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Linux/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 #include <linux/mount.h>
 69 
 70 #include <linux/uaccess.h>
 71 #include <asm/processor.h>
 72 
 73 #ifdef CONFIG_X86
 74 #include <asm/nmi.h>
 75 #include <asm/stacktrace.h>
 76 #include <asm/io.h>
 77 #endif
 78 #ifdef CONFIG_SPARC
 79 #include <asm/setup.h>
 80 #endif
 81 #ifdef CONFIG_BSD_PROCESS_ACCT
 82 #include <linux/acct.h>
 83 #endif
 84 #ifdef CONFIG_RT_MUTEXES
 85 #include <linux/rtmutex.h>
 86 #endif
 87 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
 88 #include <linux/lockdep.h>
 89 #endif
 90 #ifdef CONFIG_CHR_DEV_SG
 91 #include <scsi/sg.h>
 92 #endif
 93 
 94 #ifdef CONFIG_LOCKUP_DETECTOR
 95 #include <linux/nmi.h>
 96 #endif
 97 
 98 #if defined(CONFIG_SYSCTL)
 99 
100 /* External variables not in a header file. */
101 extern int suid_dumpable;
102 #ifdef CONFIG_COREDUMP
103 extern int core_uses_pid;
104 extern char core_pattern[];
105 extern unsigned int core_pipe_limit;
106 #endif
107 extern int pid_max;
108 extern int pid_max_min, pid_max_max;
109 extern int percpu_pagelist_fraction;
110 extern int latencytop_enabled;
111 extern unsigned 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 static int one_thousand = 1000;
130 #ifdef CONFIG_PRINTK
131 static int ten_thousand = 10000;
132 #endif
133 #ifdef CONFIG_PERF_EVENTS
134 static int six_hundred_forty_kb = 640 * 1024;
135 #endif
136 
137 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
138 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
139 
140 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
141 static int maxolduid = 65535;
142 static int minolduid;
143 
144 static int ngroups_max = NGROUPS_MAX;
145 static const int cap_last_cap = CAP_LAST_CAP;
146 
147 /*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */
148 #ifdef CONFIG_DETECT_HUNG_TASK
149 static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
150 #endif
151 
152 #ifdef CONFIG_INOTIFY_USER
153 #include <linux/inotify.h>
154 #endif
155 #ifdef CONFIG_SPARC
156 #endif
157 
158 #ifdef __hppa__
159 extern int pwrsw_enabled;
160 #endif
161 
162 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
163 extern int unaligned_enabled;
164 #endif
165 
166 #ifdef CONFIG_IA64
167 extern int unaligned_dump_stack;
168 #endif
169 
170 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
171 extern int no_unaligned_warning;
172 #endif
173 
174 #ifdef CONFIG_PROC_SYSCTL
175 
176 #define SYSCTL_WRITES_LEGACY    -1
177 #define SYSCTL_WRITES_WARN       0
178 #define SYSCTL_WRITES_STRICT     1
179 
180 static int sysctl_writes_strict = SYSCTL_WRITES_STRICT;
181 
182 static int proc_do_cad_pid(struct ctl_table *table, int write,
183                   void __user *buffer, size_t *lenp, loff_t *ppos);
184 static int proc_taint(struct ctl_table *table, int write,
185                                void __user *buffer, size_t *lenp, loff_t *ppos);
186 #endif
187 
188 #ifdef CONFIG_PRINTK
189 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
190                                 void __user *buffer, size_t *lenp, loff_t *ppos);
191 #endif
192 
193 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
194                 void __user *buffer, size_t *lenp, loff_t *ppos);
195 #ifdef CONFIG_COREDUMP
196 static int proc_dostring_coredump(struct ctl_table *table, int write,
197                 void __user *buffer, size_t *lenp, loff_t *ppos);
198 #endif
199 
200 #ifdef CONFIG_MAGIC_SYSRQ
201 /* Note: sysrq code uses it's own private copy */
202 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
203 
204 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
205                                 void __user *buffer, size_t *lenp,
206                                 loff_t *ppos)
207 {
208         int error;
209 
210         error = proc_dointvec(table, write, buffer, lenp, ppos);
211         if (error)
212                 return error;
213 
214         if (write)
215                 sysrq_toggle_support(__sysrq_enabled);
216 
217         return 0;
218 }
219 
220 #endif
221 
222 static struct ctl_table kern_table[];
223 static struct ctl_table vm_table[];
224 static struct ctl_table fs_table[];
225 static struct ctl_table debug_table[];
226 static struct ctl_table dev_table[];
227 extern struct ctl_table random_table[];
228 #ifdef CONFIG_EPOLL
229 extern struct ctl_table epoll_table[];
230 #endif
231 
232 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
233 int sysctl_legacy_va_layout;
234 #endif
235 
236 /* The default sysctl tables: */
237 
238 static struct ctl_table sysctl_base_table[] = {
239         {
240                 .procname       = "kernel",
241                 .mode           = 0555,
242                 .child          = kern_table,
243         },
244         {
245                 .procname       = "vm",
246                 .mode           = 0555,
247                 .child          = vm_table,
248         },
249         {
250                 .procname       = "fs",
251                 .mode           = 0555,
252                 .child          = fs_table,
253         },
254         {
255                 .procname       = "debug",
256                 .mode           = 0555,
257                 .child          = debug_table,
258         },
259         {
260                 .procname       = "dev",
261                 .mode           = 0555,
262                 .child          = dev_table,
263         },
264         { }
265 };
266 
267 #ifdef CONFIG_SCHED_DEBUG
268 static int min_sched_granularity_ns = 100000;           /* 100 usecs */
269 static int max_sched_granularity_ns = NSEC_PER_SEC;     /* 1 second */
270 static int min_wakeup_granularity_ns;                   /* 0 usecs */
271 static int max_wakeup_granularity_ns = NSEC_PER_SEC;    /* 1 second */
272 #ifdef CONFIG_SMP
273 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
274 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
275 #endif /* CONFIG_SMP */
276 #endif /* CONFIG_SCHED_DEBUG */
277 
278 #ifdef CONFIG_COMPACTION
279 static int min_extfrag_threshold;
280 static int max_extfrag_threshold = 1000;
281 #endif
282 
283 static struct ctl_table kern_table[] = {
284         {
285                 .procname       = "sched_child_runs_first",
286                 .data           = &sysctl_sched_child_runs_first,
287                 .maxlen         = sizeof(unsigned int),
288                 .mode           = 0644,
289                 .proc_handler   = proc_dointvec,
290         },
291 #ifdef CONFIG_SCHED_DEBUG
292         {
293                 .procname       = "sched_min_granularity_ns",
294                 .data           = &sysctl_sched_min_granularity,
295                 .maxlen         = sizeof(unsigned int),
296                 .mode           = 0644,
297                 .proc_handler   = sched_proc_update_handler,
298                 .extra1         = &min_sched_granularity_ns,
299                 .extra2         = &max_sched_granularity_ns,
300         },
301         {
302                 .procname       = "sched_latency_ns",
303                 .data           = &sysctl_sched_latency,
304                 .maxlen         = sizeof(unsigned int),
305                 .mode           = 0644,
306                 .proc_handler   = sched_proc_update_handler,
307                 .extra1         = &min_sched_granularity_ns,
308                 .extra2         = &max_sched_granularity_ns,
309         },
310         {
311                 .procname       = "sched_wakeup_granularity_ns",
312                 .data           = &sysctl_sched_wakeup_granularity,
313                 .maxlen         = sizeof(unsigned int),
314                 .mode           = 0644,
315                 .proc_handler   = sched_proc_update_handler,
316                 .extra1         = &min_wakeup_granularity_ns,
317                 .extra2         = &max_wakeup_granularity_ns,
318         },
319 #ifdef CONFIG_SMP
320         {
321                 .procname       = "sched_tunable_scaling",
322                 .data           = &sysctl_sched_tunable_scaling,
323                 .maxlen         = sizeof(enum sched_tunable_scaling),
324                 .mode           = 0644,
325                 .proc_handler   = sched_proc_update_handler,
326                 .extra1         = &min_sched_tunable_scaling,
327                 .extra2         = &max_sched_tunable_scaling,
328         },
329         {
330                 .procname       = "sched_migration_cost_ns",
331                 .data           = &sysctl_sched_migration_cost,
332                 .maxlen         = sizeof(unsigned int),
333                 .mode           = 0644,
334                 .proc_handler   = proc_dointvec,
335         },
336         {
337                 .procname       = "sched_nr_migrate",
338                 .data           = &sysctl_sched_nr_migrate,
339                 .maxlen         = sizeof(unsigned int),
340                 .mode           = 0644,
341                 .proc_handler   = proc_dointvec,
342         },
343         {
344                 .procname       = "sched_time_avg_ms",
345                 .data           = &sysctl_sched_time_avg,
346                 .maxlen         = sizeof(unsigned int),
347                 .mode           = 0644,
348                 .proc_handler   = proc_dointvec,
349         },
350 #ifdef CONFIG_SCHEDSTATS
351         {
352                 .procname       = "sched_schedstats",
353                 .data           = NULL,
354                 .maxlen         = sizeof(unsigned int),
355                 .mode           = 0644,
356                 .proc_handler   = sysctl_schedstats,
357                 .extra1         = &zero,
358                 .extra2         = &one,
359         },
360 #endif /* CONFIG_SCHEDSTATS */
361 #endif /* CONFIG_SMP */
362 #ifdef CONFIG_NUMA_BALANCING
363         {
364                 .procname       = "numa_balancing_scan_delay_ms",
365                 .data           = &sysctl_numa_balancing_scan_delay,
366                 .maxlen         = sizeof(unsigned int),
367                 .mode           = 0644,
368                 .proc_handler   = proc_dointvec,
369         },
370         {
371                 .procname       = "numa_balancing_scan_period_min_ms",
372                 .data           = &sysctl_numa_balancing_scan_period_min,
373                 .maxlen         = sizeof(unsigned int),
374                 .mode           = 0644,
375                 .proc_handler   = proc_dointvec,
376         },
377         {
378                 .procname       = "numa_balancing_scan_period_max_ms",
379                 .data           = &sysctl_numa_balancing_scan_period_max,
380                 .maxlen         = sizeof(unsigned int),
381                 .mode           = 0644,
382                 .proc_handler   = proc_dointvec,
383         },
384         {
385                 .procname       = "numa_balancing_scan_size_mb",
386                 .data           = &sysctl_numa_balancing_scan_size,
387                 .maxlen         = sizeof(unsigned int),
388                 .mode           = 0644,
389                 .proc_handler   = proc_dointvec_minmax,
390                 .extra1         = &one,
391         },
392         {
393                 .procname       = "numa_balancing",
394                 .data           = NULL, /* filled in by handler */
395                 .maxlen         = sizeof(unsigned int),
396                 .mode           = 0644,
397                 .proc_handler   = sysctl_numa_balancing,
398                 .extra1         = &zero,
399                 .extra2         = &one,
400         },
401 #endif /* CONFIG_NUMA_BALANCING */
402 #endif /* CONFIG_SCHED_DEBUG */
403         {
404                 .procname       = "sched_rt_period_us",
405                 .data           = &sysctl_sched_rt_period,
406                 .maxlen         = sizeof(unsigned int),
407                 .mode           = 0644,
408                 .proc_handler   = sched_rt_handler,
409         },
410         {
411                 .procname       = "sched_rt_runtime_us",
412                 .data           = &sysctl_sched_rt_runtime,
413                 .maxlen         = sizeof(int),
414                 .mode           = 0644,
415                 .proc_handler   = sched_rt_handler,
416         },
417         {
418                 .procname       = "sched_rr_timeslice_ms",
419                 .data           = &sched_rr_timeslice,
420                 .maxlen         = sizeof(int),
421                 .mode           = 0644,
422                 .proc_handler   = sched_rr_handler,
423         },
424 #ifdef CONFIG_SCHED_AUTOGROUP
425         {
426                 .procname       = "sched_autogroup_enabled",
427                 .data           = &sysctl_sched_autogroup_enabled,
428                 .maxlen         = sizeof(unsigned int),
429                 .mode           = 0644,
430                 .proc_handler   = proc_dointvec_minmax,
431                 .extra1         = &zero,
432                 .extra2         = &one,
433         },
434 #endif
435 #ifdef CONFIG_CFS_BANDWIDTH
436         {
437                 .procname       = "sched_cfs_bandwidth_slice_us",
438                 .data           = &sysctl_sched_cfs_bandwidth_slice,
