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) && defined(CONFIG_SMP)
 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 #ifdef CONFIG_NUMA
 874         {
 875                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 876                 .procname       = "zone_reclaim_mode",
 877                 .data           = &zone_reclaim_mode,
 878                 .maxlen         = sizeof(zone_reclaim_mode),
 879                 .mode           = 0644,
 880                 .proc_handler   = &proc_dointvec,
 881                 .strategy       = &zero,
 882         },
 883 #endif
 884         { .ctl_name = 0 }
 885 };
 886
 887 static ctl_table proc_table[] = {
 888         { .ctl_name = 0 }
 889 };
 890
 891 static ctl_table fs_table[] = {
 892         {
 893                 .ctl_name       = FS_NRINODE,
 894                 .procname       = "inode-nr",
 895                 .data           = &inodes_stat,
 896                 .maxlen         = 2*sizeof(int),
 897                 .mode           = 0444,
 898                 .proc_handler   = &proc_dointvec,
 899         },
 900         {
 901                 .ctl_name       = FS_STATINODE,
 902                 .procname       = "inode-state",
 903                 .data           = &inodes_stat,
 904                 .maxlen         = 7*sizeof(int),
 905                 .mode           = 0444,
 906                 .proc_handler   = &proc_dointvec,
 907         },
 908         {
 909                 .ctl_name       = FS_NRFILE,
 910                 .procname       = "file-nr",
 911                 .data           = &files_stat,
 912                 .maxlen         = 3*sizeof(int),
 913                 .mode           = 0444,
 914                 .proc_handler   = &proc_dointvec,
 915         },
 916         {
 917                 .ctl_name       = FS_MAXFILE,
 918                 .procname       = "file-max",
 919                 .data           = &files_stat.max_files,
 920                 .maxlen         = sizeof(int),
 921                 .mode           = 0644,
 922                 .proc_handler   = &proc_dointvec,
 923         },
 924         {
 925                 .ctl_name       = FS_DENTRY,
 926                 .procname       = "dentry-state",
 927                 .data           = &dentry_stat,
 928                 .maxlen         = 6*sizeof(int),
 929                 .mode           = 0444,
 930                 .proc_handler   = &proc_dointvec,
 931         },
 932         {
 933                 .ctl_name       = FS_OVERFLOWUID,
 934                 .procname       = "overflowuid",
 935                 .data           = &fs_overflowuid,
 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_OVERFLOWGID,
 945                 .procname       = "overflowgid",
 946                 .data           = &fs_overflowgid,
 947                 .maxlen         = sizeof(int),
 948                 .mode           = 0644,
 949                 .proc_handler   = &proc_dointvec_minmax,
 950                 .strategy       = &sysctl_intvec,
 951                 .extra1         = &minolduid,
 952                 .extra2         = &maxolduid,
 953         },
 954         {
 955                 .ctl_name       = FS_LEASES,
 956                 .procname       = "leases-enable",
 957                 .data           = &leases_enable,
 958                 .maxlen         = sizeof(int),
 959                 .mode           = 0644,
 960                 .proc_handler   = &proc_dointvec,
 961         },
 962 #ifdef CONFIG_DNOTIFY
 963         {
 964                 .ctl_name       = FS_DIR_NOTIFY,
 965                 .procname       = "dir-notify-enable",
 966                 .data           = &dir_notify_enable,
 967                 .maxlen         = sizeof(int),
 968                 .mode           = 0644,
 969                 .proc_handler   = &proc_dointvec,
 970         },
 971 #endif
 972 #ifdef CONFIG_MMU
 973         {
 974                 .ctl_name       = FS_LEASE_TIME,
 975                 .procname       = "lease-break-time",
 976                 .data           = &lease_break_time,
 977                 .maxlen         = sizeof(int),
 978                 .mode           = 0644,
 979                 .proc_handler   = &proc_dointvec,
 980         },
 981         {
 982                 .ctl_name       = FS_AIO_NR,
 983                 .procname       = "aio-nr",
 984                 .data           = &aio_nr,
 985                 .maxlen         = sizeof(aio_nr),
 986                 .mode           = 0444,
 987                 .proc_handler   = &proc_doulongvec_minmax,
 988         },
 989         {
 990                 .ctl_name       = FS_AIO_MAX_NR,
 991                 .procname       = "aio-max-nr",
 992                 .data           = &aio_max_nr,
 993                 .maxlen         = sizeof(aio_max_nr),
 994                 .mode           = 0644,
 995                 .proc_handler   = &proc_doulongvec_minmax,
 996         },
 997 #ifdef CONFIG_INOTIFY
 998         {
 999                 .ctl_name       = FS_INOTIFY,
1000                 .procname       = "inotify",
1001                 .mode           = 0555,
1002                 .child          = inotify_table,
1003         },
1004 #endif
1005 #endif
1006         {
1007                 .ctl_name       = KERN_SETUID_DUMPABLE,
1008                 .procname       = "suid_dumpable",
1009                 .data           = &suid_dumpable,
1010                 .maxlen         = sizeof(int),
1011                 .mode           = 0644,
1012                 .proc_handler   = &proc_dointvec,
1013         },
1014         { .ctl_name = 0 }
1015 };
1016
1017 static ctl_table debug_table[] = {
1018         { .ctl_name = 0 }
1019 };
1020
1021 static ctl_table dev_table[] = {
1022         { .ctl_name = 0 }
1023 };
1024
1025 extern void init_irq_proc (void);
1026
1027 static DEFINE_SPINLOCK(sysctl_lock);
1028
1029 /* called under sysctl_lock */
1030 static int use_table(struct ctl_table_header *p)
1031 {
1032         if (unlikely(p->unregistering))
1033                 return 0;
1034         p->used++;
1035         return 1;
1036 }
1037
1038 /* called under sysctl_lock */
1039 static void unuse_table(struct ctl_table_header *p)
1040 {
1041         if (!--p->used)
1042                 if (unlikely(p->unregistering))
1043                         complete(p->unregistering);
1044 }
1045
1046 /* called under sysctl_lock, will reacquire if has to wait */
1047 static void start_unregistering(struct ctl_table_header *p)
1048 {
1049         /*
1050          * if p->used is 0, nobody will ever touch that entry again;
1051          * we'll eliminate all paths to it before dropping sysctl_lock
1052          */
1053         if (unlikely(p->used)) {
1054                 struct completion wait;
1055                 init_completion(&wait);
1056                 p->unregistering = &wait;
1057                 spin_unlock(&sysctl_lock);
1058                 wait_for_completion(&wait);
1059                 spin_lock(&sysctl_lock);
1060         }
1061         /*
1062          * do not remove from the list until nobody holds it; walking the
1063          * list in do_sysctl() relies on that.
