xref: /linux/kernel/sysctl.c (revision e58e871becec2d3b04ed91c0c16fe8deac9c9dfa)
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/sched/coredump.h>
67 #include <linux/kexec.h>
68 #include <linux/bpf.h>
69 #include <linux/mount.h>
70 
71 #include <linux/uaccess.h>
72 #include <asm/processor.h>
73 
74 #ifdef CONFIG_X86
75 #include <asm/nmi.h>
76 #include <asm/stacktrace.h>
77 #include <asm/io.h>
78 #endif
79 #ifdef CONFIG_SPARC
80 #include <asm/setup.h>
81 #endif
82 #ifdef CONFIG_BSD_PROCESS_ACCT
83 #include <linux/acct.h>
84 #endif
85 #ifdef CONFIG_RT_MUTEXES
86 #include <linux/rtmutex.h>
87 #endif
88 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
89 #include <linux/lockdep.h>
90 #endif
91 #ifdef CONFIG_CHR_DEV_SG
92 #include <scsi/sg.h>
93 #endif
94 
95 #ifdef CONFIG_LOCKUP_DETECTOR
96 #include <linux/nmi.h>
97 #endif
98 
99 #if defined(CONFIG_SYSCTL)
100 
101 /* External variables not in a header file. */
102 extern int suid_dumpable;
103 #ifdef CONFIG_COREDUMP
104 extern int core_uses_pid;
105 extern char core_pattern[];
106 extern unsigned int core_pipe_limit;
107 #endif
108 extern int pid_max;
109 extern int pid_max_min, pid_max_max;
110 extern int percpu_pagelist_fraction;
111 extern int latencytop_enabled;
112 extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
113 #ifndef CONFIG_MMU
114 extern int sysctl_nr_trim_pages;
115 #endif
116 
117 /* Constants used for minimum and  maximum */
118 #ifdef CONFIG_LOCKUP_DETECTOR
119 static int sixty = 60;
120 #endif
121 
122 static int __maybe_unused neg_one = -1;
123 
124 static int zero;
125 static int __maybe_unused one = 1;
126 static int __maybe_unused two = 2;
127 static int __maybe_unused four = 4;
128 static unsigned long one_ul = 1;
129 static int one_hundred = 100;
130 static int one_thousand = 1000;
131 #ifdef CONFIG_PRINTK
132 static int ten_thousand = 10000;
133 #endif
134 #ifdef CONFIG_PERF_EVENTS
135 static int six_hundred_forty_kb = 640 * 1024;
136 #endif
137 
138 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
139 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
140 
141 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
142 static int maxolduid = 65535;
143 static int minolduid;
144 
145 static int ngroups_max = NGROUPS_MAX;
146 static const int cap_last_cap = CAP_LAST_CAP;
147 
148 /*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */
149 #ifdef CONFIG_DETECT_HUNG_TASK
150 static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
151 #endif
152 
153 #ifdef CONFIG_INOTIFY_USER
154 #include <linux/inotify.h>
155 #endif
156 #ifdef CONFIG_SPARC
157 #endif
158 
159 #ifdef __hppa__
160 extern int pwrsw_enabled;
161 #endif
162 
163 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
164 extern int unaligned_enabled;
165 #endif
166 
167 #ifdef CONFIG_IA64
168 extern int unaligned_dump_stack;
169 #endif
170 
171 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
172 extern int no_unaligned_warning;
173 #endif
174 
175 #ifdef CONFIG_PROC_SYSCTL
176 
177 #define SYSCTL_WRITES_LEGACY	-1
178 #define SYSCTL_WRITES_WARN	 0
179 #define SYSCTL_WRITES_STRICT	 1
180 
181 static int sysctl_writes_strict = SYSCTL_WRITES_STRICT;
182 
183 static int proc_do_cad_pid(struct ctl_table *table, int write,
184 		  void __user *buffer, size_t *lenp, loff_t *ppos);
185 static int proc_taint(struct ctl_table *table, int write,
186 			       void __user *buffer, size_t *lenp, loff_t *ppos);
187 #endif
188 
189 #ifdef CONFIG_PRINTK
190 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
191 				void __user *buffer, size_t *lenp, loff_t *ppos);
192 #endif
193 
194 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
195 		void __user *buffer, size_t *lenp, loff_t *ppos);
196 #ifdef CONFIG_COREDUMP
197 static int proc_dostring_coredump(struct ctl_table *table, int write,
198 		void __user *buffer, size_t *lenp, loff_t *ppos);
199 #endif
200 
201 #ifdef CONFIG_MAGIC_SYSRQ
202 /* Note: sysrq code uses it's own private copy */
203 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
204 
205 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
206 				void __user *buffer, size_t *lenp,
207 				loff_t *ppos)
208 {
209 	int error;
210 
211 	error = proc_dointvec(table, write, buffer, lenp, ppos);
212 	if (error)
213 		return error;
214 
215 	if (write)
216 		sysrq_toggle_support(__sysrq_enabled);
217 
218 	return 0;
219 }
220 
221 #endif
222 
223 static struct ctl_table kern_table[];
224 static struct ctl_table vm_table[];
225 static struct ctl_table fs_table[];
226 static struct ctl_table debug_table[];
227 static struct ctl_table dev_table[];
228 extern struct ctl_table random_table[];
229 #ifdef CONFIG_EPOLL
230 extern struct ctl_table epoll_table[];
231 #endif
232 
233 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
234 int sysctl_legacy_va_layout;
235 #endif
236 
237 /* The default sysctl tables: */
238 
239 static struct ctl_table sysctl_base_table[] = {
240 	{
241 		.procname	= "kernel",
242 		.mode		= 0555,
243 		.child		= kern_table,
244 	},
245 	{
246 		.procname	= "vm",
247 		.mode		= 0555,
248 		.child		= vm_table,
249 	},
250 	{
251 		.procname	= "fs",
252 		.mode		= 0555,
253 		.child		= fs_table,
254 	},
255 	{
256 		.procname	= "debug",
257 		.mode		= 0555,
258 		.child		= debug_table,
259 	},
260 	{
261 		.procname	= "dev",
262 		.mode		= 0555,
263 		.child		= dev_table,
264 	},
265 	{ }
266 };
267 
268 #ifdef CONFIG_SCHED_DEBUG
269 static int min_sched_granularity_ns = 100000;		/* 100 usecs */
270 static int max_sched_granularity_ns = NSEC_PER_SEC;	/* 1 second */
271 static int min_wakeup_granularity_ns;			/* 0 usecs */
272 static int max_wakeup_granularity_ns = NSEC_PER_SEC;	/* 1 second */
273 #ifdef CONFIG_SMP
274 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
275 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
276 #endif /* CONFIG_SMP */
277 #endif /* CONFIG_SCHED_DEBUG */
278 
279 #ifdef CONFIG_COMPACTION
280 static int min_extfrag_threshold;
281 static int max_extfrag_threshold = 1000;
282 #endif
283 
284 static struct ctl_table kern_table[] = {
285 	{
286 		.procname	= "sched_child_runs_first",
287 		.data		= &sysctl_sched_child_runs_first,
288 		.maxlen		= sizeof(unsigned int),
289 		.mode		= 0644,
290 		.proc_handler	= proc_dointvec,
291 	},
292 #ifdef CONFIG_SCHED_DEBUG
293 	{
294 		.procname	= "sched_min_granularity_ns",
295 		.data		= &sysctl_sched_min_granularity,
296 		.maxlen		= sizeof(unsigned int),
297 		.mode		= 0644,
298 		.proc_handler	= sched_proc_update_handler,
299 		.extra1		= &min_sched_granularity_ns,
300 		.extra2		= &max_sched_granularity_ns,
301 	},
302 	{
303 		.procname	= "sched_latency_ns",
304 		.data		= &sysctl_sched_latency,
305 		.maxlen		= sizeof(unsigned int),
306 		.mode		= 0644,
307 		.proc_handler	= sched_proc_update_handler,
308 		.extra1		= &min_sched_granularity_ns,
309 		.extra2		= &max_sched_granularity_ns,
310 	},
311 	{
312 		.procname	= "sched_wakeup_granularity_ns",
313 		.data		= &sysctl_sched_wakeup_granularity,
314 		.maxlen		= sizeof(unsigned int),
315 		.mode		= 0644,
316 		.proc_handler	= sched_proc_update_handler,
317 		.extra1		= &min_wakeup_granularity_ns,
318 		.extra2		= &max_wakeup_granularity_ns,
319 	},
320 #ifdef CONFIG_SMP
321 	{
322 		.procname	= "sched_tunable_scaling",
323 		.data		= &sysctl_sched_tunable_scaling,
324 		.maxlen		= sizeof(enum sched_tunable_scaling),
325 		.mode		= 0644,
326 		.proc_handler	= sched_proc_update_handler,
327 		.extra1		= &min_sched_tunable_scaling,
328 		.extra2		= &max_sched_tunable_scaling,
329 	},
330 	{
331 		.procname	= "sched_migration_cost_ns",
332 		.data		= &sysctl_sched_migration_cost,
333 		.maxlen		= sizeof(unsigned int),
334 		.mode		= 0644,
335 		.proc_handler	= proc_dointvec,
336 	},
337 	{
338 		.procname	= "sched_nr_migrate",
339 		.data		= &sysctl_sched_nr_migrate,
340 		.maxlen		= sizeof(unsigned int),
341 		.mode		= 0644,
342 		.proc_handler	= proc_dointvec,
343 	},
344 	{
345 		.procname	= "sched_time_avg_ms",
346 		.data		= &sysctl_sched_time_avg,
347 		.maxlen		= sizeof(unsigned int),
348 		.mode		= 0644,
349 		.proc_handler	= proc_dointvec,
350 	},
351 #ifdef CONFIG_SCHEDSTATS
352 	{
353 		.procname	= "sched_schedstats",
354 		.data		= NULL,
355 		.maxlen		= sizeof(unsigned int),
356 		.mode		= 0644,
357 		.proc_handler	= sysctl_schedstats,
358 		.extra1		= &zero,
359 		.extra2		= &one,
360 	},
361 #endif /* CONFIG_SCHEDSTATS */
362 #endif /* CONFIG_SMP */
363 #ifdef CONFIG_NUMA_BALANCING
364 	{
365 		.procname	= "numa_balancing_scan_delay_ms",
366 		.data		= &sysctl_numa_balancing_scan_delay,
367 		.maxlen		= sizeof(unsigned int),
368 		.mode		= 0644,
369 		.proc_handler	= proc_dointvec,
370 	},
371 	{
372 		.procname	= "numa_balancing_scan_period_min_ms",
373 		.data		= &sysctl_numa_balancing_scan_period_min,
374 		.maxlen		= sizeof(unsigned int),
375 		.mode		= 0644,
376 		.proc_handler	= proc_dointvec,
377 	},
378 	{
379 		.procname	= "numa_balancing_scan_period_max_ms",
380 		.data		= &sysctl_numa_balancing_scan_period_max,
381 		.maxlen		= sizeof(unsigned int),
382 		.mode		= 0644,
383 		.proc_handler	= proc_dointvec,
384 	},
385 	{
386 		.procname	= "numa_balancing_scan_size_mb",
