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                 .procname       = "perf_event_paranoid",
 943                 .data           = &sysctl_perf_event_paranoid,
 944                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
 945                 .mode           = 0644,
 946                 .proc_handler   = proc_dointvec,
 947         },
 948         {
 949                 .procname       = "perf_event_mlock_kb",
 950                 .data           = &sysctl_perf_event_mlock,
 951                 .maxlen         = sizeof(sysctl_perf_event_mlock),
 952                 .mode           = 0644,
 953                 .proc_handler   = proc_dointvec,
 954         },
 955         {
 956                 .procname       = "perf_event_max_sample_rate",
 957                 .data           = &sysctl_perf_event_sample_rate,
 958                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
 959                 .mode           = 0644,
 960                 .proc_handler   = perf_proc_update_handler,
 961         },
 962 #endif
 963 #ifdef CONFIG_KMEMCHECK
 964         {
 965                 .procname       = "kmemcheck",
 966                 .data           = &kmemcheck_enabled,
 967                 .maxlen         = sizeof(int),
 968                 .mode           = 0644,
 969                 .proc_handler   = proc_dointvec,
 970         },
 971 #endif
 972 #ifdef CONFIG_BLOCK
 973         {
 974                 .procname       = "blk_iopoll",
 975                 .data           = &blk_iopoll_enabled,
 976                 .maxlen         = sizeof(int),
 977                 .mode           = 0644,
 978                 .proc_handler   = proc_dointvec,
 979         },
 980 #endif
 981         { }
 982 };
 983
 984 static struct ctl_table vm_table[] = {
 985         {
 986                 .procname       = "overcommit_memory",
 987                 .data           = &sysctl_overcommit_memory,
 988                 .maxlen         = sizeof(sysctl_overcommit_memory),
 989                 .mode           = 0644,
 990                 .proc_handler   = proc_dointvec_minmax,
 991                 .extra1         = &zero,
 992                 .extra2         = &two,
 993         },
 994         {
 995                 .procname       = "panic_on_oom",
 996                 .data           = &sysctl_panic_on_oom,
 997                 .maxlen         = sizeof(sysctl_panic_on_oom),
 998                 .mode           = 0644,
 999                 .proc_handler   = proc_dointvec_minmax,
1000                 .extra1         = &zero,
1001                 .extra2         = &two,
1002         },
1003         {
1004                 .procname       = "oom_kill_allocating_task",
1005                 .data           = &sysctl_oom_kill_allocating_task,
1006                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1007                 .mode           = 0644,
1008                 .proc_handler   = proc_dointvec,
1009         },
1010         {
1011                 .procname       = "oom_dump_tasks",
1012                 .data           = &sysctl_oom_dump_tasks,
1013                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1014                 .mode           = 0644,
1015                 .proc_handler   = proc_dointvec,
1016         },
1017         {
1018                 .procname       = "overcommit_ratio",
1019                 .data           = &sysctl_overcommit_ratio,
1020                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1021                 .mode           = 0644,
1022                 .proc_handler   = proc_dointvec,
1023         },
1024         {
1025                 .procname       = "page-cluster",
1026                 .data           = &page_cluster,
1027                 .maxlen         = sizeof(int),
1028                 .mode           = 0644,
1029                 .proc_handler   = proc_dointvec_minmax,
1030                 .extra1         = &zero,
1031         },
1032         {
1033                 .procname       = "dirty_background_ratio",
1034                 .data           = &dirty_background_ratio,
1035                 .maxlen         = sizeof(dirty_background_ratio),
1036                 .mode           = 0644,
1037                 .proc_handler   = dirty_background_ratio_handler,
1038                 .extra1         = &zero,
1039                 .extra2         = &one_hundred,
1040         },
1041         {
1042                 .procname       = "dirty_background_bytes",
1043                 .data           = &dirty_background_bytes,
1044                 .maxlen         = sizeof(dirty_background_bytes),
1045                 .mode           = 0644,
1046                 .proc_handler   = dirty_background_bytes_handler,
1047                 .extra1         = &one_ul,
1048         },
1049         {
1050                 .procname       = "dirty_ratio",
1051                 .data           = &vm_dirty_ratio,
1052                 .maxlen         = sizeof(vm_dirty_ratio),
1053                 .mode           = 0644,
1054                 .proc_handler   = dirty_ratio_handler,
1055                 .extra1         = &zero,
1056                 .extra2         = &one_hundred,
1057         },
1058         {
1059                 .procname       = "dirty_bytes",
1060                 .data           = &vm_dirty_bytes,
1061                 .maxlen         = sizeof(vm_dirty_bytes),
1062                 .mode           = 0644,
1063                 .proc_handler   = dirty_bytes_handler,
1064                 .extra1         = &dirty_bytes_min,
1065         },
1066         {
1067                 .procname       = "dirty_writeback_centisecs",
1068                 .data           = &dirty_writeback_interval,
1069                 .maxlen         = sizeof(dirty_writeback_interval),
1070                 .mode           = 0644,
1071                 .proc_handler   = dirty_writeback_centisecs_handler,
1072         },
1073         {
1074                 .procname       = "dirty_expire_centisecs",
1075                 .data           = &dirty_expire_interval,
1076                 .maxlen         = sizeof(dirty_expire_interval),
1077                 .mode           = 0644,
1078                 .proc_handler   = proc_dointvec_minmax,
1079                 .extra1         = &zero,
1080         },
1081         {
1082                 .procname       = "nr_pdflush_threads",
1083                 .data           = &nr_pdflush_threads,
1084                 .maxlen         = sizeof nr_pdflush_threads,
1085                 .mode           = 0444 /* read-only*/,
1086                 .proc_handler   = proc_dointvec,
1087         },
1088         {
1089                 .procname       = "swappiness",
1090                 .data           = &vm_swappiness,
1091                 .maxlen         = sizeof(vm_swappiness),
1092                 .mode           = 0644,
1093                 .proc_handler   = proc_dointvec_minmax,
1094                 .extra1         = &zero,
1095                 .extra2         = &one_hundred,
1096         },
1097 #ifdef CONFIG_HUGETLB_PAGE
1098         {
1099                 .procname       = "nr_hugepages",
1100                 .data           = NULL,
1101                 .maxlen         = sizeof(unsigned long),
1102                 .mode           = 0644,
1103                 .proc_handler   = hugetlb_sysctl_handler,
1104                 .extra1         = (void *)&hugetlb_zero,
1105                 .extra2         = (void *)&hugetlb_infinity,
1106         },
1107 #ifdef CONFIG_NUMA
1108         {
1109                 .procname       = "nr_hugepages_mempolicy",
1110                 .data           = NULL,
1111                 .maxlen         = sizeof(unsigned long),
1112                 .mode           = 0644,
1113                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1114                 .extra1         = (void *)&hugetlb_zero,
1115                 .extra2         = (void *)&hugetlb_infinity,
1116         },
1117 #endif
1118          {
1119                 .procname       = "hugetlb_shm_group",
1120                 .data           = &sysctl_hugetlb_shm_group,
1121                 .maxlen         = sizeof(gid_t),
1122                 .mode           = 0644,
1123                 .proc_handler   = proc_dointvec,
1124          },
1125          {
1126                 .procname       = "hugepages_treat_as_movable",
1127                 .data           = &hugepages_treat_as_movable,
1128                 .maxlen         = sizeof(int),
1129                 .mode           = 0644,
1130                 .proc_handler   = hugetlb_treat_movable_handler,
1131         },
1132         {
1133                 .procname       = "nr_overcommit_hugepages",
1134                 .data           = NULL,
1135                 .maxlen         = sizeof(unsigned long),
1136                 .mode           = 0644,
1137                 .proc_handler   = hugetlb_overcommit_handler,
