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/aio.h>
  23 #include <linux/mm.h>
  24 #include <linux/swap.h>
  25 #include <linux/slab.h>
  26 #include <linux/sysctl.h>
  27 #include <linux/bitmap.h>
  28 #include <linux/signal.h>
  29 #include <linux/printk.h>
  30 #include <linux/proc_fs.h>
  31 #include <linux/security.h>
  32 #include <linux/ctype.h>
  33 #include <linux/kmemcheck.h>
  34 #include <linux/kmemleak.h>
  35 #include <linux/fs.h>
  36 #include <linux/init.h>
  37 #include <linux/kernel.h>
  38 #include <linux/kobject.h>
  39 #include <linux/net.h>
  40 #include <linux/sysrq.h>
  41 #include <linux/highuid.h>
  42 #include <linux/writeback.h>
  43 #include <linux/ratelimit.h>
  44 #include <linux/compaction.h>
  45 #include <linux/hugetlb.h>
  46 #include <linux/initrd.h>
  47 #include <linux/key.h>
  48 #include <linux/times.h>
  49 #include <linux/limits.h>
  50 #include <linux/dcache.h>
  51 #include <linux/dnotify.h>
  52 #include <linux/syscalls.h>
  53 #include <linux/vmstat.h>
  54 #include <linux/nfs_fs.h>
  55 #include <linux/acpi.h>
  56 #include <linux/reboot.h>
  57 #include <linux/ftrace.h>
  58 #include <linux/perf_event.h>
  59 #include <linux/kprobes.h>
  60 #include <linux/pipe_fs_i.h>
  61 #include <linux/oom.h>
  62 #include <linux/kmod.h>
  63 #include <linux/capability.h>
  64 #include <linux/binfmts.h>
  65 #include <linux/sched/sysctl.h>
  66 #include <linux/kexec.h>
  67 #include <linux/bpf.h>
  68
  69 #include <asm/uaccess.h>
  70 #include <asm/processor.h>
  71
  72 #ifdef CONFIG_X86
  73 #include <asm/nmi.h>
  74 #include <asm/stacktrace.h>
  75 #include <asm/io.h>
  76 #endif
  77 #ifdef CONFIG_SPARC
  78 #include <asm/setup.h>
  79 #endif
  80 #ifdef CONFIG_BSD_PROCESS_ACCT
  81 #include <linux/acct.h>
  82 #endif
  83 #ifdef CONFIG_RT_MUTEXES
  84 #include <linux/rtmutex.h>
  85 #endif
  86 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
  87 #include <linux/lockdep.h>
  88 #endif
  89 #ifdef CONFIG_CHR_DEV_SG
  90 #include <scsi/sg.h>
  91 #endif
  92
  93 #ifdef CONFIG_LOCKUP_DETECTOR
  94 #include <linux/nmi.h>
  95 #endif
  96
  97 #if defined(CONFIG_SYSCTL)
  98
  99 /* External variables not in a header file. */
 100 extern int suid_dumpable;
 101 #ifdef CONFIG_COREDUMP
 102 extern int core_uses_pid;
 103 extern char core_pattern[];
 104 extern unsigned int core_pipe_limit;
 105 #endif
 106 extern int pid_max;
 107 extern int pid_max_min, pid_max_max;
 108 extern int percpu_pagelist_fraction;
 109 extern int compat_log;
 110 extern int latencytop_enabled;
 111 extern int sysctl_nr_open_min, sysctl_nr_open_max;
 112 #ifndef CONFIG_MMU
 113 extern int sysctl_nr_trim_pages;
 114 #endif
 115
 116 /* Constants used for minimum and  maximum */
 117 #ifdef CONFIG_LOCKUP_DETECTOR
 118 static int sixty = 60;
 119 #endif
 120
 121 static int __maybe_unused neg_one = -1;
 122
 123 static int zero;
 124 static int __maybe_unused one = 1;
 125 static int __maybe_unused two = 2;
 126 static int __maybe_unused four = 4;
 127 static unsigned long one_ul = 1;
 128 static int one_hundred = 100;
 129 #ifdef CONFIG_PRINTK
 130 static int ten_thousand = 10000;
 131 #endif
 132
 133 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
 134 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
 135
 136 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
 137 static int maxolduid = 65535;
 138 static int minolduid;
 139
 140 static int ngroups_max = NGROUPS_MAX;
 141 static const int cap_last_cap = CAP_LAST_CAP;
 142
 143 /*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */
 144 #ifdef CONFIG_DETECT_HUNG_TASK
 145 static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
 146 #endif
 147
 148 #ifdef CONFIG_INOTIFY_USER
 149 #include <linux/inotify.h>
 150 #endif
 151 #ifdef CONFIG_SPARC
 152 #endif
 153
 154 #ifdef __hppa__
 155 extern int pwrsw_enabled;
 156 #endif
 157
 158 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
 159 extern int unaligned_enabled;
 160 #endif
 161
 162 #ifdef CONFIG_IA64
 163 extern int unaligned_dump_stack;
 164 #endif
 165
 166 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
 167 extern int no_unaligned_warning;
 168 #endif
 169
 170 #ifdef CONFIG_PROC_SYSCTL
 171
 172 #define SYSCTL_WRITES_LEGACY    -1
 173 #define SYSCTL_WRITES_WARN       0
 174 #define SYSCTL_WRITES_STRICT     1
 175
 176 static int sysctl_writes_strict = SYSCTL_WRITES_STRICT;
 177
 178 static int proc_do_cad_pid(struct ctl_table *table, int write,
 179                   void __user *buffer, size_t *lenp, loff_t *ppos);
 180 static int proc_taint(struct ctl_table *table, int write,
 181                                void __user *buffer, size_t *lenp, loff_t *ppos);
 182 #endif
 183
 184 #ifdef CONFIG_PRINTK
 185 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
 186                                 void __user *buffer, size_t *lenp, loff_t *ppos);
 187 #endif
 188
 189 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
 190                 void __user *buffer, size_t *lenp, loff_t *ppos);
 191 #ifdef CONFIG_COREDUMP
 192 static int proc_dostring_coredump(struct ctl_table *table, int write,
 193                 void __user *buffer, size_t *lenp, loff_t *ppos);
 194 #endif
 195
 196 #ifdef CONFIG_MAGIC_SYSRQ
 197 /* Note: sysrq code uses it's own private copy */
 198 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
 199
 200 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
 201                                 void __user *buffer, size_t *lenp,
 202                                 loff_t *ppos)
 203 {
 204         int error;
 205
 206         error = proc_dointvec(table, write, buffer, lenp, ppos);
 207         if (error)
 208                 return error;
 209
 210         if (write)
 211                 sysrq_toggle_support(__sysrq_enabled);
 212
 213         return 0;
 214 }
 215
 216 #endif
 217
 218 static struct ctl_table kern_table[];
 219 static struct ctl_table vm_table[];
 220 static struct ctl_table fs_table[];
 221 static struct ctl_table debug_table[];
 222 static struct ctl_table dev_table[];
 223 extern struct ctl_table random_table[];
 224 #ifdef CONFIG_EPOLL
 225 extern struct ctl_table epoll_table[];
 226 #endif
 227
 228 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
 229 int sysctl_legacy_va_layout;
 230 #endif
 231
 232 /* The default sysctl tables: */
 233
 234 static struct ctl_table sysctl_base_table[] = {
 235         {
 236                 .procname       = "kernel",
 237                 .mode           = 0555,
 238                 .child          = kern_table,
 239         },
 240         {
 241                 .procname       = "vm",
 242                 .mode           = 0555,
 243                 .child          = vm_table,
 244         },
 245         {
 246                 .procname       = "fs",
 247                 .mode           = 0555,
 248                 .child          = fs_table,
 249         },
 250         {
 251                 .procname       = "debug",
 252                 .mode           = 0555,
 253                 .child          = debug_table,
 254         },
 255         {
 256                 .procname       = "dev",
 257                 .mode           = 0555,
 258                 .child          = dev_table,
 259         },
 260         { }
 261 };
 262
 263 #ifdef CONFIG_SCHED_DEBUG
 264 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
 265 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
 266 static int min_wakeup_granularity_ns;                   /* 0 usecs */
 267 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
 268 #ifdef CONFIG_SMP
 269 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
 270 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
 271 #endif /* CONFIG_SMP */
 272 #endif /* CONFIG_SCHED_DEBUG */
 273
 274 #ifdef CONFIG_COMPACTION
 275 static int min_extfrag_threshold;
 276 static int max_extfrag_threshold = 1000;
 277 #endif
 278
 279 static struct ctl_table kern_table[] = {
 280         {
 281                 .procname       = "sched_child_runs_first",
 282                 .data           = &sysctl_sched_child_runs_first,
 283                 .maxlen         = sizeof(unsigned int),
 284                 .mode           = 0644,
 285                 .proc_handler   = proc_dointvec,
 286         },
 287 #ifdef CONFIG_SCHED_DEBUG
 288         {
 289                 .procname       = "sched_min_granularity_ns",
 290                 .data           = &sysctl_sched_min_granularity,
 291                 .maxlen         = sizeof(unsigned int),
 292                 .mode           = 0644,
 293                 .proc_handler   = sched_proc_update_handler,
 294                 .extra1         = &min_sched_granularity_ns,
 295                 .extra2         = &max_sched_granularity_ns,
 296         },
 297         {
 298                 .procname       = "sched_latency_ns",
 299                 .data           = &sysctl_sched_latency,
 300                 .maxlen         = sizeof(unsigned int),
 301                 .mode           = 0644,
 302                 .proc_handler   = sched_proc_update_handler,
 303                 .extra1         = &min_sched_granularity_ns,
 304                 .extra2         = &max_sched_granularity_ns,
 305         },
 306         {
 307                 .procname       = "sched_wakeup_granularity_ns",
 308                 .data           = &sysctl_sched_wakeup_granularity,
 309                 .maxlen         = sizeof(unsigned int),
 310                 .mode           = 0644,
 311                 .proc_handler   = sched_proc_update_handler,
 312                 .extra1         = &min_wakeup_granularity_ns,
 313                 .extra2         = &max_wakeup_granularity_ns,
 314         },
 315 #ifdef CONFIG_SMP
 316         {
 317                 .procname       = "sched_tunable_scaling",
 318                 .data           = &sysctl_sched_tunable_scaling,
 319                 .maxlen         = sizeof(enum sched_tunable_scaling),
 320                 .mode           = 0644,
 321                 .proc_handler   = sched_proc_update_handler,
 322                 .extra1         = &min_sched_tunable_scaling,
 323                 .extra2         = &max_sched_tunable_scaling,
 324         },
 325         {
 326                 .procname       = "sched_migration_cost_ns",
 327                 .data           = &sysctl_sched_migration_cost,
 328                 .maxlen         = sizeof(unsigned int),
 329                 .mode           = 0644,
 330                 .proc_handler   = proc_dointvec,
 331         },
 332         {
 333                 .procname       = "sched_nr_migrate",
 334                 .data           = &sysctl_sched_nr_migrate,
 335                 .maxlen         = sizeof(unsigned int),
 336                 .mode           = 0644,
 337                 .proc_handler   = proc_dointvec,
 338         },
 339         {
 340                 .procname       = "sched_time_avg_ms",
 341                 .data           = &sysctl_sched_time_avg,
 342                 .maxlen         = sizeof(unsigned int),
 343                 .mode           = 0644,
 344                 .proc_handler   = proc_dointvec,
 345         },
 346         {
 347                 .procname       = "sched_shares_window_ns",
 348                 .data           = &sysctl_sched_shares_window,
 349                 .maxlen         = sizeof(unsigned int),
 350                 .mode           = 0644,
 351                 .proc_handler   = proc_dointvec,
 352         },
 353 #ifdef CONFIG_SCHEDSTATS
 354         {
 355                 .procname       = "sched_schedstats",
 356                 .data           = NULL,
 357                 .maxlen         = sizeof(unsigned int),
 358                 .mode           = 0644,
 359                 .proc_handler   = sysctl_schedstats,
 360                 .extra1         = &zero,
 361                 .extra2         = &one,
 362         },
 363 #endif /* CONFIG_SCHEDSTATS */
 364 #endif /* CONFIG_SMP */
 365 #ifdef CONFIG_NUMA_BALANCING
 366         {
 367                 .procname       = "numa_balancing_scan_delay_ms",
 368                 .data           = &sysctl_numa_balancing_scan_delay,
 369                 .maxlen         = sizeof(unsigned int),
 370                 .mode           = 0644,
 371                 .proc_handler   = proc_dointvec,
 372         },
 373         {
 374                 .procname       = "numa_balancing_scan_period_min_ms",
 375                 .data           = &sysctl_numa_balancing_scan_period_min,
 376                 .maxlen         = sizeof(unsigned int),
 377                 .mode           = 0644,
 378                 .proc_handler   = proc_dointvec,
 379         },
 380         {
 381                 .procname       = "numa_balancing_scan_period_max_ms",
 382                 .data           = &sysctl_numa_balancing_scan_period_max,
 383                 .maxlen         = sizeof(unsigned int),
 384                 .mode           = 0644,
 385                 .proc_handler   = proc_dointvec,
 386         },
 387         {
 388                 .procname       = "numa_balancing_scan_size_mb",
 389                 .data           = &sysctl_numa_balancing_scan_size,
 390                 .maxlen         = sizeof(unsigned int),
 391                 .mode           = 0644,
 392                 .proc_handler   = proc_dointvec_minmax,
 393                 .extra1         = &one,
 394         },
 395         {
 396                 .procname       = "numa_balancing",
 397                 .data           = NULL, /* filled in by handler */
 398                 .maxlen         = sizeof(unsigned int),
 399                 .mode           = 0644,
 400                 .proc_handler   = sysctl_numa_balancing,
 401                 .extra1         = &zero,
 402                 .extra2         = &one,
 403         },
 404 #endif /* CONFIG_NUMA_BALANCING */
 405 #endif /* CONFIG_SCHED_DEBUG */
 406         {
 407                 .procname       = "sched_rt_period_us",
 408                 .data           = &sysctl_sched_rt_period,
 409                 .maxlen         = sizeof(unsigned int),
 410                 .mode           = 0644,
 411                 .proc_handler   = sched_rt_handler,
 412         },
 413         {
 414                 .procname       = "sched_rt_runtime_us",