439                 .maxlen         = sizeof(unsigned int),
440                 .mode           = 0644,
441                 .proc_handler   = proc_dointvec_minmax,
442                 .extra1         = &one,
443         },
444 #endif
445 #ifdef CONFIG_PROVE_LOCKING
446         {
447                 .procname       = "prove_locking",
448                 .data           = &prove_locking,
449                 .maxlen         = sizeof(int),
450                 .mode           = 0644,
451                 .proc_handler   = proc_dointvec,
452         },
453 #endif
454 #ifdef CONFIG_LOCK_STAT
455         {
456                 .procname       = "lock_stat",
457                 .data           = &lock_stat,
458                 .maxlen         = sizeof(int),
459                 .mode           = 0644,
460                 .proc_handler   = proc_dointvec,
461         },
462 #endif
463         {
464                 .procname       = "panic",
465                 .data           = &panic_timeout,
466                 .maxlen         = sizeof(int),
467                 .mode           = 0644,
468                 .proc_handler   = proc_dointvec,
469         },
470 #ifdef CONFIG_COREDUMP
471         {
472                 .procname       = "core_uses_pid",
473                 .data           = &core_uses_pid,
474                 .maxlen         = sizeof(int),
475                 .mode           = 0644,
476                 .proc_handler   = proc_dointvec,
477         },
478         {
479                 .procname       = "core_pattern",
480                 .data           = core_pattern,
481                 .maxlen         = CORENAME_MAX_SIZE,
482                 .mode           = 0644,
483                 .proc_handler   = proc_dostring_coredump,
484         },
485         {
486                 .procname       = "core_pipe_limit",
487                 .data           = &core_pipe_limit,
488                 .maxlen         = sizeof(unsigned int),
489                 .mode           = 0644,
490                 .proc_handler   = proc_dointvec,
491         },
492 #endif
493 #ifdef CONFIG_PROC_SYSCTL
494         {
495                 .procname       = "tainted",
496                 .maxlen         = sizeof(long),
497                 .mode           = 0644,
498                 .proc_handler   = proc_taint,
499         },
500         {
501                 .procname       = "sysctl_writes_strict",
502                 .data           = &sysctl_writes_strict,
503                 .maxlen         = sizeof(int),
504                 .mode           = 0644,
505                 .proc_handler   = proc_dointvec_minmax,
506                 .extra1         = &neg_one,
507                 .extra2         = &one,
508         },
509 #endif
510 #ifdef CONFIG_LATENCYTOP
511         {
512                 .procname       = "latencytop",
513                 .data           = &latencytop_enabled,
514                 .maxlen         = sizeof(int),
515                 .mode           = 0644,
516                 .proc_handler   = sysctl_latencytop,
517         },
518 #endif
519 #ifdef CONFIG_BLK_DEV_INITRD
520         {
521                 .procname       = "real-root-dev",
522                 .data           = &real_root_dev,
523                 .maxlen         = sizeof(int),
524                 .mode           = 0644,
525                 .proc_handler   = proc_dointvec,
526         },
527 #endif
528         {
529                 .procname       = "print-fatal-signals",
530                 .data           = &print_fatal_signals,
531                 .maxlen         = sizeof(int),
532                 .mode           = 0644,
533                 .proc_handler   = proc_dointvec,
534         },
535 #ifdef CONFIG_SPARC
536         {
537                 .procname       = "reboot-cmd",
538                 .data           = reboot_command,
539                 .maxlen         = 256,
540                 .mode           = 0644,
541                 .proc_handler   = proc_dostring,
542         },
543         {
544                 .procname       = "stop-a",
545                 .data           = &stop_a_enabled,
546                 .maxlen         = sizeof (int),
547                 .mode           = 0644,
548                 .proc_handler   = proc_dointvec,
549         },
550         {
551                 .procname       = "scons-poweroff",
552                 .data           = &scons_pwroff,
553                 .maxlen         = sizeof (int),
554                 .mode           = 0644,
555                 .proc_handler   = proc_dointvec,
556         },
557 #endif
558 #ifdef CONFIG_SPARC64
559         {
560                 .procname       = "tsb-ratio",
561                 .data           = &sysctl_tsb_ratio,
562                 .maxlen         = sizeof (int),
563                 .mode           = 0644,
564                 .proc_handler   = proc_dointvec,
565         },
566 #endif
567 #ifdef __hppa__
568         {
569                 .procname       = "soft-power",
570                 .data           = &pwrsw_enabled,
571                 .maxlen         = sizeof (int),
572                 .mode           = 0644,
573                 .proc_handler   = proc_dointvec,
574         },
575 #endif
576 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
577         {
578                 .procname       = "unaligned-trap",
579                 .data           = &unaligned_enabled,
580                 .maxlen         = sizeof (int),
581                 .mode           = 0644,
582                 .proc_handler   = proc_dointvec,
583         },
584 #endif
585         {
586                 .procname       = "ctrl-alt-del",
587                 .data           = &C_A_D,
588                 .maxlen         = sizeof(int),
589                 .mode           = 0644,
590                 .proc_handler   = proc_dointvec,
591         },
592 #ifdef CONFIG_FUNCTION_TRACER
593         {
594                 .procname       = "ftrace_enabled",
595                 .data           = &ftrace_enabled,
596                 .maxlen         = sizeof(int),
597                 .mode           = 0644,
598                 .proc_handler   = ftrace_enable_sysctl,
599         },
600 #endif
601 #ifdef CONFIG_STACK_TRACER
602         {
603                 .procname       = "stack_tracer_enabled",
604                 .data           = &stack_tracer_enabled,
605                 .maxlen         = sizeof(int),
606                 .mode           = 0644,
607                 .proc_handler   = stack_trace_sysctl,
608         },
609 #endif
610 #ifdef CONFIG_TRACING
611         {
612                 .procname       = "ftrace_dump_on_oops",
613                 .data           = &ftrace_dump_on_oops,
614                 .maxlen         = sizeof(int),
615                 .mode           = 0644,
616                 .proc_handler   = proc_dointvec,
617         },
618         {
619                 .procname       = "traceoff_on_warning",
620                 .data           = &__disable_trace_on_warning,
621                 .maxlen         = sizeof(__disable_trace_on_warning),
622                 .mode           = 0644,
623                 .proc_handler   = proc_dointvec,
624         },
625         {
626                 .procname       = "tracepoint_printk",
627                 .data           = &tracepoint_printk,
628                 .maxlen         = sizeof(tracepoint_printk),
629                 .mode           = 0644,
630                 .proc_handler   = tracepoint_printk_sysctl,
631         },
632 #endif
633 #ifdef CONFIG_KEXEC_CORE
634         {
635                 .procname       = "kexec_load_disabled",
636                 .data           = &kexec_load_disabled,
637                 .maxlen         = sizeof(int),
638                 .mode           = 0644,
639                 /* only handle a transition from default "" to "1" */
640                 .proc_handler   = proc_dointvec_minmax,
641                 .extra1         = &one,
642                 .extra2         = &one,
643         },
644 #endif
645 #ifdef CONFIG_MODULES
646         {
647                 .procname       = "modprobe",
648                 .data           = &modprobe_path,
649                 .maxlen         = KMOD_PATH_LEN,
650                 .mode           = 0644,
651                 .proc_handler   = proc_dostring,
652         },
653         {
654                 .procname       = "modules_disabled",
655                 .data           = &modules_disabled,
656                 .maxlen         = sizeof(int),
657                 .mode           = 0644,
658                 /* only handle a transition from default "" to "1" */
659                 .proc_handler   = proc_dointvec_minmax,
660                 .extra1         = &one,
661                 .extra2         = &one,
662         },
663 #endif
664 #ifdef CONFIG_UEVENT_HELPER
665         {
666                 .procname       = "hotplug",
667                 .data           = &uevent_helper,
668                 .maxlen         = UEVENT_HELPER_PATH_LEN,
669                 .mode           = 0644,
670                 .proc_handler   = proc_dostring,
671         },
672 #endif
673 #ifdef CONFIG_CHR_DEV_SG
674         {
675                 .procname       = "sg-big-buff",
676                 .data           = &sg_big_buff,
677                 .maxlen         = sizeof (int),
678                 .mode           = 0444,
679                 .proc_handler   = proc_dointvec,
680         },
681 #endif
682 #ifdef CONFIG_BSD_PROCESS_ACCT
683         {
684                 .procname       = "acct",
685                 .data           = &acct_parm,
686                 .maxlen         = 3*sizeof(int),
687                 .mode           = 0644,
688                 .proc_handler   = proc_dointvec,
689         },
690 #endif
691 #ifdef CONFIG_MAGIC_SYSRQ
692         {
693                 .procname       = "sysrq",
694                 .data           = &__sysrq_enabled,
695                 .maxlen         = sizeof (int),
696                 .mode           = 0644,
697                 .proc_handler   = sysrq_sysctl_handler,
698         },
699 #endif
700 #ifdef CONFIG_PROC_SYSCTL
701         {
702                 .procname       = "cad_pid",
703                 .data           = NULL,
704                 .maxlen         = sizeof (int),
705                 .mode           = 0600,
706                 .proc_handler   = proc_do_cad_pid,
707         },
708 #endif
709         {
710                 .procname       = "threads-max",
711                 .data           = NULL,
712                 .maxlen         = sizeof(int),
713                 .mode           = 0644,
714                 .proc_handler   = sysctl_max_threads,
715         },
716         {
717                 .procname       = "random",
718                 .mode           = 0555,
719                 .child          = random_table,
720         },
721         {
722                 .procname       = "usermodehelper",
723                 .mode           = 0555,
724                 .child          = usermodehelper_table,
725         },
726         {
727                 .procname       = "overflowuid",
728                 .data           = &overflowuid,
729                 .maxlen         = sizeof(int),
730                 .mode           = 0644,
731                 .proc_handler   = proc_dointvec_minmax,
732                 .extra1         = &minolduid,
733                 .extra2         = &maxolduid,
734         },
735         {
736                 .procname       = "overflowgid",
737                 .data           = &overflowgid,
738                 .maxlen         = sizeof(int),
739                 .mode           = 0644,
740                 .proc_handler   = proc_dointvec_minmax,
741                 .extra1         = &minolduid,
742                 .extra2         = &maxolduid,
743         },
744 #ifdef CONFIG_S390
745 #ifdef CONFIG_MATHEMU
746         {
747                 .procname       = "ieee_emulation_warnings",
748                 .data           = &sysctl_ieee_emulation_warnings,
749                 .maxlen         = sizeof(int),
750                 .mode           = 0644,
751                 .proc_handler   = proc_dointvec,
752         },
753 #endif
754         {
755                 .procname       = "userprocess_debug",
756                 .data           = &show_unhandled_signals,
757                 .maxlen         = sizeof(int),
758                 .mode           = 0644,
759                 .proc_handler   = proc_dointvec,
760         },
761 #endif
762         {
763                 .procname       = "pid_max",
764                 .data           = &pid_max,
765                 .maxlen         = sizeof (int),
766                 .mode           = 0644,
767                 .proc_handler   = proc_dointvec_minmax,
768                 .extra1         = &pid_max_min,
769                 .extra2         = &pid_max_max,
770         },
771         {
772                 .procname       = "panic_on_oops",
773                 .data           = &panic_on_oops,
774                 .maxlen         = sizeof(int),
775                 .mode           = 0644,
776                 .proc_handler   = proc_dointvec,
777         },
778 #if defined CONFIG_PRINTK
779         {
780                 .procname       = "printk",
781                 .data           = &console_loglevel,
