xref: /openbmc/linux/kernel/sysctl.c (revision 6dfcd296)
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 <asm/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 	{
351 		.procname	= "sched_shares_window_ns",
352 		.data		= &sysctl_sched_shares_window,
353 		.maxlen		= sizeof(unsigned int),
354 		.mode		= 0644,
355 		.proc_handler	= proc_dointvec,
356 	},
357 #ifdef CONFIG_SCHEDSTATS
358 	{
359 		.procname	= "sched_schedstats",
360 		.data		= NULL,
361 		.maxlen		= sizeof(unsigned int),
362 		.mode		= 0644,
363 		.proc_handler	= sysctl_schedstats,
364 		.extra1		= &zero,
365 		.extra2		= &one,
366 	},
367 #endif /* CONFIG_SCHEDSTATS */
368 #endif /* CONFIG_SMP */
369 #ifdef CONFIG_NUMA_BALANCING
370 	{
371 		.procname	= "numa_balancing_scan_delay_ms",
372 		.data		= &sysctl_numa_balancing_scan_delay,
373 		.maxlen		= sizeof(unsigned int),
374 		.mode		= 0644,
375 		.proc_handler	= proc_dointvec,
376 	},
377 	{
378 		.procname	= "numa_balancing_scan_period_min_ms",
379 		.data		= &sysctl_numa_balancing_scan_period_min,
380 		.maxlen		= sizeof(unsigned int),
381 		.mode		= 0644,
382 		.proc_handler	= proc_dointvec,
383 	},
384 	{
385 		.procname	= "numa_balancing_scan_period_max_ms",
386 		.data		= &sysctl_numa_balancing_scan_period_max,
387 		.maxlen		= sizeof(unsigned int),
388 		.mode		= 0644,
389 		.proc_handler	= proc_dointvec,
390 	},
391 	{
392 		.procname	= "numa_balancing_scan_size_mb",
393 		.data		= &sysctl_numa_balancing_scan_size,
394 		.maxlen		= sizeof(unsigned int),
395 		.mode		= 0644,
396 		.proc_handler	= proc_dointvec_minmax,
397 		.extra1		= &one,
398 	},
399 	{
400 		.procname	= "numa_balancing",
401 		.data		= NULL, /* filled in by handler */
402 		.maxlen		= sizeof(unsigned int),
403 		.mode		= 0644,
404 		.proc_handler	= sysctl_numa_balancing,
405 		.extra1		= &zero,
406 		.extra2		= &one,
407 	},
408 #endif /* CONFIG_NUMA_BALANCING */
409 #endif /* CONFIG_SCHED_DEBUG */
410 	{
411 		.procname	= "sched_rt_period_us",
412 		.data		= &sysctl_sched_rt_period,
413 		.maxlen		= sizeof(unsigned int),
414 		.mode		= 0644,
415 		.proc_handler	= sched_rt_handler,
416 	},
417 	{
418 		.procname	= "sched_rt_runtime_us",
419 		.data		= &sysctl_sched_rt_runtime,
420 		.maxlen		= sizeof(int),
421 		.mode		= 0644,
422 		.proc_handler	= sched_rt_handler,
423 	},
424 	{
425 		.procname	= "sched_rr_timeslice_ms",
426 		.data		= &sched_rr_timeslice,
427 		.maxlen		= sizeof(int),
428 		.mode		= 0644,
429 		.proc_handler	= sched_rr_handler,
430 	},
431 #ifdef CONFIG_SCHED_AUTOGROUP
432 	{
433 		.procname	= "sched_autogroup_enabled",
434 		.data		= &sysctl_sched_autogroup_enabled,
435 		.maxlen		= sizeof(unsigned int),
436 		.mode		= 0644,
437 		.proc_handler	= proc_dointvec_minmax,
438 		.extra1		= &zero,
439 		.extra2		= &one,
440 	},
441 #endif
442 #ifdef CONFIG_CFS_BANDWIDTH
443 	{
444 		.procname	= "sched_cfs_bandwidth_slice_us",
445 		.data		= &sysctl_sched_cfs_bandwidth_slice,
446 		.maxlen		= sizeof(unsigned int),
447 		.mode		= 0644,
448 		.proc_handler	= proc_dointvec_minmax,
449 		.extra1		= &one,
450 	},
451 #endif
452 #ifdef CONFIG_PROVE_LOCKING
453 	{
454 		.procname	= "prove_locking",
455 		.data		= &prove_locking,
456 		.maxlen		= sizeof(int),
457 		.mode		= 0644,
458 		.proc_handler	= proc_dointvec,
459 	},
460 #endif
461 #ifdef CONFIG_LOCK_STAT
462 	{
463 		.procname	= "lock_stat",
464 		.data		= &lock_stat,
465 		.maxlen		= sizeof(int),
466 		.mode		= 0644,
467 		.proc_handler	= proc_dointvec,
468 	},
469 #endif
470 	{
471 		.procname	= "panic",
472 		.data		= &panic_timeout,
473 		.maxlen		= sizeof(int),
474 		.mode		= 0644,
475 		.proc_handler	= proc_dointvec,
476 	},
477 #ifdef CONFIG_COREDUMP
478 	{
479 		.procname	= "core_uses_pid",
480 		.data		= &core_uses_pid,
481 		.maxlen		= sizeof(int),
482 		.mode		= 0644,
483 		.proc_handler	= proc_dointvec,
484 	},
485 	{
486 		.procname	= "core_pattern",
487 		.data		= core_pattern,
488 		.maxlen		= CORENAME_MAX_SIZE,
489 		.mode		= 0644,
490 		.proc_handler	= proc_dostring_coredump,
491 	},
492 	{
493 		.procname	= "core_pipe_limit",
494 		.data		= &core_pipe_limit,
495 		.maxlen		= sizeof(unsigned int),
496 		.mode		= 0644,
497 		.proc_handler	= proc_dointvec,
498 	},
499 #endif
500 #ifdef CONFIG_PROC_SYSCTL
501 	{
502 		.procname	= "tainted",
503 		.maxlen 	= sizeof(long),
504 		.mode		= 0644,
505 		.proc_handler	= proc_taint,
506 	},
507 	{
508 		.procname	= "sysctl_writes_strict",
509 		.data		= &sysctl_writes_strict,
510 		.maxlen		= sizeof(int),
511 		.mode		= 0644,
512 		.proc_handler	= proc_dointvec_minmax,
513 		.extra1		= &neg_one,
514 		.extra2		= &one,
515 	},
516 #endif
517 #ifdef CONFIG_LATENCYTOP
518 	{
519 		.procname	= "latencytop",
520 		.data		= &latencytop_enabled,
521 		.maxlen		= sizeof(int),
522 		.mode		= 0644,
523 		.proc_handler	= sysctl_latencytop,
524 	},
525 #endif
526 #ifdef CONFIG_BLK_DEV_INITRD
527 	{
528 		.procname	= "real-root-dev",
529 		.data		= &real_root_dev,
530 		.maxlen		= sizeof(int),
531 		.mode		= 0644,
532 		.proc_handler	= proc_dointvec,
533 	},
534 #endif
535 	{
536 		.procname	= "print-fatal-signals",
537 		.data		= &print_fatal_signals,
538 		.maxlen		= sizeof(int),
539 		.mode		= 0644,
540 		.proc_handler	= proc_dointvec,
541 	},
542 #ifdef CONFIG_SPARC
543 	{
544 		.procname	= "reboot-cmd",
545 		.data		= reboot_command,
546 		.maxlen		= 256,
547 		.mode		= 0644,
548 		.proc_handler	= proc_dostring,
549 	},
550 	{
551 		.procname	= "stop-a",
552 		.data		= &stop_a_enabled,
553 		.maxlen		= sizeof (int),
554 		.mode		= 0644,
555 		.proc_handler	= proc_dointvec,
556 	},
557 	{
558 		.procname	= "scons-poweroff",
559 		.data		= &scons_pwroff,
560 		.maxlen		= sizeof (int),
561 		.mode		= 0644,
562 		.proc_handler	= proc_dointvec,
563 	},
564 #endif
565 #ifdef CONFIG_SPARC64
566 	{
567 		.procname	= "tsb-ratio",
568 		.data		= &sysctl_tsb_ratio,
569 		.maxlen		= sizeof (int),
570 		.mode		= 0644,
571 		.proc_handler	= proc_dointvec,
572 	},
573 #endif
574 #ifdef __hppa__
575 	{
576 		.procname	= "soft-power",
577 		.data		= &pwrsw_enabled,
578 		.maxlen		= sizeof (int),
579 	 	.mode		= 0644,
580 		.proc_handler	= proc_dointvec,
581 	},
582 #endif
583 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
584 	{
585 		.procname	= "unaligned-trap",
586 		.data		= &unaligned_enabled,
587 		.maxlen		= sizeof (int),
588 		.mode		= 0644,
589 		.proc_handler	= proc_dointvec,
590 	},
591 #endif
592 	{
593 		.procname	= "ctrl-alt-del",
594 		.data		= &C_A_D,
595 		.maxlen		= sizeof(int),
596 		.mode		= 0644,
597 		.proc_handler	= proc_dointvec,
598 	},
599 #ifdef CONFIG_FUNCTION_TRACER
600 	{
601 		.procname	= "ftrace_enabled",
602 		.data		= &ftrace_enabled,
603 		.maxlen		= sizeof(int),
604 		.mode		= 0644,
605 		.proc_handler	= ftrace_enable_sysctl,
606 	},
607 #endif
608 #ifdef CONFIG_STACK_TRACER
609 	{
610 		.procname	= "stack_tracer_enabled",
611 		.data		= &stack_tracer_enabled,
612 		.maxlen		= sizeof(int),
613 		.mode		= 0644,
614 		.proc_handler	= stack_trace_sysctl,
615 	},
616 #endif
617 #ifdef CONFIG_TRACING
618 	{
619 		.procname	= "ftrace_dump_on_oops",
620 		.data		= &ftrace_dump_on_oops,
621 		.maxlen		= sizeof(int),
622 		.mode		= 0644,
623 		.proc_handler	= proc_dointvec,
624 	},
625 	{
626 		.procname	= "traceoff_on_warning",
627 		.data		= &__disable_trace_on_warning,
628 		.maxlen		= sizeof(__disable_trace_on_warning),
629 		.mode		= 0644,
630 		.proc_handler	= proc_dointvec,
631 	},
632 	{
633 		.procname	= "tracepoint_printk",
634 		.data		= &tracepoint_printk,
635 		.maxlen		= sizeof(tracepoint_printk),
636 		.mode		= 0644,
637 		.proc_handler	= proc_dointvec,
638 	},
639 #endif
640 #ifdef CONFIG_KEXEC_CORE
641 	{
642 		.procname	= "kexec_load_disabled",
643 		.data		= &kexec_load_disabled,
644 		.maxlen		= sizeof(int),
645 		.mode		= 0644,
646 		/* only handle a transition from default "0" to "1" */
647 		.proc_handler	= proc_dointvec_minmax,
648 		.extra1		= &one,
649 		.extra2		= &one,
650 	},
651 #endif
652 #ifdef CONFIG_MODULES
653 	{
654 		.procname	= "modprobe",
655 		.data		= &modprobe_path,
656 		.maxlen		= KMOD_PATH_LEN,
657 		.mode		= 0644,
658 		.proc_handler	= proc_dostring,
659 	},
660 	{
661 		.procname	= "modules_disabled",
662 		.data		= &modules_disabled,
663 		.maxlen		= sizeof(int),
664 		.mode		= 0644,
665 		/* only handle a transition from default "0" to "1" */
666 		.proc_handler	= proc_dointvec_minmax,
667 		.extra1		= &one,
668 		.extra2		= &one,
669 	},
670 #endif
671 #ifdef CONFIG_UEVENT_HELPER
672 	{
673 		.procname	= "hotplug",
674 		.data		= &uevent_helper,
675 		.maxlen		= UEVENT_HELPER_PATH_LEN,
676 		.mode		= 0644,
677 		.proc_handler	= proc_dostring,
678 	},
679 #endif
