xref: /linux/kernel/sysctl.c (revision 0d08df6c493898e679d9c517e77ea95c063d40ec)
1 /*
2  * sysctl.c: General linux system control interface
3  *
4  * Begun 24 March 1995, Stephen Tweedie
5  * Added /proc support, Dec 1995
6  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
7  * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
8  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
9  * Dynamic registration fixes, Stephen Tweedie.
10  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
11  * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
12  *  Horn.
13  * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
14  * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
15  * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
16  *  Wendling.
17  * The list_for_each() macro wasn't appropriate for the sysctl loop.
18  *  Removed it and replaced it with older style, 03/23/00, Bill Wendling
19  */
20 
21 #include <linux/module.h>
22 #include <linux/aio.h>
23 #include <linux/mm.h>
24 #include <linux/swap.h>
25 #include <linux/slab.h>
26 #include <linux/sysctl.h>
27 #include <linux/bitmap.h>
28 #include <linux/signal.h>
29 #include <linux/printk.h>
30 #include <linux/proc_fs.h>
31 #include <linux/security.h>
32 #include <linux/ctype.h>
33 #include <linux/kmemcheck.h>
34 #include <linux/kmemleak.h>
35 #include <linux/fs.h>
36 #include <linux/init.h>
37 #include <linux/kernel.h>
38 #include <linux/kobject.h>
39 #include <linux/net.h>
40 #include <linux/sysrq.h>
41 #include <linux/highuid.h>
42 #include <linux/writeback.h>
43 #include <linux/ratelimit.h>
44 #include <linux/compaction.h>
45 #include <linux/hugetlb.h>
46 #include <linux/initrd.h>
47 #include <linux/key.h>
48 #include <linux/times.h>
49 #include <linux/limits.h>
50 #include <linux/dcache.h>
51 #include <linux/dnotify.h>
52 #include <linux/syscalls.h>
53 #include <linux/vmstat.h>
54 #include <linux/nfs_fs.h>
55 #include <linux/acpi.h>
56 #include <linux/reboot.h>
57 #include <linux/ftrace.h>
58 #include <linux/perf_event.h>
59 #include <linux/kprobes.h>
60 #include <linux/pipe_fs_i.h>
61 #include <linux/oom.h>
62 #include <linux/kmod.h>
63 #include <linux/capability.h>
64 #include <linux/binfmts.h>
65 #include <linux/sched/sysctl.h>
66 #include <linux/kexec.h>
67 #include <linux/bpf.h>
68 
69 #include <asm/uaccess.h>
70 #include <asm/processor.h>
71 
72 #ifdef CONFIG_X86
73 #include <asm/nmi.h>
74 #include <asm/stacktrace.h>
75 #include <asm/io.h>
76 #endif
77 #ifdef CONFIG_SPARC
78 #include <asm/setup.h>
79 #endif
80 #ifdef CONFIG_BSD_PROCESS_ACCT
81 #include <linux/acct.h>
82 #endif
83 #ifdef CONFIG_RT_MUTEXES
84 #include <linux/rtmutex.h>
85 #endif
86 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
87 #include <linux/lockdep.h>
88 #endif
89 #ifdef CONFIG_CHR_DEV_SG
90 #include <scsi/sg.h>
91 #endif
92 
93 #ifdef CONFIG_LOCKUP_DETECTOR
94 #include <linux/nmi.h>
95 #endif
96 
97 #if defined(CONFIG_SYSCTL)
98 
99 /* External variables not in a header file. */
100 extern int suid_dumpable;
101 #ifdef CONFIG_COREDUMP
102 extern int core_uses_pid;
103 extern char core_pattern[];
104 extern unsigned int core_pipe_limit;
105 #endif
106 extern int pid_max;
107 extern int pid_max_min, pid_max_max;
108 extern int percpu_pagelist_fraction;
109 extern int compat_log;
110 extern int latencytop_enabled;
111 extern int sysctl_nr_open_min, sysctl_nr_open_max;
112 #ifndef CONFIG_MMU
113 extern int sysctl_nr_trim_pages;
114 #endif
115 
116 /* Constants used for minimum and  maximum */
117 #ifdef CONFIG_LOCKUP_DETECTOR
118 static int sixty = 60;
119 #endif
120 
121 static int __maybe_unused neg_one = -1;
122 
123 static int zero;
124 static int __maybe_unused one = 1;
125 static int __maybe_unused two = 2;
126 static int __maybe_unused four = 4;
127 static unsigned long one_ul = 1;
128 static int one_hundred = 100;
129 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	= "dmesg_restrict",
818 		.data		= &dmesg_restrict,
819 		.maxlen		= sizeof(int),
820 		.mode		= 0644,
821 		.proc_handler	= proc_dointvec_minmax_sysadmin,
822 		.extra1		= &zero,
823 		.extra2		= &one,
824 	},
825 	{
826 		.procname	= "kptr_restrict",
827 		.data		= &kptr_restrict,
828 		.maxlen		= sizeof(int),
829 		.mode		= 0644,
830 		.proc_handler	= proc_dointvec_minmax_sysadmin,
831 		.extra1		= &zero,
832 		.extra2		= &two,
833 	},
834 #endif
835 	{
836 		.procname	= "ngroups_max",
837 		.data		= &ngroups_max,
838 		.maxlen		= sizeof (int),
839 		.mode		= 0444,
840 		.proc_handler	= proc_dointvec,
841 	},
842 	{
843 		.procname	= "cap_last_cap",
844 		.data		= (void *)&cap_last_cap,
845 		.maxlen		= sizeof(int),
846 		.mode		= 0444,
847 		.proc_handler	= proc_dointvec,
848 	},
849 #if defined(CONFIG_LOCKUP_DETECTOR)
850 	{
851 		.procname       = "watchdog",
852 		.data           = &watchdog_user_enabled,
853 		.maxlen         = sizeof (int),
854 		.mode           = 0644,
855 		.proc_handler   = proc_watchdog,
856 		.extra1		= &zero,
857 		.extra2		= &one,
858 	},
859 	{
860 		.procname	= "watchdog_thresh",
861 		.data		= &watchdog_thresh,
862 		.maxlen		= sizeof(int),
863 		.mode		= 0644,
864 		.proc_handler	= proc_watchdog_thresh,
865 		.extra1		= &zero,
866 		.extra2		= &sixty,
867 	},
868 	{
869 		.procname       = "nmi_watchdog",
870 		.data           = &nmi_watchdog_enabled,
871 		.maxlen         = sizeof (int),
872 		.mode           = 0644,
873 		.proc_handler   = proc_nmi_watchdog,
874 		.extra1		= &zero,
875 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
876 		.extra2		= &one,
877 #else
878 		.extra2		= &zero,
879 #endif
880 	},
881 	{
882 		.procname       = "soft_watchdog",
883 		.data           = &soft_watchdog_enabled,
884 		.maxlen         = sizeof (int),
885 		.mode           = 0644,
886 		.proc_handler   = proc_soft_watchdog,
887 		.extra1		= &zero,
888 		.extra2		= &one,
889 	},
890 	{
891 		.procname	= "watchdog_cpumask",
892 		.data		= &watchdog_cpumask_bits,
893 		.maxlen		= NR_CPUS,
894 		.mode		= 0644,
895 		.proc_handler	= proc_watchdog_cpumask,
896 	},
897 	{
898 		.procname	= "softlockup_panic",
899 		.data		= &softlockup_panic,
900 		.maxlen		= sizeof(int),
901 		.mode		= 0644,
902 		.proc_handler	= proc_dointvec_minmax,
903 		.extra1		= &zero,
904 		.extra2		= &one,
905 	},
906 #ifdef CONFIG_HARDLOCKUP_DETECTOR
907 	{
908 		.procname	= "hardlockup_panic",
909 		.data		= &hardlockup_panic,
910 		.maxlen		= sizeof(int),
911 		.mode		= 0644,
912 		.proc_handler	= proc_dointvec_minmax,
913 		.extra1		= &zero,
914 		.extra2		= &one,
915 	},
916 #endif
917 #ifdef CONFIG_SMP
918 	{
919 		.procname	= "softlockup_all_cpu_backtrace",
920 		.data		= &sysctl_softlockup_all_cpu_backtrace,
921 		.maxlen		= sizeof(int),
922 		.mode		= 0644,
923 		.proc_handler	= proc_dointvec_minmax,
924 		.extra1		= &zero,
925 		.extra2		= &one,
926 	},
927 	{
928 		.procname	= "hardlockup_all_cpu_backtrace",
929 		.data		= &sysctl_hardlockup_all_cpu_backtrace,
930 		.maxlen		= sizeof(int),
931 		.mode		= 0644,
932 		.proc_handler	= proc_dointvec_minmax,
933 		.extra1		= &zero,
