kernel/sysctl.c

   1 /*
   2  * sysctl.c: General linux system control interface
   3  *
   4  * Begun 24 March 1995, Stephen Tweedie
   5  * Added /proc support, Dec 1995
   6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
   7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
   8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
   9  * Dynamic registration fixes, Stephen Tweedie.
  10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
  11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
  12  *  Horn.
  13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
  14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
  15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
  16  *  Wendling.
  17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
  18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/slab.h>
  25 #include <linux/sysctl.h>
  26 #include <linux/proc_fs.h>
  27 #include <linux/security.h>
  28 #include <linux/ctype.h>
  29 #include <linux/utsname.h>
  30 #include <linux/smp_lock.h>
  31 #include <linux/fs.h>
  32 #include <linux/init.h>
  33 #include <linux/kernel.h>
  34 #include <linux/kobject.h>
  35 #include <linux/net.h>
  36 #include <linux/sysrq.h>
  37 #include <linux/highuid.h>
  38 #include <linux/writeback.h>
  39 #include <linux/hugetlb.h>
  40 #include <linux/initrd.h>
  41 #include <linux/key.h>
  42 #include <linux/times.h>
  43 #include <linux/limits.h>
  44 #include <linux/dcache.h>
  45 #include <linux/syscalls.h>
  46 #include <linux/vmstat.h>
  47 #include <linux/nfs_fs.h>
  48 #include <linux/acpi.h>
  49 #include <linux/reboot.h>
  50 #include <linux/ftrace.h>
  51 #include <linux/slow-work.h>
  52 #include <linux/perf_counter.h>
  53
  54 #include <asm/uaccess.h>
  55 #include <asm/processor.h>
  56
  57 #ifdef CONFIG_X86
  58 #include <asm/nmi.h>
  59 #include <asm/stacktrace.h>
  60 #include <asm/io.h>
  61 #endif
  62
  63 static int deprecated_sysctl_warning(struct __sysctl_args *args);
  64
  65 #if defined(CONFIG_SYSCTL)
  66
  67 /* External variables not in a header file. */
  68 extern int C_A_D;
  69 extern int print_fatal_signals;
  70 extern int sysctl_overcommit_memory;
  71 extern int sysctl_overcommit_ratio;
  72 extern int sysctl_panic_on_oom;
  73 extern int sysctl_oom_kill_allocating_task;
  74 extern int sysctl_oom_dump_tasks;
  75 extern int max_threads;
  76 extern int core_uses_pid;
  77 extern int suid_dumpable;
  78 extern char core_pattern[];
  79 extern int pid_max;
  80 extern int min_free_kbytes;
  81 extern int pid_max_min, pid_max_max;
  82 extern int sysctl_drop_caches;
  83 extern int percpu_pagelist_fraction;
  84 extern int compat_log;
  85 extern int latencytop_enabled;
  86 extern int sysctl_nr_open_min, sysctl_nr_open_max;
  87 #ifndef CONFIG_MMU
  88 extern int sysctl_nr_trim_pages;
  89 #endif
  90 #ifdef CONFIG_RCU_TORTURE_TEST
  91 extern int rcutorture_runnable;
  92 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
  93
  94 /* Constants used for minimum and  maximum */
  95 #ifdef CONFIG_DETECT_SOFTLOCKUP
  96 static int sixty = 60;
  97 static int neg_one = -1;
  98 #endif
  99
 100 static int zero;
 101 static int __maybe_unused one = 1;
 102 static int __maybe_unused two = 2;
 103 static unsigned long one_ul = 1;
 104 static int one_hundred = 100;
 105
 106 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 107 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 108
 109 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 110 static int maxolduid = 65535;
 111 static int minolduid;
 112 static int min_percpu_pagelist_fract = 8;
 113
 114 static int ngroups_max = NGROUPS_MAX;
 115
 116 #ifdef CONFIG_MODULES
 117 extern char modprobe_path[];
 118 extern int modules_disabled;
 119 #endif
 120 #ifdef CONFIG_CHR_DEV_SG
 121 extern int sg_big_buff;
 122 #endif
 123
 124 #ifdef CONFIG_SPARC
 125 #include <asm/system.h>
 126 #endif
 127
 128 #ifdef CONFIG_SPARC64
 129 extern int sysctl_tsb_ratio;
 130 #endif
 131
 132 #ifdef __hppa__
 133 extern int pwrsw_enabled;
 134 extern int unaligned_enabled;
 135 #endif
 136
 137 #ifdef CONFIG_S390
 138 #ifdef CONFIG_MATHEMU
 139 extern int sysctl_ieee_emulation_warnings;
 140 #endif
 141 extern int sysctl_userprocess_debug;
 142 extern int spin_retry;
 143 #endif
 144
 145 #ifdef CONFIG_BSD_PROCESS_ACCT
 146 extern int acct_parm[];
 147 #endif
 148
 149 #ifdef CONFIG_IA64
 150 extern int no_unaligned_warning;
 151 extern int unaligned_dump_stack;
 152 #endif
 153
 154 #ifdef CONFIG_RT_MUTEXES
 155 extern int max_lock_depth;
 156 #endif
 157
 158 #ifdef CONFIG_PROC_SYSCTL
 159 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
 160                   void __user *buffer, size_t *lenp, loff_t *ppos);
 161 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
 162                                void __user *buffer, size_t *lenp, loff_t *ppos);
 163 #endif
 164
 165 static struct ctl_table root_table[];
 166 static struct ctl_table_root sysctl_table_root;
 167 static struct ctl_table_header root_table_header = {
 168         .count = 1,
 169         .ctl_table = root_table,
 170         .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
 171         .root = &sysctl_table_root,
 172         .set = &sysctl_table_root.default_set,
 173 };
 174 static struct ctl_table_root sysctl_table_root = {
 175         .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
 176         .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
 177 };
 178
 179 static struct ctl_table kern_table[];
 180 static struct ctl_table vm_table[];
 181 static struct ctl_table fs_table[];
 182 static struct ctl_table debug_table[];
 183 static struct ctl_table dev_table[];
 184 extern struct ctl_table random_table[];
 185 #ifdef CONFIG_INOTIFY_USER
 186 extern struct ctl_table inotify_table[];
 187 #endif
 188 #ifdef CONFIG_EPOLL
 189 extern struct ctl_table epoll_table[];
 190 #endif
 191
 192 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 193 int sysctl_legacy_va_layout;
 194 #endif
 195
 196 extern int prove_locking;
 197 extern int lock_stat;
 198
 199 /* The default sysctl tables: */
 200
 201 static struct ctl_table root_table[] = {
 202         {
 203                 .ctl_name       = CTL_KERN,
 204                 .procname       = "kernel",
 205                 .mode           = 0555,
 206                 .child          = kern_table,
 207         },
 208         {
 209                 .ctl_name       = CTL_VM,
 210                 .procname       = "vm",
 211                 .mode           = 0555,
 212                 .child          = vm_table,
 213         },
 214         {
 215                 .ctl_name       = CTL_FS,
 216                 .procname       = "fs",
 217                 .mode           = 0555,
 218                 .child          = fs_table,
 219         },
 220         {
 221                 .ctl_name       = CTL_DEBUG,
 222                 .procname       = "debug",
 223                 .mode           = 0555,
 224                 .child          = debug_table,
 225         },
 226         {
 227                 .ctl_name       = CTL_DEV,
 228                 .procname       = "dev",
 229                 .mode           = 0555,
 230                 .child          = dev_table,
 231         },
 232 /*
 233  * NOTE: do not add new entries to this table unless you have read
 234  * Documentation/sysctl/ctl_unnumbered.txt
 235  */
 236         { .ctl_name = 0 }
 237 };
 238
 239 #ifdef CONFIG_SCHED_DEBUG
 240 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 241 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 242 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 243 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 244 #endif
 245
 246 static struct ctl_table kern_table[] = {
 247 #ifdef CONFIG_SCHED_DEBUG
 248         {
 249                 .ctl_name       = CTL_UNNUMBERED,
 250                 .procname       = "sched_min_granularity_ns",
 251                 .data           = &sysctl_sched_min_granularity,
 252                 .maxlen         = sizeof(unsigned int),
 253                 .mode           = 0644,
 254                 .proc_handler   = &sched_nr_latency_handler,
 255                 .strategy       = &sysctl_intvec,
 256                 .extra1         = &min_sched_granularity_ns,
 257                 .extra2         = &max_sched_granularity_ns,
 258         },
 259         {
 260                 .ctl_name       = CTL_UNNUMBERED,
 261                 .procname       = "sched_latency_ns",
 262                 .data           = &sysctl_sched_latency,
 263                 .maxlen         = sizeof(unsigned int),
 264                 .mode           = 0644,
 265                 .proc_handler   = &sched_nr_latency_handler,
 266                 .strategy       = &sysctl_intvec,
 267                 .extra1         = &min_sched_granularity_ns,
 268                 .extra2         = &max_sched_granularity_ns,
 269         },
 270         {
 271                 .ctl_name       = CTL_UNNUMBERED,
 272                 .procname       = "sched_wakeup_granularity_ns",
 273                 .data           = &sysctl_sched_wakeup_granularity,
 274                 .maxlen         = sizeof(unsigned int),
 275                 .mode           = 0644,
 276                 .proc_handler   = &proc_dointvec_minmax,
 277                 .strategy       = &sysctl_intvec,
 278                 .extra1         = &min_wakeup_granularity_ns,
 279                 .extra2         = &max_wakeup_granularity_ns,
 280         },
 281         {
 282                 .ctl_name       = CTL_UNNUMBERED,
 283                 .procname       = "sched_shares_ratelimit",
 284                 .data           = &sysctl_sched_shares_ratelimit,
 285                 .maxlen         = sizeof(unsigned int),
 286                 .mode           = 0644,
 287                 .proc_handler   = &proc_dointvec,
 288         },
 289         {
 290                 .ctl_name       = CTL_UNNUMBERED,
 291                 .procname       = "sched_shares_thresh",
 292                 .data           = &sysctl_sched_shares_thresh,
 293                 .maxlen         = sizeof(unsigned int),
 294                 .mode           = 0644,
 295                 .proc_handler   = &proc_dointvec_minmax,
 296                 .strategy       = &sysctl_intvec,
 297                 .extra1         = &zero,
 298         },
 299         {
 300                 .ctl_name       = CTL_UNNUMBERED,
 301                 .procname       = "sched_child_runs_first",
 302                 .data           = &sysctl_sched_child_runs_first,
 303                 .maxlen         = sizeof(unsigned int),
 304                 .mode           = 0644,
 305                 .proc_handler   = &proc_dointvec,
 306         },
 307         {
 308                 .ctl_name       = CTL_UNNUMBERED,
 309                 .procname       = "sched_features",
 310                 .data           = &sysctl_sched_features,
 311                 .maxlen         = sizeof(unsigned int),
 312                 .mode           = 0644,
 313                 .proc_handler   = &proc_dointvec,
 314         },
 315         {
 316                 .ctl_name       = CTL_UNNUMBERED,
 317                 .procname       = "sched_migration_cost",
 318                 .data           = &sysctl_sched_migration_cost,
 319                 .maxlen         = sizeof(unsigned int),
 320                 .mode           = 0644,
 321                 .proc_handler   = &proc_dointvec,
 322         },
 323         {
 324                 .ctl_name       = CTL_UNNUMBERED,
 325                 .procname       = "sched_nr_migrate",
 326                 .data           = &sysctl_sched_nr_migrate,
 327                 .maxlen         = sizeof(unsigned int),
 328                 .mode           = 0644,
 329                 .proc_handler   = &proc_dointvec,
 330         },
 331 #endif
 332         {
 333                 .ctl_name       = CTL_UNNUMBERED,
 334                 .procname       = "sched_rt_period_us",
 335                 .data           = &sysctl_sched_rt_period,
 336                 .maxlen         = sizeof(unsigned int),
 337                 .mode           = 0644,
 338                 .proc_handler   = &sched_rt_handler,
 339         },
 340         {
 341                 .ctl_name       = CTL_UNNUMBERED,
 342                 .procname       = "sched_rt_runtime_us",
 343                 .data           = &sysctl_sched_rt_runtime,
 344                 .maxlen         = sizeof(int),
 345                 .mode           = 0644,
 346                 .proc_handler   = &sched_rt_handler,
 347         },
 348         {
 349                 .ctl_name       = CTL_UNNUMBERED,
 350                 .procname       = "sched_compat_yield",
 351                 .data           = &sysctl_sched_compat_yield,
 352                 .maxlen         = sizeof(unsigned int),
 353                 .mode           = 0644,
 354                 .proc_handler   = &proc_dointvec,
 355         },
 356 #ifdef CONFIG_PROVE_LOCKING
 357         {
 358                 .ctl_name       = CTL_UNNUMBERED,
 359                 .procname       = "prove_locking",
 360                 .data           = &prove_locking,
 361                 .maxlen         = sizeof(int),
 362                 .mode           = 0644,
 363                 .proc_handler   = &proc_dointvec,
 364         },
 365 #endif
 366 #ifdef CONFIG_LOCK_STAT
 367         {
 368                 .ctl_name       = CTL_UNNUMBERED,
 369                 .procname       = "lock_stat",
 370                 .data           = &lock_stat,
 371                 .maxlen         = sizeof(int),
 372                 .mode           = 0644,
 373                 .proc_handler   = &proc_dointvec,
 374         },
 375 #endif
 376         {
 377                 .ctl_name       = KERN_PANIC,
 378                 .procname       = "panic",
 379                 .data           = &panic_timeout,
 380                 .maxlen         = sizeof(int),
 381                 .mode           = 0644,
 382                 .proc_handler   = &proc_dointvec,
 383         },
 384         {
 385                 .ctl_name       = KERN_CORE_USES_PID,
 386                 .procname       = "core_uses_pid",
 387                 .data           = &core_uses_pid,
 388                 .maxlen         = sizeof(int),
 389                 .mode           = 0644,
 390                 .proc_handler   = &proc_dointvec,
 391         },
 392         {
 393                 .ctl_name       = KERN_CORE_PATTERN,
 394                 .procname       = "core_pattern",
