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/capability.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/security.h>
  41 #include <linux/initrd.h>
  42 #include <linux/times.h>
  43 #include <linux/limits.h>
  44 #include <linux/dcache.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/nfs_fs.h>
  47 #include <linux/acpi.h>
  48 #include <linux/reboot.h>
  49
  50 #include <asm/uaccess.h>
  51 #include <asm/processor.h>
  52
  53 #ifdef CONFIG_X86
  54 #include <asm/nmi.h>
  55 #include <asm/stacktrace.h>
  56 #endif
  57
  58 #if defined(CONFIG_SYSCTL)
  59
  60 /* External variables not in a header file. */
  61 extern int C_A_D;
  62 extern int print_fatal_signals;
  63 extern int sysctl_overcommit_memory;
  64 extern int sysctl_overcommit_ratio;
  65 extern int sysctl_panic_on_oom;
  66 extern int max_threads;
  67 extern int core_uses_pid;
  68 extern int suid_dumpable;
  69 extern char core_pattern[];
  70 extern int pid_max;
  71 extern int min_free_kbytes;
  72 extern int printk_ratelimit_jiffies;
  73 extern int printk_ratelimit_burst;
  74 extern int pid_max_min, pid_max_max;
  75 extern int sysctl_drop_caches;
  76 extern int percpu_pagelist_fraction;
  77 extern int compat_log;
  78 extern int maps_protect;
  79 extern int sysctl_stat_interval;
  80 extern int audit_argv_kb;
  81
  82 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  83 static int maxolduid = 65535;
  84 static int minolduid;
  85 static int min_percpu_pagelist_fract = 8;
  86
  87 static int ngroups_max = NGROUPS_MAX;
  88
  89 #ifdef CONFIG_KMOD
  90 extern char modprobe_path[];
  91 #endif
  92 #ifdef CONFIG_CHR_DEV_SG
  93 extern int sg_big_buff;
  94 #endif
  95
  96 #ifdef __sparc__
  97 extern char reboot_command [];
  98 extern int stop_a_enabled;
  99 extern int scons_pwroff;
 100 #endif
 101
 102 #ifdef __hppa__
 103 extern int pwrsw_enabled;
 104 extern int unaligned_enabled;
 105 #endif
 106
 107 #ifdef CONFIG_S390
 108 #ifdef CONFIG_MATHEMU
 109 extern int sysctl_ieee_emulation_warnings;
 110 #endif
 111 extern int sysctl_userprocess_debug;
 112 extern int spin_retry;
 113 #endif
 114
 115 extern int sysctl_hz_timer;
 116
 117 #ifdef CONFIG_BSD_PROCESS_ACCT
 118 extern int acct_parm[];
 119 #endif
 120
 121 #ifdef CONFIG_IA64
 122 extern int no_unaligned_warning;
 123 #endif
 124
 125 #ifdef CONFIG_RT_MUTEXES
 126 extern int max_lock_depth;
 127 #endif
 128
 129 #ifdef CONFIG_SYSCTL_SYSCALL
 130 static int parse_table(int __user *, int, void __user *, size_t __user *,
 131                 void __user *, size_t, ctl_table *);
 132 #endif
 133
 134
 135 #ifdef CONFIG_PROC_SYSCTL
 136 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
 137                   void __user *buffer, size_t *lenp, loff_t *ppos);
 138 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
 139                                void __user *buffer, size_t *lenp, loff_t *ppos);
 140 #endif
 141
 142 static ctl_table root_table[];
 143 static struct ctl_table_header root_table_header =
 144         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 145
 146 static ctl_table kern_table[];
 147 static ctl_table vm_table[];
 148 static ctl_table fs_table[];
 149 static ctl_table debug_table[];
 150 static ctl_table dev_table[];
 151 extern ctl_table random_table[];
 152 #ifdef CONFIG_UNIX98_PTYS
 153 extern ctl_table pty_table[];
 154 #endif
 155 #ifdef CONFIG_INOTIFY_USER
 156 extern ctl_table inotify_table[];
 157 #endif
 158
 159 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 160 int sysctl_legacy_va_layout;
 161 #endif
 162
 163 extern int prove_locking;
 164 extern int lock_stat;
 165
 166 /* The default sysctl tables: */
 167
 168 static ctl_table root_table[] = {
 169         {
 170                 .ctl_name       = CTL_KERN,
 171                 .procname       = "kernel",
 172                 .mode           = 0555,
 173                 .child          = kern_table,
 174         },
 175         {
 176                 .ctl_name       = CTL_VM,
 177                 .procname       = "vm",
 178                 .mode           = 0555,
 179                 .child          = vm_table,
 180         },
 181 #ifdef CONFIG_NET
 182         {
 183                 .ctl_name       = CTL_NET,
 184                 .procname       = "net",
 185                 .mode           = 0555,
 186                 .child          = net_table,
 187         },
 188 #endif
 189         {
 190                 .ctl_name       = CTL_FS,
 191                 .procname       = "fs",
 192                 .mode           = 0555,
 193                 .child          = fs_table,
 194         },
 195         {
 196                 .ctl_name       = CTL_DEBUG,
 197                 .procname       = "debug",
 198                 .mode           = 0555,
 199                 .child          = debug_table,
 200         },
 201         {
 202                 .ctl_name       = CTL_DEV,
 203                 .procname       = "dev",
 204                 .mode           = 0555,
 205                 .child          = dev_table,
 206         },
 207 /*
 208  * NOTE: do not add new entries to this table unless you have read
 209  * Documentation/sysctl/ctl_unnumbered.txt
 210  */
 211         { .ctl_name = 0 }
 212 };
 213
 214 #ifdef CONFIG_SCHED_DEBUG
 215 static unsigned long min_sched_granularity_ns = 100000;         /* 100 usecs */
 216 static unsigned long max_sched_granularity_ns = 1000000000;     /* 1 second */
 217 static unsigned long min_wakeup_granularity_ns;                 /* 0 usecs */
 218 static unsigned long max_wakeup_granularity_ns = 1000000000;    /* 1 second */
 219 #endif
 220
 221 static ctl_table kern_table[] = {
 222 #ifdef CONFIG_SCHED_DEBUG
 223         {
 224                 .ctl_name       = CTL_UNNUMBERED,
 225                 .procname       = "sched_min_granularity_ns",
 226                 .data           = &sysctl_sched_min_granularity,
 227                 .maxlen         = sizeof(unsigned int),
 228                 .mode           = 0644,
 229                 .proc_handler   = &proc_dointvec_minmax,
 230                 .strategy       = &sysctl_intvec,
 231                 .extra1         = &min_sched_granularity_ns,
 232                 .extra2         = &max_sched_granularity_ns,
 233         },
 234         {
 235                 .ctl_name       = CTL_UNNUMBERED,
 236                 .procname       = "sched_latency_ns",
 237                 .data           = &sysctl_sched_latency,
 238                 .maxlen         = sizeof(unsigned int),
 239                 .mode           = 0644,
 240                 .proc_handler   = &proc_dointvec_minmax,
 241                 .strategy       = &sysctl_intvec,
 242                 .extra1         = &min_sched_granularity_ns,
 243                 .extra2         = &max_sched_granularity_ns,
 244         },
 245         {
 246                 .ctl_name       = CTL_UNNUMBERED,
 247                 .procname       = "sched_wakeup_granularity_ns",
 248                 .data           = &sysctl_sched_wakeup_granularity,
 249                 .maxlen         = sizeof(unsigned int),
 250                 .mode           = 0644,
 251                 .proc_handler   = &proc_dointvec_minmax,
 252                 .strategy       = &sysctl_intvec,
 253                 .extra1         = &min_wakeup_granularity_ns,
 254                 .extra2         = &max_wakeup_granularity_ns,
 255         },
 256         {
 257                 .ctl_name       = CTL_UNNUMBERED,
 258                 .procname       = "sched_batch_wakeup_granularity_ns",
 259                 .data           = &sysctl_sched_batch_wakeup_granularity,
 260                 .maxlen         = sizeof(unsigned int),
 261                 .mode           = 0644,
 262                 .proc_handler   = &proc_dointvec_minmax,
 263                 .strategy       = &sysctl_intvec,
 264                 .extra1         = &min_wakeup_granularity_ns,
 265                 .extra2         = &max_wakeup_granularity_ns,
 266         },
 267         {
 268                 .ctl_name       = CTL_UNNUMBERED,
 269                 .procname       = "sched_child_runs_first",
 270                 .data           = &sysctl_sched_child_runs_first,
 271                 .maxlen         = sizeof(unsigned int),
 272                 .mode           = 0644,
 273                 .proc_handler   = &proc_dointvec,
 274         },
 275         {
 276                 .ctl_name       = CTL_UNNUMBERED,
 277                 .procname       = "sched_features",
 278                 .data           = &sysctl_sched_features,
 279                 .maxlen         = sizeof(unsigned int),
 280                 .mode           = 0644,
 281                 .proc_handler   = &proc_dointvec,
 282         },
 283 #endif
 284         {
 285                 .ctl_name       = CTL_UNNUMBERED,
 286                 .procname       = "sched_compat_yield",
 287                 .data           = &sysctl_sched_compat_yield,
 288                 .maxlen         = sizeof(unsigned int),
 289                 .mode           = 0644,
 290                 .proc_handler   = &proc_dointvec,
 291         },
 292 #ifdef CONFIG_PROVE_LOCKING
 293         {
 294                 .ctl_name       = CTL_UNNUMBERED,
 295                 .procname       = "prove_locking",
 296                 .data           = &prove_locking,
 297                 .maxlen         = sizeof(int),
 298                 .mode           = 0644,
 299                 .proc_handler   = &proc_dointvec,
 300         },
 301 #endif
 302 #ifdef CONFIG_LOCK_STAT
 303         {
 304                 .ctl_name       = CTL_UNNUMBERED,
 305                 .procname       = "lock_stat",
 306                 .data           = &lock_stat,
 307                 .maxlen         = sizeof(int),
 308                 .mode           = 0644,
 309                 .proc_handler   = &proc_dointvec,
 310         },
 311 #endif
 312         {
 313                 .ctl_name       = KERN_PANIC,
 314                 .procname       = "panic",
 315                 .data           = &panic_timeout,
 316                 .maxlen         = sizeof(int),
 317                 .mode           = 0644,
 318                 .proc_handler   = &proc_dointvec,
 319         },
 320         {
 321                 .ctl_name       = KERN_CORE_USES_PID,
 322                 .procname       = "core_uses_pid",
 323                 .data           = &core_uses_pid,
 324                 .maxlen         = sizeof(int),
 325                 .mode           = 0644,
 326                 .proc_handler   = &proc_dointvec,
 327         },
 328 #ifdef CONFIG_AUDITSYSCALL
 329         {
 330                 .ctl_name       = CTL_UNNUMBERED,
 331                 .procname       = "audit_argv_kb",
 332                 .data           = &audit_argv_kb,
 333                 .maxlen         = sizeof(int),
 334                 .mode           = 0644,
 335                 .proc_handler   = &proc_dointvec,
 336         },
 337 #endif
 338         {
 339                 .ctl_name       = KERN_CORE_PATTERN,
 340                 .procname       = "core_pattern",
 341                 .data           = core_pattern,
 342                 .maxlen         = CORENAME_MAX_SIZE,
 343                 .mode           = 0644,
 344                 .proc_handler   = &proc_dostring,
 345                 .strategy       = &sysctl_string,
 346         },
 347 #ifdef CONFIG_PROC_SYSCTL
 348         {
 349                 .ctl_name       = KERN_TAINTED,
 350                 .procname       = "tainted",
 351                 .data           = &tainted,
 352                 .maxlen         = sizeof(int),
 353                 .mode           = 0644,
 354                 .proc_handler   = &proc_dointvec_taint,
 355         },
 356 #endif
 357         {
 358                 .ctl_name       = KERN_CAP_BSET,
 359                 .procname       = "cap-bound",
 360                 .data           = &cap_bset,
 361                 .maxlen         = sizeof(kernel_cap_t),
 362                 .mode           = 0600,
 363                 .proc_handler   = &proc_dointvec_bset,
 364         },
 365 #ifdef CONFIG_BLK_DEV_INITRD
 366         {
 367                 .ctl_name       = KERN_REALROOTDEV,
 368                 .procname       = "real-root-dev",
 369                 .data           = &real_root_dev,
 370                 .maxlen         = sizeof(int),
 371                 .mode           = 0644,
 372                 .proc_handler   = &proc_dointvec,
 373         },
 374 #endif
 375         {
