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