kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/capability.h>
  28 #include <linux/ctype.h>
  29 #include <linux/utsname.h>
  30 #include <linux/capability.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/hugetlb.h>
  40 #include <linux/security.h>
  41 #include <linux/initrd.h>
  42 #include <linux/times.h>
  43 #include <linux/limits.h>
  44 #include <linux/dcache.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/nfs_fs.h>
  47 #include <linux/acpi.h>
  48
  49 #include <asm/uaccess.h>
  50 #include <asm/processor.h>
  51
  52 extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
  53                      void __user *buffer, size_t *lenp, loff_t *ppos);
  54
  55 #ifdef CONFIG_X86
  56 #include <asm/nmi.h>
  57 #include <asm/stacktrace.h>
  58 #endif
  59
  60 #if defined(CONFIG_SYSCTL)
  61
  62 /* External variables not in a header file. */
  63 extern int C_A_D;
  64 extern int sysctl_overcommit_memory;
  65 extern int sysctl_overcommit_ratio;
  66 extern int sysctl_panic_on_oom;
  67 extern int max_threads;
  68 extern int core_uses_pid;
  69 extern int suid_dumpable;
  70 extern char core_pattern[];
  71 extern int pid_max;
  72 extern int min_free_kbytes;
  73 extern int printk_ratelimit_jiffies;
  74 extern int printk_ratelimit_burst;
  75 extern int pid_max_min, pid_max_max;
  76 extern int sysctl_drop_caches;
  77 extern int percpu_pagelist_fraction;
  78 extern int compat_log;
  79 extern int maps_protect;
  80 extern int sysctl_stat_interval;
  81
  82 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
  83 static int maxolduid = 65535;
  84 static int minolduid;
  85 static int min_percpu_pagelist_fract = 8;
  86
  87 static int ngroups_max = NGROUPS_MAX;
  88
  89 #ifdef CONFIG_KMOD
  90 extern char modprobe_path[];
  91 #endif
  92 #ifdef CONFIG_CHR_DEV_SG
  93 extern int sg_big_buff;
  94 #endif
  95
  96 #ifdef __sparc__
  97 extern char reboot_command [];
  98 extern int stop_a_enabled;
  99 extern int scons_pwroff;
 100 #endif
 101
 102 #ifdef __hppa__
 103 extern int pwrsw_enabled;
 104 extern int unaligned_enabled;
 105 #endif
 106
 107 #ifdef CONFIG_S390
 108 #ifdef CONFIG_MATHEMU
 109 extern int sysctl_ieee_emulation_warnings;
 110 #endif
 111 extern int sysctl_userprocess_debug;
 112 extern int spin_retry;
 113 #endif
 114
 115 extern int sysctl_hz_timer;
 116
 117 #ifdef CONFIG_BSD_PROCESS_ACCT
 118 extern int acct_parm[];
 119 #endif
 120
 121 #ifdef CONFIG_IA64
 122 extern int no_unaligned_warning;
 123 #endif
 124
 125 #ifdef CONFIG_RT_MUTEXES
 126 extern int max_lock_depth;
 127 #endif
 128
 129 #ifdef CONFIG_SYSCTL_SYSCALL
 130 static int parse_table(int __user *, int, void __user *, size_t __user *,
 131                 void __user *, size_t, ctl_table *);
 132 #endif
 133
 134
 135 #ifdef CONFIG_PROC_SYSCTL
 136 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
 137                   void __user *buffer, size_t *lenp, loff_t *ppos);
 138 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
 139                                void __user *buffer, size_t *lenp, loff_t *ppos);
 140 #endif
 141
 142 static ctl_table root_table[];
 143 static struct ctl_table_header root_table_header =
 144         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
 145
 146 static ctl_table kern_table[];
 147 static ctl_table vm_table[];
 148 static ctl_table fs_table[];
 149 static ctl_table debug_table[];
 150 static ctl_table dev_table[];
 151 extern ctl_table random_table[];
 152 #ifdef CONFIG_UNIX98_PTYS
 153 extern ctl_table pty_table[];
 154 #endif
 155 #ifdef CONFIG_INOTIFY_USER
 156 extern ctl_table inotify_table[];
 157 #endif
 158
 159 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 160 int sysctl_legacy_va_layout;
 161 #endif
 162
 163
 164 /* The default sysctl tables: */
 165
 166 static ctl_table root_table[] = {
 167         {
 168                 .ctl_name       = CTL_KERN,
 169                 .procname       = "kernel",
 170                 .mode           = 0555,
 171                 .child          = kern_table,
 172         },
 173         {
 174                 .ctl_name       = CTL_VM,
 175                 .procname       = "vm",
 176                 .mode           = 0555,
 177                 .child          = vm_table,
 178         },
 179 #ifdef CONFIG_NET
 180         {
 181                 .ctl_name       = CTL_NET,
 182                 .procname       = "net",
 183                 .mode           = 0555,
 184                 .child          = net_table,
 185         },
 186 #endif
 187         {
 188                 .ctl_name       = CTL_FS,
 189                 .procname       = "fs",
 190                 .mode           = 0555,
 191                 .child          = fs_table,
 192         },
 193         {
 194                 .ctl_name       = CTL_DEBUG,
 195                 .procname       = "debug",
 196                 .mode           = 0555,
 197                 .child          = debug_table,
 198         },
 199         {
 200                 .ctl_name       = CTL_DEV,
 201                 .procname       = "dev",
 202                 .mode           = 0555,
 203                 .child          = dev_table,
 204         },
 205
 206         { .ctl_name = 0 }
 207 };
 208
 209 #ifdef CONFIG_SCHED_DEBUG
 210 static unsigned long min_sched_granularity_ns = 100000;         /* 100 usecs */
 211 static unsigned long max_sched_granularity_ns = 1000000000;     /* 1 second */
 212 static unsigned long min_wakeup_granularity_ns;                 /* 0 usecs */
 213 static unsigned long max_wakeup_granularity_ns = 1000000000;    /* 1 second */
 214 #endif
 215
 216 static ctl_table kern_table[] = {
 217 #ifdef CONFIG_SCHED_DEBUG
 218         {
 219                 .ctl_name       = CTL_UNNUMBERED,
 220                 .procname       = "sched_granularity_ns",
 221                 .data           = &sysctl_sched_granularity,
 222                 .maxlen         = sizeof(unsigned int),
 223                 .mode           = 0644,
 224                 .proc_handler   = &proc_dointvec_minmax,
 225                 .strategy       = &sysctl_intvec,
 226                 .extra1         = &min_sched_granularity_ns,
 227                 .extra2         = &max_sched_granularity_ns,
 228         },
 229         {
 230                 .ctl_name       = CTL_UNNUMBERED,
 231                 .procname       = "sched_wakeup_granularity_ns",
 232                 .data           = &sysctl_sched_wakeup_granularity,
 233                 .maxlen         = sizeof(unsigned int),
 234                 .mode           = 0644,
 235                 .proc_handler   = &proc_dointvec_minmax,
 236                 .strategy       = &sysctl_intvec,
 237                 .extra1         = &min_wakeup_granularity_ns,
 238                 .extra2         = &max_wakeup_granularity_ns,
 239         },
 240         {
 241                 .ctl_name       = CTL_UNNUMBERED,
 242                 .procname       = "sched_batch_wakeup_granularity_ns",
 243                 .data           = &sysctl_sched_batch_wakeup_granularity,
 244                 .maxlen         = sizeof(unsigned int),
 245                 .mode           = 0644,
 246                 .proc_handler   = &proc_dointvec_minmax,
 247                 .strategy       = &sysctl_intvec,
 248                 .extra1         = &min_wakeup_granularity_ns,
 249                 .extra2         = &max_wakeup_granularity_ns,
 250         },
 251         {
 252                 .ctl_name       = CTL_UNNUMBERED,
 253                 .procname       = "sched_stat_granularity_ns",
 254                 .data           = &sysctl_sched_stat_granularity,
 255                 .maxlen         = sizeof(unsigned int),
 256                 .mode           = 0644,
 257                 .proc_handler   = &proc_dointvec_minmax,
 258                 .strategy       = &sysctl_intvec,
 259                 .extra1         = &min_wakeup_granularity_ns,
 260                 .extra2         = &max_wakeup_granularity_ns,
 261         },
 262         {
 263                 .ctl_name       = CTL_UNNUMBERED,
 264                 .procname       = "sched_runtime_limit_ns",
 265                 .data           = &sysctl_sched_runtime_limit,
 266                 .maxlen         = sizeof(unsigned int),
 267                 .mode           = 0644,
 268                 .proc_handler   = &proc_dointvec_minmax,
 269                 .strategy       = &sysctl_intvec,
 270                 .extra1         = &min_sched_granularity_ns,
 271                 .extra2         = &max_sched_granularity_ns,
 272         },
 273         {
 274                 .ctl_name       = CTL_UNNUMBERED,
 275                 .procname       = "sched_child_runs_first",
 276                 .data           = &sysctl_sched_child_runs_first,
 277                 .maxlen         = sizeof(unsigned int),
 278                 .mode           = 0644,
 279                 .proc_handler   = &proc_dointvec,
 280         },
 281         {
 282                 .ctl_name       = CTL_UNNUMBERED,
 283                 .procname       = "sched_features",
 284                 .data           = &sysctl_sched_features,
 285                 .maxlen         = sizeof(unsigned int),
 286                 .mode           = 0644,
 287                 .proc_handler   = &proc_dointvec,
 288         },
 289 #endif
 290         {
 291                 .ctl_name       = KERN_PANIC,
 292                 .procname       = "panic",
 293                 .data           = &panic_timeout,
 294                 .maxlen         = sizeof(int),
 295                 .mode           = 0644,
 296                 .proc_handler   = &proc_dointvec,
 297         },
 298         {
 299                 .ctl_name       = KERN_CORE_USES_PID,
 300                 .procname       = "core_uses_pid",
 301                 .data           = &core_uses_pid,
 302                 .maxlen         = sizeof(int),
 303                 .mode           = 0644,
 304                 .proc_handler   = &proc_dointvec,
 305         },
 306         {
 307                 .ctl_name       = KERN_CORE_PATTERN,
 308                 .procname       = "core_pattern",
 309                 .data           = core_pattern,
 310                 .maxlen         = CORENAME_MAX_SIZE,
 311                 .mode           = 0644,
 312                 .proc_handler   = &proc_dostring,
 313                 .strategy       = &sysctl_string,
 314         },
 315 #ifdef CONFIG_PROC_SYSCTL
 316         {
 317                 .ctl_name       = KERN_TAINTED,
 318                 .procname       = "tainted",
 319                 .data           = &tainted,
 320                 .maxlen         = sizeof(int),
 321                 .mode           = 0644,
 322                 .proc_handler   = &proc_dointvec_taint,
 323         },
 324 #endif
 325         {
 326                 .ctl_name       = KERN_CAP_BSET,
 327                 .procname       = "cap-bound",
 328                 .data           = &cap_bset,
 329                 .maxlen         = sizeof(kernel_cap_t),
 330                 .mode           = 0600,
 331                 .proc_handler   = &proc_dointvec_bset,
 332         },
 333 #ifdef CONFIG_BLK_DEV_INITRD
 334         {
 335                 .ctl_name       = KERN_REALROOTDEV,
 336                 .procname       = "real-root-dev",
 337                 .data           = &real_root_dev,
 338                 .maxlen         = sizeof(int),
 339                 .mode           = 0644,
 340                 .proc_handler   = &proc_dointvec,
