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