 415                 .data           = &sysctl_sched_rt_runtime,
 416                 .maxlen         = sizeof(int),
 417                 .mode           = 0644,
 418                 .proc_handler   = sched_rt_handler,
 419         },
 420         {
 421                 .procname       = "sched_rr_timeslice_ms",
 422                 .data           = &sched_rr_timeslice,
 423                 .maxlen         = sizeof(int),
 424                 .mode           = 0644,
 425                 .proc_handler   = sched_rr_handler,
 426         },
 427 #ifdef CONFIG_SCHED_AUTOGROUP
 428         {
 429                 .procname       = "sched_autogroup_enabled",
 430                 .data           = &sysctl_sched_autogroup_enabled,
 431                 .maxlen         = sizeof(unsigned int),
 432                 .mode           = 0644,
 433                 .proc_handler   = proc_dointvec_minmax,
 434                 .extra1         = &zero,
 435                 .extra2         = &one,
 436         },
 437 #endif
 438 #ifdef CONFIG_CFS_BANDWIDTH
 439         {
 440                 .procname       = "sched_cfs_bandwidth_slice_us",
 441                 .data           = &sysctl_sched_cfs_bandwidth_slice,
 442                 .maxlen         = sizeof(unsigned int),
 443                 .mode           = 0644,
 444                 .proc_handler   = proc_dointvec_minmax,
 445                 .extra1         = &one,
 446         },
 447 #endif
 448 #ifdef CONFIG_PROVE_LOCKING
 449         {
 450                 .procname       = "prove_locking",
 451                 .data           = &prove_locking,
 452                 .maxlen         = sizeof(int),
 453                 .mode           = 0644,
 454                 .proc_handler   = proc_dointvec,
 455         },
 456 #endif
 457 #ifdef CONFIG_LOCK_STAT
 458         {
 459                 .procname       = "lock_stat",
 460                 .data           = &lock_stat,
 461                 .maxlen         = sizeof(int),
 462                 .mode           = 0644,
 463                 .proc_handler   = proc_dointvec,
 464         },
 465 #endif
 466         {
 467                 .procname       = "panic",
 468                 .data           = &panic_timeout,
 469                 .maxlen         = sizeof(int),
 470                 .mode           = 0644,
 471                 .proc_handler   = proc_dointvec,
 472         },
 473 #ifdef CONFIG_COREDUMP
 474         {
 475                 .procname       = "core_uses_pid",
 476                 .data           = &core_uses_pid,
 477                 .maxlen         = sizeof(int),
 478                 .mode           = 0644,
 479                 .proc_handler   = proc_dointvec,
 480         },
 481         {
 482                 .procname       = "core_pattern",
 483                 .data           = core_pattern,
 484                 .maxlen         = CORENAME_MAX_SIZE,
 485                 .mode           = 0644,
 486                 .proc_handler   = proc_dostring_coredump,
 487         },
 488         {
 489                 .procname       = "core_pipe_limit",
 490                 .data           = &core_pipe_limit,
 491                 .maxlen         = sizeof(unsigned int),
 492                 .mode           = 0644,
 493                 .proc_handler   = proc_dointvec,
 494         },
 495 #endif
 496 #ifdef CONFIG_PROC_SYSCTL
 497         {
 498                 .procname       = "tainted",
 499                 .maxlen         = sizeof(long),
 500                 .mode           = 0644,
 501                 .proc_handler   = proc_taint,
 502         },
 503         {
 504                 .procname       = "sysctl_writes_strict",
 505                 .data           = &sysctl_writes_strict,
 506                 .maxlen         = sizeof(int),
 507                 .mode           = 0644,
 508                 .proc_handler   = proc_dointvec_minmax,
 509                 .extra1         = &neg_one,
 510                 .extra2         = &one,
 511         },
 512 #endif
 513 #ifdef CONFIG_LATENCYTOP
 514         {
 515                 .procname       = "latencytop",
 516                 .data           = &latencytop_enabled,
 517                 .maxlen         = sizeof(int),
 518                 .mode           = 0644,
 519                 .proc_handler   = sysctl_latencytop,
 520         },
 521 #endif
 522 #ifdef CONFIG_BLK_DEV_INITRD
 523         {
 524                 .procname       = "real-root-dev",
 525                 .data           = &real_root_dev,
 526                 .maxlen         = sizeof(int),
 527                 .mode           = 0644,
 528                 .proc_handler   = proc_dointvec,
 529         },
 530 #endif
 531         {
 532                 .procname       = "print-fatal-signals",
 533                 .data           = &print_fatal_signals,
 534                 .maxlen         = sizeof(int),
 535                 .mode           = 0644,
 536                 .proc_handler   = proc_dointvec,
 537         },
 538 #ifdef CONFIG_SPARC
 539         {
 540                 .procname       = "reboot-cmd",
 541                 .data           = reboot_command,
 542                 .maxlen         = 256,
 543                 .mode           = 0644,
 544                 .proc_handler   = proc_dostring,
 545         },
 546         {
 547                 .procname       = "stop-a",
 548                 .data           = &stop_a_enabled,
 549                 .maxlen         = sizeof (int),
 550                 .mode           = 0644,
 551                 .proc_handler   = proc_dointvec,
 552         },
 553         {
 554                 .procname       = "scons-poweroff",
 555                 .data           = &scons_pwroff,
 556                 .maxlen         = sizeof (int),
 557                 .mode           = 0644,
 558                 .proc_handler   = proc_dointvec,
 559         },
 560 #endif
 561 #ifdef CONFIG_SPARC64
 562         {
 563                 .procname       = "tsb-ratio",
 564                 .data           = &sysctl_tsb_ratio,
 565                 .maxlen         = sizeof (int),
 566                 .mode           = 0644,
 567                 .proc_handler   = proc_dointvec,
 568         },
 569 #endif
 570 #ifdef __hppa__
 571         {
 572                 .procname       = "soft-power",
 573                 .data           = &pwrsw_enabled,
 574                 .maxlen         = sizeof (int),
 575                 .mode           = 0644,
 576                 .proc_handler   = proc_dointvec,
 577         },
 578 #endif
 579 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
 580         {
 581                 .procname       = "unaligned-trap",
 582                 .data           = &unaligned_enabled,
 583                 .maxlen         = sizeof (int),
 584                 .mode           = 0644,
 585                 .proc_handler   = proc_dointvec,
 586         },
 587 #endif
 588         {
 589                 .procname       = "ctrl-alt-del",
 590                 .data           = &C_A_D,
 591                 .maxlen         = sizeof(int),
 592                 .mode           = 0644,
 593                 .proc_handler   = proc_dointvec,
 594         },
 595 #ifdef CONFIG_FUNCTION_TRACER
 596         {
 597                 .procname       = "ftrace_enabled",
 598                 .data           = &ftrace_enabled,
 599                 .maxlen         = sizeof(int),
 600                 .mode           = 0644,
 601                 .proc_handler   = ftrace_enable_sysctl,
 602         },
 603 #endif
 604 #ifdef CONFIG_STACK_TRACER
 605         {
 606                 .procname       = "stack_tracer_enabled",
 607                 .data           = &stack_tracer_enabled,
 608                 .maxlen         = sizeof(int),
 609                 .mode           = 0644,
 610                 .proc_handler   = stack_trace_sysctl,
 611         },
 612 #endif
 613 #ifdef CONFIG_TRACING
 614         {
 615                 .procname       = "ftrace_dump_on_oops",
 616                 .data           = &ftrace_dump_on_oops,
 617                 .maxlen         = sizeof(int),
 618                 .mode           = 0644,
 619                 .proc_handler   = proc_dointvec,
 620         },
 621         {
 622                 .procname       = "traceoff_on_warning",
 623                 .data           = &__disable_trace_on_warning,
 624                 .maxlen         = sizeof(__disable_trace_on_warning),
 625                 .mode           = 0644,
 626                 .proc_handler   = proc_dointvec,
 627         },
 628         {
 629                 .procname       = "tracepoint_printk",
 630                 .data           = &tracepoint_printk,
 631                 .maxlen         = sizeof(tracepoint_printk),
 632                 .mode           = 0644,
 633                 .proc_handler   = proc_dointvec,
 634         },
 635 #endif
 636 #ifdef CONFIG_KEXEC_CORE
 637         {
 638                 .procname       = "kexec_load_disabled",
 639                 .data           = &kexec_load_disabled,
 640                 .maxlen         = sizeof(int),
 641                 .mode           = 0644,
 642                 /* only handle a transition from default "0" to "1" */
 643                 .proc_handler   = proc_dointvec_minmax,
 644                 .extra1         = &one,
 645                 .extra2         = &one,
 646         },
 647 #endif
 648 #ifdef CONFIG_MODULES
 649         {
 650                 .procname       = "modprobe",
 651                 .data           = &modprobe_path,
 652                 .maxlen         = KMOD_PATH_LEN,
 653                 .mode           = 0644,
 654                 .proc_handler   = proc_dostring,
 655         },
 656         {
 657                 .procname       = "modules_disabled",
 658                 .data           = &modules_disabled,
 659                 .maxlen         = sizeof(int),
 660                 .mode           = 0644,
 661                 /* only handle a transition from default "0" to "1" */
 662                 .proc_handler   = proc_dointvec_minmax,
 663                 .extra1         = &one,
 664                 .extra2         = &one,
 665         },
 666 #endif
 667 #ifdef CONFIG_UEVENT_HELPER
 668         {
 669                 .procname       = "hotplug",
 670                 .data           = &uevent_helper,
 671                 .maxlen         = UEVENT_HELPER_PATH_LEN,
 672                 .mode           = 0644,
 673                 .proc_handler   = proc_dostring,
 674         },
 675 #endif
 676 #ifdef CONFIG_CHR_DEV_SG
 677         {
 678                 .procname       = "sg-big-buff",
 679                 .data           = &sg_big_buff,
 680                 .maxlen         = sizeof (int),
 681                 .mode           = 0444,
 682                 .proc_handler   = proc_dointvec,
 683         },
 684 #endif
 685 #ifdef CONFIG_BSD_PROCESS_ACCT
 686         {
 687                 .procname       = "acct",
 688                 .data           = &acct_parm,
 689                 .maxlen         = 3*sizeof(int),
 690                 .mode           = 0644,
 691                 .proc_handler   = proc_dointvec,
 692         },
 693 #endif
 694 #ifdef CONFIG_MAGIC_SYSRQ
 695         {
 696                 .procname       = "sysrq",
 697                 .data           = &__sysrq_enabled,
 698                 .maxlen         = sizeof (int),
 699                 .mode           = 0644,
 700                 .proc_handler   = sysrq_sysctl_handler,
 701         },
 702 #endif
 703 #ifdef CONFIG_PROC_SYSCTL
 704         {
 705                 .procname       = "cad_pid",
 706                 .data           = NULL,
 707                 .maxlen         = sizeof (int),
 708                 .mode           = 0600,
 709                 .proc_handler   = proc_do_cad_pid,
 710         },
 711 #endif
 712         {
 713                 .procname       = "threads-max",
 714                 .data           = NULL,
 715                 .maxlen         = sizeof(int),
 716                 .mode           = 0644,
 717                 .proc_handler   = sysctl_max_threads,
 718         },
 719         {
 720                 .procname       = "random",
 721                 .mode           = 0555,
 722                 .child          = random_table,
 723         },
 724         {
 725                 .procname       = "usermodehelper",
 726                 .mode           = 0555,
 727                 .child          = usermodehelper_table,
 728         },
 729         {
 730                 .procname       = "overflowuid",
 731                 .data           = &overflowuid,
 732                 .maxlen         = sizeof(int),
 733                 .mode           = 0644,
 734                 .proc_handler   = proc_dointvec_minmax,
 735                 .extra1         = &minolduid,
 736                 .extra2         = &maxolduid,
 737         },
 738         {
 739                 .procname       = "overflowgid",
 740                 .data           = &overflowgid,
 741                 .maxlen         = sizeof(int),
 742                 .mode           = 0644,
 743                 .proc_handler   = proc_dointvec_minmax,
 744                 .extra1         = &minolduid,
 745                 .extra2         = &maxolduid,
 746         },
 747 #ifdef CONFIG_S390
 748 #ifdef CONFIG_MATHEMU
 749         {
 750                 .procname       = "ieee_emulation_warnings",
 751                 .data           = &sysctl_ieee_emulation_warnings,
 752                 .maxlen         = sizeof(int),
 753                 .mode           = 0644,
 754                 .proc_handler   = proc_dointvec,
 755         },
 756 #endif
 757         {
 758                 .procname       = "userprocess_debug",
 759                 .data           = &show_unhandled_signals,
 760                 .maxlen         = sizeof(int),
 761                 .mode           = 0644,
 762                 .proc_handler   = proc_dointvec,
 763         },
 764 #endif
 765         {
 766                 .procname       = "pid_max",
 767                 .data           = &pid_max,
 768                 .maxlen         = sizeof (int),
 769                 .mode           = 0644,
 770                 .proc_handler   = proc_dointvec_minmax,
 771                 .extra1         = &pid_max_min,
