xref: /linux/kernel/sysctl.c (revision 59024954a1e7e26b62680e1f2b5725249a6c09f7)
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 compat_log;
111 extern int latencytop_enabled;
112 extern 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 	{
352 		.procname	= "sched_shares_window_ns",
353 		.data		= &sysctl_sched_shares_window,
354 		.maxlen		= sizeof(unsigned int),
355 		.mode		= 0644,
356 		.proc_handler	= proc_dointvec,
357 	},
358 #ifdef CONFIG_SCHEDSTATS
359 	{
360 		.procname	= "sched_schedstats",
361 		.data		= NULL,
362 		.maxlen		= sizeof(unsigned int),
363 		.mode		= 0644,
364 		.proc_handler	= sysctl_schedstats,
365 		.extra1		= &zero,
366 		.extra2		= &one,
367 	},
368 #endif /* CONFIG_SCHEDSTATS */
369 #endif /* CONFIG_SMP */
370 #ifdef CONFIG_NUMA_BALANCING
371 	{
372 		.procname	= "numa_balancing_scan_delay_ms",
373 		.data		= &sysctl_numa_balancing_scan_delay,
374 		.maxlen		= sizeof(unsigned int),
375 		.mode		= 0644,
376 		.proc_handler	= proc_dointvec,
377 	},
378 	{
379 		.procname	= "numa_balancing_scan_period_min_ms",
380 		.data		= &sysctl_numa_balancing_scan_period_min,
381 		.maxlen		= sizeof(unsigned int),
382 		.mode		= 0644,
383 		.proc_handler	= proc_dointvec,
384 	},
385 	{
386 		.procname	= "numa_balancing_scan_period_max_ms",
387 		.data		= &sysctl_numa_balancing_scan_period_max,
388 		.maxlen		= sizeof(unsigned int),
389 		.mode		= 0644,
390 		.proc_handler	= proc_dointvec,
391 	},
392 	{
393 		.procname	= "numa_balancing_scan_size_mb",
394 		.data		= &sysctl_numa_balancing_scan_size,
395 		.maxlen		= sizeof(unsigned int),
396 		.mode		= 0644,
397 		.proc_handler	= proc_dointvec_minmax,
398 		.extra1		= &one,
399 	},
400 	{
401 		.procname	= "numa_balancing",
402 		.data		= NULL, /* filled in by handler */
403 		.maxlen		= sizeof(unsigned int),
404 		.mode		= 0644,
405 		.proc_handler	= sysctl_numa_balancing,
406 		.extra1		= &zero,
407 		.extra2		= &one,
408 	},
409 #endif /* CONFIG_NUMA_BALANCING */
410 #endif /* CONFIG_SCHED_DEBUG */
411 	{
412 		.procname	= "sched_rt_period_us",
413 		.data		= &sysctl_sched_rt_period,
414 		.maxlen		= sizeof(unsigned int),
415 		.mode		= 0644,
416 		.proc_handler	= sched_rt_handler,
417 	},
418 	{
419 		.procname	= "sched_rt_runtime_us",
420 		.data		= &sysctl_sched_rt_runtime,
421 		.maxlen		= sizeof(int),
422 		.mode		= 0644,
423 		.proc_handler	= sched_rt_handler,
424 	},
425 	{
426 		.procname	= "sched_rr_timeslice_ms",
427 		.data		= &sched_rr_timeslice,
428 		.maxlen		= sizeof(int),
429 		.mode		= 0644,
430 		.proc_handler	= sched_rr_handler,
431 	},
432 #ifdef CONFIG_SCHED_AUTOGROUP
433 	{
434 		.procname	= "sched_autogroup_enabled",
435 		.data		= &sysctl_sched_autogroup_enabled,
436 		.maxlen		= sizeof(unsigned int),
437 		.mode		= 0644,
438 		.proc_handler	= proc_dointvec_minmax,
439 		.extra1		= &zero,
440 		.extra2		= &one,
441 	},
442 #endif
443 #ifdef CONFIG_CFS_BANDWIDTH
444 	{
445 		.procname	= "sched_cfs_bandwidth_slice_us",
446 		.data		= &sysctl_sched_cfs_bandwidth_slice,
447 		.maxlen		= sizeof(unsigned int),
448 		.mode		= 0644,
449 		.proc_handler	= proc_dointvec_minmax,
450 		.extra1		= &one,
451 	},
452 #endif
453 #ifdef CONFIG_PROVE_LOCKING
454 	{
455 		.procname	= "prove_locking",
456 		.data		= &prove_locking,
457 		.maxlen		= sizeof(int),
458 		.mode		= 0644,
459 		.proc_handler	= proc_dointvec,
460 	},
461 #endif
462 #ifdef CONFIG_LOCK_STAT
463 	{
464 		.procname	= "lock_stat",
465 		.data		= &lock_stat,
466 		.maxlen		= sizeof(int),
467 		.mode		= 0644,
468 		.proc_handler	= proc_dointvec,
469 	},
470 #endif
471 	{
472 		.procname	= "panic",
473 		.data		= &panic_timeout,
474 		.maxlen		= sizeof(int),
475 		.mode		= 0644,
476 		.proc_handler	= proc_dointvec,
477 	},
478 #ifdef CONFIG_COREDUMP
479 	{
480 		.procname	= "core_uses_pid",
481 		.data		= &core_uses_pid,
482 		.maxlen		= sizeof(int),
483 		.mode		= 0644,
484 		.proc_handler	= proc_dointvec,
485 	},
486 	{
487 		.procname	= "core_pattern",
488 		.data		= core_pattern,
489 		.maxlen		= CORENAME_MAX_SIZE,
490 		.mode		= 0644,
491 		.proc_handler	= proc_dostring_coredump,
492 	},
493 	{
494 		.procname	= "core_pipe_limit",
495 		.data		= &core_pipe_limit,
496 		.maxlen		= sizeof(unsigned int),
497 		.mode		= 0644,
498 		.proc_handler	= proc_dointvec,
499 	},
500 #endif
501 #ifdef CONFIG_PROC_SYSCTL
502 	{
503 		.procname	= "tainted",
504 		.maxlen 	= sizeof(long),
505 		.mode		= 0644,
506 		.proc_handler	= proc_taint,
507 	},
508 	{
509 		.procname	= "sysctl_writes_strict",
510 		.data		= &sysctl_writes_strict,
511 		.maxlen		= sizeof(int),
512 		.mode		= 0644,
513 		.proc_handler	= proc_dointvec_minmax,
514 		.extra1		= &neg_one,
515 		.extra2		= &one,
516 	},
517 #endif
518 #ifdef CONFIG_LATENCYTOP
519 	{
520 		.procname	= "latencytop",
521 		.data		= &latencytop_enabled,
522 		.maxlen		= sizeof(int),
523 		.mode		= 0644,
524 		.proc_handler	= sysctl_latencytop,
525 	},
526 #endif
527 #ifdef CONFIG_BLK_DEV_INITRD
528 	{
529 		.procname	= "real-root-dev",
530 		.data		= &real_root_dev,
531 		.maxlen		= sizeof(int),
532 		.mode		= 0644,
533 		.proc_handler	= proc_dointvec,
534 	},
535 #endif
536 	{
537 		.procname	= "print-fatal-signals",
538 		.data		= &print_fatal_signals,
539 		.maxlen		= sizeof(int),
540 		.mode		= 0644,
541 		.proc_handler	= proc_dointvec,
542 	},
543 #ifdef CONFIG_SPARC
544 	{
545 		.procname	= "reboot-cmd",
546 		.data		= reboot_command,
547 		.maxlen		= 256,
548 		.mode		= 0644,
549 		.proc_handler	= proc_dostring,
550 	},
551 	{
552 		.procname	= "stop-a",
553 		.data		= &stop_a_enabled,
554 		.maxlen		= sizeof (int),
555 		.mode		= 0644,
556 		.proc_handler	= proc_dointvec,
557 	},
558 	{
559 		.procname	= "scons-poweroff",
560 		.data		= &scons_pwroff,
561 		.maxlen		= sizeof (int),
562 		.mode		= 0644,
563 		.proc_handler	= proc_dointvec,
564 	},
565 #endif
566 #ifdef CONFIG_SPARC64
567 	{
568 		.procname	= "tsb-ratio",
569 		.data		= &sysctl_tsb_ratio,
570 		.maxlen		= sizeof (int),
571 		.mode		= 0644,
572 		.proc_handler	= proc_dointvec,
573 	},
574 #endif
575 #ifdef __hppa__
576 	{
577 		.procname	= "soft-power",
578 		.data		= &pwrsw_enabled,
579 		.maxlen		= sizeof (int),
580 	 	.mode		= 0644,
581 		.proc_handler	= proc_dointvec,
582 	},
583 #endif
584 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
585 	{
586 		.procname	= "unaligned-trap",
587 		.data		= &unaligned_enabled,
588 		.maxlen		= sizeof (int),
589 		.mode		= 0644,
590 		.proc_handler	= proc_dointvec,
591 	},
592 #endif
593 	{
594 		.procname	= "ctrl-alt-del",
595 		.data		= &C_A_D,
596 		.maxlen		= sizeof(int),
597 		.mode		= 0644,
598 		.proc_handler	= proc_dointvec,
599 	},
600 #ifdef CONFIG_FUNCTION_TRACER
601 	{
602 		.procname	= "ftrace_enabled",
603 		.data		= &ftrace_enabled,
604 		.maxlen		= sizeof(int),
605 		.mode		= 0644,
606 		.proc_handler	= ftrace_enable_sysctl,
607 	},
608 #endif
609 #ifdef CONFIG_STACK_TRACER
610 	{
611 		.procname	= "stack_tracer_enabled",
612 		.data		= &stack_tracer_enabled,
613 		.maxlen		= sizeof(int),
614 		.mode		= 0644,
615 		.proc_handler	= stack_trace_sysctl,
616 	},
617 #endif
618 #ifdef CONFIG_TRACING
619 	{
620 		.procname	= "ftrace_dump_on_oops",
621 		.data		= &ftrace_dump_on_oops,
622 		.maxlen		= sizeof(int),
623 		.mode		= 0644,
624 		.proc_handler	= proc_dointvec,
625 	},
626 	{
627 		.procname	= "traceoff_on_warning",
628 		.data		= &__disable_trace_on_warning,
629 		.maxlen		= sizeof(__disable_trace_on_warning),
630 		.mode		= 0644,
631 		.proc_handler	= proc_dointvec,
632 	},
633 	{
634 		.procname	= "tracepoint_printk",
635 		.data		= &tracepoint_printk,
636 		.maxlen		= sizeof(tracepoint_printk),
637 		.mode		= 0644,
638 		.proc_handler	= proc_dointvec,
639 	},
640 #endif
641 #ifdef CONFIG_KEXEC_CORE
642 	{
643 		.procname	= "kexec_load_disabled",
644 		.data		= &kexec_load_disabled,
645 		.maxlen		= sizeof(int),
646 		.mode		= 0644,
647 		/* only handle a transition from default "0" to "1" */
648 		.proc_handler	= proc_dointvec_minmax,
649 		.extra1		= &one,
650 		.extra2		= &one,
651 	},
652 #endif
653 #ifdef CONFIG_MODULES
654 	{
655 		.procname	= "modprobe",
656 		.data		= &modprobe_path,
657 		.maxlen		= KMOD_PATH_LEN,
658 		.mode		= 0644,
659 		.proc_handler	= proc_dostring,
660 	},
661 	{
662 		.procname	= "modules_disabled",
663 		.data		= &modules_disabled,
664 		.maxlen		= sizeof(int),
665 		.mode		= 0644,
666 		/* only handle a transition from default "0" to "1" */
667 		.proc_handler	= proc_dointvec_minmax,
668 		.extra1		= &one,
669 		.extra2		= &one,
670 	},
671 #endif
672 #ifdef CONFIG_UEVENT_HELPER
673 	{
674 		.procname	= "hotplug",
675 		.data		= &uevent_helper,
676 		.maxlen		= UEVENT_HELPER_PATH_LEN,
677 		.mode		= 0644,
678 		.proc_handler	= proc_dostring,