1064          */
1065         list_del_init(&p->ctl_entry);
1066 }
1067
1068 void __init sysctl_init(void)
1069 {
1070 #ifdef CONFIG_PROC_FS
1071         register_proc_table(root_table, proc_sys_root, &root_table_header);
1072         init_irq_proc();
1073 #endif
1074 }
1075
1076 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1077                void __user *newval, size_t newlen)
1078 {
1079         struct list_head *tmp;
1080         int error = -ENOTDIR;
1081
1082         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1083                 return -ENOTDIR;
1084         if (oldval) {
1085                 int old_len;
1086                 if (!oldlenp || get_user(old_len, oldlenp))
1087                         return -EFAULT;
1088         }
1089         spin_lock(&sysctl_lock);
1090         tmp = &root_table_header.ctl_entry;
1091         do {
1092                 struct ctl_table_header *head =
1093                         list_entry(tmp, struct ctl_table_header, ctl_entry);
1094                 void *context = NULL;
1095
1096                 if (!use_table(head))
1097                         continue;
1098
1099                 spin_unlock(&sysctl_lock);
1100
1101                 error = parse_table(name, nlen, oldval, oldlenp,
1102                                         newval, newlen, head->ctl_table,
1103                                         &context);
1104                 kfree(context);
1105
1106                 spin_lock(&sysctl_lock);
1107                 unuse_table(head);
1108                 if (error != -ENOTDIR)
1109                         break;
1110         } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
1111         spin_unlock(&sysctl_lock);
1112         return error;
1113 }
1114
1115 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1116 {
1117         struct __sysctl_args tmp;
1118         int error;
1119
1120         if (copy_from_user(&tmp, args, sizeof(tmp)))
1121                 return -EFAULT;
1122
1123         lock_kernel();
1124         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1125                           tmp.newval, tmp.newlen);
1126         unlock_kernel();
1127         return error;
1128 }
1129
1130 /*
1131  * ctl_perm does NOT grant the superuser all rights automatically, because
1132  * some sysctl variables are readonly even to root.
1133  */
1134
1135 static int test_perm(int mode, int op)
1136 {
1137         if (!current->euid)
1138                 mode >>= 6;
1139         else if (in_egroup_p(0))
1140                 mode >>= 3;
1141         if ((mode & op & 0007) == op)
1142                 return 0;
1143         return -EACCES;
1144 }
1145
1146 static inline int ctl_perm(ctl_table *table, int op)
1147 {
1148         int error;
1149         error = security_sysctl(table, op);
1150         if (error)
1151                 return error;
1152         return test_perm(table->mode, op);
1153 }
1154
1155 static int parse_table(int __user *name, int nlen,
1156                        void __user *oldval, size_t __user *oldlenp,
1157                        void __user *newval, size_t newlen,
1158                        ctl_table *table, void **context)
1159 {
1160         int n;
1161 repeat:
1162         if (!nlen)
1163                 return -ENOTDIR;
1164         if (get_user(n, name))
1165                 return -EFAULT;
1166         for ( ; table->ctl_name; table++) {
1167                 if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
1168                         int error;
1169                         if (table->child) {
1170                                 if (ctl_perm(table, 001))
1171                                         return -EPERM;
1172                                 if (table->strategy) {
1173                                         error = table->strategy(
1174                                                 table, name, nlen,
1175                                                 oldval, oldlenp,
1176                                                 newval, newlen, context);
1177                                         if (error)
1178                                                 return error;
1179                                 }
1180                                 name++;
1181                                 nlen--;
1182                                 table = table->child;
1183                                 goto repeat;
1184                         }
1185                         error = do_sysctl_strategy(table, name, nlen,
1186                                                    oldval, oldlenp,
1187                                                    newval, newlen, context);
1188                         return error;
1189                 }
1190         }
1191         return -ENOTDIR;
1192 }
1193
1194 /* Perform the actual read/write of a sysctl table entry. */
1195 int do_sysctl_strategy (ctl_table *table,
1196                         int __user *name, int nlen,
1197                         void __user *oldval, size_t __user *oldlenp,
1198                         void __user *newval, size_t newlen, void **context)
1199 {
1200         int op = 0, rc;
1201         size_t len;
1202
1203         if (oldval)
1204                 op |= 004;
1205         if (newval)
1206                 op |= 002;
1207         if (ctl_perm(table, op))
1208                 return -EPERM;
1209
1210         if (table->strategy) {
1211                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1212                                      newval, newlen, context);
1213                 if (rc < 0)
1214                         return rc;
1215                 if (rc > 0)
1216                         return 0;
1217         }
1218
1219         /* If there is no strategy routine, or if the strategy returns
1220          * zero, proceed with automatic r/w */
1221         if (table->data && table->maxlen) {
1222                 if (oldval && oldlenp) {
1223                         if (get_user(len, oldlenp))
1224                                 return -EFAULT;
1225                         if (len) {
1226                                 if (len > table->maxlen)
1227                                         len = table->maxlen;
1228                                 if(copy_to_user(oldval, table->data, len))
1229                                         return -EFAULT;
1230                                 if(put_user(len, oldlenp))
1231                                         return -EFAULT;
1232                         }
1233                 }
1234                 if (newval && newlen) {
1235                         len = newlen;
1236                         if (len > table->maxlen)
1237                                 len = table->maxlen;
1238                         if(copy_from_user(table->data, newval, len))
1239                                 return -EFAULT;
1240                 }
1241         }
1242         return 0;
1243 }
1244
1245 /**
1246  * register_sysctl_table - register a sysctl hierarchy
1247  * @table: the top-level table structure
1248  * @insert_at_head: whether the entry should be inserted in front or at the end
1249  *
1250  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1251  * array. An entry with a ctl_name of 0 terminates the table.