 772                 .extra2         = &pid_max_max,
 773         },
 774         {
 775                 .procname       = "panic_on_oops",
 776                 .data           = &panic_on_oops,
 777                 .maxlen         = sizeof(int),
 778                 .mode           = 0644,
 779                 .proc_handler   = proc_dointvec,
 780         },
 781 #if defined CONFIG_PRINTK
 782         {
 783                 .procname       = "printk",
 784                 .data           = &console_loglevel,
 785                 .maxlen         = 4*sizeof(int),
 786                 .mode           = 0644,
 787                 .proc_handler   = proc_dointvec,
 788         },
 789         {
 790                 .procname       = "printk_ratelimit",
 791                 .data           = &printk_ratelimit_state.interval,
 792                 .maxlen         = sizeof(int),
 793                 .mode           = 0644,
 794                 .proc_handler   = proc_dointvec_jiffies,
 795         },
 796         {
 797                 .procname       = "printk_ratelimit_burst",
 798                 .data           = &printk_ratelimit_state.burst,
 799                 .maxlen         = sizeof(int),
 800                 .mode           = 0644,
 801                 .proc_handler   = proc_dointvec,
 802         },
 803         {
 804                 .procname       = "printk_delay",
 805                 .data           = &printk_delay_msec,
 806                 .maxlen         = sizeof(int),
 807                 .mode           = 0644,
 808                 .proc_handler   = proc_dointvec_minmax,
 809                 .extra1         = &zero,
 810                 .extra2         = &ten_thousand,
 811         },
 812         {
 813                 .procname       = "dmesg_restrict",
 814                 .data           = &dmesg_restrict,
 815                 .maxlen         = sizeof(int),
 816                 .mode           = 0644,
 817                 .proc_handler   = proc_dointvec_minmax_sysadmin,
 818                 .extra1         = &zero,
 819                 .extra2         = &one,
 820         },
 821         {
 822                 .procname       = "kptr_restrict",
 823                 .data           = &kptr_restrict,
 824                 .maxlen         = sizeof(int),
 825                 .mode           = 0644,
 826                 .proc_handler   = proc_dointvec_minmax_sysadmin,
 827                 .extra1         = &zero,
 828                 .extra2         = &two,
 829         },
 830 #endif
 831         {
 832                 .procname       = "ngroups_max",
 833                 .data           = &ngroups_max,
 834                 .maxlen         = sizeof (int),
 835                 .mode           = 0444,
 836                 .proc_handler   = proc_dointvec,
 837         },
 838         {
 839                 .procname       = "cap_last_cap",
 840                 .data           = (void *)&cap_last_cap,
 841                 .maxlen         = sizeof(int),
 842                 .mode           = 0444,
 843                 .proc_handler   = proc_dointvec,
 844         },
 845 #if defined(CONFIG_LOCKUP_DETECTOR)
 846         {
 847                 .procname       = "watchdog",
 848                 .data           = &watchdog_user_enabled,
 849                 .maxlen         = sizeof (int),
 850                 .mode           = 0644,
 851                 .proc_handler   = proc_watchdog,
 852                 .extra1         = &zero,
 853                 .extra2         = &one,
 854         },
 855         {
 856                 .procname       = "watchdog_thresh",
 857                 .data           = &watchdog_thresh,
 858                 .maxlen         = sizeof(int),
 859                 .mode           = 0644,
 860                 .proc_handler   = proc_watchdog_thresh,
 861                 .extra1         = &zero,
 862                 .extra2         = &sixty,
 863         },
 864         {
 865                 .procname       = "nmi_watchdog",
 866                 .data           = &nmi_watchdog_enabled,
 867                 .maxlen         = sizeof (int),
 868                 .mode           = 0644,
 869                 .proc_handler   = proc_nmi_watchdog,
 870                 .extra1         = &zero,
 871 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
 872                 .extra2         = &one,
 873 #else
 874                 .extra2         = &zero,
 875 #endif
 876         },
 877         {
 878                 .procname       = "soft_watchdog",
 879                 .data           = &soft_watchdog_enabled,
 880                 .maxlen         = sizeof (int),
 881                 .mode           = 0644,
 882                 .proc_handler   = proc_soft_watchdog,
 883                 .extra1         = &zero,
 884                 .extra2         = &one,
 885         },
 886         {
 887                 .procname       = "watchdog_cpumask",
 888                 .data           = &watchdog_cpumask_bits,
 889                 .maxlen         = NR_CPUS,
 890                 .mode           = 0644,
 891                 .proc_handler   = proc_watchdog_cpumask,
 892         },
 893         {
 894                 .procname       = "softlockup_panic",
 895                 .data           = &softlockup_panic,
 896                 .maxlen         = sizeof(int),
 897                 .mode           = 0644,
 898                 .proc_handler   = proc_dointvec_minmax,
 899                 .extra1         = &zero,
 900                 .extra2         = &one,
 901         },
 902 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 903         {
 904                 .procname       = "hardlockup_panic",
 905                 .data           = &hardlockup_panic,
 906                 .maxlen         = sizeof(int),
 907                 .mode           = 0644,
 908                 .proc_handler   = proc_dointvec_minmax,
 909                 .extra1         = &zero,
 910                 .extra2         = &one,
 911         },
 912 #endif
 913 #ifdef CONFIG_SMP
 914         {
 915                 .procname       = "softlockup_all_cpu_backtrace",
 916                 .data           = &sysctl_softlockup_all_cpu_backtrace,
 917                 .maxlen         = sizeof(int),
 918                 .mode           = 0644,
 919                 .proc_handler   = proc_dointvec_minmax,
 920                 .extra1         = &zero,
 921                 .extra2         = &one,
 922         },
 923         {
 924                 .procname       = "hardlockup_all_cpu_backtrace",
 925                 .data           = &sysctl_hardlockup_all_cpu_backtrace,
 926                 .maxlen         = sizeof(int),
 927                 .mode           = 0644,
 928                 .proc_handler   = proc_dointvec_minmax,
 929                 .extra1         = &zero,
 930                 .extra2         = &one,
 931         },
 932 #endif /* CONFIG_SMP */
 933 #endif
 934 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
 935         {
 936                 .procname       = "unknown_nmi_panic",
 937                 .data           = &unknown_nmi_panic,
 938                 .maxlen         = sizeof (int),
 939                 .mode           = 0644,
 940                 .proc_handler   = proc_dointvec,
 941         },
 942 #endif
 943 #if defined(CONFIG_X86)
 944         {
 945                 .procname       = "panic_on_unrecovered_nmi",
 946                 .data           = &panic_on_unrecovered_nmi,
 947                 .maxlen         = sizeof(int),
 948                 .mode           = 0644,
 949                 .proc_handler   = proc_dointvec,
 950         },
 951         {
 952                 .procname       = "panic_on_io_nmi",
 953                 .data           = &panic_on_io_nmi,
 954                 .maxlen         = sizeof(int),
 955                 .mode           = 0644,
 956                 .proc_handler   = proc_dointvec,
 957         },
 958 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 959         {
 960                 .procname       = "panic_on_stackoverflow",
 961                 .data           = &sysctl_panic_on_stackoverflow,
 962                 .maxlen         = sizeof(int),
 963                 .mode           = 0644,
 964                 .proc_handler   = proc_dointvec,
 965         },
 966 #endif
 967         {
 968                 .procname       = "bootloader_type",
 969                 .data           = &bootloader_type,
 970                 .maxlen         = sizeof (int),
 971                 .mode           = 0444,
 972                 .proc_handler   = proc_dointvec,
 973         },
 974         {
 975                 .procname       = "bootloader_version",
 976                 .data           = &bootloader_version,
 977                 .maxlen         = sizeof (int),
 978                 .mode           = 0444,
 979                 .proc_handler   = proc_dointvec,
 980         },
 981         {
 982                 .procname       = "kstack_depth_to_print",
 983                 .data           = &kstack_depth_to_print,
 984                 .maxlen         = sizeof(int),
 985                 .mode           = 0644,
 986                 .proc_handler   = proc_dointvec,
 987         },
 988         {
 989                 .procname       = "io_delay_type",
 990                 .data           = &io_delay_type,
 991                 .maxlen         = sizeof(int),
 992                 .mode           = 0644,
 993                 .proc_handler   = proc_dointvec,
 994         },
 995 #endif
 996 #if defined(CONFIG_MMU)
 997         {
 998                 .procname       = "randomize_va_space",
 999                 .data           = &randomize_va_space,
1000                 .maxlen         = sizeof(int),
1001                 .mode           = 0644,
1002                 .proc_handler   = proc_dointvec,
1003         },
1004 #endif
1005 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1006         {
1007                 .procname       = "spin_retry",
1008                 .data           = &spin_retry,
1009                 .maxlen         = sizeof (int),
1010                 .mode           = 0644,
1011                 .proc_handler   = proc_dointvec,
1012         },
1013 #endif
1014 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1015         {
1016                 .procname       = "acpi_video_flags",
1017                 .data           = &acpi_realmode_flags,
1018                 .maxlen         = sizeof (unsigned long),
1019                 .mode           = 0644,
1020                 .proc_handler   = proc_doulongvec_minmax,
1021         },
1022 #endif
1023 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1024         {
1025                 .procname       = "ignore-unaligned-usertrap",
1026                 .data           = &no_unaligned_warning,
1027                 .maxlen         = sizeof (int),
1028                 .mode           = 0644,
1029                 .proc_handler   = proc_dointvec,
1030         },
1031 #endif
1032 #ifdef CONFIG_IA64
1033         {
1034                 .procname       = "unaligned-dump-stack",
1035                 .data           = &unaligned_dump_stack,
1036                 .maxlen         = sizeof (int),
1037                 .mode           = 0644,
1038                 .proc_handler   = proc_dointvec,
1039         },
1040 #endif
1041 #ifdef CONFIG_DETECT_HUNG_TASK
1042         {
1043                 .procname       = "hung_task_panic",
1044                 .data           = &sysctl_hung_task_panic,
1045                 .maxlen         = sizeof(int),
1046                 .mode           = 0644,
1047                 .proc_handler   = proc_dointvec_minmax,
1048                 .extra1         = &zero,
1049                 .extra2         = &one,
1050         },
1051         {
1052                 .procname       = "hung_task_check_count",
1053                 .data           = &sysctl_hung_task_check_count,
1054                 .maxlen         = sizeof(int),
1055                 .mode           = 0644,
1056                 .proc_handler   = proc_dointvec_minmax,
1057                 .extra1         = &zero,
1058         },
1059         {
1060                 .procname       = "hung_task_timeout_secs",
1061                 .data           = &sysctl_hung_task_timeout_secs,
1062                 .maxlen         = sizeof(unsigned long),
1063                 .mode           = 0644,
1064                 .proc_handler   = proc_dohung_task_timeout_secs,
1065                 .extra2         = &hung_task_timeout_max,
1066         },
1067         {
1068                 .procname       = "hung_task_warnings",
1069                 .data           = &sysctl_hung_task_warnings,
1070                 .maxlen         = sizeof(int),
1071                 .mode           = 0644,
1072                 .proc_handler   = proc_dointvec_minmax,
1073                 .extra1         = &neg_one,
1074         },
1075 #endif
1076 #ifdef CONFIG_COMPAT
1077         {
1078                 .procname       = "compat-log",
1079                 .data           = &compat_log,
1080                 .maxlen         = sizeof (int),
1081                 .mode           = 0644,
1082                 .proc_handler   = proc_dointvec,
1083         },
1084 #endif
1085 #ifdef CONFIG_RT_MUTEXES
1086         {
1087                 .procname       = "max_lock_depth",
1088                 .data           = &max_lock_depth,
1089                 .maxlen         = sizeof(int),
1090                 .mode           = 0644,
1091                 .proc_handler   = proc_dointvec,
1092         },
1093 #endif
1094         {
1095                 .procname       = "poweroff_cmd",
1096                 .data           = &poweroff_cmd,
1097                 .maxlen         = POWEROFF_CMD_PATH_LEN,
1098                 .mode           = 0644,
1099                 .proc_handler   = proc_dostring,
1100         },
1101 #ifdef CONFIG_KEYS
1102         {
1103                 .procname       = "keys",
1104                 .mode           = 0555,
1105                 .child          = key_sysctls,
1106         },
1107 #endif
1108 #ifdef CONFIG_PERF_EVENTS
1109         /*
1110          * User-space scripts rely on the existence of this file
1111          * as a feature check for perf_events being enabled.