934 		.extra2		= &one,
935 	},
936 #endif /* CONFIG_SMP */
937 #endif
938 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
939 	{
940 		.procname       = "unknown_nmi_panic",
941 		.data           = &unknown_nmi_panic,
942 		.maxlen         = sizeof (int),
943 		.mode           = 0644,
944 		.proc_handler   = proc_dointvec,
945 	},
946 #endif
947 #if defined(CONFIG_X86)
948 	{
949 		.procname	= "panic_on_unrecovered_nmi",
950 		.data		= &panic_on_unrecovered_nmi,
951 		.maxlen		= sizeof(int),
952 		.mode		= 0644,
953 		.proc_handler	= proc_dointvec,
954 	},
955 	{
956 		.procname	= "panic_on_io_nmi",
957 		.data		= &panic_on_io_nmi,
958 		.maxlen		= sizeof(int),
959 		.mode		= 0644,
960 		.proc_handler	= proc_dointvec,
961 	},
962 #ifdef CONFIG_DEBUG_STACKOVERFLOW
963 	{
964 		.procname	= "panic_on_stackoverflow",
965 		.data		= &sysctl_panic_on_stackoverflow,
966 		.maxlen		= sizeof(int),
967 		.mode		= 0644,
968 		.proc_handler	= proc_dointvec,
969 	},
970 #endif
971 	{
972 		.procname	= "bootloader_type",
973 		.data		= &bootloader_type,
974 		.maxlen		= sizeof (int),
975 		.mode		= 0444,
976 		.proc_handler	= proc_dointvec,
977 	},
978 	{
979 		.procname	= "bootloader_version",
980 		.data		= &bootloader_version,
981 		.maxlen		= sizeof (int),
982 		.mode		= 0444,
983 		.proc_handler	= proc_dointvec,
984 	},
985 	{
986 		.procname	= "kstack_depth_to_print",
987 		.data		= &kstack_depth_to_print,
988 		.maxlen		= sizeof(int),
989 		.mode		= 0644,
990 		.proc_handler	= proc_dointvec,
991 	},
992 	{
993 		.procname	= "io_delay_type",
994 		.data		= &io_delay_type,
995 		.maxlen		= sizeof(int),
996 		.mode		= 0644,
997 		.proc_handler	= proc_dointvec,
998 	},
999 #endif
1000 #if defined(CONFIG_MMU)
1001 	{
1002 		.procname	= "randomize_va_space",
1003 		.data		= &randomize_va_space,
1004 		.maxlen		= sizeof(int),
1005 		.mode		= 0644,
1006 		.proc_handler	= proc_dointvec,
1007 	},
1008 #endif
1009 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1010 	{
1011 		.procname	= "spin_retry",
1012 		.data		= &spin_retry,
1013 		.maxlen		= sizeof (int),
1014 		.mode		= 0644,
1015 		.proc_handler	= proc_dointvec,
1016 	},
1017 #endif
1018 #if	defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1019 	{
1020 		.procname	= "acpi_video_flags",
1021 		.data		= &acpi_realmode_flags,
1022 		.maxlen		= sizeof (unsigned long),
1023 		.mode		= 0644,
1024 		.proc_handler	= proc_doulongvec_minmax,
1025 	},
1026 #endif
1027 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1028 	{
1029 		.procname	= "ignore-unaligned-usertrap",
1030 		.data		= &no_unaligned_warning,
1031 		.maxlen		= sizeof (int),
1032 	 	.mode		= 0644,
1033 		.proc_handler	= proc_dointvec,
1034 	},
1035 #endif
1036 #ifdef CONFIG_IA64
1037 	{
1038 		.procname	= "unaligned-dump-stack",
1039 		.data		= &unaligned_dump_stack,
1040 		.maxlen		= sizeof (int),
1041 		.mode		= 0644,
1042 		.proc_handler	= proc_dointvec,
1043 	},
1044 #endif
1045 #ifdef CONFIG_DETECT_HUNG_TASK
1046 	{
1047 		.procname	= "hung_task_panic",
1048 		.data		= &sysctl_hung_task_panic,
1049 		.maxlen		= sizeof(int),
1050 		.mode		= 0644,
1051 		.proc_handler	= proc_dointvec_minmax,
1052 		.extra1		= &zero,
1053 		.extra2		= &one,
1054 	},
1055 	{
1056 		.procname	= "hung_task_check_count",
1057 		.data		= &sysctl_hung_task_check_count,
1058 		.maxlen		= sizeof(int),
1059 		.mode		= 0644,
1060 		.proc_handler	= proc_dointvec_minmax,
1061 		.extra1		= &zero,
1062 	},
1063 	{
1064 		.procname	= "hung_task_timeout_secs",
1065 		.data		= &sysctl_hung_task_timeout_secs,
1066 		.maxlen		= sizeof(unsigned long),
1067 		.mode		= 0644,
1068 		.proc_handler	= proc_dohung_task_timeout_secs,
1069 		.extra2		= &hung_task_timeout_max,
1070 	},
1071 	{
1072 		.procname	= "hung_task_warnings",
1073 		.data		= &sysctl_hung_task_warnings,
1074 		.maxlen		= sizeof(int),
1075 		.mode		= 0644,
1076 		.proc_handler	= proc_dointvec_minmax,
1077 		.extra1		= &neg_one,
1078 	},
1079 #endif
1080 #ifdef CONFIG_COMPAT
1081 	{
1082 		.procname	= "compat-log",
1083 		.data		= &compat_log,
1084 		.maxlen		= sizeof (int),
1085 	 	.mode		= 0644,
1086 		.proc_handler	= proc_dointvec,
1087 	},
1088 #endif
1089 #ifdef CONFIG_RT_MUTEXES
1090 	{
1091 		.procname	= "max_lock_depth",
1092 		.data		= &max_lock_depth,
1093 		.maxlen		= sizeof(int),
1094 		.mode		= 0644,
1095 		.proc_handler	= proc_dointvec,
1096 	},
1097 #endif
1098 	{
1099 		.procname	= "poweroff_cmd",
1100 		.data		= &poweroff_cmd,
1101 		.maxlen		= POWEROFF_CMD_PATH_LEN,
1102 		.mode		= 0644,
1103 		.proc_handler	= proc_dostring,
1104 	},
1105 #ifdef CONFIG_KEYS
1106 	{
1107 		.procname	= "keys",
1108 		.mode		= 0555,
1109 		.child		= key_sysctls,
1110 	},
1111 #endif
1112 #ifdef CONFIG_PERF_EVENTS
1113 	/*
1114 	 * User-space scripts rely on the existence of this file
1115 	 * as a feature check for perf_events being enabled.
1116 	 *
1117 	 * So it's an ABI, do not remove!
1118 	 */
1119 	{
1120 		.procname	= "perf_event_paranoid",
1121 		.data		= &sysctl_perf_event_paranoid,
1122 		.maxlen		= sizeof(sysctl_perf_event_paranoid),
1123 		.mode		= 0644,
1124 		.proc_handler	= proc_dointvec,
1125 	},
1126 	{
1127 		.procname	= "perf_event_mlock_kb",
1128 		.data		= &sysctl_perf_event_mlock,
1129 		.maxlen		= sizeof(sysctl_perf_event_mlock),
1130 		.mode		= 0644,
1131 		.proc_handler	= proc_dointvec,
1132 	},
1133 	{
1134 		.procname	= "perf_event_max_sample_rate",
1135 		.data		= &sysctl_perf_event_sample_rate,
1136 		.maxlen		= sizeof(sysctl_perf_event_sample_rate),
1137 		.mode		= 0644,
1138 		.proc_handler	= perf_proc_update_handler,
1139 		.extra1		= &one,
1140 	},
1141 	{
1142 		.procname	= "perf_cpu_time_max_percent",
1143 		.data		= &sysctl_perf_cpu_time_max_percent,
1144 		.maxlen		= sizeof(sysctl_perf_cpu_time_max_percent),
1145 		.mode		= 0644,
1146 		.proc_handler	= perf_cpu_time_max_percent_handler,
1147 		.extra1		= &zero,
1148 		.extra2		= &one_hundred,
1149 	},
1150 	{
1151 		.procname	= "perf_event_max_stack",
1152 		.data		= NULL, /* filled in by handler */
1153 		.maxlen		= sizeof(sysctl_perf_event_max_stack),
1154 		.mode		= 0644,
1155 		.proc_handler	= perf_event_max_stack_handler,
1156 		.extra1		= &zero,
1157 		.extra2		= &six_hundred_forty_kb,
1158 	},
1159 #endif
1160 #ifdef CONFIG_KMEMCHECK
1161 	{
1162 		.procname	= "kmemcheck",
1163 		.data		= &kmemcheck_enabled,
1164 		.maxlen		= sizeof(int),
1165 		.mode		= 0644,
1166 		.proc_handler	= proc_dointvec,
1167 	},
1168 #endif
1169 	{
1170 		.procname	= "panic_on_warn",
1171 		.data		= &panic_on_warn,
1172 		.maxlen		= sizeof(int),
1173 		.mode		= 0644,
1174 		.proc_handler	= proc_dointvec_minmax,
1175 		.extra1		= &zero,
1176 		.extra2		= &one,
1177 	},
1178 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1179 	{
1180 		.procname	= "timer_migration",
1181 		.data		= &sysctl_timer_migration,
1182 		.maxlen		= sizeof(unsigned int),
1183 		.mode		= 0644,
1184 		.proc_handler	= timer_migration_handler,
1185 	},
1186 #endif
1187 #ifdef CONFIG_BPF_SYSCALL
1188 	{
1189 		.procname	= "unprivileged_bpf_disabled",
