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   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/security.h>
  28 #include <linux/ctype.h>
  29 #include <linux/utsname.h>
  30 #include <linux/kmemcheck.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/fs.h>
  33 #include <linux/init.h>
  34 #include <linux/kernel.h>
  35 #include <linux/kobject.h>
  36 #include <linux/net.h>
  37 #include <linux/sysrq.h>
  38 #include <linux/highuid.h>
  39 #include <linux/writeback.h>
  40 #include <linux/hugetlb.h>
  41 #include <linux/initrd.h>
  42 #include <linux/key.h>
  43 #include <linux/times.h>
  44 #include <linux/limits.h>
  45 #include <linux/dcache.h>
  46 #include <linux/syscalls.h>
  47 #include <linux/vmstat.h>
  48 #include <linux/nfs_fs.h>
  49 #include <linux/acpi.h>
  50 #include <linux/reboot.h>
  51 #include <linux/ftrace.h>
  52 #include <linux/slow-work.h>
  53 #include <linux/perf_counter.h>
  54
  55 #include <asm/uaccess.h>
  56 #include <asm/processor.h>
  57
  58 #ifdef CONFIG_X86
  59 #include <asm/nmi.h>
  60 #include <asm/stacktrace.h>
  61 #include <asm/io.h>
  62 #endif
  63
  64 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  65
  66 #if defined(CONFIG_SYSCTL)
  67
  68 /* External variables not in a header file. */
  69 extern int C_A_D;
  70 extern int print_fatal_signals;
  71 extern int sysctl_overcommit_memory;
  72 extern int sysctl_overcommit_ratio;
  73 extern int sysctl_panic_on_oom;
  74 extern int sysctl_oom_kill_allocating_task;
  75 extern int sysctl_oom_dump_tasks;
  76 extern int max_threads;
  77 extern int core_uses_pid;
  78 extern int suid_dumpable;
  79 extern char core_pattern[];
  80 extern int pid_max;
  81 extern int min_free_kbytes;
  82 extern int pid_max_min, pid_max_max;
  83 extern int sysctl_drop_caches;
  84 extern int percpu_pagelist_fraction;
  85 extern int compat_log;
  86 extern int latencytop_enabled;
  87 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  88 #ifndef CONFIG_MMU
  89 extern int sysctl_nr_trim_pages;
  90 #endif
  91 #ifdef CONFIG_RCU_TORTURE_TEST
  92 extern int rcutorture_runnable;
  93 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  94 extern int blk_iopoll_enabled;
  95
  96 /* Constants used for minimum and  maximum */
  97 #ifdef CONFIG_DETECT_SOFTLOCKUP
  98 static int sixty = 60;
  99 static int neg_one = -1;
 100 #endif
 101
 102 static int zero;
 103 static int __maybe_unused one = 1;
 104 static int __maybe_unused two = 2;
 105 static unsigned long one_ul = 1;
 106 static int one_hundred = 100;
 107
 108 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 109 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 110
 111 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 112 static int maxolduid = 65535;
 113 static int minolduid;
 114 static int min_percpu_pagelist_fract = 8;
 115
 116 static int ngroups_max = NGROUPS_MAX;
 117
 118 #ifdef CONFIG_MODULES
 119 extern char modprobe_path[];
 120 extern int modules_disabled;
 121 #endif
 122 #ifdef CONFIG_CHR_DEV_SG
 123 extern int sg_big_buff;
 124 #endif
 125
 126 #ifdef CONFIG_SPARC
 127 #include <asm/system.h>
 128 #endif
 129
 130 #ifdef CONFIG_SPARC64
 131 extern int sysctl_tsb_ratio;
 132 #endif
 133
 134 #ifdef __hppa__
 135 extern int pwrsw_enabled;
 136 extern int unaligned_enabled;
 137 #endif
 138
 139 #ifdef CONFIG_S390
 140 #ifdef CONFIG_MATHEMU
 141 extern int sysctl_ieee_emulation_warnings;
 142 #endif
 143 extern int sysctl_userprocess_debug;
 144 extern int spin_retry;
 145 #endif
 146
 147 #ifdef CONFIG_BSD_PROCESS_ACCT
 148 extern int acct_parm[];
 149 #endif
 150
 151 #ifdef CONFIG_IA64
 152 extern int no_unaligned_warning;
 153 extern int unaligned_dump_stack;
 154 #endif
 155
 156 #ifdef CONFIG_RT_MUTEXES
 157 extern int max_lock_depth;
 158 #endif
 159
 160 #ifdef CONFIG_PROC_SYSCTL
 161 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
 162                   void __user *buffer, size_t *lenp, loff_t *ppos);
 163 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 164                                void __user *buffer, size_t *lenp, loff_t *ppos);
 165 #endif
 166
 167 static struct ctl_table root_table[];
 168 static struct ctl_table_root sysctl_table_root;
 169 static struct ctl_table_header root_table_header = {
 170         .count = 1,
 171         .ctl_table = root_table,
 172         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 173         .root = &sysctl_table_root,
 174         .set = &sysctl_table_root.default_set,
 175 };
 176 static struct ctl_table_root sysctl_table_root = {
 177         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 178         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 179 };
 180
 181 static struct ctl_table kern_table[];
 182 static struct ctl_table vm_table[];
 183 static struct ctl_table fs_table[];
 184 static struct ctl_table debug_table[];
 185 static struct ctl_table dev_table[];
 186 extern struct ctl_table random_table[];
 187 #ifdef CONFIG_INOTIFY_USER
 188 extern struct ctl_table inotify_table[];
 189 #endif
 190 #ifdef CONFIG_EPOLL
 191 extern struct ctl_table epoll_table[];
 192 #endif
 193
 194 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 195 int sysctl_legacy_va_layout;
 196 #endif
 197
 198 extern int prove_locking;
 199 extern int lock_stat;
 200
 201 /* The default sysctl tables: */
 202
 203 static struct ctl_table root_table[] = {
 204         {
 205                 .ctl_name       = CTL_KERN,
 206                 .procname       = "kernel",
 207                 .mode           = 0555,
 208                 .child          = kern_table,
 209         },
 210         {
 211                 .ctl_name       = CTL_VM,
 212                 .procname       = "vm",
 213                 .mode           = 0555,
 214                 .child          = vm_table,
 215         },
 216         {
 217                 .ctl_name       = CTL_FS,
 218                 .procname       = "fs",
 219                 .mode           = 0555,
 220                 .child          = fs_table,
 221         },
 222         {
 223                 .ctl_name       = CTL_DEBUG,
 224                 .procname       = "debug",
 225                 .mode           = 0555,
 226                 .child          = debug_table,
 227         },
 228         {
 229                 .ctl_name       = CTL_DEV,
 230                 .procname       = "dev",
 231                 .mode           = 0555,
 232                 .child          = dev_table,
 233         },
 234 /*
 235  * NOTE: do not add new entries to this table unless you have read
 236  * Documentation/sysctl/ctl_unnumbered.txt
 237  */
 238         { .ctl_name = 0 }
 239 };
 240
 241 #ifdef CONFIG_SCHED_DEBUG
 242 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 243 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 244 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 245 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 246 #endif
 247
 248 static struct ctl_table kern_table[] = {
 249         {
 250                 .ctl_name       = CTL_UNNUMBERED,
 251                 .procname       = "sched_child_runs_first",
 252                 .data           = &sysctl_sched_child_runs_first,
 253                 .maxlen         = sizeof(unsigned int),
 254                 .mode           = 0644,
 255                 .proc_handler   = &proc_dointvec,
 256         },
 257 #ifdef CONFIG_SCHED_DEBUG
 258         {
 259                 .ctl_name       = CTL_UNNUMBERED,
 260                 .procname       = "sched_min_granularity_ns",
 261                 .data           = &sysctl_sched_min_granularity,
 262                 .maxlen         = sizeof(unsigned int),
 263                 .mode           = 0644,
 264                 .proc_handler   = &sched_nr_latency_handler,
 265                 .strategy       = &sysctl_intvec,
 266                 .extra1         = &min_sched_granularity_ns,
 267                 .extra2         = &max_sched_granularity_ns,
 268         },
 269         {
 270                 .ctl_name       = CTL_UNNUMBERED,
 271                 .procname       = "sched_latency_ns",
 272                 .data           = &sysctl_sched_latency,
 273                 .maxlen         = sizeof(unsigned int),
 274                 .mode           = 0644,
 275                 .proc_handler   = &sched_nr_latency_handler,
 276                 .strategy       = &sysctl_intvec,
 277                 .extra1         = &min_sched_granularity_ns,
 278                 .extra2         = &max_sched_granularity_ns,
 279         },
 280         {
 281                 .ctl_name       = CTL_UNNUMBERED,
 282                 .procname       = "sched_wakeup_granularity_ns",
 283                 .data           = &sysctl_sched_wakeup_granularity,
 284                 .maxlen         = sizeof(unsigned int),
 285                 .mode           = 0644,
 286                 .proc_handler   = &proc_dointvec_minmax,
 287                 .strategy       = &sysctl_intvec,
 288                 .extra1         = &min_wakeup_granularity_ns,
 289                 .extra2         = &max_wakeup_granularity_ns,
 290         },
 291         {
 292                 .ctl_name       = CTL_UNNUMBERED,
 293                 .procname       = "sched_shares_ratelimit",
 294                 .data           = &sysctl_sched_shares_ratelimit,
 295                 .maxlen         = sizeof(unsigned int),
 296                 .mode           = 0644,
 297                 .proc_handler   = &proc_dointvec,
 298         },
 299         {
 300                 .ctl_name       = CTL_UNNUMBERED,
 301                 .procname       = "sched_shares_thresh",
 302                 .data           = &sysctl_sched_shares_thresh,
 303                 .maxlen         = sizeof(unsigned int),
 304                 .mode           = 0644,
 305                 .proc_handler   = &proc_dointvec_minmax,
 306                 .strategy       = &sysctl_intvec,
 307                 .extra1         = &zero,
 308         },
 309         {
 310                 .ctl_name       = CTL_UNNUMBERED,
 311                 .procname       = "sched_features",
 312                 .data           = &sysctl_sched_features,
 313                 .maxlen         = sizeof(unsigned int),
 314                 .mode           = 0644,
 315                 .proc_handler   = &proc_dointvec,
 316         },
 317         {
 318                 .ctl_name       = CTL_UNNUMBERED,
 319                 .procname       = "sched_migration_cost",
 320                 .data           = &sysctl_sched_migration_cost,
 321                 .maxlen         = sizeof(unsigned int),
 322                 .mode           = 0644,
 323                 .proc_handler   = &proc_dointvec,
 324         },
 325         {
 326                 .ctl_name       = CTL_UNNUMBERED,
 327                 .procname       = "sched_nr_migrate",
 328                 .data           = &sysctl_sched_nr_migrate,
 329                 .maxlen         = sizeof(unsigned int),
 330                 .mode           = 0644,
 331                 .proc_handler   = &proc_dointvec,
 332         },
 333         {
 334                 .ctl_name       = CTL_UNNUMBERED,
 335                 .procname       = "sched_time_avg",
 336                 .data           = &sysctl_sched_time_avg,
 337                 .maxlen         = sizeof(unsigned int),
 338                 .mode           = 0644,
 339                 .proc_handler   = &proc_dointvec,
 340         },
 341         {
 342                 .ctl_name       = CTL_UNNUMBERED,
 343                 .procname       = "timer_migration",
 344                 .data           = &sysctl_timer_migration,
 345                 .maxlen         = sizeof(unsigned int),
 346                 .mode           = 0644,
 347                 .proc_handler   = &proc_dointvec_minmax,
 348                 .strategy       = &sysctl_intvec,
 349                 .extra1         = &zero,
 350                 .extra2         = &one,
 351         },
 352 #endif
 353         {
 354                 .ctl_name       = CTL_UNNUMBERED,
 355                 .procname       = "sched_rt_period_us",
 356                 .data           = &sysctl_sched_rt_period,
 357                 .maxlen         = sizeof(unsigned int),
 358                 .mode           = 0644,
 359                 .proc_handler   = &sched_rt_handler,
 360         },
 361         {
 362                 .ctl_name       = CTL_UNNUMBERED,
 363                 .procname       = "sched_rt_runtime_us",
 364                 .data           = &sysctl_sched_rt_runtime,
 365                 .maxlen         = sizeof(int),
 366                 .mode           = 0644,
 367                 .proc_handler   = &sched_rt_handler,
 368         },
 369         {
 370                 .ctl_name       = CTL_UNNUMBERED,
 371                 .procname       = "sched_compat_yield",
 372                 .data           = &sysctl_sched_compat_yield,
 373                 .maxlen         = sizeof(unsigned int),
 374                 .mode           = 0644,
 375                 .proc_handler   = &proc_dointvec,
 376         },
 377 #ifdef CONFIG_PROVE_LOCKING
 378         {
 379                 .ctl_name       = CTL_UNNUMBERED,
 380                 .procname       = "prove_locking",
 381                 .data           = &prove_locking,
 382                 .maxlen         = sizeof(int),
 383                 .mode           = 0644,
 384                 .proc_handler   = &proc_dointvec,
 385         },
 386 #endif
 387 #ifdef CONFIG_LOCK_STAT
 388         {
 389                 .ctl_name       = CTL_UNNUMBERED,
 390                 .procname       = "lock_stat",
 391                 .data           = &lock_stat,
 392                 .maxlen         = sizeof(int),
 393                 .mode           = 0644,
 394                 .proc_handler   = &proc_dointvec,
 395         },
 396 #endif
 397         {
 398                 .ctl_name       = KERN_PANIC,
 399                 .procname       = "panic",
 400                 .data           = &panic_timeout,
 401                 .maxlen         = sizeof(int),
 402                 .mode           = 0644,
 403                 .proc_handler   = &proc_dointvec,
 404         },
 405         {
 406                 .ctl_name       = KERN_CORE_USES_PID,
 407                 .procname       = "core_uses_pid",
 408                 .data           = &core_uses_pid,
 409                 .maxlen         = sizeof(int),
 410                 .mode           = 0644,
 411                 .proc_handler   = &proc_dointvec,
 412         },
 413         {
 414                 .ctl_name       = KERN_CORE_PATTERN,
 415                 .procname       = "core_pattern",
 416                 .data           = core_pattern,
 417                 .maxlen         = CORENAME_MAX_SIZE,
 418                 .mode           = 0644,
 419                 .proc_handler   = &proc_dostring,
 420                 .strategy       = &sysctl_string,
 421         },
 422 #ifdef CONFIG_PROC_SYSCTL
 423         {
 424                 .procname       = "tainted",