1138                 .extra1         = (void *)&hugetlb_zero,
1139                 .extra2         = (void *)&hugetlb_infinity,
1140         },
1141 #endif
1142         {
1143                 .procname       = "lowmem_reserve_ratio",
1144                 .data           = &sysctl_lowmem_reserve_ratio,
1145                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1146                 .mode           = 0644,
1147                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1148         },
1149         {
1150                 .procname       = "drop_caches",
1151                 .data           = &sysctl_drop_caches,
1152                 .maxlen         = sizeof(int),
1153                 .mode           = 0644,
1154                 .proc_handler   = drop_caches_sysctl_handler,
1155                 .extra1         = &one,
1156                 .extra2         = &three,
1157         },
1158 #ifdef CONFIG_COMPACTION
1159         {
1160                 .procname       = "compact_memory",
1161                 .data           = &sysctl_compact_memory,
1162                 .maxlen         = sizeof(int),
1163                 .mode           = 0200,
1164                 .proc_handler   = sysctl_compaction_handler,
1165         },
1166         {
1167                 .procname       = "extfrag_threshold",
1168                 .data           = &sysctl_extfrag_threshold,
1169                 .maxlen         = sizeof(int),
1170                 .mode           = 0644,
1171                 .proc_handler   = sysctl_extfrag_handler,
1172                 .extra1         = &min_extfrag_threshold,
1173                 .extra2         = &max_extfrag_threshold,
1174         },
1175
1176 #endif /* CONFIG_COMPACTION */
1177         {
1178                 .procname       = "min_free_kbytes",
1179                 .data           = &min_free_kbytes,
1180                 .maxlen         = sizeof(min_free_kbytes),
1181                 .mode           = 0644,
1182                 .proc_handler   = min_free_kbytes_sysctl_handler,
1183                 .extra1         = &zero,
1184         },
1185         {
1186                 .procname       = "percpu_pagelist_fraction",
1187                 .data           = &percpu_pagelist_fraction,
1188                 .maxlen         = sizeof(percpu_pagelist_fraction),
1189                 .mode           = 0644,
1190                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1191                 .extra1         = &min_percpu_pagelist_fract,
1192         },
1193 #ifdef CONFIG_MMU
1194         {
1195                 .procname       = "max_map_count",
1196                 .data           = &sysctl_max_map_count,
1197                 .maxlen         = sizeof(sysctl_max_map_count),
1198                 .mode           = 0644,
1199                 .proc_handler   = proc_dointvec_minmax,
1200                 .extra1         = &zero,
1201         },
1202 #else
1203         {
1204                 .procname       = "nr_trim_pages",
1205                 .data           = &sysctl_nr_trim_pages,
1206                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1207                 .mode           = 0644,
1208                 .proc_handler   = proc_dointvec_minmax,
1209                 .extra1         = &zero,
1210         },
1211 #endif
1212         {
1213                 .procname       = "laptop_mode",
1214                 .data           = &laptop_mode,
1215                 .maxlen         = sizeof(laptop_mode),
1216                 .mode           = 0644,
1217                 .proc_handler   = proc_dointvec_jiffies,
1218         },
1219         {
1220                 .procname       = "block_dump",
1221                 .data           = &block_dump,
1222                 .maxlen         = sizeof(block_dump),
1223                 .mode           = 0644,
1224                 .proc_handler   = proc_dointvec,
1225                 .extra1         = &zero,
1226         },
1227         {
1228                 .procname       = "vfs_cache_pressure",
1229                 .data           = &sysctl_vfs_cache_pressure,
1230                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1231                 .mode           = 0644,
1232                 .proc_handler   = proc_dointvec,
1233                 .extra1         = &zero,
1234         },
1235 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1236         {
1237                 .procname       = "legacy_va_layout",
1238                 .data           = &sysctl_legacy_va_layout,
1239                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1240                 .mode           = 0644,
1241                 .proc_handler   = proc_dointvec,
1242                 .extra1         = &zero,
1243         },
1244 #endif
1245 #ifdef CONFIG_NUMA
1246         {
1247                 .procname       = "zone_reclaim_mode",
1248                 .data           = &zone_reclaim_mode,
1249                 .maxlen         = sizeof(zone_reclaim_mode),
1250                 .mode           = 0644,
1251                 .proc_handler   = proc_dointvec,
1252                 .extra1         = &zero,
1253         },
1254         {
1255                 .procname       = "min_unmapped_ratio",
1256                 .data           = &sysctl_min_unmapped_ratio,
1257                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1258                 .mode           = 0644,
1259                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1260                 .extra1         = &zero,
1261                 .extra2         = &one_hundred,
1262         },
1263         {
1264                 .procname       = "min_slab_ratio",
1265                 .data           = &sysctl_min_slab_ratio,
1266                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1267                 .mode           = 0644,
1268                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1269                 .extra1         = &zero,
1270                 .extra2         = &one_hundred,
1271         },
1272 #endif
1273 #ifdef CONFIG_SMP
1274         {
1275                 .procname       = "stat_interval",
1276                 .data           = &sysctl_stat_interval,
1277                 .maxlen         = sizeof(sysctl_stat_interval),
1278                 .mode           = 0644,
1279                 .proc_handler   = proc_dointvec_jiffies,
1280         },
1281 #endif
1282 #ifdef CONFIG_MMU
1283         {
1284                 .procname       = "mmap_min_addr",
1285                 .data           = &dac_mmap_min_addr,
1286                 .maxlen         = sizeof(unsigned long),
1287                 .mode           = 0644,
1288                 .proc_handler   = mmap_min_addr_handler,
1289         },
1290 #endif
1291 #ifdef CONFIG_NUMA
1292         {
1293                 .procname       = "numa_zonelist_order",
1294                 .data           = &numa_zonelist_order,
1295                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1296                 .mode           = 0644,
1297                 .proc_handler   = numa_zonelist_order_handler,
1298         },
1299 #endif
1300 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1301    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1302         {
1303                 .procname       = "vdso_enabled",
1304                 .data           = &vdso_enabled,
1305                 .maxlen         = sizeof(vdso_enabled),
1306                 .mode           = 0644,
1307                 .proc_handler   = proc_dointvec,
1308                 .extra1         = &zero,
1309         },
1310 #endif
1311 #ifdef CONFIG_HIGHMEM
1312         {
1313                 .procname       = "highmem_is_dirtyable",
1314                 .data           = &vm_highmem_is_dirtyable,
1315                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1316                 .mode           = 0644,
1317                 .proc_handler   = proc_dointvec_minmax,
1318                 .extra1         = &zero,
1319                 .extra2         = &one,
1320         },
1321 #endif
1322         {
1323                 .procname       = "scan_unevictable_pages",
1324                 .data           = &scan_unevictable_pages,
1325                 .maxlen         = sizeof(scan_unevictable_pages),
1326                 .mode           = 0644,
1327                 .proc_handler   = scan_unevictable_handler,
1328         },
1329 #ifdef CONFIG_MEMORY_FAILURE
1330         {
1331                 .procname       = "memory_failure_early_kill",
1332                 .data           = &sysctl_memory_failure_early_kill,
1333                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1334                 .mode           = 0644,
1335                 .proc_handler   = proc_dointvec_minmax,
1336                 .extra1         = &zero,
1337                 .extra2         = &one,
1338         },
1339         {
1340                 .procname       = "memory_failure_recovery",