387 		.data		= &sysctl_numa_balancing_scan_size,
388 		.maxlen		= sizeof(unsigned int),
389 		.mode		= 0644,
390 		.proc_handler	= proc_dointvec_minmax,
391 		.extra1		= &one,
392 	},
393 	{
394 		.procname	= "numa_balancing",
395 		.data		= NULL, /* filled in by handler */
396 		.maxlen		= sizeof(unsigned int),
397 		.mode		= 0644,
398 		.proc_handler	= sysctl_numa_balancing,
399 		.extra1		= &zero,
400 		.extra2		= &one,
401 	},
402 #endif /* CONFIG_NUMA_BALANCING */
403 #endif /* CONFIG_SCHED_DEBUG */
404 	{
405 		.procname	= "sched_rt_period_us",
406 		.data		= &sysctl_sched_rt_period,
407 		.maxlen		= sizeof(unsigned int),
408 		.mode		= 0644,
409 		.proc_handler	= sched_rt_handler,
410 	},
411 	{
412 		.procname	= "sched_rt_runtime_us",
413 		.data		= &sysctl_sched_rt_runtime,
414 		.maxlen		= sizeof(int),
415 		.mode		= 0644,
416 		.proc_handler	= sched_rt_handler,
417 	},
418 	{
419 		.procname	= "sched_rr_timeslice_ms",
420 		.data		= &sysctl_sched_rr_timeslice,
421 		.maxlen		= sizeof(int),
422 		.mode		= 0644,
423 		.proc_handler	= sched_rr_handler,
424 	},
425 #ifdef CONFIG_SCHED_AUTOGROUP
426 	{
427 		.procname	= "sched_autogroup_enabled",
428 		.data		= &sysctl_sched_autogroup_enabled,
429 		.maxlen		= sizeof(unsigned int),
430 		.mode		= 0644,
431 		.proc_handler	= proc_dointvec_minmax,
432 		.extra1		= &zero,
433 		.extra2		= &one,
434 	},
435 #endif
436 #ifdef CONFIG_CFS_BANDWIDTH
437 	{
438 		.procname	= "sched_cfs_bandwidth_slice_us",
439 		.data		= &sysctl_sched_cfs_bandwidth_slice,
440 		.maxlen		= sizeof(unsigned int),
441 		.mode		= 0644,
442 		.proc_handler	= proc_dointvec_minmax,
443 		.extra1		= &one,
444 	},
445 #endif
446 #ifdef CONFIG_PROVE_LOCKING
447 	{
448 		.procname	= "prove_locking",
449 		.data		= &prove_locking,
450 		.maxlen		= sizeof(int),
451 		.mode		= 0644,
452 		.proc_handler	= proc_dointvec,
453 	},
454 #endif
455 #ifdef CONFIG_LOCK_STAT
456 	{
457 		.procname	= "lock_stat",
458 		.data		= &lock_stat,
459 		.maxlen		= sizeof(int),
460 		.mode		= 0644,
461 		.proc_handler	= proc_dointvec,
462 	},
463 #endif
464 	{
465 		.procname	= "panic",
466 		.data		= &panic_timeout,
467 		.maxlen		= sizeof(int),
468 		.mode		= 0644,
469 		.proc_handler	= proc_dointvec,
470 	},
471 #ifdef CONFIG_COREDUMP
472 	{
473 		.procname	= "core_uses_pid",
474 		.data		= &core_uses_pid,
475 		.maxlen		= sizeof(int),
476 		.mode		= 0644,
477 		.proc_handler	= proc_dointvec,
478 	},
479 	{
480 		.procname	= "core_pattern",
481 		.data		= core_pattern,
482 		.maxlen		= CORENAME_MAX_SIZE,
483 		.mode		= 0644,
484 		.proc_handler	= proc_dostring_coredump,
485 	},
486 	{
487 		.procname	= "core_pipe_limit",
488 		.data		= &core_pipe_limit,
489 		.maxlen		= sizeof(unsigned int),
490 		.mode		= 0644,
491 		.proc_handler	= proc_dointvec,
492 	},
493 #endif
494 #ifdef CONFIG_PROC_SYSCTL
495 	{
496 		.procname	= "tainted",
497 		.maxlen 	= sizeof(long),
498 		.mode		= 0644,
499 		.proc_handler	= proc_taint,
500 	},
501 	{
502 		.procname	= "sysctl_writes_strict",
503 		.data		= &sysctl_writes_strict,
504 		.maxlen		= sizeof(int),
505 		.mode		= 0644,
506 		.proc_handler	= proc_dointvec_minmax,
507 		.extra1		= &neg_one,
508 		.extra2		= &one,
509 	},
510 #endif
511 #ifdef CONFIG_LATENCYTOP
512 	{
513 		.procname	= "latencytop",
514 		.data		= &latencytop_enabled,
515 		.maxlen		= sizeof(int),
516 		.mode		= 0644,
517 		.proc_handler	= sysctl_latencytop,
518 	},
519 #endif
520 #ifdef CONFIG_BLK_DEV_INITRD
521 	{
522 		.procname	= "real-root-dev",
523 		.data		= &real_root_dev,
524 		.maxlen		= sizeof(int),
525 		.mode		= 0644,
526 		.proc_handler	= proc_dointvec,
527 	},
528 #endif
529 	{
530 		.procname	= "print-fatal-signals",
531 		.data		= &print_fatal_signals,
532 		.maxlen		= sizeof(int),
533 		.mode		= 0644,
534 		.proc_handler	= proc_dointvec,
535 	},
536 #ifdef CONFIG_SPARC
537 	{
538 		.procname	= "reboot-cmd",
539 		.data		= reboot_command,
540 		.maxlen		= 256,
541 		.mode		= 0644,
542 		.proc_handler	= proc_dostring,
543 	},
544 	{
545 		.procname	= "stop-a",
546 		.data		= &stop_a_enabled,
547 		.maxlen		= sizeof (int),
548 		.mode		= 0644,
549 		.proc_handler	= proc_dointvec,
550 	},
551 	{
552 		.procname	= "scons-poweroff",
553 		.data		= &scons_pwroff,
554 		.maxlen		= sizeof (int),
555 		.mode		= 0644,
556 		.proc_handler	= proc_dointvec,
557 	},
558 #endif
559 #ifdef CONFIG_SPARC64
560 	{
561 		.procname	= "tsb-ratio",
562 		.data		= &sysctl_tsb_ratio,
563 		.maxlen		= sizeof (int),
564 		.mode		= 0644,
565 		.proc_handler	= proc_dointvec,
566 	},
567 #endif
568 #ifdef __hppa__
569 	{
570 		.procname	= "soft-power",
571 		.data		= &pwrsw_enabled,
572 		.maxlen		= sizeof (int),
573 	 	.mode		= 0644,
574 		.proc_handler	= proc_dointvec,
575 	},
576 #endif
577 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
578 	{
579 		.procname	= "unaligned-trap",
580 		.data		= &unaligned_enabled,
581 		.maxlen		= sizeof (int),
582 		.mode		= 0644,
583 		.proc_handler	= proc_dointvec,
584 	},
585 #endif
586 	{
587 		.procname	= "ctrl-alt-del",
588 		.data		= &C_A_D,
589 		.maxlen		= sizeof(int),
590 		.mode		= 0644,
591 		.proc_handler	= proc_dointvec,
592 	},
593 #ifdef CONFIG_FUNCTION_TRACER
594 	{
595 		.procname	= "ftrace_enabled",
596 		.data		= &ftrace_enabled,
597 		.maxlen		= sizeof(int),
598 		.mode		= 0644,
599 		.proc_handler	= ftrace_enable_sysctl,
600 	},
601 #endif
602 #ifdef CONFIG_STACK_TRACER
603 	{
604 		.procname	= "stack_tracer_enabled",
605 		.data		= &stack_tracer_enabled,
606 		.maxlen		= sizeof(int),
607 		.mode		= 0644,
608 		.proc_handler	= stack_trace_sysctl,
609 	},
610 #endif
611 #ifdef CONFIG_TRACING
612 	{
613 		.procname	= "ftrace_dump_on_oops",
614 		.data		= &ftrace_dump_on_oops,
615 		.maxlen		= sizeof(int),
616 		.mode		= 0644,
617 		.proc_handler	= proc_dointvec,
618 	},
619 	{
620 		.procname	= "traceoff_on_warning",
621 		.data		= &__disable_trace_on_warning,
622 		.maxlen		= sizeof(__disable_trace_on_warning),
623 		.mode		= 0644,
624 		.proc_handler	= proc_dointvec,
625 	},
626 	{
627 		.procname	= "tracepoint_printk",
628 		.data		= &tracepoint_printk,
629 		.maxlen		= sizeof(tracepoint_printk),
630 		.mode		= 0644,
631 		.proc_handler	= tracepoint_printk_sysctl,
632 	},
633 #endif
634 #ifdef CONFIG_KEXEC_CORE
635 	{
636 		.procname	= "kexec_load_disabled",
637 		.data		= &kexec_load_disabled,
638 		.maxlen		= sizeof(int),
639 		.mode		= 0644,
640 		/* only handle a transition from default "0" to "1" */
641 		.proc_handler	= proc_dointvec_minmax,
642 		.extra1		= &one,
643 		.extra2		= &one,
644 	},
645 #endif
646 #ifdef CONFIG_MODULES
647 	{
648 		.procname	= "modprobe",
649 		.data		= &modprobe_path,
650 		.maxlen		= KMOD_PATH_LEN,
651 		.mode		= 0644,
652 		.proc_handler	= proc_dostring,
653 	},
654 	{
655 		.procname	= "modules_disabled",
656 		.data		= &modules_disabled,
657 		.maxlen		= sizeof(int),
658 		.mode		= 0644,
659 		/* only handle a transition from default "0" to "1" */
660 		.proc_handler	= proc_dointvec_minmax,
661 		.extra1		= &one,
662 		.extra2		= &one,
663 	},
664 #endif
665 #ifdef CONFIG_UEVENT_HELPER
666 	{
667 		.procname	= "hotplug",
668 		.data		= &uevent_helper,
669 		.maxlen		= UEVENT_HELPER_PATH_LEN,
670 		.mode		= 0644,
671 		.proc_handler	= proc_dostring,
672 	},
673 #endif
674 #ifdef CONFIG_CHR_DEV_SG
675 	{
676 		.procname	= "sg-big-buff",
677 		.data		= &sg_big_buff,
678 		.maxlen		= sizeof (int),
679 		.mode		= 0444,
680 		.proc_handler	= proc_dointvec,
681 	},
682 #endif
683 #ifdef CONFIG_BSD_PROCESS_ACCT
684 	{
685 		.procname	= "acct",
686 		.data		= &acct_parm,
687 		.maxlen		= 3*sizeof(int),
688 		.mode		= 0644,
689 		.proc_handler	= proc_dointvec,
690 	},
691 #endif
692 #ifdef CONFIG_MAGIC_SYSRQ
693 	{
694 		.procname	= "sysrq",
695 		.data		= &__sysrq_enabled,
696 		.maxlen		= sizeof (int),
697 		.mode		= 0644,
698 		.proc_handler	= sysrq_sysctl_handler,
699 	},
700 #endif
701 #ifdef CONFIG_PROC_SYSCTL
702 	{
703 		.procname	= "cad_pid",
704 		.data		= NULL,
705 		.maxlen		= sizeof (int),
706 		.mode		= 0600,
707 		.proc_handler	= proc_do_cad_pid,
708 	},
709 #endif
710 	{
711 		.procname	= "threads-max",
712 		.data		= NULL,
713 		.maxlen		= sizeof(int),
714 		.mode		= 0644,
715 		.proc_handler	= sysctl_max_threads,
716 	},
717 	{
718 		.procname	= "random",
719 		.mode		= 0555,
720 		.child		= random_table,
721 	},
722 	{
723 		.procname	= "usermodehelper",
724 		.mode		= 0555,
725 		.child		= usermodehelper_table,
726 	},
727 	{
728 		.procname	= "overflowuid",
729 		.data		= &overflowuid,
730 		.maxlen		= sizeof(int),
731 		.mode		= 0644,
732 		.proc_handler	= proc_dointvec_minmax,
733 		.extra1		= &minolduid,
734 		.extra2		= &maxolduid,
735 	},
736 	{
737 		.procname	= "overflowgid",
738 		.data		= &overflowgid,
739 		.maxlen		= sizeof(int),
740 		.mode		= 0644,
741 		.proc_handler	= proc_dointvec_minmax,
742 		.extra1		= &minolduid,
743 		.extra2		= &maxolduid,
744 	},
745 #ifdef CONFIG_S390
746 #ifdef CONFIG_MATHEMU
747 	{
748 		.procname	= "ieee_emulation_warnings",
749 		.data		= &sysctl_ieee_emulation_warnings,
750 		.maxlen		= sizeof(int),
751 		.mode		= 0644,
752 		.proc_handler	= proc_dointvec,
753 	},
754 #endif
755 	{
756 		.procname	= "userprocess_debug",
