git.oblomov.eu Git - linux-2.6/blob - 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 #include <linux/perf_counter.h>
  53
  54 #include <asm/uaccess.h>
  55 #include <asm/processor.h>
  56
  57 #ifdef CONFIG_X86
  58 #include <asm/nmi.h>
  59 #include <asm/stacktrace.h>
  60 #include <asm/io.h>
  61 #endif
  62
  63 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  64
  65 #if defined(CONFIG_SYSCTL)
  66
  67 /* External variables not in a header file. */
  68 extern int C_A_D;
  69 extern int print_fatal_signals;
  70 extern int sysctl_overcommit_memory;
  71 extern int sysctl_overcommit_ratio;
  72 extern int sysctl_panic_on_oom;
  73 extern int sysctl_oom_kill_allocating_task;
  74 extern int sysctl_oom_dump_tasks;
  75 extern int max_threads;
  76 extern int core_uses_pid;
  77 extern int suid_dumpable;
  78 extern char core_pattern[];
  79 extern int pid_max;
  80 extern int min_free_kbytes;
  81 extern int pid_max_min, pid_max_max;
  82 extern int sysctl_drop_caches;
  83 extern int percpu_pagelist_fraction;
  84 extern int compat_log;
  85 extern int latencytop_enabled;
  86 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  87 #ifndef CONFIG_MMU
  88 extern int sysctl_nr_trim_pages;
  89 #endif
  90 #ifdef CONFIG_RCU_TORTURE_TEST
  91 extern int rcutorture_runnable;
  92 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  93
  94 /* Constants used for minimum and  maximum */
  95 #ifdef CONFIG_DETECT_SOFTLOCKUP
  96 static int sixty = 60;
  97 static int neg_one = -1;
  98 #endif
  99
 100 static int zero;
 101 static int __maybe_unused one = 1;
 102 static int __maybe_unused two = 2;
 103 static unsigned long one_ul = 1;
 104 static int one_hundred = 100;
 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 #ifdef CONFIG_PERF_COUNTERS
 917         {
 918                 .ctl_name       = CTL_UNNUMBERED,
 919                 .procname       = "perf_counter_privileged",
 920                 .data           = &sysctl_perf_counter_priv,
 921                 .maxlen         = sizeof(sysctl_perf_counter_priv),
 922                 .mode           = 0644,
 923                 .proc_handler   = &proc_dointvec,
 924         },
 925         {
 926                 .ctl_name       = CTL_UNNUMBERED,
 927                 .procname       = "perf_counter_mlock_kb",
 928                 .data           = &sysctl_perf_counter_mlock,
 929                 .maxlen         = sizeof(sysctl_perf_counter_mlock),
 930                 .mode           = 0644,
 931                 .proc_handler   = &proc_dointvec,
 932         },
 933         {
 934                 .ctl_name       = CTL_UNNUMBERED,
 935                 .procname       = "perf_counter_int_limit",
 936                 .data           = &sysctl_perf_counter_limit,
 937                 .maxlen         = sizeof(sysctl_perf_counter_limit),
 938                 .mode           = 0644,
 939                 .proc_handler   = &proc_dointvec,
 940         },
 941 #endif
 942 /*
 943  * NOTE: do not add new entries to this table unless you have read
 944  * Documentation/sysctl/ctl_unnumbered.txt
 945  */
 946         { .ctl_name = 0 }
 947 };
 948
 949 static struct ctl_table vm_table[] = {
 950         {
 951                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 952                 .procname       = "overcommit_memory",
 953                 .data           = &sysctl_overcommit_memory,
 954                 .maxlen         = sizeof(sysctl_overcommit_memory),
 955                 .mode           = 0644,
 956                 .proc_handler   = &proc_dointvec,
 957         },
 958         {
 959                 .ctl_name       = VM_PANIC_ON_OOM,
 960                 .procname       = "panic_on_oom",
 961                 .data           = &sysctl_panic_on_oom,
 962                 .maxlen         = sizeof(sysctl_panic_on_oom),
 963                 .mode           = 0644,
 964                 .proc_handler   = &proc_dointvec,
 965         },
 966         {
 967                 .ctl_name       = CTL_UNNUMBERED,
 968                 .procname       = "oom_kill_allocating_task",
 969                 .data           = &sysctl_oom_kill_allocating_task,
 970                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 971                 .mode           = 0644,
 972                 .proc_handler   = &proc_dointvec,
 973         },
 974         {
 975                 .ctl_name       = CTL_UNNUMBERED,
 976                 .procname       = "oom_dump_tasks",
 977                 .data           = &sysctl_oom_dump_tasks,
 978                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
 979                 .mode           = 0644,
 980                 .proc_handler   = &proc_dointvec,
 981         },
 982         {
 983                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 984                 .procname       = "overcommit_ratio",
 985                 .data           = &sysctl_overcommit_ratio,
 986                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 987                 .mode           = 0644,
 988                 .proc_handler   = &proc_dointvec,
 989         },
 990         {
 991                 .ctl_name       = VM_PAGE_CLUSTER,
 992                 .procname       = "page-cluster",
 993                 .data           = &page_cluster,
 994                 .maxlen         = sizeof(int),
 995                 .mode           = 0644,
 996                 .proc_handler   = &proc_dointvec,
 997         },
 998         {
 999                 .ctl_name       = VM_DIRTY_BACKGROUND,
1000                 .procname       = "dirty_background_ratio",
1001                 .data           = &dirty_background_ratio,
1002                 .maxlen         = sizeof(dirty_background_ratio),
1003                 .mode           = 0644,
1004                 .proc_handler   = &dirty_background_ratio_handler,
1005                 .strategy       = &sysctl_intvec,
1006                 .extra1         = &zero,
1007                 .extra2         = &one_hundred,
1008         },
1009         {
1010                 .ctl_name       = CTL_UNNUMBERED,
1011                 .procname       = "dirty_background_bytes",
1012                 .data           = &dirty_background_bytes,
1013                 .maxlen         = sizeof(dirty_background_bytes),
1014                 .mode           = 0644,
1015                 .proc_handler   = &dirty_background_bytes_handler,
1016                 .strategy       = &sysctl_intvec,
1017                 .extra1         = &one_ul,
1018         },
1019         {
1020                 .ctl_name       = VM_DIRTY_RATIO,
1021                 .procname       = "dirty_ratio",
1022                 .data           = &vm_dirty_ratio,
1023                 .maxlen         = sizeof(vm_dirty_ratio),
1024                 .mode           = 0644,
1025                 .proc_handler   = &dirty_ratio_handler,
1026                 .strategy       = &sysctl_intvec,
1027                 .extra1         = &zero,
1028                 .extra2         = &one_hundred,
1029         },
1030         {
1031                 .ctl_name       = CTL_UNNUMBERED,
1032                 .procname       = "dirty_bytes",
1033                 .data           = &vm_dirty_bytes,
1034                 .maxlen         = sizeof(vm_dirty_bytes),
1035                 .mode           = 0644,
1036                 .proc_handler   = &dirty_bytes_handler,
1037                 .strategy       = &sysctl_intvec,
1038                 .extra1         = &dirty_bytes_min,
1039         },
1040         {
1041                 .procname       = "dirty_writeback_centisecs",
1042                 .data           = &dirty_writeback_interval,
1043                 .maxlen         = sizeof(dirty_writeback_interval),
1044                 .mode           = 0644,
1045                 .proc_handler   = &dirty_writeback_centisecs_handler,
1046         },
1047         {
1048                 .procname       = "dirty_expire_centisecs",
1049                 .data           = &dirty_expire_interval,
1050                 .maxlen         = sizeof(dirty_expire_interval),
1051                 .mode           = 0644,
1052                 .proc_handler   = &proc_dointvec,
1053         },
1054         {
1055                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1056                 .procname       = "nr_pdflush_threads",
1057                 .data           = &nr_pdflush_threads,
1058                 .maxlen         = sizeof nr_pdflush_threads,
1059                 .mode           = 0444 /* read-only*/,
1060                 .proc_handler   = &proc_dointvec,
1061         },
1062         {
1063                 .ctl_name       = VM_SWAPPINESS,
1064                 .procname       = "swappiness",
1065                 .data           = &vm_swappiness,
1066                 .maxlen         = sizeof(vm_swappiness),
1067                 .mode           = 0644,
1068                 .proc_handler   = &proc_dointvec_minmax,
1069                 .strategy       = &sysctl_intvec,
1070                 .extra1         = &zero,
1071                 .extra2         = &one_hundred,
1072         },
1073 #ifdef CONFIG_HUGETLB_PAGE
1074          {
1075                 .procname       = "nr_hugepages",
1076                 .data           = NULL,
1077                 .maxlen         = sizeof(unsigned long),
1078                 .mode           = 0644,
1079                 .proc_handler   = &hugetlb_sysctl_handler,
1080                 .extra1         = (void *)&hugetlb_zero,
1081                 .extra2         = (void *)&hugetlb_infinity,
1082          },
1083          {
1084                 .ctl_name       = VM_HUGETLB_GROUP,
1085                 .procname       = "hugetlb_shm_group",