1341                 .data           = &sysctl_memory_failure_recovery,
1342                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1343                 .mode           = 0644,
1344                 .proc_handler   = proc_dointvec_minmax,
1345                 .extra1         = &zero,
1346                 .extra2         = &one,
1347         },
1348 #endif
1349         { }
1350 };
1351
1352 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1353 static struct ctl_table binfmt_misc_table[] = {
1354         { }
1355 };
1356 #endif
1357
1358 static struct ctl_table fs_table[] = {
1359         {
1360                 .procname       = "inode-nr",
1361                 .data           = &inodes_stat,
1362                 .maxlen         = 2*sizeof(int),
1363                 .mode           = 0444,
1364                 .proc_handler   = proc_nr_inodes,
1365         },
1366         {
1367                 .procname       = "inode-state",
1368                 .data           = &inodes_stat,
1369                 .maxlen         = 7*sizeof(int),
1370                 .mode           = 0444,
1371                 .proc_handler   = proc_nr_inodes,
1372         },
1373         {
1374                 .procname       = "file-nr",
1375                 .data           = &files_stat,
1376                 .maxlen         = sizeof(files_stat),
1377                 .mode           = 0444,
1378                 .proc_handler   = proc_nr_files,
1379         },
1380         {
1381                 .procname       = "file-max",
1382                 .data           = &files_stat.max_files,
1383                 .maxlen         = sizeof(files_stat.max_files),
1384                 .mode           = 0644,
1385                 .proc_handler   = proc_doulongvec_minmax,
1386         },
1387         {
1388                 .procname       = "nr_open",
1389                 .data           = &sysctl_nr_open,
1390                 .maxlen         = sizeof(int),
1391                 .mode           = 0644,
1392                 .proc_handler   = proc_dointvec_minmax,
1393                 .extra1         = &sysctl_nr_open_min,
1394                 .extra2         = &sysctl_nr_open_max,
1395         },
1396         {
1397                 .procname       = "dentry-state",
1398                 .data           = &dentry_stat,
1399                 .maxlen         = 6*sizeof(int),
1400                 .mode           = 0444,
1401                 .proc_handler   = proc_nr_dentry,
1402         },
1403         {
1404                 .procname       = "overflowuid",
1405                 .data           = &fs_overflowuid,
1406                 .maxlen         = sizeof(int),
1407                 .mode           = 0644,
1408                 .proc_handler   = proc_dointvec_minmax,
1409                 .extra1         = &minolduid,
1410                 .extra2         = &maxolduid,
1411         },
1412         {
1413                 .procname       = "overflowgid",
1414                 .data           = &fs_overflowgid,
1415                 .maxlen         = sizeof(int),
1416                 .mode           = 0644,
1417                 .proc_handler   = proc_dointvec_minmax,
1418                 .extra1         = &minolduid,
1419                 .extra2         = &maxolduid,
1420         },
1421 #ifdef CONFIG_FILE_LOCKING
1422         {
1423                 .procname       = "leases-enable",
1424                 .data           = &leases_enable,
1425                 .maxlen         = sizeof(int),
1426                 .mode           = 0644,
1427                 .proc_handler   = proc_dointvec,
1428         },
1429 #endif
1430 #ifdef CONFIG_DNOTIFY
1431         {
1432                 .procname       = "dir-notify-enable",
1433                 .data           = &dir_notify_enable,
1434                 .maxlen         = sizeof(int),
1435                 .mode           = 0644,
1436                 .proc_handler   = proc_dointvec,
1437         },
1438 #endif
1439 #ifdef CONFIG_MMU
1440 #ifdef CONFIG_FILE_LOCKING
1441         {
1442                 .procname       = "lease-break-time",
1443                 .data           = &lease_break_time,
1444                 .maxlen         = sizeof(int),
1445                 .mode           = 0644,
1446                 .proc_handler   = proc_dointvec,
1447         },
1448 #endif
1449 #ifdef CONFIG_AIO
1450         {
1451                 .procname       = "aio-nr",
1452                 .data           = &aio_nr,
1453                 .maxlen         = sizeof(aio_nr),
1454                 .mode           = 0444,
1455                 .proc_handler   = proc_doulongvec_minmax,
1456         },
1457         {
1458                 .procname       = "aio-max-nr",
1459                 .data           = &aio_max_nr,
1460                 .maxlen         = sizeof(aio_max_nr),
1461                 .mode           = 0644,
1462                 .proc_handler   = proc_doulongvec_minmax,
1463         },
1464 #endif /* CONFIG_AIO */
1465 #ifdef CONFIG_INOTIFY_USER
1466         {
1467                 .procname       = "inotify",
1468                 .mode           = 0555,
1469                 .child          = inotify_table,
1470         },
1471 #endif
1472 #ifdef CONFIG_EPOLL
1473         {
1474                 .procname       = "epoll",
1475                 .mode           = 0555,
1476                 .child          = epoll_table,
1477         },
1478 #endif
1479 #endif
1480         {
1481                 .procname       = "suid_dumpable",
1482                 .data           = &suid_dumpable,
1483                 .maxlen         = sizeof(int),
1484                 .mode           = 0644,
1485                 .proc_handler   = proc_dointvec_minmax,
1486                 .extra1         = &zero,
1487                 .extra2         = &two,
1488         },
1489 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1490         {
1491                 .procname       = "binfmt_misc",
1492                 .mode           = 0555,
1493                 .child          = binfmt_misc_table,
1494         },
1495 #endif
1496         {
1497                 .procname       = "pipe-max-size",
1498                 .data           = &pipe_max_size,
1499                 .maxlen         = sizeof(int),
1500                 .mode           = 0644,
1501                 .proc_handler   = &pipe_proc_fn,
1502                 .extra1         = &pipe_min_size,
1503         },
1504         { }
1505 };
1506
1507 static struct ctl_table debug_table[] = {
1508 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1509     defined(CONFIG_S390) || defined(CONFIG_TILE)
1510         {
1511                 .procname       = "exception-trace",
1512                 .data           = &show_unhandled_signals,
1513                 .maxlen         = sizeof(int),
1514                 .mode           = 0644,
1515                 .proc_handler   = proc_dointvec
1516         },
1517 #endif
1518 #if defined(CONFIG_OPTPROBES)
1519         {
1520                 .procname       = "kprobes-optimization",
1521                 .data           = &sysctl_kprobes_optimization,
1522                 .maxlen         = sizeof(int),
1523                 .mode           = 0644,
1524                 .proc_handler   = proc_kprobes_optimization_handler,
1525                 .extra1         = &zero,
1526                 .extra2         = &one,
1527         },
1528 #endif
1529         { }
1530 };
1531
1532 static struct ctl_table dev_table[] = {
1533         { }
1534 };
1535
1536 static DEFINE_SPINLOCK(sysctl_lock);
1537
1538 /* called under sysctl_lock */
1539 static int use_table(struct ctl_table_header *p)
1540 {
1541         if (unlikely(p->unregistering))
1542                 return 0;
1543         p->used++;
1544         return 1;
1545 }
1546
1547 /* called under sysctl_lock */
1548 static void unuse_table(struct ctl_table_header *p)
1549 {
1550         if (!--p->used)
1551                 if (unlikely(p->unregistering))
1552                         complete(p->unregistering);
1553 }
1554
1555 /* called under sysctl_lock, will reacquire if has to wait */
1556 static void start_unregistering(struct ctl_table_header *p)
1557 {
1558         /*
1559          * if p->used is 0, nobody will ever touch that entry again;
1560          * we'll eliminate all paths to it before dropping sysctl_lock
1561          */
1562         if (unlikely(p->used)) {
1563                 struct completion wait;
1564                 init_completion(&wait);
1565                 p->unregistering = &wait;
1566                 spin_unlock(&sysctl_lock);
1567                 wait_for_completion(&wait);
1568                 spin_lock(&sysctl_lock);
1569         } else {
1570                 /* anything non-NULL; we'll never dereference it */
1571                 p->unregistering = ERR_PTR(-EINVAL);
1572         }
1573         /*
1574          * do not remove from the list until nobody holds it; walking the
1575          * list in do_sysctl() relies on that.
