Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx
[linux-2.6/kvm.git] / kernel / sysctl.c
blob6b005e4912b557e849f1576ff3cba2827ce8f972
1 /*
2 * sysctl.c: General linux system control interface
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
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/swap.h>
24 #include <linux/slab.h>
25 #include <linux/sysctl.h>
26 #include <linux/signal.h>
27 #include <linux/proc_fs.h>
28 #include <linux/security.h>
29 #include <linux/ctype.h>
30 #include <linux/kmemcheck.h>
31 #include <linux/fs.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/kobject.h>
35 #include <linux/net.h>
36 #include <linux/sysrq.h>
37 #include <linux/highuid.h>
38 #include <linux/writeback.h>
39 #include <linux/ratelimit.h>
40 #include <linux/compaction.h>
41 #include <linux/hugetlb.h>
42 #include <linux/initrd.h>
43 #include <linux/key.h>
44 #include <linux/times.h>
45 #include <linux/limits.h>
46 #include <linux/dcache.h>
47 #include <linux/syscalls.h>
48 #include <linux/vmstat.h>
49 #include <linux/nfs_fs.h>
50 #include <linux/acpi.h>
51 #include <linux/reboot.h>
52 #include <linux/ftrace.h>
53 #include <linux/perf_event.h>
54 #include <linux/kprobes.h>
55 #include <linux/pipe_fs_i.h>
56 #include <linux/oom.h>
58 #include <asm/uaccess.h>
59 #include <asm/processor.h>
61 #ifdef CONFIG_X86
62 #include <asm/nmi.h>
63 #include <asm/stacktrace.h>
64 #include <asm/io.h>
65 #endif
66 #ifdef CONFIG_BSD_PROCESS_ACCT
67 #include <linux/acct.h>
68 #endif
69 #ifdef CONFIG_RT_MUTEXES
70 #include <linux/rtmutex.h>
71 #endif
72 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
73 #include <linux/lockdep.h>
74 #endif
75 #ifdef CONFIG_CHR_DEV_SG
76 #include <scsi/sg.h>
77 #endif
79 #ifdef CONFIG_LOCKUP_DETECTOR
80 #include <linux/nmi.h>
81 #endif
84 #if defined(CONFIG_SYSCTL)
86 /* External variables not in a header file. */
87 extern int sysctl_overcommit_memory;
88 extern int sysctl_overcommit_ratio;
89 extern int max_threads;
90 extern int core_uses_pid;
91 extern int suid_dumpable;
92 extern char core_pattern[];
93 extern unsigned int core_pipe_limit;
94 extern int pid_max;
95 extern int min_free_kbytes;
96 extern int pid_max_min, pid_max_max;
97 extern int sysctl_drop_caches;
98 extern int percpu_pagelist_fraction;
99 extern int compat_log;
100 extern int latencytop_enabled;
101 extern int sysctl_nr_open_min, sysctl_nr_open_max;
102 #ifndef CONFIG_MMU
103 extern int sysctl_nr_trim_pages;
104 #endif
105 #ifdef CONFIG_BLOCK
106 extern int blk_iopoll_enabled;
107 #endif
109 /* Constants used for minimum and maximum */
110 #ifdef CONFIG_LOCKUP_DETECTOR
111 static int sixty = 60;
112 static int neg_one = -1;
113 #endif
115 static int zero;
116 static int __maybe_unused one = 1;
117 static int __maybe_unused two = 2;
118 static unsigned long one_ul = 1;
119 static int one_hundred = 100;
120 #ifdef CONFIG_PRINTK
121 static int ten_thousand = 10000;
122 #endif
124 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
125 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
127 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
128 static int maxolduid = 65535;
129 static int minolduid;
130 static int min_percpu_pagelist_fract = 8;
132 static int ngroups_max = NGROUPS_MAX;
134 #ifdef CONFIG_SPARC
135 #include <asm/system.h>
136 #endif
138 #ifdef CONFIG_SPARC64
139 extern int sysctl_tsb_ratio;
140 #endif
142 #ifdef __hppa__
143 extern int pwrsw_enabled;
144 extern int unaligned_enabled;
145 #endif
147 #ifdef CONFIG_S390
148 #ifdef CONFIG_MATHEMU
149 extern int sysctl_ieee_emulation_warnings;
150 #endif
151 extern int sysctl_userprocess_debug;
152 extern int spin_retry;
153 #endif
155 #ifdef CONFIG_IA64
156 extern int no_unaligned_warning;
157 extern int unaligned_dump_stack;
158 #endif
160 extern struct ratelimit_state printk_ratelimit_state;
162 #ifdef CONFIG_PROC_SYSCTL
163 static int proc_do_cad_pid(struct ctl_table *table, int write,
164 void __user *buffer, size_t *lenp, loff_t *ppos);
165 static int proc_taint(struct ctl_table *table, int write,
166 void __user *buffer, size_t *lenp, loff_t *ppos);
167 #endif
169 #ifdef CONFIG_MAGIC_SYSRQ
170 static int __sysrq_enabled; /* Note: sysrq code ises it's own private copy */
172 static int sysrq_sysctl_handler(ctl_table *table, int write,
173 void __user *buffer, size_t *lenp,
174 loff_t *ppos)
176 int error;
178 error = proc_dointvec(table, write, buffer, lenp, ppos);
179 if (error)
180 return error;
182 if (write)
183 sysrq_toggle_support(__sysrq_enabled);
185 return 0;
188 #endif
190 static struct ctl_table root_table[];
191 static struct ctl_table_root sysctl_table_root;
192 static struct ctl_table_header root_table_header = {
193 .count = 1,
194 .ctl_table = root_table,
195 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
196 .root = &sysctl_table_root,
197 .set = &sysctl_table_root.default_set,
199 static struct ctl_table_root sysctl_table_root = {
200 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
201 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
204 static struct ctl_table kern_table[];
205 static struct ctl_table vm_table[];
206 static struct ctl_table fs_table[];
207 static struct ctl_table debug_table[];
208 static struct ctl_table dev_table[];
209 extern struct ctl_table random_table[];
210 #ifdef CONFIG_INOTIFY_USER
211 extern struct ctl_table inotify_table[];
212 #endif
213 #ifdef CONFIG_EPOLL
214 extern struct ctl_table epoll_table[];
215 #endif
217 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
218 int sysctl_legacy_va_layout;
219 #endif
221 /* The default sysctl tables: */
223 static struct ctl_table root_table[] = {
225 .procname = "kernel",
226 .mode = 0555,
227 .child = kern_table,
230 .procname = "vm",
231 .mode = 0555,
232 .child = vm_table,
235 .procname = "fs",
236 .mode = 0555,
237 .child = fs_table,
240 .procname = "debug",
241 .mode = 0555,
242 .child = debug_table,
245 .procname = "dev",
246 .mode = 0555,
247 .child = dev_table,
250 * NOTE: do not add new entries to this table unless you have read
251 * Documentation/sysctl/ctl_unnumbered.txt
256 #ifdef CONFIG_SCHED_DEBUG
257 static int min_sched_granularity_ns = 100000; /* 100 usecs */
258 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
259 static int min_wakeup_granularity_ns; /* 0 usecs */
260 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
261 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
262 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
263 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
264 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
265 #endif
267 #ifdef CONFIG_COMPACTION
268 static int min_extfrag_threshold;
269 static int max_extfrag_threshold = 1000;
270 #endif
272 static struct ctl_table kern_table[] = {
274 .procname = "sched_child_runs_first",
275 .data = &sysctl_sched_child_runs_first,
276 .maxlen = sizeof(unsigned int),
277 .mode = 0644,
278 .proc_handler = proc_dointvec,
280 #ifdef CONFIG_SCHED_DEBUG
282 .procname = "sched_min_granularity_ns",
283 .data = &sysctl_sched_min_granularity,
284 .maxlen = sizeof(unsigned int),
285 .mode = 0644,
286 .proc_handler = sched_proc_update_handler,
287 .extra1 = &min_sched_granularity_ns,
288 .extra2 = &max_sched_granularity_ns,
291 .procname = "sched_latency_ns",
292 .data = &sysctl_sched_latency,