679 	},
680 #endif
681 #ifdef CONFIG_CHR_DEV_SG
682 	{
683 		.procname	= "sg-big-buff",
684 		.data		= &sg_big_buff,
685 		.maxlen		= sizeof (int),
686 		.mode		= 0444,
687 		.proc_handler	= proc_dointvec,
688 	},
689 #endif
690 #ifdef CONFIG_BSD_PROCESS_ACCT
691 	{
692 		.procname	= "acct",
693 		.data		= &acct_parm,
694 		.maxlen		= 3*sizeof(int),
695 		.mode		= 0644,
696 		.proc_handler	= proc_dointvec,
697 	},
698 #endif
699 #ifdef CONFIG_MAGIC_SYSRQ
700 	{
701 		.procname	= "sysrq",
702 		.data		= &__sysrq_enabled,
703 		.maxlen		= sizeof (int),
704 		.mode		= 0644,
705 		.proc_handler	= sysrq_sysctl_handler,
706 	},
707 #endif
708 #ifdef CONFIG_PROC_SYSCTL
709 	{
710 		.procname	= "cad_pid",
711 		.data		= NULL,
712 		.maxlen		= sizeof (int),
713 		.mode		= 0600,
714 		.proc_handler	= proc_do_cad_pid,
715 	},
716 #endif
717 	{
718 		.procname	= "threads-max",
719 		.data		= NULL,
720 		.maxlen		= sizeof(int),
721 		.mode		= 0644,
722 		.proc_handler	= sysctl_max_threads,
723 	},
724 	{
725 		.procname	= "random",
726 		.mode		= 0555,
727 		.child		= random_table,
728 	},
729 	{
730 		.procname	= "usermodehelper",
731 		.mode		= 0555,
732 		.child		= usermodehelper_table,
733 	},
734 	{
735 		.procname	= "overflowuid",
736 		.data		= &overflowuid,
737 		.maxlen		= sizeof(int),
738 		.mode		= 0644,
739 		.proc_handler	= proc_dointvec_minmax,
740 		.extra1		= &minolduid,
741 		.extra2		= &maxolduid,
742 	},
743 	{
744 		.procname	= "overflowgid",
745 		.data		= &overflowgid,
746 		.maxlen		= sizeof(int),
747 		.mode		= 0644,
748 		.proc_handler	= proc_dointvec_minmax,
749 		.extra1		= &minolduid,
750 		.extra2		= &maxolduid,
751 	},
752 #ifdef CONFIG_S390
753 #ifdef CONFIG_MATHEMU
754 	{
755 		.procname	= "ieee_emulation_warnings",
756 		.data		= &sysctl_ieee_emulation_warnings,
757 		.maxlen		= sizeof(int),
758 		.mode		= 0644,
759 		.proc_handler	= proc_dointvec,
760 	},
761 #endif
762 	{
763 		.procname	= "userprocess_debug",
764 		.data		= &show_unhandled_signals,
765 		.maxlen		= sizeof(int),
766 		.mode		= 0644,
767 		.proc_handler	= proc_dointvec,
768 	},
769 #endif
770 	{
771 		.procname	= "pid_max",
772 		.data		= &pid_max,
773 		.maxlen		= sizeof (int),
774 		.mode		= 0644,
775 		.proc_handler	= proc_dointvec_minmax,
776 		.extra1		= &pid_max_min,
777 		.extra2		= &pid_max_max,
778 	},
779 	{
780 		.procname	= "panic_on_oops",
781 		.data		= &panic_on_oops,
782 		.maxlen		= sizeof(int),
783 		.mode		= 0644,
784 		.proc_handler	= proc_dointvec,
785 	},
786 #if defined CONFIG_PRINTK
787 	{
788 		.procname	= "printk",
789 		.data		= &console_loglevel,
790 		.maxlen		= 4*sizeof(int),
791 		.mode		= 0644,
792 		.proc_handler	= proc_dointvec,
793 	},
794 	{
795 		.procname	= "printk_ratelimit",
796 		.data		= &printk_ratelimit_state.interval,
797 		.maxlen		= sizeof(int),
798 		.mode		= 0644,
799 		.proc_handler	= proc_dointvec_jiffies,
800 	},
801 	{
802 		.procname	= "printk_ratelimit_burst",
803 		.data		= &printk_ratelimit_state.burst,
804 		.maxlen		= sizeof(int),
805 		.mode		= 0644,
806 		.proc_handler	= proc_dointvec,
807 	},
808 	{
809 		.procname	= "printk_delay",
810 		.data		= &printk_delay_msec,
811 		.maxlen		= sizeof(int),
812 		.mode		= 0644,
813 		.proc_handler	= proc_dointvec_minmax,
814 		.extra1		= &zero,
815 		.extra2		= &ten_thousand,
816 	},
817 	{
818 		.procname	= "printk_devkmsg",
819 		.data		= devkmsg_log_str,
820 		.maxlen		= DEVKMSG_STR_MAX_SIZE,
821 		.mode		= 0644,
822 		.proc_handler	= devkmsg_sysctl_set_loglvl,
823 	},
824 	{
825 		.procname	= "dmesg_restrict",
826 		.data		= &dmesg_restrict,
827 		.maxlen		= sizeof(int),
828 		.mode		= 0644,
829 		.proc_handler	= proc_dointvec_minmax_sysadmin,
830 		.extra1		= &zero,
831 		.extra2		= &one,
832 	},
833 	{
834 		.procname	= "kptr_restrict",
835 		.data		= &kptr_restrict,
836 		.maxlen		= sizeof(int),
837 		.mode		= 0644,
838 		.proc_handler	= proc_dointvec_minmax_sysadmin,
839 		.extra1		= &zero,
840 		.extra2		= &two,
841 	},
842 #endif
843 	{
844 		.procname	= "ngroups_max",
845 		.data		= &ngroups_max,
846 		.maxlen		= sizeof (int),
847 		.mode		= 0444,
848 		.proc_handler	= proc_dointvec,
849 	},
850 	{
851 		.procname	= "cap_last_cap",
852 		.data		= (void *)&cap_last_cap,
853 		.maxlen		= sizeof(int),
854 		.mode		= 0444,
855 		.proc_handler	= proc_dointvec,
856 	},
857 #if defined(CONFIG_LOCKUP_DETECTOR)
858 	{
859 		.procname       = "watchdog",
860 		.data           = &watchdog_user_enabled,
861 		.maxlen         = sizeof (int),
862 		.mode           = 0644,
863 		.proc_handler   = proc_watchdog,
864 		.extra1		= &zero,
865 		.extra2		= &one,
866 	},
867 	{
868 		.procname	= "watchdog_thresh",
869 		.data		= &watchdog_thresh,
870 		.maxlen		= sizeof(int),
871 		.mode		= 0644,
872 		.proc_handler	= proc_watchdog_thresh,
873 		.extra1		= &zero,
874 		.extra2		= &sixty,
875 	},
876 	{
877 		.procname       = "nmi_watchdog",
878 		.data           = &nmi_watchdog_enabled,
879 		.maxlen         = sizeof (int),
880 		.mode           = 0644,
881 		.proc_handler   = proc_nmi_watchdog,
882 		.extra1		= &zero,
883 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
884 		.extra2		= &one,
885 #else
886 		.extra2		= &zero,
887 #endif
888 	},
889 	{
890 		.procname       = "soft_watchdog",
891 		.data           = &soft_watchdog_enabled,
892 		.maxlen         = sizeof (int),
893 		.mode           = 0644,
894 		.proc_handler   = proc_soft_watchdog,
895 		.extra1		= &zero,
896 		.extra2		= &one,
897 	},
898 	{
899 		.procname	= "watchdog_cpumask",
900 		.data		= &watchdog_cpumask_bits,
901 		.maxlen		= NR_CPUS,
902 		.mode		= 0644,
903 		.proc_handler	= proc_watchdog_cpumask,
904 	},
905 	{
906 		.procname	= "softlockup_panic",
907 		.data		= &softlockup_panic,
908 		.maxlen		= sizeof(int),
909 		.mode		= 0644,
910 		.proc_handler	= proc_dointvec_minmax,
911 		.extra1		= &zero,
912 		.extra2		= &one,
913 	},
914 #ifdef CONFIG_HARDLOCKUP_DETECTOR
915 	{
916 		.procname	= "hardlockup_panic",
917 		.data		= &hardlockup_panic,
918 		.maxlen		= sizeof(int),
919 		.mode		= 0644,
920 		.proc_handler	= proc_dointvec_minmax,
921 		.extra1		= &zero,
922 		.extra2		= &one,
923 	},
924 #endif
925 #ifdef CONFIG_SMP
926 	{
927 		.procname	= "softlockup_all_cpu_backtrace",
928 		.data		= &sysctl_softlockup_all_cpu_backtrace,
929 		.maxlen		= sizeof(int),
930 		.mode		= 0644,
931 		.proc_handler	= proc_dointvec_minmax,
932 		.extra1		= &zero,
933 		.extra2		= &one,
934 	},
935 	{
936 		.procname	= "hardlockup_all_cpu_backtrace",
937 		.data		= &sysctl_hardlockup_all_cpu_backtrace,
938 		.maxlen		= sizeof(int),
939 		.mode		= 0644,
940 		.proc_handler	= proc_dointvec_minmax,
941 		.extra1		= &zero,
942 		.extra2		= &one,
943 	},
944 #endif /* CONFIG_SMP */
945 #endif
946 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
947 	{
948 		.procname       = "unknown_nmi_panic",
949 		.data           = &unknown_nmi_panic,
950 		.maxlen         = sizeof (int),
951 		.mode           = 0644,
952 		.proc_handler   = proc_dointvec,
953 	},
954 #endif
955 #if defined(CONFIG_X86)
956 	{
957 		.procname	= "panic_on_unrecovered_nmi",
958 		.data		= &panic_on_unrecovered_nmi,
959 		.maxlen		= sizeof(int),
960 		.mode		= 0644,
961 		.proc_handler	= proc_dointvec,
962 	},
963 	{
964 		.procname	= "panic_on_io_nmi",
965 		.data		= &panic_on_io_nmi,
966 		.maxlen		= sizeof(int),
967 		.mode		= 0644,
968 		.proc_handler	= proc_dointvec,
969 	},
970 #ifdef CONFIG_DEBUG_STACKOVERFLOW
971 	{
972 		.procname	= "panic_on_stackoverflow",
973 		.data		= &sysctl_panic_on_stackoverflow,
974 		.maxlen		= sizeof(int),
975 		.mode		= 0644,
976 		.proc_handler	= proc_dointvec,
977 	},
978 #endif
979 	{
980 		.procname	= "bootloader_type",
981 		.data		= &bootloader_type,
982 		.maxlen		= sizeof (int),
983 		.mode		= 0444,
984 		.proc_handler	= proc_dointvec,
985 	},
986 	{
987 		.procname	= "bootloader_version",
988 		.data		= &bootloader_version,
989 		.maxlen		= sizeof (int),
990 		.mode		= 0444,
991 		.proc_handler	= proc_dointvec,
992 	},
993 	{
994 		.procname	= "kstack_depth_to_print",
995 		.data		= &kstack_depth_to_print,
996 		.maxlen		= sizeof(int),
997 		.mode		= 0644,
998 		.proc_handler	= proc_dointvec,
999 	},
1000 	{
1001 		.procname	= "io_delay_type",
1002 		.data		= &io_delay_type,
1003 		.maxlen		= sizeof(int),
1004 		.mode		= 0644,
1005 		.proc_handler	= proc_dointvec,
1006 	},
1007 #endif
1008 #if defined(CONFIG_MMU)
1009 	{
1010 		.procname	= "randomize_va_space",
1011 		.data		= &randomize_va_space,
1012 		.maxlen		= sizeof(int),
1013 		.mode		= 0644,
1014 		.proc_handler	= proc_dointvec,
1015 	},
1016 #endif
1017 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1018 	{
1019 		.procname	= "spin_retry",