 376                 .ctl_name       = CTL_UNNUMBERED,
 377                 .procname       = "print-fatal-signals",
 378                 .data           = &print_fatal_signals,
 379                 .maxlen         = sizeof(int),
 380                 .mode           = 0644,
 381                 .proc_handler   = &proc_dointvec,
 382         },
 383 #ifdef __sparc__
 384         {
 385                 .ctl_name       = KERN_SPARC_REBOOT,
 386                 .procname       = "reboot-cmd",
 387                 .data           = reboot_command,
 388                 .maxlen         = 256,
 389                 .mode           = 0644,
 390                 .proc_handler   = &proc_dostring,
 391                 .strategy       = &sysctl_string,
 392         },
 393         {
 394                 .ctl_name       = KERN_SPARC_STOP_A,
 395                 .procname       = "stop-a",
 396                 .data           = &stop_a_enabled,
 397                 .maxlen         = sizeof (int),
 398                 .mode           = 0644,
 399                 .proc_handler   = &proc_dointvec,
 400         },
 401         {
 402                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 403                 .procname       = "scons-poweroff",
 404                 .data           = &scons_pwroff,
 405                 .maxlen         = sizeof (int),
 406                 .mode           = 0644,
 407                 .proc_handler   = &proc_dointvec,
 408         },
 409 #endif
 410 #ifdef __hppa__
 411         {
 412                 .ctl_name       = KERN_HPPA_PWRSW,
 413                 .procname       = "soft-power",
 414                 .data           = &pwrsw_enabled,
 415                 .maxlen         = sizeof (int),
 416                 .mode           = 0644,
 417                 .proc_handler   = &proc_dointvec,
 418         },
 419         {
 420                 .ctl_name       = KERN_HPPA_UNALIGNED,
 421                 .procname       = "unaligned-trap",
 422                 .data           = &unaligned_enabled,
 423                 .maxlen         = sizeof (int),
 424                 .mode           = 0644,
 425                 .proc_handler   = &proc_dointvec,
 426         },
 427 #endif
 428         {
 429                 .ctl_name       = KERN_CTLALTDEL,
 430                 .procname       = "ctrl-alt-del",
 431                 .data           = &C_A_D,
 432                 .maxlen         = sizeof(int),
 433                 .mode           = 0644,
 434                 .proc_handler   = &proc_dointvec,
 435         },
 436         {
 437                 .ctl_name       = KERN_PRINTK,
 438                 .procname       = "printk",
 439                 .data           = &console_loglevel,
 440                 .maxlen         = 4*sizeof(int),
 441                 .mode           = 0644,
 442                 .proc_handler   = &proc_dointvec,
 443         },
 444 #ifdef CONFIG_KMOD
 445         {
 446                 .ctl_name       = KERN_MODPROBE,
 447                 .procname       = "modprobe",
 448                 .data           = &modprobe_path,
 449                 .maxlen         = KMOD_PATH_LEN,
 450                 .mode           = 0644,
 451                 .proc_handler   = &proc_dostring,
 452                 .strategy       = &sysctl_string,
 453         },
 454 #endif
 455 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 456         {
 457                 .ctl_name       = KERN_HOTPLUG,
 458                 .procname       = "hotplug",
 459                 .data           = &uevent_helper,
 460                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 461                 .mode           = 0644,
 462                 .proc_handler   = &proc_dostring,
 463                 .strategy       = &sysctl_string,
 464         },
 465 #endif
 466 #ifdef CONFIG_CHR_DEV_SG
 467         {
 468                 .ctl_name       = KERN_SG_BIG_BUFF,
 469                 .procname       = "sg-big-buff",
 470                 .data           = &sg_big_buff,
 471                 .maxlen         = sizeof (int),
 472                 .mode           = 0444,
 473                 .proc_handler   = &proc_dointvec,
 474         },
 475 #endif
 476 #ifdef CONFIG_BSD_PROCESS_ACCT
 477         {
 478                 .ctl_name       = KERN_ACCT,
 479                 .procname       = "acct",
 480                 .data           = &acct_parm,
 481                 .maxlen         = 3*sizeof(int),
 482                 .mode           = 0644,
 483                 .proc_handler   = &proc_dointvec,
 484         },
 485 #endif
 486 #ifdef CONFIG_MAGIC_SYSRQ
 487         {
 488                 .ctl_name       = KERN_SYSRQ,
 489                 .procname       = "sysrq",
 490                 .data           = &__sysrq_enabled,
 491                 .maxlen         = sizeof (int),
 492                 .mode           = 0644,
 493                 .proc_handler   = &proc_dointvec,
 494         },
 495 #endif
 496 #ifdef CONFIG_PROC_SYSCTL
 497         {
 498                 .ctl_name       = KERN_CADPID,
 499                 .procname       = "cad_pid",
 500                 .data           = NULL,
 501                 .maxlen         = sizeof (int),
 502                 .mode           = 0600,
 503                 .proc_handler   = &proc_do_cad_pid,
 504         },
 505 #endif
 506         {
 507                 .ctl_name       = KERN_MAX_THREADS,
 508                 .procname       = "threads-max",
 509                 .data           = &max_threads,
 510                 .maxlen         = sizeof(int),
 511                 .mode           = 0644,
 512                 .proc_handler   = &proc_dointvec,
 513         },
 514         {
 515                 .ctl_name       = KERN_RANDOM,
 516                 .procname       = "random",
 517                 .mode           = 0555,
 518                 .child          = random_table,
 519         },
 520 #ifdef CONFIG_UNIX98_PTYS
 521         {
 522                 .ctl_name       = KERN_PTY,
 523                 .procname       = "pty",
 524                 .mode           = 0555,
 525                 .child          = pty_table,
 526         },
 527 #endif
 528         {
 529                 .ctl_name       = KERN_OVERFLOWUID,
 530                 .procname       = "overflowuid",
 531                 .data           = &overflowuid,
 532                 .maxlen         = sizeof(int),
 533                 .mode           = 0644,
 534                 .proc_handler   = &proc_dointvec_minmax,
 535                 .strategy       = &sysctl_intvec,
 536                 .extra1         = &minolduid,
 537                 .extra2         = &maxolduid,
 538         },
 539         {
 540                 .ctl_name       = KERN_OVERFLOWGID,
 541                 .procname       = "overflowgid",
 542                 .data           = &overflowgid,
 543                 .maxlen         = sizeof(int),
 544                 .mode           = 0644,
 545                 .proc_handler   = &proc_dointvec_minmax,
 546                 .strategy       = &sysctl_intvec,
 547                 .extra1         = &minolduid,
 548                 .extra2         = &maxolduid,
 549         },
 550 #ifdef CONFIG_S390
 551 #ifdef CONFIG_MATHEMU
 552         {
 553                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 554                 .procname       = "ieee_emulation_warnings",
 555                 .data           = &sysctl_ieee_emulation_warnings,
 556                 .maxlen         = sizeof(int),
 557                 .mode           = 0644,
 558                 .proc_handler   = &proc_dointvec,
 559         },
 560 #endif
 561 #ifdef CONFIG_NO_IDLE_HZ
 562         {
 563                 .ctl_name       = KERN_HZ_TIMER,
 564                 .procname       = "hz_timer",
 565                 .data           = &sysctl_hz_timer,
 566                 .maxlen         = sizeof(int),
 567                 .mode           = 0644,
 568                 .proc_handler   = &proc_dointvec,
 569         },
 570 #endif
 571         {
 572                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 573                 .procname       = "userprocess_debug",
 574                 .data           = &sysctl_userprocess_debug,
 575                 .maxlen         = sizeof(int),
 576                 .mode           = 0644,
 577                 .proc_handler   = &proc_dointvec,
 578         },
 579 #endif
 580         {
 581                 .ctl_name       = KERN_PIDMAX,
 582                 .procname       = "pid_max",
 583                 .data           = &pid_max,
 584                 .maxlen         = sizeof (int),
 585                 .mode           = 0644,
 586                 .proc_handler   = &proc_dointvec_minmax,
 587                 .strategy       = sysctl_intvec,
 588                 .extra1         = &pid_max_min,
 589                 .extra2         = &pid_max_max,
 590         },
 591         {
 592                 .ctl_name       = KERN_PANIC_ON_OOPS,
 593                 .procname       = "panic_on_oops",
 594                 .data           = &panic_on_oops,
 595                 .maxlen         = sizeof(int),
 596                 .mode           = 0644,
 597                 .proc_handler   = &proc_dointvec,
 598         },
 599         {
 600                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 601                 .procname       = "printk_ratelimit",
 602                 .data           = &printk_ratelimit_jiffies,
 603                 .maxlen         = sizeof(int),
 604                 .mode           = 0644,
 605                 .proc_handler   = &proc_dointvec_jiffies,
 606                 .strategy       = &sysctl_jiffies,
 607         },
 608         {
 609                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 610                 .procname       = "printk_ratelimit_burst",
 611                 .data           = &printk_ratelimit_burst,
 612                 .maxlen         = sizeof(int),
 613                 .mode           = 0644,
 614                 .proc_handler   = &proc_dointvec,
 615         },
 616         {
 617                 .ctl_name       = KERN_NGROUPS_MAX,
 618                 .procname       = "ngroups_max",
 619                 .data           = &ngroups_max,
 620                 .maxlen         = sizeof (int),
 621                 .mode           = 0444,
 622                 .proc_handler   = &proc_dointvec,
 623         },
 624 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 625         {
 626                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 627                 .procname       = "unknown_nmi_panic",
 628                 .data           = &unknown_nmi_panic,
 629                 .maxlen         = sizeof (int),
 630                 .mode           = 0644,
 631                 .proc_handler   = &proc_dointvec,
 632         },
 633         {
 634                 .ctl_name       = KERN_NMI_WATCHDOG,
 635                 .procname       = "nmi_watchdog",
 636                 .data           = &nmi_watchdog_enabled,
 637                 .maxlen         = sizeof (int),
 638                 .mode           = 0644,
 639                 .proc_handler   = &proc_nmi_enabled,
 640         },
 641 #endif
 642 #if defined(CONFIG_X86)
 643         {
 644                 .ctl_name       = KERN_PANIC_ON_NMI,
 645                 .procname       = "panic_on_unrecovered_nmi",
 646                 .data           = &panic_on_unrecovered_nmi,
 647                 .maxlen         = sizeof(int),
 648                 .mode           = 0644,
 649                 .proc_handler   = &proc_dointvec,
 650         },
 651         {
 652                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 653                 .procname       = "bootloader_type",
 654                 .data           = &bootloader_type,
 655                 .maxlen         = sizeof (int),
 656                 .mode           = 0444,
 657                 .proc_handler   = &proc_dointvec,
 658         },
 659         {
 660                 .ctl_name       = CTL_UNNUMBERED,
 661                 .procname       = "kstack_depth_to_print",
 662                 .data           = &kstack_depth_to_print,
 663                 .maxlen         = sizeof(int),
 664                 .mode           = 0644,
 665                 .proc_handler   = &proc_dointvec,
 666         },
 667 #endif
 668 #if defined(CONFIG_MMU)
 669         {
 670                 .ctl_name       = KERN_RANDOMIZE,
 671                 .procname       = "randomize_va_space",
