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/proc_fs.h>
  27 #include <linux/security.h>
  28 #include <linux/ctype.h>
  29 #include <linux/utsname.h>
  30 #include <linux/smp_lock.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/hugetlb.h>
  40 #include <linux/initrd.h>
  41 #include <linux/key.h>
  42 #include <linux/times.h>
  43 #include <linux/limits.h>
  44 #include <linux/dcache.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/vmstat.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49 #include <linux/reboot.h>
  50 #include <linux/ftrace.h>
  51 #include <linux/slow-work.h>
  52
  53 #include <asm/uaccess.h>
  54 #include <asm/processor.h>
  55
  56 #ifdef CONFIG_X86
  57 #include <asm/nmi.h>
  58 #include <asm/stacktrace.h>
  59 #include <asm/io.h>
  60 #endif
  61
  62 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  63
  64 #if defined(CONFIG_SYSCTL)
  65
  66 /* External variables not in a header file. */
  67 extern int C_A_D;
  68 extern int print_fatal_signals;
  69 extern int sysctl_overcommit_memory;
  70 extern int sysctl_overcommit_ratio;
  71 extern int sysctl_panic_on_oom;
  72 extern int sysctl_oom_kill_allocating_task;
  73 extern int sysctl_oom_dump_tasks;
  74 extern int max_threads;
  75 extern int core_uses_pid;
  76 extern int suid_dumpable;
  77 extern char core_pattern[];
  78 extern int pid_max;
  79 extern int min_free_kbytes;
  80 extern int pid_max_min, pid_max_max;
  81 extern int sysctl_drop_caches;
  82 extern int percpu_pagelist_fraction;
  83 extern int compat_log;
  84 extern int latencytop_enabled;
  85 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  86 #ifndef CONFIG_MMU
  87 extern int sysctl_nr_trim_pages;
  88 #endif
  89 #ifdef CONFIG_RCU_TORTURE_TEST
  90 extern int rcutorture_runnable;
  91 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  92
  93 /* Constants used for minimum and  maximum */
  94 #ifdef CONFIG_DETECT_SOFTLOCKUP
  95 static int sixty = 60;
  96 static int neg_one = -1;
  97 #endif
  98
  99 static int zero;
 100 static int __maybe_unused one = 1;
 101 static int __maybe_unused two = 2;
 102 static unsigned long one_ul = 1;
 103 static int one_hundred = 100;
 104 static int one_thousand = 1000;
 105
 106 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 107 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 108
 109 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 110 static int maxolduid = 65535;
 111 static int minolduid;
 112 static int min_percpu_pagelist_fract = 8;
 113
 114 static int ngroups_max = NGROUPS_MAX;
 115
 116 #ifdef CONFIG_MODULES
 117 extern char modprobe_path[];
 118 #endif
 119 #ifdef CONFIG_CHR_DEV_SG
 120 extern int sg_big_buff;
 121 #endif
 122
 123 #ifdef CONFIG_SPARC
 124 #include <asm/system.h>
 125 #endif
 126
 127 #ifdef CONFIG_SPARC64
 128 extern int sysctl_tsb_ratio;
 129 #endif
 130
 131 #ifdef __hppa__
 132 extern int pwrsw_enabled;
 133 extern int unaligned_enabled;
 134 #endif
 135
 136 #ifdef CONFIG_S390
 137 #ifdef CONFIG_MATHEMU
 138 extern int sysctl_ieee_emulation_warnings;
 139 #endif
 140 extern int sysctl_userprocess_debug;
 141 extern int spin_retry;
 142 #endif
 143
 144 #ifdef CONFIG_BSD_PROCESS_ACCT
 145 extern int acct_parm[];
 146 #endif
 147
 148 #ifdef CONFIG_IA64
 149 extern int no_unaligned_warning;
 150 extern int unaligned_dump_stack;
 151 #endif
 152
 153 #ifdef CONFIG_RT_MUTEXES
 154 extern int max_lock_depth;
 155 #endif
 156
 157 #ifdef CONFIG_PROC_SYSCTL
 158 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
 159                   void __user *buffer, size_t *lenp, loff_t *ppos);
 160 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 161                                void __user *buffer, size_t *lenp, loff_t *ppos);
 162 #endif
 163
 164 static struct ctl_table root_table[];
 165 static struct ctl_table_root sysctl_table_root;
 166 static struct ctl_table_header root_table_header = {
 167         .count = 1,
 168         .ctl_table = root_table,
 169         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 170         .root = &sysctl_table_root,
 171         .set = &sysctl_table_root.default_set,
 172 };
 173 static struct ctl_table_root sysctl_table_root = {
 174         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 175         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 176 };
 177
 178 static struct ctl_table kern_table[];
 179 static struct ctl_table vm_table[];
 180 static struct ctl_table fs_table[];
 181 static struct ctl_table debug_table[];
 182 static struct ctl_table dev_table[];
 183 extern struct ctl_table random_table[];
 184 #ifdef CONFIG_INOTIFY_USER
 185 extern struct ctl_table inotify_table[];
 186 #endif
 187 #ifdef CONFIG_EPOLL
 188 extern struct ctl_table epoll_table[];
 189 #endif
 190
 191 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 192 int sysctl_legacy_va_layout;
 193 #endif
 194
 195 extern int prove_locking;
 196 extern int lock_stat;
 197
 198 /* The default sysctl tables: */
 199
 200 static struct ctl_table root_table[] = {
 201         {
 202                 .ctl_name       = CTL_KERN,
 203                 .procname       = "kernel",
 204                 .mode           = 0555,
 205                 .child          = kern_table,
 206         },
 207         {
 208                 .ctl_name       = CTL_VM,
 209                 .procname       = "vm",
 210                 .mode           = 0555,
 211                 .child          = vm_table,
 212         },
 213         {
 214                 .ctl_name       = CTL_FS,
 215                 .procname       = "fs",
 216                 .mode           = 0555,
 217                 .child          = fs_table,
 218         },
 219         {
 220                 .ctl_name       = CTL_DEBUG,
 221                 .procname       = "debug",
 222                 .mode           = 0555,
 223                 .child          = debug_table,
 224         },
 225         {
 226                 .ctl_name       = CTL_DEV,
 227                 .procname       = "dev",
 228                 .mode           = 0555,
 229                 .child          = dev_table,
 230         },
 231 /*
 232  * NOTE: do not add new entries to this table unless you have read
 233  * Documentation/sysctl/ctl_unnumbered.txt
 234  */
 235         { .ctl_name = 0 }
 236 };
 237
 238 #ifdef CONFIG_SCHED_DEBUG
 239 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 240 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 241 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 242 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 243 #endif
 244
 245 static struct ctl_table kern_table[] = {
 246 #ifdef CONFIG_SCHED_DEBUG
 247         {
 248                 .ctl_name       = CTL_UNNUMBERED,
 249                 .procname       = "sched_min_granularity_ns",
 250                 .data           = &sysctl_sched_min_granularity,
 251                 .maxlen         = sizeof(unsigned int),
 252                 .mode           = 0644,
 253                 .proc_handler   = &sched_nr_latency_handler,
 254                 .strategy       = &sysctl_intvec,
 255                 .extra1         = &min_sched_granularity_ns,
 256                 .extra2         = &max_sched_granularity_ns,
 257         },
 258         {
 259                 .ctl_name       = CTL_UNNUMBERED,
 260                 .procname       = "sched_latency_ns",
 261                 .data           = &sysctl_sched_latency,
 262                 .maxlen         = sizeof(unsigned int),
 263                 .mode           = 0644,
 264                 .proc_handler   = &sched_nr_latency_handler,
 265                 .strategy       = &sysctl_intvec,
 266                 .extra1         = &min_sched_granularity_ns,
 267                 .extra2         = &max_sched_granularity_ns,
 268         },
 269         {
 270                 .ctl_name       = CTL_UNNUMBERED,
 271                 .procname       = "sched_wakeup_granularity_ns",
 272                 .data           = &sysctl_sched_wakeup_granularity,
 273                 .maxlen         = sizeof(unsigned int),
 274                 .mode           = 0644,
 275                 .proc_handler   = &proc_dointvec_minmax,
 276                 .strategy       = &sysctl_intvec,
 277                 .extra1         = &min_wakeup_granularity_ns,
 278                 .extra2         = &max_wakeup_granularity_ns,
 279         },
 280         {
 281                 .ctl_name       = CTL_UNNUMBERED,
 282                 .procname       = "sched_shares_ratelimit",
 283                 .data           = &sysctl_sched_shares_ratelimit,
 284                 .maxlen         = sizeof(unsigned int),
 285                 .mode           = 0644,
 286                 .proc_handler   = &proc_dointvec,
 287         },
 288         {
 289                 .ctl_name       = CTL_UNNUMBERED,
 290                 .procname       = "sched_shares_thresh",
 291                 .data           = &sysctl_sched_shares_thresh,
 292                 .maxlen         = sizeof(unsigned int),
 293                 .mode           = 0644,
 294                 .proc_handler   = &proc_dointvec_minmax,
 295                 .strategy       = &sysctl_intvec,
 296                 .extra1         = &zero,
 297         },
 298         {
 299                 .ctl_name       = CTL_UNNUMBERED,
 300                 .procname       = "sched_child_runs_first",
 301                 .data           = &sysctl_sched_child_runs_first,
 302                 .maxlen         = sizeof(unsigned int),
 303                 .mode           = 0644,
 304                 .proc_handler   = &proc_dointvec,
 305         },
 306         {
 307                 .ctl_name       = CTL_UNNUMBERED,
 308                 .procname       = "sched_features",
 309                 .data           = &sysctl_sched_features,
 310                 .maxlen         = sizeof(unsigned int),
 311                 .mode           = 0644,
 312                 .proc_handler   = &proc_dointvec,
 313         },
 314         {
 315                 .ctl_name       = CTL_UNNUMBERED,
 316                 .procname       = "sched_migration_cost",
 317                 .data           = &sysctl_sched_migration_cost,
 318                 .maxlen         = sizeof(unsigned int),
 319                 .mode           = 0644,
 320                 .proc_handler   = &proc_dointvec,
 321         },
 322         {
 323                 .ctl_name       = CTL_UNNUMBERED,
 324                 .procname       = "sched_nr_migrate",
 325                 .data           = &sysctl_sched_nr_migrate,
 326                 .maxlen         = sizeof(unsigned int),
 327                 .mode           = 0644,
 328                 .proc_handler   = &proc_dointvec,
 329         },
 330 #endif
 331         {
 332                 .ctl_name       = CTL_UNNUMBERED,
 333                 .procname       = "sched_rt_period_us",
 334                 .data           = &sysctl_sched_rt_period,
 335                 .maxlen         = sizeof(unsigned int),
 336                 .mode           = 0644,
 337                 .proc_handler   = &sched_rt_handler,
 338         },
 339         {
 340                 .ctl_name       = CTL_UNNUMBERED,
 341                 .procname       = "sched_rt_runtime_us",
 342                 .data           = &sysctl_sched_rt_runtime,
 343                 .maxlen         = sizeof(int),
 344                 .mode           = 0644,
 345                 .proc_handler   = &sched_rt_handler,
 346         },
 347         {
 348                 .ctl_name       = CTL_UNNUMBERED,
 349                 .procname       = "sched_compat_yield",
 350                 .data           = &sysctl_sched_compat_yield,
 351                 .maxlen         = sizeof(unsigned int),
 352                 .mode           = 0644,
 353                 .proc_handler   = &proc_dointvec,
 354         },
 355 #ifdef CONFIG_PROVE_LOCKING
 356         {
 357                 .ctl_name       = CTL_UNNUMBERED,
 358                 .procname       = "prove_locking",
 359                 .data           = &prove_locking,
 360                 .maxlen         = sizeof(int),
 361                 .mode           = 0644,
 362                 .proc_handler   = &proc_dointvec,
 363         },
 364 #endif
 365 #ifdef CONFIG_LOCK_STAT
 366         {
 367                 .ctl_name       = CTL_UNNUMBERED,
 368                 .procname       = "lock_stat",
 369                 .data           = &lock_stat,
 370                 .maxlen         = sizeof(int),
 371                 .mode           = 0644,
 372                 .proc_handler   = &proc_dointvec,
 373         },
 374 #endif
 375         {
 376                 .ctl_name       = KERN_PANIC,
 377                 .procname       = "panic",
 378                 .data           = &panic_timeout,
 379                 .maxlen         = sizeof(int),
 380                 .mode           = 0644,
 381                 .proc_handler   = &proc_dointvec,
 382         },
 383         {
 384                 .ctl_name       = KERN_CORE_USES_PID,
 385                 .procname       = "core_uses_pid",
 386                 .data           = &core_uses_pid,
 387                 .maxlen         = sizeof(int),
 388                 .mode           = 0644,
 389                 .proc_handler   = &proc_dointvec,
 390         },
 391         {
 392                 .ctl_name       = KERN_CORE_PATTERN,
 393                 .procname       = "core_pattern",
 394                 .data           = core_pattern,
 395                 .maxlen         = CORENAME_MAX_SIZE,
 396                 .mode           = 0644,
 397                 .proc_handler   = &proc_dostring,
 398                 .strategy       = &sysctl_string,
 399         },
 400 #ifdef CONFIG_PROC_SYSCTL
 401         {
 402                 .procname       = "tainted",
 403                 .maxlen         = sizeof(long),
 404                 .mode           = 0644,
 405                 .proc_handler   = &proc_taint,
 406         },
 407 #endif
 408 #ifdef CONFIG_LATENCYTOP
 409         {
 410                 .procname       = "latencytop",
 411                 .data           = &latencytop_enabled,
 412                 .maxlen         = sizeof(int),
 413                 .mode           = 0644,
 414                 .proc_handler   = &proc_dointvec,
 415         },
 416 #endif
 417 #ifdef CONFIG_BLK_DEV_INITRD
 418         {
 419                 .ctl_name       = KERN_REALROOTDEV,
 420                 .procname       = "real-root-dev",
 421                 .data           = &real_root_dev,
 422                 .maxlen         = sizeof(int),
 423                 .mode           = 0644,
 424                 .proc_handler   = &proc_dointvec,
 425         },
 426 #endif
 427         {
 428                 .ctl_name       = CTL_UNNUMBERED,
 429                 .procname       = "print-fatal-signals",