680 #ifdef CONFIG_CHR_DEV_SG
681 	{
682 		.procname	= "sg-big-buff",
683 		.data		= &sg_big_buff,
684 		.maxlen		= sizeof (int),
685 		.mode		= 0444,
686 		.proc_handler	= proc_dointvec,
687 	},
688 #endif
689 #ifdef CONFIG_BSD_PROCESS_ACCT
690 	{
691 		.procname	= "acct",
692 		.data		= &acct_parm,
693 		.maxlen		= 3*sizeof(int),
694 		.mode		= 0644,
695 		.proc_handler	= proc_dointvec,
696 	},
697 #endif
698 #ifdef CONFIG_MAGIC_SYSRQ
699 	{
700 		.procname	= "sysrq",
701 		.data		= &__sysrq_enabled,
702 		.maxlen		= sizeof (int),
703 		.mode		= 0644,
704 		.proc_handler	= sysrq_sysctl_handler,
705 	},
706 #endif
707 #ifdef CONFIG_PROC_SYSCTL
708 	{
709 		.procname	= "cad_pid",
710 		.data		= NULL,
711 		.maxlen		= sizeof (int),
712 		.mode		= 0600,
713 		.proc_handler	= proc_do_cad_pid,
714 	},
715 #endif
716 	{
717 		.procname	= "threads-max",
718 		.data		= NULL,
719 		.maxlen		= sizeof(int),
720 		.mode		= 0644,
721 		.proc_handler	= sysctl_max_threads,
722 	},
723 	{
724 		.procname	= "random",
725 		.mode		= 0555,
726 		.child		= random_table,
727 	},
728 	{
729 		.procname	= "usermodehelper",
730 		.mode		= 0555,
731 		.child		= usermodehelper_table,
732 	},
733 	{
734 		.procname	= "overflowuid",
735 		.data		= &overflowuid,
736 		.maxlen		= sizeof(int),
737 		.mode		= 0644,
738 		.proc_handler	= proc_dointvec_minmax,
739 		.extra1		= &minolduid,
740 		.extra2		= &maxolduid,
741 	},
742 	{
743 		.procname	= "overflowgid",
744 		.data		= &overflowgid,
745 		.maxlen		= sizeof(int),
746 		.mode		= 0644,
747 		.proc_handler	= proc_dointvec_minmax,
748 		.extra1		= &minolduid,
749 		.extra2		= &maxolduid,
750 	},
751 #ifdef CONFIG_S390
752 #ifdef CONFIG_MATHEMU
753 	{
754 		.procname	= "ieee_emulation_warnings",
755 		.data		= &sysctl_ieee_emulation_warnings,
756 		.maxlen		= sizeof(int),
757 		.mode		= 0644,
758 		.proc_handler	= proc_dointvec,
759 	},
760 #endif
761 	{
762 		.procname	= "userprocess_debug",
763 		.data		= &show_unhandled_signals,
764 		.maxlen		= sizeof(int),
765 		.mode		= 0644,
766 		.proc_handler	= proc_dointvec,
767 	},
768 #endif
769 	{
770 		.procname	= "pid_max",
771 		.data		= &pid_max,
772 		.maxlen		= sizeof (int),
773 		.mode		= 0644,
774 		.proc_handler	= proc_dointvec_minmax,
775 		.extra1		= &pid_max_min,
776 		.extra2		= &pid_max_max,
777 	},
778 	{
779 		.procname	= "panic_on_oops",
780 		.data		= &panic_on_oops,
781 		.maxlen		= sizeof(int),
782 		.mode		= 0644,
783 		.proc_handler	= proc_dointvec,
784 	},
785 #if defined CONFIG_PRINTK
786 	{
787 		.procname	= "printk",
788 		.data		= &console_loglevel,
789 		.maxlen		= 4*sizeof(int),
790 		.mode		= 0644,
791 		.proc_handler	= proc_dointvec,
792 	},
793 	{
794 		.procname	= "printk_ratelimit",
795 		.data		= &printk_ratelimit_state.interval,
796 		.maxlen		= sizeof(int),
797 		.mode		= 0644,
798 		.proc_handler	= proc_dointvec_jiffies,
799 	},
800 	{
801 		.procname	= "printk_ratelimit_burst",
802 		.data		= &printk_ratelimit_state.burst,
803 		.maxlen		= sizeof(int),
804 		.mode		= 0644,
805 		.proc_handler	= proc_dointvec,
806 	},
807 	{
808 		.procname	= "printk_delay",
809 		.data		= &printk_delay_msec,
810 		.maxlen		= sizeof(int),
811 		.mode		= 0644,
812 		.proc_handler	= proc_dointvec_minmax,
813 		.extra1		= &zero,
814 		.extra2		= &ten_thousand,
815 	},
816 	{
817 		.procname	= "printk_devkmsg",
818 		.data		= devkmsg_log_str,
819 		.maxlen		= DEVKMSG_STR_MAX_SIZE,
820 		.mode		= 0644,
821 		.proc_handler	= devkmsg_sysctl_set_loglvl,
822 	},
823 	{
824 		.procname	= "dmesg_restrict",
825 		.data		= &dmesg_restrict,
826 		.maxlen		= sizeof(int),
827 		.mode		= 0644,
828 		.proc_handler	= proc_dointvec_minmax_sysadmin,
829 		.extra1		= &zero,
830 		.extra2		= &one,
831 	},
832 	{
833 		.procname	= "kptr_restrict",
834 		.data		= &kptr_restrict,
835 		.maxlen		= sizeof(int),
836 		.mode		= 0644,
837 		.proc_handler	= proc_dointvec_minmax_sysadmin,
838 		.extra1		= &zero,
839 		.extra2		= &two,
840 	},
841 #endif
842 	{
843 		.procname	= "ngroups_max",
844 		.data		= &ngroups_max,
845 		.maxlen		= sizeof (int),
846 		.mode		= 0444,
847 		.proc_handler	= proc_dointvec,
848 	},
849 	{
850 		.procname	= "cap_last_cap",
851 		.data		= (void *)&cap_last_cap,
852 		.maxlen		= sizeof(int),
853 		.mode		= 0444,
854 		.proc_handler	= proc_dointvec,
855 	},
856 #if defined(CONFIG_LOCKUP_DETECTOR)
857 	{
858 		.procname       = "watchdog",
859 		.data           = &watchdog_user_enabled,
860 		.maxlen         = sizeof (int),
861 		.mode           = 0644,
862 		.proc_handler   = proc_watchdog,
863 		.extra1		= &zero,
864 		.extra2		= &one,
865 	},
866 	{
867 		.procname	= "watchdog_thresh",
868 		.data		= &watchdog_thresh,
869 		.maxlen		= sizeof(int),
870 		.mode		= 0644,
871 		.proc_handler	= proc_watchdog_thresh,
872 		.extra1		= &zero,
873 		.extra2		= &sixty,
874 	},
875 	{
876 		.procname       = "nmi_watchdog",
877 		.data           = &nmi_watchdog_enabled,
878 		.maxlen         = sizeof (int),
879 		.mode           = 0644,
880 		.proc_handler   = proc_nmi_watchdog,
881 		.extra1		= &zero,
882 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
883 		.extra2		= &one,
884 #else
885 		.extra2		= &zero,
886 #endif
887 	},
888 	{
889 		.procname       = "soft_watchdog",
890 		.data           = &soft_watchdog_enabled,
891 		.maxlen         = sizeof (int),
892 		.mode           = 0644,
893 		.proc_handler   = proc_soft_watchdog,
894 		.extra1		= &zero,
895 		.extra2		= &one,
896 	},
897 	{
898 		.procname	= "watchdog_cpumask",
899 		.data		= &watchdog_cpumask_bits,
900 		.maxlen		= NR_CPUS,
901 		.mode		= 0644,
902 		.proc_handler	= proc_watchdog_cpumask,
903 	},
904 	{
905 		.procname	= "softlockup_panic",
906 		.data		= &softlockup_panic,
907 		.maxlen		= sizeof(int),
908 		.mode		= 0644,
909 		.proc_handler	= proc_dointvec_minmax,
910 		.extra1		= &zero,
911 		.extra2		= &one,
912 	},
913 #ifdef CONFIG_HARDLOCKUP_DETECTOR
914 	{
915 		.procname	= "hardlockup_panic",
916 		.data		= &hardlockup_panic,
917 		.maxlen		= sizeof(int),
918 		.mode		= 0644,
919 		.proc_handler	= proc_dointvec_minmax,
920 		.extra1		= &zero,
921 		.extra2		= &one,
922 	},
923 #endif
924 #ifdef CONFIG_SMP
925 	{
926 		.procname	= "softlockup_all_cpu_backtrace",
927 		.data		= &sysctl_softlockup_all_cpu_backtrace,
928 		.maxlen		= sizeof(int),
929 		.mode		= 0644,
930 		.proc_handler	= proc_dointvec_minmax,
931 		.extra1		= &zero,
932 		.extra2		= &one,
933 	},
934 	{
935 		.procname	= "hardlockup_all_cpu_backtrace",
936 		.data		= &sysctl_hardlockup_all_cpu_backtrace,
937 		.maxlen		= sizeof(int),
938 		.mode		= 0644,
939 		.proc_handler	= proc_dointvec_minmax,
940 		.extra1		= &zero,
941 		.extra2		= &one,
942 	},
943 #endif /* CONFIG_SMP */
944 #endif
945 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
946 	{
947 		.procname       = "unknown_nmi_panic",
948 		.data           = &unknown_nmi_panic,
949 		.maxlen         = sizeof (int),
950 		.mode           = 0644,
951 		.proc_handler   = proc_dointvec,
952 	},
953 #endif
954 #if defined(CONFIG_X86)
955 	{
956 		.procname	= "panic_on_unrecovered_nmi",
957 		.data		= &panic_on_unrecovered_nmi,
958 		.maxlen		= sizeof(int),
959 		.mode		= 0644,
960 		.proc_handler	= proc_dointvec,
961 	},
962 	{
963 		.procname	= "panic_on_io_nmi",
964 		.data		= &panic_on_io_nmi,
965 		.maxlen		= sizeof(int),
966 		.mode		= 0644,
967 		.proc_handler	= proc_dointvec,
968 	},
969 #ifdef CONFIG_DEBUG_STACKOVERFLOW
970 	{
971 		.procname	= "panic_on_stackoverflow",
972 		.data		= &sysctl_panic_on_stackoverflow,
973 		.maxlen		= sizeof(int),
974 		.mode		= 0644,
975 		.proc_handler	= proc_dointvec,
976 	},
977 #endif
978 	{
979 		.procname	= "bootloader_type",
980 		.data		= &bootloader_type,
981 		.maxlen		= sizeof (int),
982 		.mode		= 0444,
983 		.proc_handler	= proc_dointvec,
984 	},
985 	{
986 		.procname	= "bootloader_version",
987 		.data		= &bootloader_version,
988 		.maxlen		= sizeof (int),
989 		.mode		= 0444,
990 		.proc_handler	= proc_dointvec,
991 	},
992 	{
993 		.procname	= "kstack_depth_to_print",
994 		.data		= &kstack_depth_to_print,
995 		.maxlen		= sizeof(int),
996 		.mode		= 0644,
997 		.proc_handler	= proc_dointvec,
998 	},
999 	{
1000 		.procname	= "io_delay_type",
1001 		.data		= &io_delay_type,
1002 		.maxlen		= sizeof(int),
1003 		.mode		= 0644,
1004 		.proc_handler	= proc_dointvec,
1005 	},
1006 #endif
1007 #if defined(CONFIG_MMU)
1008 	{
1009 		.procname	= "randomize_va_space",
1010 		.data		= &randomize_va_space,
1011 		.maxlen		= sizeof(int),
1012 		.mode		= 0644,
1013 		.proc_handler	= proc_dointvec,
1014 	},
1015 #endif
1016 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1017 	{
1018 		.procname	= "spin_retry",
