git.oblomov.eu Git - linux-2.6/blob - kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/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
  50 #include <asm/uaccess.h>
  51 #include <asm/processor.h>
  52
  53 #ifdef CONFIG_X86
  54 #include <asm/nmi.h>
  55 #include <asm/stacktrace.h>
  56 #endif
  57
  58 #if defined(CONFIG_SYSCTL)
  59
  60 /* External variables not in a header file. */
  61 extern int C_A_D;
  62 extern int print_fatal_signals;
  63 extern int sysctl_overcommit_memory;
  64 extern int sysctl_overcommit_ratio;
  65 extern int sysctl_panic_on_oom;
  66 extern int max_threads;
  67 extern int core_uses_pid;
  68 extern int suid_dumpable;
  69 extern char core_pattern[];
  70 extern int pid_max;
  71 extern int min_free_kbytes;
  72 extern int printk_ratelimit_jiffies;
  73 extern int printk_ratelimit_burst;
  74 extern int pid_max_min, pid_max_max;
  75 extern int sysctl_drop_caches;
  76 extern int percpu_pagelist_fraction;
  77 extern int compat_log;
  78 extern int maps_protect;
  79 extern int sysctl_stat_interval;
  80
  81 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  82 static int maxolduid = 65535;
  83 static int minolduid;
  84 static int min_percpu_pagelist_fract = 8;
  85
  86 static int ngroups_max = NGROUPS_MAX;
  87
  88 #ifdef CONFIG_KMOD
  89 extern char modprobe_path[];
  90 #endif
  91 #ifdef CONFIG_CHR_DEV_SG
  92 extern int sg_big_buff;
  93 #endif
  94
  95 #ifdef __sparc__
  96 extern char reboot_command [];
  97 extern int stop_a_enabled;
  98 extern int scons_pwroff;
  99 #endif
 100
 101 #ifdef __hppa__
 102 extern int pwrsw_enabled;
 103 extern int unaligned_enabled;
 104 #endif
 105
 106 #ifdef CONFIG_S390
 107 #ifdef CONFIG_MATHEMU
 108 extern int sysctl_ieee_emulation_warnings;
 109 #endif
 110 extern int sysctl_userprocess_debug;
 111 extern int spin_retry;
 112 #endif
 113
 114 extern int sysctl_hz_timer;
 115
 116 #ifdef CONFIG_BSD_PROCESS_ACCT
 117 extern int acct_parm[];
 118 #endif
 119
 120 #ifdef CONFIG_IA64
 121 extern int no_unaligned_warning;
 122 #endif
 123
 124 #ifdef CONFIG_RT_MUTEXES
 125 extern int max_lock_depth;
 126 #endif
 127
 128 #ifdef CONFIG_SYSCTL_SYSCALL
 129 static int parse_table(int __user *, int, void __user *, size_t __user *,
 130                 void __user *, size_t, ctl_table *);
 131 #endif
 132
 133
 134 #ifdef CONFIG_PROC_SYSCTL
 135 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
 136                   void __user *buffer, size_t *lenp, loff_t *ppos);
 137 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
 138                                void __user *buffer, size_t *lenp, loff_t *ppos);
 139 #endif
 140
 141 static ctl_table root_table[];
 142 static struct ctl_table_header root_table_header =
 143         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 144
 145 static ctl_table kern_table[];
 146 static ctl_table vm_table[];
 147 static ctl_table fs_table[];
 148 static ctl_table debug_table[];
 149 static ctl_table dev_table[];
 150 extern ctl_table random_table[];
 151 #ifdef CONFIG_UNIX98_PTYS
 152 extern ctl_table pty_table[];
 153 #endif
 154 #ifdef CONFIG_INOTIFY_USER
 155 extern ctl_table inotify_table[];
 156 #endif
 157
 158 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 159 int sysctl_legacy_va_layout;
 160 #endif
 161
 162
 163 /* The default sysctl tables: */
 164
 165 static ctl_table root_table[] = {
 166         {
 167                 .ctl_name       = CTL_KERN,
 168                 .procname       = "kernel",
 169                 .mode           = 0555,
 170                 .child          = kern_table,
 171         },
 172         {
 173                 .ctl_name       = CTL_VM,
 174                 .procname       = "vm",
 175                 .mode           = 0555,
 176                 .child          = vm_table,
 177         },
 178 #ifdef CONFIG_NET
 179         {
 180                 .ctl_name       = CTL_NET,
 181                 .procname       = "net",
 182                 .mode           = 0555,
 183                 .child          = net_table,
 184         },
 185 #endif
 186         {
 187                 .ctl_name       = CTL_FS,
 188                 .procname       = "fs",
 189                 .mode           = 0555,
 190                 .child          = fs_table,
 191         },
 192         {
 193                 .ctl_name       = CTL_DEBUG,
 194                 .procname       = "debug",
 195                 .mode           = 0555,
 196                 .child          = debug_table,
 197         },
 198         {
 199                 .ctl_name       = CTL_DEV,
 200                 .procname       = "dev",
 201                 .mode           = 0555,
 202                 .child          = dev_table,
 203         },
 204 /*
 205  * NOTE: do not add new entries to this table unless you have read
 206  * Documentation/sysctl/ctl_unnumbered.txt
 207  */
 208         { .ctl_name = 0 }
 209 };
 210
 211 #ifdef CONFIG_SCHED_DEBUG
 212 static unsigned long min_sched_granularity_ns = 100000;         /* 100 usecs */
 213 static unsigned long max_sched_granularity_ns = 1000000000;     /* 1 second */
 214 static unsigned long min_wakeup_granularity_ns;                 /* 0 usecs */
 215 static unsigned long max_wakeup_granularity_ns = 1000000000;    /* 1 second */
 216 #endif
 217
 218 static ctl_table kern_table[] = {
 219 #ifdef CONFIG_SCHED_DEBUG
 220         {
 221                 .ctl_name       = CTL_UNNUMBERED,
 222                 .procname       = "sched_granularity_ns",
 223                 .data           = &sysctl_sched_granularity,
 224                 .maxlen         = sizeof(unsigned int),
 225                 .mode           = 0644,
 226                 .proc_handler   = &proc_dointvec_minmax,
 227                 .strategy       = &sysctl_intvec,
 228                 .extra1         = &min_sched_granularity_ns,
 229                 .extra2         = &max_sched_granularity_ns,
 230         },
 231         {
 232                 .ctl_name       = CTL_UNNUMBERED,
 233                 .procname       = "sched_wakeup_granularity_ns",
 234                 .data           = &sysctl_sched_wakeup_granularity,
 235                 .maxlen         = sizeof(unsigned int),
 236                 .mode           = 0644,
 237                 .proc_handler   = &proc_dointvec_minmax,
 238                 .strategy       = &sysctl_intvec,
 239                 .extra1         = &min_wakeup_granularity_ns,
 240                 .extra2         = &max_wakeup_granularity_ns,
 241         },
 242         {
 243                 .ctl_name       = CTL_UNNUMBERED,
 244                 .procname       = "sched_batch_wakeup_granularity_ns",
 245                 .data           = &sysctl_sched_batch_wakeup_granularity,
 246                 .maxlen         = sizeof(unsigned int),
 247                 .mode           = 0644,
 248                 .proc_handler   = &proc_dointvec_minmax,
 249                 .strategy       = &sysctl_intvec,
 250                 .extra1         = &min_wakeup_granularity_ns,
 251                 .extra2         = &max_wakeup_granularity_ns,
 252         },
 253         {
 254                 .ctl_name       = CTL_UNNUMBERED,
 255                 .procname       = "sched_stat_granularity_ns",
 256                 .data           = &sysctl_sched_stat_granularity,
 257                 .maxlen         = sizeof(unsigned int),
 258                 .mode           = 0644,
 259                 .proc_handler   = &proc_dointvec_minmax,
 260                 .strategy       = &sysctl_intvec,
 261                 .extra1         = &min_wakeup_granularity_ns,
 262                 .extra2         = &max_wakeup_granularity_ns,
 263         },
 264         {
 265                 .ctl_name       = CTL_UNNUMBERED,
 266                 .procname       = "sched_runtime_limit_ns",
 267                 .data           = &sysctl_sched_runtime_limit,
 268                 .maxlen         = sizeof(unsigned int),
 269                 .mode           = 0644,
 270                 .proc_handler   = &proc_dointvec_minmax,
 271                 .strategy       = &sysctl_intvec,
 272                 .extra1         = &min_sched_granularity_ns,
 273                 .extra2         = &max_sched_granularity_ns,
 274         },
 275         {
 276                 .ctl_name       = CTL_UNNUMBERED,
 277                 .procname       = "sched_child_runs_first",
 278                 .data           = &sysctl_sched_child_runs_first,
 279                 .maxlen         = sizeof(unsigned int),
 280                 .mode           = 0644,
 281                 .proc_handler   = &proc_dointvec,
 282         },
 283         {
 284                 .ctl_name       = CTL_UNNUMBERED,
 285                 .procname       = "sched_features",
 286                 .data           = &sysctl_sched_features,
 287                 .maxlen         = sizeof(unsigned int),
 288                 .mode           = 0644,
 289                 .proc_handler   = &proc_dointvec,
 290         },
 291 #endif
 292         {
 293                 .ctl_name       = KERN_PANIC,
 294                 .procname       = "panic",
 295                 .data           = &panic_timeout,
 296                 .maxlen         = sizeof(int),
 297                 .mode           = 0644,
 298                 .proc_handler   = &proc_dointvec,
 299         },
 300         {
 301                 .ctl_name       = KERN_CORE_USES_PID,
 302                 .procname       = "core_uses_pid",
 303                 .data           = &core_uses_pid,
 304                 .maxlen         = sizeof(int),
 305                 .mode           = 0644,
 306                 .proc_handler   = &proc_dointvec,
 307         },
 308         {
 309                 .ctl_name       = KERN_CORE_PATTERN,
 310                 .procname       = "core_pattern",
 311                 .data           = core_pattern,
 312                 .maxlen         = CORENAME_MAX_SIZE,
 313                 .mode           = 0644,
 314                 .proc_handler   = &proc_dostring,
 315                 .strategy       = &sysctl_string,
 316         },
 317 #ifdef CONFIG_PROC_SYSCTL
 318         {
 319                 .ctl_name       = KERN_TAINTED,
 320                 .procname       = "tainted",
 321                 .data           = &tainted,
 322                 .maxlen         = sizeof(int),
 323                 .mode           = 0644,
 324                 .proc_handler   = &proc_dointvec_taint,
 325         },
 326 #endif
 327         {
 328                 .ctl_name       = KERN_CAP_BSET,
 329                 .procname       = "cap-bound",
 330                 .data           = &cap_bset,
 331                 .maxlen         = sizeof(kernel_cap_t),
 332                 .mode           = 0600,
 333                 .proc_handler   = &proc_dointvec_bset,
 334         },
 335 #ifdef CONFIG_BLK_DEV_INITRD
 336         {
 337                 .ctl_name       = KERN_REALROOTDEV,
 338                 .procname       = "real-root-dev",
 339                 .data           = &real_root_dev,
 340                 .maxlen         = sizeof(int),
 341                 .mode           = 0644,
 342                 .proc_handler   = &proc_dointvec,
 343         },
 344 #endif
 345         {
 346                 .ctl_name       = CTL_UNNUMBERED,
 347                 .procname       = "print-fatal-signals",
 348                 .data           = &print_fatal_signals,
 349                 .maxlen         = sizeof(int),
 350                 .mode           = 0644,
 351                 .proc_handler   = &proc_dointvec,
 352         },
 353 #ifdef __sparc__
 354         {
 355                 .ctl_name       = KERN_SPARC_REBOOT,
 356                 .procname       = "reboot-cmd",
 357                 .data           = reboot_command,
 358                 .maxlen         = 256,
 359                 .mode           = 0644,
 360                 .proc_handler   = &proc_dostring,