757 		.data		= &show_unhandled_signals,
758 		.maxlen		= sizeof(int),
759 		.mode		= 0644,
760 		.proc_handler	= proc_dointvec,
761 	},
762 #endif
763 	{
764 		.procname	= "pid_max",
765 		.data		= &pid_max,
766 		.maxlen		= sizeof (int),
767 		.mode		= 0644,
768 		.proc_handler	= proc_dointvec_minmax,
769 		.extra1		= &pid_max_min,
770 		.extra2		= &pid_max_max,
771 	},
772 	{
773 		.procname	= "panic_on_oops",
774 		.data		= &panic_on_oops,
775 		.maxlen		= sizeof(int),
776 		.mode		= 0644,
777 		.proc_handler	= proc_dointvec,
778 	},
779 #if defined CONFIG_PRINTK
780 	{
781 		.procname	= "printk",
782 		.data		= &console_loglevel,
783 		.maxlen		= 4*sizeof(int),
784 		.mode		= 0644,
785 		.proc_handler	= proc_dointvec,
786 	},
787 	{
788 		.procname	= "printk_ratelimit",
789 		.data		= &printk_ratelimit_state.interval,
790 		.maxlen		= sizeof(int),
791 		.mode		= 0644,
792 		.proc_handler	= proc_dointvec_jiffies,
793 	},
794 	{
795 		.procname	= "printk_ratelimit_burst",
796 		.data		= &printk_ratelimit_state.burst,
797 		.maxlen		= sizeof(int),
798 		.mode		= 0644,
799 		.proc_handler	= proc_dointvec,
800 	},
801 	{
802 		.procname	= "printk_delay",
803 		.data		= &printk_delay_msec,
804 		.maxlen		= sizeof(int),
805 		.mode		= 0644,
806 		.proc_handler	= proc_dointvec_minmax,
807 		.extra1		= &zero,
808 		.extra2		= &ten_thousand,
809 	},
810 	{
811 		.procname	= "printk_devkmsg",
812 		.data		= devkmsg_log_str,
813 		.maxlen		= DEVKMSG_STR_MAX_SIZE,
814 		.mode		= 0644,
815 		.proc_handler	= devkmsg_sysctl_set_loglvl,
816 	},
817 	{
818 		.procname	= "dmesg_restrict",
819 		.data		= &dmesg_restrict,
820 		.maxlen		= sizeof(int),
821 		.mode		= 0644,
822 		.proc_handler	= proc_dointvec_minmax_sysadmin,
823 		.extra1		= &zero,
824 		.extra2		= &one,
825 	},
826 	{
827 		.procname	= "kptr_restrict",
828 		.data		= &kptr_restrict,
829 		.maxlen		= sizeof(int),
830 		.mode		= 0644,
831 		.proc_handler	= proc_dointvec_minmax_sysadmin,
832 		.extra1		= &zero,
833 		.extra2		= &two,
834 	},
835 #endif
836 	{
837 		.procname	= "ngroups_max",
838 		.data		= &ngroups_max,
839 		.maxlen		= sizeof (int),
840 		.mode		= 0444,
841 		.proc_handler	= proc_dointvec,
842 	},
843 	{
844 		.procname	= "cap_last_cap",
845 		.data		= (void *)&cap_last_cap,
846 		.maxlen		= sizeof(int),
847 		.mode		= 0444,
848 		.proc_handler	= proc_dointvec,
849 	},
850 #if defined(CONFIG_LOCKUP_DETECTOR)
851 	{
852 		.procname       = "watchdog",
853 		.data           = &watchdog_user_enabled,
854 		.maxlen         = sizeof (int),
855 		.mode           = 0644,
856 		.proc_handler   = proc_watchdog,
857 		.extra1		= &zero,
858 		.extra2		= &one,
859 	},
860 	{
861 		.procname	= "watchdog_thresh",
862 		.data		= &watchdog_thresh,
863 		.maxlen		= sizeof(int),
864 		.mode		= 0644,
865 		.proc_handler	= proc_watchdog_thresh,
866 		.extra1		= &zero,
867 		.extra2		= &sixty,
868 	},
869 	{
870 		.procname       = "nmi_watchdog",
871 		.data           = &nmi_watchdog_enabled,
872 		.maxlen         = sizeof (int),
873 		.mode           = 0644,
874 		.proc_handler   = proc_nmi_watchdog,
875 		.extra1		= &zero,
876 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
877 		.extra2		= &one,
878 #else
879 		.extra2		= &zero,
880 #endif
881 	},
882 	{
883 		.procname       = "soft_watchdog",
884 		.data           = &soft_watchdog_enabled,
885 		.maxlen         = sizeof (int),
886 		.mode           = 0644,
887 		.proc_handler   = proc_soft_watchdog,
888 		.extra1		= &zero,
889 		.extra2		= &one,
890 	},
891 	{
892 		.procname	= "watchdog_cpumask",
893 		.data		= &watchdog_cpumask_bits,
894 		.maxlen		= NR_CPUS,
895 		.mode		= 0644,
896 		.proc_handler	= proc_watchdog_cpumask,
897 	},
898 	{
899 		.procname	= "softlockup_panic",
900 		.data		= &softlockup_panic,
901 		.maxlen		= sizeof(int),
902 		.mode		= 0644,
903 		.proc_handler	= proc_dointvec_minmax,
904 		.extra1		= &zero,
905 		.extra2		= &one,
906 	},
907 #ifdef CONFIG_HARDLOCKUP_DETECTOR
908 	{
909 		.procname	= "hardlockup_panic",
910 		.data		= &hardlockup_panic,
911 		.maxlen		= sizeof(int),
912 		.mode		= 0644,
913 		.proc_handler	= proc_dointvec_minmax,
914 		.extra1		= &zero,
915 		.extra2		= &one,
916 	},
917 #endif
918 #ifdef CONFIG_SMP
919 	{
920 		.procname	= "softlockup_all_cpu_backtrace",
921 		.data		= &sysctl_softlockup_all_cpu_backtrace,
922 		.maxlen		= sizeof(int),
923 		.mode		= 0644,
924 		.proc_handler	= proc_dointvec_minmax,
925 		.extra1		= &zero,
926 		.extra2		= &one,
927 	},
928 	{
929 		.procname	= "hardlockup_all_cpu_backtrace",
930 		.data		= &sysctl_hardlockup_all_cpu_backtrace,
931 		.maxlen		= sizeof(int),
932 		.mode		= 0644,
933 		.proc_handler	= proc_dointvec_minmax,
934 		.extra1		= &zero,
935 		.extra2		= &one,
936 	},
937 #endif /* CONFIG_SMP */
938 #endif
939 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
940 	{
941 		.procname       = "unknown_nmi_panic",
942 		.data           = &unknown_nmi_panic,
943 		.maxlen         = sizeof (int),
944 		.mode           = 0644,
945 		.proc_handler   = proc_dointvec,
946 	},
947 #endif
948 #if defined(CONFIG_X86)
949 	{
950 		.procname	= "panic_on_unrecovered_nmi",
951 		.data		= &panic_on_unrecovered_nmi,
952 		.maxlen		= sizeof(int),
953 		.mode		= 0644,
954 		.proc_handler	= proc_dointvec,
955 	},
956 	{
957 		.procname	= "panic_on_io_nmi",
958 		.data		= &panic_on_io_nmi,
959 		.maxlen		= sizeof(int),
960 		.mode		= 0644,
961 		.proc_handler	= proc_dointvec,
962 	},
963 #ifdef CONFIG_DEBUG_STACKOVERFLOW
964 	{
965 		.procname	= "panic_on_stackoverflow",
966 		.data		= &sysctl_panic_on_stackoverflow,
967 		.maxlen		= sizeof(int),
968 		.mode		= 0644,
969 		.proc_handler	= proc_dointvec,
970 	},
971 #endif
972 	{
973 		.procname	= "bootloader_type",
974 		.data		= &bootloader_type,
975 		.maxlen		= sizeof (int),
976 		.mode		= 0444,
977 		.proc_handler	= proc_dointvec,
978 	},
979 	{
980 		.procname	= "bootloader_version",
981 		.data		= &bootloader_version,
982 		.maxlen		= sizeof (int),
983 		.mode		= 0444,
984 		.proc_handler	= proc_dointvec,
985 	},
986 	{
987 		.procname	= "io_delay_type",
988 		.data		= &io_delay_type,
989 		.maxlen		= sizeof(int),
990 		.mode		= 0644,
991 		.proc_handler	= proc_dointvec,
992 	},
993 #endif
994 #if defined(CONFIG_MMU)
995 	{
996 		.procname	= "randomize_va_space",
997 		.data		= &randomize_va_space,
998 		.maxlen		= sizeof(int),
999 		.mode		= 0644,
1000 		.proc_handler	= proc_dointvec,
1001 	},
1002 #endif
1003 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1004 	{
1005 		.procname	= "spin_retry",
1006 		.data		= &spin_retry,
1007 		.maxlen		= sizeof (int),
1008 		.mode		= 0644,
1009 		.proc_handler	= proc_dointvec,
1010 	},
1011 #endif
1012 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1013 	{
1014 		.procname	= "acpi_video_flags",
1015 		.data		= &acpi_realmode_flags,
1016 		.maxlen		= sizeof (unsigned long),
1017 		.mode		= 0644,
1018 		.proc_handler	= proc_doulongvec_minmax,
1019 	},
1020 #endif
1021 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1022 	{
1023 		.procname	= "ignore-unaligned-usertrap",
1024 		.data		= &no_unaligned_warning,
1025 		.maxlen		= sizeof (int),
1026 	 	.mode		= 0644,
1027 		.proc_handler	= proc_dointvec,
1028 	},
1029 #endif
1030 #ifdef CONFIG_IA64
1031 	{
1032 		.procname	= "unaligned-dump-stack",
1033 		.data		= &unaligned_dump_stack,
1034 		.maxlen		= sizeof (int),
1035 		.mode		= 0644,
1036 		.proc_handler	= proc_dointvec,
1037 	},
1038 #endif
1039 #ifdef CONFIG_DETECT_HUNG_TASK
1040 	{
1041 		.procname	= "hung_task_panic",
1042 		.data		= &sysctl_hung_task_panic,
1043 		.maxlen		= sizeof(int),
1044 		.mode		= 0644,
1045 		.proc_handler	= proc_dointvec_minmax,
1046 		.extra1		= &zero,
1047 		.extra2		= &one,
1048 	},
1049 	{
1050 		.procname	= "hung_task_check_count",
1051 		.data		= &sysctl_hung_task_check_count,
1052 		.maxlen		= sizeof(int),
1053 		.mode		= 0644,
1054 		.proc_handler	= proc_dointvec_minmax,
1055 		.extra1		= &zero,
1056 	},
1057 	{
1058 		.procname	= "hung_task_timeout_secs",
1059 		.data		= &sysctl_hung_task_timeout_secs,
1060 		.maxlen		= sizeof(unsigned long),
1061 		.mode		= 0644,
1062 		.proc_handler	= proc_dohung_task_timeout_secs,
1063 		.extra2		= &hung_task_timeout_max,
1064 	},
1065 	{
1066 		.procname	= "hung_task_warnings",
1067 		.data		= &sysctl_hung_task_warnings,
1068 		.maxlen		= sizeof(int),
1069 		.mode		= 0644,
1070 		.proc_handler	= proc_dointvec_minmax,
1071 		.extra1		= &neg_one,
1072 	},
1073 #endif
1074 #ifdef CONFIG_RT_MUTEXES
1075 	{
1076 		.procname	= "max_lock_depth",
1077 		.data		= &max_lock_depth,
1078 		.maxlen		= sizeof(int),
1079 		.mode		= 0644,
1080 		.proc_handler	= proc_dointvec,
1081 	},
1082 #endif
1083 	{
1084 		.procname	= "poweroff_cmd",
1085 		.data		= &poweroff_cmd,
1086 		.maxlen		= POWEROFF_CMD_PATH_LEN,
1087 		.mode		= 0644,
1088 		.proc_handler	= proc_dostring,
1089 	},
1090 #ifdef CONFIG_KEYS
1091 	{
1092 		.procname	= "keys",
1093 		.mode		= 0555,
1094 		.child		= key_sysctls,
1095 	},
1096 #endif
1097 #ifdef CONFIG_PERF_EVENTS
1098 	/*
1099 	 * User-space scripts rely on the existence of this file
1100 	 * as a feature check for perf_events being enabled.
