kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/config.h>
  22 #include <linux/module.h>
  23 #include <linux/mm.h>
  24 #include <linux/swap.h>
  25 #include <linux/slab.h>
  26 #include <linux/sysctl.h>
  27 #include <linux/proc_fs.h>
  28 #include <linux/capability.h>
  29 #include <linux/ctype.h>
  30 #include <linux/utsname.h>
  31 #include <linux/capability.h>
  32 #include <linux/smp_lock.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/security.h>
  42 #include <linux/initrd.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49
  50 #include <asm/uaccess.h>
  51 #include <asm/processor.h>
  52
  53 extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
  54                      void __user *buffer, size_t *lenp, loff_t *ppos);
  55
  56 #if defined(CONFIG_SYSCTL)
  57
  58 /* External variables not in a header file. */
  59 extern int C_A_D;
  60 extern int sysctl_overcommit_memory;
  61 extern int sysctl_overcommit_ratio;
  62 extern int sysctl_panic_on_oom;
  63 extern int max_threads;
  64 extern int sysrq_enabled;
  65 extern int core_uses_pid;
  66 extern int suid_dumpable;
  67 extern char core_pattern[];
  68 extern int cad_pid;
  69 extern int pid_max;
  70 extern int min_free_kbytes;
  71 extern int printk_ratelimit_jiffies;
  72 extern int printk_ratelimit_burst;
  73 extern int pid_max_min, pid_max_max;
  74 extern int sysctl_drop_caches;
  75 extern int percpu_pagelist_fraction;
  76 extern int compat_log;
  77
  78 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
  79 int unknown_nmi_panic;
  80 extern int proc_unknown_nmi_panic(ctl_table *, int, struct file *,
  81                                   void __user *, size_t *, loff_t *);
  82 #endif
  83
  84 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  85 static int maxolduid = 65535;
  86 static int minolduid;
  87 static int min_percpu_pagelist_fract = 8;
  88
  89 static int ngroups_max = NGROUPS_MAX;
  90
  91 #ifdef CONFIG_KMOD
  92 extern char modprobe_path[];
  93 #endif
  94 #ifdef CONFIG_CHR_DEV_SG
  95 extern int sg_big_buff;
  96 #endif
  97 #ifdef CONFIG_SYSVIPC
  98 extern size_t shm_ctlmax;
  99 extern size_t shm_ctlall;
 100 extern int shm_ctlmni;
 101 extern int msg_ctlmax;
 102 extern int msg_ctlmnb;
 103 extern int msg_ctlmni;
 104 extern int sem_ctls[];
 105 #endif
 106
 107 #ifdef __sparc__
 108 extern char reboot_command [];
 109 extern int stop_a_enabled;
 110 extern int scons_pwroff;
 111 #endif
 112
 113 #ifdef __hppa__
 114 extern int pwrsw_enabled;
 115 extern int unaligned_enabled;
 116 #endif
 117
 118 #ifdef CONFIG_S390
 119 #ifdef CONFIG_MATHEMU
 120 extern int sysctl_ieee_emulation_warnings;
 121 #endif
 122 extern int sysctl_userprocess_debug;
 123 extern int spin_retry;
 124 #endif
 125
 126 extern int sysctl_hz_timer;
 127
 128 #ifdef CONFIG_BSD_PROCESS_ACCT
 129 extern int acct_parm[];
 130 #endif
 131
 132 #ifdef CONFIG_IA64
 133 extern int no_unaligned_warning;
 134 #endif
 135
 136 static int parse_table(int __user *, int, void __user *, size_t __user *, void __user *, size_t,
 137                        ctl_table *, void **);
 138 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
 139                   void __user *buffer, size_t *lenp, loff_t *ppos);
 140
 141 static ctl_table root_table[];
 142 static struct ctl_table_header root_table_header =
 143         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 144
 145 static ctl_table kern_table[];
 146 static ctl_table vm_table[];
 147 static ctl_table fs_table[];
 148 static ctl_table debug_table[];
 149 static ctl_table dev_table[];
 150 extern ctl_table random_table[];
 151 #ifdef CONFIG_UNIX98_PTYS
 152 extern ctl_table pty_table[];
 153 #endif
 154 #ifdef CONFIG_INOTIFY_USER
 155 extern ctl_table inotify_table[];
 156 #endif
 157
 158 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 159 int sysctl_legacy_va_layout;
 160 #endif
 161
 162 /* /proc declarations: */
 163
 164 #ifdef CONFIG_PROC_FS
 165
 166 static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
 167 static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
 168 static int proc_opensys(struct inode *, struct file *);
 169
 170 struct file_operations proc_sys_file_operations = {
 171         .open           = proc_opensys,
 172         .read           = proc_readsys,
 173         .write          = proc_writesys,
 174 };
 175
 176 extern struct proc_dir_entry *proc_sys_root;
 177
 178 static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
 179 static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
 180 #endif
 181
 182 /* The default sysctl tables: */
 183
 184 static ctl_table root_table[] = {
 185         {
 186                 .ctl_name       = CTL_KERN,
 187                 .procname       = "kernel",
 188                 .mode           = 0555,
 189                 .child          = kern_table,
 190         },
 191         {
 192                 .ctl_name       = CTL_VM,
 193                 .procname       = "vm",
 194                 .mode           = 0555,
 195                 .child          = vm_table,
 196         },
 197 #ifdef CONFIG_NET
 198         {
 199                 .ctl_name       = CTL_NET,
 200                 .procname       = "net",
 201                 .mode           = 0555,
 202                 .child          = net_table,
 203         },
 204 #endif
 205         {
 206                 .ctl_name       = CTL_FS,
 207                 .procname       = "fs",
 208                 .mode           = 0555,
 209                 .child          = fs_table,
 210         },
 211         {
 212                 .ctl_name       = CTL_DEBUG,
 213                 .procname       = "debug",
 214                 .mode           = 0555,
 215                 .child          = debug_table,
 216         },
 217         {
 218                 .ctl_name       = CTL_DEV,
 219                 .procname       = "dev",
 220                 .mode           = 0555,
 221                 .child          = dev_table,
 222         },
 223
 224         { .ctl_name = 0 }
 225 };
 226
 227 static ctl_table kern_table[] = {
 228         {
 229                 .ctl_name       = KERN_OSTYPE,
 230                 .procname       = "ostype",
 231                 .data           = system_utsname.sysname,
 232                 .maxlen         = sizeof(system_utsname.sysname),
 233                 .mode           = 0444,
 234                 .proc_handler   = &proc_doutsstring,
 235                 .strategy       = &sysctl_string,
 236         },
 237         {
 238                 .ctl_name       = KERN_OSRELEASE,
 239                 .procname       = "osrelease",
 240                 .data           = system_utsname.release,
 241                 .maxlen         = sizeof(system_utsname.release),
 242                 .mode           = 0444,
 243                 .proc_handler   = &proc_doutsstring,
 244                 .strategy       = &sysctl_string,
 245         },
 246         {
 247                 .ctl_name       = KERN_VERSION,
 248                 .procname       = "version",
 249                 .data           = system_utsname.version,
 250                 .maxlen         = sizeof(system_utsname.version),
 251                 .mode           = 0444,
 252                 .proc_handler   = &proc_doutsstring,
 253                 .strategy       = &sysctl_string,
 254         },
 255         {
 256                 .ctl_name       = KERN_NODENAME,
 257                 .procname       = "hostname",
 258                 .data           = system_utsname.nodename,
 259                 .maxlen         = sizeof(system_utsname.nodename),
 260                 .mode           = 0644,
 261                 .proc_handler   = &proc_doutsstring,
 262                 .strategy       = &sysctl_string,
 263         },
 264         {
 265                 .ctl_name       = KERN_DOMAINNAME,
 266                 .procname       = "domainname",
 267                 .data           = system_utsname.domainname,
 268                 .maxlen         = sizeof(system_utsname.domainname),
 269                 .mode           = 0644,
 270                 .proc_handler   = &proc_doutsstring,
 271                 .strategy       = &sysctl_string,
 272         },
 273         {
 274                 .ctl_name       = KERN_PANIC,
 275                 .procname       = "panic",
 276                 .data           = &panic_timeout,
 277                 .maxlen         = sizeof(int),
 278                 .mode           = 0644,
 279                 .proc_handler   = &proc_dointvec,
 280         },
 281         {
 282                 .ctl_name       = KERN_CORE_USES_PID,
 283                 .procname       = "core_uses_pid",
 284                 .data           = &core_uses_pid,
 285                 .maxlen         = sizeof(int),
 286                 .mode           = 0644,
 287                 .proc_handler   = &proc_dointvec,
 288         },
 289         {
 290                 .ctl_name       = KERN_CORE_PATTERN,
 291                 .procname       = "core_pattern",
 292                 .data           = core_pattern,
 293                 .maxlen         = 64,
 294                 .mode           = 0644,
 295                 .proc_handler   = &proc_dostring,
 296                 .strategy       = &sysctl_string,
 297         },
 298         {
 299                 .ctl_name       = KERN_TAINTED,
 300                 .procname       = "tainted",
 301                 .data           = &tainted,
 302                 .maxlen         = sizeof(int),
 303                 .mode           = 0444,
 304                 .proc_handler   = &proc_dointvec,
 305         },
 306         {
 307                 .ctl_name       = KERN_CAP_BSET,
 308                 .procname       = "cap-bound",
 309                 .data           = &cap_bset,
 310                 .maxlen         = sizeof(kernel_cap_t),
 311                 .mode           = 0600,
 312                 .proc_handler   = &proc_dointvec_bset,
 313         },
 314 #ifdef CONFIG_BLK_DEV_INITRD
 315         {
 316                 .ctl_name       = KERN_REALROOTDEV,
 317                 .procname       = "real-root-dev",
 318                 .data           = &real_root_dev,
 319                 .maxlen         = sizeof(int),
 320                 .mode           = 0644,
 321                 .proc_handler   = &proc_dointvec,
 322         },
 323 #endif
 324 #ifdef __sparc__
 325         {
 326                 .ctl_name       = KERN_SPARC_REBOOT,
 327                 .procname       = "reboot-cmd",
 328                 .data           = reboot_command,
 329                 .maxlen         = 256,
 330                 .mode           = 0644,
 331                 .proc_handler   = &proc_dostring,
 332                 .strategy       = &sysctl_string,
 333         },
 334         {
 335                 .ctl_name       = KERN_SPARC_STOP_A,
 336                 .procname       = "stop-a",
 337                 .data           = &stop_a_enabled,
 338                 .maxlen         = sizeof (int),
 339                 .mode           = 0644,
 340                 .proc_handler   = &proc_dointvec,
 341         },
 342         {
 343                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 344                 .procname       = "scons-poweroff",
 345                 .data           = &scons_pwroff,
 346                 .maxlen         = sizeof (int),
 347                 .mode           = 0644,
 348                 .proc_handler   = &proc_dointvec,
 349         },
 350 #endif
 351 #ifdef __hppa__
 352         {
 353                 .ctl_name       = KERN_HPPA_PWRSW,
 354                 .procname       = "soft-power",
 355                 .data           = &pwrsw_enabled,
 356                 .maxlen         = sizeof (int),
 357                 .mode           = 0644,
 358                 .proc_handler   = &proc_dointvec,
 359         },
 360         {
 361                 .ctl_name       = KERN_HPPA_UNALIGNED,
 362                 .procname       = "unaligned-trap",
 363                 .data           = &unaligned_enabled,
 364                 .maxlen         = sizeof (int),
 365                 .mode           = 0644,
 366                 .proc_handler   = &proc_dointvec,
 367         },
 368 #endif
 369         {
 370                 .ctl_name       = KERN_CTLALTDEL,
 371                 .procname       = "ctrl-alt-del",
 372                 .data           = &C_A_D,
 373                 .maxlen         = sizeof(int),
 374                 .mode           = 0644,
 375                 .proc_handler   = &proc_dointvec,
 376         },
 377         {
 378                 .ctl_name       = KERN_PRINTK,
 379                 .procname       = "printk",
 380                 .data           = &console_loglevel,