293 .maxlen = sizeof(unsigned int),
294 .mode = 0644,
295 .proc_handler = sched_proc_update_handler,
296 .extra1 = &min_sched_granularity_ns,
297 .extra2 = &max_sched_granularity_ns,
300 .procname = "sched_wakeup_granularity_ns",
301 .data = &sysctl_sched_wakeup_granularity,
302 .maxlen = sizeof(unsigned int),
303 .mode = 0644,
304 .proc_handler = sched_proc_update_handler,
305 .extra1 = &min_wakeup_granularity_ns,
306 .extra2 = &max_wakeup_granularity_ns,
309 .procname = "sched_shares_ratelimit",
310 .data = &sysctl_sched_shares_ratelimit,
311 .maxlen = sizeof(unsigned int),
312 .mode = 0644,
313 .proc_handler = sched_proc_update_handler,
314 .extra1 = &min_sched_shares_ratelimit,
315 .extra2 = &max_sched_shares_ratelimit,
318 .procname = "sched_tunable_scaling",
319 .data = &sysctl_sched_tunable_scaling,
320 .maxlen = sizeof(enum sched_tunable_scaling),
321 .mode = 0644,
322 .proc_handler = sched_proc_update_handler,
323 .extra1 = &min_sched_tunable_scaling,
324 .extra2 = &max_sched_tunable_scaling,
327 .procname = "sched_shares_thresh",
328 .data = &sysctl_sched_shares_thresh,
329 .maxlen = sizeof(unsigned int),
330 .mode = 0644,
331 .proc_handler = proc_dointvec_minmax,
332 .extra1 = &zero,
335 .procname = "sched_migration_cost",
336 .data = &sysctl_sched_migration_cost,
337 .maxlen = sizeof(unsigned int),
338 .mode = 0644,
339 .proc_handler = proc_dointvec,
342 .procname = "sched_nr_migrate",
343 .data = &sysctl_sched_nr_migrate,
344 .maxlen = sizeof(unsigned int),
345 .mode = 0644,
346 .proc_handler = proc_dointvec,
349 .procname = "sched_time_avg",
350 .data = &sysctl_sched_time_avg,
351 .maxlen = sizeof(unsigned int),
352 .mode = 0644,
353 .proc_handler = proc_dointvec,
356 .procname = "timer_migration",
357 .data = &sysctl_timer_migration,
358 .maxlen = sizeof(unsigned int),
359 .mode = 0644,
360 .proc_handler = proc_dointvec_minmax,
361 .extra1 = &zero,
362 .extra2 = &one,
364 #endif
366 .procname = "sched_rt_period_us",
367 .data = &sysctl_sched_rt_period,
368 .maxlen = sizeof(unsigned int),
369 .mode = 0644,
370 .proc_handler = sched_rt_handler,
373 .procname = "sched_rt_runtime_us",
374 .data = &sysctl_sched_rt_runtime,
375 .maxlen = sizeof(int),
376 .mode = 0644,
377 .proc_handler = sched_rt_handler,
380 .procname = "sched_compat_yield",
381 .data = &sysctl_sched_compat_yield,
382 .maxlen = sizeof(unsigned int),
383 .mode = 0644,
384 .proc_handler = proc_dointvec,
386 #ifdef CONFIG_PROVE_LOCKING
388 .procname = "prove_locking",
389 .data = &prove_locking,
390 .maxlen = sizeof(int),
391 .mode = 0644,
392 .proc_handler = proc_dointvec,
394 #endif
395 #ifdef CONFIG_LOCK_STAT
397 .procname = "lock_stat",
398 .data = &lock_stat,
399 .maxlen = sizeof(int),
400 .mode = 0644,
401 .proc_handler = proc_dointvec,
403 #endif
405 .procname = "panic",
406 .data = &panic_timeout,
407 .maxlen = sizeof(int),
408 .mode = 0644,
409 .proc_handler = proc_dointvec,
412 .procname = "core_uses_pid",
413 .data = &core_uses_pid,
414 .maxlen = sizeof(int),
415 .mode = 0644,
416 .proc_handler = proc_dointvec,
419 .procname = "core_pattern",
420 .data = core_pattern,
421 .maxlen = CORENAME_MAX_SIZE,
422 .mode = 0644,
423 .proc_handler = proc_dostring,
426 .procname = "core_pipe_limit",
427 .data = &core_pipe_limit,
428 .maxlen = sizeof(unsigned int),
429 .mode = 0644,
430 .proc_handler = proc_dointvec,
432 #ifdef CONFIG_PROC_SYSCTL
434 .procname = "tainted",
435 .maxlen = sizeof(long),
436 .mode = 0644,
437 .proc_handler = proc_taint,
439 #endif
440 #ifdef CONFIG_LATENCYTOP
442 .procname = "latencytop",
443 .data = &latencytop_enabled,
444 .maxlen = sizeof(int),
445 .mode = 0644,
446 .proc_handler = proc_dointvec,
448 #endif
449 #ifdef CONFIG_BLK_DEV_INITRD
451 .procname = "real-root-dev",
452 .data = &real_root_dev,
453 .maxlen = sizeof(int),
454 .mode = 0644,
455 .proc_handler = proc_dointvec,
457 #endif
459 .procname = "print-fatal-signals",
460 .data = &print_fatal_signals,
461 .maxlen = sizeof(int),
462 .mode = 0644,
463 .proc_handler = proc_dointvec,
465 #ifdef CONFIG_SPARC
467 .procname = "reboot-cmd",
468 .data = reboot_command,
469 .maxlen = 256,
470 .mode = 0644,
471 .proc_handler = proc_dostring,
474 .procname = "stop-a",
475 .data = &stop_a_enabled,
476 .maxlen = sizeof (int),
477 .mode = 0644,
478 .proc_handler = proc_dointvec,
481 .procname = "scons-poweroff",
482 .data = &scons_pwroff,
483 .maxlen = sizeof (int),
484 .mode = 0644,
485 .proc_handler = proc_dointvec,
487 #endif
488 #ifdef CONFIG_SPARC64
490 .procname = "tsb-ratio",
491 .data = &sysctl_tsb_ratio,
492 .maxlen = sizeof (int),
493 .mode = 0644,
494 .proc_handler = proc_dointvec,
496 #endif
497 #ifdef __hppa__
499 .procname = "soft-power",
500 .data = &pwrsw_enabled,
501 .maxlen = sizeof (int),
502 .mode = 0644,
503 .proc_handler = proc_dointvec,
506 .procname = "unaligned-trap",
507 .data = &unaligned_enabled,
508 .maxlen = sizeof (int),
509 .mode = 0644,
510 .proc_handler = proc_dointvec,
512 #endif
514 .procname = "ctrl-alt-del",
515 .data = &C_A_D,
516 .maxlen = sizeof(int),
517 .mode = 0644,
518 .proc_handler = proc_dointvec,
520 #ifdef CONFIG_FUNCTION_TRACER
522 .procname = "ftrace_enabled",
523 .data = &ftrace_enabled,
524 .maxlen = sizeof(int),
525 .mode = 0644,
526 .proc_handler = ftrace_enable_sysctl,
528 #endif
529 #ifdef CONFIG_STACK_TRACER
531 .procname = "stack_tracer_enabled",
532 .data = &stack_tracer_enabled,
533 .maxlen = sizeof(int),
534 .mode = 0644,
535 .proc_handler = stack_trace_sysctl,
537 #endif
538 #ifdef CONFIG_TRACING
540 .procname = "ftrace_dump_on_oops",
541 .data = &ftrace_dump_on_oops,
542 .maxlen = sizeof(int),
543 .mode = 0644,
544 .proc_handler = proc_dointvec,
546 #endif
547 #ifdef CONFIG_MODULES
549 .procname = "modprobe",
550 .data = &modprobe_path,
551 .maxlen = KMOD_PATH_LEN,
552 .mode = 0644,
553 .proc_handler = proc_dostring,
556 .procname = "modules_disabled",
557 .data = &modules_disabled,
558 .maxlen = sizeof(int),
559 .mode = 0644,
560 /* only handle a transition from default "0" to "1" */
561 .proc_handler = proc_dointvec_minmax,
562 .extra1 = &one,
563 .extra2 = &one,
565 #endif
566 #ifdef CONFIG_HOTPLUG
568 .procname = "hotplug",
569 .data = &uevent_helper,
570 .maxlen = UEVENT_HELPER_PATH_LEN,
571 .mode = 0644,
572 .proc_handler = proc_dostring,
574 #endif
575 #ifdef CONFIG_CHR_DEV_SG
577 .procname = "sg-big-buff",
578 .data = &sg_big_buff,
579 .maxlen = sizeof (int),
580 .mode = 0444,
581 .proc_handler = proc_dointvec,
583 #endif
584 #ifdef CONFIG_BSD_PROCESS_ACCT
586 .procname = "acct",
587 .data = &acct_parm,
588 .maxlen = 3*sizeof(int),
589 .mode = 0644,
590 .proc_handler = proc_dointvec,
592 #endif
593 #ifdef CONFIG_MAGIC_SYSRQ
595 .procname = "sysrq",
596 .data = &__sysrq_enabled,
597 .maxlen = sizeof (int),
598 .mode = 0644,
599 .proc_handler = sysrq_sysctl_handler,
601 #endif
602 #ifdef CONFIG_PROC_SYSCTL
604 .procname = "cad_pid",
605 .data = NULL,
606 .maxlen = sizeof (int),
607 .mode = 0600,
608 .proc_handler = proc_do_cad_pid,
610 #endif
612 .procname = "threads-max",
613 .data = &max_threads,
614 .maxlen = sizeof(int),
615 .mode = 0644,
616 .proc_handler = proc_dointvec,
619 .procname = "random",
620 .mode = 0555,
621 .child = random_table,
624 .procname = "overflowuid",
625 .data = &overflowuid,
626 .maxlen = sizeof(int),
627 .mode = 0644,