1576          */
1577         list_del_init(&p->ctl_entry);
1578 }
1579
1580 void sysctl_head_get(struct ctl_table_header *head)
1581 {
1582         spin_lock(&sysctl_lock);
1583         head->count++;
1584         spin_unlock(&sysctl_lock);
1585 }
1586
1587 static void free_head(struct rcu_head *rcu)
1588 {
1589         kfree(container_of(rcu, struct ctl_table_header, rcu));
1590 }
1591
1592 void sysctl_head_put(struct ctl_table_header *head)
1593 {
1594         spin_lock(&sysctl_lock);
1595         if (!--head->count)
1596                 call_rcu(&head->rcu, free_head);
1597         spin_unlock(&sysctl_lock);
1598 }
1599
1600 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1601 {
1602         if (!head)
1603                 BUG();
1604         spin_lock(&sysctl_lock);
1605         if (!use_table(head))
1606                 head = ERR_PTR(-ENOENT);
1607         spin_unlock(&sysctl_lock);
1608         return head;
1609 }
1610
1611 void sysctl_head_finish(struct ctl_table_header *head)
1612 {
1613         if (!head)
1614                 return;
1615         spin_lock(&sysctl_lock);
1616         unuse_table(head);
1617         spin_unlock(&sysctl_lock);
1618 }
1619
1620 static struct ctl_table_set *
1621 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1622 {
1623         struct ctl_table_set *set = &root->default_set;
1624         if (root->lookup)
1625                 set = root->lookup(root, namespaces);
1626         return set;
1627 }
1628
1629 static struct list_head *
1630 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1631 {
1632         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1633         return &set->list;
1634 }
1635
1636 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1637                                             struct ctl_table_header *prev)
1638 {
1639         struct ctl_table_root *root;
1640         struct list_head *header_list;
1641         struct ctl_table_header *head;
1642         struct list_head *tmp;
1643
1644         spin_lock(&sysctl_lock);
1645         if (prev) {
1646                 head = prev;
1647                 tmp = &prev->ctl_entry;
1648                 unuse_table(prev);
1649                 goto next;
1650         }
1651         tmp = &root_table_header.ctl_entry;
1652         for (;;) {
1653                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1654
1655                 if (!use_table(head))
1656                         goto next;
1657                 spin_unlock(&sysctl_lock);
1658                 return head;
1659         next:
1660                 root = head->root;
1661                 tmp = tmp->next;
1662                 header_list = lookup_header_list(root, namespaces);
1663                 if (tmp != header_list)
1664                         continue;
1665
1666                 do {
1667                         root = list_entry(root->root_list.next,
1668                                         struct ctl_table_root, root_list);
1669                         if (root == &sysctl_table_root)
1670                                 goto out;
1671                         header_list = lookup_header_list(root, namespaces);
1672                 } while (list_empty(header_list));
1673                 tmp = header_list->next;
1674         }
1675 out:
1676         spin_unlock(&sysctl_lock);
1677         return NULL;
1678 }
1679
1680 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1681 {
1682         return __sysctl_head_next(current->nsproxy, prev);
1683 }
1684
1685 void register_sysctl_root(struct ctl_table_root *root)
1686 {
1687         spin_lock(&sysctl_lock);
1688         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1689         spin_unlock(&sysctl_lock);
1690 }
1691
1692 /*
1693  * sysctl_perm does NOT grant the superuser all rights automatically, because
1694  * some sysctl variables are readonly even to root.
1695  */
1696
1697 static int test_perm(int mode, int op)
1698 {
1699         if (!current_euid())
1700                 mode >>= 6;
1701         else if (in_egroup_p(0))
1702                 mode >>= 3;
1703         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1704                 return 0;
1705         return -EACCES;
1706 }
1707
1708 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1709 {
1710         int mode;
1711
1712         if (root->permissions)
1713                 mode = root->permissions(root, current->nsproxy, table);
1714         else
1715                 mode = table->mode;
1716
1717         return test_perm(mode, op);
1718 }
1719
1720 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1721 {
1722         for (; table->procname; table++) {
1723                 table->parent = parent;
1724                 if (table->child)
1725                         sysctl_set_parent(table, table->child);
1726         }
1727 }
1728
1729 static __init int sysctl_init(void)
1730 {
1731         sysctl_set_parent(NULL, root_table);
1732 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1733         sysctl_check_table(current->nsproxy, root_table);
1734 #endif
1735         return 0;
1736 }
1737
1738 core_initcall(sysctl_init);
1739
1740 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1741                                       struct ctl_table *table)
1742 {
1743         struct ctl_table *p;
1744         const char *s = branch->procname;
1745
1746         /* branch should have named subdirectory as its first element */
1747         if (!s || !branch->child)
1748                 return NULL;
1749
1750         /* ... and nothing else */
1751         if (branch[1].procname)
1752                 return NULL;
1753
1754         /* table should contain subdirectory with the same name */
1755         for (p = table; p->procname; p++) {
1756                 if (!p->child)
1757                         continue;
1758                 if (p->procname && strcmp(p->procname, s) == 0)
1759                         return p;
1760         }
1761         return NULL;
1762 }
1763
1764 /* see if attaching q to p would be an improvement */
1765 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1766 {
1767         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1768         struct ctl_table *next;
1769         int is_better = 0;
1770         int not_in_parent = !p->attached_by;
1771
1772         while ((next = is_branch_in(by, to)) != NULL) {
1773                 if (by == q->attached_by)
1774                         is_better = 1;
1775                 if (to == p->attached_by)
1776                         not_in_parent = 1;
1777                 by = by->child;
1778                 to = next->child;
1779         }
1780
1781         if (is_better && not_in_parent) {
1782                 q->attached_by = by;
1783                 q->attached_to = to;
1784                 q->parent = p;
1785         }
1786 }
1787
1788 /**
1789  * __register_sysctl_paths - register a sysctl hierarchy
1790  * @root: List of sysctl headers to register on
1791  * @namespaces: Data to compute which lists of sysctl entries are visible
1792  * @path: The path to the directory the sysctl table is in.
1793  * @table: the top-level table structure
1794  *
1795  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1796  * array. A completely 0 filled entry terminates the table.
1797  *
1798  * The members of the &struct ctl_table structure are used as follows:
1799  *
1800  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1801  *            enter a sysctl file
1802  *
1803  * data - a pointer to data for use by proc_handler
1804  *
1805  * maxlen - the maximum size in bytes of the data
1806  *
1807  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1808  *
1809  * child - a pointer to the child sysctl table if this entry is a directory, or
1810  *         %NULL.
1811  *
1812  * proc_handler - the text handler routine (described below)
1813  *
1814  * de - for internal use by the sysctl routines
1815  *
1816  * extra1, extra2 - extra pointers usable by the proc handler routines
1817  *
1818  * Leaf nodes in the sysctl tree will be represented by a single file
1819  * under /proc; non-leaf nodes will be represented by directories.
1820  *
1821  * sysctl(2) can automatically manage read and write requests through
1822  * the sysctl table.  The data and maxlen fields of the ctl_table
1823  * struct enable minimal validation of the values being written to be
1824  * performed, and the mode field allows minimal authentication.
1825  *
1826  * There must be a proc_handler routine for any terminal nodes
1827  * mirrored under /proc/sys (non-terminals are handled by a built-in
1828  * directory handler).  Several default handlers are available to
1829  * cover common cases -
1830  *
1831  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1832  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1833  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1834  *
1835  * It is the handler's job to read the input buffer from user memory
1836  * and process it. The handler should return 0 on success.
1837  *
1838  * This routine returns %NULL on a failure to register, and a pointer
1839  * to the table header on success.
1840  */
1841 struct ctl_table_header *__register_sysctl_paths(
1842         struct ctl_table_root *root,
1843         struct nsproxy *namespaces,
1844         const struct ctl_path *path, struct ctl_table *table)
1845 {
1846         struct ctl_table_header *header;
1847         struct ctl_table *new, **prevp;
1848         unsigned int n, npath;
1849         struct ctl_table_set *set;
1850
1851         /* Count the path components */
1852         for (npath = 0; path[npath].procname; ++npath)
1853                 ;
1854
1855         /*
1856          * For each path component, allocate a 2-element ctl_table array.
1857          * The first array element will be filled with the sysctl entry
1858          * for this, the second will be the sentinel (procname == 0).
1859          *
1860          * We allocate everything in one go so that we don't have to
1861          * worry about freeing additional memory in unregister_sysctl_table.
1862          */
1863         header = kzalloc(sizeof(struct ctl_table_header) +
1864                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1865         if (!header)
1866                 return NULL;
1867
1868         new = (struct ctl_table *) (header + 1);
1869
1870         /* Now connect the dots */
1871         prevp = &header->ctl_table;
1872         for (n = 0; n < npath; ++n, ++path) {
1873                 /* Copy the procname */
1874                 new->procname = path->procname;
1875                 new->mode     = 0555;
1876
1877                 *prevp = new;
1878                 prevp = &new->child;
1879
1880                 new += 2;
1881         }
1882         *prevp = table;
1883         header->ctl_table_arg = table;
1884
1885         INIT_LIST_HEAD(&header->ctl_entry);
1886         header->used = 0;
1887         header->unregistering = NULL;
1888         header->root = root;
1889         sysctl_set_parent(NULL, header->ctl_table);
1890         header->count = 1;
1891 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1892         if (sysctl_check_table(namespaces, header->ctl_table)) {
1893                 kfree(header);
1894                 return NULL;
1895         }
1896 #endif
1897         spin_lock(&sysctl_lock);
1898         header->set = lookup_header_set(root, namespaces);
1899         header->attached_by = header->ctl_table;
1900         header->attached_to = root_table;
1901         header->parent = &root_table_header;
1902         for (set = header->set; set; set = set->parent) {
1903                 struct ctl_table_header *p;
1904                 list_for_each_entry(p, &set->list, ctl_entry) {
1905                         if (p->unregistering)
1906                                 continue;
1907                         try_attach(p, header);
1908                 }
1909         }
1910         header->parent->count++;
1911         list_add_tail(&header->ctl_entry, &header->set->list);
1912         spin_unlock(&sysctl_lock);
1913
1914         return header;
1915 }
1916
1917 /**
1918  * register_sysctl_table_path - register a sysctl table hierarchy
1919  * @path: The path to the directory the sysctl table is in.