1252  *
1253  * The members of the &ctl_table structure are used as follows:
1254  *
1255  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1256  *            must be unique within that level of sysctl
1257  *
1258  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1259  *            enter a sysctl file
1260  *
1261  * data - a pointer to data for use by proc_handler
1262  *
1263  * maxlen - the maximum size in bytes of the data
1264  *
1265  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1266  *
1267  * child - a pointer to the child sysctl table if this entry is a directory, or
1268  *         %NULL.
1269  *
1270  * proc_handler - the text handler routine (described below)
1271  *
1272  * strategy - the strategy routine (described below)
1273  *
1274  * de - for internal use by the sysctl routines
1275  *
1276  * extra1, extra2 - extra pointers usable by the proc handler routines
1277  *
1278  * Leaf nodes in the sysctl tree will be represented by a single file
1279  * under /proc; non-leaf nodes will be represented by directories.
1280  *
1281  * sysctl(2) can automatically manage read and write requests through
1282  * the sysctl table.  The data and maxlen fields of the ctl_table
1283  * struct enable minimal validation of the values being written to be
1284  * performed, and the mode field allows minimal authentication.
1285  *
1286  * More sophisticated management can be enabled by the provision of a
1287  * strategy routine with the table entry.  This will be called before
1288  * any automatic read or write of the data is performed.
1289  *
1290  * The strategy routine may return
1291  *
1292  * < 0 - Error occurred (error is passed to user process)
1293  *
1294  * 0   - OK - proceed with automatic read or write.
1295  *
1296  * > 0 - OK - read or write has been done by the strategy routine, so
1297  *       return immediately.
1298  *
1299  * There must be a proc_handler routine for any terminal nodes
1300  * mirrored under /proc/sys (non-terminals are handled by a built-in
1301  * directory handler).  Several default handlers are available to
1302  * cover common cases -
1303  *
1304  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1305  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1306  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1307  *
1308  * It is the handler's job to read the input buffer from user memory
1309  * and process it. The handler should return 0 on success.
1310  *
1311  * This routine returns %NULL on a failure to register, and a pointer
1312  * to the table header on success.
1313  */
1314 struct ctl_table_header *register_sysctl_table(ctl_table * table,
1315                                                int insert_at_head)
1316 {
1317         struct ctl_table_header *tmp;
1318         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1319         if (!tmp)
1320                 return NULL;
1321         tmp->ctl_table = table;
1322         INIT_LIST_HEAD(&tmp->ctl_entry);
1323         tmp->used = 0;
1324         tmp->unregistering = NULL;
1325         spin_lock(&sysctl_lock);
1326         if (insert_at_head)
1327                 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
1328         else
1329                 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1330         spin_unlock(&sysctl_lock);
1331 #ifdef CONFIG_PROC_FS
1332         register_proc_table(table, proc_sys_root, tmp);
1333 #endif
1334         return tmp;
1335 }
1336
1337 /**
1338  * unregister_sysctl_table - unregister a sysctl table hierarchy
1339  * @header: the header returned from register_sysctl_table
1340  *
1341  * Unregisters the sysctl table and all children. proc entries may not
1342  * actually be removed until they are no longer used by anyone.
1343  */
1344 void unregister_sysctl_table(struct ctl_table_header * header)
1345 {
1346         might_sleep();
1347         spin_lock(&sysctl_lock);
1348         start_unregistering(header);
1349 #ifdef CONFIG_PROC_FS
1350         unregister_proc_table(header->ctl_table, proc_sys_root);
1351 #endif
1352         spin_unlock(&sysctl_lock);
1353         kfree(header);
1354 }
1355
1356 /*
1357  * /proc/sys support
1358  */
1359
1360 #ifdef CONFIG_PROC_FS
1361
1362 /* Scan the sysctl entries in table and add them all into /proc */
1363 static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
1364 {
1365         struct proc_dir_entry *de;
1366         int len;
1367         mode_t mode;
1368
1369         for (; table->ctl_name; table++) {
1370                 /* Can't do anything without a proc name. */
1371                 if (!table->procname)
1372                         continue;
1373                 /* Maybe we can't do anything with it... */
1374                 if (!table->proc_handler && !table->child) {
1375                         printk(KERN_WARNING "SYSCTL: Can't register %s\n",
1376                                 table->procname);
1377                         continue;
1378                 }
1379
1380                 len = strlen(table->procname);
1381                 mode = table->mode;
1382
1383                 de = NULL;
1384                 if (table->proc_handler)
1385                         mode |= S_IFREG;
1386                 else {
1387                         mode |= S_IFDIR;
1388                         for (de = root->subdir; de; de = de->next) {
1389                                 if (proc_match(len, table->procname, de))
1390                                         break;
1391                         }
1392                         /* If the subdir exists already, de is non-NULL */
1393                 }
1394
1395                 if (!de) {
1396                         de = create_proc_entry(table->procname, mode, root);
1397                         if (!de)
1398                                 continue;
1399                         de->set = set;
1400                         de->data = (void *) table;
1401                         if (table->proc_handler)
1402                                 de->proc_fops = &proc_sys_file_operations;
1403                 }
1404                 table->de = de;
1405                 if (de->mode & S_IFDIR)
1406                         register_proc_table(table->child, de, set);
1407         }
1408 }
1409
1410 /*
1411  * Unregister a /proc sysctl table and any subdirectories.
1412  */
1413 static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
1414 {
1415         struct proc_dir_entry *de;
1416         for (; table->ctl_name; table++) {
1417                 if (!(de = table->de))
1418                         continue;
1419                 if (de->mode & S_IFDIR) {
1420                         if (!table->child) {
1421                                 printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
1422                                 continue;
1423                         }
1424                         unregister_proc_table(table->child, de);
1425
1426                         /* Don't unregister directories which still have entries.. */
1427                         if (de->subdir)
1428                                 continue;
1429                 }
1430
1431                 /*
1432                  * In any case, mark the entry as goner; we'll keep it
1433                  * around if it's busy, but we'll know to do nothing with
1434                  * its fields.  We are under sysctl_lock here.