 341         },
 342 #endif
 343 #ifdef __sparc__
 344         {
 345                 .ctl_name       = KERN_SPARC_REBOOT,
 346                 .procname       = "reboot-cmd",
 347                 .data           = reboot_command,
 348                 .maxlen         = 256,
 349                 .mode           = 0644,
 350                 .proc_handler   = &proc_dostring,
 351                 .strategy       = &sysctl_string,
 352         },
 353         {
 354                 .ctl_name       = KERN_SPARC_STOP_A,
 355                 .procname       = "stop-a",
 356                 .data           = &stop_a_enabled,
 357                 .maxlen         = sizeof (int),
 358                 .mode           = 0644,
 359                 .proc_handler   = &proc_dointvec,
 360         },
 361         {
 362                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 363                 .procname       = "scons-poweroff",
 364                 .data           = &scons_pwroff,
 365                 .maxlen         = sizeof (int),
 366                 .mode           = 0644,
 367                 .proc_handler   = &proc_dointvec,
 368         },
 369 #endif
 370 #ifdef __hppa__
 371         {
 372                 .ctl_name       = KERN_HPPA_PWRSW,
 373                 .procname       = "soft-power",
 374                 .data           = &pwrsw_enabled,
 375                 .maxlen         = sizeof (int),
 376                 .mode           = 0644,
 377                 .proc_handler   = &proc_dointvec,
 378         },
 379         {
 380                 .ctl_name       = KERN_HPPA_UNALIGNED,
 381                 .procname       = "unaligned-trap",
 382                 .data           = &unaligned_enabled,
 383                 .maxlen         = sizeof (int),
 384                 .mode           = 0644,
 385                 .proc_handler   = &proc_dointvec,
 386         },
 387 #endif
 388         {
 389                 .ctl_name       = KERN_CTLALTDEL,
 390                 .procname       = "ctrl-alt-del",
 391                 .data           = &C_A_D,
 392                 .maxlen         = sizeof(int),
 393                 .mode           = 0644,
 394                 .proc_handler   = &proc_dointvec,
 395         },
 396         {
 397                 .ctl_name       = KERN_PRINTK,
 398                 .procname       = "printk",
 399                 .data           = &console_loglevel,
 400                 .maxlen         = 4*sizeof(int),
 401                 .mode           = 0644,
 402                 .proc_handler   = &proc_dointvec,
 403         },
 404 #ifdef CONFIG_KMOD
 405         {
 406                 .ctl_name       = KERN_MODPROBE,
 407                 .procname       = "modprobe",
 408                 .data           = &modprobe_path,
 409                 .maxlen         = KMOD_PATH_LEN,
 410                 .mode           = 0644,
 411                 .proc_handler   = &proc_dostring,
 412                 .strategy       = &sysctl_string,
 413         },
 414 #endif
 415 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 416         {
 417                 .ctl_name       = KERN_HOTPLUG,
 418                 .procname       = "hotplug",
 419                 .data           = &uevent_helper,
 420                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 421                 .mode           = 0644,
 422                 .proc_handler   = &proc_dostring,
 423                 .strategy       = &sysctl_string,
 424         },
 425 #endif
 426 #ifdef CONFIG_CHR_DEV_SG
 427         {
 428                 .ctl_name       = KERN_SG_BIG_BUFF,
 429                 .procname       = "sg-big-buff",
 430                 .data           = &sg_big_buff,
 431                 .maxlen         = sizeof (int),
 432                 .mode           = 0444,
 433                 .proc_handler   = &proc_dointvec,
 434         },
 435 #endif
 436 #ifdef CONFIG_BSD_PROCESS_ACCT
 437         {
 438                 .ctl_name       = KERN_ACCT,
 439                 .procname       = "acct",
 440                 .data           = &acct_parm,
 441                 .maxlen         = 3*sizeof(int),
 442                 .mode           = 0644,
 443                 .proc_handler   = &proc_dointvec,
 444         },
 445 #endif
 446 #ifdef CONFIG_MAGIC_SYSRQ
 447         {
 448                 .ctl_name       = KERN_SYSRQ,
 449                 .procname       = "sysrq",
 450                 .data           = &__sysrq_enabled,
 451                 .maxlen         = sizeof (int),
 452                 .mode           = 0644,
 453                 .proc_handler   = &proc_dointvec,
 454         },
 455 #endif
 456 #ifdef CONFIG_PROC_SYSCTL
 457         {
 458                 .ctl_name       = KERN_CADPID,
 459                 .procname       = "cad_pid",
 460                 .data           = NULL,
 461                 .maxlen         = sizeof (int),
 462                 .mode           = 0600,
 463                 .proc_handler   = &proc_do_cad_pid,
 464         },
 465 #endif
 466         {
 467                 .ctl_name       = KERN_MAX_THREADS,
 468                 .procname       = "threads-max",
 469                 .data           = &max_threads,
 470                 .maxlen         = sizeof(int),
 471                 .mode           = 0644,
 472                 .proc_handler   = &proc_dointvec,
 473         },
 474         {
 475                 .ctl_name       = KERN_RANDOM,
 476                 .procname       = "random",
 477                 .mode           = 0555,
 478                 .child          = random_table,
 479         },
 480 #ifdef CONFIG_UNIX98_PTYS
 481         {
 482                 .ctl_name       = KERN_PTY,
 483                 .procname       = "pty",
 484                 .mode           = 0555,
 485                 .child          = pty_table,
 486         },
 487 #endif
 488         {
 489                 .ctl_name       = KERN_OVERFLOWUID,
 490                 .procname       = "overflowuid",
 491                 .data           = &overflowuid,
 492                 .maxlen         = sizeof(int),
 493                 .mode           = 0644,
 494                 .proc_handler   = &proc_dointvec_minmax,
 495                 .strategy       = &sysctl_intvec,
 496                 .extra1         = &minolduid,
 497                 .extra2         = &maxolduid,
 498         },
 499         {
 500                 .ctl_name       = KERN_OVERFLOWGID,
 501                 .procname       = "overflowgid",
 502                 .data           = &overflowgid,
 503                 .maxlen         = sizeof(int),
 504                 .mode           = 0644,
 505                 .proc_handler   = &proc_dointvec_minmax,
 506                 .strategy       = &sysctl_intvec,
 507                 .extra1         = &minolduid,
 508                 .extra2         = &maxolduid,
 509         },
 510 #ifdef CONFIG_S390
 511 #ifdef CONFIG_MATHEMU
 512         {
 513                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 514                 .procname       = "ieee_emulation_warnings",
 515                 .data           = &sysctl_ieee_emulation_warnings,
 516                 .maxlen         = sizeof(int),
 517                 .mode           = 0644,
 518                 .proc_handler   = &proc_dointvec,
 519         },
 520 #endif
 521 #ifdef CONFIG_NO_IDLE_HZ
 522         {
 523                 .ctl_name       = KERN_HZ_TIMER,
 524                 .procname       = "hz_timer",
 525                 .data           = &sysctl_hz_timer,
 526                 .maxlen         = sizeof(int),
 527                 .mode           = 0644,
 528                 .proc_handler   = &proc_dointvec,
 529         },
 530 #endif
 531         {
 532                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 533                 .procname       = "userprocess_debug",
 534                 .data           = &sysctl_userprocess_debug,
 535                 .maxlen         = sizeof(int),
 536                 .mode           = 0644,
 537                 .proc_handler   = &proc_dointvec,
 538         },
 539 #endif
 540         {
 541                 .ctl_name       = KERN_PIDMAX,
 542                 .procname       = "pid_max",
 543                 .data           = &pid_max,
 544                 .maxlen         = sizeof (int),
 545                 .mode           = 0644,
 546                 .proc_handler   = &proc_dointvec_minmax,
 547                 .strategy       = sysctl_intvec,
 548                 .extra1         = &pid_max_min,
 549                 .extra2         = &pid_max_max,
 550         },
 551         {
 552                 .ctl_name       = KERN_PANIC_ON_OOPS,
 553                 .procname       = "panic_on_oops",
 554                 .data           = &panic_on_oops,
 555                 .maxlen         = sizeof(int),
 556                 .mode           = 0644,
 557                 .proc_handler   = &proc_dointvec,
 558         },
 559         {
 560                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 561                 .procname       = "printk_ratelimit",
 562                 .data           = &printk_ratelimit_jiffies,
 563                 .maxlen         = sizeof(int),
 564                 .mode           = 0644,
 565                 .proc_handler   = &proc_dointvec_jiffies,
 566                 .strategy       = &sysctl_jiffies,
 567         },
 568         {
 569                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 570                 .procname       = "printk_ratelimit_burst",
 571                 .data           = &printk_ratelimit_burst,
 572                 .maxlen         = sizeof(int),
 573                 .mode           = 0644,
 574                 .proc_handler   = &proc_dointvec,
 575         },
 576         {
 577                 .ctl_name       = KERN_NGROUPS_MAX,
 578                 .procname       = "ngroups_max",
 579                 .data           = &ngroups_max,
 580                 .maxlen         = sizeof (int),
 581                 .mode           = 0444,
 582                 .proc_handler   = &proc_dointvec,
 583         },
 584 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 585         {
 586                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 587                 .procname       = "unknown_nmi_panic",
 588                 .data           = &unknown_nmi_panic,
 589                 .maxlen         = sizeof (int),
 590                 .mode           = 0644,
 591                 .proc_handler   = &proc_dointvec,
 592         },
 593         {
 594                 .ctl_name       = KERN_NMI_WATCHDOG,
 595                 .procname       = "nmi_watchdog",
 596                 .data           = &nmi_watchdog_enabled,
 597                 .maxlen         = sizeof (int),
 598                 .mode           = 0644,
 599                 .proc_handler   = &proc_nmi_enabled,
 600         },
 601 #endif
 602 #if defined(CONFIG_X86)
 603         {
 604                 .ctl_name       = KERN_PANIC_ON_NMI,
 605                 .procname       = "panic_on_unrecovered_nmi",
 606                 .data           = &panic_on_unrecovered_nmi,
 607                 .maxlen         = sizeof(int),
 608                 .mode           = 0644,
 609                 .proc_handler   = &proc_dointvec,
 610         },
 611         {
 612                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 613                 .procname       = "bootloader_type",
 614                 .data           = &bootloader_type,
