xref: /linux/kernel/sysctl.c (revision a0d3c7c5c07cfbe00ab89438ddf82482f5a99422)
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 #endif
1525 #ifdef CONFIG_MMU
1526 	{
1527 		.procname	= "mmap_min_addr",
1528 		.data		= &dac_mmap_min_addr,
1529 		.maxlen		= sizeof(unsigned long),
1530 		.mode		= 0644,
1531 		.proc_handler	= mmap_min_addr_handler,
1532 	},
1533 #endif
1534 #ifdef CONFIG_NUMA
1535 	{
1536 		.procname	= "numa_zonelist_order",
1537 		.data		= &numa_zonelist_order,
1538 		.maxlen		= NUMA_ZONELIST_ORDER_LEN,
1539 		.mode		= 0644,
1540 		.proc_handler	= numa_zonelist_order_handler,
1541 	},
1542 #endif
1543 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1544    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1545 	{
1546 		.procname	= "vdso_enabled",
1547 #ifdef CONFIG_X86_32
1548 		.data		= &vdso32_enabled,
1549 		.maxlen		= sizeof(vdso32_enabled),
1550 #else
1551 		.data		= &vdso_enabled,
1552 		.maxlen		= sizeof(vdso_enabled),
1553 #endif
1554 		.mode		= 0644,
1555 		.proc_handler	= proc_dointvec,
1556 		.extra1		= &zero,
1557 	},
1558 #endif
1559 #ifdef CONFIG_HIGHMEM
1560 	{
1561 		.procname	= "highmem_is_dirtyable",
1562 		.data		= &vm_highmem_is_dirtyable,
1563 		.maxlen		= sizeof(vm_highmem_is_dirtyable),
1564 		.mode		= 0644,
1565 		.proc_handler	= proc_dointvec_minmax,
1566 		.extra1		= &zero,
1567 		.extra2		= &one,
1568 	},
1569 #endif
1570 #ifdef CONFIG_MEMORY_FAILURE
1571 	{
1572 		.procname	= "memory_failure_early_kill",
1573 		.data		= &sysctl_memory_failure_early_kill,
1574 		.maxlen		= sizeof(sysctl_memory_failure_early_kill),
1575 		.mode		= 0644,
1576 		.proc_handler	= proc_dointvec_minmax,
1577 		.extra1		= &zero,
1578 		.extra2		= &one,
1579 	},
1580 	{
1581 		.procname	= "memory_failure_recovery",
1582 		.data		= &sysctl_memory_failure_recovery,
1583 		.maxlen		= sizeof(sysctl_memory_failure_recovery),
1584 		.mode		= 0644,
1585 		.proc_handler	= proc_dointvec_minmax,
1586 		.extra1		= &zero,
1587 		.extra2		= &one,
1588 	},
1589 #endif
1590 	{
1591 		.procname	= "user_reserve_kbytes",
1592 		.data		= &sysctl_user_reserve_kbytes,
1593 		.maxlen		= sizeof(sysctl_user_reserve_kbytes),
1594 		.mode		= 0644,
1595 		.proc_handler	= proc_doulongvec_minmax,
1596 	},
1597 	{
1598 		.procname	= "admin_reserve_kbytes",
1599 		.data		= &sysctl_admin_reserve_kbytes,
1600 		.maxlen		= sizeof(sysctl_admin_reserve_kbytes),
1601 		.mode		= 0644,
1602 		.proc_handler	= proc_doulongvec_minmax,
1603 	},
1604 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1605 	{
1606 		.procname	= "mmap_rnd_bits",
1607 		.data		= &mmap_rnd_bits,
1608 		.maxlen		= sizeof(mmap_rnd_bits),
1609 		.mode		= 0600,
1610 		.proc_handler	= proc_dointvec_minmax,
1611 		.extra1		= (void *)&mmap_rnd_bits_min,
1612 		.extra2		= (void *)&mmap_rnd_bits_max,
1613 	},
1614 #endif
1615 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1616 	{
1617 		.procname	= "mmap_rnd_compat_bits",
1618 		.data		= &mmap_rnd_compat_bits,
1619 		.maxlen		= sizeof(mmap_rnd_compat_bits),
1620 		.mode		= 0600,
1621 		.proc_handler	= proc_dointvec_minmax,
1622 		.extra1		= (void *)&mmap_rnd_compat_bits_min,
1623 		.extra2		= (void *)&mmap_rnd_compat_bits_max,
1624 	},
1625 #endif
1626 	{ }
1627 };
1628 
1629 static struct ctl_table fs_table[] = {
1630 	{
1631 		.procname	= "inode-nr",
1632 		.data		= &inodes_stat,
1633 		.maxlen		= 2*sizeof(long),
1634 		.mode		= 0444,
1635 		.proc_handler	= proc_nr_inodes,
1636 	},
1637 	{
1638 		.procname	= "inode-state",
1639 		.data		= &inodes_stat,
1640 		.maxlen		= 7*sizeof(long),
1641 		.mode		= 0444,
1642 		.proc_handler	= proc_nr_inodes,
1643 	},
1644 	{
1645 		.procname	= "file-nr",
1646 		.data		= &files_stat,
1647 		.maxlen		= sizeof(files_stat),
1648 		.mode		= 0444,
1649 		.proc_handler	= proc_nr_files,
1650 	},
1651 	{
1652 		.procname	= "file-max",
1653 		.data		= &files_stat.max_files,
1654 		.maxlen		= sizeof(files_stat.max_files),
1655 		.mode		= 0644,
1656 		.proc_handler	= proc_doulongvec_minmax,
1657 	},
1658 	{
1659 		.procname	= "nr_open",
1660 		.data		= &sysctl_nr_open,
1661 		.maxlen		= sizeof(int),
1662 		.mode		= 0644,
1663 		.proc_handler	= proc_dointvec_minmax,
1664 		.extra1		= &sysctl_nr_open_min,
1665 		.extra2		= &sysctl_nr_open_max,
1666 	},
1667 	{
1668 		.procname	= "dentry-state",