1101 	 *
1102 	 * So it's an ABI, do not remove!
1103 	 */
1104 	{
1105 		.procname	= "perf_event_paranoid",
1106 		.data		= &sysctl_perf_event_paranoid,
1107 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
1108 		.mode		= 0644,
1109 		.proc_handler	= proc_dointvec,
1110 	},
1111 	{
1112 		.procname	= "perf_event_mlock_kb",
1113 		.data		= &sysctl_perf_event_mlock,
1114 		.maxlen		= sizeof(sysctl_perf_event_mlock),
1115 		.mode		= 0644,
1116 		.proc_handler	= proc_dointvec,
1117 	},
1118 	{
1119 		.procname	= "perf_event_max_sample_rate",
1120 		.data		= &sysctl_perf_event_sample_rate,
1121 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
1122 		.mode		= 0644,
1123 		.proc_handler	= perf_proc_update_handler,
1124 		.extra1		= &one,
1125 	},
1126 	{
1127 		.procname	= "perf_cpu_time_max_percent",
1128 		.data		= &sysctl_perf_cpu_time_max_percent,
1129 		.maxlen		= sizeof(sysctl_perf_cpu_time_max_percent),
1130 		.mode		= 0644,
1131 		.proc_handler	= perf_cpu_time_max_percent_handler,
1132 		.extra1		= &zero,
1133 		.extra2		= &one_hundred,
1134 	},
1135 	{
1136 		.procname	= "perf_event_max_stack",
1137 		.data		= &sysctl_perf_event_max_stack,
1138 		.maxlen		= sizeof(sysctl_perf_event_max_stack),
1139 		.mode		= 0644,
1140 		.proc_handler	= perf_event_max_stack_handler,
1141 		.extra1		= &zero,
1142 		.extra2		= &six_hundred_forty_kb,
1143 	},
1144 	{
1145 		.procname	= "perf_event_max_contexts_per_stack",
1146 		.data		= &sysctl_perf_event_max_contexts_per_stack,
1147 		.maxlen		= sizeof(sysctl_perf_event_max_contexts_per_stack),
1148 		.mode		= 0644,
1149 		.proc_handler	= perf_event_max_stack_handler,
1150 		.extra1		= &zero,
1151 		.extra2		= &one_thousand,
1152 	},
1153 #endif
1154 #ifdef CONFIG_KMEMCHECK
1155 	{
1156 		.procname	= "kmemcheck",
1157 		.data		= &kmemcheck_enabled,
1158 		.maxlen		= sizeof(int),
1159 		.mode		= 0644,
1160 		.proc_handler	= proc_dointvec,
1161 	},
1162 #endif
1163 	{
1164 		.procname	= "panic_on_warn",
1165 		.data		= &panic_on_warn,
1166 		.maxlen		= sizeof(int),
1167 		.mode		= 0644,
1168 		.proc_handler	= proc_dointvec_minmax,
1169 		.extra1		= &zero,
1170 		.extra2		= &one,
1171 	},
1172 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1173 	{
1174 		.procname	= "timer_migration",
1175 		.data		= &sysctl_timer_migration,
1176 		.maxlen		= sizeof(unsigned int),
1177 		.mode		= 0644,
1178 		.proc_handler	= timer_migration_handler,
1179 		.extra1		= &zero,
1180 		.extra2		= &one,
1181 	},
1182 #endif
1183 #ifdef CONFIG_BPF_SYSCALL
1184 	{
1185 		.procname	= "unprivileged_bpf_disabled",
1186 		.data		= &sysctl_unprivileged_bpf_disabled,
1187 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
1188 		.mode		= 0644,
1189 		/* only handle a transition from default "0" to "1" */
1190 		.proc_handler	= proc_dointvec_minmax,
1191 		.extra1		= &one,
1192 		.extra2		= &one,
1193 	},
1194 #endif
1195 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
1196 	{
1197 		.procname	= "panic_on_rcu_stall",
1198 		.data		= &sysctl_panic_on_rcu_stall,
1199 		.maxlen		= sizeof(sysctl_panic_on_rcu_stall),
1200 		.mode		= 0644,
1201 		.proc_handler	= proc_dointvec_minmax,
1202 		.extra1		= &zero,
1203 		.extra2		= &one,
1204 	},
1205 #endif
1206 	{ }
1207 };
1208 
1209 static struct ctl_table vm_table[] = {
1210 	{
1211 		.procname	= "overcommit_memory",
1212 		.data		= &sysctl_overcommit_memory,
1213 		.maxlen		= sizeof(sysctl_overcommit_memory),
1214 		.mode		= 0644,
1215 		.proc_handler	= proc_dointvec_minmax,
1216 		.extra1		= &zero,
1217 		.extra2		= &two,
1218 	},
1219 	{
1220 		.procname	= "panic_on_oom",
1221 		.data		= &sysctl_panic_on_oom,
1222 		.maxlen		= sizeof(sysctl_panic_on_oom),
1223 		.mode		= 0644,
1224 		.proc_handler	= proc_dointvec_minmax,
1225 		.extra1		= &zero,
1226 		.extra2		= &two,
1227 	},
1228 	{
1229 		.procname	= "oom_kill_allocating_task",
1230 		.data		= &sysctl_oom_kill_allocating_task,
1231 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
1232 		.mode		= 0644,
1233 		.proc_handler	= proc_dointvec,
1234 	},
1235 	{
1236 		.procname	= "oom_dump_tasks",
1237 		.data		= &sysctl_oom_dump_tasks,
1238 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1239 		.mode		= 0644,
1240 		.proc_handler	= proc_dointvec,
1241 	},
1242 	{
1243 		.procname	= "overcommit_ratio",
1244 		.data		= &sysctl_overcommit_ratio,
1245 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1246 		.mode		= 0644,
1247 		.proc_handler	= overcommit_ratio_handler,
1248 	},
1249 	{
1250 		.procname	= "overcommit_kbytes",
1251 		.data		= &sysctl_overcommit_kbytes,
1252 		.maxlen		= sizeof(sysctl_overcommit_kbytes),
1253 		.mode		= 0644,
1254 		.proc_handler	= overcommit_kbytes_handler,
1255 	},
1256 	{
1257 		.procname	= "page-cluster",
1258 		.data		= &page_cluster,
1259 		.maxlen		= sizeof(int),
1260 		.mode		= 0644,
1261 		.proc_handler	= proc_dointvec_minmax,
1262 		.extra1		= &zero,
1263 	},
1264 	{
1265 		.procname	= "dirty_background_ratio",
1266 		.data		= &dirty_background_ratio,
1267 		.maxlen		= sizeof(dirty_background_ratio),
1268 		.mode		= 0644,
1269 		.proc_handler	= dirty_background_ratio_handler,
1270 		.extra1		= &zero,
1271 		.extra2		= &one_hundred,
1272 	},
1273 	{
1274 		.procname	= "dirty_background_bytes",
1275 		.data		= &dirty_background_bytes,
1276 		.maxlen		= sizeof(dirty_background_bytes),
1277 		.mode		= 0644,
1278 		.proc_handler	= dirty_background_bytes_handler,
1279 		.extra1		= &one_ul,
1280 	},
1281 	{
1282 		.procname	= "dirty_ratio",
1283 		.data		= &vm_dirty_ratio,
1284 		.maxlen		= sizeof(vm_dirty_ratio),
1285 		.mode		= 0644,
1286 		.proc_handler	= dirty_ratio_handler,
1287 		.extra1		= &zero,
1288 		.extra2		= &one_hundred,
1289 	},
1290 	{
1291 		.procname	= "dirty_bytes",
1292 		.data		= &vm_dirty_bytes,
1293 		.maxlen		= sizeof(vm_dirty_bytes),
1294 		.mode		= 0644,
1295 		.proc_handler	= dirty_bytes_handler,
1296 		.extra1		= &dirty_bytes_min,
1297 	},
1298 	{
1299 		.procname	= "dirty_writeback_centisecs",
1300 		.data		= &dirty_writeback_interval,
1301 		.maxlen		= sizeof(dirty_writeback_interval),
1302 		.mode		= 0644,
1303 		.proc_handler	= dirty_writeback_centisecs_handler,
1304 	},
1305 	{
1306 		.procname	= "dirty_expire_centisecs",
1307 		.data		= &dirty_expire_interval,
1308 		.maxlen		= sizeof(dirty_expire_interval),
1309 		.mode		= 0644,
1310 		.proc_handler	= proc_dointvec_minmax,
1311 		.extra1		= &zero,
1312 	},
1313 	{
1314 		.procname	= "dirtytime_expire_seconds",
1315 		.data		= &dirtytime_expire_interval,
1316 		.maxlen		= sizeof(dirty_expire_interval),
1317 		.mode		= 0644,
1318 		.proc_handler	= dirtytime_interval_handler,
1319 		.extra1		= &zero,
1320 	},
1321 	{
1322 		.procname       = "nr_pdflush_threads",
1323 		.mode           = 0444 /* read-only */,
1324 		.proc_handler   = pdflush_proc_obsolete,
1325 	},
1326 	{
1327 		.procname	= "swappiness",
1328 		.data		= &vm_swappiness,
1329 		.maxlen		= sizeof(vm_swappiness),
1330 		.mode		= 0644,
1331 		.proc_handler	= proc_dointvec_minmax,
1332 		.extra1		= &zero,
1333 		.extra2		= &one_hundred,
1334 	},
1335 #ifdef CONFIG_HUGETLB_PAGE
1336 	{
1337 		.procname	= "nr_hugepages",
1338 		.data		= NULL,
1339 		.maxlen		= sizeof(unsigned long),
1340 		.mode		= 0644,
1341 		.proc_handler	= hugetlb_sysctl_handler,
1342 	},
1343 #ifdef CONFIG_NUMA
1344 	{
1345 		.procname       = "nr_hugepages_mempolicy",
1346 		.data           = NULL,
1347 		.maxlen         = sizeof(unsigned long),
1348 		.mode           = 0644,
1349 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1350 	},
1351 #endif
1352 	 {
1353 		.procname	= "hugetlb_shm_group",
1354 		.data		= &sysctl_hugetlb_shm_group,
1355 		.maxlen		= sizeof(gid_t),
1356 		.mode		= 0644,
1357 		.proc_handler	= proc_dointvec,
1358 	 },
1359 	 {
1360 		.procname	= "hugepages_treat_as_movable",
1361 		.data		= &hugepages_treat_as_movable,
1362 		.maxlen		= sizeof(int),
1363 		.mode		= 0644,
1364 		.proc_handler	= proc_dointvec,
1365 	},
1366 	{
1367 		.procname	= "nr_overcommit_hugepages",
1368 		.data		= NULL,
1369 		.maxlen		= sizeof(unsigned long),
1370 		.mode		= 0644,
1371 		.proc_handler	= hugetlb_overcommit_handler,
1372 	},
1373 #endif
1374 	{
1375 		.procname	= "lowmem_reserve_ratio",
1376 		.data		= &sysctl_lowmem_reserve_ratio,
1377 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1378 		.mode		= 0644,
1379 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1380 	},
1381 	{
1382 		.procname	= "drop_caches",
1383 		.data		= &sysctl_drop_caches,
1384 		.maxlen		= sizeof(int),
1385 		.mode		= 0644,
1386 		.proc_handler	= drop_caches_sysctl_handler,
1387 		.extra1		= &one,
1388 		.extra2		= &four,
1389 	},
1390 #ifdef CONFIG_COMPACTION
1391 	{
1392 		.procname	= "compact_memory",
1393 		.data		= &sysctl_compact_memory,
1394 		.maxlen		= sizeof(int),
1395 		.mode		= 0200,
1396 		.proc_handler	= sysctl_compaction_handler,
1397 	},
1398 	{
1399 		.procname	= "extfrag_threshold",
1400 		.data		= &sysctl_extfrag_threshold,
1401 		.maxlen		= sizeof(int),
1402 		.mode		= 0644,
1403 		.proc_handler	= sysctl_extfrag_handler,
1404 		.extra1		= &min_extfrag_threshold,
1405 		.extra2		= &max_extfrag_threshold,