1020 		.data		= &spin_retry,
1021 		.maxlen		= sizeof (int),
1022 		.mode		= 0644,
1023 		.proc_handler	= proc_dointvec,
1024 	},
1025 #endif
1026 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1027 	{
1028 		.procname	= "acpi_video_flags",
1029 		.data		= &acpi_realmode_flags,
1030 		.maxlen		= sizeof (unsigned long),
1031 		.mode		= 0644,
1032 		.proc_handler	= proc_doulongvec_minmax,
1033 	},
1034 #endif
1035 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1036 	{
1037 		.procname	= "ignore-unaligned-usertrap",
1038 		.data		= &no_unaligned_warning,
1039 		.maxlen		= sizeof (int),
1040 	 	.mode		= 0644,
1041 		.proc_handler	= proc_dointvec,
1042 	},
1043 #endif
1044 #ifdef CONFIG_IA64
1045 	{
1046 		.procname	= "unaligned-dump-stack",
1047 		.data		= &unaligned_dump_stack,
1048 		.maxlen		= sizeof (int),
1049 		.mode		= 0644,
1050 		.proc_handler	= proc_dointvec,
1051 	},
1052 #endif
1053 #ifdef CONFIG_DETECT_HUNG_TASK
1054 	{
1055 		.procname	= "hung_task_panic",
1056 		.data		= &sysctl_hung_task_panic,
1057 		.maxlen		= sizeof(int),
1058 		.mode		= 0644,
1059 		.proc_handler	= proc_dointvec_minmax,
1060 		.extra1		= &zero,
1061 		.extra2		= &one,
1062 	},
1063 	{
1064 		.procname	= "hung_task_check_count",
1065 		.data		= &sysctl_hung_task_check_count,
1066 		.maxlen		= sizeof(int),
1067 		.mode		= 0644,
1068 		.proc_handler	= proc_dointvec_minmax,
1069 		.extra1		= &zero,
1070 	},
1071 	{
1072 		.procname	= "hung_task_timeout_secs",
1073 		.data		= &sysctl_hung_task_timeout_secs,
1074 		.maxlen		= sizeof(unsigned long),
1075 		.mode		= 0644,
1076 		.proc_handler	= proc_dohung_task_timeout_secs,
1077 		.extra2		= &hung_task_timeout_max,
1078 	},
1079 	{
1080 		.procname	= "hung_task_warnings",
1081 		.data		= &sysctl_hung_task_warnings,
1082 		.maxlen		= sizeof(int),
1083 		.mode		= 0644,
1084 		.proc_handler	= proc_dointvec_minmax,
1085 		.extra1		= &neg_one,
1086 	},
1087 #endif
1088 #ifdef CONFIG_COMPAT
1089 	{
1090 		.procname	= "compat-log",
1091 		.data		= &compat_log,
1092 		.maxlen		= sizeof (int),
1093 	 	.mode		= 0644,
1094 		.proc_handler	= proc_dointvec,
1095 	},
1096 #endif
1097 #ifdef CONFIG_RT_MUTEXES
1098 	{
1099 		.procname	= "max_lock_depth",
1100 		.data		= &max_lock_depth,
1101 		.maxlen		= sizeof(int),
1102 		.mode		= 0644,
1103 		.proc_handler	= proc_dointvec,
1104 	},
1105 #endif
1106 	{
1107 		.procname	= "poweroff_cmd",
1108 		.data		= &poweroff_cmd,
1109 		.maxlen		= POWEROFF_CMD_PATH_LEN,
1110 		.mode		= 0644,
1111 		.proc_handler	= proc_dostring,
1112 	},
1113 #ifdef CONFIG_KEYS
1114 	{
1115 		.procname	= "keys",
1116 		.mode		= 0555,
1117 		.child		= key_sysctls,
1118 	},
1119 #endif
1120 #ifdef CONFIG_PERF_EVENTS
1121 	/*
1122 	 * User-space scripts rely on the existence of this file
1123 	 * as a feature check for perf_events being enabled.
1124 	 *
1125 	 * So it's an ABI, do not remove!
1126 	 */
1127 	{
1128 		.procname	= "perf_event_paranoid",
1129 		.data		= &sysctl_perf_event_paranoid,
1130 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
1131 		.mode		= 0644,
1132 		.proc_handler	= proc_dointvec,
1133 	},
1134 	{
1135 		.procname	= "perf_event_mlock_kb",
1136 		.data		= &sysctl_perf_event_mlock,
1137 		.maxlen		= sizeof(sysctl_perf_event_mlock),
1138 		.mode		= 0644,
1139 		.proc_handler	= proc_dointvec,
1140 	},
1141 	{
1142 		.procname	= "perf_event_max_sample_rate",
1143 		.data		= &sysctl_perf_event_sample_rate,
1144 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
1145 		.mode		= 0644,
1146 		.proc_handler	= perf_proc_update_handler,
1147 		.extra1		= &one,
1148 	},
1149 	{
1150 		.procname	= "perf_cpu_time_max_percent",
1151 		.data		= &sysctl_perf_cpu_time_max_percent,
1152 		.maxlen		= sizeof(sysctl_perf_cpu_time_max_percent),
1153 		.mode		= 0644,
1154 		.proc_handler	= perf_cpu_time_max_percent_handler,
1155 		.extra1		= &zero,
1156 		.extra2		= &one_hundred,
1157 	},
1158 	{
1159 		.procname	= "perf_event_max_stack",
1160 		.data		= &sysctl_perf_event_max_stack,
1161 		.maxlen		= sizeof(sysctl_perf_event_max_stack),
1162 		.mode		= 0644,
1163 		.proc_handler	= perf_event_max_stack_handler,
1164 		.extra1		= &zero,
1165 		.extra2		= &six_hundred_forty_kb,
1166 	},
1167 	{
1168 		.procname	= "perf_event_max_contexts_per_stack",
1169 		.data		= &sysctl_perf_event_max_contexts_per_stack,
1170 		.maxlen		= sizeof(sysctl_perf_event_max_contexts_per_stack),
1171 		.mode		= 0644,
1172 		.proc_handler	= perf_event_max_stack_handler,
1173 		.extra1		= &zero,
1174 		.extra2		= &one_thousand,
1175 	},
1176 #endif
1177 #ifdef CONFIG_KMEMCHECK
1178 	{
1179 		.procname	= "kmemcheck",
1180 		.data		= &kmemcheck_enabled,
1181 		.maxlen		= sizeof(int),
1182 		.mode		= 0644,
1183 		.proc_handler	= proc_dointvec,
1184 	},
1185 #endif
1186 	{
1187 		.procname	= "panic_on_warn",
1188 		.data		= &panic_on_warn,
1189 		.maxlen		= sizeof(int),
1190 		.mode		= 0644,
1191 		.proc_handler	= proc_dointvec_minmax,
1192 		.extra1		= &zero,
1193 		.extra2		= &one,
1194 	},
1195 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1196 	{
1197 		.procname	= "timer_migration",
1198 		.data		= &sysctl_timer_migration,
1199 		.maxlen		= sizeof(unsigned int),
1200 		.mode		= 0644,
1201 		.proc_handler	= timer_migration_handler,
1202 	},
1203 #endif
1204 #ifdef CONFIG_BPF_SYSCALL
1205 	{
1206 		.procname	= "unprivileged_bpf_disabled",
1207 		.data		= &sysctl_unprivileged_bpf_disabled,
1208 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
1209 		.mode		= 0644,
1210 		/* only handle a transition from default "0" to "1" */
1211 		.proc_handler	= proc_dointvec_minmax,
1212 		.extra1		= &one,
1213 		.extra2		= &one,
1214 	},
1215 #endif
1216 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
1217 	{
1218 		.procname	= "panic_on_rcu_stall",
1219 		.data		= &sysctl_panic_on_rcu_stall,
1220 		.maxlen		= sizeof(sysctl_panic_on_rcu_stall),
1221 		.mode		= 0644,
1222 		.proc_handler	= proc_dointvec_minmax,
1223 		.extra1		= &zero,
1224 		.extra2		= &one,
1225 	},
1226 #endif
1227 	{ }
1228 };
1229 
1230 static struct ctl_table vm_table[] = {
1231 	{
1232 		.procname	= "overcommit_memory",
1233 		.data		= &sysctl_overcommit_memory,
1234 		.maxlen		= sizeof(sysctl_overcommit_memory),
1235 		.mode		= 0644,
1236 		.proc_handler	= proc_dointvec_minmax,
1237 		.extra1		= &zero,
1238 		.extra2		= &two,
1239 	},
1240 	{
1241 		.procname	= "panic_on_oom",
1242 		.data		= &sysctl_panic_on_oom,
1243 		.maxlen		= sizeof(sysctl_panic_on_oom),
1244 		.mode		= 0644,
1245 		.proc_handler	= proc_dointvec_minmax,
1246 		.extra1		= &zero,
1247 		.extra2		= &two,
1248 	},
1249 	{
1250 		.procname	= "oom_kill_allocating_task",
1251 		.data		= &sysctl_oom_kill_allocating_task,
1252 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
1253 		.mode		= 0644,
1254 		.proc_handler	= proc_dointvec,
1255 	},
1256 	{
1257 		.procname	= "oom_dump_tasks",
1258 		.data		= &sysctl_oom_dump_tasks,
1259 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1260 		.mode		= 0644,
1261 		.proc_handler	= proc_dointvec,
1262 	},
1263 	{
1264 		.procname	= "overcommit_ratio",
1265 		.data		= &sysctl_overcommit_ratio,
1266 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1267 		.mode		= 0644,
1268 		.proc_handler	= overcommit_ratio_handler,
1269 	},
1270 	{
1271 		.procname	= "overcommit_kbytes",
1272 		.data		= &sysctl_overcommit_kbytes,
1273 		.maxlen		= sizeof(sysctl_overcommit_kbytes),
1274 		.mode		= 0644,
1275 		.proc_handler	= overcommit_kbytes_handler,
1276 	},
1277 	{
1278 		.procname	= "page-cluster",
1279 		.data		= &page_cluster,
1280 		.maxlen		= sizeof(int),
1281 		.mode		= 0644,
1282 		.proc_handler	= proc_dointvec_minmax,
1283 		.extra1		= &zero,
1284 	},
1285 	{
1286 		.procname	= "dirty_background_ratio",
1287 		.data		= &dirty_background_ratio,
1288 		.maxlen		= sizeof(dirty_background_ratio),
1289 		.mode		= 0644,
1290 		.proc_handler	= dirty_background_ratio_handler,
1291 		.extra1		= &zero,
1292 		.extra2		= &one_hundred,
1293 	},
1294 	{
1295 		.procname	= "dirty_background_bytes",
1296 		.data		= &dirty_background_bytes,
1297 		.maxlen		= sizeof(dirty_background_bytes),
1298 		.mode		= 0644,
1299 		.proc_handler	= dirty_background_bytes_handler,
1300 		.extra1		= &one_ul,
1301 	},
1302 	{
1303 		.procname	= "dirty_ratio",
1304 		.data		= &vm_dirty_ratio,
1305 		.maxlen		= sizeof(vm_dirty_ratio),
1306 		.mode		= 0644,
1307 		.proc_handler	= dirty_ratio_handler,
1308 		.extra1		= &zero,
1309 		.extra2		= &one_hundred,
1310 	},
1311 	{
1312 		.procname	= "dirty_bytes",
1313 		.data		= &vm_dirty_bytes,
1314 		.maxlen		= sizeof(vm_dirty_bytes),
1315 		.mode		= 0644,
1316 		.proc_handler	= dirty_bytes_handler,
1317 		.extra1		= &dirty_bytes_min,
1318 	},
1319 	{