1920  * @table: the top-level table structure
1921  *
1922  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1923  * array. A completely 0 filled entry terminates the table.
1924  *
1925  * See __register_sysctl_paths for more details.
1926  */
1927 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1928                                                 struct ctl_table *table)
1929 {
1930         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1931                                         path, table);
1932 }
1933
1934 /**
1935  * register_sysctl_table - register a sysctl table hierarchy
1936  * @table: the top-level table structure
1937  *
1938  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1939  * array. A completely 0 filled entry terminates the table.
1940  *
1941  * See register_sysctl_paths for more details.
1942  */
1943 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1944 {
1945         static const struct ctl_path null_path[] = { {} };
1946
1947         return register_sysctl_paths(null_path, table);
1948 }
1949
1950 /**
1951  * unregister_sysctl_table - unregister a sysctl table hierarchy
1952  * @header: the header returned from register_sysctl_table
1953  *
1954  * Unregisters the sysctl table and all children. proc entries may not
1955  * actually be removed until they are no longer used by anyone.
1956  */
1957 void unregister_sysctl_table(struct ctl_table_header * header)
1958 {
1959         might_sleep();
1960
1961         if (header == NULL)
1962                 return;
1963
1964         spin_lock(&sysctl_lock);
1965         start_unregistering(header);
1966         if (!--header->parent->count) {
1967                 WARN_ON(1);
1968                 call_rcu(&header->parent->rcu, free_head);
1969         }
1970         if (!--header->count)
1971                 call_rcu(&header->rcu, free_head);
1972         spin_unlock(&sysctl_lock);
1973 }
1974
1975 int sysctl_is_seen(struct ctl_table_header *p)
1976 {
1977         struct ctl_table_set *set = p->set;
1978         int res;
1979         spin_lock(&sysctl_lock);
1980         if (p->unregistering)
1981                 res = 0;
1982         else if (!set->is_seen)
1983                 res = 1;
1984         else
1985                 res = set->is_seen(set);
1986         spin_unlock(&sysctl_lock);
1987         return res;
1988 }
1989
1990 void setup_sysctl_set(struct ctl_table_set *p,
1991         struct ctl_table_set *parent,
1992         int (*is_seen)(struct ctl_table_set *))
1993 {
1994         INIT_LIST_HEAD(&p->list);
1995         p->parent = parent ? parent : &sysctl_table_root.default_set;
1996         p->is_seen = is_seen;
1997 }
1998
1999 #else /* !CONFIG_SYSCTL */
2000 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2001 {
2002         return NULL;
2003 }
2004
2005 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2006                                                     struct ctl_table *table)
2007 {
2008         return NULL;
2009 }
2010
2011 void unregister_sysctl_table(struct ctl_table_header * table)
2012 {
2013 }
2014
2015 void setup_sysctl_set(struct ctl_table_set *p,
2016         struct ctl_table_set *parent,
2017         int (*is_seen)(struct ctl_table_set *))
2018 {
2019 }
2020
2021 void sysctl_head_put(struct ctl_table_header *head)
2022 {
2023 }
2024
2025 #endif /* CONFIG_SYSCTL */
2026
2027 /*
2028  * /proc/sys support
2029  */
2030
2031 #ifdef CONFIG_PROC_SYSCTL
2032
2033 static int _proc_do_string(void* data, int maxlen, int write,
2034                            void __user *buffer,
2035                            size_t *lenp, loff_t *ppos)
2036 {
2037         size_t len;
2038         char __user *p;
2039         char c;
2040
2041         if (!data || !maxlen || !*lenp) {
2042                 *lenp = 0;
2043                 return 0;
2044         }
2045
2046         if (write) {
2047                 len = 0;
2048                 p = buffer;
2049                 while (len < *lenp) {
2050                         if (get_user(c, p++))
2051                                 return -EFAULT;
2052                         if (c == 0 || c == '\n')
2053                                 break;
2054                         len++;
2055                 }
2056                 if (len >= maxlen)
2057                         len = maxlen-1;
2058                 if(copy_from_user(data, buffer, len))
2059                         return -EFAULT;
2060                 ((char *) data)[len] = 0;
2061                 *ppos += *lenp;
2062         } else {
2063                 len = strlen(data);
2064                 if (len > maxlen)
2065                         len = maxlen;
2066
2067                 if (*ppos > len) {
2068                         *lenp = 0;
2069                         return 0;
2070                 }
2071
2072                 data += *ppos;
2073                 len  -= *ppos;
2074
2075                 if (len > *lenp)
2076                         len = *lenp;
2077                 if (len)
2078                         if(copy_to_user(buffer, data, len))
2079                                 return -EFAULT;
2080                 if (len < *lenp) {
2081                         if(put_user('\n', ((char __user *) buffer) + len))
2082                                 return -EFAULT;
2083                         len++;
2084                 }
2085                 *lenp = len;
2086                 *ppos += len;
2087         }
2088         return 0;
2089 }
2090
2091 /**
2092  * proc_dostring - read a string sysctl
2093  * @table: the sysctl table
2094  * @write: %TRUE if this is a write to the sysctl file
2095  * @buffer: the user buffer
2096  * @lenp: the size of the user buffer
2097  * @ppos: file position
2098  *
2099  * Reads/writes a string from/to the user buffer. If the kernel
2100  * buffer provided is not large enough to hold the string, the
2101  * string is truncated. The copied string is %NULL-terminated.
2102  * If the string is being read by the user process, it is copied
2103  * and a newline '\n' is added. It is truncated if the buffer is
2104  * not large enough.
2105  *
2106  * Returns 0 on success.
2107  */
2108 int proc_dostring(struct ctl_table *table, int write,
2109                   void __user *buffer, size_t *lenp, loff_t *ppos)
2110 {
2111         return _proc_do_string(table->data, table->maxlen, write,
2112                                buffer, lenp, ppos);
2113 }
2114
2115 static size_t proc_skip_spaces(char **buf)
2116 {
2117         size_t ret;
2118         char *tmp = skip_spaces(*buf);
2119         ret = tmp - *buf;
2120         *buf = tmp;
2121         return ret;
2122 }
2123
2124 static void proc_skip_char(char **buf, size_t *size, const char v)
2125 {
2126         while (*size) {
2127                 if (**buf != v)
2128                         break;
2129                 (*size)--;
2130                 (*buf)++;
2131         }
2132 }
2133
2134 #define TMPBUFLEN 22
2135 /**
2136  * proc_get_long - reads an ASCII formatted integer from a user buffer
2137  *
2138  * @buf: a kernel buffer
2139  * @size: size of the kernel buffer
2140  * @val: this is where the number will be stored
2141  * @neg: set to %TRUE if number is negative
2142  * @perm_tr: a vector which contains the allowed trailers
2143  * @perm_tr_len: size of the perm_tr vector
2144  * @tr: pointer to store the trailer character
2145  *
2146  * In case of success %0 is returned and @buf and @size are updated with
2147  * the amount of bytes read. If @tr is non-NULL and a trailing
2148  * character exists (size is non-zero after returning from this
2149  * function), @tr is updated with the trailing character.