1190 		.data		= &sysctl_unprivileged_bpf_disabled,
1191 		.maxlen		= sizeof(sysctl_unprivileged_bpf_disabled),
1192 		.mode		= 0644,
1193 		/* only handle a transition from default "0" to "1" */
1194 		.proc_handler	= proc_dointvec_minmax,
1195 		.extra1		= &one,
1196 		.extra2		= &one,
1197 	},
1198 #endif
1199 	{ }
1200 };
1201 
1202 static struct ctl_table vm_table[] = {
1203 	{
1204 		.procname	= "overcommit_memory",
1205 		.data		= &sysctl_overcommit_memory,
1206 		.maxlen		= sizeof(sysctl_overcommit_memory),
1207 		.mode		= 0644,
1208 		.proc_handler	= proc_dointvec_minmax,
1209 		.extra1		= &zero,
1210 		.extra2		= &two,
1211 	},
1212 	{
1213 		.procname	= "panic_on_oom",
1214 		.data		= &sysctl_panic_on_oom,
1215 		.maxlen		= sizeof(sysctl_panic_on_oom),
1216 		.mode		= 0644,
1217 		.proc_handler	= proc_dointvec_minmax,
1218 		.extra1		= &zero,
1219 		.extra2		= &two,
1220 	},
1221 	{
1222 		.procname	= "oom_kill_allocating_task",
1223 		.data		= &sysctl_oom_kill_allocating_task,
1224 		.maxlen		= sizeof(sysctl_oom_kill_allocating_task),
1225 		.mode		= 0644,
1226 		.proc_handler	= proc_dointvec,
1227 	},
1228 	{
1229 		.procname	= "oom_dump_tasks",
1230 		.data		= &sysctl_oom_dump_tasks,
1231 		.maxlen		= sizeof(sysctl_oom_dump_tasks),
1232 		.mode		= 0644,
1233 		.proc_handler	= proc_dointvec,
1234 	},
1235 	{
1236 		.procname	= "overcommit_ratio",
1237 		.data		= &sysctl_overcommit_ratio,
1238 		.maxlen		= sizeof(sysctl_overcommit_ratio),
1239 		.mode		= 0644,
1240 		.proc_handler	= overcommit_ratio_handler,
1241 	},
1242 	{
1243 		.procname	= "overcommit_kbytes",
1244 		.data		= &sysctl_overcommit_kbytes,
1245 		.maxlen		= sizeof(sysctl_overcommit_kbytes),
1246 		.mode		= 0644,
1247 		.proc_handler	= overcommit_kbytes_handler,
1248 	},
1249 	{
1250 		.procname	= "page-cluster",
1251 		.data		= &page_cluster,
1252 		.maxlen		= sizeof(int),
1253 		.mode		= 0644,
1254 		.proc_handler	= proc_dointvec_minmax,
1255 		.extra1		= &zero,
1256 	},
1257 	{
1258 		.procname	= "dirty_background_ratio",
1259 		.data		= &dirty_background_ratio,
1260 		.maxlen		= sizeof(dirty_background_ratio),
1261 		.mode		= 0644,
1262 		.proc_handler	= dirty_background_ratio_handler,
1263 		.extra1		= &zero,
1264 		.extra2		= &one_hundred,
1265 	},
1266 	{
1267 		.procname	= "dirty_background_bytes",
1268 		.data		= &dirty_background_bytes,
1269 		.maxlen		= sizeof(dirty_background_bytes),
1270 		.mode		= 0644,
1271 		.proc_handler	= dirty_background_bytes_handler,
1272 		.extra1		= &one_ul,
1273 	},
1274 	{
1275 		.procname	= "dirty_ratio",
1276 		.data		= &vm_dirty_ratio,
1277 		.maxlen		= sizeof(vm_dirty_ratio),
1278 		.mode		= 0644,
1279 		.proc_handler	= dirty_ratio_handler,
1280 		.extra1		= &zero,
1281 		.extra2		= &one_hundred,
1282 	},
1283 	{
1284 		.procname	= "dirty_bytes",
1285 		.data		= &vm_dirty_bytes,
1286 		.maxlen		= sizeof(vm_dirty_bytes),
1287 		.mode		= 0644,
1288 		.proc_handler	= dirty_bytes_handler,
1289 		.extra1		= &dirty_bytes_min,
1290 	},
1291 	{
1292 		.procname	= "dirty_writeback_centisecs",
1293 		.data		= &dirty_writeback_interval,
1294 		.maxlen		= sizeof(dirty_writeback_interval),
1295 		.mode		= 0644,
1296 		.proc_handler	= dirty_writeback_centisecs_handler,
1297 	},
1298 	{
1299 		.procname	= "dirty_expire_centisecs",
1300 		.data		= &dirty_expire_interval,
1301 		.maxlen		= sizeof(dirty_expire_interval),
1302 		.mode		= 0644,
1303 		.proc_handler	= proc_dointvec_minmax,
1304 		.extra1		= &zero,
1305 	},
1306 	{
1307 		.procname	= "dirtytime_expire_seconds",
1308 		.data		= &dirtytime_expire_interval,
1309 		.maxlen		= sizeof(dirty_expire_interval),
1310 		.mode		= 0644,
1311 		.proc_handler	= dirtytime_interval_handler,
1312 		.extra1		= &zero,
1313 	},
1314 	{
1315 		.procname       = "nr_pdflush_threads",
1316 		.mode           = 0444 /* read-only */,
1317 		.proc_handler   = pdflush_proc_obsolete,
1318 	},
1319 	{
1320 		.procname	= "swappiness",
1321 		.data		= &vm_swappiness,
1322 		.maxlen		= sizeof(vm_swappiness),
1323 		.mode		= 0644,
1324 		.proc_handler	= proc_dointvec_minmax,
1325 		.extra1		= &zero,
1326 		.extra2		= &one_hundred,
1327 	},
1328 #ifdef CONFIG_HUGETLB_PAGE
1329 	{
1330 		.procname	= "nr_hugepages",
1331 		.data		= NULL,
1332 		.maxlen		= sizeof(unsigned long),
1333 		.mode		= 0644,
1334 		.proc_handler	= hugetlb_sysctl_handler,
1335 	},
1336 #ifdef CONFIG_NUMA
1337 	{
1338 		.procname       = "nr_hugepages_mempolicy",
1339 		.data           = NULL,
1340 		.maxlen         = sizeof(unsigned long),
1341 		.mode           = 0644,
1342 		.proc_handler   = &hugetlb_mempolicy_sysctl_handler,
1343 	},
1344 #endif
1345 	 {
1346 		.procname	= "hugetlb_shm_group",
1347 		.data		= &sysctl_hugetlb_shm_group,
1348 		.maxlen		= sizeof(gid_t),
1349 		.mode		= 0644,
1350 		.proc_handler	= proc_dointvec,
1351 	 },
1352 	 {
1353 		.procname	= "hugepages_treat_as_movable",
1354 		.data		= &hugepages_treat_as_movable,
1355 		.maxlen		= sizeof(int),
1356 		.mode		= 0644,
1357 		.proc_handler	= proc_dointvec,
1358 	},
1359 	{
1360 		.procname	= "nr_overcommit_hugepages",
1361 		.data		= NULL,
1362 		.maxlen		= sizeof(unsigned long),
1363 		.mode		= 0644,
1364 		.proc_handler	= hugetlb_overcommit_handler,
1365 	},
1366 #endif
1367 	{
1368 		.procname	= "lowmem_reserve_ratio",
1369 		.data		= &sysctl_lowmem_reserve_ratio,
1370 		.maxlen		= sizeof(sysctl_lowmem_reserve_ratio),
1371 		.mode		= 0644,
1372 		.proc_handler	= lowmem_reserve_ratio_sysctl_handler,
1373 	},
1374 	{
1375 		.procname	= "drop_caches",
1376 		.data		= &sysctl_drop_caches,
1377 		.maxlen		= sizeof(int),
1378 		.mode		= 0644,
1379 		.proc_handler	= drop_caches_sysctl_handler,
1380 		.extra1		= &one,
1381 		.extra2		= &four,
1382 	},
1383 #ifdef CONFIG_COMPACTION
1384 	{
1385 		.procname	= "compact_memory",
1386 		.data		= &sysctl_compact_memory,
1387 		.maxlen		= sizeof(int),
1388 		.mode		= 0200,
1389 		.proc_handler	= sysctl_compaction_handler,
1390 	},
1391 	{
1392 		.procname	= "extfrag_threshold",
1393 		.data		= &sysctl_extfrag_threshold,
1394 		.maxlen		= sizeof(int),
1395 		.mode		= 0644,
1396 		.proc_handler	= sysctl_extfrag_handler,
1397 		.extra1		= &min_extfrag_threshold,
1398 		.extra2		= &max_extfrag_threshold,
1399 	},
1400 	{
1401 		.procname	= "compact_unevictable_allowed",
1402 		.data		= &sysctl_compact_unevictable_allowed,
1403 		.maxlen		= sizeof(int),
1404 		.mode		= 0644,
1405 		.proc_handler	= proc_dointvec,
1406 		.extra1		= &zero,
1407 		.extra2		= &one,
1408 	},
1409 
1410 #endif /* CONFIG_COMPACTION */
1411 	{
1412 		.procname	= "min_free_kbytes",
1413 		.data		= &min_free_kbytes,
1414 		.maxlen		= sizeof(min_free_kbytes),
1415 		.mode		= 0644,
1416 		.proc_handler	= min_free_kbytes_sysctl_handler,
1417 		.extra1		= &zero,
1418 	},
1419 	{
1420 		.procname	= "watermark_scale_factor",
1421 		.data		= &watermark_scale_factor,
1422 		.maxlen		= sizeof(watermark_scale_factor),
1423 		.mode		= 0644,
1424 		.proc_handler	= watermark_scale_factor_sysctl_handler,
1425 		.extra1		= &one,