1112          *
1113          * So it's an ABI, do not remove!
1114          */
1115         {
1116                 .procname       = "perf_event_paranoid",
1117                 .data           = &sysctl_perf_event_paranoid,
1118                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
1119                 .mode           = 0644,
1120                 .proc_handler   = proc_dointvec,
1121         },
1122         {
1123                 .procname       = "perf_event_mlock_kb",
1124                 .data           = &sysctl_perf_event_mlock,
1125                 .maxlen         = sizeof(sysctl_perf_event_mlock),
1126                 .mode           = 0644,
1127                 .proc_handler   = proc_dointvec,
1128         },
1129         {
1130                 .procname       = "perf_event_max_sample_rate",
1131                 .data           = &sysctl_perf_event_sample_rate,
1132                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
1133                 .mode           = 0644,
1134                 .proc_handler   = perf_proc_update_handler,
1135                 .extra1         = &one,
1136         },
1137         {
1138                 .procname       = "perf_cpu_time_max_percent",
1139                 .data           = &sysctl_perf_cpu_time_max_percent,
1140                 .maxlen         = sizeof(sysctl_perf_cpu_time_max_percent),
1141                 .mode           = 0644,
1142                 .proc_handler   = perf_cpu_time_max_percent_handler,
1143                 .extra1         = &zero,
1144                 .extra2         = &one_hundred,
1145         },
1146 #endif
1147 #ifdef CONFIG_KMEMCHECK
1148         {
1149                 .procname       = "kmemcheck",
1150                 .data           = &kmemcheck_enabled,
1151                 .maxlen         = sizeof(int),
1152                 .mode           = 0644,
1153                 .proc_handler   = proc_dointvec,
1154         },
1155 #endif
1156         {
1157                 .procname       = "panic_on_warn",
1158                 .data           = &panic_on_warn,
1159                 .maxlen         = sizeof(int),
1160                 .mode           = 0644,
1161                 .proc_handler   = proc_dointvec_minmax,
1162                 .extra1         = &zero,
1163                 .extra2         = &one,
1164         },
1165 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1166         {
1167                 .procname       = "timer_migration",
1168                 .data           = &sysctl_timer_migration,
1169                 .maxlen         = sizeof(unsigned int),
1170                 .mode           = 0644,
1171                 .proc_handler   = timer_migration_handler,
1172         },
1173 #endif
1174 #ifdef CONFIG_BPF_SYSCALL
1175         {
1176                 .procname       = "unprivileged_bpf_disabled",
1177                 .data           = &sysctl_unprivileged_bpf_disabled,
1178                 .maxlen         = sizeof(sysctl_unprivileged_bpf_disabled),
1179                 .mode           = 0644,
1180                 /* only handle a transition from default "0" to "1" */
1181                 .proc_handler   = proc_dointvec_minmax,
1182                 .extra1         = &one,
1183                 .extra2         = &one,
1184         },
1185 #endif
1186         { }
1187 };
1188
1189 static struct ctl_table vm_table[] = {
1190         {
1191                 .procname       = "overcommit_memory",
1192                 .data           = &sysctl_overcommit_memory,
1193                 .maxlen         = sizeof(sysctl_overcommit_memory),
1194                 .mode           = 0644,
1195                 .proc_handler   = proc_dointvec_minmax,
1196                 .extra1         = &zero,
1197                 .extra2         = &two,
1198         },
1199         {
1200                 .procname       = "panic_on_oom",
1201                 .data           = &sysctl_panic_on_oom,
1202                 .maxlen         = sizeof(sysctl_panic_on_oom),
1203                 .mode           = 0644,
1204                 .proc_handler   = proc_dointvec_minmax,
1205                 .extra1         = &zero,
1206                 .extra2         = &two,
1207         },
1208         {
1209                 .procname       = "oom_kill_allocating_task",
1210                 .data           = &sysctl_oom_kill_allocating_task,
1211                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1212                 .mode           = 0644,
1213                 .proc_handler   = proc_dointvec,
1214         },
1215         {
1216                 .procname       = "oom_dump_tasks",
1217                 .data           = &sysctl_oom_dump_tasks,
1218                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1219                 .mode           = 0644,
1220                 .proc_handler   = proc_dointvec,
1221         },
1222         {
1223                 .procname       = "overcommit_ratio",
1224                 .data           = &sysctl_overcommit_ratio,
1225                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1226                 .mode           = 0644,
1227                 .proc_handler   = overcommit_ratio_handler,
1228         },
1229         {
1230                 .procname       = "overcommit_kbytes",
1231                 .data           = &sysctl_overcommit_kbytes,
1232                 .maxlen         = sizeof(sysctl_overcommit_kbytes),
1233                 .mode           = 0644,
1234                 .proc_handler   = overcommit_kbytes_handler,
1235         },
1236         {
1237                 .procname       = "page-cluster",
1238                 .data           = &page_cluster,
1239                 .maxlen         = sizeof(int),
1240                 .mode           = 0644,
1241                 .proc_handler   = proc_dointvec_minmax,
1242                 .extra1         = &zero,
1243         },
1244         {
1245                 .procname       = "dirty_background_ratio",
1246                 .data           = &dirty_background_ratio,
1247                 .maxlen         = sizeof(dirty_background_ratio),
1248                 .mode           = 0644,
1249                 .proc_handler   = dirty_background_ratio_handler,
1250                 .extra1         = &zero,
1251                 .extra2         = &one_hundred,
1252         },
1253         {
1254                 .procname       = "dirty_background_bytes",
1255                 .data           = &dirty_background_bytes,
1256                 .maxlen         = sizeof(dirty_background_bytes),
1257                 .mode           = 0644,
1258                 .proc_handler   = dirty_background_bytes_handler,
1259                 .extra1         = &one_ul,
1260         },
1261         {
1262                 .procname       = "dirty_ratio",
1263                 .data           = &vm_dirty_ratio,
1264                 .maxlen         = sizeof(vm_dirty_ratio),
1265                 .mode           = 0644,
1266                 .proc_handler   = dirty_ratio_handler,
1267                 .extra1         = &zero,
1268                 .extra2         = &one_hundred,
1269         },
1270         {
1271                 .procname       = "dirty_bytes",
1272                 .data           = &vm_dirty_bytes,
1273                 .maxlen         = sizeof(vm_dirty_bytes),
1274                 .mode           = 0644,
1275                 .proc_handler   = dirty_bytes_handler,
1276                 .extra1         = &dirty_bytes_min,
1277         },
1278         {
1279                 .procname       = "dirty_writeback_centisecs",
1280                 .data           = &dirty_writeback_interval,
1281                 .maxlen         = sizeof(dirty_writeback_interval),
1282                 .mode           = 0644,
1283                 .proc_handler   = dirty_writeback_centisecs_handler,
1284         },
1285         {
1286                 .procname       = "dirty_expire_centisecs",
1287                 .data           = &dirty_expire_interval,
1288                 .maxlen         = sizeof(dirty_expire_interval),
1289                 .mode           = 0644,
1290                 .proc_handler   = proc_dointvec_minmax,
1291                 .extra1         = &zero,
1292         },
1293         {
1294                 .procname       = "dirtytime_expire_seconds",
1295                 .data           = &dirtytime_expire_interval,
1296                 .maxlen         = sizeof(dirty_expire_interval),
1297                 .mode           = 0644,
1298                 .proc_handler   = dirtytime_interval_handler,
1299                 .extra1         = &zero,
1300         },
1301         {
1302                 .procname       = "nr_pdflush_threads",
1303                 .mode           = 0444 /* read-only */,
1304                 .proc_handler   = pdflush_proc_obsolete,
1305         },
1306         {
1307                 .procname       = "swappiness",
1308                 .data           = &vm_swappiness,
1309                 .maxlen         = sizeof(vm_swappiness),
1310                 .mode           = 0644,
1311                 .proc_handler   = proc_dointvec_minmax,
1312                 .extra1         = &zero,
1313                 .extra2         = &one_hundred,
1314         },
1315 #ifdef CONFIG_HUGETLB_PAGE
1316         {
1317                 .procname       = "nr_hugepages",
1318                 .data           = NULL,
1319                 .maxlen         = sizeof(unsigned long),
1320                 .mode           = 0644,
1321                 .proc_handler   = hugetlb_sysctl_handler,
1322         },
1323 #ifdef CONFIG_NUMA
1324         {
1325                 .procname       = "nr_hugepages_mempolicy",
1326                 .data           = NULL,
1327                 .maxlen         = sizeof(unsigned long),
1328                 .mode           = 0644,
1329                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1330         },
1331 #endif
1332          {
1333                 .procname       = "hugetlb_shm_group",
1334                 .data           = &sysctl_hugetlb_shm_group,
1335                 .maxlen         = sizeof(gid_t),
1336                 .mode           = 0644,
1337                 .proc_handler   = proc_dointvec,
1338          },
1339          {
1340                 .procname       = "hugepages_treat_as_movable",
1341                 .data           = &hugepages_treat_as_movable,
1342                 .maxlen         = sizeof(int),
1343                 .mode           = 0644,
1344                 .proc_handler   = proc_dointvec,
1345         },
1346         {
1347                 .procname       = "nr_overcommit_hugepages",
1348                 .data           = NULL,
1349                 .maxlen         = sizeof(unsigned long),
1350                 .mode           = 0644,
1351                 .proc_handler   = hugetlb_overcommit_handler,
1352         },
1353 #endif
1354         {
1355                 .procname       = "lowmem_reserve_ratio",
1356                 .data           = &sysctl_lowmem_reserve_ratio,
1357                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1358                 .mode           = 0644,
1359                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1360         },
1361         {
1362                 .procname       = "drop_caches",
1363                 .data           = &sysctl_drop_caches,
1364                 .maxlen         = sizeof(int),
1365                 .mode           = 0644,
1366                 .proc_handler   = drop_caches_sysctl_handler,
1367                 .extra1         = &one,
1368                 .extra2         = &four,
1369         },
1370 #ifdef CONFIG_COMPACTION
1371         {
1372                 .procname       = "compact_memory",
1373                 .data           = &sysctl_compact_memory,
1374                 .maxlen         = sizeof(int),
1375                 .mode           = 0200,
1376                 .proc_handler   = sysctl_compaction_handler,
1377         },
1378         {
1379                 .procname       = "extfrag_threshold",
1380                 .data           = &sysctl_extfrag_threshold,
1381                 .maxlen         = sizeof(int),
1382                 .mode           = 0644,
1383                 .proc_handler   = sysctl_extfrag_handler,
1384                 .extra1         = &min_extfrag_threshold,
1385                 .extra2         = &max_extfrag_threshold,
1386         },
1387         {
1388                 .procname       = "compact_unevictable_allowed",
1389                 .data           = &sysctl_compact_unevictable_allowed,