 395                 .data           = core_pattern,
 396                 .maxlen         = CORENAME_MAX_SIZE,
 397                 .mode           = 0644,
 398                 .proc_handler   = &proc_dostring,
 399                 .strategy       = &sysctl_string,
 400         },
 401 #ifdef CONFIG_PROC_SYSCTL
 402         {
 403                 .procname       = "tainted",
 404                 .maxlen         = sizeof(long),
 405                 .mode           = 0644,
 406                 .proc_handler   = &proc_taint,
 407         },
 408 #endif
 409 #ifdef CONFIG_LATENCYTOP
 410         {
 411                 .procname       = "latencytop",
 412                 .data           = &latencytop_enabled,
 413                 .maxlen         = sizeof(int),
 414                 .mode           = 0644,
 415                 .proc_handler   = &proc_dointvec,
 416         },
 417 #endif
 418 #ifdef CONFIG_BLK_DEV_INITRD
 419         {
 420                 .ctl_name       = KERN_REALROOTDEV,
 421                 .procname       = "real-root-dev",
 422                 .data           = &real_root_dev,
 423                 .maxlen         = sizeof(int),
 424                 .mode           = 0644,
 425                 .proc_handler   = &proc_dointvec,
 426         },
 427 #endif
 428         {
 429                 .ctl_name       = CTL_UNNUMBERED,
 430                 .procname       = "print-fatal-signals",
 431                 .data           = &print_fatal_signals,
 432                 .maxlen         = sizeof(int),
 433                 .mode           = 0644,
 434                 .proc_handler   = &proc_dointvec,
 435         },
 436 #ifdef CONFIG_SPARC
 437         {
 438                 .ctl_name       = KERN_SPARC_REBOOT,
 439                 .procname       = "reboot-cmd",
 440                 .data           = reboot_command,
 441                 .maxlen         = 256,
 442                 .mode           = 0644,
 443                 .proc_handler   = &proc_dostring,
 444                 .strategy       = &sysctl_string,
 445         },
 446         {
 447                 .ctl_name       = KERN_SPARC_STOP_A,
 448                 .procname       = "stop-a",
 449                 .data           = &stop_a_enabled,
 450                 .maxlen         = sizeof (int),
 451                 .mode           = 0644,
 452                 .proc_handler   = &proc_dointvec,
 453         },
 454         {
 455                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
 456                 .procname       = "scons-poweroff",
 457                 .data           = &scons_pwroff,
 458                 .maxlen         = sizeof (int),
 459                 .mode           = 0644,
 460                 .proc_handler   = &proc_dointvec,
 461         },
 462 #endif
 463 #ifdef CONFIG_SPARC64
 464         {
 465                 .ctl_name       = CTL_UNNUMBERED,
 466                 .procname       = "tsb-ratio",
 467                 .data           = &sysctl_tsb_ratio,
 468                 .maxlen         = sizeof (int),
 469                 .mode           = 0644,
 470                 .proc_handler   = &proc_dointvec,
 471         },
 472 #endif
 473 #ifdef __hppa__
 474         {
 475                 .ctl_name       = KERN_HPPA_PWRSW,
 476                 .procname       = "soft-power",
 477                 .data           = &pwrsw_enabled,
 478                 .maxlen         = sizeof (int),
 479                 .mode           = 0644,
 480                 .proc_handler   = &proc_dointvec,
 481         },
 482         {
 483                 .ctl_name       = KERN_HPPA_UNALIGNED,
 484                 .procname       = "unaligned-trap",
 485                 .data           = &unaligned_enabled,
 486                 .maxlen         = sizeof (int),
 487                 .mode           = 0644,
 488                 .proc_handler   = &proc_dointvec,
 489         },
 490 #endif
 491         {
 492                 .ctl_name       = KERN_CTLALTDEL,
 493                 .procname       = "ctrl-alt-del",
 494                 .data           = &C_A_D,
 495                 .maxlen         = sizeof(int),
 496                 .mode           = 0644,
 497                 .proc_handler   = &proc_dointvec,
 498         },
 499 #ifdef CONFIG_FUNCTION_TRACER
 500         {
 501                 .ctl_name       = CTL_UNNUMBERED,
 502                 .procname       = "ftrace_enabled",
 503                 .data           = &ftrace_enabled,
 504                 .maxlen         = sizeof(int),
 505                 .mode           = 0644,
 506                 .proc_handler   = &ftrace_enable_sysctl,
 507         },
 508 #endif
 509 #ifdef CONFIG_STACK_TRACER
 510         {
 511                 .ctl_name       = CTL_UNNUMBERED,
 512                 .procname       = "stack_tracer_enabled",
 513                 .data           = &stack_tracer_enabled,
 514                 .maxlen         = sizeof(int),
 515                 .mode           = 0644,
 516                 .proc_handler   = &stack_trace_sysctl,
 517         },
 518 #endif
 519 #ifdef CONFIG_TRACING
 520         {
 521                 .ctl_name       = CTL_UNNUMBERED,
 522                 .procname       = "ftrace_dump_on_oops",
 523                 .data           = &ftrace_dump_on_oops,
 524                 .maxlen         = sizeof(int),
 525                 .mode           = 0644,
 526                 .proc_handler   = &proc_dointvec,
 527         },
 528 #endif
 529 #ifdef CONFIG_MODULES
 530         {
 531                 .ctl_name       = KERN_MODPROBE,
 532                 .procname       = "modprobe",
 533                 .data           = &modprobe_path,
 534                 .maxlen         = KMOD_PATH_LEN,
 535                 .mode           = 0644,
 536                 .proc_handler   = &proc_dostring,
 537                 .strategy       = &sysctl_string,
 538         },
 539         {
 540                 .ctl_name       = CTL_UNNUMBERED,
 541                 .procname       = "modules_disabled",
 542                 .data           = &modules_disabled,
 543                 .maxlen         = sizeof(int),
 544                 .mode           = 0644,
 545                 /* only handle a transition from default "0" to "1" */
 546                 .proc_handler   = &proc_dointvec_minmax,
 547                 .extra1         = &one,
 548                 .extra2         = &one,
 549         },
 550 #endif
 551 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
 552         {
 553                 .ctl_name       = KERN_HOTPLUG,
 554                 .procname       = "hotplug",
 555                 .data           = &uevent_helper,
 556                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 557                 .mode           = 0644,
 558                 .proc_handler   = &proc_dostring,
 559                 .strategy       = &sysctl_string,
 560         },
 561 #endif
 562 #ifdef CONFIG_CHR_DEV_SG
 563         {
 564                 .ctl_name       = KERN_SG_BIG_BUFF,
 565                 .procname       = "sg-big-buff",
 566                 .data           = &sg_big_buff,
 567                 .maxlen         = sizeof (int),
 568                 .mode           = 0444,
 569                 .proc_handler   = &proc_dointvec,
 570         },
 571 #endif
 572 #ifdef CONFIG_BSD_PROCESS_ACCT
 573         {
 574                 .ctl_name       = KERN_ACCT,
 575                 .procname       = "acct",
 576                 .data           = &acct_parm,
 577                 .maxlen         = 3*sizeof(int),
 578                 .mode           = 0644,
 579                 .proc_handler   = &proc_dointvec,
 580         },
 581 #endif
 582 #ifdef CONFIG_MAGIC_SYSRQ
 583         {
 584                 .ctl_name       = KERN_SYSRQ,
 585                 .procname       = "sysrq",
 586                 .data           = &__sysrq_enabled,
 587                 .maxlen         = sizeof (int),
 588                 .mode           = 0644,
 589                 .proc_handler   = &proc_dointvec,
 590         },
 591 #endif
 592 #ifdef CONFIG_PROC_SYSCTL
 593         {
 594                 .procname       = "cad_pid",
 595                 .data           = NULL,
 596                 .maxlen         = sizeof (int),
 597                 .mode           = 0600,
 598                 .proc_handler   = &proc_do_cad_pid,
 599         },
 600 #endif
 601         {
 602                 .ctl_name       = KERN_MAX_THREADS,
 603                 .procname       = "threads-max",
 604                 .data           = &max_threads,
 605                 .maxlen         = sizeof(int),
 606                 .mode           = 0644,
 607                 .proc_handler   = &proc_dointvec,
 608         },
 609         {
 610                 .ctl_name       = KERN_RANDOM,
 611                 .procname       = "random",
 612                 .mode           = 0555,
 613                 .child          = random_table,
 614         },
 615         {
 616                 .ctl_name       = KERN_OVERFLOWUID,
 617                 .procname       = "overflowuid",
 618                 .data           = &overflowuid,
 619                 .maxlen         = sizeof(int),
 620                 .mode           = 0644,
 621                 .proc_handler   = &proc_dointvec_minmax,
 622                 .strategy       = &sysctl_intvec,
 623                 .extra1         = &minolduid,
 624                 .extra2         = &maxolduid,
 625         },
 626         {
 627                 .ctl_name       = KERN_OVERFLOWGID,
 628                 .procname       = "overflowgid",
 629                 .data           = &overflowgid,
 630                 .maxlen         = sizeof(int),
 631                 .mode           = 0644,
 632                 .proc_handler   = &proc_dointvec_minmax,
 633                 .strategy       = &sysctl_intvec,
 634                 .extra1         = &minolduid,
 635                 .extra2         = &maxolduid,
 636         },
 637 #ifdef CONFIG_S390
 638 #ifdef CONFIG_MATHEMU
 639         {
 640                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
 641                 .procname       = "ieee_emulation_warnings",
 642                 .data           = &sysctl_ieee_emulation_warnings,
 643                 .maxlen         = sizeof(int),
 644                 .mode           = 0644,
 645                 .proc_handler   = &proc_dointvec,
 646         },
 647 #endif
 648         {
 649                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
 650                 .procname       = "userprocess_debug",
 651                 .data           = &sysctl_userprocess_debug,
 652                 .maxlen         = sizeof(int),
 653                 .mode           = 0644,
 654                 .proc_handler   = &proc_dointvec,
 655         },
 656 #endif
 657         {
 658                 .ctl_name       = KERN_PIDMAX,
 659                 .procname       = "pid_max",
 660                 .data           = &pid_max,
 661                 .maxlen         = sizeof (int),
 662                 .mode           = 0644,
 663                 .proc_handler   = &proc_dointvec_minmax,
 664                 .strategy       = sysctl_intvec,
 665                 .extra1         = &pid_max_min,
 666                 .extra2         = &pid_max_max,
 667         },
 668         {
 669                 .ctl_name       = KERN_PANIC_ON_OOPS,
 670                 .procname       = "panic_on_oops",
 671                 .data           = &panic_on_oops,
 672                 .maxlen         = sizeof(int),
 673                 .mode           = 0644,
 674                 .proc_handler   = &proc_dointvec,
 675         },
 676 #if defined CONFIG_PRINTK
 677         {
 678                 .ctl_name       = KERN_PRINTK,
 679                 .procname       = "printk",
 680                 .data           = &console_loglevel,
 681                 .maxlen         = 4*sizeof(int),
 682                 .mode           = 0644,
 683                 .proc_handler   = &proc_dointvec,
 684         },
 685         {
 686                 .ctl_name       = KERN_PRINTK_RATELIMIT,
 687                 .procname       = "printk_ratelimit",
 688                 .data           = &printk_ratelimit_state.interval,
 689                 .maxlen         = sizeof(int),
 690                 .mode           = 0644,
 691                 .proc_handler   = &proc_dointvec_jiffies,
 692                 .strategy       = &sysctl_jiffies,
 693         },
 694         {
 695                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
 696                 .procname       = "printk_ratelimit_burst",
 697                 .data           = &printk_ratelimit_state.burst,
 698                 .maxlen         = sizeof(int),
 699                 .mode           = 0644,
 700                 .proc_handler   = &proc_dointvec,
 701         },
 702 #endif
 703         {
 704                 .ctl_name       = KERN_NGROUPS_MAX,
 705                 .procname       = "ngroups_max",
 706                 .data           = &ngroups_max,
 707                 .maxlen         = sizeof (int),
 708                 .mode           = 0444,
 709                 .proc_handler   = &proc_dointvec,
 710         },
 711 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 712         {
 713                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
 714                 .procname       = "unknown_nmi_panic",
 715                 .data           = &unknown_nmi_panic,
 716                 .maxlen         = sizeof (int),
 717                 .mode           = 0644,
 718                 .proc_handler   = &proc_dointvec,
 719         },
 720         {
 721                 .procname       = "nmi_watchdog",
 722                 .data           = &nmi_watchdog_enabled,
 723                 .maxlen         = sizeof (int),
 724                 .mode           = 0644,
 725                 .proc_handler   = &proc_nmi_enabled,
 726         },
 727 #endif
 728 #if defined(CONFIG_X86)
 729         {
 730                 .ctl_name       = KERN_PANIC_ON_NMI,
 731                 .procname       = "panic_on_unrecovered_nmi",
 732                 .data           = &panic_on_unrecovered_nmi,
 733                 .maxlen         = sizeof(int),
 734                 .mode           = 0644,
 735                 .proc_handler   = &proc_dointvec,
 736         },
 737         {
 738                 .ctl_name       = KERN_BOOTLOADER_TYPE,
 739                 .procname       = "bootloader_type",
 740                 .data           = &bootloader_type,
 741                 .maxlen         = sizeof (int),
