces,
1845         const struct ctl_path *path, struct ctl_table *table)
1846 {
1847         struct ctl_table_header *header;
1848         struct ctl_table *new, **prevp;
1849         unsigned int n, npath;
1850         struct ctl_table_set *set;
1851
1852         /* Count the path components */
1853         for (npath = 0; path[npath].procname; ++npath)
1854                 ;
1855
1856         /*
1857          * For each path component, allocate a 2-element ctl_table array.
1858          * The first array element will be filled with the sysctl entry
1859          * for this, the second will be the sentinel (procname == 0).
1860          *
1861          * We allocate everything in one go so that we don't have to
1862          * worry about freeing additional memory in unregister_sysctl_table.
1863          */
1864         header = kzalloc(sizeof(struct ctl_table_header) +
1865                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1866         if (!header)
1867                 return NULL;
1868
1869         new = (struct ctl_table *) (header + 1);
1870
1871         /* Now connect the dots */
1872         prevp = &header->ctl_table;
1873         for (n = 0; n < npath; ++n, ++path) {
1874                 /* Copy the procname */
1875                 new->procname = path->procname;
1876                 new->mode     = 0555;
1877
1878                 *prevp = new;
1879                 prevp = &new->child;
1880
1881                 new += 2;
1882         }
1883         *prevp = table;
1884         header->ctl_table_arg = table;
1885
1886         INIT_LIST_HEAD(&header->ctl_entry);
1887         header->used = 0;
1888         header->unregistering = NULL;
1889         header->root = root;
1890         sysctl_set_parent(NULL, header->ctl_table);
1891         header->count = 1;
1892 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1893         if (sysctl_check_table(namespaces, header->ctl_table)) {
1894                 kfree(header);
1895                 return NULL;
1896         }
1897 #endif
1898         spin_lock(&sysctl_lock);
1899         header->set = lookup_header_set(root, namespaces);
1900         header->attached_by = header->ctl_table;
1901         header->attached_to = root_table;
1902         header->parent = &root_table_header;
1903         for (set = header->set; set; set = set->parent) {
1904                 struct ctl_table_header *p;
1905                 list_for_each_entry(p, &set->list, ctl_entry) {
1906                         if (p->unregistering)
1907                                 continue;
1908                         try_attach(p, header);
1909                 }
1910         }
1911         header->parent->count++;
1912         list_add_tail(&header->ctl_entry, &header->set->list);
1913         spin_unlock(&sysctl_lock);
1914
1915         return header;
1916 }
1917
1918 /**
1919  * register_sysctl_table_path - register a sysctl table hierarchy
1920  * @path: The path to the directory the sysctl table is in.
1921  * @table: the top-level table structure
1922  *
1923  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1924  * array. A completely 0 filled entry terminates the table.
1925  *
1926  * See __register_sysctl_paths for more details.
1927  */
1928 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1929                                                 struct ctl_table *table)
1930 {
1931         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1932                                         path, table);
1933 }
1934
1935 /**
1936  * register_sysctl_table - register a sysctl table hierarchy
1937  * @table: the top-level table structure
1938  *
1939  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1940  * array. A completely 0 filled entry terminates the table.
1941  *
1942  * See register_sysctl_paths for more details.
1943  */
1944 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1945 {
1946         static const struct ctl_path null_path[] = { {} };
1947
1948         return register_sysctl_paths(null_path, table);
1949 }
1950
1951 /**
1952  * unregister_sysctl_table - unregister a sysctl table hierarchy
1953  * @header: the header returned from register_sysctl_table
1954  *
1955  * Unregisters the sysctl table and all children. proc entries may not
1956  * actually be removed until they are no longer used by anyone.