 615                 .maxlen         = sizeof (int),
 616                 .mode           = 0444,
 617                 .proc_handler   = &proc_dointvec,
 618         },
 619         {
 620                 .ctl_name       = CTL_UNNUMBERED,
 621                 .procname       = "kstack_depth_to_print",
 622                 .data           = &kstack_depth_to_print,
 623                 .maxlen         = sizeof(int),
 624                 .mode           = 0644,
 625                 .proc_handler   = &proc_dointvec,
 626         },
 627 #endif
 628 #if defined(CONFIG_MMU)
 629         {
 630                 .ctl_name       = KERN_RANDOMIZE,
 631                 .procname       = "randomize_va_space",
 632                 .data           = &randomize_va_space,
 633                 .maxlen         = sizeof(int),
 634                 .mode           = 0644,
 635                 .proc_handler   = &proc_dointvec,
 636         },
 637 #endif
 638 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 639         {
 640                 .ctl_name       = KERN_SPIN_RETRY,
 641                 .procname       = "spin_retry",
 642                 .data           = &spin_retry,
 643                 .maxlen         = sizeof (int),
 644                 .mode           = 0644,
 645                 .proc_handler   = &proc_dointvec,
 646         },
 647 #endif
 648 #ifdef CONFIG_ACPI_SLEEP
 649         {
 650                 .ctl_name       = KERN_ACPI_VIDEO_FLAGS,
 651                 .procname       = "acpi_video_flags",
 652                 .data           = &acpi_video_flags,
 653                 .maxlen         = sizeof (unsigned long),
 654                 .mode           = 0644,
 655                 .proc_handler   = &proc_doulongvec_minmax,
 656         },
 657 #endif
 658 #ifdef CONFIG_IA64
 659         {
 660                 .ctl_name       = KERN_IA64_UNALIGNED,
 661                 .procname       = "ignore-unaligned-usertrap",
 662                 .data           = &no_unaligned_warning,
 663                 .maxlen         = sizeof (int),
 664                 .mode           = 0644,
 665                 .proc_handler   = &proc_dointvec,
 666         },
 667 #endif
 668 #ifdef CONFIG_COMPAT
 669         {
 670                 .ctl_name       = KERN_COMPAT_LOG,
 671                 .procname       = "compat-log",
 672                 .data           = &compat_log,
 673                 .maxlen         = sizeof (int),
 674                 .mode           = 0644,
 675                 .proc_handler   = &proc_dointvec,
 676         },
 677 #endif
 678 #ifdef CONFIG_RT_MUTEXES
 679         {
 680                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 681                 .procname       = "max_lock_depth",
 682                 .data           = &max_lock_depth,
 683                 .maxlen         = sizeof(int),
 684                 .mode           = 0644,
 685                 .proc_handler   = &proc_dointvec,
 686         },
 687 #endif
 688 #ifdef CONFIG_PROC_FS
 689         {
 690                 .ctl_name       = CTL_UNNUMBERED,
 691                 .procname       = "maps_protect",
 692                 .data           = &maps_protect,
 693                 .maxlen         = sizeof(int),
 694                 .mode           = 0644,
 695                 .proc_handler   = &proc_dointvec,
 696         },
 697 #endif
 698
 699         { .ctl_name = 0 }
 700 };
 701
 702 /* Constants for minimum and maximum testing in vm_table.
 703    We use these as one-element integer vectors. */
 704 static int zero;
 705 static int one_hundred = 100;
 706
 707
 708 static ctl_table vm_table[] = {
 709         {
 710                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 711                 .procname       = "overcommit_memory",
 712                 .data           = &sysctl_overcommit_memory,
 713                 .maxlen         = sizeof(sysctl_overcommit_memory),
 714                 .mode           = 0644,
 715                 .proc_handler   = &proc_dointvec,
 716         },
 717         {
 718                 .ctl_name       = VM_PANIC_ON_OOM,
 719                 .procname       = "panic_on_oom",
 720                 .data           = &sysctl_panic_on_oom,
 721                 .maxlen         = sizeof(sysctl_panic_on_oom),
 722                 .mode           = 0644,
 723                 .proc_handler   = &proc_dointvec,
 724         },
 725         {
 726                 .ctl_name       = VM_OVERCOMMIT_RATIO,
 727                 .procname       = "overcommit_ratio",
 728                 .data           = &sysctl_overcommit_ratio,
 729                 .maxlen         = sizeof(sysctl_overcommit_ratio),
 730                 .mode           = 0644,
 731                 .proc_handler   = &proc_dointvec,
 732         },
 733         {
 734                 .ctl_name       = VM_PAGE_CLUSTER,
 735                 .procname       = "page-cluster",
 736                 .data           = &page_cluster,
 737                 .maxlen         = sizeof(int),
 738                 .mode           = 0644,
 739                 .proc_handler   = &proc_dointvec,
 740         },
 741         {
 742                 .ctl_name       = VM_DIRTY_BACKGROUND,
 743                 .procname       = "dirty_background_ratio",
 744                 .data           = &dirty_background_ratio,
 745                 .maxlen         = sizeof(dirty_background_ratio),
 746                 .mode           = 0644,
 747                 .proc_handler   = &proc_dointvec_minmax,
 748                 .strategy       = &sysctl_intvec,
 749                 .extra1         = &zero,
 750                 .extra2         = &one_hundred,
 751         },
 752         {
 753                 .ctl_name       = VM_DIRTY_RATIO,
 754                 .procname       = "dirty_ratio",
 755                 .data           = &vm_dirty_ratio,
 756                 .maxlen         = sizeof(vm_dirty_ratio),
 757                 .mode           = 0644,
 758                 .proc_handler   = &proc_dointvec_minmax,
 759                 .strategy       = &sysctl_intvec,
 760                 .extra1         = &zero,
 761                 .extra2         = &one_hundred,
 762         },
 763         {
 764                 .ctl_name       = VM_DIRTY_WB_CS,
 765                 .procname       = "dirty_writeback_centisecs",
 766                 .data           = &dirty_writeback_interval,
 767                 .maxlen         = sizeof(dirty_writeback_interval),
 768                 .mode           = 0644,
 769                 .proc_handler   = &dirty_writeback_centisecs_handler,
 770         },
 771         {
 772                 .ctl_name       = VM_DIRTY_EXPIRE_CS,
 773                 .procname       = "dirty_expire_centisecs",
 774                 .data           = &dirty_expire_interval,
 775                 .maxlen         = sizeof(dirty_expire_interval),
 776                 .mode           = 0644,
 777                 .proc_handler   = &proc_dointvec_userhz_jiffies,
 778         },
 779         {
 780                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
 781                 .procname       = "nr_pdflush_threads",
 782                 .data           = &nr_pdflush_threads,
 783                 .maxlen         = sizeof nr_pdflush_threads,
 784                 .mode           = 0444 /* read-only*/,
 785                 .proc_handler   = &proc_dointvec,
 786         },
 787         {
 788                 .ctl_name       = VM_SWAPPINESS,
 789                 .procname       = "swappiness",
 790                 .data           = &vm_swappiness,
 791                 .maxlen         = sizeof(vm_swappiness),
 792                 .mode           = 0644,
 793                 .proc_handler   = &proc_dointvec_minmax,
 794                 .strategy       = &sysctl_intvec,
 795                 .extra1         = &zero,
 796                 .extra2         = &one_hundred,
 797         },
 798 #ifdef CONFIG_HUGETLB_PAGE
 799          {
 800                 .ctl_name       = VM_HUGETLB_PAGES,
 801                 .procname       = "nr_hugepages",
 802                 .data           = &max_huge_pages,
 803                 .maxlen         = sizeof(unsigned long),
 804                 .mode           = 0644,
 805                 .proc_handler   = &hugetlb_sysctl_handler,
 806                 .extra1         = (void *)&hugetlb_zero,
 807                 .extra2         = (void *)&hugetlb_infinity,
 808          },
 809          {
 810                 .ctl_name       = VM_HUGETLB_GROUP,
 811                 .procname       = "hugetlb_shm_group",
 812                 .data           = &sysctl_hugetlb_shm_group,
 813                 .maxlen         = sizeof(gid_t),
 814                 .mode           = 0644,
 815                 .proc_handler   = &proc_dointvec,
 816          },
 817 #endif
 818         {
 819                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
 820                 .procname       = "lowmem_reserve_ratio",
 821                 .data           = &sysctl_lowmem_reserve_ratio,
 822                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
 823                 .mode           = 0644,
 824                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
 825                 .strategy       = &sysctl_intvec,
 826         },
 827         {
 828                 .ctl_name       = VM_DROP_PAGECACHE,
 829                 .procname       = "drop_caches",
 830                 .data           = &sysctl_drop_caches,
 831                 .maxlen         = sizeof(int),
 832                 .mode           = 0644,
 833                 .proc_handler   = drop_caches_sysctl_handler,
 834                 .strategy       = &sysctl_intvec,
 835         },
 836         {
 837                 .ctl_name       = VM_MIN_FREE_KBYTES,
 838                 .procname       = "min_free_kbytes",
 839                 .data           = &min_free_kbytes,
 840                 .maxlen         = sizeof(min_free_kbytes),
 841                 .mode           = 0644,
 842                 .proc_handler   = &min_free_kbytes_sysctl_handler,
 843                 .strategy       = &sysctl_intvec,
 844                 .extra1         = &zero,
 845         },
 846         {
 847                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
 848                 .procname       = "percpu_pagelist_fraction",
 849                 .data           = &percpu_pagelist_fraction,
 850                 .maxlen         = sizeof(percpu_pagelist_fraction),
 851                 .mode           = 0644,
 852                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
 853                 .strategy       = &sysctl_intvec,
 854                 .extra1         = &min_percpu_pagelist_fract,
 855         },
 856 #ifdef CONFIG_MMU
 857         {
 858                 .ctl_name       = VM_MAX_MAP_COUNT,
 859                 .procname       = "max_map_count",
 860                 .data           = &sysctl_max_map_count,
 861                 .maxlen         = sizeof(sysctl_max_map_count),
 862                 .mode           = 0644,
 863                 .proc_handler   = &proc_dointvec
 864         },
 865 #endif
 866         {
 867                 .ctl_name       = VM_LAPTOP_MODE,
 868                 .procname       = "laptop_mode",
 869                 .data           = &laptop_mode,
 870                 .maxlen         = sizeof(laptop_mode),
 871                 .mode           = 0644,
 872                 .proc_handler   = &proc_dointvec_jiffies,