 361                 .strategy       = &sysctl_string,
 362         },
 363         {
 364                 .ctl_name       = KERN_SPARC_STOP_A,
 365                 .procname       = "stop-a",
 366                 .data           = &stop_a_enabled,
 367                 .maxlen         = sizeof (int),
 368                 .mode           = 0644,
 369                 .proc_handler   = &proc_dointvec,
 370         },
 371         {
 372                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 373                 .procname       = "scons-poweroff",
 374                 .data           = &scons_pwroff,
 375                 .maxlen         = sizeof (int),
 376                 .mode           = 0644,
 377                 .proc_handler   = &proc_dointvec,
 378         },
 379 #endif
 380 #ifdef __hppa__
 381         {
 382                 .ctl_name       = KERN_HPPA_PWRSW,
 383                 .procname       = "soft-power",
 384                 .data           = &pwrsw_enabled,
 385                 .maxlen         = sizeof (int),
 386                 .mode           = 0644,
 387                 .proc_handler   = &proc_dointvec,
 388         },
 389         {
 390                 .ctl_name       = KERN_HPPA_UNALIGNED,
 391                 .procname       = "unaligned-trap",
 392                 .data           = &unaligned_enabled,
 393                 .maxlen         = sizeof (int),
 394                 .mode           = 0644,
 395                 .proc_handler   = &proc_dointvec,
 396         },
 397 #endif
 398         {
 399                 .ctl_name       = KERN_CTLALTDEL,
 400                 .procname       = "ctrl-alt-del",
 401                 .data           = &C_A_D,
 402                 .maxlen         = sizeof(int),
 403                 .mode           = 0644,
 404                 .proc_handler   = &proc_dointvec,
 405         },
 406         {
 407                 .ctl_name       = KERN_PRINTK,
 408                 .procname       = "printk",
 409                 .data           = &console_loglevel,
 410                 .maxlen         = 4*sizeof(int),
 411                 .mode           = 0644,
 412                 .proc_handler   = &proc_dointvec,
 413         },
 414 #ifdef CONFIG_KMOD
 415         {
 416                 .ctl_name       = KERN_MODPROBE,
 417                 .procname       = "modprobe",
 418                 .data           = &modprobe_path,
 419                 .maxlen         = KMOD_PATH_LEN,
 420                 .mode           = 0644,
 421                 .proc_handler   = &proc_dostring,
 422                 .strategy       = &sysctl_string,
 423         },
 424 #endif
 425 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 426         {
 427                 .ctl_name       = KERN_HOTPLUG,
 428                 .procname       = "hotplug",
 429                 .data           = &uevent_helper,
 430                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 431                 .mode           = 0644,
 432                 .proc_handler   = &proc_dostring,
 433                 .strategy       = &sysctl_string,
 434         },
 435 #endif
 436 #ifdef CONFIG_CHR_DEV_SG
 437         {
 438                 .ctl_name       = KERN_SG_BIG_BUFF,
 439                 .procname       = "sg-big-buff",
 440                 .data           = &sg_big_buff,
 441                 .maxlen         = sizeof (int),
 442                 .mode           = 0444,
 443                 .proc_handler   = &proc_dointvec,
 444         },
 445 #endif
 446 #ifdef CONFIG_BSD_PROCESS_ACCT
 447         {
 448                 .ctl_name       = KERN_ACCT,
 449                 .procname       = "acct",
 450                 .data           = &acct_parm,
 451                 .maxlen         = 3*sizeof(int),
 452                 .mode           = 0644,
 453                 .proc_handler   = &proc_dointvec,
 454         },
 455 #endif
 456 #ifdef CONFIG_MAGIC_SYSRQ
 457         {
 458                 .ctl_name       = KERN_SYSRQ,
 459                 .procname       = "sysrq",
 460                 .data           = &__sysrq_enabled,
 461                 .maxlen         = sizeof (int),
 462                 .mode           = 0644,
 463                 .proc_handler   = &proc_dointvec,
 464         },
 465 #endif
 466 #ifdef CONFIG_PROC_SYSCTL
 467         {
 468                 .ctl_name       = KERN_CADPID,
 469                 .procname       = "cad_pid",
 470                 .data           = NULL,
 471                 .maxlen         = sizeof (int),
 472                 .mode           = 0600,
 473                 .proc_handler   = &proc_do_cad_pid,
 474         },
 475 #endif
 476         {
 477                 .ctl_name       = KERN_MAX_THREADS,
 478                 .procname       = "threads-max",
 479                 .data           = &max_threads,
 480                 .maxlen         = sizeof(int),
 481                 .mode           = 0644,
 482                 .proc_handler   = &proc_dointvec,
 483         },
 484         {
 485                 .ctl_name       = KERN_RANDOM,
 486                 .procname       = "random",
 487                 .mode           = 0555,
 488                 .child          = random_table,
 489         },
 490 #ifdef CONFIG_UNIX98_PTYS
 491         {
 492                 .ctl_name       = KERN_PTY,
 493                 .procname       = "pty",
 494                 .mode           = 0555,
 495                 .child          = pty_table,
 496         },
 497 #endif
 498         {
 499                 .ctl_name       = KERN_OVERFLOWUID,
 500                 .procname       = "overflowuid",
 501                 .data           = &overflowuid,
 502                 .maxlen         = sizeof(int),
 503                 .mode           = 0644,
 504                 .proc_handler   = &proc_dointvec_minmax,
 505                 .strategy       = &sysctl_intvec,
 506                 .extra1         = &minolduid,
 507                 .extra2         = &maxolduid,
 508         },
 509         {
 510                 .ctl_name       = KERN_OVERFLOWGID,
 511                 .procname       = "overflowgid",
 512                 .data           = &overflowgid,
 513                 .maxlen         = sizeof(int),
 514                 .mode           = 0644,
 515                 .proc_handler   = &proc_dointvec_minmax,
 516                 .strategy       = &sysctl_intvec,
 517                 .extra1         = &minolduid,
 518                 .extra2         = &maxolduid,
 519         },
 520 #ifdef CONFIG_S390
 521 #ifdef CONFIG_MATHEMU
 522         {
 523                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 524                 .procname       = "ieee_emulation_warnings",
 525                 .data           = &sysctl_ieee_emulation_warnings,
 526                 .maxlen         = sizeof(int),
 527                 .mode           = 0644,
 528                 .proc_handler   = &proc_dointvec,
 529         },
 530 #endif
 531 #ifdef CONFIG_NO_IDLE_HZ
 532         {
 533                 .ctl_name       = KERN_HZ_TIMER,
 534                 .procname       = "hz_timer",
 535                 .data           = &sysctl_hz_timer,
 536                 .maxlen         = sizeof(int),
 537                 .mode           = 0644,
 538                 .proc_handler   = &proc_dointvec,
 539         },
 540 #endif
 541         {
 542                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 543                 .procname       = "userprocess_debug",
 544                 .data           = &sysctl_userprocess_debug,
 545                 .maxlen         = sizeof(int),
 546                 .mode           = 0644,
 547                 .proc_handler   = &proc_dointvec,
 548         },
 549 #endif
 550         {
 551                 .ctl_name       = KERN_PIDMAX,
 552                 .procname       = "pid_max",
 553                 .data           = &pid_max,
 554                 .maxlen         = sizeof (int),
 555                 .mode           = 0644,
 556                 .proc_handler   = &proc_dointvec_minmax,
 557                 .strategy       = sysctl_intvec,
 558                 .extra1         = &pid_max_min,
 559                 .extra2         = &pid_max_max,
 560         },
 561         {
 562                 .ctl_name       = KERN_PANIC_ON_OOPS,
 563                 .procname       = "panic_on_oops",
 564                 .data           = &panic_on_oops,
 565                 .maxlen         = sizeof(int),
 566                 .mode           = 0644,
 567                 .proc_handler   = &proc_dointvec,
 568         },
 569         {
 570                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 571                 .procname       = "printk_ratelimit",
 572                 .data           = &printk_ratelimit_jiffies,
 573                 .maxlen         = sizeof(int),
 574                 .mode           = 0644,
 575                 .proc_handler   = &proc_dointvec_jiffies,
 576                 .strategy       = &sysctl_jiffies,
 577         },
 578         {
 579                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 580                 .procname       = "printk_ratelimit_burst",
 581                 .data           = &printk_ratelimit_burst,
 582                 .maxlen         = sizeof(int),
 583                 .mode           = 0644,
 584                 .proc_handler   = &proc_dointvec,
 585         },
 586         {
 587                 .ctl_name       = KERN_NGROUPS_MAX,
 588                 .procname       = "ngroups_max",
 589                 .data           = &ngroups_max,
 590                 .maxlen         = sizeof (int),
 591                 .mode           = 0444,
 592                 .proc_handler   = &proc_dointvec,
 593         },
 594 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 595         {
 596                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 597                 .procname       = "unknown_nmi_panic",
 598                 .data           = &unknown_nmi_panic,
 599                 .maxlen         = sizeof (int),
 600                 .mode           = 0644,
 601                 .proc_handler   = &proc_dointvec,
 602         },
 603         {
 604                 .ctl_name       = KERN_NMI_WATCHDOG,
 605                 .procname       = "nmi_watchdog",
 606                 .data           = &nmi_watchdog_enabled,
 607                 .maxlen         = sizeof (int),
 608                 .mode           = 0644,
 609                 .proc_handler   = &proc_nmi_enabled,
 610         },
 611 #endif
 612 #if defined(CONFIG_X86)
 613         {
 614                 .ctl_name       = KERN_PANIC_ON_NMI,
 615                 .procname       = "panic_on_unrecovered_nmi",
 616                 .data           = &panic_on_unrecovered_nmi,
 617                 .maxlen         = sizeof(int),
 618                 .mode           = 0644,
 619                 .proc_handler   = &proc_dointvec,
 620         },
 621         {
 622                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 623                 .procname       = "bootloader_type",
 624                 .data           = &bootloader_type,
 625                 .maxlen         = sizeof (int),
 626                 .mode           = 0444,
 627                 .proc_handler   = &proc_dointvec,
 628         },
 629         {
 630                 .ctl_name       = CTL_UNNUMBERED,
 631                 .procname       = "kstack_depth_to_print",
 632                 .data           = &kstack_depth_to_print,
 633                 .maxlen         = sizeof(int),
 634                 .mode           = 0644,
 635                 .proc_handler   = &proc_dointvec,
 636         },
 637 #endif
 638 #if defined(CONFIG_MMU)
 639         {
 640                 .ctl_name       = KERN_RANDOMIZE,
 641                 .procname       = "randomize_va_space",
 642                 .data           = &randomize_va_space,