 425                 .maxlen         = sizeof(long),
 426                 .mode           = 0644,
 427                 .proc_handler   = &proc_taint,
 428         },
 429 #endif
 430 #ifdef CONFIG_LATENCYTOP
 431         {
 432                 .procname       = "latencytop",
 433                 .data           = &latencytop_enabled,
 434                 .maxlen         = sizeof(int),
 435                 .mode           = 0644,
 436                 .proc_handler   = &proc_dointvec,
 437         },
 438 #endif
 439 #ifdef CONFIG_BLK_DEV_INITRD
 440         {
 441                 .ctl_name       = KERN_REALROOTDEV,
 442                 .procname       = "real-root-dev",
 443                 .data           = &real_root_dev,
 444                 .maxlen         = sizeof(int),
 445                 .mode           = 0644,
 446                 .proc_handler   = &proc_dointvec,
 447         },
 448 #endif
 449         {
 450                 .ctl_name       = CTL_UNNUMBERED,
 451                 .procname       = "print-fatal-signals",
 452                 .data           = &print_fatal_signals,
 453                 .maxlen         = sizeof(int),
 454                 .mode           = 0644,
 455                 .proc_handler   = &proc_dointvec,
 456         },
 457 #ifdef CONFIG_SPARC
 458         {
 459                 .ctl_name       = KERN_SPARC_REBOOT,
 460                 .procname       = "reboot-cmd",
 461                 .data           = reboot_command,
 462                 .maxlen         = 256,
 463                 .mode           = 0644,
 464                 .proc_handler   = &proc_dostring,
 465                 .strategy       = &sysctl_string,
 466         },
 467         {
 468                 .ctl_name       = KERN_SPARC_STOP_A,
 469                 .procname       = "stop-a",
 470                 .data           = &stop_a_enabled,
 471                 .maxlen         = sizeof (int),
 472                 .mode           = 0644,
 473                 .proc_handler   = &proc_dointvec,
 474         },
 475         {
 476                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 477                 .procname       = "scons-poweroff",
 478                 .data           = &scons_pwroff,
 479                 .maxlen         = sizeof (int),
 480                 .mode           = 0644,
 481                 .proc_handler   = &proc_dointvec,
 482         },
 483 #endif
 484 #ifdef CONFIG_SPARC64
 485         {
 486                 .ctl_name       = CTL_UNNUMBERED,
 487                 .procname       = "tsb-ratio",
 488                 .data           = &sysctl_tsb_ratio,
 489                 .maxlen         = sizeof (int),
 490                 .mode           = 0644,
 491                 .proc_handler   = &proc_dointvec,
 492         },
 493 #endif
 494 #ifdef __hppa__
 495         {
 496                 .ctl_name       = KERN_HPPA_PWRSW,
 497                 .procname       = "soft-power",
 498                 .data           = &pwrsw_enabled,
 499                 .maxlen         = sizeof (int),
 500                 .mode           = 0644,
 501                 .proc_handler   = &proc_dointvec,
 502         },
 503         {
 504                 .ctl_name       = KERN_HPPA_UNALIGNED,
 505                 .procname       = "unaligned-trap",
 506                 .data           = &unaligned_enabled,
 507                 .maxlen         = sizeof (int),
 508                 .mode           = 0644,
 509                 .proc_handler   = &proc_dointvec,
 510         },
 511 #endif
 512         {
 513                 .ctl_name       = KERN_CTLALTDEL,
 514                 .procname       = "ctrl-alt-del",
 515                 .data           = &C_A_D,
 516                 .maxlen         = sizeof(int),
 517                 .mode           = 0644,
 518                 .proc_handler   = &proc_dointvec,
 519         },
 520 #ifdef CONFIG_FUNCTION_TRACER
 521         {
 522                 .ctl_name       = CTL_UNNUMBERED,
 523                 .procname       = "ftrace_enabled",
 524                 .data           = &ftrace_enabled,
 525                 .maxlen         = sizeof(int),
 526                 .mode           = 0644,
 527                 .proc_handler   = &ftrace_enable_sysctl,
 528         },
 529 #endif
 530 #ifdef CONFIG_STACK_TRACER
 531         {
 532                 .ctl_name       = CTL_UNNUMBERED,
 533                 .procname       = "stack_tracer_enabled",
 534                 .data           = &stack_tracer_enabled,
 535                 .maxlen         = sizeof(int),
 536                 .mode           = 0644,
 537                 .proc_handler   = &stack_trace_sysctl,
 538         },
 539 #endif
 540 #ifdef CONFIG_TRACING
 541         {
 542                 .ctl_name       = CTL_UNNUMBERED,
 543                 .procname       = "ftrace_dump_on_oops",
 544                 .data           = &ftrace_dump_on_oops,
 545                 .maxlen         = sizeof(int),
 546                 .mode           = 0644,
 547                 .proc_handler   = &proc_dointvec,
 548         },
 549 #endif
 550 #ifdef CONFIG_MODULES
 551         {
 552                 .ctl_name       = KERN_MODPROBE,
 553                 .procname       = "modprobe",
 554                 .data           = &modprobe_path,
 555                 .maxlen         = KMOD_PATH_LEN,
 556                 .mode           = 0644,
 557                 .proc_handler   = &proc_dostring,
 558                 .strategy       = &sysctl_string,
 559         },
 560         {
 561                 .ctl_name       = CTL_UNNUMBERED,
 562                 .procname       = "modules_disabled",
 563                 .data           = &modules_disabled,
 564                 .maxlen         = sizeof(int),
 565                 .mode           = 0644,
 566                 /* only handle a transition from default "0" to "1" */
 567                 .proc_handler   = &proc_dointvec_minmax,
 568                 .extra1         = &one,
 569                 .extra2         = &one,
 570         },
 571 #endif
 572 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 573         {
 574                 .ctl_name       = KERN_HOTPLUG,
 575                 .procname       = "hotplug",
 576                 .data           = &uevent_helper,
 577                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 578                 .mode           = 0644,
 579                 .proc_handler   = &proc_dostring,
 580                 .strategy       = &sysctl_string,
 581         },
 582 #endif
 583 #ifdef CONFIG_CHR_DEV_SG
 584         {
 585                 .ctl_name       = KERN_SG_BIG_BUFF,
 586                 .procname       = "sg-big-buff",
 587                 .data           = &sg_big_buff,
 588                 .maxlen         = sizeof (int),
 589                 .mode           = 0444,
 590                 .proc_handler   = &proc_dointvec,
 591         },
 592 #endif
 593 #ifdef CONFIG_BSD_PROCESS_ACCT
 594         {
 595                 .ctl_name       = KERN_ACCT,
 596                 .procname       = "acct",
 597                 .data           = &acct_parm,
 598                 .maxlen         = 3*sizeof(int),
 599                 .mode           = 0644,
 600                 .proc_handler   = &proc_dointvec,
 601         },
 602 #endif
 603 #ifdef CONFIG_MAGIC_SYSRQ
 604         {
 605                 .ctl_name       = KERN_SYSRQ,
 606                 .procname       = "sysrq",
 607                 .data           = &__sysrq_enabled,
 608                 .maxlen         = sizeof (int),
 609                 .mode           = 0644,
 610                 .proc_handler   = &proc_dointvec,
 611         },
 612 #endif
 613 #ifdef CONFIG_PROC_SYSCTL
 614         {
 615                 .procname       = "cad_pid",
 616                 .data           = NULL,
 617                 .maxlen         = sizeof (int),
 618                 .mode           = 0600,
 619                 .proc_handler   = &proc_do_cad_pid,
 620         },
 621 #endif
 622         {
 623                 .ctl_name       = KERN_MAX_THREADS,
 624                 .procname       = "threads-max",
 625                 .data           = &max_threads,
 626                 .maxlen         = sizeof(int),
 627                 .mode           = 0644,
 628                 .proc_handler   = &proc_dointvec,
 629         },
 630         {
 631                 .ctl_name       = KERN_RANDOM,
 632                 .procname       = "random",
 633                 .mode           = 0555,
 634                 .child          = random_table,
 635         },
 636         {
 637                 .ctl_name       = KERN_OVERFLOWUID,
 638                 .procname       = "overflowuid",
 639                 .data           = &overflowuid,
 640                 .maxlen         = sizeof(int),
 641                 .mode           = 0644,
 642                 .proc_handler   = &proc_dointvec_minmax,
 643                 .strategy       = &sysctl_intvec,
 644                 .extra1         = &minolduid,
 645                 .extra2         = &maxolduid,
 646         },
 647         {
 648                 .ctl_name       = KERN_OVERFLOWGID,
 649                 .procname       = "overflowgid",
 650                 .data           = &overflowgid,
 651                 .maxlen         = sizeof(int),
 652                 .mode           = 0644,
 653                 .proc_handler   = &proc_dointvec_minmax,
 654                 .strategy       = &sysctl_intvec,
 655                 .extra1         = &minolduid,
 656                 .extra2         = &maxolduid,
 657         },
 658 #ifdef CONFIG_S390
 659 #ifdef CONFIG_MATHEMU
 660         {
 661                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 662                 .procname       = "ieee_emulation_warnings",
 663                 .data           = &sysctl_ieee_emulation_warnings,
 664                 .maxlen         = sizeof(int),
 665                 .mode           = 0644,
 666                 .proc_handler   = &proc_dointvec,
 667         },
 668 #endif
 669         {
 670                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 671                 .procname       = "userprocess_debug",
 672                 .data           = &sysctl_userprocess_debug,
 673                 .maxlen         = sizeof(int),
 674                 .mode           = 0644,
 675                 .proc_handler   = &proc_dointvec,
 676         },
 677 #endif
 678         {
 679                 .ctl_name       = KERN_PIDMAX,
 680                 .procname       = "pid_max",
 681                 .data           = &pid_max,
 682                 .maxlen         = sizeof (int),
 683                 .mode           = 0644,
 684                 .proc_handler   = &proc_dointvec_minmax,
 685                 .strategy       = sysctl_intvec,
 686                 .extra1         = &pid_max_min,
 687                 .extra2         = &pid_max_max,
 688         },
 689         {
 690                 .ctl_name       = KERN_PANIC_ON_OOPS,
 691                 .procname       = "panic_on_oops",
 692                 .data           = &panic_on_oops,
 693                 .maxlen         = sizeof(int),
 694                 .mode           = 0644,
 695                 .proc_handler   = &proc_dointvec,
 696         },
 697 #if defined CONFIG_PRINTK
 698         {
 699                 .ctl_name       = KERN_PRINTK,
 700                 .procname       = "printk",
 701                 .data           = &console_loglevel,
 702                 .maxlen         = 4*sizeof(int),
 703                 .mode           = 0644,
 704                 .proc_handler   = &proc_dointvec,
 705         },
 706         {
 707                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 708                 .procname       = "printk_ratelimit",
 709                 .data           = &printk_ratelimit_state.interval,
 710                 .maxlen         = sizeof(int),
 711                 .mode           = 0644,
 712                 .proc_handler   = &proc_dointvec_jiffies,
 713                 .strategy       = &sysctl_jiffies,
 714         },
 715         {
 716                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 717                 .procname       = "printk_ratelimit_burst",
 718                 .data           = &printk_ratelimit_state.burst,
 719                 .maxlen         = sizeof(int),
 720                 .mode           = 0644,
 721                 .proc_handler   = &proc_dointvec,
 722         },
 723 #endif
 724         {
 725                 .ctl_name       = KERN_NGROUPS_MAX,
 726                 .procname       = "ngroups_max",
 727                 .data           = &ngroups_max,
 728                 .maxlen         = sizeof (int),
 729                 .mode           = 0444,
 730                 .proc_handler   = &proc_dointvec,
 731         },
 732 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 733         {
 734                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 735                 .procname       = "unknown_nmi_panic",
 736                 .data           = &unknown_nmi_panic,
 737                 .maxlen         = sizeof (int),
 738                 .mode           = 0644,
 739                 .proc_handler   = &proc_dointvec,
 740         },
 741         {
 742                 .procname       = "nmi_watchdog",
 743                 .data           = &nmi_watchdog_enabled,
 744                 .maxlen         = sizeof (int),
 745                 .mode           = 0644,
 746                 .proc_handler   = &proc_nmi_enabled,
 747         },
 748 #endif
 749 #if defined(CONFIG_X86)
 750         {
 751                 .ctl_name       = KERN_PANIC_ON_NMI,
 752                 .procname       = "panic_on_unrecovered_nmi",
 753                 .data           = &panic_on_unrecovered_nmi,
 754                 .maxlen         = sizeof(int),
 755                 .mode           = 0644,
 756                 .proc_handler   = &proc_dointvec,
 757         },
 758         {
 759                 .ctl_name       = CTL_UNNUMBERED,
 760                 .procname       = "panic_on_io_nmi",
 761                 .data           = &panic_on_io_nmi,
 762                 .maxlen         = sizeof(int),
 763                 .mode           = 0644,
 764                 .proc_handler   = &proc_dointvec,
 765         },
 766         {
 767                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 768                 .procname       = "bootloader_type",
 769                 .data           = &bootloader_type,
 770                 .maxlen         = sizeof (int),
 771                 .mode           = 0444,
 772                 .proc_handler   = &proc_dointvec,
 773         },
 774         {
 775                 .ctl_name       = CTL_UNNUMBERED,
 776                 .procname       = "bootloader_version",
 777                 .data           = &bootloader_version,
 778                 .maxlen         = sizeof (int),
 779                 .mode           = 0444,