1435                  */
1436                 de->data = NULL;
1437
1438                 /* Don't unregister proc entries that are still being used.. */
1439                 if (atomic_read(&de->count))
1440                         continue;
1441
1442                 table->de = NULL;
1443                 remove_proc_entry(table->procname, root);
1444         }
1445 }
1446
1447 static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
1448                           size_t count, loff_t *ppos)
1449 {
1450         int op;
1451         struct proc_dir_entry *de = PDE(file->f_dentry->d_inode);
1452         struct ctl_table *table;
1453         size_t res;
1454         ssize_t error = -ENOTDIR;
1455
1456         spin_lock(&sysctl_lock);
1457         if (de && de->data && use_table(de->set)) {
1458                 /*
1459                  * at that point we know that sysctl was not unregistered
1460                  * and won't be until we finish
1461                  */
1462                 spin_unlock(&sysctl_lock);
1463                 table = (struct ctl_table *) de->data;
1464                 if (!table || !table->proc_handler)
1465                         goto out;
1466                 error = -EPERM;
1467                 op = (write ? 002 : 004);
1468                 if (ctl_perm(table, op))
1469                         goto out;
1470
1471                 /* careful: calling conventions are nasty here */
1472                 res = count;
1473                 error = (*table->proc_handler)(table, write, file,
1474                                                 buf, &res, ppos);
1475                 if (!error)
1476                         error = res;
1477         out:
1478                 spin_lock(&sysctl_lock);
1479                 unuse_table(de->set);
1480         }
1481         spin_unlock(&sysctl_lock);
1482         return error;
1483 }
1484
1485 static int proc_opensys(struct inode *inode, struct file *file)
1486 {
1487         if (file->f_mode & FMODE_WRITE) {
1488                 /*
1489                  * sysctl entries that are not writable,
1490                  * are _NOT_ writable, capabilities or not.
1491                  */
1492                 if (!(inode->i_mode & S_IWUSR))
1493                         return -EPERM;
1494         }
1495
1496         return 0;
1497 }
1498
1499 static ssize_t proc_readsys(struct file * file, char __user * buf,
1500                             size_t count, loff_t *ppos)
1501 {
1502         return do_rw_proc(0, file, buf, count, ppos);
1503 }
1504
1505 static ssize_t proc_writesys(struct file * file, const char __user * buf,
1506                              size_t count, loff_t *ppos)
1507 {
1508         return do_rw_proc(1, file, (char __user *) buf, count, ppos);
1509 }
1510
1511 /**
1512  * proc_dostring - read a string sysctl
1513  * @table: the sysctl table
1514  * @write: %TRUE if this is a write to the sysctl file
1515  * @filp: the file structure
1516  * @buffer: the user buffer
1517  * @lenp: the size of the user buffer
1518  * @ppos: file position
1519  *
1520  * Reads/writes a string from/to the user buffer. If the kernel
1521  * buffer provided is not large enough to hold the string, the
1522  * string is truncated. The copied string is %NULL-terminated.
1523  * If the string is being read by the user process, it is copied
1524  * and a newline '\n' is added. It is truncated if the buffer is
1525  * not large enough.
1526  *
1527  * Returns 0 on success.
1528  */
1529 int proc_dostring(ctl_table *table, int write, struct file *filp,
1530                   void __user *buffer, size_t *lenp, loff_t *ppos)
1531 {
1532         size_t len;
1533         char __user *p;
1534         char c;
1535
1536         if (!table->data || !table->maxlen || !*lenp ||
1537             (*ppos && !write)) {
1538                 *lenp = 0;
1539                 return 0;
1540         }
1541
1542         if (write) {
1543                 len = 0;
1544                 p = buffer;
1545                 while (len < *lenp) {
1546                         if (get_user(c, p++))
1547                                 return -EFAULT;
1548                         if (c == 0 || c == '\n')
1549                                 break;
1550                         len++;
1551                 }
1552                 if (len >= table->maxlen)
1553                         len = table->maxlen-1;
1554                 if(copy_from_user(table->data, buffer, len))
1555                         return -EFAULT;
1556                 ((char *) table->data)[len] = 0;
1557                 *ppos += *lenp;
1558         } else {
1559                 len = strlen(table->data);
1560                 if (len > table->maxlen)
1561                         len = table->maxlen;
1562                 if (len > *lenp)
1563                         len = *lenp;
1564                 if (len)
1565                         if(copy_to_user(buffer, table->data, len))
1566                                 return -EFAULT;
1567                 if (len < *lenp) {
1568                         if(put_user('\n', ((char __user *) buffer) + len))
1569                                 return -EFAULT;
1570                         len++;
1571                 }
1572                 *lenp = len;
1573                 *ppos += len;
1574         }
1575         return 0;
1576 }
1577
1578 /*
1579  *      Special case of dostring for the UTS structure. This has locks
1580  *      to observe. Should this be in kernel/sys.c ????