 643                 .maxlen         = sizeof(int),
 644                 .mode           = 0644,
 645                 .proc_handler   = &proc_dointvec,
 646         },
 647 #endif
 648 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 649         {
 650                 .ctl_name       = KERN_SPIN_RETRY,
 651                 .procname       = "spin_retry",
 652                 .data           = &spin_retry,
 653                 .maxlen         = sizeof (int),
 654                 .mode           = 0644,
 655                 .proc_handler   = &proc_dointvec,
 656         },
 657 #endif
 658 #ifdef CONFIG_ACPI_SLEEP
 659         {
 660                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 661                 .procname       = "acpi_video_flags",
 662                 .data           = &acpi_video_flags,
 663                 .maxlen         = sizeof (unsigned long),
 664                 .mode           = 0644,
 665                 .proc_handler   = &proc_doulongvec_minmax,
 666         },
 667 #endif
 668 #ifdef CONFIG_IA64
 669         {
 670                 .ctl_name       = KERN_IA64_UNALIGNED,
 671                 .procname       = "ignore-unaligned-usertrap",
 672                 .data           = &no_unaligned_warning,
 673                 .maxlen         = sizeof (int),
 674                 .mode           = 0644,
 675                 .proc_handler   = &proc_dointvec,
 676         },
 677 #endif
 678 #ifdef CONFIG_COMPAT
 679         {
 680                 .ctl_name       = KERN_COMPAT_LOG,
 681                 .procname       = "compat-log",
 682                 .data           = &compat_log,
 683                 .maxlen         = sizeof (int),
 684                 .mode           = 0644,
 685                 .proc_handler   = &proc_dointvec,
 686         },
 687 #endif
 688 #ifdef CONFIG_RT_MUTEXES
 689         {
 690                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 691                 .procname       = "max_lock_depth",
 692                 .data           = &max_lock_depth,
 693                 .maxlen         = sizeof(int),
 694                 .mode           = 0644,
 695                 .proc_handler   = &proc_dointvec,
 696         },
 697 #endif
 698 #ifdef CONFIG_PROC_FS
 699         {
 700                 .ctl_name       = CTL_UNNUMBERED,
 701                 .procname       = "maps_protect",
 702                 .data           = &maps_protect,
 703                 .maxlen         = sizeof(int),
 704                 .mode           = 0644,
 705                 .proc_handler   = &proc_dointvec,
 706         },
 707 #endif
 708
 709         { .ctl_name = 0 }
 710 };
 711
 712 /* Constants for minimum and maximum testing in vm_table.
 713    We use these as one-element integer vectors. */
 714 static int zero;
 715 static int one_hundred = 100;
 716
 717
 718 static ctl_table vm_table[] = {
 719         {
 720                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 721                 .procname       = "overcommit_memory",
 722                 .data           = &sysctl_overcommit_memory,
 723                 .maxlen         = sizeof(sysctl_overcommit_memory),
 724                 .mode           = 0644,
 725                 .proc_handler   = &proc_dointvec,
 726         },
 727         {
 728                 .ctl_name       = VM_PANIC_ON_OOM,
 729                 .procname       = "panic_on_oom",
 730                 .data           = &sysctl_panic_on_oom,
 731                 .maxlen         = sizeof(sysctl_panic_on_oom),
 732                 .mode           = 0644,
 733                 .proc_handler   = &proc_dointvec,
 734         },
 735         {
 736                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 737                 .procname       = "overcommit_ratio",
 738                 .data           = &sysctl_overcommit_ratio,
 739                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 740                 .mode           = 0644,
 741                 .proc_handler   = &proc_dointvec,
 742         },
 743         {
 744                 .ctl_name       = VM_PAGE_CLUSTER,
 745                 .procname       = "page-cluster",
 746                 .data           = &page_cluster,
 747                 .maxlen         = sizeof(int),
 748                 .mode           = 0644,
 749                 .proc_handler   = &proc_dointvec,
 750         },
 751         {
 752                 .ctl_name       = VM_DIRTY_BACKGROUND,
 753                 .procname       = "dirty_background_ratio",
 754                 .data           = &dirty_background_ratio,
 755                 .maxlen         = sizeof(dirty_background_ratio),
 756                 .mode           = 0644,
 757                 .proc_handler   = &proc_dointvec_minmax,
 758                 .strategy       = &sysctl_intvec,
 759                 .extra1         = &zero,
 760                 .extra2         = &one_hundred,
 761         },
 762         {
 763                 .ctl_name       = VM_DIRTY_RATIO,
 764                 .procname       = "dirty_ratio",
 765                 .data           = &vm_dirty_ratio,
 766                 .maxlen         = sizeof(vm_dirty_ratio),
 767                 .mode           = 0644,
 768                 .proc_handler   = &proc_dointvec_minmax,
 769                 .strategy       = &sysctl_intvec,
 770                 .extra1         = &zero,
 771                 .extra2         = &one_hundred,
 772         },
 773         {
 774                 .ctl_name       = VM_DIRTY_WB_CS,
 775                 .procname       = "dirty_writeback_centisecs",
 776                 .data           = &dirty_writeback_interval,
 777                 .maxlen         = sizeof(dirty_writeback_interval),
 778                 .mode           = 0644,
 779                 .proc_handler   = &dirty_writeback_centisecs_handler,
 780         },
 781         {
 782                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 783                 .procname       = "dirty_expire_centisecs",
 784                 .data           = &dirty_expire_interval,
 785                 .maxlen         = sizeof(dirty_expire_interval),
 786                 .mode           = 0644,
 787                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 788         },
 789         {
 790                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 791                 .procname       = "nr_pdflush_threads",
 792                 .data           = &nr_pdflush_threads,
 793                 .maxlen         = sizeof nr_pdflush_threads,
 794                 .mode           = 0444 /* read-only*/,
 795                 .proc_handler   = &proc_dointvec,
 796         },
 797         {
 798                 .ctl_name       = VM_SWAPPINESS,
 799                 .procname       = "swappiness",
 800                 .data           = &vm_swappiness,
 801                 .maxlen         = sizeof(vm_swappiness),
 802                 .mode           = 0644,
 803                 .proc_handler   = &proc_dointvec_minmax,
 804                 .strategy       = &sysctl_intvec,
 805                 .extra1         = &zero,
 806                 .extra2         = &one_hundred,
 807         },
 808 #ifdef CONFIG_HUGETLB_PAGE
 809          {
 810                 .ctl_name       = VM_HUGETLB_PAGES,
 811                 .procname       = "nr_hugepages",
 812                 .data           = &max_huge_pages,
 813                 .maxlen         = sizeof(unsigned long),
 814                 .mode           = 0644,
 815                 .proc_handler   = &hugetlb_sysctl_handler,
 816                 .extra1         = (void *)&hugetlb_zero,
 817                 .extra2         = (void *)&hugetlb_infinity,
 818          },
 819          {
 820                 .ctl_name       = VM_HUGETLB_GROUP,
 821                 .procname       = "hugetlb_shm_group",
 822                 .data           = &sysctl_hugetlb_shm_group,
 823                 .maxlen         = sizeof(gid_t),
 824                 .mode           = 0644,
 825                 .proc_handler   = &proc_dointvec,
 826          },
 827          {
 828                 .ctl_name       = CTL_UNNUMBERED,
 829                 .procname       = "hugepages_treat_as_movable",
 830                 .data           = &hugepages_treat_as_movable,
 831                 .maxlen         = sizeof(int),
 832                 .mode           = 0644,
 833                 .proc_handler   = &hugetlb_treat_movable_handler,
 834         },
 835 #endif
 836         {
 837                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 838                 .procname       = "lowmem_reserve_ratio",
 839                 .data           = &sysctl_lowmem_reserve_ratio,
 840                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 841                 .mode           = 0644,
 842                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 843                 .strategy       = &sysctl_intvec,
 844         },
 845         {
 846                 .ctl_name       = VM_DROP_PAGECACHE,
 847                 .procname       = "drop_caches",
 848                 .data           = &sysctl_drop_caches,
 849                 .maxlen         = sizeof(int),
 850                 .mode           = 0644,
 851                 .proc_handler   = drop_caches_sysctl_handler,
 852                 .strategy       = &sysctl_intvec,
 853         },
 854         {
 855                 .ctl_name       = VM_MIN_FREE_KBYTES,
 856                 .procname       = "min_free_kbytes",
 857                 .data           = &min_free_kbytes,
 858                 .maxlen         = sizeof(min_free_kbytes),
 859                 .mode           = 0644,
 860                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 861                 .strategy       = &sysctl_intvec,
 862                 .extra1         = &zero,
 863         },
 864         {
 865                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 866                 .procname       = "percpu_pagelist_fraction",
 867                 .data           = &percpu_pagelist_fraction,
 868                 .maxlen         = sizeof(percpu_pagelist_fraction),
 869                 .mode           = 0644,
 870                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 871                 .strategy       = &sysctl_intvec,
 872                 .extra1         = &min_percpu_pagelist_fract,
 873         },
 874 #ifdef CONFIG_MMU
 875         {
 876                 .ctl_name       = VM_MAX_MAP_COUNT,
 877                 .procname       = "max_map_count",
 878                 .data           = &sysctl_max_map_count,
 879                 .maxlen         = sizeof(sysctl_max_map_count),
 880                 .mode           = 0644,
 881                 .proc_handler   = &proc_dointvec
 882         },
 883 #endif
 884         {
 885                 .ctl_name       = VM_LAPTOP_MODE,
 886                 .procname       = "laptop_mode",
 887                 .data           = &laptop_mode,
 888                 .maxlen         = sizeof(laptop_mode),
 889                 .mode           = 0644,
 890                 .proc_handler   = &proc_dointvec_jiffies,
 891                 .strategy       = &sysctl_jiffies,
 892         },
 893         {
 894                 .ctl_name       = VM_BLOCK_DUMP,
 895                 .procname       = "block_dump",
 896                 .data           = &block_dump,
 897                 .maxlen         = sizeof(block_dump),
 898                 .mode           = 0644,
 899                 .proc_handler   = &proc_dointvec,
 900                 .strategy       = &sysctl_intvec,
 901                 .extra1         = &zero,
 902         },
 903         {
 904                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 905                 .procname       = "vfs_cache_pressure",
 906                 .data           = &sysctl_vfs_cache_pressure,