 742                 .mode           = 0444,
 743                 .proc_handler   = &proc_dointvec,
 744         },
 745         {
 746                 .ctl_name       = CTL_UNNUMBERED,
 747                 .procname       = "bootloader_version",
 748                 .data           = &bootloader_version,
 749                 .maxlen         = sizeof (int),
 750                 .mode           = 0444,
 751                 .proc_handler   = &proc_dointvec,
 752         },
 753         {
 754                 .ctl_name       = CTL_UNNUMBERED,
 755                 .procname       = "kstack_depth_to_print",
 756                 .data           = &kstack_depth_to_print,
 757                 .maxlen         = sizeof(int),
 758                 .mode           = 0644,
 759                 .proc_handler   = &proc_dointvec,
 760         },
 761         {
 762                 .ctl_name       = CTL_UNNUMBERED,
 763                 .procname       = "io_delay_type",
 764                 .data           = &io_delay_type,
 765                 .maxlen         = sizeof(int),
 766                 .mode           = 0644,
 767                 .proc_handler   = &proc_dointvec,
 768         },
 769 #endif
 770 #if defined(CONFIG_MMU)
 771         {
 772                 .ctl_name       = KERN_RANDOMIZE,
 773                 .procname       = "randomize_va_space",
 774                 .data           = &randomize_va_space,
 775                 .maxlen         = sizeof(int),
 776                 .mode           = 0644,
 777                 .proc_handler   = &proc_dointvec,
 778         },
 779 #endif
 780 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
 781         {
 782                 .ctl_name       = KERN_SPIN_RETRY,
 783                 .procname       = "spin_retry",
 784                 .data           = &spin_retry,
 785                 .maxlen         = sizeof (int),
 786                 .mode           = 0644,
 787                 .proc_handler   = &proc_dointvec,
 788         },
 789 #endif
 790 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
 791         {
 792                 .procname       = "acpi_video_flags",
 793                 .data           = &acpi_realmode_flags,
 794                 .maxlen         = sizeof (unsigned long),
 795                 .mode           = 0644,
 796                 .proc_handler   = &proc_doulongvec_minmax,
 797         },
 798 #endif
 799 #ifdef CONFIG_IA64
 800         {
 801                 .ctl_name       = KERN_IA64_UNALIGNED,
 802                 .procname       = "ignore-unaligned-usertrap",
 803                 .data           = &no_unaligned_warning,
 804                 .maxlen         = sizeof (int),
 805                 .mode           = 0644,
 806                 .proc_handler   = &proc_dointvec,
 807         },
 808         {
 809                 .ctl_name       = CTL_UNNUMBERED,
 810                 .procname       = "unaligned-dump-stack",
 811                 .data           = &unaligned_dump_stack,
 812                 .maxlen         = sizeof (int),
 813                 .mode           = 0644,
 814                 .proc_handler   = &proc_dointvec,
 815         },
 816 #endif
 817 #ifdef CONFIG_DETECT_SOFTLOCKUP
 818         {
 819                 .ctl_name       = CTL_UNNUMBERED,
 820                 .procname       = "softlockup_panic",
 821                 .data           = &softlockup_panic,
 822                 .maxlen         = sizeof(int),
 823                 .mode           = 0644,
 824                 .proc_handler   = &proc_dointvec_minmax,
 825                 .strategy       = &sysctl_intvec,
 826                 .extra1         = &zero,
 827                 .extra2         = &one,
 828         },
 829         {
 830                 .ctl_name       = CTL_UNNUMBERED,
 831                 .procname       = "softlockup_thresh",
 832                 .data           = &softlockup_thresh,
 833                 .maxlen         = sizeof(int),
 834                 .mode           = 0644,
 835                 .proc_handler   = &proc_dosoftlockup_thresh,
 836                 .strategy       = &sysctl_intvec,
 837                 .extra1         = &neg_one,
 838                 .extra2         = &sixty,
 839         },
 840 #endif
 841 #ifdef CONFIG_DETECT_HUNG_TASK
 842         {
 843                 .ctl_name       = CTL_UNNUMBERED,
 844                 .procname       = "hung_task_panic",
 845                 .data           = &sysctl_hung_task_panic,
 846                 .maxlen         = sizeof(int),
 847                 .mode           = 0644,
 848                 .proc_handler   = &proc_dointvec_minmax,
 849                 .strategy       = &sysctl_intvec,
 850                 .extra1         = &zero,
 851                 .extra2         = &one,
 852         },
 853         {
 854                 .ctl_name       = CTL_UNNUMBERED,
 855                 .procname       = "hung_task_check_count",
 856                 .data           = &sysctl_hung_task_check_count,
 857                 .maxlen         = sizeof(unsigned long),
 858                 .mode           = 0644,
 859                 .proc_handler   = &proc_doulongvec_minmax,
 860                 .strategy       = &sysctl_intvec,
 861         },
 862         {
 863                 .ctl_name       = CTL_UNNUMBERED,
 864                 .procname       = "hung_task_timeout_secs",
 865                 .data           = &sysctl_hung_task_timeout_secs,
 866                 .maxlen         = sizeof(unsigned long),
 867                 .mode           = 0644,
 868                 .proc_handler   = &proc_dohung_task_timeout_secs,
 869                 .strategy       = &sysctl_intvec,
 870         },
 871         {
 872                 .ctl_name       = CTL_UNNUMBERED,
 873                 .procname       = "hung_task_warnings",
 874                 .data           = &sysctl_hung_task_warnings,
 875                 .maxlen         = sizeof(unsigned long),
 876                 .mode           = 0644,
 877                 .proc_handler   = &proc_doulongvec_minmax,
 878                 .strategy       = &sysctl_intvec,
 879         },
 880 #endif
 881 #ifdef CONFIG_COMPAT
 882         {
 883                 .ctl_name       = KERN_COMPAT_LOG,
 884                 .procname       = "compat-log",
 885                 .data           = &compat_log,
 886                 .maxlen         = sizeof (int),
 887                 .mode           = 0644,
 888                 .proc_handler   = &proc_dointvec,
 889         },
 890 #endif
 891 #ifdef CONFIG_RT_MUTEXES
 892         {
 893                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
 894                 .procname       = "max_lock_depth",
 895                 .data           = &max_lock_depth,
 896                 .maxlen         = sizeof(int),
 897                 .mode           = 0644,
 898                 .proc_handler   = &proc_dointvec,
 899         },
 900 #endif
 901         {
 902                 .ctl_name       = CTL_UNNUMBERED,
 903                 .procname       = "poweroff_cmd",
 904                 .data           = &poweroff_cmd,
 905                 .maxlen         = POWEROFF_CMD_PATH_LEN,
 906                 .mode           = 0644,
 907                 .proc_handler   = &proc_dostring,
 908                 .strategy       = &sysctl_string,
 909         },
 910 #ifdef CONFIG_KEYS
 911         {
 912                 .ctl_name       = CTL_UNNUMBERED,
 913                 .procname       = "keys",
 914                 .mode           = 0555,
 915                 .child          = key_sysctls,
 916         },
 917 #endif
 918 #ifdef CONFIG_RCU_TORTURE_TEST
 919         {
 920                 .ctl_name       = CTL_UNNUMBERED,
 921                 .procname       = "rcutorture_runnable",
 922                 .data           = &rcutorture_runnable,
 923                 .maxlen         = sizeof(int),
 924                 .mode           = 0644,
 925                 .proc_handler   = &proc_dointvec,
 926         },
 927 #endif
 928 #ifdef CONFIG_SLOW_WORK
 929         {
 930                 .ctl_name       = CTL_UNNUMBERED,
 931                 .procname       = "slow-work",
 932                 .mode           = 0555,
 933                 .child          = slow_work_sysctls,
 934         },
 935 #endif
 936 #ifdef CONFIG_PERF_COUNTERS
 937         {
 938                 .ctl_name       = CTL_UNNUMBERED,
 939                 .procname       = "perf_counter_paranoid",
 940                 .data           = &sysctl_perf_counter_paranoid,
 941                 .maxlen         = sizeof(sysctl_perf_counter_paranoid),
 942                 .mode           = 0644,
 943                 .proc_handler   = &proc_dointvec,
 944         },
 945         {
 946                 .ctl_name       = CTL_UNNUMBERED,
 947                 .procname       = "perf_counter_mlock_kb",
 948                 .data           = &sysctl_perf_counter_mlock,
 949                 .maxlen         = sizeof(sysctl_perf_counter_mlock),
 950                 .mode           = 0644,
 951                 .proc_handler   = &proc_dointvec,
 952         },
 953         {
 954                 .ctl_name       = CTL_UNNUMBERED,
 955                 .procname       = "perf_counter_max_sample_rate",
 956                 .data           = &sysctl_perf_counter_sample_rate,
 957                 .maxlen         = sizeof(sysctl_perf_counter_sample_rate),
 958                 .mode           = 0644,
 959                 .proc_handler   = &proc_dointvec,
 960         },
 961 #endif
 962 /*
 963  * NOTE: do not add new entries to this table unless you have read
 964  * Documentation/sysctl/ctl_unnumbered.txt
 965  */
 966         { .ctl_name = 0 }
 967 };
 968
 969 static struct ctl_table vm_table[] = {
 970         {
 971                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
 972                 .procname       = "overcommit_memory",
 973                 .data           = &sysctl_overcommit_memory,
 974                 .maxlen         = sizeof(sysctl_overcommit_memory),
 975                 .mode           = 0644,
 976                 .proc_handler   = &proc_dointvec,
 977         },
 978         {
 979                 .ctl_name       = VM_PANIC_ON_OOM,
 980                 .procname       = "panic_on_oom",
 981                 .data           = &sysctl_panic_on_oom,
 982                 .maxlen         = sizeof(sysctl_panic_on_oom),
 983                 .mode           = 0644,
 984                 .proc_handler   = &proc_dointvec,
 985         },
 986         {
 987                 .ctl_name       = CTL_UNNUMBERED,
 988                 .procname       = "oom_kill_allocating_task",
 989                 .data           = &sysctl_oom_kill_allocating_task,
 990                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
 991                 .mode           = 0644,
 992                 .proc_handler   = &proc_dointvec,
 993         },
 994         {
 995                 .ctl_name       = CTL_UNNUMBERED,
 996                 .procname       = "oom_dump_tasks",
 997                 .data           = &sysctl_oom_dump_tasks,
 998                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
 999                 .mode           = 0644,
1000                 .proc_handler   = &proc_dointvec,
1001         },
1002         {
1003                 .ctl_name       = VM_OVERCOMMIT_RATIO,
1004                 .procname       = "overcommit_ratio",
1005                 .data           = &sysctl_overcommit_ratio,
1006                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1007                 .mode           = 0644,
1008                 .proc_handler   = &proc_dointvec,
1009         },
1010         {
1011                 .ctl_name       = VM_PAGE_CLUSTER,
1012                 .procname       = "page-cluster",
1013                 .data           = &page_cluster,
1014                 .maxlen         = sizeof(int),
1015                 .mode           = 0644,
1016                 .proc_handler   = &proc_dointvec,
1017         },
1018         {
1019                 .ctl_name       = VM_DIRTY_BACKGROUND,
1020                 .procname       = "dirty_background_ratio",
1021                 .data           = &dirty_background_ratio,
1022                 .maxlen         = sizeof(dirty_background_ratio),
1023                 .mode           = 0644,
1024                 .proc_handler   = &dirty_background_ratio_handler,
1025                 .strategy       = &sysctl_intvec,
1026                 .extra1         = &zero,
1027                 .extra2         = &one_hundred,
1028         },
1029         {
1030                 .ctl_name       = CTL_UNNUMBERED,
1031                 .procname       = "dirty_background_bytes",
1032                 .data           = &dirty_background_bytes,
1033                 .maxlen         = sizeof(dirty_background_bytes),
1034                 .mode           = 0644,
1035                 .proc_handler   = &dirty_background_bytes_handler,
1036                 .strategy       = &sysctl_intvec,
1037                 .extra1         = &one_ul,
1038         },
1039         {
1040                 .ctl_name       = VM_DIRTY_RATIO,
1041                 .procname       = "dirty_ratio",
1042                 .data           = &vm_dirty_ratio,
1043                 .maxlen         = sizeof(vm_dirty_ratio),
1044                 .mode           = 0644,
1045                 .proc_handler   = &dirty_ratio_handler,
1046                 .strategy       = &sysctl_intvec,
1047                 .extra1         = &zero,
1048                 .extra2         = &one_hundred,
1049         },
1050         {
1051                 .ctl_name       = CTL_UNNUMBERED,
1052                 .procname       = "dirty_bytes",
1053                 .data           = &vm_dirty_bytes,
1054                 .maxlen         = sizeof(vm_dirty_bytes),
1055                 .mode           = 0644,
1056                 .proc_handler   = &dirty_bytes_handler,
1057                 .strategy       = &sysctl_intvec,
1058                 .extra1         = &dirty_bytes_min,
1059         },
1060         {
1061                 .procname       = "dirty_writeback_centisecs",
1062                 .data           = &dirty_writeback_interval,
1063                 .maxlen         = sizeof(dirty_writeback_interval),
1064                 .mode           = 0644,
1065                 .proc_handler   = &dirty_writeback_centisecs_handler,
1066         },
1067         {
1068                 .procname       = "dirty_expire_centisecs",
1069                 .data           = &dirty_expire_interval,