1086                 .data           = &sysctl_hugetlb_shm_group,
1087                 .maxlen         = sizeof(gid_t),
1088                 .mode           = 0644,
1089                 .proc_handler   = &proc_dointvec,
1090          },
1091          {
1092                 .ctl_name       = CTL_UNNUMBERED,
1093                 .procname       = "hugepages_treat_as_movable",
1094                 .data           = &hugepages_treat_as_movable,
1095                 .maxlen         = sizeof(int),
1096                 .mode           = 0644,
1097                 .proc_handler   = &hugetlb_treat_movable_handler,
1098         },
1099         {
1100                 .ctl_name       = CTL_UNNUMBERED,
1101                 .procname       = "nr_overcommit_hugepages",
1102                 .data           = NULL,
1103                 .maxlen         = sizeof(unsigned long),
1104                 .mode           = 0644,
1105                 .proc_handler   = &hugetlb_overcommit_handler,
1106                 .extra1         = (void *)&hugetlb_zero,
1107                 .extra2         = (void *)&hugetlb_infinity,
1108         },
1109 #endif
1110         {
1111                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1112                 .procname       = "lowmem_reserve_ratio",
1113                 .data           = &sysctl_lowmem_reserve_ratio,
1114                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1115                 .mode           = 0644,
1116                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1117                 .strategy       = &sysctl_intvec,
1118         },
1119         {
1120                 .ctl_name       = VM_DROP_PAGECACHE,
1121                 .procname       = "drop_caches",
1122                 .data           = &sysctl_drop_caches,
1123                 .maxlen         = sizeof(int),
1124                 .mode           = 0644,
1125                 .proc_handler   = drop_caches_sysctl_handler,
1126                 .strategy       = &sysctl_intvec,
1127         },
1128         {
1129                 .ctl_name       = VM_MIN_FREE_KBYTES,
1130                 .procname       = "min_free_kbytes",
1131                 .data           = &min_free_kbytes,
1132                 .maxlen         = sizeof(min_free_kbytes),
1133                 .mode           = 0644,
1134                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1135                 .strategy       = &sysctl_intvec,
1136                 .extra1         = &zero,
1137         },
1138         {
1139                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1140                 .procname       = "percpu_pagelist_fraction",
1141                 .data           = &percpu_pagelist_fraction,
1142                 .maxlen         = sizeof(percpu_pagelist_fraction),
1143                 .mode           = 0644,
1144                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1145                 .strategy       = &sysctl_intvec,
1146                 .extra1         = &min_percpu_pagelist_fract,
1147         },
1148 #ifdef CONFIG_MMU
1149         {
1150                 .ctl_name       = VM_MAX_MAP_COUNT,
1151                 .procname       = "max_map_count",
1152                 .data           = &sysctl_max_map_count,
1153                 .maxlen         = sizeof(sysctl_max_map_count),
1154                 .mode           = 0644,
1155                 .proc_handler   = &proc_dointvec
1156         },
1157 #else
1158         {
1159                 .ctl_name       = CTL_UNNUMBERED,
1160                 .procname       = "nr_trim_pages",
1161                 .data           = &sysctl_nr_trim_pages,
1162                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1163                 .mode           = 0644,
1164                 .proc_handler   = &proc_dointvec_minmax,
1165                 .strategy       = &sysctl_intvec,
1166                 .extra1         = &zero,
1167         },
1168 #endif
1169         {
1170                 .ctl_name       = VM_LAPTOP_MODE,
1171                 .procname       = "laptop_mode",
1172                 .data           = &laptop_mode,
1173                 .maxlen         = sizeof(laptop_mode),
1174                 .mode           = 0644,
1175                 .proc_handler   = &proc_dointvec_jiffies,
1176                 .strategy       = &sysctl_jiffies,
1177         },
1178         {
1179                 .ctl_name       = VM_BLOCK_DUMP,
1180                 .procname       = "block_dump",
1181                 .data           = &block_dump,
1182                 .maxlen         = sizeof(block_dump),
1183                 .mode           = 0644,
1184                 .proc_handler   = &proc_dointvec,
1185                 .strategy       = &sysctl_intvec,
1186                 .extra1         = &zero,
1187         },
1188         {
1189                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1190                 .procname       = "vfs_cache_pressure",
1191                 .data           = &sysctl_vfs_cache_pressure,
1192                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1193                 .mode           = 0644,
1194                 .proc_handler   = &proc_dointvec,
1195                 .strategy       = &sysctl_intvec,
1196                 .extra1         = &zero,
1197         },
1198 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1199         {
1200                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1201                 .procname       = "legacy_va_layout",
1202                 .data           = &sysctl_legacy_va_layout,
1203                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1204                 .mode           = 0644,
1205                 .proc_handler   = &proc_dointvec,
1206                 .strategy       = &sysctl_intvec,
1207                 .extra1         = &zero,
1208         },
1209 #endif
1210 #ifdef CONFIG_NUMA
1211         {
1212                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1213                 .procname       = "zone_reclaim_mode",
1214                 .data           = &zone_reclaim_mode,
1215                 .maxlen         = sizeof(zone_reclaim_mode),
1216                 .mode           = 0644,
1217                 .proc_handler   = &proc_dointvec,
1218                 .strategy       = &sysctl_intvec,
1219                 .extra1         = &zero,
1220         },
1221         {
1222                 .ctl_name       = VM_MIN_UNMAPPED,
1223                 .procname       = "min_unmapped_ratio",
1224                 .data           = &sysctl_min_unmapped_ratio,
1225                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1226                 .mode           = 0644,
1227                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1228                 .strategy       = &sysctl_intvec,
1229                 .extra1         = &zero,
1230                 .extra2         = &one_hundred,
1231         },
1232         {
1233                 .ctl_name       = VM_MIN_SLAB,
1234                 .procname       = "min_slab_ratio",
1235                 .data           = &sysctl_min_slab_ratio,
1236                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1237                 .mode           = 0644,
1238                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1239                 .strategy       = &sysctl_intvec,
1240                 .extra1         = &zero,
1241                 .extra2         = &one_hundred,
1242         },
1243 #endif
1244 #ifdef CONFIG_SMP
1245         {
1246                 .ctl_name       = CTL_UNNUMBERED,
1247                 .procname       = "stat_interval",
1248                 .data           = &sysctl_stat_interval,
1249                 .maxlen         = sizeof(sysctl_stat_interval),
1250                 .mode           = 0644,
1251                 .proc_handler   = &proc_dointvec_jiffies,
1252                 .strategy       = &sysctl_jiffies,
1253         },
1254 #endif
1255 #ifdef CONFIG_SECURITY
1256         {
1257                 .ctl_name       = CTL_UNNUMBERED,
1258                 .procname       = "mmap_min_addr",
1259                 .data           = &mmap_min_addr,
1260                 .maxlen         = sizeof(unsigned long),
1261                 .mode           = 0644,
1262                 .proc_handler   = &proc_doulongvec_minmax,
1263         },
1264 #endif
1265 #ifdef CONFIG_NUMA
1266         {
1267                 .ctl_name       = CTL_UNNUMBERED,
1268                 .procname       = "numa_zonelist_order",
1269                 .data           = &numa_zonelist_order,
1270                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1271                 .mode           = 0644,
1272                 .proc_handler   = &numa_zonelist_order_handler,
1273                 .strategy       = &sysctl_string,
1274         },
1275 #endif
1276 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1277    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1278         {
1279                 .ctl_name       = VM_VDSO_ENABLED,
1280                 .procname       = "vdso_enabled",
1281                 .data           = &vdso_enabled,
1282                 .maxlen         = sizeof(vdso_enabled),
1283                 .mode           = 0644,
1284                 .proc_handler   = &proc_dointvec,
1285                 .strategy       = &sysctl_intvec,
1286                 .extra1         = &zero,
1287         },
1288 #endif
1289 #ifdef CONFIG_HIGHMEM
1290         {
1291                 .ctl_name       = CTL_UNNUMBERED,
1292                 .procname       = "highmem_is_dirtyable",
1293                 .data           = &vm_highmem_is_dirtyable,