 672                 .data           = &randomize_va_space,
 673                 .maxlen         = sizeof(int),
 674                 .mode           = 0644,
 675                 .proc_handler   = &proc_dointvec,
 676         },
 677 #endif
 678 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 679         {
 680                 .ctl_name       = KERN_SPIN_RETRY,
 681                 .procname       = "spin_retry",
 682                 .data           = &spin_retry,
 683                 .maxlen         = sizeof (int),
 684                 .mode           = 0644,
 685                 .proc_handler   = &proc_dointvec,
 686         },
 687 #endif
 688 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 689         {
 690                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 691                 .procname       = "acpi_video_flags",
 692                 .data           = &acpi_realmode_flags,
 693                 .maxlen         = sizeof (unsigned long),
 694                 .mode           = 0644,
 695                 .proc_handler   = &proc_doulongvec_minmax,
 696         },
 697 #endif
 698 #ifdef CONFIG_IA64
 699         {
 700                 .ctl_name       = KERN_IA64_UNALIGNED,
 701                 .procname       = "ignore-unaligned-usertrap",
 702                 .data           = &no_unaligned_warning,
 703                 .maxlen         = sizeof (int),
 704                 .mode           = 0644,
 705                 .proc_handler   = &proc_dointvec,
 706         },
 707 #endif
 708 #ifdef CONFIG_COMPAT
 709         {
 710                 .ctl_name       = KERN_COMPAT_LOG,
 711                 .procname       = "compat-log",
 712                 .data           = &compat_log,
 713                 .maxlen         = sizeof (int),
 714                 .mode           = 0644,
 715                 .proc_handler   = &proc_dointvec,
 716         },
 717 #endif
 718 #ifdef CONFIG_RT_MUTEXES
 719         {
 720                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 721                 .procname       = "max_lock_depth",
 722                 .data           = &max_lock_depth,
 723                 .maxlen         = sizeof(int),
 724                 .mode           = 0644,
 725                 .proc_handler   = &proc_dointvec,
 726         },
 727 #endif
 728 #ifdef CONFIG_PROC_FS
 729         {
 730                 .ctl_name       = CTL_UNNUMBERED,
 731                 .procname       = "maps_protect",
 732                 .data           = &maps_protect,
 733                 .maxlen         = sizeof(int),
 734                 .mode           = 0644,
 735                 .proc_handler   = &proc_dointvec,
 736         },
 737 #endif
 738         {
 739                 .ctl_name       = CTL_UNNUMBERED,
 740                 .procname       = "poweroff_cmd",
 741                 .data           = &poweroff_cmd,
 742                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 743                 .mode           = 0644,
 744                 .proc_handler   = &proc_dostring,
 745                 .strategy       = &sysctl_string,
 746         },
 747 /*
 748  * NOTE: do not add new entries to this table unless you have read
 749  * Documentation/sysctl/ctl_unnumbered.txt
 750  */
 751         { .ctl_name = 0 }
 752 };
 753
 754 /* Constants for minimum and maximum testing in vm_table.
 755    We use these as one-element integer vectors. */
 756 static int zero;
 757 static int two = 2;
 758 static int one_hundred = 100;
 759
 760
 761 static ctl_table vm_table[] = {
 762         {
 763                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 764                 .procname       = "overcommit_memory",
 765                 .data           = &sysctl_overcommit_memory,
 766                 .maxlen         = sizeof(sysctl_overcommit_memory),
 767                 .mode           = 0644,
 768                 .proc_handler   = &proc_dointvec,
 769         },
 770         {
 771                 .ctl_name       = VM_PANIC_ON_OOM,
 772                 .procname       = "panic_on_oom",
 773                 .data           = &sysctl_panic_on_oom,
 774                 .maxlen         = sizeof(sysctl_panic_on_oom),
 775                 .mode           = 0644,
 776                 .proc_handler   = &proc_dointvec,
 777         },
 778         {
 779                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 780                 .procname       = "overcommit_ratio",
 781                 .data           = &sysctl_overcommit_ratio,
 782                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 783                 .mode           = 0644,
 784                 .proc_handler   = &proc_dointvec,
 785         },
 786         {
 787                 .ctl_name       = VM_PAGE_CLUSTER,
 788                 .procname       = "page-cluster",
 789                 .data           = &page_cluster,
 790                 .maxlen         = sizeof(int),
 791                 .mode           = 0644,
 792                 .proc_handler   = &proc_dointvec,
 793         },
 794         {
 795                 .ctl_name       = VM_DIRTY_BACKGROUND,
 796                 .procname       = "dirty_background_ratio",
 797                 .data           = &dirty_background_ratio,
 798                 .maxlen         = sizeof(dirty_background_ratio),
 799                 .mode           = 0644,
 800                 .proc_handler   = &proc_dointvec_minmax,
 801                 .strategy       = &sysctl_intvec,
 802                 .extra1         = &zero,
 803                 .extra2         = &one_hundred,
 804         },
 805         {
 806                 .ctl_name       = VM_DIRTY_RATIO,
 807                 .procname       = "dirty_ratio",
 808                 .data           = &vm_dirty_ratio,
 809                 .maxlen         = sizeof(vm_dirty_ratio),
 810                 .mode           = 0644,
 811                 .proc_handler   = &proc_dointvec_minmax,
 812                 .strategy       = &sysctl_intvec,
 813                 .extra1         = &zero,
 814                 .extra2         = &one_hundred,
 815         },
 816         {
 817                 .ctl_name       = VM_DIRTY_WB_CS,
 818                 .procname       = "dirty_writeback_centisecs",
 819                 .data           = &dirty_writeback_interval,
 820                 .maxlen         = sizeof(dirty_writeback_interval),
 821                 .mode           = 0644,
 822                 .proc_handler   = &dirty_writeback_centisecs_handler,
 823         },
 824         {
 825                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 826                 .procname       = "dirty_expire_centisecs",
 827                 .data           = &dirty_expire_interval,
 828                 .maxlen         = sizeof(dirty_expire_interval),
 829                 .mode           = 0644,
 830                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 831         },
 832         {
 833                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 834                 .procname       = "nr_pdflush_threads",
 835                 .data           = &nr_pdflush_threads,
 836                 .maxlen         = sizeof nr_pdflush_threads,
 837                 .mode           = 0444 /* read-only*/,
 838                 .proc_handler   = &proc_dointvec,
 839         },
 840         {
 841                 .ctl_name       = VM_SWAPPINESS,
 842                 .procname       = "swappiness",
 843                 .data           = &vm_swappiness,
 844                 .maxlen         = sizeof(vm_swappiness),
 845                 .mode           = 0644,
 846                 .proc_handler   = &proc_dointvec_minmax,
 847                 .strategy       = &sysctl_intvec,
 848                 .extra1         = &zero,
 849                 .extra2         = &one_hundred,
 850         },
 851 #ifdef CONFIG_HUGETLB_PAGE
 852          {
 853                 .ctl_name       = VM_HUGETLB_PAGES,
 854                 .procname       = "nr_hugepages",
 855                 .data           = &max_huge_pages,
 856                 .maxlen         = sizeof(unsigned long),
 857                 .mode           = 0644,
 858                 .proc_handler   = &hugetlb_sysctl_handler,
 859                 .extra1         = (void *)&hugetlb_zero,
 860                 .extra2         = (void *)&hugetlb_infinity,
 861          },
 862          {
 863                 .ctl_name       = VM_HUGETLB_GROUP,
 864                 .procname       = "hugetlb_shm_group",
 865                 .data           = &sysctl_hugetlb_shm_group,
 866                 .maxlen         = sizeof(gid_t),
 867                 .mode           = 0644,
 868                 .proc_handler   = &proc_dointvec,
 869          },
 870          {
 871                 .ctl_name       = CTL_UNNUMBERED,
 872                 .procname       = "hugepages_treat_as_movable",
 873                 .data           = &hugepages_treat_as_movable,
 874                 .maxlen         = sizeof(int),
 875                 .mode           = 0644,
 876                 .proc_handler   = &hugetlb_treat_movable_handler,
 877         },
 878 #endif
 879         {
 880                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 881                 .procname       = "lowmem_reserve_ratio",
 882                 .data           = &sysctl_lowmem_reserve_ratio,
 883                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 884                 .mode           = 0644,
 885                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 886                 .strategy       = &sysctl_intvec,
 887         },
 888         {
 889                 .ctl_name       = VM_DROP_PAGECACHE,
 890                 .procname       = "drop_caches",
 891                 .data           = &sysctl_drop_caches,
 892                 .maxlen         = sizeof(int),
 893                 .mode           = 0644,
 894                 .proc_handler   = drop_caches_sysctl_handler,
 895                 .strategy       = &sysctl_intvec,
 896         },
 897         {
 898                 .ctl_name       = VM_MIN_FREE_KBYTES,
 899                 .procname       = "min_free_kbytes",
 900                 .data           = &min_free_kbytes,
 901                 .maxlen         = sizeof(min_free_kbytes),
 902                 .mode           = 0644,
 903                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 904                 .strategy       = &sysctl_intvec,
 905                 .extra1         = &zero,
 906         },
 907         {
 908                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 909                 .procname       = "percpu_pagelist_fraction",
 910                 .data           = &percpu_pagelist_fraction,
 911                 .maxlen         = sizeof(percpu_pagelist_fraction),
 912                 .mode           = 0644,
 913                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 914                 .strategy       = &sysctl_intvec,
 915                 .extra1         = &min_percpu_pagelist_fract,
 916         },
 917 #ifdef CONFIG_MMU
 918         {
 919                 .ctl_name       = VM_MAX_MAP_COUNT,
 920                 .procname       = "max_map_count",
 921                 .data           = &sysctl_max_map_count,
 922                 .maxlen         = sizeof(sysctl_max_map_count),
 923                 .mode           = 0644,
 924                 .proc_handler   = &proc_dointvec
 925         },
 926 #endif
 927         {
 928                 .ctl_name       = VM_LAPTOP_MODE,
 929                 .procname       = "laptop_mode",
 930                 .data           = &laptop_mode,
 931                 .maxlen         = sizeof(laptop_mode),
 932                 .mode           = 0644,
 933                 .proc_handler   = &proc_dointvec_jiffies,
 934                 .strategy       = &sysctl_jiffies,
 935         },
 936         {
 937                 .ctl_name       = VM_BLOCK_DUMP,
 938                 .procname       = "block_dump",
 939                 .data           = &block_dump,
 940                 .maxlen         = sizeof(block_dump),
 941                 .mode           = 0644,
 942                 .proc_handler   = &proc_dointvec,
 943                 .strategy       = &sysctl_intvec,
 944                 .extra1         = &zero,
 945         },
 946         {
 947                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 948                 .procname       = "vfs_cache_pressure",
 949                 .data           = &sysctl_vfs_cache_pressure,
