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