1957  */
1958 void unregister_sysctl_table(struct ctl_table_header * header)
1959 {
1960         might_sleep();
1961
1962         if (header == NULL)
1963                 return;
1964
1965         spin_lock(&sysctl_lock);
1966         start_unregistering(header);
1967         if (!--header->parent->count) {
1968                 WARN_ON(1);
1969                 kfree_rcu(header->parent, rcu);
1970         }
1971         if (!--header->count)
1972                 kfree_rcu(header, rcu);
1973         spin_unlock(&sysctl_lock);
1974 }
1975
1976 int sysctl_is_seen(struct ctl_table_header *p)
1977 {
1978         struct ctl_table_set *set = p->set;
1979         int res;
1980         spin_lock(&sysctl_lock);
1981         if (p->unregistering)
1982                 res = 0;
1983         else if (!set->is_seen)
1984                 res = 1;
1985         else
1986                 res = set->is_seen(set);
1987         spin_unlock(&sysctl_lock);
1988         return res;
1989 }
1990
1991 void setup_sysctl_set(struct ctl_table_set *p,
1992         struct ctl_table_set *parent,
1993         int (*is_seen)(struct ctl_table_set *))
1994 {
1995         INIT_LIST_HEAD(&p->list);
1996         p->parent = parent ? parent : &sysctl_table_root.default_set;
1997         p->is_seen = is_seen;
1998 }
1999
2000 #else /* !CONFIG_SYSCTL */
2001 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2002 {
2003         return NULL;
2004 }
2005
2006 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2007                                                     struct ctl_table *table)
2008 {
2009         return NULL;
2010 }
2011
2012 void unregister_sysctl_table(struct ctl_table_header * table)
2013 {
2014 }
2015
2016 void setup_sysctl_set(struct ctl_table_set *p,
2017         struct ctl_table_set *parent,
2018         int (*is_seen)(struct ctl_table_set *))
2019 {
2020 }
2021
2022 void sysctl_head_put(struct ctl_table_header *head)
2023 {
2024 }
2025
2026 #endif /* CONFIG_SYSCTL */
2027
2028 /*
2029  * /proc/sys support
2030  */
2031
2032 #ifdef CONFIG_PROC_SYSCTL
2033
2034 static int _proc_do_string(void* data, int maxlen, int write,
2035                            void __user *buffer,
2036                            size_t *lenp, loff_t *ppos)
2037 {
2038         size_t len;
2039         char __user *p;
2040         char c;
2041
2042         if (!data || !maxlen || !*lenp) {
2043                 *lenp = 0;
2044                 return 0;
2045         }
2046
2047         if (write) {
2048                 len = 0;
2049                 p = buffer;
2050                 while (len < *lenp) {
2051                         if (get_user(c, p++))
2052                                 return -EFAULT;
2053                         if (c == 0 || c == '\n')
2054                                 break;
2055                         len++;
2056                 }
2057                 if (len >= maxlen)
2058                         len = maxlen-1;
2059                 if(copy_from_user(data, buffer, len))
2060                         return -EFAULT;
2061                 ((char *) data)[len] = 0;
2062                 *ppos += *lenp;
2063         } else {
2064                 len = strlen(data);
2065                 if (len > maxlen)
2066                         len = maxlen;
2067
2068                 if (*ppos > len) {
2069                         *lenp = 0;
2070                         return 0;
2071                 }
2072
2073                 data += *ppos;
2074                 len  -= *ppos;
2075
2076                 if (len > *lenp)
2077                         len = *lenp;
2078                 if (len)
2079                         if(copy_to_user(buffer, data, len))
2080                                 return -EFAULT;
2081                 if (len < *lenp) {
2082                         if(put_user('\n', ((char __user *) buffer) + len))
2083                                 return -EFAULT;
2084                         len++;
2085                 }
2086                 *lenp = len;
2087                 *ppos += len;
2088         }
2089         return 0;
2090 }
2091
2092 /**
2093  * proc_dostring - read a string sysctl
2094  * @table: the sysctl table
2095  * @write: %TRUE if this is a write to the sysctl file
2096  * @buffer: the user buffer
2097  * @lenp: the size of the user buffer
2098  * @ppos: file position
2099  *
2100  * Reads/writes a string from/to the user buffer. If the kernel
2101  * buffer provided is not large enough to hold the string, the
2102  * string is truncated. The copied string is %NULL-terminated.
2103  * If the string is being read by the user process, it is copied
2104  * and a newline '\n' is added. It is truncated if the buffer is
2105  * not large enough.
2106  *
2107  * Returns 0 on success.