 381                 .maxlen         = 4*sizeof(int),
 382                 .mode           = 0644,
 383                 .proc_handler   = &proc_dointvec,
 384         },
 385 #ifdef CONFIG_KMOD
 386         {
 387                 .ctl_name       = KERN_MODPROBE,
 388                 .procname       = "modprobe",
 389                 .data           = &modprobe_path,
 390                 .maxlen         = KMOD_PATH_LEN,
 391                 .mode           = 0644,
 392                 .proc_handler   = &proc_dostring,
 393                 .strategy       = &sysctl_string,
 394         },
 395 #endif
 396 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 397         {
 398                 .ctl_name       = KERN_HOTPLUG,
 399                 .procname       = "hotplug",
 400                 .data           = &uevent_helper,
 401                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 402                 .mode           = 0644,
 403                 .proc_handler   = &proc_dostring,
 404                 .strategy       = &sysctl_string,
 405         },
 406 #endif
 407 #ifdef CONFIG_CHR_DEV_SG
 408         {
 409                 .ctl_name       = KERN_SG_BIG_BUFF,
 410                 .procname       = "sg-big-buff",
 411                 .data           = &sg_big_buff,
 412                 .maxlen         = sizeof (int),
 413                 .mode           = 0444,
 414                 .proc_handler   = &proc_dointvec,
 415         },
 416 #endif
 417 #ifdef CONFIG_BSD_PROCESS_ACCT
 418         {
 419                 .ctl_name       = KERN_ACCT,
 420                 .procname       = "acct",
 421                 .data           = &acct_parm,
 422                 .maxlen         = 3*sizeof(int),
 423                 .mode           = 0644,
 424                 .proc_handler   = &proc_dointvec,
 425         },
 426 #endif
 427 #ifdef CONFIG_SYSVIPC
 428         {
 429                 .ctl_name       = KERN_SHMMAX,
 430                 .procname       = "shmmax",
 431                 .data           = &shm_ctlmax,
 432                 .maxlen         = sizeof (size_t),
 433                 .mode           = 0644,
 434                 .proc_handler   = &proc_doulongvec_minmax,
 435         },
 436         {
 437                 .ctl_name       = KERN_SHMALL,
 438                 .procname       = "shmall",
 439                 .data           = &shm_ctlall,
 440                 .maxlen         = sizeof (size_t),
 441                 .mode           = 0644,
 442                 .proc_handler   = &proc_doulongvec_minmax,
 443         },
 444         {
 445                 .ctl_name       = KERN_SHMMNI,
 446                 .procname       = "shmmni",
 447                 .data           = &shm_ctlmni,
 448                 .maxlen         = sizeof (int),
 449                 .mode           = 0644,
 450                 .proc_handler   = &proc_dointvec,
 451         },
 452         {
 453                 .ctl_name       = KERN_MSGMAX,
 454                 .procname       = "msgmax",
 455                 .data           = &msg_ctlmax,
 456                 .maxlen         = sizeof (int),
 457                 .mode           = 0644,
 458                 .proc_handler   = &proc_dointvec,
 459         },
 460         {
 461                 .ctl_name       = KERN_MSGMNI,
 462                 .procname       = "msgmni",
 463                 .data           = &msg_ctlmni,
 464                 .maxlen         = sizeof (int),
 465                 .mode           = 0644,
 466                 .proc_handler   = &proc_dointvec,
 467         },
 468         {
 469                 .ctl_name       = KERN_MSGMNB,
 470                 .procname       =  "msgmnb",
 471                 .data           = &msg_ctlmnb,
 472                 .maxlen         = sizeof (int),
 473                 .mode           = 0644,
 474                 .proc_handler   = &proc_dointvec,
 475         },
 476         {
 477                 .ctl_name       = KERN_SEM,
 478                 .procname       = "sem",
 479                 .data           = &sem_ctls,
 480                 .maxlen         = 4*sizeof (int),
 481                 .mode           = 0644,
 482                 .proc_handler   = &proc_dointvec,
 483         },
 484 #endif
 485 #ifdef CONFIG_MAGIC_SYSRQ
 486         {
 487                 .ctl_name       = KERN_SYSRQ,
 488                 .procname       = "sysrq",
 489                 .data           = &sysrq_enabled,
 490                 .maxlen         = sizeof (int),
 491                 .mode           = 0644,
 492                 .proc_handler   = &proc_dointvec,
 493         },
 494 #endif
 495         {
 496                 .ctl_name       = KERN_CADPID,
 497                 .procname       = "cad_pid",
 498                 .data           = &cad_pid,
 499                 .maxlen         = sizeof (int),
 500                 .mode           = 0600,
 501                 .proc_handler   = &proc_dointvec,
 502         },
 503         {
 504                 .ctl_name       = KERN_MAX_THREADS,
 505                 .procname       = "threads-max",
 506                 .data           = &max_threads,
 507                 .maxlen         = sizeof(int),
 508                 .mode           = 0644,
 509                 .proc_handler   = &proc_dointvec,
 510         },
 511         {
 512                 .ctl_name       = KERN_RANDOM,
 513                 .procname       = "random",
 514                 .mode           = 0555,
 515                 .child          = random_table,
 516         },
 517 #ifdef CONFIG_UNIX98_PTYS
 518         {
 519                 .ctl_name       = KERN_PTY,
 520                 .procname       = "pty",
 521                 .mode           = 0555,
 522                 .child          = pty_table,
 523         },
 524 #endif
 525         {
 526                 .ctl_name       = KERN_OVERFLOWUID,
 527                 .procname       = "overflowuid",
 528                 .data           = &overflowuid,
 529                 .maxlen         = sizeof(int),
 530                 .mode           = 0644,
 531                 .proc_handler   = &proc_dointvec_minmax,
 532                 .strategy       = &sysctl_intvec,
 533                 .extra1         = &minolduid,
 534                 .extra2         = &maxolduid,
 535         },
 536         {
 537                 .ctl_name       = KERN_OVERFLOWGID,
 538                 .procname       = "overflowgid",
 539                 .data           = &overflowgid,
 540                 .maxlen         = sizeof(int),
 541                 .mode           = 0644,
 542                 .proc_handler   = &proc_dointvec_minmax,
 543                 .strategy       = &sysctl_intvec,
 544                 .extra1         = &minolduid,
 545                 .extra2         = &maxolduid,
 546         },
 547 #ifdef CONFIG_S390
 548 #ifdef CONFIG_MATHEMU
 549         {
 550                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 551                 .procname       = "ieee_emulation_warnings",
 552                 .data           = &sysctl_ieee_emulation_warnings,
 553                 .maxlen         = sizeof(int),
 554                 .mode           = 0644,
 555                 .proc_handler   = &proc_dointvec,
 556         },
 557 #endif
 558 #ifdef CONFIG_NO_IDLE_HZ
 559         {
 560                 .ctl_name       = KERN_HZ_TIMER,
 561                 .procname       = "hz_timer",
 562                 .data           = &sysctl_hz_timer,
 563                 .maxlen         = sizeof(int),
 564                 .mode           = 0644,
 565                 .proc_handler   = &proc_dointvec,
 566         },
 567 #endif
 568         {
 569                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 570                 .procname       = "userprocess_debug",
 571                 .data           = &sysctl_userprocess_debug,
 572                 .maxlen         = sizeof(int),
 573                 .mode           = 0644,
 574                 .proc_handler   = &proc_dointvec,
 575         },
 576 #endif
 577         {
 578                 .ctl_name       = KERN_PIDMAX,
 579                 .procname       = "pid_max",
 580                 .data           = &pid_max,
 581                 .maxlen         = sizeof (int),
 582                 .mode           = 0644,
 583                 .proc_handler   = &proc_dointvec_minmax,
 584                 .strategy       = sysctl_intvec,
 585                 .extra1         = &pid_max_min,
 586                 .extra2         = &pid_max_max,
 587         },
 588         {
 589                 .ctl_name       = KERN_PANIC_ON_OOPS,
 590                 .procname       = "panic_on_oops",
 591                 .data           = &panic_on_oops,
 592                 .maxlen         = sizeof(int),
 593                 .mode           = 0644,
 594                 .proc_handler   = &proc_dointvec,
 595         },
 596         {
 597                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 598                 .procname       = "printk_ratelimit",
 599                 .data           = &printk_ratelimit_jiffies,
 600                 .maxlen         = sizeof(int),
 601                 .mode           = 0644,
 602                 .proc_handler   = &proc_dointvec_jiffies,
 603                 .strategy       = &sysctl_jiffies,
 604         },
 605         {
 606                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 607                 .procname       = "printk_ratelimit_burst",
 608                 .data           = &printk_ratelimit_burst,
 609                 .maxlen         = sizeof(int),
 610                 .mode           = 0644,
 611                 .proc_handler   = &proc_dointvec,
 612         },
 613         {
 614                 .ctl_name       = KERN_NGROUPS_MAX,
 615                 .procname       = "ngroups_max",
 616                 .data           = &ngroups_max,
 617                 .maxlen         = sizeof (int),
 618                 .mode           = 0444,
 619                 .proc_handler   = &proc_dointvec,
 620         },
 621 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 622         {
 623                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 624                 .procname       = "unknown_nmi_panic",
 625                 .data           = &unknown_nmi_panic,
 626                 .maxlen         = sizeof (int),
 627                 .mode           = 0644,
 628                 .proc_handler   = &proc_unknown_nmi_panic,
 629         },
 630 #endif
 631 #if defined(CONFIG_X86)
 632         {
 633                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 634                 .procname       = "bootloader_type",
 635                 .data           = &bootloader_type,
 636                 .maxlen         = sizeof (int),
 637                 .mode           = 0444,
 638                 .proc_handler   = &proc_dointvec,
 639         },
 640 #endif
 641 #if defined(CONFIG_MMU)
 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 #endif
 651 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 652         {
 653                 .ctl_name       = KERN_SPIN_RETRY,
 654                 .procname       = "spin_retry",
 655                 .data           = &spin_retry,
 656                 .maxlen         = sizeof (int),
 657                 .mode           = 0644,
 658                 .proc_handler   = &proc_dointvec,
 659         },
 660 #endif
 661 #ifdef CONFIG_ACPI_SLEEP
 662         {
 663                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 664                 .procname       = "acpi_video_flags",
 665                 .data           = &acpi_video_flags,
 666                 .maxlen         = sizeof (unsigned long),
 667                 .mode           = 0644,
 668                 .proc_handler   = &proc_doulongvec_minmax,
 669         },
 670 #endif
 671 #ifdef CONFIG_IA64
 672         {
 673                 .ctl_name       = KERN_IA64_UNALIGNED,
 674                 .procname       = "ignore-unaligned-usertrap",
 675                 .data           = &no_unaligned_warning,
 676                 .maxlen         = sizeof (int),
 677                 .mode           = 0644,
 678                 .proc_handler   = &proc_dointvec,
 679         },
 680 #endif
 681 #ifdef CONFIG_COMPAT
 682         {
 683                 .ctl_name       = KERN_COMPAT_LOG,
 684                 .procname       = "compat-log",
 685                 .data           = &compat_log,
 686                 .maxlen         = sizeof (int),
 687                 .mode           = 0644,
 688                 .proc_handler   = &proc_dointvec,
 689         },
 690 #endif
 691         { .ctl_name = 0 }
 692 };
 693
 694 /* Constants for minimum and maximum testing in vm_table.