1426 		.extra2		= &one_thousand,
1427 	},
1428 	{
1429 		.procname	= "percpu_pagelist_fraction",
1430 		.data		= &percpu_pagelist_fraction,
1431 		.maxlen		= sizeof(percpu_pagelist_fraction),
1432 		.mode		= 0644,
1433 		.proc_handler	= percpu_pagelist_fraction_sysctl_handler,
1434 		.extra1		= &zero,
1435 	},
1436 #ifdef CONFIG_MMU
1437 	{
1438 		.procname	= "max_map_count",
1439 		.data		= &sysctl_max_map_count,
1440 		.maxlen		= sizeof(sysctl_max_map_count),
1441 		.mode		= 0644,
1442 		.proc_handler	= proc_dointvec_minmax,
1443 		.extra1		= &zero,
1444 	},
1445 #else
1446 	{
1447 		.procname	= "nr_trim_pages",
1448 		.data		= &sysctl_nr_trim_pages,
1449 		.maxlen		= sizeof(sysctl_nr_trim_pages),
1450 		.mode		= 0644,
1451 		.proc_handler	= proc_dointvec_minmax,
1452 		.extra1		= &zero,
1453 	},
1454 #endif
1455 	{
1456 		.procname	= "laptop_mode",
1457 		.data		= &laptop_mode,
1458 		.maxlen		= sizeof(laptop_mode),
1459 		.mode		= 0644,
1460 		.proc_handler	= proc_dointvec_jiffies,
1461 	},
1462 	{
1463 		.procname	= "block_dump",
1464 		.data		= &block_dump,
1465 		.maxlen		= sizeof(block_dump),
1466 		.mode		= 0644,
1467 		.proc_handler	= proc_dointvec,
1468 		.extra1		= &zero,
1469 	},
1470 	{
1471 		.procname	= "vfs_cache_pressure",
1472 		.data		= &sysctl_vfs_cache_pressure,
1473 		.maxlen		= sizeof(sysctl_vfs_cache_pressure),
1474 		.mode		= 0644,
1475 		.proc_handler	= proc_dointvec,
1476 		.extra1		= &zero,
1477 	},
1478 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1479 	{
1480 		.procname	= "legacy_va_layout",
1481 		.data		= &sysctl_legacy_va_layout,
1482 		.maxlen		= sizeof(sysctl_legacy_va_layout),
1483 		.mode		= 0644,
1484 		.proc_handler	= proc_dointvec,
1485 		.extra1		= &zero,
1486 	},
1487 #endif
1488 #ifdef CONFIG_NUMA
1489 	{
1490 		.procname	= "zone_reclaim_mode",
1491 		.data		= &zone_reclaim_mode,
1492 		.maxlen		= sizeof(zone_reclaim_mode),
1493 		.mode		= 0644,
1494 		.proc_handler	= proc_dointvec,
1495 		.extra1		= &zero,
1496 	},
1497 	{
1498 		.procname	= "min_unmapped_ratio",
1499 		.data		= &sysctl_min_unmapped_ratio,
1500 		.maxlen		= sizeof(sysctl_min_unmapped_ratio),
1501 		.mode		= 0644,
1502 		.proc_handler	= sysctl_min_unmapped_ratio_sysctl_handler,
1503 		.extra1		= &zero,
1504 		.extra2		= &one_hundred,
1505 	},
1506 	{
1507 		.procname	= "min_slab_ratio",
1508 		.data		= &sysctl_min_slab_ratio,
1509 		.maxlen		= sizeof(sysctl_min_slab_ratio),
1510 		.mode		= 0644,
1511 		.proc_handler	= sysctl_min_slab_ratio_sysctl_handler,
1512 		.extra1		= &zero,
1513 		.extra2		= &one_hundred,
1514 	},
1515 #endif
1516 #ifdef CONFIG_SMP
1517 	{
1518 		.procname	= "stat_interval",
1519 		.data		= &sysctl_stat_interval,
1520 		.maxlen		= sizeof(sysctl_stat_interval),
1521 		.mode		= 0644,
1522 		.proc_handler	= proc_dointvec_jiffies,
1523 	},
1524 	{
1525 		.procname	= "stat_refresh",
1526 		.data		= NULL,
1527 		.maxlen		= 0,
1528 		.mode		= 0600,
1529 		.proc_handler	= vmstat_refresh,
1530 	},
1531 #endif
1532 #ifdef CONFIG_MMU
1533 	{
1534 		.procname	= "mmap_min_addr",
1535 		.data		= &dac_mmap_min_addr,
1536 		.maxlen		= sizeof(unsigned long),
1537 		.mode		= 0644,
1538 		.proc_handler	= mmap_min_addr_handler,
1539 	},
1540 #endif
1541 #ifdef CONFIG_NUMA
1542 	{
1543 		.procname	= "numa_zonelist_order",
1544 		.data		= &numa_zonelist_order,
1545 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1546 		.mode		= 0644,
1547 		.proc_handler	= numa_zonelist_order_handler,
1548 	},
1549 #endif
1550 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1551    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1552 	{
1553 		.procname	= "vdso_enabled",
1554 #ifdef CONFIG_X86_32
1555 		.data		= &vdso32_enabled,
1556 		.maxlen		= sizeof(vdso32_enabled),
1557 #else
1558 		.data		= &vdso_enabled,
1559 		.maxlen		= sizeof(vdso_enabled),
1560 #endif
1561 		.mode		= 0644,
1562 		.proc_handler	= proc_dointvec,
1563 		.extra1		= &zero,
1564 	},
1565 #endif
1566 #ifdef CONFIG_HIGHMEM
1567 	{
1568 		.procname	= "highmem_is_dirtyable",
1569 		.data		= &vm_highmem_is_dirtyable,
1570 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1571 		.mode		= 0644,
1572 		.proc_handler	= proc_dointvec_minmax,
1573 		.extra1		= &zero,
1574 		.extra2		= &one,
1575 	},
1576 #endif
1577 #ifdef CONFIG_MEMORY_FAILURE
1578 	{
1579 		.procname	= "memory_failure_early_kill",
1580 		.data		= &sysctl_memory_failure_early_kill,
1581 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1582 		.mode		= 0644,
1583 		.proc_handler	= proc_dointvec_minmax,
1584 		.extra1		= &zero,
1585 		.extra2		= &one,
1586 	},
1587 	{
1588 		.procname	= "memory_failure_recovery",
1589 		.data		= &sysctl_memory_failure_recovery,
1590 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1591 		.mode		= 0644,
1592 		.proc_handler	= proc_dointvec_minmax,
1593 		.extra1		= &zero,
1594 		.extra2		= &one,
1595 	},
1596 #endif
1597 	{
1598 		.procname	= "user_reserve_kbytes",
1599 		.data		= &sysctl_user_reserve_kbytes,
1600 		.maxlen		= sizeof(sysctl_user_reserve_kbytes),
1601 		.mode		= 0644,
1602 		.proc_handler	= proc_doulongvec_minmax,
1603 	},
1604 	{
1605 		.procname	= "admin_reserve_kbytes",
1606 		.data		= &sysctl_admin_reserve_kbytes,
1607 		.maxlen		= sizeof(sysctl_admin_reserve_kbytes),
1608 		.mode		= 0644,
1609 		.proc_handler	= proc_doulongvec_minmax,
1610 	},
1611 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1612 	{
1613 		.procname	= "mmap_rnd_bits",
1614 		.data		= &mmap_rnd_bits,
1615 		.maxlen		= sizeof(mmap_rnd_bits),
1616 		.mode		= 0600,
1617 		.proc_handler	= proc_dointvec_minmax,
1618 		.extra1		= (void *)&mmap_rnd_bits_min,
1619 		.extra2		= (void *)&mmap_rnd_bits_max,
1620 	},
1621 #endif
1622 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1623 	{
1624 		.procname	= "mmap_rnd_compat_bits",
1625 		.data		= &mmap_rnd_compat_bits,
1626 		.maxlen		= sizeof(mmap_rnd_compat_bits),
1627 		.mode		= 0600,
1628 		.proc_handler	= proc_dointvec_minmax,
1629 		.extra1		= (void *)&mmap_rnd_compat_bits_min,
1630 		.extra2		= (void *)&mmap_rnd_compat_bits_max,
1631 	},
1632 #endif
1633 	{ }
1634 };
1635 
1636 static struct ctl_table fs_table[] = {
1637 	{
1638 		.procname	= "inode-nr",
1639 		.data		= &inodes_stat,
1640 		.maxlen		= 2*sizeof(long),
1641 		.mode		= 0444,
1642 		.proc_handler	= proc_nr_inodes,
1643 	},
1644 	{
1645 		.procname	= "inode-state",
1646 		.data		= &inodes_stat,
1647 		.maxlen		= 7*sizeof(long),
1648 		.mode		= 0444,
1649 		.proc_handler	= proc_nr_inodes,
1650 	},
1651 	{
1652 		.procname	= "file-nr",
1653 		.data		= &files_stat,
1654 		.maxlen		= sizeof(files_stat),
1655 		.mode		= 0444,
1656 		.proc_handler	= proc_nr_files,
1657 	},
1658 	{
1659 		.procname	= "file-max",
1660 		.data		= &files_stat.max_files,
1661 		.maxlen		= sizeof(files_stat.max_files),
1662 		.mode		= 0644,
1663 		.proc_handler	= proc_doulongvec_minmax,
1664 	},
1665 	{
1666 		.procname	= "nr_open",
1667 		.data		= &sysctl_nr_open,
1668 		.maxlen		= sizeof(int),
1669 		.mode		= 0644,
1670 		.proc_handler	= proc_dointvec_minmax,