2108  */
2109 int proc_dostring(struct ctl_table *table, int write,
2110                   void __user *buffer, size_t *lenp, loff_t *ppos)
2111 {
2112         return _proc_do_string(table->data, table->maxlen, write,
2113                                buffer, lenp, ppos);
2114 }
2115
2116 static size_t proc_skip_spaces(char **buf)
2117 {
2118         size_t ret;
2119         char *tmp = skip_spaces(*buf);
2120         ret = tmp - *buf;
2121         *buf = tmp;
2122         return ret;
2123 }
2124
2125 static void proc_skip_char(char **buf, size_t *size, const char v)
2126 {
2127         while (*size) {
2128                 if (**buf != v)
2129                         break;
2130                 (*size)--;
2131                 (*buf)++;
2132         }
2133 }
2134
2135 #define TMPBUFLEN 22
2136 /**
2137  * proc_get_long - reads an ASCII formatted integer from a user buffer
2138  *
2139  * @buf: a kernel buffer
2140  * @size: size of the kernel buffer
2141  * @val: this is where the number will be stored
2142  * @neg: set to %TRUE if number is negative
2143  * @perm_tr: a vector which contains the allowed trailers
2144  * @perm_tr_len: size of the perm_tr vector
2145  * @tr: pointer to store the trailer character
2146  *
2147  * In case of success %0 is returned and @buf and @size are updated with
2148  * the amount of bytes read. If @tr is non-NULL and a trailing
2149  * character exists (size is non-zero after returning from this
2150  * function), @tr is updated with the trailing character.
2151  */
2152 static int proc_get_long(char **buf, size_t *size,
2153                           unsigned long *val, bool *neg,
2154                           const char *perm_tr, unsigned perm_tr_len, char *tr)
2155 {
2156         int len;
2157         char *p, tmp[TMPBUFLEN];
2158
2159         if (!*size)
2160                 return -EINVAL;
2161
2162         len = *size;
2163         if (len > TMPBUFLEN - 1)
2164                 len = TMPBUFLEN - 1;
2165
2166         memcpy(tmp, *buf, len);
2167
2168         tmp[len] = 0;
2169         p = tmp;
2170         if (*p == '-' && *size > 1) {
2171                 *neg = true;
2172                 p++;
2173         } else
2174                 *neg = false;
2175         if (!isdigit(*p))
2176                 return -EINVAL;
2177
2178         *val = simple_strtoul(p, &p, 0);
2179
2180         len = p - tmp;
2181
2182         /* We don't know if the next char is whitespace thus we may accept
2183          * invalid integers (e.g. 1234...a) or two integers instead of one
2184          * (e.g. 123...1). So lets not allow such large numbers. */
2185         if (len == TMPBUFLEN - 1)
2186                 return -EINVAL;
2187
2188         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2189                 return -EINVAL;
2190
2191         if (tr && (len < *size))
2192                 *tr = *p;
2193
2194         *buf += len;
2195         *size -= len;
2196
2197         return 0;
2198 }
2199
2200 /**
2201  * proc_put_long - converts an integer to a decimal ASCII formatted string
2202  *
2203  * @buf: the user buffer
2204  * @size: the size of the user buffer
2205  * @val: the integer to be converted
2206  * @neg: sign of the number, %TRUE for negative
2207  *
2208  * In case of success %0 is returned and @buf and @size are updated with
2209  * the amount of bytes written.
2210  */
2211 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2212                           bool neg)
2213 {
2214         int len;
2215         char tmp[TMPBUFLEN], *p = tmp;
2216
2217         sprintf(p, "%s%lu", neg ? "-" : "", val);
2218         len = strlen(tmp);
2219         if (len > *size)
2220                 len = *size;
2221         if (copy_to_user(*buf, tmp, len))
2222                 return -EFAULT;
2223         *size -= len;
2224         *buf += len;
2225         return 0;
2226 }
2227 #undef TMPBUFLEN
2228
2229 static int proc_put_char(void __user **buf, size_t *size, char c)
2230 {
2231         if (*size) {
2232                 char __user **buffer = (char __user **)buf;
2233                 if (put_user(c, *buffer))
2234                         return -EFAULT;
2235                 (*size)--, (*buffer)++;
2236                 *buf = *buffer;
2237         }
2238         return 0;
2239 }
2240
2241 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2242                                  int *valp,
2243                                  int write, void *data)
2244 {
2245         if (write) {
2246                 *valp = *negp ? -*lvalp : *lvalp;
2247         } else {
2248                 int val = *valp;
2249                 if (val < 0) {
2250                         *negp = true;
2251                         *lvalp = (unsigned long)-val;
2252                 } else {