1019 		.data		= &spin_retry,
1020 		.maxlen		= sizeof (int),
1021 		.mode		= 0644,
1022 		.proc_handler	= proc_dointvec,
1023 	},
1024 #endif
1025 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1026 	{
1027 		.procname	= "acpi_video_flags",
1028 		.data		= &acpi_realmode_flags,
1029 		.maxlen		= sizeof (unsigned long),
1030 		.mode		= 0644,
1031 		.proc_handler	= proc_doulongvec_minmax,
1032 	},
1033 #endif
1034 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1035 	{
1036 		.procname	= "ignore-unaligned-usertrap",
1037 		.data		= &no_unaligned_warning,
1038 		.maxlen		= sizeof (int),
1039 	 	.mode		= 0644,
1040 		.proc_handler	= proc_dointvec,
1041 	},
1042 #endif
1043 #ifdef CONFIG_IA64
1044 	{
1045 		.procname	= "unaligned-dump-stack",
1046 		.data		= &unaligned_dump_stack,
1047 		.maxlen		= sizeof (int),
1048 		.mode		= 0644,
1049 		.proc_handler	= proc_dointvec,
1050 	},
1051 #endif
1052 #ifdef CONFIG_DETECT_HUNG_TASK
1053 	{
1054 		.procname	= "hung_task_panic",
1055 		.data		= &sysctl_hung_task_panic,
1056 		.maxlen		= sizeof(int),
1057 		.mode		= 0644,
1058 		.proc_handler	= proc_dointvec_minmax,
1059 		.extra1		= &zero,
1060 		.extra2		= &one,
1061 	},
1062 	{
1063 		.procname	= "hung_task_check_count",
1064 		.data		= &sysctl_hung_task_check_count,
1065 		.maxlen		= sizeof(int),
1066 		.mode		= 0644,
1067 		.proc_handler	= proc_dointvec_minmax,
1068 		.extra1		= &zero,
1069 	},
1070 	{
1071 		.procname	= "hung_task_timeout_secs",
1072 		.data		= &sysctl_hung_task_timeout_secs,
1073 		.maxlen		= sizeof(unsigned long),
1074 		.mode		= 0644,
1075 		.proc_handler	= proc_dohung_task_timeout_secs,
1076 		.extra2		= &hung_task_timeout_max,
1077 	},
1078 	{
1079 		.procname	= "hung_task_warnings",
1080 		.data		= &sysctl_hung_task_warnings,
1081 		.maxlen		= sizeof(int),
1082 		.mode		= 0644,
1083 		.proc_handler	= proc_dointvec_minmax,
1084 		.extra1		= &neg_one,
1085 	},
1086 #endif
1087 #ifdef CONFIG_RT_MUTEXES
1088 	{
1089 		.procname	= "max_lock_depth",
1090 		.data		= &max_lock_depth,
1091 		.maxlen		= sizeof(int),
1092 		.mode		= 0644,
1093 		.proc_handler	= proc_dointvec,
1094 	},
1095 #endif
1096 	{
1097 		.procname	= "poweroff_cmd",
1098 		.data		= &poweroff_cmd,
1099 		.maxlen		= POWEROFF_CMD_PATH_LEN,
1100 		.mode		= 0644,
1101 		.proc_handler	= proc_dostring,
1102 	},
1103 #ifdef CONFIG_KEYS
1104 	{
1105 		.procname	= "keys",
1106 		.mode		= 0555,
1107 		.child		= key_sysctls,
1108 	},
1109 #endif
1110 #ifdef CONFIG_PERF_EVENTS
1111 	/*
1112 	 * User-space scripts rely on the existence of this file
1113 	 * as a feature check for perf_events being enabled.
1114 	 *
1115 	 * So it's an ABI, do not remove!
1116 	 */
1117 	{
1118 		.procname	= "perf_event_paranoid",
1119 		.data		= &sysctl_perf_event_paranoid,
1120 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
1121 		.mode		= 0644,
1122 		.proc_handler	= proc_dointvec,
1123 	},
1124 	{
1125 		.procname	= "perf_event_mlock_kb",
1126 		.data		= &sysctl_perf_event_mlock,
1127 		.maxlen		= sizeof(sysctl_perf_event_mlock),
1128 		.mode		= 0644,
1129 		.proc_handler	= proc_dointvec,
1130 	},
1131 	{
1132 		.procname	= "perf_event_max_sample_rate",
1133 		.data		= &sysctl_perf_event_sample_rate,
1134 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
1135 		.mode		= 0644,
1136 		.proc_handler	= perf_proc_update_handler,
1137 		.extra1		= &one,
1138 	},
1139 	{
1140 		.procname	= "perf_cpu_time_max_percent",
1141 		.data		= &sysctl_perf_cpu_time_max_percent,
1142 		.maxlen		= sizeof(sysctl_perf_cpu_time_max_percent),
1143 		.mode		= 0644,
1144 		.proc_handler	= perf_cpu_time_max_percent_handler,
1145 		.extra1		= &zero,
1146 		.extra2		= &one_hundred,
1147 	},
1148 	{
1149 		.procname	= "perf_event_max_stack",
1150 		.data		= &sysctl_perf_event_max_stack,
1151 		.maxlen		= sizeof(sysctl_perf_event_max_stack),
1152 		.mode		= 0644,
1153 		.proc_handler	= perf_event_max_stack_handler,
1154 		.extra1		= &zero,
1155 		.extra2		= &six_hundred_forty_kb,
1156 	},
1157 	{
1158 		.procname	= "perf_event_max_contexts_per_stack",
1159 		.data		= &sysctl_perf_event_max_contexts_per_stack,
1160 		.maxlen		= sizeof(sysctl_perf_event_max_contexts_per_stack),
1161 		.mode		= 0644,
1162 		.proc_handler	= perf_event_max_stack_handler,
1163 		.extra1		= &zero,
1164 		.extra2		= &one_thousand,
1165 	},
1166 #endif
1167 #ifdef CONFIG_KMEMCHECK
1168 	{
1169 		.procname	= "kmemcheck",
1170 		.data		= &kmemcheck_enabled,
1171 		.maxlen		= sizeof(int),
1172 		.mode		= 0644,
1173 		.proc_handler	= proc_dointvec,
1174 	},
1175 #endif
1176 	{
1177 		.procname	= "panic_on_warn",
1178 		.data		= &panic_on_warn,
1179 		.maxlen		= sizeof(int),
1180 		.mode		= 0644,
1181 		.proc_handler	= proc_dointvec_minmax,
1182 		.extra1		= &zero,
1183 		.extra2		= &one,
1184 	},
1185 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1186 	{
1187 		.procname	= "timer_migration",
1188 		.data		= &sysctl_timer_migration,
1189 		.maxlen		= sizeof(unsigned int),
1190 		.mode		= 0644,
1191 		.proc_handler	= timer_migration_handler,
1192 	},
1193 #endif
1194 #ifdef CONFIG_BPF_SYSCALL
1195 	{
1196 		.procname	= "unprivileged_bpf_disabled",
1197 		.data		= &sysctl_unprivileged_bpf_disabled,
1198 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
1199 		.mode		= 0644,
1200 		/* only handle a transition from default "0" to "1" */
1201 		.proc_handler	= proc_dointvec_minmax,
1202 		.extra1		= &one,
1203 		.extra2		= &one,
1204 	},
1205 #endif
1206 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
1207 	{
1208 		.procname	= "panic_on_rcu_stall",
1209 		.data		= &sysctl_panic_on_rcu_stall,
1210 		.maxlen		= sizeof(sysctl_panic_on_rcu_stall),
1211 		.mode		= 0644,
1212 		.proc_handler	= proc_dointvec_minmax,
1213 		.extra1		= &zero,
1214 		.extra2		= &one,
1215 	},
1216 #endif
1217 	{ }
1218 };
1219 
1220 static struct ctl_table vm_table[] = {
1221 	{
1222 		.procname	= "overcommit_memory",
1223 		.data		= &sysctl_overcommit_memory,
1224 		.maxlen		= sizeof(sysctl_overcommit_memory),
1225 		.mode		= 0644,
1226 		.proc_handler	= proc_dointvec_minmax,
1227 		.extra1		= &zero,
1228 		.extra2		= &two,
1229 	},
1230 	{
1231 		.procname	= "panic_on_oom",
1232 		.data		= &sysctl_panic_on_oom,
1233 		.maxlen		= sizeof(sysctl_panic_on_oom),
1234 		.mode		= 0644,
1235 		.proc_handler	= proc_dointvec_minmax,
1236 		.extra1		= &zero,
1237 		.extra2		= &two,
1238 	},
1239 	{
1240 		.procname	= "oom_kill_allocating_task",
1241 		.data		= &sysctl_oom_kill_allocating_task,
1242 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
1243 		.mode		= 0644,
1244 		.proc_handler	= proc_dointvec,
1245 	},
1246 	{
1247 		.procname	= "oom_dump_tasks",
1248 		.data		= &sysctl_oom_dump_tasks,
1249 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1250 		.mode		= 0644,
1251 		.proc_handler	= proc_dointvec,
1252 	},
1253 	{
1254 		.procname	= "overcommit_ratio",
1255 		.data		= &sysctl_overcommit_ratio,
1256 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1257 		.mode		= 0644,
1258 		.proc_handler	= overcommit_ratio_handler,
1259 	},
1260 	{
1261 		.procname	= "overcommit_kbytes",
1262 		.data		= &sysctl_overcommit_kbytes,
1263 		.maxlen		= sizeof(sysctl_overcommit_kbytes),
1264 		.mode		= 0644,
1265 		.proc_handler	= overcommit_kbytes_handler,
1266 	},
1267 	{
1268 		.procname	= "page-cluster",
1269 		.data		= &page_cluster,
1270 		.maxlen		= sizeof(int),
1271 		.mode		= 0644,
1272 		.proc_handler	= proc_dointvec_minmax,
1273 		.extra1		= &zero,
1274 	},
1275 	{
1276 		.procname	= "dirty_background_ratio",
1277 		.data		= &dirty_background_ratio,
1278 		.maxlen		= sizeof(dirty_background_ratio),
1279 		.mode		= 0644,
1280 		.proc_handler	= dirty_background_ratio_handler,
1281 		.extra1		= &zero,
1282 		.extra2		= &one_hundred,
1283 	},
1284 	{
1285 		.procname	= "dirty_background_bytes",
1286 		.data		= &dirty_background_bytes,
1287 		.maxlen		= sizeof(dirty_background_bytes),
1288 		.mode		= 0644,
1289 		.proc_handler	= dirty_background_bytes_handler,
1290 		.extra1		= &one_ul,
1291 	},
1292 	{
1293 		.procname	= "dirty_ratio",
1294 		.data		= &vm_dirty_ratio,
1295 		.maxlen		= sizeof(vm_dirty_ratio),
1296 		.mode		= 0644,
1297 		.proc_handler	= dirty_ratio_handler,
1298 		.extra1		= &zero,
1299 		.extra2		= &one_hundred,
1300 	},
1301 	{
1302 		.procname	= "dirty_bytes",
1303 		.data		= &vm_dirty_bytes,
1304 		.maxlen		= sizeof(vm_dirty_bytes),
1305 		.mode		= 0644,
1306 		.proc_handler	= dirty_bytes_handler,
1307 		.extra1		= &dirty_bytes_min,
1308 	},
1309 	{
1310 		.procname	= "dirty_writeback_centisecs",
1311 		.data		= &dirty_writeback_interval,
1312 		.maxlen		= sizeof(dirty_writeback_interval),
1313 		.mode		= 0644,