1070                 .maxlen         = sizeof(dirty_expire_interval),
1071                 .mode           = 0644,
1072                 .proc_handler   = &proc_dointvec,
1073         },
1074         {
1075                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
1076                 .procname       = "nr_pdflush_threads",
1077                 .data           = &nr_pdflush_threads,
1078                 .maxlen         = sizeof nr_pdflush_threads,
1079                 .mode           = 0444 /* read-only*/,
1080                 .proc_handler   = &proc_dointvec,
1081         },
1082         {
1083                 .ctl_name       = VM_SWAPPINESS,
1084                 .procname       = "swappiness",
1085                 .data           = &vm_swappiness,
1086                 .maxlen         = sizeof(vm_swappiness),
1087                 .mode           = 0644,
1088                 .proc_handler   = &proc_dointvec_minmax,
1089                 .strategy       = &sysctl_intvec,
1090                 .extra1         = &zero,
1091                 .extra2         = &one_hundred,
1092         },
1093 #ifdef CONFIG_HUGETLB_PAGE
1094          {
1095                 .procname       = "nr_hugepages",
1096                 .data           = NULL,
1097                 .maxlen         = sizeof(unsigned long),
1098                 .mode           = 0644,
1099                 .proc_handler   = &hugetlb_sysctl_handler,
1100                 .extra1         = (void *)&hugetlb_zero,
1101                 .extra2         = (void *)&hugetlb_infinity,
1102          },
1103          {
1104                 .ctl_name       = VM_HUGETLB_GROUP,
1105                 .procname       = "hugetlb_shm_group",
1106                 .data           = &sysctl_hugetlb_shm_group,
1107                 .maxlen         = sizeof(gid_t),
1108                 .mode           = 0644,
1109                 .proc_handler   = &proc_dointvec,
1110          },
1111          {
1112                 .ctl_name       = CTL_UNNUMBERED,
1113                 .procname       = "hugepages_treat_as_movable",
1114                 .data           = &hugepages_treat_as_movable,
1115                 .maxlen         = sizeof(int),
1116                 .mode           = 0644,
1117                 .proc_handler   = &hugetlb_treat_movable_handler,
1118         },
1119         {
1120                 .ctl_name       = CTL_UNNUMBERED,
1121                 .procname       = "nr_overcommit_hugepages",
1122                 .data           = NULL,
1123                 .maxlen         = sizeof(unsigned long),
1124                 .mode           = 0644,
1125                 .proc_handler   = &hugetlb_overcommit_handler,
1126                 .extra1         = (void *)&hugetlb_zero,
1127                 .extra2         = (void *)&hugetlb_infinity,
1128         },
1129 #endif
1130         {
1131                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
1132                 .procname       = "lowmem_reserve_ratio",
1133                 .data           = &sysctl_lowmem_reserve_ratio,
1134                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1135                 .mode           = 0644,
1136                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
1137                 .strategy       = &sysctl_intvec,
1138         },
1139         {
1140                 .ctl_name       = VM_DROP_PAGECACHE,
1141                 .procname       = "drop_caches",
1142                 .data           = &sysctl_drop_caches,
1143                 .maxlen         = sizeof(int),
1144                 .mode           = 0644,
1145                 .proc_handler   = drop_caches_sysctl_handler,
1146                 .strategy       = &sysctl_intvec,
1147         },
1148         {
1149                 .ctl_name       = VM_MIN_FREE_KBYTES,
1150                 .procname       = "min_free_kbytes",
1151                 .data           = &min_free_kbytes,
1152                 .maxlen         = sizeof(min_free_kbytes),
1153                 .mode           = 0644,
1154                 .proc_handler   = &min_free_kbytes_sysctl_handler,
1155                 .strategy       = &sysctl_intvec,
1156                 .extra1         = &zero,
1157         },
1158         {
1159                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
1160                 .procname       = "percpu_pagelist_fraction",
1161                 .data           = &percpu_pagelist_fraction,
1162                 .maxlen         = sizeof(percpu_pagelist_fraction),
1163                 .mode           = 0644,
1164                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
1165                 .strategy       = &sysctl_intvec,
1166                 .extra1         = &min_percpu_pagelist_fract,
1167         },
1168 #ifdef CONFIG_MMU
1169         {
1170                 .ctl_name       = VM_MAX_MAP_COUNT,
1171                 .procname       = "max_map_count",
1172                 .data           = &sysctl_max_map_count,
1173                 .maxlen         = sizeof(sysctl_max_map_count),
1174                 .mode           = 0644,
1175                 .proc_handler   = &proc_dointvec
1176         },
1177 #else
1178         {
1179                 .ctl_name       = CTL_UNNUMBERED,
1180                 .procname       = "nr_trim_pages",
1181                 .data           = &sysctl_nr_trim_pages,
1182                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1183                 .mode           = 0644,
1184                 .proc_handler   = &proc_dointvec_minmax,
1185                 .strategy       = &sysctl_intvec,
1186                 .extra1         = &zero,
1187         },
1188 #endif
1189         {
1190                 .ctl_name       = VM_LAPTOP_MODE,
1191                 .procname       = "laptop_mode",
1192                 .data           = &laptop_mode,
1193                 .maxlen         = sizeof(laptop_mode),
1194                 .mode           = 0644,
1195                 .proc_handler   = &proc_dointvec_jiffies,
1196                 .strategy       = &sysctl_jiffies,
1197         },
1198         {
1199                 .ctl_name       = VM_BLOCK_DUMP,
1200                 .procname       = "block_dump",
1201                 .data           = &block_dump,
1202                 .maxlen         = sizeof(block_dump),
1203                 .mode           = 0644,
1204                 .proc_handler   = &proc_dointvec,
1205                 .strategy       = &sysctl_intvec,
1206                 .extra1         = &zero,
1207         },
1208         {
1209                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
1210                 .procname       = "vfs_cache_pressure",
1211                 .data           = &sysctl_vfs_cache_pressure,
1212                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1213                 .mode           = 0644,
1214                 .proc_handler   = &proc_dointvec,
1215                 .strategy       = &sysctl_intvec,
1216                 .extra1         = &zero,
1217         },
1218 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1219         {
1220                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
1221                 .procname       = "legacy_va_layout",
1222                 .data           = &sysctl_legacy_va_layout,
1223                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1224                 .mode           = 0644,
1225                 .proc_handler   = &proc_dointvec,
1226                 .strategy       = &sysctl_intvec,
1227                 .extra1         = &zero,
1228         },
1229 #endif
1230 #ifdef CONFIG_NUMA
1231         {
1232                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1233                 .procname       = "zone_reclaim_mode",
1234                 .data           = &zone_reclaim_mode,
1235                 .maxlen         = sizeof(zone_reclaim_mode),
1236                 .mode           = 0644,
1237                 .proc_handler   = &proc_dointvec,
1238                 .strategy       = &sysctl_intvec,
1239                 .extra1         = &zero,
1240         },
1241         {
1242                 .ctl_name       = VM_MIN_UNMAPPED,
1243                 .procname       = "min_unmapped_ratio",
1244                 .data           = &sysctl_min_unmapped_ratio,
1245                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1246                 .mode           = 0644,
1247                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1248                 .strategy       = &sysctl_intvec,
1249                 .extra1         = &zero,
1250                 .extra2         = &one_hundred,
1251         },
1252         {
1253                 .ctl_name       = VM_MIN_SLAB,
1254                 .procname       = "min_slab_ratio",
1255                 .data           = &sysctl_min_slab_ratio,
1256                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1257                 .mode           = 0644,
1258                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1259                 .strategy       = &sysctl_intvec,
1260                 .extra1         = &zero,
1261                 .extra2         = &one_hundred,
1262         },
1263 #endif
1264 #ifdef CONFIG_SMP
1265         {
1266                 .ctl_name       = CTL_UNNUMBERED,
1267                 .procname       = "stat_interval",
1268                 .data           = &sysctl_stat_interval,
1269                 .maxlen         = sizeof(sysctl_stat_interval),
1270                 .mode           = 0644,
1271                 .proc_handler   = &proc_dointvec_jiffies,
1272                 .strategy       = &sysctl_jiffies,
1273         },
1274 #endif
1275         {
1276                 .ctl_name       = CTL_UNNUMBERED,
1277                 .procname       = "mmap_min_addr",
1278                 .data           = &mmap_min_addr,
1279                 .maxlen         = sizeof(unsigned long),
1280                 .mode           = 0644,
1281                 .proc_handler   = &proc_doulongvec_minmax,
1282         },
1283 #ifdef CONFIG_NUMA
1284         {
1285                 .ctl_name       = CTL_UNNUMBERED,
1286                 .procname       = "numa_zonelist_order",
1287                 .data           = &numa_zonelist_order,
1288                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1289                 .mode           = 0644,
1290                 .proc_handler   = &numa_zonelist_order_handler,
1291                 .strategy       = &sysctl_string,
1292         },
1293 #endif
1294 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1295    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1296         {
1297                 .ctl_name       = VM_VDSO_ENABLED,
1298                 .procname       = "vdso_enabled",
1299                 .data           = &vdso_enabled,
1300                 .maxlen         = sizeof(vdso_enabled),
1301                 .mode           = 0644,
1302                 .proc_handler   = &proc_dointvec,
1303                 .strategy       = &sysctl_intvec,
1304                 .extra1         = &zero,
1305         },
1306 #endif
1307 #ifdef CONFIG_HIGHMEM
1308         {
1309                 .ctl_name       = CTL_UNNUMBERED,
1310                 .procname       = "highmem_is_dirtyable",
1311                 .data           = &vm_highmem_is_dirtyable,
1312                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1313                 .mode           = 0644,
1314                 .proc_handler   = &proc_dointvec_minmax,
1315                 .strategy       = &sysctl_intvec,
1316                 .extra1         = &zero,
1317                 .extra2         = &one,
1318         },
1319 #endif
1320 #ifdef CONFIG_UNEVICTABLE_LRU
1321         {
1322                 .ctl_name       = CTL_UNNUMBERED,
1323                 .procname       = "scan_unevictable_pages",
1324                 .data           = &scan_unevictable_pages,
1325                 .maxlen         = sizeof(scan_unevictable_pages),
1326                 .mode           = 0644,
1327                 .proc_handler   = &scan_unevictable_handler,
1328         },
1329 #endif
1330 /*
1331  * NOTE: do not add new entries to this table unless you have read
1332  * Documentation/sysctl/ctl_unnumbered.txt
1333  */
1334         { .ctl_name = 0 }
1335 };
1336
1337 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1338 static struct ctl_table binfmt_misc_table[] = {
1339         { .ctl_name = 0 }
1340 };
1341 #endif
1342
1343 static struct ctl_table fs_table[] = {
1344         {
1345                 .ctl_name       = FS_NRINODE,
1346                 .procname       = "inode-nr",
1347                 .data           = &inodes_stat,
1348                 .maxlen         = 2*sizeof(int),
1349                 .mode           = 0444,
1350                 .proc_handler   = &proc_dointvec,
1351         },
1352         {
1353                 .ctl_name       = FS_STATINODE,
1354                 .procname       = "inode-state",
1355                 .data           = &inodes_stat,
1356                 .maxlen         = 7*sizeof(int),
1357                 .mode           = 0444,
1358                 .proc_handler   = &proc_dointvec,
1359         },
1360         {
1361                 .procname       = "file-nr",
1362                 .data           = &files_stat,
1363                 .maxlen         = 3*sizeof(int),
1364                 .mode           = 0444,
1365                 .proc_handler   = &proc_nr_files,
1366         },
1367         {
1368                 .ctl_name       = FS_MAXFILE,
1369                 .procname       = "file-max",
1370                 .data           = &files_stat.max_files,
1371                 .maxlen         = sizeof(int),
1372                 .mode           = 0644,
1373                 .proc_handler   = &proc_dointvec,
1374         },
1375         {
1376                 .ctl_name       = CTL_UNNUMBERED,
1377                 .procname       = "nr_open",
1378                 .data           = &sysctl_nr_open,
1379                 .maxlen         = sizeof(int),
1380                 .mode           = 0644,
1381                 .proc_handler   = &proc_dointvec_minmax,
1382                 .extra1         = &sysctl_nr_open_min,
1383                 .extra2         = &sysctl_nr_open_max,
1384         },
1385         {
1386                 .ctl_name       = FS_DENTRY,
1387                 .procname       = "dentry-state",
1388                 .data           = &dentry_stat,
1389                 .maxlen         = 6*sizeof(int),
1390                 .mode           = 0444,