 950                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 951                 .mode           = 0644,
 952                 .proc_handler   = &proc_dointvec,
 953                 .strategy       = &sysctl_intvec,
 954                 .extra1         = &zero,
 955         },
 956 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 957         {
 958                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 959                 .procname       = "legacy_va_layout",
 960                 .data           = &sysctl_legacy_va_layout,
 961                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 962                 .mode           = 0644,
 963                 .proc_handler   = &proc_dointvec,
 964                 .strategy       = &sysctl_intvec,
 965                 .extra1         = &zero,
 966         },
 967 #endif
 968 #ifdef CONFIG_NUMA
 969         {
 970                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 971                 .procname       = "zone_reclaim_mode",
 972                 .data           = &zone_reclaim_mode,
 973                 .maxlen         = sizeof(zone_reclaim_mode),
 974                 .mode           = 0644,
 975                 .proc_handler   = &proc_dointvec,
 976                 .strategy       = &sysctl_intvec,
 977                 .extra1         = &zero,
 978         },
 979         {
 980                 .ctl_name       = VM_MIN_UNMAPPED,
 981                 .procname       = "min_unmapped_ratio",
 982                 .data           = &sysctl_min_unmapped_ratio,
 983                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
 984                 .mode           = 0644,
 985                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
 986                 .strategy       = &sysctl_intvec,
 987                 .extra1         = &zero,
 988                 .extra2         = &one_hundred,
 989         },
 990         {
 991                 .ctl_name       = VM_MIN_SLAB,
 992                 .procname       = "min_slab_ratio",
 993                 .data           = &sysctl_min_slab_ratio,
 994                 .maxlen         = sizeof(sysctl_min_slab_ratio),
 995                 .mode           = 0644,
 996                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
 997                 .strategy       = &sysctl_intvec,
 998                 .extra1         = &zero,
 999                 .extra2         = &one_hundred,
1000         },
1001 #endif
1002 #ifdef CONFIG_SMP
1003         {
1004                 .ctl_name       = CTL_UNNUMBERED,
1005                 .procname       = "stat_interval",
1006                 .data           = &sysctl_stat_interval,
1007                 .maxlen         = sizeof(sysctl_stat_interval),
1008                 .mode           = 0644,
1009                 .proc_handler   = &proc_dointvec_jiffies,
1010                 .strategy       = &sysctl_jiffies,
1011         },
1012 #endif
1013 #ifdef CONFIG_SECURITY
1014         {
1015                 .ctl_name       = CTL_UNNUMBERED,
1016                 .procname       = "mmap_min_addr",
1017                 .data           = &mmap_min_addr,
1018                 .maxlen         = sizeof(unsigned long),
1019                 .mode           = 0644,
1020                 .proc_handler   = &proc_doulongvec_minmax,
1021         },
1022 #endif
1023 #ifdef CONFIG_NUMA
1024         {
1025                 .ctl_name       = CTL_UNNUMBERED,
1026                 .procname       = "numa_zonelist_order",
1027                 .data           = &numa_zonelist_order,
1028                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1029                 .mode           = 0644,
1030                 .proc_handler   = &numa_zonelist_order_handler,
1031                 .strategy       = &sysctl_string,
1032         },
1033 #endif
1034 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1035    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1036         {
1037                 .ctl_name       = VM_VDSO_ENABLED,
1038                 .procname       = "vdso_enabled",
1039                 .data           = &vdso_enabled,
1040                 .maxlen         = sizeof(vdso_enabled),
1041                 .mode           = 0644,
1042                 .proc_handler   = &proc_dointvec,
1043                 .strategy       = &sysctl_intvec,
1044                 .extra1         = &zero,
1045         },
1046 #endif
1047 /*
1048  * NOTE: do not add new entries to this table unless you have read
1049  * Documentation/sysctl/ctl_unnumbered.txt
1050  */
1051         { .ctl_name = 0 }
1052 };
1053
1054 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1055 static ctl_table binfmt_misc_table[] = {
1056         { .ctl_name = 0 }
1057 };
1058 #endif
1059
1060 static ctl_table fs_table[] = {
1061         {
1062                 .ctl_name       = FS_NRINODE,
1063                 .procname       = "inode-nr",
1064                 .data           = &inodes_stat,
1065                 .maxlen         = 2*sizeof(int),
1066                 .mode           = 0444,
1067                 .proc_handler   = &proc_dointvec,
1068         },
1069         {
1070                 .ctl_name       = FS_STATINODE,
1071                 .procname       = "inode-state",
1072                 .data           = &inodes_stat,
1073                 .maxlen         = 7*sizeof(int),
1074                 .mode           = 0444,
1075                 .proc_handler   = &proc_dointvec,
1076         },
1077         {
1078                 .ctl_name       = FS_NRFILE,
1079                 .procname       = "file-nr",
1080                 .data           = &files_stat,
1081                 .maxlen         = 3*sizeof(int),
1082                 .mode           = 0444,
1083                 .proc_handler   = &proc_nr_files,
1084         },
1085         {
1086                 .ctl_name       = FS_MAXFILE,
1087                 .procname       = "file-max",
1088                 .data           = &files_stat.max_files,
1089                 .maxlen         = sizeof(int),
1090                 .mode           = 0644,
1091                 .proc_handler   = &proc_dointvec,
1092         },
1093         {
1094                 .ctl_name       = FS_DENTRY,
1095                 .procname       = "dentry-state",
1096                 .data           = &dentry_stat,
1097                 .maxlen         = 6*sizeof(int),
1098                 .mode           = 0444,
1099                 .proc_handler   = &proc_dointvec,
1100         },
1101         {
1102                 .ctl_name       = FS_OVERFLOWUID,
1103                 .procname       = "overflowuid",
1104                 .data           = &fs_overflowuid,
1105                 .maxlen         = sizeof(int),
1106                 .mode           = 0644,
1107                 .proc_handler   = &proc_dointvec_minmax,
1108                 .strategy       = &sysctl_intvec,
1109                 .extra1         = &minolduid,
1110                 .extra2         = &maxolduid,
1111         },
1112         {
1113                 .ctl_name       = FS_OVERFLOWGID,
1114                 .procname       = "overflowgid",
1115                 .data           = &fs_overflowgid,
1116                 .maxlen         = sizeof(int),
1117                 .mode           = 0644,
1118                 .proc_handler   = &proc_dointvec_minmax,
1119                 .strategy       = &sysctl_intvec,
1120                 .extra1         = &minolduid,
1121                 .extra2         = &maxolduid,
1122         },
1123         {
1124                 .ctl_name       = FS_LEASES,
1125                 .procname       = "leases-enable",
1126                 .data           = &leases_enable,
1127                 .maxlen         = sizeof(int),
1128                 .mode           = 0644,
1129                 .proc_handler   = &proc_dointvec,
1130         },
1131 #ifdef CONFIG_DNOTIFY
1132         {
1133                 .ctl_name       = FS_DIR_NOTIFY,
1134                 .procname       = "dir-notify-enable",
1135                 .data           = &dir_notify_enable,
1136                 .maxlen         = sizeof(int),
1137                 .mode           = 0644,
1138                 .proc_handler   = &proc_dointvec,
1139         },
1140 #endif
1141 #ifdef CONFIG_MMU
1142         {
1143                 .ctl_name       = FS_LEASE_TIME,
1144                 .procname       = "lease-break-time",
1145                 .data           = &lease_break_time,
1146                 .maxlen         = sizeof(int),
1147                 .mode           = 0644,
1148                 .proc_handler   = &proc_dointvec_minmax,
1149                 .strategy       = &sysctl_intvec,
1150                 .extra1         = &zero,
1151                 .extra2         = &two,
1152         },
1153         {
1154                 .ctl_name       = FS_AIO_NR,
1155                 .procname       = "aio-nr",
1156                 .data           = &aio_nr,
1157                 .maxlen         = sizeof(aio_nr),
1158                 .mode           = 0444,
1159                 .proc_handler   = &proc_doulongvec_minmax,
1160         },
1161         {
1162                 .ctl_name       = FS_AIO_MAX_NR,
1163                 .procname       = "aio-max-nr",
1164                 .data           = &aio_max_nr,
1165                 .maxlen         = sizeof(aio_max_nr),
1166                 .mode           = 0644,
1167                 .proc_handler   = &proc_doulongvec_minmax,
1168         },
1169 #ifdef CONFIG_INOTIFY_USER
1170         {
1171                 .ctl_name       = FS_INOTIFY,
1172                 .procname       = "inotify",
1173                 .mode           = 0555,
1174                 .child          = inotify_table,
1175         },
1176 #endif
1177 #endif
1178         {
1179                 .ctl_name       = KERN_SETUID_DUMPABLE,
1180                 .procname       = "suid_dumpable",
1181                 .data           = &suid_dumpable,
1182                 .maxlen         = sizeof(int),
1183                 .mode           = 0644,
1184                 .proc_handler   = &proc_dointvec,
1185         },
1186 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1187         {
1188                 .ctl_name       = CTL_UNNUMBERED,
1189                 .procname       = "binfmt_misc",
1190                 .mode           = 0555,
1191                 .child          = binfmt_misc_table,
1192         },
1193 #endif
1194 /*
1195  * NOTE: do not add new entries to this table unless you have read
1196  * Documentation/sysctl/ctl_unnumbered.txt
1197  */
1198         { .ctl_name = 0 }
1199 };
1200
1201 static ctl_table debug_table[] = {
1202 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1203         {
1204                 .ctl_name       = CTL_UNNUMBERED,
1205                 .procname       = "exception-trace",
1206                 .data           = &show_unhandled_signals,
1207                 .maxlen         = sizeof(int),
1208                 .mode           = 0644,
1209                 .proc_handler   = proc_dointvec
1210         },
1211 #endif
1212         { .ctl_name = 0 }
1213 };
1214
1215 static ctl_table dev_table[] = {
1216         { .ctl_name = 0 }
1217 };
1218
1219 static DEFINE_SPINLOCK(sysctl_lock);
1220
1221 /* called under sysctl_lock */
1222 static int use_table(struct ctl_table_header *p)
1223 {
1224         if (unlikely(p->unregistering))
1225                 return 0;
1226         p->used++;
1227         return 1;
1228 }
1229
1230 /* called under sysctl_lock */
1231 static void unuse_table(struct ctl_table_header *p)
1232 {
1233         if (!--p->used)
1234                 if (unlikely(p->unregistering))
1235                         complete(p->unregistering);
1236 }
1237
1238 /* called under sysctl_lock, will reacquire if has to wait */
1239 static void start_unregistering(struct ctl_table_header *p)
1240 {
1241         /*
1242          * if p->used is 0, nobody will ever touch that entry again;
1243          * we'll eliminate all paths to it before dropping sysctl_lock
1244          */
1245         if (unlikely(p->used)) {
1246                 struct completion wait;
1247                 init_completion(&wait);
1248                 p->unregistering = &wait;
1249                 spin_unlock(&sysctl_lock);
1250                 wait_for_completion(&wait);
1251                 spin_lock(&sysctl_lock);
1252         }
1253         /*
1254          * do not remove from the list until nobody holds it; walking the
1255          * list in do_sysctl() relies on that.