 780                 .proc_handler   = &proc_dointvec,
 781         },
 782         {
 783                 .ctl_name       = CTL_UNNUMBERED,
 784                 .procname       = "kstack_depth_to_print",
 785                 .data           = &kstack_depth_to_print,
 786                 .maxlen         = sizeof(int),
 787                 .mode           = 0644,
 788                 .proc_handler   = &proc_dointvec,
 789         },
 790         {
 791                 .ctl_name       = CTL_UNNUMBERED,
 792                 .procname       = "io_delay_type",
 793                 .data           = &io_delay_type,
 794                 .maxlen         = sizeof(int),
 795                 .mode           = 0644,
 796                 .proc_handler   = &proc_dointvec,
 797         },
 798 #endif
 799 #if defined(CONFIG_MMU)
 800         {
 801                 .ctl_name       = KERN_RANDOMIZE,
 802                 .procname       = "randomize_va_space",
 803                 .data           = &randomize_va_space,
 804                 .maxlen         = sizeof(int),
 805                 .mode           = 0644,
 806                 .proc_handler   = &proc_dointvec,
 807         },
 808 #endif
 809 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 810         {
 811                 .ctl_name       = KERN_SPIN_RETRY,
 812                 .procname       = "spin_retry",
 813                 .data           = &spin_retry,
 814                 .maxlen         = sizeof (int),
 815                 .mode           = 0644,
 816                 .proc_handler   = &proc_dointvec,
 817         },
 818 #endif
 819 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 820         {
 821                 .procname       = "acpi_video_flags",
 822                 .data           = &acpi_realmode_flags,
 823                 .maxlen         = sizeof (unsigned long),
 824                 .mode           = 0644,
 825                 .proc_handler   = &proc_doulongvec_minmax,
 826         },
 827 #endif
 828 #ifdef CONFIG_IA64
 829         {
 830                 .ctl_name       = KERN_IA64_UNALIGNED,
 831                 .procname       = "ignore-unaligned-usertrap",
 832                 .data           = &no_unaligned_warning,
 833                 .maxlen         = sizeof (int),
 834                 .mode           = 0644,
 835                 .proc_handler   = &proc_dointvec,
 836         },
 837         {
 838                 .ctl_name       = CTL_UNNUMBERED,
 839                 .procname       = "unaligned-dump-stack",
 840                 .data           = &unaligned_dump_stack,
 841                 .maxlen         = sizeof (int),
 842                 .mode           = 0644,
 843                 .proc_handler   = &proc_dointvec,
 844         },
 845 #endif
 846 #ifdef CONFIG_DETECT_SOFTLOCKUP
 847         {
 848                 .ctl_name       = CTL_UNNUMBERED,
 849                 .procname       = "softlockup_panic",
 850                 .data           = &softlockup_panic,
 851                 .maxlen         = sizeof(int),
 852                 .mode           = 0644,
 853                 .proc_handler   = &proc_dointvec_minmax,
 854                 .strategy       = &sysctl_intvec,
 855                 .extra1         = &zero,
 856                 .extra2         = &one,
 857         },
 858         {
 859                 .ctl_name       = CTL_UNNUMBERED,
 860                 .procname       = "softlockup_thresh",
 861                 .data           = &softlockup_thresh,
 862                 .maxlen         = sizeof(int),
 863                 .mode           = 0644,
 864                 .proc_handler   = &proc_dosoftlockup_thresh,
 865                 .strategy       = &sysctl_intvec,
 866                 .extra1         = &neg_one,
 867                 .extra2         = &sixty,
 868         },
 869 #endif
 870 #ifdef CONFIG_DETECT_HUNG_TASK
 871         {
 872                 .ctl_name       = CTL_UNNUMBERED,
 873                 .procname       = "hung_task_panic",
 874                 .data           = &sysctl_hung_task_panic,
 875                 .maxlen         = sizeof(int),
 876                 .mode           = 0644,
 877                 .proc_handler   = &proc_dointvec_minmax,
 878                 .strategy       = &sysctl_intvec,
 879                 .extra1         = &zero,
 880                 .extra2         = &one,
 881         },
 882         {
 883                 .ctl_name       = CTL_UNNUMBERED,
 884                 .procname       = "hung_task_check_count",
 885                 .data           = &sysctl_hung_task_check_count,
 886                 .maxlen         = sizeof(unsigned long),
 887                 .mode           = 0644,
 888                 .proc_handler   = &proc_doulongvec_minmax,
 889                 .strategy       = &sysctl_intvec,
 890         },
 891         {
 892                 .ctl_name       = CTL_UNNUMBERED,
 893                 .procname       = "hung_task_timeout_secs",
 894                 .data           = &sysctl_hung_task_timeout_secs,
 895                 .maxlen         = sizeof(unsigned long),
 896                 .mode           = 0644,
 897                 .proc_handler   = &proc_dohung_task_timeout_secs,
 898                 .strategy       = &sysctl_intvec,
 899         },
 900         {
 901                 .ctl_name       = CTL_UNNUMBERED,
 902                 .procname       = "hung_task_warnings",
 903                 .data           = &sysctl_hung_task_warnings,
 904                 .maxlen         = sizeof(unsigned long),
 905                 .mode           = 0644,
 906                 .proc_handler   = &proc_doulongvec_minmax,
 907                 .strategy       = &sysctl_intvec,
 908         },
 909 #endif
 910 #ifdef CONFIG_COMPAT
 911         {
 912                 .ctl_name       = KERN_COMPAT_LOG,
 913                 .procname       = "compat-log",
 914                 .data           = &compat_log,
 915                 .maxlen         = sizeof (int),
 916                 .mode           = 0644,
 917                 .proc_handler   = &proc_dointvec,
 918         },
 919 #endif
 920 #ifdef CONFIG_RT_MUTEXES
 921         {
 922                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 923                 .procname       = "max_lock_depth",
 924                 .data           = &max_lock_depth,
 925                 .maxlen         = sizeof(int),
 926                 .mode           = 0644,
 927                 .proc_handler   = &proc_dointvec,
 928         },
 929 #endif
 930         {
 931                 .ctl_name       = CTL_UNNUMBERED,
 932                 .procname       = "poweroff_cmd",
 933                 .data           = &poweroff_cmd,
 934                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 935                 .mode           = 0644,
 936                 .proc_handler   = &proc_dostring,
 937                 .strategy       = &sysctl_string,
 938         },
 939 #ifdef CONFIG_KEYS
 940         {
 941                 .ctl_name       = CTL_UNNUMBERED,
 942                 .procname       = "keys",
 943                 .mode           = 0555,
 944                 .child          = key_sysctls,
 945         },
 946 #endif
 947 #ifdef CONFIG_RCU_TORTURE_TEST
 948         {
 949                 .ctl_name       = CTL_UNNUMBERED,
 950                 .procname       = "rcutorture_runnable",
 951                 .data           = &rcutorture_runnable,
 952                 .maxlen         = sizeof(int),
 953                 .mode           = 0644,
 954                 .proc_handler   = &proc_dointvec,
 955         },
 956 #endif
 957 #ifdef CONFIG_SLOW_WORK
 958         {
 959                 .ctl_name       = CTL_UNNUMBERED,
 960                 .procname       = "slow-work",
 961                 .mode           = 0555,
 962                 .child          = slow_work_sysctls,
 963         },
 964 #endif
 965 #ifdef CONFIG_PERF_COUNTERS
 966         {
 967                 .ctl_name       = CTL_UNNUMBERED,
 968                 .procname       = "perf_counter_paranoid",
 969                 .data           = &sysctl_perf_counter_paranoid,
 970                 .maxlen         = sizeof(sysctl_perf_counter_paranoid),
 971                 .mode           = 0644,
 972                 .proc_handler   = &proc_dointvec,
 973         },
 974         {
 975                 .ctl_name       = CTL_UNNUMBERED,
 976                 .procname       = "perf_counter_mlock_kb",
 977                 .data           = &sysctl_perf_counter_mlock,
 978                 .maxlen         = sizeof(sysctl_perf_counter_mlock),
 979                 .mode           = 0644,
 980                 .proc_handler   = &proc_dointvec,
 981         },
 982         {
 983                 .ctl_name       = CTL_UNNUMBERED,
 984                 .procname       = "perf_counter_max_sample_rate",
 985                 .data           = &sysctl_perf_counter_sample_rate,
 986                 .maxlen         = sizeof(sysctl_perf_counter_sample_rate),
 987                 .mode           = 0644,
 988                 .proc_handler   = &proc_dointvec,
 989         },
 990 #endif
 991 #ifdef CONFIG_KMEMCHECK
 992         {
 993                 .ctl_name       = CTL_UNNUMBERED,
 994                 .procname       = "kmemcheck",
 995                 .data           = &kmemcheck_enabled,
 996                 .maxlen         = sizeof(int),
 997                 .mode           = 0644,
 998                 .proc_handler   = &proc_dointvec,
 999         },
1000 #endif
1001         {
1002                 .ctl_name       = CTL_UNNUMBERED,
1003                 .procname       = "blk_iopoll",
1004                 .data           = &blk_iopoll_enabled,
1005                 .maxlen         = sizeof(int),
1006                 .mode           = 0644,
1007                 .proc_handler   = &proc_dointvec,
1008         },
1009 /*
1010  * NOTE: do not add new entries to this table unless you have read
1011  * Documentation/sysctl/ctl_unnumbered.txt
1012  */
1013         { .ctl_name = 0 }
1014 };
1015
1016 static struct ctl_table vm_table[] = {
1017         {
1018                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
1019                 .procname       = "overcommit_memory",
1020                 .data           = &sysctl_overcommit_memory,
1021                 .maxlen         = sizeof(sysctl_overcommit_memory),
1022                 .mode           = 0644,
1023                 .proc_handler   = &proc_dointvec,
1024         },
1025         {
1026                 .ctl_name       = VM_PANIC_ON_OOM,
1027                 .procname       = "panic_on_oom",
1028                 .data           = &sysctl_panic_on_oom,
1029                 .maxlen         = sizeof(sysctl_panic_on_oom),
1030                 .mode           = 0644,
1031                 .proc_handler   = &proc_dointvec,
1032         },
1033         {
1034                 .ctl_name       = CTL_UNNUMBERED,
1035                 .procname       = "oom_kill_allocating_task",
1036                 .data           = &sysctl_oom_kill_allocating_task,
1037                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1038                 .mode           = 0644,
1039                 .proc_handler   = &proc_dointvec,
1040         },
1041         {
1042                 .ctl_name       = CTL_UNNUMBERED,
1043                 .procname       = "oom_dump_tasks",
1044                 .data           = &sysctl_oom_dump_tasks,
1045                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1046                 .mode           = 0644,
1047                 .proc_handler   = &proc_dointvec,
1048         },
1049         {
1050                 .ctl_name       = VM_OVERCOMMIT_RATIO,
1051                 .procname       = "overcommit_ratio",
1052                 .data           = &sysctl_overcommit_ratio,
1053                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1054                 .mode           = 0644,
1055                 .proc_handler   = &proc_dointvec,
1056         },
1057         {
1058                 .ctl_name       = VM_PAGE_CLUSTER,
1059                 .procname       = "page-cluster",
1060                 .data           = &page_cluster,
1061                 .maxlen         = sizeof(int),
1062                 .mode           = 0644,
1063                 .proc_handler   = &proc_dointvec,
1064         },
1065         {
1066                 .ctl_name       = VM_DIRTY_BACKGROUND,
1067                 .procname       = "dirty_background_ratio",
1068                 .data           = &dirty_background_ratio,
1069                 .maxlen         = sizeof(dirty_background_ratio),
1070                 .mode           = 0644,
1071                 .proc_handler   = &dirty_background_ratio_handler,
1072                 .strategy       = &sysctl_intvec,
1073                 .extra1         = &zero,
1074                 .extra2         = &one_hundred,
1075         },
1076         {
1077                 .ctl_name       = CTL_UNNUMBERED,
1078                 .procname       = "dirty_background_bytes",
1079                 .data           = &dirty_background_bytes,
1080                 .maxlen         = sizeof(dirty_background_bytes),
1081                 .mode           = 0644,
1082                 .proc_handler   = &dirty_background_bytes_handler,
1083                 .strategy       = &sysctl_intvec,
1084                 .extra1         = &one_ul,
1085         },
1086         {
1087                 .ctl_name       = VM_DIRTY_RATIO,
1088                 .procname       = "dirty_ratio",
1089                 .data           = &vm_dirty_ratio,
1090                 .maxlen         = sizeof(vm_dirty_ratio),
1091                 .mode           = 0644,
1092                 .proc_handler   = &dirty_ratio_handler,
1093                 .strategy       = &sysctl_intvec,
1094                 .extra1         = &zero,
1095                 .extra2         = &one_hundred,
1096         },
1097         {
1098                 .ctl_name       = CTL_UNNUMBERED,
1099                 .procname       = "dirty_bytes",
1100                 .data           = &vm_dirty_bytes,
1101                 .maxlen         = sizeof(vm_dirty_bytes),
1102                 .mode           = 0644,
1103                 .proc_handler   = &dirty_bytes_handler,
1104                 .strategy       = &sysctl_intvec,
1105                 .extra1         = &dirty_bytes_min,
1106         },
1107         {
1108                 .procname       = "dirty_writeback_centisecs",
1109                 .data           = &dirty_writeback_interval,
1110                 .maxlen         = sizeof(dirty_writeback_interval),
1111                 .mode           = 0644,
1112                 .proc_handler   = &dirty_writeback_centisecs_handler,
1113         },
1114         {
1115                 .procname       = "dirty_expire_centisecs",
1116                 .data           = &dirty_expire_interval,
1117                 .maxlen         = sizeof(dirty_expire_interval),
1118                 .mode           = 0644,
1119                 .proc_handler   = &proc_dointvec,