1671 		.extra1		= &sysctl_nr_open_min,
1672 		.extra2		= &sysctl_nr_open_max,
1673 	},
1674 	{
1675 		.procname	= "dentry-state",
1676 		.data		= &dentry_stat,
1677 		.maxlen		= 6*sizeof(long),
1678 		.mode		= 0444,
1679 		.proc_handler	= proc_nr_dentry,
1680 	},
1681 	{
1682 		.procname	= "overflowuid",
1683 		.data		= &fs_overflowuid,
1684 		.maxlen		= sizeof(int),
1685 		.mode		= 0644,
1686 		.proc_handler	= proc_dointvec_minmax,
1687 		.extra1		= &minolduid,
1688 		.extra2		= &maxolduid,
1689 	},
1690 	{
1691 		.procname	= "overflowgid",
1692 		.data		= &fs_overflowgid,
1693 		.maxlen		= sizeof(int),
1694 		.mode		= 0644,
1695 		.proc_handler	= proc_dointvec_minmax,
1696 		.extra1		= &minolduid,
1697 		.extra2		= &maxolduid,
1698 	},
1699 #ifdef CONFIG_FILE_LOCKING
1700 	{
1701 		.procname	= "leases-enable",
1702 		.data		= &leases_enable,
1703 		.maxlen		= sizeof(int),
1704 		.mode		= 0644,
1705 		.proc_handler	= proc_dointvec,
1706 	},
1707 #endif
1708 #ifdef CONFIG_DNOTIFY
1709 	{
1710 		.procname	= "dir-notify-enable",
1711 		.data		= &dir_notify_enable,
1712 		.maxlen		= sizeof(int),
1713 		.mode		= 0644,
1714 		.proc_handler	= proc_dointvec,
1715 	},
1716 #endif
1717 #ifdef CONFIG_MMU
1718 #ifdef CONFIG_FILE_LOCKING
1719 	{
1720 		.procname	= "lease-break-time",
1721 		.data		= &lease_break_time,
1722 		.maxlen		= sizeof(int),
1723 		.mode		= 0644,
1724 		.proc_handler	= proc_dointvec,
1725 	},
1726 #endif
1727 #ifdef CONFIG_AIO
1728 	{
1729 		.procname	= "aio-nr",
1730 		.data		= &aio_nr,
1731 		.maxlen		= sizeof(aio_nr),
1732 		.mode		= 0444,
1733 		.proc_handler	= proc_doulongvec_minmax,
1734 	},
1735 	{
1736 		.procname	= "aio-max-nr",
1737 		.data		= &aio_max_nr,
1738 		.maxlen		= sizeof(aio_max_nr),
1739 		.mode		= 0644,
1740 		.proc_handler	= proc_doulongvec_minmax,
1741 	},
1742 #endif /* CONFIG_AIO */
1743 #ifdef CONFIG_INOTIFY_USER
1744 	{
1745 		.procname	= "inotify",
1746 		.mode		= 0555,
1747 		.child		= inotify_table,
1748 	},
1749 #endif
1750 #ifdef CONFIG_EPOLL
1751 	{
1752 		.procname	= "epoll",
1753 		.mode		= 0555,
1754 		.child		= epoll_table,
1755 	},
1756 #endif
1757 #endif
1758 	{
1759 		.procname	= "protected_symlinks",
1760 		.data		= &sysctl_protected_symlinks,
1761 		.maxlen		= sizeof(int),
1762 		.mode		= 0600,
1763 		.proc_handler	= proc_dointvec_minmax,
1764 		.extra1		= &zero,
1765 		.extra2		= &one,
1766 	},
1767 	{
1768 		.procname	= "protected_hardlinks",
1769 		.data		= &sysctl_protected_hardlinks,
1770 		.maxlen		= sizeof(int),
1771 		.mode		= 0600,
1772 		.proc_handler	= proc_dointvec_minmax,
1773 		.extra1		= &zero,
1774 		.extra2		= &one,
1775 	},
1776 	{
1777 		.procname	= "suid_dumpable",
1778 		.data		= &suid_dumpable,
1779 		.maxlen		= sizeof(int),
1780 		.mode		= 0644,
1781 		.proc_handler	= proc_dointvec_minmax_coredump,
1782 		.extra1		= &zero,
1783 		.extra2		= &two,
1784 	},
1785 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1786 	{
1787 		.procname	= "binfmt_misc",
1788 		.mode		= 0555,
1789 		.child		= sysctl_mount_point,
1790 	},
1791 #endif
1792 	{
1793 		.procname	= "pipe-max-size",
1794 		.data		= &pipe_max_size,
1795 		.maxlen		= sizeof(int),
1796 		.mode		= 0644,
1797 		.proc_handler	= &pipe_proc_fn,
1798 		.extra1		= &pipe_min_size,
1799 	},
1800 	{
1801 		.procname	= "pipe-user-pages-hard",
1802 		.data		= &pipe_user_pages_hard,
1803 		.maxlen		= sizeof(pipe_user_pages_hard),
1804 		.mode		= 0644,
1805 		.proc_handler	= proc_doulongvec_minmax,
1806 	},
1807 	{
1808 		.procname	= "pipe-user-pages-soft",
1809 		.data		= &pipe_user_pages_soft,
1810 		.maxlen		= sizeof(pipe_user_pages_soft),
1811 		.mode		= 0644,
1812 		.proc_handler	= proc_doulongvec_minmax,
1813 	},
1814 	{ }
1815 };
1816 
1817 static struct ctl_table debug_table[] = {
1818 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1819 	{
1820 		.procname	= "exception-trace",
1821 		.data		= &show_unhandled_signals,
1822 		.maxlen		= sizeof(int),
1823 		.mode		= 0644,
1824 		.proc_handler	= proc_dointvec
1825 	},
1826 #endif
1827 #if defined(CONFIG_OPTPROBES)
1828 	{
1829 		.procname	= "kprobes-optimization",
1830 		.data		= &sysctl_kprobes_optimization,
1831 		.maxlen		= sizeof(int),
1832 		.mode		= 0644,
1833 		.proc_handler	= proc_kprobes_optimization_handler,
1834 		.extra1		= &zero,
1835 		.extra2		= &one,
1836 	},
1837 #endif
1838 	{ }
1839 };
1840 
1841 static struct ctl_table dev_table[] = {
1842 	{ }
1843 };
1844 
1845 int __init sysctl_init(void)
1846 {
1847 	struct ctl_table_header *hdr;
1848 
1849 	hdr = register_sysctl_table(sysctl_base_table);
1850 	kmemleak_not_leak(hdr);
1851 	return 0;
1852 }
1853 
1854 #endif /* CONFIG_SYSCTL */
1855 
1856 /*
1857  * /proc/sys support
1858  */
1859 
1860 #ifdef CONFIG_PROC_SYSCTL
1861 
1862 static int _proc_do_string(char *data, int maxlen, int write,
1863 			   char __user *buffer,
1864 			   size_t *lenp, loff_t *ppos)
1865 {
1866 	size_t len;
1867 	char __user *p;
1868 	char c;
1869 
1870 	if (!data || !maxlen || !*lenp) {
1871 		*lenp = 0;
1872 		return 0;
1873 	}
1874 
1875 	if (write) {
1876 		if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1877 			/* Only continue writes not past the end of buffer. */
1878 			len = strlen(data);
1879 			if (len > maxlen - 1)
1880 				len = maxlen - 1;
1881 
1882 			if (*ppos > len)
1883 				return 0;
1884 			len = *ppos;
1885 		} else {
1886 			/* Start writing from beginning of buffer. */
1887 			len = 0;
1888 		}
1889 
1890 		*ppos += *lenp;
1891 		p = buffer;
1892 		while ((p - buffer) < *lenp && len < maxlen - 1) {
1893 			if (get_user(c, p++))
1894 				return -EFAULT;
1895 			if (c == 0 || c == '\n')
1896 				break;
1897 			data[len++] = c;
1898 		}
1899 		data[len] = 0;
1900 	} else {
1901 		len = strlen(data);
1902 		if (len > maxlen)
1903 			len = maxlen;
1904 
1905 		if (*ppos > len) {
1906 			*lenp = 0;
1907 			return 0;
1908 		}
1909 
1910 		data += *ppos;
1911 		len  -= *ppos;
1912 
1913 		if (len > *lenp)
1914 			len = *lenp;
1915 		if (len)
1916 			if (copy_to_user(buffer, data, len))
1917 				return -EFAULT;
1918 		if (len < *lenp) {
1919 			if (put_user('\n', buffer + len))
1920 				return -EFAULT;
1921 			len++;
1922 		}
1923 		*lenp = len;
1924 		*ppos += len;
1925 	}
1926 	return 0;
1927 }
1928 
1929 static void warn_sysctl_write(struct ctl_table *table)
1930 {
1931 	pr_warn_once("%s wrote to %s when file position was not 0!\n"
1932 		"This will not be supported in the future. To silence this\n"
1933 		"warning, set kernel.sysctl_writes_strict = -1\n",
1934 		current->comm, table->procname);
1935 }
1936 
1937 /**
1938  * proc_dostring - read a string sysctl
1939  * @table: the sysctl table
1940  * @write: %TRUE if this is a write to the sysctl file
1941  * @buffer: the user buffer
1942  * @lenp: the size of the user buffer
1943  * @ppos: file position
1944  *
1945  * Reads/writes a string from/to the user buffer. If the kernel
1946  * buffer provided is not large enough to hold the string, the
1947  * string is truncated. The copied string is %NULL-terminated.