 695    We use these as one-element integer vectors. */
 696 static int zero;
 697 static int one_hundred = 100;
 698
 699
 700 static ctl_table vm_table[] = {
 701         {
 702                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 703                 .procname       = "overcommit_memory",
 704                 .data           = &sysctl_overcommit_memory,
 705                 .maxlen         = sizeof(sysctl_overcommit_memory),
 706                 .mode           = 0644,
 707                 .proc_handler   = &proc_dointvec,
 708         },
 709         {
 710                 .ctl_name       = VM_PANIC_ON_OOM,
 711                 .procname       = "panic_on_oom",
 712                 .data           = &sysctl_panic_on_oom,
 713                 .maxlen         = sizeof(sysctl_panic_on_oom),
 714                 .mode           = 0644,
 715                 .proc_handler   = &proc_dointvec,
 716         },
 717         {
 718                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 719                 .procname       = "overcommit_ratio",
 720                 .data           = &sysctl_overcommit_ratio,
 721                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 722                 .mode           = 0644,
 723                 .proc_handler   = &proc_dointvec,
 724         },
 725         {
 726                 .ctl_name       = VM_PAGE_CLUSTER,
 727                 .procname       = "page-cluster",
 728                 .data           = &page_cluster,
 729                 .maxlen         = sizeof(int),
 730                 .mode           = 0644,
 731                 .proc_handler   = &proc_dointvec,
 732         },
 733         {
 734                 .ctl_name       = VM_DIRTY_BACKGROUND,
 735                 .procname       = "dirty_background_ratio",
 736                 .data           = &dirty_background_ratio,
 737                 .maxlen         = sizeof(dirty_background_ratio),
 738                 .mode           = 0644,
 739                 .proc_handler   = &proc_dointvec_minmax,
 740                 .strategy       = &sysctl_intvec,
 741                 .extra1         = &zero,
 742                 .extra2         = &one_hundred,
 743         },
 744         {
 745                 .ctl_name       = VM_DIRTY_RATIO,
 746                 .procname       = "dirty_ratio",
 747                 .data           = &vm_dirty_ratio,
 748                 .maxlen         = sizeof(vm_dirty_ratio),
 749                 .mode           = 0644,
 750                 .proc_handler   = &proc_dointvec_minmax,
 751                 .strategy       = &sysctl_intvec,
 752                 .extra1         = &zero,
 753                 .extra2         = &one_hundred,
 754         },
 755         {
 756                 .ctl_name       = VM_DIRTY_WB_CS,
 757                 .procname       = "dirty_writeback_centisecs",
 758                 .data           = &dirty_writeback_interval,
 759                 .maxlen         = sizeof(dirty_writeback_interval),
 760                 .mode           = 0644,
 761                 .proc_handler   = &dirty_writeback_centisecs_handler,
 762         },
 763         {
 764                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 765                 .procname       = "dirty_expire_centisecs",
 766                 .data           = &dirty_expire_interval,
 767                 .maxlen         = sizeof(dirty_expire_interval),
 768                 .mode           = 0644,
 769                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 770         },
 771         {
 772                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 773                 .procname       = "nr_pdflush_threads",
 774                 .data           = &nr_pdflush_threads,
 775                 .maxlen         = sizeof nr_pdflush_threads,
 776                 .mode           = 0444 /* read-only*/,
 777                 .proc_handler   = &proc_dointvec,
 778         },
 779         {
 780                 .ctl_name       = VM_SWAPPINESS,
 781                 .procname       = "swappiness",
 782                 .data           = &vm_swappiness,
 783                 .maxlen         = sizeof(vm_swappiness),
 784                 .mode           = 0644,
 785                 .proc_handler   = &proc_dointvec_minmax,
 786                 .strategy       = &sysctl_intvec,
 787                 .extra1         = &zero,
 788                 .extra2         = &one_hundred,
 789         },
 790 #ifdef CONFIG_HUGETLB_PAGE
 791          {
 792                 .ctl_name       = VM_HUGETLB_PAGES,
 793                 .procname       = "nr_hugepages",
 794                 .data           = &max_huge_pages,
 795                 .maxlen         = sizeof(unsigned long),
 796                 .mode           = 0644,
 797                 .proc_handler   = &hugetlb_sysctl_handler,
 798                 .extra1         = (void *)&hugetlb_zero,
 799                 .extra2         = (void *)&hugetlb_infinity,
 800          },
 801          {
 802                 .ctl_name       = VM_HUGETLB_GROUP,
 803                 .procname       = "hugetlb_shm_group",
 804                 .data           = &sysctl_hugetlb_shm_group,
 805                 .maxlen         = sizeof(gid_t),
 806                 .mode           = 0644,
 807                 .proc_handler   = &proc_dointvec,
 808          },
 809 #endif
 810         {
 811                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 812                 .procname       = "lowmem_reserve_ratio",
 813                 .data           = &sysctl_lowmem_reserve_ratio,
 814                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 815                 .mode           = 0644,
 816                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 817                 .strategy       = &sysctl_intvec,
 818         },
 819         {
 820                 .ctl_name       = VM_DROP_PAGECACHE,
 821                 .procname       = "drop_caches",
 822                 .data           = &sysctl_drop_caches,
 823                 .maxlen         = sizeof(int),
 824                 .mode           = 0644,
 825                 .proc_handler   = drop_caches_sysctl_handler,
 826                 .strategy       = &sysctl_intvec,
 827         },
 828         {
 829                 .ctl_name       = VM_MIN_FREE_KBYTES,
 830                 .procname       = "min_free_kbytes",
 831                 .data           = &min_free_kbytes,
 832                 .maxlen         = sizeof(min_free_kbytes),
 833                 .mode           = 0644,
 834                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 835                 .strategy       = &sysctl_intvec,
 836                 .extra1         = &zero,
 837         },
 838         {
 839                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 840                 .procname       = "percpu_pagelist_fraction",
 841                 .data           = &percpu_pagelist_fraction,
 842                 .maxlen         = sizeof(percpu_pagelist_fraction),
 843                 .mode           = 0644,
 844                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 845                 .strategy       = &sysctl_intvec,
 846                 .extra1         = &min_percpu_pagelist_fract,
 847         },
 848 #ifdef CONFIG_MMU
 849         {
 850                 .ctl_name       = VM_MAX_MAP_COUNT,
 851                 .procname       = "max_map_count",
 852                 .data           = &sysctl_max_map_count,
 853                 .maxlen         = sizeof(sysctl_max_map_count),
 854                 .mode           = 0644,
 855                 .proc_handler   = &proc_dointvec
 856         },
 857 #endif
 858         {
 859                 .ctl_name       = VM_LAPTOP_MODE,
 860                 .procname       = "laptop_mode",
 861                 .data           = &laptop_mode,
 862                 .maxlen         = sizeof(laptop_mode),
 863                 .mode           = 0644,
 864                 .proc_handler   = &proc_dointvec_jiffies,
 865                 .strategy       = &sysctl_jiffies,
 866         },
 867         {
 868                 .ctl_name       = VM_BLOCK_DUMP,
 869                 .procname       = "block_dump",
 870                 .data           = &block_dump,
 871                 .maxlen         = sizeof(block_dump),
 872                 .mode           = 0644,
 873                 .proc_handler   = &proc_dointvec,
 874                 .strategy       = &sysctl_intvec,
 875                 .extra1         = &zero,
 876         },
 877         {
 878                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 879                 .procname       = "vfs_cache_pressure",
 880                 .data           = &sysctl_vfs_cache_pressure,
 881                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 882                 .mode           = 0644,
 883                 .proc_handler   = &proc_dointvec,
 884                 .strategy       = &sysctl_intvec,
 885                 .extra1         = &zero,
 886         },
 887 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 888         {
 889                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 890                 .procname       = "legacy_va_layout",
 891                 .data           = &sysctl_legacy_va_layout,
 892                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 893                 .mode           = 0644,
 894                 .proc_handler   = &proc_dointvec,
 895                 .strategy       = &sysctl_intvec,
 896                 .extra1         = &zero,
 897         },
 898 #endif
 899 #ifdef CONFIG_SWAP
 900         {
 901                 .ctl_name       = VM_SWAP_TOKEN_TIMEOUT,
 902                 .procname       = "swap_token_timeout",
 903                 .data           = &swap_token_default_timeout,
 904                 .maxlen         = sizeof(swap_token_default_timeout),
 905                 .mode           = 0644,
 906                 .proc_handler   = &proc_dointvec_jiffies,
 907                 .strategy       = &sysctl_jiffies,
 908         },