1669 		.data		= &dentry_stat,
1670 		.maxlen		= 6*sizeof(long),
1671 		.mode		= 0444,
1672 		.proc_handler	= proc_nr_dentry,
1673 	},
1674 	{
1675 		.procname	= "overflowuid",
1676 		.data		= &fs_overflowuid,
1677 		.maxlen		= sizeof(int),
1678 		.mode		= 0644,
1679 		.proc_handler	= proc_dointvec_minmax,
1680 		.extra1		= &minolduid,
1681 		.extra2		= &maxolduid,
1682 	},
1683 	{
1684 		.procname	= "overflowgid",
1685 		.data		= &fs_overflowgid,
1686 		.maxlen		= sizeof(int),
1687 		.mode		= 0644,
1688 		.proc_handler	= proc_dointvec_minmax,
1689 		.extra1		= &minolduid,
1690 		.extra2		= &maxolduid,
1691 	},
1692 #ifdef CONFIG_FILE_LOCKING
1693 	{
1694 		.procname	= "leases-enable",
1695 		.data		= &leases_enable,
1696 		.maxlen		= sizeof(int),
1697 		.mode		= 0644,
1698 		.proc_handler	= proc_dointvec,
1699 	},
1700 #endif
1701 #ifdef CONFIG_DNOTIFY
1702 	{
1703 		.procname	= "dir-notify-enable",
1704 		.data		= &dir_notify_enable,
1705 		.maxlen		= sizeof(int),
1706 		.mode		= 0644,
1707 		.proc_handler	= proc_dointvec,
1708 	},
1709 #endif
1710 #ifdef CONFIG_MMU
1711 #ifdef CONFIG_FILE_LOCKING
1712 	{
1713 		.procname	= "lease-break-time",
1714 		.data		= &lease_break_time,
1715 		.maxlen		= sizeof(int),
1716 		.mode		= 0644,
1717 		.proc_handler	= proc_dointvec,
1718 	},
1719 #endif
1720 #ifdef CONFIG_AIO
1721 	{
1722 		.procname	= "aio-nr",
1723 		.data		= &aio_nr,
1724 		.maxlen		= sizeof(aio_nr),
1725 		.mode		= 0444,
1726 		.proc_handler	= proc_doulongvec_minmax,
1727 	},
1728 	{
1729 		.procname	= "aio-max-nr",
1730 		.data		= &aio_max_nr,
1731 		.maxlen		= sizeof(aio_max_nr),
1732 		.mode		= 0644,
1733 		.proc_handler	= proc_doulongvec_minmax,
1734 	},
1735 #endif /* CONFIG_AIO */
1736 #ifdef CONFIG_INOTIFY_USER
1737 	{
1738 		.procname	= "inotify",
1739 		.mode		= 0555,
1740 		.child		= inotify_table,
1741 	},
1742 #endif
1743 #ifdef CONFIG_EPOLL
1744 	{
1745 		.procname	= "epoll",
1746 		.mode		= 0555,
1747 		.child		= epoll_table,
1748 	},
1749 #endif
1750 #endif
1751 	{
1752 		.procname	= "protected_symlinks",
1753 		.data		= &sysctl_protected_symlinks,
1754 		.maxlen		= sizeof(int),
1755 		.mode		= 0600,
1756 		.proc_handler	= proc_dointvec_minmax,
1757 		.extra1		= &zero,
1758 		.extra2		= &one,
1759 	},
1760 	{
1761 		.procname	= "protected_hardlinks",
1762 		.data		= &sysctl_protected_hardlinks,
1763 		.maxlen		= sizeof(int),
1764 		.mode		= 0600,
1765 		.proc_handler	= proc_dointvec_minmax,
1766 		.extra1		= &zero,
1767 		.extra2		= &one,
1768 	},
1769 	{
1770 		.procname	= "suid_dumpable",
1771 		.data		= &suid_dumpable,
1772 		.maxlen		= sizeof(int),
1773 		.mode		= 0644,
1774 		.proc_handler	= proc_dointvec_minmax_coredump,
1775 		.extra1		= &zero,
1776 		.extra2		= &two,
1777 	},
1778 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1779 	{
1780 		.procname	= "binfmt_misc",
1781 		.mode		= 0555,
1782 		.child		= sysctl_mount_point,
1783 	},
1784 #endif
1785 	{
1786 		.procname	= "pipe-max-size",
1787 		.data		= &pipe_max_size,
1788 		.maxlen		= sizeof(int),
1789 		.mode		= 0644,
1790 		.proc_handler	= &pipe_proc_fn,
1791 		.extra1		= &pipe_min_size,
1792 	},
1793 	{
1794 		.procname	= "pipe-user-pages-hard",
1795 		.data		= &pipe_user_pages_hard,
1796 		.maxlen		= sizeof(pipe_user_pages_hard),
1797 		.mode		= 0644,
1798 		.proc_handler	= proc_doulongvec_minmax,
1799 	},
1800 	{
1801 		.procname	= "pipe-user-pages-soft",
1802 		.data		= &pipe_user_pages_soft,
1803 		.maxlen		= sizeof(pipe_user_pages_soft),
1804 		.mode		= 0644,
1805 		.proc_handler	= proc_doulongvec_minmax,
1806 	},
1807 	{ }
1808 };
1809 
1810 static struct ctl_table debug_table[] = {
1811 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1812 	{
1813 		.procname	= "exception-trace",
1814 		.data		= &show_unhandled_signals,
1815 		.maxlen		= sizeof(int),
1816 		.mode		= 0644,
1817 		.proc_handler	= proc_dointvec
1818 	},
1819 #endif
1820 #if defined(CONFIG_OPTPROBES)
1821 	{
1822 		.procname	= "kprobes-optimization",
1823 		.data		= &sysctl_kprobes_optimization,
1824 		.maxlen		= sizeof(int),
1825 		.mode		= 0644,
1826 		.proc_handler	= proc_kprobes_optimization_handler,
1827 		.extra1		= &zero,
1828 		.extra2		= &one,
1829 	},
1830 #endif
1831 	{ }
1832 };
1833 
1834 static struct ctl_table dev_table[] = {
1835 	{ }
1836 };