1391                 .proc_handler   = &proc_dointvec,
1392         },
1393         {
1394                 .ctl_name       = FS_OVERFLOWUID,
1395                 .procname       = "overflowuid",
1396                 .data           = &fs_overflowuid,
1397                 .maxlen         = sizeof(int),
1398                 .mode           = 0644,
1399                 .proc_handler   = &proc_dointvec_minmax,
1400                 .strategy       = &sysctl_intvec,
1401                 .extra1         = &minolduid,
1402                 .extra2         = &maxolduid,
1403         },
1404         {
1405                 .ctl_name       = FS_OVERFLOWGID,
1406                 .procname       = "overflowgid",
1407                 .data           = &fs_overflowgid,
1408                 .maxlen         = sizeof(int),
1409                 .mode           = 0644,
1410                 .proc_handler   = &proc_dointvec_minmax,
1411                 .strategy       = &sysctl_intvec,
1412                 .extra1         = &minolduid,
1413                 .extra2         = &maxolduid,
1414         },
1415 #ifdef CONFIG_FILE_LOCKING
1416         {
1417                 .ctl_name       = FS_LEASES,
1418                 .procname       = "leases-enable",
1419                 .data           = &leases_enable,
1420                 .maxlen         = sizeof(int),
1421                 .mode           = 0644,
1422                 .proc_handler   = &proc_dointvec,
1423         },
1424 #endif
1425 #ifdef CONFIG_DNOTIFY
1426         {
1427                 .ctl_name       = FS_DIR_NOTIFY,
1428                 .procname       = "dir-notify-enable",
1429                 .data           = &dir_notify_enable,
1430                 .maxlen         = sizeof(int),
1431                 .mode           = 0644,
1432                 .proc_handler   = &proc_dointvec,
1433         },
1434 #endif
1435 #ifdef CONFIG_MMU
1436 #ifdef CONFIG_FILE_LOCKING
1437         {
1438                 .ctl_name       = FS_LEASE_TIME,
1439                 .procname       = "lease-break-time",
1440                 .data           = &lease_break_time,
1441                 .maxlen         = sizeof(int),
1442                 .mode           = 0644,
1443                 .proc_handler   = &proc_dointvec,
1444         },
1445 #endif
1446 #ifdef CONFIG_AIO
1447         {
1448                 .procname       = "aio-nr",
1449                 .data           = &aio_nr,
1450                 .maxlen         = sizeof(aio_nr),
1451                 .mode           = 0444,
1452                 .proc_handler   = &proc_doulongvec_minmax,
1453         },
1454         {
1455                 .procname       = "aio-max-nr",
1456                 .data           = &aio_max_nr,
1457                 .maxlen         = sizeof(aio_max_nr),
1458                 .mode           = 0644,
1459                 .proc_handler   = &proc_doulongvec_minmax,
1460         },
1461 #endif /* CONFIG_AIO */
1462 #ifdef CONFIG_INOTIFY_USER
1463         {
1464                 .ctl_name       = FS_INOTIFY,
1465                 .procname       = "inotify",
1466                 .mode           = 0555,
1467                 .child          = inotify_table,
1468         },
1469 #endif
1470 #ifdef CONFIG_EPOLL
1471         {
1472                 .procname       = "epoll",
1473                 .mode           = 0555,
1474                 .child          = epoll_table,
1475         },
1476 #endif
1477 #endif
1478         {
1479                 .ctl_name       = KERN_SETUID_DUMPABLE,
1480                 .procname       = "suid_dumpable",
1481                 .data           = &suid_dumpable,
1482                 .maxlen         = sizeof(int),
1483                 .mode           = 0644,
1484                 .proc_handler   = &proc_dointvec_minmax,
1485                 .strategy       = &sysctl_intvec,
1486                 .extra1         = &zero,
1487                 .extra2         = &two,
1488         },
1489 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1490         {
1491                 .ctl_name       = CTL_UNNUMBERED,
1492                 .procname       = "binfmt_misc",
1493                 .mode           = 0555,
1494                 .child          = binfmt_misc_table,
1495         },
1496 #endif
1497 /*
1498  * NOTE: do not add new entries to this table unless you have read
1499  * Documentation/sysctl/ctl_unnumbered.txt
1500  */
1501         { .ctl_name = 0 }
1502 };
1503
1504 static struct ctl_table debug_table[] = {
1505 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1506         {
1507                 .ctl_name       = CTL_UNNUMBERED,
1508                 .procname       = "exception-trace",
1509                 .data           = &show_unhandled_signals,
1510                 .maxlen         = sizeof(int),
1511                 .mode           = 0644,
1512                 .proc_handler   = proc_dointvec
1513         },
1514 #endif
1515         { .ctl_name = 0 }
1516 };
1517
1518 static struct ctl_table dev_table[] = {
1519         { .ctl_name = 0 }
1520 };
1521
1522 static DEFINE_SPINLOCK(sysctl_lock);
1523
1524 /* called under sysctl_lock */
1525 static int use_table(struct ctl_table_header *p)
1526 {
1527         if (unlikely(p->unregistering))
1528                 return 0;
1529         p->used++;
1530         return 1;
1531 }
1532
1533 /* called under sysctl_lock */
1534 static void unuse_table(struct ctl_table_header *p)
1535 {
1536         if (!--p->used)
1537                 if (unlikely(p->unregistering))
1538                         complete(p->unregistering);
1539 }
1540
1541 /* called under sysctl_lock, will reacquire if has to wait */
1542 static void start_unregistering(struct ctl_table_header *p)
1543 {
1544         /*
1545          * if p->used is 0, nobody will ever touch that entry again;
1546          * we'll eliminate all paths to it before dropping sysctl_lock
1547          */
1548         if (unlikely(p->used)) {
1549                 struct completion wait;
1550                 init_completion(&wait);
1551                 p->unregistering = &wait;
1552                 spin_unlock(&sysctl_lock);
1553                 wait_for_completion(&wait);
1554                 spin_lock(&sysctl_lock);
1555         } else {
1556                 /* anything non-NULL; we'll never dereference it */
1557                 p->unregistering = ERR_PTR(-EINVAL);
1558         }
1559         /*
1560          * do not remove from the list until nobody holds it; walking the
1561          * list in do_sysctl() relies on that.
1562          */
1563         list_del_init(&p->ctl_entry);
1564 }
1565
1566 void sysctl_head_get(struct ctl_table_header *head)
1567 {
1568         spin_lock(&sysctl_lock);
1569         head->count++;
1570         spin_unlock(&sysctl_lock);
1571 }
1572
1573 void sysctl_head_put(struct ctl_table_header *head)
1574 {
1575         spin_lock(&sysctl_lock);
1576         if (!--head->count)
1577                 kfree(head);
1578         spin_unlock(&sysctl_lock);
1579 }
1580
1581 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1582 {
1583         if (!head)
1584                 BUG();
1585         spin_lock(&sysctl_lock);
1586         if (!use_table(head))
1587                 head = ERR_PTR(-ENOENT);
1588         spin_unlock(&sysctl_lock);
1589         return head;
1590 }
1591
1592 void sysctl_head_finish(struct ctl_table_header *head)
1593 {
1594         if (!head)
1595                 return;
1596         spin_lock(&sysctl_lock);
1597         unuse_table(head);
1598         spin_unlock(&sysctl_lock);
1599 }
1600
1601 static struct ctl_table_set *
1602 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1603 {
1604         struct ctl_table_set *set = &root->default_set;
1605         if (root->lookup)
1606                 set = root->lookup(root, namespaces);
1607         return set;
1608 }
1609
1610 static struct list_head *
1611 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1612 {
1613         struct ctl_table_set *set = lookup_header_set(root, namespaces);
1614         return &set->list;
1615 }
1616
1617 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1618                                             struct ctl_table_header *prev)
1619 {
1620         struct ctl_table_root *root;
1621         struct list_head *header_list;
1622         struct ctl_table_header *head;
1623         struct list_head *tmp;
1624
1625         spin_lock(&sysctl_lock);
1626         if (prev) {
1627                 head = prev;
1628                 tmp = &prev->ctl_entry;
1629                 unuse_table(prev);
1630                 goto next;
1631         }
1632         tmp = &root_table_header.ctl_entry;
1633         for (;;) {
1634                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1635
1636                 if (!use_table(head))
1637                         goto next;
1638                 spin_unlock(&sysctl_lock);
1639                 return head;
1640         next:
1641                 root = head->root;
1642                 tmp = tmp->next;
1643                 header_list = lookup_header_list(root, namespaces);
1644                 if (tmp != header_list)
1645                         continue;
1646
1647                 do {
1648                         root = list_entry(root->root_list.next,
1649                                         struct ctl_table_root, root_list);
1650                         if (root == &sysctl_table_root)
1651                                 goto out;
1652                         header_list = lookup_header_list(root, namespaces);
1653                 } while (list_empty(header_list));
1654                 tmp = header_list->next;
1655         }
1656 out:
1657         spin_unlock(&sysctl_lock);
1658         return NULL;
1659 }
1660
1661 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1662 {
1663         return __sysctl_head_next(current->nsproxy, prev);
1664 }
1665
1666 void register_sysctl_root(struct ctl_table_root *root)
1667 {
1668         spin_lock(&sysctl_lock);
1669         list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1670         spin_unlock(&sysctl_lock);
1671 }
1672
1673 #ifdef CONFIG_SYSCTL_SYSCALL
1674 /* Perform the actual read/write of a sysctl table entry. */
1675 static int do_sysctl_strategy(struct ctl_table_root *root,
1676                         struct ctl_table *table,
1677                         void __user *oldval, size_t __user *oldlenp,
1678                         void __user *newval, size_t newlen)
1679 {
1680         int op = 0, rc;
1681
1682         if (oldval)
1683                 op |= MAY_READ;
1684         if (newval)
1685                 op |= MAY_WRITE;
1686         if (sysctl_perm(root, table, op))
1687                 return -EPERM;
1688
1689         if (table->strategy) {
1690                 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1691                 if (rc < 0)
1692                         return rc;
1693                 if (rc > 0)
1694                         return 0;
1695         }
1696
1697         /* If there is no strategy routine, or if the strategy returns
1698          * zero, proceed with automatic r/w */
1699         if (table->data && table->maxlen) {
1700                 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1701                 if (rc < 0)
1702                         return rc;
1703         }
1704         return 0;
1705 }
1706
1707 static int parse_table(int __user *name, int nlen,
1708                        void __user *oldval, size_t __user *oldlenp,
1709                        void __user *newval, size_t newlen,
1710                        struct ctl_table_root *root,
1711                        struct ctl_table *table)
1712 {
1713         int n;
1714 repeat:
1715         if (!nlen)
1716                 return -ENOTDIR;
1717         if (get_user(n, name))
1718                 return -EFAULT;
1719         for ( ; table->ctl_name || table->procname; table++) {
1720                 if (!table->ctl_name)
1721                         continue;
1722                 if (n == table->ctl_name) {
1723                         int error;
1724                         if (table->child) {
1725                                 if (sysctl_perm(root, table, MAY_EXEC))
1726                                         return -EPERM;
1727                                 name++;
1728                                 nlen--;
1729                                 table = table->child;
1730                                 goto repeat;
1731                         }
1732                         error = do_sysctl_strategy(root, table,
1733                                                    oldval, oldlenp,
1734                                                    newval, newlen);
1735                         return error;
1736                 }
1737         }
1738         return -ENOTDIR;
1739 }
1740
1741 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1742                void __user *newval, size_t newlen)
1743 {
1744         struct ctl_table_header *head;
1745         int error = -ENOTDIR;
1746
1747         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1748                 return -ENOTDIR;
1749         if (oldval) {
1750                 int old_len;
1751                 if (!oldlenp || get_user(old_len, oldlenp))
1752                         return -EFAULT;
1753         }
1754
1755         for (head = sysctl_head_next(NULL); head;
1756                         head = sysctl_head_next(head)) {
1757                 error = parse_table(name, nlen, oldval, oldlenp,
1758                                         newval, newlen,
1759                                         head->root, head->ctl_table);
1760                 if (error != -ENOTDIR) {
1761                         sysctl_head_finish(head);
1762                         break;
1763                 }
1764         }
1765         return error;
1766 }
1767
1768 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1769 {
1770         struct __sysctl_args tmp;
1771         int error;
1772
1773         if (copy_from_user(&tmp, args, sizeof(tmp)))
1774                 return -EFAULT;
1775
1776         error = deprecated_sysctl_warning(&tmp);
1777         if (error)
1778                 goto out;
1779
1780         lock_kernel();
1781         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1782                           tmp.newval, tmp.newlen);
1783         unlock_kernel();
1784 out:
1785         return error;
1786 }
1787 #endif /* CONFIG_SYSCTL_SYSCALL */
1788
1789 /*
1790  * sysctl_perm does NOT grant the superuser all rights automatically, because
1791  * some sysctl variables are readonly even to root.