1314 		.proc_handler	= dirty_writeback_centisecs_handler,
1315 	},
1316 	{
1317 		.procname	= "dirty_expire_centisecs",
1318 		.data		= &dirty_expire_interval,
1319 		.maxlen		= sizeof(dirty_expire_interval),
1320 		.mode		= 0644,
1321 		.proc_handler	= proc_dointvec_minmax,
1322 		.extra1		= &zero,
1323 	},
1324 	{
1325 		.procname	= "dirtytime_expire_seconds",
1326 		.data		= &dirtytime_expire_interval,
1327 		.maxlen		= sizeof(dirty_expire_interval),
1328 		.mode		= 0644,
1329 		.proc_handler	= dirtytime_interval_handler,
1330 		.extra1		= &zero,
1331 	},
1332 	{
1333 		.procname       = "nr_pdflush_threads",
1334 		.mode           = 0444 /* read-only */,
1335 		.proc_handler   = pdflush_proc_obsolete,
1336 	},
1337 	{
1338 		.procname	= "swappiness",
1339 		.data		= &vm_swappiness,
1340 		.maxlen		= sizeof(vm_swappiness),
1341 		.mode		= 0644,
1342 		.proc_handler	= proc_dointvec_minmax,
1343 		.extra1		= &zero,
1344 		.extra2		= &one_hundred,
1345 	},
1346 #ifdef CONFIG_HUGETLB_PAGE
1347 	{
1348 		.procname	= "nr_hugepages",
1349 		.data		= NULL,
1350 		.maxlen		= sizeof(unsigned long),
1351 		.mode		= 0644,
1352 		.proc_handler	= hugetlb_sysctl_handler,
1353 	},
1354 #ifdef CONFIG_NUMA
1355 	{
1356 		.procname       = "nr_hugepages_mempolicy",
1357 		.data           = NULL,
1358 		.maxlen         = sizeof(unsigned long),
1359 		.mode           = 0644,
1360 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1361 	},
1362 #endif
1363 	 {
1364 		.procname	= "hugetlb_shm_group",
1365 		.data		= &sysctl_hugetlb_shm_group,
1366 		.maxlen		= sizeof(gid_t),
1367 		.mode		= 0644,
1368 		.proc_handler	= proc_dointvec,
1369 	 },
1370 	 {
1371 		.procname	= "hugepages_treat_as_movable",
1372 		.data		= &hugepages_treat_as_movable,
1373 		.maxlen		= sizeof(int),
1374 		.mode		= 0644,
1375 		.proc_handler	= proc_dointvec,
1376 	},
1377 	{
1378 		.procname	= "nr_overcommit_hugepages",
1379 		.data		= NULL,
1380 		.maxlen		= sizeof(unsigned long),
1381 		.mode		= 0644,
1382 		.proc_handler	= hugetlb_overcommit_handler,
1383 	},
1384 #endif
1385 	{
1386 		.procname	= "lowmem_reserve_ratio",
1387 		.data		= &sysctl_lowmem_reserve_ratio,
1388 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1389 		.mode		= 0644,
1390 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1391 	},
1392 	{
1393 		.procname	= "drop_caches",
1394 		.data		= &sysctl_drop_caches,
1395 		.maxlen		= sizeof(int),
1396 		.mode		= 0644,
1397 		.proc_handler	= drop_caches_sysctl_handler,
1398 		.extra1		= &one,
1399 		.extra2		= &four,
1400 	},
1401 #ifdef CONFIG_COMPACTION
1402 	{
1403 		.procname	= "compact_memory",
1404 		.data		= &sysctl_compact_memory,
1405 		.maxlen		= sizeof(int),
1406 		.mode		= 0200,
1407 		.proc_handler	= sysctl_compaction_handler,
1408 	},
1409 	{
1410 		.procname	= "extfrag_threshold",
1411 		.data		= &sysctl_extfrag_threshold,
1412 		.maxlen		= sizeof(int),
1413 		.mode		= 0644,
1414 		.proc_handler	= sysctl_extfrag_handler,
1415 		.extra1		= &min_extfrag_threshold,
1416 		.extra2		= &max_extfrag_threshold,
1417 	},
1418 	{
1419 		.procname	= "compact_unevictable_allowed",
1420 		.data		= &sysctl_compact_unevictable_allowed,
1421 		.maxlen		= sizeof(int),
1422 		.mode		= 0644,
1423 		.proc_handler	= proc_dointvec,
1424 		.extra1		= &zero,
1425 		.extra2		= &one,
1426 	},
1427 
1428 #endif /* CONFIG_COMPACTION */
1429 	{
1430 		.procname	= "min_free_kbytes",
1431 		.data		= &min_free_kbytes,
1432 		.maxlen		= sizeof(min_free_kbytes),
1433 		.mode		= 0644,
1434 		.proc_handler	= min_free_kbytes_sysctl_handler,
1435 		.extra1		= &zero,
1436 	},
1437 	{
1438 		.procname	= "watermark_scale_factor",
1439 		.data		= &watermark_scale_factor,
1440 		.maxlen		= sizeof(watermark_scale_factor),
1441 		.mode		= 0644,
1442 		.proc_handler	= watermark_scale_factor_sysctl_handler,
1443 		.extra1		= &one,
1444 		.extra2		= &one_thousand,
1445 	},
1446 	{
1447 		.procname	= "percpu_pagelist_fraction",
1448 		.data		= &percpu_pagelist_fraction,
1449 		.maxlen		= sizeof(percpu_pagelist_fraction),
1450 		.mode		= 0644,
1451 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1452 		.extra1		= &zero,
1453 	},
1454 #ifdef CONFIG_MMU
1455 	{
1456 		.procname	= "max_map_count",
1457 		.data		= &sysctl_max_map_count,
1458 		.maxlen		= sizeof(sysctl_max_map_count),
1459 		.mode		= 0644,
1460 		.proc_handler	= proc_dointvec_minmax,
1461 		.extra1		= &zero,
1462 	},
1463 #else
1464 	{
1465 		.procname	= "nr_trim_pages",
1466 		.data		= &sysctl_nr_trim_pages,
1467 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1468 		.mode		= 0644,
1469 		.proc_handler	= proc_dointvec_minmax,
1470 		.extra1		= &zero,
1471 	},
1472 #endif
1473 	{
1474 		.procname	= "laptop_mode",
1475 		.data		= &laptop_mode,
1476 		.maxlen		= sizeof(laptop_mode),
1477 		.mode		= 0644,
1478 		.proc_handler	= proc_dointvec_jiffies,
1479 	},
1480 	{
1481 		.procname	= "block_dump",
1482 		.data		= &block_dump,
1483 		.maxlen		= sizeof(block_dump),
1484 		.mode		= 0644,
1485 		.proc_handler	= proc_dointvec,
1486 		.extra1		= &zero,
1487 	},
1488 	{
1489 		.procname	= "vfs_cache_pressure",
1490 		.data		= &sysctl_vfs_cache_pressure,
1491 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1492 		.mode		= 0644,
1493 		.proc_handler	= proc_dointvec,
1494 		.extra1		= &zero,
1495 	},
1496 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1497 	{
1498 		.procname	= "legacy_va_layout",
1499 		.data		= &sysctl_legacy_va_layout,
1500 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1501 		.mode		= 0644,
1502 		.proc_handler	= proc_dointvec,
1503 		.extra1		= &zero,
1504 	},
1505 #endif
1506 #ifdef CONFIG_NUMA
1507 	{
1508 		.procname	= "zone_reclaim_mode",
1509 		.data		= &node_reclaim_mode,
1510 		.maxlen		= sizeof(node_reclaim_mode),
1511 		.mode		= 0644,
1512 		.proc_handler	= proc_dointvec,
1513 		.extra1		= &zero,
1514 	},
1515 	{
1516 		.procname	= "min_unmapped_ratio",
1517 		.data		= &sysctl_min_unmapped_ratio,
1518 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1519 		.mode		= 0644,
1520 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1521 		.extra1		= &zero,
1522 		.extra2		= &one_hundred,
1523 	},
1524 	{
1525 		.procname	= "min_slab_ratio",
1526 		.data		= &sysctl_min_slab_ratio,
1527 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1528 		.mode		= 0644,
1529 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1530 		.extra1		= &zero,
1531 		.extra2		= &one_hundred,
1532 	},
1533 #endif
1534 #ifdef CONFIG_SMP
1535 	{
1536 		.procname	= "stat_interval",
1537 		.data		= &sysctl_stat_interval,
1538 		.maxlen		= sizeof(sysctl_stat_interval),
1539 		.mode		= 0644,
1540 		.proc_handler	= proc_dointvec_jiffies,
1541 	},
1542 	{
1543 		.procname	= "stat_refresh",
1544 		.data		= NULL,
1545 		.maxlen		= 0,
1546 		.mode		= 0600,
1547 		.proc_handler	= vmstat_refresh,
1548 	},
1549 #endif
1550 #ifdef CONFIG_MMU
1551 	{
1552 		.procname	= "mmap_min_addr",
1553 		.data		= &dac_mmap_min_addr,
1554 		.maxlen		= sizeof(unsigned long),
1555 		.mode		= 0644,
1556 		.proc_handler	= mmap_min_addr_handler,
1557 	},
1558 #endif
1559 #ifdef CONFIG_NUMA
1560 	{
1561 		.procname	= "numa_zonelist_order",
1562 		.data		= &numa_zonelist_order,
1563 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1564 		.mode		= 0644,
1565 		.proc_handler	= numa_zonelist_order_handler,
1566 	},
1567 #endif
1568 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1569    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1570 	{
1571 		.procname	= "vdso_enabled",
1572 #ifdef CONFIG_X86_32
1573 		.data		= &vdso32_enabled,
1574 		.maxlen		= sizeof(vdso32_enabled),
1575 #else
1576 		.data		= &vdso_enabled,
1577 		.maxlen		= sizeof(vdso_enabled),
1578 #endif
1579 		.mode		= 0644,
1580 		.proc_handler	= proc_dointvec,
1581 		.extra1		= &zero,
1582 	},
1583 #endif
1584 #ifdef CONFIG_HIGHMEM
1585 	{
1586 		.procname	= "highmem_is_dirtyable",
1587 		.data		= &vm_highmem_is_dirtyable,
1588 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1589 		.mode		= 0644,
1590 		.proc_handler	= proc_dointvec_minmax,
1591 		.extra1		= &zero,
1592 		.extra2		= &one,
1593 	},
1594 #endif
1595 #ifdef CONFIG_MEMORY_FAILURE
1596 	{
1597 		.procname	= "memory_failure_early_kill",
1598 		.data		= &sysctl_memory_failure_early_kill,
1599 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1600 		.mode		= 0644,
1601 		.proc_handler	= proc_dointvec_minmax,
1602 		.extra1		= &zero,
1603 		.extra2		= &one,
1604 	},
1605 	{
1606 		.procname	= "memory_failure_recovery",
1607 		.data		= &sysctl_memory_failure_recovery,
1608 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1609 		.mode		= 0644,
1610 		.proc_handler	= proc_dointvec_minmax,