1294                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1295                 .mode           = 0644,
1296                 .proc_handler   = &proc_dointvec_minmax,
1297                 .strategy       = &sysctl_intvec,
1298                 .extra1         = &zero,
1299                 .extra2         = &one,
1300         },
1301 #endif
1302 #ifdef CONFIG_UNEVICTABLE_LRU
1303         {
1304                 .ctl_name       = CTL_UNNUMBERED,
1305                 .procname       = "scan_unevictable_pages",
1306                 .data           = &scan_unevictable_pages,
1307                 .maxlen         = sizeof(scan_unevictable_pages),
1308                 .mode           = 0644,
1309                 .proc_handler   = &scan_unevictable_handler,
1310         },
1311 #endif
1312 /*
1313  * NOTE: do not add new entries to this table unless you have read
1314  * Documentation/sysctl/ctl_unnumbered.txt
1315  */
1316         { .ctl_name = 0 }
1317 };
1318
1319 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1320 static struct ctl_table binfmt_misc_table[] = {
1321         { .ctl_name = 0 }
1322 };
1323 #endif
1324
1325 static struct ctl_table fs_table[] = {
1326         {
1327                 .ctl_name       = FS_NRINODE,
1328                 .procname       = "inode-nr",
1329                 .data           = &inodes_stat,
1330                 .maxlen         = 2*sizeof(int),
1331                 .mode           = 0444,
1332                 .proc_handler   = &proc_dointvec,
1333         },
1334         {
1335                 .ctl_name       = FS_STATINODE,
1336                 .procname       = "inode-state",
1337                 .data           = &inodes_stat,
1338                 .maxlen         = 7*sizeof(int),
1339                 .mode           = 0444,
1340                 .proc_handler   = &proc_dointvec,
1341         },
1342         {
1343                 .procname       = "file-nr",
1344                 .data           = &files_stat,
1345                 .maxlen         = 3*sizeof(int),
1346                 .mode           = 0444,
1347                 .proc_handler   = &proc_nr_files,
1348         },
1349         {
1350                 .ctl_name       = FS_MAXFILE,
1351                 .procname       = "file-max",
1352                 .data           = &files_stat.max_files,
1353                 .maxlen         = sizeof(int),
1354                 .mode           = 0644,
1355                 .proc_handler   = &proc_dointvec,
1356         },
1357         {
1358                 .ctl_name       = CTL_UNNUMBERED,
1359                 .procname       = "nr_open",
1360                 .data           = &sysctl_nr_open,
1361                 .maxlen         = sizeof(int),
1362                 .mode           = 0644,
1363                 .proc_handler   = &proc_dointvec_minmax,
1364                 .extra1         = &sysctl_nr_open_min,
1365                 .extra2         = &sysctl_nr_open_max,
1366         },
1367         {
1368                 .ctl_name       = FS_DENTRY,
1369                 .procname       = "dentry-state",
1370                 .data           = &dentry_stat,
1371                 .maxlen         = 6*sizeof(int),
1372                 .mode           = 0444,
1373                 .proc_handler   = &proc_dointvec,
1374         },
1375         {
1376                 .ctl_name       = FS_OVERFLOWUID,
1377                 .procname       = "overflowuid",
1378                 .data           = &fs_overflowuid,
1379                 .maxlen         = sizeof(int),
1380                 .mode           = 0644,
1381                 .proc_handler   = &proc_dointvec_minmax,
1382                 .strategy       = &sysctl_intvec,
1383                 .extra1         = &minolduid,
1384                 .extra2         = &maxolduid,
1385         },
1386         {
1387                 .ctl_name       = FS_OVERFLOWGID,
1388                 .procname       = "overflowgid",
1389                 .data           = &fs_overflowgid,
1390                 .maxlen         = sizeof(int),
1391                 .mode           = 0644,
1392                 .proc_handler   = &proc_dointvec_minmax,
1393                 .strategy       = &sysctl_intvec,
1394                 .extra1         = &minolduid,
1395                 .extra2         = &maxolduid,
1396         },
1397 #ifdef CONFIG_FILE_LOCKING
1398         {
1399                 .ctl_name       = FS_LEASES,
1400                 .procname       = "leases-enable",
1401                 .data           = &leases_enable,
1402                 .maxlen         = sizeof(int),
1403                 .mode           = 0644,
1404                 .proc_handler   = &proc_dointvec,
1405         },
1406 #endif
1407 #ifdef CONFIG_DNOTIFY
1408         {
1409                 .ctl_name       = FS_DIR_NOTIFY,
1410                 .procname       = "dir-notify-enable",
1411                 .data           = &dir_notify_enable,
1412                 .maxlen         = sizeof(int),
1413                 .mode           = 0644,
1414                 .proc_handler   = &proc_dointvec,
1415         },
1416 #endif
1417 #ifdef CONFIG_MMU
1418 #ifdef CONFIG_FILE_LOCKING
1419         {
1420                 .ctl_name       = FS_LEASE_TIME,
1421                 .procname       = "lease-break-time",
1422                 .data           = &lease_break_time,
1423                 .maxlen         = sizeof(int),
1424                 .mode           = 0644,
1425                 .proc_handler   = &proc_dointvec,
1426         },
1427 #endif
1428 #ifdef CONFIG_AIO
1429         {
1430                 .procname       = "aio-nr",
1431                 .data           = &aio_nr,
1432                 .maxlen         = sizeof(aio_nr),
1433                 .mode           = 0444,
1434                 .proc_handler   = &proc_doulongvec_minmax,
1435         },
1436         {
1437                 .procname       = "aio-max-nr",
1438                 .data           = &aio_max_nr,
1439                 .maxlen         = sizeof(aio_max_nr),
1440                 .mode           = 0644,
1441                 .proc_handler   = &proc_doulongvec_minmax,
1442         },
1443 #endif /* CONFIG_AIO */
1444 #ifdef CONFIG_INOTIFY_USER
1445         {
1446                 .ctl_name       = FS_INOTIFY,
1447                 .procname       = "inotify",
1448                 .mode           = 0555,
1449                 .child          = inotify_table,
1450         },
1451 #endif
1452 #ifdef CONFIG_EPOLL
1453         {
1454                 .procname       = "epoll",
1455                 .mode           = 0555,
1456                 .child          = epoll_table,
1457         },
1458 #endif
1459 #endif
1460         {
1461                 .ctl_name       = KERN_SETUID_DUMPABLE,
1462                 .procname       = "suid_dumpable",
1463                 .data           = &suid_dumpable,
1464                 .maxlen         = sizeof(int),
1465                 .mode           = 0644,
1466                 .proc_handler   = &proc_dointvec_minmax,
1467                 .strategy       = &sysctl_intvec,
1468                 .extra1         = &zero,
1469                 .extra2         = &two,
1470         },
1471 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1472         {
1473                 .ctl_name       = CTL_UNNUMBERED,
1474                 .procname       = "binfmt_misc",
1475                 .mode           = 0555,
1476                 .child          = binfmt_misc_table,
1477         },
1478 #endif
1479 /*
1480  * NOTE: do not add new entries to this table unless you have read
1481  * Documentation/sysctl/ctl_unnumbered.txt
1482  */
1483         { .ctl_name = 0 }
1484 };
1485
1486 static struct ctl_table debug_table[] = {
1487 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1488         {
1489                 .ctl_name       = CTL_UNNUMBERED,
1490                 .procname       = "exception-trace",
1491                 .data           = &show_unhandled_signals,
1492                 .maxlen         = sizeof(int),
1493                 .mode           = 0644,
1494                 .proc_handler   = proc_dointvec
1495         },
1496 #endif
1497         { .ctl_name = 0 }
1498 };
1499
1500 static struct ctl_table dev_table[] = {
1501         { .ctl_name = 0 }
1502 };
1503
1504 static DEFINE_SPINLOCK(sysctl_lock);
1505
1506 /* called under sysctl_lock */
1507 static int use_table(struct ctl_table_header *p)
1508 {
1509         if (unlikely(p->unregistering))
1510                 return 0;
1511         p->used++;
1512         return 1;
1513 }
1514
1515 /* called under sysctl_lock */
1516 static void unuse_table(struct ctl_table_header *p)
1517 {
1518         if (!--p->used)
1519                 if (unlikely(p->unregistering))
1520                         complete(p->unregistering);
1521 }
1522
1523 /* called under sysctl_lock, will reacquire if has to wait */
1524 static void start_unregistering(struct ctl_table_header *p)
1525 {
1526         /*
1527          * if p->used is 0, nobody will ever touch that entry again;
1528          * we'll eliminate all paths to it before dropping sysctl_lock
1529          */
1530         if (unlikely(p->used)) {
1531                 struct completion wait;
1532                 init_completion(&wait);
1533                 p->unregistering = &wait;
1534                 spin_unlock(&sysctl_lock);
1535                 wait_for_completion(&wait);
1536                 spin_lock(&sysctl_lock);
1537         } else {
1538                 /* anything non-NULL; we'll never dereference it */
1539                 p->unregistering = ERR_PTR(-EINVAL);
1540         }
1541         /*
1542          * do not remove from the list until nobody holds it; walking the
1543          * list in do_sysctl() relies on that.