1120         },
1121         {
1122                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1123                 .procname       = "nr_pdflush_threads",
1124                 .data           = &nr_pdflush_threads,
1125                 .maxlen         = sizeof nr_pdflush_threads,
1126                 .mode           = 0444 /* read-only*/,
1127                 .proc_handler   = &proc_dointvec,
1128         },
1129         {
1130                 .ctl_name       = VM_SWAPPINESS,
1131                 .procname       = "swappiness",
1132                 .data           = &vm_swappiness,
1133                 .maxlen         = sizeof(vm_swappiness),
1134                 .mode           = 0644,
1135                 .proc_handler   = &proc_dointvec_minmax,
1136                 .strategy       = &sysctl_intvec,
1137                 .extra1         = &zero,
1138                 .extra2         = &one_hundred,
1139         },
1140 #ifdef CONFIG_HUGETLB_PAGE
1141          {
1142                 .procname       = "nr_hugepages",
1143                 .data           = NULL,
1144                 .maxlen         = sizeof(unsigned long),
1145                 .mode           = 0644,
1146                 .proc_handler   = &hugetlb_sysctl_handler,
1147                 .extra1         = (void *)&hugetlb_zero,
1148                 .extra2         = (void *)&hugetlb_infinity,
1149          },
1150          {
1151                 .ctl_name       = VM_HUGETLB_GROUP,
1152                 .procname       = "hugetlb_shm_group",
1153                 .data           = &sysctl_hugetlb_shm_group,
1154                 .maxlen         = sizeof(gid_t),
1155                 .mode           = 0644,
1156                 .proc_handler   = &proc_dointvec,
1157          },
1158          {
1159                 .ctl_name       = CTL_UNNUMBERED,
1160                 .procname       = "hugepages_treat_as_movable",
1161                 .data           = &hugepages_treat_as_movable,
1162                 .maxlen         = sizeof(int),
1163                 .mode           = 0644,
1164                 .proc_handler   = &hugetlb_treat_movable_handler,
1165         },
1166         {
1167                 .ctl_name       = CTL_UNNUMBERED,
1168                 .procname       = "nr_overcommit_hugepages",
1169                 .data           = NULL,
1170                 .maxlen         = sizeof(unsigned long),
1171                 .mode           = 0644,
1172                 .proc_handler   = &hugetlb_overcommit_handler,
1173                 .extra1         = (void *)&hugetlb_zero,
1174                 .extra2         = (void *)&hugetlb_infinity,
1175         },
1176 #endif
1177         {
1178                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1179                 .procname       = "lowmem_reserve_ratio",
1180                 .data           = &sysctl_lowmem_reserve_ratio,
1181                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1182                 .mode           = 0644,
1183                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1184                 .strategy       = &sysctl_intvec,
1185         },
1186         {
1187                 .ctl_name       = VM_DROP_PAGECACHE,
1188                 .procname       = "drop_caches",
1189                 .data           = &sysctl_drop_caches,
1190                 .maxlen         = sizeof(int),
1191                 .mode           = 0644,
1192                 .proc_handler   = drop_caches_sysctl_handler,
1193                 .strategy       = &sysctl_intvec,
1194         },
1195         {
1196                 .ctl_name       = VM_MIN_FREE_KBYTES,
1197                 .procname       = "min_free_kbytes",
1198                 .data           = &min_free_kbytes,
1199                 .maxlen         = sizeof(min_free_kbytes),
1200                 .mode           = 0644,
1201                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1202                 .strategy       = &sysctl_intvec,
1203                 .extra1         = &zero,
1204         },
1205         {
1206                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1207                 .procname       = "percpu_pagelist_fraction",
1208                 .data           = &percpu_pagelist_fraction,
1209                 .maxlen         = sizeof(percpu_pagelist_fraction),
1210                 .mode           = 0644,
1211                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1212                 .strategy       = &sysctl_intvec,
1213                 .extra1         = &min_percpu_pagelist_fract,
1214         },
1215 #ifdef CONFIG_MMU
1216         {
1217                 .ctl_name       = VM_MAX_MAP_COUNT,
1218                 .procname       = "max_map_count",
1219                 .data           = &sysctl_max_map_count,
1220                 .maxlen         = sizeof(sysctl_max_map_count),
1221                 .mode           = 0644,
1222                 .proc_handler   = &proc_dointvec
1223         },
1224 #else
1225         {
1226                 .ctl_name       = CTL_UNNUMBERED,
1227                 .procname       = "nr_trim_pages",
1228                 .data           = &sysctl_nr_trim_pages,
1229                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1230                 .mode           = 0644,
1231                 .proc_handler   = &proc_dointvec_minmax,
1232                 .strategy       = &sysctl_intvec,
1233                 .extra1         = &zero,
1234         },
1235 #endif
1236         {
1237                 .ctl_name       = VM_LAPTOP_MODE,
1238                 .procname       = "laptop_mode",
1239                 .data           = &laptop_mode,
1240                 .maxlen         = sizeof(laptop_mode),
1241                 .mode           = 0644,
1242                 .proc_handler   = &proc_dointvec_jiffies,
1243                 .strategy       = &sysctl_jiffies,
1244         },
1245         {
1246                 .ctl_name       = VM_BLOCK_DUMP,
1247                 .procname       = "block_dump",
1248                 .data           = &block_dump,
1249                 .maxlen         = sizeof(block_dump),
1250                 .mode           = 0644,
1251                 .proc_handler   = &proc_dointvec,
1252                 .strategy       = &sysctl_intvec,
1253                 .extra1         = &zero,
1254         },
1255         {
1256                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1257                 .procname       = "vfs_cache_pressure",
1258                 .data           = &sysctl_vfs_cache_pressure,
1259                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1260                 .mode           = 0644,
1261                 .proc_handler   = &proc_dointvec,
1262                 .strategy       = &sysctl_intvec,
1263                 .extra1         = &zero,
1264         },
1265 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1266         {
1267                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1268                 .procname       = "legacy_va_layout",
1269                 .data           = &sysctl_legacy_va_layout,
1270                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1271                 .mode           = 0644,
1272                 .proc_handler   = &proc_dointvec,
1273                 .strategy       = &sysctl_intvec,
1274                 .extra1         = &zero,
1275         },
1276 #endif
1277 #ifdef CONFIG_NUMA
1278         {
1279                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1280                 .procname       = "zone_reclaim_mode",
1281                 .data           = &zone_reclaim_mode,
1282                 .maxlen         = sizeof(zone_reclaim_mode),
1283                 .mode           = 0644,
1284                 .proc_handler   = &proc_dointvec,
1285                 .strategy       = &sysctl_intvec,
1286                 .extra1         = &zero,
1287         },
1288         {
1289                 .ctl_name       = VM_MIN_UNMAPPED,
1290                 .procname       = "min_unmapped_ratio",
1291                 .data           = &sysctl_min_unmapped_ratio,
1292                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1293                 .mode           = 0644,
1294                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1295                 .strategy       = &sysctl_intvec,
1296                 .extra1         = &zero,
1297                 .extra2         = &one_hundred,
1298         },
1299         {
1300                 .ctl_name       = VM_MIN_SLAB,
1301                 .procname       = "min_slab_ratio",
1302                 .data           = &sysctl_min_slab_ratio,
1303                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1304                 .mode           = 0644,
1305                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1306                 .strategy       = &sysctl_intvec,
1307                 .extra1         = &zero,
1308                 .extra2         = &one_hundred,
1309         },
1310 #endif
1311 #ifdef CONFIG_SMP
1312         {
1313                 .ctl_name       = CTL_UNNUMBERED,
1314                 .procname       = "stat_interval",
1315                 .data           = &sysctl_stat_interval,
1316                 .maxlen         = sizeof(sysctl_stat_interval),
1317                 .mode           = 0644,
1318                 .proc_handler   = &proc_dointvec_jiffies,
1319                 .strategy       = &sysctl_jiffies,
1320         },
1321 #endif
1322         {
1323                 .ctl_name       = CTL_UNNUMBERED,
1324                 .procname       = "mmap_min_addr",
1325                 .data           = &dac_mmap_min_addr,
1326                 .maxlen         = sizeof(unsigned long),
1327                 .mode           = 0644,
1328                 .proc_handler   = &mmap_min_addr_handler,
1329         },
1330 #ifdef CONFIG_NUMA
1331         {
1332                 .ctl_name       = CTL_UNNUMBERED,
1333                 .procname       = "numa_zonelist_order",
1334                 .data           = &numa_zonelist_order,
1335                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1336                 .mode           = 0644,
1337                 .proc_handler   = &numa_zonelist_order_handler,
1338                 .strategy       = &sysctl_string,
1339         },
1340 #endif
1341 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1342    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1343         {
1344                 .ctl_name       = VM_VDSO_ENABLED,
1345                 .procname       = "vdso_enabled",
1346                 .data           = &vdso_enabled,
1347                 .maxlen         = sizeof(vdso_enabled),
1348                 .mode           = 0644,
1349                 .proc_handler   = &proc_dointvec,
1350                 .strategy       = &sysctl_intvec,
1351                 .extra1         = &zero,
1352         },
1353 #endif
1354 #ifdef CONFIG_HIGHMEM
1355         {
1356                 .ctl_name       = CTL_UNNUMBERED,
1357                 .procname       = "highmem_is_dirtyable",
1358                 .data           = &vm_highmem_is_dirtyable,
1359                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1360                 .mode           = 0644,
1361                 .proc_handler   = &proc_dointvec_minmax,
1362                 .strategy       = &sysctl_intvec,
1363                 .extra1         = &zero,
1364                 .extra2         = &one,
1365         },
1366 #endif
1367         {
1368                 .ctl_name       = CTL_UNNUMBERED,
1369                 .procname       = "scan_unevictable_pages",
1370                 .data           = &scan_unevictable_pages,
1371                 .maxlen         = sizeof(scan_unevictable_pages),
1372                 .mode           = 0644,
1373                 .proc_handler   = &scan_unevictable_handler,
1374         },
1375 #ifdef CONFIG_MEMORY_FAILURE
1376         {
1377                 .ctl_name       = CTL_UNNUMBERED,
1378                 .procname       = "memory_failure_early_kill",
1379                 .data           = &sysctl_memory_failure_early_kill,
1380                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1381                 .mode           = 0644,
1382                 .proc_handler   = &proc_dointvec_minmax,
1383                 .strategy       = &sysctl_intvec,
1384                 .extra1         = &zero,
1385                 .extra2         = &one,
1386         },
1387         {
1388                 .ctl_name       = CTL_UNNUMBERED,
1389                 .procname       = "memory_failure_recovery",
1390                 .data           = &sysctl_memory_failure_recovery,
1391                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1392                 .mode           = 0644,
1393                 .proc_handler   = &proc_dointvec_minmax,
1394                 .strategy       = &sysctl_intvec,
1395                 .extra1         = &zero,
1396                 .extra2         = &one,
1397         },
1398 #endif
1399
1400 /*
1401  * NOTE: do not add new entries to this table unless you have read
1402  * Documentation/sysctl/ctl_unnumbered.txt
1403  */
1404         { .ctl_name = 0 }
1405 };
1406
1407 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1408 static struct ctl_table binfmt_misc_table[] = {
1409         { .ctl_name = 0 }
1410 };
1411 #endif
1412
1413 static struct ctl_table fs_table[] = {
1414         {
1415                 .ctl_name       = FS_NRINODE,
1416                 .procname       = "inode-nr",
1417                 .data           = &inodes_stat,
1418                 .maxlen         = 2*sizeof(int),
1419                 .mode           = 0444,
1420                 .proc_handler   = &proc_dointvec,
1421         },
1422         {
1423                 .ctl_name       = FS_STATINODE,
1424                 .procname       = "inode-state",
1425                 .data           = &inodes_stat,
1426                 .maxlen         = 7*sizeof(int),
1427                 .mode           = 0444,
1428                 .proc_handler   = &proc_dointvec,
1429         },
1430         {
1431                 .procname       = "file-nr",
1432                 .data           = &files_stat,
1433                 .maxlen         = 3*sizeof(int),
1434                 .mode           = 0444,
1435                 .proc_handler   = &proc_nr_files,
1436         },
1437         {
1438                 .ctl_name       = FS_MAXFILE,
1439                 .procname       = "file-max",
1440                 .data           = &files_stat.max_files,
1441                 .maxlen         = sizeof(int),
1442                 .mode           = 0644,
1443                 .proc_handler   = &proc_dointvec,
1444         },
1445         {
1446                 .ctl_name       = CTL_UNNUMBERED,
1447                 .procname       = "nr_open",
1448                 .data           = &sysctl_nr_open,
1449                 .maxlen         = sizeof(int),
1450                 .mode           = 0644,