1792  */
1793
1794 static int test_perm(int mode, int op)
1795 {
1796         if (!current_euid())
1797                 mode >>= 6;
1798         else if (in_egroup_p(0))
1799                 mode >>= 3;
1800         if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1801                 return 0;
1802         return -EACCES;
1803 }
1804
1805 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1806 {
1807         int error;
1808         int mode;
1809
1810         error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1811         if (error)
1812                 return error;
1813
1814         if (root->permissions)
1815                 mode = root->permissions(root, current->nsproxy, table);
1816         else
1817                 mode = table->mode;
1818
1819         return test_perm(mode, op);
1820 }
1821
1822 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1823 {
1824         for (; table->ctl_name || table->procname; table++) {
1825                 table->parent = parent;
1826                 if (table->child)
1827                         sysctl_set_parent(table, table->child);
1828         }
1829 }
1830
1831 static __init int sysctl_init(void)
1832 {
1833         sysctl_set_parent(NULL, root_table);
1834 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1835         {
1836                 int err;
1837                 err = sysctl_check_table(current->nsproxy, root_table);
1838         }
1839 #endif
1840         return 0;
1841 }
1842
1843 core_initcall(sysctl_init);
1844
1845 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1846                                       struct ctl_table *table)
1847 {
1848         struct ctl_table *p;
1849         const char *s = branch->procname;
1850
1851         /* branch should have named subdirectory as its first element */
1852         if (!s || !branch->child)
1853                 return NULL;
1854
1855         /* ... and nothing else */
1856         if (branch[1].procname || branch[1].ctl_name)
1857                 return NULL;
1858
1859         /* table should contain subdirectory with the same name */
1860         for (p = table; p->procname || p->ctl_name; p++) {
1861                 if (!p->child)
1862                         continue;
1863                 if (p->procname && strcmp(p->procname, s) == 0)
1864                         return p;
1865         }
1866         return NULL;
1867 }
1868
1869 /* see if attaching q to p would be an improvement */
1870 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1871 {
1872         struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1873         struct ctl_table *next;
1874         int is_better = 0;
1875         int not_in_parent = !p->attached_by;
1876
1877         while ((next = is_branch_in(by, to)) != NULL) {
1878                 if (by == q->attached_by)
1879                         is_better = 1;
1880                 if (to == p->attached_by)
1881                         not_in_parent = 1;
1882                 by = by->child;
1883                 to = next->child;
1884         }
1885
1886         if (is_better && not_in_parent) {
1887                 q->attached_by = by;
1888                 q->attached_to = to;
1889                 q->parent = p;
1890         }
1891 }
1892
1893 /**
1894  * __register_sysctl_paths - register a sysctl hierarchy
1895  * @root: List of sysctl headers to register on
1896  * @namespaces: Data to compute which lists of sysctl entries are visible
1897  * @path: The path to the directory the sysctl table is in.
1898  * @table: the top-level table structure
1899  *
1900  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1901  * array. A completely 0 filled entry terminates the table.
1902  *
1903  * The members of the &struct ctl_table structure are used as follows:
1904  *
1905  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1906  *            must be unique within that level of sysctl
1907  *
1908  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1909  *            enter a sysctl file
1910  *
1911  * data - a pointer to data for use by proc_handler
1912  *
1913  * maxlen - the maximum size in bytes of the data
1914  *
1915  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1916  *
1917  * child - a pointer to the child sysctl table if this entry is a directory, or
1918  *         %NULL.
1919  *
1920  * proc_handler - the text handler routine (described below)
1921  *
1922  * strategy - the strategy routine (described below)
1923  *
1924  * de - for internal use by the sysctl routines
1925  *
1926  * extra1, extra2 - extra pointers usable by the proc handler routines
1927  *
1928  * Leaf nodes in the sysctl tree will be represented by a single file
1929  * under /proc; non-leaf nodes will be represented by directories.
1930  *
1931  * sysctl(2) can automatically manage read and write requests through
1932  * the sysctl table.  The data and maxlen fields of the ctl_table
1933  * struct enable minimal validation of the values being written to be
1934  * performed, and the mode field allows minimal authentication.
1935  *
1936  * More sophisticated management can be enabled by the provision of a
1937  * strategy routine with the table entry.  This will be called before
1938  * any automatic read or write of the data is performed.
1939  *
1940  * The strategy routine may return
1941  *
1942  * < 0 - Error occurred (error is passed to user process)
1943  *
1944  * 0   - OK - proceed with automatic read or write.
1945  *
1946  * > 0 - OK - read or write has been done by the strategy routine, so
1947  *       return immediately.
1948  *
1949  * There must be a proc_handler routine for any terminal nodes
1950  * mirrored under /proc/sys (non-terminals are handled by a built-in
1951  * directory handler).  Several default handlers are available to
1952  * cover common cases -
1953  *
1954  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1955  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1956  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1957  *
1958  * It is the handler's job to read the input buffer from user memory
1959  * and process it. The handler should return 0 on success.
1960  *
1961  * This routine returns %NULL on a failure to register, and a pointer
1962  * to the table header on success.
1963  */
1964 struct ctl_table_header *__register_sysctl_paths(
1965         struct ctl_table_root *root,
1966         struct nsproxy *namespaces,
1967         const struct ctl_path *path, struct ctl_table *table)
1968 {
1969         struct ctl_table_header *header;
1970         struct ctl_table *new, **prevp;
1971         unsigned int n, npath;
1972         struct ctl_table_set *set;
1973
1974         /* Count the path components */
1975         for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1976                 ;
1977
1978         /*
1979          * For each path component, allocate a 2-element ctl_table array.
1980          * The first array element will be filled with the sysctl entry
1981          * for this, the second will be the sentinel (ctl_name == 0).
1982          *
1983          * We allocate everything in one go so that we don't have to
1984          * worry about freeing additional memory in unregister_sysctl_table.
1985          */
1986         header = kzalloc(sizeof(struct ctl_table_header) +
1987                          (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1988         if (!header)
1989                 return NULL;
1990
1991         new = (struct ctl_table *) (header + 1);
1992
1993         /* Now connect the dots */
1994         prevp = &header->ctl_table;
1995         for (n = 0; n < npath; ++n, ++path) {
1996                 /* Copy the procname */
1997                 new->procname = path->procname;
1998                 new->ctl_name = path->ctl_name;
1999                 new->mode     = 0555;
2000
2001                 *prevp = new;
2002                 prevp = &new->child;
2003
2004                 new += 2;
2005         }
2006         *prevp = table;
2007         header->ctl_table_arg = table;
2008
2009         INIT_LIST_HEAD(&header->ctl_entry);
2010         header->used = 0;
2011         header->unregistering = NULL;
2012         header->root = root;
2013         sysctl_set_parent(NULL, header->ctl_table);
2014         header->count = 1;
2015 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
2016         if (sysctl_check_table(namespaces, header->ctl_table)) {
2017                 kfree(header);
2018                 return NULL;
2019         }
2020 #endif
2021         spin_lock(&sysctl_lock);
2022         header->set = lookup_header_set(root, namespaces);
2023         header->attached_by = header->ctl_table;
2024         header->attached_to = root_table;
2025         header->parent = &root_table_header;
2026         for (set = header->set; set; set = set->parent) {
2027                 struct ctl_table_header *p;
2028                 list_for_each_entry(p, &set->list, ctl_entry) {
2029                         if (p->unregistering)
2030                                 continue;
2031                         try_attach(p, header);
2032                 }
2033         }
2034         header->parent->count++;
2035         list_add_tail(&header->ctl_entry, &header->set->list);
2036         spin_unlock(&sysctl_lock);
2037
2038         return header;
2039 }
2040
2041 /**
2042  * register_sysctl_table_path - register a sysctl table hierarchy
2043  * @path: The path to the directory the sysctl table is in.
2044  * @table: the top-level table structure
2045  *
2046  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2047  * array. A completely 0 filled entry terminates the table.
2048  *
2049  * See __register_sysctl_paths for more details.
2050  */
2051 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2052                                                 struct ctl_table *table)
2053 {
2054         return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2055                                         path, table);
2056 }
2057
2058 /**
2059  * register_sysctl_table - register a sysctl table hierarchy
2060  * @table: the top-level table structure
2061  *
2062  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2063  * array. A completely 0 filled entry terminates the table.
2064  *
2065  * See register_sysctl_paths for more details.
2066  */
2067 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2068 {
2069         static const struct ctl_path null_path[] = { {} };
2070
2071         return register_sysctl_paths(null_path, table);
2072 }
2073
2074 /**
2075  * unregister_sysctl_table - unregister a sysctl table hierarchy
2076  * @header: the header returned from register_sysctl_table
2077  *
2078  * Unregisters the sysctl table and all children. proc entries may not
2079  * actually be removed until they are no longer used by anyone.
2080  */
2081 void unregister_sysctl_table(struct ctl_table_header * header)
2082 {
2083         might_sleep();
2084
2085         if (header == NULL)
2086                 return;
2087
2088         spin_lock(&sysctl_lock);
2089         start_unregistering(header);
2090         if (!--header->parent->count) {
2091                 WARN_ON(1);
2092                 kfree(header->parent);
2093         }
2094         if (!--header->count)
2095                 kfree(header);
2096         spin_unlock(&sysctl_lock);
2097 }
2098
2099 int sysctl_is_seen(struct ctl_table_header *p)
2100 {
2101         struct ctl_table_set *set = p->set;
2102         int res;
2103         spin_lock(&sysctl_lock);
2104         if (p->unregistering)
2105                 res = 0;
2106         else if (!set->is_seen)
2107                 res = 1;
2108         else
2109                 res = set->is_seen(set);
2110         spin_unlock(&sysctl_lock);
2111         return res;
2112 }
2113
2114 void setup_sysctl_set(struct ctl_table_set *p,
2115         struct ctl_table_set *parent,
2116         int (*is_seen)(struct ctl_table_set *))
2117 {
2118         INIT_LIST_HEAD(&p->list);
2119         p->parent = parent ? parent : &sysctl_table_root.default_set;
2120         p->is_seen = is_seen;
2121 }
2122
2123 #else /* !CONFIG_SYSCTL */
2124 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2125 {
2126         return NULL;
2127 }
2128
2129 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2130                                                     struct ctl_table *table)
2131 {
2132         return NULL;
2133 }
2134
2135 void unregister_sysctl_table(struct ctl_table_header * table)
2136 {
2137 }
2138
2139 void setup_sysctl_set(struct ctl_table_set *p,
2140         struct ctl_table_set *parent,
2141         int (*is_seen)(struct ctl_table_set *))
2142 {
2143 }
2144
2145 void sysctl_head_put(struct ctl_table_header *head)
2146 {
2147 }
2148
2149 #endif /* CONFIG_SYSCTL */
2150
2151 /*
2152  * /proc/sys support
2153  */
2154
2155 #ifdef CONFIG_PROC_SYSCTL
2156
2157 static int _proc_do_string(void* data, int maxlen, int write,
2158                            struct file *filp, void __user *buffer,
2159                            size_t *lenp, loff_t *ppos)
2160 {
2161         size_t len;
2162         char __user *p;
2163         char c;
2164
2165         if (!data || !maxlen || !*lenp) {
2166                 *lenp = 0;
2167                 return 0;
2168         }
2169
2170         if (write) {
2171                 len = 0;
2172                 p = buffer;
2173                 while (len < *lenp) {
2174                         if (get_user(c, p++))
2175                                 return -EFAULT;
2176                         if (c == 0 || c == '\n')
2177                                 break;
2178                         len++;
2179                 }
2180                 if (len >= maxlen)
2181                         len = maxlen-1;
2182                 if(copy_from_user(data, buffer, len))
2183                         return -EFAULT;
2184                 ((char *) data)[len] = 0;
2185                 *ppos += *lenp;
2186         } else {
2187                 len = strlen(data);
2188                 if (len > maxlen)
2189                         len = maxlen;
2190
2191                 if (*ppos > len) {
2192                         *lenp = 0;
2193                         return 0;
2194                 }
2195
2196                 data += *ppos;
2197                 len  -= *ppos;
2198
2199                 if (len > *lenp)
2200                         len = *lenp;
2201                 if (len)
2202                         if(copy_to_user(buffer, data, len))
2203                                 return -EFAULT;
2204                 if (len < *lenp) {
2205                         if(put_user('\n', ((char __user *) buffer) + len))
2206                                 return -EFAULT;
2207                         len++;
2208                 }
2209                 *lenp = len;
2210                 *ppos += len;
2211         }
2212         return 0;
2213 }
2214
2215 /**
2216  * proc_dostring - read a string sysctl
2217  * @table: the sysctl table
2218  * @write: %TRUE if this is a write to the sysctl file
2219  * @filp: the file structure
2220  * @buffer: the user buffer
2221  * @lenp: the size of the user buffer
2222  * @ppos: file position
2223  *
2224  * Reads/writes a string from/to the user buffer. If the kernel
2225  * buffer provided is not large enough to hold the string, the
2226  * string is truncated. The copied string is %NULL-terminated.
2227  * If the string is being read by the user process, it is copied
2228  * and a newline '\n' is added. It is truncated if the buffer is
2229  * not large enough.
2230  *
2231  * Returns 0 on success.