 430                 .data           = &print_fatal_signals,
 431                 .maxlen         = sizeof(int),
 432                 .mode           = 0644,
 433                 .proc_handler   = &proc_dointvec,
 434         },
 435 #ifdef CONFIG_SPARC
 436         {
 437                 .ctl_name       = KERN_SPARC_REBOOT,
 438                 .procname       = "reboot-cmd",
 439                 .data           = reboot_command,
 440                 .maxlen         = 256,
 441                 .mode           = 0644,
 442                 .proc_handler   = &proc_dostring,
 443                 .strategy       = &sysctl_string,
 444         },
 445         {
 446                 .ctl_name       = KERN_SPARC_STOP_A,
 447                 .procname       = "stop-a",
 448                 .data           = &stop_a_enabled,
 449                 .maxlen         = sizeof (int),
 450                 .mode           = 0644,
 451                 .proc_handler   = &proc_dointvec,
 452         },
 453         {
 454                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 455                 .procname       = "scons-poweroff",
 456                 .data           = &scons_pwroff,
 457                 .maxlen         = sizeof (int),
 458                 .mode           = 0644,
 459                 .proc_handler   = &proc_dointvec,
 460         },
 461 #endif
 462 #ifdef CONFIG_SPARC64
 463         {
 464                 .ctl_name       = CTL_UNNUMBERED,
 465                 .procname       = "tsb-ratio",
 466                 .data           = &sysctl_tsb_ratio,
 467                 .maxlen         = sizeof (int),
 468                 .mode           = 0644,
 469                 .proc_handler   = &proc_dointvec,
 470         },
 471 #endif
 472 #ifdef __hppa__
 473         {
 474                 .ctl_name       = KERN_HPPA_PWRSW,
 475                 .procname       = "soft-power",
 476                 .data           = &pwrsw_enabled,
 477                 .maxlen         = sizeof (int),
 478                 .mode           = 0644,
 479                 .proc_handler   = &proc_dointvec,
 480         },
 481         {
 482                 .ctl_name       = KERN_HPPA_UNALIGNED,
 483                 .procname       = "unaligned-trap",
 484                 .data           = &unaligned_enabled,
 485                 .maxlen         = sizeof (int),
 486                 .mode           = 0644,
 487                 .proc_handler   = &proc_dointvec,
 488         },
 489 #endif
 490         {
 491                 .ctl_name       = KERN_CTLALTDEL,
 492                 .procname       = "ctrl-alt-del",
 493                 .data           = &C_A_D,
 494                 .maxlen         = sizeof(int),
 495                 .mode           = 0644,
 496                 .proc_handler   = &proc_dointvec,
 497         },
 498 #ifdef CONFIG_FUNCTION_TRACER
 499         {
 500                 .ctl_name       = CTL_UNNUMBERED,
 501                 .procname       = "ftrace_enabled",
 502                 .data           = &ftrace_enabled,
 503                 .maxlen         = sizeof(int),
 504                 .mode           = 0644,
 505                 .proc_handler   = &ftrace_enable_sysctl,
 506         },
 507 #endif
 508 #ifdef CONFIG_STACK_TRACER
 509         {
 510                 .ctl_name       = CTL_UNNUMBERED,
 511                 .procname       = "stack_tracer_enabled",
 512                 .data           = &stack_tracer_enabled,
 513                 .maxlen         = sizeof(int),
 514                 .mode           = 0644,
 515                 .proc_handler   = &stack_trace_sysctl,
 516         },
 517 #endif
 518 #ifdef CONFIG_TRACING
 519         {
 520                 .ctl_name       = CTL_UNNUMBERED,
 521                 .procname       = "ftrace_dump_on_oops",
 522                 .data           = &ftrace_dump_on_oops,
 523                 .maxlen         = sizeof(int),
 524                 .mode           = 0644,
 525                 .proc_handler   = &proc_dointvec,
 526         },
 527 #endif
 528 #ifdef CONFIG_MODULES
 529         {
 530                 .ctl_name       = KERN_MODPROBE,
 531                 .procname       = "modprobe",
 532                 .data           = &modprobe_path,
 533                 .maxlen         = KMOD_PATH_LEN,
 534                 .mode           = 0644,
 535                 .proc_handler   = &proc_dostring,
 536                 .strategy       = &sysctl_string,
 537         },
 538 #endif
 539 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 540         {
 541                 .ctl_name       = KERN_HOTPLUG,
 542                 .procname       = "hotplug",
 543                 .data           = &uevent_helper,
 544                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 545                 .mode           = 0644,
 546                 .proc_handler   = &proc_dostring,
 547                 .strategy       = &sysctl_string,
 548         },
 549 #endif
 550 #ifdef CONFIG_CHR_DEV_SG
 551         {
 552                 .ctl_name       = KERN_SG_BIG_BUFF,
 553                 .procname       = "sg-big-buff",
 554                 .data           = &sg_big_buff,
 555                 .maxlen         = sizeof (int),
 556                 .mode           = 0444,
 557                 .proc_handler   = &proc_dointvec,
 558         },
 559 #endif
 560 #ifdef CONFIG_BSD_PROCESS_ACCT
 561         {
 562                 .ctl_name       = KERN_ACCT,
 563                 .procname       = "acct",
 564                 .data           = &acct_parm,
 565                 .maxlen         = 3*sizeof(int),
 566                 .mode           = 0644,
 567                 .proc_handler   = &proc_dointvec,
 568         },
 569 #endif
 570 #ifdef CONFIG_MAGIC_SYSRQ
 571         {
 572                 .ctl_name       = KERN_SYSRQ,
 573                 .procname       = "sysrq",
 574                 .data           = &__sysrq_enabled,
 575                 .maxlen         = sizeof (int),
 576                 .mode           = 0644,
 577                 .proc_handler   = &proc_dointvec,
 578         },
 579 #endif
 580 #ifdef CONFIG_PROC_SYSCTL
 581         {
 582                 .procname       = "cad_pid",
 583                 .data           = NULL,
 584                 .maxlen         = sizeof (int),
 585                 .mode           = 0600,
 586                 .proc_handler   = &proc_do_cad_pid,
 587         },
 588 #endif
 589         {
 590                 .ctl_name       = KERN_MAX_THREADS,
 591                 .procname       = "threads-max",
 592                 .data           = &max_threads,
 593                 .maxlen         = sizeof(int),
 594                 .mode           = 0644,
 595                 .proc_handler   = &proc_dointvec,
 596         },
 597         {
 598                 .ctl_name       = KERN_RANDOM,
 599                 .procname       = "random",
 600                 .mode           = 0555,
 601                 .child          = random_table,
 602         },
 603         {
 604                 .ctl_name       = KERN_OVERFLOWUID,
 605                 .procname       = "overflowuid",
 606                 .data           = &overflowuid,
 607                 .maxlen         = sizeof(int),
 608                 .mode           = 0644,
 609                 .proc_handler   = &proc_dointvec_minmax,
 610                 .strategy       = &sysctl_intvec,
 611                 .extra1         = &minolduid,
 612                 .extra2         = &maxolduid,
 613         },
 614         {
 615                 .ctl_name       = KERN_OVERFLOWGID,
 616                 .procname       = "overflowgid",
 617                 .data           = &overflowgid,
 618                 .maxlen         = sizeof(int),
 619                 .mode           = 0644,
 620                 .proc_handler   = &proc_dointvec_minmax,
 621                 .strategy       = &sysctl_intvec,
 622                 .extra1         = &minolduid,
 623                 .extra2         = &maxolduid,
 624         },
 625 #ifdef CONFIG_S390
 626 #ifdef CONFIG_MATHEMU
 627         {
 628                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 629                 .procname       = "ieee_emulation_warnings",
 630                 .data           = &sysctl_ieee_emulation_warnings,
 631                 .maxlen         = sizeof(int),
 632                 .mode           = 0644,
 633                 .proc_handler   = &proc_dointvec,
 634         },
 635 #endif
 636         {
 637                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 638                 .procname       = "userprocess_debug",
 639                 .data           = &sysctl_userprocess_debug,
 640                 .maxlen         = sizeof(int),
 641                 .mode           = 0644,
 642                 .proc_handler   = &proc_dointvec,
 643         },
 644 #endif
 645         {
 646                 .ctl_name       = KERN_PIDMAX,
 647                 .procname       = "pid_max",
 648                 .data           = &pid_max,
 649                 .maxlen         = sizeof (int),
 650                 .mode           = 0644,
 651                 .proc_handler   = &proc_dointvec_minmax,
 652                 .strategy       = sysctl_intvec,
 653                 .extra1         = &pid_max_min,
 654                 .extra2         = &pid_max_max,
 655         },
 656         {
 657                 .ctl_name       = KERN_PANIC_ON_OOPS,
 658                 .procname       = "panic_on_oops",
 659                 .data           = &panic_on_oops,
 660                 .maxlen         = sizeof(int),
 661                 .mode           = 0644,
 662                 .proc_handler   = &proc_dointvec,
 663         },
 664 #if defined CONFIG_PRINTK
 665         {
 666                 .ctl_name       = KERN_PRINTK,
 667                 .procname       = "printk",
 668                 .data           = &console_loglevel,
 669                 .maxlen         = 4*sizeof(int),
 670                 .mode           = 0644,
 671                 .proc_handler   = &proc_dointvec,
 672         },
 673         {
 674                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 675                 .procname       = "printk_ratelimit",
 676                 .data           = &printk_ratelimit_state.interval,
 677                 .maxlen         = sizeof(int),
 678                 .mode           = 0644,
 679                 .proc_handler   = &proc_dointvec_jiffies,
 680                 .strategy       = &sysctl_jiffies,
 681         },
 682         {
 683                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 684                 .procname       = "printk_ratelimit_burst",
 685                 .data           = &printk_ratelimit_state.burst,
 686                 .maxlen         = sizeof(int),
 687                 .mode           = 0644,
 688                 .proc_handler   = &proc_dointvec,
 689         },
 690 #endif
 691         {
 692                 .ctl_name       = KERN_NGROUPS_MAX,
 693                 .procname       = "ngroups_max",
 694                 .data           = &ngroups_max,
 695                 .maxlen         = sizeof (int),
 696                 .mode           = 0444,
 697                 .proc_handler   = &proc_dointvec,
 698         },
 699 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 700         {
 701                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 702                 .procname       = "unknown_nmi_panic",
 703                 .data           = &unknown_nmi_panic,
 704                 .maxlen         = sizeof (int),
 705                 .mode           = 0644,
 706                 .proc_handler   = &proc_dointvec,
 707         },
 708         {
 709                 .procname       = "nmi_watchdog",
 710                 .data           = &nmi_watchdog_enabled,
 711                 .maxlen         = sizeof (int),
 712                 .mode           = 0644,
 713                 .proc_handler   = &proc_nmi_enabled,
 714         },
 715 #endif
 716 #if defined(CONFIG_X86)
 717         {
 718                 .ctl_name       = KERN_PANIC_ON_NMI,
 719                 .procname       = "panic_on_unrecovered_nmi",
 720                 .data           = &panic_on_unrecovered_nmi,
 721                 .maxlen         = sizeof(int),
 722                 .mode           = 0644,
 723                 .proc_handler   = &proc_dointvec,
 724         },
 725         {
 726                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 727                 .procname       = "bootloader_type",
 728                 .data           = &bootloader_type,
 729                 .maxlen         = sizeof (int),
 730                 .mode           = 0444,
 731                 .proc_handler   = &proc_dointvec,
 732         },
 733         {
 734                 .ctl_name       = CTL_UNNUMBERED,
 735                 .procname       = "kstack_depth_to_print",
 736                 .data           = &kstack_depth_to_print,
 737                 .maxlen         = sizeof(int),
 738                 .mode           = 0644,
 739                 .proc_handler   = &proc_dointvec,
 740         },
 741         {
 742                 .ctl_name       = CTL_UNNUMBERED,
 743                 .procname       = "io_delay_type",
 744                 .data           = &io_delay_type,
 745                 .maxlen         = sizeof(int),
 746                 .mode           = 0644,
 747                 .proc_handler   = &proc_dointvec,
 748         },
 749 #endif
 750 #if defined(CONFIG_MMU)
 751         {
 752                 .ctl_name       = KERN_RANDOMIZE,
 753                 .procname       = "randomize_va_space",
 754                 .data           = &randomize_va_space,
 755                 .maxlen         = sizeof(int),
 756                 .mode           = 0644,
 757                 .proc_handler   = &proc_dointvec,
 758         },
 759 #endif
 760 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 761         {
 762                 .ctl_name       = KERN_SPIN_RETRY,
 763                 .procname       = "spin_retry",
 764                 .data           = &spin_retry,
 765                 .maxlen         = sizeof (int),
 766                 .mode           = 0644,
 767                 .proc_handler   = &proc_dointvec,
 768         },
 769 #endif
 770 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 771         {
 772                 .procname       = "acpi_video_flags",
 773                 .data           = &acpi_realmode_flags,
 774                 .maxlen         = sizeof (unsigned long),
 775                 .mode           = 0644,
 776                 .proc_handler   = &proc_doulongvec_minmax,
 777         },
 778 #endif
 779 #ifdef CONFIG_IA64
 780         {
 781                 .ctl_name       = KERN_IA64_UNALIGNED,
 782                 .procname       = "ignore-unaligned-usertrap",