 907                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 908                 .mode           = 0644,
 909                 .proc_handler   = &proc_dointvec,
 910                 .strategy       = &sysctl_intvec,
 911                 .extra1         = &zero,
 912         },
 913 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 914         {
 915                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 916                 .procname       = "legacy_va_layout",
 917                 .data           = &sysctl_legacy_va_layout,
 918                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 919                 .mode           = 0644,
 920                 .proc_handler   = &proc_dointvec,
 921                 .strategy       = &sysctl_intvec,
 922                 .extra1         = &zero,
 923         },
 924 #endif
 925 #ifdef CONFIG_NUMA
 926         {
 927                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 928                 .procname       = "zone_reclaim_mode",
 929                 .data           = &zone_reclaim_mode,
 930                 .maxlen         = sizeof(zone_reclaim_mode),
 931                 .mode           = 0644,
 932                 .proc_handler   = &proc_dointvec,
 933                 .strategy       = &sysctl_intvec,
 934                 .extra1         = &zero,
 935         },
 936         {
 937                 .ctl_name       = VM_MIN_UNMAPPED,
 938                 .procname       = "min_unmapped_ratio",
 939                 .data           = &sysctl_min_unmapped_ratio,
 940                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
 941                 .mode           = 0644,
 942                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
 943                 .strategy       = &sysctl_intvec,
 944                 .extra1         = &zero,
 945                 .extra2         = &one_hundred,
 946         },
 947         {
 948                 .ctl_name       = VM_MIN_SLAB,
 949                 .procname       = "min_slab_ratio",
 950                 .data           = &sysctl_min_slab_ratio,
 951                 .maxlen         = sizeof(sysctl_min_slab_ratio),
 952                 .mode           = 0644,
 953                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
 954                 .strategy       = &sysctl_intvec,
 955                 .extra1         = &zero,
 956                 .extra2         = &one_hundred,
 957         },
 958 #endif
 959 #ifdef CONFIG_SMP
 960         {
 961                 .ctl_name       = CTL_UNNUMBERED,
 962                 .procname       = "stat_interval",
 963                 .data           = &sysctl_stat_interval,
 964                 .maxlen         = sizeof(sysctl_stat_interval),
 965                 .mode           = 0644,
 966                 .proc_handler   = &proc_dointvec_jiffies,
 967                 .strategy       = &sysctl_jiffies,
 968         },
 969 #endif
 970 #ifdef CONFIG_SECURITY
 971         {
 972                 .ctl_name       = CTL_UNNUMBERED,
 973                 .procname       = "mmap_min_addr",
 974                 .data           = &mmap_min_addr,
 975                 .maxlen         = sizeof(unsigned long),
 976                 .mode           = 0644,
 977                 .proc_handler   = &proc_doulongvec_minmax,
 978         },
 979 #ifdef CONFIG_NUMA
 980         {
 981                 .ctl_name       = CTL_UNNUMBERED,
 982                 .procname       = "numa_zonelist_order",
 983                 .data           = &numa_zonelist_order,
 984                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
 985                 .mode           = 0644,
 986                 .proc_handler   = &numa_zonelist_order_handler,
 987                 .strategy       = &sysctl_string,
 988         },
 989 #endif
 990 #endif
 991 #if defined(CONFIG_X86_32) || \
 992    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
 993         {
 994                 .ctl_name       = VM_VDSO_ENABLED,
 995                 .procname       = "vdso_enabled",
 996                 .data           = &vdso_enabled,
 997                 .maxlen         = sizeof(vdso_enabled),
 998                 .mode           = 0644,
 999                 .proc_handler   = &proc_dointvec,
1000                 .strategy       = &sysctl_intvec,
1001                 .extra1         = &zero,
1002         },
1003 #endif
1004 /*
1005  * NOTE: do not add new entries to this table unless you have read
1006  * Documentation/sysctl/ctl_unnumbered.txt
1007  */
1008         { .ctl_name = 0 }
1009 };
1010
1011 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1012 static ctl_table binfmt_misc_table[] = {
1013         { .ctl_name = 0 }
1014 };
1015 #endif
1016
1017 static ctl_table fs_table[] = {
1018         {
1019                 .ctl_name       = FS_NRINODE,
1020                 .procname       = "inode-nr",
1021                 .data           = &inodes_stat,
1022                 .maxlen         = 2*sizeof(int),
1023                 .mode           = 0444,
1024                 .proc_handler   = &proc_dointvec,
1025         },
1026         {
1027                 .ctl_name       = FS_STATINODE,
1028                 .procname       = "inode-state",
1029                 .data           = &inodes_stat,
1030                 .maxlen         = 7*sizeof(int),
1031                 .mode           = 0444,
1032                 .proc_handler   = &proc_dointvec,
1033         },
1034         {
1035                 .ctl_name       = FS_NRFILE,
1036                 .procname       = "file-nr",
1037                 .data           = &files_stat,
1038                 .maxlen         = 3*sizeof(int),
1039                 .mode           = 0444,
1040                 .proc_handler   = &proc_nr_files,
1041         },
1042         {
1043                 .ctl_name       = FS_MAXFILE,
1044                 .procname       = "file-max",
1045                 .data           = &files_stat.max_files,
1046                 .maxlen         = sizeof(int),
1047                 .mode           = 0644,
1048                 .proc_handler   = &proc_dointvec,
1049         },
1050         {
1051                 .ctl_name       = FS_DENTRY,
1052                 .procname       = "dentry-state",
1053                 .data           = &dentry_stat,
1054                 .maxlen         = 6*sizeof(int),
1055                 .mode           = 0444,
1056                 .proc_handler   = &proc_dointvec,
1057         },
1058         {
1059                 .ctl_name       = FS_OVERFLOWUID,
1060                 .procname       = "overflowuid",
1061                 .data           = &fs_overflowuid,
1062                 .maxlen         = sizeof(int),
1063                 .mode           = 0644,
1064                 .proc_handler   = &proc_dointvec_minmax,
1065                 .strategy       = &sysctl_intvec,
1066                 .extra1         = &minolduid,
1067                 .extra2         = &maxolduid,
1068         },
1069         {
1070                 .ctl_name       = FS_OVERFLOWGID,
1071                 .procname       = "overflowgid",
1072                 .data           = &fs_overflowgid,
1073                 .maxlen         = sizeof(int),
1074                 .mode           = 0644,
1075                 .proc_handler   = &proc_dointvec_minmax,
1076                 .strategy       = &sysctl_intvec,
1077                 .extra1         = &minolduid,
1078                 .extra2         = &maxolduid,
1079         },
1080         {
1081                 .ctl_name       = FS_LEASES,
1082                 .procname       = "leases-enable",
1083                 .data           = &leases_enable,
1084                 .maxlen         = sizeof(int),
1085                 .mode           = 0644,
1086                 .proc_handler   = &proc_dointvec,
1087         },
1088 #ifdef CONFIG_DNOTIFY
1089         {
1090                 .ctl_name       = FS_DIR_NOTIFY,
1091                 .procname       = "dir-notify-enable",
1092                 .data           = &dir_notify_enable,
1093                 .maxlen         = sizeof(int),
1094                 .mode           = 0644,
1095                 .proc_handler   = &proc_dointvec,
1096         },
1097 #endif
1098 #ifdef CONFIG_MMU
1099         {
1100                 .ctl_name       = FS_LEASE_TIME,
1101                 .procname       = "lease-break-time",
1102                 .data           = &lease_break_time,
1103                 .maxlen         = sizeof(int),
1104                 .mode           = 0644,
1105                 .proc_handler   = &proc_dointvec,
1106         },
1107         {
1108                 .ctl_name       = FS_AIO_NR,
1109                 .procname       = "aio-nr",
1110                 .data           = &aio_nr,
1111                 .maxlen         = sizeof(aio_nr),
1112                 .mode           = 0444,
1113                 .proc_handler   = &proc_doulongvec_minmax,
1114         },
1115         {
1116                 .ctl_name       = FS_AIO_MAX_NR,
1117                 .procname       = "aio-max-nr",
1118                 .data           = &aio_max_nr,
1119                 .maxlen         = sizeof(aio_max_nr),
1120                 .mode           = 0644,
1121                 .proc_handler   = &proc_doulongvec_minmax,
1122         },
1123 #ifdef CONFIG_INOTIFY_USER
1124         {
1125                 .ctl_name       = FS_INOTIFY,
1126                 .procname       = "inotify",
1127                 .mode           = 0555,
1128                 .child          = inotify_table,
1129         },
1130 #endif
1131 #endif
1132         {
1133                 .ctl_name       = KERN_SETUID_DUMPABLE,
1134                 .procname       = "suid_dumpable",
1135                 .data           = &suid_dumpable,
1136                 .maxlen         = sizeof(int),
1137                 .mode           = 0644,
1138                 .proc_handler   = &proc_dointvec,
1139         },
1140 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1141         {
1142                 .ctl_name       = CTL_UNNUMBERED,
1143                 .procname       = "binfmt_misc",
1144                 .mode           = 0555,
1145                 .child          = binfmt_misc_table,
1146         },
1147 #endif
1148 /*
1149  * NOTE: do not add new entries to this table unless you have read
1150  * Documentation/sysctl/ctl_unnumbered.txt
1151  */
1152         { .ctl_name = 0 }
1153 };
1154
1155 static ctl_table debug_table[] = {
1156         { .ctl_name = 0 }
1157 };
1158
1159 static ctl_table dev_table[] = {
1160         { .ctl_name = 0 }
1161 };
1162
1163 static DEFINE_SPINLOCK(sysctl_lock);
1164
1165 /* called under sysctl_lock */
1166 static int use_table(struct ctl_table_header *p)
1167 {
1168         if (unlikely(p->unregistering))
1169                 return 0;
1170         p->used++;
1171         return 1;
1172 }
1173
1174 /* called under sysctl_lock */
1175 static void unuse_table(struct ctl_table_header *p)
1176 {
1177         if (!--p->used)
1178                 if (unlikely(p->unregistering))
1179                         complete(p->unregistering);
1180 }
1181
1182 /* called under sysctl_lock, will reacquire if has to wait */
1183 static void start_unregistering(struct ctl_table_header *p)
1184 {
1185         /*
1186          * if p->used is 0, nobody will ever touch that entry again;
1187          * we'll eliminate all paths to it before dropping sysctl_lock
1188          */
1189         if (unlikely(p->used)) {
1190                 struct completion wait;
1191                 init_completion(&wait);
1192                 p->unregistering = &wait;
1193                 spin_unlock(&sysctl_lock);
1194                 wait_for_completion(&wait);
1195                 spin_lock(&sysctl_lock);
1196         }
1197         /*
1198          * do not remove from the list until nobody holds it; walking the
1199          * list in do_sysctl() relies on that.