1948  * If the string is being read by the user process, it is copied
1949  * and a newline '\n' is added. It is truncated if the buffer is
1950  * not large enough.
1951  *
1952  * Returns 0 on success.
1953  */
1954 int proc_dostring(struct ctl_table *table, int write,
1955 		  void __user *buffer, size_t *lenp, loff_t *ppos)
1956 {
1957 	if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1958 		warn_sysctl_write(table);
1959 
1960 	return _proc_do_string((char *)(table->data), table->maxlen, write,
1961 			       (char __user *)buffer, lenp, ppos);
1962 }
1963 
1964 static size_t proc_skip_spaces(char **buf)
1965 {
1966 	size_t ret;
1967 	char *tmp = skip_spaces(*buf);
1968 	ret = tmp - *buf;
1969 	*buf = tmp;
1970 	return ret;
1971 }
1972 
1973 static void proc_skip_char(char **buf, size_t *size, const char v)
1974 {
1975 	while (*size) {
1976 		if (**buf != v)
1977 			break;
1978 		(*size)--;
1979 		(*buf)++;
1980 	}
1981 }
1982 
1983 #define TMPBUFLEN 22
1984 /**
1985  * proc_get_long - reads an ASCII formatted integer from a user buffer
1986  *
1987  * @buf: a kernel buffer
1988  * @size: size of the kernel buffer
1989  * @val: this is where the number will be stored
1990  * @neg: set to %TRUE if number is negative
1991  * @perm_tr: a vector which contains the allowed trailers
1992  * @perm_tr_len: size of the perm_tr vector
1993  * @tr: pointer to store the trailer character
1994  *
1995  * In case of success %0 is returned and @buf and @size are updated with
1996  * the amount of bytes read. If @tr is non-NULL and a trailing
1997  * character exists (size is non-zero after returning from this
1998  * function), @tr is updated with the trailing character.
1999  */
2000 static int proc_get_long(char **buf, size_t *size,
2001 			  unsigned long *val, bool *neg,
2002 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
2003 {
2004 	int len;
2005 	char *p, tmp[TMPBUFLEN];
2006 
2007 	if (!*size)
2008 		return -EINVAL;
2009 
2010 	len = *size;
2011 	if (len > TMPBUFLEN - 1)
2012 		len = TMPBUFLEN - 1;
2013 
2014 	memcpy(tmp, *buf, len);
2015 
2016 	tmp[len] = 0;
2017 	p = tmp;
2018 	if (*p == '-' && *size > 1) {
2019 		*neg = true;
2020 		p++;
2021 	} else
2022 		*neg = false;
2023 	if (!isdigit(*p))
2024 		return -EINVAL;
2025 
2026 	*val = simple_strtoul(p, &p, 0);
2027 
2028 	len = p - tmp;
2029 
2030 	/* We don't know if the next char is whitespace thus we may accept
2031 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2032 	 * (e.g. 123...1). So lets not allow such large numbers. */
2033 	if (len == TMPBUFLEN - 1)
2034 		return -EINVAL;
2035 
2036 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2037 		return -EINVAL;
2038 
2039 	if (tr && (len < *size))
2040 		*tr = *p;
2041 
2042 	*buf += len;
2043 	*size -= len;
2044 
2045 	return 0;
2046 }
2047 
2048 /**
2049  * proc_put_long - converts an integer to a decimal ASCII formatted string
2050  *
2051  * @buf: the user buffer
2052  * @size: the size of the user buffer
2053  * @val: the integer to be converted
2054  * @neg: sign of the number, %TRUE for negative
2055  *
2056  * In case of success %0 is returned and @buf and @size are updated with
2057  * the amount of bytes written.
2058  */
2059 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2060 			  bool neg)
2061 {
2062 	int len;
2063 	char tmp[TMPBUFLEN], *p = tmp;
2064 
2065 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2066 	len = strlen(tmp);
2067 	if (len > *size)
2068 		len = *size;
2069 	if (copy_to_user(*buf, tmp, len))
2070 		return -EFAULT;
2071 	*size -= len;
2072 	*buf += len;
2073 	return 0;
2074 }
2075 #undef TMPBUFLEN
2076 
2077 static int proc_put_char(void __user **buf, size_t *size, char c)
2078 {
2079 	if (*size) {
2080 		char __user **buffer = (char __user **)buf;
2081 		if (put_user(c, *buffer))
2082 			return -EFAULT;
2083 		(*size)--, (*buffer)++;
2084 		*buf = *buffer;
2085 	}
2086 	return 0;
2087 }
2088 
2089 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2090 				 int *valp,
2091 				 int write, void *data)
2092 {
2093 	if (write) {
2094 		if (*negp) {
2095 			if (*lvalp > (unsigned long) INT_MAX + 1)
2096 				return -EINVAL;
2097 			*valp = -*lvalp;
2098 		} else {
2099 			if (*lvalp > (unsigned long) INT_MAX)
2100 				return -EINVAL;
2101 			*valp = *lvalp;
2102 		}
2103 	} else {
2104 		int val = *valp;
2105 		if (val < 0) {
2106 			*negp = true;
2107 			*lvalp = -(unsigned long)val;
2108 		} else {
2109 			*negp = false;
2110 			*lvalp = (unsigned long)val;
2111 		}
2112 	}
2113 	return 0;
2114 }
2115 
2116 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2117 
2118 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2119 		  int write, void __user *buffer,
2120 		  size_t *lenp, loff_t *ppos,
2121 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2122 			      int write, void *data),
2123 		  void *data)
2124 {
2125 	int *i, vleft, first = 1, err = 0;
2126 	size_t left;
2127 	char *kbuf = NULL, *p;
2128 
2129 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2130 		*lenp = 0;
2131 		return 0;
2132 	}
2133 
2134 	i = (int *) tbl_data;
2135 	vleft = table->maxlen / sizeof(*i);
2136 	left = *lenp;
2137 
2138 	if (!conv)
2139 		conv = do_proc_dointvec_conv;
2140 
2141 	if (write) {
2142 		if (*ppos) {
2143 			switch (sysctl_writes_strict) {
2144 			case SYSCTL_WRITES_STRICT:
2145 				goto out;
2146 			case SYSCTL_WRITES_WARN:
2147 				warn_sysctl_write(table);
2148 				break;
2149 			default:
2150 				break;
2151 			}
2152 		}
2153 
2154 		if (left > PAGE_SIZE - 1)
2155 			left = PAGE_SIZE - 1;
2156 		p = kbuf = memdup_user_nul(buffer, left);
2157 		if (IS_ERR(kbuf))
2158 			return PTR_ERR(kbuf);
2159 	}
2160 
2161 	for (; left && vleft--; i++, first=0) {
2162 		unsigned long lval;
2163 		bool neg;
2164 
2165 		if (write) {
2166 			left -= proc_skip_spaces(&p);
2167 
2168 			if (!left)
2169 				break;
2170 			err = proc_get_long(&p, &left, &lval, &neg,
2171 					     proc_wspace_sep,
2172 					     sizeof(proc_wspace_sep), NULL);
2173 			if (err)
2174 				break;
2175 			if (conv(&neg, &lval, i, 1, data)) {
2176 				err = -EINVAL;
2177 				break;
2178 			}
2179 		} else {
2180 			if (conv(&neg, &lval, i, 0, data)) {
2181 				err = -EINVAL;
2182 				break;
2183 			}
2184 			if (!first)
2185 				err = proc_put_char(&buffer, &left, '\t');
2186 			if (err)
2187 				break;
2188 			err = proc_put_long(&buffer, &left, lval, neg);
2189 			if (err)
2190 				break;
2191 		}
2192 	}
2193 
2194 	if (!write && !first && left && !err)
2195 		err = proc_put_char(&buffer, &left, '\n');
2196 	if (write && !err && left)
2197 		left -= proc_skip_spaces(&p);
2198 	if (write) {
2199 		kfree(kbuf);
2200 		if (first)
2201 			return err ? : -EINVAL;
2202 	}
2203 	*lenp -= left;
2204 out:
2205 	*ppos += *lenp;
2206 	return err;
2207 }
2208 
2209 static int do_proc_dointvec(struct ctl_table *table, int write,
2210 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2211 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2212 			      int write, void *data),
2213 		  void *data)
2214 {
2215 	return __do_proc_dointvec(table->data, table, write,
2216 			buffer, lenp, ppos, conv, data);
2217 }
2218 
2219 /**
2220  * proc_dointvec - read a vector of integers
2221  * @table: the sysctl table
2222  * @write: %TRUE if this is a write to the sysctl file
2223  * @buffer: the user buffer
2224  * @lenp: the size of the user buffer
2225  * @ppos: file position
2226  *
2227  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2228  * values from/to the user buffer, treated as an ASCII string.
2229  *
2230  * Returns 0 on success.