1451                 .proc_handler   = &proc_dointvec_minmax,
1452                 .extra1         = &sysctl_nr_open_min,
1453                 .extra2         = &sysctl_nr_open_max,
1454         },
1455         {
1456                 .ctl_name       = FS_DENTRY,
1457                 .procname       = "dentry-state",
1458                 .data           = &dentry_stat,
1459                 .maxlen         = 6*sizeof(int),
1460                 .mode           = 0444,
1461                 .proc_handler   = &proc_dointvec,
1462         },
1463         {
1464                 .ctl_name       = FS_OVERFLOWUID,
1465                 .procname       = "overflowuid",
1466                 .data           = &fs_overflowuid,
1467                 .maxlen         = sizeof(int),
1468                 .mode           = 0644,
1469                 .proc_handler   = &proc_dointvec_minmax,
1470                 .strategy       = &sysctl_intvec,
1471                 .extra1         = &minolduid,
1472                 .extra2         = &maxolduid,
1473         },
1474         {
1475                 .ctl_name       = FS_OVERFLOWGID,
1476                 .procname       = "overflowgid",
1477                 .data           = &fs_overflowgid,
1478                 .maxlen         = sizeof(int),
1479                 .mode           = 0644,
1480                 .proc_handler   = &proc_dointvec_minmax,
1481                 .strategy       = &sysctl_intvec,
1482                 .extra1         = &minolduid,
1483                 .extra2         = &maxolduid,
1484         },
1485 #ifdef CONFIG_FILE_LOCKING
1486         {
1487                 .ctl_name       = FS_LEASES,
1488                 .procname       = "leases-enable",
1489                 .data           = &leases_enable,
1490                 .maxlen         = sizeof(int),
1491                 .mode           = 0644,
1492                 .proc_handler   = &proc_dointvec,
1493         },
1494 #endif
1495 #ifdef CONFIG_DNOTIFY
1496         {
1497                 .ctl_name       = FS_DIR_NOTIFY,
1498                 .procname       = "dir-notify-enable",
1499                 .data           = &dir_notify_enable,
1500                 .maxlen         = sizeof(int),
1501                 .mode           = 0644,
1502                 .proc_handler   = &proc_dointvec,
1503         },
1504 #endif
1505 #ifdef CONFIG_MMU
1506 #ifdef CONFIG_FILE_LOCKING
1507         {
1508                 .ctl_name       = FS_LEASE_TIME,
1509                 .procname       = "lease-break-time",
1510                 .data           = &lease_break_time,
1511                 .maxlen         = sizeof(int),
1512                 .mode           = 0644,
1513                 .proc_handler   = &proc_dointvec,
1514         },
1515 #endif
1516 #ifdef CONFIG_AIO
1517         {
1518                 .procname       = "aio-nr",
1519                 .data           = &aio_nr,
1520                 .maxlen         = sizeof(aio_nr),
1521                 .mode           = 0444,
1522                 .proc_handler   = &proc_doulongvec_minmax,
1523         },
1524         {
1525                 .procname       = "aio-max-nr",
1526                 .data           = &aio_max_nr,
1527                 .maxlen         = sizeof(aio_max_nr),
1528                 .mode           = 0644,
1529                 .proc_handler   = &proc_doulongvec_minmax,
1530         },
1531 #endif /* CONFIG_AIO */
1532 #ifdef CONFIG_INOTIFY_USER
1533         {
1534                 .ctl_name       = FS_INOTIFY,
1535                 .procname       = "inotify",
1536                 .mode           = 0555,
1537                 .child          = inotify_table,
1538         },
1539 #endif
1540 #ifdef CONFIG_EPOLL
1541         {
1542                 .procname       = "epoll",
1543                 .mode           = 0555,
1544                 .child          = epoll_table,
1545         },
1546 #endif
1547 #endif
1548         {
1549                 .ctl_name       = KERN_SETUID_DUMPABLE,
1550                 .procname       = "suid_dumpable",
1551                 .data           = &suid_dumpable,
1552                 .maxlen         = sizeof(int),
1553                 .mode           = 0644,
1554                 .proc_handler   = &proc_dointvec_minmax,
1555                 .strategy       = &sysctl_intvec,
1556                 .extra1         = &zero,
1557                 .extra2         = &two,
1558         },
1559 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1560         {
1561                 .ctl_name       = CTL_UNNUMBERED,
1562                 .procname       = "binfmt_misc",
1563                 .mode           = 0555,
1564                 .child          = binfmt_misc_table,
1565         },
1566 #endif
1567 /*
1568  * NOTE: do not add new entries to this table unless you have read
1569  * Documentation/sysctl/ctl_unnumbered.txt
1570  */
1571         { .ctl_name = 0 }
1572 };
1573
1574 static struct ctl_table debug_table[] = {
1575 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1576         {
1577                 .ctl_name       = CTL_UNNUMBERED,
1578                 .procname       = "exception-trace",
1579                 .data           = &show_unhandled_signals,
1580                 .maxlen         = sizeof(int),
1581                 .mode           = 0644,
1582                 .proc_handler   = proc_dointvec
1583         },
1584 #endif
1585         { .ctl_name = 0 }
1586 };
1587
1588 static struct ctl_table dev_table[] = {
1589         { .ctl_name = 0 }
1590 };
1591
1592 static DEFINE_SPINLOCK(sysctl_lock);
1593
1594 /* called under sysctl_lock */
1595 static int use_table(struct ctl_table_header *p)
1596 {
1597         if (unlikely(p->unregistering))
1598                 return 0;
1599         p->used++;
1600         return 1;
1601 }
1602
1603 /* called under sysctl_lock */
1604 static void unuse_table(struct ctl_table_header *p)
1605 {
1606         if (!--p->used)
1607                 if (unlikely(p->unregistering))
1608                         complete(p->unregistering);
1609 }
1610
1611 /* called under sysctl_lock, will reacquire if has to wait */
1612 static void start_unregistering(struct ctl_table_header *p)
1613 {
1614         /*
1615          * if p->used is 0, nobody will ever touch that entry again;
1616          * we'll eliminate all paths to it before dropping sysctl_lock
1617          */
1618         if (unlikely(p->used)) {
1619                 struct completion wait;
1620                 init_completion(&wait);
1621                 p->unregistering = &wait;
1622                 spin_unlock(&sysctl_lock);
1623                 wait_for_completion(&wait);
1624                 spin_lock(&sysctl_lock);
1625         } else {
1626                 /* anything non-NULL; we'll never dereference it */
1627                 p->unregistering = ERR_PTR(-EINVAL);
1628         }
1629         /*
1630          * do not remove from the list until nobody holds it; walking the
1631          * list in do_sysctl() relies on that.
1632          */
1633         list_del_init(&p->ctl_entry);
1634 }
1635
1636 void sysctl_head_get(struct ctl_table_header *head)
1637 {
1638         spin_lock(&sysctl_lock);
1639         head->count++;
1640         spin_unlock(&sysctl_lock);
1641 }
1642
1643 void sysctl_head_put(struct ctl_table_header *head)
1644 {
1645         spin_lock(&sysctl_lock);
1646         if (!--head->count)
1647                 kfree(head);
1648         spin_unlock(&sysctl_lock);
1649 }
1650
1651 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1652 {
1653         if (!head)
1654                 BUG();
1655         spin_lock(&sysctl_lock);
1656         if (!use_table(head))
1657                 head = ERR_PTR(-ENOENT);
1658         spin_unlock(&sysctl_lock);
1659         return head;
1660 }
1661
1662 void sysctl_head_finish(struct ctl_table_header *head)
1663 {
1664         if (!head)
1665                 return;
1666         spin_lock(&sysctl_lock);
1667         unuse_table(head);
1668         spin_unlock(&sysctl_lock);
1669 }
1670
1671 static struct ctl_table_set *
1672 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1673 {
1674         struct ctl_table_set *set = &root->default_set;
1675         if (root->lookup)
1676                 set = root->lookup(root, namespaces);
1677         return set;
1678 }
1679
1680 static struct list_head *
1681 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1682 {
1683         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1684         return &set->list;
1685 }
1686
1687 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1688                                             struct ctl_table_header *prev)
1689 {
1690         struct ctl_table_root *root;
1691         struct list_head *header_list;
1692         struct ctl_table_header *head;
1693         struct list_head *tmp;
1694
1695         spin_lock(&sysctl_lock);
1696         if (prev) {
1697                 head = prev;
1698                 tmp = &prev->ctl_entry;
1699                 unuse_table(prev);
1700                 goto next;
1701         }
1702         tmp = &root_table_header.ctl_entry;
1703         for (;;) {
1704                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1705
1706                 if (!use_table(head))
1707                         goto next;
1708                 spin_unlock(&sysctl_lock);
1709                 return head;
1710         next:
1711                 root = head->root;
1712                 tmp = tmp->next;
1713                 header_list = lookup_header_list(root, namespaces);
1714                 if (tmp != header_list)
1715                         continue;
1716
1717                 do {
1718                         root = list_entry(root->root_list.next,
1719                                         struct ctl_table_root, root_list);
1720                         if (root == &sysctl_table_root)
1721                                 goto out;
1722                         header_list = lookup_header_list(root, namespaces);
1723                 } while (list_empty(header_list));
1724                 tmp = header_list->next;
1725         }
1726 out:
1727         spin_unlock(&sysctl_lock);
1728         return NULL;
1729 }
1730
1731 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1732 {
1733         return __sysctl_head_next(current->nsproxy, prev);
1734 }
1735
1736 void register_sysctl_root(struct ctl_table_root *root)
1737 {
1738         spin_lock(&sysctl_lock);
1739         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1740         spin_unlock(&sysctl_lock);
1741 }
1742
1743 #ifdef CONFIG_SYSCTL_SYSCALL
1744 /* Perform the actual read/write of a sysctl table entry. */
1745 static int do_sysctl_strategy(struct ctl_table_root *root,
1746                         struct ctl_table *table,
1747                         void __user *oldval, size_t __user *oldlenp,
1748                         void __user *newval, size_t newlen)
1749 {
1750         int op = 0, rc;
1751
1752         if (oldval)
1753                 op |= MAY_READ;
1754         if (newval)
1755                 op |= MAY_WRITE;
1756         if (sysctl_perm(root, table, op))
1757                 return -EPERM;
1758
1759         if (table->strategy) {
1760                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1761                 if (rc < 0)
1762                         return rc;
1763                 if (rc > 0)
1764                         return 0;
1765         }
1766
1767         /* If there is no strategy routine, or if the strategy returns
1768          * zero, proceed with automatic r/w */
1769         if (table->data && table->maxlen) {
1770                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1771                 if (rc < 0)
1772                         return rc;
1773         }
1774         return 0;
1775 }
1776
1777 static int parse_table(int __user *name, int nlen,
1778                        void __user *oldval, size_t __user *oldlenp,
1779                        void __user *newval, size_t newlen,
1780                        struct ctl_table_root *root,
1781                        struct ctl_table *table)
1782 {
1783         int n;
1784 repeat:
1785         if (!nlen)
1786                 return -ENOTDIR;
1787         if (get_user(n, name))
1788                 return -EFAULT;
1789         for ( ; table->ctl_name || table->procname; table++) {
1790                 if (!table->ctl_name)
1791                         continue;
1792                 if (n == table->ctl_name) {
1793                         int error;
1794                         if (table->child) {
1795                                 if (sysctl_perm(root, table, MAY_EXEC))
1796                                         return -EPERM;
1797                                 name++;
1798                                 nlen--;
1799                                 table = table->child;
1800                                 goto repeat;
1801                         }
1802                         error = do_sysctl_strategy(root, table,
1803                                                    oldval, oldlenp,
1804                                                    newval, newlen);
1805                         return error;
1806                 }
1807         }
1808         return -ENOTDIR;
1809 }
1810
1811 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1812                void __user *newval, size_t newlen)
1813 {
1814         struct ctl_table_header *head;
1815         int error = -ENOTDIR;
1816
1817         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1818                 return -ENOTDIR;
1819         if (oldval) {
1820                 int old_len;
1821                 if (!oldlenp || get_user(old_len, oldlenp))
1822                         return -EFAULT;
1823         }
1824
1825         for (head = sysctl_head_next(NULL); head;
1826                         head = sysctl_head_next(head)) {
1827                 error = parse_table(name, nlen, oldval, oldlenp,
1828                                         newval, newlen,
1829                                         head->root, head->ctl_table);
1830                 if (error != -ENOTDIR) {
1831                         sysctl_head_finish(head);
1832                         break;
1833                 }
1834         }
1835         return error;
1836 }
1837
1838 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1839 {
1840         struct __sysctl_args tmp;
1841         int error;
1842
1843         if (copy_from_user(&tmp, args, sizeof(tmp)))
1844                 return -EFAULT;
1845
1846         error = deprecated_sysctl_warning(&tmp);
1847         if (error)
1848                 goto out;
1849
1850         lock_kernel();
1851         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1852                           tmp.newval, tmp.newlen);
1853         unlock_kernel();
1854 out:
1855         return error;
1856 }
1857 #endif /* CONFIG_SYSCTL_SYSCALL */
1858
1859 /*
1860  * sysctl_perm does NOT grant the superuser all rights automatically, because
1861  * some sysctl variables are readonly even to root.