782                 .maxlen         = 4*sizeof(int),
783                 .mode           = 0644,
784                 .proc_handler   = proc_dointvec,
785         },
786         {
787                 .procname       = "printk_ratelimit",
788                 .data           = &printk_ratelimit_state.interval,
789                 .maxlen         = sizeof(int),
790                 .mode           = 0644,
791                 .proc_handler   = proc_dointvec_jiffies,
792         },
793         {
794                 .procname       = "printk_ratelimit_burst",
795                 .data           = &printk_ratelimit_state.burst,
796                 .maxlen         = sizeof(int),
797                 .mode           = 0644,
798                 .proc_handler   = proc_dointvec,
799         },
800         {
801                 .procname       = "printk_delay",
802                 .data           = &printk_delay_msec,
803                 .maxlen         = sizeof(int),
804                 .mode           = 0644,
805                 .proc_handler   = proc_dointvec_minmax,
806                 .extra1         = &zero,
807                 .extra2         = &ten_thousand,
808         },
809         {
810                 .procname       = "printk_devkmsg",
811                 .data           = devkmsg_log_str,
812                 .maxlen         = DEVKMSG_STR_MAX_SIZE,
813                 .mode           = 0644,
814                 .proc_handler   = devkmsg_sysctl_set_loglvl,
815         },
816         {
817                 .procname       = "dmesg_restrict",
818                 .data           = &dmesg_restrict,
819                 .maxlen         = sizeof(int),
820                 .mode           = 0644,
821                 .proc_handler   = proc_dointvec_minmax_sysadmin,
822                 .extra1         = &zero,
823                 .extra2         = &one,
824         },
825         {
826                 .procname       = "kptr_restrict",
827                 .data           = &kptr_restrict,
828                 .maxlen         = sizeof(int),
829                 .mode           = 0644,
830                 .proc_handler   = proc_dointvec_minmax_sysadmin,
831                 .extra1         = &zero,
832                 .extra2         = &two,
833         },
834 #endif
835         {
836                 .procname       = "ngroups_max",
837                 .data           = &ngroups_max,
838                 .maxlen         = sizeof (int),
839                 .mode           = 0444,
840                 .proc_handler   = proc_dointvec,
841         },
842         {
843                 .procname       = "cap_last_cap",
844                 .data           = (void *)&cap_last_cap,
845                 .maxlen         = sizeof(int),
846                 .mode           = 0444,
847                 .proc_handler   = proc_dointvec,
848         },
849 #if defined(CONFIG_LOCKUP_DETECTOR)
850         {
851                 .procname       = "watchdog",
852                 .data           = &watchdog_user_enabled,
853                 .maxlen         = sizeof (int),
854                 .mode           = 0644,
855                 .proc_handler   = proc_watchdog,
856                 .extra1         = &zero,
857                 .extra2         = &one,
858         },
859         {
860                 .procname       = "watchdog_thresh",
861                 .data           = &watchdog_thresh,
862                 .maxlen         = sizeof(int),
863                 .mode           = 0644,
864                 .proc_handler   = proc_watchdog_thresh,
865                 .extra1         = &zero,
866                 .extra2         = &sixty,
867         },
868         {
869                 .procname       = "nmi_watchdog",
870                 .data           = &nmi_watchdog_enabled,
871                 .maxlen         = sizeof (int),
872                 .mode           = 0644,
873                 .proc_handler   = proc_nmi_watchdog,
874                 .extra1         = &zero,
875 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
876                 .extra2         = &one,
877 #else
878                 .extra2         = &zero,
879 #endif
880         },
881         {
882                 .procname       = "soft_watchdog",
883                 .data           = &soft_watchdog_enabled,
884                 .maxlen         = sizeof (int),
885                 .mode           = 0644,
886                 .proc_handler   = proc_soft_watchdog,
887                 .extra1         = &zero,
888                 .extra2         = &one,
889         },
890         {
891                 .procname       = "watchdog_cpumask",
892                 .data           = &watchdog_cpumask_bits,
893                 .maxlen         = NR_CPUS,
894                 .mode           = 0644,
895                 .proc_handler   = proc_watchdog_cpumask,
896         },
897         {
898                 .procname       = "softlockup_panic",
899                 .data           = &softlockup_panic,
900                 .maxlen         = sizeof(int),
901                 .mode           = 0644,
902                 .proc_handler   = proc_dointvec_minmax,
903                 .extra1         = &zero,
904                 .extra2         = &one,
905         },
906 #ifdef CONFIG_HARDLOCKUP_DETECTOR
907         {
908                 .procname       = "hardlockup_panic",
909                 .data           = &hardlockup_panic,
910                 .maxlen         = sizeof(int),
911                 .mode           = 0644,
912                 .proc_handler   = proc_dointvec_minmax,
913                 .extra1         = &zero,
914                 .extra2         = &one,
915         },
916 #endif
917 #ifdef CONFIG_SMP
918         {
919                 .procname       = "softlockup_all_cpu_backtrace",
920                 .data           = &sysctl_softlockup_all_cpu_backtrace,
921                 .maxlen         = sizeof(int),
922                 .mode           = 0644,
923                 .proc_handler   = proc_dointvec_minmax,
924                 .extra1         = &zero,
925                 .extra2         = &one,
926         },
927         {
928                 .procname       = "hardlockup_all_cpu_backtrace",
929                 .data           = &sysctl_hardlockup_all_cpu_backtrace,
930                 .maxlen         = sizeof(int),
931                 .mode           = 0644,
932                 .proc_handler   = proc_dointvec_minmax,
933                 .extra1         = &zero,
934                 .extra2         = &one,
935         },
936 #endif /* CONFIG_SMP */
937 #endif
938 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
939         {
940                 .procname       = "unknown_nmi_panic",
941                 .data           = &unknown_nmi_panic,
942                 .maxlen         = sizeof (int),
943                 .mode           = 0644,
944                 .proc_handler   = proc_dointvec,
945         },
946 #endif
947 #if defined(CONFIG_X86)
948         {
949                 .procname       = "panic_on_unrecovered_nmi",
950                 .data           = &panic_on_unrecovered_nmi,
951                 .maxlen         = sizeof(int),
952                 .mode           = 0644,
953                 .proc_handler   = proc_dointvec,
954         },
955         {
956                 .procname       = "panic_on_io_nmi",
957                 .data           = &panic_on_io_nmi,
958                 .maxlen         = sizeof(int),
959                 .mode           = 0644,
960                 .proc_handler   = proc_dointvec,
961         },
962 #ifdef CONFIG_DEBUG_STACKOVERFLOW
963         {
964                 .procname       = "panic_on_stackoverflow",
965                 .data           = &sysctl_panic_on_stackoverflow,
966                 .maxlen         = sizeof(int),
967                 .mode           = 0644,
968                 .proc_handler   = proc_dointvec,
969         },
970 #endif
971         {
972                 .procname       = "bootloader_type",
973                 .data           = &bootloader_type,
974                 .maxlen         = sizeof (int),
975                 .mode           = 0444,
976                 .proc_handler   = proc_dointvec,
977         },
978         {
979                 .procname       = "bootloader_version",
980                 .data           = &bootloader_version,
981                 .maxlen         = sizeof (int),
982                 .mode           = 0444,
983                 .proc_handler   = proc_dointvec,
984         },
985         {
986                 .procname       = "io_delay_type",
987                 .data           = &io_delay_type,
988                 .maxlen         = sizeof(int),
989                 .mode           = 0644,
990                 .proc_handler   = proc_dointvec,
991         },
992 #endif
993 #if defined(CONFIG_MMU)
994         {
995                 .procname       = "randomize_va_space",
996                 .data           = &randomize_va_space,
997                 .maxlen         = sizeof(int),
998                 .mode           = 0644,
999                 .proc_handler   = proc_dointvec,
1000         },
1001 #endif
1002 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1003         {
1004                 .procname       = "spin_retry",
1005                 .data           = &spin_retry,
1006                 .maxlen         = sizeof (int),
1007                 .mode           = 0644,
1008                 .proc_handler   = proc_dointvec,
1009         },
1010 #endif
1011 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1012         {
1013                 .procname       = "acpi_video_flags",
1014                 .data           = &acpi_realmode_flags,
1015                 .maxlen         = sizeof (unsigned long),
1016                 .mode           = 0644,
1017                 .proc_handler   = proc_doulongvec_minmax,
1018         },
1019 #endif
1020 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1021         {
1022                 .procname       = "ignore-unaligned-usertrap",
1023                 .data           = &no_unaligned_warning,
1024                 .maxlen         = sizeof (int),
1025                 .mode           = 0644,
1026                 .proc_handler   = proc_dointvec,
1027         },
1028 #endif
1029 #ifdef CONFIG_IA64
1030         {
1031                 .procname       = "unaligned-dump-stack",
1032                 .data           = &unaligned_dump_stack,
1033                 .maxlen         = sizeof (int),
1034                 .mode           = 0644,
1035                 .proc_handler   = proc_dointvec,
1036         },
1037 #endif
1038 #ifdef CONFIG_DETECT_HUNG_TASK
1039         {
1040                 .procname       = "hung_task_panic",
1041                 .data           = &sysctl_hung_task_panic,
1042                 .maxlen         = sizeof(int),
1043                 .mode           = 0644,
1044                 .proc_handler   = proc_dointvec_minmax,
1045                 .extra1         = &zero,
1046                 .extra2         = &one,
1047         },
1048         {
1049                 .procname       = "hung_task_check_count",
1050                 .data           = &sysctl_hung_task_check_count,
1051                 .maxlen         = sizeof(int),
1052                 .mode           = 0644,
1053                 .proc_handler   = proc_dointvec_minmax,
1054                 .extra1         = &zero,
1055         },
1056         {
1057                 .procname       = "hung_task_timeout_secs",
1058                 .data           = &sysctl_hung_task_timeout_secs,
1059                 .maxlen         = sizeof(unsigned long),
1060                 .mode           = 0644,
1061                 .proc_handler   = proc_dohung_task_timeout_secs,
1062                 .extra2         = &hung_task_timeout_max,
1063         },
1064         {
1065                 .procname       = "hung_task_warnings",
1066                 .data           = &sysctl_hung_task_warnings,
1067                 .maxlen         = sizeof(int),
1068                 .mode           = 0644,
1069                 .proc_handler   = proc_dointvec_minmax,
1070                 .extra1         = &neg_one,
1071         },
1072 #endif
1073 #ifdef CONFIG_RT_MUTEXES
1074         {
1075                 .procname       = "max_lock_depth",
1076                 .data           = &max_lock_depth,
1077                 .maxlen         = sizeof(int),
1078                 .mode           = 0644,
1079                 .proc_handler   = proc_dointvec,
1080         },
1081 #endif
1082         {
1083                 .procname       = "poweroff_cmd",
1084                 .data           = &poweroff_cmd,
1085                 .maxlen         = POWEROFF_CMD_PATH_LEN,
1086                 .mode           = 0644,
1087                 .proc_handler   = proc_dostring,
1088         },
1089 #ifdef CONFIG_KEYS
1090         {
1091                 .procname       = "keys",
1092                 .mode           = 0555,
1093                 .child          = key_sysctls,
1094         },
1095 #endif
1096 #ifdef CONFIG_PERF_EVENTS
1097         /*
1098          * User-space scripts rely on the existence of this file
1099          * as a feature check for perf_events being enabled.
1100          *
1101          * So it's an ABI, do not remove!