 783                 .data           = &no_unaligned_warning,
 784                 .maxlen         = sizeof (int),
 785                 .mode           = 0644,
 786                 .proc_handler   = &proc_dointvec,
 787         },
 788         {
 789                 .ctl_name       = CTL_UNNUMBERED,
 790                 .procname       = "unaligned-dump-stack",
 791                 .data           = &unaligned_dump_stack,
 792                 .maxlen         = sizeof (int),
 793                 .mode           = 0644,
 794                 .proc_handler   = &proc_dointvec,
 795         },
 796 #endif
 797 #ifdef CONFIG_DETECT_SOFTLOCKUP
 798         {
 799                 .ctl_name       = CTL_UNNUMBERED,
 800                 .procname       = "softlockup_panic",
 801                 .data           = &softlockup_panic,
 802                 .maxlen         = sizeof(int),
 803                 .mode           = 0644,
 804                 .proc_handler   = &proc_dointvec_minmax,
 805                 .strategy       = &sysctl_intvec,
 806                 .extra1         = &zero,
 807                 .extra2         = &one,
 808         },
 809         {
 810                 .ctl_name       = CTL_UNNUMBERED,
 811                 .procname       = "softlockup_thresh",
 812                 .data           = &softlockup_thresh,
 813                 .maxlen         = sizeof(int),
 814                 .mode           = 0644,
 815                 .proc_handler   = &proc_dosoftlockup_thresh,
 816                 .strategy       = &sysctl_intvec,
 817                 .extra1         = &neg_one,
 818                 .extra2         = &sixty,
 819         },
 820 #endif
 821 #ifdef CONFIG_DETECT_HUNG_TASK
 822         {
 823                 .ctl_name       = CTL_UNNUMBERED,
 824                 .procname       = "hung_task_panic",
 825                 .data           = &sysctl_hung_task_panic,
 826                 .maxlen         = sizeof(int),
 827                 .mode           = 0644,
 828                 .proc_handler   = &proc_dointvec_minmax,
 829                 .strategy       = &sysctl_intvec,
 830                 .extra1         = &zero,
 831                 .extra2         = &one,
 832         },
 833         {
 834                 .ctl_name       = CTL_UNNUMBERED,
 835                 .procname       = "hung_task_check_count",
 836                 .data           = &sysctl_hung_task_check_count,
 837                 .maxlen         = sizeof(unsigned long),
 838                 .mode           = 0644,
 839                 .proc_handler   = &proc_doulongvec_minmax,
 840                 .strategy       = &sysctl_intvec,
 841         },
 842         {
 843                 .ctl_name       = CTL_UNNUMBERED,
 844                 .procname       = "hung_task_timeout_secs",
 845                 .data           = &sysctl_hung_task_timeout_secs,
 846                 .maxlen         = sizeof(unsigned long),
 847                 .mode           = 0644,
 848                 .proc_handler   = &proc_dohung_task_timeout_secs,
 849                 .strategy       = &sysctl_intvec,
 850         },
 851         {
 852                 .ctl_name       = CTL_UNNUMBERED,
 853                 .procname       = "hung_task_warnings",
 854                 .data           = &sysctl_hung_task_warnings,
 855                 .maxlen         = sizeof(unsigned long),
 856                 .mode           = 0644,
 857                 .proc_handler   = &proc_doulongvec_minmax,
 858                 .strategy       = &sysctl_intvec,
 859         },
 860 #endif
 861 #ifdef CONFIG_COMPAT
 862         {
 863                 .ctl_name       = KERN_COMPAT_LOG,
 864                 .procname       = "compat-log",
 865                 .data           = &compat_log,
 866                 .maxlen         = sizeof (int),
 867                 .mode           = 0644,
 868                 .proc_handler   = &proc_dointvec,
 869         },
 870 #endif
 871 #ifdef CONFIG_RT_MUTEXES
 872         {
 873                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 874                 .procname       = "max_lock_depth",
 875                 .data           = &max_lock_depth,
 876                 .maxlen         = sizeof(int),
 877                 .mode           = 0644,
 878                 .proc_handler   = &proc_dointvec,
 879         },
 880 #endif
 881         {
 882                 .ctl_name       = CTL_UNNUMBERED,
 883                 .procname       = "poweroff_cmd",
 884                 .data           = &poweroff_cmd,
 885                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 886                 .mode           = 0644,
 887                 .proc_handler   = &proc_dostring,
 888                 .strategy       = &sysctl_string,
 889         },
 890 #ifdef CONFIG_KEYS
 891         {
 892                 .ctl_name       = CTL_UNNUMBERED,
 893                 .procname       = "keys",
 894                 .mode           = 0555,
 895                 .child          = key_sysctls,
 896         },
 897 #endif
 898 #ifdef CONFIG_RCU_TORTURE_TEST
 899         {
 900                 .ctl_name       = CTL_UNNUMBERED,
 901                 .procname       = "rcutorture_runnable",
 902                 .data           = &rcutorture_runnable,
 903                 .maxlen         = sizeof(int),
 904                 .mode           = 0644,
 905                 .proc_handler   = &proc_dointvec,
 906         },
 907 #endif
 908 #ifdef CONFIG_SLOW_WORK
 909         {
 910                 .ctl_name       = CTL_UNNUMBERED,
 911                 .procname       = "slow-work",
 912                 .mode           = 0555,
 913                 .child          = slow_work_sysctls,
 914         },
 915 #endif
 916 /*
 917  * NOTE: do not add new entries to this table unless you have read
 918  * Documentation/sysctl/ctl_unnumbered.txt
 919  */
 920         { .ctl_name = 0 }
 921 };
 922
 923 static struct ctl_table vm_table[] = {
 924         {
 925                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 926                 .procname       = "overcommit_memory",
 927                 .data           = &sysctl_overcommit_memory,
 928                 .maxlen         = sizeof(sysctl_overcommit_memory),
 929                 .mode           = 0644,
 930                 .proc_handler   = &proc_dointvec,
 931         },
 932         {
 933                 .ctl_name       = VM_PANIC_ON_OOM,
 934                 .procname       = "panic_on_oom",
 935                 .data           = &sysctl_panic_on_oom,
 936                 .maxlen         = sizeof(sysctl_panic_on_oom),
 937                 .mode           = 0644,
 938                 .proc_handler   = &proc_dointvec,
 939         },
 940         {
 941                 .ctl_name       = CTL_UNNUMBERED,
 942                 .procname       = "oom_kill_allocating_task",
 943                 .data           = &sysctl_oom_kill_allocating_task,
 944                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 945                 .mode           = 0644,
 946                 .proc_handler   = &proc_dointvec,
 947         },
 948         {
 949                 .ctl_name       = CTL_UNNUMBERED,
 950                 .procname       = "oom_dump_tasks",
 951                 .data           = &sysctl_oom_dump_tasks,
 952                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
 953                 .mode           = 0644,
 954                 .proc_handler   = &proc_dointvec,
 955         },
 956         {
 957                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 958                 .procname       = "overcommit_ratio",
 959                 .data           = &sysctl_overcommit_ratio,
 960                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 961                 .mode           = 0644,
 962                 .proc_handler   = &proc_dointvec,
 963         },
 964         {
 965                 .ctl_name       = VM_PAGE_CLUSTER,
 966                 .procname       = "page-cluster",
 967                 .data           = &page_cluster,
 968                 .maxlen         = sizeof(int),
 969                 .mode           = 0644,
 970                 .proc_handler   = &proc_dointvec,
 971         },
 972         {
 973                 .ctl_name       = VM_DIRTY_BACKGROUND,
 974                 .procname       = "dirty_background_ratio",
 975                 .data           = &dirty_background_ratio,
 976                 .maxlen         = sizeof(dirty_background_ratio),
 977                 .mode           = 0644,
 978                 .proc_handler   = &dirty_background_ratio_handler,
 979                 .strategy       = &sysctl_intvec,
 980                 .extra1         = &zero,
 981                 .extra2         = &one_hundred,
 982         },
 983         {
 984                 .ctl_name       = CTL_UNNUMBERED,
 985                 .procname       = "dirty_background_bytes",
 986                 .data           = &dirty_background_bytes,
 987                 .maxlen         = sizeof(dirty_background_bytes),
 988                 .mode           = 0644,
 989                 .proc_handler   = &dirty_background_bytes_handler,
 990                 .strategy       = &sysctl_intvec,
 991                 .extra1         = &one_ul,
 992         },
 993         {
 994                 .ctl_name       = VM_DIRTY_RATIO,
 995                 .procname       = "dirty_ratio",
 996                 .data           = &vm_dirty_ratio,
 997                 .maxlen         = sizeof(vm_dirty_ratio),
 998                 .mode           = 0644,
 999                 .proc_handler   = &dirty_ratio_handler,
1000                 .strategy       = &sysctl_intvec,
1001                 .extra1         = &zero,
1002                 .extra2         = &one_hundred,
1003         },
1004         {
1005                 .ctl_name       = CTL_UNNUMBERED,
1006                 .procname       = "dirty_bytes",
1007                 .data           = &vm_dirty_bytes,
1008                 .maxlen         = sizeof(vm_dirty_bytes),
1009                 .mode           = 0644,
1010                 .proc_handler   = &dirty_bytes_handler,
1011                 .strategy       = &sysctl_intvec,
1012                 .extra1         = &dirty_bytes_min,
1013         },
1014         {
1015                 .procname       = "dirty_writeback_centisecs",
1016                 .data           = &dirty_writeback_interval,
1017                 .maxlen         = sizeof(dirty_writeback_interval),
1018                 .mode           = 0644,
1019                 .proc_handler   = &dirty_writeback_centisecs_handler,
1020         },
1021         {
1022                 .procname       = "dirty_expire_centisecs",
1023                 .data           = &dirty_expire_interval,
1024                 .maxlen         = sizeof(dirty_expire_interval),
1025                 .mode           = 0644,
1026                 .proc_handler   = &proc_dointvec,
1027         },
1028         {
1029                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1030                 .procname       = "nr_pdflush_threads",
1031                 .data           = &nr_pdflush_threads,
1032                 .maxlen         = sizeof nr_pdflush_threads,
1033                 .mode           = 0444 /* read-only*/,
1034                 .proc_handler   = &proc_dointvec,
1035         },
1036         {
1037                 .ctl_name       = CTL_UNNUMBERED,
1038                 .procname       = "nr_pdflush_threads_min",
1039                 .data           = &nr_pdflush_threads_min,
1040                 .maxlen         = sizeof nr_pdflush_threads_min,
1041                 .mode           = 0644 /* read-write */,
1042                 .proc_handler   = &proc_dointvec_minmax,
1043                 .strategy       = &sysctl_intvec,
1044                 .extra1         = &one,
1045                 .extra2         = &nr_pdflush_threads_max,
1046         },
1047         {
1048                 .ctl_name       = CTL_UNNUMBERED,
1049                 .procname       = "nr_pdflush_threads_max",
1050                 .data           = &nr_pdflush_threads_max,
1051                 .maxlen         = sizeof nr_pdflush_threads_max,
1052                 .mode           = 0644 /* read-write */,
1053                 .proc_handler   = &proc_dointvec_minmax,
1054                 .strategy       = &sysctl_intvec,
1055                 .extra1         = &nr_pdflush_threads_min,
1056                 .extra2         = &one_thousand,
1057         },
1058         {
1059                 .ctl_name       = VM_SWAPPINESS,
1060                 .procname       = "swappiness",
1061                 .data           = &vm_swappiness,
1062                 .maxlen         = sizeof(vm_swappiness),
1063                 .mode           = 0644,
1064                 .proc_handler   = &proc_dointvec_minmax,
1065                 .strategy       = &sysctl_intvec,
1066                 .extra1         = &zero,
1067                 .extra2         = &one_hundred,
1068         },
1069 #ifdef CONFIG_HUGETLB_PAGE
1070          {
1071                 .procname       = "nr_hugepages",
1072                 .data           = NULL,
1073                 .maxlen         = sizeof(unsigned long),
1074                 .mode           = 0644,
1075                 .proc_handler   = &hugetlb_sysctl_handler,
1076                 .extra1         = (void *)&hugetlb_zero,
1077                 .extra2         = (void *)&hugetlb_infinity,
1078          },
1079          {
1080                 .ctl_name       = VM_HUGETLB_GROUP,
1081                 .procname       = "hugetlb_shm_group",
1082                 .data           = &sysctl_hugetlb_shm_group,
1083                 .maxlen         = sizeof(gid_t),
1084                 .mode           = 0644,
1085                 .proc_handler   = &proc_dointvec,
1086          },
1087          {
1088                 .ctl_name       = CTL_UNNUMBERED,
1089                 .procname       = "hugepages_treat_as_movable",
1090                 .data           = &hugepages_treat_as_movable,
1091                 .maxlen         = sizeof(int),
1092                 .mode           = 0644,
1093                 .proc_handler   = &hugetlb_treat_movable_handler,
1094         },
1095         {
1096                 .ctl_name       = CTL_UNNUMBERED,
1097                 .procname       = "nr_overcommit_hugepages",
1098                 .data           = NULL,
1099                 .maxlen         = sizeof(unsigned long),
1100                 .mode           = 0644,
1101                 .proc_handler   = &hugetlb_overcommit_handler,
1102                 .extra1         = (void *)&hugetlb_zero,
1103                 .extra2         = (void *)&hugetlb_infinity,
1104         },
1105 #endif
1106         {
1107                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1108                 .procname       = "lowmem_reserve_ratio",