1837 
1838 int __init sysctl_init(void)
1839 {
1840 	struct ctl_table_header *hdr;
1841 
1842 	hdr = register_sysctl_table(sysctl_base_table);
1843 	kmemleak_not_leak(hdr);
1844 	return 0;
1845 }
1846 
1847 #endif /* CONFIG_SYSCTL */
1848 
1849 /*
1850  * /proc/sys support
1851  */
1852 
1853 #ifdef CONFIG_PROC_SYSCTL
1854 
1855 static int _proc_do_string(char *data, int maxlen, int write,
1856 			   char __user *buffer,
1857 			   size_t *lenp, loff_t *ppos)
1858 {
1859 	size_t len;
1860 	char __user *p;
1861 	char c;
1862 
1863 	if (!data || !maxlen || !*lenp) {
1864 		*lenp = 0;
1865 		return 0;
1866 	}
1867 
1868 	if (write) {
1869 		if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1870 			/* Only continue writes not past the end of buffer. */
1871 			len = strlen(data);
1872 			if (len > maxlen - 1)
1873 				len = maxlen - 1;
1874 
1875 			if (*ppos > len)
1876 				return 0;
1877 			len = *ppos;
1878 		} else {
1879 			/* Start writing from beginning of buffer. */
1880 			len = 0;
1881 		}
1882 
1883 		*ppos += *lenp;
1884 		p = buffer;
1885 		while ((p - buffer) < *lenp && len < maxlen - 1) {
1886 			if (get_user(c, p++))
1887 				return -EFAULT;
1888 			if (c == 0 || c == '\n')
1889 				break;
1890 			data[len++] = c;
1891 		}
1892 		data[len] = 0;
1893 	} else {
1894 		len = strlen(data);
1895 		if (len > maxlen)
1896 			len = maxlen;
1897 
1898 		if (*ppos > len) {
1899 			*lenp = 0;
1900 			return 0;
1901 		}
1902 
1903 		data += *ppos;
1904 		len  -= *ppos;
1905 
1906 		if (len > *lenp)
1907 			len = *lenp;
1908 		if (len)
1909 			if (copy_to_user(buffer, data, len))
1910 				return -EFAULT;
1911 		if (len < *lenp) {
1912 			if (put_user('\n', buffer + len))
1913 				return -EFAULT;
1914 			len++;
1915 		}
1916 		*lenp = len;
1917 		*ppos += len;
1918 	}
1919 	return 0;
1920 }
1921 
1922 static void warn_sysctl_write(struct ctl_table *table)
1923 {
1924 	pr_warn_once("%s wrote to %s when file position was not 0!\n"
1925 		"This will not be supported in the future. To silence this\n"
1926 		"warning, set kernel.sysctl_writes_strict = -1\n",
1927 		current->comm, table->procname);
1928 }
1929 
1930 /**
1931  * proc_dostring - read a string sysctl
1932  * @table: the sysctl table
1933  * @write: %TRUE if this is a write to the sysctl file
1934  * @buffer: the user buffer
1935  * @lenp: the size of the user buffer
1936  * @ppos: file position
1937  *
1938  * Reads/writes a string from/to the user buffer. If the kernel
1939  * buffer provided is not large enough to hold the string, the
1940  * string is truncated. The copied string is %NULL-terminated.
1941  * If the string is being read by the user process, it is copied
1942  * and a newline '\n' is added. It is truncated if the buffer is
1943  * not large enough.
1944  *
1945  * Returns 0 on success.
1946  */
1947 int proc_dostring(struct ctl_table *table, int write,
1948 		  void __user *buffer, size_t *lenp, loff_t *ppos)
1949 {
1950 	if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1951 		warn_sysctl_write(table);
1952 
1953 	return _proc_do_string((char *)(table->data), table->maxlen, write,
1954 			       (char __user *)buffer, lenp, ppos);
1955 }
1956 
1957 static size_t proc_skip_spaces(char **buf)
1958 {
1959 	size_t ret;
1960 	char *tmp = skip_spaces(*buf);
1961 	ret = tmp - *buf;
1962 	*buf = tmp;
1963 	return ret;
1964 }
1965 
1966 static void proc_skip_char(char **buf, size_t *size, const char v)
1967 {
1968 	while (*size) {
1969 		if (**buf != v)
1970 			break;
1971 		(*size)--;
1972 		(*buf)++;
1973 	}
1974 }
1975 
1976 #define TMPBUFLEN 22
1977 /**
1978  * proc_get_long - reads an ASCII formatted integer from a user buffer
1979  *
1980  * @buf: a kernel buffer
1981  * @size: size of the kernel buffer
1982  * @val: this is where the number will be stored
1983  * @neg: set to %TRUE if number is negative
1984  * @perm_tr: a vector which contains the allowed trailers
1985  * @perm_tr_len: size of the perm_tr vector
1986  * @tr: pointer to store the trailer character
1987  *
1988  * In case of success %0 is returned and @buf and @size are updated with
1989  * the amount of bytes read. If @tr is non-NULL and a trailing
1990  * character exists (size is non-zero after returning from this
1991  * function), @tr is updated with the trailing character.