1406 	},
1407 	{
1408 		.procname	= "compact_unevictable_allowed",
1409 		.data		= &sysctl_compact_unevictable_allowed,
1410 		.maxlen		= sizeof(int),
1411 		.mode		= 0644,
1412 		.proc_handler	= proc_dointvec,
1413 		.extra1		= &zero,
1414 		.extra2		= &one,
1415 	},
1416 
1417 #endif /* CONFIG_COMPACTION */
1418 	{
1419 		.procname	= "min_free_kbytes",
1420 		.data		= &min_free_kbytes,
1421 		.maxlen		= sizeof(min_free_kbytes),
1422 		.mode		= 0644,
1423 		.proc_handler	= min_free_kbytes_sysctl_handler,
1424 		.extra1		= &zero,
1425 	},
1426 	{
1427 		.procname	= "watermark_scale_factor",
1428 		.data		= &watermark_scale_factor,
1429 		.maxlen		= sizeof(watermark_scale_factor),
1430 		.mode		= 0644,
1431 		.proc_handler	= watermark_scale_factor_sysctl_handler,
1432 		.extra1		= &one,
1433 		.extra2		= &one_thousand,
1434 	},
1435 	{
1436 		.procname	= "percpu_pagelist_fraction",
1437 		.data		= &percpu_pagelist_fraction,
1438 		.maxlen		= sizeof(percpu_pagelist_fraction),
1439 		.mode		= 0644,
1440 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1441 		.extra1		= &zero,
1442 	},
1443 #ifdef CONFIG_MMU
1444 	{
1445 		.procname	= "max_map_count",
1446 		.data		= &sysctl_max_map_count,
1447 		.maxlen		= sizeof(sysctl_max_map_count),
1448 		.mode		= 0644,
1449 		.proc_handler	= proc_dointvec_minmax,
1450 		.extra1		= &zero,
1451 	},
1452 #else
1453 	{
1454 		.procname	= "nr_trim_pages",
1455 		.data		= &sysctl_nr_trim_pages,
1456 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1457 		.mode		= 0644,
1458 		.proc_handler	= proc_dointvec_minmax,
1459 		.extra1		= &zero,
1460 	},
1461 #endif
1462 	{
1463 		.procname	= "laptop_mode",
1464 		.data		= &laptop_mode,
1465 		.maxlen		= sizeof(laptop_mode),
1466 		.mode		= 0644,
1467 		.proc_handler	= proc_dointvec_jiffies,
1468 	},
1469 	{
1470 		.procname	= "block_dump",
1471 		.data		= &block_dump,
1472 		.maxlen		= sizeof(block_dump),
1473 		.mode		= 0644,
1474 		.proc_handler	= proc_dointvec,
1475 		.extra1		= &zero,
1476 	},
1477 	{
1478 		.procname	= "vfs_cache_pressure",
1479 		.data		= &sysctl_vfs_cache_pressure,
1480 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1481 		.mode		= 0644,
1482 		.proc_handler	= proc_dointvec,
1483 		.extra1		= &zero,
1484 	},
1485 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1486 	{
1487 		.procname	= "legacy_va_layout",
1488 		.data		= &sysctl_legacy_va_layout,
1489 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1490 		.mode		= 0644,
1491 		.proc_handler	= proc_dointvec,
1492 		.extra1		= &zero,
1493 	},
1494 #endif
1495 #ifdef CONFIG_NUMA
1496 	{
1497 		.procname	= "zone_reclaim_mode",
1498 		.data		= &node_reclaim_mode,
1499 		.maxlen		= sizeof(node_reclaim_mode),
1500 		.mode		= 0644,
1501 		.proc_handler	= proc_dointvec,
1502 		.extra1		= &zero,
1503 	},
1504 	{
1505 		.procname	= "min_unmapped_ratio",
1506 		.data		= &sysctl_min_unmapped_ratio,
1507 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1508 		.mode		= 0644,
1509 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1510 		.extra1		= &zero,
1511 		.extra2		= &one_hundred,
1512 	},
1513 	{
1514 		.procname	= "min_slab_ratio",
1515 		.data		= &sysctl_min_slab_ratio,
1516 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1517 		.mode		= 0644,
1518 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1519 		.extra1		= &zero,
1520 		.extra2		= &one_hundred,
1521 	},
1522 #endif
1523 #ifdef CONFIG_SMP
1524 	{
1525 		.procname	= "stat_interval",
1526 		.data		= &sysctl_stat_interval,
1527 		.maxlen		= sizeof(sysctl_stat_interval),
1528 		.mode		= 0644,
1529 		.proc_handler	= proc_dointvec_jiffies,
1530 	},
1531 	{
1532 		.procname	= "stat_refresh",
1533 		.data		= NULL,
1534 		.maxlen		= 0,
1535 		.mode		= 0600,
1536 		.proc_handler	= vmstat_refresh,
1537 	},
1538 #endif
1539 #ifdef CONFIG_MMU
1540 	{
1541 		.procname	= "mmap_min_addr",
1542 		.data		= &dac_mmap_min_addr,
1543 		.maxlen		= sizeof(unsigned long),
1544 		.mode		= 0644,
1545 		.proc_handler	= mmap_min_addr_handler,
1546 	},
1547 #endif
1548 #ifdef CONFIG_NUMA
1549 	{
1550 		.procname	= "numa_zonelist_order",
1551 		.data		= &numa_zonelist_order,
1552 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1553 		.mode		= 0644,
1554 		.proc_handler	= numa_zonelist_order_handler,
1555 	},
1556 #endif
1557 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1558    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1559 	{
1560 		.procname	= "vdso_enabled",
1561 #ifdef CONFIG_X86_32
1562 		.data		= &vdso32_enabled,
1563 		.maxlen		= sizeof(vdso32_enabled),
1564 #else
1565 		.data		= &vdso_enabled,
1566 		.maxlen		= sizeof(vdso_enabled),
1567 #endif
1568 		.mode		= 0644,
1569 		.proc_handler	= proc_dointvec,
1570 		.extra1		= &zero,
1571 	},
1572 #endif
1573 #ifdef CONFIG_HIGHMEM
1574 	{
1575 		.procname	= "highmem_is_dirtyable",
1576 		.data		= &vm_highmem_is_dirtyable,
1577 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1578 		.mode		= 0644,
1579 		.proc_handler	= proc_dointvec_minmax,
1580 		.extra1		= &zero,
1581 		.extra2		= &one,
1582 	},
1583 #endif
1584 #ifdef CONFIG_MEMORY_FAILURE
1585 	{
1586 		.procname	= "memory_failure_early_kill",
1587 		.data		= &sysctl_memory_failure_early_kill,
1588 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1589 		.mode		= 0644,
1590 		.proc_handler	= proc_dointvec_minmax,
1591 		.extra1		= &zero,
1592 		.extra2		= &one,
1593 	},
1594 	{
1595 		.procname	= "memory_failure_recovery",
1596 		.data		= &sysctl_memory_failure_recovery,
1597 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1598 		.mode		= 0644,
1599 		.proc_handler	= proc_dointvec_minmax,
1600 		.extra1		= &zero,
1601 		.extra2		= &one,
1602 	},
1603 #endif
1604 	{
1605 		.procname	= "user_reserve_kbytes",
1606 		.data		= &sysctl_user_reserve_kbytes,
1607 		.maxlen		= sizeof(sysctl_user_reserve_kbytes),
1608 		.mode		= 0644,
1609 		.proc_handler	= proc_doulongvec_minmax,
1610 	},
1611 	{
1612 		.procname	= "admin_reserve_kbytes",
1613 		.data		= &sysctl_admin_reserve_kbytes,
1614 		.maxlen		= sizeof(sysctl_admin_reserve_kbytes),
1615 		.mode		= 0644,
1616 		.proc_handler	= proc_doulongvec_minmax,
1617 	},
1618 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1619 	{
1620 		.procname	= "mmap_rnd_bits",
1621 		.data		= &mmap_rnd_bits,
1622 		.maxlen		= sizeof(mmap_rnd_bits),
1623 		.mode		= 0600,
1624 		.proc_handler	= proc_dointvec_minmax,
1625 		.extra1		= (void *)&mmap_rnd_bits_min,
1626 		.extra2		= (void *)&mmap_rnd_bits_max,
1627 	},
1628 #endif
1629 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1630 	{
1631 		.procname	= "mmap_rnd_compat_bits",
1632 		.data		= &mmap_rnd_compat_bits,
1633 		.maxlen		= sizeof(mmap_rnd_compat_bits),
1634 		.mode		= 0600,
1635 		.proc_handler	= proc_dointvec_minmax,
1636 		.extra1		= (void *)&mmap_rnd_compat_bits_min,
1637 		.extra2		= (void *)&mmap_rnd_compat_bits_max,
1638 	},
1639 #endif
1640 	{ }
1641 };
1642 
1643 static struct ctl_table fs_table[] = {
1644 	{
1645 		.procname	= "inode-nr",
1646 		.data		= &inodes_stat,
1647 		.maxlen		= 2*sizeof(long),
1648 		.mode		= 0444,
1649 		.proc_handler	= proc_nr_inodes,
1650 	},
1651 	{
1652 		.procname	= "inode-state",
1653 		.data		= &inodes_stat,
1654 		.maxlen		= 7*sizeof(long),
1655 		.mode		= 0444,
1656 		.proc_handler	= proc_nr_inodes,
1657 	},
1658 	{
1659 		.procname	= "file-nr",
1660 		.data		= &files_stat,
1661 		.maxlen		= sizeof(files_stat),
1662 		.mode		= 0444,
1663 		.proc_handler	= proc_nr_files,
1664 	},
1665 	{
1666 		.procname	= "file-max",
1667 		.data		= &files_stat.max_files,
1668 		.maxlen		= sizeof(files_stat.max_files),
1669 		.mode		= 0644,
1670 		.proc_handler	= proc_doulongvec_minmax,
1671 	},
1672 	{
1673 		.procname	= "nr_open",
1674 		.data		= &sysctl_nr_open,
1675 		.maxlen		= sizeof(unsigned int),
1676 		.mode		= 0644,
1677 		.proc_handler	= proc_dointvec_minmax,
1678 		.extra1		= &sysctl_nr_open_min,
1679 		.extra2		= &sysctl_nr_open_max,
1680 	},
1681 	{
1682 		.procname	= "dentry-state",
1683 		.data		= &dentry_stat,
1684 		.maxlen		= 6*sizeof(long),
1685 		.mode		= 0444,
1686 		.proc_handler	= proc_nr_dentry,
1687 	},
1688 	{
1689 		.procname	= "overflowuid",
1690 		.data		= &fs_overflowuid,
1691 		.maxlen		= sizeof(int),
1692 		.mode		= 0644,
1693 		.proc_handler	= proc_dointvec_minmax,
1694 		.extra1		= &minolduid,
1695 		.extra2		= &maxolduid,
1696 	},
1697 	{
1698 		.procname	= "overflowgid",
1699 		.data		= &fs_overflowgid,
1700 		.maxlen		= sizeof(int),
1701 		.mode		= 0644,
1702 		.proc_handler	= proc_dointvec_minmax,
1703 		.extra1		= &minolduid,
1704 		.extra2		= &maxolduid,
1705 	},
1706 #ifdef CONFIG_FILE_LOCKING
1707 	{
1708 		.procname	= "leases-enable",
1709 		.data		= &leases_enable,
1710 		.maxlen		= sizeof(int),
1711 		.mode		= 0644,
1712 		.proc_handler	= proc_dointvec,
1713 	},
1714 #endif
1715 #ifdef CONFIG_DNOTIFY
1716 	{
1717 		.procname	= "dir-notify-enable",
1718 		.data		= &dir_notify_enable,
1719 		.maxlen		= sizeof(int),
1720 		.mode		= 0644,
1721 		.proc_handler	= proc_dointvec,
1722 	},
1723 #endif
1724 #ifdef CONFIG_MMU
1725 #ifdef CONFIG_FILE_LOCKING
1726 	{
1727 		.procname	= "lease-break-time",