1109                 .data           = &sysctl_lowmem_reserve_ratio,
1110                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1111                 .mode           = 0644,
1112                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1113                 .strategy       = &sysctl_intvec,
1114         },
1115         {
1116                 .ctl_name       = VM_DROP_PAGECACHE,
1117                 .procname       = "drop_caches",
1118                 .data           = &sysctl_drop_caches,
1119                 .maxlen         = sizeof(int),
1120                 .mode           = 0644,
1121                 .proc_handler   = drop_caches_sysctl_handler,
1122                 .strategy       = &sysctl_intvec,
1123         },
1124         {
1125                 .ctl_name       = VM_MIN_FREE_KBYTES,
1126                 .procname       = "min_free_kbytes",
1127                 .data           = &min_free_kbytes,
1128                 .maxlen         = sizeof(min_free_kbytes),
1129                 .mode           = 0644,
1130                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1131                 .strategy       = &sysctl_intvec,
1132                 .extra1         = &zero,
1133         },
1134         {
1135                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1136                 .procname       = "percpu_pagelist_fraction",
1137                 .data           = &percpu_pagelist_fraction,
1138                 .maxlen         = sizeof(percpu_pagelist_fraction),
1139                 .mode           = 0644,
1140                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1141                 .strategy       = &sysctl_intvec,
1142                 .extra1         = &min_percpu_pagelist_fract,
1143         },
1144 #ifdef CONFIG_MMU
1145         {
1146                 .ctl_name       = VM_MAX_MAP_COUNT,
1147                 .procname       = "max_map_count",
1148                 .data           = &sysctl_max_map_count,
1149                 .maxlen         = sizeof(sysctl_max_map_count),
1150                 .mode           = 0644,
1151                 .proc_handler   = &proc_dointvec
1152         },
1153 #else
1154         {
1155                 .ctl_name       = CTL_UNNUMBERED,
1156                 .procname       = "nr_trim_pages",
1157                 .data           = &sysctl_nr_trim_pages,
1158                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1159                 .mode           = 0644,
1160                 .proc_handler   = &proc_dointvec_minmax,
1161                 .strategy       = &sysctl_intvec,
1162                 .extra1         = &zero,
1163         },
1164 #endif
1165         {
1166                 .ctl_name       = VM_LAPTOP_MODE,
1167                 .procname       = "laptop_mode",
1168                 .data           = &laptop_mode,
1169                 .maxlen         = sizeof(laptop_mode),
1170                 .mode           = 0644,
1171                 .proc_handler   = &proc_dointvec_jiffies,
1172                 .strategy       = &sysctl_jiffies,
1173         },
1174         {
1175                 .ctl_name       = VM_BLOCK_DUMP,
1176                 .procname       = "block_dump",
1177                 .data           = &block_dump,
1178                 .maxlen         = sizeof(block_dump),
1179                 .mode           = 0644,
1180                 .proc_handler   = &proc_dointvec,
1181                 .strategy       = &sysctl_intvec,
1182                 .extra1         = &zero,
1183         },
1184         {
1185                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1186                 .procname       = "vfs_cache_pressure",
1187                 .data           = &sysctl_vfs_cache_pressure,
1188                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1189                 .mode           = 0644,
1190                 .proc_handler   = &proc_dointvec,
1191                 .strategy       = &sysctl_intvec,
1192                 .extra1         = &zero,
1193         },
1194 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1195         {
1196                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1197                 .procname       = "legacy_va_layout",
1198                 .data           = &sysctl_legacy_va_layout,
1199                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1200                 .mode           = 0644,
1201                 .proc_handler   = &proc_dointvec,
1202                 .strategy       = &sysctl_intvec,
1203                 .extra1         = &zero,
1204         },
1205 #endif
1206 #ifdef CONFIG_NUMA
1207         {
1208                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1209                 .procname       = "zone_reclaim_mode",
1210                 .data           = &zone_reclaim_mode,
1211                 .maxlen         = sizeof(zone_reclaim_mode),
1212                 .mode           = 0644,
1213                 .proc_handler   = &proc_dointvec,
1214                 .strategy       = &sysctl_intvec,
1215                 .extra1         = &zero,
1216         },
1217         {
1218                 .ctl_name       = VM_MIN_UNMAPPED,
1219                 .procname       = "min_unmapped_ratio",
1220                 .data           = &sysctl_min_unmapped_ratio,
1221                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1222                 .mode           = 0644,
1223                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1224                 .strategy       = &sysctl_intvec,
1225                 .extra1         = &zero,
1226                 .extra2         = &one_hundred,
1227         },
1228         {
1229                 .ctl_name       = VM_MIN_SLAB,
1230                 .procname       = "min_slab_ratio",
1231                 .data           = &sysctl_min_slab_ratio,
1232                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1233                 .mode           = 0644,
1234                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1235                 .strategy       = &sysctl_intvec,
1236                 .extra1         = &zero,
1237                 .extra2         = &one_hundred,
1238         },
1239 #endif
1240 #ifdef CONFIG_SMP
1241         {
1242                 .ctl_name       = CTL_UNNUMBERED,
1243                 .procname       = "stat_interval",
1244                 .data           = &sysctl_stat_interval,
1245                 .maxlen         = sizeof(sysctl_stat_interval),
1246                 .mode           = 0644,
1247                 .proc_handler   = &proc_dointvec_jiffies,
1248                 .strategy       = &sysctl_jiffies,
1249         },
1250 #endif
1251 #ifdef CONFIG_SECURITY
1252         {
1253                 .ctl_name       = CTL_UNNUMBERED,
1254                 .procname       = "mmap_min_addr",
1255                 .data           = &mmap_min_addr,
1256                 .maxlen         = sizeof(unsigned long),
1257                 .mode           = 0644,
1258                 .proc_handler   = &proc_doulongvec_minmax,
1259         },
1260 #endif
1261 #ifdef CONFIG_NUMA
1262         {
1263                 .ctl_name       = CTL_UNNUMBERED,
1264                 .procname       = "numa_zonelist_order",
1265                 .data           = &numa_zonelist_order,
1266                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1267                 .mode           = 0644,
1268                 .proc_handler   = &numa_zonelist_order_handler,
1269                 .strategy       = &sysctl_string,
1270         },
1271 #endif
1272 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1273    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1274         {
1275                 .ctl_name       = VM_VDSO_ENABLED,
1276                 .procname       = "vdso_enabled",
1277                 .data           = &vdso_enabled,
1278                 .maxlen         = sizeof(vdso_enabled),
1279                 .mode           = 0644,
1280                 .proc_handler   = &proc_dointvec,
1281                 .strategy       = &sysctl_intvec,
1282                 .extra1         = &zero,
1283         },
1284 #endif
1285 #ifdef CONFIG_HIGHMEM
1286         {
1287                 .ctl_name       = CTL_UNNUMBERED,
1288                 .procname       = "highmem_is_dirtyable",
1289                 .data           = &vm_highmem_is_dirtyable,
1290                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1291                 .mode           = 0644,
1292                 .proc_handler   = &proc_dointvec_minmax,
1293                 .strategy       = &sysctl_intvec,
1294                 .extra1         = &zero,
1295                 .extra2         = &one,
1296         },
1297 #endif
1298 #ifdef CONFIG_UNEVICTABLE_LRU
1299         {
1300                 .ctl_name       = CTL_UNNUMBERED,
1301                 .procname       = "scan_unevictable_pages",
1302                 .data           = &scan_unevictable_pages,
1303                 .maxlen         = sizeof(scan_unevictable_pages),
1304                 .mode           = 0644,
1305                 .proc_handler   = &scan_unevictable_handler,
1306         },
1307 #endif
1308 /*
1309  * NOTE: do not add new entries to this table unless you have read
1310  * Documentation/sysctl/ctl_unnumbered.txt
1311  */
1312         { .ctl_name = 0 }
1313 };
1314
1315 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1316 static struct ctl_table binfmt_misc_table[] = {
1317         { .ctl_name = 0 }
1318 };
1319 #endif
1320
1321 static struct ctl_table fs_table[] = {
1322         {
1323                 .ctl_name       = FS_NRINODE,
1324                 .procname       = "inode-nr",
1325                 .data           = &inodes_stat,
1326                 .maxlen         = 2*sizeof(int),
1327                 .mode           = 0444,
1328                 .proc_handler   = &proc_dointvec,
1329         },
1330         {
1331                 .ctl_name       = FS_STATINODE,
1332                 .procname       = "inode-state",
1333                 .data           = &inodes_stat,
1334                 .maxlen         = 7*sizeof(int),
1335                 .mode           = 0444,
1336                 .proc_handler   = &proc_dointvec,
1337         },
1338         {
1339                 .procname       = "file-nr",
1340                 .data           = &files_stat,
1341                 .maxlen         = 3*sizeof(int),
1342                 .mode           = 0444,
1343                 .proc_handler   = &proc_nr_files,
1344         },
1345         {
1346                 .ctl_name       = FS_MAXFILE,
1347                 .procname       = "file-max",
1348                 .data           = &files_stat.max_files,
1349                 .maxlen         = sizeof(int),
1350                 .mode           = 0644,
1351                 .proc_handler   = &proc_dointvec,
1352         },
1353         {
1354                 .ctl_name       = CTL_UNNUMBERED,
1355                 .procname       = "nr_open",
1356                 .data           = &sysctl_nr_open,
1357                 .maxlen         = sizeof(int),
1358                 .mode           = 0644,
1359                 .proc_handler   = &proc_dointvec_minmax,
1360                 .extra1         = &sysctl_nr_open_min,
1361                 .extra2         = &sysctl_nr_open_max,
1362         },
1363         {
1364                 .ctl_name       = FS_DENTRY,
1365                 .procname       = "dentry-state",
1366                 .data           = &dentry_stat,
1367                 .maxlen         = 6*sizeof(int),
1368                 .mode           = 0444,
1369                 .proc_handler   = &proc_dointvec,
1370         },
1371         {
1372                 .ctl_name       = FS_OVERFLOWUID,
1373                 .procname       = "overflowuid",
1374                 .data           = &fs_overflowuid,
1375                 .maxlen         = sizeof(int),
1376                 .mode           = 0644,
1377                 .proc_handler   = &proc_dointvec_minmax,
1378                 .strategy       = &sysctl_intvec,
1379                 .extra1         = &minolduid,
1380                 .extra2         = &maxolduid,
1381         },
1382         {
1383                 .ctl_name       = FS_OVERFLOWGID,
1384                 .procname       = "overflowgid",
1385                 .data           = &fs_overflowgid,
1386                 .maxlen         = sizeof(int),
1387                 .mode           = 0644,
1388                 .proc_handler   = &proc_dointvec_minmax,
1389                 .strategy       = &sysctl_intvec,
1390                 .extra1         = &minolduid,
1391                 .extra2         = &maxolduid,
1392         },
1393 #ifdef CONFIG_FILE_LOCKING
1394         {
1395                 .ctl_name       = FS_LEASES,
1396                 .procname       = "leases-enable",
1397                 .data           = &leases_enable,
1398                 .maxlen         = sizeof(int),
1399                 .mode           = 0644,
1400                 .proc_handler   = &proc_dointvec,
1401         },
1402 #endif
1403 #ifdef CONFIG_DNOTIFY
1404         {
1405                 .ctl_name       = FS_DIR_NOTIFY,
1406                 .procname       = "dir-notify-enable",
1407                 .data           = &dir_notify_enable,
1408                 .maxlen         = sizeof(int),
1409                 .mode           = 0644,
1410                 .proc_handler   = &proc_dointvec,
1411         },
1412 #endif
1413 #ifdef CONFIG_MMU
1414 #ifdef CONFIG_FILE_LOCKING
1415         {
1416                 .ctl_name       = FS_LEASE_TIME,
1417                 .procname       = "lease-break-time",
1418                 .data           = &lease_break_time,
1419                 .maxlen         = sizeof(int),
1420                 .mode           = 0644,
1421                 .proc_handler   = &proc_dointvec,
1422         },
1423 #endif
1424 #ifdef CONFIG_AIO
1425         {
1426                 .procname       = "aio-nr",
1427                 .data           = &aio_nr,
1428                 .maxlen         = sizeof(aio_nr),
1429                 .mode           = 0444,
1430                 .proc_handler   = &proc_doulongvec_minmax,
1431         },
1432         {
1433                 .procname       = "aio-max-nr",
1434                 .data           = &aio_max_nr,
1435                 .maxlen         = sizeof(aio_max_nr),
1436                 .mode           = 0644,
1437                 .proc_handler   = &proc_doulongvec_minmax,
1438         },
1439 #endif /* CONFIG_AIO */
1440 #ifdef CONFIG_INOTIFY_USER
1441         {
1442                 .ctl_name       = FS_INOTIFY,
1443                 .procname       = "inotify",
1444                 .mode           = 0555,
1445                 .child          = inotify_table,
1446         },