1611 		.extra1		= &zero,
1612 		.extra2		= &one,
1613 	},
1614 #endif
1615 	{
1616 		.procname	= "user_reserve_kbytes",
1617 		.data		= &sysctl_user_reserve_kbytes,
1618 		.maxlen		= sizeof(sysctl_user_reserve_kbytes),
1619 		.mode		= 0644,
1620 		.proc_handler	= proc_doulongvec_minmax,
1621 	},
1622 	{
1623 		.procname	= "admin_reserve_kbytes",
1624 		.data		= &sysctl_admin_reserve_kbytes,
1625 		.maxlen		= sizeof(sysctl_admin_reserve_kbytes),
1626 		.mode		= 0644,
1627 		.proc_handler	= proc_doulongvec_minmax,
1628 	},
1629 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1630 	{
1631 		.procname	= "mmap_rnd_bits",
1632 		.data		= &mmap_rnd_bits,
1633 		.maxlen		= sizeof(mmap_rnd_bits),
1634 		.mode		= 0600,
1635 		.proc_handler	= proc_dointvec_minmax,
1636 		.extra1		= (void *)&mmap_rnd_bits_min,
1637 		.extra2		= (void *)&mmap_rnd_bits_max,
1638 	},
1639 #endif
1640 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1641 	{
1642 		.procname	= "mmap_rnd_compat_bits",
1643 		.data		= &mmap_rnd_compat_bits,
1644 		.maxlen		= sizeof(mmap_rnd_compat_bits),
1645 		.mode		= 0600,
1646 		.proc_handler	= proc_dointvec_minmax,
1647 		.extra1		= (void *)&mmap_rnd_compat_bits_min,
1648 		.extra2		= (void *)&mmap_rnd_compat_bits_max,
1649 	},
1650 #endif
1651 	{ }
1652 };
1653 
1654 static struct ctl_table fs_table[] = {
1655 	{
1656 		.procname	= "inode-nr",
1657 		.data		= &inodes_stat,
1658 		.maxlen		= 2*sizeof(long),
1659 		.mode		= 0444,
1660 		.proc_handler	= proc_nr_inodes,
1661 	},
1662 	{
1663 		.procname	= "inode-state",
1664 		.data		= &inodes_stat,
1665 		.maxlen		= 7*sizeof(long),
1666 		.mode		= 0444,
1667 		.proc_handler	= proc_nr_inodes,
1668 	},
1669 	{
1670 		.procname	= "file-nr",
1671 		.data		= &files_stat,
1672 		.maxlen		= sizeof(files_stat),
1673 		.mode		= 0444,
1674 		.proc_handler	= proc_nr_files,
1675 	},
1676 	{
1677 		.procname	= "file-max",
1678 		.data		= &files_stat.max_files,
1679 		.maxlen		= sizeof(files_stat.max_files),
1680 		.mode		= 0644,
1681 		.proc_handler	= proc_doulongvec_minmax,
1682 	},
1683 	{
1684 		.procname	= "nr_open",
1685 		.data		= &sysctl_nr_open,
1686 		.maxlen		= sizeof(unsigned int),
1687 		.mode		= 0644,
1688 		.proc_handler	= proc_dointvec_minmax,
1689 		.extra1		= &sysctl_nr_open_min,
1690 		.extra2		= &sysctl_nr_open_max,
1691 	},
1692 	{
1693 		.procname	= "dentry-state",
1694 		.data		= &dentry_stat,
1695 		.maxlen		= 6*sizeof(long),
1696 		.mode		= 0444,
1697 		.proc_handler	= proc_nr_dentry,
1698 	},
1699 	{
1700 		.procname	= "overflowuid",
1701 		.data		= &fs_overflowuid,
1702 		.maxlen		= sizeof(int),
1703 		.mode		= 0644,
1704 		.proc_handler	= proc_dointvec_minmax,
1705 		.extra1		= &minolduid,
1706 		.extra2		= &maxolduid,
1707 	},
1708 	{
1709 		.procname	= "overflowgid",
1710 		.data		= &fs_overflowgid,
1711 		.maxlen		= sizeof(int),
1712 		.mode		= 0644,
1713 		.proc_handler	= proc_dointvec_minmax,
1714 		.extra1		= &minolduid,
1715 		.extra2		= &maxolduid,
1716 	},
1717 #ifdef CONFIG_FILE_LOCKING
1718 	{
1719 		.procname	= "leases-enable",
1720 		.data		= &leases_enable,
1721 		.maxlen		= sizeof(int),
1722 		.mode		= 0644,
1723 		.proc_handler	= proc_dointvec,
1724 	},
1725 #endif
1726 #ifdef CONFIG_DNOTIFY
1727 	{
1728 		.procname	= "dir-notify-enable",
1729 		.data		= &dir_notify_enable,
1730 		.maxlen		= sizeof(int),
1731 		.mode		= 0644,
1732 		.proc_handler	= proc_dointvec,
1733 	},
1734 #endif
1735 #ifdef CONFIG_MMU
1736 #ifdef CONFIG_FILE_LOCKING
1737 	{
1738 		.procname	= "lease-break-time",
1739 		.data		= &lease_break_time,
1740 		.maxlen		= sizeof(int),
1741 		.mode		= 0644,
1742 		.proc_handler	= proc_dointvec,
1743 	},
1744 #endif
1745 #ifdef CONFIG_AIO
1746 	{
1747 		.procname	= "aio-nr",
1748 		.data		= &aio_nr,
1749 		.maxlen		= sizeof(aio_nr),
1750 		.mode		= 0444,
1751 		.proc_handler	= proc_doulongvec_minmax,
1752 	},
1753 	{
1754 		.procname	= "aio-max-nr",
1755 		.data		= &aio_max_nr,
1756 		.maxlen		= sizeof(aio_max_nr),
1757 		.mode		= 0644,
1758 		.proc_handler	= proc_doulongvec_minmax,
1759 	},
1760 #endif /* CONFIG_AIO */
1761 #ifdef CONFIG_INOTIFY_USER
1762 	{
1763 		.procname	= "inotify",
1764 		.mode		= 0555,
1765 		.child		= inotify_table,
1766 	},
1767 #endif
1768 #ifdef CONFIG_EPOLL
1769 	{
1770 		.procname	= "epoll",
1771 		.mode		= 0555,
1772 		.child		= epoll_table,
1773 	},
1774 #endif
1775 #endif
1776 	{
1777 		.procname	= "protected_symlinks",
1778 		.data		= &sysctl_protected_symlinks,
1779 		.maxlen		= sizeof(int),
1780 		.mode		= 0600,
1781 		.proc_handler	= proc_dointvec_minmax,
1782 		.extra1		= &zero,
1783 		.extra2		= &one,
1784 	},
1785 	{
1786 		.procname	= "protected_hardlinks",
1787 		.data		= &sysctl_protected_hardlinks,
1788 		.maxlen		= sizeof(int),
1789 		.mode		= 0600,
1790 		.proc_handler	= proc_dointvec_minmax,
1791 		.extra1		= &zero,
1792 		.extra2		= &one,
1793 	},
1794 	{
1795 		.procname	= "suid_dumpable",
1796 		.data		= &suid_dumpable,
1797 		.maxlen		= sizeof(int),
1798 		.mode		= 0644,
1799 		.proc_handler	= proc_dointvec_minmax_coredump,
1800 		.extra1		= &zero,
1801 		.extra2		= &two,
1802 	},
1803 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1804 	{
1805 		.procname	= "binfmt_misc",
1806 		.mode		= 0555,
1807 		.child		= sysctl_mount_point,
1808 	},
1809 #endif
1810 	{
1811 		.procname	= "pipe-max-size",
1812 		.data		= &pipe_max_size,
1813 		.maxlen		= sizeof(int),
1814 		.mode		= 0644,
1815 		.proc_handler	= &pipe_proc_fn,
1816 		.extra1		= &pipe_min_size,
1817 	},
1818 	{
1819 		.procname	= "pipe-user-pages-hard",
1820 		.data		= &pipe_user_pages_hard,
1821 		.maxlen		= sizeof(pipe_user_pages_hard),
1822 		.mode		= 0644,
1823 		.proc_handler	= proc_doulongvec_minmax,
1824 	},
1825 	{
1826 		.procname	= "pipe-user-pages-soft",
1827 		.data		= &pipe_user_pages_soft,
1828 		.maxlen		= sizeof(pipe_user_pages_soft),
1829 		.mode		= 0644,
1830 		.proc_handler	= proc_doulongvec_minmax,
1831 	},
1832 	{
1833 		.procname	= "mount-max",
1834 		.data		= &sysctl_mount_max,
1835 		.maxlen		= sizeof(unsigned int),
1836 		.mode		= 0644,
1837 		.proc_handler	= proc_dointvec_minmax,
1838 		.extra1		= &one,
1839 	},
1840 	{ }
1841 };
1842 
1843 static struct ctl_table debug_table[] = {
1844 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1845 	{
1846 		.procname	= "exception-trace",
1847 		.data		= &show_unhandled_signals,
1848 		.maxlen		= sizeof(int),
1849 		.mode		= 0644,
1850 		.proc_handler	= proc_dointvec
1851 	},
1852 #endif
1853 #if defined(CONFIG_OPTPROBES)
1854 	{
1855 		.procname	= "kprobes-optimization",
1856 		.data		= &sysctl_kprobes_optimization,
1857 		.maxlen		= sizeof(int),
1858 		.mode		= 0644,
1859 		.proc_handler	= proc_kprobes_optimization_handler,
1860 		.extra1		= &zero,
1861 		.extra2		= &one,
1862 	},
1863 #endif
1864 	{ }
1865 };
1866 
1867 static struct ctl_table dev_table[] = {
1868 	{ }
1869 };
1870 
1871 int __init sysctl_init(void)
1872 {
1873 	struct ctl_table_header *hdr;
1874 
1875 	hdr = register_sysctl_table(sysctl_base_table);
1876 	kmemleak_not_leak(hdr);
1877 	return 0;
1878 }
1879 
1880 #endif /* CONFIG_SYSCTL */
1881 
1882 /*
1883  * /proc/sys support
1884  */
1885 
1886 #ifdef CONFIG_PROC_SYSCTL
1887 
1888 static int _proc_do_string(char *data, int maxlen, int write,
1889 			   char __user *buffer,
1890 			   size_t *lenp, loff_t *ppos)
1891 {
1892 	size_t len;
1893 	char __user *p;
1894 	char c;
1895 
1896 	if (!data || !maxlen || !*lenp) {
1897 		*lenp = 0;
1898 		return 0;
1899 	}
1900 
1901 	if (write) {
1902 		if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1903 			/* Only continue writes not past the end of buffer. */
1904 			len = strlen(data);
1905 			if (len > maxlen - 1)
1906 				len = maxlen - 1;
1907 
1908 			if (*ppos > len)
1909 				return 0;
1910 			len = *ppos;
1911 		} else {
1912 			/* Start writing from beginning of buffer. */
1913 			len = 0;
1914 		}
1915 
1916 		*ppos += *lenp;
1917 		p = buffer;
1918 		while ((p - buffer) < *lenp && len < maxlen - 1) {
1919 			if (get_user(c, p++))
1920 				return -EFAULT;
1921 			if (c == 0 || c == '\n')
1922 				break;
1923 			data[len++] = c;
1924 		}
1925 		data[len] = 0;
1926 	} else {
1927 		len = strlen(data);
1928 		if (len > maxlen)
1929 			len = maxlen;
1930 
1931 		if (*ppos > len) {
1932 			*lenp = 0;
1933 			return 0;
1934 		}
1935 
1936 		data += *ppos;
1937 		len  -= *ppos;
1938 
1939 		if (len > *lenp)
1940 			len = *lenp;
1941 		if (len)
1942 			if (copy_to_user(buffer, data, len))
1943 				return -EFAULT;
1944 		if (len < *lenp) {
1945 			if (put_user('\n', buffer + len))
1946 				return -EFAULT;
1947 			len++;
1948 		}
1949 		*lenp = len;
1950 		*ppos += len;
1951 	}
1952 	return 0;
1953 }