1256          */
1257         list_del_init(&p->ctl_entry);
1258 }
1259
1260 void sysctl_head_finish(struct ctl_table_header *head)
1261 {
1262         if (!head)
1263                 return;
1264         spin_lock(&sysctl_lock);
1265         unuse_table(head);
1266         spin_unlock(&sysctl_lock);
1267 }
1268
1269 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1270 {
1271         struct ctl_table_header *head;
1272         struct list_head *tmp;
1273         spin_lock(&sysctl_lock);
1274         if (prev) {
1275                 tmp = &prev->ctl_entry;
1276                 unuse_table(prev);
1277                 goto next;
1278         }
1279         tmp = &root_table_header.ctl_entry;
1280         for (;;) {
1281                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1282
1283                 if (!use_table(head))
1284                         goto next;
1285                 spin_unlock(&sysctl_lock);
1286                 return head;
1287         next:
1288                 tmp = tmp->next;
1289                 if (tmp == &root_table_header.ctl_entry)
1290                         break;
1291         }
1292         spin_unlock(&sysctl_lock);
1293         return NULL;
1294 }
1295
1296 #ifdef CONFIG_SYSCTL_SYSCALL
1297 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1298                void __user *newval, size_t newlen)
1299 {
1300         struct ctl_table_header *head;
1301         int error = -ENOTDIR;
1302
1303         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1304                 return -ENOTDIR;
1305         if (oldval) {
1306                 int old_len;
1307                 if (!oldlenp || get_user(old_len, oldlenp))
1308                         return -EFAULT;
1309         }
1310
1311         for (head = sysctl_head_next(NULL); head;
1312                         head = sysctl_head_next(head)) {
1313                 error = parse_table(name, nlen, oldval, oldlenp,
1314                                         newval, newlen, head->ctl_table);
1315                 if (error != -ENOTDIR) {
1316                         sysctl_head_finish(head);
1317                         break;
1318                 }
1319         }
1320         return error;
1321 }
1322
1323 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1324 {
1325         struct __sysctl_args tmp;
1326         int error;
1327
1328         if (copy_from_user(&tmp, args, sizeof(tmp)))
1329                 return -EFAULT;
1330
1331         lock_kernel();
1332         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1333                           tmp.newval, tmp.newlen);
1334         unlock_kernel();
1335         return error;
1336 }
1337 #endif /* CONFIG_SYSCTL_SYSCALL */
1338
1339 /*
1340  * sysctl_perm does NOT grant the superuser all rights automatically, because
1341  * some sysctl variables are readonly even to root.
1342  */
1343
1344 static int test_perm(int mode, int op)
1345 {
1346         if (!current->euid)
1347                 mode >>= 6;
1348         else if (in_egroup_p(0))
1349                 mode >>= 3;
1350         if ((mode & op & 0007) == op)
1351                 return 0;
1352         return -EACCES;
1353 }
1354
1355 int sysctl_perm(ctl_table *table, int op)
1356 {
1357         int error;
1358         error = security_sysctl(table, op);
1359         if (error)
1360                 return error;
1361         return test_perm(table->mode, op);
1362 }
1363
1364 #ifdef CONFIG_SYSCTL_SYSCALL
1365 static int parse_table(int __user *name, int nlen,
1366                        void __user *oldval, size_t __user *oldlenp,
1367                        void __user *newval, size_t newlen,
1368                        ctl_table *table)
1369 {
1370         int n;
1371 repeat:
1372         if (!nlen)
1373                 return -ENOTDIR;
1374         if (get_user(n, name))
1375                 return -EFAULT;
1376         for ( ; table->ctl_name || table->procname; table++) {
1377                 if (!table->ctl_name)
1378                         continue;
1379                 if (n == table->ctl_name) {
1380                         int error;
1381                         if (table->child) {
1382                                 if (sysctl_perm(table, 001))
1383                                         return -EPERM;
1384                                 name++;
1385                                 nlen--;
1386                                 table = table->child;
1387                                 goto repeat;
1388                         }
1389                         error = do_sysctl_strategy(table, name, nlen,
1390                                                    oldval, oldlenp,
1391                                                    newval, newlen);
1392                         return error;
1393                 }
1394         }
1395         return -ENOTDIR;
1396 }
1397
1398 /* Perform the actual read/write of a sysctl table entry. */
1399 int do_sysctl_strategy (ctl_table *table,
1400                         int __user *name, int nlen,
1401                         void __user *oldval, size_t __user *oldlenp,
1402                         void __user *newval, size_t newlen)
1403 {
1404         int op = 0, rc;
1405         size_t len;
1406
1407         if (oldval)
1408                 op |= 004;
1409         if (newval)
1410                 op |= 002;
1411         if (sysctl_perm(table, op))
1412                 return -EPERM;
1413
1414         if (table->strategy) {
1415                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1416                                      newval, newlen);
1417                 if (rc < 0)
1418                         return rc;
1419                 if (rc > 0)
1420                         return 0;
1421         }
1422
1423         /* If there is no strategy routine, or if the strategy returns
1424          * zero, proceed with automatic r/w */
1425         if (table->data && table->maxlen) {
1426                 if (oldval && oldlenp) {
1427                         if (get_user(len, oldlenp))
1428                                 return -EFAULT;
1429                         if (len) {
1430                                 if (len > table->maxlen)
1431                                         len = table->maxlen;
1432                                 if(copy_to_user(oldval, table->data, len))
1433                                         return -EFAULT;
1434                                 if(put_user(len, oldlenp))
1435                                         return -EFAULT;
1436                         }
1437                 }
1438                 if (newval && newlen) {
1439                         len = newlen;
1440                         if (len > table->maxlen)
1441                                 len = table->maxlen;
1442                         if(copy_from_user(table->data, newval, len))
1443                                 return -EFAULT;
1444                 }
1445         }
1446         return 0;
1447 }
1448 #endif /* CONFIG_SYSCTL_SYSCALL */
1449
1450 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1451 {
1452         for (; table->ctl_name || table->procname; table++) {
1453                 table->parent = parent;
1454                 if (table->child)
1455                         sysctl_set_parent(table, table->child);
1456         }
1457 }
1458
1459 static __init int sysctl_init(void)
1460 {
1461         sysctl_set_parent(NULL, root_table);
1462         return 0;
1463 }
1464
1465 core_initcall(sysctl_init);
1466
1467 /**
1468  * register_sysctl_table - register a sysctl hierarchy
1469  * @table: the top-level table structure
1470  *
1471  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1472  * array. An entry with a ctl_name of 0 terminates the table.
1473  *
1474  * The members of the &ctl_table structure are used as follows:
1475  *
1476  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1477  *            must be unique within that level of sysctl
1478  *
1479  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1480  *            enter a sysctl file
1481  *
1482  * data - a pointer to data for use by proc_handler
1483  *
1484  * maxlen - the maximum size in bytes of the data
1485  *
1486  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1487  *
1488  * child - a pointer to the child sysctl table if this entry is a directory, or
1489  *         %NULL.
1490  *
1491  * proc_handler - the text handler routine (described below)
1492  *
1493  * strategy - the strategy routine (described below)
1494  *
1495  * de - for internal use by the sysctl routines
1496  *
1497  * extra1, extra2 - extra pointers usable by the proc handler routines
1498  *
1499  * Leaf nodes in the sysctl tree will be represented by a single file
1500  * under /proc; non-leaf nodes will be represented by directories.