1992  */
1993 static int proc_get_long(char **buf, size_t *size,
1994 			  unsigned long *val, bool *neg,
1995 			  const char *perm_tr, unsigned perm_tr_len, char *tr)
1996 {
1997 	int len;
1998 	char *p, tmp[TMPBUFLEN];
1999 
2000 	if (!*size)
2001 		return -EINVAL;
2002 
2003 	len = *size;
2004 	if (len > TMPBUFLEN - 1)
2005 		len = TMPBUFLEN - 1;
2006 
2007 	memcpy(tmp, *buf, len);
2008 
2009 	tmp[len] = 0;
2010 	p = tmp;
2011 	if (*p == '-' && *size > 1) {
2012 		*neg = true;
2013 		p++;
2014 	} else
2015 		*neg = false;
2016 	if (!isdigit(*p))
2017 		return -EINVAL;
2018 
2019 	*val = simple_strtoul(p, &p, 0);
2020 
2021 	len = p - tmp;
2022 
2023 	/* We don't know if the next char is whitespace thus we may accept
2024 	 * invalid integers (e.g. 1234...a) or two integers instead of one
2025 	 * (e.g. 123...1). So lets not allow such large numbers. */
2026 	if (len == TMPBUFLEN - 1)
2027 		return -EINVAL;
2028 
2029 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2030 		return -EINVAL;
2031 
2032 	if (tr && (len < *size))
2033 		*tr = *p;
2034 
2035 	*buf += len;
2036 	*size -= len;
2037 
2038 	return 0;
2039 }
2040 
2041 /**
2042  * proc_put_long - converts an integer to a decimal ASCII formatted string
2043  *
2044  * @buf: the user buffer
2045  * @size: the size of the user buffer
2046  * @val: the integer to be converted
2047  * @neg: sign of the number, %TRUE for negative
2048  *
2049  * In case of success %0 is returned and @buf and @size are updated with
2050  * the amount of bytes written.
2051  */
2052 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2053 			  bool neg)
2054 {
2055 	int len;
2056 	char tmp[TMPBUFLEN], *p = tmp;
2057 
2058 	sprintf(p, "%s%lu", neg ? "-" : "", val);
2059 	len = strlen(tmp);
2060 	if (len > *size)
2061 		len = *size;
2062 	if (copy_to_user(*buf, tmp, len))
2063 		return -EFAULT;
2064 	*size -= len;
2065 	*buf += len;
2066 	return 0;
2067 }
2068 #undef TMPBUFLEN
2069 
2070 static int proc_put_char(void __user **buf, size_t *size, char c)
2071 {
2072 	if (*size) {
2073 		char __user **buffer = (char __user **)buf;
2074 		if (put_user(c, *buffer))
2075 			return -EFAULT;
2076 		(*size)--, (*buffer)++;
2077 		*buf = *buffer;
2078 	}
2079 	return 0;
2080 }
2081 
2082 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2083 				 int *valp,
2084 				 int write, void *data)
2085 {
2086 	if (write) {
2087 		if (*negp) {
2088 			if (*lvalp > (unsigned long) INT_MAX + 1)
2089 				return -EINVAL;
2090 			*valp = -*lvalp;
2091 		} else {
2092 			if (*lvalp > (unsigned long) INT_MAX)
2093 				return -EINVAL;
2094 			*valp = *lvalp;
2095 		}
2096 	} else {
2097 		int val = *valp;
2098 		if (val < 0) {
2099 			*negp = true;
2100 			*lvalp = -(unsigned long)val;
2101 		} else {
2102 			*negp = false;
2103 			*lvalp = (unsigned long)val;
2104 		}
2105 	}
2106 	return 0;
2107 }
2108 
2109 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2110 
2111 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2112 		  int write, void __user *buffer,
2113 		  size_t *lenp, loff_t *ppos,
2114 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2115 			      int write, void *data),
2116 		  void *data)
2117 {
2118 	int *i, vleft, first = 1, err = 0;
2119 	size_t left;
2120 	char *kbuf = NULL, *p;
2121 
2122 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2123 		*lenp = 0;
2124 		return 0;
2125 	}
2126 
2127 	i = (int *) tbl_data;
2128 	vleft = table->maxlen / sizeof(*i);
2129 	left = *lenp;
2130 
2131 	if (!conv)
2132 		conv = do_proc_dointvec_conv;
2133 
2134 	if (write) {
2135 		if (*ppos) {
2136 			switch (sysctl_writes_strict) {
2137 			case SYSCTL_WRITES_STRICT:
2138 				goto out;
2139 			case SYSCTL_WRITES_WARN:
2140 				warn_sysctl_write(table);
2141 				break;
2142 			default:
2143 				break;
2144 			}
2145 		}
2146 
2147 		if (left > PAGE_SIZE - 1)
2148 			left = PAGE_SIZE - 1;
2149 		p = kbuf = memdup_user_nul(buffer, left);
2150 		if (IS_ERR(kbuf))
2151 			return PTR_ERR(kbuf);
2152 	}
2153 
2154 	for (; left && vleft--; i++, first=0) {
2155 		unsigned long lval;
2156 		bool neg;
2157 
2158 		if (write) {
2159 			left -= proc_skip_spaces(&p);
2160 
2161 			if (!left)
2162 				break;
2163 			err = proc_get_long(&p, &left, &lval, &neg,
2164 					     proc_wspace_sep,
2165 					     sizeof(proc_wspace_sep), NULL);
2166 			if (err)