2232  */
2233 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2234                   void __user *buffer, size_t *lenp, loff_t *ppos)
2235 {
2236         return _proc_do_string(table->data, table->maxlen, write, filp,
2237                                buffer, lenp, ppos);
2238 }
2239
2240
2241 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2242                                  int *valp,
2243                                  int write, void *data)
2244 {
2245         if (write) {
2246                 *valp = *negp ? -*lvalp : *lvalp;
2247         } else {
2248                 int val = *valp;
2249                 if (val < 0) {
2250                         *negp = -1;
2251                         *lvalp = (unsigned long)-val;
2252                 } else {
2253                         *negp = 0;
2254                         *lvalp = (unsigned long)val;
2255                 }
2256         }
2257         return 0;
2258 }
2259
2260 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2261                   int write, struct file *filp, void __user *buffer,
2262                   size_t *lenp, loff_t *ppos,
2263                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2264                               int write, void *data),
2265                   void *data)
2266 {
2267 #define TMPBUFLEN 21
2268         int *i, vleft, first=1, neg, val;
2269         unsigned long lval;
2270         size_t left, len;
2271
2272         char buf[TMPBUFLEN], *p;
2273         char __user *s = buffer;
2274
2275         if (!tbl_data || !table->maxlen || !*lenp ||
2276             (*ppos && !write)) {
2277                 *lenp = 0;
2278                 return 0;
2279         }
2280
2281         i = (int *) tbl_data;
2282         vleft = table->maxlen / sizeof(*i);
2283         left = *lenp;
2284
2285         if (!conv)
2286                 conv = do_proc_dointvec_conv;
2287
2288         for (; left && vleft--; i++, first=0) {
2289                 if (write) {
2290                         while (left) {
2291                                 char c;
2292                                 if (get_user(c, s))
2293                                         return -EFAULT;
2294                                 if (!isspace(c))
2295                                         break;
2296                                 left--;
2297                                 s++;
2298                         }
2299                         if (!left)
2300                                 break;
2301                         neg = 0;
2302                         len = left;
2303                         if (len > sizeof(buf) - 1)
2304                                 len = sizeof(buf) - 1;
2305                         if (copy_from_user(buf, s, len))
2306                                 return -EFAULT;
2307                         buf[len] = 0;
2308                         p = buf;
2309                         if (*p == '-' && left > 1) {
2310                                 neg = 1;
2311                                 p++;
2312                         }
2313                         if (*p < '0' || *p > '9')
2314                                 break;
2315
2316                         lval = simple_strtoul(p, &p, 0);
2317
2318                         len = p-buf;
2319                         if ((len < left) && *p && !isspace(*p))
2320                                 break;
2321                         if (neg)
2322                                 val = -val;
2323                         s += len;
2324                         left -= len;
2325
2326                         if (conv(&neg, &lval, i, 1, data))
2327                                 break;
2328                 } else {
2329                         p = buf;
2330                         if (!first)
2331                                 *p++ = '\t';
2332
2333                         if (conv(&neg, &lval, i, 0, data))
2334                                 break;
2335
2336                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
2337                         len = strlen(buf);
2338                         if (len > left)
2339                                 len = left;
2340                         if(copy_to_user(s, buf, len))
2341                                 return -EFAULT;
2342                         left -= len;
2343                         s += len;
2344                 }
2345         }
2346
2347         if (!write && !first && left) {
2348                 if(put_user('\n', s))
2349                         return -EFAULT;
2350                 left--, s++;
2351         }
2352         if (write) {
2353                 while (left) {
2354                         char c;
2355                         if (get_user(c, s++))
2356                                 return -EFAULT;
2357                         if (!isspace(c))
2358                                 break;
2359                         left--;
2360                 }
2361         }
2362         if (write && first)
2363                 return -EINVAL;
2364         *lenp -= left;
2365         *ppos += *lenp;
2366         return 0;
2367 #undef TMPBUFLEN
2368 }
2369
2370 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2371                   void __user *buffer, size_t *lenp, loff_t *ppos,
2372                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2373                               int write, void *data),
2374                   void *data)
2375 {
2376         return __do_proc_dointvec(table->data, table, write, filp,
2377                         buffer, lenp, ppos, conv, data);
2378 }
2379
2380 /**
2381  * proc_dointvec - read a vector of integers
2382  * @table: the sysctl table
2383  * @write: %TRUE if this is a write to the sysctl file
2384  * @filp: the file structure
2385  * @buffer: the user buffer
2386  * @lenp: the size of the user buffer
2387  * @ppos: file position
2388  *
2389  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2390  * values from/to the user buffer, treated as an ASCII string.
2391  *
2392  * Returns 0 on success.
2393  */
2394 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2395                      void __user *buffer, size_t *lenp, loff_t *ppos)
2396 {
2397     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2398                             NULL,NULL);
2399 }
2400
2401 /*
2402  * Taint values can only be increased
2403  * This means we can safely use a temporary.
2404  */
2405 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2406                                void __user *buffer, size_t *lenp, loff_t *ppos)
2407 {
2408         struct ctl_table t;
2409         unsigned long tmptaint = get_taint();
2410         int err;
2411
2412         if (write && !capable(CAP_SYS_ADMIN))
2413                 return -EPERM;
2414
2415         t = *table;
2416         t.data = &tmptaint;
2417         err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2418         if (err < 0)
2419                 return err;
2420
2421         if (write) {
2422                 /*
2423                  * Poor man's atomic or. Not worth adding a primitive
2424                  * to everyone's atomic.h for this
2425                  */
2426                 int i;
2427                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2428                         if ((tmptaint >> i) & 1)
2429                                 add_taint(i);
2430                 }
2431         }
2432
2433         return err;
2434 }
2435
2436 struct do_proc_dointvec_minmax_conv_param {
2437         int *min;
2438         int *max;
2439 };
2440
2441 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2442                                         int *valp,
2443                                         int write, void *data)
2444 {
2445         struct do_proc_dointvec_minmax_conv_param *param = data;
2446         if (write) {
2447                 int val = *negp ? -*lvalp : *lvalp;
2448                 if ((param->min && *param->min > val) ||
2449                     (param->max && *param->max < val))
2450                         return -EINVAL;
2451                 *valp = val;
2452         } else {
2453                 int val = *valp;
2454                 if (val < 0) {
2455                         *negp = -1;
2456                         *lvalp = (unsigned long)-val;
2457                 } else {
2458                         *negp = 0;
2459                         *lvalp = (unsigned long)val;
2460                 }
2461         }
2462         return 0;
2463 }
2464
2465 /**
2466  * proc_dointvec_minmax - read a vector of integers with min/max values
2467  * @table: the sysctl table
2468  * @write: %TRUE if this is a write to the sysctl file
2469  * @filp: the file structure
2470  * @buffer: the user buffer
2471  * @lenp: the size of the user buffer
2472  * @ppos: file position
2473  *
2474  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2475  * values from/to the user buffer, treated as an ASCII string.
2476  *
2477  * This routine will ensure the values are within the range specified by
2478  * table->extra1 (min) and table->extra2 (max).
2479  *
2480  * Returns 0 on success.
2481  */
2482 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2483                   void __user *buffer, size_t *lenp, loff_t *ppos)
2484 {
2485         struct do_proc_dointvec_minmax_conv_param param = {
2486                 .min = (int *) table->extra1,
2487                 .max = (int *) table->extra2,
2488         };
2489         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2490                                 do_proc_dointvec_minmax_conv, &param);
2491 }
2492
2493 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2494                                      struct file *filp,
2495                                      void __user *buffer,
2496                                      size_t *lenp, loff_t *ppos,
2497                                      unsigned long convmul,
2498                                      unsigned long convdiv)
2499 {
2500 #define TMPBUFLEN 21
2501         unsigned long *i, *min, *max, val;
2502         int vleft, first=1, neg;
2503         size_t len, left;
2504         char buf[TMPBUFLEN], *p;
2505         char __user *s = buffer;
2506
2507         if (!data || !table->maxlen || !*lenp ||
2508             (*ppos && !write)) {
2509                 *lenp = 0;
2510                 return 0;
2511         }
2512
2513         i = (unsigned long *) data;
2514         min = (unsigned long *) table->extra1;
2515         max = (unsigned long *) table->extra2;
2516         vleft = table->maxlen / sizeof(unsigned long);
2517         left = *lenp;
2518
2519         for (; left && vleft--; i++, min++, max++, first=0) {
2520                 if (write) {
2521                         while (left) {
2522                                 char c;
2523                                 if (get_user(c, s))
2524                                         return -EFAULT;
2525                                 if (!isspace(c))
2526                                         break;
2527                                 left--;
2528                                 s++;
2529                         }
2530                         if (!left)
2531                                 break;
2532                         neg = 0;
2533                         len = left;
2534                         if (len > TMPBUFLEN-1)
2535                                 len = TMPBUFLEN-1;
2536                         if (copy_from_user(buf, s, len))
2537                                 return -EFAULT;
2538                         buf[len] = 0;
2539                         p = buf;
2540                         if (*p == '-' && left > 1) {
2541                                 neg = 1;
2542                                 p++;
2543                         }
2544                         if (*p < '0' || *p > '9')
2545                                 break;
2546                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2547                         len = p-buf;
2548                         if ((len < left) && *p && !isspace(*p))
2549                                 break;
2550                         if (neg)
2551                                 val = -val;
2552                         s += len;
2553                         left -= len;
2554
2555                         if(neg)
2556                                 continue;
2557                         if ((min && val < *min) || (max && val > *max))
2558                                 continue;
2559                         *i = val;
2560                 } else {
2561                         p = buf;
2562                         if (!first)
2563                                 *p++ = '\t';
2564                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2565                         len = strlen(buf);
2566                         if (len > left)
2567                                 len = left;
2568                         if(copy_to_user(s, buf, len))
2569                                 return -EFAULT;
2570                         left -= len;
2571                         s += len;
2572                 }
2573         }
2574
2575         if (!write && !first && left) {
2576                 if(put_user('\n', s))
2577                         return -EFAULT;
2578                 left--, s++;
2579         }
2580         if (write) {
2581                 while (left) {
2582                         char c;
2583                         if (get_user(c, s++))
2584                                 return -EFAULT;
2585                         if (!isspace(c))
2586                                 break;
2587                         left--;
2588                 }
2589         }
2590         if (write && first)
2591                 return -EINVAL;
2592         *lenp -= left;
2593         *ppos += *lenp;
2594         return 0;
2595 #undef TMPBUFLEN
2596 }
2597
2598 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2599                                      struct file *filp,
2600                                      void __user *buffer,
2601                                      size_t *lenp, loff_t *ppos,
2602                                      unsigned long convmul,
2603                                      unsigned long convdiv)
2604 {
2605         return __do_proc_doulongvec_minmax(table->data, table, write,
2606                         filp, buffer, lenp, ppos, convmul, convdiv);
2607 }
2608
2609 /**
2610  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2611  * @table: the sysctl table
2612  * @write: %TRUE if this is a write to the sysctl file
2613  * @filp: the file structure
2614  * @buffer: the user buffer
2615  * @lenp: the size of the user buffer
2616  * @ppos: file position
2617  *
2618  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2619  * values from/to the user buffer, treated as an ASCII string.
2620  *
2621  * This routine will ensure the values are within the range specified by
2622  * table->extra1 (min) and table->extra2 (max).
2623  *
2624  * Returns 0 on success.
2625  */
2626 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2627                            void __user *buffer, size_t *lenp, loff_t *ppos)
2628 {
2629     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2630 }
2631
2632 /**
2633  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2634  * @table: the sysctl table
2635  * @write: %TRUE if this is a write to the sysctl file
2636  * @filp: the file structure
2637  * @buffer: the user buffer
2638  * @lenp: the size of the user buffer
2639  * @ppos: file position
2640  *
2641  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2642  * values from/to the user buffer, treated as an ASCII string. The values
2643  * are treated as milliseconds, and converted to jiffies when they are stored.
2644  *
2645  * This routine will ensure the values are within the range specified by
2646  * table->extra1 (min) and table->extra2 (max).
2647  *
2648  * Returns 0 on success.
2649  */
2650 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2651                                       struct file *filp,
2652                                       void __user *buffer,
2653                                       size_t *lenp, loff_t *ppos)
2654 {
2655     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2656                                      lenp, ppos, HZ, 1000l);
2657 }
2658
2659
2660 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2661                                          int *valp,
2662                                          int write, void *data)
2663 {
2664         if (write) {
2665                 if (*lvalp > LONG_MAX / HZ)
2666                         return 1;
2667                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2668         } else {
2669                 int val = *valp;
2670                 unsigned long lval;
2671                 if (val < 0) {
2672                         *negp = -1;
2673                         lval = (unsigned long)-val;
2674                 } else {
2675                         *negp = 0;
2676                         lval = (unsigned long)val;
2677                 }
2678                 *lvalp = lval / HZ;
2679         }
2680         return 0;
2681 }
2682
2683 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2684                                                 int *valp,
2685                                                 int write, void *data)
2686 {
2687         if (write) {
2688                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2689                         return 1;
2690                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2691         } else {
2692                 int val = *valp;
2693                 unsigned long lval;
2694                 if (val < 0) {
2695                         *negp = -1;
2696                         lval = (unsigned long)-val;
2697                 } else {
2698                         *negp = 0;
2699                         lval = (unsigned long)val;
2700                 }
2701                 *lvalp = jiffies_to_clock_t(lval);
2702         }
2703         return 0;
2704 }
2705
2706 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2707                                             int *valp,
2708                                             int write, void *data)
2709 {
2710         if (write) {
2711                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2712         } else {
2713                 int val = *valp;
2714                 unsigned long lval;
2715                 if (val < 0) {
2716                         *negp = -1;
2717                         lval = (unsigned long)-val;
2718                 } else {
2719                         *negp = 0;
2720                         lval = (unsigned long)val;
2721                 }
2722                 *lvalp = jiffies_to_msecs(lval);
2723         }
2724         return 0;
2725 }
2726
2727 /**
2728  * proc_dointvec_jiffies - read a vector of integers as seconds
2729  * @table: the sysctl table
2730  * @write: %TRUE if this is a write to the sysctl file
2731  * @filp: the file structure
2732  * @buffer: the user buffer
2733  * @lenp: the size of the user buffer
2734  * @ppos: file position
2735  *
2736  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2737  * values from/to the user buffer, treated as an ASCII string.
2738  * The values read are assumed to be in seconds, and are converted into
2739  * jiffies.
2740  *
2741  * Returns 0 on success.