2253                         *negp = false;
2254                         *lvalp = (unsigned long)val;
2255                 }
2256         }
2257         return 0;
2258 }
2259
2260 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2261
2262 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2263                   int write, void __user *buffer,
2264                   size_t *lenp, loff_t *ppos,
2265                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2266                               int write, void *data),
2267                   void *data)
2268 {
2269         int *i, vleft, first = 1, err = 0;
2270         unsigned long page = 0;
2271         size_t left;
2272         char *kbuf;
2273
2274         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2275                 *lenp = 0;
2276                 return 0;
2277         }
2278
2279         i = (int *) tbl_data;
2280         vleft = table->maxlen / sizeof(*i);
2281         left = *lenp;
2282
2283         if (!conv)
2284                 conv = do_proc_dointvec_conv;
2285
2286         if (write) {
2287                 if (left > PAGE_SIZE - 1)
2288                         left = PAGE_SIZE - 1;
2289                 page = __get_free_page(GFP_TEMPORARY);
2290                 kbuf = (char *) page;
2291                 if (!kbuf)
2292                         return -ENOMEM;
2293                 if (copy_from_user(kbuf, buffer, left)) {
2294                         err = -EFAULT;
2295                         goto free;
2296                 }
2297                 kbuf[left] = 0;
2298         }
2299
2300         for (; left && vleft--; i++, first=0) {
2301                 unsigned long lval;
2302                 bool neg;
2303
2304                 if (write) {
2305                         left -= proc_skip_spaces(&kbuf);
2306
2307                         if (!left)
2308                                 break;
2309                         err = proc_get_long(&kbuf, &left, &lval, &neg,
2310                                              proc_wspace_sep,
2311                                              sizeof(proc_wspace_sep), NULL);
2312                         if (err)
2313                                 break;
2314                         if (conv(&neg, &lval, i, 1, data)) {
2315                                 err = -EINVAL;
2316                                 break;
2317                         }
2318                 } else {
2319                         if (conv(&neg, &lval, i, 0, data)) {
2320                                 err = -EINVAL;
2321                                 break;
2322                         }
2323                         if (!first)
2324                                 err = proc_put_char(&buffer, &left, '\t');
2325                         if (err)
2326                                 break;
2327                         err = proc_put_long(&buffer, &left, lval, neg);
2328                         if (err)
2329                                 break;
2330                 }
2331         }
2332
2333         if (!write && !first && left && !err)
2334                 err = proc_put_char(&buffer, &left, '\n');
2335         if (write && !err && left)
2336                 left -= proc_skip_spaces(&kbuf);
2337 free:
2338         if (write) {
2339                 free_page(page);
2340                 if (first)
2341                         return err ? : -EINVAL;
2342         }
2343         *lenp -= left;
2344         *ppos += *lenp;
2345         return err;
2346 }
2347
2348 static int do_proc_dointvec(struct ctl_table *table, int write,
2349                   void __user *buffer, size_t *lenp, loff_t *ppos,
2350                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2351                               int write, void *data),
2352                   void *data)
2353 {
2354         return __do_proc_dointvec(table->data, table, write,
2355                         buffer, lenp, ppos, conv, data);
2356 }
2357
2358 /**
2359  * proc_dointvec - read a vector of integers
2360  * @table: the sysctl table
2361  * @write: %TRUE if this is a write to the sysctl file
2362  * @buffer: the user buffer
2363  * @lenp: the size of the user buffer
2364  * @ppos: file position
2365  *
2366  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2367  * values from/to the user buffer, treated as an ASCII string.
2368  *
2369  * Returns 0 on success.
2370  */
2371 int proc_dointvec(struct ctl_table *table, int write,
2372                      void __user *buffer, size_t *lenp, loff_t *ppos)
2373 {
2374     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2375                             NULL,NULL);
2376 }
2377
2378 /*
2379  * Taint values can only be increased
2380  * This means we can safely use a temporary.