1544          */
1545         list_del_init(&p->ctl_entry);
1546 }
1547
1548 void sysctl_head_get(struct ctl_table_header *head)
1549 {
1550         spin_lock(&sysctl_lock);
1551         head->count++;
1552         spin_unlock(&sysctl_lock);
1553 }
1554
1555 void sysctl_head_put(struct ctl_table_header *head)
1556 {
1557         spin_lock(&sysctl_lock);
1558         if (!--head->count)
1559                 kfree(head);
1560         spin_unlock(&sysctl_lock);
1561 }
1562
1563 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1564 {
1565         if (!head)
1566                 BUG();
1567         spin_lock(&sysctl_lock);
1568         if (!use_table(head))
1569                 head = ERR_PTR(-ENOENT);
1570         spin_unlock(&sysctl_lock);
1571         return head;
1572 }
1573
1574 void sysctl_head_finish(struct ctl_table_header *head)
1575 {
1576         if (!head)
1577                 return;
1578         spin_lock(&sysctl_lock);
1579         unuse_table(head);
1580         spin_unlock(&sysctl_lock);
1581 }
1582
1583 static struct ctl_table_set *
1584 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1585 {
1586         struct ctl_table_set *set = &root->default_set;
1587         if (root->lookup)
1588                 set = root->lookup(root, namespaces);
1589         return set;
1590 }
1591
1592 static struct list_head *
1593 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1594 {
1595         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1596         return &set->list;
1597 }
1598
1599 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1600                                             struct ctl_table_header *prev)
1601 {
1602         struct ctl_table_root *root;
1603         struct list_head *header_list;
1604         struct ctl_table_header *head;
1605         struct list_head *tmp;
1606
1607         spin_lock(&sysctl_lock);
1608         if (prev) {
1609                 head = prev;
1610                 tmp = &prev->ctl_entry;
1611                 unuse_table(prev);
1612                 goto next;
1613         }
1614         tmp = &root_table_header.ctl_entry;
1615         for (;;) {
1616                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1617
1618                 if (!use_table(head))
1619                         goto next;
1620                 spin_unlock(&sysctl_lock);
1621                 return head;
1622         next:
1623                 root = head->root;
1624                 tmp = tmp->next;
1625                 header_list = lookup_header_list(root, namespaces);
1626                 if (tmp != header_list)
1627                         continue;
1628
1629                 do {
1630                         root = list_entry(root->root_list.next,
1631                                         struct ctl_table_root, root_list);
1632                         if (root == &sysctl_table_root)
1633                                 goto out;
1634                         header_list = lookup_header_list(root, namespaces);
1635                 } while (list_empty(header_list));
1636                 tmp = header_list->next;
1637         }
1638 out:
1639         spin_unlock(&sysctl_lock);
1640         return NULL;
1641 }
1642
1643 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1644 {
1645         return __sysctl_head_next(current->nsproxy, prev);
1646 }
1647
1648 void register_sysctl_root(struct ctl_table_root *root)
1649 {
1650         spin_lock(&sysctl_lock);
1651         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1652         spin_unlock(&sysctl_lock);
1653 }
1654
1655 #ifdef CONFIG_SYSCTL_SYSCALL
1656 /* Perform the actual read/write of a sysctl table entry. */
1657 static int do_sysctl_strategy(struct ctl_table_root *root,
1658                         struct ctl_table *table,
1659                         void __user *oldval, size_t __user *oldlenp,
1660                         void __user *newval, size_t newlen)
1661 {
1662         int op = 0, rc;
1663
1664         if (oldval)
1665                 op |= MAY_READ;
1666         if (newval)
1667                 op |= MAY_WRITE;
1668         if (sysctl_perm(root, table, op))
1669                 return -EPERM;
1670
1671         if (table->strategy) {
1672                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1673                 if (rc < 0)
1674                         return rc;
1675                 if (rc > 0)
1676                         return 0;
1677         }
1678
1679         /* If there is no strategy routine, or if the strategy returns
1680          * zero, proceed with automatic r/w */
1681         if (table->data && table->maxlen) {
1682                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1683                 if (rc < 0)
1684                         return rc;
1685         }
1686         return 0;
1687 }
1688
1689 static int parse_table(int __user *name, int nlen,
1690                        void __user *oldval, size_t __user *oldlenp,
1691                        void __user *newval, size_t newlen,
1692                        struct ctl_table_root *root,
1693                        struct ctl_table *table)
1694 {
1695         int n;
1696 repeat:
1697         if (!nlen)
1698                 return -ENOTDIR;
1699         if (get_user(n, name))
1700                 return -EFAULT;
1701         for ( ; table->ctl_name || table->procname; table++) {
1702                 if (!table->ctl_name)
1703                         continue;
1704                 if (n == table->ctl_name) {
1705                         int error;
1706                         if (table->child) {
1707                                 if (sysctl_perm(root, table, MAY_EXEC))
1708                                         return -EPERM;
1709                                 name++;
1710                                 nlen--;
1711                                 table = table->child;
1712                                 goto repeat;
1713                         }
1714                         error = do_sysctl_strategy(root, table,
1715                                                    oldval, oldlenp,
1716                                                    newval, newlen);
1717                         return error;
1718                 }
1719         }
1720         return -ENOTDIR;
1721 }
1722
1723 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1724                void __user *newval, size_t newlen)
1725 {
1726         struct ctl_table_header *head;
1727         int error = -ENOTDIR;
1728
1729         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1730                 return -ENOTDIR;
1731         if (oldval) {
1732                 int old_len;
1733                 if (!oldlenp || get_user(old_len, oldlenp))
1734                         return -EFAULT;
1735         }
1736
1737         for (head = sysctl_head_next(NULL); head;
1738                         head = sysctl_head_next(head)) {
1739                 error = parse_table(name, nlen, oldval, oldlenp,
1740                                         newval, newlen,
1741                                         head->root, head->ctl_table);
1742                 if (error != -ENOTDIR) {
1743                         sysctl_head_finish(head);
1744                         break;
1745                 }
1746         }
1747         return error;
1748 }
1749
1750 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1751 {
1752         struct __sysctl_args tmp;
1753         int error;
1754
1755         if (copy_from_user(&tmp, args, sizeof(tmp)))
1756                 return -EFAULT;
1757
1758         error = deprecated_sysctl_warning(&tmp);
1759         if (error)
1760                 goto out;
1761
1762         lock_kernel();
1763         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1764                           tmp.newval, tmp.newlen);
1765         unlock_kernel();
1766 out:
1767         return error;
1768 }
1769 #endif /* CONFIG_SYSCTL_SYSCALL */
1770
1771 /*
1772  * sysctl_perm does NOT grant the superuser all rights automatically, because
1773  * some sysctl variables are readonly even to root.
1774  */
1775
1776 static int test_perm(int mode, int op)
1777 {
1778         if (!current_euid())
1779                 mode >>= 6;
1780         else if (in_egroup_p(0))
1781                 mode >>= 3;
1782         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1783                 return 0;
1784         return -EACCES;
1785 }
1786
1787 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1788 {
1789         int error;
1790         int mode;
1791
1792         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1793         if (error)
1794                 return error;
1795
1796         if (root->permissions)
1797                 mode = root->permissions(root, current->nsproxy, table);
1798         else
1799                 mode = table->mode;
1800
1801         return test_perm(mode, op);
1802 }
1803
1804 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1805 {
1806         for (; table->ctl_name || table->procname; table++) {
1807                 table->parent = parent;
1808                 if (table->child)
1809                         sysctl_set_parent(table, table->child);
1810         }
1811 }
1812
1813 static __init int sysctl_init(void)
1814 {
1815         sysctl_set_parent(NULL, root_table);
1816 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1817         {
1818                 int err;
1819                 err = sysctl_check_table(current->nsproxy, root_table);
1820         }
1821 #endif
1822         return 0;
1823 }
1824
1825 core_initcall(sysctl_init);
1826
1827 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1828                                       struct ctl_table *table)
1829 {
1830         struct ctl_table *p;
1831         const char *s = branch->procname;
1832
1833         /* branch should have named subdirectory as its first element */
1834         if (!s || !branch->child)
1835                 return NULL;
1836
1837         /* ... and nothing else */
1838         if (branch[1].procname || branch[1].ctl_name)
1839                 return NULL;
1840
1841         /* table should contain subdirectory with the same name */
1842         for (p = table; p->procname || p->ctl_name; p++) {
1843                 if (!p->child)
1844                         continue;
1845                 if (p->procname && strcmp(p->procname, s) == 0)
1846                         return p;
1847         }
1848         return NULL;
1849 }
1850
1851 /* see if attaching q to p would be an improvement */
1852 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1853 {
1854         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1855         struct ctl_table *next;
1856         int is_better = 0;
1857         int not_in_parent = !p->attached_by;
1858
1859         while ((next = is_branch_in(by, to)) != NULL) {
1860                 if (by == q->attached_by)
1861                         is_better = 1;
1862                 if (to == p->attached_by)
1863                         not_in_parent = 1;
1864                 by = by->child;
1865                 to = next->child;
1866         }
1867
1868         if (is_better && not_in_parent) {
1869                 q->attached_by = by;
1870                 q->attached_to = to;
1871                 q->parent = p;
1872         }
1873 }
1874
1875 /**
1876  * __register_sysctl_paths - register a sysctl hierarchy
1877  * @root: List of sysctl headers to register on
1878  * @namespaces: Data to compute which lists of sysctl entries are visible
1879  * @path: The path to the directory the sysctl table is in.
1880  * @table: the top-level table structure
1881  *
1882  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1883  * array. A completely 0 filled entry terminates the table.
1884  *
1885  * The members of the &struct ctl_table structure are used as follows:
1886  *
1887  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1888  *            must be unique within that level of sysctl
1889  *
1890  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1891  *            enter a sysctl file
1892  *
1893  * data - a pointer to data for use by proc_handler
1894  *
1895  * maxlen - the maximum size in bytes of the data
1896  *
1897  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1898  *
1899  * child - a pointer to the child sysctl table if this entry is a directory, or
1900  *         %NULL.
1901  *
1902  * proc_handler - the text handler routine (described below)
1903  *
1904  * strategy - the strategy routine (described below)
1905  *
1906  * de - for internal use by the sysctl routines
1907  *
1908  * extra1, extra2 - extra pointers usable by the proc handler routines
1909  *
1910  * Leaf nodes in the sysctl tree will be represented by a single file
1911  * under /proc; non-leaf nodes will be represented by directories.
1912  *
1913  * sysctl(2) can automatically manage read and write requests through
1914  * the sysctl table.  The data and maxlen fields of the ctl_table
1915  * struct enable minimal validation of the values being written to be
1916  * performed, and the mode field allows minimal authentication.
1917  *
1918  * More sophisticated management can be enabled by the provision of a
1919  * strategy routine with the table entry.  This will be called before
1920  * any automatic read or write of the data is performed.