1320 		.procname	= "dirty_writeback_centisecs",
1321 		.data		= &dirty_writeback_interval,
1322 		.maxlen		= sizeof(dirty_writeback_interval),
1323 		.mode		= 0644,
1324 		.proc_handler	= dirty_writeback_centisecs_handler,
1325 	},
1326 	{
1327 		.procname	= "dirty_expire_centisecs",
1328 		.data		= &dirty_expire_interval,
1329 		.maxlen		= sizeof(dirty_expire_interval),
1330 		.mode		= 0644,
1331 		.proc_handler	= proc_dointvec_minmax,
1332 		.extra1		= &zero,
1333 	},
1334 	{
1335 		.procname	= "dirtytime_expire_seconds",
1336 		.data		= &dirtytime_expire_interval,
1337 		.maxlen		= sizeof(dirty_expire_interval),
1338 		.mode		= 0644,
1339 		.proc_handler	= dirtytime_interval_handler,
1340 		.extra1		= &zero,
1341 	},
1342 	{
1343 		.procname       = "nr_pdflush_threads",
1344 		.mode           = 0444 /* read-only */,
1345 		.proc_handler   = pdflush_proc_obsolete,
1346 	},
1347 	{
1348 		.procname	= "swappiness",
1349 		.data		= &vm_swappiness,
1350 		.maxlen		= sizeof(vm_swappiness),
1351 		.mode		= 0644,
1352 		.proc_handler	= proc_dointvec_minmax,
1353 		.extra1		= &zero,
1354 		.extra2		= &one_hundred,
1355 	},
1356 #ifdef CONFIG_HUGETLB_PAGE
1357 	{
1358 		.procname	= "nr_hugepages",
1359 		.data		= NULL,
1360 		.maxlen		= sizeof(unsigned long),
1361 		.mode		= 0644,
1362 		.proc_handler	= hugetlb_sysctl_handler,
1363 	},
1364 #ifdef CONFIG_NUMA
1365 	{
1366 		.procname       = "nr_hugepages_mempolicy",
1367 		.data           = NULL,
1368 		.maxlen         = sizeof(unsigned long),
1369 		.mode           = 0644,
1370 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1371 	},
1372 #endif
1373 	 {
1374 		.procname	= "hugetlb_shm_group",
1375 		.data		= &sysctl_hugetlb_shm_group,
1376 		.maxlen		= sizeof(gid_t),
1377 		.mode		= 0644,
1378 		.proc_handler	= proc_dointvec,
1379 	 },
1380 	 {
1381 		.procname	= "hugepages_treat_as_movable",
1382 		.data		= &hugepages_treat_as_movable,
1383 		.maxlen		= sizeof(int),
1384 		.mode		= 0644,
1385 		.proc_handler	= proc_dointvec,
1386 	},
1387 	{
1388 		.procname	= "nr_overcommit_hugepages",
1389 		.data		= NULL,
1390 		.maxlen		= sizeof(unsigned long),
1391 		.mode		= 0644,
1392 		.proc_handler	= hugetlb_overcommit_handler,
1393 	},
1394 #endif
1395 	{
1396 		.procname	= "lowmem_reserve_ratio",
1397 		.data		= &sysctl_lowmem_reserve_ratio,
1398 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1399 		.mode		= 0644,
1400 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1401 	},
1402 	{
1403 		.procname	= "drop_caches",
1404 		.data		= &sysctl_drop_caches,
1405 		.maxlen		= sizeof(int),
1406 		.mode		= 0644,
1407 		.proc_handler	= drop_caches_sysctl_handler,
1408 		.extra1		= &one,
1409 		.extra2		= &four,
1410 	},
1411 #ifdef CONFIG_COMPACTION
1412 	{
1413 		.procname	= "compact_memory",
1414 		.data		= &sysctl_compact_memory,
1415 		.maxlen		= sizeof(int),
1416 		.mode		= 0200,
1417 		.proc_handler	= sysctl_compaction_handler,
1418 	},
1419 	{
1420 		.procname	= "extfrag_threshold",
1421 		.data		= &sysctl_extfrag_threshold,
1422 		.maxlen		= sizeof(int),
1423 		.mode		= 0644,
1424 		.proc_handler	= sysctl_extfrag_handler,
1425 		.extra1		= &min_extfrag_threshold,
1426 		.extra2		= &max_extfrag_threshold,
1427 	},
1428 	{
1429 		.procname	= "compact_unevictable_allowed",
1430 		.data		= &sysctl_compact_unevictable_allowed,
1431 		.maxlen		= sizeof(int),
1432 		.mode		= 0644,
1433 		.proc_handler	= proc_dointvec,
1434 		.extra1		= &zero,
1435 		.extra2		= &one,
1436 	},
1437 
1438 #endif /* CONFIG_COMPACTION */
1439 	{
1440 		.procname	= "min_free_kbytes",
1441 		.data		= &min_free_kbytes,
1442 		.maxlen		= sizeof(min_free_kbytes),
1443 		.mode		= 0644,
1444 		.proc_handler	= min_free_kbytes_sysctl_handler,
1445 		.extra1		= &zero,
1446 	},
1447 	{
1448 		.procname	= "watermark_scale_factor",
1449 		.data		= &watermark_scale_factor,
1450 		.maxlen		= sizeof(watermark_scale_factor),
1451 		.mode		= 0644,
1452 		.proc_handler	= watermark_scale_factor_sysctl_handler,
1453 		.extra1		= &one,
1454 		.extra2		= &one_thousand,
1455 	},
1456 	{
1457 		.procname	= "percpu_pagelist_fraction",
1458 		.data		= &percpu_pagelist_fraction,
1459 		.maxlen		= sizeof(percpu_pagelist_fraction),
1460 		.mode		= 0644,
1461 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1462 		.extra1		= &zero,
1463 	},
1464 #ifdef CONFIG_MMU
1465 	{
1466 		.procname	= "max_map_count",
1467 		.data		= &sysctl_max_map_count,
1468 		.maxlen		= sizeof(sysctl_max_map_count),
1469 		.mode		= 0644,
1470 		.proc_handler	= proc_dointvec_minmax,
1471 		.extra1		= &zero,
1472 	},
1473 #else
1474 	{
1475 		.procname	= "nr_trim_pages",
1476 		.data		= &sysctl_nr_trim_pages,
1477 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1478 		.mode		= 0644,
1479 		.proc_handler	= proc_dointvec_minmax,
1480 		.extra1		= &zero,
1481 	},
1482 #endif
1483 	{
1484 		.procname	= "laptop_mode",
1485 		.data		= &laptop_mode,
1486 		.maxlen		= sizeof(laptop_mode),
1487 		.mode		= 0644,
1488 		.proc_handler	= proc_dointvec_jiffies,
1489 	},
1490 	{
1491 		.procname	= "block_dump",
1492 		.data		= &block_dump,
1493 		.maxlen		= sizeof(block_dump),
1494 		.mode		= 0644,
1495 		.proc_handler	= proc_dointvec,
1496 		.extra1		= &zero,
1497 	},
1498 	{
1499 		.procname	= "vfs_cache_pressure",
1500 		.data		= &sysctl_vfs_cache_pressure,
1501 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1502 		.mode		= 0644,
1503 		.proc_handler	= proc_dointvec,
1504 		.extra1		= &zero,
1505 	},
1506 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1507 	{
1508 		.procname	= "legacy_va_layout",
1509 		.data		= &sysctl_legacy_va_layout,
1510 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1511 		.mode		= 0644,
1512 		.proc_handler	= proc_dointvec,
1513 		.extra1		= &zero,
1514 	},
1515 #endif
1516 #ifdef CONFIG_NUMA
1517 	{
1518 		.procname	= "zone_reclaim_mode",
1519 		.data		= &node_reclaim_mode,
1520 		.maxlen		= sizeof(node_reclaim_mode),
1521 		.mode		= 0644,
1522 		.proc_handler	= proc_dointvec,
1523 		.extra1		= &zero,
1524 	},
1525 	{
1526 		.procname	= "min_unmapped_ratio",
1527 		.data		= &sysctl_min_unmapped_ratio,
1528 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1529 		.mode		= 0644,
1530 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1531 		.extra1		= &zero,
1532 		.extra2		= &one_hundred,
1533 	},
1534 	{
1535 		.procname	= "min_slab_ratio",
1536 		.data		= &sysctl_min_slab_ratio,
1537 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1538 		.mode		= 0644,
1539 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1540 		.extra1		= &zero,
1541 		.extra2		= &one_hundred,
1542 	},
1543 #endif
1544 #ifdef CONFIG_SMP
1545 	{
1546 		.procname	= "stat_interval",
1547 		.data		= &sysctl_stat_interval,
1548 		.maxlen		= sizeof(sysctl_stat_interval),
1549 		.mode		= 0644,
1550 		.proc_handler	= proc_dointvec_jiffies,
1551 	},
1552 	{
1553 		.procname	= "stat_refresh",
1554 		.data		= NULL,
1555 		.maxlen		= 0,
1556 		.mode		= 0600,
1557 		.proc_handler	= vmstat_refresh,
1558 	},
1559 #endif
1560 #ifdef CONFIG_MMU
1561 	{
1562 		.procname	= "mmap_min_addr",
1563 		.data		= &dac_mmap_min_addr,
1564 		.maxlen		= sizeof(unsigned long),
1565 		.mode		= 0644,
1566 		.proc_handler	= mmap_min_addr_handler,
1567 	},
1568 #endif
1569 #ifdef CONFIG_NUMA
1570 	{
1571 		.procname	= "numa_zonelist_order",
1572 		.data		= &numa_zonelist_order,
1573 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1574 		.mode		= 0644,
1575 		.proc_handler	= numa_zonelist_order_handler,
1576 	},
1577 #endif
1578 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1579    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1580 	{
1581 		.procname	= "vdso_enabled",
1582 #ifdef CONFIG_X86_32
1583 		.data		= &vdso32_enabled,
1584 		.maxlen		= sizeof(vdso32_enabled),
1585 #else
1586 		.data		= &vdso_enabled,
1587 		.maxlen		= sizeof(vdso_enabled),
1588 #endif
1589 		.mode		= 0644,
1590 		.proc_handler	= proc_dointvec,
1591 		.extra1		= &zero,
1592 	},
1593 #endif
1594 #ifdef CONFIG_HIGHMEM
1595 	{
1596 		.procname	= "highmem_is_dirtyable",
1597 		.data		= &vm_highmem_is_dirtyable,
1598 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1599 		.mode		= 0644,
1600 		.proc_handler	= proc_dointvec_minmax,
1601 		.extra1		= &zero,
1602 		.extra2		= &one,
1603 	},
1604 #endif
1605 #ifdef CONFIG_MEMORY_FAILURE
1606 	{
1607 		.procname	= "memory_failure_early_kill",
1608 		.data		= &sysctl_memory_failure_early_kill,
1609 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1610 		.mode		= 0644,
1611 		.proc_handler	= proc_dointvec_minmax,
1612 		.extra1		= &zero,
1613 		.extra2		= &one,
1614 	},
1615 	{
1616 		.procname	= "memory_failure_recovery",
1617 		.data		= &sysctl_memory_failure_recovery,