628 .proc_handler = proc_dointvec_minmax,
629 .extra1 = &minolduid,
630 .extra2 = &maxolduid,
633 .procname = "overflowgid",
634 .data = &overflowgid,
635 .maxlen = sizeof(int),
636 .mode = 0644,
637 .proc_handler = proc_dointvec_minmax,
638 .extra1 = &minolduid,
639 .extra2 = &maxolduid,
641 #ifdef CONFIG_S390
642 #ifdef CONFIG_MATHEMU
644 .procname = "ieee_emulation_warnings",
645 .data = &sysctl_ieee_emulation_warnings,
646 .maxlen = sizeof(int),
647 .mode = 0644,
648 .proc_handler = proc_dointvec,
650 #endif
652 .procname = "userprocess_debug",
653 .data = &show_unhandled_signals,
654 .maxlen = sizeof(int),
655 .mode = 0644,
656 .proc_handler = proc_dointvec,
658 #endif
660 .procname = "pid_max",
661 .data = &pid_max,
662 .maxlen = sizeof (int),
663 .mode = 0644,
664 .proc_handler = proc_dointvec_minmax,
665 .extra1 = &pid_max_min,
666 .extra2 = &pid_max_max,
669 .procname = "panic_on_oops",
670 .data = &panic_on_oops,
671 .maxlen = sizeof(int),
672 .mode = 0644,
673 .proc_handler = proc_dointvec,
675 #if defined CONFIG_PRINTK
677 .procname = "printk",
678 .data = &console_loglevel,
679 .maxlen = 4*sizeof(int),
680 .mode = 0644,
681 .proc_handler = proc_dointvec,
684 .procname = "printk_ratelimit",
685 .data = &printk_ratelimit_state.interval,
686 .maxlen = sizeof(int),
687 .mode = 0644,
688 .proc_handler = proc_dointvec_jiffies,
691 .procname = "printk_ratelimit_burst",
692 .data = &printk_ratelimit_state.burst,
693 .maxlen = sizeof(int),
694 .mode = 0644,
695 .proc_handler = proc_dointvec,
698 .procname = "printk_delay",
699 .data = &printk_delay_msec,
700 .maxlen = sizeof(int),
701 .mode = 0644,
702 .proc_handler = proc_dointvec_minmax,
703 .extra1 = &zero,
704 .extra2 = &ten_thousand,
706 #endif
708 .procname = "ngroups_max",
709 .data = &ngroups_max,
710 .maxlen = sizeof (int),
711 .mode = 0444,
712 .proc_handler = proc_dointvec,
714 #if defined(CONFIG_LOCKUP_DETECTOR)
716 .procname = "watchdog",
717 .data = &watchdog_enabled,
718 .maxlen = sizeof (int),
719 .mode = 0644,
720 .proc_handler = proc_dowatchdog_enabled,
723 .procname = "watchdog_thresh",
724 .data = &softlockup_thresh,
725 .maxlen = sizeof(int),
726 .mode = 0644,
727 .proc_handler = proc_dowatchdog_thresh,
728 .extra1 = &neg_one,
729 .extra2 = &sixty,
732 .procname = "softlockup_panic",
733 .data = &softlockup_panic,
734 .maxlen = sizeof(int),
735 .mode = 0644,
736 .proc_handler = proc_dointvec_minmax,
737 .extra1 = &zero,
738 .extra2 = &one,
740 #endif
741 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) && !defined(CONFIG_LOCKUP_DETECTOR)
743 .procname = "unknown_nmi_panic",
744 .data = &unknown_nmi_panic,
745 .maxlen = sizeof (int),
746 .mode = 0644,
747 .proc_handler = proc_dointvec,
750 .procname = "nmi_watchdog",
751 .data = &nmi_watchdog_enabled,
752 .maxlen = sizeof (int),
753 .mode = 0644,
754 .proc_handler = proc_nmi_enabled,
756 #endif
757 #if defined(CONFIG_X86)
759 .procname = "panic_on_unrecovered_nmi",
760 .data = &panic_on_unrecovered_nmi,
761 .maxlen = sizeof(int),
762 .mode = 0644,
763 .proc_handler = proc_dointvec,
766 .procname = "panic_on_io_nmi",
767 .data = &panic_on_io_nmi,
768 .maxlen = sizeof(int),
769 .mode = 0644,
770 .proc_handler = proc_dointvec,
773 .procname = "bootloader_type",
774 .data = &bootloader_type,
775 .maxlen = sizeof (int),
776 .mode = 0444,
777 .proc_handler = proc_dointvec,
780 .procname = "bootloader_version",
781 .data = &bootloader_version,
782 .maxlen = sizeof (int),
783 .mode = 0444,
784 .proc_handler = proc_dointvec,
787 .procname = "kstack_depth_to_print",
788 .data = &kstack_depth_to_print,
789 .maxlen = sizeof(int),
790 .mode = 0644,
791 .proc_handler = proc_dointvec,
794 .procname = "io_delay_type",
795 .data = &io_delay_type,
796 .maxlen = sizeof(int),
797 .mode = 0644,
798 .proc_handler = proc_dointvec,
800 #endif
801 #if defined(CONFIG_MMU)
803 .procname = "randomize_va_space",
804 .data = &randomize_va_space,
805 .maxlen = sizeof(int),
806 .mode = 0644,
807 .proc_handler = proc_dointvec,
809 #endif
810 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
812 .procname = "spin_retry",
813 .data = &spin_retry,
814 .maxlen = sizeof (int),
815 .mode = 0644,
816 .proc_handler = proc_dointvec,
818 #endif
819 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
821 .procname = "acpi_video_flags",
822 .data = &acpi_realmode_flags,
823 .maxlen = sizeof (unsigned long),
824 .mode = 0644,
825 .proc_handler = proc_doulongvec_minmax,
827 #endif
828 #ifdef CONFIG_IA64
830 .procname = "ignore-unaligned-usertrap",
831 .data = &no_unaligned_warning,
832 .maxlen = sizeof (int),
833 .mode = 0644,
834 .proc_handler = proc_dointvec,
837 .procname = "unaligned-dump-stack",
838 .data = &unaligned_dump_stack,
839 .maxlen = sizeof (int),
840 .mode = 0644,
841 .proc_handler = proc_dointvec,
843 #endif
844 #ifdef CONFIG_DETECT_HUNG_TASK
846 .procname = "hung_task_panic",
847 .data = &sysctl_hung_task_panic,
848 .maxlen = sizeof(int),
849 .mode = 0644,
850 .proc_handler = proc_dointvec_minmax,
851 .extra1 = &zero,
852 .extra2 = &one,
855 .procname = "hung_task_check_count",
856 .data = &sysctl_hung_task_check_count,
857 .maxlen = sizeof(unsigned long),
858 .mode = 0644,
859 .proc_handler = proc_doulongvec_minmax,
862 .procname = "hung_task_timeout_secs",
863 .data = &sysctl_hung_task_timeout_secs,
864 .maxlen = sizeof(unsigned long),
865 .mode = 0644,
866 .proc_handler = proc_dohung_task_timeout_secs,
869 .procname = "hung_task_warnings",
870 .data = &sysctl_hung_task_warnings,
871 .maxlen = sizeof(unsigned long),
872 .mode = 0644,
873 .proc_handler = proc_doulongvec_minmax,
875 #endif
876 #ifdef CONFIG_COMPAT
878 .procname = "compat-log",
879 .data = &compat_log,
880 .maxlen = sizeof (int),
881 .mode = 0644,
882 .proc_handler = proc_dointvec,
884 #endif
885 #ifdef CONFIG_RT_MUTEXES
887 .procname = "max_lock_depth",
888 .data = &max_lock_depth,
889 .maxlen = sizeof(int),
890 .mode = 0644,
891 .proc_handler = proc_dointvec,
893 #endif
895 .procname = "poweroff_cmd",
896 .data = &poweroff_cmd,
897 .maxlen = POWEROFF_CMD_PATH_LEN,
898 .mode = 0644,
899 .proc_handler = proc_dostring,
901 #ifdef CONFIG_KEYS
903 .procname = "keys",
904 .mode = 0555,
905 .child = key_sysctls,
907 #endif
908 #ifdef CONFIG_RCU_TORTURE_TEST
910 .procname = "rcutorture_runnable",
911 .data = &rcutorture_runnable,
912 .maxlen = sizeof(int),
913 .mode = 0644,
914 .proc_handler = proc_dointvec,
916 #endif
917 #ifdef CONFIG_PERF_EVENTS
919 .procname = "perf_event_paranoid",
920 .data = &sysctl_perf_event_paranoid,
921 .maxlen = sizeof(sysctl_perf_event_paranoid),
922 .mode = 0644,
923 .proc_handler = proc_dointvec,
926 .procname = "perf_event_mlock_kb",
927 .data = &sysctl_perf_event_mlock,
928 .maxlen = sizeof(sysctl_perf_event_mlock),
929 .mode = 0644,
930 .proc_handler = proc_dointvec,
933 .procname = "perf_event_max_sample_rate",
934 .data = &sysctl_perf_event_sample_rate,
935 .maxlen = sizeof(sysctl_perf_event_sample_rate),
936 .mode = 0644,
937 .proc_handler = proc_dointvec,
939 #endif
940 #ifdef CONFIG_KMEMCHECK
942 .procname = "kmemcheck",
943 .data = &kmemcheck_enabled,
944 .maxlen = sizeof(int),
945 .mode = 0644,
946 .proc_handler = proc_dointvec,
948 #endif
949 #ifdef CONFIG_BLOCK
951 .procname = "blk_iopoll",
952 .data = &blk_iopoll_enabled,
953 .maxlen = sizeof(int),