 873                 .strategy       = &sysctl_jiffies,
 874         },
 875         {
 876                 .ctl_name       = VM_BLOCK_DUMP,
 877                 .procname       = "block_dump",
 878                 .data           = &block_dump,
 879                 .maxlen         = sizeof(block_dump),
 880                 .mode           = 0644,
 881                 .proc_handler   = &proc_dointvec,
 882                 .strategy       = &sysctl_intvec,
 883                 .extra1         = &zero,
 884         },
 885         {
 886                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
 887                 .procname       = "vfs_cache_pressure",
 888                 .data           = &sysctl_vfs_cache_pressure,
 889                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
 890                 .mode           = 0644,
 891                 .proc_handler   = &proc_dointvec,
 892                 .strategy       = &sysctl_intvec,
 893                 .extra1         = &zero,
 894         },
 895 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 896         {
 897                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
 898                 .procname       = "legacy_va_layout",
 899                 .data           = &sysctl_legacy_va_layout,
 900                 .maxlen         = sizeof(sysctl_legacy_va_layout),
 901                 .mode           = 0644,
 902                 .proc_handler   = &proc_dointvec,
 903                 .strategy       = &sysctl_intvec,
 904                 .extra1         = &zero,
 905         },
 906 #endif
 907 #ifdef CONFIG_NUMA
 908         {
 909                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
 910                 .procname       = "zone_reclaim_mode",
 911                 .data           = &zone_reclaim_mode,
 912                 .maxlen         = sizeof(zone_reclaim_mode),
 913                 .mode           = 0644,
 914                 .proc_handler   = &proc_dointvec,
 915                 .strategy       = &sysctl_intvec,
 916                 .extra1         = &zero,
 917         },
 918         {
 919                 .ctl_name       = VM_MIN_UNMAPPED,
 920                 .procname       = "min_unmapped_ratio",
 921                 .data           = &sysctl_min_unmapped_ratio,
 922                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
 923                 .mode           = 0644,
 924                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
 925                 .strategy       = &sysctl_intvec,
 926                 .extra1         = &zero,
 927                 .extra2         = &one_hundred,
 928         },
 929         {
 930                 .ctl_name       = VM_MIN_SLAB,
 931                 .procname       = "min_slab_ratio",
 932                 .data           = &sysctl_min_slab_ratio,
 933                 .maxlen         = sizeof(sysctl_min_slab_ratio),
 934                 .mode           = 0644,
 935                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
 936                 .strategy       = &sysctl_intvec,
 937                 .extra1         = &zero,
 938                 .extra2         = &one_hundred,
 939         },
 940 #endif
 941 #ifdef CONFIG_SMP
 942         {
 943                 .ctl_name       = CTL_UNNUMBERED,
 944                 .procname       = "stat_interval",
 945                 .data           = &sysctl_stat_interval,
 946                 .maxlen         = sizeof(sysctl_stat_interval),
 947                 .mode           = 0644,
 948                 .proc_handler   = &proc_dointvec_jiffies,
 949                 .strategy       = &sysctl_jiffies,
 950         },
 951 #endif
 952 #if defined(CONFIG_X86_32) || \
 953    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
 954         {
 955                 .ctl_name       = VM_VDSO_ENABLED,
 956                 .procname       = "vdso_enabled",
 957                 .data           = &vdso_enabled,
 958                 .maxlen         = sizeof(vdso_enabled),
 959                 .mode           = 0644,
 960                 .proc_handler   = &proc_dointvec,
 961                 .strategy       = &sysctl_intvec,
 962                 .extra1         = &zero,
 963         },
 964 #endif
 965         { .ctl_name = 0 }
 966 };
 967
 968 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
 969 static ctl_table binfmt_misc_table[] = {
 970         { .ctl_name = 0 }
 971 };
 972 #endif
 973
 974 static ctl_table fs_table[] = {
 975         {
 976                 .ctl_name       = FS_NRINODE,
 977                 .procname       = "inode-nr",
 978                 .data           = &inodes_stat,
 979                 .maxlen         = 2*sizeof(int),
 980                 .mode           = 0444,
 981                 .proc_handler   = &proc_dointvec,
 982         },
 983         {
 984                 .ctl_name       = FS_STATINODE,
 985                 .procname       = "inode-state",
 986                 .data           = &inodes_stat,
 987                 .maxlen         = 7*sizeof(int),
 988                 .mode           = 0444,
 989                 .proc_handler   = &proc_dointvec,
 990         },
 991         {
 992                 .ctl_name       = FS_NRFILE,
 993                 .procname       = "file-nr",
 994                 .data           = &files_stat,
 995                 .maxlen         = 3*sizeof(int),
 996                 .mode           = 0444,
 997                 .proc_handler   = &proc_nr_files,
 998         },
 999         {
1000                 .ctl_name       = FS_MAXFILE,
1001                 .procname       = "file-max",
1002                 .data           = &files_stat.max_files,
1003                 .maxlen         = sizeof(int),
1004                 .mode           = 0644,
1005                 .proc_handler   = &proc_dointvec,
1006         },
1007         {
1008                 .ctl_name       = FS_DENTRY,
1009                 .procname       = "dentry-state",
1010                 .data           = &dentry_stat,
1011                 .maxlen         = 6*sizeof(int),
1012                 .mode           = 0444,
1013                 .proc_handler   = &proc_dointvec,
1014         },
1015         {
1016                 .ctl_name       = FS_OVERFLOWUID,
1017                 .procname       = "overflowuid",
1018                 .data           = &fs_overflowuid,
1019                 .maxlen         = sizeof(int),
1020                 .mode           = 0644,
1021                 .proc_handler   = &proc_dointvec_minmax,
1022                 .strategy       = &sysctl_intvec,
1023                 .extra1         = &minolduid,
1024                 .extra2         = &maxolduid,
1025         },
1026         {
1027                 .ctl_name       = FS_OVERFLOWGID,
1028                 .procname       = "overflowgid",
1029                 .data           = &fs_overflowgid,
1030                 .maxlen         = sizeof(int),
1031                 .mode           = 0644,
1032                 .proc_handler   = &proc_dointvec_minmax,
1033                 .strategy       = &sysctl_intvec,
1034                 .extra1         = &minolduid,
1035                 .extra2         = &maxolduid,
1036         },
1037         {
1038                 .ctl_name       = FS_LEASES,
1039                 .procname       = "leases-enable",
1040                 .data           = &leases_enable,
1041                 .maxlen         = sizeof(int),
1042                 .mode           = 0644,
1043                 .proc_handler   = &proc_dointvec,
1044         },
1045 #ifdef CONFIG_DNOTIFY
1046         {
1047                 .ctl_name       = FS_DIR_NOTIFY,
1048                 .procname       = "dir-notify-enable",
1049                 .data           = &dir_notify_enable,
1050                 .maxlen         = sizeof(int),
1051                 .mode           = 0644,
1052                 .proc_handler   = &proc_dointvec,
1053         },
1054 #endif
1055 #ifdef CONFIG_MMU
1056         {
1057                 .ctl_name       = FS_LEASE_TIME,
1058                 .procname       = "lease-break-time",
1059                 .data           = &lease_break_time,
1060                 .maxlen         = sizeof(int),
1061                 .mode           = 0644,
1062                 .proc_handler   = &proc_dointvec,
1063         },
1064         {
1065                 .ctl_name       = FS_AIO_NR,
1066                 .procname       = "aio-nr",
1067                 .data           = &aio_nr,
1068                 .maxlen         = sizeof(aio_nr),
1069                 .mode           = 0444,
1070                 .proc_handler   = &proc_doulongvec_minmax,
1071         },
1072         {
1073                 .ctl_name       = FS_AIO_MAX_NR,
1074                 .procname       = "aio-max-nr",
1075                 .data           = &aio_max_nr,
1076                 .maxlen         = sizeof(aio_max_nr),
1077                 .mode           = 0644,
1078                 .proc_handler   = &proc_doulongvec_minmax,
1079         },
1080 #ifdef CONFIG_INOTIFY_USER
1081         {
1082                 .ctl_name       = FS_INOTIFY,
1083                 .procname       = "inotify",
1084                 .mode           = 0555,
1085                 .child          = inotify_table,
1086         },
1087 #endif
1088 #endif
1089         {
1090                 .ctl_name       = KERN_SETUID_DUMPABLE,
1091                 .procname       = "suid_dumpable",
1092                 .data           = &suid_dumpable,
1093                 .maxlen         = sizeof(int),
1094                 .mode           = 0644,
1095                 .proc_handler   = &proc_dointvec,
1096         },
1097 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1098         {
1099                 .ctl_name       = CTL_UNNUMBERED,
1100                 .procname       = "binfmt_misc",
1101                 .mode           = 0555,
1102                 .child          = binfmt_misc_table,
1103         },
1104 #endif
1105         { .ctl_name = 0 }
1106 };
1107
1108 static ctl_table debug_table[] = {
1109         { .ctl_name = 0 }
1110 };
1111
1112 static ctl_table dev_table[] = {
1113         { .ctl_name = 0 }
1114 };
1115
1116 static DEFINE_SPINLOCK(sysctl_lock);
1117
1118 /* called under sysctl_lock */
1119 static int use_table(struct ctl_table_header *p)
1120 {
1121         if (unlikely(p->unregistering))
1122                 return 0;
1123         p->used++;
1124         return 1;
1125 }
1126
1127 /* called under sysctl_lock */
1128 static void unuse_table(struct ctl_table_header *p)
1129 {
1130         if (!--p->used)
1131                 if (unlikely(p->unregistering))
1132                         complete(p->unregistering);
1133 }
1134
1135 /* called under sysctl_lock, will reacquire if has to wait */
1136 static void start_unregistering(struct ctl_table_header *p)
1137 {
1138         /*
1139          * if p->used is 0, nobody will ever touch that entry again;
1140          * we'll eliminate all paths to it before dropping sysctl_lock
1141          */
1142         if (unlikely(p->used)) {
1143                 struct completion wait;
1144                 init_completion(&wait);
1145                 p->unregistering = &wait;
1146                 spin_unlock(&sysctl_lock);
1147                 wait_for_completion(&wait);
1148                 spin_lock(&sysctl_lock);
1149         }
1150         /*
1151          * do not remove from the list until nobody holds it; walking the
1152          * list in do_sysctl() relies on that.