1954 
1955 static void warn_sysctl_write(struct ctl_table *table)
1956 {
1957 	pr_warn_once("%s wrote to %s when file position was not 0!\n"
1958 		"This will not be supported in the future. To silence this\n"
1959 		"warning, set kernel.sysctl_writes_strict = -1\n",
1960 		current->comm, table->procname);
1961 }
1962 
1963 /**
1964  * proc_dostring - read a string sysctl
1965  * @table: the sysctl table
1966  * @write: %TRUE if this is a write to the sysctl file
1967  * @buffer: the user buffer
1968  * @lenp: the size of the user buffer
1969  * @ppos: file position
1970  *
1971  * Reads/writes a string from/to the user buffer. If the kernel
1972  * buffer provided is not large enough to hold the string, the
1973  * string is truncated. The copied string is %NULL-terminated.
1974  * If the string is being read by the user process, it is copied
1975  * and a newline '\n' is added. It is truncated if the buffer is
1976  * not large enough.
1977  *
1978  * Returns 0 on success.
1979  */
1980 int proc_dostring(struct ctl_table *table, int write,
1981 		  void __user *buffer, size_t *lenp, loff_t *ppos)
1982 {
1983 	if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1984 		warn_sysctl_write(table);
1985 
1986 	return _proc_do_string((char *)(table->data), table->maxlen, write,
1987 			       (char __user *)buffer, lenp, ppos);
1988 }
1989 
1990 static size_t proc_skip_spaces(char **buf)
1991 {
1992 	size_t ret;
1993 	char *tmp = skip_spaces(*buf);
1994 	ret = tmp - *buf;
1995 	*buf = tmp;
1996 	return ret;
1997 }
1998 
1999 static void proc_skip_char(char **buf, size_t *size, const char v)
2000 {
2001 	while (*size) {
2002 		if (**buf != v)
2003 			break;
2004 		(*size)--;
2005 		(*buf)++;
2006 	}
2007 }
2008 
2009 #define TMPBUFLEN 22
2010 /**
2011  * proc_get_long - reads an ASCII formatted integer from a user buffer
2012  *
2013  * @buf: a kernel buffer
2014  * @size: size of the kernel buffer
2015  * @val: this is where the number will be stored
2016  * @neg: set to %TRUE if number is negative
2017  * @perm_tr: a vector which contains the allowed trailers
2018  * @perm_tr_len: size of the perm_tr vector
2019  * @tr: pointer to store the trailer character
2020  *
2021  * In case of success %0 is returned and @buf and @size are updated with
2022  * the amount of bytes read. If @tr is non-NULL and a trailing
2023  * character exists (size is non-zero after returning from this
2024  * function), @tr is updated with the trailing character.
2025  */
2026 static int proc_get_long(char **buf, size_t *size,
2027 			  unsigned long *val, bool *neg,
2028 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
2029 {
2030 	int len;
2031 	char *p, tmp[TMPBUFLEN];
2032 
2033 	if (!*size)
2034 		return -EINVAL;
2035 
2036 	len = *size;
2037 	if (len > TMPBUFLEN - 1)
2038 		len = TMPBUFLEN - 1;
2039 
2040 	memcpy(tmp, *buf, len);
2041 
2042 	tmp[len] = 0;
2043 	p = tmp;
2044 	if (*p == '-' && *size > 1) {
2045 		*neg = true;
2046 		p++;
2047 	} else
2048 		*neg = false;
2049 	if (!isdigit(*p))
2050 		return -EINVAL;
2051 
2052 	*val = simple_strtoul(p, &p, 0);
2053 
2054 	len = p - tmp;
2055 
2056 	/* We don't know if the next char is whitespace thus we may accept
2057 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2058 	 * (e.g. 123...1). So lets not allow such large numbers. */
2059 	if (len == TMPBUFLEN - 1)
2060 		return -EINVAL;
2061 
2062 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2063 		return -EINVAL;
2064 
2065 	if (tr && (len < *size))
2066 		*tr = *p;
2067 
2068 	*buf += len;
2069 	*size -= len;
2070 
2071 	return 0;
2072 }
2073 
2074 /**
2075  * proc_put_long - converts an integer to a decimal ASCII formatted string
2076  *
2077  * @buf: the user buffer
2078  * @size: the size of the user buffer
2079  * @val: the integer to be converted
2080  * @neg: sign of the number, %TRUE for negative
2081  *
2082  * In case of success %0 is returned and @buf and @size are updated with
2083  * the amount of bytes written.
2084  */
2085 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2086 			  bool neg)
2087 {
2088 	int len;
2089 	char tmp[TMPBUFLEN], *p = tmp;
2090 
2091 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2092 	len = strlen(tmp);
2093 	if (len > *size)
2094 		len = *size;
2095 	if (copy_to_user(*buf, tmp, len))
2096 		return -EFAULT;
2097 	*size -= len;
2098 	*buf += len;
2099 	return 0;
2100 }
2101 #undef TMPBUFLEN
2102 
2103 static int proc_put_char(void __user **buf, size_t *size, char c)
2104 {
2105 	if (*size) {
2106 		char __user **buffer = (char __user **)buf;
2107 		if (put_user(c, *buffer))
2108 			return -EFAULT;
2109 		(*size)--, (*buffer)++;
2110 		*buf = *buffer;
2111 	}
2112 	return 0;
2113 }
2114 
2115 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2116 				 int *valp,
2117 				 int write, void *data)
2118 {
2119 	if (write) {
2120 		if (*negp) {
2121 			if (*lvalp > (unsigned long) INT_MAX + 1)
2122 				return -EINVAL;
2123 			*valp = -*lvalp;
2124 		} else {
2125 			if (*lvalp > (unsigned long) INT_MAX)
2126 				return -EINVAL;
2127 			*valp = *lvalp;
2128 		}
2129 	} else {
2130 		int val = *valp;
2131 		if (val < 0) {
2132 			*negp = true;
2133 			*lvalp = -(unsigned long)val;
2134 		} else {
2135 			*negp = false;
2136 			*lvalp = (unsigned long)val;
2137 		}
2138 	}
2139 	return 0;
2140 }
2141 
2142 static int do_proc_douintvec_conv(bool *negp, unsigned long *lvalp,
2143 				 int *valp,
2144 				 int write, void *data)
2145 {
2146 	if (write) {
2147 		if (*negp)
2148 			return -EINVAL;
2149 		*valp = *lvalp;
2150 	} else {
2151 		unsigned int val = *valp;
2152 		*lvalp = (unsigned long)val;
2153 	}
2154 	return 0;
2155 }
2156 
2157 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2158 
2159 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2160 		  int write, void __user *buffer,
2161 		  size_t *lenp, loff_t *ppos,
2162 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2163 			      int write, void *data),
2164 		  void *data)
2165 {
2166 	int *i, vleft, first = 1, err = 0;
2167 	size_t left;
2168 	char *kbuf = NULL, *p;
2169 
2170 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2171 		*lenp = 0;
2172 		return 0;
2173 	}
2174 
2175 	i = (int *) tbl_data;
2176 	vleft = table->maxlen / sizeof(*i);
2177 	left = *lenp;
2178 
2179 	if (!conv)
2180 		conv = do_proc_dointvec_conv;
2181 
2182 	if (write) {
2183 		if (*ppos) {
2184 			switch (sysctl_writes_strict) {
2185 			case SYSCTL_WRITES_STRICT:
2186 				goto out;
2187 			case SYSCTL_WRITES_WARN:
2188 				warn_sysctl_write(table);
2189 				break;
2190 			default:
2191 				break;
2192 			}
2193 		}
2194 
2195 		if (left > PAGE_SIZE - 1)
2196 			left = PAGE_SIZE - 1;
2197 		p = kbuf = memdup_user_nul(buffer, left);
2198 		if (IS_ERR(kbuf))
2199 			return PTR_ERR(kbuf);
2200 	}
2201 
2202 	for (; left && vleft--; i++, first=0) {
2203 		unsigned long lval;
2204 		bool neg;
2205 
2206 		if (write) {
2207 			left -= proc_skip_spaces(&p);
2208 
2209 			if (!left)
2210 				break;
2211 			err = proc_get_long(&p, &left, &lval, &neg,
2212 					     proc_wspace_sep,
2213 					     sizeof(proc_wspace_sep), NULL);
2214 			if (err)
2215 				break;
2216 			if (conv(&neg, &lval, i, 1, data)) {
2217 				err = -EINVAL;
2218 				break;
2219 			}
2220 		} else {
2221 			if (conv(&neg, &lval, i, 0, data)) {
2222 				err = -EINVAL;
2223 				break;
2224 			}
2225 			if (!first)
2226 				err = proc_put_char(&buffer, &left, '\t');
2227 			if (err)
2228 				break;
2229 			err = proc_put_long(&buffer, &left, lval, neg);
2230 			if (err)
2231 				break;
2232 		}
2233 	}
2234 
2235 	if (!write && !first && left && !err)
2236 		err = proc_put_char(&buffer, &left, '\n');
2237 	if (write && !err && left)
2238 		left -= proc_skip_spaces(&p);
2239 	if (write) {
2240 		kfree(kbuf);
2241 		if (first)
2242 			return err ? : -EINVAL;
2243 	}
2244 	*lenp -= left;
2245 out:
2246 	*ppos += *lenp;
2247 	return err;
2248 }
2249 
2250 static int do_proc_dointvec(struct ctl_table *table, int write,
2251 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2252 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2253 			      int write, void *data),
2254 		  void *data)
2255 {
2256 	return __do_proc_dointvec(table->data, table, write,
2257 			buffer, lenp, ppos, conv, data);
2258 }
2259 
2260 /**
2261  * proc_dointvec - read a vector of integers
2262  * @table: the sysctl table
2263  * @write: %TRUE if this is a write to the sysctl file
2264  * @buffer: the user buffer
2265  * @lenp: the size of the user buffer
2266  * @ppos: file position
2267  *
2268  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2269  * values from/to the user buffer, treated as an ASCII string.