1447 #endif
1448 #ifdef CONFIG_EPOLL
1449         {
1450                 .procname       = "epoll",
1451                 .mode           = 0555,
1452                 .child          = epoll_table,
1453         },
1454 #endif
1455 #endif
1456         {
1457                 .ctl_name       = KERN_SETUID_DUMPABLE,
1458                 .procname       = "suid_dumpable",
1459                 .data           = &suid_dumpable,
1460                 .maxlen         = sizeof(int),
1461                 .mode           = 0644,
1462                 .proc_handler   = &proc_dointvec_minmax,
1463                 .strategy       = &sysctl_intvec,
1464                 .extra1         = &zero,
1465                 .extra2         = &two,
1466         },
1467 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1468         {
1469                 .ctl_name       = CTL_UNNUMBERED,
1470                 .procname       = "binfmt_misc",
1471                 .mode           = 0555,
1472                 .child          = binfmt_misc_table,
1473         },
1474 #endif
1475 /*
1476  * NOTE: do not add new entries to this table unless you have read
1477  * Documentation/sysctl/ctl_unnumbered.txt
1478  */
1479         { .ctl_name = 0 }
1480 };
1481
1482 static struct ctl_table debug_table[] = {
1483 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1484         {
1485                 .ctl_name       = CTL_UNNUMBERED,
1486                 .procname       = "exception-trace",
1487                 .data           = &show_unhandled_signals,
1488                 .maxlen         = sizeof(int),
1489                 .mode           = 0644,
1490                 .proc_handler   = proc_dointvec
1491         },
1492 #endif
1493         { .ctl_name = 0 }
1494 };
1495
1496 static struct ctl_table dev_table[] = {
1497         { .ctl_name = 0 }
1498 };
1499
1500 static DEFINE_SPINLOCK(sysctl_lock);
1501
1502 /* called under sysctl_lock */
1503 static int use_table(struct ctl_table_header *p)
1504 {
1505         if (unlikely(p->unregistering))
1506                 return 0;
1507         p->used++;
1508         return 1;
1509 }
1510
1511 /* called under sysctl_lock */
1512 static void unuse_table(struct ctl_table_header *p)
1513 {
1514         if (!--p->used)
1515                 if (unlikely(p->unregistering))
1516                         complete(p->unregistering);
1517 }
1518
1519 /* called under sysctl_lock, will reacquire if has to wait */
1520 static void start_unregistering(struct ctl_table_header *p)
1521 {
1522         /*
1523          * if p->used is 0, nobody will ever touch that entry again;
1524          * we'll eliminate all paths to it before dropping sysctl_lock
1525          */
1526         if (unlikely(p->used)) {
1527                 struct completion wait;
1528                 init_completion(&wait);
1529                 p->unregistering = &wait;
1530                 spin_unlock(&sysctl_lock);
1531                 wait_for_completion(&wait);
1532                 spin_lock(&sysctl_lock);
1533         } else {
1534                 /* anything non-NULL; we'll never dereference it */
1535                 p->unregistering = ERR_PTR(-EINVAL);
1536         }
1537         /*
1538          * do not remove from the list until nobody holds it; walking the
1539          * list in do_sysctl() relies on that.
1540          */
1541         list_del_init(&p->ctl_entry);
1542 }
1543
1544 void sysctl_head_get(struct ctl_table_header *head)
1545 {
1546         spin_lock(&sysctl_lock);
1547         head->count++;
1548         spin_unlock(&sysctl_lock);
1549 }
1550
1551 void sysctl_head_put(struct ctl_table_header *head)
1552 {
1553         spin_lock(&sysctl_lock);
1554         if (!--head->count)
1555                 kfree(head);
1556         spin_unlock(&sysctl_lock);
1557 }
1558
1559 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1560 {
1561         if (!head)
1562                 BUG();
1563         spin_lock(&sysctl_lock);
1564         if (!use_table(head))
1565                 head = ERR_PTR(-ENOENT);
1566         spin_unlock(&sysctl_lock);
1567         return head;
1568 }
1569
1570 void sysctl_head_finish(struct ctl_table_header *head)
1571 {
1572         if (!head)
1573                 return;
1574         spin_lock(&sysctl_lock);
1575         unuse_table(head);
1576         spin_unlock(&sysctl_lock);
1577 }
1578
1579 static struct ctl_table_set *
1580 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1581 {
1582         struct ctl_table_set *set = &root->default_set;
1583         if (root->lookup)
1584                 set = root->lookup(root, namespaces);
1585         return set;
1586 }
1587
1588 static struct list_head *
1589 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1590 {
1591         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1592         return &set->list;
1593 }
1594
1595 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1596                                             struct ctl_table_header *prev)
1597 {
1598         struct ctl_table_root *root;
1599         struct list_head *header_list;
1600         struct ctl_table_header *head;
1601         struct list_head *tmp;
1602
1603         spin_lock(&sysctl_lock);
1604         if (prev) {
1605                 head = prev;
1606                 tmp = &prev->ctl_entry;
1607                 unuse_table(prev);
1608                 goto next;
1609         }
1610         tmp = &root_table_header.ctl_entry;
1611         for (;;) {
1612                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1613
1614                 if (!use_table(head))
1615                         goto next;
1616                 spin_unlock(&sysctl_lock);
1617                 return head;
1618         next:
1619                 root = head->root;
1620                 tmp = tmp->next;
1621                 header_list = lookup_header_list(root, namespaces);
1622                 if (tmp != header_list)
1623                         continue;
1624
1625                 do {
1626                         root = list_entry(root->root_list.next,
1627                                         struct ctl_table_root, root_list);
1628                         if (root == &sysctl_table_root)
1629                                 goto out;
1630                         header_list = lookup_header_list(root, namespaces);
1631                 } while (list_empty(header_list));
1632                 tmp = header_list->next;
1633         }
1634 out:
1635         spin_unlock(&sysctl_lock);
1636         return NULL;
1637 }
1638
1639 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1640 {
1641         return __sysctl_head_next(current->nsproxy, prev);
1642 }
1643
1644 void register_sysctl_root(struct ctl_table_root *root)
1645 {
1646         spin_lock(&sysctl_lock);
1647         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1648         spin_unlock(&sysctl_lock);
1649 }
1650
1651 #ifdef CONFIG_SYSCTL_SYSCALL
1652 /* Perform the actual read/write of a sysctl table entry. */
1653 static int do_sysctl_strategy(struct ctl_table_root *root,
1654                         struct ctl_table *table,
1655                         void __user *oldval, size_t __user *oldlenp,
1656                         void __user *newval, size_t newlen)
1657 {
1658         int op = 0, rc;
1659
1660         if (oldval)
1661                 op |= MAY_READ;
1662         if (newval)
1663                 op |= MAY_WRITE;
1664         if (sysctl_perm(root, table, op))
1665                 return -EPERM;
1666
1667         if (table->strategy) {
1668                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1669                 if (rc < 0)
1670                         return rc;
1671                 if (rc > 0)
1672                         return 0;
1673         }
1674
1675         /* If there is no strategy routine, or if the strategy returns
1676          * zero, proceed with automatic r/w */
1677         if (table->data && table->maxlen) {
1678                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1679                 if (rc < 0)
1680                         return rc;
1681         }
1682         return 0;
1683 }
1684
1685 static int parse_table(int __user *name, int nlen,
1686                        void __user *oldval, size_t __user *oldlenp,
1687                        void __user *newval, size_t newlen,
1688                        struct ctl_table_root *root,
1689                        struct ctl_table *table)
1690 {
1691         int n;
1692 repeat:
1693         if (!nlen)
1694                 return -ENOTDIR;
1695         if (get_user(n, name))
1696                 return -EFAULT;
1697         for ( ; table->ctl_name || table->procname; table++) {
1698                 if (!table->ctl_name)
1699                         continue;
1700                 if (n == table->ctl_name) {
1701                         int error;
1702                         if (table->child) {
1703                                 if (sysctl_perm(root, table, MAY_EXEC))
1704                                         return -EPERM;
1705                                 name++;
1706                                 nlen--;
1707                                 table = table->child;
1708                                 goto repeat;
1709                         }
1710                         error = do_sysctl_strategy(root, table,
1711                                                    oldval, oldlenp,
1712                                                    newval, newlen);
1713                         return error;
1714                 }
1715         }
1716         return -ENOTDIR;
1717 }
1718
1719 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1720                void __user *newval, size_t newlen)
1721 {
1722         struct ctl_table_header *head;
1723         int error = -ENOTDIR;
1724
1725         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1726                 return -ENOTDIR;
1727         if (oldval) {
1728                 int old_len;
1729                 if (!oldlenp || get_user(old_len, oldlenp))
1730                         return -EFAULT;
1731         }
1732
1733         for (head = sysctl_head_next(NULL); head;
1734                         head = sysctl_head_next(head)) {
1735                 error = parse_table(name, nlen, oldval, oldlenp,
1736                                         newval, newlen,
1737                                         head->root, head->ctl_table);
1738                 if (error != -ENOTDIR) {
1739                         sysctl_head_finish(head);
1740                         break;
1741                 }
1742         }
1743         return error;
1744 }
1745
1746 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1747 {
1748         struct __sysctl_args tmp;
1749         int error;
1750
1751         if (copy_from_user(&tmp, args, sizeof(tmp)))
1752                 return -EFAULT;
1753
1754         error = deprecated_sysctl_warning(&tmp);
1755         if (error)
1756                 goto out;
1757
1758         lock_kernel();
1759         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1760                           tmp.newval, tmp.newlen);
1761         unlock_kernel();
1762 out:
1763         return error;
1764 }
1765 #endif /* CONFIG_SYSCTL_SYSCALL */
1766
1767 /*
1768  * sysctl_perm does NOT grant the superuser all rights automatically, because
1769  * some sysctl variables are readonly even to root.
1770  */
1771
1772 static int test_perm(int mode, int op)
1773 {
1774         if (!current_euid())
1775                 mode >>= 6;
1776         else if (in_egroup_p(0))
1777                 mode >>= 3;
1778         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1779                 return 0;
1780         return -EACCES;
1781 }
1782
1783 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1784 {
1785         int error;
1786         int mode;
1787
1788         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1789         if (error)
1790                 return error;
1791
1792         if (root->permissions)
1793                 mode = root->permissions(root, current->nsproxy, table);
1794         else
1795                 mode = table->mode;
1796
1797         return test_perm(mode, op);
1798 }
1799
1800 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1801 {
1802         for (; table->ctl_name || table->procname; table++) {
1803                 table->parent = parent;
1804                 if (table->child)
1805                         sysctl_set_parent(table, table->child);
1806         }
1807 }
1808
1809 static __init int sysctl_init(void)
1810 {
1811         sysctl_set_parent(NULL, root_table);
1812 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1813         {
1814                 int err;
1815                 err = sysctl_check_table(current->nsproxy, root_table);
1816         }
1817 #endif
1818         return 0;
1819 }
1820
1821 core_initcall(sysctl_init);
1822
1823 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1824                                       struct ctl_table *table)
1825 {
1826         struct ctl_table *p;
1827         const char *s = branch->procname;
1828
1829         /* branch should have named subdirectory as its first element */
1830         if (!s || !branch->child)
1831                 return NULL;
1832
1833         /* ... and nothing else */
1834         if (branch[1].procname || branch[1].ctl_name)
1835                 return NULL;
1836
1837         /* table should contain subdirectory with the same name */
1838         for (p = table; p->procname || p->ctl_name; p++) {
1839                 if (!p->child)
1840                         continue;
1841                 if (p->procname && strcmp(p->procname, s) == 0)
1842                         return p;
1843         }
1844         return NULL;
1845 }
1846
1847 /* see if attaching q to p would be an improvement */
1848 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1849 {
1850         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1851         struct ctl_table *next;
1852         int is_better = 0;
1853         int not_in_parent = !p->attached_by;
1854
1855         while ((next = is_branch_in(by, to)) != NULL) {
1856                 if (by == q->attached_by)
1857                         is_better = 1;
1858                 if (to == p->attached_by)
1859                         not_in_parent = 1;
1860                 by = by->child;
1861                 to = next->child;
1862         }
1863
1864         if (is_better && not_in_parent) {
1865                 q->attached_by = by;
1866                 q->attached_to = to;
1867                 q->parent = p;
1868         }
1869 }
1870
1871 /**
1872  * __register_sysctl_paths - register a sysctl hierarchy
1873  * @root: List of sysctl headers to register on
1874  * @namespaces: Data to compute which lists of sysctl entries are visible
1875  * @path: The path to the directory the sysctl table is in.