1581  */
1582
1583 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
1584                   void __user *buffer, size_t *lenp, loff_t *ppos)
1585 {
1586         int r;
1587
1588         if (!write) {
1589                 down_read(&uts_sem);
1590                 r=proc_dostring(table,0,filp,buffer,lenp, ppos);
1591                 up_read(&uts_sem);
1592         } else {
1593                 down_write(&uts_sem);
1594                 r=proc_dostring(table,1,filp,buffer,lenp, ppos);
1595                 up_write(&uts_sem);
1596         }
1597         return r;
1598 }
1599
1600 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1601                                  int *valp,
1602                                  int write, void *data)
1603 {
1604         if (write) {
1605                 *valp = *negp ? -*lvalp : *lvalp;
1606         } else {
1607                 int val = *valp;
1608                 if (val < 0) {
1609                         *negp = -1;
1610                         *lvalp = (unsigned long)-val;
1611                 } else {
1612                         *negp = 0;
1613                         *lvalp = (unsigned long)val;
1614                 }
1615         }
1616         return 0;
1617 }
1618
1619 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1620                   void __user *buffer, size_t *lenp, loff_t *ppos,
1621                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1622                               int write, void *data),
1623                   void *data)
1624 {
1625 #define TMPBUFLEN 21
1626         int *i, vleft, first=1, neg, val;
1627         unsigned long lval;
1628         size_t left, len;
1629
1630         char buf[TMPBUFLEN], *p;
1631         char __user *s = buffer;
1632
1633         if (!table->data || !table->maxlen || !*lenp ||
1634             (*ppos && !write)) {
1635                 *lenp = 0;
1636                 return 0;
1637         }
1638
1639         i = (int *) table->data;
1640         vleft = table->maxlen / sizeof(*i);
1641         left = *lenp;
1642
1643         if (!conv)
1644                 conv = do_proc_dointvec_conv;
1645
1646         for (; left && vleft--; i++, first=0) {
1647                 if (write) {
1648                         while (left) {
1649                                 char c;
1650                                 if (get_user(c, s))
1651                                         return -EFAULT;
1652                                 if (!isspace(c))
1653                                         break;
1654                                 left--;
1655                                 s++;
1656                         }
1657                         if (!left)
1658                                 break;
1659                         neg = 0;
1660                         len = left;
1661                         if (len > sizeof(buf) - 1)
1662                                 len = sizeof(buf) - 1;
1663                         if (copy_from_user(buf, s, len))
1664                                 return -EFAULT;
1665                         buf[len] = 0;
1666                         p = buf;
1667                         if (*p == '-' && left > 1) {
1668                                 neg = 1;
1669                                 left--, p++;
1670                         }
1671                         if (*p < '0' || *p > '9')
1672                                 break;
1673
1674                         lval = simple_strtoul(p, &p, 0);
1675
1676                         len = p-buf;
1677                         if ((len < left) && *p && !isspace(*p))
1678                                 break;
1679                         if (neg)
1680                                 val = -val;
1681                         s += len;
1682                         left -= len;
1683
1684                         if (conv(&neg, &lval, i, 1, data))
1685                                 break;
1686                 } else {
1687                         p = buf;
1688                         if (!first)
1689                                 *p++ = '\t';
1690
1691                         if (conv(&neg, &lval, i, 0, data))
1692                                 break;
1693
1694                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1695                         len = strlen(buf);
1696                         if (len > left)
1697                                 len = left;
1698                         if(copy_to_user(s, buf, len))
1699                                 return -EFAULT;
1700                         left -= len;
1701                         s += len;
1702                 }
1703         }
1704
1705         if (!write && !first && left) {
1706                 if(put_user('\n', s))
1707                         return -EFAULT;
1708                 left--, s++;
1709         }
1710         if (write) {
1711                 while (left) {
1712                         char c;
1713                         if (get_user(c, s++))
1714                                 return -EFAULT;
1715                         if (!isspace(c))
1716                                 break;
1717                         left--;
1718                 }
1719         }
1720         if (write && first)
1721                 return -EINVAL;
1722         *lenp -= left;
1723         *ppos += *lenp;
1724         return 0;
1725 #undef TMPBUFLEN
1726 }
1727
1728 /**
1729  * proc_dointvec - read a vector of integers
1730  * @table: the sysctl table
1731  * @write: %TRUE if this is a write to the sysctl file
1732  * @filp: the file structure
1733  * @buffer: the user buffer
1734  * @lenp: the size of the user buffer
1735  * @ppos: file position
1736  *
1737  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1738  * values from/to the user buffer, treated as an ASCII string.
1739  *
1740  * Returns 0 on success.
1741  */
1742 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1743                      void __user *buffer, size_t *lenp, loff_t *ppos)
1744 {
1745     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1746                             NULL,NULL);
1747 }
1748
1749 #define OP_SET  0
1750 #define OP_AND  1
1751 #define OP_OR   2
1752 #define OP_MAX  3
1753 #define OP_MIN  4
1754
1755 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1756                                       int *valp,
1757                                       int write, void *data)
1758 {
1759         int op = *(int *)data;
1760         if (write) {
1761                 int val = *negp ? -*lvalp : *lvalp;
1762                 switch(op) {
1763                 case OP_SET:    *valp = val; break;
1764                 case OP_AND:    *valp &= val; break;
1765                 case OP_OR:     *valp |= val; break;
1766                 case OP_MAX:    if(*valp < val)
1767                                         *valp = val;
1768                                 break;
1769                 case OP_MIN:    if(*valp > val)
1770                                 *valp = val;
1771                                 break;
1772                 }
1773         } else {
1774                 int val = *valp;
1775                 if (val < 0) {
1776                         *negp = -1;
1777                         *lvalp = (unsigned long)-val;
1778                 } else {
1779                         *negp = 0;
1780                         *lvalp = (unsigned long)val;
1781                 }
1782         }
1783         return 0;
1784 }
1785
1786 /*
1787  *      init may raise the set.
1788  */
1789
1790 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1791                         void __user *buffer, size_t *lenp, loff_t *ppos)
1792 {
1793         int op;
1794
1795         if (!capable(CAP_SYS_MODULE)) {
1796                 return -EPERM;
1797         }
1798
1799         op = (current->pid == 1) ? OP_SET : OP_AND;
1800         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1801                                 do_proc_dointvec_bset_conv,&op);
1802 }
1803
1804 struct do_proc_dointvec_minmax_conv_param {
1805         int *min;
1806         int *max;
1807 };
1808
1809 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1810                                         int *valp,
1811                                         int write, void *data)
1812 {
1813         struct do_proc_dointvec_minmax_conv_param *param = data;
1814         if (write) {
1815                 int val = *negp ? -*lvalp : *lvalp;
1816                 if ((param->min && *param->min > val) ||
1817                     (param->max && *param->max < val))
1818                         return -EINVAL;
1819                 *valp = val;
1820         } else {
1821                 int val = *valp;
1822                 if (val < 0) {
1823                         *negp = -1;
1824                         *lvalp = (unsigned long)-val;
1825                 } else {
1826                         *negp = 0;
1827                         *lvalp = (unsigned long)val;
1828                 }
1829         }
1830         return 0;
1831 }
1832
1833 /**
1834  * proc_dointvec_minmax - read a vector of integers with min/max values
1835  * @table: the sysctl table
1836  * @write: %TRUE if this is a write to the sysctl file
1837  * @filp: the file structure
1838  * @buffer: the user buffer
1839  * @lenp: the size of the user buffer
1840  * @ppos: file position
1841  *
1842  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1843  * values from/to the user buffer, treated as an ASCII string.
1844  *
1845  * This routine will ensure the values are within the range specified by
1846  * table->extra1 (min) and table->extra2 (max).
1847  *
1848  * Returns 0 on success.