 909 #endif
 910 #ifdef CONFIG_NUMA
 911         {
 912                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 913                 .procname       = "zone_reclaim_mode",
 914                 .data           = &zone_reclaim_mode,
 915                 .maxlen         = sizeof(zone_reclaim_mode),
 916                 .mode           = 0644,
 917                 .proc_handler   = &proc_dointvec,
 918                 .strategy       = &sysctl_intvec,
 919                 .extra1         = &zero,
 920         },
 921         {
 922                 .ctl_name       = VM_ZONE_RECLAIM_INTERVAL,
 923                 .procname       = "zone_reclaim_interval",
 924                 .data           = &zone_reclaim_interval,
 925                 .maxlen         = sizeof(zone_reclaim_interval),
 926                 .mode           = 0644,
 927                 .proc_handler   = &proc_dointvec_jiffies,
 928                 .strategy       = &sysctl_jiffies,
 929         },
 930 #endif
 931         { .ctl_name = 0 }
 932 };
 933
 934 static ctl_table fs_table[] = {
 935         {
 936                 .ctl_name       = FS_NRINODE,
 937                 .procname       = "inode-nr",
 938                 .data           = &inodes_stat,
 939                 .maxlen         = 2*sizeof(int),
 940                 .mode           = 0444,
 941                 .proc_handler   = &proc_dointvec,
 942         },
 943         {
 944                 .ctl_name       = FS_STATINODE,
 945                 .procname       = "inode-state",
 946                 .data           = &inodes_stat,
 947                 .maxlen         = 7*sizeof(int),
 948                 .mode           = 0444,
 949                 .proc_handler   = &proc_dointvec,
 950         },
 951         {
 952                 .ctl_name       = FS_NRFILE,
 953                 .procname       = "file-nr",
 954                 .data           = &files_stat,
 955                 .maxlen         = 3*sizeof(int),
 956                 .mode           = 0444,
 957                 .proc_handler   = &proc_nr_files,
 958         },
 959         {
 960                 .ctl_name       = FS_MAXFILE,
 961                 .procname       = "file-max",
 962                 .data           = &files_stat.max_files,
 963                 .maxlen         = sizeof(int),
 964                 .mode           = 0644,
 965                 .proc_handler   = &proc_dointvec,
 966         },
 967         {
 968                 .ctl_name       = FS_DENTRY,
 969                 .procname       = "dentry-state",
 970                 .data           = &dentry_stat,
 971                 .maxlen         = 6*sizeof(int),
 972                 .mode           = 0444,
 973                 .proc_handler   = &proc_dointvec,
 974         },
 975         {
 976                 .ctl_name       = FS_OVERFLOWUID,
 977                 .procname       = "overflowuid",
 978                 .data           = &fs_overflowuid,
 979                 .maxlen         = sizeof(int),
 980                 .mode           = 0644,
 981                 .proc_handler   = &proc_dointvec_minmax,
 982                 .strategy       = &sysctl_intvec,
 983                 .extra1         = &minolduid,
 984                 .extra2         = &maxolduid,
 985         },
 986         {
 987                 .ctl_name       = FS_OVERFLOWGID,
 988                 .procname       = "overflowgid",
 989                 .data           = &fs_overflowgid,
 990                 .maxlen         = sizeof(int),
 991                 .mode           = 0644,
 992                 .proc_handler   = &proc_dointvec_minmax,
 993                 .strategy       = &sysctl_intvec,
 994                 .extra1         = &minolduid,
 995                 .extra2         = &maxolduid,
 996         },
 997         {
 998                 .ctl_name       = FS_LEASES,
 999                 .procname       = "leases-enable",
1000                 .data           = &leases_enable,
1001                 .maxlen         = sizeof(int),
1002                 .mode           = 0644,
1003                 .proc_handler   = &proc_dointvec,
1004         },
1005 #ifdef CONFIG_DNOTIFY
1006         {
1007                 .ctl_name       = FS_DIR_NOTIFY,
1008                 .procname       = "dir-notify-enable",
1009                 .data           = &dir_notify_enable,
1010                 .maxlen         = sizeof(int),
1011                 .mode           = 0644,
1012                 .proc_handler   = &proc_dointvec,
1013         },
1014 #endif
1015 #ifdef CONFIG_MMU
1016         {
1017                 .ctl_name       = FS_LEASE_TIME,
1018                 .procname       = "lease-break-time",
1019                 .data           = &lease_break_time,
1020                 .maxlen         = sizeof(int),
1021                 .mode           = 0644,
1022                 .proc_handler   = &proc_dointvec,
1023         },
1024         {
1025                 .ctl_name       = FS_AIO_NR,
1026                 .procname       = "aio-nr",
1027                 .data           = &aio_nr,
1028                 .maxlen         = sizeof(aio_nr),
1029                 .mode           = 0444,
1030                 .proc_handler   = &proc_doulongvec_minmax,
1031         },
1032         {
1033                 .ctl_name       = FS_AIO_MAX_NR,
1034                 .procname       = "aio-max-nr",
1035                 .data           = &aio_max_nr,
1036                 .maxlen         = sizeof(aio_max_nr),
1037                 .mode           = 0644,
1038                 .proc_handler   = &proc_doulongvec_minmax,
1039         },
1040 #ifdef CONFIG_INOTIFY_USER
1041         {
1042                 .ctl_name       = FS_INOTIFY,
1043                 .procname       = "inotify",
1044                 .mode           = 0555,
1045                 .child          = inotify_table,
1046         },
1047 #endif
1048 #endif
1049         {
1050                 .ctl_name       = KERN_SETUID_DUMPABLE,
1051                 .procname       = "suid_dumpable",
1052                 .data           = &suid_dumpable,
1053                 .maxlen         = sizeof(int),
1054                 .mode           = 0644,
1055                 .proc_handler   = &proc_dointvec,
1056         },
1057         { .ctl_name = 0 }
1058 };
1059
1060 static ctl_table debug_table[] = {
1061         { .ctl_name = 0 }
1062 };
1063
1064 static ctl_table dev_table[] = {
1065         { .ctl_name = 0 }
1066 };
1067
1068 extern void init_irq_proc (void);
1069
1070 static DEFINE_SPINLOCK(sysctl_lock);
1071
1072 /* called under sysctl_lock */
1073 static int use_table(struct ctl_table_header *p)
1074 {
1075         if (unlikely(p->unregistering))
1076                 return 0;
1077         p->used++;
1078         return 1;
1079 }
1080
1081 /* called under sysctl_lock */
1082 static void unuse_table(struct ctl_table_header *p)
1083 {
1084         if (!--p->used)
1085                 if (unlikely(p->unregistering))
1086                         complete(p->unregistering);
1087 }
1088
1089 /* called under sysctl_lock, will reacquire if has to wait */
1090 static void start_unregistering(struct ctl_table_header *p)
1091 {
1092         /*
1093          * if p->used is 0, nobody will ever touch that entry again;
1094          * we'll eliminate all paths to it before dropping sysctl_lock
1095          */
1096         if (unlikely(p->used)) {
1097                 struct completion wait;
1098                 init_completion(&wait);
1099                 p->unregistering = &wait;
1100                 spin_unlock(&sysctl_lock);
1101                 wait_for_completion(&wait);
1102                 spin_lock(&sysctl_lock);
1103         }
1104         /*
1105          * do not remove from the list until nobody holds it; walking the
1106          * list in do_sysctl() relies on that.
1107          */
1108         list_del_init(&p->ctl_entry);
1109 }
1110
1111 void __init sysctl_init(void)
1112 {
1113 #ifdef CONFIG_PROC_FS
1114         register_proc_table(root_table, proc_sys_root, &root_table_header);
1115         init_irq_proc();
1116 #endif
1117 }
1118
1119 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1120                void __user *newval, size_t newlen)
1121 {
1122         struct list_head *tmp;
1123         int error = -ENOTDIR;
1124
1125         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1126                 return -ENOTDIR;
1127         if (oldval) {
1128                 int old_len;
1129                 if (!oldlenp || get_user(old_len, oldlenp))
1130                         return -EFAULT;
1131         }
1132         spin_lock(&sysctl_lock);
1133         tmp = &root_table_header.ctl_entry;
1134         do {
1135                 struct ctl_table_header *head =
1136                         list_entry(tmp, struct ctl_table_header, ctl_entry);
1137                 void *context = NULL;
1138
1139                 if (!use_table(head))
1140                         continue;
1141
1142                 spin_unlock(&sysctl_lock);
1143
1144                 error = parse_table(name, nlen, oldval, oldlenp,
1145                                         newval, newlen, head->ctl_table,
1146                                         &context);
1147                 kfree(context);
1148
1149                 spin_lock(&sysctl_lock);
1150                 unuse_table(head);
1151                 if (error != -ENOTDIR)
1152                         break;
1153         } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
1154         spin_unlock(&sysctl_lock);
1155         return error;
1156 }
1157
1158 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1159 {
1160         struct __sysctl_args tmp;
1161         int error;
1162
1163         if (copy_from_user(&tmp, args, sizeof(tmp)))
1164                 return -EFAULT;
1165
1166         lock_kernel();
1167         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1168                           tmp.newval, tmp.newlen);
1169         unlock_kernel();
1170         return error;
1171 }
1172
1173 /*
1174  * ctl_perm does NOT grant the superuser all rights automatically, because
1175  * some sysctl variables are readonly even to root.