1102          */
1103         {
1104                 .procname       = "perf_event_paranoid",
1105                 .data           = &sysctl_perf_event_paranoid,
1106                 .maxlen         = sizeof(sysctl_perf_event_paranoid),
1107                 .mode           = 0644,
1108                 .proc_handler   = proc_dointvec,
1109         },
1110         {
1111                 .procname       = "perf_event_mlock_kb",
1112                 .data           = &sysctl_perf_event_mlock,
1113                 .maxlen         = sizeof(sysctl_perf_event_mlock),
1114                 .mode           = 0644,
1115                 .proc_handler   = proc_dointvec,
1116         },
1117         {
1118                 .procname       = "perf_event_max_sample_rate",
1119                 .data           = &sysctl_perf_event_sample_rate,
1120                 .maxlen         = sizeof(sysctl_perf_event_sample_rate),
1121                 .mode           = 0644,
1122                 .proc_handler   = perf_proc_update_handler,
1123                 .extra1         = &one,
1124         },
1125         {
1126                 .procname       = "perf_cpu_time_max_percent",
1127                 .data           = &sysctl_perf_cpu_time_max_percent,
1128                 .maxlen         = sizeof(sysctl_perf_cpu_time_max_percent),
1129                 .mode           = 0644,
1130                 .proc_handler   = perf_cpu_time_max_percent_handler,
1131                 .extra1         = &zero,
1132                 .extra2         = &one_hundred,
1133         },
1134         {
1135                 .procname       = "perf_event_max_stack",
1136                 .data           = &sysctl_perf_event_max_stack,
1137                 .maxlen         = sizeof(sysctl_perf_event_max_stack),
1138                 .mode           = 0644,
1139                 .proc_handler   = perf_event_max_stack_handler,
1140                 .extra1         = &zero,
1141                 .extra2         = &six_hundred_forty_kb,
1142         },
1143         {
1144                 .procname       = "perf_event_max_contexts_per_stack",
1145                 .data           = &sysctl_perf_event_max_contexts_per_stack,
1146                 .maxlen         = sizeof(sysctl_perf_event_max_contexts_per_stack),
1147                 .mode           = 0644,
1148                 .proc_handler   = perf_event_max_stack_handler,
1149                 .extra1         = &zero,
1150                 .extra2         = &one_thousand,
1151         },
1152 #endif
1153 #ifdef CONFIG_KMEMCHECK
1154         {
1155                 .procname       = "kmemcheck",
1156                 .data           = &kmemcheck_enabled,
1157                 .maxlen         = sizeof(int),
1158                 .mode           = 0644,
1159                 .proc_handler   = proc_dointvec,
1160         },
1161 #endif
1162         {
1163                 .procname       = "panic_on_warn",
1164                 .data           = &panic_on_warn,
1165                 .maxlen         = sizeof(int),
1166                 .mode           = 0644,
1167                 .proc_handler   = proc_dointvec_minmax,
1168                 .extra1         = &zero,
1169                 .extra2         = &one,
1170         },
1171 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1172         {
1173                 .procname       = "timer_migration",
1174                 .data           = &sysctl_timer_migration,
1175                 .maxlen         = sizeof(unsigned int),
1176                 .mode           = 0644,
1177                 .proc_handler   = timer_migration_handler,
1178         },
1179 #endif
1180 #ifdef CONFIG_BPF_SYSCALL
1181         {
1182                 .procname       = "unprivileged_bpf_disabled",
1183                 .data           = &sysctl_unprivileged_bpf_disabled,
1184                 .maxlen         = sizeof(sysctl_unprivileged_bpf_disabled),
1185                 .mode           = 0644,
1186                 /* only handle a transition from default "" to "1" */
1187                 .proc_handler   = proc_dointvec_minmax,
1188                 .extra1         = &one,
1189                 .extra2         = &one,
1190         },
1191 #endif
1192 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
1193         {
1194                 .procname       = "panic_on_rcu_stall",
1195                 .data           = &sysctl_panic_on_rcu_stall,
1196                 .maxlen         = sizeof(sysctl_panic_on_rcu_stall),
1197                 .mode           = 0644,
1198                 .proc_handler   = proc_dointvec_minmax,
1199                 .extra1         = &zero,
1200                 .extra2         = &one,
1201         },
1202 #endif
1203         { }
1204 };
1205 
1206 static struct ctl_table vm_table[] = {
1207         {
1208                 .procname       = "overcommit_memory",
1209                 .data           = &sysctl_overcommit_memory,
1210                 .maxlen         = sizeof(sysctl_overcommit_memory),
1211                 .mode           = 0644,
1212                 .proc_handler   = proc_dointvec_minmax,
1213                 .extra1         = &zero,
1214                 .extra2         = &two,
1215         },
1216         {
1217                 .procname       = "panic_on_oom",
1218                 .data           = &sysctl_panic_on_oom,
1219                 .maxlen         = sizeof(sysctl_panic_on_oom),
1220                 .mode           = 0644,
1221                 .proc_handler   = proc_dointvec_minmax,
1222                 .extra1         = &zero,
1223                 .extra2         = &two,
1224         },
1225         {
1226                 .procname       = "oom_kill_allocating_task",
1227                 .data           = &sysctl_oom_kill_allocating_task,
1228                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
1229                 .mode           = 0644,
1230                 .proc_handler   = proc_dointvec,
1231         },
1232         {
1233                 .procname       = "oom_dump_tasks",
1234                 .data           = &sysctl_oom_dump_tasks,
1235                 .maxlen         = sizeof(sysctl_oom_dump_tasks),
1236                 .mode           = 0644,
1237                 .proc_handler   = proc_dointvec,
1238         },
1239         {
1240                 .procname       = "overcommit_ratio",
1241                 .data           = &sysctl_overcommit_ratio,
1242                 .maxlen         = sizeof(sysctl_overcommit_ratio),
1243                 .mode           = 0644,
1244                 .proc_handler   = overcommit_ratio_handler,
1245         },
1246         {
1247                 .procname       = "overcommit_kbytes",
1248                 .data           = &sysctl_overcommit_kbytes,
1249                 .maxlen         = sizeof(sysctl_overcommit_kbytes),
1250                 .mode           = 0644,
1251                 .proc_handler   = overcommit_kbytes_handler,
1252         },
1253         {
1254                 .procname       = "page-cluster", 
1255                 .data           = &page_cluster,
1256                 .maxlen         = sizeof(int),
1257                 .mode           = 0644,
1258                 .proc_handler   = proc_dointvec_minmax,
1259                 .extra1         = &zero,
1260         },
1261         {
1262                 .procname       = "dirty_background_ratio",
1263                 .data           = &dirty_background_ratio,
1264                 .maxlen         = sizeof(dirty_background_ratio),
1265                 .mode           = 0644,
1266                 .proc_handler   = dirty_background_ratio_handler,
1267                 .extra1         = &zero,
1268                 .extra2         = &one_hundred,
1269         },
1270         {
1271                 .procname       = "dirty_background_bytes",
1272                 .data           = &dirty_background_bytes,
1273                 .maxlen         = sizeof(dirty_background_bytes),
1274                 .mode           = 0644,
1275                 .proc_handler   = dirty_background_bytes_handler,
1276                 .extra1         = &one_ul,
1277         },
1278         {
1279                 .procname       = "dirty_ratio",
1280                 .data           = &vm_dirty_ratio,
1281                 .maxlen         = sizeof(vm_dirty_ratio),
1282                 .mode           = 0644,
1283                 .proc_handler   = dirty_ratio_handler,
1284                 .extra1         = &zero,
1285                 .extra2         = &one_hundred,
1286         },
1287         {
1288                 .procname       = "dirty_bytes",
1289                 .data           = &vm_dirty_bytes,
1290                 .maxlen         = sizeof(vm_dirty_bytes),
1291                 .mode           = 0644,
1292                 .proc_handler   = dirty_bytes_handler,
1293                 .extra1         = &dirty_bytes_min,
1294         },
1295         {
1296                 .procname       = "dirty_writeback_centisecs",
1297                 .data           = &dirty_writeback_interval,
1298                 .maxlen         = sizeof(dirty_writeback_interval),
1299                 .mode           = 0644,
1300                 .proc_handler   = dirty_writeback_centisecs_handler,
1301         },
1302         {
1303                 .procname       = "dirty_expire_centisecs",
1304                 .data           = &dirty_expire_interval,
1305                 .maxlen         = sizeof(dirty_expire_interval),
1306                 .mode           = 0644,
1307                 .proc_handler   = proc_dointvec_minmax,
1308                 .extra1         = &zero,
1309         },
1310         {
1311                 .procname       = "dirtytime_expire_seconds",
1312                 .data           = &dirtytime_expire_interval,
1313                 .maxlen         = sizeof(dirty_expire_interval),
1314                 .mode           = 0644,
1315                 .proc_handler   = dirtytime_interval_handler,
1316                 .extra1         = &zero,
1317         },
1318         {
1319                 .procname       = "nr_pdflush_threads",
1320                 .mode           = 0444 /* read-only */,
1321                 .proc_handler   = pdflush_proc_obsolete,
1322         },
1323         {
1324                 .procname       = "swappiness",
1325                 .data           = &vm_swappiness,
1326                 .maxlen         = sizeof(vm_swappiness),
1327                 .mode           = 0644,
1328                 .proc_handler   = proc_dointvec_minmax,
1329                 .extra1         = &zero,
1330                 .extra2         = &one_hundred,
1331         },
1332 #ifdef CONFIG_HUGETLB_PAGE
1333         {
1334                 .procname       = "nr_hugepages",
1335                 .data           = NULL,
1336                 .maxlen         = sizeof(unsigned long),
1337                 .mode           = 0644,
1338                 .proc_handler   = hugetlb_sysctl_handler,
1339         },
1340 #ifdef CONFIG_NUMA
1341         {
1342                 .procname       = "nr_hugepages_mempolicy",
1343                 .data           = NULL,
1344                 .maxlen         = sizeof(unsigned long),
1345                 .mode           = 0644,
1346                 .proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1347         },
1348 #endif
1349          {
1350                 .procname       = "hugetlb_shm_group",
1351                 .data           = &sysctl_hugetlb_shm_group,
1352                 .maxlen         = sizeof(gid_t),
1353                 .mode           = 0644,
1354                 .proc_handler   = proc_dointvec,
1355          },
1356          {
1357                 .procname       = "hugepages_treat_as_movable",
1358                 .data           = &hugepages_treat_as_movable,
1359                 .maxlen         = sizeof(int),
1360                 .mode           = 0644,
1361                 .proc_handler   = proc_dointvec,
1362         },
1363         {
1364                 .procname       = "nr_overcommit_hugepages",
1365                 .data           = NULL,
1366                 .maxlen         = sizeof(unsigned long),
1367                 .mode           = 0644,
1368                 .proc_handler   = hugetlb_overcommit_handler,
1369         },
1370 #endif
1371         {
1372                 .procname       = "lowmem_reserve_ratio",
1373                 .data           = &sysctl_lowmem_reserve_ratio,
1374                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
1375                 .mode           = 0644,
1376                 .proc_handler   = lowmem_reserve_ratio_sysctl_handler,
1377         },
1378         {
1379                 .procname       = "drop_caches",
1380                 .data           = &sysctl_drop_caches,
1381                 .maxlen         = sizeof(int),
1382                 .mode           = 0644,
1383                 .proc_handler   = drop_caches_sysctl_handler,
1384                 .extra1         = &one,
1385                 .extra2         = &four,
1386         },
1387 #ifdef CONFIG_COMPACTION
1388         {
1389                 .procname       = "compact_memory",
1390                 .data           = &sysctl_compact_memory,
1391                 .maxlen         = sizeof(int),
1392                 .mode           = 0200,
1393                 .proc_handler   = sysctl_compaction_handler,
1394         },
1395         {
1396                 .procname       = "extfrag_threshold",