1153          */
1154         list_del_init(&p->ctl_entry);
1155 }
1156
1157 void sysctl_head_finish(struct ctl_table_header *head)
1158 {
1159         if (!head)
1160                 return;
1161         spin_lock(&sysctl_lock);
1162         unuse_table(head);
1163         spin_unlock(&sysctl_lock);
1164 }
1165
1166 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1167 {
1168         struct ctl_table_header *head;
1169         struct list_head *tmp;
1170         spin_lock(&sysctl_lock);
1171         if (prev) {
1172                 tmp = &prev->ctl_entry;
1173                 unuse_table(prev);
1174                 goto next;
1175         }
1176         tmp = &root_table_header.ctl_entry;
1177         for (;;) {
1178                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1179
1180                 if (!use_table(head))
1181                         goto next;
1182                 spin_unlock(&sysctl_lock);
1183                 return head;
1184         next:
1185                 tmp = tmp->next;
1186                 if (tmp == &root_table_header.ctl_entry)
1187                         break;
1188         }
1189         spin_unlock(&sysctl_lock);
1190         return NULL;
1191 }
1192
1193 #ifdef CONFIG_SYSCTL_SYSCALL
1194 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1195                void __user *newval, size_t newlen)
1196 {
1197         struct ctl_table_header *head;
1198         int error = -ENOTDIR;
1199
1200         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1201                 return -ENOTDIR;
1202         if (oldval) {
1203                 int old_len;
1204                 if (!oldlenp || get_user(old_len, oldlenp))
1205                         return -EFAULT;
1206         }
1207
1208         for (head = sysctl_head_next(NULL); head;
1209                         head = sysctl_head_next(head)) {
1210                 error = parse_table(name, nlen, oldval, oldlenp,
1211                                         newval, newlen, head->ctl_table);
1212                 if (error != -ENOTDIR) {
1213                         sysctl_head_finish(head);
1214                         break;
1215                 }
1216         }
1217         return error;
1218 }
1219
1220 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1221 {
1222         struct __sysctl_args tmp;
1223         int error;
1224
1225         if (copy_from_user(&tmp, args, sizeof(tmp)))
1226                 return -EFAULT;
1227
1228         lock_kernel();
1229         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1230                           tmp.newval, tmp.newlen);
1231         unlock_kernel();
1232         return error;
1233 }
1234 #endif /* CONFIG_SYSCTL_SYSCALL */
1235
1236 /*
1237  * sysctl_perm does NOT grant the superuser all rights automatically, because
1238  * some sysctl variables are readonly even to root.
1239  */
1240
1241 static int test_perm(int mode, int op)
1242 {
1243         if (!current->euid)
1244                 mode >>= 6;
1245         else if (in_egroup_p(0))
1246                 mode >>= 3;
1247         if ((mode & op & 0007) == op)
1248                 return 0;
1249         return -EACCES;
1250 }
1251
1252 int sysctl_perm(ctl_table *table, int op)
1253 {
1254         int error;
1255         error = security_sysctl(table, op);
1256         if (error)
1257                 return error;
1258         return test_perm(table->mode, op);
1259 }
1260
1261 #ifdef CONFIG_SYSCTL_SYSCALL
1262 static int parse_table(int __user *name, int nlen,
1263                        void __user *oldval, size_t __user *oldlenp,
1264                        void __user *newval, size_t newlen,
1265                        ctl_table *table)
1266 {
1267         int n;
1268 repeat:
1269         if (!nlen)
1270                 return -ENOTDIR;
1271         if (get_user(n, name))
1272                 return -EFAULT;
1273         for ( ; table->ctl_name || table->procname; table++) {
1274                 if (!table->ctl_name)
1275                         continue;
1276                 if (n == table->ctl_name) {
1277                         int error;
1278                         if (table->child) {
1279                                 if (sysctl_perm(table, 001))
1280                                         return -EPERM;
1281                                 name++;
1282                                 nlen--;
1283                                 table = table->child;
1284                                 goto repeat;
1285                         }
1286                         error = do_sysctl_strategy(table, name, nlen,
1287                                                    oldval, oldlenp,
1288                                                    newval, newlen);
1289                         return error;
1290                 }
1291         }
1292         return -ENOTDIR;
1293 }
1294
1295 /* Perform the actual read/write of a sysctl table entry. */
1296 int do_sysctl_strategy (ctl_table *table,
1297                         int __user *name, int nlen,
1298                         void __user *oldval, size_t __user *oldlenp,
1299                         void __user *newval, size_t newlen)
1300 {
1301         int op = 0, rc;
1302         size_t len;
1303
1304         if (oldval)
1305                 op |= 004;
1306         if (newval)
1307                 op |= 002;
1308         if (sysctl_perm(table, op))
1309                 return -EPERM;
1310
1311         if (table->strategy) {
1312                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1313                                      newval, newlen);
1314                 if (rc < 0)
1315                         return rc;
1316                 if (rc > 0)
1317                         return 0;
1318         }
1319
1320         /* If there is no strategy routine, or if the strategy returns
1321          * zero, proceed with automatic r/w */
1322         if (table->data && table->maxlen) {
1323                 if (oldval && oldlenp) {
1324                         if (get_user(len, oldlenp))
1325                                 return -EFAULT;
1326                         if (len) {
1327                                 if (len > table->maxlen)
1328                                         len = table->maxlen;
1329                                 if(copy_to_user(oldval, table->data, len))
1330                                         return -EFAULT;
1331                                 if(put_user(len, oldlenp))
1332                                         return -EFAULT;
1333                         }
1334                 }
1335                 if (newval && newlen) {
1336                         len = newlen;
1337                         if (len > table->maxlen)
1338                                 len = table->maxlen;
1339                         if(copy_from_user(table->data, newval, len))
1340                                 return -EFAULT;
1341                 }
1342         }
1343         return 0;
1344 }
1345 #endif /* CONFIG_SYSCTL_SYSCALL */
1346
1347 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1348 {
1349         for (; table->ctl_name || table->procname; table++) {
1350                 table->parent = parent;
1351                 if (table->child)
1352                         sysctl_set_parent(table, table->child);
1353         }
1354 }
1355
1356 static __init int sysctl_init(void)
1357 {
1358         sysctl_set_parent(NULL, root_table);
1359         return 0;
1360 }
1361
1362 core_initcall(sysctl_init);
1363
1364 /**
1365  * register_sysctl_table - register a sysctl hierarchy
1366  * @table: the top-level table structure
1367  *
1368  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1369  * array. An entry with a ctl_name of 0 terminates the table.
1370  *
1371  * The members of the &ctl_table structure are used as follows:
1372  *
1373  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1374  *            must be unique within that level of sysctl
1375  *
1376  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1377  *            enter a sysctl file
1378  *
1379  * data - a pointer to data for use by proc_handler
1380  *
1381  * maxlen - the maximum size in bytes of the data
1382  *
1383  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1384  *
1385  * child - a pointer to the child sysctl table if this entry is a directory, or
1386  *         %NULL.
1387  *
1388  * proc_handler - the text handler routine (described below)
1389  *
1390  * strategy - the strategy routine (described below)
1391  *
1392  * de - for internal use by the sysctl routines
1393  *
1394  * extra1, extra2 - extra pointers usable by the proc handler routines
1395  *
1396  * Leaf nodes in the sysctl tree will be represented by a single file
1397  * under /proc; non-leaf nodes will be represented by directories.
1398  *
1399  * sysctl(2) can automatically manage read and write requests through
1400  * the sysctl table.  The data and maxlen fields of the ctl_table
1401  * struct enable minimal validation of the values being written to be
1402  * performed, and the mode field allows minimal authentication.
1403  *
1404  * More sophisticated management can be enabled by the provision of a
1405  * strategy routine with the table entry.  This will be called before
1406  * any automatic read or write of the data is performed.
1407  *
1408  * The strategy routine may return
1409  *
1410  * < 0 - Error occurred (error is passed to user process)
1411  *
1412  * 0   - OK - proceed with automatic read or write.
1413  *
1414  * > 0 - OK - read or write has been done by the strategy routine, so
1415  *       return immediately.
1416  *
1417  * There must be a proc_handler routine for any terminal nodes
1418  * mirrored under /proc/sys (non-terminals are handled by a built-in
1419  * directory handler).  Several default handlers are available to
1420  * cover common cases -
1421  *
1422  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1423  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1424  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1425  *
1426  * It is the handler's job to read the input buffer from user memory
1427  * and process it. The handler should return 0 on success.