2381  */
2382 static int proc_taint(struct ctl_table *table, int write,
2383                                void __user *buffer, size_t *lenp, loff_t *ppos)
2384 {
2385         struct ctl_table t;
2386         unsigned long tmptaint = get_taint();
2387         int err;
2388
2389         if (write && !capable(CAP_SYS_ADMIN))
2390                 return -EPERM;
2391
2392         t = *table;
2393         t.data = &tmptaint;
2394         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2395         if (err < 0)
2396                 return err;
2397
2398         if (write) {
2399                 /*
2400                  * Poor man's atomic or. Not worth adding a primitive
2401                  * to everyone's atomic.h for this
2402                  */
2403                 int i;
2404                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2405                         if ((tmptaint >> i) & 1)
2406                                 add_taint(i);
2407                 }
2408         }
2409
2410         return err;
2411 }
2412
2413 #ifdef CONFIG_PRINTK
2414 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2415                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2416 {
2417         if (write && !capable(CAP_SYS_ADMIN))
2418                 return -EPERM;
2419
2420         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2421 }
2422 #endif
2423
2424 struct do_proc_dointvec_minmax_conv_param {
2425         int *min;
2426         int *max;
2427 };
2428
2429 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2430                                         int *valp,
2431                                         int write, void *data)
2432 {
2433         struct do_proc_dointvec_minmax_conv_param *param = data;
2434         if (write) {
2435                 int val = *negp ? -*lvalp : *lvalp;
2436                 if ((param->min && *param->min > val) ||
2437                     (param->max && *param->max < val))
2438                         return -EINVAL;
2439                 *valp = val;
2440         } else {
2441                 int val = *valp;
2442                 if (val < 0) {
2443                         *negp = true;
2444                         *lvalp = (unsigned long)-val;
2445                 } else {
2446                         *negp = false;
2447                         *lvalp = (unsigned long)val;
2448                 }
2449         }
2450         return 0;
2451 }
2452
2453 /**
2454  * proc_dointvec_minmax - read a vector of integers with min/max values
2455  * @table: the sysctl table
2456  * @write: %TRUE if this is a write to the sysctl file
2457  * @buffer: the user buffer
2458  * @lenp: the size of the user buffer
2459  * @ppos: file position
2460  *
2461  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2462  * values from/to the user buffer, treated as an ASCII string.
2463  *
2464  * This routine will ensure the values are within the range specified by
2465  * table->extra1 (min) and table->extra2 (max).
2466  *
2467  * Returns 0 on success.
2468  */
2469 int proc_dointvec_minmax(struct ctl_table *table, int write,
2470                   void __user *buffer, size_t *lenp, loff_t *ppos)
2471 {
2472         struct do_proc_dointvec_minmax_conv_param param = {
2473                 .min = (int *) table->extra1,
2474                 .max = (int *) table->extra2,
2475         };
2476         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2477                                 do_proc_dointvec_minmax_conv, &param);
2478 }
2479
2480 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2481                                      void __user *buffer,
2482                                      size_t *lenp, loff_t *ppos,
2483                                      unsigned long convmul,
2484                                      unsigned long convdiv)
2485 {
2486         unsigned long *i, *min, *max;
2487         int vleft, first = 1, err = 0;
2488         unsigned long page = 0;
2489         size_t left;
2490         char *kbuf;
2491
2492         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2493                 *lenp = 0;
2494                 return 0;
2495         }
2496
2497         i = (unsigned long *) data;
2498         min = (unsigned long *) table->extra1;
2499         max = (unsigned long *) table->extra2;
2500         vleft = table->maxlen / sizeof(unsigned long);
2501         left = *lenp;
2502
2503         if (write) {
2504                 if (left > PAGE_SIZE - 1)
2505                         left = PAGE_SIZE - 1;
2506                 page = __get_free_page(GFP_TEMPORARY);
2507                 kbuf = (char *) page;
2508                 if (!kbuf)
2509                         return -ENOMEM;
2510                 if (copy_from_user(kbuf, buffer, left)) {
2511                         err = -EFAULT;
2512                         goto free;
2513                 }
2514                 kbuf[left] = 0;
2515         }
2516
2517         for (; left && vleft--; i++, first = 0) {
2518                 unsigned long val;
2519
2520                 if (write) {
2521                         bool neg;
2522
2523                         left -= proc_skip_spaces(&kbuf);
2524
2525                         err = proc_get_long(&kbuf, &left, &val, &neg,
2526                                              proc_wspace_sep,
2527                                              sizeof(proc_wspace_sep), NULL);
2528                         if (err)
2529                                 break;
2530                         if (neg)
2531                                 continue;
2532                         if ((min && val < *min) || (max && val > *max))
2533                                 continue;
2534                         *i = val;
2535                 } else {
2536                         val = convdiv * (*i) / convmul;
2537                         if (!first)
2538                                 err = proc_put_char(&buffer, &left, '\t');
2539                         err = proc_put_long(&buffer, &left, val, false);
2540                         if (err)
2541                                 break;
2542                 }
2543         }
2544
2545         if (!write && !first && left && !err)
2546                 err = proc_put_char(&buffer, &left, '\n');
2547         if (write && !err)
2548                 left -= proc_skip_spaces(&kbuf);
2549 free:
2550         if (write) {
2551                 free_page(page);
2552                 if (first)
2553                         return err ? : -EINVAL;
2554         }
2555         *lenp -= left;
2556         *ppos += *lenp;
2557         return err;
2558 }
2559
2560 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2561                                      void __user *buffer,
2562                                      size_t *lenp, loff_t *ppos,
2563                                      unsigned long convmul,
2564                                      unsigned long convdiv)
2565 {
2566         return __do_proc_doulongvec_minmax(table->data, table, write,
2567                         buffer, lenp, ppos, convmul, convdiv);
2568 }
2569
2570 /**
2571  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2572  * @table: the sysctl table
2573  * @write: %TRUE if this is a write to the sysctl file
2574  * @buffer: the user buffer
2575  * @lenp: the size of the user buffer
2576  * @ppos: file position
2577  *
2578  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2579  * values from/to the user buffer, treated as an ASCII string.