1397                 .data           = &sysctl_extfrag_threshold,
1398                 .maxlen         = sizeof(int),
1399                 .mode           = 0644,
1400                 .proc_handler   = sysctl_extfrag_handler,
1401                 .extra1         = &min_extfrag_threshold,
1402                 .extra2         = &max_extfrag_threshold,
1403         },
1404         {
1405                 .procname       = "compact_unevictable_allowed",
1406                 .data           = &sysctl_compact_unevictable_allowed,
1407                 .maxlen         = sizeof(int),
1408                 .mode           = 0644,
1409                 .proc_handler   = proc_dointvec,
1410                 .extra1         = &zero,
1411                 .extra2         = &one,
1412         },
1413 
1414 #endif /* CONFIG_COMPACTION */
1415         {
1416                 .procname       = "min_free_kbytes",
1417                 .data           = &min_free_kbytes,
1418                 .maxlen         = sizeof(min_free_kbytes),
1419                 .mode           = 0644,
1420                 .proc_handler   = min_free_kbytes_sysctl_handler,
1421                 .extra1         = &zero,
1422         },
1423         {
1424                 .procname       = "watermark_scale_factor",
1425                 .data           = &watermark_scale_factor,
1426                 .maxlen         = sizeof(watermark_scale_factor),
1427                 .mode           = 0644,
1428                 .proc_handler   = watermark_scale_factor_sysctl_handler,
1429                 .extra1         = &one,
1430                 .extra2         = &one_thousand,
1431         },
1432         {
1433                 .procname       = "percpu_pagelist_fraction",
1434                 .data           = &percpu_pagelist_fraction,
1435                 .maxlen         = sizeof(percpu_pagelist_fraction),
1436                 .mode           = 0644,
1437                 .proc_handler   = percpu_pagelist_fraction_sysctl_handler,
1438                 .extra1         = &zero,
1439         },
1440 #ifdef CONFIG_MMU
1441         {
1442                 .procname       = "max_map_count",
1443                 .data           = &sysctl_max_map_count,
1444                 .maxlen         = sizeof(sysctl_max_map_count),
1445                 .mode           = 0644,
1446                 .proc_handler   = proc_dointvec_minmax,
1447                 .extra1         = &zero,
1448         },
1449 #else
1450         {
1451                 .procname       = "nr_trim_pages",
1452                 .data           = &sysctl_nr_trim_pages,
1453                 .maxlen         = sizeof(sysctl_nr_trim_pages),
1454                 .mode           = 0644,
1455                 .proc_handler   = proc_dointvec_minmax,
1456                 .extra1         = &zero,
1457         },
1458 #endif
1459         {
1460                 .procname       = "laptop_mode",
1461                 .data           = &laptop_mode,
1462                 .maxlen         = sizeof(laptop_mode),
1463                 .mode           = 0644,
1464                 .proc_handler   = proc_dointvec_jiffies,
1465         },
1466         {
1467                 .procname       = "block_dump",
1468                 .data           = &block_dump,
1469                 .maxlen         = sizeof(block_dump),
1470                 .mode           = 0644,
1471                 .proc_handler   = proc_dointvec,
1472                 .extra1         = &zero,
1473         },
1474         {
1475                 .procname       = "vfs_cache_pressure",
1476                 .data           = &sysctl_vfs_cache_pressure,
1477                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
1478                 .mode           = 0644,
1479                 .proc_handler   = proc_dointvec,
1480                 .extra1         = &zero,
1481         },
1482 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1483         {
1484                 .procname       = "legacy_va_layout",
1485                 .data           = &sysctl_legacy_va_layout,
1486                 .maxlen         = sizeof(sysctl_legacy_va_layout),
1487                 .mode           = 0644,
1488                 .proc_handler   = proc_dointvec,
1489                 .extra1         = &zero,
1490         },
1491 #endif
1492 #ifdef CONFIG_NUMA
1493         {
1494                 .procname       = "zone_reclaim_mode",
1495                 .data           = &node_reclaim_mode,
1496                 .maxlen         = sizeof(node_reclaim_mode),
1497                 .mode           = 0644,
1498                 .proc_handler   = proc_dointvec,
1499                 .extra1         = &zero,
1500         },
1501         {
1502                 .procname       = "min_unmapped_ratio",
1503                 .data           = &sysctl_min_unmapped_ratio,
1504                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1505                 .mode           = 0644,
1506                 .proc_handler   = sysctl_min_unmapped_ratio_sysctl_handler,
1507                 .extra1         = &zero,
1508                 .extra2         = &one_hundred,
1509         },
1510         {
1511                 .procname       = "min_slab_ratio",
1512                 .data           = &sysctl_min_slab_ratio,
1513                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1514                 .mode           = 0644,
1515                 .proc_handler   = sysctl_min_slab_ratio_sysctl_handler,
1516                 .extra1         = &zero,
1517                 .extra2         = &one_hundred,
1518         },
1519 #endif
1520 #ifdef CONFIG_SMP
1521         {
1522                 .procname       = "stat_interval",
1523                 .data           = &sysctl_stat_interval,
1524                 .maxlen         = sizeof(sysctl_stat_interval),
1525                 .mode           = 0644,
1526                 .proc_handler   = proc_dointvec_jiffies,
1527         },
1528         {
1529                 .procname       = "stat_refresh",
1530                 .data           = NULL,
1531                 .maxlen         = 0,
1532                 .mode           = 0600,
1533                 .proc_handler   = vmstat_refresh,
1534         },
1535 #endif
1536 #ifdef CONFIG_MMU
1537         {
1538                 .procname       = "mmap_min_addr",
1539                 .data           = &dac_mmap_min_addr,
1540                 .maxlen         = sizeof(unsigned long),
1541                 .mode           = 0644,
1542                 .proc_handler   = mmap_min_addr_handler,
1543         },
1544 #endif
1545 #ifdef CONFIG_NUMA
1546         {
1547                 .procname       = "numa_zonelist_order",
1548                 .data           = &numa_zonelist_order,
1549                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1550                 .mode           = 0644,
1551                 .proc_handler   = numa_zonelist_order_handler,
1552         },
1553 #endif
1554 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1555    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1556         {
1557                 .procname       = "vdso_enabled",
1558 #ifdef CONFIG_X86_32
1559                 .data           = &vdso32_enabled,
1560                 .maxlen         = sizeof(vdso32_enabled),
1561 #else
1562                 .data           = &vdso_enabled,
1563                 .maxlen         = sizeof(vdso_enabled),
1564 #endif
1565                 .mode           = 0644,
1566                 .proc_handler   = proc_dointvec,
1567                 .extra1         = &zero,
1568         },
1569 #endif
1570 #ifdef CONFIG_HIGHMEM
1571         {
1572                 .procname       = "highmem_is_dirtyable",
1573                 .data           = &vm_highmem_is_dirtyable,
1574                 .maxlen         = sizeof(vm_highmem_is_dirtyable),
1575                 .mode           = 0644,
1576                 .proc_handler   = proc_dointvec_minmax,
1577                 .extra1         = &zero,
1578                 .extra2         = &one,
1579         },
1580 #endif
1581 #ifdef CONFIG_MEMORY_FAILURE
1582         {
1583                 .procname       = "memory_failure_early_kill",
1584                 .data           = &sysctl_memory_failure_early_kill,
1585                 .maxlen         = sizeof(sysctl_memory_failure_early_kill),
1586                 .mode           = 0644,
1587                 .proc_handler   = proc_dointvec_minmax,
1588                 .extra1         = &zero,
1589                 .extra2         = &one,
1590         },
1591         {
1592                 .procname       = "memory_failure_recovery",
1593                 .data           = &sysctl_memory_failure_recovery,
1594                 .maxlen         = sizeof(sysctl_memory_failure_recovery),
1595                 .mode           = 0644,
1596                 .proc_handler   = proc_dointvec_minmax,
1597                 .extra1         = &zero,
1598                 .extra2         = &one,
1599         },
1600 #endif
1601         {
1602                 .procname       = "user_reserve_kbytes",
1603                 .data           = &sysctl_user_reserve_kbytes,
1604                 .maxlen         = sizeof(sysctl_user_reserve_kbytes),
1605                 .mode           = 0644,
1606                 .proc_handler   = proc_doulongvec_minmax,
1607         },
1608         {
1609                 .procname       = "admin_reserve_kbytes",
1610                 .data           = &sysctl_admin_reserve_kbytes,
1611                 .maxlen         = sizeof(sysctl_admin_reserve_kbytes),
1612                 .mode           = 0644,
1613                 .proc_handler   = proc_doulongvec_minmax,
1614         },
1615 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1616         {
1617                 .procname       = "mmap_rnd_bits",
1618                 .data           = &mmap_rnd_bits,
1619                 .maxlen         = sizeof(mmap_rnd_bits),
1620                 .mode           = 0600,
1621                 .proc_handler   = proc_dointvec_minmax,
1622                 .extra1         = (void *)&mmap_rnd_bits_min,
1623                 .extra2         = (void *)&mmap_rnd_bits_max,
1624         },
1625 #endif
1626 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1627         {
1628                 .procname       = "mmap_rnd_compat_bits",
1629                 .data           = &mmap_rnd_compat_bits,
1630                 .maxlen         = sizeof(mmap_rnd_compat_bits),
1631                 .mode           = 0600,
1632                 .proc_handler   = proc_dointvec_minmax,
1633                 .extra1         = (void *)&mmap_rnd_compat_bits_min,
1634                 .extra2         = (void *)&mmap_rnd_compat_bits_max,
1635         },
1636 #endif
1637         { }
1638 };
1639 
1640 static struct ctl_table fs_table[] = {
1641         {
1642                 .procname       = "inode-nr",
1643                 .data           = &inodes_stat,
1644                 .maxlen         = 2*sizeof(long),
1645                 .mode           = 0444,
1646                 .proc_handler   = proc_nr_inodes,
1647         },
1648         {
1649                 .procname       = "inode-state",
1650                 .data           = &inodes_stat,
1651                 .maxlen         = 7*sizeof(long),
1652                 .mode           = 0444,
1653                 .proc_handler   = proc_nr_inodes,
1654         },
1655         {
1656                 .procname       = "file-nr",
1657                 .data           = &files_stat,
1658                 .maxlen         = sizeof(files_stat),
1659                 .mode           = 0444,
1660                 .proc_handler   = proc_nr_files,
1661         },
1662         {
1663                 .procname       = "file-max",
1664                 .data           = &files_stat.max_files,
1665                 .maxlen         = sizeof(files_stat.max_files),
1666                 .mode           = 0644,
1667                 .proc_handler   = proc_doulongvec_minmax,
1668         },
1669         {
1670                 .procname       = "nr_open",
1671                 .data           = &sysctl_nr_open,
1672                 .maxlen         = sizeof(unsigned int),
1673                 .mode           = 0644,
1674                 .proc_handler   = proc_dointvec_minmax,
1675                 .extra1         = &sysctl_nr_open_min,
1676                 .extra2         = &sysctl_nr_open_max,
1677         },
1678         {
1679                 .procname       = "dentry-state",
1680                 .data           = &dentry_stat,
1681                 .maxlen         = 6*sizeof(long),
1682                 .mode           = 0444,
1683                 .proc_handler   = proc_nr_dentry,
1684         },
1685         {
1686                 .procname       = "overflowuid",
1687                 .data           = &fs_overflowuid,
1688                 .maxlen         = sizeof(int),
1689                 .mode           = 0644,
1690                 .proc_handler   = proc_dointvec_minmax,
1691                 .extra1         = &minolduid,
1692                 .extra2         = &maxolduid,
1693         },
1694         {
1695                 .procname       = "overflowgid",
1696                 .data           = &fs_overflowgid,
1697                 .maxlen         = sizeof(int),
1698                 .mode           = 0644,
1699                 .proc_handler   = proc_dointvec_minmax,