1200          */
1201         list_del_init(&p->ctl_entry);
1202 }
1203
1204 void sysctl_head_finish(struct ctl_table_header *head)
1205 {
1206         if (!head)
1207                 return;
1208         spin_lock(&sysctl_lock);
1209         unuse_table(head);
1210         spin_unlock(&sysctl_lock);
1211 }
1212
1213 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1214 {
1215         struct ctl_table_header *head;
1216         struct list_head *tmp;
1217         spin_lock(&sysctl_lock);
1218         if (prev) {
1219                 tmp = &prev->ctl_entry;
1220                 unuse_table(prev);
1221                 goto next;
1222         }
1223         tmp = &root_table_header.ctl_entry;
1224         for (;;) {
1225                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1226
1227                 if (!use_table(head))
1228                         goto next;
1229                 spin_unlock(&sysctl_lock);
1230                 return head;
1231         next:
1232                 tmp = tmp->next;
1233                 if (tmp == &root_table_header.ctl_entry)
1234                         break;
1235         }
1236         spin_unlock(&sysctl_lock);
1237         return NULL;
1238 }
1239
1240 #ifdef CONFIG_SYSCTL_SYSCALL
1241 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1242                void __user *newval, size_t newlen)
1243 {
1244         struct ctl_table_header *head;
1245         int error = -ENOTDIR;
1246
1247         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1248                 return -ENOTDIR;
1249         if (oldval) {
1250                 int old_len;
1251                 if (!oldlenp || get_user(old_len, oldlenp))
1252                         return -EFAULT;
1253         }
1254
1255         for (head = sysctl_head_next(NULL); head;
1256                         head = sysctl_head_next(head)) {
1257                 error = parse_table(name, nlen, oldval, oldlenp,
1258                                         newval, newlen, head->ctl_table);
1259                 if (error != -ENOTDIR) {
1260                         sysctl_head_finish(head);
1261                         break;
1262                 }
1263         }
1264         return error;
1265 }
1266
1267 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1268 {
1269         struct __sysctl_args tmp;
1270         int error;
1271
1272         if (copy_from_user(&tmp, args, sizeof(tmp)))
1273                 return -EFAULT;
1274
1275         lock_kernel();
1276         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1277                           tmp.newval, tmp.newlen);
1278         unlock_kernel();
1279         return error;
1280 }
1281 #endif /* CONFIG_SYSCTL_SYSCALL */
1282
1283 /*
1284  * sysctl_perm does NOT grant the superuser all rights automatically, because
1285  * some sysctl variables are readonly even to root.
1286  */
1287
1288 static int test_perm(int mode, int op)
1289 {
1290         if (!current->euid)
1291                 mode >>= 6;
1292         else if (in_egroup_p(0))
1293                 mode >>= 3;
1294         if ((mode & op & 0007) == op)
1295                 return 0;
1296         return -EACCES;
1297 }
1298
1299 int sysctl_perm(ctl_table *table, int op)
1300 {
1301         int error;
1302         error = security_sysctl(table, op);
1303         if (error)
1304                 return error;
1305         return test_perm(table->mode, op);
1306 }
1307
1308 #ifdef CONFIG_SYSCTL_SYSCALL
1309 static int parse_table(int __user *name, int nlen,
1310                        void __user *oldval, size_t __user *oldlenp,
1311                        void __user *newval, size_t newlen,
1312                        ctl_table *table)
1313 {
1314         int n;
1315 repeat:
1316         if (!nlen)
1317                 return -ENOTDIR;
1318         if (get_user(n, name))
1319                 return -EFAULT;
1320         for ( ; table->ctl_name || table->procname; table++) {
1321                 if (!table->ctl_name)
1322                         continue;
1323                 if (n == table->ctl_name) {
1324                         int error;
1325                         if (table->child) {
1326                                 if (sysctl_perm(table, 001))
1327                                         return -EPERM;
1328                                 name++;
1329                                 nlen--;
1330                                 table = table->child;
1331                                 goto repeat;
1332                         }
1333                         error = do_sysctl_strategy(table, name, nlen,
1334                                                    oldval, oldlenp,
1335                                                    newval, newlen);
1336                         return error;
1337                 }
1338         }
1339         return -ENOTDIR;
1340 }
1341
1342 /* Perform the actual read/write of a sysctl table entry. */
1343 int do_sysctl_strategy (ctl_table *table,
1344                         int __user *name, int nlen,
1345                         void __user *oldval, size_t __user *oldlenp,
1346                         void __user *newval, size_t newlen)
1347 {
1348         int op = 0, rc;
1349         size_t len;
1350
1351         if (oldval)
1352                 op |= 004;
1353         if (newval)
1354                 op |= 002;
1355         if (sysctl_perm(table, op))
1356                 return -EPERM;
1357
1358         if (table->strategy) {
1359                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1360                                      newval, newlen);
1361                 if (rc < 0)
1362                         return rc;
1363                 if (rc > 0)
1364                         return 0;
1365         }
1366
1367         /* If there is no strategy routine, or if the strategy returns
1368          * zero, proceed with automatic r/w */
1369         if (table->data && table->maxlen) {
1370                 if (oldval && oldlenp) {
1371                         if (get_user(len, oldlenp))
1372                                 return -EFAULT;
1373                         if (len) {
1374                                 if (len > table->maxlen)
1375                                         len = table->maxlen;
1376                                 if(copy_to_user(oldval, table->data, len))
1377                                         return -EFAULT;
1378                                 if(put_user(len, oldlenp))
1379                                         return -EFAULT;
1380                         }
1381                 }
1382                 if (newval && newlen) {
1383                         len = newlen;
1384                         if (len > table->maxlen)
1385                                 len = table->maxlen;
1386                         if(copy_from_user(table->data, newval, len))
1387                                 return -EFAULT;
1388                 }
1389         }
1390         return 0;
1391 }
1392 #endif /* CONFIG_SYSCTL_SYSCALL */
1393
1394 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1395 {
1396         for (; table->ctl_name || table->procname; table++) {
1397                 table->parent = parent;
1398                 if (table->child)
1399                         sysctl_set_parent(table, table->child);
1400         }
1401 }
1402
1403 static __init int sysctl_init(void)
1404 {
1405         sysctl_set_parent(NULL, root_table);
1406         return 0;
1407 }
1408
1409 core_initcall(sysctl_init);
1410
1411 /**
1412  * register_sysctl_table - register a sysctl hierarchy
1413  * @table: the top-level table structure
1414  *
1415  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1416  * array. An entry with a ctl_name of 0 terminates the table.
1417  *
1418  * The members of the &ctl_table structure are used as follows:
1419  *
1420  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1421  *            must be unique within that level of sysctl
1422  *
1423  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1424  *            enter a sysctl file
1425  *
1426  * data - a pointer to data for use by proc_handler
1427  *
1428  * maxlen - the maximum size in bytes of the data
1429  *
1430  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1431  *
1432  * child - a pointer to the child sysctl table if this entry is a directory, or
1433  *         %NULL.
1434  *
1435  * proc_handler - the text handler routine (described below)
1436  *
1437  * strategy - the strategy routine (described below)
1438  *
1439  * de - for internal use by the sysctl routines
1440  *
1441  * extra1, extra2 - extra pointers usable by the proc handler routines
1442  *
1443  * Leaf nodes in the sysctl tree will be represented by a single file
1444  * under /proc; non-leaf nodes will be represented by directories.
1445  *
1446  * sysctl(2) can automatically manage read and write requests through
1447  * the sysctl table.  The data and maxlen fields of the ctl_table
1448  * struct enable minimal validation of the values being written to be
1449  * performed, and the mode field allows minimal authentication.
1450  *
1451  * More sophisticated management can be enabled by the provision of a
1452  * strategy routine with the table entry.  This will be called before
1453  * any automatic read or write of the data is performed.
1454  *
1455  * The strategy routine may return
1456  *
1457  * < 0 - Error occurred (error is passed to user process)
1458  *
1459  * 0   - OK - proceed with automatic read or write.
1460  *
1461  * > 0 - OK - read or write has been done by the strategy routine, so
1462  *       return immediately.
1463  *
1464  * There must be a proc_handler routine for any terminal nodes
1465  * mirrored under /proc/sys (non-terminals are handled by a built-in
1466  * directory handler).  Several default handlers are available to
1467  * cover common cases -
1468  *
1469  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1470  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1471  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1472  *
1473  * It is the handler's job to read the input buffer from user memory
1474  * and process it. The handler should return 0 on success.