1501  *
1502  * sysctl(2) can automatically manage read and write requests through
1503  * the sysctl table.  The data and maxlen fields of the ctl_table
1504  * struct enable minimal validation of the values being written to be
1505  * performed, and the mode field allows minimal authentication.
1506  *
1507  * More sophisticated management can be enabled by the provision of a
1508  * strategy routine with the table entry.  This will be called before
1509  * any automatic read or write of the data is performed.
1510  *
1511  * The strategy routine may return
1512  *
1513  * < 0 - Error occurred (error is passed to user process)
1514  *
1515  * 0   - OK - proceed with automatic read or write.
1516  *
1517  * > 0 - OK - read or write has been done by the strategy routine, so
1518  *       return immediately.
1519  *
1520  * There must be a proc_handler routine for any terminal nodes
1521  * mirrored under /proc/sys (non-terminals are handled by a built-in
1522  * directory handler).  Several default handlers are available to
1523  * cover common cases -
1524  *
1525  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1526  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1527  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1528  *
1529  * It is the handler's job to read the input buffer from user memory
1530  * and process it. The handler should return 0 on success.
1531  *
1532  * This routine returns %NULL on a failure to register, and a pointer
1533  * to the table header on success.
1534  */
1535 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1536 {
1537         struct ctl_table_header *tmp;
1538         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1539         if (!tmp)
1540                 return NULL;
1541         tmp->ctl_table = table;
1542         INIT_LIST_HEAD(&tmp->ctl_entry);
1543         tmp->used = 0;
1544         tmp->unregistering = NULL;
1545         sysctl_set_parent(NULL, table);
1546         spin_lock(&sysctl_lock);
1547         list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1548         spin_unlock(&sysctl_lock);
1549         return tmp;
1550 }
1551
1552 /**
1553  * unregister_sysctl_table - unregister a sysctl table hierarchy
1554  * @header: the header returned from register_sysctl_table
1555  *
1556  * Unregisters the sysctl table and all children. proc entries may not
1557  * actually be removed until they are no longer used by anyone.
1558  */
1559 void unregister_sysctl_table(struct ctl_table_header * header)
1560 {
1561         might_sleep();
1562         spin_lock(&sysctl_lock);
1563         start_unregistering(header);
1564         spin_unlock(&sysctl_lock);
1565         kfree(header);
1566 }
1567
1568 #else /* !CONFIG_SYSCTL */
1569 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1570 {
1571         return NULL;
1572 }
1573
1574 void unregister_sysctl_table(struct ctl_table_header * table)
1575 {
1576 }
1577
1578 #endif /* CONFIG_SYSCTL */
1579
1580 /*
1581  * /proc/sys support
1582  */
1583
1584 #ifdef CONFIG_PROC_SYSCTL
1585
1586 static int _proc_do_string(void* data, int maxlen, int write,
1587                            struct file *filp, void __user *buffer,
1588                            size_t *lenp, loff_t *ppos)
1589 {
1590         size_t len;
1591         char __user *p;
1592         char c;
1593
1594         if (!data || !maxlen || !*lenp) {
1595                 *lenp = 0;
1596                 return 0;
1597         }
1598
1599         if (write) {
1600                 len = 0;
1601                 p = buffer;
1602                 while (len < *lenp) {
1603                         if (get_user(c, p++))
1604                                 return -EFAULT;
1605                         if (c == 0 || c == '\n')
1606                                 break;
1607                         len++;
1608                 }
1609                 if (len >= maxlen)
1610                         len = maxlen-1;
1611                 if(copy_from_user(data, buffer, len))
1612                         return -EFAULT;
1613                 ((char *) data)[len] = 0;
1614                 *ppos += *lenp;
1615         } else {
1616                 len = strlen(data);
1617                 if (len > maxlen)
1618                         len = maxlen;
1619
1620                 if (*ppos > len) {
1621                         *lenp = 0;
1622                         return 0;
1623                 }
1624
1625                 data += *ppos;
1626                 len  -= *ppos;
1627
1628                 if (len > *lenp)
1629                         len = *lenp;
1630                 if (len)
1631                         if(copy_to_user(buffer, data, len))
1632                                 return -EFAULT;
1633                 if (len < *lenp) {
1634                         if(put_user('\n', ((char __user *) buffer) + len))
1635                                 return -EFAULT;
1636                         len++;
1637                 }
1638                 *lenp = len;
1639                 *ppos += len;
1640         }
1641         return 0;
1642 }
1643
1644 /**
1645  * proc_dostring - read a string sysctl
1646  * @table: the sysctl table
1647  * @write: %TRUE if this is a write to the sysctl file
1648  * @filp: the file structure
1649  * @buffer: the user buffer
1650  * @lenp: the size of the user buffer
1651  * @ppos: file position
1652  *
1653  * Reads/writes a string from/to the user buffer. If the kernel
1654  * buffer provided is not large enough to hold the string, the
1655  * string is truncated. The copied string is %NULL-terminated.
1656  * If the string is being read by the user process, it is copied
1657  * and a newline '\n' is added. It is truncated if the buffer is
1658  * not large enough.
1659  *
1660  * Returns 0 on success.
1661  */
1662 int proc_dostring(ctl_table *table, int write, struct file *filp,
1663                   void __user *buffer, size_t *lenp, loff_t *ppos)
1664 {
1665         return _proc_do_string(table->data, table->maxlen, write, filp,
1666                                buffer, lenp, ppos);
1667 }
1668
1669
1670 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1671                                  int *valp,
1672                                  int write, void *data)
1673 {
1674         if (write) {
1675                 *valp = *negp ? -*lvalp : *lvalp;
1676         } else {
1677                 int val = *valp;
1678                 if (val < 0) {
1679                         *negp = -1;
1680                         *lvalp = (unsigned long)-val;
1681                 } else {
1682                         *negp = 0;
1683                         *lvalp = (unsigned long)val;
1684                 }
1685         }
1686         return 0;
1687 }
1688
1689 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1690                   int write, struct file *filp, void __user *buffer,
1691                   size_t *lenp, loff_t *ppos,
1692                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1693                               int write, void *data),
1694                   void *data)
1695 {
1696 #define TMPBUFLEN 21
1697         int *i, vleft, first=1, neg, val;
1698         unsigned long lval;
1699         size_t left, len;
1700
1701         char buf[TMPBUFLEN], *p;
1702         char __user *s = buffer;
1703
1704         if (!tbl_data || !table->maxlen || !*lenp ||
1705             (*ppos && !write)) {
1706                 *lenp = 0;
1707                 return 0;
1708         }
1709
1710         i = (int *) tbl_data;
1711         vleft = table->maxlen / sizeof(*i);
1712         left = *lenp;
1713
1714         if (!conv)
1715                 conv = do_proc_dointvec_conv;
1716
1717         for (; left && vleft--; i++, first=0) {
1718                 if (write) {
1719                         while (left) {
1720                                 char c;
1721                                 if (get_user(c, s))
1722                                         return -EFAULT;
1723                                 if (!isspace(c))
1724                                         break;
1725                                 left--;
1726                                 s++;
1727                         }
1728                         if (!left)
1729                                 break;
1730                         neg = 0;
1731                         len = left;
1732                         if (len > sizeof(buf) - 1)
1733                                 len = sizeof(buf) - 1;
1734                         if (copy_from_user(buf, s, len))
1735                                 return -EFAULT;
1736                         buf[len] = 0;
1737                         p = buf;
1738                         if (*p == '-' && left > 1) {
1739                                 neg = 1;
1740                                 p++;
1741                         }
1742                         if (*p < '0' || *p > '9')
1743                                 break;
1744
1745                         lval = simple_strtoul(p, &p, 0);
1746
1747                         len = p-buf;
1748                         if ((len < left) && *p && !isspace(*p))
1749                                 break;
1750                         if (neg)
1751                                 val = -val;
1752                         s += len;
1753                         left -= len;
1754
1755                         if (conv(&neg, &lval, i, 1, data))
1756                                 break;
1757                 } else {
1758                         p = buf;
1759                         if (!first)
1760                                 *p++ = '\t';
1761
1762                         if (conv(&neg, &lval, i, 0, data))
1763                                 break;
1764
1765                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1766                         len = strlen(buf);
1767                         if (len > left)
1768                                 len = left;
1769                         if(copy_to_user(s, buf, len))
1770                                 return -EFAULT;
1771                         left -= len;
1772                         s += len;
1773                 }
1774         }
1775
1776         if (!write && !first && left) {
1777                 if(put_user('\n', s))
1778                         return -EFAULT;
1779                 left--, s++;
1780         }
1781         if (write) {
1782                 while (left) {
1783                         char c;
1784                         if (get_user(c, s++))
1785                                 return -EFAULT;
1786                         if (!isspace(c))
1787                                 break;
1788                         left--;
1789                 }
1790         }
1791         if (write && first)
1792                 return -EINVAL;
1793         *lenp -= left;
1794         *ppos += *lenp;
1795         return 0;
1796 #undef TMPBUFLEN
1797 }
1798
1799 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1800                   void __user *buffer, size_t *lenp, loff_t *ppos,
1801                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1802                               int write, void *data),
1803                   void *data)
1804 {
1805         return __do_proc_dointvec(table->data, table, write, filp,
1806                         buffer, lenp, ppos, conv, data);
1807 }
1808
1809 /**
1810  * proc_dointvec - read a vector of integers
1811  * @table: the sysctl table
1812  * @write: %TRUE if this is a write to the sysctl file
1813  * @filp: the file structure
1814  * @buffer: the user buffer
1815  * @lenp: the size of the user buffer
1816  * @ppos: file position
1817  *
1818  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1819  * values from/to the user buffer, treated as an ASCII string.
1820  *
1821  * Returns 0 on success.
1822  */
1823 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1824                      void __user *buffer, size_t *lenp, loff_t *ppos)
1825 {
1826     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1827                             NULL,NULL);
1828 }
1829
1830 #define OP_SET  0
1831 #define OP_AND  1
1832 #define OP_OR   2
1833
1834 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1835                                       int *valp,
1836                                       int write, void *data)
1837 {
1838         int op = *(int *)data;
1839         if (write) {
1840                 int val = *negp ? -*lvalp : *lvalp;
1841                 switch(op) {
1842                 case OP_SET:    *valp = val; break;
1843                 case OP_AND:    *valp &= val; break;
1844                 case OP_OR:     *valp |= val; break;
1845                 }
1846         } else {
1847                 int val = *valp;
1848                 if (val < 0) {
1849                         *negp = -1;
1850                         *lvalp = (unsigned long)-val;
1851                 } else {
1852                         *negp = 0;
1853                         *lvalp = (unsigned long)val;
1854                 }
1855         }
1856         return 0;
1857 }
1858
1859 /*
1860  *      init may raise the set.