1700                 .extra1         = &minolduid,
1701                 .extra2         = &maxolduid,
1702         },
1703 #ifdef CONFIG_FILE_LOCKING
1704         {
1705                 .procname       = "leases-enable",
1706                 .data           = &leases_enable,
1707                 .maxlen         = sizeof(int),
1708                 .mode           = 0644,
1709                 .proc_handler   = proc_dointvec,
1710         },
1711 #endif
1712 #ifdef CONFIG_DNOTIFY
1713         {
1714                 .procname       = "dir-notify-enable",
1715                 .data           = &dir_notify_enable,
1716                 .maxlen         = sizeof(int),
1717                 .mode           = 0644,
1718                 .proc_handler   = proc_dointvec,
1719         },
1720 #endif
1721 #ifdef CONFIG_MMU
1722 #ifdef CONFIG_FILE_LOCKING
1723         {
1724                 .procname       = "lease-break-time",
1725                 .data           = &lease_break_time,
1726                 .maxlen         = sizeof(int),
1727                 .mode           = 0644,
1728                 .proc_handler   = proc_dointvec,
1729         },
1730 #endif
1731 #ifdef CONFIG_AIO
1732         {
1733                 .procname       = "aio-nr",
1734                 .data           = &aio_nr,
1735                 .maxlen         = sizeof(aio_nr),
1736                 .mode           = 0444,
1737                 .proc_handler   = proc_doulongvec_minmax,
1738         },
1739         {
1740                 .procname       = "aio-max-nr",
1741                 .data           = &aio_max_nr,
1742                 .maxlen         = sizeof(aio_max_nr),
1743                 .mode           = 0644,
1744                 .proc_handler   = proc_doulongvec_minmax,
1745         },
1746 #endif /* CONFIG_AIO */
1747 #ifdef CONFIG_INOTIFY_USER
1748         {
1749                 .procname       = "inotify",
1750                 .mode           = 0555,
1751                 .child          = inotify_table,
1752         },
1753 #endif  
1754 #ifdef CONFIG_EPOLL
1755         {
1756                 .procname       = "epoll",
1757                 .mode           = 0555,
1758                 .child          = epoll_table,
1759         },
1760 #endif
1761 #endif
1762         {
1763                 .procname       = "protected_symlinks",
1764                 .data           = &sysctl_protected_symlinks,
1765                 .maxlen         = sizeof(int),
1766                 .mode           = 0600,
1767                 .proc_handler   = proc_dointvec_minmax,
1768                 .extra1         = &zero,
1769                 .extra2         = &one,
1770         },
1771         {
1772                 .procname       = "protected_hardlinks",
1773                 .data           = &sysctl_protected_hardlinks,
1774                 .maxlen         = sizeof(int),
1775                 .mode           = 0600,
1776                 .proc_handler   = proc_dointvec_minmax,
1777                 .extra1         = &zero,
1778                 .extra2         = &one,
1779         },
1780         {
1781                 .procname       = "suid_dumpable",
1782                 .data           = &suid_dumpable,
1783                 .maxlen         = sizeof(int),
1784                 .mode           = 0644,
1785                 .proc_handler   = proc_dointvec_minmax_coredump,
1786                 .extra1         = &zero,
1787                 .extra2         = &two,
1788         },
1789 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1790         {
1791                 .procname       = "binfmt_misc",
1792                 .mode           = 0555,
1793                 .child          = sysctl_mount_point,
1794         },
1795 #endif
1796         {
1797                 .procname       = "pipe-max-size",
1798                 .data           = &pipe_max_size,
1799                 .maxlen         = sizeof(int),
1800                 .mode           = 0644,
1801                 .proc_handler   = &pipe_proc_fn,
1802                 .extra1         = &pipe_min_size,
1803         },
1804         {
1805                 .procname       = "pipe-user-pages-hard",
1806                 .data           = &pipe_user_pages_hard,
1807                 .maxlen         = sizeof(pipe_user_pages_hard),
1808                 .mode           = 0644,
1809                 .proc_handler   = proc_doulongvec_minmax,
1810         },
1811         {
1812                 .procname       = "pipe-user-pages-soft",
1813                 .data           = &pipe_user_pages_soft,
1814                 .maxlen         = sizeof(pipe_user_pages_soft),
1815                 .mode           = 0644,
1816                 .proc_handler   = proc_doulongvec_minmax,
1817         },
1818         {
1819                 .procname       = "mount-max",
1820                 .data           = &sysctl_mount_max,
1821                 .maxlen         = sizeof(unsigned int),
1822                 .mode           = 0644,
1823                 .proc_handler   = proc_dointvec_minmax,
1824                 .extra1         = &one,
1825         },
1826         { }
1827 };
1828 
1829 static struct ctl_table debug_table[] = {
1830 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1831         {
1832                 .procname       = "exception-trace",
1833                 .data           = &show_unhandled_signals,
1834                 .maxlen         = sizeof(int),
1835                 .mode           = 0644,
1836                 .proc_handler   = proc_dointvec
1837         },
1838 #endif
1839 #if defined(CONFIG_OPTPROBES)
1840         {
1841                 .procname       = "kprobes-optimization",
1842                 .data           = &sysctl_kprobes_optimization,
1843                 .maxlen         = sizeof(int),
1844                 .mode           = 0644,
1845                 .proc_handler   = proc_kprobes_optimization_handler,
1846                 .extra1         = &zero,
1847                 .extra2         = &one,
1848         },
1849 #endif
1850         { }
1851 };
1852 
1853 static struct ctl_table dev_table[] = {
1854         { }
1855 };
1856 
1857 int __init sysctl_init(void)
1858 {
1859         struct ctl_table_header *hdr;
1860 
1861         hdr = register_sysctl_table(sysctl_base_table);
1862         kmemleak_not_leak(hdr);
1863         return 0;
1864 }
1865 
1866 #endif /* CONFIG_SYSCTL */
1867 
1868 /*
1869  * /proc/sys support
1870  */
1871 
1872 #ifdef CONFIG_PROC_SYSCTL
1873 
1874 static int _proc_do_string(char *data, int maxlen, int write,
1875                            char __user *buffer,
1876                            size_t *lenp, loff_t *ppos)
1877 {
1878         size_t len;
1879         char __user *p;
1880         char c;
1881 
1882         if (!data || !maxlen || !*lenp) {
1883                 *lenp = 0;
1884                 return 0;
1885         }
1886 
1887         if (write) {
1888                 if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1889                         /* Only continue writes not past the end of buffer. */
1890                         len = strlen(data);
1891                         if (len > maxlen - 1)
1892                                 len = maxlen - 1;
1893 
1894                         if (*ppos > len)
1895                                 return 0;
1896                         len = *ppos;
1897                 } else {
1898                         /* Start writing from beginning of buffer. */
1899                         len = 0;
1900                 }
1901 
1902                 *ppos += *lenp;
1903                 p = buffer;
1904                 while ((p - buffer) < *lenp && len < maxlen - 1) {
1905                         if (get_user(c, p++))
1906                                 return -EFAULT;
1907                         if (c == 0 || c == '\n')
1908                                 break;
1909                         data[len++] = c;
1910                 }
1911                 data[len] = 0;
1912         } else {
1913                 len = strlen(data);
1914                 if (len > maxlen)
1915                         len = maxlen;
1916 
1917                 if (*ppos > len) {
1918                         *lenp = 0;
1919                         return 0;
1920                 }
1921 
1922                 data += *ppos;
1923                 len  -= *ppos;
1924 
1925                 if (len > *lenp)
1926                         len = *lenp;
1927                 if (len)
1928                         if (copy_to_user(buffer, data, len))
1929                                 return -EFAULT;
1930                 if (len < *lenp) {
1931                         if (put_user('\n', buffer + len))
1932                                 return -EFAULT;
1933                         len++;
1934                 }
1935                 *lenp = len;
1936                 *ppos += len;
1937         }
1938         return 0;
1939 }
1940 
1941 static void warn_sysctl_write(struct ctl_table *table)
1942 {
1943         pr_warn_once("%s wrote to %s when file position was not 0!\n"
1944                 "This will not be supported in the future. To silence this\n"
1945                 "warning, set kernel.sysctl_writes_strict = -1\n",
1946                 current->comm, table->procname);
1947 }
1948 
1949 /**
1950  * proc_dostring - read a string sysctl
1951  * @table: the sysctl table
1952  * @write: %TRUE if this is a write to the sysctl file
1953  * @buffer: the user buffer
1954  * @lenp: the size of the user buffer
1955  * @ppos: file position
1956  *
1957  * Reads/writes a string from/to the user buffer. If the kernel
1958  * buffer provided is not large enough to hold the string, the
1959  * string is truncated. The copied string is %NULL-terminated.
1960  * If the string is being read by the user process, it is copied
1961  * and a newline '\n' is added. It is truncated if the buffer is
1962  * not large enough.
1963  *
1964  * Returns 0 on success.
1965  */
1966 int proc_dostring(struct ctl_table *table, int write,
1967                   void __user *buffer, size_t *lenp, loff_t *ppos)
1968 {
1969         if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1970                 warn_sysctl_write(table);
1971 
1972         return _proc_do_string((char *)(table->data), table->maxlen, write,
1973                                (char __user *)buffer, lenp, ppos);
1974 }
1975 
1976 static size_t proc_skip_spaces(char **buf)
1977 {
1978         size_t ret;
1979         char *tmp = skip_spaces(*buf);
1980         ret = tmp - *buf;
1981         *buf = tmp;
1982         return ret;
1983 }
1984 
1985 static void proc_skip_char(char **buf, size_t *size, const char v)
1986 {
1987         while (*size) {
1988                 if (**buf != v)
1989                         break;
1990                 (*size)--;
1991                 (*buf)++;
1992         }
1993 }
1994 
1995 #define TMPBUFLEN 22
1996 /**
1997  * proc_get_long - reads an ASCII formatted integer from a user buffer
1998  *
1999  * @buf: a kernel buffer
2000  * @size: size of the kernel buffer
2001  * @val: this is where the number will be stored
2002  * @neg: set to %TRUE if number is negative
2003  * @perm_tr: a vector which contains the allowed trailers
2004  * @perm_tr_len: size of the perm_tr vector
2005  * @tr: pointer to store the trailer character
2006  *
2007  * In case of success %0 is returned and @buf and @size are updated with
2008  * the amount of bytes read. If @tr is non-NULL and a trailing
2009  * character exists (size is non-zero after returning from this
2010  * function), @tr is updated with the trailing character.
2011  */
2012 static int proc_get_long(char **buf, size_t *size,
2013                           unsigned long *val, bool *neg,
2014                           const char *perm_tr, unsigned perm_tr_len, char *tr)
2015 {
2016         int len;
2017         char *p, tmp[TMPBUFLEN];
2018 
2019         if (!*size)
2020                 return -EINVAL;
2021 
2022         len = *size;
2023         if (len > TMPBUFLEN - 1)
2024                 len = TMPBUFLEN - 1;
2025 
2026         memcpy(tmp, *buf, len);
2027 
2028         tmp[len] = 0;
2029         p = tmp;
2030         if (*p == '-' && *size > 1) {
2031                 *neg = true;
2032                 p++;
2033         } else
2034                 *neg = false;
2035         if (!isdigit(*p))
2036                 return -EINVAL;
2037 
2038         *val = simple_strtoul(p, &p, 0);
2039 
2040         len = p - tmp;
2041 
2042         /* We don't know if the next char is whitespace thus we may accept
2043          * invalid integers (e.g. 1234...a) or two integers instead of one
2044          * (e.g. 123...1). So lets not allow such large numbers. */
2045         if (len == TMPBUFLEN - 1)
2046                 return -EINVAL;
2047 
2048         if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2049                 return -EINVAL;
2050 
2051         if (tr && (len < *size))
2052                 *tr = *p;
2053 
2054         *buf += len;
2055         *size -= len;
2056 
2057         return 0;
2058 }
2059 
2060 /**
2061  * proc_put_long - converts an integer to a decimal ASCII formatted string
2062  *
2063  * @buf: the user buffer
2064  * @size: the size of the user buffer
2065  * @val: the integer to be converted
2066  * @neg: sign of the number, %TRUE for negative
2067  *
2068  * In case of success %0 is returned and @buf and @size are updated with
2069  * the amount of bytes written.