1390                 .maxlen         = sizeof(int),
1391                 .mode           = 0644,
1392                 .proc_handler   = proc_dointvec,
1393                 .extra1         = &zero,
1394                 .extra2         = &one,
1395         },
1396
1397 #endif /* CONFIG_COMPACTION */
1398         {
1399                 .procname       = "min_free_kbytes",
1400                 .data           = &min_free_kbytes,
1401                 .maxlen         = sizeof(min_free_kbytes),
1402                 .mode           = 0644,
1403                 .proc_handler   = min_free_kbytes_sysctl_handler,
1404                 .extra1         = &zero,
1405         },
1406         {
1407                 .procname       = "percpu_pagelist_fraction",
1408                 .data           = &percpu_pagelist_fraction,
1409                 .maxlen         = sizeof(percpu_pagelist_fraction),
1410                 .mode           = 0644,
1411                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1412                 .extra1         = &zero,
1413         },
1414 #ifdef CONFIG_MMU
1415         {
1416                 .procname       = "max_map_count",
1417                 .data           = &sysctl_max_map_count,
1418                 .maxlen         = sizeof(sysctl_max_map_count),
1419                 .mode           = 0644,
1420                 .proc_handler   = proc_dointvec_minmax,
1421                 .extra1         = &zero,
1422         },
1423 #else
1424         {
1425                 .procname       = "nr_trim_pages",
1426                 .data           = &sysctl_nr_trim_pages,
1427                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1428                 .mode           = 0644,
1429                 .proc_handler   = proc_dointvec_minmax,
1430                 .extra1         = &zero,
1431         },
1432 #endif
1433         {
1434                 .procname       = "laptop_mode",
1435                 .data           = &laptop_mode,
1436                 .maxlen         = sizeof(laptop_mode),
1437                 .mode           = 0644,
1438                 .proc_handler   = proc_dointvec_jiffies,
1439         },
1440         {
1441                 .procname       = "block_dump",
1442                 .data           = &block_dump,
1443                 .maxlen         = sizeof(block_dump),
1444                 .mode           = 0644,
1445                 .proc_handler   = proc_dointvec,
1446                 .extra1         = &zero,
1447         },
1448         {
1449                 .procname       = "vfs_cache_pressure",
1450                 .data           = &sysctl_vfs_cache_pressure,
1451                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1452                 .mode           = 0644,
1453                 .proc_handler   = proc_dointvec,
1454                 .extra1         = &zero,
1455         },
1456 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1457         {
1458                 .procname       = "legacy_va_layout",
1459                 .data           = &sysctl_legacy_va_layout,
1460                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1461                 .mode           = 0644,
1462                 .proc_handler   = proc_dointvec,
1463                 .extra1         = &zero,
1464         },
1465 #endif
1466 #ifdef CONFIG_NUMA
1467         {
1468                 .procname       = "zone_reclaim_mode",
1469                 .data           = &zone_reclaim_mode,
1470                 .maxlen         = sizeof(zone_reclaim_mode),
1471                 .mode           = 0644,
1472                 .proc_handler   = proc_dointvec,
1473                 .extra1         = &zero,
1474         },
1475         {
1476                 .procname       = "min_unmapped_ratio",
1477                 .data           = &sysctl_min_unmapped_ratio,
1478                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1479                 .mode           = 0644,
1480                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1481                 .extra1         = &zero,
1482                 .extra2         = &one_hundred,
1483         },
1484         {
1485                 .procname       = "min_slab_ratio",
1486                 .data           = &sysctl_min_slab_ratio,
1487                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1488                 .mode           = 0644,
1489                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1490                 .extra1         = &zero,
1491                 .extra2         = &one_hundred,
1492         },
1493 #endif
1494 #ifdef CONFIG_SMP
1495         {
1496                 .procname       = "stat_interval",
1497                 .data           = &sysctl_stat_interval,
1498                 .maxlen         = sizeof(sysctl_stat_interval),
1499                 .mode           = 0644,
1500                 .proc_handler   = proc_dointvec_jiffies,
1501         },
1502 #endif
1503 #ifdef CONFIG_MMU
1504         {
1505                 .procname       = "mmap_min_addr",
1506                 .data           = &dac_mmap_min_addr,
1507                 .maxlen         = sizeof(unsigned long),
1508                 .mode           = 0644,
1509                 .proc_handler   = mmap_min_addr_handler,
1510         },
1511 #endif
1512 #ifdef CONFIG_NUMA
1513         {
1514                 .procname       = "numa_zonelist_order",
1515                 .data           = &numa_zonelist_order,
1516                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1517                 .mode           = 0644,
1518                 .proc_handler   = numa_zonelist_order_handler,
1519         },
1520 #endif
1521 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1522    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1523         {
1524                 .procname       = "vdso_enabled",
1525 #ifdef CONFIG_X86_32
1526                 .data           = &vdso32_enabled,
1527                 .maxlen         = sizeof(vdso32_enabled),
1528 #else
1529                 .data           = &vdso_enabled,
1530                 .maxlen         = sizeof(vdso_enabled),
1531 #endif
1532                 .mode           = 0644,
1533                 .proc_handler   = proc_dointvec,
1534                 .extra1         = &zero,
1535         },
1536 #endif
1537 #ifdef CONFIG_HIGHMEM
1538         {
1539                 .procname       = "highmem_is_dirtyable",
1540                 .data           = &vm_highmem_is_dirtyable,
1541                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1542                 .mode           = 0644,
1543                 .proc_handler   = proc_dointvec_minmax,
1544                 .extra1         = &zero,
1545                 .extra2         = &one,
1546         },
1547 #endif
1548 #ifdef CONFIG_MEMORY_FAILURE
1549         {
1550                 .procname       = "memory_failure_early_kill",
1551                 .data           = &sysctl_memory_failure_early_kill,
1552                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1553                 .mode           = 0644,
1554                 .proc_handler   = proc_dointvec_minmax,
1555                 .extra1         = &zero,
1556                 .extra2         = &one,
1557         },
1558         {
1559                 .procname       = "memory_failure_recovery",
1560                 .data           = &sysctl_memory_failure_recovery,
1561                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1562                 .mode           = 0644,
1563                 .proc_handler   = proc_dointvec_minmax,
1564                 .extra1         = &zero,
1565                 .extra2         = &one,
1566         },
1567 #endif
1568         {
1569                 .procname       = "user_reserve_kbytes",
1570                 .data           = &sysctl_user_reserve_kbytes,
1571                 .maxlen         = sizeof(sysctl_user_reserve_kbytes),
1572                 .mode           = 0644,
1573                 .proc_handler   = proc_doulongvec_minmax,
1574         },
1575         {
1576                 .procname       = "admin_reserve_kbytes",
1577                 .data           = &sysctl_admin_reserve_kbytes,
1578                 .maxlen         = sizeof(sysctl_admin_reserve_kbytes),
1579                 .mode           = 0644,
1580                 .proc_handler   = proc_doulongvec_minmax,
1581         },
1582 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1583         {
1584                 .procname       = "mmap_rnd_bits",
1585                 .data           = &mmap_rnd_bits,
1586                 .maxlen         = sizeof(mmap_rnd_bits),
1587                 .mode           = 0600,
1588                 .proc_handler   = proc_dointvec_minmax,
1589                 .extra1         = (void *)&mmap_rnd_bits_min,
1590                 .extra2         = (void *)&mmap_rnd_bits_max,
1591         },
1592 #endif
1593 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1594         {
1595                 .procname       = "mmap_rnd_compat_bits",
1596                 .data           = &mmap_rnd_compat_bits,
1597                 .maxlen         = sizeof(mmap_rnd_compat_bits),
1598                 .mode           = 0600,
1599                 .proc_handler   = proc_dointvec_minmax,
1600                 .extra1         = (void *)&mmap_rnd_compat_bits_min,
1601                 .extra2         = (void *)&mmap_rnd_compat_bits_max,
1602         },
1603 #endif
1604         { }
1605 };
1606
1607 static struct ctl_table fs_table[] = {
1608         {
1609                 .procname       = "inode-nr",
1610                 .data           = &inodes_stat,
1611                 .maxlen         = 2*sizeof(long),
1612                 .mode           = 0444,
1613                 .proc_handler   = proc_nr_inodes,
1614         },
1615         {
1616                 .procname       = "inode-state",
1617                 .data           = &inodes_stat,
1618                 .maxlen         = 7*sizeof(long),
1619                 .mode           = 0444,
1620                 .proc_handler   = proc_nr_inodes,
1621         },
1622         {
1623                 .procname       = "file-nr",
1624                 .data           = &files_stat,
1625                 .maxlen         = sizeof(files_stat),
1626                 .mode           = 0444,
1627                 .proc_handler   = proc_nr_files,
1628         },
1629         {
1630                 .procname       = "file-max",
1631                 .data           = &files_stat.max_files,
1632                 .maxlen         = sizeof(files_stat.max_files),
1633                 .mode           = 0644,
1634                 .proc_handler   = proc_doulongvec_minmax,
1635         },
1636         {
1637                 .procname       = "nr_open",
1638                 .data           = &sysctl_nr_open,
1639                 .maxlen         = sizeof(int),
1640                 .mode           = 0644,
1641                 .proc_handler   = proc_dointvec_minmax,
1642                 .extra1         = &sysctl_nr_open_min,
1643                 .extra2         = &sysctl_nr_open_max,
1644         },
1645         {
1646                 .procname       = "dentry-state",
1647                 .data           = &dentry_stat,
1648                 .maxlen         = 6*sizeof(long),
1649                 .mode           = 0444,
1650                 .proc_handler   = proc_nr_dentry,
1651         },
1652         {
1653                 .procname       = "overflowuid",
1654                 .data           = &fs_overflowuid,
1655                 .maxlen         = sizeof(int),
1656                 .mode           = 0644,
1657                 .proc_handler   = proc_dointvec_minmax,
1658                 .extra1         = &minolduid,
1659                 .extra2         = &maxolduid,
1660         },
1661         {
1662                 .procname       = "overflowgid",
1663                 .data           = &fs_overflowgid,
1664                 .maxlen         = sizeof(int),
1665                 .mode           = 0644,
1666                 .proc_handler   = proc_dointvec_minmax,
1667                 .extra1         = &minolduid,
1668                 .extra2         = &maxolduid,
1669         },
1670 #ifdef CONFIG_FILE_LOCKING
1671         {
1672                 .procname       = "leases-enable",
1673                 .data           = &leases_enable,
1674                 .maxlen         = sizeof(int),
1675                 .mode           = 0644,
1676                 .proc_handler   = proc_dointvec,
1677         },
1678 #endif