1861  */
1862
1863 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1864                         void __user *buffer, size_t *lenp, loff_t *ppos)
1865 {
1866         int op;
1867
1868         if (write && !capable(CAP_SYS_MODULE)) {
1869                 return -EPERM;
1870         }
1871
1872         op = is_init(current) ? OP_SET : OP_AND;
1873         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1874                                 do_proc_dointvec_bset_conv,&op);
1875 }
1876
1877 /*
1878  *      Taint values can only be increased
1879  */
1880 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1881                                void __user *buffer, size_t *lenp, loff_t *ppos)
1882 {
1883         int op;
1884
1885         if (write && !capable(CAP_SYS_ADMIN))
1886                 return -EPERM;
1887
1888         op = OP_OR;
1889         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1890                                 do_proc_dointvec_bset_conv,&op);
1891 }
1892
1893 struct do_proc_dointvec_minmax_conv_param {
1894         int *min;
1895         int *max;
1896 };
1897
1898 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1899                                         int *valp,
1900                                         int write, void *data)
1901 {
1902         struct do_proc_dointvec_minmax_conv_param *param = data;
1903         if (write) {
1904                 int val = *negp ? -*lvalp : *lvalp;
1905                 if ((param->min && *param->min > val) ||
1906                     (param->max && *param->max < val))
1907                         return -EINVAL;
1908                 *valp = val;
1909         } else {
1910                 int val = *valp;
1911                 if (val < 0) {
1912                         *negp = -1;
1913                         *lvalp = (unsigned long)-val;
1914                 } else {
1915                         *negp = 0;
1916                         *lvalp = (unsigned long)val;
1917                 }
1918         }
1919         return 0;
1920 }
1921
1922 /**
1923  * proc_dointvec_minmax - read a vector of integers with min/max values
1924  * @table: the sysctl table
1925  * @write: %TRUE if this is a write to the sysctl file
1926  * @filp: the file structure
1927  * @buffer: the user buffer
1928  * @lenp: the size of the user buffer
1929  * @ppos: file position
1930  *
1931  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1932  * values from/to the user buffer, treated as an ASCII string.
1933  *
1934  * This routine will ensure the values are within the range specified by
1935  * table->extra1 (min) and table->extra2 (max).
1936  *
1937  * Returns 0 on success.
1938  */
1939 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1940                   void __user *buffer, size_t *lenp, loff_t *ppos)
1941 {
1942         struct do_proc_dointvec_minmax_conv_param param = {
1943                 .min = (int *) table->extra1,
1944                 .max = (int *) table->extra2,
1945         };
1946         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1947                                 do_proc_dointvec_minmax_conv, &param);
1948 }
1949
1950 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1951                                      struct file *filp,
1952                                      void __user *buffer,
1953                                      size_t *lenp, loff_t *ppos,
1954                                      unsigned long convmul,
1955                                      unsigned long convdiv)
1956 {
1957 #define TMPBUFLEN 21
1958         unsigned long *i, *min, *max, val;
1959         int vleft, first=1, neg;
1960         size_t len, left;
1961         char buf[TMPBUFLEN], *p;
1962         char __user *s = buffer;
1963
1964         if (!data || !table->maxlen || !*lenp ||
1965             (*ppos && !write)) {
1966                 *lenp = 0;
1967                 return 0;
1968         }
1969
1970         i = (unsigned long *) data;
1971         min = (unsigned long *) table->extra1;
1972         max = (unsigned long *) table->extra2;
1973         vleft = table->maxlen / sizeof(unsigned long);
1974         left = *lenp;
1975
1976         for (; left && vleft--; i++, min++, max++, first=0) {
1977                 if (write) {
1978                         while (left) {
1979                                 char c;
1980                                 if (get_user(c, s))
1981                                         return -EFAULT;
1982                                 if (!isspace(c))
1983                                         break;
1984                                 left--;
1985                                 s++;
1986                         }
1987                         if (!left)
1988                                 break;
1989                         neg = 0;
1990                         len = left;
1991                         if (len > TMPBUFLEN-1)
1992                                 len = TMPBUFLEN-1;
1993                         if (copy_from_user(buf, s, len))
1994                                 return -EFAULT;
1995                         buf[len] = 0;
1996                         p = buf;
1997                         if (*p == '-' && left > 1) {
1998                                 neg = 1;
1999                                 p++;
2000                         }
2001                         if (*p < '0' || *p > '9')
2002                                 break;
2003                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2004                         len = p-buf;
2005                         if ((len < left) && *p && !isspace(*p))
2006                                 break;
2007                         if (neg)
2008                                 val = -val;
2009                         s += len;
2010                         left -= len;
2011
2012                         if(neg)
2013                                 continue;
2014                         if ((min && val < *min) || (max && val > *max))
2015                                 continue;
2016                         *i = val;
2017                 } else {
2018                         p = buf;
2019                         if (!first)
2020                                 *p++ = '\t';
2021                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2022                         len = strlen(buf);
2023                         if (len > left)
2024                                 len = left;
2025                         if(copy_to_user(s, buf, len))
2026                                 return -EFAULT;
2027                         left -= len;
2028                         s += len;
2029                 }
2030         }
2031
2032         if (!write && !first && left) {
2033                 if(put_user('\n', s))
2034                         return -EFAULT;
2035                 left--, s++;
2036         }
2037         if (write) {
2038                 while (left) {
2039                         char c;
2040                         if (get_user(c, s++))
2041                                 return -EFAULT;
2042                         if (!isspace(c))
2043                                 break;
2044                         left--;
2045                 }
2046         }
2047         if (write && first)
2048                 return -EINVAL;
2049         *lenp -= left;
2050         *ppos += *lenp;
2051         return 0;
2052 #undef TMPBUFLEN
2053 }
2054
2055 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
2056                                      struct file *filp,
2057                                      void __user *buffer,
2058                                      size_t *lenp, loff_t *ppos,
2059                                      unsigned long convmul,
2060                                      unsigned long convdiv)
2061 {
2062         return __do_proc_doulongvec_minmax(table->data, table, write,
2063                         filp, buffer, lenp, ppos, convmul, convdiv);
2064 }
2065
2066 /**
2067  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2068  * @table: the sysctl table
2069  * @write: %TRUE if this is a write to the sysctl file
2070  * @filp: the file structure
2071  * @buffer: the user buffer
2072  * @lenp: the size of the user buffer
2073  * @ppos: file position
2074  *
2075  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2076  * values from/to the user buffer, treated as an ASCII string.
2077  *
2078  * This routine will ensure the values are within the range specified by
2079  * table->extra1 (min) and table->extra2 (max).
2080  *
2081  * Returns 0 on success.
2082  */
2083 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2084                            void __user *buffer, size_t *lenp, loff_t *ppos)
2085 {
2086     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2087 }
2088
2089 /**
2090  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2091  * @table: the sysctl table
2092  * @write: %TRUE if this is a write to the sysctl file
2093  * @filp: the file structure
2094  * @buffer: the user buffer
2095  * @lenp: the size of the user buffer
2096  * @ppos: file position
2097  *
2098  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2099  * values from/to the user buffer, treated as an ASCII string. The values
2100  * are treated as milliseconds, and converted to jiffies when they are stored.
2101  *
2102  * This routine will ensure the values are within the range specified by
2103  * table->extra1 (min) and table->extra2 (max).
2104  *
2105  * Returns 0 on success.
2106  */
2107 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2108                                       struct file *filp,
2109                                       void __user *buffer,
2110                                       size_t *lenp, loff_t *ppos)
2111 {
2112     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2113                                      lenp, ppos, HZ, 1000l);
2114 }
2115
2116
2117 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2118                                          int *valp,
2119                                          int write, void *data)
2120 {
2121         if (write) {
2122                 if (*lvalp > LONG_MAX / HZ)
2123                         return 1;
2124                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2125         } else {
2126                 int val = *valp;
2127                 unsigned long lval;
2128                 if (val < 0) {
2129                         *negp = -1;
2130                         lval = (unsigned long)-val;
2131                 } else {
2132                         *negp = 0;
2133                         lval = (unsigned long)val;
2134                 }
2135                 *lvalp = lval / HZ;
2136         }
2137         return 0;
2138 }
2139
2140 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2141                                                 int *valp,
2142                                                 int write, void *data)
2143 {
2144         if (write) {
2145                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2146                         return 1;
2147                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2148         } else {
2149                 int val = *valp;
2150                 unsigned long lval;
2151                 if (val < 0) {
2152                         *negp = -1;
2153                         lval = (unsigned long)-val;
2154                 } else {
2155                         *negp = 0;
2156                         lval = (unsigned long)val;
2157                 }
2158                 *lvalp = jiffies_to_clock_t(lval);
2159         }
2160         return 0;
2161 }
2162
2163 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2164                                             int *valp,
2165                                             int write, void *data)
2166 {
2167         if (write) {
2168                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2169         } else {
2170                 int val = *valp;
2171                 unsigned long lval;
2172                 if (val < 0) {
2173                         *negp = -1;
2174                         lval = (unsigned long)-val;
2175                 } else {
2176                         *negp = 0;
2177                         lval = (unsigned long)val;
2178                 }
2179                 *lvalp = jiffies_to_msecs(lval);
2180         }
2181         return 0;
2182 }
2183
2184 /**
2185  * proc_dointvec_jiffies - read a vector of integers as seconds
2186  * @table: the sysctl table
2187  * @write: %TRUE if this is a write to the sysctl file
2188  * @filp: the file structure
2189  * @buffer: the user buffer
2190  * @lenp: the size of the user buffer
2191  * @ppos: file position
2192  *
2193  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2194  * values from/to the user buffer, treated as an ASCII string.
2195  * The values read are assumed to be in seconds, and are converted into
2196  * jiffies.
2197  *
2198  * Returns 0 on success.
2199  */
2200 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2201                           void __user *buffer, size_t *lenp, loff_t *ppos)
2202 {
2203     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2204                             do_proc_dointvec_jiffies_conv,NULL);
2205 }
2206
2207 /**
2208  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2209  * @table: the sysctl table
2210  * @write: %TRUE if this is a write to the sysctl file
2211  * @filp: the file structure
2212  * @buffer: the user buffer
2213  * @lenp: the size of the user buffer
2214  * @ppos: pointer to the file position
2215  *
2216  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2217  * values from/to the user buffer, treated as an ASCII string.
2218  * The values read are assumed to be in 1/USER_HZ seconds, and
2219  * are converted into jiffies.
2220  *
2221  * Returns 0 on success.