954 .mode = 0644,
955 .proc_handler = proc_dointvec,
957 #endif
959 * NOTE: do not add new entries to this table unless you have read
960 * Documentation/sysctl/ctl_unnumbered.txt
965 static struct ctl_table vm_table[] = {
967 .procname = "overcommit_memory",
968 .data = &sysctl_overcommit_memory,
969 .maxlen = sizeof(sysctl_overcommit_memory),
970 .mode = 0644,
971 .proc_handler = proc_dointvec,
974 .procname = "panic_on_oom",
975 .data = &sysctl_panic_on_oom,
976 .maxlen = sizeof(sysctl_panic_on_oom),
977 .mode = 0644,
978 .proc_handler = proc_dointvec,
981 .procname = "oom_kill_allocating_task",
982 .data = &sysctl_oom_kill_allocating_task,
983 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
984 .mode = 0644,
985 .proc_handler = proc_dointvec,
988 .procname = "oom_dump_tasks",
989 .data = &sysctl_oom_dump_tasks,
990 .maxlen = sizeof(sysctl_oom_dump_tasks),
991 .mode = 0644,
992 .proc_handler = proc_dointvec,
995 .procname = "overcommit_ratio",
996 .data = &sysctl_overcommit_ratio,
997 .maxlen = sizeof(sysctl_overcommit_ratio),
998 .mode = 0644,
999 .proc_handler = proc_dointvec,
1002 .procname = "page-cluster",
1003 .data = &page_cluster,
1004 .maxlen = sizeof(int),
1005 .mode = 0644,
1006 .proc_handler = proc_dointvec,
1009 .procname = "dirty_background_ratio",
1010 .data = &dirty_background_ratio,
1011 .maxlen = sizeof(dirty_background_ratio),
1012 .mode = 0644,
1013 .proc_handler = dirty_background_ratio_handler,
1014 .extra1 = &zero,
1015 .extra2 = &one_hundred,
1018 .procname = "dirty_background_bytes",
1019 .data = &dirty_background_bytes,
1020 .maxlen = sizeof(dirty_background_bytes),
1021 .mode = 0644,
1022 .proc_handler = dirty_background_bytes_handler,
1023 .extra1 = &one_ul,
1026 .procname = "dirty_ratio",
1027 .data = &vm_dirty_ratio,
1028 .maxlen = sizeof(vm_dirty_ratio),
1029 .mode = 0644,
1030 .proc_handler = dirty_ratio_handler,
1031 .extra1 = &zero,
1032 .extra2 = &one_hundred,
1035 .procname = "dirty_bytes",
1036 .data = &vm_dirty_bytes,
1037 .maxlen = sizeof(vm_dirty_bytes),
1038 .mode = 0644,
1039 .proc_handler = dirty_bytes_handler,
1040 .extra1 = &dirty_bytes_min,
1043 .procname = "dirty_writeback_centisecs",
1044 .data = &dirty_writeback_interval,
1045 .maxlen = sizeof(dirty_writeback_interval),
1046 .mode = 0644,
1047 .proc_handler = dirty_writeback_centisecs_handler,
1050 .procname = "dirty_expire_centisecs",
1051 .data = &dirty_expire_interval,
1052 .maxlen = sizeof(dirty_expire_interval),
1053 .mode = 0644,
1054 .proc_handler = proc_dointvec,
1057 .procname = "nr_pdflush_threads",
1058 .data = &nr_pdflush_threads,
1059 .maxlen = sizeof nr_pdflush_threads,
1060 .mode = 0444 /* read-only*/,
1061 .proc_handler = proc_dointvec,
1064 .procname = "swappiness",
1065 .data = &vm_swappiness,
1066 .maxlen = sizeof(vm_swappiness),
1067 .mode = 0644,
1068 .proc_handler = proc_dointvec_minmax,
1069 .extra1 = &zero,
1070 .extra2 = &one_hundred,
1072 #ifdef CONFIG_HUGETLB_PAGE
1074 .procname = "nr_hugepages",
1075 .data = NULL,
1076 .maxlen = sizeof(unsigned long),
1077 .mode = 0644,
1078 .proc_handler = hugetlb_sysctl_handler,
1079 .extra1 = (void *)&hugetlb_zero,
1080 .extra2 = (void *)&hugetlb_infinity,
1082 #ifdef CONFIG_NUMA
1084 .procname = "nr_hugepages_mempolicy",
1085 .data = NULL,
1086 .maxlen = sizeof(unsigned long),
1087 .mode = 0644,
1088 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1089 .extra1 = (void *)&hugetlb_zero,
1090 .extra2 = (void *)&hugetlb_infinity,
1092 #endif
1094 .procname = "hugetlb_shm_group",
1095 .data = &sysctl_hugetlb_shm_group,
1096 .maxlen = sizeof(gid_t),
1097 .mode = 0644,
1098 .proc_handler = proc_dointvec,
1101 .procname = "hugepages_treat_as_movable",
1102 .data = &hugepages_treat_as_movable,
1103 .maxlen = sizeof(int),
1104 .mode = 0644,
1105 .proc_handler = hugetlb_treat_movable_handler,
1108 .procname = "nr_overcommit_hugepages",
1109 .data = NULL,
1110 .maxlen = sizeof(unsigned long),
1111 .mode = 0644,
1112 .proc_handler = hugetlb_overcommit_handler,
1113 .extra1 = (void *)&hugetlb_zero,
1114 .extra2 = (void *)&hugetlb_infinity,
1116 #endif
1118 .procname = "lowmem_reserve_ratio",
1119 .data = &sysctl_lowmem_reserve_ratio,
1120 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1121 .mode = 0644,
1122 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1125 .procname = "drop_caches",
1126 .data = &sysctl_drop_caches,
1127 .maxlen = sizeof(int),
1128 .mode = 0644,
1129 .proc_handler = drop_caches_sysctl_handler,
1131 #ifdef CONFIG_COMPACTION
1133 .procname = "compact_memory",
1134 .data = &sysctl_compact_memory,
1135 .maxlen = sizeof(int),
1136 .mode = 0200,
1137 .proc_handler = sysctl_compaction_handler,
1140 .procname = "extfrag_threshold",
1141 .data = &sysctl_extfrag_threshold,
1142 .maxlen = sizeof(int),
1143 .mode = 0644,
1144 .proc_handler = sysctl_extfrag_handler,
1145 .extra1 = &min_extfrag_threshold,
1146 .extra2 = &max_extfrag_threshold,
1149 #endif /* CONFIG_COMPACTION */
1151 .procname = "min_free_kbytes",
1152 .data = &min_free_kbytes,
1153 .maxlen = sizeof(min_free_kbytes),
1154 .mode = 0644,
1155 .proc_handler = min_free_kbytes_sysctl_handler,
1156 .extra1 = &zero,
1159 .procname = "percpu_pagelist_fraction",
1160 .data = &percpu_pagelist_fraction,
1161 .maxlen = sizeof(percpu_pagelist_fraction),
1162 .mode = 0644,
1163 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1164 .extra1 = &min_percpu_pagelist_fract,
1166 #ifdef CONFIG_MMU
1168 .procname = "max_map_count",
1169 .data = &sysctl_max_map_count,
1170 .maxlen = sizeof(sysctl_max_map_count),
1171 .mode = 0644,
1172 .proc_handler = proc_dointvec_minmax,
1173 .extra1 = &zero,
1175 #else
1177 .procname = "nr_trim_pages",
1178 .data = &sysctl_nr_trim_pages,
1179 .maxlen = sizeof(sysctl_nr_trim_pages),
1180 .mode = 0644,
1181 .proc_handler = proc_dointvec_minmax,
1182 .extra1 = &zero,
1184 #endif
1186 .procname = "laptop_mode",
1187 .data = &laptop_mode,
1188 .maxlen = sizeof(laptop_mode),
1189 .mode = 0644,
1190 .proc_handler = proc_dointvec_jiffies,
1193 .procname = "block_dump",
1194 .data = &block_dump,
1195 .maxlen = sizeof(block_dump),
1196 .mode = 0644,
1197 .proc_handler = proc_dointvec,
1198 .extra1 = &zero,
1201 .procname = "vfs_cache_pressure",
1202 .data = &sysctl_vfs_cache_pressure,
1203 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1204 .mode = 0644,
1205 .proc_handler = proc_dointvec,
1206 .extra1 = &zero,
1208 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1210 .procname = "legacy_va_layout",
1211 .data = &sysctl_legacy_va_layout,
1212 .maxlen = sizeof(sysctl_legacy_va_layout),
1213 .mode = 0644,
1214 .proc_handler = proc_dointvec,
1215 .extra1 = &zero,
1217 #endif
1218 #ifdef CONFIG_NUMA
1220 .procname = "zone_reclaim_mode",
1221 .data = &zone_reclaim_mode,
1222 .maxlen = sizeof(zone_reclaim_mode),
1223 .mode = 0644,
1224 .proc_handler = proc_dointvec,
1225 .extra1 = &zero,
1228 .procname = "min_unmapped_ratio",
1229 .data = &sysctl_min_unmapped_ratio,
1230 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1231 .mode = 0644,
1232 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1233 .extra1 = &zero,
1234 .extra2 = &one_hundred,
1237 .procname = "min_slab_ratio",
1238 .data = &sysctl_min_slab_ratio,
1239 .maxlen = sizeof(sysctl_min_slab_ratio),
1240 .mode = 0644,
