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