1849  */
1850 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1851                   void __user *buffer, size_t *lenp, loff_t *ppos)
1852 {
1853         struct do_proc_dointvec_minmax_conv_param param = {
1854                 .min = (int *) table->extra1,
1855                 .max = (int *) table->extra2,
1856         };
1857         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1858                                 do_proc_dointvec_minmax_conv, &param);
1859 }
1860
1861 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1862                                      struct file *filp,
1863                                      void __user *buffer,
1864                                      size_t *lenp, loff_t *ppos,
1865                                      unsigned long convmul,
1866                                      unsigned long convdiv)
1867 {
1868 #define TMPBUFLEN 21
1869         unsigned long *i, *min, *max, val;
1870         int vleft, first=1, neg;
1871         size_t len, left;
1872         char buf[TMPBUFLEN], *p;
1873         char __user *s = buffer;
1874
1875         if (!table->data || !table->maxlen || !*lenp ||
1876             (*ppos && !write)) {
1877                 *lenp = 0;
1878                 return 0;
1879         }
1880
1881         i = (unsigned long *) table->data;
1882         min = (unsigned long *) table->extra1;
1883         max = (unsigned long *) table->extra2;
1884         vleft = table->maxlen / sizeof(unsigned long);
1885         left = *lenp;
1886
1887         for (; left && vleft--; i++, min++, max++, first=0) {
1888                 if (write) {
1889                         while (left) {
1890                                 char c;
1891                                 if (get_user(c, s))
1892                                         return -EFAULT;
1893                                 if (!isspace(c))
1894                                         break;
1895                                 left--;
1896                                 s++;
1897                         }
1898                         if (!left)
1899                                 break;
1900                         neg = 0;
1901                         len = left;
1902                         if (len > TMPBUFLEN-1)
1903                                 len = TMPBUFLEN-1;
1904                         if (copy_from_user(buf, s, len))
1905                                 return -EFAULT;
1906                         buf[len] = 0;
1907                         p = buf;
1908                         if (*p == '-' && left > 1) {
1909                                 neg = 1;
1910                                 left--, p++;
1911                         }
1912                         if (*p < '0' || *p > '9')
1913                                 break;
1914                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1915                         len = p-buf;
1916                         if ((len < left) && *p && !isspace(*p))
1917                                 break;
1918                         if (neg)
1919                                 val = -val;
1920                         s += len;
1921                         left -= len;
1922
1923                         if(neg)
1924                                 continue;
1925                         if ((min && val < *min) || (max && val > *max))
1926                                 continue;
1927                         *i = val;
1928                 } else {
1929                         p = buf;
1930                         if (!first)
1931                                 *p++ = '\t';
1932                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1933                         len = strlen(buf);
1934                         if (len > left)
1935                                 len = left;
1936                         if(copy_to_user(s, buf, len))
1937                                 return -EFAULT;
1938                         left -= len;
1939                         s += len;
1940                 }
1941         }
1942
1943         if (!write && !first && left) {
1944                 if(put_user('\n', s))
1945                         return -EFAULT;
1946                 left--, s++;
1947         }
1948         if (write) {
1949                 while (left) {
1950                         char c;
1951                         if (get_user(c, s++))
1952                                 return -EFAULT;
1953                         if (!isspace(c))
1954                                 break;
1955                         left--;
1956                 }
1957         }
1958         if (write && first)
1959                 return -EINVAL;
1960         *lenp -= left;
1961         *ppos += *lenp;
1962         return 0;
1963 #undef TMPBUFLEN
1964 }
1965
1966 /**
1967  * proc_doulongvec_minmax - read a vector of long integers with min/max values
1968  * @table: the sysctl table
1969  * @write: %TRUE if this is a write to the sysctl file
1970  * @filp: the file structure
1971  * @buffer: the user buffer
1972  * @lenp: the size of the user buffer
1973  * @ppos: file position
1974  *
1975  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1976  * values from/to the user buffer, treated as an ASCII string.
1977  *
1978  * This routine will ensure the values are within the range specified by
1979  * table->extra1 (min) and table->extra2 (max).
1980  *
1981  * Returns 0 on success.
1982  */
1983 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
1984                            void __user *buffer, size_t *lenp, loff_t *ppos)
1985 {
1986     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
1987 }
1988
1989 /**
1990  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
1991  * @table: the sysctl table
1992  * @write: %TRUE if this is a write to the sysctl file
1993  * @filp: the file structure
1994  * @buffer: the user buffer
1995  * @lenp: the size of the user buffer
1996  * @ppos: file position
1997  *
1998  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1999  * values from/to the user buffer, treated as an ASCII string. The values
2000  * are treated as milliseconds, and converted to jiffies when they are stored.
2001  *
2002  * This routine will ensure the values are within the range specified by
2003  * table->extra1 (min) and table->extra2 (max).
2004  *
2005  * Returns 0 on success.
2006  */
2007 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2008                                       struct file *filp,
2009                                       void __user *buffer,
2010                                       size_t *lenp, loff_t *ppos)
2011 {
2012     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2013                                      lenp, ppos, HZ, 1000l);
2014 }
2015
2016
2017 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2018                                          int *valp,
2019                                          int write, void *data)
2020 {
2021         if (write) {
2022                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2023         } else {
2024                 int val = *valp;
2025                 unsigned long lval;
2026                 if (val < 0) {
2027                         *negp = -1;
2028                         lval = (unsigned long)-val;
2029                 } else {
2030                         *negp = 0;
2031                         lval = (unsigned long)val;
2032                 }
2033                 *lvalp = lval / HZ;
2034         }
2035         return 0;
2036 }
2037
2038 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2039                                                 int *valp,
2040                                                 int write, void *data)
2041 {
2042         if (write) {
2043                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2044         } else {
2045                 int val = *valp;
2046                 unsigned long lval;
2047                 if (val < 0) {
2048                         *negp = -1;
2049                         lval = (unsigned long)-val;
2050                 } else {
2051                         *negp = 0;
2052                         lval = (unsigned long)val;
2053                 }
2054                 *lvalp = jiffies_to_clock_t(lval);
2055         }
2056         return 0;
2057 }
2058
2059 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2060                                             int *valp,
2061                                             int write, void *data)
2062 {
2063         if (write) {
2064                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2065         } else {
2066                 int val = *valp;
2067                 unsigned long lval;
2068                 if (val < 0) {
2069                         *negp = -1;
2070                         lval = (unsigned long)-val;
2071                 } else {
2072                         *negp = 0;
2073                         lval = (unsigned long)val;
2074                 }
2075                 *lvalp = jiffies_to_msecs(lval);
2076         }
2077         return 0;
2078 }
2079
2080 /**
2081  * proc_dointvec_jiffies - read a vector of integers as seconds
2082  * @table: the sysctl table
2083  * @write: %TRUE if this is a write to the sysctl file
2084  * @filp: the file structure
2085  * @buffer: the user buffer
2086  * @lenp: the size of the user buffer
2087  * @ppos: file position
2088  *
2089  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2090  * values from/to the user buffer, treated as an ASCII string.