2270  *
2271  * Returns 0 on success.
2272  */
2273 int proc_dointvec(struct ctl_table *table, int write,
2274 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2275 {
2276 	return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
2277 }
2278 
2279 /**
2280  * proc_douintvec - read a vector of unsigned integers
2281  * @table: the sysctl table
2282  * @write: %TRUE if this is a write to the sysctl file
2283  * @buffer: the user buffer
2284  * @lenp: the size of the user buffer
2285  * @ppos: file position
2286  *
2287  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
2288  * values from/to the user buffer, treated as an ASCII string.
2289  *
2290  * Returns 0 on success.
2291  */
2292 int proc_douintvec(struct ctl_table *table, int write,
2293 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2294 {
2295 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2296 				do_proc_douintvec_conv, NULL);
2297 }
2298 
2299 /*
2300  * Taint values can only be increased
2301  * This means we can safely use a temporary.
2302  */
2303 static int proc_taint(struct ctl_table *table, int write,
2304 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2305 {
2306 	struct ctl_table t;
2307 	unsigned long tmptaint = get_taint();
2308 	int err;
2309 
2310 	if (write && !capable(CAP_SYS_ADMIN))
2311 		return -EPERM;
2312 
2313 	t = *table;
2314 	t.data = &tmptaint;
2315 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2316 	if (err < 0)
2317 		return err;
2318 
2319 	if (write) {
2320 		/*
2321 		 * Poor man's atomic or. Not worth adding a primitive
2322 		 * to everyone's atomic.h for this
2323 		 */
2324 		int i;
2325 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2326 			if ((tmptaint >> i) & 1)
2327 				add_taint(i, LOCKDEP_STILL_OK);
2328 		}
2329 	}
2330 
2331 	return err;
2332 }
2333 
2334 #ifdef CONFIG_PRINTK
2335 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2336 				void __user *buffer, size_t *lenp, loff_t *ppos)
2337 {
2338 	if (write && !capable(CAP_SYS_ADMIN))
2339 		return -EPERM;
2340 
2341 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2342 }
2343 #endif
2344 
2345 struct do_proc_dointvec_minmax_conv_param {
2346 	int *min;
2347 	int *max;
2348 };
2349 
2350 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2351 					int *valp,
2352 					int write, void *data)
2353 {
2354 	struct do_proc_dointvec_minmax_conv_param *param = data;
2355 	if (write) {
2356 		int val = *negp ? -*lvalp : *lvalp;
2357 		if ((param->min && *param->min > val) ||
2358 		    (param->max && *param->max < val))
2359 			return -EINVAL;
2360 		*valp = val;
2361 	} else {
2362 		int val = *valp;
2363 		if (val < 0) {
2364 			*negp = true;
2365 			*lvalp = -(unsigned long)val;
2366 		} else {
2367 			*negp = false;
2368 			*lvalp = (unsigned long)val;
2369 		}
2370 	}
2371 	return 0;
2372 }
2373 
2374 /**
2375  * proc_dointvec_minmax - read a vector of integers with min/max values
2376  * @table: the sysctl table
2377  * @write: %TRUE if this is a write to the sysctl file
2378  * @buffer: the user buffer
2379  * @lenp: the size of the user buffer
2380  * @ppos: file position
2381  *
2382  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2383  * values from/to the user buffer, treated as an ASCII string.
2384  *
2385  * This routine will ensure the values are within the range specified by
2386  * table->extra1 (min) and table->extra2 (max).
2387  *
2388  * Returns 0 on success.
2389  */
2390 int proc_dointvec_minmax(struct ctl_table *table, int write,
2391 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2392 {
2393 	struct do_proc_dointvec_minmax_conv_param param = {
2394 		.min = (int *) table->extra1,
2395 		.max = (int *) table->extra2,
2396 	};
2397 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2398 				do_proc_dointvec_minmax_conv, &param);
2399 }
2400 
2401 static void validate_coredump_safety(void)
2402 {
2403 #ifdef CONFIG_COREDUMP
2404 	if (suid_dumpable == SUID_DUMP_ROOT &&
2405 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
2406 		printk(KERN_WARNING "Unsafe core_pattern used with "\
2407 			"suid_dumpable=2. Pipe handler or fully qualified "\
2408 			"core dump path required.\n");
2409 	}
2410 #endif
2411 }
2412 
2413 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2414 		void __user *buffer, size_t *lenp, loff_t *ppos)
2415 {
2416 	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2417 	if (!error)
2418 		validate_coredump_safety();
2419 	return error;
2420 }
2421 
2422 #ifdef CONFIG_COREDUMP
2423 static int proc_dostring_coredump(struct ctl_table *table, int write,
2424 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2425 {
2426 	int error = proc_dostring(table, write, buffer, lenp, ppos);
2427 	if (!error)
2428 		validate_coredump_safety();
2429 	return error;
2430 }
2431 #endif
2432 
2433 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2434 				     void __user *buffer,
2435 				     size_t *lenp, loff_t *ppos,
2436 				     unsigned long convmul,
2437 				     unsigned long convdiv)
2438 {
2439 	unsigned long *i, *min, *max;
2440 	int vleft, first = 1, err = 0;
2441 	size_t left;
2442 	char *kbuf = NULL, *p;
2443 
2444 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2445 		*lenp = 0;
2446 		return 0;
2447 	}
2448 
2449 	i = (unsigned long *) data;
2450 	min = (unsigned long *) table->extra1;
2451 	max = (unsigned long *) table->extra2;
2452 	vleft = table->maxlen / sizeof(unsigned long);
2453 	left = *lenp;
2454 
2455 	if (write) {
2456 		if (*ppos) {
2457 			switch (sysctl_writes_strict) {
2458 			case SYSCTL_WRITES_STRICT:
2459 				goto out;
2460 			case SYSCTL_WRITES_WARN:
2461 				warn_sysctl_write(table);
2462 				break;
2463 			default:
2464 				break;
2465 			}
2466 		}
2467 
2468 		if (left > PAGE_SIZE - 1)
2469 			left = PAGE_SIZE - 1;
2470 		p = kbuf = memdup_user_nul(buffer, left);
2471 		if (IS_ERR(kbuf))
2472 			return PTR_ERR(kbuf);
2473 	}
2474 
2475 	for (; left && vleft--; i++, first = 0) {
2476 		unsigned long val;
2477 
2478 		if (write) {
2479 			bool neg;
2480 
2481 			left -= proc_skip_spaces(&p);
2482 
2483 			err = proc_get_long(&p, &left, &val, &neg,
2484 					     proc_wspace_sep,
2485 					     sizeof(proc_wspace_sep), NULL);
2486 			if (err)
2487 				break;
2488 			if (neg)
2489 				continue;
2490 			if ((min && val < *min) || (max && val > *max))
2491 				continue;
2492 			*i = val;
2493 		} else {
2494 			val = convdiv * (*i) / convmul;
2495 			if (!first) {
2496 				err = proc_put_char(&buffer, &left, '\t');
2497 				if (err)
2498 					break;
2499 			}
2500 			err = proc_put_long(&buffer, &left, val, false);
2501 			if (err)
2502 				break;
2503 		}
2504 	}
2505 
2506 	if (!write && !first && left && !err)
2507 		err = proc_put_char(&buffer, &left, '\n');
2508 	if (write && !err)
2509 		left -= proc_skip_spaces(&p);
2510 	if (write) {
2511 		kfree(kbuf);
2512 		if (first)
2513 			return err ? : -EINVAL;
2514 	}
2515 	*lenp -= left;
2516 out:
2517 	*ppos += *lenp;
2518 	return err;
2519 }
2520 
2521 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2522 				     void __user *buffer,
2523 				     size_t *lenp, loff_t *ppos,
2524 				     unsigned long convmul,
2525 				     unsigned long convdiv)
2526 {
2527 	return __do_proc_doulongvec_minmax(table->data, table, write,
2528 			buffer, lenp, ppos, convmul, convdiv);
2529 }
2530 
2531 /**
2532  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2533  * @table: the sysctl table
2534  * @write: %TRUE if this is a write to the sysctl file
2535  * @buffer: the user buffer
2536  * @lenp: the size of the user buffer
2537  * @ppos: file position
2538  *
2539  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2540  * values from/to the user buffer, treated as an ASCII string.
2541  *
2542  * This routine will ensure the values are within the range specified by
2543  * table->extra1 (min) and table->extra2 (max).
2544  *
2545  * Returns 0 on success.