1475  *
1476  * This routine returns %NULL on a failure to register, and a pointer
1477  * to the table header on success.
1478  */
1479 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1480 {
1481         struct ctl_table_header *tmp;
1482         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1483         if (!tmp)
1484                 return NULL;
1485         tmp->ctl_table = table;
1486         INIT_LIST_HEAD(&tmp->ctl_entry);
1487         tmp->used = 0;
1488         tmp->unregistering = NULL;
1489         sysctl_set_parent(NULL, table);
1490         spin_lock(&sysctl_lock);
1491         list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1492         spin_unlock(&sysctl_lock);
1493         return tmp;
1494 }
1495
1496 /**
1497  * unregister_sysctl_table - unregister a sysctl table hierarchy
1498  * @header: the header returned from register_sysctl_table
1499  *
1500  * Unregisters the sysctl table and all children. proc entries may not
1501  * actually be removed until they are no longer used by anyone.
1502  */
1503 void unregister_sysctl_table(struct ctl_table_header * header)
1504 {
1505         might_sleep();
1506         spin_lock(&sysctl_lock);
1507         start_unregistering(header);
1508         spin_unlock(&sysctl_lock);
1509         kfree(header);
1510 }
1511
1512 #else /* !CONFIG_SYSCTL */
1513 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1514 {
1515         return NULL;
1516 }
1517
1518 void unregister_sysctl_table(struct ctl_table_header * table)
1519 {
1520 }
1521
1522 #endif /* CONFIG_SYSCTL */
1523
1524 /*
1525  * /proc/sys support
1526  */
1527
1528 #ifdef CONFIG_PROC_SYSCTL
1529
1530 static int _proc_do_string(void* data, int maxlen, int write,
1531                            struct file *filp, void __user *buffer,
1532                            size_t *lenp, loff_t *ppos)
1533 {
1534         size_t len;
1535         char __user *p;
1536         char c;
1537
1538         if (!data || !maxlen || !*lenp) {
1539                 *lenp = 0;
1540                 return 0;
1541         }
1542
1543         if (write) {
1544                 len = 0;
1545                 p = buffer;
1546                 while (len < *lenp) {
1547                         if (get_user(c, p++))
1548                                 return -EFAULT;
1549                         if (c == 0 || c == '\n')
1550                                 break;
1551                         len++;
1552                 }
1553                 if (len >= maxlen)
1554                         len = maxlen-1;
1555                 if(copy_from_user(data, buffer, len))
1556                         return -EFAULT;
1557                 ((char *) data)[len] = 0;
1558                 *ppos += *lenp;
1559         } else {
1560                 len = strlen(data);
1561                 if (len > maxlen)
1562                         len = maxlen;
1563
1564                 if (*ppos > len) {
1565                         *lenp = 0;
1566                         return 0;
1567                 }
1568
1569                 data += *ppos;
1570                 len  -= *ppos;
1571
1572                 if (len > *lenp)
1573                         len = *lenp;
1574                 if (len)
1575                         if(copy_to_user(buffer, data, len))
1576                                 return -EFAULT;
1577                 if (len < *lenp) {
1578                         if(put_user('\n', ((char __user *) buffer) + len))
1579                                 return -EFAULT;
1580                         len++;
1581                 }
1582                 *lenp = len;
1583                 *ppos += len;
1584         }
1585         return 0;
1586 }
1587
1588 /**
1589  * proc_dostring - read a string sysctl
1590  * @table: the sysctl table
1591  * @write: %TRUE if this is a write to the sysctl file
1592  * @filp: the file structure
1593  * @buffer: the user buffer
1594  * @lenp: the size of the user buffer
1595  * @ppos: file position
1596  *
1597  * Reads/writes a string from/to the user buffer. If the kernel
1598  * buffer provided is not large enough to hold the string, the
1599  * string is truncated. The copied string is %NULL-terminated.
1600  * If the string is being read by the user process, it is copied
1601  * and a newline '\n' is added. It is truncated if the buffer is
1602  * not large enough.
1603  *
1604  * Returns 0 on success.
1605  */
1606 int proc_dostring(ctl_table *table, int write, struct file *filp,
1607                   void __user *buffer, size_t *lenp, loff_t *ppos)
1608 {
1609         return _proc_do_string(table->data, table->maxlen, write, filp,
1610                                buffer, lenp, ppos);
1611 }
1612
1613
1614 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1615                                  int *valp,
1616                                  int write, void *data)
1617 {
1618         if (write) {
1619                 *valp = *negp ? -*lvalp : *lvalp;
1620         } else {
1621                 int val = *valp;
1622                 if (val < 0) {
1623                         *negp = -1;
1624                         *lvalp = (unsigned long)-val;
1625                 } else {
1626                         *negp = 0;
1627                         *lvalp = (unsigned long)val;
1628                 }
1629         }
1630         return 0;
1631 }
1632
1633 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1634                   int write, struct file *filp, void __user *buffer,
1635                   size_t *lenp, loff_t *ppos,
1636                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1637                               int write, void *data),
1638                   void *data)
1639 {
1640 #define TMPBUFLEN 21
1641         int *i, vleft, first=1, neg, val;
1642         unsigned long lval;
1643         size_t left, len;
1644
1645         char buf[TMPBUFLEN], *p;
1646         char __user *s = buffer;
1647
1648         if (!tbl_data || !table->maxlen || !*lenp ||
1649             (*ppos && !write)) {
1650                 *lenp = 0;
1651                 return 0;
1652         }
1653
1654         i = (int *) tbl_data;
1655         vleft = table->maxlen / sizeof(*i);
1656         left = *lenp;
1657
1658         if (!conv)
1659                 conv = do_proc_dointvec_conv;
1660
1661         for (; left && vleft--; i++, first=0) {
1662                 if (write) {
1663                         while (left) {
1664                                 char c;
1665                                 if (get_user(c, s))
1666                                         return -EFAULT;
1667                                 if (!isspace(c))
1668                                         break;
1669                                 left--;
1670                                 s++;
1671                         }
1672                         if (!left)
1673                                 break;
1674                         neg = 0;
1675                         len = left;
1676                         if (len > sizeof(buf) - 1)
1677                                 len = sizeof(buf) - 1;
1678                         if (copy_from_user(buf, s, len))
1679                                 return -EFAULT;
1680                         buf[len] = 0;
1681                         p = buf;
1682                         if (*p == '-' && left > 1) {
1683                                 neg = 1;
1684                                 p++;
1685                         }
1686                         if (*p < '0' || *p > '9')
1687                                 break;
1688
1689                         lval = simple_strtoul(p, &p, 0);
1690
1691                         len = p-buf;
1692                         if ((len < left) && *p && !isspace(*p))
1693                                 break;
1694                         if (neg)
1695                                 val = -val;
1696                         s += len;
1697                         left -= len;
1698
1699                         if (conv(&neg, &lval, i, 1, data))
1700                                 break;
1701                 } else {
1702                         p = buf;
1703                         if (!first)
1704                                 *p++ = '\t';
1705
1706                         if (conv(&neg, &lval, i, 0, data))
1707                                 break;
1708
1709                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1710                         len = strlen(buf);
1711                         if (len > left)
1712                                 len = left;
1713                         if(copy_to_user(s, buf, len))
1714                                 return -EFAULT;
1715                         left -= len;
1716                         s += len;
1717                 }
1718         }
1719
1720         if (!write && !first && left) {
1721                 if(put_user('\n', s))
1722                         return -EFAULT;
1723                 left--, s++;
1724         }
1725         if (write) {
1726                 while (left) {
1727                         char c;
1728                         if (get_user(c, s++))
1729                                 return -EFAULT;
1730                         if (!isspace(c))
1731                                 break;
1732                         left--;
1733                 }
1734         }
1735         if (write && first)
1736                 return -EINVAL;
1737         *lenp -= left;
1738         *ppos += *lenp;
1739         return 0;
1740 #undef TMPBUFLEN
1741 }
1742
1743 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1744                   void __user *buffer, size_t *lenp, loff_t *ppos,
1745                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1746                               int write, void *data),
1747                   void *data)
1748 {
1749         return __do_proc_dointvec(table->data, table, write, filp,
1750                         buffer, lenp, ppos, conv, data);
1751 }
1752
1753 /**
1754  * proc_dointvec - read a vector of integers
1755  * @table: the sysctl table
1756  * @write: %TRUE if this is a write to the sysctl file
1757  * @filp: the file structure
1758  * @buffer: the user buffer
1759  * @lenp: the size of the user buffer
1760  * @ppos: file position
1761  *
1762  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1763  * values from/to the user buffer, treated as an ASCII string.
1764  *
1765  * Returns 0 on success.
1766  */
1767 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1768                      void __user *buffer, size_t *lenp, loff_t *ppos)
1769 {
1770     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1771                             NULL,NULL);
1772 }
1773
1774 #define OP_SET  0
1775 #define OP_AND  1
1776 #define OP_OR   2
1777
1778 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1779                                       int *valp,
1780                                       int write, void *data)
1781 {
1782         int op = *(int *)data;
1783         if (write) {
1784                 int val = *negp ? -*lvalp : *lvalp;
1785                 switch(op) {
1786                 case OP_SET:    *valp = val; break;
1787                 case OP_AND:    *valp &= val; break;
1788                 case OP_OR:     *valp |= val; break;
1789                 }
1790         } else {
1791                 int val = *valp;
1792                 if (val < 0) {
1793                         *negp = -1;
1794                         *lvalp = (unsigned long)-val;
1795                 } else {
1796                         *negp = 0;
1797                         *lvalp = (unsigned long)val;
1798                 }
1799         }
1800         return 0;
1801 }
1802
1803 /*
1804  *      init may raise the set.