1241 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1242 .extra1 = &zero,
1243 .extra2 = &one_hundred,
1245 #endif
1246 #ifdef CONFIG_SMP
1248 .procname = "stat_interval",
1249 .data = &sysctl_stat_interval,
1250 .maxlen = sizeof(sysctl_stat_interval),
1251 .mode = 0644,
1252 .proc_handler = proc_dointvec_jiffies,
1254 #endif
1255 #ifdef CONFIG_MMU
1257 .procname = "mmap_min_addr",
1258 .data = &dac_mmap_min_addr,
1259 .maxlen = sizeof(unsigned long),
1260 .mode = 0644,
1261 .proc_handler = mmap_min_addr_handler,
1263 #endif
1264 #ifdef CONFIG_NUMA
1266 .procname = "numa_zonelist_order",
1267 .data = &numa_zonelist_order,
1268 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1269 .mode = 0644,
1270 .proc_handler = numa_zonelist_order_handler,
1272 #endif
1273 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1274 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1276 .procname = "vdso_enabled",
1277 .data = &vdso_enabled,
1278 .maxlen = sizeof(vdso_enabled),
1279 .mode = 0644,
1280 .proc_handler = proc_dointvec,
1281 .extra1 = &zero,
1283 #endif
1284 #ifdef CONFIG_HIGHMEM
1286 .procname = "highmem_is_dirtyable",
1287 .data = &vm_highmem_is_dirtyable,
1288 .maxlen = sizeof(vm_highmem_is_dirtyable),
1289 .mode = 0644,
1290 .proc_handler = proc_dointvec_minmax,
1291 .extra1 = &zero,
1292 .extra2 = &one,
1294 #endif
1296 .procname = "scan_unevictable_pages",
1297 .data = &scan_unevictable_pages,
1298 .maxlen = sizeof(scan_unevictable_pages),
1299 .mode = 0644,
1300 .proc_handler = scan_unevictable_handler,
1302 #ifdef CONFIG_MEMORY_FAILURE
1304 .procname = "memory_failure_early_kill",
1305 .data = &sysctl_memory_failure_early_kill,
1306 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1307 .mode = 0644,
1308 .proc_handler = proc_dointvec_minmax,
1309 .extra1 = &zero,
1310 .extra2 = &one,
1313 .procname = "memory_failure_recovery",
1314 .data = &sysctl_memory_failure_recovery,
1315 .maxlen = sizeof(sysctl_memory_failure_recovery),
1316 .mode = 0644,
1317 .proc_handler = proc_dointvec_minmax,
1318 .extra1 = &zero,
1319 .extra2 = &one,
1321 #endif
1324 * NOTE: do not add new entries to this table unless you have read
1325 * Documentation/sysctl/ctl_unnumbered.txt
1330 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1331 static struct ctl_table binfmt_misc_table[] = {
1334 #endif
1336 static struct ctl_table fs_table[] = {
1338 .procname = "inode-nr",
1339 .data = &inodes_stat,
1340 .maxlen = 2*sizeof(int),
1341 .mode = 0444,
1342 .proc_handler = proc_dointvec,
1345 .procname = "inode-state",
1346 .data = &inodes_stat,
1347 .maxlen = 7*sizeof(int),
1348 .mode = 0444,
1349 .proc_handler = proc_dointvec,
1352 .procname = "file-nr",
1353 .data = &files_stat,
1354 .maxlen = 3*sizeof(int),
1355 .mode = 0444,
1356 .proc_handler = proc_nr_files,
1359 .procname = "file-max",
1360 .data = &files_stat.max_files,
1361 .maxlen = sizeof(int),
1362 .mode = 0644,
1363 .proc_handler = proc_dointvec,
1366 .procname = "nr_open",
1367 .data = &sysctl_nr_open,
1368 .maxlen = sizeof(int),
1369 .mode = 0644,
1370 .proc_handler = proc_dointvec_minmax,
1371 .extra1 = &sysctl_nr_open_min,
1372 .extra2 = &sysctl_nr_open_max,
1375 .procname = "dentry-state",
1376 .data = &dentry_stat,
1377 .maxlen = 6*sizeof(int),
1378 .mode = 0444,
1379 .proc_handler = proc_dointvec,
1382 .procname = "overflowuid",
1383 .data = &fs_overflowuid,
1384 .maxlen = sizeof(int),
1385 .mode = 0644,
1386 .proc_handler = proc_dointvec_minmax,
1387 .extra1 = &minolduid,
1388 .extra2 = &maxolduid,
1391 .procname = "overflowgid",
1392 .data = &fs_overflowgid,
1393 .maxlen = sizeof(int),
1394 .mode = 0644,
1395 .proc_handler = proc_dointvec_minmax,
1396 .extra1 = &minolduid,
1397 .extra2 = &maxolduid,
1399 #ifdef CONFIG_FILE_LOCKING
1401 .procname = "leases-enable",
1402 .data = &leases_enable,
1403 .maxlen = sizeof(int),
1404 .mode = 0644,
1405 .proc_handler = proc_dointvec,
1407 #endif
1408 #ifdef CONFIG_DNOTIFY
1410 .procname = "dir-notify-enable",
1411 .data = &dir_notify_enable,
1412 .maxlen = sizeof(int),
1413 .mode = 0644,
1414 .proc_handler = proc_dointvec,
1416 #endif
1417 #ifdef CONFIG_MMU
1418 #ifdef CONFIG_FILE_LOCKING
1420 .procname = "lease-break-time",
1421 .data = &lease_break_time,
1422 .maxlen = sizeof(int),
1423 .mode = 0644,
1424 .proc_handler = proc_dointvec,
1426 #endif
1427 #ifdef CONFIG_AIO
1429 .procname = "aio-nr",
1430 .data = &aio_nr,
1431 .maxlen = sizeof(aio_nr),
1432 .mode = 0444,
1433 .proc_handler = proc_doulongvec_minmax,
1436 .procname = "aio-max-nr",
1437 .data = &aio_max_nr,
1438 .maxlen = sizeof(aio_max_nr),
1439 .mode = 0644,
1440 .proc_handler = proc_doulongvec_minmax,
1442 #endif /* CONFIG_AIO */
1443 #ifdef CONFIG_INOTIFY_USER
1445 .procname = "inotify",
1446 .mode = 0555,
1447 .child = inotify_table,
1449 #endif
1450 #ifdef CONFIG_EPOLL
1452 .procname = "epoll",
1453 .mode = 0555,
1454 .child = epoll_table,
1456 #endif
1457 #endif
1459 .procname = "suid_dumpable",
1460 .data = &suid_dumpable,
1461 .maxlen = sizeof(int),
1462 .mode = 0644,
1463 .proc_handler = proc_dointvec_minmax,
1464 .extra1 = &zero,
1465 .extra2 = &two,
1467 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1469 .procname = "binfmt_misc",
1470 .mode = 0555,
1471 .child = binfmt_misc_table,
1473 #endif
1475 .procname = "pipe-max-size",
1476 .data = &pipe_max_size,
1477 .maxlen = sizeof(int),
1478 .mode = 0644,
1479 .proc_handler = &pipe_proc_fn,
1480 .extra1 = &pipe_min_size,
1483 * NOTE: do not add new entries to this table unless you have read
1484 * Documentation/sysctl/ctl_unnumbered.txt
1489 static struct ctl_table debug_table[] = {
1490 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1491 defined(CONFIG_S390)
1493 .procname = "exception-trace",
1494 .data = &show_unhandled_signals,
1495 .maxlen = sizeof(int),
1496 .mode = 0644,
1497 .proc_handler = proc_dointvec
1499 #endif
1500 #if defined(CONFIG_OPTPROBES)
1502 .procname = "kprobes-optimization",
1503 .data = &sysctl_kprobes_optimization,
1504 .maxlen = sizeof(int),
1505 .mode = 0644,
1506 .proc_handler = proc_kprobes_optimization_handler,
1507 .extra1 = &zero,
1508 .extra2 = &one,
1510 #endif
1514 static struct ctl_table dev_table[] = {
1518 static DEFINE_SPINLOCK(sysctl_lock);
1520 /* called under sysctl_lock */
1521 static int use_table(struct ctl_table_header *p)
1523 if (unlikely(p->unregistering))
1524 return 0;
1525 p->used++;
1526 return 1;
1529 /* called under sysctl_lock */
1530 static void unuse_table(struct ctl_table_header *p)
1532 if (!--p->used)
1533 if (unlikely(p->unregistering))
1534 complete(p->unregistering);
1537 /* called under sysctl_lock, will reacquire if has to wait */
1538 static void start_unregistering(struct ctl_table_header *p)
1541 * if p->used is 0, nobody will ever touch that entry again;
1542 * we'll eliminate all paths to it before dropping sysctl_lock
1544 if (unlikely(p->used)) {
1545 struct completion wait;
1546 init_completion(&wait);
1547 p->unregistering = &wait;
1548 spin_unlock(&sysctl_lock);
1549 wait_for_completion(&wait);
1550 spin_lock(&sysctl_lock);
1551 } else {
1552 /* anything non-NULL; we'll never dereference it */
1553 p->unregistering = ERR_PTR(-EINVAL);
1556 * do not remove from the list until nobody holds it; walking the
1557 * list in do_sysctl() relies on that.