1618 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1619 		.mode		= 0644,
1620 		.proc_handler	= proc_dointvec_minmax,
1621 		.extra1		= &zero,
1622 		.extra2		= &one,
1623 	},
1624 #endif
1625 	{
1626 		.procname	= "user_reserve_kbytes",
1627 		.data		= &sysctl_user_reserve_kbytes,
1628 		.maxlen		= sizeof(sysctl_user_reserve_kbytes),
1629 		.mode		= 0644,
1630 		.proc_handler	= proc_doulongvec_minmax,
1631 	},
1632 	{
1633 		.procname	= "admin_reserve_kbytes",
1634 		.data		= &sysctl_admin_reserve_kbytes,
1635 		.maxlen		= sizeof(sysctl_admin_reserve_kbytes),
1636 		.mode		= 0644,
1637 		.proc_handler	= proc_doulongvec_minmax,
1638 	},
1639 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1640 	{
1641 		.procname	= "mmap_rnd_bits",
1642 		.data		= &mmap_rnd_bits,
1643 		.maxlen		= sizeof(mmap_rnd_bits),
1644 		.mode		= 0600,
1645 		.proc_handler	= proc_dointvec_minmax,
1646 		.extra1		= (void *)&mmap_rnd_bits_min,
1647 		.extra2		= (void *)&mmap_rnd_bits_max,
1648 	},
1649 #endif
1650 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1651 	{
1652 		.procname	= "mmap_rnd_compat_bits",
1653 		.data		= &mmap_rnd_compat_bits,
1654 		.maxlen		= sizeof(mmap_rnd_compat_bits),
1655 		.mode		= 0600,
1656 		.proc_handler	= proc_dointvec_minmax,
1657 		.extra1		= (void *)&mmap_rnd_compat_bits_min,
1658 		.extra2		= (void *)&mmap_rnd_compat_bits_max,
1659 	},
1660 #endif
1661 	{ }
1662 };
1663 
1664 static struct ctl_table fs_table[] = {
1665 	{
1666 		.procname	= "inode-nr",
1667 		.data		= &inodes_stat,
1668 		.maxlen		= 2*sizeof(long),
1669 		.mode		= 0444,
1670 		.proc_handler	= proc_nr_inodes,
1671 	},
1672 	{
1673 		.procname	= "inode-state",
1674 		.data		= &inodes_stat,
1675 		.maxlen		= 7*sizeof(long),
1676 		.mode		= 0444,
1677 		.proc_handler	= proc_nr_inodes,
1678 	},
1679 	{
1680 		.procname	= "file-nr",
1681 		.data		= &files_stat,
1682 		.maxlen		= sizeof(files_stat),
1683 		.mode		= 0444,
1684 		.proc_handler	= proc_nr_files,
1685 	},
1686 	{
1687 		.procname	= "file-max",
1688 		.data		= &files_stat.max_files,
1689 		.maxlen		= sizeof(files_stat.max_files),
1690 		.mode		= 0644,
1691 		.proc_handler	= proc_doulongvec_minmax,
1692 	},
1693 	{
1694 		.procname	= "nr_open",
1695 		.data		= &sysctl_nr_open,
1696 		.maxlen		= sizeof(int),
1697 		.mode		= 0644,
1698 		.proc_handler	= proc_dointvec_minmax,
1699 		.extra1		= &sysctl_nr_open_min,
1700 		.extra2		= &sysctl_nr_open_max,
1701 	},
1702 	{
1703 		.procname	= "dentry-state",
1704 		.data		= &dentry_stat,
1705 		.maxlen		= 6*sizeof(long),
1706 		.mode		= 0444,
1707 		.proc_handler	= proc_nr_dentry,
1708 	},
1709 	{
1710 		.procname	= "overflowuid",
1711 		.data		= &fs_overflowuid,
1712 		.maxlen		= sizeof(int),
1713 		.mode		= 0644,
1714 		.proc_handler	= proc_dointvec_minmax,
1715 		.extra1		= &minolduid,
1716 		.extra2		= &maxolduid,
1717 	},
1718 	{
1719 		.procname	= "overflowgid",
1720 		.data		= &fs_overflowgid,
1721 		.maxlen		= sizeof(int),
1722 		.mode		= 0644,
1723 		.proc_handler	= proc_dointvec_minmax,
1724 		.extra1		= &minolduid,
1725 		.extra2		= &maxolduid,
1726 	},
1727 #ifdef CONFIG_FILE_LOCKING
1728 	{
1729 		.procname	= "leases-enable",
1730 		.data		= &leases_enable,
1731 		.maxlen		= sizeof(int),
1732 		.mode		= 0644,
1733 		.proc_handler	= proc_dointvec,
1734 	},
1735 #endif
1736 #ifdef CONFIG_DNOTIFY
1737 	{
1738 		.procname	= "dir-notify-enable",
1739 		.data		= &dir_notify_enable,
1740 		.maxlen		= sizeof(int),
1741 		.mode		= 0644,
1742 		.proc_handler	= proc_dointvec,
1743 	},
1744 #endif
1745 #ifdef CONFIG_MMU
1746 #ifdef CONFIG_FILE_LOCKING
1747 	{
1748 		.procname	= "lease-break-time",
1749 		.data		= &lease_break_time,
1750 		.maxlen		= sizeof(int),
1751 		.mode		= 0644,
1752 		.proc_handler	= proc_dointvec,
1753 	},
1754 #endif
1755 #ifdef CONFIG_AIO
1756 	{
1757 		.procname	= "aio-nr",
1758 		.data		= &aio_nr,
1759 		.maxlen		= sizeof(aio_nr),
1760 		.mode		= 0444,
1761 		.proc_handler	= proc_doulongvec_minmax,
1762 	},
1763 	{
1764 		.procname	= "aio-max-nr",
1765 		.data		= &aio_max_nr,
1766 		.maxlen		= sizeof(aio_max_nr),
1767 		.mode		= 0644,
1768 		.proc_handler	= proc_doulongvec_minmax,
1769 	},
1770 #endif /* CONFIG_AIO */
1771 #ifdef CONFIG_INOTIFY_USER
1772 	{
1773 		.procname	= "inotify",
1774 		.mode		= 0555,
1775 		.child		= inotify_table,
1776 	},
1777 #endif
1778 #ifdef CONFIG_EPOLL
1779 	{
1780 		.procname	= "epoll",
1781 		.mode		= 0555,
1782 		.child		= epoll_table,
1783 	},
1784 #endif
1785 #endif
1786 	{
1787 		.procname	= "protected_symlinks",
1788 		.data		= &sysctl_protected_symlinks,
1789 		.maxlen		= sizeof(int),
1790 		.mode		= 0600,
1791 		.proc_handler	= proc_dointvec_minmax,
1792 		.extra1		= &zero,
1793 		.extra2		= &one,
1794 	},
1795 	{
1796 		.procname	= "protected_hardlinks",
1797 		.data		= &sysctl_protected_hardlinks,
1798 		.maxlen		= sizeof(int),
1799 		.mode		= 0600,
1800 		.proc_handler	= proc_dointvec_minmax,
1801 		.extra1		= &zero,
1802 		.extra2		= &one,
1803 	},
1804 	{
1805 		.procname	= "suid_dumpable",
1806 		.data		= &suid_dumpable,
1807 		.maxlen		= sizeof(int),
1808 		.mode		= 0644,
1809 		.proc_handler	= proc_dointvec_minmax_coredump,
1810 		.extra1		= &zero,
1811 		.extra2		= &two,
1812 	},
1813 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1814 	{
1815 		.procname	= "binfmt_misc",
1816 		.mode		= 0555,
1817 		.child		= sysctl_mount_point,
1818 	},
1819 #endif
1820 	{
1821 		.procname	= "pipe-max-size",
1822 		.data		= &pipe_max_size,
1823 		.maxlen		= sizeof(int),
1824 		.mode		= 0644,
1825 		.proc_handler	= &pipe_proc_fn,
1826 		.extra1		= &pipe_min_size,
1827 	},
1828 	{
1829 		.procname	= "pipe-user-pages-hard",
1830 		.data		= &pipe_user_pages_hard,
1831 		.maxlen		= sizeof(pipe_user_pages_hard),
1832 		.mode		= 0644,
1833 		.proc_handler	= proc_doulongvec_minmax,
1834 	},
1835 	{
1836 		.procname	= "pipe-user-pages-soft",
1837 		.data		= &pipe_user_pages_soft,
1838 		.maxlen		= sizeof(pipe_user_pages_soft),
1839 		.mode		= 0644,
1840 		.proc_handler	= proc_doulongvec_minmax,
1841 	},
1842 	{
1843 		.procname	= "mount-max",
1844 		.data		= &sysctl_mount_max,
1845 		.maxlen		= sizeof(unsigned int),
1846 		.mode		= 0644,
1847 		.proc_handler	= proc_dointvec_minmax,
1848 		.extra1		= &one,
1849 	},
1850 	{ }
1851 };
1852 
1853 static struct ctl_table debug_table[] = {
1854 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1855 	{
1856 		.procname	= "exception-trace",
1857 		.data		= &show_unhandled_signals,
1858 		.maxlen		= sizeof(int),
1859 		.mode		= 0644,
1860 		.proc_handler	= proc_dointvec
1861 	},
1862 #endif
1863 #if defined(CONFIG_OPTPROBES)
1864 	{
1865 		.procname	= "kprobes-optimization",
1866 		.data		= &sysctl_kprobes_optimization,
1867 		.maxlen		= sizeof(int),
1868 		.mode		= 0644,
1869 		.proc_handler	= proc_kprobes_optimization_handler,
1870 		.extra1		= &zero,
1871 		.extra2		= &one,
1872 	},
1873 #endif
1874 	{ }
1875 };
1876 
1877 static struct ctl_table dev_table[] = {
1878 	{ }
1879 };
1880 
1881 int __init sysctl_init(void)
1882 {
1883 	struct ctl_table_header *hdr;
1884 
1885 	hdr = register_sysctl_table(sysctl_base_table);
1886 	kmemleak_not_leak(hdr);
1887 	return 0;
1888 }
1889 
1890 #endif /* CONFIG_SYSCTL */
1891 
1892 /*
1893  * /proc/sys support
1894  */
1895 
1896 #ifdef CONFIG_PROC_SYSCTL
1897 
1898 static int _proc_do_string(char *data, int maxlen, int write,
1899 			   char __user *buffer,
1900 			   size_t *lenp, loff_t *ppos)
1901 {
1902 	size_t len;
1903 	char __user *p;
1904 	char c;
1905 
1906 	if (!data || !maxlen || !*lenp) {
1907 		*lenp = 0;
1908 		return 0;
1909 	}
1910 
1911 	if (write) {
1912 		if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1913 			/* Only continue writes not past the end of buffer. */
1914 			len = strlen(data);
1915 			if (len > maxlen - 1)
1916 				len = maxlen - 1;
1917 
1918 			if (*ppos > len)
1919 				return 0;
1920 			len = *ppos;
1921 		} else {
1922 			/* Start writing from beginning of buffer. */
1923 			len = 0;
1924 		}
1925 
1926 		*ppos += *lenp;
1927 		p = buffer;
1928 		while ((p - buffer) < *lenp && len < maxlen - 1) {
1929 			if (get_user(c, p++))
1930 				return -EFAULT;
1931 			if (c == 0 || c == '\n')
1932 				break;
1933 			data[len++] = c;
1934 		}
1935 		data[len] = 0;
1936 	} else {
1937 		len = strlen(data);
1938 		if (len > maxlen)
1939 			len = maxlen;
1940 
1941 		if (*ppos > len) {
1942 			*lenp = 0;
1943 			return 0;
1944 		}
1945 
1946 		data += *ppos;
1947 		len  -= *ppos;
1948 
1949 		if (len > *lenp)
1950 			len = *lenp;
1951 		if (len)
1952 			if (copy_to_user(buffer, data, len))
1953 				return -EFAULT;
1954 		if (len < *lenp) {
1955 			if (put_user('\n', buffer + len))
1956 				return -EFAULT;
1957 			len++;
1958 		}
1959 		*lenp = len;