2150  */
2151 static int proc_get_long(char **buf, size_t *size,
2152                           unsigned long *val, bool *neg,
2153                           const char *perm_tr, unsigned perm_tr_len, char *tr)
2154 {
2155         int len;
2156         char *p, tmp[TMPBUFLEN];
2157
2158         if (!*size)
2159                 return -EINVAL;
2160
2161         len = *size;
2162         if (len > TMPBUFLEN - 1)
2163                 len = TMPBUFLEN - 1;
2164
2165         memcpy(tmp, *buf, len);
2166
2167         tmp[len] = 0;
2168         p = tmp;
2169         if (*p == '-' && *size > 1) {
2170                 *neg = true;
2171                 p++;
2172         } else
2173                 *neg = false;
2174         if (!isdigit(*p))
2175                 return -EINVAL;
2176
2177         *val = simple_strtoul(p, &p, 0);
2178
2179         len = p - tmp;
2180
2181         /* We don't know if the next char is whitespace thus we may accept
2182          * invalid integers (e.g. 1234...a) or two integers instead of one
2183          * (e.g. 123...1). So lets not allow such large numbers. */
2184         if (len == TMPBUFLEN - 1)
2185                 return -EINVAL;
2186
2187         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2188                 return -EINVAL;
2189
2190         if (tr && (len < *size))
2191                 *tr = *p;
2192
2193         *buf += len;
2194         *size -= len;
2195
2196         return 0;
2197 }
2198
2199 /**
2200  * proc_put_long - converts an integer to a decimal ASCII formatted string
2201  *
2202  * @buf: the user buffer
2203  * @size: the size of the user buffer
2204  * @val: the integer to be converted
2205  * @neg: sign of the number, %TRUE for negative
2206  *
2207  * In case of success %0 is returned and @buf and @size are updated with
2208  * the amount of bytes written.
2209  */
2210 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2211                           bool neg)
2212 {
2213         int len;
2214         char tmp[TMPBUFLEN], *p = tmp;
2215
2216         sprintf(p, "%s%lu", neg ? "-" : "", val);
2217         len = strlen(tmp);
2218         if (len > *size)
2219                 len = *size;
2220         if (copy_to_user(*buf, tmp, len))
2221                 return -EFAULT;
2222         *size -= len;
2223         *buf += len;
2224         return 0;
2225 }
2226 #undef TMPBUFLEN
2227
2228 static int proc_put_char(void __user **buf, size_t *size, char c)
2229 {
2230         if (*size) {
2231                 char __user **buffer = (char __user **)buf;
2232                 if (put_user(c, *buffer))
2233                         return -EFAULT;
2234                 (*size)--, (*buffer)++;
2235                 *buf = *buffer;
2236         }
2237         return 0;
2238 }
2239
2240 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2241                                  int *valp,
2242                                  int write, void *data)
2243 {
2244         if (write) {
2245                 *valp = *negp ? -*lvalp : *lvalp;
2246         } else {
2247                 int val = *valp;
2248                 if (val < 0) {
2249                         *negp = true;
2250                         *lvalp = (unsigned long)-val;
2251                 } else {
2252                         *negp = false;
2253                         *lvalp = (unsigned long)val;
2254                 }
2255         }
2256         return 0;
2257 }
2258
2259 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2260
2261 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2262                   int write, void __user *buffer,
2263                   size_t *lenp, loff_t *ppos,
2264                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2265                               int write, void *data),
2266                   void *data)
2267 {
2268         int *i, vleft, first = 1, err = 0;
2269         unsigned long page = 0;
2270         size_t left;
2271         char *kbuf;
2272
2273         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2274                 *lenp = 0;
2275                 return 0;
2276         }
2277
2278         i = (int *) tbl_data;
2279         vleft = table->maxlen / sizeof(*i);
2280         left = *lenp;
2281
2282         if (!conv)
2283                 conv = do_proc_dointvec_conv;
2284
2285         if (write) {
2286                 if (left > PAGE_SIZE - 1)
2287                         left = PAGE_SIZE - 1;
2288                 page = __get_free_page(GFP_TEMPORARY);
2289                 kbuf = (char *) page;
2290                 if (!kbuf)
2291                         return -ENOMEM;
2292                 if (copy_from_user(kbuf, buffer, left)) {
2293                         err = -EFAULT;
2294                         goto free;
2295                 }
2296                 kbuf[left] = 0;
2297         }
2298
2299         for (; left && vleft--; i++, first=0) {
2300                 unsigned long lval;
2301                 bool neg;
2302
2303                 if (write) {
2304                         left -= proc_skip_spaces(&kbuf);
2305
2306                         if (!left)
2307                                 break;
2308                         err = proc_get_long(&kbuf, &left, &lval, &neg,
2309                                              proc_wspace_sep,
2310                                              sizeof(proc_wspace_sep), NULL);
2311                         if (err)
2312                                 break;
2313                         if (conv(&neg, &lval, i, 1, data)) {
2314                                 err = -EINVAL;
2315                                 break;
2316                         }
2317                 } else {
2318                         if (conv(&neg, &lval, i, 0, data)) {
2319                                 err = -EINVAL;
2320                                 break;
2321                         }
2322                         if (!first)
2323                                 err = proc_put_char(&buffer, &left, '\t');
2324                         if (err)
2325                                 break;
2326                         err = proc_put_long(&buffer, &left, lval, neg);
2327                         if (err)
2328                                 break;
2329                 }
2330         }
2331
2332         if (!write && !first && left && !err)
2333                 err = proc_put_char(&buffer, &left, '\n');
2334         if (write && !err && left)
2335                 left -= proc_skip_spaces(&kbuf);
2336 free:
2337         if (write) {
2338                 free_page(page);
2339                 if (first)
2340                         return err ? : -EINVAL;
2341         }
2342         *lenp -= left;
2343         *ppos += *lenp;
2344         return err;
2345 }
2346
2347 static int do_proc_dointvec(struct ctl_table *table, int write,
2348                   void __user *buffer, size_t *lenp, loff_t *ppos,
2349                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2350                               int write, void *data),
2351                   void *data)
2352 {
2353         return __do_proc_dointvec(table->data, table, write,
2354                         buffer, lenp, ppos, conv, data);
2355 }
2356
2357 /**
2358  * proc_dointvec - read a vector of integers
2359  * @table: the sysctl table
2360  * @write: %TRUE if this is a write to the sysctl file
2361  * @buffer: the user buffer
2362  * @lenp: the size of the user buffer
2363  * @ppos: file position
2364  *
2365  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2366  * values from/to the user buffer, treated as an ASCII string.
2367  *
2368  * Returns 0 on success.
2369  */
2370 int proc_dointvec(struct ctl_table *table, int write,
2371                      void __user *buffer, size_t *lenp, loff_t *ppos)
2372 {
2373     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2374                             NULL,NULL);
2375 }
2376
2377 /*
2378  * Taint values can only be increased
2379  * This means we can safely use a temporary.
2380  */
2381 static int proc_taint(struct ctl_table *table, int write,
2382                                void __user *buffer, size_t *lenp, loff_t *ppos)
2383 {
2384         struct ctl_table t;
2385         unsigned long tmptaint = get_taint();
2386         int err;
2387
2388         if (write && !capable(CAP_SYS_ADMIN))
2389                 return -EPERM;
2390
2391         t = *table;
2392         t.data = &tmptaint;
2393         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2394         if (err < 0)
2395                 return err;
2396
2397         if (write) {
2398                 /*
2399                  * Poor man's atomic or. Not worth adding a primitive
2400                  * to everyone's atomic.h for this
2401                  */
2402                 int i;
2403                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2404                         if ((tmptaint >> i) & 1)
2405                                 add_taint(i);
2406                 }
2407         }
2408
2409         return err;
2410 }
2411
2412 #ifdef CONFIG_PRINTK
2413 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2414                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2415 {
2416         if (write && !capable(CAP_SYS_ADMIN))
2417                 return -EPERM;
2418
2419         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2420 }
2421 #endif
2422
2423 struct do_proc_dointvec_minmax_conv_param {
2424         int *min;
2425         int *max;
2426 };
2427
2428 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2429                                         int *valp,
2430                                         int write, void *data)
2431 {
2432         struct do_proc_dointvec_minmax_conv_param *param = data;
2433         if (write) {
2434                 int val = *negp ? -*lvalp : *lvalp;
2435                 if ((param->min && *param->min > val) ||
2436                     (param->max && *param->max < val))
2437                         return -EINVAL;
2438                 *valp = val;
2439         } else {
2440                 int val = *valp;
2441                 if (val < 0) {
2442                         *negp = true;
2443                         *lvalp = (unsigned long)-val;
2444                 } else {
2445                         *negp = false;
2446                         *lvalp = (unsigned long)val;
2447                 }
2448         }
2449         return 0;
2450 }
2451
2452 /**
2453  * proc_dointvec_minmax - read a vector of integers with min/max values
2454  * @table: the sysctl table
2455  * @write: %TRUE if this is a write to the sysctl file
2456  * @buffer: the user buffer
2457  * @lenp: the size of the user buffer
2458  * @ppos: file position
2459  *
2460  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2461  * values from/to the user buffer, treated as an ASCII string.