2231  */
2232 int proc_dointvec(struct ctl_table *table, int write,
2233 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2234 {
2235     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2236 		    	    NULL,NULL);
2237 }
2238 
2239 /*
2240  * Taint values can only be increased
2241  * This means we can safely use a temporary.
2242  */
2243 static int proc_taint(struct ctl_table *table, int write,
2244 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2245 {
2246 	struct ctl_table t;
2247 	unsigned long tmptaint = get_taint();
2248 	int err;
2249 
2250 	if (write && !capable(CAP_SYS_ADMIN))
2251 		return -EPERM;
2252 
2253 	t = *table;
2254 	t.data = &tmptaint;
2255 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2256 	if (err < 0)
2257 		return err;
2258 
2259 	if (write) {
2260 		/*
2261 		 * Poor man's atomic or. Not worth adding a primitive
2262 		 * to everyone's atomic.h for this
2263 		 */
2264 		int i;
2265 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2266 			if ((tmptaint >> i) & 1)
2267 				add_taint(i, LOCKDEP_STILL_OK);
2268 		}
2269 	}
2270 
2271 	return err;
2272 }
2273 
2274 #ifdef CONFIG_PRINTK
2275 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2276 				void __user *buffer, size_t *lenp, loff_t *ppos)
2277 {
2278 	if (write && !capable(CAP_SYS_ADMIN))
2279 		return -EPERM;
2280 
2281 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2282 }
2283 #endif
2284 
2285 struct do_proc_dointvec_minmax_conv_param {
2286 	int *min;
2287 	int *max;
2288 };
2289 
2290 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2291 					int *valp,
2292 					int write, void *data)
2293 {
2294 	struct do_proc_dointvec_minmax_conv_param *param = data;
2295 	if (write) {
2296 		int val = *negp ? -*lvalp : *lvalp;
2297 		if ((param->min && *param->min > val) ||
2298 		    (param->max && *param->max < val))
2299 			return -EINVAL;
2300 		*valp = val;
2301 	} else {
2302 		int val = *valp;
2303 		if (val < 0) {
2304 			*negp = true;
2305 			*lvalp = -(unsigned long)val;
2306 		} else {
2307 			*negp = false;
2308 			*lvalp = (unsigned long)val;
2309 		}
2310 	}
2311 	return 0;
2312 }
2313 
2314 /**
2315  * proc_dointvec_minmax - read a vector of integers with min/max values
2316  * @table: the sysctl table
2317  * @write: %TRUE if this is a write to the sysctl file
2318  * @buffer: the user buffer
2319  * @lenp: the size of the user buffer
2320  * @ppos: file position
2321  *
2322  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2323  * values from/to the user buffer, treated as an ASCII string.
2324  *
2325  * This routine will ensure the values are within the range specified by
2326  * table->extra1 (min) and table->extra2 (max).
2327  *
2328  * Returns 0 on success.
2329  */
2330 int proc_dointvec_minmax(struct ctl_table *table, int write,
2331 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2332 {
2333 	struct do_proc_dointvec_minmax_conv_param param = {
2334 		.min = (int *) table->extra1,
2335 		.max = (int *) table->extra2,
2336 	};
2337 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2338 				do_proc_dointvec_minmax_conv, &param);
2339 }
2340 
2341 static void validate_coredump_safety(void)
2342 {
2343 #ifdef CONFIG_COREDUMP
2344 	if (suid_dumpable == SUID_DUMP_ROOT &&
2345 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
2346 		printk(KERN_WARNING "Unsafe core_pattern used with "\
2347 			"suid_dumpable=2. Pipe handler or fully qualified "\
2348 			"core dump path required.\n");
2349 	}
2350 #endif
2351 }
2352 
2353 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2354 		void __user *buffer, size_t *lenp, loff_t *ppos)
2355 {
2356 	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2357 	if (!error)
2358 		validate_coredump_safety();
2359 	return error;
2360 }
2361 
2362 #ifdef CONFIG_COREDUMP
2363 static int proc_dostring_coredump(struct ctl_table *table, int write,
2364 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2365 {
2366 	int error = proc_dostring(table, write, buffer, lenp, ppos);
2367 	if (!error)
2368 		validate_coredump_safety();
2369 	return error;
2370 }
2371 #endif
2372 
2373 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2374 				     void __user *buffer,
2375 				     size_t *lenp, loff_t *ppos,
2376 				     unsigned long convmul,
2377 				     unsigned long convdiv)
2378 {
2379 	unsigned long *i, *min, *max;
2380 	int vleft, first = 1, err = 0;
2381 	size_t left;
2382 	char *kbuf = NULL, *p;
2383 
2384 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2385 		*lenp = 0;
2386 		return 0;
2387 	}
2388 
2389 	i = (unsigned long *) data;
2390 	min = (unsigned long *) table->extra1;
2391 	max = (unsigned long *) table->extra2;
2392 	vleft = table->maxlen / sizeof(unsigned long);
2393 	left = *lenp;
2394 
2395 	if (write) {
2396 		if (*ppos) {
2397 			switch (sysctl_writes_strict) {
2398 			case SYSCTL_WRITES_STRICT:
2399 				goto out;
2400 			case SYSCTL_WRITES_WARN:
2401 				warn_sysctl_write(table);
2402 				break;
2403 			default:
2404 				break;
2405 			}
2406 		}
2407 
2408 		if (left > PAGE_SIZE - 1)
2409 			left = PAGE_SIZE - 1;
2410 		p = kbuf = memdup_user_nul(buffer, left);
2411 		if (IS_ERR(kbuf))
2412 			return PTR_ERR(kbuf);
2413 	}
2414 
2415 	for (; left && vleft--; i++, first = 0) {
2416 		unsigned long val;
2417 
2418 		if (write) {
2419 			bool neg;
2420 
2421 			left -= proc_skip_spaces(&p);
2422 
2423 			err = proc_get_long(&p, &left, &val, &neg,
2424 					     proc_wspace_sep,
2425 					     sizeof(proc_wspace_sep), NULL);
2426 			if (err)
2427 				break;
2428 			if (neg)
2429 				continue;
2430 			if ((min && val < *min) || (max && val > *max))
2431 				continue;
2432 			*i = val;
2433 		} else {
2434 			val = convdiv * (*i) / convmul;
2435 			if (!first) {
2436 				err = proc_put_char(&buffer, &left, '\t');
2437 				if (err)
2438 					break;
2439 			}
2440 			err = proc_put_long(&buffer, &left, val, false);
2441 			if (err)
2442 				break;
2443 		}
2444 	}
2445 
2446 	if (!write && !first && left && !err)
2447 		err = proc_put_char(&buffer, &left, '\n');
2448 	if (write && !err)
2449 		left -= proc_skip_spaces(&p);
2450 	if (write) {
2451 		kfree(kbuf);
2452 		if (first)
2453 			return err ? : -EINVAL;
2454 	}
2455 	*lenp -= left;
2456 out:
2457 	*ppos += *lenp;
2458 	return err;
2459 }
2460 
2461 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2462 				     void __user *buffer,
2463 				     size_t *lenp, loff_t *ppos,
2464 				     unsigned long convmul,
2465 				     unsigned long convdiv)
2466 {
2467 	return __do_proc_doulongvec_minmax(table->data, table, write,
2468 			buffer, lenp, ppos, convmul, convdiv);
2469 }
2470 
2471 /**
2472  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2473  * @table: the sysctl table
2474  * @write: %TRUE if this is a write to the sysctl file
2475  * @buffer: the user buffer
2476  * @lenp: the size of the user buffer
2477  * @ppos: file position
2478  *
2479  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2480  * values from/to the user buffer, treated as an ASCII string.
2481  *
2482  * This routine will ensure the values are within the range specified by
2483  * table->extra1 (min) and table->extra2 (max).
2484  *
2485  * Returns 0 on success.
2486  */
2487 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2488 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2489 {
2490     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2491 }
2492 
2493 /**
2494  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2495  * @table: the sysctl table
2496  * @write: %TRUE if this is a write to the sysctl file
2497  * @buffer: the user buffer
2498  * @lenp: the size of the user buffer
2499  * @ppos: file position
2500  *
2501  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2502  * values from/to the user buffer, treated as an ASCII string. The values
2503  * are treated as milliseconds, and converted to jiffies when they are stored.
2504  *
2505  * This routine will ensure the values are within the range specified by
2506  * table->extra1 (min) and table->extra2 (max).
2507  *
2508  * Returns 0 on success.