1428  *
1429  * This routine returns %NULL on a failure to register, and a pointer
1430  * to the table header on success.
1431  */
1432 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1433 {
1434         struct ctl_table_header *tmp;
1435         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1436         if (!tmp)
1437                 return NULL;
1438         tmp->ctl_table = table;
1439         INIT_LIST_HEAD(&tmp->ctl_entry);
1440         tmp->used = 0;
1441         tmp->unregistering = NULL;
1442         sysctl_set_parent(NULL, table);
1443         spin_lock(&sysctl_lock);
1444         list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1445         spin_unlock(&sysctl_lock);
1446         return tmp;
1447 }
1448
1449 /**
1450  * unregister_sysctl_table - unregister a sysctl table hierarchy
1451  * @header: the header returned from register_sysctl_table
1452  *
1453  * Unregisters the sysctl table and all children. proc entries may not
1454  * actually be removed until they are no longer used by anyone.
1455  */
1456 void unregister_sysctl_table(struct ctl_table_header * header)
1457 {
1458         might_sleep();
1459         spin_lock(&sysctl_lock);
1460         start_unregistering(header);
1461         spin_unlock(&sysctl_lock);
1462         kfree(header);
1463 }
1464
1465 #else /* !CONFIG_SYSCTL */
1466 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1467 {
1468         return NULL;
1469 }
1470
1471 void unregister_sysctl_table(struct ctl_table_header * table)
1472 {
1473 }
1474
1475 #endif /* CONFIG_SYSCTL */
1476
1477 /*
1478  * /proc/sys support
1479  */
1480
1481 #ifdef CONFIG_PROC_SYSCTL
1482
1483 static int _proc_do_string(void* data, int maxlen, int write,
1484                            struct file *filp, void __user *buffer,
1485                            size_t *lenp, loff_t *ppos)
1486 {
1487         size_t len;
1488         char __user *p;
1489         char c;
1490
1491         if (!data || !maxlen || !*lenp) {
1492                 *lenp = 0;
1493                 return 0;
1494         }
1495
1496         if (write) {
1497                 len = 0;
1498                 p = buffer;
1499                 while (len < *lenp) {
1500                         if (get_user(c, p++))
1501                                 return -EFAULT;
1502                         if (c == 0 || c == '\n')
1503                                 break;
1504                         len++;
1505                 }
1506                 if (len >= maxlen)
1507                         len = maxlen-1;
1508                 if(copy_from_user(data, buffer, len))
1509                         return -EFAULT;
1510                 ((char *) data)[len] = 0;
1511                 *ppos += *lenp;
1512         } else {
1513                 len = strlen(data);
1514                 if (len > maxlen)
1515                         len = maxlen;
1516
1517                 if (*ppos > len) {
1518                         *lenp = 0;
1519                         return 0;
1520                 }
1521
1522                 data += *ppos;
1523                 len  -= *ppos;
1524
1525                 if (len > *lenp)
1526                         len = *lenp;
1527                 if (len)
1528                         if(copy_to_user(buffer, data, len))
1529                                 return -EFAULT;
1530                 if (len < *lenp) {
1531                         if(put_user('\n', ((char __user *) buffer) + len))
1532                                 return -EFAULT;
1533                         len++;
1534                 }
1535                 *lenp = len;
1536                 *ppos += len;
1537         }
1538         return 0;
1539 }
1540
1541 /**
1542  * proc_dostring - read a string sysctl
1543  * @table: the sysctl table
1544  * @write: %TRUE if this is a write to the sysctl file
1545  * @filp: the file structure
1546  * @buffer: the user buffer
1547  * @lenp: the size of the user buffer
1548  * @ppos: file position
1549  *
1550  * Reads/writes a string from/to the user buffer. If the kernel
1551  * buffer provided is not large enough to hold the string, the
1552  * string is truncated. The copied string is %NULL-terminated.
1553  * If the string is being read by the user process, it is copied
1554  * and a newline '\n' is added. It is truncated if the buffer is
1555  * not large enough.
1556  *
1557  * Returns 0 on success.
1558  */
1559 int proc_dostring(ctl_table *table, int write, struct file *filp,
1560                   void __user *buffer, size_t *lenp, loff_t *ppos)
1561 {
1562         return _proc_do_string(table->data, table->maxlen, write, filp,
1563                                buffer, lenp, ppos);
1564 }
1565
1566
1567 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1568                                  int *valp,
1569                                  int write, void *data)
1570 {
1571         if (write) {
1572                 *valp = *negp ? -*lvalp : *lvalp;
1573         } else {
1574                 int val = *valp;
1575                 if (val < 0) {
1576                         *negp = -1;
1577                         *lvalp = (unsigned long)-val;
1578                 } else {
1579                         *negp = 0;
1580                         *lvalp = (unsigned long)val;
1581                 }
1582         }
1583         return 0;
1584 }
1585
1586 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1587                   int write, struct file *filp, void __user *buffer,
1588                   size_t *lenp, loff_t *ppos,
1589                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1590                               int write, void *data),
1591                   void *data)
1592 {
1593 #define TMPBUFLEN 21
1594         int *i, vleft, first=1, neg, val;
1595         unsigned long lval;
1596         size_t left, len;
1597
1598         char buf[TMPBUFLEN], *p;
1599         char __user *s = buffer;
1600
1601         if (!tbl_data || !table->maxlen || !*lenp ||
1602             (*ppos && !write)) {
1603                 *lenp = 0;
1604                 return 0;
1605         }
1606
1607         i = (int *) tbl_data;
1608         vleft = table->maxlen / sizeof(*i);
1609         left = *lenp;
1610
1611         if (!conv)
1612                 conv = do_proc_dointvec_conv;
1613
1614         for (; left && vleft--; i++, first=0) {
1615                 if (write) {
1616                         while (left) {
1617                                 char c;
1618                                 if (get_user(c, s))
1619                                         return -EFAULT;
1620                                 if (!isspace(c))
1621                                         break;
1622                                 left--;
1623                                 s++;
1624                         }
1625                         if (!left)
1626                                 break;
1627                         neg = 0;
1628                         len = left;
1629                         if (len > sizeof(buf) - 1)
1630                                 len = sizeof(buf) - 1;
1631                         if (copy_from_user(buf, s, len))
1632                                 return -EFAULT;
1633                         buf[len] = 0;
1634                         p = buf;
1635                         if (*p == '-' && left > 1) {
1636                                 neg = 1;
1637                                 p++;
1638                         }
1639                         if (*p < '0' || *p > '9')
1640                                 break;
1641
1642                         lval = simple_strtoul(p, &p, 0);
1643
1644                         len = p-buf;
1645                         if ((len < left) && *p && !isspace(*p))
1646                                 break;
1647                         if (neg)
1648                                 val = -val;
1649                         s += len;
1650                         left -= len;
1651
1652                         if (conv(&neg, &lval, i, 1, data))
1653                                 break;
1654                 } else {
1655                         p = buf;
1656                         if (!first)
1657                                 *p++ = '\t';
1658
1659                         if (conv(&neg, &lval, i, 0, data))
1660                                 break;
1661
1662                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1663                         len = strlen(buf);
1664                         if (len > left)
1665                                 len = left;
1666                         if(copy_to_user(s, buf, len))
1667                                 return -EFAULT;
1668                         left -= len;
1669                         s += len;
1670                 }
1671         }
1672
1673         if (!write && !first && left) {
1674                 if(put_user('\n', s))
1675                         return -EFAULT;
1676                 left--, s++;
1677         }
1678         if (write) {
1679                 while (left) {
1680                         char c;
1681                         if (get_user(c, s++))
1682                                 return -EFAULT;
1683                         if (!isspace(c))
1684                                 break;
1685                         left--;
1686                 }
1687         }
1688         if (write && first)
1689                 return -EINVAL;
1690         *lenp -= left;
1691         *ppos += *lenp;
1692         return 0;
1693 #undef TMPBUFLEN
1694 }
1695
1696 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1697                   void __user *buffer, size_t *lenp, loff_t *ppos,
1698                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1699                               int write, void *data),
1700                   void *data)
1701 {
1702         return __do_proc_dointvec(table->data, table, write, filp,
1703                         buffer, lenp, ppos, conv, data);
1704 }
1705
1706 /**
1707  * proc_dointvec - read a vector of integers
1708  * @table: the sysctl table
1709  * @write: %TRUE if this is a write to the sysctl file
1710  * @filp: the file structure
1711  * @buffer: the user buffer
1712  * @lenp: the size of the user buffer
1713  * @ppos: file position
1714  *
1715  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1716  * values from/to the user buffer, treated as an ASCII string.
1717  *
1718  * Returns 0 on success.
1719  */
1720 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1721                      void __user *buffer, size_t *lenp, loff_t *ppos)
1722 {
1723     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1724                             NULL,NULL);
1725 }
1726
1727 #define OP_SET  0
1728 #define OP_AND  1
1729 #define OP_OR   2
1730
1731 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1732                                       int *valp,
1733                                       int write, void *data)
1734 {
1735         int op = *(int *)data;
1736         if (write) {
1737                 int val = *negp ? -*lvalp : *lvalp;
1738                 switch(op) {
1739                 case OP_SET:    *valp = val; break;
1740                 case OP_AND:    *valp &= val; break;
1741                 case OP_OR:     *valp |= val; break;
1742                 }
1743         } else {
1744                 int val = *valp;
1745                 if (val < 0) {
1746                         *negp = -1;
1747                         *lvalp = (unsigned long)-val;
1748                 } else {
1749                         *negp = 0;
1750                         *lvalp = (unsigned long)val;
1751                 }
1752         }
1753         return 0;
1754 }
1755
1756 /*
1757  *      init may raise the set.
