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