2546  */
2547 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2548 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2549 {
2550     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2551 }
2552 
2553 /**
2554  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2555  * @table: the sysctl table
2556  * @write: %TRUE if this is a write to the sysctl file
2557  * @buffer: the user buffer
2558  * @lenp: the size of the user buffer
2559  * @ppos: file position
2560  *
2561  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2562  * values from/to the user buffer, treated as an ASCII string. The values
2563  * are treated as milliseconds, and converted to jiffies when they are stored.
2564  *
2565  * This routine will ensure the values are within the range specified by
2566  * table->extra1 (min) and table->extra2 (max).
2567  *
2568  * Returns 0 on success.
2569  */
2570 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2571 				      void __user *buffer,
2572 				      size_t *lenp, loff_t *ppos)
2573 {
2574     return do_proc_doulongvec_minmax(table, write, buffer,
2575 				     lenp, ppos, HZ, 1000l);
2576 }
2577 
2578 
2579 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2580 					 int *valp,
2581 					 int write, void *data)
2582 {
2583 	if (write) {
2584 		if (*lvalp > LONG_MAX / HZ)
2585 			return 1;
2586 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2587 	} else {
2588 		int val = *valp;
2589 		unsigned long lval;
2590 		if (val < 0) {
2591 			*negp = true;
2592 			lval = -(unsigned long)val;
2593 		} else {
2594 			*negp = false;
2595 			lval = (unsigned long)val;
2596 		}
2597 		*lvalp = lval / HZ;
2598 	}
2599 	return 0;
2600 }
2601 
2602 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2603 						int *valp,
2604 						int write, void *data)
2605 {
2606 	if (write) {
2607 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2608 			return 1;
2609 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2610 	} else {
2611 		int val = *valp;
2612 		unsigned long lval;
2613 		if (val < 0) {
2614 			*negp = true;
2615 			lval = -(unsigned long)val;
2616 		} else {
2617 			*negp = false;
2618 			lval = (unsigned long)val;
2619 		}
2620 		*lvalp = jiffies_to_clock_t(lval);
2621 	}
2622 	return 0;
2623 }
2624 
2625 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2626 					    int *valp,
2627 					    int write, void *data)
2628 {
2629 	if (write) {
2630 		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2631 
2632 		if (jif > INT_MAX)
2633 			return 1;
2634 		*valp = (int)jif;
2635 	} else {
2636 		int val = *valp;
2637 		unsigned long lval;
2638 		if (val < 0) {
2639 			*negp = true;
2640 			lval = -(unsigned long)val;
2641 		} else {
2642 			*negp = false;
2643 			lval = (unsigned long)val;
2644 		}
2645 		*lvalp = jiffies_to_msecs(lval);
2646 	}
2647 	return 0;
2648 }
2649 
2650 /**
2651  * proc_dointvec_jiffies - read a vector of integers as seconds
2652  * @table: the sysctl table
2653  * @write: %TRUE if this is a write to the sysctl file
2654  * @buffer: the user buffer
2655  * @lenp: the size of the user buffer
2656  * @ppos: file position
2657  *
2658  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2659  * values from/to the user buffer, treated as an ASCII string.
2660  * The values read are assumed to be in seconds, and are converted into
2661  * jiffies.
2662  *
2663  * Returns 0 on success.
2664  */
2665 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2666 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2667 {
2668     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2669 		    	    do_proc_dointvec_jiffies_conv,NULL);
2670 }
2671 
2672 /**
2673  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2674  * @table: the sysctl table
2675  * @write: %TRUE if this is a write to the sysctl file
2676  * @buffer: the user buffer
2677  * @lenp: the size of the user buffer
2678  * @ppos: pointer to the file position
2679  *
2680  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2681  * values from/to the user buffer, treated as an ASCII string.
2682  * The values read are assumed to be in 1/USER_HZ seconds, and
2683  * are converted into jiffies.
2684  *
2685  * Returns 0 on success.
2686  */
2687 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2688 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2689 {
2690     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2691 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2692 }
2693 
2694 /**
2695  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2696  * @table: the sysctl table
2697  * @write: %TRUE if this is a write to the sysctl file
2698  * @buffer: the user buffer
2699  * @lenp: the size of the user buffer
2700  * @ppos: file position
2701  * @ppos: the current position in the file
2702  *
2703  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2704  * values from/to the user buffer, treated as an ASCII string.
2705  * The values read are assumed to be in 1/1000 seconds, and
2706  * are converted into jiffies.
2707  *
2708  * Returns 0 on success.
2709  */
2710 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2711 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2712 {
2713 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2714 				do_proc_dointvec_ms_jiffies_conv, NULL);
2715 }
2716 
2717 static int proc_do_cad_pid(struct ctl_table *table, int write,
2718 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2719 {
2720 	struct pid *new_pid;
2721 	pid_t tmp;
2722 	int r;
2723 
2724 	tmp = pid_vnr(cad_pid);
2725 
2726 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2727 			       lenp, ppos, NULL, NULL);
2728 	if (r || !write)
2729 		return r;
2730 
2731 	new_pid = find_get_pid(tmp);
2732 	if (!new_pid)
2733 		return -ESRCH;
2734 
2735 	put_pid(xchg(&cad_pid, new_pid));
2736 	return 0;
2737 }
2738 
2739 /**
2740  * proc_do_large_bitmap - read/write from/to a large bitmap
2741  * @table: the sysctl table
2742  * @write: %TRUE if this is a write to the sysctl file
2743  * @buffer: the user buffer
2744  * @lenp: the size of the user buffer
2745  * @ppos: file position
2746  *
2747  * The bitmap is stored at table->data and the bitmap length (in bits)
2748  * in table->maxlen.
2749  *
2750  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2751  * large bitmaps may be represented in a compact manner. Writing into
2752  * the file will clear the bitmap then update it with the given input.
2753  *
2754  * Returns 0 on success.
2755  */
2756 int proc_do_large_bitmap(struct ctl_table *table, int write,
2757 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2758 {
2759 	int err = 0;
2760 	bool first = 1;
2761 	size_t left = *lenp;
2762 	unsigned long bitmap_len = table->maxlen;
2763 	unsigned long *bitmap = *(unsigned long **) table->data;
2764 	unsigned long *tmp_bitmap = NULL;
2765 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2766 
2767 	if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2768 		*lenp = 0;
2769 		return 0;
2770 	}
2771 
2772 	if (write) {
2773 		char *kbuf, *p;
2774 
2775 		if (left > PAGE_SIZE - 1)
2776 			left = PAGE_SIZE - 1;
2777 
2778 		p = kbuf = memdup_user_nul(buffer, left);
2779 		if (IS_ERR(kbuf))
2780 			return PTR_ERR(kbuf);
2781 
2782 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2783 				     GFP_KERNEL);
2784 		if (!tmp_bitmap) {
2785 			kfree(kbuf);
2786 			return -ENOMEM;
2787 		}
2788 		proc_skip_char(&p, &left, '\n');
2789 		while (!err && left) {
2790 			unsigned long val_a, val_b;
2791 			bool neg;
2792 
2793 			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2794 					     sizeof(tr_a), &c);
2795 			if (err)
2796 				break;
2797 			if (val_a >= bitmap_len || neg) {
2798 				err = -EINVAL;
2799 				break;
2800 			}
2801 
2802 			val_b = val_a;
2803 			if (left) {
2804 				p++;
2805 				left--;
2806 			}
2807 
2808 			if (c == '-') {
2809 				err = proc_get_long(&p, &left, &val_b,
2810 						     &neg, tr_b, sizeof(tr_b),
2811 						     &c);
2812 				if (err)
2813 					break;
2814 				if (val_b >= bitmap_len || neg ||
2815 				    val_a > val_b) {
2816 					err = -EINVAL;
2817 					break;
2818 				}
2819 				if (left) {
2820 					p++;
2821 					left--;
2822 				}
2823 			}
2824 
2825 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2826 			first = 0;
2827 			proc_skip_char(&p, &left, '\n');
2828 		}
2829 		kfree(kbuf);
2830 	} else {
2831 		unsigned long bit_a, bit_b = 0;
2832 
2833 		while (left) {
2834 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2835 			if (bit_a >= bitmap_len)
2836 				break;
2837 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2838 						   bit_a + 1) - 1;
2839 
2840 			if (!first) {
2841 				err = proc_put_char(&buffer, &left, ',');
2842 				if (err)
2843 					break;
2844 			}
2845 			err = proc_put_long(&buffer, &left, bit_a, false);
2846 			if (err)
2847 				break;
2848 			if (bit_a != bit_b) {
2849 				err = proc_put_char(&buffer, &left, '-');
2850 				if (err)
2851 					break;
2852 				err = proc_put_long(&buffer, &left, bit_b, false);
2853 				if (err)
2854 					break;
2855 			}
2856 
2857 			first = 0; bit_b++;
2858 		}
2859 		if (!err)
2860 			err = proc_put_char(&buffer, &left, '\n');
2861 	}
2862 
2863 	if (!err) {
2864 		if (write) {
2865 			if (*ppos)
2866 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2867 			else
2868 				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2869 		}
2870 		kfree(tmp_bitmap);
2871 		*lenp -= left;
2872 		*ppos += *lenp;
2873 		return 0;
2874 	} else {
2875 		kfree(tmp_bitmap);
2876 		return err;
2877 	}
2878 }
2879 
2880 #else /* CONFIG_PROC_SYSCTL */
2881 
2882 int proc_dostring(struct ctl_table *table, int write,
2883 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2884 {
2885 	return -ENOSYS;
2886 }
2887 
2888 int proc_dointvec(struct ctl_table *table, int write,
2889 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2890 {
2891 	return -ENOSYS;
2892 }
2893 
2894 int proc_douintvec(struct ctl_table *table, int write,
2895 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2896 {
2897 	return -ENOSYS;
2898 }
2899 
2900 int proc_dointvec_minmax(struct ctl_table *table, int write,
2901 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2902 {
2903 	return -ENOSYS;
2904 }
2905 
2906 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2907 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2908 {
2909 	return -ENOSYS;
2910 }
2911 
2912 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2913 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2914 {
2915 	return -ENOSYS;
2916 }
2917 
2918 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2919 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2920 {
2921 	return -ENOSYS;
2922 }
2923 
2924 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2925 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2926 {
2927 	return -ENOSYS;
2928 }
2929 
2930 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2931 				      void __user *buffer,
2932 				      size_t *lenp, loff_t *ppos)
2933 {
2934     return -ENOSYS;
2935 }
2936 
2937 
2938 #endif /* CONFIG_PROC_SYSCTL */
2939 
2940 /*
2941  * No sense putting this after each symbol definition, twice,
2942  * exception granted :-)
2943  */
2944 EXPORT_SYMBOL(proc_dointvec);
2945 EXPORT_SYMBOL(proc_douintvec);
2946 EXPORT_SYMBOL(proc_dointvec_jiffies);
2947 EXPORT_SYMBOL(proc_dointvec_minmax);
2948 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2949 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2950 EXPORT_SYMBOL(proc_dostring);
2951 EXPORT_SYMBOL(proc_doulongvec_minmax);
2952 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2953