2167 				break;
2168 			if (conv(&neg, &lval, i, 1, data)) {
2169 				err = -EINVAL;
2170 				break;
2171 			}
2172 		} else {
2173 			if (conv(&neg, &lval, i, 0, data)) {
2174 				err = -EINVAL;
2175 				break;
2176 			}
2177 			if (!first)
2178 				err = proc_put_char(&buffer, &left, '\t');
2179 			if (err)
2180 				break;
2181 			err = proc_put_long(&buffer, &left, lval, neg);
2182 			if (err)
2183 				break;
2184 		}
2185 	}
2186 
2187 	if (!write && !first && left && !err)
2188 		err = proc_put_char(&buffer, &left, '\n');
2189 	if (write && !err && left)
2190 		left -= proc_skip_spaces(&p);
2191 	if (write) {
2192 		kfree(kbuf);
2193 		if (first)
2194 			return err ? : -EINVAL;
2195 	}
2196 	*lenp -= left;
2197 out:
2198 	*ppos += *lenp;
2199 	return err;
2200 }
2201 
2202 static int do_proc_dointvec(struct ctl_table *table, int write,
2203 		  void __user *buffer, size_t *lenp, loff_t *ppos,
2204 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2205 			      int write, void *data),
2206 		  void *data)
2207 {
2208 	return __do_proc_dointvec(table->data, table, write,
2209 			buffer, lenp, ppos, conv, data);
2210 }
2211 
2212 /**
2213  * proc_dointvec - read a vector of integers
2214  * @table: the sysctl table
2215  * @write: %TRUE if this is a write to the sysctl file
2216  * @buffer: the user buffer
2217  * @lenp: the size of the user buffer
2218  * @ppos: file position
2219  *
2220  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2221  * values from/to the user buffer, treated as an ASCII string.
2222  *
2223  * Returns 0 on success.
2224  */
2225 int proc_dointvec(struct ctl_table *table, int write,
2226 		     void __user *buffer, size_t *lenp, loff_t *ppos)
2227 {
2228     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2229 		    	    NULL,NULL);
2230 }
2231 
2232 /*
2233  * Taint values can only be increased
2234  * This means we can safely use a temporary.
2235  */
2236 static int proc_taint(struct ctl_table *table, int write,
2237 			       void __user *buffer, size_t *lenp, loff_t *ppos)
2238 {
2239 	struct ctl_table t;
2240 	unsigned long tmptaint = get_taint();
2241 	int err;
2242 
2243 	if (write && !capable(CAP_SYS_ADMIN))
2244 		return -EPERM;
2245 
2246 	t = *table;
2247 	t.data = &tmptaint;
2248 	err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2249 	if (err < 0)
2250 		return err;
2251 
2252 	if (write) {
2253 		/*
2254 		 * Poor man's atomic or. Not worth adding a primitive
2255 		 * to everyone's atomic.h for this
2256 		 */
2257 		int i;
2258 		for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2259 			if ((tmptaint >> i) & 1)
2260 				add_taint(i, LOCKDEP_STILL_OK);
2261 		}
2262 	}
2263 
2264 	return err;
2265 }
2266 
2267 #ifdef CONFIG_PRINTK
2268 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2269 				void __user *buffer, size_t *lenp, loff_t *ppos)
2270 {
2271 	if (write && !capable(CAP_SYS_ADMIN))
2272 		return -EPERM;
2273 
2274 	return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2275 }
2276 #endif
2277 
2278 struct do_proc_dointvec_minmax_conv_param {
2279 	int *min;
2280 	int *max;
2281 };
2282 
2283 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2284 					int *valp,
2285 					int write, void *data)
2286 {
2287 	struct do_proc_dointvec_minmax_conv_param *param = data;
2288 	if (write) {
2289 		int val = *negp ? -*lvalp : *lvalp;
2290 		if ((param->min && *param->min > val) ||
2291 		    (param->max && *param->max < val))
2292 			return -EINVAL;
2293 		*valp = val;
2294 	} else {
2295 		int val = *valp;
2296 		if (val < 0) {
2297 			*negp = true;
2298 			*lvalp = -(unsigned long)val;
2299 		} else {
2300 			*negp = false;
2301 			*lvalp = (unsigned long)val;
2302 		}
2303 	}
2304 	return 0;
2305 }
2306 
2307 /**
2308  * proc_dointvec_minmax - read a vector of integers with min/max values
2309  * @table: the sysctl table
2310  * @write: %TRUE if this is a write to the sysctl file
2311  * @buffer: the user buffer
2312  * @lenp: the size of the user buffer
2313  * @ppos: file position
2314  *
2315  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2316  * values from/to the user buffer, treated as an ASCII string.
2317  *
2318  * This routine will ensure the values are within the range specified by
2319  * table->extra1 (min) and table->extra2 (max).
2320  *
2321  * Returns 0 on success.