1960 		*ppos += len;
1961 	}
1962 	return 0;
1963 }
1964 
1965 static void warn_sysctl_write(struct ctl_table *table)
1966 {
1967 	pr_warn_once("%s wrote to %s when file position was not 0!\n"
1968 		"This will not be supported in the future. To silence this\n"
1969 		"warning, set kernel.sysctl_writes_strict = -1\n",
1970 		current->comm, table->procname);
1971 }
1972 
1973 /**
1974  * proc_dostring - read a string sysctl
1975  * @table: the sysctl table
1976  * @write: %TRUE if this is a write to the sysctl file
1977  * @buffer: the user buffer
1978  * @lenp: the size of the user buffer
1979  * @ppos: file position
1980  *
1981  * Reads/writes a string from/to the user buffer. If the kernel
1982  * buffer provided is not large enough to hold the string, the
1983  * string is truncated. The copied string is %NULL-terminated.
1984  * If the string is being read by the user process, it is copied
1985  * and a newline '\n' is added. It is truncated if the buffer is
1986  * not large enough.
1987  *
1988  * Returns 0 on success.
1989  */
1990 int proc_dostring(struct ctl_table *table, int write,
1991 		  void __user *buffer, size_t *lenp, loff_t *ppos)
1992 {
1993 	if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1994 		warn_sysctl_write(table);
1995 
1996 	return _proc_do_string((char *)(table->data), table->maxlen, write,
1997 			       (char __user *)buffer, lenp, ppos);
1998 }
1999 
2000 static size_t proc_skip_spaces(char **buf)
2001 {
2002 	size_t ret;
2003 	char *tmp = skip_spaces(*buf);
2004 	ret = tmp - *buf;
2005 	*buf = tmp;
2006 	return ret;
2007 }
2008 
2009 static void proc_skip_char(char **buf, size_t *size, const char v)
2010 {
2011 	while (*size) {
2012 		if (**buf != v)
2013 			break;
2014 		(*size)--;
2015 		(*buf)++;
2016 	}
2017 }
2018 
2019 #define TMPBUFLEN 22
2020 /**
2021  * proc_get_long - reads an ASCII formatted integer from a user buffer
2022  *
2023  * @buf: a kernel buffer
2024  * @size: size of the kernel buffer
2025  * @val: this is where the number will be stored
2026  * @neg: set to %TRUE if number is negative
2027  * @perm_tr: a vector which contains the allowed trailers
2028  * @perm_tr_len: size of the perm_tr vector
2029  * @tr: pointer to store the trailer character
2030  *
2031  * In case of success %0 is returned and @buf and @size are updated with
2032  * the amount of bytes read. If @tr is non-NULL and a trailing
2033  * character exists (size is non-zero after returning from this
2034  * function), @tr is updated with the trailing character.
2035  */
2036 static int proc_get_long(char **buf, size_t *size,
2037 			  unsigned long *val, bool *neg,
2038 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
2039 {
2040 	int len;
2041 	char *p, tmp[TMPBUFLEN];
2042 
2043 	if (!*size)
2044 		return -EINVAL;
2045 
2046 	len = *size;
2047 	if (len > TMPBUFLEN - 1)
2048 		len = TMPBUFLEN - 1;
2049 
2050 	memcpy(tmp, *buf, len);
2051 
2052 	tmp[len] = 0;
2053 	p = tmp;
2054 	if (*p == '-' && *size > 1) {
2055 		*neg = true;
2056 		p++;
2057 	} else
2058 		*neg = false;
2059 	if (!isdigit(*p))
2060 		return -EINVAL;
2061 
2062 	*val = simple_strtoul(p, &p, 0);
2063 
2064 	len = p - tmp;
2065 
2066 	/* We don't know if the next char is whitespace thus we may accept
2067 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2068 	 * (e.g. 123...1). So lets not allow such large numbers. */
2069 	if (len == TMPBUFLEN - 1)
2070 		return -EINVAL;
2071 
2072 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2073 		return -EINVAL;
2074 
2075 	if (tr && (len < *size))
2076 		*tr = *p;
2077 
2078 	*buf += len;
2079 	*size -= len;
2080 
2081 	return 0;
2082 }
2083 
2084 /**
2085  * proc_put_long - converts an integer to a decimal ASCII formatted string
2086  *
2087  * @buf: the user buffer
2088  * @size: the size of the user buffer
2089  * @val: the integer to be converted
2090  * @neg: sign of the number, %TRUE for negative
2091  *
2092  * In case of success %0 is returned and @buf and @size are updated with
2093  * the amount of bytes written.
2094  */
2095 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2096 			  bool neg)
2097 {
2098 	int len;
2099 	char tmp[TMPBUFLEN], *p = tmp;
2100 
2101 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2102 	len = strlen(tmp);
2103 	if (len > *size)
2104 		len = *size;
2105 	if (copy_to_user(*buf, tmp, len))
2106 		return -EFAULT;
2107 	*size -= len;
2108 	*buf += len;
2109 	return 0;
2110 }
2111 #undef TMPBUFLEN
2112 
2113 static int proc_put_char(void __user **buf, size_t *size, char c)
2114 {
2115 	if (*size) {
2116 		char __user **buffer = (char __user **)buf;
2117 		if (put_user(c, *buffer))
2118 			return -EFAULT;
2119 		(*size)--, (*buffer)++;
2120 		*buf = *buffer;
2121 	}
2122 	return 0;
2123 }
2124 
2125 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2126 				 int *valp,
2127 				 int write, void *data)
2128 {
2129 	if (write) {
2130 		if (*negp) {
2131 			if (*lvalp > (unsigned long) INT_MAX + 1)
2132 				return -EINVAL;
2133 			*valp = -*lvalp;
2134 		} else {
2135 			if (*lvalp > (unsigned long) INT_MAX)
2136 				return -EINVAL;
2137 			*valp = *lvalp;
2138 		}
2139 	} else {
2140 		int val = *valp;
2141 		if (val < 0) {
2142 			*negp = true;
2143 			*lvalp = -(unsigned long)val;
2144 		} else {
2145 			*negp = false;
2146 			*lvalp = (unsigned long)val;
2147 		}
2148 	}
2149 	return 0;
2150 }
2151 
2152 static int do_proc_douintvec_conv(bool *negp, unsigned long *lvalp,
2153 				 int *valp,
2154 				 int write, void *data)
2155 {
2156 	if (write) {
2157 		if (*negp)
2158 			return -EINVAL;
2159 		*valp = *lvalp;
2160 	} else {
2161 		unsigned int val = *valp;
2162 		*lvalp = (unsigned long)val;
2163 	}
2164 	return 0;
2165 }
2166 
2167 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2168 
2169 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2170 		  int write, void __user *buffer,
2171 		  size_t *lenp, loff_t *ppos,
2172 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2173 			      int write, void *data),
2174 		  void *data)
2175 {
2176 	int *i, vleft, first = 1, err = 0;
2177 	size_t left;
2178 	char *kbuf = NULL, *p;
2179 
2180 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2181 		*lenp = 0;
2182 		return 0;
2183 	}
2184 
2185 	i = (int *) tbl_data;
2186 	vleft = table->maxlen / sizeof(*i);
2187 	left = *lenp;
2188 
2189 	if (!conv)
2190 		conv = do_proc_dointvec_conv;
2191 
2192 	if (write) {
2193 		if (*ppos) {
2194 			switch (sysctl_writes_strict) {
2195 			case SYSCTL_WRITES_STRICT:
2196 				goto out;
2197 			case SYSCTL_WRITES_WARN:
2198 				warn_sysctl_write(table);
2199 				break;
2200 			default:
2201 				break;
2202 			}
2203 		}
2204 
2205 		if (left > PAGE_SIZE - 1)
2206 			left = PAGE_SIZE - 1;
2207 		p = kbuf = memdup_user_nul(buffer, left);
2208 		if (IS_ERR(kbuf))
2209 			return PTR_ERR(kbuf);
2210 	}
2211 
2212 	for (; left && vleft--; i++, first=0) {
2213 		unsigned long lval;
2214 		bool neg;
2215 
2216 		if (write) {
2217 			left -= proc_skip_spaces(&p);
2218 
2219 			if (!left)
2220 				break;
2221 			err = proc_get_long(&p, &left, &lval, &neg,
2222 					     proc_wspace_sep,
2223 					     sizeof(proc_wspace_sep), NULL);
2224 			if (err)
2225 				break;
2226 			if (conv(&neg, &lval, i, 1, data)) {
2227 				err = -EINVAL;
2228 				break;
2229 			}
2230 		} else {
2231 			if (conv(&neg, &lval, i, 0, data)) {
2232 				err = -EINVAL;
2233 				break;
2234 			}
2235 			if (!first)
2236 				err = proc_put_char(&buffer, &left, '\t');
2237 			if (err)
2238 				break;
2239 			err = proc_put_long(&buffer, &left, lval, neg);
2240 			if (err)
2241 				break;
2242 		}
2243 	}
2244 
2245 	if (!write && !first && left && !err)
2246 		err = proc_put_char(&buffer, &left, '\n');
2247 	if (write && !err && left)
2248 		left -= proc_skip_spaces(&p);
2249 	if (write) {
2250 		kfree(kbuf);
2251 		if (first)
2252 			return err ? : -EINVAL;
2253 	}
2254 	*lenp -= left;
2255 out:
2256 	*ppos += *lenp;
2257 	return err;
2258 }
2259 
2260 static int do_proc_dointvec(struct ctl_table *table, int write,
2261 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2262 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2263 			      int write, void *data),
2264 		  void *data)
2265 {
2266 	return __do_proc_dointvec(table->data, table, write,
2267 			buffer, lenp, ppos, conv, data);
2268 }
2269 
2270 /**
2271  * proc_dointvec - read a vector of integers
2272  * @table: the sysctl table
2273  * @write: %TRUE if this is a write to the sysctl file
2274  * @buffer: the user buffer
2275  * @lenp: the size of the user buffer
2276  * @ppos: file position
2277  *
2278  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2279  * values from/to the user buffer, treated as an ASCII string.