1862  */
1863
1864 static int test_perm(int mode, int op)
1865 {
1866         if (!current_euid())
1867                 mode >>= 6;
1868         else if (in_egroup_p(0))
1869                 mode >>= 3;
1870         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1871                 return 0;
1872         return -EACCES;
1873 }
1874
1875 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1876 {
1877         int error;
1878         int mode;
1879
1880         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1881         if (error)
1882                 return error;
1883
1884         if (root->permissions)
1885                 mode = root->permissions(root, current->nsproxy, table);
1886         else
1887                 mode = table->mode;
1888
1889         return test_perm(mode, op);
1890 }
1891
1892 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1893 {
1894         for (; table->ctl_name || table->procname; table++) {
1895                 table->parent = parent;
1896                 if (table->child)
1897                         sysctl_set_parent(table, table->child);
1898         }
1899 }
1900
1901 static __init int sysctl_init(void)
1902 {
1903         sysctl_set_parent(NULL, root_table);
1904 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1905         {
1906                 int err;
1907                 err = sysctl_check_table(current->nsproxy, root_table);
1908         }
1909 #endif
1910         return 0;
1911 }
1912
1913 core_initcall(sysctl_init);
1914
1915 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1916                                       struct ctl_table *table)
1917 {
1918         struct ctl_table *p;
1919         const char *s = branch->procname;
1920
1921         /* branch should have named subdirectory as its first element */
1922         if (!s || !branch->child)
1923                 return NULL;
1924
1925         /* ... and nothing else */
1926         if (branch[1].procname || branch[1].ctl_name)
1927                 return NULL;
1928
1929         /* table should contain subdirectory with the same name */
1930         for (p = table; p->procname || p->ctl_name; p++) {
1931                 if (!p->child)
1932                         continue;
1933                 if (p->procname && strcmp(p->procname, s) == 0)
1934                         return p;
1935         }
1936         return NULL;
1937 }
1938
1939 /* see if attaching q to p would be an improvement */
1940 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1941 {
1942         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1943         struct ctl_table *next;
1944         int is_better = 0;
1945         int not_in_parent = !p->attached_by;
1946
1947         while ((next = is_branch_in(by, to)) != NULL) {
1948                 if (by == q->attached_by)
1949                         is_better = 1;
1950                 if (to == p->attached_by)
1951                         not_in_parent = 1;
1952                 by = by->child;
1953                 to = next->child;
1954         }
1955
1956         if (is_better && not_in_parent) {
1957                 q->attached_by = by;
1958                 q->attached_to = to;
1959                 q->parent = p;
1960         }
1961 }
1962
1963 /**
1964  * __register_sysctl_paths - register a sysctl hierarchy
1965  * @root: List of sysctl headers to register on
1966  * @namespaces: Data to compute which lists of sysctl entries are visible
1967  * @path: The path to the directory the sysctl table is in.
1968  * @table: the top-level table structure
1969  *
1970  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1971  * array. A completely 0 filled entry terminates the table.
1972  *
1973  * The members of the &struct ctl_table structure are used as follows:
1974  *
1975  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1976  *            must be unique within that level of sysctl
1977  *
1978  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1979  *            enter a sysctl file
1980  *
1981  * data - a pointer to data for use by proc_handler
1982  *
1983  * maxlen - the maximum size in bytes of the data
1984  *
1985  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1986  *
1987  * child - a pointer to the child sysctl table if this entry is a directory, or
1988  *         %NULL.
1989  *
1990  * proc_handler - the text handler routine (described below)
1991  *
1992  * strategy - the strategy routine (described below)
1993  *
1994  * de - for internal use by the sysctl routines
1995  *
1996  * extra1, extra2 - extra pointers usable by the proc handler routines
1997  *
1998  * Leaf nodes in the sysctl tree will be represented by a single file
1999  * under /proc; non-leaf nodes will be represented by directories.
2000  *
2001  * sysctl(2) can automatically manage read and write requests through
2002  * the sysctl table.  The data and maxlen fields of the ctl_table
2003  * struct enable minimal validation of the values being written to be
2004  * performed, and the mode field allows minimal authentication.
2005  *
2006  * More sophisticated management can be enabled by the provision of a
2007  * strategy routine with the table entry.  This will be called before
2008  * any automatic read or write of the data is performed.
2009  *
2010  * The strategy routine may return
2011  *
2012  * < 0 - Error occurred (error is passed to user process)
2013  *
2014  * 0   - OK - proceed with automatic read or write.
2015  *
2016  * > 0 - OK - read or write has been done by the strategy routine, so
2017  *       return immediately.
2018  *
2019  * There must be a proc_handler routine for any terminal nodes
2020  * mirrored under /proc/sys (non-terminals are handled by a built-in
2021  * directory handler).  Several default handlers are available to
2022  * cover common cases -
2023  *
2024  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
2025  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
2026  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
2027  *
2028  * It is the handler's job to read the input buffer from user memory
2029  * and process it. The handler should return 0 on success.
2030  *
2031  * This routine returns %NULL on a failure to register, and a pointer
2032  * to the table header on success.
2033  */
2034 struct ctl_table_header *__register_sysctl_paths(
2035         struct ctl_table_root *root,
2036         struct nsproxy *namespaces,
2037         const struct ctl_path *path, struct ctl_table *table)
2038 {
2039         struct ctl_table_header *header;
2040         struct ctl_table *new, **prevp;
2041         unsigned int n, npath;
2042         struct ctl_table_set *set;
2043
2044         /* Count the path components */
2045         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
2046                 ;
2047
2048         /*
2049          * For each path component, allocate a 2-element ctl_table array.
2050          * The first array element will be filled with the sysctl entry
2051          * for this, the second will be the sentinel (ctl_name == 0).
2052          *
2053          * We allocate everything in one go so that we don't have to
2054          * worry about freeing additional memory in unregister_sysctl_table.
2055          */
2056         header = kzalloc(sizeof(struct ctl_table_header) +
2057                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
2058         if (!header)
2059                 return NULL;
2060
2061         new = (struct ctl_table *) (header + 1);
2062
2063         /* Now connect the dots */
2064         prevp = &header->ctl_table;
2065         for (n = 0; n < npath; ++n, ++path) {
2066                 /* Copy the procname */
2067                 new->procname = path->procname;
2068                 new->ctl_name = path->ctl_name;
2069                 new->mode     = 0555;
2070
2071                 *prevp = new;
2072                 prevp = &new->child;
2073
2074                 new += 2;
2075         }
2076         *prevp = table;
2077         header->ctl_table_arg = table;
2078
2079         INIT_LIST_HEAD(&header->ctl_entry);
2080         header->used = 0;
2081         header->unregistering = NULL;
2082         header->root = root;
2083         sysctl_set_parent(NULL, header->ctl_table);
2084         header->count = 1;
2085 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2086         if (sysctl_check_table(namespaces, header->ctl_table)) {
2087                 kfree(header);
2088                 return NULL;
2089         }
2090 #endif
2091         spin_lock(&sysctl_lock);
2092         header->set = lookup_header_set(root, namespaces);
2093         header->attached_by = header->ctl_table;
2094         header->attached_to = root_table;
2095         header->parent = &root_table_header;
2096         for (set = header->set; set; set = set->parent) {
2097                 struct ctl_table_header *p;
2098                 list_for_each_entry(p, &set->list, ctl_entry) {
2099                         if (p->unregistering)
2100                                 continue;
2101                         try_attach(p, header);
2102                 }
2103         }
2104         header->parent->count++;
2105         list_add_tail(&header->ctl_entry, &header->set->list);
2106         spin_unlock(&sysctl_lock);
2107
2108         return header;
2109 }
2110
2111 /**
2112  * register_sysctl_table_path - register a sysctl table hierarchy
2113  * @path: The path to the directory the sysctl table is in.
2114  * @table: the top-level table structure
2115  *
2116  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2117  * array. A completely 0 filled entry terminates the table.
2118  *
2119  * See __register_sysctl_paths for more details.
2120  */
2121 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2122                                                 struct ctl_table *table)
2123 {
2124         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2125                                         path, table);
2126 }
2127
2128 /**
2129  * register_sysctl_table - register a sysctl table hierarchy
2130  * @table: the top-level table structure
2131  *
2132  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2133  * array. A completely 0 filled entry terminates the table.
2134  *
2135  * See register_sysctl_paths for more details.
2136  */
2137 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2138 {
2139         static const struct ctl_path null_path[] = { {} };
2140
2141         return register_sysctl_paths(null_path, table);
2142 }
2143
2144 /**
2145  * unregister_sysctl_table - unregister a sysctl table hierarchy
2146  * @header: the header returned from register_sysctl_table
2147  *
2148  * Unregisters the sysctl table and all children. proc entries may not
2149  * actually be removed until they are no longer used by anyone.
2150  */
2151 void unregister_sysctl_table(struct ctl_table_header * header)
2152 {
2153         might_sleep();
2154
2155         if (header == NULL)
2156                 return;
2157
2158         spin_lock(&sysctl_lock);
2159         start_unregistering(header);
2160         if (!--header->parent->count) {
2161                 WARN_ON(1);
2162                 kfree(header->parent);
2163         }
2164         if (!--header->count)
2165                 kfree(header);
2166         spin_unlock(&sysctl_lock);
2167 }
2168
2169 int sysctl_is_seen(struct ctl_table_header *p)
2170 {
2171         struct ctl_table_set *set = p->set;
2172         int res;
2173         spin_lock(&sysctl_lock);
2174         if (p->unregistering)
2175                 res = 0;
2176         else if (!set->is_seen)
2177                 res = 1;
2178         else
2179                 res = set->is_seen(set);
2180         spin_unlock(&sysctl_lock);
2181         return res;
2182 }
2183
2184 void setup_sysctl_set(struct ctl_table_set *p,
2185         struct ctl_table_set *parent,
2186         int (*is_seen)(struct ctl_table_set *))
2187 {
2188         INIT_LIST_HEAD(&p->list);
2189         p->parent = parent ? parent : &sysctl_table_root.default_set;
2190         p->is_seen = is_seen;
2191 }
2192
2193 #else /* !CONFIG_SYSCTL */
2194 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2195 {
2196         return NULL;
2197 }
2198
2199 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2200                                                     struct ctl_table *table)
2201 {
2202         return NULL;
2203 }
2204
2205 void unregister_sysctl_table(struct ctl_table_header * table)
2206 {
2207 }
2208
2209 void setup_sysctl_set(struct ctl_table_set *p,
2210         struct ctl_table_set *parent,
2211         int (*is_seen)(struct ctl_table_set *))
2212 {
2213 }
2214
2215 void sysctl_head_put(struct ctl_table_header *head)
2216 {
2217 }
2218
2219 #endif /* CONFIG_SYSCTL */
2220
2221 /*
2222  * /proc/sys support
2223  */
2224
2225 #ifdef CONFIG_PROC_SYSCTL
2226
2227 static int _proc_do_string(void* data, int maxlen, int write,
2228                            struct file *filp, void __user *buffer,
2229                            size_t *lenp, loff_t *ppos)
2230 {
2231         size_t len;
2232         char __user *p;
2233         char c;
2234
2235         if (!data || !maxlen || !*lenp) {
2236                 *lenp = 0;
2237                 return 0;
2238         }
2239
2240         if (write) {
2241                 len = 0;
2242                 p = buffer;
2243                 while (len < *lenp) {
2244                         if (get_user(c, p++))
2245                                 return -EFAULT;
2246                         if (c == 0 || c == '\n')
2247                                 break;
2248                         len++;
2249                 }
2250                 if (len >= maxlen)
2251                         len = maxlen-1;
2252                 if(copy_from_user(data, buffer, len))
2253                         return -EFAULT;
2254                 ((char *) data)[len] = 0;
2255                 *ppos += *lenp;
2256         } else {
2257                 len = strlen(data);
2258                 if (len > maxlen)
2259                         len = maxlen;
2260
2261                 if (*ppos > len) {
2262                         *lenp = 0;
2263                         return 0;
2264                 }
2265
2266                 data += *ppos;
2267                 len  -= *ppos;
2268
2269                 if (len > *lenp)
2270                         len = *lenp;
2271                 if (len)
2272                         if(copy_to_user(buffer, data, len))
2273                                 return -EFAULT;
2274                 if (len < *lenp) {
2275                         if(put_user('\n', ((char __user *) buffer) + len))
2276                                 return -EFAULT;
2277                         len++;
2278                 }
2279                 *lenp = len;
2280                 *ppos += len;
2281         }
2282         return 0;
2283 }
2284
2285 /**
2286  * proc_dostring - read a string sysctl
2287  * @table: the sysctl table
2288  * @write: %TRUE if this is a write to the sysctl file
2289  * @filp: the file structure
2290  * @buffer: the user buffer
2291  * @lenp: the size of the user buffer
2292  * @ppos: file position
2293  *
2294  * Reads/writes a string from/to the user buffer. If the kernel
2295  * buffer provided is not large enough to hold the string, the
2296  * string is truncated. The copied string is %NULL-terminated.
2297  * If the string is being read by the user process, it is copied
2298  * and a newline '\n' is added. It is truncated if the buffer is
2299  * not large enough.
2300  *
2301  * Returns 0 on success.
