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