1758  */
1759
1760 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1761                         void __user *buffer, size_t *lenp, loff_t *ppos)
1762 {
1763         int op;
1764
1765         if (write && !capable(CAP_SYS_MODULE)) {
1766                 return -EPERM;
1767         }
1768
1769         op = is_init(current) ? OP_SET : OP_AND;
1770         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1771                                 do_proc_dointvec_bset_conv,&op);
1772 }
1773
1774 /*
1775  *      Taint values can only be increased
1776  */
1777 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1778                                void __user *buffer, size_t *lenp, loff_t *ppos)
1779 {
1780         int op;
1781
1782         if (write && !capable(CAP_SYS_ADMIN))
1783                 return -EPERM;
1784
1785         op = OP_OR;
1786         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1787                                 do_proc_dointvec_bset_conv,&op);
1788 }
1789
1790 struct do_proc_dointvec_minmax_conv_param {
1791         int *min;
1792         int *max;
1793 };
1794
1795 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1796                                         int *valp,
1797                                         int write, void *data)
1798 {
1799         struct do_proc_dointvec_minmax_conv_param *param = data;
1800         if (write) {
1801                 int val = *negp ? -*lvalp : *lvalp;
1802                 if ((param->min && *param->min > val) ||
1803                     (param->max && *param->max < val))
1804                         return -EINVAL;
1805                 *valp = val;
1806         } else {
1807                 int val = *valp;
1808                 if (val < 0) {
1809                         *negp = -1;
1810                         *lvalp = (unsigned long)-val;
1811                 } else {
1812                         *negp = 0;
1813                         *lvalp = (unsigned long)val;
1814                 }
1815         }
1816         return 0;
1817 }
1818
1819 /**
1820  * proc_dointvec_minmax - read a vector of integers with min/max values
1821  * @table: the sysctl table
1822  * @write: %TRUE if this is a write to the sysctl file
1823  * @filp: the file structure
1824  * @buffer: the user buffer
1825  * @lenp: the size of the user buffer
1826  * @ppos: file position
1827  *
1828  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1829  * values from/to the user buffer, treated as an ASCII string.
1830  *
1831  * This routine will ensure the values are within the range specified by
1832  * table->extra1 (min) and table->extra2 (max).
1833  *
1834  * Returns 0 on success.
1835  */
1836 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1837                   void __user *buffer, size_t *lenp, loff_t *ppos)
1838 {
1839         struct do_proc_dointvec_minmax_conv_param param = {
1840                 .min = (int *) table->extra1,
1841                 .max = (int *) table->extra2,
1842         };
1843         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1844                                 do_proc_dointvec_minmax_conv, &param);
1845 }
1846
1847 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1848                                      struct file *filp,
1849                                      void __user *buffer,
1850                                      size_t *lenp, loff_t *ppos,
1851                                      unsigned long convmul,
1852                                      unsigned long convdiv)
1853 {
1854 #define TMPBUFLEN 21
1855         unsigned long *i, *min, *max, val;
1856         int vleft, first=1, neg;
1857         size_t len, left;
1858         char buf[TMPBUFLEN], *p;
1859         char __user *s = buffer;
1860
1861         if (!data || !table->maxlen || !*lenp ||
1862             (*ppos && !write)) {
1863                 *lenp = 0;
1864                 return 0;
1865         }
1866
1867         i = (unsigned long *) data;
1868         min = (unsigned long *) table->extra1;
1869         max = (unsigned long *) table->extra2;
1870         vleft = table->maxlen / sizeof(unsigned long);
1871         left = *lenp;
1872
1873         for (; left && vleft--; i++, min++, max++, first=0) {
1874                 if (write) {
1875                         while (left) {
1876                                 char c;
1877                                 if (get_user(c, s))
1878                                         return -EFAULT;
1879                                 if (!isspace(c))
1880                                         break;
1881                                 left--;
1882                                 s++;
1883                         }
1884                         if (!left)
1885                                 break;
1886                         neg = 0;
1887                         len = left;
1888                         if (len > TMPBUFLEN-1)
1889                                 len = TMPBUFLEN-1;
1890                         if (copy_from_user(buf, s, len))
1891                                 return -EFAULT;
1892                         buf[len] = 0;
1893                         p = buf;
1894                         if (*p == '-' && left > 1) {
1895                                 neg = 1;
1896                                 p++;
1897                         }
1898                         if (*p < '0' || *p > '9')
1899                                 break;
1900                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1901                         len = p-buf;
1902                         if ((len < left) && *p && !isspace(*p))
1903                                 break;
1904                         if (neg)
1905                                 val = -val;
1906                         s += len;
1907                         left -= len;
1908
1909                         if(neg)
1910                                 continue;
1911                         if ((min && val < *min) || (max && val > *max))
1912                                 continue;
1913                         *i = val;
1914                 } else {
1915                         p = buf;
1916                         if (!first)
1917                                 *p++ = '\t';
1918                         sprintf(p, "%lu", convdiv * (*i) / convmul);
1919                         len = strlen(buf);
1920                         if (len > left)
1921                                 len = left;
1922                         if(copy_to_user(s, buf, len))
1923                                 return -EFAULT;
1924                         left -= len;
1925                         s += len;
1926                 }
1927         }
1928
1929         if (!write && !first && left) {
1930                 if(put_user('\n', s))
1931                         return -EFAULT;
1932                 left--, s++;
1933         }
1934         if (write) {
1935                 while (left) {
1936                         char c;
1937                         if (get_user(c, s++))
1938                                 return -EFAULT;
1939                         if (!isspace(c))
1940                                 break;
1941                         left--;
1942                 }
1943         }
1944         if (write && first)
1945                 return -EINVAL;
1946         *lenp -= left;
1947         *ppos += *lenp;
1948         return 0;
1949 #undef TMPBUFLEN
1950 }
1951
1952 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1953                                      struct file *filp,
1954                                      void __user *buffer,
1955                                      size_t *lenp, loff_t *ppos,
1956                                      unsigned long convmul,
1957                                      unsigned long convdiv)
1958 {
1959         return __do_proc_doulongvec_minmax(table->data, table, write,
1960                         filp, buffer, lenp, ppos, convmul, convdiv);
1961 }
1962
1963 /**
1964  * proc_doulongvec_minmax - read a vector of long integers with min/max values
1965  * @table: the sysctl table
1966  * @write: %TRUE if this is a write to the sysctl file
1967  * @filp: the file structure
1968  * @buffer: the user buffer
1969  * @lenp: the size of the user buffer
1970  * @ppos: file position
1971  *
1972  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1973  * values from/to the user buffer, treated as an ASCII string.
1974  *
1975  * This routine will ensure the values are within the range specified by
1976  * table->extra1 (min) and table->extra2 (max).
1977  *
1978  * Returns 0 on success.
1979  */
1980 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
1981                            void __user *buffer, size_t *lenp, loff_t *ppos)
1982 {
1983     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
1984 }
1985
1986 /**
1987  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
1988  * @table: the sysctl table
1989  * @write: %TRUE if this is a write to the sysctl file
1990  * @filp: the file structure
1991  * @buffer: the user buffer
1992  * @lenp: the size of the user buffer
1993  * @ppos: file position
1994  *
1995  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1996  * values from/to the user buffer, treated as an ASCII string. The values
1997  * are treated as milliseconds, and converted to jiffies when they are stored.
1998  *
1999  * This routine will ensure the values are within the range specified by
2000  * table->extra1 (min) and table->extra2 (max).
2001  *
2002  * Returns 0 on success.
2003  */
2004 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2005                                       struct file *filp,
2006                                       void __user *buffer,
2007                                       size_t *lenp, loff_t *ppos)
2008 {
2009     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2010                                      lenp, ppos, HZ, 1000l);
2011 }
2012
2013
2014 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2015                                          int *valp,
2016                                          int write, void *data)
2017 {
2018         if (write) {
2019                 if (*lvalp > LONG_MAX / HZ)
2020                         return 1;
2021                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2022         } else {
2023                 int val = *valp;
2024                 unsigned long lval;
2025                 if (val < 0) {
2026                         *negp = -1;
2027                         lval = (unsigned long)-val;
2028                 } else {
2029                         *negp = 0;
2030                         lval = (unsigned long)val;
2031                 }
2032                 *lvalp = lval / HZ;
2033         }
2034         return 0;
2035 }
2036
2037 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2038                                                 int *valp,
2039                                                 int write, void *data)
2040 {
2041         if (write) {
2042                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2043                         return 1;
2044                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2045         } else {
2046                 int val = *valp;
2047                 unsigned long lval;
2048                 if (val < 0) {
2049                         *negp = -1;
2050                         lval = (unsigned long)-val;
2051                 } else {
2052                         *negp = 0;
2053                         lval = (unsigned long)val;
2054                 }
2055                 *lvalp = jiffies_to_clock_t(lval);
2056         }
2057         return 0;
2058 }
2059
2060 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2061                                             int *valp,
2062                                             int write, void *data)
2063 {
2064         if (write) {
2065                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2066         } else {
2067                 int val = *valp;
2068                 unsigned long lval;
2069                 if (val < 0) {
2070                         *negp = -1;
2071                         lval = (unsigned long)-val;
2072                 } else {
2073                         *negp = 0;
2074                         lval = (unsigned long)val;
2075                 }
2076                 *lvalp = jiffies_to_msecs(lval);
2077         }
2078         return 0;
2079 }
2080
2081 /**
2082  * proc_dointvec_jiffies - read a vector of integers as seconds
2083  * @table: the sysctl table
2084  * @write: %TRUE if this is a write to the sysctl file
2085  * @filp: the file structure
2086  * @buffer: the user buffer
2087  * @lenp: the size of the user buffer
2088  * @ppos: file position
2089  *
2090  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2091  * values from/to the user buffer, treated as an ASCII string.
2092  * The values read are assumed to be in seconds, and are converted into
2093  * jiffies.
2094  *
2095  * Returns 0 on success.
2096  */
2097 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2098                           void __user *buffer, size_t *lenp, loff_t *ppos)
2099 {
2100     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2101                             do_proc_dointvec_jiffies_conv,NULL);
2102 }
2103
2104 /**
2105  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2106  * @table: the sysctl table
2107  * @write: %TRUE if this is a write to the sysctl file
2108  * @filp: the file structure
2109  * @buffer: the user buffer
2110  * @lenp: the size of the user buffer
2111  * @ppos: pointer to the file position
2112  *
2113  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2114  * values from/to the user buffer, treated as an ASCII string.
2115  * The values read are assumed to be in 1/USER_HZ seconds, and
2116  * are converted into jiffies.