1728 		.data		= &lease_break_time,
1729 		.maxlen		= sizeof(int),
1730 		.mode		= 0644,
1731 		.proc_handler	= proc_dointvec,
1732 	},
1733 #endif
1734 #ifdef CONFIG_AIO
1735 	{
1736 		.procname	= "aio-nr",
1737 		.data		= &aio_nr,
1738 		.maxlen		= sizeof(aio_nr),
1739 		.mode		= 0444,
1740 		.proc_handler	= proc_doulongvec_minmax,
1741 	},
1742 	{
1743 		.procname	= "aio-max-nr",
1744 		.data		= &aio_max_nr,
1745 		.maxlen		= sizeof(aio_max_nr),
1746 		.mode		= 0644,
1747 		.proc_handler	= proc_doulongvec_minmax,
1748 	},
1749 #endif /* CONFIG_AIO */
1750 #ifdef CONFIG_INOTIFY_USER
1751 	{
1752 		.procname	= "inotify",
1753 		.mode		= 0555,
1754 		.child		= inotify_table,
1755 	},
1756 #endif
1757 #ifdef CONFIG_EPOLL
1758 	{
1759 		.procname	= "epoll",
1760 		.mode		= 0555,
1761 		.child		= epoll_table,
1762 	},
1763 #endif
1764 #endif
1765 	{
1766 		.procname	= "protected_symlinks",
1767 		.data		= &sysctl_protected_symlinks,
1768 		.maxlen		= sizeof(int),
1769 		.mode		= 0600,
1770 		.proc_handler	= proc_dointvec_minmax,
1771 		.extra1		= &zero,
1772 		.extra2		= &one,
1773 	},
1774 	{
1775 		.procname	= "protected_hardlinks",
1776 		.data		= &sysctl_protected_hardlinks,
1777 		.maxlen		= sizeof(int),
1778 		.mode		= 0600,
1779 		.proc_handler	= proc_dointvec_minmax,
1780 		.extra1		= &zero,
1781 		.extra2		= &one,
1782 	},
1783 	{
1784 		.procname	= "suid_dumpable",
1785 		.data		= &suid_dumpable,
1786 		.maxlen		= sizeof(int),
1787 		.mode		= 0644,
1788 		.proc_handler	= proc_dointvec_minmax_coredump,
1789 		.extra1		= &zero,
1790 		.extra2		= &two,
1791 	},
1792 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1793 	{
1794 		.procname	= "binfmt_misc",
1795 		.mode		= 0555,
1796 		.child		= sysctl_mount_point,
1797 	},
1798 #endif
1799 	{
1800 		.procname	= "pipe-max-size",
1801 		.data		= &pipe_max_size,
1802 		.maxlen		= sizeof(int),
1803 		.mode		= 0644,
1804 		.proc_handler	= &pipe_proc_fn,
1805 		.extra1		= &pipe_min_size,
1806 	},
1807 	{
1808 		.procname	= "pipe-user-pages-hard",
1809 		.data		= &pipe_user_pages_hard,
1810 		.maxlen		= sizeof(pipe_user_pages_hard),
1811 		.mode		= 0644,
1812 		.proc_handler	= proc_doulongvec_minmax,
1813 	},
1814 	{
1815 		.procname	= "pipe-user-pages-soft",
1816 		.data		= &pipe_user_pages_soft,
1817 		.maxlen		= sizeof(pipe_user_pages_soft),
1818 		.mode		= 0644,
1819 		.proc_handler	= proc_doulongvec_minmax,
1820 	},
1821 	{
1822 		.procname	= "mount-max",
1823 		.data		= &sysctl_mount_max,
1824 		.maxlen		= sizeof(unsigned int),
1825 		.mode		= 0644,
1826 		.proc_handler	= proc_dointvec_minmax,
1827 		.extra1		= &one,
1828 	},
1829 	{ }
1830 };
1831 
1832 static struct ctl_table debug_table[] = {
1833 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1834 	{
1835 		.procname	= "exception-trace",
1836 		.data		= &show_unhandled_signals,
1837 		.maxlen		= sizeof(int),
1838 		.mode		= 0644,
1839 		.proc_handler	= proc_dointvec
1840 	},
1841 #endif
1842 #if defined(CONFIG_OPTPROBES)
1843 	{
1844 		.procname	= "kprobes-optimization",
1845 		.data		= &sysctl_kprobes_optimization,
1846 		.maxlen		= sizeof(int),
1847 		.mode		= 0644,
1848 		.proc_handler	= proc_kprobes_optimization_handler,
1849 		.extra1		= &zero,
1850 		.extra2		= &one,
1851 	},
1852 #endif
1853 	{ }
1854 };
1855 
1856 static struct ctl_table dev_table[] = {
1857 	{ }
1858 };
1859 
1860 int __init sysctl_init(void)
1861 {
1862 	struct ctl_table_header *hdr;
1863 
1864 	hdr = register_sysctl_table(sysctl_base_table);
1865 	kmemleak_not_leak(hdr);
1866 	return 0;
1867 }
1868 
1869 #endif /* CONFIG_SYSCTL */
1870 
1871 /*
1872  * /proc/sys support
1873  */
1874 
1875 #ifdef CONFIG_PROC_SYSCTL
1876 
1877 static int _proc_do_string(char *data, int maxlen, int write,
1878 			   char __user *buffer,
1879 			   size_t *lenp, loff_t *ppos)
1880 {
1881 	size_t len;
1882 	char __user *p;
1883 	char c;
1884 
1885 	if (!data || !maxlen || !*lenp) {
1886 		*lenp = 0;
1887 		return 0;
1888 	}
1889 
1890 	if (write) {
1891 		if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1892 			/* Only continue writes not past the end of buffer. */
1893 			len = strlen(data);
1894 			if (len > maxlen - 1)
1895 				len = maxlen - 1;
1896 
1897 			if (*ppos > len)
1898 				return 0;
1899 			len = *ppos;
1900 		} else {
1901 			/* Start writing from beginning of buffer. */
1902 			len = 0;
1903 		}
1904 
1905 		*ppos += *lenp;
1906 		p = buffer;
1907 		while ((p - buffer) < *lenp && len < maxlen - 1) {
1908 			if (get_user(c, p++))
1909 				return -EFAULT;
1910 			if (c == 0 || c == '\n')
1911 				break;
1912 			data[len++] = c;
1913 		}
1914 		data[len] = 0;
1915 	} else {
1916 		len = strlen(data);
1917 		if (len > maxlen)
1918 			len = maxlen;
1919 
1920 		if (*ppos > len) {
1921 			*lenp = 0;
1922 			return 0;
1923 		}
1924 
1925 		data += *ppos;
1926 		len  -= *ppos;
1927 
1928 		if (len > *lenp)
1929 			len = *lenp;
1930 		if (len)
1931 			if (copy_to_user(buffer, data, len))
1932 				return -EFAULT;
1933 		if (len < *lenp) {
1934 			if (put_user('\n', buffer + len))
1935 				return -EFAULT;
1936 			len++;
1937 		}
1938 		*lenp = len;
1939 		*ppos += len;
1940 	}
1941 	return 0;
1942 }
1943 
1944 static void warn_sysctl_write(struct ctl_table *table)
1945 {
1946 	pr_warn_once("%s wrote to %s when file position was not 0!\n"
1947 		"This will not be supported in the future. To silence this\n"
1948 		"warning, set kernel.sysctl_writes_strict = -1\n",
1949 		current->comm, table->procname);
1950 }
1951 
1952 /**
1953  * proc_dostring - read a string sysctl
1954  * @table: the sysctl table
1955  * @write: %TRUE if this is a write to the sysctl file
1956  * @buffer: the user buffer
1957  * @lenp: the size of the user buffer
1958  * @ppos: file position
1959  *
1960  * Reads/writes a string from/to the user buffer. If the kernel
1961  * buffer provided is not large enough to hold the string, the
1962  * string is truncated. The copied string is %NULL-terminated.
1963  * If the string is being read by the user process, it is copied
1964  * and a newline '\n' is added. It is truncated if the buffer is
1965  * not large enough.
1966  *
1967  * Returns 0 on success.
1968  */
1969 int proc_dostring(struct ctl_table *table, int write,
1970 		  void __user *buffer, size_t *lenp, loff_t *ppos)
1971 {
1972 	if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1973 		warn_sysctl_write(table);
1974 
1975 	return _proc_do_string((char *)(table->data), table->maxlen, write,
1976 			       (char __user *)buffer, lenp, ppos);
1977 }
1978 
1979 static size_t proc_skip_spaces(char **buf)
1980 {
1981 	size_t ret;
1982 	char *tmp = skip_spaces(*buf);
1983 	ret = tmp - *buf;
1984 	*buf = tmp;
1985 	return ret;
1986 }
1987 
1988 static void proc_skip_char(char **buf, size_t *size, const char v)
1989 {
1990 	while (*size) {
1991 		if (**buf != v)
1992 			break;
1993 		(*size)--;
1994 		(*buf)++;
1995 	}
1996 }
1997 
1998 #define TMPBUFLEN 22
1999 /**
2000  * proc_get_long - reads an ASCII formatted integer from a user buffer
2001  *
2002  * @buf: a kernel buffer
2003  * @size: size of the kernel buffer
2004  * @val: this is where the number will be stored
2005  * @neg: set to %TRUE if number is negative
2006  * @perm_tr: a vector which contains the allowed trailers
2007  * @perm_tr_len: size of the perm_tr vector
2008  * @tr: pointer to store the trailer character
2009  *
2010  * In case of success %0 is returned and @buf and @size are updated with
2011  * the amount of bytes read. If @tr is non-NULL and a trailing
2012  * character exists (size is non-zero after returning from this
2013  * function), @tr is updated with the trailing character.
2014  */
2015 static int proc_get_long(char **buf, size_t *size,
2016 			  unsigned long *val, bool *neg,
2017 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
2018 {
2019 	int len;
2020 	char *p, tmp[TMPBUFLEN];
2021 
2022 	if (!*size)
2023 		return -EINVAL;
2024 
2025 	len = *size;
2026 	if (len > TMPBUFLEN - 1)
2027 		len = TMPBUFLEN - 1;
2028 
2029 	memcpy(tmp, *buf, len);
2030 
2031 	tmp[len] = 0;
2032 	p = tmp;
2033 	if (*p == '-' && *size > 1) {
2034 		*neg = true;
2035 		p++;
2036 	} else
2037 		*neg = false;
2038 	if (!isdigit(*p))
2039 		return -EINVAL;
2040 
2041 	*val = simple_strtoul(p, &p, 0);
2042 
2043 	len = p - tmp;
2044 
2045 	/* We don't know if the next char is whitespace thus we may accept
2046 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2047 	 * (e.g. 123...1). So lets not allow such large numbers. */
2048 	if (len == TMPBUFLEN - 1)
2049 		return -EINVAL;
2050 
2051 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2052 		return -EINVAL;
2053 
2054 	if (tr && (len < *size))
2055 		*tr = *p;
2056 
2057 	*buf += len;
2058 	*size -= len;
2059 
2060 	return 0;
2061 }
2062 
2063 /**
2064  * proc_put_long - converts an integer to a decimal ASCII formatted string
2065  *
2066  * @buf: the user buffer
2067  * @size: the size of the user buffer
2068  * @val: the integer to be converted
2069  * @neg: sign of the number, %TRUE for negative
2070  *
2071  * In case of success %0 is returned and @buf and @size are updated with
2072  * the amount of bytes written.