1876  * @table: the top-level table structure
1877  *
1878  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1879  * array. A completely 0 filled entry terminates the table.
1880  *
1881  * The members of the &struct ctl_table structure are used as follows:
1882  *
1883  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1884  *            must be unique within that level of sysctl
1885  *
1886  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1887  *            enter a sysctl file
1888  *
1889  * data - a pointer to data for use by proc_handler
1890  *
1891  * maxlen - the maximum size in bytes of the data
1892  *
1893  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1894  *
1895  * child - a pointer to the child sysctl table if this entry is a directory, or
1896  *         %NULL.
1897  *
1898  * proc_handler - the text handler routine (described below)
1899  *
1900  * strategy - the strategy routine (described below)
1901  *
1902  * de - for internal use by the sysctl routines
1903  *
1904  * extra1, extra2 - extra pointers usable by the proc handler routines
1905  *
1906  * Leaf nodes in the sysctl tree will be represented by a single file
1907  * under /proc; non-leaf nodes will be represented by directories.
1908  *
1909  * sysctl(2) can automatically manage read and write requests through
1910  * the sysctl table.  The data and maxlen fields of the ctl_table
1911  * struct enable minimal validation of the values being written to be
1912  * performed, and the mode field allows minimal authentication.
1913  *
1914  * More sophisticated management can be enabled by the provision of a
1915  * strategy routine with the table entry.  This will be called before
1916  * any automatic read or write of the data is performed.
1917  *
1918  * The strategy routine may return
1919  *
1920  * < 0 - Error occurred (error is passed to user process)
1921  *
1922  * 0   - OK - proceed with automatic read or write.
1923  *
1924  * > 0 - OK - read or write has been done by the strategy routine, so
1925  *       return immediately.
1926  *
1927  * There must be a proc_handler routine for any terminal nodes
1928  * mirrored under /proc/sys (non-terminals are handled by a built-in
1929  * directory handler).  Several default handlers are available to
1930  * cover common cases -
1931  *
1932  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1933  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1934  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1935  *
1936  * It is the handler's job to read the input buffer from user memory
1937  * and process it. The handler should return 0 on success.
1938  *
1939  * This routine returns %NULL on a failure to register, and a pointer
1940  * to the table header on success.
1941  */
1942 struct ctl_table_header *__register_sysctl_paths(
1943         struct ctl_table_root *root,
1944         struct nsproxy *namespaces,
1945         const struct ctl_path *path, struct ctl_table *table)
1946 {
1947         struct ctl_table_header *header;
1948         struct ctl_table *new, **prevp;
1949         unsigned int n, npath;
1950         struct ctl_table_set *set;
1951
1952         /* Count the path components */
1953         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1954                 ;
1955
1956         /*
1957          * For each path component, allocate a 2-element ctl_table array.
1958          * The first array element will be filled with the sysctl entry
1959          * for this, the second will be the sentinel (ctl_name == 0).
1960          *
1961          * We allocate everything in one go so that we don't have to
1962          * worry about freeing additional memory in unregister_sysctl_table.
1963          */
1964         header = kzalloc(sizeof(struct ctl_table_header) +
1965                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1966         if (!header)
1967                 return NULL;
1968
1969         new = (struct ctl_table *) (header + 1);
1970
1971         /* Now connect the dots */
1972         prevp = &header->ctl_table;
1973         for (n = 0; n < npath; ++n, ++path) {
1974                 /* Copy the procname */
1975                 new->procname = path->procname;
1976                 new->ctl_name = path->ctl_name;
1977                 new->mode     = 0555;
1978
1979                 *prevp = new;
1980                 prevp = &new->child;
1981
1982                 new += 2;
1983         }
1984         *prevp = table;
1985         header->ctl_table_arg = table;
1986
1987         INIT_LIST_HEAD(&header->ctl_entry);
1988         header->used = 0;
1989         header->unregistering = NULL;
1990         header->root = root;
1991         sysctl_set_parent(NULL, header->ctl_table);
1992         header->count = 1;
1993 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1994         if (sysctl_check_table(namespaces, header->ctl_table)) {
1995                 kfree(header);
1996                 return NULL;
1997         }
1998 #endif
1999         spin_lock(&sysctl_lock);
2000         header->set = lookup_header_set(root, namespaces);
2001         header->attached_by = header->ctl_table;
2002         header->attached_to = root_table;
2003         header->parent = &root_table_header;
2004         for (set = header->set; set; set = set->parent) {
2005                 struct ctl_table_header *p;
2006                 list_for_each_entry(p, &set->list, ctl_entry) {
2007                         if (p->unregistering)
2008                                 continue;
2009                         try_attach(p, header);
2010                 }
2011         }
2012         header->parent->count++;
2013         list_add_tail(&header->ctl_entry, &header->set->list);
2014         spin_unlock(&sysctl_lock);
2015
2016         return header;
2017 }
2018
2019 /**
2020  * register_sysctl_table_path - register a sysctl table hierarchy
2021  * @path: The path to the directory the sysctl table is in.
2022  * @table: the top-level table structure
2023  *
2024  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2025  * array. A completely 0 filled entry terminates the table.
2026  *
2027  * See __register_sysctl_paths for more details.
2028  */
2029 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2030                                                 struct ctl_table *table)
2031 {
2032         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2033                                         path, table);
2034 }
2035
2036 /**
2037  * register_sysctl_table - register a sysctl table hierarchy
2038  * @table: the top-level table structure
2039  *
2040  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2041  * array. A completely 0 filled entry terminates the table.
2042  *
2043  * See register_sysctl_paths for more details.
2044  */
2045 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2046 {
2047         static const struct ctl_path null_path[] = { {} };
2048
2049         return register_sysctl_paths(null_path, table);
2050 }
2051
2052 /**
2053  * unregister_sysctl_table - unregister a sysctl table hierarchy
2054  * @header: the header returned from register_sysctl_table
2055  *
2056  * Unregisters the sysctl table and all children. proc entries may not
2057  * actually be removed until they are no longer used by anyone.
2058  */
2059 void unregister_sysctl_table(struct ctl_table_header * header)
2060 {
2061         might_sleep();
2062
2063         if (header == NULL)
2064                 return;
2065
2066         spin_lock(&sysctl_lock);
2067         start_unregistering(header);
2068         if (!--header->parent->count) {
2069                 WARN_ON(1);
2070                 kfree(header->parent);
2071         }
2072         if (!--header->count)
2073                 kfree(header);
2074         spin_unlock(&sysctl_lock);
2075 }
2076
2077 int sysctl_is_seen(struct ctl_table_header *p)
2078 {
2079         struct ctl_table_set *set = p->set;
2080         int res;
2081         spin_lock(&sysctl_lock);
2082         if (p->unregistering)
2083                 res = 0;
2084         else if (!set->is_seen)
2085                 res = 1;
2086         else
2087                 res = set->is_seen(set);
2088         spin_unlock(&sysctl_lock);
2089         return res;
2090 }
2091
2092 void setup_sysctl_set(struct ctl_table_set *p,
2093         struct ctl_table_set *parent,
2094         int (*is_seen)(struct ctl_table_set *))
2095 {
2096         INIT_LIST_HEAD(&p->list);
2097         p->parent = parent ? parent : &sysctl_table_root.default_set;
2098         p->is_seen = is_seen;
2099 }
2100
2101 #else /* !CONFIG_SYSCTL */
2102 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2103 {
2104         return NULL;
2105 }
2106
2107 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2108                                                     struct ctl_table *table)
2109 {
2110         return NULL;
2111 }
2112
2113 void unregister_sysctl_table(struct ctl_table_header * table)
2114 {
2115 }
2116
2117 void setup_sysctl_set(struct ctl_table_set *p,
2118         struct ctl_table_set *parent,
2119         int (*is_seen)(struct ctl_table_set *))
2120 {
2121 }
2122
2123 void sysctl_head_put(struct ctl_table_header *head)
2124 {
2125 }
2126
2127 #endif /* CONFIG_SYSCTL */
2128
2129 /*
2130  * /proc/sys support
2131  */
2132
2133 #ifdef CONFIG_PROC_SYSCTL
2134
2135 static int _proc_do_string(void* data, int maxlen, int write,
2136                            struct file *filp, void __user *buffer,
2137                            size_t *lenp, loff_t *ppos)
2138 {
2139         size_t len;
2140         char __user *p;
2141         char c;
2142
2143         if (!data || !maxlen || !*lenp) {
2144                 *lenp = 0;
2145                 return 0;
2146         }
2147
2148         if (write) {
2149                 len = 0;
2150                 p = buffer;
2151                 while (len < *lenp) {
2152                         if (get_user(c, p++))
2153                                 return -EFAULT;
2154                         if (c == 0 || c == '\n')
2155                                 break;
2156                         len++;
2157                 }
2158                 if (len >= maxlen)
2159                         len = maxlen-1;
2160                 if(copy_from_user(data, buffer, len))
2161                         return -EFAULT;
2162                 ((char *) data)[len] = 0;
2163                 *ppos += *lenp;
2164         } else {
2165                 len = strlen(data);
2166                 if (len > maxlen)
2167                         len = maxlen;
2168
2169                 if (*ppos > len) {
2170                         *lenp = 0;
2171                         return 0;
2172                 }
2173
2174                 data += *ppos;
2175                 len  -= *ppos;
2176
2177                 if (len > *lenp)
2178                         len = *lenp;
2179                 if (len)
2180                         if(copy_to_user(buffer, data, len))
2181                                 return -EFAULT;
2182                 if (len < *lenp) {
2183                         if(put_user('\n', ((char __user *) buffer) + len))
2184                                 return -EFAULT;
2185                         len++;
2186                 }
2187                 *lenp = len;
2188                 *ppos += len;
2189         }
2190         return 0;
2191 }
2192
2193 /**
2194  * proc_dostring - read a string sysctl
2195  * @table: the sysctl table
2196  * @write: %TRUE if this is a write to the sysctl file
2197  * @filp: the file structure
2198  * @buffer: the user buffer
2199  * @lenp: the size of the user buffer
2200  * @ppos: file position
2201  *
2202  * Reads/writes a string from/to the user buffer. If the kernel
2203  * buffer provided is not large enough to hold the string, the
2204  * string is truncated. The copied string is %NULL-terminated.
2205  * If the string is being read by the user process, it is copied
2206  * and a newline '\n' is added. It is truncated if the buffer is
2207  * not large enough.
2208  *
2209  * Returns 0 on success.