2280  *
2281  * Returns 0 on success.
2282  */
2283 int proc_dointvec(struct ctl_table *table, int write,
2284 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2285 {
2286 	return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
2287 }
2288 
2289 /**
2290  * proc_douintvec - read a vector of unsigned integers
2291  * @table: the sysctl table
2292  * @write: %TRUE if this is a write to the sysctl file
2293  * @buffer: the user buffer
2294  * @lenp: the size of the user buffer
2295  * @ppos: file position
2296  *
2297  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
2298  * values from/to the user buffer, treated as an ASCII string.
2299  *
2300  * Returns 0 on success.
2301  */
2302 int proc_douintvec(struct ctl_table *table, int write,
2303 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2304 {
2305 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2306 				do_proc_douintvec_conv, NULL);
2307 }
2308 
2309 /*
2310  * Taint values can only be increased
2311  * This means we can safely use a temporary.
2312  */
2313 static int proc_taint(struct ctl_table *table, int write,
2314 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2315 {
2316 	struct ctl_table t;
2317 	unsigned long tmptaint = get_taint();
2318 	int err;
2319 
2320 	if (write && !capable(CAP_SYS_ADMIN))
2321 		return -EPERM;
2322 
2323 	t = *table;
2324 	t.data = &tmptaint;
2325 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2326 	if (err < 0)
2327 		return err;
2328 
2329 	if (write) {
2330 		/*
2331 		 * Poor man's atomic or. Not worth adding a primitive
2332 		 * to everyone's atomic.h for this
2333 		 */
2334 		int i;
2335 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2336 			if ((tmptaint >> i) & 1)
2337 				add_taint(i, LOCKDEP_STILL_OK);
2338 		}
2339 	}
2340 
2341 	return err;
2342 }
2343 
2344 #ifdef CONFIG_PRINTK
2345 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2346 				void __user *buffer, size_t *lenp, loff_t *ppos)
2347 {
2348 	if (write && !capable(CAP_SYS_ADMIN))
2349 		return -EPERM;
2350 
2351 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2352 }
2353 #endif
2354 
2355 struct do_proc_dointvec_minmax_conv_param {
2356 	int *min;
2357 	int *max;
2358 };
2359 
2360 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2361 					int *valp,
2362 					int write, void *data)
2363 {
2364 	struct do_proc_dointvec_minmax_conv_param *param = data;
2365 	if (write) {
2366 		int val = *negp ? -*lvalp : *lvalp;
2367 		if ((param->min && *param->min > val) ||
2368 		    (param->max && *param->max < val))
2369 			return -EINVAL;
2370 		*valp = val;
2371 	} else {
2372 		int val = *valp;
2373 		if (val < 0) {
2374 			*negp = true;
2375 			*lvalp = -(unsigned long)val;
2376 		} else {
2377 			*negp = false;
2378 			*lvalp = (unsigned long)val;
2379 		}
2380 	}
2381 	return 0;
2382 }
2383 
2384 /**
2385  * proc_dointvec_minmax - read a vector of integers with min/max values
2386  * @table: the sysctl table
2387  * @write: %TRUE if this is a write to the sysctl file
2388  * @buffer: the user buffer
2389  * @lenp: the size of the user buffer
2390  * @ppos: file position
2391  *
2392  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2393  * values from/to the user buffer, treated as an ASCII string.
2394  *
2395  * This routine will ensure the values are within the range specified by
2396  * table->extra1 (min) and table->extra2 (max).
2397  *
2398  * Returns 0 on success.
2399  */
2400 int proc_dointvec_minmax(struct ctl_table *table, int write,
2401 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2402 {
2403 	struct do_proc_dointvec_minmax_conv_param param = {
2404 		.min = (int *) table->extra1,
2405 		.max = (int *) table->extra2,
2406 	};
2407 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2408 				do_proc_dointvec_minmax_conv, &param);
2409 }
2410 
2411 static void validate_coredump_safety(void)
2412 {
2413 #ifdef CONFIG_COREDUMP
2414 	if (suid_dumpable == SUID_DUMP_ROOT &&
2415 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
2416 		printk(KERN_WARNING "Unsafe core_pattern used with "\
2417 			"suid_dumpable=2. Pipe handler or fully qualified "\
2418 			"core dump path required.\n");
2419 	}
2420 #endif
2421 }
2422 
2423 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2424 		void __user *buffer, size_t *lenp, loff_t *ppos)
2425 {
2426 	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2427 	if (!error)
2428 		validate_coredump_safety();
2429 	return error;
2430 }
2431 
2432 #ifdef CONFIG_COREDUMP
2433 static int proc_dostring_coredump(struct ctl_table *table, int write,
2434 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2435 {
2436 	int error = proc_dostring(table, write, buffer, lenp, ppos);
2437 	if (!error)
2438 		validate_coredump_safety();
2439 	return error;
2440 }
2441 #endif
2442 
2443 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2444 				     void __user *buffer,
2445 				     size_t *lenp, loff_t *ppos,
2446 				     unsigned long convmul,
2447 				     unsigned long convdiv)
2448 {
2449 	unsigned long *i, *min, *max;
2450 	int vleft, first = 1, err = 0;
2451 	size_t left;
2452 	char *kbuf = NULL, *p;
2453 
2454 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2455 		*lenp = 0;
2456 		return 0;
2457 	}
2458 
2459 	i = (unsigned long *) data;
2460 	min = (unsigned long *) table->extra1;
2461 	max = (unsigned long *) table->extra2;
2462 	vleft = table->maxlen / sizeof(unsigned long);
2463 	left = *lenp;
2464 
2465 	if (write) {
2466 		if (*ppos) {
2467 			switch (sysctl_writes_strict) {
2468 			case SYSCTL_WRITES_STRICT:
2469 				goto out;
2470 			case SYSCTL_WRITES_WARN:
2471 				warn_sysctl_write(table);
2472 				break;
2473 			default:
2474 				break;
2475 			}
2476 		}
2477 
2478 		if (left > PAGE_SIZE - 1)
2479 			left = PAGE_SIZE - 1;
2480 		p = kbuf = memdup_user_nul(buffer, left);
2481 		if (IS_ERR(kbuf))
2482 			return PTR_ERR(kbuf);
2483 	}
2484 
2485 	for (; left && vleft--; i++, first = 0) {
2486 		unsigned long val;
2487 
2488 		if (write) {
2489 			bool neg;
2490 
2491 			left -= proc_skip_spaces(&p);
2492 
2493 			err = proc_get_long(&p, &left, &val, &neg,
2494 					     proc_wspace_sep,
2495 					     sizeof(proc_wspace_sep), NULL);
2496 			if (err)
2497 				break;
2498 			if (neg)
2499 				continue;
2500 			if ((min && val < *min) || (max && val > *max))
2501 				continue;
2502 			*i = val;
2503 		} else {
2504 			val = convdiv * (*i) / convmul;
2505 			if (!first) {
2506 				err = proc_put_char(&buffer, &left, '\t');
2507 				if (err)
2508 					break;
2509 			}
2510 			err = proc_put_long(&buffer, &left, val, false);
2511 			if (err)
2512 				break;
2513 		}
2514 	}
2515 
2516 	if (!write && !first && left && !err)
2517 		err = proc_put_char(&buffer, &left, '\n');
2518 	if (write && !err)
2519 		left -= proc_skip_spaces(&p);
2520 	if (write) {
2521 		kfree(kbuf);
2522 		if (first)
2523 			return err ? : -EINVAL;
2524 	}
2525 	*lenp -= left;
2526 out:
2527 	*ppos += *lenp;
2528 	return err;
2529 }
2530 
2531 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2532 				     void __user *buffer,
2533 				     size_t *lenp, loff_t *ppos,
2534 				     unsigned long convmul,
2535 				     unsigned long convdiv)
2536 {
2537 	return __do_proc_doulongvec_minmax(table->data, table, write,
2538 			buffer, lenp, ppos, convmul, convdiv);
2539 }
2540 
2541 /**
2542  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2543  * @table: the sysctl table
2544  * @write: %TRUE if this is a write to the sysctl file
2545  * @buffer: the user buffer
2546  * @lenp: the size of the user buffer
2547  * @ppos: file position
2548  *
2549  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2550  * values from/to the user buffer, treated as an ASCII string.
2551  *
2552  * This routine will ensure the values are within the range specified by
2553  * table->extra1 (min) and table->extra2 (max).
2554  *
2555  * Returns 0 on success.