2322  */
2323 int proc_dointvec_minmax(struct ctl_table *table, int write,
2324 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2325 {
2326 	struct do_proc_dointvec_minmax_conv_param param = {
2327 		.min = (int *) table->extra1,
2328 		.max = (int *) table->extra2,
2329 	};
2330 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2331 				do_proc_dointvec_minmax_conv, &param);
2332 }
2333 
2334 static void validate_coredump_safety(void)
2335 {
2336 #ifdef CONFIG_COREDUMP
2337 	if (suid_dumpable == SUID_DUMP_ROOT &&
2338 	    core_pattern[0] != '/' && core_pattern[0] != '|') {
2339 		printk(KERN_WARNING "Unsafe core_pattern used with "\
2340 			"suid_dumpable=2. Pipe handler or fully qualified "\
2341 			"core dump path required.\n");
2342 	}
2343 #endif
2344 }
2345 
2346 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2347 		void __user *buffer, size_t *lenp, loff_t *ppos)
2348 {
2349 	int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2350 	if (!error)
2351 		validate_coredump_safety();
2352 	return error;
2353 }
2354 
2355 #ifdef CONFIG_COREDUMP
2356 static int proc_dostring_coredump(struct ctl_table *table, int write,
2357 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2358 {
2359 	int error = proc_dostring(table, write, buffer, lenp, ppos);
2360 	if (!error)
2361 		validate_coredump_safety();
2362 	return error;
2363 }
2364 #endif
2365 
2366 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2367 				     void __user *buffer,
2368 				     size_t *lenp, loff_t *ppos,
2369 				     unsigned long convmul,
2370 				     unsigned long convdiv)
2371 {
2372 	unsigned long *i, *min, *max;
2373 	int vleft, first = 1, err = 0;
2374 	size_t left;
2375 	char *kbuf = NULL, *p;
2376 
2377 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2378 		*lenp = 0;
2379 		return 0;
2380 	}
2381 
2382 	i = (unsigned long *) data;
2383 	min = (unsigned long *) table->extra1;
2384 	max = (unsigned long *) table->extra2;
2385 	vleft = table->maxlen / sizeof(unsigned long);
2386 	left = *lenp;
2387 
2388 	if (write) {
2389 		if (*ppos) {
2390 			switch (sysctl_writes_strict) {
2391 			case SYSCTL_WRITES_STRICT:
2392 				goto out;
2393 			case SYSCTL_WRITES_WARN:
2394 				warn_sysctl_write(table);
2395 				break;
2396 			default:
2397 				break;
2398 			}
2399 		}
2400 
2401 		if (left > PAGE_SIZE - 1)
2402 			left = PAGE_SIZE - 1;
2403 		p = kbuf = memdup_user_nul(buffer, left);
2404 		if (IS_ERR(kbuf))
2405 			return PTR_ERR(kbuf);
2406 	}
2407 
2408 	for (; left && vleft--; i++, first = 0) {
2409 		unsigned long val;
2410 
2411 		if (write) {
2412 			bool neg;
2413 
2414 			left -= proc_skip_spaces(&p);
2415 
2416 			err = proc_get_long(&p, &left, &val, &neg,
2417 					     proc_wspace_sep,
2418 					     sizeof(proc_wspace_sep), NULL);
2419 			if (err)
2420 				break;
2421 			if (neg)
2422 				continue;
2423 			if ((min && val < *min) || (max && val > *max))
2424 				continue;
2425 			*i = val;
2426 		} else {
2427 			val = convdiv * (*i) / convmul;
2428 			if (!first) {
2429 				err = proc_put_char(&buffer, &left, '\t');
2430 				if (err)
2431 					break;
2432 			}
2433 			err = proc_put_long(&buffer, &left, val, false);
2434 			if (err)
2435 				break;
2436 		}
2437 	}
2438 
2439 	if (!write && !first && left && !err)
2440 		err = proc_put_char(&buffer, &left, '\n');
2441 	if (write && !err)
2442 		left -= proc_skip_spaces(&p);
2443 	if (write) {
2444 		kfree(kbuf);
2445 		if (first)
2446 			return err ? : -EINVAL;
2447 	}
2448 	*lenp -= left;
2449 out:
2450 	*ppos += *lenp;
2451 	return err;
2452 }
2453 
2454 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2455 				     void __user *buffer,
2456 				     size_t *lenp, loff_t *ppos,
2457 				     unsigned long convmul,
2458 				     unsigned long convdiv)
2459 {
2460 	return __do_proc_doulongvec_minmax(table->data, table, write,
2461 			buffer, lenp, ppos, convmul, convdiv);
2462 }
2463 
2464 /**
2465  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2466  * @table: the sysctl table
2467  * @write: %TRUE if this is a write to the sysctl file
2468  * @buffer: the user buffer
2469  * @lenp: the size of the user buffer
2470  * @ppos: file position
2471  *
2472  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2473  * values from/to the user buffer, treated as an ASCII string.
2474  *
2475  * This routine will ensure the values are within the range specified by
2476  * table->extra1 (min) and table->extra2 (max).
2477  *
2478  * Returns 0 on success.
2479  */
2480 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2481 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2482 {
2483     return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2484 }
2485 
2486 /**
2487  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2488  * @table: the sysctl table
2489  * @write: %TRUE if this is a write to the sysctl file
2490  * @buffer: the user buffer
2491  * @lenp: the size of the user buffer
2492  * @ppos: file position
2493  *
2494  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2495  * values from/to the user buffer, treated as an ASCII string. The values
2496  * are treated as milliseconds, and converted to jiffies when they are stored.
2497  *
2498  * This routine will ensure the values are within the range specified by
2499  * table->extra1 (min) and table->extra2 (max).
2500  *
2501  * Returns 0 on success.