1805  */
1806
1807 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1808                         void __user *buffer, size_t *lenp, loff_t *ppos)
1809 {
1810         int op;
1811
1812         if (write && !capable(CAP_SYS_MODULE)) {
1813                 return -EPERM;
1814         }
1815
1816         op = is_init(current) ? OP_SET : OP_AND;
1817         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1818                                 do_proc_dointvec_bset_conv,&op);
1819 }
1820
1821 /*
1822  *      Taint values can only be increased
1823  */
1824 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1825                                void __user *buffer, size_t *lenp, loff_t *ppos)
1826 {
1827         int op;
1828
1829         if (write && !capable(CAP_SYS_ADMIN))
1830                 return -EPERM;
1831
1832         op = OP_OR;
1833         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1834                                 do_proc_dointvec_bset_conv,&op);
1835 }
1836
1837 struct do_proc_dointvec_minmax_conv_param {
1838         int *min;
1839         int *max;
1840 };
1841
1842 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1843                                         int *valp,
1844                                         int write, void *data)
1845 {
1846         struct do_proc_dointvec_minmax_conv_param *param = data;
1847         if (write) {
1848                 int val = *negp ? -*lvalp : *lvalp;
1849                 if ((param->min && *param->min > val) ||
1850                     (param->max && *param->max < val))
1851                         return -EINVAL;
1852                 *valp = val;
1853         } else {
1854                 int val = *valp;
1855                 if (val < 0) {
1856                         *negp = -1;
1857                         *lvalp = (unsigned long)-val;
1858                 } else {
1859                         *negp = 0;
1860                         *lvalp = (unsigned long)val;
1861                 }
1862         }
1863         return 0;
1864 }
1865
1866 /**
1867  * proc_dointvec_minmax - read a vector of integers with min/max values
1868  * @table: the sysctl table
1869  * @write: %TRUE if this is a write to the sysctl file
1870  * @filp: the file structure
1871  * @buffer: the user buffer
1872  * @lenp: the size of the user buffer
1873  * @ppos: file position
1874  *
1875  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1876  * values from/to the user buffer, treated as an ASCII string.
1877  *
1878  * This routine will ensure the values are within the range specified by
1879  * table->extra1 (min) and table->extra2 (max).
1880  *
1881  * Returns 0 on success.
1882  */
1883 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1884                   void __user *buffer, size_t *lenp, loff_t *ppos)
1885 {
1886         struct do_proc_dointvec_minmax_conv_param param = {
1887                 .min = (int *) table->extra1,
1888                 .max = (int *) table->extra2,
1889         };
1890         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1891                                 do_proc_dointvec_minmax_conv, &param);
1892 }
1893
1894 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1895                                      struct file *filp,
1896                                      void __user *buffer,
1897                                      size_t *lenp, loff_t *ppos,
1898                                      unsigned long convmul,
1899                                      unsigned long convdiv)
1900 {
1901 #define TMPBUFLEN 21
1902         unsigned long *i, *min, *max, val;
1903         int vleft, first=1, neg;
1904         size_t len, left;
1905         char buf[TMPBUFLEN], *p;
1906         char __user *s = buffer;
1907
1908         if (!data || !table->maxlen || !*lenp ||
1909             (*ppos && !write)) {
1910                 *lenp = 0;
1911                 return 0;
1912         }
1913
1914         i = (unsigned long *) data;
1915         min = (unsigned long *) table->extra1;
1916         max = (unsigned long *) table->extra2;
1917         vleft = table->maxlen / sizeof(unsigned long);
1918         left = *lenp;
1919
1920         for (; left && vleft--; i++, min++, max++, first=0) {
1921                 if (write) {
1922                         while (left) {
1923                                 char c;
1924                                 if (get_user(c, s))
1925                                         return -EFAULT;
1926                                 if (!isspace(c))
1927                                         break;
1928                                 left--;
1929                                 s++;
1930                         }
1931                         if (!left)
1932                                 break;
1933                         neg = 0;
1934                         len = left;
1935                         if (len > TMPBUFLEN-1)
1936                                 len = TMPBUFLEN-1;
1937                         if (copy_from_user(buf, s, len))
1938                                 return -EFAULT;
1939                         buf[len] = 0;
1940                         p = buf;
1941                         if (*p == '-' && left > 1) {
1942                                 neg = 1;
1943                                 p++;
1944                         }
1945                         if (*p < '0' || *p > '9')
1946                                 break;
1947                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1948                         len = p-buf;
1949                         if ((len < left) && *p && !isspace(*p))
1950                                 break;
1951                         if (neg)
1952                                 val = -val;
1953                         s += len;
1954                         left -= len;
1955
1956                         if(neg)
1957                                 continue;
1958                         if ((min && val < *min) || (max && val > *max))
1959                                 continue;
1960                         *i = val;
1961                 } else {
1962                         p = buf;
1963                         if (!first)
1964                                 *p++ = '\t';
1965                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1966                         len = strlen(buf);
1967                         if (len > left)
1968                                 len = left;
1969                         if(copy_to_user(s, buf, len))
1970                                 return -EFAULT;
1971                         left -= len;
1972                         s += len;
1973                 }
1974         }
1975
1976         if (!write && !first && left) {
1977                 if(put_user('\n', s))
1978                         return -EFAULT;
1979                 left--, s++;
1980         }
1981         if (write) {
1982                 while (left) {
1983                         char c;
1984                         if (get_user(c, s++))
1985                                 return -EFAULT;
1986                         if (!isspace(c))
1987                                 break;
1988                         left--;
1989                 }
1990         }
1991         if (write && first)
1992                 return -EINVAL;
1993         *lenp -= left;
1994         *ppos += *lenp;
1995         return 0;
1996 #undef TMPBUFLEN
1997 }
1998
1999 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
2000                                      struct file *filp,
2001                                      void __user *buffer,
2002                                      size_t *lenp, loff_t *ppos,
2003                                      unsigned long convmul,
2004                                      unsigned long convdiv)
2005 {
2006         return __do_proc_doulongvec_minmax(table->data, table, write,
2007                         filp, buffer, lenp, ppos, convmul, convdiv);
2008 }
2009
2010 /**
2011  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2012  * @table: the sysctl table
2013  * @write: %TRUE if this is a write to the sysctl file
2014  * @filp: the file structure
2015  * @buffer: the user buffer
2016  * @lenp: the size of the user buffer
2017  * @ppos: file position
2018  *
2019  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2020  * values from/to the user buffer, treated as an ASCII string.
2021  *
2022  * This routine will ensure the values are within the range specified by
2023  * table->extra1 (min) and table->extra2 (max).
2024  *
2025  * Returns 0 on success.
2026  */
2027 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2028                            void __user *buffer, size_t *lenp, loff_t *ppos)
2029 {
2030     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2031 }
2032
2033 /**
2034  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2035  * @table: the sysctl table
2036  * @write: %TRUE if this is a write to the sysctl file
2037  * @filp: the file structure
2038  * @buffer: the user buffer
2039  * @lenp: the size of the user buffer
2040  * @ppos: file position
2041  *
2042  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2043  * values from/to the user buffer, treated as an ASCII string. The values
2044  * are treated as milliseconds, and converted to jiffies when they are stored.
2045  *
2046  * This routine will ensure the values are within the range specified by
2047  * table->extra1 (min) and table->extra2 (max).
2048  *
2049  * Returns 0 on success.
2050  */
2051 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2052                                       struct file *filp,
2053                                       void __user *buffer,
2054                                       size_t *lenp, loff_t *ppos)
2055 {
2056     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2057                                      lenp, ppos, HZ, 1000l);
2058 }
2059
2060
2061 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2062                                          int *valp,
2063                                          int write, void *data)
2064 {
2065         if (write) {
2066                 if (*lvalp > LONG_MAX / HZ)
2067                         return 1;
2068                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2069         } else {
2070                 int val = *valp;
2071                 unsigned long lval;
2072                 if (val < 0) {
2073                         *negp = -1;
2074                         lval = (unsigned long)-val;
2075                 } else {
2076                         *negp = 0;
2077                         lval = (unsigned long)val;
2078                 }
2079                 *lvalp = lval / HZ;
2080         }
2081         return 0;
2082 }
2083
2084 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2085                                                 int *valp,
2086                                                 int write, void *data)
2087 {
2088         if (write) {
2089                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2090                         return 1;
2091                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2092         } else {
2093                 int val = *valp;
2094                 unsigned long lval;
2095                 if (val < 0) {
2096                         *negp = -1;
2097                         lval = (unsigned long)-val;
2098                 } else {
2099                         *negp = 0;
2100                         lval = (unsigned long)val;
2101                 }
2102                 *lvalp = jiffies_to_clock_t(lval);
2103         }
2104         return 0;
2105 }
2106
2107 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2108                                             int *valp,
2109                                             int write, void *data)
2110 {
2111         if (write) {
2112                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2113         } else {
2114                 int val = *valp;
2115                 unsigned long lval;
2116                 if (val < 0) {
2117                         *negp = -1;
2118                         lval = (unsigned long)-val;
2119                 } else {
2120                         *negp = 0;
2121                         lval = (unsigned long)val;
2122                 }
2123                 *lvalp = jiffies_to_msecs(lval);
2124         }
2125         return 0;
2126 }
2127
2128 /**
2129  * proc_dointvec_jiffies - read a vector of integers as seconds
2130  * @table: the sysctl table
2131  * @write: %TRUE if this is a write to the sysctl file
2132  * @filp: the file structure
2133  * @buffer: the user buffer
2134  * @lenp: the size of the user buffer
2135  * @ppos: file position
2136  *
2137  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2138  * values from/to the user buffer, treated as an ASCII string.
2139  * The values read are assumed to be in seconds, and are converted into
2140  * jiffies.
2141  *
2142  * Returns 0 on success.
2143  */
2144 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2145                           void __user *buffer, size_t *lenp, loff_t *ppos)
2146 {
2147     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2148                             do_proc_dointvec_jiffies_conv,NULL);
2149 }
2150
2151 /**
2152  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2153  * @table: the sysctl table
2154  * @write: %TRUE if this is a write to the sysctl file
2155  * @filp: the file structure
2156  * @buffer: the user buffer
2157  * @lenp: the size of the user buffer
2158  * @ppos: pointer to the file position
2159  *
2160  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2161  * values from/to the user buffer, treated as an ASCII string.
2162  * The values read are assumed to be in 1/USER_HZ seconds, and
2163  * are converted into jiffies.
2164  *
2165  * Returns 0 on success.
2166  */
2167 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2168                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2169 {
2170     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2171                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2172 }
2173
2174 /**
2175  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2176  * @table: the sysctl table
2177  * @write: %TRUE if this is a write to the sysctl file
2178  * @filp: the file structure
2179  * @buffer: the user buffer
2180  * @lenp: the size of the user buffer
2181  * @ppos: file position
2182  * @ppos: the current position in the file
2183  *
2184  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2185  * values from/to the user buffer, treated as an ASCII string.