2210  */
2211 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2212                   void __user *buffer, size_t *lenp, loff_t *ppos)
2213 {
2214         return _proc_do_string(table->data, table->maxlen, write, filp,
2215                                buffer, lenp, ppos);
2216 }
2217
2218
2219 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2220                                  int *valp,
2221                                  int write, void *data)
2222 {
2223         if (write) {
2224                 *valp = *negp ? -*lvalp : *lvalp;
2225         } else {
2226                 int val = *valp;
2227                 if (val < 0) {
2228                         *negp = -1;
2229                         *lvalp = (unsigned long)-val;
2230                 } else {
2231                         *negp = 0;
2232                         *lvalp = (unsigned long)val;
2233                 }
2234         }
2235         return 0;
2236 }
2237
2238 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2239                   int write, struct file *filp, void __user *buffer,
2240                   size_t *lenp, loff_t *ppos,
2241                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2242                               int write, void *data),
2243                   void *data)
2244 {
2245 #define TMPBUFLEN 21
2246         int *i, vleft, first=1, neg, val;
2247         unsigned long lval;
2248         size_t left, len;
2249
2250         char buf[TMPBUFLEN], *p;
2251         char __user *s = buffer;
2252
2253         if (!tbl_data || !table->maxlen || !*lenp ||
2254             (*ppos && !write)) {
2255                 *lenp = 0;
2256                 return 0;
2257         }
2258
2259         i = (int *) tbl_data;
2260         vleft = table->maxlen / sizeof(*i);
2261         left = *lenp;
2262
2263         if (!conv)
2264                 conv = do_proc_dointvec_conv;
2265
2266         for (; left && vleft--; i++, first=0) {
2267                 if (write) {
2268                         while (left) {
2269                                 char c;
2270                                 if (get_user(c, s))
2271                                         return -EFAULT;
2272                                 if (!isspace(c))
2273                                         break;
2274                                 left--;
2275                                 s++;
2276                         }
2277                         if (!left)
2278                                 break;
2279                         neg = 0;
2280                         len = left;
2281                         if (len > sizeof(buf) - 1)
2282                                 len = sizeof(buf) - 1;
2283                         if (copy_from_user(buf, s, len))
2284                                 return -EFAULT;
2285                         buf[len] = 0;
2286                         p = buf;
2287                         if (*p == '-' && left > 1) {
2288                                 neg = 1;
2289                                 p++;
2290                         }
2291                         if (*p < '0' || *p > '9')
2292                                 break;
2293
2294                         lval = simple_strtoul(p, &p, 0);
2295
2296                         len = p-buf;
2297                         if ((len < left) && *p && !isspace(*p))
2298                                 break;
2299                         if (neg)
2300                                 val = -val;
2301                         s += len;
2302                         left -= len;
2303
2304                         if (conv(&neg, &lval, i, 1, data))
2305                                 break;
2306                 } else {
2307                         p = buf;
2308                         if (!first)
2309                                 *p++ = '\t';
2310
2311                         if (conv(&neg, &lval, i, 0, data))
2312                                 break;
2313
2314                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2315                         len = strlen(buf);
2316                         if (len > left)
2317                                 len = left;
2318                         if(copy_to_user(s, buf, len))
2319                                 return -EFAULT;
2320                         left -= len;
2321                         s += len;
2322                 }
2323         }
2324
2325         if (!write && !first && left) {
2326                 if(put_user('\n', s))
2327                         return -EFAULT;
2328                 left--, s++;
2329         }
2330         if (write) {
2331                 while (left) {
2332                         char c;
2333                         if (get_user(c, s++))
2334                                 return -EFAULT;
2335                         if (!isspace(c))
2336                                 break;
2337                         left--;
2338                 }
2339         }
2340         if (write && first)
2341                 return -EINVAL;
2342         *lenp -= left;
2343         *ppos += *lenp;
2344         return 0;
2345 #undef TMPBUFLEN
2346 }
2347
2348 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2349                   void __user *buffer, size_t *lenp, loff_t *ppos,
2350                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2351                               int write, void *data),
2352                   void *data)
2353 {
2354         return __do_proc_dointvec(table->data, table, write, filp,
2355                         buffer, lenp, ppos, conv, data);
2356 }
2357
2358 /**
2359  * proc_dointvec - read a vector of integers
2360  * @table: the sysctl table
2361  * @write: %TRUE if this is a write to the sysctl file
2362  * @filp: the file structure
2363  * @buffer: the user buffer
2364  * @lenp: the size of the user buffer
2365  * @ppos: file position
2366  *
2367  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2368  * values from/to the user buffer, treated as an ASCII string.
2369  *
2370  * Returns 0 on success.
2371  */
2372 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2373                      void __user *buffer, size_t *lenp, loff_t *ppos)
2374 {
2375     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2376                             NULL,NULL);
2377 }
2378
2379 /*
2380  * Taint values can only be increased
2381  * This means we can safely use a temporary.
2382  */
2383 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2384                                void __user *buffer, size_t *lenp, loff_t *ppos)
2385 {
2386         struct ctl_table t;
2387         unsigned long tmptaint = get_taint();
2388         int err;
2389
2390         if (write && !capable(CAP_SYS_ADMIN))
2391                 return -EPERM;
2392
2393         t = *table;
2394         t.data = &tmptaint;
2395         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2396         if (err < 0)
2397                 return err;
2398
2399         if (write) {
2400                 /*
2401                  * Poor man's atomic or. Not worth adding a primitive
2402                  * to everyone's atomic.h for this
2403                  */
2404                 int i;
2405                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2406                         if ((tmptaint >> i) & 1)
2407                                 add_taint(i);
2408                 }
2409         }
2410
2411         return err;
2412 }
2413
2414 struct do_proc_dointvec_minmax_conv_param {
2415         int *min;
2416         int *max;
2417 };
2418
2419 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2420                                         int *valp,
2421                                         int write, void *data)
2422 {
2423         struct do_proc_dointvec_minmax_conv_param *param = data;
2424         if (write) {
2425                 int val = *negp ? -*lvalp : *lvalp;
2426                 if ((param->min && *param->min > val) ||
2427                     (param->max && *param->max < val))
2428                         return -EINVAL;
2429                 *valp = val;
2430         } else {
2431                 int val = *valp;
2432                 if (val < 0) {
2433                         *negp = -1;
2434                         *lvalp = (unsigned long)-val;
2435                 } else {
2436                         *negp = 0;
2437                         *lvalp = (unsigned long)val;
2438                 }
2439         }
2440         return 0;
2441 }
2442
2443 /**
2444  * proc_dointvec_minmax - read a vector of integers with min/max values
2445  * @table: the sysctl table
2446  * @write: %TRUE if this is a write to the sysctl file
2447  * @filp: the file structure
2448  * @buffer: the user buffer
2449  * @lenp: the size of the user buffer
2450  * @ppos: file position
2451  *
2452  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2453  * values from/to the user buffer, treated as an ASCII string.
2454  *
2455  * This routine will ensure the values are within the range specified by
2456  * table->extra1 (min) and table->extra2 (max).
2457  *
2458  * Returns 0 on success.
2459  */
2460 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2461                   void __user *buffer, size_t *lenp, loff_t *ppos)
2462 {
2463         struct do_proc_dointvec_minmax_conv_param param = {
2464                 .min = (int *) table->extra1,
2465                 .max = (int *) table->extra2,
2466         };
2467         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2468                                 do_proc_dointvec_minmax_conv, &param);
2469 }
2470
2471 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2472                                      struct file *filp,
2473                                      void __user *buffer,
2474                                      size_t *lenp, loff_t *ppos,
2475                                      unsigned long convmul,
2476                                      unsigned long convdiv)
2477 {
2478 #define TMPBUFLEN 21
2479         unsigned long *i, *min, *max, val;
2480         int vleft, first=1, neg;
2481         size_t len, left;
2482         char buf[TMPBUFLEN], *p;
2483         char __user *s = buffer;
2484
2485         if (!data || !table->maxlen || !*lenp ||
2486             (*ppos && !write)) {
2487                 *lenp = 0;
2488                 return 0;
2489         }
2490
2491         i = (unsigned long *) data;
2492         min = (unsigned long *) table->extra1;
2493         max = (unsigned long *) table->extra2;
2494         vleft = table->maxlen / sizeof(unsigned long);
2495         left = *lenp;
2496
2497         for (; left && vleft--; i++, min++, max++, first=0) {
2498                 if (write) {
2499                         while (left) {
2500                                 char c;
2501                                 if (get_user(c, s))
2502                                         return -EFAULT;
2503                                 if (!isspace(c))
2504                                         break;
2505                                 left--;
2506                                 s++;
2507                         }
2508                         if (!left)
2509                                 break;
2510                         neg = 0;
2511                         len = left;
2512                         if (len > TMPBUFLEN-1)
2513                                 len = TMPBUFLEN-1;
2514                         if (copy_from_user(buf, s, len))
2515                                 return -EFAULT;
2516                         buf[len] = 0;
2517                         p = buf;
2518                         if (*p == '-' && left > 1) {
2519                                 neg = 1;
2520                                 p++;
2521                         }
2522                         if (*p < '0' || *p > '9')
2523                                 break;
2524                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2525                         len = p-buf;
2526                         if ((len < left) && *p && !isspace(*p))
2527                                 break;
2528                         if (neg)
2529                                 val = -val;
2530                         s += len;
2531                         left -= len;
2532
2533                         if(neg)
2534                                 continue;
2535                         if ((min && val < *min) || (max && val > *max))
2536                                 continue;
2537                         *i = val;
2538                 } else {
2539                         p = buf;
2540                         if (!first)
2541                                 *p++ = '\t';
2542                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2543                         len = strlen(buf);
2544                         if (len > left)
2545                                 len = left;
2546                         if(copy_to_user(s, buf, len))
2547                                 return -EFAULT;
2548                         left -= len;
2549                         s += len;
2550                 }
2551         }
2552
2553         if (!write && !first && left) {
2554                 if(put_user('\n', s))
2555                         return -EFAULT;
2556                 left--, s++;
2557         }
2558         if (write) {
2559                 while (left) {
2560                         char c;
2561                         if (get_user(c, s++))
2562                                 return -EFAULT;
2563                         if (!isspace(c))
2564                                 break;
2565                         left--;
2566                 }
2567         }
2568         if (write && first)
2569                 return -EINVAL;
2570         *lenp -= left;
2571         *ppos += *lenp;
2572         return 0;
2573 #undef TMPBUFLEN
2574 }
2575
2576 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2577                                      struct file *filp,
2578                                      void __user *buffer,
2579                                      size_t *lenp, loff_t *ppos,
2580                                      unsigned long convmul,
2581                                      unsigned long convdiv)
2582 {
2583         return __do_proc_doulongvec_minmax(table->data, table, write,
2584                         filp, buffer, lenp, ppos, convmul, convdiv);
2585 }
2586
2587 /**
2588  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2589  * @table: the sysctl table
2590  * @write: %TRUE if this is a write to the sysctl file
2591  * @filp: the file structure
2592  * @buffer: the user buffer
2593  * @lenp: the size of the user buffer
2594  * @ppos: file position
2595  *
2596  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2597  * values from/to the user buffer, treated as an ASCII string.
2598  *
2599  * This routine will ensure the values are within the range specified by
2600  * table->extra1 (min) and table->extra2 (max).
2601  *
2602  * Returns 0 on success.
2603  */
2604 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2605                            void __user *buffer, size_t *lenp, loff_t *ppos)
2606 {
2607     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2608 }
2609
2610 /**
2611  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2612  * @table: the sysctl table
2613  * @write: %TRUE if this is a write to the sysctl file
2614  * @filp: the file structure
2615  * @buffer: the user buffer
2616  * @lenp: the size of the user buffer
2617  * @ppos: file position
2618  *
2619  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2620  * values from/to the user buffer, treated as an ASCII string. The values
2621  * are treated as milliseconds, and converted to jiffies when they are stored.
2622  *
2623  * This routine will ensure the values are within the range specified by
2624  * table->extra1 (min) and table->extra2 (max).
2625  *
2626  * Returns 0 on success.
2627  */
2628 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2629                                       struct file *filp,
2630                                       void __user *buffer,
2631                                       size_t *lenp, loff_t *ppos)
2632 {
2633     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2634                                      lenp, ppos, HZ, 1000l);
2635 }
2636
2637
2638 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2639                                          int *valp,
2640                                          int write, void *data)
2641 {
2642         if (write) {
2643                 if (*lvalp > LONG_MAX / HZ)
2644                         return 1;
2645                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2646         } else {
2647                 int val = *valp;
2648                 unsigned long lval;
2649                 if (val < 0) {
2650                         *negp = -1;
2651                         lval = (unsigned long)-val;
2652                 } else {
2653                         *negp = 0;
2654                         lval = (unsigned long)val;
2655                 }
2656                 *lvalp = lval / HZ;
2657         }
2658         return 0;
2659 }
2660
2661 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2662                                                 int *valp,
2663                                                 int write, void *data)
2664 {
2665         if (write) {
2666                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2667                         return 1;
2668                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2669         } else {
2670                 int val = *valp;
2671                 unsigned long lval;
2672                 if (val < 0) {
2673                         *negp = -1;
2674                         lval = (unsigned long)-val;
2675                 } else {
2676                         *negp = 0;
2677                         lval = (unsigned long)val;
2678                 }
2679                 *lvalp = jiffies_to_clock_t(lval);
2680         }
2681         return 0;
2682 }
2683
2684 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2685                                             int *valp,
2686                                             int write, void *data)
2687 {
2688         if (write) {
2689                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2690         } else {
2691                 int val = *valp;
2692                 unsigned long lval;
2693                 if (val < 0) {
2694                         *negp = -1;
2695                         lval = (unsigned long)-val;
2696                 } else {
2697                         *negp = 0;
2698                         lval = (unsigned long)val;
2699                 }
2700                 *lvalp = jiffies_to_msecs(lval);
2701         }
2702         return 0;
2703 }
2704
2705 /**
2706  * proc_dointvec_jiffies - read a vector of integers as seconds
2707  * @table: the sysctl table
2708  * @write: %TRUE if this is a write to the sysctl file
2709  * @filp: the file structure
2710  * @buffer: the user buffer
2711  * @lenp: the size of the user buffer
2712  * @ppos: file position
2713  *
2714  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2715  * values from/to the user buffer, treated as an ASCII string.
2716  * The values read are assumed to be in seconds, and are converted into
2717  * jiffies.
2718  *
2719  * Returns 0 on success.
2720  */
2721 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2722                           void __user *buffer, size_t *lenp, loff_t *ppos)
2723 {
2724     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2725                             do_proc_dointvec_jiffies_conv,NULL);
2726 }
2727
2728 /**
2729  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2730  * @table: the sysctl table
2731  * @write: %TRUE if this is a write to the sysctl file
2732  * @filp: the file structure
2733  * @buffer: the user buffer
2734  * @lenp: the size of the user buffer
2735  * @ppos: pointer to the file position
2736  *
2737  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2738  * values from/to the user buffer, treated as an ASCII string.