1921  *
1922  * The strategy routine may return
1923  *
1924  * < 0 - Error occurred (error is passed to user process)
1925  *
1926  * 0   - OK - proceed with automatic read or write.
1927  *
1928  * > 0 - OK - read or write has been done by the strategy routine, so
1929  *       return immediately.
1930  *
1931  * There must be a proc_handler routine for any terminal nodes
1932  * mirrored under /proc/sys (non-terminals are handled by a built-in
1933  * directory handler).  Several default handlers are available to
1934  * cover common cases -
1935  *
1936  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1937  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1938  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1939  *
1940  * It is the handler's job to read the input buffer from user memory
1941  * and process it. The handler should return 0 on success.
1942  *
1943  * This routine returns %NULL on a failure to register, and a pointer
1944  * to the table header on success.
1945  */
1946 struct ctl_table_header *__register_sysctl_paths(
1947         struct ctl_table_root *root,
1948         struct nsproxy *namespaces,
1949         const struct ctl_path *path, struct ctl_table *table)
1950 {
1951         struct ctl_table_header *header;
1952         struct ctl_table *new, **prevp;
1953         unsigned int n, npath;
1954         struct ctl_table_set *set;
1955
1956         /* Count the path components */
1957         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1958                 ;
1959
1960         /*
1961          * For each path component, allocate a 2-element ctl_table array.
1962          * The first array element will be filled with the sysctl entry
1963          * for this, the second will be the sentinel (ctl_name == 0).
1964          *
1965          * We allocate everything in one go so that we don't have to
1966          * worry about freeing additional memory in unregister_sysctl_table.
1967          */
1968         header = kzalloc(sizeof(struct ctl_table_header) +
1969                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1970         if (!header)
1971                 return NULL;
1972
1973         new = (struct ctl_table *) (header + 1);
1974
1975         /* Now connect the dots */
1976         prevp = &header->ctl_table;
1977         for (n = 0; n < npath; ++n, ++path) {
1978                 /* Copy the procname */
1979                 new->procname = path->procname;
1980                 new->ctl_name = path->ctl_name;
1981                 new->mode     = 0555;
1982
1983                 *prevp = new;
1984                 prevp = &new->child;
1985
1986                 new += 2;
1987         }
1988         *prevp = table;
1989         header->ctl_table_arg = table;
1990
1991         INIT_LIST_HEAD(&header->ctl_entry);
1992         header->used = 0;
1993         header->unregistering = NULL;
1994         header->root = root;
1995         sysctl_set_parent(NULL, header->ctl_table);
1996         header->count = 1;
1997 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1998         if (sysctl_check_table(namespaces, header->ctl_table)) {
1999                 kfree(header);
2000                 return NULL;
2001         }
2002 #endif
2003         spin_lock(&sysctl_lock);
2004         header->set = lookup_header_set(root, namespaces);
2005         header->attached_by = header->ctl_table;
2006         header->attached_to = root_table;
2007         header->parent = &root_table_header;
2008         for (set = header->set; set; set = set->parent) {
2009                 struct ctl_table_header *p;
2010                 list_for_each_entry(p, &set->list, ctl_entry) {
2011                         if (p->unregistering)
2012                                 continue;
2013                         try_attach(p, header);
2014                 }
2015         }
2016         header->parent->count++;
2017         list_add_tail(&header->ctl_entry, &header->set->list);
2018         spin_unlock(&sysctl_lock);
2019
2020         return header;
2021 }
2022
2023 /**
2024  * register_sysctl_table_path - register a sysctl table hierarchy
2025  * @path: The path to the directory the sysctl table is in.
2026  * @table: the top-level table structure
2027  *
2028  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2029  * array. A completely 0 filled entry terminates the table.
2030  *
2031  * See __register_sysctl_paths for more details.
2032  */
2033 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2034                                                 struct ctl_table *table)
2035 {
2036         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2037                                         path, table);
2038 }
2039
2040 /**
2041  * register_sysctl_table - register a sysctl table hierarchy
2042  * @table: the top-level table structure
2043  *
2044  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2045  * array. A completely 0 filled entry terminates the table.
2046  *
2047  * See register_sysctl_paths for more details.
2048  */
2049 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2050 {
2051         static const struct ctl_path null_path[] = { {} };
2052
2053         return register_sysctl_paths(null_path, table);
2054 }
2055
2056 /**
2057  * unregister_sysctl_table - unregister a sysctl table hierarchy
2058  * @header: the header returned from register_sysctl_table
2059  *
2060  * Unregisters the sysctl table and all children. proc entries may not
2061  * actually be removed until they are no longer used by anyone.
2062  */
2063 void unregister_sysctl_table(struct ctl_table_header * header)
2064 {
2065         might_sleep();
2066
2067         if (header == NULL)
2068                 return;
2069
2070         spin_lock(&sysctl_lock);
2071         start_unregistering(header);
2072         if (!--header->parent->count) {
2073                 WARN_ON(1);
2074                 kfree(header->parent);
2075         }
2076         if (!--header->count)
2077                 kfree(header);
2078         spin_unlock(&sysctl_lock);
2079 }
2080
2081 int sysctl_is_seen(struct ctl_table_header *p)
2082 {
2083         struct ctl_table_set *set = p->set;
2084         int res;
2085         spin_lock(&sysctl_lock);
2086         if (p->unregistering)
2087                 res = 0;
2088         else if (!set->is_seen)
2089                 res = 1;
2090         else
2091                 res = set->is_seen(set);
2092         spin_unlock(&sysctl_lock);
2093         return res;
2094 }
2095
2096 void setup_sysctl_set(struct ctl_table_set *p,
2097         struct ctl_table_set *parent,
2098         int (*is_seen)(struct ctl_table_set *))
2099 {
2100         INIT_LIST_HEAD(&p->list);
2101         p->parent = parent ? parent : &sysctl_table_root.default_set;
2102         p->is_seen = is_seen;
2103 }
2104
2105 #else /* !CONFIG_SYSCTL */
2106 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2107 {
2108         return NULL;
2109 }
2110
2111 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2112                                                     struct ctl_table *table)
2113 {
2114         return NULL;
2115 }
2116
2117 void unregister_sysctl_table(struct ctl_table_header * table)
2118 {
2119 }
2120
2121 void setup_sysctl_set(struct ctl_table_set *p,
2122         struct ctl_table_set *parent,
2123         int (*is_seen)(struct ctl_table_set *))
2124 {
2125 }
2126
2127 void sysctl_head_put(struct ctl_table_header *head)
2128 {
2129 }
2130
2131 #endif /* CONFIG_SYSCTL */
2132
2133 /*
2134  * /proc/sys support
2135  */
2136
2137 #ifdef CONFIG_PROC_SYSCTL
2138
2139 static int _proc_do_string(void* data, int maxlen, int write,
2140                            struct file *filp, void __user *buffer,
2141                            size_t *lenp, loff_t *ppos)
2142 {
2143         size_t len;
2144         char __user *p;
2145         char c;
2146
2147         if (!data || !maxlen || !*lenp) {
2148                 *lenp = 0;
2149                 return 0;
2150         }
2151
2152         if (write) {
2153                 len = 0;
2154                 p = buffer;
2155                 while (len < *lenp) {
2156                         if (get_user(c, p++))
2157                                 return -EFAULT;
2158                         if (c == 0 || c == '\n')
2159                                 break;
2160                         len++;
2161                 }
2162                 if (len >= maxlen)
2163                         len = maxlen-1;
2164                 if(copy_from_user(data, buffer, len))
2165                         return -EFAULT;
2166                 ((char *) data)[len] = 0;
2167                 *ppos += *lenp;
2168         } else {
2169                 len = strlen(data);
2170                 if (len > maxlen)
2171                         len = maxlen;
2172
2173                 if (*ppos > len) {
2174                         *lenp = 0;
2175                         return 0;
2176                 }
2177
2178                 data += *ppos;
2179                 len  -= *ppos;
2180
2181                 if (len > *lenp)
2182                         len = *lenp;
2183                 if (len)
2184                         if(copy_to_user(buffer, data, len))
2185                                 return -EFAULT;
2186                 if (len < *lenp) {
2187                         if(put_user('\n', ((char __user *) buffer) + len))
2188                                 return -EFAULT;
2189                         len++;
2190                 }
2191                 *lenp = len;
2192                 *ppos += len;
2193         }
2194         return 0;
2195 }
2196
2197 /**
2198  * proc_dostring - read a string sysctl
2199  * @table: the sysctl table
2200  * @write: %TRUE if this is a write to the sysctl file
2201  * @filp: the file structure
2202  * @buffer: the user buffer
2203  * @lenp: the size of the user buffer
2204  * @ppos: file position
2205  *
2206  * Reads/writes a string from/to the user buffer. If the kernel
2207  * buffer provided is not large enough to hold the string, the
2208  * string is truncated. The copied string is %NULL-terminated.
2209  * If the string is being read by the user process, it is copied
2210  * and a newline '\n' is added. It is truncated if the buffer is
2211  * not large enough.
2212  *
2213  * Returns 0 on success.