2556  */
2557 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2558 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2559 {
2560     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2561 }
2562 
2563 /**
2564  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2565  * @table: the sysctl table
2566  * @write: %TRUE if this is a write to the sysctl file
2567  * @buffer: the user buffer
2568  * @lenp: the size of the user buffer
2569  * @ppos: file position
2570  *
2571  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2572  * values from/to the user buffer, treated as an ASCII string. The values
2573  * are treated as milliseconds, and converted to jiffies when they are stored.
2574  *
2575  * This routine will ensure the values are within the range specified by
2576  * table->extra1 (min) and table->extra2 (max).
2577  *
2578  * Returns 0 on success.
2579  */
2580 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2581 				      void __user *buffer,
2582 				      size_t *lenp, loff_t *ppos)
2583 {
2584     return do_proc_doulongvec_minmax(table, write, buffer,
2585 				     lenp, ppos, HZ, 1000l);
2586 }
2587 
2588 
2589 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2590 					 int *valp,
2591 					 int write, void *data)
2592 {
2593 	if (write) {
2594 		if (*lvalp > LONG_MAX / HZ)
2595 			return 1;
2596 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2597 	} else {
2598 		int val = *valp;
2599 		unsigned long lval;
2600 		if (val < 0) {
2601 			*negp = true;
2602 			lval = -(unsigned long)val;
2603 		} else {
2604 			*negp = false;
2605 			lval = (unsigned long)val;
2606 		}
2607 		*lvalp = lval / HZ;
2608 	}
2609 	return 0;
2610 }
2611 
2612 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2613 						int *valp,
2614 						int write, void *data)
2615 {
2616 	if (write) {
2617 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2618 			return 1;
2619 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2620 	} else {
2621 		int val = *valp;
2622 		unsigned long lval;
2623 		if (val < 0) {
2624 			*negp = true;
2625 			lval = -(unsigned long)val;
2626 		} else {
2627 			*negp = false;
2628 			lval = (unsigned long)val;
2629 		}
2630 		*lvalp = jiffies_to_clock_t(lval);
2631 	}
2632 	return 0;
2633 }
2634 
2635 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2636 					    int *valp,
2637 					    int write, void *data)
2638 {
2639 	if (write) {
2640 		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2641 
2642 		if (jif > INT_MAX)
2643 			return 1;
2644 		*valp = (int)jif;
2645 	} else {
2646 		int val = *valp;
2647 		unsigned long lval;
2648 		if (val < 0) {
2649 			*negp = true;
2650 			lval = -(unsigned long)val;
2651 		} else {
2652 			*negp = false;
2653 			lval = (unsigned long)val;
2654 		}
2655 		*lvalp = jiffies_to_msecs(lval);
2656 	}
2657 	return 0;
2658 }
2659 
2660 /**
2661  * proc_dointvec_jiffies - read a vector of integers as seconds
2662  * @table: the sysctl table
2663  * @write: %TRUE if this is a write to the sysctl file
2664  * @buffer: the user buffer
2665  * @lenp: the size of the user buffer
2666  * @ppos: file position
2667  *
2668  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2669  * values from/to the user buffer, treated as an ASCII string.
2670  * The values read are assumed to be in seconds, and are converted into
2671  * jiffies.
2672  *
2673  * Returns 0 on success.
2674  */
2675 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2676 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2677 {
2678     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2679 		    	    do_proc_dointvec_jiffies_conv,NULL);
2680 }
2681 
2682 /**
2683  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2684  * @table: the sysctl table
2685  * @write: %TRUE if this is a write to the sysctl file
2686  * @buffer: the user buffer
2687  * @lenp: the size of the user buffer
2688  * @ppos: pointer to the file position
2689  *
2690  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2691  * values from/to the user buffer, treated as an ASCII string.
2692  * The values read are assumed to be in 1/USER_HZ seconds, and
2693  * are converted into jiffies.
2694  *
2695  * Returns 0 on success.
2696  */
2697 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2698 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2699 {
2700     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2701 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2702 }
2703 
2704 /**
2705  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2706  * @table: the sysctl table
2707  * @write: %TRUE if this is a write to the sysctl file
2708  * @buffer: the user buffer
2709  * @lenp: the size of the user buffer
2710  * @ppos: file position
2711  * @ppos: the current position in the file
2712  *
2713  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2714  * values from/to the user buffer, treated as an ASCII string.
2715  * The values read are assumed to be in 1/1000 seconds, and
2716  * are converted into jiffies.
2717  *
2718  * Returns 0 on success.
2719  */
2720 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2721 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2722 {
2723 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2724 				do_proc_dointvec_ms_jiffies_conv, NULL);
2725 }
2726 
2727 static int proc_do_cad_pid(struct ctl_table *table, int write,
2728 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2729 {
2730 	struct pid *new_pid;
2731 	pid_t tmp;
2732 	int r;
2733 
2734 	tmp = pid_vnr(cad_pid);
2735 
2736 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2737 			       lenp, ppos, NULL, NULL);
2738 	if (r || !write)
2739 		return r;
2740 
2741 	new_pid = find_get_pid(tmp);
2742 	if (!new_pid)
2743 		return -ESRCH;
2744 
2745 	put_pid(xchg(&cad_pid, new_pid));
2746 	return 0;
2747 }
2748 
2749 /**
2750  * proc_do_large_bitmap - read/write from/to a large bitmap
2751  * @table: the sysctl table
2752  * @write: %TRUE if this is a write to the sysctl file
2753  * @buffer: the user buffer
2754  * @lenp: the size of the user buffer
2755  * @ppos: file position
2756  *
2757  * The bitmap is stored at table->data and the bitmap length (in bits)
2758  * in table->maxlen.
2759  *
2760  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2761  * large bitmaps may be represented in a compact manner. Writing into
2762  * the file will clear the bitmap then update it with the given input.
2763  *
2764  * Returns 0 on success.
2765  */
2766 int proc_do_large_bitmap(struct ctl_table *table, int write,
2767 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2768 {
2769 	int err = 0;
2770 	bool first = 1;
2771 	size_t left = *lenp;
2772 	unsigned long bitmap_len = table->maxlen;
2773 	unsigned long *bitmap = *(unsigned long **) table->data;
2774 	unsigned long *tmp_bitmap = NULL;
2775 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2776 
2777 	if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2778 		*lenp = 0;
2779 		return 0;
2780 	}
2781 
2782 	if (write) {
2783 		char *kbuf, *p;
2784 
2785 		if (left > PAGE_SIZE - 1)
2786 			left = PAGE_SIZE - 1;
2787 
2788 		p = kbuf = memdup_user_nul(buffer, left);
2789 		if (IS_ERR(kbuf))
2790 			return PTR_ERR(kbuf);
2791 
2792 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2793 				     GFP_KERNEL);
2794 		if (!tmp_bitmap) {
2795 			kfree(kbuf);
2796 			return -ENOMEM;
2797 		}
2798 		proc_skip_char(&p, &left, '\n');
2799 		while (!err && left) {
2800 			unsigned long val_a, val_b;
2801 			bool neg;
2802 
2803 			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2804 					     sizeof(tr_a), &c);
2805 			if (err)
2806 				break;
2807 			if (val_a >= bitmap_len || neg) {
2808 				err = -EINVAL;
2809 				break;
2810 			}
2811 
2812 			val_b = val_a;
2813 			if (left) {
2814 				p++;
2815 				left--;
2816 			}
2817 
2818 			if (c == '-') {
2819 				err = proc_get_long(&p, &left, &val_b,
2820 						     &neg, tr_b, sizeof(tr_b),
2821 						     &c);
2822 				if (err)
2823 					break;
2824 				if (val_b >= bitmap_len || neg ||
2825 				    val_a > val_b) {
2826 					err = -EINVAL;
2827 					break;
2828 				}
2829 				if (left) {
2830 					p++;
2831 					left--;
2832 				}
2833 			}
2834 
2835 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2836 			first = 0;
2837 			proc_skip_char(&p, &left, '\n');
2838 		}
2839 		kfree(kbuf);
2840 	} else {
2841 		unsigned long bit_a, bit_b = 0;
2842 
2843 		while (left) {
2844 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2845 			if (bit_a >= bitmap_len)
2846 				break;
2847 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2848 						   bit_a + 1) - 1;
2849 
2850 			if (!first) {
2851 				err = proc_put_char(&buffer, &left, ',');
2852 				if (err)
2853 					break;
2854 			}
2855 			err = proc_put_long(&buffer, &left, bit_a, false);
2856 			if (err)
2857 				break;
2858 			if (bit_a != bit_b) {
2859 				err = proc_put_char(&buffer, &left, '-');
2860 				if (err)
2861 					break;
2862 				err = proc_put_long(&buffer, &left, bit_b, false);
2863 				if (err)
2864 					break;
2865 			}
2866 
2867 			first = 0; bit_b++;
2868 		}
2869 		if (!err)
2870 			err = proc_put_char(&buffer, &left, '\n');
2871 	}
2872 
2873 	if (!err) {
2874 		if (write) {
2875 			if (*ppos)
2876 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2877 			else
2878 				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2879 		}
2880 		kfree(tmp_bitmap);
2881 		*lenp -= left;
2882 		*ppos += *lenp;
2883 		return 0;
2884 	} else {
2885 		kfree(tmp_bitmap);
2886 		return err;
2887 	}
2888 }
2889 
2890 #else /* CONFIG_PROC_SYSCTL */
2891 
2892 int proc_dostring(struct ctl_table *table, int write,
2893 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2894 {
2895 	return -ENOSYS;
2896 }
2897 
2898 int proc_dointvec(struct ctl_table *table, int write,
2899 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2900 {
2901 	return -ENOSYS;
2902 }
2903 
2904 int proc_douintvec(struct ctl_table *table, int write,
2905 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2906 {
2907 	return -ENOSYS;
2908 }
2909 
2910 int proc_dointvec_minmax(struct ctl_table *table, int write,
2911 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2912 {
2913 	return -ENOSYS;
2914 }
2915 
2916 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2917 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2918 {
2919 	return -ENOSYS;
2920 }
2921 
2922 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2923 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2924 {
2925 	return -ENOSYS;
2926 }
2927 
2928 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2929 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2930 {
2931 	return -ENOSYS;
2932 }
2933 
2934 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2935 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2936 {
2937 	return -ENOSYS;
2938 }
2939 
2940 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2941 				      void __user *buffer,
2942 				      size_t *lenp, loff_t *ppos)
2943 {
2944     return -ENOSYS;
2945 }
2946 
2947 
2948 #endif /* CONFIG_PROC_SYSCTL */
2949 
2950 /*
2951  * No sense putting this after each symbol definition, twice,
2952  * exception granted :-)
2953  */
2954 EXPORT_SYMBOL(proc_dointvec);
2955 EXPORT_SYMBOL(proc_douintvec);
2956 EXPORT_SYMBOL(proc_dointvec_jiffies);
2957 EXPORT_SYMBOL(proc_dointvec_minmax);
2958 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2959 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2960 EXPORT_SYMBOL(proc_dostring);
2961 EXPORT_SYMBOL(proc_doulongvec_minmax);
2962 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2963