2186  * The values read are assumed to be in 1/1000 seconds, and
2187  * are converted into jiffies.
2188  *
2189  * Returns 0 on success.
2190  */
2191 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2192                              void __user *buffer, size_t *lenp, loff_t *ppos)
2193 {
2194         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2195                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2196 }
2197
2198 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2199                            void __user *buffer, size_t *lenp, loff_t *ppos)
2200 {
2201         struct pid *new_pid;
2202         pid_t tmp;
2203         int r;
2204
2205         tmp = pid_nr(cad_pid);
2206
2207         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2208                                lenp, ppos, NULL, NULL);
2209         if (r || !write)
2210                 return r;
2211
2212         new_pid = find_get_pid(tmp);
2213         if (!new_pid)
2214                 return -ESRCH;
2215
2216         put_pid(xchg(&cad_pid, new_pid));
2217         return 0;
2218 }
2219
2220 #else /* CONFIG_PROC_FS */
2221
2222 int proc_dostring(ctl_table *table, int write, struct file *filp,
2223                   void __user *buffer, size_t *lenp, loff_t *ppos)
2224 {
2225         return -ENOSYS;
2226 }
2227
2228 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2229                   void __user *buffer, size_t *lenp, loff_t *ppos)
2230 {
2231         return -ENOSYS;
2232 }
2233
2234 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2235                         void __user *buffer, size_t *lenp, loff_t *ppos)
2236 {
2237         return -ENOSYS;
2238 }
2239
2240 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2241                     void __user *buffer, size_t *lenp, loff_t *ppos)
2242 {
2243         return -ENOSYS;
2244 }
2245
2246 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2247                     void __user *buffer, size_t *lenp, loff_t *ppos)
2248 {
2249         return -ENOSYS;
2250 }
2251
2252 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2253                     void __user *buffer, size_t *lenp, loff_t *ppos)
2254 {
2255         return -ENOSYS;
2256 }
2257
2258 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2259                              void __user *buffer, size_t *lenp, loff_t *ppos)
2260 {
2261         return -ENOSYS;
2262 }
2263
2264 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2265                     void __user *buffer, size_t *lenp, loff_t *ppos)
2266 {
2267         return -ENOSYS;
2268 }
2269
2270 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2271                                       struct file *filp,
2272                                       void __user *buffer,
2273                                       size_t *lenp, loff_t *ppos)
2274 {
2275     return -ENOSYS;
2276 }
2277
2278
2279 #endif /* CONFIG_PROC_FS */
2280
2281
2282 #ifdef CONFIG_SYSCTL_SYSCALL
2283 /*
2284  * General sysctl support routines
2285  */
2286
2287 /* The generic string strategy routine: */
2288 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2289                   void __user *oldval, size_t __user *oldlenp,
2290                   void __user *newval, size_t newlen)
2291 {
2292         if (!table->data || !table->maxlen)
2293                 return -ENOTDIR;
2294
2295         if (oldval && oldlenp) {
2296                 size_t bufsize;
2297                 if (get_user(bufsize, oldlenp))
2298                         return -EFAULT;
2299                 if (bufsize) {
2300                         size_t len = strlen(table->data), copied;
2301
2302                         /* This shouldn't trigger for a well-formed sysctl */
2303                         if (len > table->maxlen)
2304                                 len = table->maxlen;
2305
2306                         /* Copy up to a max of bufsize-1 bytes of the string */
2307                         copied = (len >= bufsize) ? bufsize - 1 : len;
2308
2309                         if (copy_to_user(oldval, table->data, copied) ||
2310                             put_user(0, (char __user *)(oldval + copied)))
2311                                 return -EFAULT;
2312                         if (put_user(len, oldlenp))
2313                                 return -EFAULT;
2314                 }
2315         }
2316         if (newval && newlen) {
2317                 size_t len = newlen;
2318                 if (len > table->maxlen)
2319                         len = table->maxlen;
2320                 if(copy_from_user(table->data, newval, len))
2321                         return -EFAULT;
2322                 if (len == table->maxlen)
2323                         len--;
2324                 ((char *) table->data)[len] = 0;
2325         }
2326         return 1;
2327 }
2328
2329 /*
2330  * This function makes sure that all of the integers in the vector
2331  * are between the minimum and maximum values given in the arrays
2332  * table->extra1 and table->extra2, respectively.
2333  */
2334 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2335                 void __user *oldval, size_t __user *oldlenp,
2336                 void __user *newval, size_t newlen)
2337 {
2338
2339         if (newval && newlen) {
2340                 int __user *vec = (int __user *) newval;
2341                 int *min = (int *) table->extra1;
2342                 int *max = (int *) table->extra2;
2343                 size_t length;
2344                 int i;
2345
2346                 if (newlen % sizeof(int) != 0)
2347                         return -EINVAL;
2348
2349                 if (!table->extra1 && !table->extra2)
2350                         return 0;
2351
2352                 if (newlen > table->maxlen)
2353                         newlen = table->maxlen;
2354                 length = newlen / sizeof(int);
2355
2356                 for (i = 0; i < length; i++) {
2357                         int value;
2358                         if (get_user(value, vec + i))
2359                                 return -EFAULT;
2360                         if (min && value < min[i])
2361                                 return -EINVAL;
2362                         if (max && value > max[i])
2363                                 return -EINVAL;
2364                 }
2365         }
2366         return 0;
2367 }
2368
2369 /* Strategy function to convert jiffies to seconds */
2370 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2371                 void __user *oldval, size_t __user *oldlenp,
2372                 void __user *newval, size_t newlen)
2373 {
2374         if (oldval && oldlenp) {
2375                 size_t olen;
2376
2377                 if (get_user(olen, oldlenp))
2378                         return -EFAULT;
2379                 if (olen) {
2380                         int val;
2381
2382                         if (olen < sizeof(int))
2383                                 return -EINVAL;
2384
2385                         val = *(int *)(table->data) / HZ;
2386                         if (put_user(val, (int __user *)oldval))
2387                                 return -EFAULT;
2388                         if (put_user(sizeof(int), oldlenp))
2389                                 return -EFAULT;
2390                 }
2391         }
2392         if (newval && newlen) {
2393                 int new;
2394                 if (newlen != sizeof(int))
2395                         return -EINVAL;
2396                 if (get_user(new, (int __user *)newval))
2397                         return -EFAULT;
2398                 *(int *)(table->data) = new*HZ;
2399         }
2400         return 1;
2401 }
2402
2403 /* Strategy function to convert jiffies to seconds */
2404 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2405                 void __user *oldval, size_t __user *oldlenp,
2406                 void __user *newval, size_t newlen)
2407 {
2408         if (oldval && oldlenp) {
2409                 size_t olen;
2410
2411                 if (get_user(olen, oldlenp))
2412                         return -EFAULT;
2413                 if (olen) {
2414                         int val;
2415
2416                         if (olen < sizeof(int))
2417                                 return -EINVAL;
2418
2419                         val = jiffies_to_msecs(*(int *)(table->data));
2420                         if (put_user(val, (int __user *)oldval))
2421                                 return -EFAULT;
2422                         if (put_user(sizeof(int), oldlenp))
2423                                 return -EFAULT;
2424                 }
2425         }
2426         if (newval && newlen) {
2427                 int new;
2428                 if (newlen != sizeof(int))
2429                         return -EINVAL;
2430                 if (get_user(new, (int __user *)newval))
2431                         return -EFAULT;
2432                 *(int *)(table->data) = msecs_to_jiffies(new);
2433         }
2434         return 1;
2435 }
2436
2437
2438
2439 #else /* CONFIG_SYSCTL_SYSCALL */
2440
2441
2442 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2443 {
2444         static int msg_count;
2445         struct __sysctl_args tmp;
2446         int name[CTL_MAXNAME];
2447         int i;
2448
2449         /* Read in the sysctl name for better debug message logging */
2450         if (copy_from_user(&tmp, args, sizeof(tmp)))
2451                 return -EFAULT;
2452         if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2453                 return -ENOTDIR;
2454         for (i = 0; i < tmp.nlen; i++)
2455                 if (get_user(name[i], tmp.name + i))
2456                         return -EFAULT;
2457
2458         /* Ignore accesses to kernel.version */
2459         if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2460                 goto out;
2461
2462         if (msg_count < 5) {
2463                 msg_count++;
2464                 printk(KERN_INFO
2465                         "warning: process `%s' used the removed sysctl "
2466                         "system call with ", current->comm);
2467                 for (i = 0; i < tmp.nlen; i++)
2468                         printk("%d.", name[i]);
2469                 printk("\n");
2470         }
2471 out:
2472         return -ENOSYS;
2473 }
2474
2475 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2476                   void __user *oldval, size_t __user *oldlenp,
2477                   void __user *newval, size_t newlen)
2478 {
2479         return -ENOSYS;
2480 }
2481
2482 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2483                 void __user *oldval, size_t __user *oldlenp,
2484                 void __user *newval, size_t newlen)
2485 {
2486         return -ENOSYS;
2487 }
2488
2489 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2490                 void __user *oldval, size_t __user *oldlenp,
2491                 void __user *newval, size_t newlen)
2492 {
2493         return -ENOSYS;
2494 }
2495
2496 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2497                 void __user *oldval, size_t __user *oldlenp,
2498                 void __user *newval, size_t newlen)
2499 {
2500         return -ENOSYS;
2501 }
2502
2503 #endif /* CONFIG_SYSCTL_SYSCALL */
2504
2505 /*
2506  * No sense putting this after each symbol definition, twice,
2507  * exception granted :-)
2508  */
2509 EXPORT_SYMBOL(proc_dointvec);
2510 EXPORT_SYMBOL(proc_dointvec_jiffies);
2511 EXPORT_SYMBOL(proc_dointvec_minmax);
2512 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2513 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2514 EXPORT_SYMBOL(proc_dostring);
2515 EXPORT_SYMBOL(proc_doulongvec_minmax);
2516 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2517 EXPORT_SYMBOL(register_sysctl_table);
2518 EXPORT_SYMBOL(sysctl_intvec);
2519 EXPORT_SYMBOL(sysctl_jiffies);
2520 EXPORT_SYMBOL(sysctl_ms_jiffies);
2521 EXPORT_SYMBOL(sysctl_string);
2522 EXPORT_SYMBOL(unregister_sysctl_table);