2580  *
2581  * This routine will ensure the values are within the range specified by
2582  * table->extra1 (min) and table->extra2 (max).
2583  *
2584  * Returns 0 on success.
2585  */
2586 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2587                            void __user *buffer, size_t *lenp, loff_t *ppos)
2588 {
2589     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2590 }
2591
2592 /**
2593  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2594  * @table: the sysctl table
2595  * @write: %TRUE if this is a write to the sysctl file
2596  * @buffer: the user buffer
2597  * @lenp: the size of the user buffer
2598  * @ppos: file position
2599  *
2600  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2601  * values from/to the user buffer, treated as an ASCII string. The values
2602  * are treated as milliseconds, and converted to jiffies when they are stored.
2603  *
2604  * This routine will ensure the values are within the range specified by
2605  * table->extra1 (min) and table->extra2 (max).
2606  *
2607  * Returns 0 on success.
2608  */
2609 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2610                                       void __user *buffer,
2611                                       size_t *lenp, loff_t *ppos)
2612 {
2613     return do_proc_doulongvec_minmax(table, write, buffer,
2614                                      lenp, ppos, HZ, 1000l);
2615 }
2616
2617
2618 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2619                                          int *valp,
2620                                          int write, void *data)
2621 {
2622         if (write) {
2623                 if (*lvalp > LONG_MAX / HZ)
2624                         return 1;
2625                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2626         } else {
2627                 int val = *valp;
2628                 unsigned long lval;
2629                 if (val < 0) {
2630                         *negp = true;
2631                         lval = (unsigned long)-val;
2632                 } else {
2633                         *negp = false;
2634                         lval = (unsigned long)val;
2635                 }
2636                 *lvalp = lval / HZ;
2637         }
2638         return 0;
2639 }
2640
2641 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2642                                                 int *valp,
2643                                                 int write, void *data)
2644 {
2645         if (write) {
2646                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2647                         return 1;
2648                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2649         } else {
2650                 int val = *valp;
2651                 unsigned long lval;
2652                 if (val < 0) {
2653                         *negp = true;
2654                         lval = (unsigned long)-val;
2655                 } else {
2656                         *negp = false;
2657                         lval = (unsigned long)val;
2658                 }
2659                 *lvalp = jiffies_to_clock_t(lval);
2660         }
2661         return 0;
2662 }
2663
2664 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2665                                             int *valp,
2666                                             int write, void *data)
2667 {
2668         if (write) {
2669                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2670         } else {
2671                 int val = *valp;
2672                 unsigned long lval;
2673                 if (val < 0) {
2674                         *negp = true;
2675                         lval = (unsigned long)-val;
2676                 } else {
2677                         *negp = false;
2678                         lval = (unsigned long)val;
2679                 }
2680                 *lvalp = jiffies_to_msecs(lval);
2681         }
2682         return 0;
2683 }
2684
2685 /**
2686  * proc_dointvec_jiffies - read a vector of integers as seconds
2687  * @table: the sysctl table
2688  * @write: %TRUE if this is a write to the sysctl file
2689  * @buffer: the user buffer
2690  * @lenp: the size of the user buffer
2691  * @ppos: file position
2692  *
2693  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2694  * values from/to the user buffer, treated as an ASCII string.
2695  * The values read are assumed to be in seconds, and are converted into
2696  * jiffies.
2697  *
2698  * Returns 0 on success.
2699  */
2700 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2701                           void __user *buffer, size_t *lenp, loff_t *ppos)
2702 {
2703     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2704                             do_proc_dointvec_jiffies_conv,NULL);
2705 }
2706
2707 /**
2708  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2709  * @table: the sysctl table
2710  * @write: %TRUE if this is a write to the sysctl file
2711  * @buffer: the user buffer
2712  * @lenp: the size of the user buffer
2713  * @ppos: pointer to the file position
2714  *
2715  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2716  * values from/to the user buffer, treated as an ASCII string.