1176  */
1177
1178 static int test_perm(int mode, int op)
1179 {
1180         if (!current->euid)
1181                 mode >>= 6;
1182         else if (in_egroup_p(0))
1183                 mode >>= 3;
1184         if ((mode & op & 0007) == op)
1185                 return 0;
1186         return -EACCES;
1187 }
1188
1189 static inline int ctl_perm(ctl_table *table, int op)
1190 {
1191         int error;
1192         error = security_sysctl(table, op);
1193         if (error)
1194                 return error;
1195         return test_perm(table->mode, op);
1196 }
1197
1198 static int parse_table(int __user *name, int nlen,
1199                        void __user *oldval, size_t __user *oldlenp,
1200                        void __user *newval, size_t newlen,
1201                        ctl_table *table, void **context)
1202 {
1203         int n;
1204 repeat:
1205         if (!nlen)
1206                 return -ENOTDIR;
1207         if (get_user(n, name))
1208                 return -EFAULT;
1209         for ( ; table->ctl_name; table++) {
1210                 if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
1211                         int error;
1212                         if (table->child) {
1213                                 if (ctl_perm(table, 001))
1214                                         return -EPERM;
1215                                 if (table->strategy) {
1216                                         error = table->strategy(
1217                                                 table, name, nlen,
1218                                                 oldval, oldlenp,
1219                                                 newval, newlen, context);
1220                                         if (error)
1221                                                 return error;
1222                                 }
1223                                 name++;
1224                                 nlen--;
1225                                 table = table->child;
1226                                 goto repeat;
1227                         }
1228                         error = do_sysctl_strategy(table, name, nlen,
1229                                                    oldval, oldlenp,
1230                                                    newval, newlen, context);
1231                         return error;
1232                 }
1233         }
1234         return -ENOTDIR;
1235 }
1236
1237 /* Perform the actual read/write of a sysctl table entry. */
1238 int do_sysctl_strategy (ctl_table *table,
1239                         int __user *name, int nlen,
1240                         void __user *oldval, size_t __user *oldlenp,
1241                         void __user *newval, size_t newlen, void **context)
1242 {
1243         int op = 0, rc;
1244         size_t len;
1245
1246         if (oldval)
1247                 op |= 004;
1248         if (newval)
1249                 op |= 002;
1250         if (ctl_perm(table, op))
1251                 return -EPERM;
1252
1253         if (table->strategy) {
1254                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1255                                      newval, newlen, context);
1256                 if (rc < 0)
1257                         return rc;
1258                 if (rc > 0)
1259                         return 0;
1260         }
1261
1262         /* If there is no strategy routine, or if the strategy returns
1263          * zero, proceed with automatic r/w */
1264         if (table->data && table->maxlen) {
1265                 if (oldval && oldlenp) {
1266                         if (get_user(len, oldlenp))
1267                                 return -EFAULT;
1268                         if (len) {
1269                                 if (len > table->maxlen)
1270                                         len = table->maxlen;
1271                                 if(copy_to_user(oldval, table->data, len))
1272                                         return -EFAULT;
1273                                 if(put_user(len, oldlenp))
1274                                         return -EFAULT;
1275                         }
1276                 }
1277                 if (newval && newlen) {
1278                         len = newlen;
1279                         if (len > table->maxlen)
1280                                 len = table->maxlen;
1281                         if(copy_from_user(table->data, newval, len))
1282                                 return -EFAULT;
1283                 }
1284         }
1285         return 0;
1286 }
1287
1288 /**
1289  * register_sysctl_table - register a sysctl hierarchy
1290  * @table: the top-level table structure
1291  * @insert_at_head: whether the entry should be inserted in front or at the end
1292  *
1293  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1294  * array. An entry with a ctl_name of 0 terminates the table.
1295  *
1296  * The members of the &ctl_table structure are used as follows:
1297  *
1298  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1299  *            must be unique within that level of sysctl
1300  *
1301  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1302  *            enter a sysctl file
1303  *
1304  * data - a pointer to data for use by proc_handler
1305  *
1306  * maxlen - the maximum size in bytes of the data
1307  *
1308  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1309  *
1310  * child - a pointer to the child sysctl table if this entry is a directory, or
1311  *         %NULL.
1312  *
1313  * proc_handler - the text handler routine (described below)
1314  *
1315  * strategy - the strategy routine (described below)
1316  *
1317  * de - for internal use by the sysctl routines
1318  *
1319  * extra1, extra2 - extra pointers usable by the proc handler routines
1320  *
1321  * Leaf nodes in the sysctl tree will be represented by a single file
1322  * under /proc; non-leaf nodes will be represented by directories.
1323  *
1324  * sysctl(2) can automatically manage read and write requests through
1325  * the sysctl table.  The data and maxlen fields of the ctl_table
1326  * struct enable minimal validation of the values being written to be
1327  * performed, and the mode field allows minimal authentication.
1328  *
1329  * More sophisticated management can be enabled by the provision of a
1330  * strategy routine with the table entry.  This will be called before
1331  * any automatic read or write of the data is performed.
1332  *
1333  * The strategy routine may return
1334  *
1335  * < 0 - Error occurred (error is passed to user process)
1336  *
1337  * 0   - OK - proceed with automatic read or write.
1338  *
1339  * > 0 - OK - read or write has been done by the strategy routine, so
1340  *       return immediately.
1341  *
1342  * There must be a proc_handler routine for any terminal nodes
1343  * mirrored under /proc/sys (non-terminals are handled by a built-in
1344  * directory handler).  Several default handlers are available to
1345  * cover common cases -
1346  *
1347  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1348  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1349  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1350  *
1351  * It is the handler's job to read the input buffer from user memory
1352  * and process it. The handler should return 0 on success.
1353  *
1354  * This routine returns %NULL on a failure to register, and a pointer
1355  * to the table header on success.
1356  */
1357 struct ctl_table_header *register_sysctl_table(ctl_table * table,
1358                                                int insert_at_head)
1359 {
1360         struct ctl_table_header *tmp;
1361         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1362         if (!tmp)
1363                 return NULL;
1364         tmp->ctl_table = table;
1365         INIT_LIST_HEAD(&tmp->ctl_entry);
1366         tmp->used = 0;
1367         tmp->unregistering = NULL;
1368         spin_lock(&sysctl_lock);
1369         if (insert_at_head)
1370                 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
1371         else
1372                 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1373         spin_unlock(&sysctl_lock);
1374 #ifdef CONFIG_PROC_FS
1375         register_proc_table(table, proc_sys_root, tmp);
1376 #endif
1377         return tmp;
1378 }
1379
1380 /**
1381  * unregister_sysctl_table - unregister a sysctl table hierarchy
1382  * @header: the header returned from register_sysctl_table
1383  *
1384  * Unregisters the sysctl table and all children. proc entries may not
1385  * actually be removed until they are no longer used by anyone.
1386  */
1387 void unregister_sysctl_table(struct ctl_table_header * header)
1388 {
1389         might_sleep();
1390         spin_lock(&sysctl_lock);
1391         start_unregistering(header);
1392 #ifdef CONFIG_PROC_FS
1393         unregister_proc_table(header->ctl_table, proc_sys_root);
1394 #endif
1395         spin_unlock(&sysctl_lock);
1396         kfree(header);
1397 }
1398
1399 /*
1400  * /proc/sys support
1401  */
1402
1403 #ifdef CONFIG_PROC_FS
1404
1405 /* Scan the sysctl entries in table and add them all into /proc */
1406 static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
1407 {
1408         struct proc_dir_entry *de;
1409         int len;
1410         mode_t mode;
1411
1412         for (; table->ctl_name; table++) {
1413                 /* Can't do anything without a proc name. */
1414                 if (!table->procname)
1415                         continue;
1416                 /* Maybe we can't do anything with it... */
1417                 if (!table->proc_handler && !table->child) {
1418                         printk(KERN_WARNING "SYSCTL: Can't register %s\n",
1419                                 table->procname);
1420                         continue;
1421                 }
1422
1423                 len = strlen(table->procname);
1424                 mode = table->mode;
1425
1426                 de = NULL;
1427                 if (table->proc_handler)
1428                         mode |= S_IFREG;
1429                 else {
1430                         mode |= S_IFDIR;
1431                         for (de = root->subdir; de; de = de->next) {
1432                                 if (proc_match(len, table->procname, de))
1433                                         break;
1434                         }
1435                         /* If the subdir exists already, de is non-NULL */
1436                 }
1437
1438                 if (!de) {
1439                         de = create_proc_entry(table->procname, mode, root);
1440                         if (!de)
1441                                 continue;
1442                         de->set = set;
1443                         de->data = (void *) table;
1444                         if (table->proc_handler)
1445                                 de->proc_fops = &proc_sys_file_operations;
1446                 }
1447                 table->de = de;
1448                 if (de->mode & S_IFDIR)
1449                         register_proc_table(table->child, de, set);
1450         }
1451 }
1452
1453 /*
1454  * Unregister a /proc sysctl table and any subdirectories.
1455  */
1456 static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
1457 {
1458         struct proc_dir_entry *de;
1459         for (; table->ctl_name; table++) {
1460                 if (!(de = table->de))
1461                         continue;
1462                 if (de->mode & S_IFDIR) {
1463                         if (!table->child) {
1464                                 printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
1465                                 continue;
1466                         }
1467                         unregister_proc_table(table->child, de);
1468
1469                         /* Don't unregister directories which still have entries.. */
1470                         if (de->subdir)
1471                                 continue;
1472                 }
1473
1474                 /*
1475                  * In any case, mark the entry as goner; we'll keep it
1476                  * around if it's busy, but we'll know to do nothing with
1477                  * its fields.  We are under sysctl_lock here.