2462  *
2463  * This routine will ensure the values are within the range specified by
2464  * table->extra1 (min) and table->extra2 (max).
2465  *
2466  * Returns 0 on success.
2467  */
2468 int proc_dointvec_minmax(struct ctl_table *table, int write,
2469                   void __user *buffer, size_t *lenp, loff_t *ppos)
2470 {
2471         struct do_proc_dointvec_minmax_conv_param param = {
2472                 .min = (int *) table->extra1,
2473                 .max = (int *) table->extra2,
2474         };
2475         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2476                                 do_proc_dointvec_minmax_conv, &param);
2477 }
2478
2479 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2480                                      void __user *buffer,
2481                                      size_t *lenp, loff_t *ppos,
2482                                      unsigned long convmul,
2483                                      unsigned long convdiv)
2484 {
2485         unsigned long *i, *min, *max;
2486         int vleft, first = 1, err = 0;
2487         unsigned long page = 0;
2488         size_t left;
2489         char *kbuf;
2490
2491         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2492                 *lenp = 0;
2493                 return 0;
2494         }
2495
2496         i = (unsigned long *) data;
2497         min = (unsigned long *) table->extra1;
2498         max = (unsigned long *) table->extra2;
2499         vleft = table->maxlen / sizeof(unsigned long);
2500         left = *lenp;
2501
2502         if (write) {
2503                 if (left > PAGE_SIZE - 1)
2504                         left = PAGE_SIZE - 1;
2505                 page = __get_free_page(GFP_TEMPORARY);
2506                 kbuf = (char *) page;
2507                 if (!kbuf)
2508                         return -ENOMEM;
2509                 if (copy_from_user(kbuf, buffer, left)) {
2510                         err = -EFAULT;
2511                         goto free;
2512                 }
2513                 kbuf[left] = 0;
2514         }
2515
2516         for (; left && vleft--; i++, first = 0) {
2517                 unsigned long val;
2518
2519                 if (write) {
2520                         bool neg;
2521
2522                         left -= proc_skip_spaces(&kbuf);
2523
2524                         err = proc_get_long(&kbuf, &left, &val, &neg,
2525                                              proc_wspace_sep,
2526                                              sizeof(proc_wspace_sep), NULL);
2527                         if (err)
2528                                 break;
2529                         if (neg)
2530                                 continue;
2531                         if ((min && val < *min) || (max && val > *max))
2532                                 continue;
2533                         *i = val;
2534                 } else {
2535                         val = convdiv * (*i) / convmul;
2536                         if (!first)
2537                                 err = proc_put_char(&buffer, &left, '\t');
2538                         err = proc_put_long(&buffer, &left, val, false);
2539                         if (err)
2540                                 break;
2541                 }
2542         }
2543
2544         if (!write && !first && left && !err)
2545                 err = proc_put_char(&buffer, &left, '\n');
2546         if (write && !err)
2547                 left -= proc_skip_spaces(&kbuf);
2548 free:
2549         if (write) {
2550                 free_page(page);
2551                 if (first)
2552                         return err ? : -EINVAL;
2553         }
2554         *lenp -= left;
2555         *ppos += *lenp;
2556         return err;
2557 }
2558
2559 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2560                                      void __user *buffer,
2561                                      size_t *lenp, loff_t *ppos,
2562                                      unsigned long convmul,
2563                                      unsigned long convdiv)
2564 {
2565         return __do_proc_doulongvec_minmax(table->data, table, write,
2566                         buffer, lenp, ppos, convmul, convdiv);
2567 }
2568
2569 /**
2570  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2571  * @table: the sysctl table
2572  * @write: %TRUE if this is a write to the sysctl file
2573  * @buffer: the user buffer
2574  * @lenp: the size of the user buffer
2575  * @ppos: file position
2576  *
2577  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2578  * values from/to the user buffer, treated as an ASCII string.
2579  *
2580  * This routine will ensure the values are within the range specified by
2581  * table->extra1 (min) and table->extra2 (max).
2582  *
2583  * Returns 0 on success.
2584  */
2585 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2586                            void __user *buffer, size_t *lenp, loff_t *ppos)
2587 {
2588     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2589 }
2590
2591 /**
2592  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2593  * @table: the sysctl table
2594  * @write: %TRUE if this is a write to the sysctl file
2595  * @buffer: the user buffer
2596  * @lenp: the size of the user buffer
2597  * @ppos: file position
2598  *
2599  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2600  * values from/to the user buffer, treated as an ASCII string. The values
2601  * are treated as milliseconds, and converted to jiffies when they are stored.
2602  *
2603  * This routine will ensure the values are within the range specified by
2604  * table->extra1 (min) and table->extra2 (max).
2605  *
2606  * Returns 0 on success.
2607  */
2608 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2609                                       void __user *buffer,
2610                                       size_t *lenp, loff_t *ppos)
2611 {
2612     return do_proc_doulongvec_minmax(table, write, buffer,
2613                                      lenp, ppos, HZ, 1000l);
2614 }
2615
2616
2617 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2618                                          int *valp,
2619                                          int write, void *data)
2620 {
2621         if (write) {
2622                 if (*lvalp > LONG_MAX / HZ)
2623                         return 1;
2624                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2625         } else {
2626                 int val = *valp;
2627                 unsigned long lval;
2628                 if (val < 0) {
2629                         *negp = true;
2630                         lval = (unsigned long)-val;
2631                 } else {
2632                         *negp = false;
2633                         lval = (unsigned long)val;
2634                 }
2635                 *lvalp = lval / HZ;
2636         }
2637         return 0;
2638 }
2639
2640 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2641                                                 int *valp,
2642                                                 int write, void *data)
2643 {
2644         if (write) {
2645                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2646                         return 1;
2647                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2648         } else {
2649                 int val = *valp;
2650                 unsigned long lval;
2651                 if (val < 0) {
2652                         *negp = true;
2653                         lval = (unsigned long)-val;
2654                 } else {
2655                         *negp = false;
2656                         lval = (unsigned long)val;
2657                 }
2658                 *lvalp = jiffies_to_clock_t(lval);
2659         }
2660         return 0;
2661 }
2662
2663 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2664                                             int *valp,
2665                                             int write, void *data)
2666 {
2667         if (write) {
2668                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2669         } else {
2670                 int val = *valp;
2671                 unsigned long lval;
2672                 if (val < 0) {
2673                         *negp = true;
2674                         lval = (unsigned long)-val;
2675                 } else {
2676                         *negp = false;
2677                         lval = (unsigned long)val;
2678                 }
2679                 *lvalp = jiffies_to_msecs(lval);
2680         }
2681         return 0;
2682 }
2683
2684 /**
2685  * proc_dointvec_jiffies - read a vector of integers as seconds
2686  * @table: the sysctl table
2687  * @write: %TRUE if this is a write to the sysctl file
2688  * @buffer: the user buffer
2689  * @lenp: the size of the user buffer
2690  * @ppos: file position
2691  *
2692  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2693  * values from/to the user buffer, treated as an ASCII string.
2694  * The values read are assumed to be in seconds, and are converted into
2695  * jiffies.
2696  *
2697  * Returns 0 on success.
2698  */
2699 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2700                           void __user *buffer, size_t *lenp, loff_t *ppos)
2701 {
2702     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2703                             do_proc_dointvec_jiffies_conv,NULL);
2704 }
2705
2706 /**
2707  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2708  * @table: the sysctl table
2709  * @write: %TRUE if this is a write to the sysctl file
2710  * @buffer: the user buffer
2711  * @lenp: the size of the user buffer
2712  * @ppos: pointer to the file position
2713  *
2714  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2715  * values from/to the user buffer, treated as an ASCII string.
2716  * The values read are assumed to be in 1/USER_HZ seconds, and
2717  * are converted into jiffies.
2718  *
2719  * Returns 0 on success.