2717  * The values read are assumed to be in 1/USER_HZ seconds, and
2718  * are converted into jiffies.
2719  *
2720  * Returns 0 on success.
2721  */
2722 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2723                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2724 {
2725     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2726                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2727 }
2728
2729 /**
2730  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2731  * @table: the sysctl table
2732  * @write: %TRUE if this is a write to the sysctl file
2733  * @buffer: the user buffer
2734  * @lenp: the size of the user buffer
2735  * @ppos: file position
2736  * @ppos: the current position in the file
2737  *
2738  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2739  * values from/to the user buffer, treated as an ASCII string.
2740  * The values read are assumed to be in 1/1000 seconds, and
2741  * are converted into jiffies.
2742  *
2743  * Returns 0 on success.
2744  */
2745 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2746                              void __user *buffer, size_t *lenp, loff_t *ppos)
2747 {
2748         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2749                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2750 }
2751
2752 static int proc_do_cad_pid(struct ctl_table *table, int write,
2753                            void __user *buffer, size_t *lenp, loff_t *ppos)
2754 {
2755         struct pid *new_pid;
2756         pid_t tmp;
2757         int r;
2758
2759         tmp = pid_vnr(cad_pid);
2760
2761         r = __do_proc_dointvec(&tmp, table, write, buffer,
2762                                lenp, ppos, NULL, NULL);
2763         if (r || !write)
2764                 return r;
2765
2766         new_pid = find_get_pid(tmp);
2767         if (!new_pid)
2768                 return -ESRCH;
2769
2770         put_pid(xchg(&cad_pid, new_pid));
2771         return 0;
2772 }
2773
2774 /**
2775  * proc_do_large_bitmap - read/write from/to a large bitmap
2776  * @table: the sysctl table
2777  * @write: %TRUE if this is a write to the sysctl file
2778  * @buffer: the user buffer
2779  * @lenp: the size of the user buffer
2780  * @ppos: file position
2781  *
2782  * The bitmap is stored at table->data and the bitmap length (in bits)
2783  * in table->maxlen.
2784  *
2785  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2786  * large bitmaps may be represented in a compact manner. Writing into
2787  * the file will clear the bitmap then update it with the given input.
2788  *
2789  * Returns 0 on success.
2790  */
2791 int proc_do_large_bitmap(struct ctl_table *table, int write,
2792                          void __user *buffer, size_t *lenp, loff_t *ppos)
2793 {
2794         int err = 0;
2795         bool first = 1;
2796         size_t left = *lenp;
2797         unsigned long bitmap_len = table->maxlen;
2798         unsigned long *bitmap = (unsigned long *) table->data;
2799         unsigned long *tmp_bitmap = NULL;
2800         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2801
2802         if (!bitmap_len || !left || (*ppos && !write)) {
2803                 *lenp = 0;
2804                 return 0;
2805         }
2806
2807         if (write) {
2808                 unsigned long page = 0;
2809                 char *kbuf;
2810
2811                 if (left > PAGE_SIZE - 1)
2812                         left = PAGE_SIZE - 1;
2813
2814                 page = __get_free_page(GFP_TEMPORARY);
2815                 kbuf = (char *) page;
2816                 if (!kbuf)
2817                         return -ENOMEM;
2818                 if (copy_from_user(kbuf, buffer, left)) {
2819                         free_page(page);
2820                         return -EFAULT;
2821                 }
2822                 kbuf[left] = 0;
2823
2824                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2825                                      GFP_KERNEL);
2826                 if (!tmp_bitmap) {
2827                         free_page(page);
2828                         return -ENOMEM;
2829                 }
2830                 proc_skip_char(&kbuf, &left, '\n');
2831                 while (!err && left) {
2832                         unsigned long val_a, val_b;
2833                         bool neg;
2834
2835                         err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2836                                              sizeof(tr_a), &c);
2837                         if (err)
2838                                 break;
2839                         if (val_a >= bitmap_len || neg) {
2840                                 err = -EINVAL;
2841                                 break;
2842                         }
2843
2844                         val_b = val_a;
2845                         if (left) {
2846                                 kbuf++;
2847                                 left--;
2848                         }
2849
2850                         if (c == '-') {
2851                                 err = proc_get_long(&kbuf, &left, &val_b,
2852                                                      &neg, tr_b, sizeof(tr_b),
2853                                                      &c);