2739  * The values read are assumed to be in 1/USER_HZ seconds, and
2740  * are converted into jiffies.
2741  *
2742  * Returns 0 on success.
2743  */
2744 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2745                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2746 {
2747     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2748                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2749 }
2750
2751 /**
2752  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2753  * @table: the sysctl table
2754  * @write: %TRUE if this is a write to the sysctl file
2755  * @filp: the file structure
2756  * @buffer: the user buffer
2757  * @lenp: the size of the user buffer
2758  * @ppos: file position
2759  * @ppos: the current position in the file
2760  *
2761  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2762  * values from/to the user buffer, treated as an ASCII string.
2763  * The values read are assumed to be in 1/1000 seconds, and
2764  * are converted into jiffies.
2765  *
2766  * Returns 0 on success.
2767  */
2768 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2769                              void __user *buffer, size_t *lenp, loff_t *ppos)
2770 {
2771         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2772                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2773 }
2774
2775 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2776                            void __user *buffer, size_t *lenp, loff_t *ppos)
2777 {
2778         struct pid *new_pid;
2779         pid_t tmp;
2780         int r;
2781
2782         tmp = pid_vnr(cad_pid);
2783
2784         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2785                                lenp, ppos, NULL, NULL);
2786         if (r || !write)
2787                 return r;
2788
2789         new_pid = find_get_pid(tmp);
2790         if (!new_pid)
2791                 return -ESRCH;
2792
2793         put_pid(xchg(&cad_pid, new_pid));
2794         return 0;
2795 }
2796
2797 #else /* CONFIG_PROC_FS */
2798
2799 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2800                   void __user *buffer, size_t *lenp, loff_t *ppos)
2801 {
2802         return -ENOSYS;
2803 }
2804
2805 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2806                   void __user *buffer, size_t *lenp, loff_t *ppos)
2807 {
2808         return -ENOSYS;
2809 }
2810
2811 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2812                     void __user *buffer, size_t *lenp, loff_t *ppos)
2813 {
2814         return -ENOSYS;
2815 }
2816
2817 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2818                     void __user *buffer, size_t *lenp, loff_t *ppos)
2819 {
2820         return -ENOSYS;
2821 }
2822
2823 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2824                     void __user *buffer, size_t *lenp, loff_t *ppos)
2825 {
2826         return -ENOSYS;
2827 }
2828
2829 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2830                              void __user *buffer, size_t *lenp, loff_t *ppos)
2831 {
2832         return -ENOSYS;
2833 }
2834
2835 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2836                     void __user *buffer, size_t *lenp, loff_t *ppos)
2837 {
2838         return -ENOSYS;
2839 }
2840
2841 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2842                                       struct file *filp,
2843                                       void __user *buffer,
2844                                       size_t *lenp, loff_t *ppos)
2845 {
2846     return -ENOSYS;
2847 }
2848
2849
2850 #endif /* CONFIG_PROC_FS */
2851
2852
2853 #ifdef CONFIG_SYSCTL_SYSCALL
2854 /*
2855  * General sysctl support routines
2856  */
2857
2858 /* The generic sysctl data routine (used if no strategy routine supplied) */
2859 int sysctl_data(struct ctl_table *table,
2860                 void __user *oldval, size_t __user *oldlenp,
2861                 void __user *newval, size_t newlen)
2862 {
2863         size_t len;
2864
2865         /* Get out of I don't have a variable */
2866         if (!table->data || !table->maxlen)
2867                 return -ENOTDIR;
2868
2869         if (oldval && oldlenp) {
2870                 if (get_user(len, oldlenp))
2871                         return -EFAULT;
2872                 if (len) {
2873                         if (len > table->maxlen)
2874                                 len = table->maxlen;
2875                         if (copy_to_user(oldval, table->data, len))
2876                                 return -EFAULT;
2877                         if (put_user(len, oldlenp))
2878                                 return -EFAULT;
2879                 }
2880         }
2881
2882         if (newval && newlen) {
2883                 if (newlen > table->maxlen)
2884                         newlen = table->maxlen;
2885
2886                 if (copy_from_user(table->data, newval, newlen))
2887                         return -EFAULT;
2888         }
2889         return 1;
2890 }
2891
2892 /* The generic string strategy routine: */
2893 int sysctl_string(struct ctl_table *table,
2894                   void __user *oldval, size_t __user *oldlenp,
2895                   void __user *newval, size_t newlen)
2896 {
2897         if (!table->data || !table->maxlen)
2898                 return -ENOTDIR;
2899
2900         if (oldval && oldlenp) {
2901                 size_t bufsize;
2902                 if (get_user(bufsize, oldlenp))
2903                         return -EFAULT;
2904                 if (bufsize) {
2905                         size_t len = strlen(table->data), copied;
2906
2907                         /* This shouldn't trigger for a well-formed sysctl */
2908                         if (len > table->maxlen)
2909                                 len = table->maxlen;
2910
2911                         /* Copy up to a max of bufsize-1 bytes of the string */
2912                         copied = (len >= bufsize) ? bufsize - 1 : len;
2913
2914                         if (copy_to_user(oldval, table->data, copied) ||
2915                             put_user(0, (char __user *)(oldval + copied)))
2916                                 return -EFAULT;
2917                         if (put_user(len, oldlenp))
2918                                 return -EFAULT;
2919                 }
2920         }
2921         if (newval && newlen) {
2922                 size_t len = newlen;
2923                 if (len > table->maxlen)
2924                         len = table->maxlen;
2925                 if(copy_from_user(table->data, newval, len))
2926                         return -EFAULT;
2927                 if (len == table->maxlen)
2928                         len--;
2929                 ((char *) table->data)[len] = 0;
2930         }
2931         return 1;
2932 }
2933
2934 /*
2935  * This function makes sure that all of the integers in the vector
2936  * are between the minimum and maximum values given in the arrays
2937  * table->extra1 and table->extra2, respectively.
2938  */
2939 int sysctl_intvec(struct ctl_table *table,
2940                 void __user *oldval, size_t __user *oldlenp,
2941                 void __user *newval, size_t newlen)
2942 {
2943
2944         if (newval && newlen) {
2945                 int __user *vec = (int __user *) newval;
2946                 int *min = (int *) table->extra1;
2947                 int *max = (int *) table->extra2;
2948                 size_t length;
2949                 int i;
2950
2951                 if (newlen % sizeof(int) != 0)
2952                         return -EINVAL;
2953
2954                 if (!table->extra1 && !table->extra2)
2955                         return 0;
2956
2957                 if (newlen > table->maxlen)
2958                         newlen = table->maxlen;
2959                 length = newlen / sizeof(int);
2960
2961                 for (i = 0; i < length; i++) {
2962                         int value;
2963                         if (get_user(value, vec + i))
2964                                 return -EFAULT;
2965                         if (min && value < min[i])
2966                                 return -EINVAL;
2967                         if (max && value > max[i])
2968                                 return -EINVAL;
2969                 }
2970         }
2971         return 0;
2972 }
2973
2974 /* Strategy function to convert jiffies to seconds */
2975 int sysctl_jiffies(struct ctl_table *table,
2976                 void __user *oldval, size_t __user *oldlenp,
2977                 void __user *newval, size_t newlen)
2978 {
2979         if (oldval && oldlenp) {
2980                 size_t olen;
2981
2982                 if (get_user(olen, oldlenp))
2983                         return -EFAULT;
2984                 if (olen) {
2985                         int val;
2986
2987                         if (olen < sizeof(int))
2988                                 return -EINVAL;
2989
2990                         val = *(int *)(table->data) / HZ;
2991                         if (put_user(val, (int __user *)oldval))
2992                                 return -EFAULT;
2993                         if (put_user(sizeof(int), oldlenp))
2994                                 return -EFAULT;
2995                 }
2996         }
2997         if (newval && newlen) {
2998                 int new;
2999                 if (newlen != sizeof(int))
3000                         return -EINVAL;
3001                 if (get_user(new, (int __user *)newval))
3002                         return -EFAULT;
3003                 *(int *)(table->data) = new*HZ;
3004         }
3005         return 1;
3006 }
3007
3008 /* Strategy function to convert jiffies to seconds */
3009 int sysctl_ms_jiffies(struct ctl_table *table,
3010                 void __user *oldval, size_t __user *oldlenp,
3011                 void __user *newval, size_t newlen)
3012 {
3013         if (oldval && oldlenp) {
3014                 size_t olen;
3015
3016                 if (get_user(olen, oldlenp))
3017                         return -EFAULT;
3018                 if (olen) {
3019                         int val;
3020
3021                         if (olen < sizeof(int))
3022                                 return -EINVAL;
3023
3024                         val = jiffies_to_msecs(*(int *)(table->data));
3025                         if (put_user(val, (int __user *)oldval))
3026                                 return -EFAULT;
3027                         if (put_user(sizeof(int), oldlenp))
3028                                 return -EFAULT;
3029                 }
3030         }
3031         if (newval && newlen) {
3032                 int new;
3033                 if (newlen != sizeof(int))
3034                         return -EINVAL;
3035                 if (get_user(new, (int __user *)newval))
3036                         return -EFAULT;
3037                 *(int *)(table->data) = msecs_to_jiffies(new);
3038         }
3039         return 1;
3040 }
3041
3042
3043
3044 #else /* CONFIG_SYSCTL_SYSCALL */
3045
3046
3047 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3048 {
3049         struct __sysctl_args tmp;
3050         int error;
3051
3052         if (copy_from_user(&tmp, args, sizeof(tmp)))
3053                 return -EFAULT;
3054
3055         error = deprecated_sysctl_warning(&tmp);
3056
3057         /* If no error reading the parameters then just -ENOSYS ... */
3058         if (!error)
3059                 error = -ENOSYS;
3060
3061         return error;
3062 }
3063
3064 int sysctl_data(struct ctl_table *table,
3065                   void __user *oldval, size_t __user *oldlenp,
3066                   void __user *newval, size_t newlen)
3067 {
3068         return -ENOSYS;
3069 }
3070
3071 int sysctl_string(struct ctl_table *table,
3072                   void __user *oldval, size_t __user *oldlenp,
3073                   void __user *newval, size_t newlen)
3074 {
3075         return -ENOSYS;
3076 }
3077
3078 int sysctl_intvec(struct ctl_table *table,
3079                 void __user *oldval, size_t __user *oldlenp,
3080                 void __user *newval, size_t newlen)
3081 {
3082         return -ENOSYS;
3083 }
3084
3085 int sysctl_jiffies(struct ctl_table *table,
3086                 void __user *oldval, size_t __user *oldlenp,
3087                 void __user *newval, size_t newlen)
3088 {
3089         return -ENOSYS;
3090 }
3091
3092 int sysctl_ms_jiffies(struct ctl_table *table,
3093                 void __user *oldval, size_t __user *oldlenp,
3094                 void __user *newval, size_t newlen)
3095 {
3096         return -ENOSYS;
3097 }
3098
3099 #endif /* CONFIG_SYSCTL_SYSCALL */
3100
3101 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3102 {
3103         static int msg_count;
3104         int name[CTL_MAXNAME];
3105         int i;
3106
3107         /* Check args->nlen. */
3108         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3109                 return -ENOTDIR;
3110
3111         /* Read in the sysctl name for better debug message logging */
3112         for (i = 0; i < args->nlen; i++)
3113                 if (get_user(name[i], args->name + i))
3114                         return -EFAULT;
3115
3116         /* Ignore accesses to kernel.version */
3117         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3118                 return 0;
3119
3120         if (msg_count < 5) {
3121                 msg_count++;
3122                 printk(KERN_INFO
3123                         "warning: process `%s' used the deprecated sysctl "
3124                         "system call with ", current->comm);
3125                 for (i = 0; i < args->nlen; i++)
3126                         printk("%d.", name[i]);
3127                 printk("\n");
3128         }
3129         return 0;
3130 }
3131
3132 /*
3133  * No sense putting this after each symbol definition, twice,
3134  * exception granted :-)
3135  */
3136 EXPORT_SYMBOL(proc_dointvec);
3137 EXPORT_SYMBOL(proc_dointvec_jiffies);
3138 EXPORT_SYMBOL(proc_dointvec_minmax);
3139 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3140 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3141 EXPORT_SYMBOL(proc_dostring);
3142 EXPORT_SYMBOL(proc_doulongvec_minmax);
3143 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3144 EXPORT_SYMBOL(register_sysctl_table);
3145 EXPORT_SYMBOL(register_sysctl_paths);
3146 EXPORT_SYMBOL(sysctl_intvec);
3147 EXPORT_SYMBOL(sysctl_jiffies);
3148 EXPORT_SYMBOL(sysctl_ms_jiffies);
3149 EXPORT_SYMBOL(sysctl_string);
3150 EXPORT_SYMBOL(sysctl_data);
3151 EXPORT_SYMBOL(unregister_sysctl_table);