2070  */
2071 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2072                           bool neg)
2073 {
2074         int len;
2075         char tmp[TMPBUFLEN], *p = tmp;
2076 
2077         sprintf(p, "%s%lu", neg ? "-" : "", val);
2078         len = strlen(tmp);
2079         if (len > *size)
2080                 len = *size;
2081         if (copy_to_user(*buf, tmp, len))
2082                 return -EFAULT;
2083         *size -= len;
2084         *buf += len;
2085         return 0;
2086 }
2087 #undef TMPBUFLEN
2088 
2089 static int proc_put_char(void __user **buf, size_t *size, char c)
2090 {
2091         if (*size) {
2092                 char __user **buffer = (char __user **)buf;
2093                 if (put_user(c, *buffer))
2094                         return -EFAULT;
2095                 (*size)--, (*buffer)++;
2096                 *buf = *buffer;
2097         }
2098         return 0;
2099 }
2100 
2101 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2102                                  int *valp,
2103                                  int write, void *data)
2104 {
2105         if (write) {
2106                 if (*negp) {
2107                         if (*lvalp > (unsigned long) INT_MAX + 1)
2108                                 return -EINVAL;
2109                         *valp = -*lvalp;
2110                 } else {
2111                         if (*lvalp > (unsigned long) INT_MAX)
2112                                 return -EINVAL;
2113                         *valp = *lvalp;
2114                 }
2115         } else {
2116                 int val = *valp;
2117                 if (val < 0) {
2118                         *negp = true;
2119                         *lvalp = -(unsigned long)val;
2120                 } else {
2121                         *negp = false;
2122                         *lvalp = (unsigned long)val;
2123                 }
2124         }
2125         return 0;
2126 }
2127 
2128 static int do_proc_douintvec_conv(bool *negp, unsigned long *lvalp,
2129                                  int *valp,
2130                                  int write, void *data)
2131 {
2132         if (write) {
2133                 if (*negp)
2134                         return -EINVAL;
2135                 *valp = *lvalp;
2136         } else {
2137                 unsigned int val = *valp;
2138                 *lvalp = (unsigned long)val;
2139         }
2140         return 0;
2141 }
2142 
2143 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2144 
2145 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2146                   int write, void __user *buffer,
2147                   size_t *lenp, loff_t *ppos,
2148                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2149                               int write, void *data),
2150                   void *data)
2151 {
2152         int *i, vleft, first = 1, err = 0;
2153         size_t left;
2154         char *kbuf = NULL, *p;
2155         
2156         if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2157                 *lenp = 0;
2158                 return 0;
2159         }
2160         
2161         i = (int *) tbl_data;
2162         vleft = table->maxlen / sizeof(*i);
2163         left = *lenp;
2164 
2165         if (!conv)
2166                 conv = do_proc_dointvec_conv;
2167 
2168         if (write) {
2169                 if (*ppos) {
2170                         switch (sysctl_writes_strict) {
2171                         case SYSCTL_WRITES_STRICT:
2172                                 goto out;
2173                         case SYSCTL_WRITES_WARN:
2174                                 warn_sysctl_write(table);
2175                                 break;
2176                         default:
2177                                 break;
2178                         }
2179                 }
2180 
2181                 if (left > PAGE_SIZE - 1)
2182                         left = PAGE_SIZE - 1;
2183                 p = kbuf = memdup_user_nul(buffer, left);
2184                 if (IS_ERR(kbuf))
2185                         return PTR_ERR(kbuf);
2186         }
2187 
2188         for (; left && vleft--; i++, first=0) {
2189                 unsigned long lval;
2190                 bool neg;
2191 
2192                 if (write) {
2193                         left -= proc_skip_spaces(&p);
2194 
2195                         if (!left)
2196                                 break;
2197                         err = proc_get_long(&p, &left, &lval, &neg,
2198                                              proc_wspace_sep,
2199                                              sizeof(proc_wspace_sep), NULL);
2200                         if (err)
2201                                 break;
2202                         if (conv(&neg, &lval, i, 1, data)) {
2203                                 err = -EINVAL;
2204                                 break;
2205                         }
2206                 } else {
2207                         if (conv(&neg, &lval, i, 0, data)) {
2208                                 err = -EINVAL;
2209                                 break;
2210                         }
2211                         if (!first)
2212                                 err = proc_put_char(&buffer, &left, '\t');
2213                         if (err)
2214                                 break;
2215                         err = proc_put_long(&buffer, &left, lval, neg);
2216                         if (err)
2217                                 break;
2218                 }
2219         }
2220 
2221         if (!write && !first && left && !err)
2222                 err = proc_put_char(&buffer, &left, '\n');
2223         if (write && !err && left)
2224                 left -= proc_skip_spaces(&p);
2225         if (write) {
2226                 kfree(kbuf);
2227                 if (first)
2228                         return err ? : -EINVAL;
2229         }
2230         *lenp -= left;
2231 out:
2232         *ppos += *lenp;
2233         return err;
2234 }
2235 
2236 static int do_proc_dointvec(struct ctl_table *table, int write,
2237                   void __user *buffer, size_t *lenp, loff_t *ppos,
2238                   int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2239                               int write, void *data),
2240                   void *data)
2241 {
2242         return __do_proc_dointvec(table->data, table, write,
2243                         buffer, lenp, ppos, conv, data);
2244 }
2245 
2246 /**
2247  * proc_dointvec - read a vector of integers
2248  * @table: the sysctl table
2249  * @write: %TRUE if this is a write to the sysctl file
2250  * @buffer: the user buffer
2251  * @lenp: the size of the user buffer
2252  * @ppos: file position
2253  *
2254  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2255  * values from/to the user buffer, treated as an ASCII string. 
2256  *
2257  * Returns 0 on success.
2258  */
2259 int proc_dointvec(struct ctl_table *table, int write,
2260                      void __user *buffer, size_t *lenp, loff_t *ppos)
2261 {
2262         return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
2263 }
2264 
2265 /**
2266  * proc_douintvec - read a vector of unsigned integers
2267  * @table: the sysctl table
2268  * @write: %TRUE if this is a write to the sysctl file
2269  * @buffer: the user buffer
2270  * @lenp: the size of the user buffer
2271  * @ppos: file position
2272  *
2273  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
2274  * values from/to the user buffer, treated as an ASCII string.
2275  *
2276  * Returns 0 on success.
2277  */
2278 int proc_douintvec(struct ctl_table *table, int write,
2279                      void __user *buffer, size_t *lenp, loff_t *ppos)
2280 {
2281         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2282                                 do_proc_douintvec_conv, NULL);
2283 }
2284 
2285 /*
2286  * Taint values can only be increased
2287  * This means we can safely use a temporary.
2288  */
2289 static int proc_taint(struct ctl_table *table, int write,
2290                                void __user *buffer, size_t *lenp, loff_t *ppos)
2291 {
2292         struct ctl_table t;
2293         unsigned long tmptaint = get_taint();
2294         int err;
2295 
2296         if (write && !capable(CAP_SYS_ADMIN))
2297                 return -EPERM;
2298 
2299         t = *table;
2300         t.data = &tmptaint;
2301         err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2302         if (err < 0)
2303                 return err;
2304 
2305         if (write) {
2306                 /*
2307                  * Poor man's atomic or. Not worth adding a primitive
2308                  * to everyone's atomic.h for this
2309                  */
2310                 int i;
2311                 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2312                         if ((tmptaint >> i) & 1)
2313                                 add_taint(i, LOCKDEP_STILL_OK);
2314                 }
2315         }
2316 
2317         return err;
2318 }
2319 
2320 #ifdef CONFIG_PRINTK
2321 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2322                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2323 {
2324         if (write && !capable(CAP_SYS_ADMIN))
2325                 return -EPERM;
2326 
2327         return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2328 }
2329 #endif
2330 
2331 struct do_proc_dointvec_minmax_conv_param {
2332         int *min;
2333         int *max;
2334 };
2335 
2336 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2337                                         int *valp,
2338                                         int write, void *data)
2339 {
2340         struct do_proc_dointvec_minmax_conv_param *param = data;
2341         if (write) {
2342                 int val = *negp ? -*lvalp : *lvalp;
2343                 if ((param->min && *param->min > val) ||
2344                     (param->max && *param->max < val))
2345                         return -EINVAL;
2346                 *valp = val;
2347         } else {
2348                 int val = *valp;
2349                 if (val < 0) {
2350                         *negp = true;
2351                         *lvalp = -(unsigned long)val;
2352                 } else {
2353                         *negp = false;
2354                         *lvalp = (unsigned long)val;
2355                 }
2356         }
2357         return 0;
2358 }
2359 
2360 /**
2361  * proc_dointvec_minmax - read a vector of integers with min/max values
2362  * @table: the sysctl table
2363  * @write: %TRUE if this is a write to the sysctl file
2364  * @buffer: the user buffer
2365  * @lenp: the size of the user buffer
2366  * @ppos: file position
2367  *
2368  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2369  * values from/to the user buffer, treated as an ASCII string.
2370  *
2371  * This routine will ensure the values are within the range specified by
2372  * table->extra1 (min) and table->extra2 (max).
2373  *
2374  * Returns 0 on success.
2375  */
2376 int proc_dointvec_minmax(struct ctl_table *table, int write,
2377                   void __user *buffer, size_t *lenp, loff_t *ppos)
2378 {
2379         struct do_proc_dointvec_minmax_conv_param param = {
2380                 .min = (int *) table->extra1,
2381                 .max = (int *) table->extra2,
2382         };
2383         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2384                                 do_proc_dointvec_minmax_conv, &param);
2385 }
2386 
2387 static void validate_coredump_safety(void)
2388 {
2389 #ifdef CONFIG_COREDUMP
2390         if (suid_dumpable == SUID_DUMP_ROOT &&
2391             core_pattern[0] != '/' && core_pattern[0] != '|') {
2392                 printk(KERN_WARNING
2393 "Unsafe core_pattern used with fs.suid_dumpable=2.\n"
2394 "Pipe handler or fully qualified core dump path required.\n"
2395 "Set kernel.core_pattern before fs.suid_dumpable.\n"
2396                 );
2397         }
2398 #endif
2399 }
2400 
2401 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2402                 void __user *buffer, size_t *lenp, loff_t *ppos)
2403 {
2404         int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2405         if (!error)
2406                 validate_coredump_safety();
2407         return error;
2408 }
2409 
2410 #ifdef CONFIG_COREDUMP
2411 static int proc_dostring_coredump(struct ctl_table *table, int write,
2412                   void __user *buffer, size_t *lenp, loff_t *ppos)
2413 {
2414         int error = proc_dostring(table, write, buffer, lenp, ppos);
2415         if (!error)
2416                 validate_coredump_safety();
2417         return error;
2418 }
2419 #endif
2420 
2421 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2422                                      void __user *buffer,
2423                                      size_t *lenp, loff_t *ppos,
2424                                      unsigned long convmul,
2425                                      unsigned long convdiv)
2426 {
2427         unsigned long *i, *min, *max;
2428         int vleft, first = 1, err = 0;
2429         size_t left;
2430         char *kbuf = NULL, *p;
2431 
2432         if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2433                 *lenp = 0;
2434                 return 0;
2435         }
2436 
2437         i = (unsigned long *) data;
2438         min = (unsigned long *) table->extra1;
2439         max = (unsigned long *) table->extra2;
2440         vleft = table->maxlen / sizeof(unsigned long);
2441         left = *lenp;
2442 
2443         if (write) {
2444                 if (*ppos) {
2445                         switch (sysctl_writes_strict) {
2446                         case SYSCTL_WRITES_STRICT:
2447                                 goto out;
2448                         case SYSCTL_WRITES_WARN:
2449                                 warn_sysctl_write(table);
2450                                 break;
2451                         default:
2452                                 break;
2453                         }
2454                 }
2455 
2456                 if (left > PAGE_SIZE - 1)
2457                         left = PAGE_SIZE - 1;
2458                 p = kbuf = memdup_user_nul(buffer, left);
2459                 if (IS_ERR(kbuf))
2460                         return PTR_ERR(kbuf);
2461         }
2462 
2463         for (; left && vleft--; i++, first = 0) {
2464                 unsigned long val;
2465 
2466                 if (write) {
2467                         bool neg;
2468 
2469                         left -= proc_skip_spaces(&p);
2470 
2471                         err = proc_get_long(&p, &left, &val, &neg,
2472                                              proc_wspace_sep,
2473                                              sizeof(proc_wspace_sep), NULL);
2474                         if (err)
2475                                 break;
2476                         if (neg)
2477                                 continue;
2478                         val = convmul * val / convdiv;
2479                         if ((min && val < *min) || (max && val > *max))
2480                                 continue;
2481                         *i = val;
2482                 } else {
2483                         val = convdiv * (*i) / convmul;
2484                         if (!first) {
2485                                 err = proc_put_char(&buffer, &left, '\t');
2486                                 if (err)
2487                                         break;
2488                         }
2489                         err = proc_put_long(&buffer, &left, val, false);
2490                         if (err)
2491                                 break;
2492                 }
2493         }
2494 
2495         if (!write && !first && left && !err)
2496                 err = proc_put_char(&buffer, &left, '\n');
2497         if (write && !err)
2498                 left -= proc_skip_spaces(&p);
2499         if (write) {
2500                 kfree(kbuf);
2501                 if (first)
2502                         return err ? : -EINVAL;
2503         }
2504         *lenp -= left;
2505 out:
2506         *ppos += *lenp;
2507         return err;
2508 }
2509 
2510 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2511                                      void __user *buffer,
2512                                      size_t *lenp, loff_t *ppos,
2513                                      unsigned long convmul,
2514                                      unsigned long convdiv)
2515 {
2516         return __do_proc_doulongvec_minmax(table->data, table, write,
2517                         buffer, lenp, ppos, convmul, convdiv);
2518 }
2519 
2520 /**
2521  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2522  * @table: the sysctl table
2523  * @write: %TRUE if this is a write to the sysctl file
2524  * @buffer: the user buffer
2525  * @lenp: the size of the user buffer
2526  * @ppos: file position
2527  *
2528  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2529  * values from/to the user buffer, treated as an ASCII string.