1679 #ifdef CONFIG_DNOTIFY
1680         {
1681                 .procname       = "dir-notify-enable",
1682                 .data           = &dir_notify_enable,
1683                 .maxlen         = sizeof(int),
1684                 .mode           = 0644,
1685                 .proc_handler   = proc_dointvec,
1686         },
1687 #endif
1688 #ifdef CONFIG_MMU
1689 #ifdef CONFIG_FILE_LOCKING
1690         {
1691                 .procname       = "lease-break-time",
1692                 .data           = &lease_break_time,
1693                 .maxlen         = sizeof(int),
1694                 .mode           = 0644,
1695                 .proc_handler   = proc_dointvec,
1696         },
1697 #endif
1698 #ifdef CONFIG_AIO
1699         {
1700                 .procname       = "aio-nr",
1701                 .data           = &aio_nr,
1702                 .maxlen         = sizeof(aio_nr),
1703                 .mode           = 0444,
1704                 .proc_handler   = proc_doulongvec_minmax,
1705         },
1706         {
1707                 .procname       = "aio-max-nr",
1708                 .data           = &aio_max_nr,
1709                 .maxlen         = sizeof(aio_max_nr),
1710                 .mode           = 0644,
1711                 .proc_handler   = proc_doulongvec_minmax,
1712         },
1713 #endif /* CONFIG_AIO */
1714 #ifdef CONFIG_INOTIFY_USER
1715         {
1716                 .procname       = "inotify",
1717                 .mode           = 0555,
1718                 .child          = inotify_table,
1719         },
1720 #endif
1721 #ifdef CONFIG_EPOLL
1722         {
1723                 .procname       = "epoll",
1724                 .mode           = 0555,
1725                 .child          = epoll_table,
1726         },
1727 #endif
1728 #endif
1729         {
1730                 .procname       = "protected_symlinks",
1731                 .data           = &sysctl_protected_symlinks,
1732                 .maxlen         = sizeof(int),
1733                 .mode           = 0600,
1734                 .proc_handler   = proc_dointvec_minmax,
1735                 .extra1         = &zero,
1736                 .extra2         = &one,
1737         },
1738         {
1739                 .procname       = "protected_hardlinks",
1740                 .data           = &sysctl_protected_hardlinks,
1741                 .maxlen         = sizeof(int),
1742                 .mode           = 0600,
1743                 .proc_handler   = proc_dointvec_minmax,
1744                 .extra1         = &zero,
1745                 .extra2         = &one,
1746         },
1747         {
1748                 .procname       = "suid_dumpable",
1749                 .data           = &suid_dumpable,
1750                 .maxlen         = sizeof(int),
1751                 .mode           = 0644,
1752                 .proc_handler   = proc_dointvec_minmax_coredump,
1753                 .extra1         = &zero,
1754                 .extra2         = &two,
1755         },
1756 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1757         {
1758                 .procname       = "binfmt_misc",
1759                 .mode           = 0555,
1760                 .child          = sysctl_mount_point,
1761         },
1762 #endif
1763         {
1764                 .procname       = "pipe-max-size",
1765                 .data           = &pipe_max_size,
1766                 .maxlen         = sizeof(int),
1767                 .mode           = 0644,
1768                 .proc_handler   = &pipe_proc_fn,
1769                 .extra1         = &pipe_min_size,
1770         },
1771         {
1772                 .procname       = "pipe-user-pages-hard",
1773                 .data           = &pipe_user_pages_hard,
1774                 .maxlen         = sizeof(pipe_user_pages_hard),
1775                 .mode           = 0644,
1776                 .proc_handler   = proc_doulongvec_minmax,
1777         },
1778         {
1779                 .procname       = "pipe-user-pages-soft",
1780                 .data           = &pipe_user_pages_soft,
1781                 .maxlen         = sizeof(pipe_user_pages_soft),
1782                 .mode           = 0644,
1783                 .proc_handler   = proc_doulongvec_minmax,
1784         },
1785         { }
1786 };
1787
1788 static struct ctl_table debug_table[] = {
1789 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1790         {
1791                 .procname       = "exception-trace",
1792                 .data           = &show_unhandled_signals,
1793                 .maxlen         = sizeof(int),
1794                 .mode           = 0644,
1795                 .proc_handler   = proc_dointvec
1796         },
1797 #endif
1798 #if defined(CONFIG_OPTPROBES)
1799         {
1800                 .procname       = "kprobes-optimization",
1801                 .data           = &sysctl_kprobes_optimization,
1802                 .maxlen         = sizeof(int),
1803                 .mode           = 0644,
1804                 .proc_handler   = proc_kprobes_optimization_handler,
1805                 .extra1         = &zero,
1806                 .extra2         = &one,
1807         },
1808 #endif
1809         { }
1810 };
1811
1812 static struct ctl_table dev_table[] = {
1813         { }
1814 };
1815
1816 int __init sysctl_init(void)
1817 {
1818         struct ctl_table_header *hdr;
1819
1820         hdr = register_sysctl_table(sysctl_base_table);
1821         kmemleak_not_leak(hdr);
1822         return 0;
1823 }
1824
1825 #endif /* CONFIG_SYSCTL */
1826
1827 /*
1828  * /proc/sys support
1829  */
1830
1831 #ifdef CONFIG_PROC_SYSCTL
1832
1833 static int _proc_do_string(char *data, int maxlen, int write,
1834                            char __user *buffer,
1835                            size_t *lenp, loff_t *ppos)
1836 {
1837         size_t len;
1838         char __user *p;
1839         char c;
1840
1841         if (!data || !maxlen || !*lenp) {
1842                 *lenp = 0;
1843                 return 0;
1844         }
1845
1846         if (write) {
1847                 if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1848                         /* Only continue writes not past the end of buffer. */
1849                         len = strlen(data);
1850                         if (len > maxlen - 1)
1851                                 len = maxlen - 1;
1852
1853                         if (*ppos > len)
1854                                 return 0;
1855                         len = *ppos;
1856                 } else {
1857                         /* Start writing from beginning of buffer. */
1858                         len = 0;
1859                 }
1860
1861                 *ppos += *lenp;
1862                 p = buffer;
1863                 while ((p - buffer) < *lenp && len < maxlen - 1) {
1864                         if (get_user(c, p++))
1865                                 return -EFAULT;
1866                         if (c == 0 || c == '\n')
1867                                 break;
1868                         data[len++] = c;
1869                 }
1870                 data[len] = 0;
1871         } else {
1872                 len = strlen(data);
1873                 if (len > maxlen)
1874                         len = maxlen;
1875
1876                 if (*ppos > len) {
1877                         *lenp = 0;
1878                         return 0;
1879                 }
1880
1881                 data += *ppos;
1882                 len  -= *ppos;
1883
1884                 if (len > *lenp)
1885                         len = *lenp;
1886                 if (len)
1887                         if (copy_to_user(buffer, data, len))
1888                                 return -EFAULT;
1889                 if (len < *lenp) {
1890                         if (put_user('\n', buffer + len))
1891                                 return -EFAULT;
1892                         len++;
1893                 }
1894                 *lenp = len;
1895                 *ppos += len;
1896         }
1897         return 0;
1898 }
1899
1900 static void warn_sysctl_write(struct ctl_table *table)
1901 {
1902         pr_warn_once("%s wrote to %s when file position was not 0!\n"
1903                 "This will not be supported in the future. To silence this\n"
1904                 "warning, set kernel.sysctl_writes_strict = -1\n",
1905                 current->comm, table->procname);
1906 }
1907
1908 /**
1909  * proc_dostring - read a string sysctl
1910  * @table: the sysctl table
1911  * @write: %TRUE if this is a write to the sysctl file
1912  * @buffer: the user buffer
1913  * @lenp: the size of the user buffer
1914  * @ppos: file position
1915  *
1916  * Reads/writes a string from/to the user buffer. If the kernel
1917  * buffer provided is not large enough to hold the string, the
1918  * string is truncated. The copied string is %NULL-terminated.
1919  * If the string is being read by the user process, it is copied
1920  * and a newline '\n' is added. It is truncated if the buffer is
1921  * not large enough.
1922  *
1923  * Returns 0 on success.
1924  */
1925 int proc_dostring(struct ctl_table *table, int write,
1926                   void __user *buffer, size_t *lenp, loff_t *ppos)
1927 {
1928         if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1929                 warn_sysctl_write(table);
1930
1931         return _proc_do_string((char *)(table->data), table->maxlen, write,
1932                                (char __user *)buffer, lenp, ppos);
1933 }
1934
1935 static size_t proc_skip_spaces(char **buf)
1936 {
1937         size_t ret;
1938         char *tmp = skip_spaces(*buf);
1939         ret = tmp - *buf;
1940         *buf = tmp;
1941         return ret;
1942 }
1943
1944 static void proc_skip_char(char **buf, size_t *size, const char v)
1945 {
1946         while (*size) {
1947                 if (**buf != v)
1948                         break;
1949                 (*size)--;
1950                 (*buf)++;
1951         }
1952 }
1953
1954 #define TMPBUFLEN 22
1955 /**
1956  * proc_get_long - reads an ASCII formatted integer from a user buffer
1957  *
1958  * @buf: a kernel buffer
1959  * @size: size of the kernel buffer
1960  * @val: this is where the number will be stored
1961  * @neg: set to %TRUE if number is negative
1962  * @perm_tr: a vector which contains the allowed trailers
1963  * @perm_tr_len: size of the perm_tr vector
1964  * @tr: pointer to store the trailer character
1965  *
1966  * In case of success %0 is returned and @buf and @size are updated with
1967  * the amount of bytes read. If @tr is non-NULL and a trailing
1968  * character exists (size is non-zero after returning from this
1969  * function), @tr is updated with the trailing character.
1970  */
1971 static int proc_get_long(char **buf, size_t *size,
1972                           unsigned long *val, bool *neg,
1973                           const char *perm_tr, unsigned perm_tr_len, char *tr)
1974 {
1975         int len;
1976         char *p, tmp[TMPBUFLEN];
1977
1978         if (!*size)
1979                 return -EINVAL;
1980
1981         len = *size;
1982         if (len > TMPBUFLEN - 1)
1983                 len = TMPBUFLEN - 1;
1984
1985         memcpy(tmp, *buf, len);
1986
1987         tmp[len] = 0;
1988         p = tmp;
1989         if (*p == '-' && *size > 1) {
1990                 *neg = true;
1991                 p++;
1992         } else
1993                 *neg = false;
1994         if (!isdigit(*p))
1995                 return -EINVAL;
1996
1997         *val = simple_strtoul(p, &p, 0);
1998
1999         len = p - tmp;
2000
2001         /* We don't know if the next char is whitespace thus we may accept
2002          * invalid integers (e.g. 1234...a) or two integers instead of one
2003          * (e.g. 123...1). So lets not allow such large numbers. */
2004         if (len == TMPBUFLEN - 1)
2005                 return -EINVAL;
2006
2007         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2008                 return -EINVAL;
2009
2010         if (tr && (len < *size))
2011                 *tr = *p;
2012
2013         *buf += len;
2014         *size -= len;
2015
2016         return 0;
2017 }
2018
2019 /**
2020  * proc_put_long - converts an integer to a decimal ASCII formatted string
2021  *
2022  * @buf: the user buffer
2023  * @size: the size of the user buffer
2024  * @val: the integer to be converted
2025  * @neg: sign of the number, %TRUE for negative
2026  *
2027  * In case of success %0 is returned and @buf and @size are updated with
2028  * the amount of bytes written.