1478                  */
1479                 de->data = NULL;
1480
1481                 /* Don't unregister proc entries that are still being used.. */
1482                 if (atomic_read(&de->count))
1483                         continue;
1484
1485                 table->de = NULL;
1486                 remove_proc_entry(table->procname, root);
1487         }
1488 }
1489
1490 static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
1491                           size_t count, loff_t *ppos)
1492 {
1493         int op;
1494         struct proc_dir_entry *de = PDE(file->f_dentry->d_inode);
1495         struct ctl_table *table;
1496         size_t res;
1497         ssize_t error = -ENOTDIR;
1498
1499         spin_lock(&sysctl_lock);
1500         if (de && de->data && use_table(de->set)) {
1501                 /*
1502                  * at that point we know that sysctl was not unregistered
1503                  * and won't be until we finish
1504                  */
1505                 spin_unlock(&sysctl_lock);
1506                 table = (struct ctl_table *) de->data;
1507                 if (!table || !table->proc_handler)
1508                         goto out;
1509                 error = -EPERM;
1510                 op = (write ? 002 : 004);
1511                 if (ctl_perm(table, op))
1512                         goto out;
1513
1514                 /* careful: calling conventions are nasty here */
1515                 res = count;
1516                 error = (*table->proc_handler)(table, write, file,
1517                                                 buf, &res, ppos);
1518                 if (!error)
1519                         error = res;
1520         out:
1521                 spin_lock(&sysctl_lock);
1522                 unuse_table(de->set);
1523         }
1524         spin_unlock(&sysctl_lock);
1525         return error;
1526 }
1527
1528 static int proc_opensys(struct inode *inode, struct file *file)
1529 {
1530         if (file->f_mode & FMODE_WRITE) {
1531                 /*
1532                  * sysctl entries that are not writable,
1533                  * are _NOT_ writable, capabilities or not.
1534                  */
1535                 if (!(inode->i_mode & S_IWUSR))
1536                         return -EPERM;
1537         }
1538
1539         return 0;
1540 }
1541
1542 static ssize_t proc_readsys(struct file * file, char __user * buf,
1543                             size_t count, loff_t *ppos)
1544 {
1545         return do_rw_proc(0, file, buf, count, ppos);
1546 }
1547
1548 static ssize_t proc_writesys(struct file * file, const char __user * buf,
1549                              size_t count, loff_t *ppos)
1550 {
1551         return do_rw_proc(1, file, (char __user *) buf, count, ppos);
1552 }
1553
1554 /**
1555  * proc_dostring - read a string sysctl
1556  * @table: the sysctl table
1557  * @write: %TRUE if this is a write to the sysctl file
1558  * @filp: the file structure
1559  * @buffer: the user buffer
1560  * @lenp: the size of the user buffer
1561  * @ppos: file position
1562  *
1563  * Reads/writes a string from/to the user buffer. If the kernel
1564  * buffer provided is not large enough to hold the string, the
1565  * string is truncated. The copied string is %NULL-terminated.
1566  * If the string is being read by the user process, it is copied
1567  * and a newline '\n' is added. It is truncated if the buffer is
1568  * not large enough.
1569  *
1570  * Returns 0 on success.
1571  */
1572 int proc_dostring(ctl_table *table, int write, struct file *filp,
1573                   void __user *buffer, size_t *lenp, loff_t *ppos)
1574 {
1575         size_t len;
1576         char __user *p;
1577         char c;
1578
1579         if (!table->data || !table->maxlen || !*lenp ||
1580             (*ppos && !write)) {
1581                 *lenp = 0;
1582                 return 0;
1583         }
1584
1585         if (write) {
1586                 len = 0;
1587                 p = buffer;
1588                 while (len < *lenp) {
1589                         if (get_user(c, p++))
1590                                 return -EFAULT;
1591                         if (c == 0 || c == '\n')
1592                                 break;
1593                         len++;
1594                 }
1595                 if (len >= table->maxlen)
1596                         len = table->maxlen-1;
1597                 if(copy_from_user(table->data, buffer, len))
1598                         return -EFAULT;
1599                 ((char *) table->data)[len] = 0;
1600                 *ppos += *lenp;
1601         } else {
1602                 len = strlen(table->data);
1603                 if (len > table->maxlen)
1604                         len = table->maxlen;
1605                 if (len > *lenp)
1606                         len = *lenp;
1607                 if (len)
1608                         if(copy_to_user(buffer, table->data, len))
1609                                 return -EFAULT;
1610                 if (len < *lenp) {
1611                         if(put_user('\n', ((char __user *) buffer) + len))
1612                                 return -EFAULT;
1613                         len++;
1614                 }
1615                 *lenp = len;
1616                 *ppos += len;
1617         }
1618         return 0;
1619 }
1620
1621 /*
1622  *      Special case of dostring for the UTS structure. This has locks
1623  *      to observe. Should this be in kernel/sys.c ????
1624  */
1625
1626 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
1627                   void __user *buffer, size_t *lenp, loff_t *ppos)
1628 {
1629         int r;
1630
1631         if (!write) {
1632                 down_read(&uts_sem);
1633                 r=proc_dostring(table,0,filp,buffer,lenp, ppos);
1634                 up_read(&uts_sem);
1635         } else {
1636                 down_write(&uts_sem);
1637                 r=proc_dostring(table,1,filp,buffer,lenp, ppos);
1638                 up_write(&uts_sem);
1639         }
1640         return r;
1641 }
1642
1643 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1644                                  int *valp,
1645                                  int write, void *data)
1646 {
1647         if (write) {
1648                 *valp = *negp ? -*lvalp : *lvalp;
1649         } else {
1650                 int val = *valp;
1651                 if (val < 0) {
1652                         *negp = -1;
1653                         *lvalp = (unsigned long)-val;
1654                 } else {
1655                         *negp = 0;
1656                         *lvalp = (unsigned long)val;
1657                 }
1658         }
1659         return 0;
1660 }
1661
1662 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1663                   void __user *buffer, size_t *lenp, loff_t *ppos,
1664                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1665                               int write, void *data),
1666                   void *data)
1667 {
1668 #define TMPBUFLEN 21
1669         int *i, vleft, first=1, neg, val;
1670         unsigned long lval;
1671         size_t left, len;
1672
1673         char buf[TMPBUFLEN], *p;
1674         char __user *s = buffer;
1675
1676         if (!table->data || !table->maxlen || !*lenp ||
1677             (*ppos && !write)) {
1678                 *lenp = 0;
1679                 return 0;
1680         }
1681
1682         i = (int *) table->data;
1683         vleft = table->maxlen / sizeof(*i);
1684         left = *lenp;
1685
1686         if (!conv)
1687                 conv = do_proc_dointvec_conv;
1688
1689         for (; left && vleft--; i++, first=0) {
1690                 if (write) {
1691                         while (left) {
1692                                 char c;
1693                                 if (get_user(c, s))
1694                                         return -EFAULT;
1695                                 if (!isspace(c))
1696                                         break;
1697                                 left--;
1698                                 s++;
1699                         }
1700                         if (!left)
1701                                 break;
1702                         neg = 0;
1703                         len = left;
1704                         if (len > sizeof(buf) - 1)
1705                                 len = sizeof(buf) - 1;
1706                         if (copy_from_user(buf, s, len))
1707                                 return -EFAULT;
1708                         buf[len] = 0;
1709                         p = buf;
1710                         if (*p == '-' && left > 1) {
1711                                 neg = 1;
1712                                 left--, p++;
1713                         }
1714                         if (*p < '0' || *p > '9')
1715                                 break;
1716
1717                         lval = simple_strtoul(p, &p, 0);
1718
1719                         len = p-buf;
1720                         if ((len < left) && *p && !isspace(*p))
1721                                 break;
1722                         if (neg)
1723                                 val = -val;
1724                         s += len;
1725                         left -= len;
1726
1727                         if (conv(&neg, &lval, i, 1, data))
1728                                 break;
1729                 } else {
1730                         p = buf;
1731                         if (!first)
1732                                 *p++ = '\t';
1733
1734                         if (conv(&neg, &lval, i, 0, data))
1735                                 break;
1736
1737                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1738                         len = strlen(buf);
1739                         if (len > left)
1740                                 len = left;
1741                         if(copy_to_user(s, buf, len))
1742                                 return -EFAULT;
1743                         left -= len;
1744                         s += len;
1745                 }
1746         }
1747
1748         if (!write && !first && left) {
1749                 if(put_user('\n', s))
1750                         return -EFAULT;
1751                 left--, s++;
1752         }
1753         if (write) {
1754                 while (left) {
1755                         char c;
1756                         if (get_user(c, s++))
1757                                 return -EFAULT;
1758                         if (!isspace(c))
1759                                 break;
1760                         left--;
1761                 }
1762         }
1763         if (write && first)
1764                 return -EINVAL;
1765         *lenp -= left;
1766         *ppos += *lenp;
1767         return 0;
1768 #undef TMPBUFLEN
1769 }
1770
1771 /**
1772  * proc_dointvec - read a vector of integers
1773  * @table: the sysctl table
1774  * @write: %TRUE if this is a write to the sysctl file
1775  * @filp: the file structure
1776  * @buffer: the user buffer
1777  * @lenp: the size of the user buffer
1778  * @ppos: file position
1779  *
1780  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1781  * values from/to the user buffer, treated as an ASCII string.
1782  *
1783  * Returns 0 on success.
1784  */
1785 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1786                      void __user *buffer, size_t *lenp, loff_t *ppos)
1787 {
1788     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1789                             NULL,NULL);
1790 }
1791
1792 #define OP_SET  0
1793 #define OP_AND  1
1794 #define OP_OR   2
1795 #define OP_MAX  3
1796 #define OP_MIN  4
1797
1798 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1799                                       int *valp,
1800                                       int write, void *data)
1801 {
1802         int op = *(int *)data;
1803         if (write) {
1804                 int val = *negp ? -*lvalp : *lvalp;
1805                 switch(op) {
1806                 case OP_SET:    *valp = val; break;
1807                 case OP_AND:    *valp &= val; break;
1808                 case OP_OR:     *valp |= val; break;
1809                 case OP_MAX:    if(*valp < val)
1810                                         *valp = val;
1811                                 break;
1812                 case OP_MIN:    if(*valp > val)
1813                                 *valp = val;
1814                                 break;
1815                 }
1816         } else {
1817                 int val = *valp;
1818                 if (val < 0) {
1819                         *negp = -1;
1820                         *lvalp = (unsigned long)-val;
1821                 } else {
1822                         *negp = 0;
1823                         *lvalp = (unsigned long)val;
1824                 }
1825         }
1826         return 0;
1827 }
1828
1829 /*
1830  *      init may raise the set.