2509  */
2510 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2511 				      void __user *buffer,
2512 				      size_t *lenp, loff_t *ppos)
2513 {
2514     return do_proc_doulongvec_minmax(table, write, buffer,
2515 				     lenp, ppos, HZ, 1000l);
2516 }
2517 
2518 
2519 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2520 					 int *valp,
2521 					 int write, void *data)
2522 {
2523 	if (write) {
2524 		if (*lvalp > LONG_MAX / HZ)
2525 			return 1;
2526 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2527 	} else {
2528 		int val = *valp;
2529 		unsigned long lval;
2530 		if (val < 0) {
2531 			*negp = true;
2532 			lval = -(unsigned long)val;
2533 		} else {
2534 			*negp = false;
2535 			lval = (unsigned long)val;
2536 		}
2537 		*lvalp = lval / HZ;
2538 	}
2539 	return 0;
2540 }
2541 
2542 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2543 						int *valp,
2544 						int write, void *data)
2545 {
2546 	if (write) {
2547 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2548 			return 1;
2549 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2550 	} else {
2551 		int val = *valp;
2552 		unsigned long lval;
2553 		if (val < 0) {
2554 			*negp = true;
2555 			lval = -(unsigned long)val;
2556 		} else {
2557 			*negp = false;
2558 			lval = (unsigned long)val;
2559 		}
2560 		*lvalp = jiffies_to_clock_t(lval);
2561 	}
2562 	return 0;
2563 }
2564 
2565 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2566 					    int *valp,
2567 					    int write, void *data)
2568 {
2569 	if (write) {
2570 		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2571 
2572 		if (jif > INT_MAX)
2573 			return 1;
2574 		*valp = (int)jif;
2575 	} else {
2576 		int val = *valp;
2577 		unsigned long lval;
2578 		if (val < 0) {
2579 			*negp = true;
2580 			lval = -(unsigned long)val;
2581 		} else {
2582 			*negp = false;
2583 			lval = (unsigned long)val;
2584 		}
2585 		*lvalp = jiffies_to_msecs(lval);
2586 	}
2587 	return 0;
2588 }
2589 
2590 /**
2591  * proc_dointvec_jiffies - read a vector of integers as seconds
2592  * @table: the sysctl table
2593  * @write: %TRUE if this is a write to the sysctl file
2594  * @buffer: the user buffer
2595  * @lenp: the size of the user buffer
2596  * @ppos: file position
2597  *
2598  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2599  * values from/to the user buffer, treated as an ASCII string.
2600  * The values read are assumed to be in seconds, and are converted into
2601  * jiffies.
2602  *
2603  * Returns 0 on success.
2604  */
2605 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2606 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2607 {
2608     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2609 		    	    do_proc_dointvec_jiffies_conv,NULL);
2610 }
2611 
2612 /**
2613  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2614  * @table: the sysctl table
2615  * @write: %TRUE if this is a write to the sysctl file
2616  * @buffer: the user buffer
2617  * @lenp: the size of the user buffer
2618  * @ppos: pointer to the file position
2619  *
2620  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2621  * values from/to the user buffer, treated as an ASCII string.
2622  * The values read are assumed to be in 1/USER_HZ seconds, and
2623  * are converted into jiffies.
2624  *
2625  * Returns 0 on success.
2626  */
2627 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2628 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2629 {
2630     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2631 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2632 }
2633 
2634 /**
2635  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2636  * @table: the sysctl table
2637  * @write: %TRUE if this is a write to the sysctl file
2638  * @buffer: the user buffer
2639  * @lenp: the size of the user buffer
2640  * @ppos: file position
2641  * @ppos: the current position in the file
2642  *
2643  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2644  * values from/to the user buffer, treated as an ASCII string.
2645  * The values read are assumed to be in 1/1000 seconds, and
2646  * are converted into jiffies.
2647  *
2648  * Returns 0 on success.
2649  */
2650 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2651 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2652 {
2653 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2654 				do_proc_dointvec_ms_jiffies_conv, NULL);
2655 }
2656 
2657 static int proc_do_cad_pid(struct ctl_table *table, int write,
2658 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2659 {
2660 	struct pid *new_pid;
2661 	pid_t tmp;
2662 	int r;
2663 
2664 	tmp = pid_vnr(cad_pid);
2665 
2666 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2667 			       lenp, ppos, NULL, NULL);
2668 	if (r || !write)
2669 		return r;
2670 
2671 	new_pid = find_get_pid(tmp);
2672 	if (!new_pid)
2673 		return -ESRCH;
2674 
2675 	put_pid(xchg(&cad_pid, new_pid));
2676 	return 0;
2677 }
2678 
2679 /**
2680  * proc_do_large_bitmap - read/write from/to a large bitmap
2681  * @table: the sysctl table
2682  * @write: %TRUE if this is a write to the sysctl file
2683  * @buffer: the user buffer
2684  * @lenp: the size of the user buffer
2685  * @ppos: file position
2686  *
2687  * The bitmap is stored at table->data and the bitmap length (in bits)
2688  * in table->maxlen.
2689  *
2690  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2691  * large bitmaps may be represented in a compact manner. Writing into
2692  * the file will clear the bitmap then update it with the given input.
2693  *
2694  * Returns 0 on success.
2695  */
2696 int proc_do_large_bitmap(struct ctl_table *table, int write,
2697 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2698 {
2699 	int err = 0;
2700 	bool first = 1;
2701 	size_t left = *lenp;
2702 	unsigned long bitmap_len = table->maxlen;
2703 	unsigned long *bitmap = *(unsigned long **) table->data;
2704 	unsigned long *tmp_bitmap = NULL;
2705 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2706 
2707 	if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2708 		*lenp = 0;
2709 		return 0;
2710 	}
2711 
2712 	if (write) {
2713 		char *kbuf, *p;
2714 
2715 		if (left > PAGE_SIZE - 1)
2716 			left = PAGE_SIZE - 1;
2717 
2718 		p = kbuf = memdup_user_nul(buffer, left);
2719 		if (IS_ERR(kbuf))
2720 			return PTR_ERR(kbuf);
2721 
2722 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2723 				     GFP_KERNEL);
2724 		if (!tmp_bitmap) {
2725 			kfree(kbuf);
2726 			return -ENOMEM;
2727 		}
2728 		proc_skip_char(&p, &left, '\n');
2729 		while (!err && left) {
2730 			unsigned long val_a, val_b;
2731 			bool neg;
2732 
2733 			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2734 					     sizeof(tr_a), &c);
2735 			if (err)
2736 				break;
2737 			if (val_a >= bitmap_len || neg) {
2738 				err = -EINVAL;
2739 				break;
2740 			}
2741 
2742 			val_b = val_a;
2743 			if (left) {
2744 				p++;
2745 				left--;
2746 			}
2747 
2748 			if (c == '-') {
2749 				err = proc_get_long(&p, &left, &val_b,
2750 						     &neg, tr_b, sizeof(tr_b),
2751 						     &c);
2752 				if (err)
2753 					break;
2754 				if (val_b >= bitmap_len || neg ||
2755 				    val_a > val_b) {
2756 					err = -EINVAL;
2757 					break;
2758 				}
2759 				if (left) {
2760 					p++;
2761 					left--;
2762 				}
2763 			}
2764 
2765 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2766 			first = 0;
2767 			proc_skip_char(&p, &left, '\n');
2768 		}
2769 		kfree(kbuf);
2770 	} else {
2771 		unsigned long bit_a, bit_b = 0;
2772 
2773 		while (left) {
2774 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2775 			if (bit_a >= bitmap_len)
2776 				break;
2777 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2778 						   bit_a + 1) - 1;
2779 
2780 			if (!first) {
2781 				err = proc_put_char(&buffer, &left, ',');
2782 				if (err)
2783 					break;
2784 			}
2785 			err = proc_put_long(&buffer, &left, bit_a, false);
2786 			if (err)
2787 				break;
2788 			if (bit_a != bit_b) {
2789 				err = proc_put_char(&buffer, &left, '-');
2790 				if (err)
2791 					break;
2792 				err = proc_put_long(&buffer, &left, bit_b, false);
2793 				if (err)
2794 					break;
2795 			}
2796 
2797 			first = 0; bit_b++;
2798 		}
2799 		if (!err)
2800 			err = proc_put_char(&buffer, &left, '\n');
2801 	}
2802 
2803 	if (!err) {
2804 		if (write) {
2805 			if (*ppos)
2806 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2807 			else
2808 				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2809 		}
2810 		kfree(tmp_bitmap);
2811 		*lenp -= left;
2812 		*ppos += *lenp;
2813 		return 0;
2814 	} else {
2815 		kfree(tmp_bitmap);
2816 		return err;
2817 	}
2818 }
2819 
2820 #else /* CONFIG_PROC_SYSCTL */
2821 
2822 int proc_dostring(struct ctl_table *table, int write,
2823 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2824 {
2825 	return -ENOSYS;
2826 }
2827 
2828 int proc_dointvec(struct ctl_table *table, int write,
2829 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2830 {
2831 	return -ENOSYS;
2832 }
2833 
2834 int proc_dointvec_minmax(struct ctl_table *table, int write,
2835 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2836 {
2837 	return -ENOSYS;
2838 }
2839 
2840 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2841 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2842 {
2843 	return -ENOSYS;
2844 }
2845 
2846 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2847 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2848 {
2849 	return -ENOSYS;
2850 }
2851 
2852 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2853 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2854 {
2855 	return -ENOSYS;
2856 }
2857 
2858 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2859 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2860 {
2861 	return -ENOSYS;
2862 }
2863 
2864 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2865 				      void __user *buffer,
2866 				      size_t *lenp, loff_t *ppos)
2867 {
2868     return -ENOSYS;
2869 }
2870 
2871 
2872 #endif /* CONFIG_PROC_SYSCTL */
2873 
2874 /*
2875  * No sense putting this after each symbol definition, twice,
2876  * exception granted :-)
2877  */
2878 EXPORT_SYMBOL(proc_dointvec);
2879 EXPORT_SYMBOL(proc_dointvec_jiffies);
2880 EXPORT_SYMBOL(proc_dointvec_minmax);
2881 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2882 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2883 EXPORT_SYMBOL(proc_dostring);
2884 EXPORT_SYMBOL(proc_doulongvec_minmax);
2885 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2886