1559 list_del_init(&p->ctl_entry);
1562 void sysctl_head_get(struct ctl_table_header *head)
1564 spin_lock(&sysctl_lock);
1565 head->count++;
1566 spin_unlock(&sysctl_lock);
1569 void sysctl_head_put(struct ctl_table_header *head)
1571 spin_lock(&sysctl_lock);
1572 if (!--head->count)
1573 kfree(head);
1574 spin_unlock(&sysctl_lock);
1577 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1579 if (!head)
1580 BUG();
1581 spin_lock(&sysctl_lock);
1582 if (!use_table(head))
1583 head = ERR_PTR(-ENOENT);
1584 spin_unlock(&sysctl_lock);
1585 return head;
1588 void sysctl_head_finish(struct ctl_table_header *head)
1590 if (!head)
1591 return;
1592 spin_lock(&sysctl_lock);
1593 unuse_table(head);
1594 spin_unlock(&sysctl_lock);
1597 static struct ctl_table_set *
1598 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1600 struct ctl_table_set *set = &root->default_set;
1601 if (root->lookup)
1602 set = root->lookup(root, namespaces);
1603 return set;
1606 static struct list_head *
1607 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1609 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1610 return &set->list;
1613 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1614 struct ctl_table_header *prev)
1616 struct ctl_table_root *root;
1617 struct list_head *header_list;
1618 struct ctl_table_header *head;
1619 struct list_head *tmp;
1621 spin_lock(&sysctl_lock);
1622 if (prev) {
1623 head = prev;
1624 tmp = &prev->ctl_entry;
1625 unuse_table(prev);
1626 goto next;
1628 tmp = &root_table_header.ctl_entry;
1629 for (;;) {
1630 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1632 if (!use_table(head))
1633 goto next;
1634 spin_unlock(&sysctl_lock);
1635 return head;
1636 next:
1637 root = head->root;
1638 tmp = tmp->next;
1639 header_list = lookup_header_list(root, namespaces);
1640 if (tmp != header_list)
1641 continue;
1643 do {
1644 root = list_entry(root->root_list.next,
1645 struct ctl_table_root, root_list);
1646 if (root == &sysctl_table_root)
1647 goto out;
1648 header_list = lookup_header_list(root, namespaces);
1649 } while (list_empty(header_list));
1650 tmp = header_list->next;
1652 out:
1653 spin_unlock(&sysctl_lock);
1654 return NULL;
1657 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1659 return __sysctl_head_next(current->nsproxy, prev);
1662 void register_sysctl_root(struct ctl_table_root *root)
1664 spin_lock(&sysctl_lock);
1665 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1666 spin_unlock(&sysctl_lock);
1670 * sysctl_perm does NOT grant the superuser all rights automatically, because
1671 * some sysctl variables are readonly even to root.
1674 static int test_perm(int mode, int op)
1676 if (!current_euid())
1677 mode >>= 6;
1678 else if (in_egroup_p(0))
1679 mode >>= 3;
1680 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1681 return 0;
1682 return -EACCES;
1685 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1687 int error;
1688 int mode;
1690 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1691 if (error)
1692 return error;
1694 if (root->permissions)
1695 mode = root->permissions(root, current->nsproxy, table);
1696 else
1697 mode = table->mode;
1699 return test_perm(mode, op);
1702 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1704 for (; table->procname; table++) {
1705 table->parent = parent;
1706 if (table->child)
1707 sysctl_set_parent(table, table->child);
1711 static __init int sysctl_init(void)
1713 sysctl_set_parent(NULL, root_table);
1714 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1716 int err;
1717 err = sysctl_check_table(current->nsproxy, root_table);
1719 #endif
1720 return 0;
1723 core_initcall(sysctl_init);
1725 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1726 struct ctl_table *table)
1728 struct ctl_table *p;
1729 const char *s = branch->procname;
1731 /* branch should have named subdirectory as its first element */
1732 if (!s || !branch->child)
1733 return NULL;
1735 /* ... and nothing else */
1736 if (branch[1].procname)
1737 return NULL;
1739 /* table should contain subdirectory with the same name */
1740 for (p = table; p->procname; p++) {
1741 if (!p->child)
1742 continue;
1743 if (p->procname && strcmp(p->procname, s) == 0)
1744 return p;
1746 return NULL;
1749 /* see if attaching q to p would be an improvement */
1750 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1752 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1753 struct ctl_table *next;
1754 int is_better = 0;
1755 int not_in_parent = !p->attached_by;
1757 while ((next = is_branch_in(by, to)) != NULL) {
1758 if (by == q->attached_by)
1759 is_better = 1;
1760 if (to == p->attached_by)
1761 not_in_parent = 1;
1762 by = by->child;
1763 to = next->child;
1766 if (is_better && not_in_parent) {
1767 q->attached_by = by;
1768 q->attached_to = to;
1769 q->parent = p;
1774 * __register_sysctl_paths - register a sysctl hierarchy
1775 * @root: List of sysctl headers to register on
1776 * @namespaces: Data to compute which lists of sysctl entries are visible
1777 * @path: The path to the directory the sysctl table is in.
1778 * @table: the top-level table structure
1780 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1781 * array. A completely 0 filled entry terminates the table.
1783 * The members of the &struct ctl_table structure are used as follows:
1785 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1786 * enter a sysctl file
1788 * data - a pointer to data for use by proc_handler
1790 * maxlen - the maximum size in bytes of the data
1792 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1794 * child - a pointer to the child sysctl table if this entry is a directory, or
1795 * %NULL.
1797 * proc_handler - the text handler routine (described below)
1799 * de - for internal use by the sysctl routines
1801 * extra1, extra2 - extra pointers usable by the proc handler routines
1803 * Leaf nodes in the sysctl tree will be represented by a single file
1804 * under /proc; non-leaf nodes will be represented by directories.
1806 * sysctl(2) can automatically manage read and write requests through
1807 * the sysctl table. The data and maxlen fields of the ctl_table
1808 * struct enable minimal validation of the values being written to be
1809 * performed, and the mode field allows minimal authentication.
1811 * There must be a proc_handler routine for any terminal nodes
1812 * mirrored under /proc/sys (non-terminals are handled by a built-in
1813 * directory handler). Several default handlers are available to
1814 * cover common cases -
1816 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1817 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1818 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1820 * It is the handler's job to read the input buffer from user memory
1821 * and process it. The handler should return 0 on success.
1823 * This routine returns %NULL on a failure to register, and a pointer
1824 * to the table header on success.
1826 struct ctl_table_header *__register_sysctl_paths(
1827 struct ctl_table_root *root,
1828 struct nsproxy *namespaces,
1829 const struct ctl_path *path, struct ctl_table *table)
1831 struct ctl_table_header *header;
1832 struct ctl_table *new, **prevp;
1833 unsigned int n, npath;
1834 struct ctl_table_set *set;
1836 /* Count the path components */
1837 for (npath = 0; path[npath].procname; ++npath)
1841 * For each path component, allocate a 2-element ctl_table array.
1842 * The first array element will be filled with the sysctl entry
1843 * for this, the second will be the sentinel (procname == 0).
1845 * We allocate everything in one go so that we don't have to
1846 * worry about freeing additional memory in unregister_sysctl_table.
1848 header = kzalloc(sizeof(struct ctl_table_header) +
1849 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1850 if (!header)
1851 return NULL;
1853 new = (struct ctl_table *) (header + 1);
1855 /* Now connect the dots */
1856 prevp = &header->ctl_table;
1857 for (n = 0; n < npath; ++n, ++path) {
1858 /* Copy the procname */
1859 new->procname = path->procname;
1860 new->mode = 0555;
1862 *prevp = new;
1863 prevp = &new->child;
1865 new += 2;
1867 *prevp = table;
1868 header->ctl_table_arg = table;
1870 INIT_LIST_HEAD(&header->ctl_entry);
1871 header->used = 0;
1872 header->unregistering = NULL;
1873 header->root = root;
1874 sysctl_set_parent(NULL, header->ctl_table);
1875 header->count = 1;
1876 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1877 if (sysctl_check_table(namespaces, header->ctl_table)) {
1878 kfree(header);
1879 return NULL;
1881 #endif
1882 spin_lock(&sysctl_lock);
1883 header->set = lookup_header_set(root, namespaces);
1884 header->attached_by = header->ctl_table;
1885 header->attached_to = root_table;
1886 header->parent = &root_table_header;
1887 for (set = header->set; set; set = set->parent) {
1888 struct ctl_table_header *p;
1889 list_for_each_entry(p, &set->list, ctl_entry) {
1890 if (p->unregistering)
1891 continue;
1892 try_attach(p, header);
1895 header->parent->count++;
1896 list_add_tail(&header->ctl_entry, &header->set->list);
1897 spin_unlock(&sysctl_lock);
1899 return header;
1903 * register_sysctl_table_path - register a sysctl table hierarchy
1904 * @path: The path to the directory the sysctl table is in.