2214  */
2215 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2216                   void __user *buffer, size_t *lenp, loff_t *ppos)
2217 {
2218         return _proc_do_string(table->data, table->maxlen, write, filp,
2219                                buffer, lenp, ppos);
2220 }
2221
2222
2223 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2224                                  int *valp,
2225                                  int write, void *data)
2226 {
2227         if (write) {
2228                 *valp = *negp ? -*lvalp : *lvalp;
2229         } else {
2230                 int val = *valp;
2231                 if (val < 0) {
2232                         *negp = -1;
2233                         *lvalp = (unsigned long)-val;
2234                 } else {
2235                         *negp = 0;
2236                         *lvalp = (unsigned long)val;
2237                 }
2238         }
2239         return 0;
2240 }
2241
2242 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2243                   int write, struct file *filp, void __user *buffer,
2244                   size_t *lenp, loff_t *ppos,
2245                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2246                               int write, void *data),
2247                   void *data)
2248 {
2249 #define TMPBUFLEN 21
2250         int *i, vleft, first=1, neg, val;
2251         unsigned long lval;
2252         size_t left, len;
2253
2254         char buf[TMPBUFLEN], *p;
2255         char __user *s = buffer;
2256
2257         if (!tbl_data || !table->maxlen || !*lenp ||
2258             (*ppos && !write)) {
2259                 *lenp = 0;
2260                 return 0;
2261         }
2262
2263         i = (int *) tbl_data;
2264         vleft = table->maxlen / sizeof(*i);
2265         left = *lenp;
2266
2267         if (!conv)
2268                 conv = do_proc_dointvec_conv;
2269
2270         for (; left && vleft--; i++, first=0) {
2271                 if (write) {
2272                         while (left) {
2273                                 char c;
2274                                 if (get_user(c, s))
2275                                         return -EFAULT;
2276                                 if (!isspace(c))
2277                                         break;
2278                                 left--;
2279                                 s++;
2280                         }
2281                         if (!left)
2282                                 break;
2283                         neg = 0;
2284                         len = left;
2285                         if (len > sizeof(buf) - 1)
2286                                 len = sizeof(buf) - 1;
2287                         if (copy_from_user(buf, s, len))
2288                                 return -EFAULT;
2289                         buf[len] = 0;
2290                         p = buf;
2291                         if (*p == '-' && left > 1) {
2292                                 neg = 1;
2293                                 p++;
2294                         }
2295                         if (*p < '0' || *p > '9')
2296                                 break;
2297
2298                         lval = simple_strtoul(p, &p, 0);
2299
2300                         len = p-buf;
2301                         if ((len < left) && *p && !isspace(*p))
2302                                 break;
2303                         if (neg)
2304                                 val = -val;
2305                         s += len;
2306                         left -= len;
2307
2308                         if (conv(&neg, &lval, i, 1, data))
2309                                 break;
2310                 } else {
2311                         p = buf;
2312                         if (!first)
2313                                 *p++ = '\t';
2314
2315                         if (conv(&neg, &lval, i, 0, data))
2316                                 break;
2317
2318                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2319                         len = strlen(buf);
2320                         if (len > left)
2321                                 len = left;
2322                         if(copy_to_user(s, buf, len))
2323                                 return -EFAULT;
2324                         left -= len;
2325                         s += len;
2326                 }
2327         }
2328
2329         if (!write && !first && left) {
2330                 if(put_user('\n', s))
2331                         return -EFAULT;
2332                 left--, s++;
2333         }
2334         if (write) {
2335                 while (left) {
2336                         char c;
2337                         if (get_user(c, s++))
2338                                 return -EFAULT;
2339                         if (!isspace(c))
2340                                 break;
2341                         left--;
2342                 }
2343         }
2344         if (write && first)
2345                 return -EINVAL;
2346         *lenp -= left;
2347         *ppos += *lenp;
2348         return 0;
2349 #undef TMPBUFLEN
2350 }
2351
2352 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2353                   void __user *buffer, size_t *lenp, loff_t *ppos,
2354                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2355                               int write, void *data),
2356                   void *data)
2357 {
2358         return __do_proc_dointvec(table->data, table, write, filp,
2359                         buffer, lenp, ppos, conv, data);
2360 }
2361
2362 /**
2363  * proc_dointvec - read a vector of integers
2364  * @table: the sysctl table
2365  * @write: %TRUE if this is a write to the sysctl file
2366  * @filp: the file structure
2367  * @buffer: the user buffer
2368  * @lenp: the size of the user buffer
2369  * @ppos: file position
2370  *
2371  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2372  * values from/to the user buffer, treated as an ASCII string.
2373  *
2374  * Returns 0 on success.
2375  */
2376 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2377                      void __user *buffer, size_t *lenp, loff_t *ppos)
2378 {
2379     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2380                             NULL,NULL);
2381 }
2382
2383 /*
2384  * Taint values can only be increased
2385  * This means we can safely use a temporary.
2386  */
2387 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2388                                void __user *buffer, size_t *lenp, loff_t *ppos)
2389 {
2390         struct ctl_table t;
2391         unsigned long tmptaint = get_taint();
2392         int err;
2393
2394         if (write && !capable(CAP_SYS_ADMIN))
2395                 return -EPERM;
2396
2397         t = *table;
2398         t.data = &tmptaint;
2399         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2400         if (err < 0)
2401                 return err;
2402
2403         if (write) {
2404                 /*
2405                  * Poor man's atomic or. Not worth adding a primitive
2406                  * to everyone's atomic.h for this
2407                  */
2408                 int i;
2409                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2410                         if ((tmptaint >> i) & 1)
2411                                 add_taint(i);
2412                 }
2413         }
2414
2415         return err;
2416 }
2417
2418 struct do_proc_dointvec_minmax_conv_param {
2419         int *min;
2420         int *max;
2421 };
2422
2423 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2424                                         int *valp,
2425                                         int write, void *data)
2426 {
2427         struct do_proc_dointvec_minmax_conv_param *param = data;
2428         if (write) {
2429                 int val = *negp ? -*lvalp : *lvalp;
2430                 if ((param->min && *param->min > val) ||
2431                     (param->max && *param->max < val))
2432                         return -EINVAL;
2433                 *valp = val;
2434         } else {
2435                 int val = *valp;
2436                 if (val < 0) {
2437                         *negp = -1;
2438                         *lvalp = (unsigned long)-val;
2439                 } else {
2440                         *negp = 0;
2441                         *lvalp = (unsigned long)val;
2442                 }
2443         }
2444         return 0;
2445 }
2446
2447 /**
2448  * proc_dointvec_minmax - read a vector of integers with min/max values
2449  * @table: the sysctl table
2450  * @write: %TRUE if this is a write to the sysctl file
2451  * @filp: the file structure
2452  * @buffer: the user buffer
2453  * @lenp: the size of the user buffer
2454  * @ppos: file position
2455  *
2456  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2457  * values from/to the user buffer, treated as an ASCII string.
2458  *
2459  * This routine will ensure the values are within the range specified by
2460  * table->extra1 (min) and table->extra2 (max).
2461  *
2462  * Returns 0 on success.
2463  */
2464 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2465                   void __user *buffer, size_t *lenp, loff_t *ppos)
2466 {
2467         struct do_proc_dointvec_minmax_conv_param param = {
2468                 .min = (int *) table->extra1,
2469                 .max = (int *) table->extra2,
2470         };
2471         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2472                                 do_proc_dointvec_minmax_conv, &param);
2473 }
2474
2475 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2476                                      struct file *filp,
2477                                      void __user *buffer,
2478                                      size_t *lenp, loff_t *ppos,
2479                                      unsigned long convmul,
2480                                      unsigned long convdiv)
2481 {
2482 #define TMPBUFLEN 21
2483         unsigned long *i, *min, *max, val;
2484         int vleft, first=1, neg;
2485         size_t len, left;
2486         char buf[TMPBUFLEN], *p;
2487         char __user *s = buffer;
2488
2489         if (!data || !table->maxlen || !*lenp ||
2490             (*ppos && !write)) {
2491                 *lenp = 0;
2492                 return 0;
2493         }
2494
2495         i = (unsigned long *) data;
2496         min = (unsigned long *) table->extra1;
2497         max = (unsigned long *) table->extra2;
2498         vleft = table->maxlen / sizeof(unsigned long);
2499         left = *lenp;
2500
2501         for (; left && vleft--; i++, min++, max++, first=0) {
2502                 if (write) {
2503                         while (left) {
2504                                 char c;
2505                                 if (get_user(c, s))
2506                                         return -EFAULT;
2507                                 if (!isspace(c))
2508                                         break;
2509                                 left--;
2510                                 s++;
2511                         }
2512                         if (!left)
2513                                 break;
2514                         neg = 0;
2515                         len = left;
2516                         if (len > TMPBUFLEN-1)
2517                                 len = TMPBUFLEN-1;
2518                         if (copy_from_user(buf, s, len))
2519                                 return -EFAULT;
2520                         buf[len] = 0;
2521                         p = buf;
2522                         if (*p == '-' && left > 1) {
2523                                 neg = 1;
2524                                 p++;
2525                         }
2526                         if (*p < '0' || *p > '9')
2527                                 break;
2528                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2529                         len = p-buf;
2530                         if ((len < left) && *p && !isspace(*p))
2531                                 break;
2532                         if (neg)
2533                                 val = -val;
2534                         s += len;
2535                         left -= len;
2536
2537                         if(neg)
2538                                 continue;
2539                         if ((min && val < *min) || (max && val > *max))
2540                                 continue;
2541                         *i = val;
2542                 } else {
2543                         p = buf;
2544                         if (!first)
2545                                 *p++ = '\t';
2546                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2547                         len = strlen(buf);
2548                         if (len > left)
2549                                 len = left;
2550                         if(copy_to_user(s, buf, len))
2551                                 return -EFAULT;
2552                         left -= len;
2553                         s += len;
2554                 }
2555         }
2556
2557         if (!write && !first && left) {
2558                 if(put_user('\n', s))
2559                         return -EFAULT;
2560                 left--, s++;
2561         }
2562         if (write) {
2563                 while (left) {
2564                         char c;
2565                         if (get_user(c, s++))
2566                                 return -EFAULT;
2567                         if (!isspace(c))
2568                                 break;
2569                         left--;
2570                 }
2571         }
2572         if (write && first)
2573                 return -EINVAL;
2574         *lenp -= left;
2575         *ppos += *lenp;
2576         return 0;
2577 #undef TMPBUFLEN
2578 }
2579
2580 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2581                                      struct file *filp,
2582                                      void __user *buffer,
2583                                      size_t *lenp, loff_t *ppos,
2584                                      unsigned long convmul,
2585                                      unsigned long convdiv)
2586 {
2587         return __do_proc_doulongvec_minmax(table->data, table, write,
2588                         filp, buffer, lenp, ppos, convmul, convdiv);
2589 }
2590
2591 /**
2592  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2593  * @table: the sysctl table
2594  * @write: %TRUE if this is a write to the sysctl file
2595  * @filp: the file structure
2596  * @buffer: the user buffer
2597  * @lenp: the size of the user buffer
2598  * @ppos: file position
2599  *
2600  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2601  * values from/to the user buffer, treated as an ASCII string.