2091  * The values read are assumed to be in seconds, and are converted into
2092  * jiffies.
2093  *
2094  * Returns 0 on success.
2095  */
2096 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2097                           void __user *buffer, size_t *lenp, loff_t *ppos)
2098 {
2099     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2100                             do_proc_dointvec_jiffies_conv,NULL);
2101 }
2102
2103 /**
2104  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2105  * @table: the sysctl table
2106  * @write: %TRUE if this is a write to the sysctl file
2107  * @filp: the file structure
2108  * @buffer: the user buffer
2109  * @lenp: the size of the user buffer
2110  * @ppos: pointer to the file position
2111  *
2112  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2113  * values from/to the user buffer, treated as an ASCII string.
2114  * The values read are assumed to be in 1/USER_HZ seconds, and
2115  * are converted into jiffies.
2116  *
2117  * Returns 0 on success.
2118  */
2119 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2120                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2121 {
2122     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2123                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2124 }
2125
2126 /**
2127  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2128  * @table: the sysctl table
2129  * @write: %TRUE if this is a write to the sysctl file
2130  * @filp: the file structure
2131  * @buffer: the user buffer
2132  * @lenp: the size of the user buffer
2133  * @ppos: file position
2134  * @ppos: the current position in the file
2135  *
2136  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2137  * values from/to the user buffer, treated as an ASCII string.
2138  * The values read are assumed to be in 1/1000 seconds, and
2139  * are converted into jiffies.
2140  *
2141  * Returns 0 on success.
2142  */
2143 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2144                              void __user *buffer, size_t *lenp, loff_t *ppos)
2145 {
2146         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2147                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2148 }
2149
2150 #else /* CONFIG_PROC_FS */
2151
2152 int proc_dostring(ctl_table *table, int write, struct file *filp,
2153                   void __user *buffer, size_t *lenp, loff_t *ppos)
2154 {
2155         return -ENOSYS;
2156 }
2157
2158 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
2159                             void __user *buffer, size_t *lenp, loff_t *ppos)
2160 {
2161         return -ENOSYS;
2162 }
2163
2164 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2165                   void __user *buffer, size_t *lenp, loff_t *ppos)
2166 {
2167         return -ENOSYS;
2168 }
2169
2170 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2171                         void __user *buffer, size_t *lenp, loff_t *ppos)
2172 {
2173         return -ENOSYS;
2174 }
2175
2176 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2177                     void __user *buffer, size_t *lenp, loff_t *ppos)
2178 {
2179         return -ENOSYS;
2180 }
2181
2182 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2183                     void __user *buffer, size_t *lenp, loff_t *ppos)
2184 {
2185         return -ENOSYS;
2186 }
2187
2188 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2189                     void __user *buffer, size_t *lenp, loff_t *ppos)
2190 {
2191         return -ENOSYS;
2192 }
2193
2194 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2195                              void __user *buffer, size_t *lenp, loff_t *ppos)
2196 {
2197         return -ENOSYS;
2198 }
2199
2200 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2201                     void __user *buffer, size_t *lenp, loff_t *ppos)
2202 {
2203         return -ENOSYS;
2204 }
2205
2206 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2207                                       struct file *filp,
2208                                       void __user *buffer,
2209                                       size_t *lenp, loff_t *ppos)
2210 {
2211     return -ENOSYS;
2212 }
2213
2214
2215 #endif /* CONFIG_PROC_FS */
2216
2217
2218 /*
2219  * General sysctl support routines
2220  */
2221
2222 /* The generic string strategy routine: */
2223 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2224                   void __user *oldval, size_t __user *oldlenp,
2225                   void __user *newval, size_t newlen, void **context)
2226 {
2227         if (!table->data || !table->maxlen)
2228                 return -ENOTDIR;
2229
2230         if (oldval && oldlenp) {
2231                 size_t bufsize;
2232                 if (get_user(bufsize, oldlenp))
2233                         return -EFAULT;
2234                 if (bufsize) {
2235                         size_t len = strlen(table->data), copied;
2236
2237                         /* This shouldn't trigger for a well-formed sysctl */
2238                         if (len > table->maxlen)
2239                                 len = table->maxlen;
2240
2241                         /* Copy up to a max of bufsize-1 bytes of the string */
2242                         copied = (len >= bufsize) ? bufsize - 1 : len;
2243
2244                         if (copy_to_user(oldval, table->data, copied) ||
2245                             put_user(0, (char __user *)(oldval + copied)))
2246                                 return -EFAULT;
2247                         if (put_user(len, oldlenp))
2248                                 return -EFAULT;
2249                 }
2250         }
2251         if (newval && newlen) {
2252                 size_t len = newlen;
2253                 if (len > table->maxlen)
2254                         len = table->maxlen;
2255                 if(copy_from_user(table->data, newval, len))
2256                         return -EFAULT;
2257                 if (len == table->maxlen)
2258                         len--;
2259                 ((char *) table->data)[len] = 0;
2260         }
2261         return 1;
2262 }
2263
2264 /*
2265  * This function makes sure that all of the integers in the vector
2266  * are between the minimum and maximum values given in the arrays
2267  * table->extra1 and table->extra2, respectively.