2117  *
2118  * Returns 0 on success.
2119  */
2120 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2121                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2122 {
2123     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2124                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2125 }
2126
2127 /**
2128  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
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  * @ppos: the current position in the file
2136  *
2137  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2138  * values from/to the user buffer, treated as an ASCII string.
2139  * The values read are assumed to be in 1/1000 seconds, and
2140  * are converted into jiffies.
2141  *
2142  * Returns 0 on success.
2143  */
2144 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2145                              void __user *buffer, size_t *lenp, loff_t *ppos)
2146 {
2147         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2148                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2149 }
2150
2151 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2152                            void __user *buffer, size_t *lenp, loff_t *ppos)
2153 {
2154         struct pid *new_pid;
2155         pid_t tmp;
2156         int r;
2157
2158         tmp = pid_nr(cad_pid);
2159
2160         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2161                                lenp, ppos, NULL, NULL);
2162         if (r || !write)
2163                 return r;
2164
2165         new_pid = find_get_pid(tmp);
2166         if (!new_pid)
2167                 return -ESRCH;
2168
2169         put_pid(xchg(&cad_pid, new_pid));
2170         return 0;
2171 }
2172
2173 #else /* CONFIG_PROC_FS */
2174
2175 int proc_dostring(ctl_table *table, int write, struct file *filp,
2176                   void __user *buffer, size_t *lenp, loff_t *ppos)
2177 {
2178         return -ENOSYS;
2179 }
2180
2181 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2182                   void __user *buffer, size_t *lenp, loff_t *ppos)
2183 {
2184         return -ENOSYS;
2185 }
2186
2187 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2188                         void __user *buffer, size_t *lenp, loff_t *ppos)
2189 {
2190         return -ENOSYS;
2191 }
2192
2193 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2194                     void __user *buffer, size_t *lenp, loff_t *ppos)
2195 {
2196         return -ENOSYS;
2197 }
2198
2199 int proc_dointvec_jiffies(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 int proc_dointvec_userhz_jiffies(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_ms_jiffies(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_doulongvec_minmax(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_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2224                                       struct file *filp,
2225                                       void __user *buffer,
2226                                       size_t *lenp, loff_t *ppos)
2227 {
2228     return -ENOSYS;
2229 }
2230
2231
2232 #endif /* CONFIG_PROC_FS */
2233
2234
2235 #ifdef CONFIG_SYSCTL_SYSCALL
2236 /*
2237  * General sysctl support routines
2238  */
2239
2240 /* The generic string strategy routine: */
2241 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2242                   void __user *oldval, size_t __user *oldlenp,
2243                   void __user *newval, size_t newlen)
2244 {
2245         if (!table->data || !table->maxlen)
2246                 return -ENOTDIR;
2247
2248         if (oldval && oldlenp) {
2249                 size_t bufsize;
2250                 if (get_user(bufsize, oldlenp))
2251                         return -EFAULT;
2252                 if (bufsize) {
2253                         size_t len = strlen(table->data), copied;
2254
2255                         /* This shouldn't trigger for a well-formed sysctl */
2256                         if (len > table->maxlen)
2257                                 len = table->maxlen;
2258
2259                         /* Copy up to a max of bufsize-1 bytes of the string */
2260                         copied = (len >= bufsize) ? bufsize - 1 : len;
2261
2262                         if (copy_to_user(oldval, table->data, copied) ||
2263                             put_user(0, (char __user *)(oldval + copied)))
2264                                 return -EFAULT;
2265                         if (put_user(len, oldlenp))
2266                                 return -EFAULT;
2267                 }
2268         }
2269         if (newval && newlen) {
2270                 size_t len = newlen;
2271                 if (len > table->maxlen)
2272                         len = table->maxlen;
2273                 if(copy_from_user(table->data, newval, len))
2274                         return -EFAULT;
2275                 if (len == table->maxlen)
2276                         len--;
2277                 ((char *) table->data)[len] = 0;
2278         }
2279         return 1;
2280 }
2281
2282 /*
2283  * This function makes sure that all of the integers in the vector
2284  * are between the minimum and maximum values given in the arrays
2285  * table->extra1 and table->extra2, respectively.
2286  */
2287 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2288                 void __user *oldval, size_t __user *oldlenp,
2289                 void __user *newval, size_t newlen)
2290 {
2291
2292         if (newval && newlen) {
2293                 int __user *vec = (int __user *) newval;
2294                 int *min = (int *) table->extra1;
2295                 int *max = (int *) table->extra2;
2296                 size_t length;
2297                 int i;
2298
2299                 if (newlen % sizeof(int) != 0)
2300                         return -EINVAL;
2301
2302                 if (!table->extra1 && !table->extra2)
2303                         return 0;
2304
2305                 if (newlen > table->maxlen)
2306                         newlen = table->maxlen;
2307                 length = newlen / sizeof(int);
2308
2309                 for (i = 0; i < length; i++) {
2310                         int value;
2311                         if (get_user(value, vec + i))
2312                                 return -EFAULT;
2313                         if (min && value < min[i])
2314                                 return -EINVAL;
2315                         if (max && value > max[i])
2316                                 return -EINVAL;
2317                 }
2318         }
2319         return 0;
2320 }
2321
2322 /* Strategy function to convert jiffies to seconds */
2323 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2324                 void __user *oldval, size_t __user *oldlenp,
2325                 void __user *newval, size_t newlen)
2326 {
2327         if (oldval && oldlenp) {
2328                 size_t olen;
2329
2330                 if (get_user(olen, oldlenp))
2331                         return -EFAULT;
2332                 if (olen) {
2333                         int val;
2334
2335                         if (olen < sizeof(int))
2336                                 return -EINVAL;
2337
2338                         val = *(int *)(table->data) / HZ;
2339                         if (put_user(val, (int __user *)oldval))
2340                                 return -EFAULT;
2341                         if (put_user(sizeof(int), oldlenp))
2342                                 return -EFAULT;
2343                 }
2344         }
2345         if (newval && newlen) {
2346                 int new;
2347                 if (newlen != sizeof(int))
2348                         return -EINVAL;
2349                 if (get_user(new, (int __user *)newval))
2350                         return -EFAULT;
2351                 *(int *)(table->data) = new*HZ;
2352         }
2353         return 1;
2354 }
2355
2356 /* Strategy function to convert jiffies to seconds */
2357 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2358                 void __user *oldval, size_t __user *oldlenp,
2359                 void __user *newval, size_t newlen)
2360 {
2361         if (oldval && oldlenp) {
2362                 size_t olen;
2363
2364                 if (get_user(olen, oldlenp))
2365                         return -EFAULT;
2366                 if (olen) {
2367                         int val;
2368
2369                         if (olen < sizeof(int))
2370                                 return -EINVAL;
2371
2372                         val = jiffies_to_msecs(*(int *)(table->data));
2373                         if (put_user(val, (int __user *)oldval))
2374                                 return -EFAULT;
2375                         if (put_user(sizeof(int), oldlenp))
2376                                 return -EFAULT;
2377                 }
2378         }
2379         if (newval && newlen) {
2380                 int new;
2381                 if (newlen != sizeof(int))
2382                         return -EINVAL;
2383                 if (get_user(new, (int __user *)newval))
2384                         return -EFAULT;
2385                 *(int *)(table->data) = msecs_to_jiffies(new);
2386         }
2387         return 1;
2388 }
2389
2390
2391
2392 #else /* CONFIG_SYSCTL_SYSCALL */
2393
2394
2395 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2396 {
2397         static int msg_count;
2398         struct __sysctl_args tmp;
2399         int name[CTL_MAXNAME];
2400         int i;
2401
2402         /* Read in the sysctl name for better debug message logging */
2403         if (copy_from_user(&tmp, args, sizeof(tmp)))
2404                 return -EFAULT;
2405         if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2406                 return -ENOTDIR;
2407         for (i = 0; i < tmp.nlen; i++)
2408                 if (get_user(name[i], tmp.name + i))
2409                         return -EFAULT;
2410
2411         /* Ignore accesses to kernel.version */
2412         if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2413                 goto out;
2414
2415         if (msg_count < 5) {
2416                 msg_count++;
2417                 printk(KERN_INFO
2418                         "warning: process `%s' used the removed sysctl "
2419                         "system call with ", current->comm);
2420                 for (i = 0; i < tmp.nlen; i++)
2421                         printk("%d.", name[i]);
2422                 printk("\n");
2423         }
2424 out:
2425         return -ENOSYS;
2426 }
2427
2428 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2429                   void __user *oldval, size_t __user *oldlenp,
2430                   void __user *newval, size_t newlen)
2431 {
2432         return -ENOSYS;
2433 }
2434
2435 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2436                 void __user *oldval, size_t __user *oldlenp,
2437                 void __user *newval, size_t newlen)
2438 {
2439         return -ENOSYS;
2440 }
2441
2442 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2443                 void __user *oldval, size_t __user *oldlenp,
2444                 void __user *newval, size_t newlen)
2445 {
2446         return -ENOSYS;
2447 }
2448
2449 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2450                 void __user *oldval, size_t __user *oldlenp,
2451                 void __user *newval, size_t newlen)
2452 {
2453         return -ENOSYS;
2454 }
2455
2456 #endif /* CONFIG_SYSCTL_SYSCALL */
2457
2458 /*
2459  * No sense putting this after each symbol definition, twice,
2460  * exception granted :-)
2461  */
2462 EXPORT_SYMBOL(proc_dointvec);
2463 EXPORT_SYMBOL(proc_dointvec_jiffies);
2464 EXPORT_SYMBOL(proc_dointvec_minmax);
2465 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2466 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2467 EXPORT_SYMBOL(proc_dostring);
2468 EXPORT_SYMBOL(proc_doulongvec_minmax);
2469 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2470 EXPORT_SYMBOL(register_sysctl_table);
2471 EXPORT_SYMBOL(sysctl_intvec);
2472 EXPORT_SYMBOL(sysctl_jiffies);
2473 EXPORT_SYMBOL(sysctl_ms_jiffies);
2474 EXPORT_SYMBOL(sysctl_string);
2475 EXPORT_SYMBOL(unregister_sysctl_table);