2073  */
2074 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2075 			  bool neg)
2076 {
2077 	int len;
2078 	char tmp[TMPBUFLEN], *p = tmp;
2079 
2080 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2081 	len = strlen(tmp);
2082 	if (len > *size)
2083 		len = *size;
2084 	if (copy_to_user(*buf, tmp, len))
2085 		return -EFAULT;
2086 	*size -= len;
2087 	*buf += len;
2088 	return 0;
2089 }
2090 #undef TMPBUFLEN
2091 
2092 static int proc_put_char(void __user **buf, size_t *size, char c)
2093 {
2094 	if (*size) {
2095 		char __user **buffer = (char __user **)buf;
2096 		if (put_user(c, *buffer))
2097 			return -EFAULT;
2098 		(*size)--, (*buffer)++;
2099 		*buf = *buffer;
2100 	}
2101 	return 0;
2102 }
2103 
2104 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2105 				 int *valp,
2106 				 int write, void *data)
2107 {
2108 	if (write) {
2109 		if (*negp) {
2110 			if (*lvalp > (unsigned long) INT_MAX + 1)
2111 				return -EINVAL;
2112 			*valp = -*lvalp;
2113 		} else {
2114 			if (*lvalp > (unsigned long) INT_MAX)
2115 				return -EINVAL;
2116 			*valp = *lvalp;
2117 		}
2118 	} else {
2119 		int val = *valp;
2120 		if (val < 0) {
2121 			*negp = true;
2122 			*lvalp = -(unsigned long)val;
2123 		} else {
2124 			*negp = false;
2125 			*lvalp = (unsigned long)val;
2126 		}
2127 	}
2128 	return 0;
2129 }
2130 
2131 static int do_proc_douintvec_conv(bool *negp, unsigned long *lvalp,
2132 				 int *valp,
2133 				 int write, void *data)
2134 {
2135 	if (write) {
2136 		if (*negp)
2137 			return -EINVAL;
2138 		if (*lvalp > UINT_MAX)
2139 			return -EINVAL;
2140 		*valp = *lvalp;
2141 	} else {
2142 		unsigned int val = *valp;
2143 		*negp = false;
2144 		*lvalp = (unsigned long)val;
2145 	}
2146 	return 0;
2147 }
2148 
2149 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2150 
2151 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2152 		  int write, void __user *buffer,
2153 		  size_t *lenp, loff_t *ppos,
2154 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2155 			      int write, void *data),
2156 		  void *data)
2157 {
2158 	int *i, vleft, first = 1, err = 0;
2159 	size_t left;
2160 	char *kbuf = NULL, *p;
2161 
2162 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2163 		*lenp = 0;
2164 		return 0;
2165 	}
2166 
2167 	i = (int *) tbl_data;
2168 	vleft = table->maxlen / sizeof(*i);
2169 	left = *lenp;
2170 
2171 	if (!conv)
2172 		conv = do_proc_dointvec_conv;
2173 
2174 	if (write) {
2175 		if (*ppos) {
2176 			switch (sysctl_writes_strict) {
2177 			case SYSCTL_WRITES_STRICT:
2178 				goto out;
2179 			case SYSCTL_WRITES_WARN:
2180 				warn_sysctl_write(table);
2181 				break;
2182 			default:
2183 				break;
2184 			}
2185 		}
2186 
2187 		if (left > PAGE_SIZE - 1)
2188 			left = PAGE_SIZE - 1;
2189 		p = kbuf = memdup_user_nul(buffer, left);
2190 		if (IS_ERR(kbuf))
2191 			return PTR_ERR(kbuf);
2192 	}
2193 
2194 	for (; left && vleft--; i++, first=0) {
2195 		unsigned long lval;
2196 		bool neg;
2197 
2198 		if (write) {
2199 			left -= proc_skip_spaces(&p);
2200 
2201 			if (!left)
2202 				break;
2203 			err = proc_get_long(&p, &left, &lval, &neg,
2204 					     proc_wspace_sep,
2205 					     sizeof(proc_wspace_sep), NULL);
2206 			if (err)
2207 				break;
2208 			if (conv(&neg, &lval, i, 1, data)) {
2209 				err = -EINVAL;
2210 				break;
2211 			}
2212 		} else {
2213 			if (conv(&neg, &lval, i, 0, data)) {
2214 				err = -EINVAL;
2215 				break;
2216 			}
2217 			if (!first)
2218 				err = proc_put_char(&buffer, &left, '\t');
2219 			if (err)
2220 				break;
2221 			err = proc_put_long(&buffer, &left, lval, neg);
2222 			if (err)
2223 				break;
2224 		}
2225 	}
2226 
2227 	if (!write && !first && left && !err)
2228 		err = proc_put_char(&buffer, &left, '\n');
2229 	if (write && !err && left)
2230 		left -= proc_skip_spaces(&p);
2231 	if (write) {
2232 		kfree(kbuf);
2233 		if (first)
2234 			return err ? : -EINVAL;
2235 	}
2236 	*lenp -= left;
2237 out:
2238 	*ppos += *lenp;
2239 	return err;
2240 }
2241 
2242 static int do_proc_dointvec(struct ctl_table *table, int write,
2243 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2244 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2245 			      int write, void *data),
2246 		  void *data)
2247 {
2248 	return __do_proc_dointvec(table->data, table, write,
2249 			buffer, lenp, ppos, conv, data);
2250 }
2251 
2252 /**
2253  * proc_dointvec - read a vector of integers
2254  * @table: the sysctl table
2255  * @write: %TRUE if this is a write to the sysctl file
2256  * @buffer: the user buffer
2257  * @lenp: the size of the user buffer
2258  * @ppos: file position
2259  *
2260  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2261  * values from/to the user buffer, treated as an ASCII string.
2262  *
2263  * Returns 0 on success.
2264  */
2265 int proc_dointvec(struct ctl_table *table, int write,
2266 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2267 {
2268 	return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
2269 }
2270 
2271 /**
2272  * proc_douintvec - read a vector of unsigned integers
2273  * @table: the sysctl table
2274  * @write: %TRUE if this is a write to the sysctl file
2275  * @buffer: the user buffer
2276  * @lenp: the size of the user buffer
2277  * @ppos: file position
2278  *
2279  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
2280  * values from/to the user buffer, treated as an ASCII string.
2281  *
2282  * Returns 0 on success.
2283  */
2284 int proc_douintvec(struct ctl_table *table, int write,
2285 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2286 {
2287 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2288 				do_proc_douintvec_conv, NULL);
2289 }
2290 
2291 /*
2292  * Taint values can only be increased
2293  * This means we can safely use a temporary.
2294  */
2295 static int proc_taint(struct ctl_table *table, int write,
2296 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2297 {
2298 	struct ctl_table t;
2299 	unsigned long tmptaint = get_taint();
2300 	int err;
2301 
2302 	if (write && !capable(CAP_SYS_ADMIN))
2303 		return -EPERM;
2304 
2305 	t = *table;
2306 	t.data = &tmptaint;
2307 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2308 	if (err < 0)
2309 		return err;
2310 
2311 	if (write) {
2312 		/*
2313 		 * Poor man's atomic or. Not worth adding a primitive
2314 		 * to everyone's atomic.h for this
2315 		 */
2316 		int i;
2317 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2318 			if ((tmptaint >> i) & 1)
2319 				add_taint(i, LOCKDEP_STILL_OK);
2320 		}
2321 	}
2322 
2323 	return err;
2324 }
2325 
2326 #ifdef CONFIG_PRINTK
2327 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2328 				void __user *buffer, size_t *lenp, loff_t *ppos)
2329 {
2330 	if (write && !capable(CAP_SYS_ADMIN))
2331 		return -EPERM;
2332 
2333 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2334 }
2335 #endif
2336 
2337 struct do_proc_dointvec_minmax_conv_param {
2338 	int *min;
2339 	int *max;
2340 };
2341 
2342 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2343 					int *valp,
2344 					int write, void *data)
2345 {
2346 	struct do_proc_dointvec_minmax_conv_param *param = data;
2347 	if (write) {
2348 		int val = *negp ? -*lvalp : *lvalp;
2349 		if ((param->min && *param->min > val) ||
2350 		    (param->max && *param->max < val))
2351 			return -EINVAL;
2352 		*valp = val;
2353 	} else {
2354 		int val = *valp;
2355 		if (val < 0) {
2356 			*negp = true;
2357 			*lvalp = -(unsigned long)val;
2358 		} else {
2359 			*negp = false;
2360 			*lvalp = (unsigned long)val;
2361 		}
2362 	}
2363 	return 0;
2364 }
2365 
2366 /**
2367  * proc_dointvec_minmax - read a vector of integers with min/max values
2368  * @table: the sysctl table
2369  * @write: %TRUE if this is a write to the sysctl file
2370  * @buffer: the user buffer
2371  * @lenp: the size of the user buffer
2372  * @ppos: file position
2373  *
2374  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2375  * values from/to the user buffer, treated as an ASCII string.
2376  *
2377  * This routine will ensure the values are within the range specified by
2378  * table->extra1 (min) and table->extra2 (max).
2379  *
2380  * Returns 0 on success.
2381  */
2382 int proc_dointvec_minmax(struct ctl_table *table, int write,
2383 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2384 {
2385 	struct do_proc_dointvec_minmax_conv_param param = {
2386 		.min = (int *) table->extra1,
2387 		.max = (int *) table->extra2,
2388 	};
2389 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2390 				do_proc_dointvec_minmax_conv, &param);
2391 }
2392 
2393 static void validate_coredump_safety(void)
2394 {
2395 #ifdef CONFIG_COREDUMP
2396 	if (suid_dumpable == SUID_DUMP_ROOT &&
2397 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
2398 		printk(KERN_WARNING
2399 "Unsafe core_pattern used with fs.suid_dumpable=2.\n"
2400 "Pipe handler or fully qualified core dump path required.\n"
2401 "Set kernel.core_pattern before fs.suid_dumpable.\n"
2402 		);
2403 	}
2404 #endif
2405 }
2406 
2407 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2408 		void __user *buffer, size_t *lenp, loff_t *ppos)
2409 {
2410 	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2411 	if (!error)
2412 		validate_coredump_safety();
2413 	return error;
2414 }
2415 
2416 #ifdef CONFIG_COREDUMP
2417 static int proc_dostring_coredump(struct ctl_table *table, int write,
2418 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2419 {
2420 	int error = proc_dostring(table, write, buffer, lenp, ppos);
2421 	if (!error)
2422 		validate_coredump_safety();
2423 	return error;
2424 }
2425 #endif
2426 
2427 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2428 				     void __user *buffer,
2429 				     size_t *lenp, loff_t *ppos,
2430 				     unsigned long convmul,
2431 				     unsigned long convdiv)
2432 {
2433 	unsigned long *i, *min, *max;
2434 	int vleft, first = 1, err = 0;
2435 	size_t left;
2436 	char *kbuf = NULL, *p;
2437 
2438 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2439 		*lenp = 0;
2440 		return 0;
2441 	}
2442 
2443 	i = (unsigned long *) data;
2444 	min = (unsigned long *) table->extra1;
2445 	max = (unsigned long *) table->extra2;
2446 	vleft = table->maxlen / sizeof(unsigned long);
2447 	left = *lenp;
2448 
2449 	if (write) {
2450 		if (*ppos) {
2451 			switch (sysctl_writes_strict) {
2452 			case SYSCTL_WRITES_STRICT:
2453 				goto out;
2454 			case SYSCTL_WRITES_WARN:
2455 				warn_sysctl_write(table);
2456 				break;
2457 			default:
2458 				break;
2459 			}
2460 		}
2461 
2462 		if (left > PAGE_SIZE - 1)
2463 			left = PAGE_SIZE - 1;
2464 		p = kbuf = memdup_user_nul(buffer, left);
2465 		if (IS_ERR(kbuf))
2466 			return PTR_ERR(kbuf);
2467 	}
2468 
2469 	for (; left && vleft--; i++, first = 0) {
2470 		unsigned long val;
2471 
2472 		if (write) {
2473 			bool neg;
2474 
2475 			left -= proc_skip_spaces(&p);
2476 
2477 			err = proc_get_long(&p, &left, &val, &neg,
2478 					     proc_wspace_sep,
2479 					     sizeof(proc_wspace_sep), NULL);
2480 			if (err)
2481 				break;
2482 			if (neg)
2483 				continue;
2484 			val = convmul * val / convdiv;
2485 			if ((min && val < *min) || (max && val > *max))
2486 				continue;
2487 			*i = val;
2488 		} else {
2489 			val = convdiv * (*i) / convmul;
2490 			if (!first) {
2491 				err = proc_put_char(&buffer, &left, '\t');
2492 				if (err)
2493 					break;
2494 			}
2495 			err = proc_put_long(&buffer, &left, val, false);
2496 			if (err)
2497 				break;
2498 		}
2499 	}
2500 
2501 	if (!write && !first && left && !err)
2502 		err = proc_put_char(&buffer, &left, '\n');
2503 	if (write && !err)
2504 		left -= proc_skip_spaces(&p);
2505 	if (write) {
2506 		kfree(kbuf);
2507 		if (first)
2508 			return err ? : -EINVAL;
2509 	}
2510 	*lenp -= left;
2511 out:
2512 	*ppos += *lenp;
2513 	return err;
2514 }
2515 
2516 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2517 				     void __user *buffer,
2518 				     size_t *lenp, loff_t *ppos,
2519 				     unsigned long convmul,
2520 				     unsigned long convdiv)
2521 {
2522 	return __do_proc_doulongvec_minmax(table->data, table, write,
2523 			buffer, lenp, ppos, convmul, convdiv);
2524 }
2525 
2526 /**
2527  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2528  * @table: the sysctl table
2529  * @write: %TRUE if this is a write to the sysctl file
2530  * @buffer: the user buffer
2531  * @lenp: the size of the user buffer
2532  * @ppos: file position
2533  *
2534  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2535  * values from/to the user buffer, treated as an ASCII string.