2268  */
2269 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2270                 void __user *oldval, size_t __user *oldlenp,
2271                 void __user *newval, size_t newlen, void **context)
2272 {
2273
2274         if (newval && newlen) {
2275                 int __user *vec = (int __user *) newval;
2276                 int *min = (int *) table->extra1;
2277                 int *max = (int *) table->extra2;
2278                 size_t length;
2279                 int i;
2280
2281                 if (newlen % sizeof(int) != 0)
2282                         return -EINVAL;
2283
2284                 if (!table->extra1 && !table->extra2)
2285                         return 0;
2286
2287                 if (newlen > table->maxlen)
2288                         newlen = table->maxlen;
2289                 length = newlen / sizeof(int);
2290
2291                 for (i = 0; i < length; i++) {
2292                         int value;
2293                         if (get_user(value, vec + i))
2294                                 return -EFAULT;
2295                         if (min && value < min[i])
2296                                 return -EINVAL;
2297                         if (max && value > max[i])
2298                                 return -EINVAL;
2299                 }
2300         }
2301         return 0;
2302 }
2303
2304 /* Strategy function to convert jiffies to seconds */
2305 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2306                 void __user *oldval, size_t __user *oldlenp,
2307                 void __user *newval, size_t newlen, void **context)
2308 {
2309         if (oldval) {
2310                 size_t olen;
2311                 if (oldlenp) {
2312                         if (get_user(olen, oldlenp))
2313                                 return -EFAULT;
2314                         if (olen!=sizeof(int))
2315                                 return -EINVAL;
2316                 }
2317                 if (put_user(*(int *)(table->data)/HZ, (int __user *)oldval) ||
2318                     (oldlenp && put_user(sizeof(int),oldlenp)))
2319                         return -EFAULT;
2320         }
2321         if (newval && newlen) {
2322                 int new;
2323                 if (newlen != sizeof(int))
2324                         return -EINVAL;
2325                 if (get_user(new, (int __user *)newval))
2326                         return -EFAULT;
2327                 *(int *)(table->data) = new*HZ;
2328         }
2329         return 1;
2330 }
2331
2332 /* Strategy function to convert jiffies to seconds */
2333 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2334                 void __user *oldval, size_t __user *oldlenp,
2335                 void __user *newval, size_t newlen, void **context)
2336 {
2337         if (oldval) {
2338                 size_t olen;
2339                 if (oldlenp) {
2340                         if (get_user(olen, oldlenp))
2341                                 return -EFAULT;
2342                         if (olen!=sizeof(int))
2343                                 return -EINVAL;
2344                 }
2345                 if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
2346                     (oldlenp && put_user(sizeof(int),oldlenp)))
2347                         return -EFAULT;
2348         }
2349         if (newval && newlen) {
2350                 int new;
2351                 if (newlen != sizeof(int))
2352                         return -EINVAL;
2353                 if (get_user(new, (int __user *)newval))
2354                         return -EFAULT;
2355                 *(int *)(table->data) = msecs_to_jiffies(new);
2356         }
2357         return 1;
2358 }
2359
2360 #else /* CONFIG_SYSCTL */
2361
2362
2363 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2364 {
2365         return -ENOSYS;
2366 }
2367
2368 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2369                   void __user *oldval, size_t __user *oldlenp,
2370                   void __user *newval, size_t newlen, void **context)
2371 {
2372         return -ENOSYS;
2373 }
2374
2375 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2376                 void __user *oldval, size_t __user *oldlenp,
2377                 void __user *newval, size_t newlen, void **context)
2378 {
2379         return -ENOSYS;
2380 }
2381
2382 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2383                 void __user *oldval, size_t __user *oldlenp,
2384                 void __user *newval, size_t newlen, void **context)
2385 {
2386         return -ENOSYS;
2387 }
2388
2389 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2390                 void __user *oldval, size_t __user *oldlenp,
2391                 void __user *newval, size_t newlen, void **context)
2392 {
2393         return -ENOSYS;
2394 }
2395
2396 int proc_dostring(ctl_table *table, int write, struct file *filp,
2397                   void __user *buffer, size_t *lenp, loff_t *ppos)
2398 {
2399         return -ENOSYS;
2400 }
2401
2402 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2403                   void __user *buffer, size_t *lenp, loff_t *ppos)
2404 {
2405         return -ENOSYS;
2406 }
2407
2408 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2409                         void __user *buffer, size_t *lenp, loff_t *ppos)
2410 {
2411         return -ENOSYS;
2412 }
2413
2414 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2415                     void __user *buffer, size_t *lenp, loff_t *ppos)
2416 {
2417         return -ENOSYS;
2418 }
2419
2420 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2421                           void __user *buffer, size_t *lenp, loff_t *ppos)
2422 {
2423         return -ENOSYS;
2424 }
2425
2426 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2427                           void __user *buffer, size_t *lenp, loff_t *ppos)
2428 {
2429         return -ENOSYS;
2430 }
2431
2432 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2433                              void __user *buffer, size_t *lenp, loff_t *ppos)
2434 {
2435         return -ENOSYS;
2436 }
2437
2438 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2439                     void __user *buffer, size_t *lenp, loff_t *ppos)
2440 {
2441         return -ENOSYS;
2442 }
2443
2444 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2445                                       struct file *filp,
2446                                       void __user *buffer,
2447                                       size_t *lenp, loff_t *ppos)
2448 {
2449     return -ENOSYS;
2450 }
2451
2452 struct ctl_table_header * register_sysctl_table(ctl_table * table,
2453                                                 int insert_at_head)
2454 {
2455         return NULL;
2456 }
2457
2458 void unregister_sysctl_table(struct ctl_table_header * table)
2459 {
2460 }
2461
2462 #endif /* CONFIG_SYSCTL */
2463
2464 /*
2465  * No sense putting this after each symbol definition, twice,
2466  * exception granted :-)
2467  */
2468 EXPORT_SYMBOL(proc_dointvec);
2469 EXPORT_SYMBOL(proc_dointvec_jiffies);
2470 EXPORT_SYMBOL(proc_dointvec_minmax);
2471 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2472 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2473 EXPORT_SYMBOL(proc_dostring);
2474 EXPORT_SYMBOL(proc_doulongvec_minmax);
2475 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2476 EXPORT_SYMBOL(register_sysctl_table);
2477 EXPORT_SYMBOL(sysctl_intvec);
2478 EXPORT_SYMBOL(sysctl_jiffies);
2479 EXPORT_SYMBOL(sysctl_ms_jiffies);
2480 EXPORT_SYMBOL(sysctl_string);
2481 EXPORT_SYMBOL(unregister_sysctl_table);