2720  */
2721 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2722                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2723 {
2724     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2725                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2726 }
2727
2728 /**
2729  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2730  * @table: the sysctl table
2731  * @write: %TRUE if this is a write to the sysctl file
2732  * @buffer: the user buffer
2733  * @lenp: the size of the user buffer
2734  * @ppos: file position
2735  * @ppos: the current position in the file
2736  *
2737  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2738  * values from/to the user buffer, treated as an ASCII string.
2739  * The values read are assumed to be in 1/1000 seconds, and
2740  * are converted into jiffies.
2741  *
2742  * Returns 0 on success.
2743  */
2744 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2745                              void __user *buffer, size_t *lenp, loff_t *ppos)
2746 {
2747         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2748                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2749 }
2750
2751 static int proc_do_cad_pid(struct ctl_table *table, int write,
2752                            void __user *buffer, size_t *lenp, loff_t *ppos)
2753 {
2754         struct pid *new_pid;
2755         pid_t tmp;
2756         int r;
2757
2758         tmp = pid_vnr(cad_pid);
2759
2760         r = __do_proc_dointvec(&tmp, table, write, buffer,
2761                                lenp, ppos, NULL, NULL);
2762         if (r || !write)
2763                 return r;
2764
2765         new_pid = find_get_pid(tmp);
2766         if (!new_pid)
2767                 return -ESRCH;
2768
2769         put_pid(xchg(&cad_pid, new_pid));
2770         return 0;
2771 }
2772
2773 /**
2774  * proc_do_large_bitmap - read/write from/to a large bitmap
2775  * @table: the sysctl table
2776  * @write: %TRUE if this is a write to the sysctl file
2777  * @buffer: the user buffer
2778  * @lenp: the size of the user buffer
2779  * @ppos: file position
2780  *
2781  * The bitmap is stored at table->data and the bitmap length (in bits)
2782  * in table->maxlen.
2783  *
2784  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2785  * large bitmaps may be represented in a compact manner. Writing into
2786  * the file will clear the bitmap then update it with the given input.
2787  *
2788  * Returns 0 on success.
2789  */
2790 int proc_do_large_bitmap(struct ctl_table *table, int write,
2791                          void __user *buffer, size_t *lenp, loff_t *ppos)
2792 {
2793         int err = 0;
2794         bool first = 1;
2795         size_t left = *lenp;
2796         unsigned long bitmap_len = table->maxlen;
2797         unsigned long *bitmap = (unsigned long *) table->data;
2798         unsigned long *tmp_bitmap = NULL;
2799         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2800
2801         if (!bitmap_len || !left || (*ppos && !write)) {
2802                 *lenp = 0;
2803                 return 0;
2804         }
2805
2806         if (write) {
2807                 unsigned long page = 0;
2808                 char *kbuf;
2809
2810                 if (left > PAGE_SIZE - 1)
2811                         left = PAGE_SIZE - 1;
2812
2813                 page = __get_free_page(GFP_TEMPORARY);
2814                 kbuf = (char *) page;
2815                 if (!kbuf)
2816                         return -ENOMEM;
2817                 if (copy_from_user(kbuf, buffer, left)) {
2818                         free_page(page);
2819                         return -EFAULT;
2820                 }
2821                 kbuf[left] = 0;
2822
2823                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2824                                      GFP_KERNEL);
2825                 if (!tmp_bitmap) {
2826                         free_page(page);
2827                         return -ENOMEM;
2828                 }
2829                 proc_skip_char(&kbuf, &left, '\n');
2830                 while (!err && left) {
2831                         unsigned long val_a, val_b;
2832                         bool neg;
2833
2834                         err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2835                                              sizeof(tr_a), &c);
2836                         if (err)
2837                                 break;
2838                         if (val_a >= bitmap_len || neg) {
2839                                 err = -EINVAL;
2840                                 break;
2841                         }
2842
2843                         val_b = val_a;
2844                         if (left) {
2845                                 kbuf++;
2846                                 left--;
2847                         }
2848
2849                         if (c == '-') {
2850                                 err = proc_get_long(&kbuf, &left, &val_b,
2851                                                      &neg, tr_b, sizeof(tr_b),
2852                                                      &c);
2853                                 if (err)
2854                                         break;
2855                                 if (val_b >= bitmap_len || neg ||
2856                                     val_a > val_b) {
2857                                         err = -EINVAL;
2858                                         break;
2859                                 }
2860                                 if (left) {
2861                                         kbuf++;
2862                                         left--;
2863                                 }
2864                         }
2865
2866                         while (val_a <= val_b)
2867                                 set_bit(val_a++, tmp_bitmap);
2868
2869                         first = 0;
2870                         proc_skip_char(&kbuf, &left, '\n');
2871                 }
2872                 free_page(page);
2873         } else {
2874                 unsigned long bit_a, bit_b = 0;
2875
2876                 while (left) {
2877                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2878                         if (bit_a >= bitmap_len)
2879                                 break;
2880                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2881                                                    bit_a + 1) - 1;
2882
2883                         if (!first) {
2884                                 err = proc_put_char(&buffer, &left, ',');
2885                                 if (err)
2886                                         break;
2887                         }
2888                         err = proc_put_long(&buffer, &left, bit_a, false);
2889                         if (err)
2890                                 break;
2891                         if (bit_a != bit_b) {
2892                                 err = proc_put_char(&buffer, &left, '-');
2893                                 if (err)
2894                                         break;
2895                                 err = proc_put_long(&buffer, &left, bit_b, false);
2896                                 if (err)
2897                                         break;
2898                         }
2899
2900                         first = 0; bit_b++;
2901                 }
2902                 if (!err)
2903                         err = proc_put_char(&buffer, &left, '\n');
2904         }
2905
2906         if (!err) {
2907                 if (write) {
2908                         if (*ppos)
2909                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2910                         else
2911                                 memcpy(bitmap, tmp_bitmap,
2912                                         BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2913                 }
2914                 kfree(tmp_bitmap);
2915                 *lenp -= left;
2916                 *ppos += *lenp;
2917                 return 0;
2918         } else {
2919                 kfree(tmp_bitmap);
2920                 return err;
2921         }
2922 }
2923
2924 #else /* CONFIG_PROC_SYSCTL */
2925
2926 int proc_dostring(struct ctl_table *table, int write,
2927                   void __user *buffer, size_t *lenp, loff_t *ppos)
2928 {
2929         return -ENOSYS;
2930 }
2931
2932 int proc_dointvec(struct ctl_table *table, int write,
2933                   void __user *buffer, size_t *lenp, loff_t *ppos)
2934 {
2935         return -ENOSYS;
2936 }
2937
2938 int proc_dointvec_minmax(struct ctl_table *table, int write,
2939                     void __user *buffer, size_t *lenp, loff_t *ppos)
2940 {
2941         return -ENOSYS;
2942 }
2943
2944 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2945                     void __user *buffer, size_t *lenp, loff_t *ppos)
2946 {
2947         return -ENOSYS;
2948 }
2949
2950 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2951                     void __user *buffer, size_t *lenp, loff_t *ppos)
2952 {
2953         return -ENOSYS;
2954 }
2955
2956 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2957                              void __user *buffer, size_t *lenp, loff_t *ppos)
2958 {
2959         return -ENOSYS;
2960 }
2961
2962 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2963                     void __user *buffer, size_t *lenp, loff_t *ppos)
2964 {
2965         return -ENOSYS;
2966 }
2967
2968 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2969                                       void __user *buffer,
2970                                       size_t *lenp, loff_t *ppos)
2971 {
2972     return -ENOSYS;
2973 }
2974
2975
2976 #endif /* CONFIG_PROC_SYSCTL */
2977
2978 /*
2979  * No sense putting this after each symbol definition, twice,
2980  * exception granted :-)
2981  */
2982 EXPORT_SYMBOL(proc_dointvec);
2983 EXPORT_SYMBOL(proc_dointvec_jiffies);
2984 EXPORT_SYMBOL(proc_dointvec_minmax);
2985 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2986 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2987 EXPORT_SYMBOL(proc_dostring);
2988 EXPORT_SYMBOL(proc_doulongvec_minmax);
2989 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2990 EXPORT_SYMBOL(register_sysctl_table);
2991 EXPORT_SYMBOL(register_sysctl_paths);
2992 EXPORT_SYMBOL(unregister_sysctl_table);