1831  */
1832
1833 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1834                         void __user *buffer, size_t *lenp, loff_t *ppos)
1835 {
1836         int op;
1837
1838         if (!capable(CAP_SYS_MODULE)) {
1839                 return -EPERM;
1840         }
1841
1842         op = (current->pid == 1) ? OP_SET : OP_AND;
1843         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1844                                 do_proc_dointvec_bset_conv,&op);
1845 }
1846
1847 struct do_proc_dointvec_minmax_conv_param {
1848         int *min;
1849         int *max;
1850 };
1851
1852 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1853                                         int *valp,
1854                                         int write, void *data)
1855 {
1856         struct do_proc_dointvec_minmax_conv_param *param = data;
1857         if (write) {
1858                 int val = *negp ? -*lvalp : *lvalp;
1859                 if ((param->min && *param->min > val) ||
1860                     (param->max && *param->max < val))
1861                         return -EINVAL;
1862                 *valp = val;
1863         } else {
1864                 int val = *valp;
1865                 if (val < 0) {
1866                         *negp = -1;
1867                         *lvalp = (unsigned long)-val;
1868                 } else {
1869                         *negp = 0;
1870                         *lvalp = (unsigned long)val;
1871                 }
1872         }
1873         return 0;
1874 }
1875
1876 /**
1877  * proc_dointvec_minmax - read a vector of integers with min/max values
1878  * @table: the sysctl table
1879  * @write: %TRUE if this is a write to the sysctl file
1880  * @filp: the file structure
1881  * @buffer: the user buffer
1882  * @lenp: the size of the user buffer
1883  * @ppos: file position
1884  *
1885  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1886  * values from/to the user buffer, treated as an ASCII string.
1887  *
1888  * This routine will ensure the values are within the range specified by
1889  * table->extra1 (min) and table->extra2 (max).
1890  *
1891  * Returns 0 on success.
1892  */
1893 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1894                   void __user *buffer, size_t *lenp, loff_t *ppos)
1895 {
1896         struct do_proc_dointvec_minmax_conv_param param = {
1897                 .min = (int *) table->extra1,
1898                 .max = (int *) table->extra2,
1899         };
1900         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1901                                 do_proc_dointvec_minmax_conv, &param);
1902 }
1903
1904 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1905                                      struct file *filp,
1906                                      void __user *buffer,
1907                                      size_t *lenp, loff_t *ppos,
1908                                      unsigned long convmul,
1909                                      unsigned long convdiv)
1910 {
1911 #define TMPBUFLEN 21
1912         unsigned long *i, *min, *max, val;
1913         int vleft, first=1, neg;
1914         size_t len, left;
1915         char buf[TMPBUFLEN], *p;
1916         char __user *s = buffer;
1917
1918         if (!table->data || !table->maxlen || !*lenp ||
1919             (*ppos && !write)) {
1920                 *lenp = 0;
1921                 return 0;
1922         }
1923
1924         i = (unsigned long *) table->data;
1925         min = (unsigned long *) table->extra1;
1926         max = (unsigned long *) table->extra2;
1927         vleft = table->maxlen / sizeof(unsigned long);
1928         left = *lenp;
1929
1930         for (; left && vleft--; i++, min++, max++, first=0) {
1931                 if (write) {
1932                         while (left) {
1933                                 char c;
1934                                 if (get_user(c, s))
1935                                         return -EFAULT;
1936                                 if (!isspace(c))
1937                                         break;
1938                                 left--;
1939                                 s++;
1940                         }
1941                         if (!left)
1942                                 break;
1943                         neg = 0;
1944                         len = left;
1945                         if (len > TMPBUFLEN-1)
1946                                 len = TMPBUFLEN-1;
1947                         if (copy_from_user(buf, s, len))
1948                                 return -EFAULT;
1949                         buf[len] = 0;
1950                         p = buf;
1951                         if (*p == '-' && left > 1) {
1952                                 neg = 1;
1953                                 left--, p++;
1954                         }
1955                         if (*p < '0' || *p > '9')
1956                                 break;
1957                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1958                         len = p-buf;
1959                         if ((len < left) && *p && !isspace(*p))
1960                                 break;
1961                         if (neg)
1962                                 val = -val;
1963                         s += len;
1964                         left -= len;
1965
1966                         if(neg)
1967                                 continue;
1968                         if ((min && val < *min) || (max && val > *max))
1969                                 continue;
1970                         *i = val;
1971                 } else {
1972                         p = buf;
1973                         if (!first)
1974                                 *p++ = '\t';
1975                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1976                         len = strlen(buf);
1977                         if (len > left)
1978                                 len = left;
1979                         if(copy_to_user(s, buf, len))
1980                                 return -EFAULT;
1981                         left -= len;
1982                         s += len;
1983                 }
1984         }
1985
1986         if (!write && !first && left) {
1987                 if(put_user('\n', s))
1988                         return -EFAULT;
1989                 left--, s++;
1990         }
1991         if (write) {
1992                 while (left) {
1993                         char c;
1994                         if (get_user(c, s++))
1995                                 return -EFAULT;
1996                         if (!isspace(c))
1997                                 break;
1998                         left--;
1999                 }
2000         }
2001         if (write && first)
2002                 return -EINVAL;
2003         *lenp -= left;
2004         *ppos += *lenp;
2005         return 0;
2006 #undef TMPBUFLEN
2007 }
2008
2009 /**
2010  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2011  * @table: the sysctl table
2012  * @write: %TRUE if this is a write to the sysctl file
2013  * @filp: the file structure
2014  * @buffer: the user buffer
2015  * @lenp: the size of the user buffer
2016  * @ppos: file position
2017  *
2018  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2019  * values from/to the user buffer, treated as an ASCII string.
2020  *
2021  * This routine will ensure the values are within the range specified by
2022  * table->extra1 (min) and table->extra2 (max).
2023  *
2024  * Returns 0 on success.
2025  */
2026 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2027                            void __user *buffer, size_t *lenp, loff_t *ppos)
2028 {
2029     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2030 }
2031
2032 /**
2033  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2034  * @table: the sysctl table
2035  * @write: %TRUE if this is a write to the sysctl file
2036  * @filp: the file structure
2037  * @buffer: the user buffer
2038  * @lenp: the size of the user buffer
2039  * @ppos: file position
2040  *
2041  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2042  * values from/to the user buffer, treated as an ASCII string. The values
2043  * are treated as milliseconds, and converted to jiffies when they are stored.
2044  *
2045  * This routine will ensure the values are within the range specified by
2046  * table->extra1 (min) and table->extra2 (max).
2047  *
2048  * Returns 0 on success.
2049  */
2050 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2051                                       struct file *filp,
2052                                       void __user *buffer,
2053                                       size_t *lenp, loff_t *ppos)
2054 {
2055     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2056                                      lenp, ppos, HZ, 1000l);
2057 }
2058
2059
2060 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2061                                          int *valp,
2062                                          int write, void *data)
2063 {
2064         if (write) {
2065                 if (*lvalp > LONG_MAX / HZ)
2066                         return 1;
2067                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2068         } else {
2069                 int val = *valp;
2070                 unsigned long lval;
2071                 if (val < 0) {
2072                         *negp = -1;
2073                         lval = (unsigned long)-val;
2074                 } else {
2075                         *negp = 0;
2076                         lval = (unsigned long)val;
2077                 }
2078                 *lvalp = lval / HZ;
2079         }
2080         return 0;
2081 }
2082
2083 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2084                                                 int *valp,
2085                                                 int write, void *data)
2086 {
2087         if (write) {
2088                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2089                         return 1;
2090                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2091         } else {
2092                 int val = *valp;
2093                 unsigned long lval;
2094                 if (val < 0) {
2095                         *negp = -1;
2096                         lval = (unsigned long)-val;
2097                 } else {
2098                         *negp = 0;
2099                         lval = (unsigned long)val;
2100                 }
2101                 *lvalp = jiffies_to_clock_t(lval);
2102         }
2103         return 0;
2104 }
2105
2106 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2107                                             int *valp,
2108                                             int write, void *data)
2109 {
2110         if (write) {
2111                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2112         } else {
2113                 int val = *valp;
2114                 unsigned long lval;
2115                 if (val < 0) {
2116                         *negp = -1;
2117                         lval = (unsigned long)-val;
2118                 } else {
2119                         *negp = 0;
2120                         lval = (unsigned long)val;
2121                 }
2122                 *lvalp = jiffies_to_msecs(lval);
2123         }
2124         return 0;
2125 }
2126
2127 /**
2128  * proc_dointvec_jiffies - read a vector of integers as seconds
2129  * @table: the sysctl table
2130  * @write: %TRUE if this is a write to the sysctl file
2131  * @filp: the file structure
2132  * @buffer: the user buffer
2133  * @lenp: the size of the user buffer
2134  * @ppos: file position
2135  *
2136  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2137  * values from/to the user buffer, treated as an ASCII string.
2138  * The values read are assumed to be in seconds, and are converted into
2139  * jiffies.
2140  *
2141  * Returns 0 on success.
2142  */
2143 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2144                           void __user *buffer, size_t *lenp, loff_t *ppos)
2145 {
2146     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2147                             do_proc_dointvec_jiffies_conv,NULL);
2148 }
2149
2150 /**
2151  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2152  * @table: the sysctl table
2153  * @write: %TRUE if this is a write to the sysctl file
2154  * @filp: the file structure
2155  * @buffer: the user buffer
2156  * @lenp: the size of the user buffer
2157  * @ppos: pointer to the file position
2158  *
2159  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2160  * values from/to the user buffer, treated as an ASCII string.
2161  * The values read are assumed to be in 1/USER_HZ seconds, and
2162  * are converted into jiffies.
2163  *
2164  * Returns 0 on success.
2165  */
2166 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2167                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2168 {
2169     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2170                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2171 }
2172
2173 /**
2174  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2175  * @table: the sysctl table
2176  * @write: %TRUE if this is a write to the sysctl file
2177  * @filp: the file structure
2178  * @buffer: the user buffer
2179  * @lenp: the size of the user buffer
2180  * @ppos: file position
2181  * @ppos: the current position in the file
2182  *
2183  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2184  * values from/to the user buffer, treated as an ASCII string.
2185  * The values read are assumed to be in 1/1000 seconds, and
2186  * are converted into jiffies.