1905 * @table: the top-level table structure
1907 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1908 * array. A completely 0 filled entry terminates the table.
1910 * See __register_sysctl_paths for more details.
1912 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1913 struct ctl_table *table)
1915 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1916 path, table);
1920 * register_sysctl_table - register a sysctl table hierarchy
1921 * @table: the top-level table structure
1923 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1924 * array. A completely 0 filled entry terminates the table.
1926 * See register_sysctl_paths for more details.
1928 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1930 static const struct ctl_path null_path[] = { {} };
1932 return register_sysctl_paths(null_path, table);
1936 * unregister_sysctl_table - unregister a sysctl table hierarchy
1937 * @header: the header returned from register_sysctl_table
1939 * Unregisters the sysctl table and all children. proc entries may not
1940 * actually be removed until they are no longer used by anyone.
1942 void unregister_sysctl_table(struct ctl_table_header * header)
1944 might_sleep();
1946 if (header == NULL)
1947 return;
1949 spin_lock(&sysctl_lock);
1950 start_unregistering(header);
1951 if (!--header->parent->count) {
1952 WARN_ON(1);
1953 kfree(header->parent);
1955 if (!--header->count)
1956 kfree(header);
1957 spin_unlock(&sysctl_lock);
1960 int sysctl_is_seen(struct ctl_table_header *p)
1962 struct ctl_table_set *set = p->set;
1963 int res;
1964 spin_lock(&sysctl_lock);
1965 if (p->unregistering)
1966 res = 0;
1967 else if (!set->is_seen)
1968 res = 1;
1969 else
1970 res = set->is_seen(set);
1971 spin_unlock(&sysctl_lock);
1972 return res;
1975 void setup_sysctl_set(struct ctl_table_set *p,
1976 struct ctl_table_set *parent,
1977 int (*is_seen)(struct ctl_table_set *))
1979 INIT_LIST_HEAD(&p->list);
1980 p->parent = parent ? parent : &sysctl_table_root.default_set;
1981 p->is_seen = is_seen;
1984 #else /* !CONFIG_SYSCTL */
1985 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1987 return NULL;
1990 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1991 struct ctl_table *table)
1993 return NULL;
1996 void unregister_sysctl_table(struct ctl_table_header * table)
2000 void setup_sysctl_set(struct ctl_table_set *p,
2001 struct ctl_table_set *parent,
2002 int (*is_seen)(struct ctl_table_set *))
2006 void sysctl_head_put(struct ctl_table_header *head)
2010 #endif /* CONFIG_SYSCTL */
2013 * /proc/sys support
2016 #ifdef CONFIG_PROC_SYSCTL
2018 static int _proc_do_string(void* data, int maxlen, int write,
2019 void __user *buffer,
2020 size_t *lenp, loff_t *ppos)
2022 size_t len;
2023 char __user *p;
2024 char c;
2026 if (!data || !maxlen || !*lenp) {
2027 *lenp = 0;
2028 return 0;
2031 if (write) {
2032 len = 0;
2033 p = buffer;
2034 while (len < *lenp) {
2035 if (get_user(c, p++))
2036 return -EFAULT;
2037 if (c == 0 || c == '\n')
2038 break;
2039 len++;
2041 if (len >= maxlen)
2042 len = maxlen-1;
2043 if(copy_from_user(data, buffer, len))
2044 return -EFAULT;
2045 ((char *) data)[len] = 0;
2046 *ppos += *lenp;
2047 } else {
2048 len = strlen(data);
2049 if (len > maxlen)
2050 len = maxlen;
2052 if (*ppos > len) {
2053 *lenp = 0;
2054 return 0;
2057 data += *ppos;
2058 len -= *ppos;
2060 if (len > *lenp)
2061 len = *lenp;
2062 if (len)
2063 if(copy_to_user(buffer, data, len))
2064 return -EFAULT;
2065 if (len < *lenp) {
2066 if(put_user('\n', ((char __user *) buffer) + len))
2067 return -EFAULT;
2068 len++;
2070 *lenp = len;
2071 *ppos += len;
2073 return 0;
2077 * proc_dostring - read a string sysctl
2078 * @table: the sysctl table
2079 * @write: %TRUE if this is a write to the sysctl file
2080 * @buffer: the user buffer
2081 * @lenp: the size of the user buffer
2082 * @ppos: file position
2084 * Reads/writes a string from/to the user buffer. If the kernel
2085 * buffer provided is not large enough to hold the string, the
2086 * string is truncated. The copied string is %NULL-terminated.
2087 * If the string is being read by the user process, it is copied
2088 * and a newline '\n' is added. It is truncated if the buffer is
2089 * not large enough.
2091 * Returns 0 on success.
2093 int proc_dostring(struct ctl_table *table, int write,
2094 void __user *buffer, size_t *lenp, loff_t *ppos)
2096 return _proc_do_string(table->data, table->maxlen, write,
2097 buffer, lenp, ppos);
2100 static size_t proc_skip_spaces(char **buf)
2102 size_t ret;
2103 char *tmp = skip_spaces(*buf);
2104 ret = tmp - *buf;
2105 *buf = tmp;
2106 return ret;
2109 static void proc_skip_char(char **buf, size_t *size, const char v)
2111 while (*size) {
2112 if (**buf != v)
2113 break;
2114 (*size)--;
2115 (*buf)++;
2119 #define TMPBUFLEN 22
2121 * proc_get_long - reads an ASCII formatted integer from a user buffer
2123 * @buf: a kernel buffer
2124 * @size: size of the kernel buffer
2125 * @val: this is where the number will be stored
2126 * @neg: set to %TRUE if number is negative
2127 * @perm_tr: a vector which contains the allowed trailers
2128 * @perm_tr_len: size of the perm_tr vector
2129 * @tr: pointer to store the trailer character
2131 * In case of success %0 is returned and @buf and @size are updated with
2132 * the amount of bytes read. If @tr is non-NULL and a trailing
2133 * character exists (size is non-zero after returning from this
2134 * function), @tr is updated with the trailing character.
2136 static int proc_get_long(char **buf, size_t *size,
2137 unsigned long *val, bool *neg,
2138 const char *perm_tr, unsigned perm_tr_len, char *tr)
2140 int len;
2141 char *p, tmp[TMPBUFLEN];
2143 if (!*size)
2144 return -EINVAL;
2146 len = *size;
2147 if (len > TMPBUFLEN - 1)
2148 len = TMPBUFLEN - 1;
2150 memcpy(tmp, *buf, len);
2152 tmp[len] = 0;
2153 p = tmp;
2154 if (*p == '-' && *size > 1) {
2155 *neg = true;
2156 p++;
2157 } else
2158 *neg = false;
2159 if (!isdigit(*p))
2160 return -EINVAL;
2162 *val = simple_strtoul(p, &p, 0);
2164 len = p - tmp;
2166 /* We don't know if the next char is whitespace thus we may accept
2167 * invalid integers (e.g. 1234...a) or two integers instead of one
2168 * (e.g. 123...1). So lets not allow such large numbers. */
2169 if (len == TMPBUFLEN - 1)
2170 return -EINVAL;
2172 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2173 return -EINVAL;
2175 if (tr && (len < *size))
2176 *tr = *p;
2178 *buf += len;
2179 *size -= len;
2181 return 0;
2185 * proc_put_long - converts an integer to a decimal ASCII formatted string
2187 * @buf: the user buffer
2188 * @size: the size of the user buffer
2189 * @val: the integer to be converted
2190 * @neg: sign of the number, %TRUE for negative
2192 * In case of success %0 is returned and @buf and @size are updated with
2193 * the amount of bytes written.