2602  *
2603  * This routine will ensure the values are within the range specified by
2604  * table->extra1 (min) and table->extra2 (max).
2605  *
2606  * Returns 0 on success.
2607  */
2608 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2609                            void __user *buffer, size_t *lenp, loff_t *ppos)
2610 {
2611     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2612 }
2613
2614 /**
2615  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2616  * @table: the sysctl table
2617  * @write: %TRUE if this is a write to the sysctl file
2618  * @filp: the file structure
2619  * @buffer: the user buffer
2620  * @lenp: the size of the user buffer
2621  * @ppos: file position
2622  *
2623  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2624  * values from/to the user buffer, treated as an ASCII string. The values
2625  * are treated as milliseconds, and converted to jiffies when they are stored.
2626  *
2627  * This routine will ensure the values are within the range specified by
2628  * table->extra1 (min) and table->extra2 (max).
2629  *
2630  * Returns 0 on success.
2631  */
2632 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2633                                       struct file *filp,
2634                                       void __user *buffer,
2635                                       size_t *lenp, loff_t *ppos)
2636 {
2637     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2638                                      lenp, ppos, HZ, 1000l);
2639 }
2640
2641
2642 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2643                                          int *valp,
2644                                          int write, void *data)
2645 {
2646         if (write) {
2647                 if (*lvalp > LONG_MAX / HZ)
2648                         return 1;
2649                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2650         } else {
2651                 int val = *valp;
2652                 unsigned long lval;
2653                 if (val < 0) {
2654                         *negp = -1;
2655                         lval = (unsigned long)-val;
2656                 } else {
2657                         *negp = 0;
2658                         lval = (unsigned long)val;
2659                 }
2660                 *lvalp = lval / HZ;
2661         }
2662         return 0;
2663 }
2664
2665 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2666                                                 int *valp,
2667                                                 int write, void *data)
2668 {
2669         if (write) {
2670                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2671                         return 1;
2672                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2673         } else {
2674                 int val = *valp;
2675                 unsigned long lval;
2676                 if (val < 0) {
2677                         *negp = -1;
2678                         lval = (unsigned long)-val;
2679                 } else {
2680                         *negp = 0;
2681                         lval = (unsigned long)val;
2682                 }
2683                 *lvalp = jiffies_to_clock_t(lval);
2684         }
2685         return 0;
2686 }
2687
2688 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2689                                             int *valp,
2690                                             int write, void *data)
2691 {
2692         if (write) {
2693                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2694         } else {
2695                 int val = *valp;
2696                 unsigned long lval;
2697                 if (val < 0) {
2698                         *negp = -1;
2699                         lval = (unsigned long)-val;
2700                 } else {
2701                         *negp = 0;
2702                         lval = (unsigned long)val;
2703                 }
2704                 *lvalp = jiffies_to_msecs(lval);
2705         }
2706         return 0;
2707 }
2708
2709 /**
2710  * proc_dointvec_jiffies - read a vector of integers as seconds
2711  * @table: the sysctl table
2712  * @write: %TRUE if this is a write to the sysctl file
2713  * @filp: the file structure
2714  * @buffer: the user buffer
2715  * @lenp: the size of the user buffer
2716  * @ppos: file position
2717  *
2718  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2719  * values from/to the user buffer, treated as an ASCII string.
2720  * The values read are assumed to be in seconds, and are converted into
2721  * jiffies.
2722  *
2723  * Returns 0 on success.
2724  */
2725 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2726                           void __user *buffer, size_t *lenp, loff_t *ppos)
2727 {
2728     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2729                             do_proc_dointvec_jiffies_conv,NULL);
2730 }
2731
2732 /**
2733  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2734  * @table: the sysctl table
2735  * @write: %TRUE if this is a write to the sysctl file
2736  * @filp: the file structure
2737  * @buffer: the user buffer
2738  * @lenp: the size of the user buffer
2739  * @ppos: pointer to the file position
2740  *
2741  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2742  * values from/to the user buffer, treated as an ASCII string.
2743  * The values read are assumed to be in 1/USER_HZ seconds, and
2744  * are converted into jiffies.
2745  *
2746  * Returns 0 on success.
2747  */
2748 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2749                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2750 {
2751     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2752                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2753 }
2754
2755 /**
2756  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2757  * @table: the sysctl table
2758  * @write: %TRUE if this is a write to the sysctl file
2759  * @filp: the file structure
2760  * @buffer: the user buffer
2761  * @lenp: the size of the user buffer
2762  * @ppos: file position
2763  * @ppos: the current position in the file
2764  *
2765  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2766  * values from/to the user buffer, treated as an ASCII string.
2767  * The values read are assumed to be in 1/1000 seconds, and
2768  * are converted into jiffies.
2769  *
2770  * Returns 0 on success.
2771  */
2772 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2773                              void __user *buffer, size_t *lenp, loff_t *ppos)
2774 {
2775         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2776                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2777 }
2778
2779 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2780                            void __user *buffer, size_t *lenp, loff_t *ppos)
2781 {
2782         struct pid *new_pid;
2783         pid_t tmp;
2784         int r;
2785
2786         tmp = pid_vnr(cad_pid);
2787
2788         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2789                                lenp, ppos, NULL, NULL);
2790         if (r || !write)
2791                 return r;
2792
2793         new_pid = find_get_pid(tmp);
2794         if (!new_pid)
2795                 return -ESRCH;
2796
2797         put_pid(xchg(&cad_pid, new_pid));
2798         return 0;
2799 }
2800
2801 #else /* CONFIG_PROC_FS */
2802
2803 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2804                   void __user *buffer, size_t *lenp, loff_t *ppos)
2805 {
2806         return -ENOSYS;
2807 }
2808
2809 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2810                   void __user *buffer, size_t *lenp, loff_t *ppos)
2811 {
2812         return -ENOSYS;
2813 }
2814
2815 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2816                     void __user *buffer, size_t *lenp, loff_t *ppos)
2817 {
2818         return -ENOSYS;
2819 }
2820
2821 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2822                     void __user *buffer, size_t *lenp, loff_t *ppos)
2823 {
2824         return -ENOSYS;
2825 }
2826
2827 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2828                     void __user *buffer, size_t *lenp, loff_t *ppos)
2829 {
2830         return -ENOSYS;
2831 }
2832
2833 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2834                              void __user *buffer, size_t *lenp, loff_t *ppos)
2835 {
2836         return -ENOSYS;
2837 }
2838
2839 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2840                     void __user *buffer, size_t *lenp, loff_t *ppos)
2841 {
2842         return -ENOSYS;
2843 }
2844
2845 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2846                                       struct file *filp,
2847                                       void __user *buffer,
2848                                       size_t *lenp, loff_t *ppos)
2849 {
2850     return -ENOSYS;
2851 }
2852
2853
2854 #endif /* CONFIG_PROC_FS */
2855
2856
2857 #ifdef CONFIG_SYSCTL_SYSCALL
2858 /*
2859  * General sysctl support routines
2860  */
2861
2862 /* The generic sysctl data routine (used if no strategy routine supplied) */
2863 int sysctl_data(struct ctl_table *table,
2864                 void __user *oldval, size_t __user *oldlenp,
2865                 void __user *newval, size_t newlen)
2866 {
2867         size_t len;
2868
2869         /* Get out of I don't have a variable */
2870         if (!table->data || !table->maxlen)
2871                 return -ENOTDIR;
2872
2873         if (oldval && oldlenp) {
2874                 if (get_user(len, oldlenp))
2875                         return -EFAULT;
2876                 if (len) {
2877                         if (len > table->maxlen)
2878                                 len = table->maxlen;
2879                         if (copy_to_user(oldval, table->data, len))
2880                                 return -EFAULT;
2881                         if (put_user(len, oldlenp))
2882                                 return -EFAULT;
2883                 }
2884         }
2885
2886         if (newval && newlen) {
2887                 if (newlen > table->maxlen)
2888                         newlen = table->maxlen;
2889
2890                 if (copy_from_user(table->data, newval, newlen))
2891                         return -EFAULT;
2892         }
2893         return 1;
2894 }
2895
2896 /* The generic string strategy routine: */
2897 int sysctl_string(struct ctl_table *table,
2898                   void __user *oldval, size_t __user *oldlenp,
2899                   void __user *newval, size_t newlen)
2900 {
2901         if (!table->data || !table->maxlen)
2902                 return -ENOTDIR;
2903
2904         if (oldval && oldlenp) {
2905                 size_t bufsize;
2906                 if (get_user(bufsize, oldlenp))
2907                         return -EFAULT;
2908                 if (bufsize) {
2909                         size_t len = strlen(table->data), copied;
2910
2911                         /* This shouldn't trigger for a well-formed sysctl */
2912                         if (len > table->maxlen)
2913                                 len = table->maxlen;
2914
2915                         /* Copy up to a max of bufsize-1 bytes of the string */
2916                         copied = (len >= bufsize) ? bufsize - 1 : len;
2917
2918                         if (copy_to_user(oldval, table->data, copied) ||
2919                             put_user(0, (char __user *)(oldval + copied)))
2920                                 return -EFAULT;
2921                         if (put_user(len, oldlenp))
2922                                 return -EFAULT;
2923                 }
2924         }
2925         if (newval && newlen) {
2926                 size_t len = newlen;
2927                 if (len > table->maxlen)
2928                         len = table->maxlen;
2929                 if(copy_from_user(table->data, newval, len))
2930                         return -EFAULT;
2931                 if (len == table->maxlen)
2932                         len--;
2933                 ((char *) table->data)[len] = 0;
2934         }
2935         return 1;
2936 }
2937
2938 /*
2939  * This function makes sure that all of the integers in the vector
2940  * are between the minimum and maximum values given in the arrays
2941  * table->extra1 and table->extra2, respectively.