2187  *
2188  * Returns 0 on success.
2189  */
2190 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2191                              void __user *buffer, size_t *lenp, loff_t *ppos)
2192 {
2193         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2194                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2195 }
2196
2197 #else /* CONFIG_PROC_FS */
2198
2199 int proc_dostring(ctl_table *table, int write, struct file *filp,
2200                   void __user *buffer, size_t *lenp, loff_t *ppos)
2201 {
2202         return -ENOSYS;
2203 }
2204
2205 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
2206                             void __user *buffer, size_t *lenp, loff_t *ppos)
2207 {
2208         return -ENOSYS;
2209 }
2210
2211 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2212                   void __user *buffer, size_t *lenp, loff_t *ppos)
2213 {
2214         return -ENOSYS;
2215 }
2216
2217 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2218                         void __user *buffer, size_t *lenp, loff_t *ppos)
2219 {
2220         return -ENOSYS;
2221 }
2222
2223 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2224                     void __user *buffer, size_t *lenp, loff_t *ppos)
2225 {
2226         return -ENOSYS;
2227 }
2228
2229 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2230                     void __user *buffer, size_t *lenp, loff_t *ppos)
2231 {
2232         return -ENOSYS;
2233 }
2234
2235 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2236                     void __user *buffer, size_t *lenp, loff_t *ppos)
2237 {
2238         return -ENOSYS;
2239 }
2240
2241 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2242                              void __user *buffer, size_t *lenp, loff_t *ppos)
2243 {
2244         return -ENOSYS;
2245 }
2246
2247 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2248                     void __user *buffer, size_t *lenp, loff_t *ppos)
2249 {
2250         return -ENOSYS;
2251 }
2252
2253 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2254                                       struct file *filp,
2255                                       void __user *buffer,
2256                                       size_t *lenp, loff_t *ppos)
2257 {
2258     return -ENOSYS;
2259 }
2260
2261
2262 #endif /* CONFIG_PROC_FS */
2263
2264
2265 /*
2266  * General sysctl support routines
2267  */
2268
2269 /* The generic string strategy routine: */
2270 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2271                   void __user *oldval, size_t __user *oldlenp,
2272                   void __user *newval, size_t newlen, void **context)
2273 {
2274         if (!table->data || !table->maxlen)
2275                 return -ENOTDIR;
2276
2277         if (oldval && oldlenp) {
2278                 size_t bufsize;
2279                 if (get_user(bufsize, oldlenp))
2280                         return -EFAULT;
2281                 if (bufsize) {
2282                         size_t len = strlen(table->data), copied;
2283
2284                         /* This shouldn't trigger for a well-formed sysctl */
2285                         if (len > table->maxlen)
2286                                 len = table->maxlen;
2287
2288                         /* Copy up to a max of bufsize-1 bytes of the string */
2289                         copied = (len >= bufsize) ? bufsize - 1 : len;
2290
2291                         if (copy_to_user(oldval, table->data, copied) ||
2292                             put_user(0, (char __user *)(oldval + copied)))
2293                                 return -EFAULT;
2294                         if (put_user(len, oldlenp))
2295                                 return -EFAULT;
2296                 }
2297         }
2298         if (newval && newlen) {
2299                 size_t len = newlen;
2300                 if (len > table->maxlen)
2301                         len = table->maxlen;
2302                 if(copy_from_user(table->data, newval, len))
2303                         return -EFAULT;
2304                 if (len == table->maxlen)
2305                         len--;
2306                 ((char *) table->data)[len] = 0;
2307         }
2308         return 1;
2309 }
2310
2311 /*
2312  * This function makes sure that all of the integers in the vector
2313  * are between the minimum and maximum values given in the arrays
2314  * table->extra1 and table->extra2, respectively.
2315  */
2316 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2317                 void __user *oldval, size_t __user *oldlenp,
2318                 void __user *newval, size_t newlen, void **context)
2319 {
2320
2321         if (newval && newlen) {
2322                 int __user *vec = (int __user *) newval;
2323                 int *min = (int *) table->extra1;
2324                 int *max = (int *) table->extra2;
2325                 size_t length;
2326                 int i;
2327
2328                 if (newlen % sizeof(int) != 0)
2329                         return -EINVAL;
2330
2331                 if (!table->extra1 && !table->extra2)
2332                         return 0;
2333
2334                 if (newlen > table->maxlen)
2335                         newlen = table->maxlen;
2336                 length = newlen / sizeof(int);
2337
2338                 for (i = 0; i < length; i++) {
2339                         int value;
2340                         if (get_user(value, vec + i))
2341                                 return -EFAULT;
2342                         if (min && value < min[i])
2343                                 return -EINVAL;
2344                         if (max && value > max[i])
2345                                 return -EINVAL;
2346                 }
2347         }
2348         return 0;
2349 }
2350
2351 /* Strategy function to convert jiffies to seconds */
2352 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2353                 void __user *oldval, size_t __user *oldlenp,
2354                 void __user *newval, size_t newlen, void **context)
2355 {
2356         if (oldval) {
2357                 size_t olen;
2358                 if (oldlenp) {
2359                         if (get_user(olen, oldlenp))
2360                                 return -EFAULT;
2361                         if (olen!=sizeof(int))
2362                                 return -EINVAL;
2363                 }
2364                 if (put_user(*(int *)(table->data)/HZ, (int __user *)oldval) ||
2365                     (oldlenp && put_user(sizeof(int),oldlenp)))
2366                         return -EFAULT;
2367         }
2368         if (newval && newlen) {
2369                 int new;
2370                 if (newlen != sizeof(int))
2371                         return -EINVAL;
2372                 if (get_user(new, (int __user *)newval))
2373                         return -EFAULT;
2374                 *(int *)(table->data) = new*HZ;
2375         }
2376         return 1;
2377 }
2378
2379 /* Strategy function to convert jiffies to seconds */
2380 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2381                 void __user *oldval, size_t __user *oldlenp,
2382                 void __user *newval, size_t newlen, void **context)
2383 {
2384         if (oldval) {
2385                 size_t olen;
2386                 if (oldlenp) {
2387                         if (get_user(olen, oldlenp))
2388                                 return -EFAULT;
2389                         if (olen!=sizeof(int))
2390                                 return -EINVAL;
2391                 }
2392                 if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
2393                     (oldlenp && put_user(sizeof(int),oldlenp)))
2394                         return -EFAULT;
2395         }
2396         if (newval && newlen) {
2397                 int new;
2398                 if (newlen != sizeof(int))
2399                         return -EINVAL;
2400                 if (get_user(new, (int __user *)newval))
2401                         return -EFAULT;
2402                 *(int *)(table->data) = msecs_to_jiffies(new);
2403         }
2404         return 1;
2405 }
2406
2407 #else /* CONFIG_SYSCTL */
2408
2409
2410 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2411 {
2412         return -ENOSYS;
2413 }
2414
2415 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2416                   void __user *oldval, size_t __user *oldlenp,
2417                   void __user *newval, size_t newlen, void **context)
2418 {
2419         return -ENOSYS;
2420 }
2421
2422 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2423                 void __user *oldval, size_t __user *oldlenp,
2424                 void __user *newval, size_t newlen, void **context)
2425 {
2426         return -ENOSYS;
2427 }
2428
2429 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2430                 void __user *oldval, size_t __user *oldlenp,
2431                 void __user *newval, size_t newlen, void **context)
2432 {
2433         return -ENOSYS;
2434 }
2435
2436 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2437                 void __user *oldval, size_t __user *oldlenp,
2438                 void __user *newval, size_t newlen, void **context)
2439 {
2440         return -ENOSYS;
2441 }
2442
2443 int proc_dostring(ctl_table *table, int write, struct file *filp,
2444                   void __user *buffer, size_t *lenp, loff_t *ppos)
2445 {
2446         return -ENOSYS;
2447 }
2448
2449 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2450                   void __user *buffer, size_t *lenp, loff_t *ppos)
2451 {
2452         return -ENOSYS;
2453 }
2454
2455 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2456                         void __user *buffer, size_t *lenp, loff_t *ppos)
2457 {
2458         return -ENOSYS;
2459 }
2460
2461 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2462                     void __user *buffer, size_t *lenp, loff_t *ppos)
2463 {
2464         return -ENOSYS;
2465 }
2466
2467 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2468                           void __user *buffer, size_t *lenp, loff_t *ppos)
2469 {
2470         return -ENOSYS;
2471 }
2472
2473 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2474                           void __user *buffer, size_t *lenp, loff_t *ppos)
2475 {
2476         return -ENOSYS;
2477 }
2478
2479 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2480                              void __user *buffer, size_t *lenp, loff_t *ppos)
2481 {
2482         return -ENOSYS;
2483 }
2484
2485 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2486                     void __user *buffer, size_t *lenp, loff_t *ppos)
2487 {
2488         return -ENOSYS;
2489 }
2490
2491 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2492                                       struct file *filp,
2493                                       void __user *buffer,
2494                                       size_t *lenp, loff_t *ppos)
2495 {
2496     return -ENOSYS;
2497 }
2498
2499 struct ctl_table_header * register_sysctl_table(ctl_table * table,
2500                                                 int insert_at_head)
2501 {
2502         return NULL;
2503 }
2504
2505 void unregister_sysctl_table(struct ctl_table_header * table)
2506 {
2507 }
2508
2509 #endif /* CONFIG_SYSCTL */
2510
2511 /*
2512  * No sense putting this after each symbol definition, twice,
2513  * exception granted :-)
2514  */
2515 EXPORT_SYMBOL(proc_dointvec);
2516 EXPORT_SYMBOL(proc_dointvec_jiffies);
2517 EXPORT_SYMBOL(proc_dointvec_minmax);
2518 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2519 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2520 EXPORT_SYMBOL(proc_dostring);
2521 EXPORT_SYMBOL(proc_doulongvec_minmax);
2522 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2523 EXPORT_SYMBOL(register_sysctl_table);
2524 EXPORT_SYMBOL(sysctl_intvec);
2525 EXPORT_SYMBOL(sysctl_jiffies);
2526 EXPORT_SYMBOL(sysctl_ms_jiffies);
2527 EXPORT_SYMBOL(sysctl_string);
2528 EXPORT_SYMBOL(unregister_sysctl_table);