2536  *
2537  * This routine will ensure the values are within the range specified by
2538  * table->extra1 (min) and table->extra2 (max).
2539  *
2540  * Returns 0 on success.
2541  */
2542 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2543 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2544 {
2545     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2546 }
2547 
2548 /**
2549  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2550  * @table: the sysctl table
2551  * @write: %TRUE if this is a write to the sysctl file
2552  * @buffer: the user buffer
2553  * @lenp: the size of the user buffer
2554  * @ppos: file position
2555  *
2556  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2557  * values from/to the user buffer, treated as an ASCII string. The values
2558  * are treated as milliseconds, and converted to jiffies when they are stored.
2559  *
2560  * This routine will ensure the values are within the range specified by
2561  * table->extra1 (min) and table->extra2 (max).
2562  *
2563  * Returns 0 on success.
2564  */
2565 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2566 				      void __user *buffer,
2567 				      size_t *lenp, loff_t *ppos)
2568 {
2569     return do_proc_doulongvec_minmax(table, write, buffer,
2570 				     lenp, ppos, HZ, 1000l);
2571 }
2572 
2573 
2574 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2575 					 int *valp,
2576 					 int write, void *data)
2577 {
2578 	if (write) {
2579 		if (*lvalp > INT_MAX / HZ)
2580 			return 1;
2581 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2582 	} else {
2583 		int val = *valp;
2584 		unsigned long lval;
2585 		if (val < 0) {
2586 			*negp = true;
2587 			lval = -(unsigned long)val;
2588 		} else {
2589 			*negp = false;
2590 			lval = (unsigned long)val;
2591 		}
2592 		*lvalp = lval / HZ;
2593 	}
2594 	return 0;
2595 }
2596 
2597 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2598 						int *valp,
2599 						int write, void *data)
2600 {
2601 	if (write) {
2602 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2603 			return 1;
2604 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2605 	} else {
2606 		int val = *valp;
2607 		unsigned long lval;
2608 		if (val < 0) {
2609 			*negp = true;
2610 			lval = -(unsigned long)val;
2611 		} else {
2612 			*negp = false;
2613 			lval = (unsigned long)val;
2614 		}
2615 		*lvalp = jiffies_to_clock_t(lval);
2616 	}
2617 	return 0;
2618 }
2619 
2620 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2621 					    int *valp,
2622 					    int write, void *data)
2623 {
2624 	if (write) {
2625 		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2626 
2627 		if (jif > INT_MAX)
2628 			return 1;
2629 		*valp = (int)jif;
2630 	} else {
2631 		int val = *valp;
2632 		unsigned long lval;
2633 		if (val < 0) {
2634 			*negp = true;
2635 			lval = -(unsigned long)val;
2636 		} else {
2637 			*negp = false;
2638 			lval = (unsigned long)val;
2639 		}
2640 		*lvalp = jiffies_to_msecs(lval);
2641 	}
2642 	return 0;
2643 }
2644 
2645 /**
2646  * proc_dointvec_jiffies - read a vector of integers as seconds
2647  * @table: the sysctl table
2648  * @write: %TRUE if this is a write to the sysctl file
2649  * @buffer: the user buffer
2650  * @lenp: the size of the user buffer
2651  * @ppos: file position
2652  *
2653  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2654  * values from/to the user buffer, treated as an ASCII string.
2655  * The values read are assumed to be in seconds, and are converted into
2656  * jiffies.
2657  *
2658  * Returns 0 on success.
2659  */
2660 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2661 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2662 {
2663     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2664 		    	    do_proc_dointvec_jiffies_conv,NULL);
2665 }
2666 
2667 /**
2668  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2669  * @table: the sysctl table
2670  * @write: %TRUE if this is a write to the sysctl file
2671  * @buffer: the user buffer
2672  * @lenp: the size of the user buffer
2673  * @ppos: pointer to the file position
2674  *
2675  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2676  * values from/to the user buffer, treated as an ASCII string.
2677  * The values read are assumed to be in 1/USER_HZ seconds, and
2678  * are converted into jiffies.
2679  *
2680  * Returns 0 on success.
2681  */
2682 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2683 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2684 {
2685     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2686 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2687 }
2688 
2689 /**
2690  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2691  * @table: the sysctl table
2692  * @write: %TRUE if this is a write to the sysctl file
2693  * @buffer: the user buffer
2694  * @lenp: the size of the user buffer
2695  * @ppos: file position
2696  * @ppos: the current position in the file
2697  *
2698  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2699  * values from/to the user buffer, treated as an ASCII string.
2700  * The values read are assumed to be in 1/1000 seconds, and
2701  * are converted into jiffies.
2702  *
2703  * Returns 0 on success.
2704  */
2705 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2706 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2707 {
2708 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2709 				do_proc_dointvec_ms_jiffies_conv, NULL);
2710 }
2711 
2712 static int proc_do_cad_pid(struct ctl_table *table, int write,
2713 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2714 {
2715 	struct pid *new_pid;
2716 	pid_t tmp;
2717 	int r;
2718 
2719 	tmp = pid_vnr(cad_pid);
2720 
2721 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2722 			       lenp, ppos, NULL, NULL);
2723 	if (r || !write)
2724 		return r;
2725 
2726 	new_pid = find_get_pid(tmp);
2727 	if (!new_pid)
2728 		return -ESRCH;
2729 
2730 	put_pid(xchg(&cad_pid, new_pid));
2731 	return 0;
2732 }
2733 
2734 /**
2735  * proc_do_large_bitmap - read/write from/to a large bitmap
2736  * @table: the sysctl table
2737  * @write: %TRUE if this is a write to the sysctl file
2738  * @buffer: the user buffer
2739  * @lenp: the size of the user buffer
2740  * @ppos: file position
2741  *
2742  * The bitmap is stored at table->data and the bitmap length (in bits)
2743  * in table->maxlen.
2744  *
2745  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2746  * large bitmaps may be represented in a compact manner. Writing into
2747  * the file will clear the bitmap then update it with the given input.
2748  *
2749  * Returns 0 on success.
2750  */
2751 int proc_do_large_bitmap(struct ctl_table *table, int write,
2752 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2753 {
2754 	int err = 0;
2755 	bool first = 1;
2756 	size_t left = *lenp;
2757 	unsigned long bitmap_len = table->maxlen;
2758 	unsigned long *bitmap = *(unsigned long **) table->data;
2759 	unsigned long *tmp_bitmap = NULL;
2760 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2761 
2762 	if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2763 		*lenp = 0;
2764 		return 0;
2765 	}
2766 
2767 	if (write) {
2768 		char *kbuf, *p;
2769 
2770 		if (left > PAGE_SIZE - 1)
2771 			left = PAGE_SIZE - 1;
2772 
2773 		p = kbuf = memdup_user_nul(buffer, left);
2774 		if (IS_ERR(kbuf))
2775 			return PTR_ERR(kbuf);
2776 
2777 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2778 				     GFP_KERNEL);
2779 		if (!tmp_bitmap) {
2780 			kfree(kbuf);
2781 			return -ENOMEM;
2782 		}
2783 		proc_skip_char(&p, &left, '\n');
2784 		while (!err && left) {
2785 			unsigned long val_a, val_b;
2786 			bool neg;
2787 
2788 			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2789 					     sizeof(tr_a), &c);
2790 			if (err)
2791 				break;
2792 			if (val_a >= bitmap_len || neg) {
2793 				err = -EINVAL;
2794 				break;
2795 			}
2796 
2797 			val_b = val_a;
2798 			if (left) {
2799 				p++;
2800 				left--;
2801 			}
2802 
2803 			if (c == '-') {
2804 				err = proc_get_long(&p, &left, &val_b,
2805 						     &neg, tr_b, sizeof(tr_b),
2806 						     &c);
2807 				if (err)
2808 					break;
2809 				if (val_b >= bitmap_len || neg ||
2810 				    val_a > val_b) {
2811 					err = -EINVAL;
2812 					break;
2813 				}
2814 				if (left) {
2815 					p++;
2816 					left--;
2817 				}
2818 			}
2819 
2820 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2821 			first = 0;
2822 			proc_skip_char(&p, &left, '\n');
2823 		}
2824 		kfree(kbuf);
2825 	} else {
2826 		unsigned long bit_a, bit_b = 0;
2827 
2828 		while (left) {
2829 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2830 			if (bit_a >= bitmap_len)
2831 				break;
2832 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2833 						   bit_a + 1) - 1;
2834 
2835 			if (!first) {
2836 				err = proc_put_char(&buffer, &left, ',');
2837 				if (err)
2838 					break;
2839 			}
2840 			err = proc_put_long(&buffer, &left, bit_a, false);
2841 			if (err)
2842 				break;
2843 			if (bit_a != bit_b) {
2844 				err = proc_put_char(&buffer, &left, '-');
2845 				if (err)
2846 					break;
2847 				err = proc_put_long(&buffer, &left, bit_b, false);
2848 				if (err)
2849 					break;
2850 			}
2851 
2852 			first = 0; bit_b++;
2853 		}
2854 		if (!err)
2855 			err = proc_put_char(&buffer, &left, '\n');
2856 	}
2857 
2858 	if (!err) {
2859 		if (write) {
2860 			if (*ppos)
2861 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2862 			else
2863 				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2864 		}
2865 		kfree(tmp_bitmap);
2866 		*lenp -= left;
2867 		*ppos += *lenp;
2868 		return 0;
2869 	} else {
2870 		kfree(tmp_bitmap);
2871 		return err;
2872 	}
2873 }
2874 
2875 #else /* CONFIG_PROC_SYSCTL */
2876 
2877 int proc_dostring(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_dointvec(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_douintvec(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_minmax(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_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_userhz_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_dointvec_ms_jiffies(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_minmax(struct ctl_table *table, int write,
2920 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2921 {
2922 	return -ENOSYS;
2923 }
2924 
2925 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2926 				      void __user *buffer,
2927 				      size_t *lenp, loff_t *ppos)
2928 {
2929     return -ENOSYS;
2930 }
2931 
2932 
2933 #endif /* CONFIG_PROC_SYSCTL */
2934 
2935 /*
2936  * No sense putting this after each symbol definition, twice,
2937  * exception granted :-)
2938  */
2939 EXPORT_SYMBOL(proc_dointvec);
2940 EXPORT_SYMBOL(proc_douintvec);
2941 EXPORT_SYMBOL(proc_dointvec_jiffies);
2942 EXPORT_SYMBOL(proc_dointvec_minmax);
2943 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2944 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2945 EXPORT_SYMBOL(proc_dostring);
2946 EXPORT_SYMBOL(proc_doulongvec_minmax);
2947 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2948