2222  */
2223 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2224                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2225 {
2226     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2227                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2228 }
2229
2230 /**
2231  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2232  * @table: the sysctl table
2233  * @write: %TRUE if this is a write to the sysctl file
2234  * @filp: the file structure
2235  * @buffer: the user buffer
2236  * @lenp: the size of the user buffer
2237  * @ppos: file position
2238  * @ppos: the current position in the file
2239  *
2240  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2241  * values from/to the user buffer, treated as an ASCII string.
2242  * The values read are assumed to be in 1/1000 seconds, and
2243  * are converted into jiffies.
2244  *
2245  * Returns 0 on success.
2246  */
2247 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2248                              void __user *buffer, size_t *lenp, loff_t *ppos)
2249 {
2250         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2251                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2252 }
2253
2254 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2255                            void __user *buffer, size_t *lenp, loff_t *ppos)
2256 {
2257         struct pid *new_pid;
2258         pid_t tmp;
2259         int r;
2260
2261         tmp = pid_nr(cad_pid);
2262
2263         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2264                                lenp, ppos, NULL, NULL);
2265         if (r || !write)
2266                 return r;
2267
2268         new_pid = find_get_pid(tmp);
2269         if (!new_pid)
2270                 return -ESRCH;
2271
2272         put_pid(xchg(&cad_pid, new_pid));
2273         return 0;
2274 }
2275
2276 #else /* CONFIG_PROC_FS */
2277
2278 int proc_dostring(ctl_table *table, int write, struct file *filp,
2279                   void __user *buffer, size_t *lenp, loff_t *ppos)
2280 {
2281         return -ENOSYS;
2282 }
2283
2284 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2285                   void __user *buffer, size_t *lenp, loff_t *ppos)
2286 {
2287         return -ENOSYS;
2288 }
2289
2290 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2291                         void __user *buffer, size_t *lenp, loff_t *ppos)
2292 {
2293         return -ENOSYS;
2294 }
2295
2296 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2297                     void __user *buffer, size_t *lenp, loff_t *ppos)
2298 {
2299         return -ENOSYS;
2300 }
2301
2302 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2303                     void __user *buffer, size_t *lenp, loff_t *ppos)
2304 {
2305         return -ENOSYS;
2306 }
2307
2308 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2309                     void __user *buffer, size_t *lenp, loff_t *ppos)
2310 {
2311         return -ENOSYS;
2312 }
2313
2314 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2315                              void __user *buffer, size_t *lenp, loff_t *ppos)
2316 {
2317         return -ENOSYS;
2318 }
2319
2320 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2321                     void __user *buffer, size_t *lenp, loff_t *ppos)
2322 {
2323         return -ENOSYS;
2324 }
2325
2326 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2327                                       struct file *filp,
2328                                       void __user *buffer,
2329                                       size_t *lenp, loff_t *ppos)
2330 {
2331     return -ENOSYS;
2332 }
2333
2334
2335 #endif /* CONFIG_PROC_FS */
2336
2337
2338 #ifdef CONFIG_SYSCTL_SYSCALL
2339 /*
2340  * General sysctl support routines
2341  */
2342
2343 /* The generic string strategy routine: */
2344 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2345                   void __user *oldval, size_t __user *oldlenp,
2346                   void __user *newval, size_t newlen)
2347 {
2348         if (!table->data || !table->maxlen)
2349                 return -ENOTDIR;
2350
2351         if (oldval && oldlenp) {
2352                 size_t bufsize;
2353                 if (get_user(bufsize, oldlenp))
2354                         return -EFAULT;
2355                 if (bufsize) {
2356                         size_t len = strlen(table->data), copied;
2357
2358                         /* This shouldn't trigger for a well-formed sysctl */
2359                         if (len > table->maxlen)
2360                                 len = table->maxlen;
2361
2362                         /* Copy up to a max of bufsize-1 bytes of the string */
2363                         copied = (len >= bufsize) ? bufsize - 1 : len;
2364
2365                         if (copy_to_user(oldval, table->data, copied) ||
2366                             put_user(0, (char __user *)(oldval + copied)))
2367                                 return -EFAULT;
2368                         if (put_user(len, oldlenp))
2369                                 return -EFAULT;
2370                 }
2371         }
2372         if (newval && newlen) {
2373                 size_t len = newlen;
2374                 if (len > table->maxlen)
2375                         len = table->maxlen;
2376                 if(copy_from_user(table->data, newval, len))
2377                         return -EFAULT;
2378                 if (len == table->maxlen)
2379                         len--;
2380                 ((char *) table->data)[len] = 0;
2381         }
2382         return 1;
2383 }
2384
2385 /*
2386  * This function makes sure that all of the integers in the vector
2387  * are between the minimum and maximum values given in the arrays
2388  * table->extra1 and table->extra2, respectively.
2389  */
2390 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2391                 void __user *oldval, size_t __user *oldlenp,
2392                 void __user *newval, size_t newlen)
2393 {
2394
2395         if (newval && newlen) {
2396                 int __user *vec = (int __user *) newval;
2397                 int *min = (int *) table->extra1;
2398                 int *max = (int *) table->extra2;
2399                 size_t length;
2400                 int i;
2401
2402                 if (newlen % sizeof(int) != 0)
2403                         return -EINVAL;
2404
2405                 if (!table->extra1 && !table->extra2)
2406                         return 0;
2407
2408                 if (newlen > table->maxlen)
2409                         newlen = table->maxlen;
2410                 length = newlen / sizeof(int);
2411
2412                 for (i = 0; i < length; i++) {
2413                         int value;
2414                         if (get_user(value, vec + i))
2415                                 return -EFAULT;
2416                         if (min && value < min[i])
2417                                 return -EINVAL;
2418                         if (max && value > max[i])
2419                                 return -EINVAL;
2420                 }
2421         }
2422         return 0;
2423 }
2424
2425 /* Strategy function to convert jiffies to seconds */
2426 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2427                 void __user *oldval, size_t __user *oldlenp,
2428                 void __user *newval, size_t newlen)
2429 {
2430         if (oldval && oldlenp) {
2431                 size_t olen;
2432
2433                 if (get_user(olen, oldlenp))
2434                         return -EFAULT;
2435                 if (olen) {
2436                         int val;
2437
2438                         if (olen < sizeof(int))
2439                                 return -EINVAL;
2440
2441                         val = *(int *)(table->data) / HZ;
2442                         if (put_user(val, (int __user *)oldval))
2443                                 return -EFAULT;
2444                         if (put_user(sizeof(int), oldlenp))
2445                                 return -EFAULT;
2446                 }
2447         }
2448         if (newval && newlen) {
2449                 int new;
2450                 if (newlen != sizeof(int))
2451                         return -EINVAL;
2452                 if (get_user(new, (int __user *)newval))
2453                         return -EFAULT;
2454                 *(int *)(table->data) = new*HZ;
2455         }
2456         return 1;
2457 }
2458
2459 /* Strategy function to convert jiffies to seconds */
2460 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2461                 void __user *oldval, size_t __user *oldlenp,
2462                 void __user *newval, size_t newlen)
2463 {
2464         if (oldval && oldlenp) {
2465                 size_t olen;
2466
2467                 if (get_user(olen, oldlenp))
2468                         return -EFAULT;
2469                 if (olen) {
2470                         int val;
2471
2472                         if (olen < sizeof(int))
2473                                 return -EINVAL;
2474
2475                         val = jiffies_to_msecs(*(int *)(table->data));
2476                         if (put_user(val, (int __user *)oldval))
2477                                 return -EFAULT;
2478                         if (put_user(sizeof(int), oldlenp))
2479                                 return -EFAULT;
2480                 }
2481         }
2482         if (newval && newlen) {
2483                 int new;
2484                 if (newlen != sizeof(int))
2485                         return -EINVAL;
2486                 if (get_user(new, (int __user *)newval))
2487                         return -EFAULT;
2488                 *(int *)(table->data) = msecs_to_jiffies(new);
2489         }
2490         return 1;
2491 }
2492
2493
2494
2495 #else /* CONFIG_SYSCTL_SYSCALL */
2496
2497
2498 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2499 {
2500         static int msg_count;
2501         struct __sysctl_args tmp;
2502         int name[CTL_MAXNAME];
2503         int i;
2504
2505         /* Read in the sysctl name for better debug message logging */
2506         if (copy_from_user(&tmp, args, sizeof(tmp)))
2507                 return -EFAULT;
2508         if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2509                 return -ENOTDIR;
2510         for (i = 0; i < tmp.nlen; i++)
2511                 if (get_user(name[i], tmp.name + i))
2512                         return -EFAULT;
2513
2514         /* Ignore accesses to kernel.version */
2515         if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2516                 goto out;
2517
2518         if (msg_count < 5) {
2519                 msg_count++;
2520                 printk(KERN_INFO
2521                         "warning: process `%s' used the removed sysctl "
2522                         "system call with ", current->comm);
2523                 for (i = 0; i < tmp.nlen; i++)
2524                         printk("%d.", name[i]);
2525                 printk("\n");
2526         }
2527 out:
2528         return -ENOSYS;
2529 }
2530
2531 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2532                   void __user *oldval, size_t __user *oldlenp,
2533                   void __user *newval, size_t newlen)
2534 {
2535         return -ENOSYS;
2536 }
2537
2538 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2539                 void __user *oldval, size_t __user *oldlenp,
2540                 void __user *newval, size_t newlen)
2541 {
2542         return -ENOSYS;
2543 }
2544
2545 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2546                 void __user *oldval, size_t __user *oldlenp,
2547                 void __user *newval, size_t newlen)
2548 {
2549         return -ENOSYS;
2550 }
2551
2552 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2553                 void __user *oldval, size_t __user *oldlenp,
2554                 void __user *newval, size_t newlen)
2555 {
2556         return -ENOSYS;
2557 }
2558
2559 #endif /* CONFIG_SYSCTL_SYSCALL */
2560
2561 /*
2562  * No sense putting this after each symbol definition, twice,
2563  * exception granted :-)
2564  */
2565 EXPORT_SYMBOL(proc_dointvec);
2566 EXPORT_SYMBOL(proc_dointvec_jiffies);
2567 EXPORT_SYMBOL(proc_dointvec_minmax);
2568 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2569 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2570 EXPORT_SYMBOL(proc_dostring);
2571 EXPORT_SYMBOL(proc_doulongvec_minmax);
2572 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2573 EXPORT_SYMBOL(register_sysctl_table);
2574 EXPORT_SYMBOL(sysctl_intvec);
2575 EXPORT_SYMBOL(sysctl_jiffies);
2576 EXPORT_SYMBOL(sysctl_ms_jiffies);
2577 EXPORT_SYMBOL(sysctl_string);
2578 EXPORT_SYMBOL(unregister_sysctl_table);