2530  *
2531  * This routine will ensure the values are within the range specified by
2532  * table->extra1 (min) and table->extra2 (max).
2533  *
2534  * Returns 0 on success.
2535  */
2536 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2537                            void __user *buffer, size_t *lenp, loff_t *ppos)
2538 {
2539     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2540 }
2541 
2542 /**
2543  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2544  * @table: the sysctl table
2545  * @write: %TRUE if this is a write to the sysctl file
2546  * @buffer: the user buffer
2547  * @lenp: the size of the user buffer
2548  * @ppos: file position
2549  *
2550  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2551  * values from/to the user buffer, treated as an ASCII string. The values
2552  * are treated as milliseconds, and converted to jiffies when they are stored.
2553  *
2554  * This routine will ensure the values are within the range specified by
2555  * table->extra1 (min) and table->extra2 (max).
2556  *
2557  * Returns 0 on success.
2558  */
2559 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2560                                       void __user *buffer,
2561                                       size_t *lenp, loff_t *ppos)
2562 {
2563     return do_proc_doulongvec_minmax(table, write, buffer,
2564                                      lenp, ppos, HZ, 1000l);
2565 }
2566 
2567 
2568 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2569                                          int *valp,
2570                                          int write, void *data)
2571 {
2572         if (write) {
2573                 if (*lvalp > LONG_MAX / HZ)
2574                         return 1;
2575                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2576         } else {
2577                 int val = *valp;
2578                 unsigned long lval;
2579                 if (val < 0) {
2580                         *negp = true;
2581                         lval = -(unsigned long)val;
2582                 } else {
2583                         *negp = false;
2584                         lval = (unsigned long)val;
2585                 }
2586                 *lvalp = lval / HZ;
2587         }
2588         return 0;
2589 }
2590 
2591 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2592                                                 int *valp,
2593                                                 int write, void *data)
2594 {
2595         if (write) {
2596                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2597                         return 1;
2598                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2599         } else {
2600                 int val = *valp;
2601                 unsigned long lval;
2602                 if (val < 0) {
2603                         *negp = true;
2604                         lval = -(unsigned long)val;
2605                 } else {
2606                         *negp = false;
2607                         lval = (unsigned long)val;
2608                 }
2609                 *lvalp = jiffies_to_clock_t(lval);
2610         }
2611         return 0;
2612 }
2613 
2614 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2615                                             int *valp,
2616                                             int write, void *data)
2617 {
2618         if (write) {
2619                 unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2620 
2621                 if (jif > INT_MAX)
2622                         return 1;
2623                 *valp = (int)jif;
2624         } else {
2625                 int val = *valp;
2626                 unsigned long lval;
2627                 if (val < 0) {
2628                         *negp = true;
2629                         lval = -(unsigned long)val;
2630                 } else {
2631                         *negp = false;
2632                         lval = (unsigned long)val;
2633                 }
2634                 *lvalp = jiffies_to_msecs(lval);
2635         }
2636         return 0;
2637 }
2638 
2639 /**
2640  * proc_dointvec_jiffies - read a vector of integers as seconds
2641  * @table: the sysctl table
2642  * @write: %TRUE if this is a write to the sysctl file
2643  * @buffer: the user buffer
2644  * @lenp: the size of the user buffer
2645  * @ppos: file position
2646  *
2647  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2648  * values from/to the user buffer, treated as an ASCII string. 
2649  * The values read are assumed to be in seconds, and are converted into
2650  * jiffies.
2651  *
2652  * Returns 0 on success.
2653  */
2654 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2655                           void __user *buffer, size_t *lenp, loff_t *ppos)
2656 {
2657     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2658                             do_proc_dointvec_jiffies_conv,NULL);
2659 }
2660 
2661 /**
2662  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2663  * @table: the sysctl table
2664  * @write: %TRUE if this is a write to the sysctl file
2665  * @buffer: the user buffer
2666  * @lenp: the size of the user buffer
2667  * @ppos: pointer to the file position
2668  *
2669  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2670  * values from/to the user buffer, treated as an ASCII string. 
2671  * The values read are assumed to be in 1/USER_HZ seconds, and 
2672  * are converted into jiffies.
2673  *
2674  * Returns 0 on success.
2675  */
2676 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2677                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2678 {
2679     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2680                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2681 }
2682 
2683 /**
2684  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2685  * @table: the sysctl table
2686  * @write: %TRUE if this is a write to the sysctl file
2687  * @buffer: the user buffer
2688  * @lenp: the size of the user buffer
2689  * @ppos: file position
2690  * @ppos: the current position in the file
2691  *
2692  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2693  * values from/to the user buffer, treated as an ASCII string. 
2694  * The values read are assumed to be in 1/1000 seconds, and 
2695  * are converted into jiffies.
2696  *
2697  * Returns 0 on success.
2698  */
2699 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2700                              void __user *buffer, size_t *lenp, loff_t *ppos)
2701 {
2702         return do_proc_dointvec(table, write, buffer, lenp, ppos,
2703                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2704 }
2705 
2706 static int proc_do_cad_pid(struct ctl_table *table, int write,
2707                            void __user *buffer, size_t *lenp, loff_t *ppos)
2708 {
2709         struct pid *new_pid;
2710         pid_t tmp;
2711         int r;
2712 
2713         tmp = pid_vnr(cad_pid);
2714 
2715         r = __do_proc_dointvec(&tmp, table, write, buffer,
2716                                lenp, ppos, NULL, NULL);
2717         if (r || !write)
2718                 return r;
2719 
2720         new_pid = find_get_pid(tmp);
2721         if (!new_pid)
2722                 return -ESRCH;
2723 
2724         put_pid(xchg(&cad_pid, new_pid));
2725         return 0;
2726 }
2727 
2728 /**
2729  * proc_do_large_bitmap - read/write from/to a large bitmap
2730  * @table: the sysctl table
2731  * @write: %TRUE if this is a write to the sysctl file
2732  * @buffer: the user buffer
2733  * @lenp: the size of the user buffer
2734  * @ppos: file position
2735  *
2736  * The bitmap is stored at table->data and the bitmap length (in bits)
2737  * in table->maxlen.
2738  *
2739  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2740  * large bitmaps may be represented in a compact manner. Writing into
2741  * the file will clear the bitmap then update it with the given input.
2742  *
2743  * Returns 0 on success.
2744  */
2745 int proc_do_large_bitmap(struct ctl_table *table, int write,
2746                          void __user *buffer, size_t *lenp, loff_t *ppos)
2747 {
2748         int err = 0;
2749         bool first = 1;
2750         size_t left = *lenp;
2751         unsigned long bitmap_len = table->maxlen;
2752         unsigned long *bitmap = *(unsigned long **) table->data;
2753         unsigned long *tmp_bitmap = NULL;
2754         char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2755 
2756         if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2757                 *lenp = 0;
2758                 return 0;
2759         }
2760 
2761         if (write) {
2762                 char *kbuf, *p;
2763 
2764                 if (left > PAGE_SIZE - 1)
2765                         left = PAGE_SIZE - 1;
2766 
2767                 p = kbuf = memdup_user_nul(buffer, left);
2768                 if (IS_ERR(kbuf))
2769                         return PTR_ERR(kbuf);
2770 
2771                 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2772                                      GFP_KERNEL);
2773                 if (!tmp_bitmap) {
2774                         kfree(kbuf);
2775                         return -ENOMEM;
2776                 }
2777                 proc_skip_char(&p, &left, '\n');
2778                 while (!err && left) {
2779                         unsigned long val_a, val_b;
2780                         bool neg;
2781 
2782                         err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2783                                              sizeof(tr_a), &c);
2784                         if (err)
2785                                 break;
2786                         if (val_a >= bitmap_len || neg) {
2787                                 err = -EINVAL;
2788                                 break;
2789                         }
2790 
2791                         val_b = val_a;
2792                         if (left) {
2793                                 p++;
2794                                 left--;
2795                         }
2796 
2797                         if (c == '-') {
2798                                 err = proc_get_long(&p, &left, &val_b,
2799                                                      &neg, tr_b, sizeof(tr_b),
2800                                                      &c);
2801                                 if (err)
2802                                         break;
2803                                 if (val_b >= bitmap_len || neg ||
2804                                     val_a > val_b) {
2805                                         err = -EINVAL;
2806                                         break;
2807                                 }
2808                                 if (left) {
2809                                         p++;
2810                                         left--;
2811                                 }
2812                         }
2813 
2814                         bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2815                         first = 0;
2816                         proc_skip_char(&p, &left, '\n');
2817                 }
2818                 kfree(kbuf);
2819         } else {
2820                 unsigned long bit_a, bit_b = 0;
2821 
2822                 while (left) {
2823                         bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2824                         if (bit_a >= bitmap_len)
2825                                 break;
2826                         bit_b = find_next_zero_bit(bitmap, bitmap_len,
2827                                                    bit_a + 1) - 1;
2828 
2829                         if (!first) {
2830                                 err = proc_put_char(&buffer, &left, ',');
2831                                 if (err)
2832                                         break;
2833                         }
2834                         err = proc_put_long(&buffer, &left, bit_a, false);
2835                         if (err)
2836                                 break;
2837                         if (bit_a != bit_b) {
2838                                 err = proc_put_char(&buffer, &left, '-');
2839                                 if (err)
2840                                         break;
2841                                 err = proc_put_long(&buffer, &left, bit_b, false);
2842                                 if (err)
2843                                         break;
2844                         }
2845 
2846                         first = 0; bit_b++;
2847                 }
2848                 if (!err)
2849                         err = proc_put_char(&buffer, &left, '\n');
2850         }
2851 
2852         if (!err) {
2853                 if (write) {
2854                         if (*ppos)
2855                                 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2856                         else
2857                                 bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2858                 }
2859                 kfree(tmp_bitmap);
2860                 *lenp -= left;
2861                 *ppos += *lenp;
2862                 return 0;
2863         } else {
2864                 kfree(tmp_bitmap);
2865                 return err;
2866         }
2867 }
2868 
2869 #else /* CONFIG_PROC_SYSCTL */
2870 
2871 int proc_dostring(struct ctl_table *table, int write,
2872                   void __user *buffer, size_t *lenp, loff_t *ppos)
2873 {
2874         return -ENOSYS;
2875 }
2876 
2877 int proc_dointvec(struct ctl_table *table, int write,
2878                   void __user *buffer, size_t *lenp, loff_t *ppos)
2879 {
2880         return -ENOSYS;
2881 }
2882 
2883 int proc_douintvec(struct ctl_table *table, int write,
2884                   void __user *buffer, size_t *lenp, loff_t *ppos)
2885 {
2886         return -ENOSYS;
2887 }
2888 
2889 int proc_dointvec_minmax(struct ctl_table *table, int write,
2890                     void __user *buffer, size_t *lenp, loff_t *ppos)
2891 {
2892         return -ENOSYS;
2893 }
2894 
2895 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2896                     void __user *buffer, size_t *lenp, loff_t *ppos)
2897 {
2898         return -ENOSYS;
2899 }
2900 
2901 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2902                     void __user *buffer, size_t *lenp, loff_t *ppos)
2903 {
2904         return -ENOSYS;
2905 }
2906 
2907 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2908                              void __user *buffer, size_t *lenp, loff_t *ppos)
2909 {
2910         return -ENOSYS;
2911 }
2912 
2913 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2914                     void __user *buffer, size_t *lenp, loff_t *ppos)
2915 {
2916         return -ENOSYS;
2917 }
2918 
2919 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2920                                       void __user *buffer,
2921                                       size_t *lenp, loff_t *ppos)
2922 {
2923     return -ENOSYS;
2924 }
2925 
2926 
2927 #endif /* CONFIG_PROC_SYSCTL */
2928 
2929 /*
2930  * No sense putting this after each symbol definition, twice,
2931  * exception granted :-)
2932  */
2933 EXPORT_SYMBOL(proc_dointvec);
2934 EXPORT_SYMBOL(proc_douintvec);
2935 EXPORT_SYMBOL(proc_dointvec_jiffies);
2936 EXPORT_SYMBOL(proc_dointvec_minmax);
2937 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2938 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2939 EXPORT_SYMBOL(proc_dostring);
2940 EXPORT_SYMBOL(proc_doulongvec_minmax);
2941 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2942 

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