2942  */
2943 int sysctl_intvec(struct ctl_table *table,
2944                 void __user *oldval, size_t __user *oldlenp,
2945                 void __user *newval, size_t newlen)
2946 {
2947
2948         if (newval && newlen) {
2949                 int __user *vec = (int __user *) newval;
2950                 int *min = (int *) table->extra1;
2951                 int *max = (int *) table->extra2;
2952                 size_t length;
2953                 int i;
2954
2955                 if (newlen % sizeof(int) != 0)
2956                         return -EINVAL;
2957
2958                 if (!table->extra1 && !table->extra2)
2959                         return 0;
2960
2961                 if (newlen > table->maxlen)
2962                         newlen = table->maxlen;
2963                 length = newlen / sizeof(int);
2964
2965                 for (i = 0; i < length; i++) {
2966                         int value;
2967                         if (get_user(value, vec + i))
2968                                 return -EFAULT;
2969                         if (min && value < min[i])
2970                                 return -EINVAL;
2971                         if (max && value > max[i])
2972                                 return -EINVAL;
2973                 }
2974         }
2975         return 0;
2976 }
2977
2978 /* Strategy function to convert jiffies to seconds */
2979 int sysctl_jiffies(struct ctl_table *table,
2980                 void __user *oldval, size_t __user *oldlenp,
2981                 void __user *newval, size_t newlen)
2982 {
2983         if (oldval && oldlenp) {
2984                 size_t olen;
2985
2986                 if (get_user(olen, oldlenp))
2987                         return -EFAULT;
2988                 if (olen) {
2989                         int val;
2990
2991                         if (olen < sizeof(int))
2992                                 return -EINVAL;
2993
2994                         val = *(int *)(table->data) / HZ;
2995                         if (put_user(val, (int __user *)oldval))
2996                                 return -EFAULT;
2997                         if (put_user(sizeof(int), oldlenp))
2998                                 return -EFAULT;
2999                 }
3000         }
3001         if (newval && newlen) {
3002                 int new;
3003                 if (newlen != sizeof(int))
3004                         return -EINVAL;
3005                 if (get_user(new, (int __user *)newval))
3006                         return -EFAULT;
3007                 *(int *)(table->data) = new*HZ;
3008         }
3009         return 1;
3010 }
3011
3012 /* Strategy function to convert jiffies to seconds */
3013 int sysctl_ms_jiffies(struct ctl_table *table,
3014                 void __user *oldval, size_t __user *oldlenp,
3015                 void __user *newval, size_t newlen)
3016 {
3017         if (oldval && oldlenp) {
3018                 size_t olen;
3019
3020                 if (get_user(olen, oldlenp))
3021                         return -EFAULT;
3022                 if (olen) {
3023                         int val;
3024
3025                         if (olen < sizeof(int))
3026                                 return -EINVAL;
3027
3028                         val = jiffies_to_msecs(*(int *)(table->data));
3029                         if (put_user(val, (int __user *)oldval))
3030                                 return -EFAULT;
3031                         if (put_user(sizeof(int), oldlenp))
3032                                 return -EFAULT;
3033                 }
3034         }
3035         if (newval && newlen) {
3036                 int new;
3037                 if (newlen != sizeof(int))
3038                         return -EINVAL;
3039                 if (get_user(new, (int __user *)newval))
3040                         return -EFAULT;
3041                 *(int *)(table->data) = msecs_to_jiffies(new);
3042         }
3043         return 1;
3044 }
3045
3046
3047
3048 #else /* CONFIG_SYSCTL_SYSCALL */
3049
3050
3051 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3052 {
3053         struct __sysctl_args tmp;
3054         int error;
3055
3056         if (copy_from_user(&tmp, args, sizeof(tmp)))
3057                 return -EFAULT;
3058
3059         error = deprecated_sysctl_warning(&tmp);
3060
3061         /* If no error reading the parameters then just -ENOSYS ... */
3062         if (!error)
3063                 error = -ENOSYS;
3064
3065         return error;
3066 }
3067
3068 int sysctl_data(struct ctl_table *table,
3069                   void __user *oldval, size_t __user *oldlenp,
3070                   void __user *newval, size_t newlen)
3071 {
3072         return -ENOSYS;
3073 }
3074
3075 int sysctl_string(struct ctl_table *table,
3076                   void __user *oldval, size_t __user *oldlenp,
3077                   void __user *newval, size_t newlen)
3078 {
3079         return -ENOSYS;
3080 }
3081
3082 int sysctl_intvec(struct ctl_table *table,
3083                 void __user *oldval, size_t __user *oldlenp,
3084                 void __user *newval, size_t newlen)
3085 {
3086         return -ENOSYS;
3087 }
3088
3089 int sysctl_jiffies(struct ctl_table *table,
3090                 void __user *oldval, size_t __user *oldlenp,
3091                 void __user *newval, size_t newlen)
3092 {
3093         return -ENOSYS;
3094 }
3095
3096 int sysctl_ms_jiffies(struct ctl_table *table,
3097                 void __user *oldval, size_t __user *oldlenp,
3098                 void __user *newval, size_t newlen)
3099 {
3100         return -ENOSYS;
3101 }
3102
3103 #endif /* CONFIG_SYSCTL_SYSCALL */
3104
3105 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3106 {
3107         static int msg_count;
3108         int name[CTL_MAXNAME];
3109         int i;
3110
3111         /* Check args->nlen. */
3112         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3113                 return -ENOTDIR;
3114
3115         /* Read in the sysctl name for better debug message logging */
3116         for (i = 0; i < args->nlen; i++)
3117                 if (get_user(name[i], args->name + i))
3118                         return -EFAULT;
3119
3120         /* Ignore accesses to kernel.version */
3121         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3122                 return 0;
3123
3124         if (msg_count < 5) {
3125                 msg_count++;
3126                 printk(KERN_INFO
3127                         "warning: process `%s' used the deprecated sysctl "
3128                         "system call with ", current->comm);
3129                 for (i = 0; i < args->nlen; i++)
3130                         printk("%d.", name[i]);
3131                 printk("\n");
3132         }
3133         return 0;
3134 }
3135
3136 /*
3137  * No sense putting this after each symbol definition, twice,
3138  * exception granted :-)
3139  */
3140 EXPORT_SYMBOL(proc_dointvec);
3141 EXPORT_SYMBOL(proc_dointvec_jiffies);
3142 EXPORT_SYMBOL(proc_dointvec_minmax);
3143 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3144 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3145 EXPORT_SYMBOL(proc_dostring);
3146 EXPORT_SYMBOL(proc_doulongvec_minmax);
3147 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3148 EXPORT_SYMBOL(register_sysctl_table);
3149 EXPORT_SYMBOL(register_sysctl_paths);
3150 EXPORT_SYMBOL(sysctl_intvec);
3151 EXPORT_SYMBOL(sysctl_jiffies);
3152 EXPORT_SYMBOL(sysctl_ms_jiffies);
3153 EXPORT_SYMBOL(sysctl_string);
3154 EXPORT_SYMBOL(sysctl_data);
3155 EXPORT_SYMBOL(unregister_sysctl_table);