2302  */
2303 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2304                   void __user *buffer, size_t *lenp, loff_t *ppos)
2305 {
2306         return _proc_do_string(table->data, table->maxlen, write, filp,
2307                                buffer, lenp, ppos);
2308 }
2309
2310
2311 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2312                                  int *valp,
2313                                  int write, void *data)
2314 {
2315         if (write) {
2316                 *valp = *negp ? -*lvalp : *lvalp;
2317         } else {
2318                 int val = *valp;
2319                 if (val < 0) {
2320                         *negp = -1;
2321                         *lvalp = (unsigned long)-val;
2322                 } else {
2323                         *negp = 0;
2324                         *lvalp = (unsigned long)val;
2325                 }
2326         }
2327         return 0;
2328 }
2329
2330 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2331                   int write, struct file *filp, void __user *buffer,
2332                   size_t *lenp, loff_t *ppos,
2333                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2334                               int write, void *data),
2335                   void *data)
2336 {
2337 #define TMPBUFLEN 21
2338         int *i, vleft, first = 1, neg;
2339         unsigned long lval;
2340         size_t left, len;
2341
2342         char buf[TMPBUFLEN], *p;
2343         char __user *s = buffer;
2344
2345         if (!tbl_data || !table->maxlen || !*lenp ||
2346             (*ppos && !write)) {
2347                 *lenp = 0;
2348                 return 0;
2349         }
2350
2351         i = (int *) tbl_data;
2352         vleft = table->maxlen / sizeof(*i);
2353         left = *lenp;
2354
2355         if (!conv)
2356                 conv = do_proc_dointvec_conv;
2357
2358         for (; left && vleft--; i++, first=0) {
2359                 if (write) {
2360                         while (left) {
2361                                 char c;
2362                                 if (get_user(c, s))
2363                                         return -EFAULT;
2364                                 if (!isspace(c))
2365                                         break;
2366                                 left--;
2367                                 s++;
2368                         }
2369                         if (!left)
2370                                 break;
2371                         neg = 0;
2372                         len = left;
2373                         if (len > sizeof(buf) - 1)
2374                                 len = sizeof(buf) - 1;
2375                         if (copy_from_user(buf, s, len))
2376                                 return -EFAULT;
2377                         buf[len] = 0;
2378                         p = buf;
2379                         if (*p == '-' && left > 1) {
2380                                 neg = 1;
2381                                 p++;
2382                         }
2383                         if (*p < '0' || *p > '9')
2384                                 break;
2385
2386                         lval = simple_strtoul(p, &p, 0);
2387
2388                         len = p-buf;
2389                         if ((len < left) && *p && !isspace(*p))
2390                                 break;
2391                         s += len;
2392                         left -= len;
2393
2394                         if (conv(&neg, &lval, i, 1, data))
2395                                 break;
2396                 } else {
2397                         p = buf;
2398                         if (!first)
2399                                 *p++ = '\t';
2400
2401                         if (conv(&neg, &lval, i, 0, data))
2402                                 break;
2403
2404                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2405                         len = strlen(buf);
2406                         if (len > left)
2407                                 len = left;
2408                         if(copy_to_user(s, buf, len))
2409                                 return -EFAULT;
2410                         left -= len;
2411                         s += len;
2412                 }
2413         }
2414
2415         if (!write && !first && left) {
2416                 if(put_user('\n', s))
2417                         return -EFAULT;
2418                 left--, s++;
2419         }
2420         if (write) {
2421                 while (left) {
2422                         char c;
2423                         if (get_user(c, s++))
2424                                 return -EFAULT;
2425                         if (!isspace(c))
2426                                 break;
2427                         left--;
2428                 }
2429         }
2430         if (write && first)
2431                 return -EINVAL;
2432         *lenp -= left;
2433         *ppos += *lenp;
2434         return 0;
2435 #undef TMPBUFLEN
2436 }
2437
2438 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2439                   void __user *buffer, size_t *lenp, loff_t *ppos,
2440                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2441                               int write, void *data),
2442                   void *data)
2443 {
2444         return __do_proc_dointvec(table->data, table, write, filp,
2445                         buffer, lenp, ppos, conv, data);
2446 }
2447
2448 /**
2449  * proc_dointvec - read a vector of integers
2450  * @table: the sysctl table
2451  * @write: %TRUE if this is a write to the sysctl file
2452  * @filp: the file structure
2453  * @buffer: the user buffer
2454  * @lenp: the size of the user buffer
2455  * @ppos: file position
2456  *
2457  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2458  * values from/to the user buffer, treated as an ASCII string.
2459  *
2460  * Returns 0 on success.
2461  */
2462 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2463                      void __user *buffer, size_t *lenp, loff_t *ppos)
2464 {
2465     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2466                             NULL,NULL);
2467 }
2468
2469 /*
2470  * Taint values can only be increased
2471  * This means we can safely use a temporary.
2472  */
2473 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2474                                void __user *buffer, size_t *lenp, loff_t *ppos)
2475 {
2476         struct ctl_table t;
2477         unsigned long tmptaint = get_taint();
2478         int err;
2479
2480         if (write && !capable(CAP_SYS_ADMIN))
2481                 return -EPERM;
2482
2483         t = *table;
2484         t.data = &tmptaint;
2485         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2486         if (err < 0)
2487                 return err;
2488
2489         if (write) {
2490                 /*
2491                  * Poor man's atomic or. Not worth adding a primitive
2492                  * to everyone's atomic.h for this
2493                  */
2494                 int i;
2495                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2496                         if ((tmptaint >> i) & 1)
2497                                 add_taint(i);
2498                 }
2499         }
2500
2501         return err;
2502 }
2503
2504 struct do_proc_dointvec_minmax_conv_param {
2505         int *min;
2506         int *max;
2507 };
2508
2509 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2510                                         int *valp,
2511                                         int write, void *data)
2512 {
2513         struct do_proc_dointvec_minmax_conv_param *param = data;
2514         if (write) {
2515                 int val = *negp ? -*lvalp : *lvalp;
2516                 if ((param->min && *param->min > val) ||
2517                     (param->max && *param->max < val))
2518                         return -EINVAL;
2519                 *valp = val;
2520         } else {
2521                 int val = *valp;
2522                 if (val < 0) {
2523                         *negp = -1;
2524                         *lvalp = (unsigned long)-val;
2525                 } else {
2526                         *negp = 0;
2527                         *lvalp = (unsigned long)val;
2528                 }
2529         }
2530         return 0;
2531 }
2532
2533 /**
2534  * proc_dointvec_minmax - read a vector of integers with min/max values
2535  * @table: the sysctl table
2536  * @write: %TRUE if this is a write to the sysctl file
2537  * @filp: the file structure
2538  * @buffer: the user buffer
2539  * @lenp: the size of the user buffer
2540  * @ppos: file position
2541  *
2542  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2543  * values from/to the user buffer, treated as an ASCII string.
2544  *
2545  * This routine will ensure the values are within the range specified by
2546  * table->extra1 (min) and table->extra2 (max).
2547  *
2548  * Returns 0 on success.
2549  */
2550 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2551                   void __user *buffer, size_t *lenp, loff_t *ppos)
2552 {
2553         struct do_proc_dointvec_minmax_conv_param param = {
2554                 .min = (int *) table->extra1,
2555                 .max = (int *) table->extra2,
2556         };
2557         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2558                                 do_proc_dointvec_minmax_conv, &param);
2559 }
2560
2561 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2562                                      struct file *filp,
2563                                      void __user *buffer,
2564                                      size_t *lenp, loff_t *ppos,
2565                                      unsigned long convmul,
2566                                      unsigned long convdiv)
2567 {
2568 #define TMPBUFLEN 21
2569         unsigned long *i, *min, *max, val;
2570         int vleft, first=1, neg;
2571         size_t len, left;
2572         char buf[TMPBUFLEN], *p;
2573         char __user *s = buffer;
2574
2575         if (!data || !table->maxlen || !*lenp ||
2576             (*ppos && !write)) {
2577                 *lenp = 0;
2578                 return 0;
2579         }
2580
2581         i = (unsigned long *) data;
2582         min = (unsigned long *) table->extra1;
2583         max = (unsigned long *) table->extra2;
2584         vleft = table->maxlen / sizeof(unsigned long);
2585         left = *lenp;
2586
2587         for (; left && vleft--; i++, min++, max++, first=0) {
2588                 if (write) {
2589                         while (left) {
2590                                 char c;
2591                                 if (get_user(c, s))
2592                                         return -EFAULT;
2593                                 if (!isspace(c))
2594                                         break;
2595                                 left--;
2596                                 s++;
2597                         }
2598                         if (!left)
2599                                 break;
2600                         neg = 0;
2601                         len = left;
2602                         if (len > TMPBUFLEN-1)
2603                                 len = TMPBUFLEN-1;
2604                         if (copy_from_user(buf, s, len))
2605                                 return -EFAULT;
2606                         buf[len] = 0;
2607                         p = buf;
2608                         if (*p == '-' && left > 1) {
2609                                 neg = 1;
2610                                 p++;
2611                         }
2612                         if (*p < '0' || *p > '9')
2613                                 break;
2614                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2615                         len = p-buf;
2616                         if ((len < left) && *p && !isspace(*p))
2617                                 break;
2618                         if (neg)
2619                                 val = -val;
2620                         s += len;
2621                         left -= len;
2622
2623                         if(neg)
2624                                 continue;
2625                         if ((min && val < *min) || (max && val > *max))
2626                                 continue;
2627                         *i = val;
2628                 } else {
2629                         p = buf;
2630                         if (!first)
2631                                 *p++ = '\t';
2632                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2633                         len = strlen(buf);
2634                         if (len > left)
2635                                 len = left;
2636                         if(copy_to_user(s, buf, len))
2637                                 return -EFAULT;
2638                         left -= len;
2639                         s += len;
2640                 }
2641         }
2642
2643         if (!write && !first && left) {
2644                 if(put_user('\n', s))
2645                         return -EFAULT;
2646                 left--, s++;
2647         }
2648         if (write) {
2649                 while (left) {
2650                         char c;
2651                         if (get_user(c, s++))
2652                                 return -EFAULT;
2653                         if (!isspace(c))
2654                                 break;
2655                         left--;
2656                 }
2657         }
2658         if (write && first)
2659                 return -EINVAL;
2660         *lenp -= left;
2661         *ppos += *lenp;
2662         return 0;
2663 #undef TMPBUFLEN
2664 }
2665
2666 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2667                                      struct file *filp,
2668                                      void __user *buffer,
2669                                      size_t *lenp, loff_t *ppos,
2670                                      unsigned long convmul,
2671                                      unsigned long convdiv)
2672 {
2673         return __do_proc_doulongvec_minmax(table->data, table, write,
2674                         filp, buffer, lenp, ppos, convmul, convdiv);
2675 }
2676
2677 /**
2678  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2679  * @table: the sysctl table
2680  * @write: %TRUE if this is a write to the sysctl file
2681  * @filp: the file structure
2682  * @buffer: the user buffer
2683  * @lenp: the size of the user buffer
2684  * @ppos: file position
2685  *
2686  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2687  * values from/to the user buffer, treated as an ASCII string.
2688  *
2689  * This routine will ensure the values are within the range specified by
2690  * table->extra1 (min) and table->extra2 (max).
2691  *
2692  * Returns 0 on success.
2693  */
2694 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2695                            void __user *buffer, size_t *lenp, loff_t *ppos)
2696 {
2697     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2698 }
2699
2700 /**
2701  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2702  * @table: the sysctl table
2703  * @write: %TRUE if this is a write to the sysctl file
2704  * @filp: the file structure
2705  * @buffer: the user buffer
2706  * @lenp: the size of the user buffer
2707  * @ppos: file position
2708  *
2709  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2710  * values from/to the user buffer, treated as an ASCII string. The values
2711  * are treated as milliseconds, and converted to jiffies when they are stored.
2712  *
2713  * This routine will ensure the values are within the range specified by
2714  * table->extra1 (min) and table->extra2 (max).
2715  *
2716  * Returns 0 on success.
2717  */
2718 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2719                                       struct file *filp,
2720                                       void __user *buffer,
2721                                       size_t *lenp, loff_t *ppos)
2722 {
2723     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2724                                      lenp, ppos, HZ, 1000l);
2725 }
2726
2727
2728 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2729                                          int *valp,
2730                                          int write, void *data)
2731 {
2732         if (write) {
2733                 if (*lvalp > LONG_MAX / HZ)
2734                         return 1;
2735                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2736         } else {
2737                 int val = *valp;
2738                 unsigned long lval;
2739                 if (val < 0) {
2740                         *negp = -1;
2741                         lval = (unsigned long)-val;
2742                 } else {
2743                         *negp = 0;
2744                         lval = (unsigned long)val;
2745                 }
2746                 *lvalp = lval / HZ;
2747         }
2748         return 0;
2749 }
2750
2751 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2752                                                 int *valp,
2753                                                 int write, void *data)
2754 {
2755         if (write) {
2756                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2757                         return 1;
2758                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2759         } else {
2760                 int val = *valp;
2761                 unsigned long lval;
2762                 if (val < 0) {
2763                         *negp = -1;
2764                         lval = (unsigned long)-val;
2765                 } else {
2766                         *negp = 0;
2767                         lval = (unsigned long)val;
2768                 }
2769                 *lvalp = jiffies_to_clock_t(lval);
2770         }
2771         return 0;
2772 }
2773
2774 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2775                                             int *valp,
2776                                             int write, void *data)
2777 {
2778         if (write) {
2779                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2780         } else {
2781                 int val = *valp;
2782                 unsigned long lval;
2783                 if (val < 0) {
2784                         *negp = -1;
2785                         lval = (unsigned long)-val;
2786                 } else {
2787                         *negp = 0;
2788                         lval = (unsigned long)val;
2789                 }
2790                 *lvalp = jiffies_to_msecs(lval);
2791         }
2792         return 0;
2793 }
2794
2795 /**
2796  * proc_dointvec_jiffies - read a vector of integers as seconds
2797  * @table: the sysctl table
2798  * @write: %TRUE if this is a write to the sysctl file
2799  * @filp: the file structure
2800  * @buffer: the user buffer
2801  * @lenp: the size of the user buffer
2802  * @ppos: file position
2803  *
2804  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2805  * values from/to the user buffer, treated as an ASCII string.