2502  */
2503 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2504 				      void __user *buffer,
2505 				      size_t *lenp, loff_t *ppos)
2506 {
2507     return do_proc_doulongvec_minmax(table, write, buffer,
2508 				     lenp, ppos, HZ, 1000l);
2509 }
2510 
2511 
2512 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2513 					 int *valp,
2514 					 int write, void *data)
2515 {
2516 	if (write) {
2517 		if (*lvalp > LONG_MAX / HZ)
2518 			return 1;
2519 		*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2520 	} else {
2521 		int val = *valp;
2522 		unsigned long lval;
2523 		if (val < 0) {
2524 			*negp = true;
2525 			lval = -(unsigned long)val;
2526 		} else {
2527 			*negp = false;
2528 			lval = (unsigned long)val;
2529 		}
2530 		*lvalp = lval / HZ;
2531 	}
2532 	return 0;
2533 }
2534 
2535 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2536 						int *valp,
2537 						int write, void *data)
2538 {
2539 	if (write) {
2540 		if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2541 			return 1;
2542 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2543 	} else {
2544 		int val = *valp;
2545 		unsigned long lval;
2546 		if (val < 0) {
2547 			*negp = true;
2548 			lval = -(unsigned long)val;
2549 		} else {
2550 			*negp = false;
2551 			lval = (unsigned long)val;
2552 		}
2553 		*lvalp = jiffies_to_clock_t(lval);
2554 	}
2555 	return 0;
2556 }
2557 
2558 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2559 					    int *valp,
2560 					    int write, void *data)
2561 {
2562 	if (write) {
2563 		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2564 
2565 		if (jif > INT_MAX)
2566 			return 1;
2567 		*valp = (int)jif;
2568 	} else {
2569 		int val = *valp;
2570 		unsigned long lval;
2571 		if (val < 0) {
2572 			*negp = true;
2573 			lval = -(unsigned long)val;
2574 		} else {
2575 			*negp = false;
2576 			lval = (unsigned long)val;
2577 		}
2578 		*lvalp = jiffies_to_msecs(lval);
2579 	}
2580 	return 0;
2581 }
2582 
2583 /**
2584  * proc_dointvec_jiffies - read a vector of integers as seconds
2585  * @table: the sysctl table
2586  * @write: %TRUE if this is a write to the sysctl file
2587  * @buffer: the user buffer
2588  * @lenp: the size of the user buffer
2589  * @ppos: file position
2590  *
2591  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2592  * values from/to the user buffer, treated as an ASCII string.
2593  * The values read are assumed to be in seconds, and are converted into
2594  * jiffies.
2595  *
2596  * Returns 0 on success.
2597  */
2598 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2599 			  void __user *buffer, size_t *lenp, loff_t *ppos)
2600 {
2601     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2602 		    	    do_proc_dointvec_jiffies_conv,NULL);
2603 }
2604 
2605 /**
2606  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2607  * @table: the sysctl table
2608  * @write: %TRUE if this is a write to the sysctl file
2609  * @buffer: the user buffer
2610  * @lenp: the size of the user buffer
2611  * @ppos: pointer to the file position
2612  *
2613  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2614  * values from/to the user buffer, treated as an ASCII string.
2615  * The values read are assumed to be in 1/USER_HZ seconds, and
2616  * are converted into jiffies.
2617  *
2618  * Returns 0 on success.
2619  */
2620 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2621 				 void __user *buffer, size_t *lenp, loff_t *ppos)
2622 {
2623     return do_proc_dointvec(table,write,buffer,lenp,ppos,
2624 		    	    do_proc_dointvec_userhz_jiffies_conv,NULL);
2625 }
2626 
2627 /**
2628  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2629  * @table: the sysctl table
2630  * @write: %TRUE if this is a write to the sysctl file
2631  * @buffer: the user buffer
2632  * @lenp: the size of the user buffer
2633  * @ppos: file position
2634  * @ppos: the current position in the file
2635  *
2636  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2637  * values from/to the user buffer, treated as an ASCII string.
2638  * The values read are assumed to be in 1/1000 seconds, and
2639  * are converted into jiffies.
2640  *
2641  * Returns 0 on success.
2642  */
2643 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2644 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2645 {
2646 	return do_proc_dointvec(table, write, buffer, lenp, ppos,
2647 				do_proc_dointvec_ms_jiffies_conv, NULL);
2648 }
2649 
2650 static int proc_do_cad_pid(struct ctl_table *table, int write,
2651 			   void __user *buffer, size_t *lenp, loff_t *ppos)
2652 {
2653 	struct pid *new_pid;
2654 	pid_t tmp;
2655 	int r;
2656 
2657 	tmp = pid_vnr(cad_pid);
2658 
2659 	r = __do_proc_dointvec(&tmp, table, write, buffer,
2660 			       lenp, ppos, NULL, NULL);
2661 	if (r || !write)
2662 		return r;
2663 
2664 	new_pid = find_get_pid(tmp);
2665 	if (!new_pid)
2666 		return -ESRCH;
2667 
2668 	put_pid(xchg(&cad_pid, new_pid));
2669 	return 0;
2670 }
2671 
2672 /**
2673  * proc_do_large_bitmap - read/write from/to a large bitmap
2674  * @table: the sysctl table
2675  * @write: %TRUE if this is a write to the sysctl file
2676  * @buffer: the user buffer
2677  * @lenp: the size of the user buffer
2678  * @ppos: file position
2679  *
2680  * The bitmap is stored at table->data and the bitmap length (in bits)
2681  * in table->maxlen.
2682  *
2683  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2684  * large bitmaps may be represented in a compact manner. Writing into
2685  * the file will clear the bitmap then update it with the given input.