2742  */
2743 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2744                           void __user *buffer, size_t *lenp, loff_t *ppos)
2745 {
2746     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2747                             do_proc_dointvec_jiffies_conv,NULL);
2748 }
2749
2750 /**
2751  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2752  * @table: the sysctl table
2753  * @write: %TRUE if this is a write to the sysctl file
2754  * @filp: the file structure
2755  * @buffer: the user buffer
2756  * @lenp: the size of the user buffer
2757  * @ppos: pointer to the file position
2758  *
2759  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2760  * values from/to the user buffer, treated as an ASCII string.
2761  * The values read are assumed to be in 1/USER_HZ seconds, and
2762  * are converted into jiffies.
2763  *
2764  * Returns 0 on success.
2765  */
2766 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2767                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2768 {
2769     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2770                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2771 }
2772
2773 /**
2774  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2775  * @table: the sysctl table
2776  * @write: %TRUE if this is a write to the sysctl file
2777  * @filp: the file structure
2778  * @buffer: the user buffer
2779  * @lenp: the size of the user buffer
2780  * @ppos: file position
2781  * @ppos: the current position in the file
2782  *
2783  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2784  * values from/to the user buffer, treated as an ASCII string.
2785  * The values read are assumed to be in 1/1000 seconds, and
2786  * are converted into jiffies.
2787  *
2788  * Returns 0 on success.
2789  */
2790 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2791                              void __user *buffer, size_t *lenp, loff_t *ppos)
2792 {
2793         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2794                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2795 }
2796
2797 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2798                            void __user *buffer, size_t *lenp, loff_t *ppos)
2799 {
2800         struct pid *new_pid;
2801         pid_t tmp;
2802         int r;
2803
2804         tmp = pid_vnr(cad_pid);
2805
2806         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2807                                lenp, ppos, NULL, NULL);
2808         if (r || !write)
2809                 return r;
2810
2811         new_pid = find_get_pid(tmp);
2812         if (!new_pid)
2813                 return -ESRCH;
2814
2815         put_pid(xchg(&cad_pid, new_pid));
2816         return 0;
2817 }
2818
2819 #else /* CONFIG_PROC_FS */
2820
2821 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2822                   void __user *buffer, size_t *lenp, loff_t *ppos)
2823 {
2824         return -ENOSYS;
2825 }
2826
2827 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2828                   void __user *buffer, size_t *lenp, loff_t *ppos)
2829 {
2830         return -ENOSYS;
2831 }
2832
2833 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2834                     void __user *buffer, size_t *lenp, loff_t *ppos)
2835 {
2836         return -ENOSYS;
2837 }
2838
2839 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2840                     void __user *buffer, size_t *lenp, loff_t *ppos)
2841 {
2842         return -ENOSYS;
2843 }
2844
2845 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2846                     void __user *buffer, size_t *lenp, loff_t *ppos)
2847 {
2848         return -ENOSYS;
2849 }
2850
2851 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2852                              void __user *buffer, size_t *lenp, loff_t *ppos)
2853 {
2854         return -ENOSYS;
2855 }
2856
2857 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2858                     void __user *buffer, size_t *lenp, loff_t *ppos)
2859 {
2860         return -ENOSYS;
2861 }
2862
2863 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2864                                       struct file *filp,
2865                                       void __user *buffer,
2866                                       size_t *lenp, loff_t *ppos)
2867 {
2868     return -ENOSYS;
2869 }
2870
2871
2872 #endif /* CONFIG_PROC_FS */
2873
2874
2875 #ifdef CONFIG_SYSCTL_SYSCALL
2876 /*
2877  * General sysctl support routines
2878  */
2879
2880 /* The generic sysctl data routine (used if no strategy routine supplied) */
2881 int sysctl_data(struct ctl_table *table,
2882                 void __user *oldval, size_t __user *oldlenp,
2883                 void __user *newval, size_t newlen)
2884 {
2885         size_t len;
2886
2887         /* Get out of I don't have a variable */
2888         if (!table->data || !table->maxlen)
2889                 return -ENOTDIR;
2890
2891         if (oldval && oldlenp) {
2892                 if (get_user(len, oldlenp))
2893                         return -EFAULT;
2894                 if (len) {
2895                         if (len > table->maxlen)
2896                                 len = table->maxlen;
2897                         if (copy_to_user(oldval, table->data, len))
2898                                 return -EFAULT;
2899                         if (put_user(len, oldlenp))
2900                                 return -EFAULT;
2901                 }
2902         }
2903
2904         if (newval && newlen) {
2905                 if (newlen > table->maxlen)
2906                         newlen = table->maxlen;
2907
2908                 if (copy_from_user(table->data, newval, newlen))
2909                         return -EFAULT;
2910         }
2911         return 1;
2912 }
2913
2914 /* The generic string strategy routine: */
2915 int sysctl_string(struct ctl_table *table,
2916                   void __user *oldval, size_t __user *oldlenp,
2917                   void __user *newval, size_t newlen)
2918 {
2919         if (!table->data || !table->maxlen)
2920                 return -ENOTDIR;
2921
2922         if (oldval && oldlenp) {
2923                 size_t bufsize;
2924                 if (get_user(bufsize, oldlenp))
2925                         return -EFAULT;
2926                 if (bufsize) {
2927                         size_t len = strlen(table->data), copied;
2928
2929                         /* This shouldn't trigger for a well-formed sysctl */
2930                         if (len > table->maxlen)
2931                                 len = table->maxlen;
2932
2933                         /* Copy up to a max of bufsize-1 bytes of the string */
2934                         copied = (len >= bufsize) ? bufsize - 1 : len;
2935
2936                         if (copy_to_user(oldval, table->data, copied) ||
2937                             put_user(0, (char __user *)(oldval + copied)))
2938                                 return -EFAULT;
2939                         if (put_user(len, oldlenp))
2940                                 return -EFAULT;
2941                 }
2942         }
2943         if (newval && newlen) {
2944                 size_t len = newlen;
2945                 if (len > table->maxlen)
2946                         len = table->maxlen;
2947                 if(copy_from_user(table->data, newval, len))
2948                         return -EFAULT;
2949                 if (len == table->maxlen)
2950                         len--;
2951                 ((char *) table->data)[len] = 0;
2952         }
2953         return 1;
2954 }
2955
2956 /*
2957  * This function makes sure that all of the integers in the vector
2958  * are between the minimum and maximum values given in the arrays
2959  * table->extra1 and table->extra2, respectively.
2960  */
2961 int sysctl_intvec(struct ctl_table *table,
2962                 void __user *oldval, size_t __user *oldlenp,
2963                 void __user *newval, size_t newlen)
2964 {
2965
2966         if (newval && newlen) {
2967                 int __user *vec = (int __user *) newval;
2968                 int *min = (int *) table->extra1;
2969                 int *max = (int *) table->extra2;
2970                 size_t length;
2971                 int i;
2972
2973                 if (newlen % sizeof(int) != 0)
2974                         return -EINVAL;
2975
2976                 if (!table->extra1 && !table->extra2)
2977                         return 0;
2978
2979                 if (newlen > table->maxlen)
2980                         newlen = table->maxlen;
2981                 length = newlen / sizeof(int);
2982
2983                 for (i = 0; i < length; i++) {
2984                         int value;
2985                         if (get_user(value, vec + i))
2986                                 return -EFAULT;
2987                         if (min && value < min[i])
2988                                 return -EINVAL;
2989                         if (max && value > max[i])
2990                                 return -EINVAL;
2991                 }
2992         }
2993         return 0;
2994 }
2995
2996 /* Strategy function to convert jiffies to seconds */
2997 int sysctl_jiffies(struct ctl_table *table,
2998                 void __user *oldval, size_t __user *oldlenp,
2999                 void __user *newval, size_t newlen)
3000 {
3001         if (oldval && oldlenp) {
3002                 size_t olen;
3003
3004                 if (get_user(olen, oldlenp))
3005                         return -EFAULT;
3006                 if (olen) {
3007                         int val;
3008
3009                         if (olen < sizeof(int))
3010                                 return -EINVAL;
3011
3012                         val = *(int *)(table->data) / HZ;
3013                         if (put_user(val, (int __user *)oldval))
3014                                 return -EFAULT;
3015                         if (put_user(sizeof(int), oldlenp))
3016                                 return -EFAULT;
3017                 }
3018         }
3019         if (newval && newlen) {
3020                 int new;
3021                 if (newlen != sizeof(int))
3022                         return -EINVAL;
3023                 if (get_user(new, (int __user *)newval))
3024                         return -EFAULT;
3025                 *(int *)(table->data) = new*HZ;
3026         }
3027         return 1;
3028 }
3029
3030 /* Strategy function to convert jiffies to seconds */
3031 int sysctl_ms_jiffies(struct ctl_table *table,
3032                 void __user *oldval, size_t __user *oldlenp,
3033                 void __user *newval, size_t newlen)
3034 {
3035         if (oldval && oldlenp) {
3036                 size_t olen;
3037
3038                 if (get_user(olen, oldlenp))
3039                         return -EFAULT;
3040                 if (olen) {
3041                         int val;
3042
3043                         if (olen < sizeof(int))
3044                                 return -EINVAL;
3045
3046                         val = jiffies_to_msecs(*(int *)(table->data));
3047                         if (put_user(val, (int __user *)oldval))
3048                                 return -EFAULT;
3049                         if (put_user(sizeof(int), oldlenp))
3050                                 return -EFAULT;
3051                 }
3052         }
3053         if (newval && newlen) {
3054                 int new;
3055                 if (newlen != sizeof(int))
3056                         return -EINVAL;
3057                 if (get_user(new, (int __user *)newval))
3058                         return -EFAULT;
3059                 *(int *)(table->data) = msecs_to_jiffies(new);
3060         }
3061         return 1;
3062 }
3063
3064
3065
3066 #else /* CONFIG_SYSCTL_SYSCALL */
3067
3068
3069 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3070 {
3071         struct __sysctl_args tmp;
3072         int error;
3073
3074         if (copy_from_user(&tmp, args, sizeof(tmp)))
3075                 return -EFAULT;
3076
3077         error = deprecated_sysctl_warning(&tmp);
3078
3079         /* If no error reading the parameters then just -ENOSYS ... */
3080         if (!error)
3081                 error = -ENOSYS;
3082
3083         return error;
3084 }
3085
3086 int sysctl_data(struct ctl_table *table,
3087                   void __user *oldval, size_t __user *oldlenp,
3088                   void __user *newval, size_t newlen)
3089 {
3090         return -ENOSYS;
3091 }
3092
3093 int sysctl_string(struct ctl_table *table,
3094                   void __user *oldval, size_t __user *oldlenp,
3095                   void __user *newval, size_t newlen)
3096 {
3097         return -ENOSYS;
3098 }
3099
3100 int sysctl_intvec(struct ctl_table *table,
3101                 void __user *oldval, size_t __user *oldlenp,
3102                 void __user *newval, size_t newlen)
3103 {
3104         return -ENOSYS;
3105 }
3106
3107 int sysctl_jiffies(struct ctl_table *table,
3108                 void __user *oldval, size_t __user *oldlenp,
3109                 void __user *newval, size_t newlen)
3110 {
3111         return -ENOSYS;
3112 }
3113
3114 int sysctl_ms_jiffies(struct ctl_table *table,
3115                 void __user *oldval, size_t __user *oldlenp,
3116                 void __user *newval, size_t newlen)
3117 {
3118         return -ENOSYS;
3119 }
3120
3121 #endif /* CONFIG_SYSCTL_SYSCALL */
3122
3123 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3124 {
3125         static int msg_count;
3126         int name[CTL_MAXNAME];
3127         int i;
3128
3129         /* Check args->nlen. */
3130         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3131                 return -ENOTDIR;
3132
3133         /* Read in the sysctl name for better debug message logging */
3134         for (i = 0; i < args->nlen; i++)
3135                 if (get_user(name[i], args->name + i))
3136                         return -EFAULT;
3137
3138         /* Ignore accesses to kernel.version */
3139         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3140                 return 0;
3141
3142         if (msg_count < 5) {
3143                 msg_count++;
3144                 printk(KERN_INFO
3145                         "warning: process `%s' used the deprecated sysctl "
3146                         "system call with ", current->comm);
3147                 for (i = 0; i < args->nlen; i++)
3148                         printk("%d.", name[i]);
3149                 printk("\n");
3150         }
3151         return 0;
3152 }
3153
3154 /*
3155  * No sense putting this after each symbol definition, twice,
3156  * exception granted :-)
3157  */
3158 EXPORT_SYMBOL(proc_dointvec);
3159 EXPORT_SYMBOL(proc_dointvec_jiffies);
3160 EXPORT_SYMBOL(proc_dointvec_minmax);
3161 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3162 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3163 EXPORT_SYMBOL(proc_dostring);
3164 EXPORT_SYMBOL(proc_doulongvec_minmax);
3165 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3166 EXPORT_SYMBOL(register_sysctl_table);
3167 EXPORT_SYMBOL(register_sysctl_paths);
3168 EXPORT_SYMBOL(sysctl_intvec);
3169 EXPORT_SYMBOL(sysctl_jiffies);
3170 EXPORT_SYMBOL(sysctl_ms_jiffies);
3171 EXPORT_SYMBOL(sysctl_string);
3172 EXPORT_SYMBOL(sysctl_data);
3173 EXPORT_SYMBOL(unregister_sysctl_table);