2806  * The values read are assumed to be in seconds, and are converted into
2807  * jiffies.
2808  *
2809  * Returns 0 on success.
2810  */
2811 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2812                           void __user *buffer, size_t *lenp, loff_t *ppos)
2813 {
2814     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2815                             do_proc_dointvec_jiffies_conv,NULL);
2816 }
2817
2818 /**
2819  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2820  * @table: the sysctl table
2821  * @write: %TRUE if this is a write to the sysctl file
2822  * @filp: the file structure
2823  * @buffer: the user buffer
2824  * @lenp: the size of the user buffer
2825  * @ppos: pointer to the file position
2826  *
2827  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2828  * values from/to the user buffer, treated as an ASCII string.
2829  * The values read are assumed to be in 1/USER_HZ seconds, and
2830  * are converted into jiffies.
2831  *
2832  * Returns 0 on success.
2833  */
2834 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2835                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2836 {
2837     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2838                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2839 }
2840
2841 /**
2842  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2843  * @table: the sysctl table
2844  * @write: %TRUE if this is a write to the sysctl file
2845  * @filp: the file structure
2846  * @buffer: the user buffer
2847  * @lenp: the size of the user buffer
2848  * @ppos: file position
2849  * @ppos: the current position in the file
2850  *
2851  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2852  * values from/to the user buffer, treated as an ASCII string.
2853  * The values read are assumed to be in 1/1000 seconds, and
2854  * are converted into jiffies.
2855  *
2856  * Returns 0 on success.
2857  */
2858 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2859                              void __user *buffer, size_t *lenp, loff_t *ppos)
2860 {
2861         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2862                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2863 }
2864
2865 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2866                            void __user *buffer, size_t *lenp, loff_t *ppos)
2867 {
2868         struct pid *new_pid;
2869         pid_t tmp;
2870         int r;
2871
2872         tmp = pid_vnr(cad_pid);
2873
2874         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2875                                lenp, ppos, NULL, NULL);
2876         if (r || !write)
2877                 return r;
2878
2879         new_pid = find_get_pid(tmp);
2880         if (!new_pid)
2881                 return -ESRCH;
2882
2883         put_pid(xchg(&cad_pid, new_pid));
2884         return 0;
2885 }
2886
2887 #else /* CONFIG_PROC_FS */
2888
2889 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2890                   void __user *buffer, size_t *lenp, loff_t *ppos)
2891 {
2892         return -ENOSYS;
2893 }
2894
2895 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2896                   void __user *buffer, size_t *lenp, loff_t *ppos)
2897 {
2898         return -ENOSYS;
2899 }
2900
2901 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2902                     void __user *buffer, size_t *lenp, loff_t *ppos)
2903 {
2904         return -ENOSYS;
2905 }
2906
2907 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2908                     void __user *buffer, size_t *lenp, loff_t *ppos)
2909 {
2910         return -ENOSYS;
2911 }
2912
2913 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2914                     void __user *buffer, size_t *lenp, loff_t *ppos)
2915 {
2916         return -ENOSYS;
2917 }
2918
2919 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2920                              void __user *buffer, size_t *lenp, loff_t *ppos)
2921 {
2922         return -ENOSYS;
2923 }
2924
2925 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2926                     void __user *buffer, size_t *lenp, loff_t *ppos)
2927 {
2928         return -ENOSYS;
2929 }
2930
2931 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2932                                       struct file *filp,
2933                                       void __user *buffer,
2934                                       size_t *lenp, loff_t *ppos)
2935 {
2936     return -ENOSYS;
2937 }
2938
2939
2940 #endif /* CONFIG_PROC_FS */
2941
2942
2943 #ifdef CONFIG_SYSCTL_SYSCALL
2944 /*
2945  * General sysctl support routines
2946  */
2947
2948 /* The generic sysctl data routine (used if no strategy routine supplied) */
2949 int sysctl_data(struct ctl_table *table,
2950                 void __user *oldval, size_t __user *oldlenp,
2951                 void __user *newval, size_t newlen)
2952 {
2953         size_t len;
2954
2955         /* Get out of I don't have a variable */
2956         if (!table->data || !table->maxlen)
2957                 return -ENOTDIR;
2958
2959         if (oldval && oldlenp) {
2960                 if (get_user(len, oldlenp))
2961                         return -EFAULT;
2962                 if (len) {
2963                         if (len > table->maxlen)
2964                                 len = table->maxlen;
2965                         if (copy_to_user(oldval, table->data, len))
2966                                 return -EFAULT;
2967                         if (put_user(len, oldlenp))
2968                                 return -EFAULT;
2969                 }
2970         }
2971
2972         if (newval && newlen) {
2973                 if (newlen > table->maxlen)
2974                         newlen = table->maxlen;
2975
2976                 if (copy_from_user(table->data, newval, newlen))
2977                         return -EFAULT;
2978         }
2979         return 1;
2980 }
2981
2982 /* The generic string strategy routine: */
2983 int sysctl_string(struct ctl_table *table,
2984                   void __user *oldval, size_t __user *oldlenp,
2985                   void __user *newval, size_t newlen)
2986 {
2987         if (!table->data || !table->maxlen)
2988                 return -ENOTDIR;
2989
2990         if (oldval && oldlenp) {
2991                 size_t bufsize;
2992                 if (get_user(bufsize, oldlenp))
2993                         return -EFAULT;
2994                 if (bufsize) {
2995                         size_t len = strlen(table->data), copied;
2996
2997                         /* This shouldn't trigger for a well-formed sysctl */
2998                         if (len > table->maxlen)
2999                                 len = table->maxlen;
3000
3001                         /* Copy up to a max of bufsize-1 bytes of the string */
3002                         copied = (len >= bufsize) ? bufsize - 1 : len;
3003
3004                         if (copy_to_user(oldval, table->data, copied) ||
3005                             put_user(0, (char __user *)(oldval + copied)))
3006                                 return -EFAULT;
3007                         if (put_user(len, oldlenp))
3008                                 return -EFAULT;
3009                 }
3010         }
3011         if (newval && newlen) {
3012                 size_t len = newlen;
3013                 if (len > table->maxlen)
3014                         len = table->maxlen;
3015                 if(copy_from_user(table->data, newval, len))
3016                         return -EFAULT;
3017                 if (len == table->maxlen)
3018                         len--;
3019                 ((char *) table->data)[len] = 0;
3020         }
3021         return 1;
3022 }
3023
3024 /*
3025  * This function makes sure that all of the integers in the vector
3026  * are between the minimum and maximum values given in the arrays
3027  * table->extra1 and table->extra2, respectively.
3028  */
3029 int sysctl_intvec(struct ctl_table *table,
3030                 void __user *oldval, size_t __user *oldlenp,
3031                 void __user *newval, size_t newlen)
3032 {
3033
3034         if (newval && newlen) {
3035                 int __user *vec = (int __user *) newval;
3036                 int *min = (int *) table->extra1;
3037                 int *max = (int *) table->extra2;
3038                 size_t length;
3039                 int i;
3040
3041                 if (newlen % sizeof(int) != 0)
3042                         return -EINVAL;
3043
3044                 if (!table->extra1 && !table->extra2)
3045                         return 0;
3046
3047                 if (newlen > table->maxlen)
3048                         newlen = table->maxlen;
3049                 length = newlen / sizeof(int);
3050
3051                 for (i = 0; i < length; i++) {
3052                         int value;
3053                         if (get_user(value, vec + i))
3054                                 return -EFAULT;
3055                         if (min && value < min[i])
3056                                 return -EINVAL;
3057                         if (max && value > max[i])
3058                                 return -EINVAL;
3059                 }
3060         }
3061         return 0;
3062 }
3063
3064 /* Strategy function to convert jiffies to seconds */
3065 int sysctl_jiffies(struct ctl_table *table,
3066                 void __user *oldval, size_t __user *oldlenp,
3067                 void __user *newval, size_t newlen)
3068 {
3069         if (oldval && oldlenp) {
3070                 size_t olen;
3071
3072                 if (get_user(olen, oldlenp))
3073                         return -EFAULT;
3074                 if (olen) {
3075                         int val;
3076
3077                         if (olen < sizeof(int))
3078                                 return -EINVAL;
3079
3080                         val = *(int *)(table->data) / HZ;
3081                         if (put_user(val, (int __user *)oldval))
3082                                 return -EFAULT;
3083                         if (put_user(sizeof(int), oldlenp))
3084                                 return -EFAULT;
3085                 }
3086         }
3087         if (newval && newlen) {
3088                 int new;
3089                 if (newlen != sizeof(int))
3090                         return -EINVAL;
3091                 if (get_user(new, (int __user *)newval))
3092                         return -EFAULT;
3093                 *(int *)(table->data) = new*HZ;
3094         }
3095         return 1;
3096 }
3097
3098 /* Strategy function to convert jiffies to seconds */
3099 int sysctl_ms_jiffies(struct ctl_table *table,
3100                 void __user *oldval, size_t __user *oldlenp,
3101                 void __user *newval, size_t newlen)
3102 {
3103         if (oldval && oldlenp) {
3104                 size_t olen;
3105
3106                 if (get_user(olen, oldlenp))
3107                         return -EFAULT;
3108                 if (olen) {
3109                         int val;
3110
3111                         if (olen < sizeof(int))
3112                                 return -EINVAL;
3113
3114                         val = jiffies_to_msecs(*(int *)(table->data));
3115                         if (put_user(val, (int __user *)oldval))
3116                                 return -EFAULT;
3117                         if (put_user(sizeof(int), oldlenp))
3118                                 return -EFAULT;
3119                 }
3120         }
3121         if (newval && newlen) {
3122                 int new;
3123                 if (newlen != sizeof(int))
3124                         return -EINVAL;
3125                 if (get_user(new, (int __user *)newval))
3126                         return -EFAULT;
3127                 *(int *)(table->data) = msecs_to_jiffies(new);
3128         }
3129         return 1;
3130 }
3131
3132
3133
3134 #else /* CONFIG_SYSCTL_SYSCALL */
3135
3136
3137 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3138 {
3139         struct __sysctl_args tmp;
3140         int error;
3141
3142         if (copy_from_user(&tmp, args, sizeof(tmp)))
3143                 return -EFAULT;
3144
3145         error = deprecated_sysctl_warning(&tmp);
3146
3147         /* If no error reading the parameters then just -ENOSYS ... */
3148         if (!error)
3149                 error = -ENOSYS;
3150
3151         return error;
3152 }
3153
3154 int sysctl_data(struct ctl_table *table,
3155                   void __user *oldval, size_t __user *oldlenp,
3156                   void __user *newval, size_t newlen)
3157 {
3158         return -ENOSYS;
3159 }
3160
3161 int sysctl_string(struct ctl_table *table,
3162                   void __user *oldval, size_t __user *oldlenp,
3163                   void __user *newval, size_t newlen)
3164 {
3165         return -ENOSYS;
3166 }
3167
3168 int sysctl_intvec(struct ctl_table *table,
3169                 void __user *oldval, size_t __user *oldlenp,
3170                 void __user *newval, size_t newlen)
3171 {
3172         return -ENOSYS;
3173 }
3174
3175 int sysctl_jiffies(struct ctl_table *table,
3176                 void __user *oldval, size_t __user *oldlenp,
3177                 void __user *newval, size_t newlen)
3178 {
3179         return -ENOSYS;
3180 }
3181
3182 int sysctl_ms_jiffies(struct ctl_table *table,
3183                 void __user *oldval, size_t __user *oldlenp,
3184                 void __user *newval, size_t newlen)
3185 {
3186         return -ENOSYS;
3187 }
3188
3189 #endif /* CONFIG_SYSCTL_SYSCALL */
3190
3191 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3192 {
3193         static int msg_count;
3194         int name[CTL_MAXNAME];
3195         int i;
3196
3197         /* Check args->nlen. */
3198         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3199                 return -ENOTDIR;
3200
3201         /* Read in the sysctl name for better debug message logging */
3202         for (i = 0; i < args->nlen; i++)
3203                 if (get_user(name[i], args->name + i))
3204                         return -EFAULT;
3205
3206         /* Ignore accesses to kernel.version */
3207         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3208                 return 0;
3209
3210         if (msg_count < 5) {
3211                 msg_count++;
3212                 printk(KERN_INFO
3213                         "warning: process `%s' used the deprecated sysctl "
3214                         "system call with ", current->comm);
3215                 for (i = 0; i < args->nlen; i++)
3216                         printk("%d.", name[i]);
3217                 printk("\n");
3218         }
3219         return 0;
3220 }
3221
3222 /*
3223  * No sense putting this after each symbol definition, twice,
3224  * exception granted :-)
3225  */
3226 EXPORT_SYMBOL(proc_dointvec);
3227 EXPORT_SYMBOL(proc_dointvec_jiffies);
3228 EXPORT_SYMBOL(proc_dointvec_minmax);
3229 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3230 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3231 EXPORT_SYMBOL(proc_dostring);
3232 EXPORT_SYMBOL(proc_doulongvec_minmax);
3233 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3234 EXPORT_SYMBOL(register_sysctl_table);
3235 EXPORT_SYMBOL(register_sysctl_paths);
3236 EXPORT_SYMBOL(sysctl_intvec);
3237 EXPORT_SYMBOL(sysctl_jiffies);
3238 EXPORT_SYMBOL(sysctl_ms_jiffies);
3239 EXPORT_SYMBOL(sysctl_string);
3240 EXPORT_SYMBOL(sysctl_data);
3241 EXPORT_SYMBOL(unregister_sysctl_table);