2686  *
2687  * Returns 0 on success.
2688  */
2689 int proc_do_large_bitmap(struct ctl_table *table, int write,
2690 			 void __user *buffer, size_t *lenp, loff_t *ppos)
2691 {
2692 	int err = 0;
2693 	bool first = 1;
2694 	size_t left = *lenp;
2695 	unsigned long bitmap_len = table->maxlen;
2696 	unsigned long *bitmap = *(unsigned long **) table->data;
2697 	unsigned long *tmp_bitmap = NULL;
2698 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2699 
2700 	if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2701 		*lenp = 0;
2702 		return 0;
2703 	}
2704 
2705 	if (write) {
2706 		char *kbuf, *p;
2707 
2708 		if (left > PAGE_SIZE - 1)
2709 			left = PAGE_SIZE - 1;
2710 
2711 		p = kbuf = memdup_user_nul(buffer, left);
2712 		if (IS_ERR(kbuf))
2713 			return PTR_ERR(kbuf);
2714 
2715 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2716 				     GFP_KERNEL);
2717 		if (!tmp_bitmap) {
2718 			kfree(kbuf);
2719 			return -ENOMEM;
2720 		}
2721 		proc_skip_char(&p, &left, '\n');
2722 		while (!err && left) {
2723 			unsigned long val_a, val_b;
2724 			bool neg;
2725 
2726 			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2727 					     sizeof(tr_a), &c);
2728 			if (err)
2729 				break;
2730 			if (val_a >= bitmap_len || neg) {
2731 				err = -EINVAL;
2732 				break;
2733 			}
2734 
2735 			val_b = val_a;
2736 			if (left) {
2737 				p++;
2738 				left--;
2739 			}
2740 
2741 			if (c == '-') {
2742 				err = proc_get_long(&p, &left, &val_b,
2743 						     &neg, tr_b, sizeof(tr_b),
2744 						     &c);
2745 				if (err)
2746 					break;
2747 				if (val_b >= bitmap_len || neg ||
2748 				    val_a > val_b) {
2749 					err = -EINVAL;
2750 					break;
2751 				}
2752 				if (left) {
2753 					p++;
2754 					left--;
2755 				}
2756 			}
2757 
2758 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2759 			first = 0;
2760 			proc_skip_char(&p, &left, '\n');
2761 		}
2762 		kfree(kbuf);
2763 	} else {
2764 		unsigned long bit_a, bit_b = 0;
2765 
2766 		while (left) {
2767 			bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2768 			if (bit_a >= bitmap_len)
2769 				break;
2770 			bit_b = find_next_zero_bit(bitmap, bitmap_len,
2771 						   bit_a + 1) - 1;
2772 
2773 			if (!first) {
2774 				err = proc_put_char(&buffer, &left, ',');
2775 				if (err)
2776 					break;
2777 			}
2778 			err = proc_put_long(&buffer, &left, bit_a, false);
2779 			if (err)
2780 				break;
2781 			if (bit_a != bit_b) {
2782 				err = proc_put_char(&buffer, &left, '-');
2783 				if (err)
2784 					break;
2785 				err = proc_put_long(&buffer, &left, bit_b, false);
2786 				if (err)
2787 					break;
2788 			}
2789 
2790 			first = 0; bit_b++;
2791 		}
2792 		if (!err)
2793 			err = proc_put_char(&buffer, &left, '\n');
2794 	}
2795 
2796 	if (!err) {
2797 		if (write) {
2798 			if (*ppos)
2799 				bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2800 			else
2801 				bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2802 		}
2803 		kfree(tmp_bitmap);
2804 		*lenp -= left;
2805 		*ppos += *lenp;
2806 		return 0;
2807 	} else {
2808 		kfree(tmp_bitmap);
2809 		return err;
2810 	}
2811 }
2812 
2813 #else /* CONFIG_PROC_SYSCTL */
2814 
2815 int proc_dostring(struct ctl_table *table, int write,
2816 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2817 {
2818 	return -ENOSYS;
2819 }
2820 
2821 int proc_dointvec(struct ctl_table *table, int write,
2822 		  void __user *buffer, size_t *lenp, loff_t *ppos)
2823 {
2824 	return -ENOSYS;
2825 }
2826 
2827 int proc_dointvec_minmax(struct ctl_table *table, int write,
2828 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2829 {
2830 	return -ENOSYS;
2831 }
2832 
2833 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2834 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2835 {
2836 	return -ENOSYS;
2837 }
2838 
2839 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2840 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2841 {
2842 	return -ENOSYS;
2843 }
2844 
2845 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2846 			     void __user *buffer, size_t *lenp, loff_t *ppos)
2847 {
2848 	return -ENOSYS;
2849 }
2850 
2851 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2852 		    void __user *buffer, size_t *lenp, loff_t *ppos)
2853 {
2854 	return -ENOSYS;
2855 }
2856 
2857 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2858 				      void __user *buffer,
2859 				      size_t *lenp, loff_t *ppos)
2860 {
2861     return -ENOSYS;
2862 }
2863 
2864 
2865 #endif /* CONFIG_PROC_SYSCTL */
2866 
2867 /*
2868  * No sense putting this after each symbol definition, twice,
2869  * exception granted :-)
2870  */
2871 EXPORT_SYMBOL(proc_dointvec);
2872 EXPORT_SYMBOL(proc_dointvec_jiffies);
2873 EXPORT_SYMBOL(proc_dointvec_minmax);
2874 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2875 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2876 EXPORT_SYMBOL(proc_dostring);
2877 EXPORT_SYMBOL(proc_doulongvec_minmax);
2878 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2879