2029  */
2030 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2031                           bool neg)
2032 {
2033         int len;
2034         char tmp[TMPBUFLEN], *p = tmp;
2035
2036         sprintf(p, "%s%lu", neg ? "-" : "", val);
2037         len = strlen(tmp);
2038         if (len > *size)
2039                 len = *size;
2040         if (copy_to_user(*buf, tmp, len))
2041                 return -EFAULT;
2042         *size -= len;
2043         *buf += len;
2044         return 0;
2045 }
2046 #undef TMPBUFLEN
2047
2048 static int proc_put_char(void __user **buf, size_t *size, char c)
2049 {
2050         if (*size) {
2051                 char __user **buffer = (char __user **)buf;
2052                 if (put_user(c, *buffer))
2053                         return -EFAULT;
2054                 (*size)--, (*buffer)++;
2055                 *buf = *buffer;
2056         }
2057         return 0;
2058 }
2059
2060 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2061                                  int *valp,
2062                                  int write, void *data)
2063 {
2064         if (write) {
2065                 if (*negp) {
2066                         if (*lvalp > (unsigned long) INT_MAX + 1)
2067                                 return -EINVAL;
2068                         *valp = -*lvalp;
2069                 } else {
2070                         if (*lvalp > (unsigned long) INT_MAX)
2071                                 return -EINVAL;
2072                         *valp = *lvalp;
2073                 }
2074         } else {
2075                 int val = *valp;
2076                 if (val < 0) {
2077                         *negp = true;
2078                         *lvalp = -(unsigned long)val;
2079                 } else {
2080                         *negp = false;
2081                         *lvalp = (unsigned long)val;
2082                 }
2083         }
2084         return 0;
2085 }
2086
2087 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2088
2089 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2090                   int write, void __user *buffer,
2091                   size_t *lenp, loff_t *ppos,
2092                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2093                               int write, void *data),
2094                   void *data)
2095 {
2096         int *i, vleft, first = 1, err = 0;
2097         size_t left;
2098         char *kbuf = NULL, *p;
2099
2100         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2101                 *lenp = 0;
2102                 return 0;
2103         }
2104
2105         i = (int *) tbl_data;
2106         vleft = table->maxlen / sizeof(*i);
2107         left = *lenp;
2108
2109         if (!conv)
2110                 conv = do_proc_dointvec_conv;
2111
2112         if (write) {
2113                 if (*ppos) {
2114                         switch (sysctl_writes_strict) {
2115                         case SYSCTL_WRITES_STRICT:
2116                                 goto out;
2117                         case SYSCTL_WRITES_WARN:
2118                                 warn_sysctl_write(table);
2119                                 break;
2120                         default:
2121                                 break;
2122                         }
2123                 }
2124
2125                 if (left > PAGE_SIZE - 1)
2126                         left = PAGE_SIZE - 1;
2127                 p = kbuf = memdup_user_nul(buffer, left);
2128                 if (IS_ERR(kbuf))
2129                         return PTR_ERR(kbuf);
2130         }
2131
2132         for (; left && vleft--; i++, first=0) {
2133                 unsigned long lval;
2134                 bool neg;
2135
2136                 if (write) {
2137                         left -= proc_skip_spaces(&p);
2138
2139                         if (!left)
2140                                 break;
2141                         err = proc_get_long(&p, &left, &lval, &neg,
2142                                              proc_wspace_sep,
2143                                              sizeof(proc_wspace_sep), NULL);
2144                         if (err)
2145                                 break;
2146                         if (conv(&neg, &lval, i, 1, data)) {
2147                                 err = -EINVAL;
2148                                 break;
2149                         }
2150                 } else {
2151                         if (conv(&neg, &lval, i, 0, data)) {
2152                                 err = -EINVAL;
2153                                 break;
2154                         }
2155                         if (!first)
2156                                 err = proc_put_char(&buffer, &left, '\t');
2157                         if (err)
2158                                 break;
2159                         err = proc_put_long(&buffer, &left, lval, neg);
2160                         if (err)
2161                                 break;
2162                 }
2163         }
2164
2165         if (!write && !first && left && !err)
2166                 err = proc_put_char(&buffer, &left, '\n');
2167         if (write && !err && left)
2168                 left -= proc_skip_spaces(&p);
2169         if (write) {
2170                 kfree(kbuf);
2171                 if (first)
2172                         return err ? : -EINVAL;
2173         }
2174         *lenp -= left;
2175 out:
2176         *ppos += *lenp;
2177         return err;
2178 }
2179
2180 static int do_proc_dointvec(struct ctl_table *table, int write,
2181                   void __user *buffer, size_t *lenp, loff_t *ppos,
2182                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2183                               int write, void *data),
2184                   void *data)
2185 {
2186         return __do_proc_dointvec(table->data, table, write,
2187                         buffer, lenp, ppos, conv, data);
2188 }
2189
2190 /**
2191  * proc_dointvec - read a vector of integers
2192  * @table: the sysctl table
2193  * @write: %TRUE if this is a write to the sysctl file
2194  * @buffer: the user buffer
2195  * @lenp: the size of the user buffer
2196  * @ppos: file position
2197  *
2198  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2199  * values from/to the user buffer, treated as an ASCII string.
2200  *
2201  * Returns 0 on success.
2202  */
2203 int proc_dointvec(struct ctl_table *table, int write,
2204                      void __user *buffer, size_t *lenp, loff_t *ppos)
2205 {
2206     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2207                             NULL,NULL);
2208 }
2209
2210 /*
2211  * Taint values can only be increased
2212  * This means we can safely use a temporary.
2213  */
2214 static int proc_taint(struct ctl_table *table, int write,
2215                                void __user *buffer, size_t *lenp, loff_t *ppos)
2216 {
2217         struct ctl_table t;
2218         unsigned long tmptaint = get_taint();
2219         int err;
2220
2221         if (write && !capable(CAP_SYS_ADMIN))
2222                 return -EPERM;
2223
2224         t = *table;
2225         t.data = &tmptaint;
2226         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2227         if (err < 0)
2228                 return err;
2229
2230         if (write) {
2231                 /*
2232                  * Poor man's atomic or. Not worth adding a primitive
2233                  * to everyone's atomic.h for this
2234                  */
2235                 int i;
2236                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2237                         if ((tmptaint >> i) & 1)
2238                                 add_taint(i, LOCKDEP_STILL_OK);
2239                 }
2240         }
2241
2242         return err;
2243 }
2244
2245 #ifdef CONFIG_PRINTK
2246 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2247                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2248 {
2249         if (write && !capable(CAP_SYS_ADMIN))
2250                 return -EPERM;
2251
2252         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2253 }
2254 #endif
2255
2256 struct do_proc_dointvec_minmax_conv_param {
2257         int *min;
2258         int *max;
2259 };
2260
2261 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2262                                         int *valp,
2263                                         int write, void *data)
2264 {
2265         struct do_proc_dointvec_minmax_conv_param *param = data;
2266         if (write) {
2267                 int val = *negp ? -*lvalp : *lvalp;
2268                 if ((param->min && *param->min > val) ||
2269                     (param->max && *param->max < val))
2270                         return -EINVAL;
2271                 *valp = val;
2272         } else {
2273                 int val = *valp;
2274                 if (val < 0) {
2275                         *negp = true;
2276                         *lvalp = -(unsigned long)val;
2277                 } else {
2278                         *negp = false;
2279                         *lvalp = (unsigned long)val;
2280                 }
2281         }
2282         return 0;
2283 }
2284
2285 /**
2286  * proc_dointvec_minmax - read a vector of integers with min/max values
2287  * @table: the sysctl table
2288  * @write: %TRUE if this is a write to the sysctl file
2289  * @buffer: the user buffer
2290  * @lenp: the size of the user buffer
2291  * @ppos: file position
2292  *
2293  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2294  * values from/to the user buffer, treated as an ASCII string.
2295  *
2296  * This routine will ensure the values are within the range specified by
2297  * table->extra1 (min) and table->extra2 (max).
2298  *
2299  * Returns 0 on success.
2300  */
2301 int proc_dointvec_minmax(struct ctl_table *table, int write,
2302                   void __user *buffer, size_t *lenp, loff_t *ppos)
2303 {
2304         struct do_proc_dointvec_minmax_conv_param param = {
2305                 .min = (int *) table->extra1,
2306                 .max = (int *) table->extra2,
2307         };
2308         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2309                                 do_proc_dointvec_minmax_conv, &param);
2310 }
2311
2312 static void validate_coredump_safety(void)
2313 {
2314 #ifdef CONFIG_COREDUMP
2315         if (suid_dumpable == SUID_DUMP_ROOT &&
2316             core_pattern[0] != '/' && core_pattern[0] != '|') {
2317                 printk(KERN_WARNING "Unsafe core_pattern used with "\
2318                         "suid_dumpable=2. Pipe handler or fully qualified "\
2319                         "core dump path required.\n");
2320         }
2321 #endif
2322 }
2323
2324 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2325                 void __user *buffer, size_t *lenp, loff_t *ppos)
2326 {
2327         int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2328         if (!error)
2329                 validate_coredump_safety();
2330         return error;
2331 }
2332
2333 #ifdef CONFIG_COREDUMP
2334 static int proc_dostring_coredump(struct ctl_table *table, int write,
2335                   void __user *buffer, size_t *lenp, loff_t *ppos)
2336 {
2337         int error = proc_dostring(table, write, buffer, lenp, ppos);
2338         if (!error)
2339                 validate_coredump_safety();
2340         return error;
2341 }
2342 #endif
2343
2344 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2345                                      void __user *buffer,
2346                                      size_t *lenp, loff_t *ppos,
2347                                      unsigned long convmul,
2348                                      unsigned long convdiv)
2349 {
2350         unsigned long *i, *min, *max;
2351         int vleft, first = 1, err = 0;
2352         size_t left;
2353         char *kbuf = NULL, *p;
2354
2355         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2356                 *lenp = 0;
2357                 return 0;
2358         }
2359
2360         i = (unsigned long *) data;
2361         min = (unsigned long *) table->extra1;
2362         max = (unsigned long *) table->extra2;
2363         vleft = table->maxlen / sizeof(unsigned long);
2364         left = *lenp;
2365
2366         if (write) {
2367                 if (*ppos) {
2368                         switch (sysctl_writes_strict) {
2369                         case SYSCTL_WRITES_STRICT:
2370                                 goto out;
2371                         case SYSCTL_WRITES_WARN:
2372                                 warn_sysctl_write(table);
2373                                 break;
2374                         default:
2375                                 break;
2376                         }
2377                 }
2378
2379                 if (left > PAGE_SIZE - 1)
2380                         left = PAGE_SIZE - 1;
2381                 p = kbuf = memdup_user_nul(buffer, left);
2382                 if (IS_ERR(kbuf))
2383                         return PTR_ERR(kbuf);
2384         }
2385
2386         for (; left && vleft--; i++, first = 0) {
2387                 unsigned long val;
2388
2389                 if (write) {
2390                         bool neg;
2391
2392                         left -= proc_skip_spaces(&p);
2393
2394                         err = proc_get_long(&p, &left, &val, &neg,
2395                                              proc_wspace_sep,
2396                                              sizeof(proc_wspace_sep), NULL);
2397                         if (err)
2398                                 break;
2399                         if (neg)
2400                                 continue;
2401                         if ((min && val < *min) || (max && val > *max))
2402                                 continue;
2403                         *i = val;
2404                 } else {
2405                         val = convdiv * (*i) / convmul;
2406                         if (!first) {
2407                                 err = proc_put_char(&buffer, &left, '\t');
2408                                 if (err)
2409                                         break;
2410                         }
2411                         err = proc_put_long(&buffer, &left, val, false);
2412                         if (err)
2413                                 break;
2414                 }
2415         }
2416
2417         if (!write && !first && left && !err)
2418                 err = proc_put_char(&buffer, &left, '\n');
2419         if (write && !err)
2420                 left -= proc_skip_spaces(&p);
2421         if (write) {
2422                 kfree(kbuf);
2423                 if (first)
2424                         return err ? : -EINVAL;
2425         }
2426         *lenp -= left;
2427 out:
2428         *ppos += *lenp;
2429         return err;
2430 }
2431
2432 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2433                                      void __user *buffer,
2434                                      size_t *lenp, loff_t *ppos,
2435                                      unsigned long convmul,
2436                                      unsigned long convdiv)
2437 {
2438         return __do_proc_doulongvec_minmax(table->data, table, write,
2439                         buffer, lenp, ppos, convmul, convdiv);
2440 }
2441
2442 /**
2443  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2444  * @table: the sysctl table
2445  * @write: %TRUE if this is a write to the sysctl file
2446  * @buffer: the user buffer
2447  * @lenp: the size of the user buffer
2448  * @ppos: file position
2449  *
2450  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2451  * values from/to the user buffer, treated as an ASCII string.