2854                                 if (err)
2855                                         break;
2856                                 if (val_b >= bitmap_len || neg ||
2857                                     val_a > val_b) {
2858                                         err = -EINVAL;
2859                                         break;
2860                                 }
2861                                 if (left) {
2862                                         kbuf++;
2863                                         left--;
2864                                 }
2865                         }
2866
2867                         while (val_a <= val_b)
2868                                 set_bit(val_a++, tmp_bitmap);
2869
2870                         first = 0;
2871                         proc_skip_char(&kbuf, &left, '\n');
2872                 }
2873                 free_page(page);
2874         } else {
2875                 unsigned long bit_a, bit_b = 0;
2876
2877                 while (left) {
2878                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2879                         if (bit_a >= bitmap_len)
2880                                 break;
2881                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2882                                                    bit_a + 1) - 1;
2883
2884                         if (!first) {
2885                                 err = proc_put_char(&buffer, &left, ',');
2886                                 if (err)
2887                                         break;
2888                         }
2889                         err = proc_put_long(&buffer, &left, bit_a, false);
2890                         if (err)
2891                                 break;
2892                         if (bit_a != bit_b) {
2893                                 err = proc_put_char(&buffer, &left, '-');
2894                                 if (err)
2895                                         break;
2896                                 err = proc_put_long(&buffer, &left, bit_b, false);
2897                                 if (err)
2898                                         break;
2899                         }
2900
2901                         first = 0; bit_b++;
2902                 }
2903                 if (!err)
2904                         err = proc_put_char(&buffer, &left, '\n');
2905         }
2906
2907         if (!err) {
2908                 if (write) {
2909                         if (*ppos)
2910                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2911                         else
2912                                 memcpy(bitmap, tmp_bitmap,
2913                                         BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2914                 }
2915                 kfree(tmp_bitmap);
2916                 *lenp -= left;
2917                 *ppos += *lenp;
2918                 return 0;
2919         } else {
2920                 kfree(tmp_bitmap);
2921                 return err;
2922         }
2923 }
2924
2925 #else /* CONFIG_PROC_SYSCTL */
2926
2927 int proc_dostring(struct ctl_table *table, int write,
2928                   void __user *buffer, size_t *lenp, loff_t *ppos)
2929 {
2930         return -ENOSYS;
2931 }
2932
2933 int proc_dointvec(struct ctl_table *table, int write,
2934                   void __user *buffer, size_t *lenp, loff_t *ppos)
2935 {
2936         return -ENOSYS;
2937 }
2938
2939 int proc_dointvec_minmax(struct ctl_table *table, int write,
2940                     void __user *buffer, size_t *lenp, loff_t *ppos)
2941 {
2942         return -ENOSYS;
2943 }
2944
2945 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2946                     void __user *buffer, size_t *lenp, loff_t *ppos)
2947 {
2948         return -ENOSYS;
2949 }
2950
2951 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2952                     void __user *buffer, size_t *lenp, loff_t *ppos)
2953 {
2954         return -ENOSYS;
2955 }
2956
2957 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2958                              void __user *buffer, size_t *lenp, loff_t *ppos)
2959 {
2960         return -ENOSYS;
2961 }
2962
2963 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2964                     void __user *buffer, size_t *lenp, loff_t *ppos)
2965 {
2966         return -ENOSYS;
2967 }
2968
2969 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2970                                       void __user *buffer,
2971                                       size_t *lenp, loff_t *ppos)
2972 {
2973     return -ENOSYS;
2974 }
2975
2976
2977 #endif /* CONFIG_PROC_SYSCTL */
2978
2979 /*
2980  * No sense putting this after each symbol definition, twice,
2981  * exception granted :-)
2982  */
2983 EXPORT_SYMBOL(proc_dointvec);
2984 EXPORT_SYMBOL(proc_dointvec_jiffies);
2985 EXPORT_SYMBOL(proc_dointvec_minmax);
2986 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2987 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2988 EXPORT_SYMBOL(proc_dostring);
2989 EXPORT_SYMBOL(proc_doulongvec_minmax);
2990 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2991 EXPORT_SYMBOL(register_sysctl_table);
2992 EXPORT_SYMBOL(register_sysctl_paths);
2993 EXPORT_SYMBOL(unregister_sysctl_table);