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