2452  *
2453  * This routine will ensure the values are within the range specified by
2454  * table->extra1 (min) and table->extra2 (max).
2455  *
2456  * Returns 0 on success.
2457  */
2458 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2459                            void __user *buffer, size_t *lenp, loff_t *ppos)
2460 {
2461     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2462 }
2463
2464 /**
2465  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2466  * @table: the sysctl table
2467  * @write: %TRUE if this is a write to the sysctl file
2468  * @buffer: the user buffer
2469  * @lenp: the size of the user buffer
2470  * @ppos: file position
2471  *
2472  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2473  * values from/to the user buffer, treated as an ASCII string. The values
2474  * are treated as milliseconds, and converted to jiffies when they are stored.
2475  *
2476  * This routine will ensure the values are within the range specified by
2477  * table->extra1 (min) and table->extra2 (max).
2478  *
2479  * Returns 0 on success.
2480  */
2481 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2482                                       void __user *buffer,
2483                                       size_t *lenp, loff_t *ppos)
2484 {
2485     return do_proc_doulongvec_minmax(table, write, buffer,
2486                                      lenp, ppos, HZ, 1000l);
2487 }
2488
2489
2490 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2491                                          int *valp,
2492                                          int write, void *data)
2493 {
2494         if (write) {
2495                 if (*lvalp > LONG_MAX / HZ)
2496                         return 1;
2497                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2498         } else {
2499                 int val = *valp;
2500                 unsigned long lval;
2501                 if (val < 0) {
2502                         *negp = true;
2503                         lval = -(unsigned long)val;
2504                 } else {
2505                         *negp = false;
2506                         lval = (unsigned long)val;
2507                 }
2508                 *lvalp = lval / HZ;
2509         }
2510         return 0;
2511 }
2512
2513 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2514                                                 int *valp,
2515                                                 int write, void *data)
2516 {
2517         if (write) {
2518                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2519                         return 1;
2520                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2521         } else {
2522                 int val = *valp;
2523                 unsigned long lval;
2524                 if (val < 0) {
2525                         *negp = true;
2526                         lval = -(unsigned long)val;
2527                 } else {
2528                         *negp = false;
2529                         lval = (unsigned long)val;
2530                 }
2531                 *lvalp = jiffies_to_clock_t(lval);
2532         }
2533         return 0;
2534 }
2535
2536 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2537                                             int *valp,
2538                                             int write, void *data)
2539 {
2540         if (write) {
2541                 unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2542
2543                 if (jif > INT_MAX)
2544                         return 1;
2545                 *valp = (int)jif;
2546         } else {
2547                 int val = *valp;
2548                 unsigned long lval;
2549                 if (val < 0) {
2550                         *negp = true;
2551                         lval = -(unsigned long)val;
2552                 } else {
2553                         *negp = false;
2554                         lval = (unsigned long)val;
2555                 }
2556                 *lvalp = jiffies_to_msecs(lval);
2557         }
2558         return 0;
2559 }
2560
2561 /**
2562  * proc_dointvec_jiffies - read a vector of integers as seconds
2563  * @table: the sysctl table
2564  * @write: %TRUE if this is a write to the sysctl file
2565  * @buffer: the user buffer
2566  * @lenp: the size of the user buffer
2567  * @ppos: file position
2568  *
2569  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2570  * values from/to the user buffer, treated as an ASCII string.
2571  * The values read are assumed to be in seconds, and are converted into
2572  * jiffies.
2573  *
2574  * Returns 0 on success.
2575  */
2576 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2577                           void __user *buffer, size_t *lenp, loff_t *ppos)
2578 {
2579     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2580                             do_proc_dointvec_jiffies_conv,NULL);
2581 }
2582
2583 /**
2584  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2585  * @table: the sysctl table
2586  * @write: %TRUE if this is a write to the sysctl file
2587  * @buffer: the user buffer
2588  * @lenp: the size of the user buffer
2589  * @ppos: pointer to the file position
2590  *
2591  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2592  * values from/to the user buffer, treated as an ASCII string.
2593  * The values read are assumed to be in 1/USER_HZ seconds, and
2594  * are converted into jiffies.
2595  *
2596  * Returns 0 on success.
2597  */
2598 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2599                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2600 {
2601     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2602                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2603 }
2604
2605 /**
2606  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2607  * @table: the sysctl table
2608  * @write: %TRUE if this is a write to the sysctl file
2609  * @buffer: the user buffer
2610  * @lenp: the size of the user buffer
2611  * @ppos: file position
2612  * @ppos: the current position in the file
2613  *
2614  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2615  * values from/to the user buffer, treated as an ASCII string.
2616  * The values read are assumed to be in 1/1000 seconds, and
2617  * are converted into jiffies.
2618  *
2619  * Returns 0 on success.
2620  */
2621 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2622                              void __user *buffer, size_t *lenp, loff_t *ppos)
2623 {
2624         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2625                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2626 }
2627
2628 static int proc_do_cad_pid(struct ctl_table *table, int write,
2629                            void __user *buffer, size_t *lenp, loff_t *ppos)
2630 {
2631         struct pid *new_pid;
2632         pid_t tmp;
2633         int r;
2634
2635         tmp = pid_vnr(cad_pid);
2636
2637         r = __do_proc_dointvec(&tmp, table, write, buffer,
2638                                lenp, ppos, NULL, NULL);
2639         if (r || !write)
2640                 return r;
2641
2642         new_pid = find_get_pid(tmp);
2643         if (!new_pid)
2644                 return -ESRCH;
2645
2646         put_pid(xchg(&cad_pid, new_pid));
2647         return 0;
2648 }
2649
2650 /**
2651  * proc_do_large_bitmap - read/write from/to a large bitmap
2652  * @table: the sysctl table
2653  * @write: %TRUE if this is a write to the sysctl file
2654  * @buffer: the user buffer
2655  * @lenp: the size of the user buffer
2656  * @ppos: file position
2657  *
2658  * The bitmap is stored at table->data and the bitmap length (in bits)
2659  * in table->maxlen.
2660  *
2661  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2662  * large bitmaps may be represented in a compact manner. Writing into
2663  * the file will clear the bitmap then update it with the given input.
2664  *
2665  * Returns 0 on success.
2666  */
2667 int proc_do_large_bitmap(struct ctl_table *table, int write,
2668                          void __user *buffer, size_t *lenp, loff_t *ppos)
2669 {
2670         int err = 0;
2671         bool first = 1;
2672         size_t left = *lenp;
2673         unsigned long bitmap_len = table->maxlen;
2674         unsigned long *bitmap = *(unsigned long **) table->data;
2675         unsigned long *tmp_bitmap = NULL;
2676         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2677
2678         if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2679                 *lenp = 0;
2680                 return 0;
2681         }
2682
2683         if (write) {
2684                 char *kbuf, *p;
2685
2686                 if (left > PAGE_SIZE - 1)
2687                         left = PAGE_SIZE - 1;
2688
2689                 p = kbuf = memdup_user_nul(buffer, left);
2690                 if (IS_ERR(kbuf))
2691                         return PTR_ERR(kbuf);
2692
2693                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2694                                      GFP_KERNEL);
2695                 if (!tmp_bitmap) {
2696                         kfree(kbuf);
2697                         return -ENOMEM;
2698                 }
2699                 proc_skip_char(&p, &left, '\n');
2700                 while (!err && left) {
2701                         unsigned long val_a, val_b;
2702                         bool neg;
2703
2704                         err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2705                                              sizeof(tr_a), &c);
2706                         if (err)
2707                                 break;
2708                         if (val_a >= bitmap_len || neg) {
2709                                 err = -EINVAL;
2710                                 break;
2711                         }
2712
2713                         val_b = val_a;
2714                         if (left) {
2715                                 p++;
2716                                 left--;
2717                         }
2718
2719                         if (c == '-') {
2720                                 err = proc_get_long(&p, &left, &val_b,
2721                                                      &neg, tr_b, sizeof(tr_b),
2722                                                      &c);
2723                                 if (err)
2724                                         break;
2725                                 if (val_b >= bitmap_len || neg ||
2726                                     val_a > val_b) {
2727                                         err = -EINVAL;
2728                                         break;
2729                                 }
2730                                 if (left) {
2731                                         p++;
2732                                         left--;
2733                                 }
2734                         }
2735
2736                         bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2737                         first = 0;
2738                         proc_skip_char(&p, &left, '\n');
2739                 }
2740                 kfree(kbuf);
2741         } else {
2742                 unsigned long bit_a, bit_b = 0;
2743
2744                 while (left) {
2745                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2746                         if (bit_a >= bitmap_len)
2747                                 break;
2748                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2749                                                    bit_a + 1) - 1;
2750
2751                         if (!first) {
2752                                 err = proc_put_char(&buffer, &left, ',');
2753                                 if (err)
2754                                         break;
2755                         }
2756                         err = proc_put_long(&buffer, &left, bit_a, false);
2757                         if (err)
2758                                 break;
2759                         if (bit_a != bit_b) {
2760                                 err = proc_put_char(&buffer, &left, '-');
2761                                 if (err)
2762                                         break;
2763                                 err = proc_put_long(&buffer, &left, bit_b, false);
2764                                 if (err)
2765                                         break;
2766                         }
2767
2768                         first = 0; bit_b++;
2769                 }
2770                 if (!err)
2771                         err = proc_put_char(&buffer, &left, '\n');
2772         }
2773
2774         if (!err) {
2775                 if (write) {
2776                         if (*ppos)
2777                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2778                         else
2779                                 bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2780                 }
2781                 kfree(tmp_bitmap);
2782                 *lenp -= left;
2783                 *ppos += *lenp;
2784                 return 0;
2785         } else {
2786                 kfree(tmp_bitmap);
2787                 return err;
2788         }
2789 }
2790
2791 #else /* CONFIG_PROC_SYSCTL */
2792
2793 int proc_dostring(struct ctl_table *table, int write,
2794                   void __user *buffer, size_t *lenp, loff_t *ppos)
2795 {
2796         return -ENOSYS;
2797 }
2798
2799 int proc_dointvec(struct ctl_table *table, int write,
2800                   void __user *buffer, size_t *lenp, loff_t *ppos)
2801 {
2802         return -ENOSYS;
2803 }
2804
2805 int proc_dointvec_minmax(struct ctl_table *table, int write,
2806                     void __user *buffer, size_t *lenp, loff_t *ppos)
2807 {
2808         return -ENOSYS;
2809 }
2810
2811 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2812                     void __user *buffer, size_t *lenp, loff_t *ppos)
2813 {
2814         return -ENOSYS;
2815 }
2816
2817 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2818                     void __user *buffer, size_t *lenp, loff_t *ppos)
2819 {
2820         return -ENOSYS;
2821 }
2822
2823 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2824                              void __user *buffer, size_t *lenp, loff_t *ppos)
2825 {
2826         return -ENOSYS;
2827 }
2828
2829 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2830                     void __user *buffer, size_t *lenp, loff_t *ppos)
2831 {
2832         return -ENOSYS;
2833 }
2834
2835 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2836                                       void __user *buffer,
2837                                       size_t *lenp, loff_t *ppos)
2838 {
2839     return -ENOSYS;
2840 }
2841
2842
2843 #endif /* CONFIG_PROC_SYSCTL */
2844
2845 /*
2846  * No sense putting this after each symbol definition, twice,
2847  * exception granted :-)
2848  */
2849 EXPORT_SYMBOL(proc_dointvec);
2850 EXPORT_SYMBOL(proc_dointvec_jiffies);
2851 EXPORT_SYMBOL(proc_dointvec_minmax);
2852 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2853 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2854 EXPORT_SYMBOL(proc_dostring);
2855 EXPORT_SYMBOL(proc_doulongvec_minmax);
2856 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);