2195 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2196 bool neg)
2198 int len;
2199 char tmp[TMPBUFLEN], *p = tmp;
2201 sprintf(p, "%s%lu", neg ? "-" : "", val);
2202 len = strlen(tmp);
2203 if (len > *size)
2204 len = *size;
2205 if (copy_to_user(*buf, tmp, len))
2206 return -EFAULT;
2207 *size -= len;
2208 *buf += len;
2209 return 0;
2211 #undef TMPBUFLEN
2213 static int proc_put_char(void __user **buf, size_t *size, char c)
2215 if (*size) {
2216 char __user **buffer = (char __user **)buf;
2217 if (put_user(c, *buffer))
2218 return -EFAULT;
2219 (*size)--, (*buffer)++;
2220 *buf = *buffer;
2222 return 0;
2225 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2226 int *valp,
2227 int write, void *data)
2229 if (write) {
2230 *valp = *negp ? -*lvalp : *lvalp;
2231 } else {
2232 int val = *valp;
2233 if (val < 0) {
2234 *negp = true;
2235 *lvalp = (unsigned long)-val;
2236 } else {
2237 *negp = false;
2238 *lvalp = (unsigned long)val;
2241 return 0;
2244 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2246 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2247 int write, void __user *buffer,
2248 size_t *lenp, loff_t *ppos,
2249 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2250 int write, void *data),
2251 void *data)
2253 int *i, vleft, first = 1, err = 0;
2254 unsigned long page = 0;
2255 size_t left;
2256 char *kbuf;
2258 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2259 *lenp = 0;
2260 return 0;
2263 i = (int *) tbl_data;
2264 vleft = table->maxlen / sizeof(*i);
2265 left = *lenp;
2267 if (!conv)
2268 conv = do_proc_dointvec_conv;
2270 if (write) {
2271 if (left > PAGE_SIZE - 1)
2272 left = PAGE_SIZE - 1;
2273 page = __get_free_page(GFP_TEMPORARY);
2274 kbuf = (char *) page;
2275 if (!kbuf)
2276 return -ENOMEM;
2277 if (copy_from_user(kbuf, buffer, left)) {
2278 err = -EFAULT;
2279 goto free;
2281 kbuf[left] = 0;
2284 for (; left && vleft--; i++, first=0) {
2285 unsigned long lval;
2286 bool neg;
2288 if (write) {
2289 left -= proc_skip_spaces(&kbuf);
2291 if (!left)
2292 break;
2293 err = proc_get_long(&kbuf, &left, &lval, &neg,
2294 proc_wspace_sep,
2295 sizeof(proc_wspace_sep), NULL);
2296 if (err)
2297 break;
2298 if (conv(&neg, &lval, i, 1, data)) {
2299 err = -EINVAL;
2300 break;
2302 } else {
2303 if (conv(&neg, &lval, i, 0, data)) {
2304 err = -EINVAL;
2305 break;
2307 if (!first)
2308 err = proc_put_char(&buffer, &left, '\t');
2309 if (err)
2310 break;
2311 err = proc_put_long(&buffer, &left, lval, neg);
2312 if (err)
2313 break;
2317 if (!write && !first && left && !err)
2318 err = proc_put_char(&buffer, &left, '\n');
2319 if (write && !err && left)
2320 left -= proc_skip_spaces(&kbuf);
2321 free:
2322 if (write) {
2323 free_page(page);
2324 if (first)
2325 return err ? : -EINVAL;
2327 *lenp -= left;
2328 *ppos += *lenp;
2329 return err;
2332 static int do_proc_dointvec(struct ctl_table *table, int write,
2333 void __user *buffer, size_t *lenp, loff_t *ppos,
2334 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2335 int write, void *data),
2336 void *data)
2338 return __do_proc_dointvec(table->data, table, write,
2339 buffer, lenp, ppos, conv, data);
2343 * proc_dointvec - read a vector of integers
2344 * @table: the sysctl table
2345 * @write: %TRUE if this is a write to the sysctl file
2346 * @buffer: the user buffer
2347 * @lenp: the size of the user buffer
2348 * @ppos: file position
2350 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2351 * values from/to the user buffer, treated as an ASCII string.
2353 * Returns 0 on success.
2355 int proc_dointvec(struct ctl_table *table, int write,
2356 void __user *buffer, size_t *lenp, loff_t *ppos)
2358 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2359 NULL,NULL);
2363 * Taint values can only be increased
2364 * This means we can safely use a temporary.
2366 static int proc_taint(struct ctl_table *table, int write,
2367 void __user *buffer, size_t *lenp, loff_t *ppos)
2369 struct ctl_table t;
2370 unsigned long tmptaint = get_taint();
2371 int err;
2373 if (write && !capable(CAP_SYS_ADMIN))
2374 return -EPERM;
2376 t = *table;
2377 t.data = &tmptaint;
2378 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2379 if (err < 0)
2380 return err;
2382 if (write) {
2384 * Poor man's atomic or. Not worth adding a primitive
2385 * to everyone's atomic.h for this
2387 int i;
2388 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2389 if ((tmptaint >> i) & 1)
2390 add_taint(i);
2394 return err;
2397 struct do_proc_dointvec_minmax_conv_param {
2398 int *min;
2399 int *max;
2402 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2403 int *valp,
2404 int write, void *data)
2406 struct do_proc_dointvec_minmax_conv_param *param = data;
2407 if (write) {
2408 int val = *negp ? -*lvalp : *lvalp;
2409 if ((param->min && *param->min > val) ||
2410 (param->max && *param->max < val))
2411 return -EINVAL;
2412 *valp = val;
2413 } else {
2414 int val = *valp;
2415 if (val < 0) {
2416 *negp = true;
2417 *lvalp = (unsigned long)-val;
2418 } else {
2419 *negp = false;
2420 *lvalp = (unsigned long)val;
2423 return 0;
2427 * proc_dointvec_minmax - read a vector of integers with min/max values
2428 * @table: the sysctl table
2429 * @write: %TRUE if this is a write to the sysctl file
2430 * @buffer: the user buffer
2431 * @lenp: the size of the user buffer
2432 * @ppos: file position
2434 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2435 * values from/to the user buffer, treated as an ASCII string.
2437 * This routine will ensure the values are within the range specified by
2438 * table->extra1 (min) and table->extra2 (max).
2440 * Returns 0 on success.
2442 int proc_dointvec_minmax(struct ctl_table *table, int write,
2443 void __user *buffer, size_t *lenp, loff_t *ppos)
2445 struct do_proc_dointvec_minmax_conv_param param = {
2446 .min = (int *) table->extra1,
2447 .max = (int *) table->extra2,
2449 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2450 do_proc_dointvec_minmax_conv, &param);
2453 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2454 void __user *buffer,
2455 size_t *lenp, loff_t *ppos,
2456 unsigned long convmul,
2457 unsigned long convdiv)
2459 unsigned long *i, *min, *max;
2460 int vleft, first = 1, err = 0;
2461 unsigned long page = 0;
2462 size_t left;
2463 char *kbuf;
2465 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2466 *lenp = 0;
2467 return 0;
2470 i = (unsigned long *) data;
2471 min = (unsigned long *) table->extra1;
2472 max = (unsigned long *) table->extra2;
2473 vleft = table->maxlen / sizeof(unsigned long);
2474 left = *lenp;
2476 if (write) {
2477 if (left > PAGE_SIZE - 1)
2478 left = PAGE_SIZE - 1;
2479 page = __get_free_page(GFP_TEMPORARY);
2480 kbuf = (char *) page;
2481 if (!kbuf)
2482 return -ENOMEM;
2483 if (copy_from_user(kbuf, buffer, left)) {
2484 err = -EFAULT;
2485 goto free;
2487 kbuf[left] = 0;
2490 for (; left && vleft--; i++, min++, max++, first=0) {
2491 unsigned long val;
2493 if (write) {
2494 bool neg;
2496 left -= proc_skip_spaces(&kbuf);
2498 err = proc_get_long(&kbuf, &left, &val, &neg,
2499 proc_wspace_sep,
2500 sizeof(proc_wspace_sep), NULL);
2501 if (err)
2502 break;
2503 if (neg)
2504 continue;
2505 if ((min && val < *min) || (max && val > *max))
2506 continue;
2507 *i = val;
2508 } else {
2509 val = convdiv * (*i) / convmul;
2510 if (!first)
2511 err = proc_put_char(&buffer, &left, '\t');
2512 err = proc_put_long(&buffer, &left, val, false);
2513 if (err)
2514 break;
2518 if (!write && !first && left && !err)
2519 err = proc_put_char(&buffer, &left, '\n');
2520 if (write && !err)
2521 left -= proc_skip_spaces(&kbuf);
2522 free:
2523 if (write) {
2524 free_page(page);
2525 if (first)
2526 return err ? : -EINVAL;
2528 *lenp -= left;
2529 *ppos += *lenp;
2530 return err;
2533 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2534 void __user *buffer,
2535 size_t *lenp, loff_t *ppos,
2536 unsigned long convmul,
2537 unsigned long convdiv)
2539 return __do_proc_doulongvec_minmax(table->data, table, write,
2540 buffer, lenp, ppos, convmul, convdiv);
2544 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2545 * @table: the sysctl table
2546 * @write: %TRUE if this is a write to the sysctl file
2547 * @buffer: the user buffer
2548 * @lenp: the size of the user buffer
2549 * @ppos: file position
2551 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2552 * values from/to the user buffer, treated as an ASCII string.
2554 * This routine will ensure the values are within the range specified by
2555 * table->extra1 (min) and table->extra2 (max).
2557 * Returns 0 on success.
2559 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2560 void __user *buffer, size_t *lenp, loff_t *ppos)
2562 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2566 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2567 * @table: the sysctl table
2568 * @write: %TRUE if this is a write to the sysctl file
2569 * @buffer: the user buffer
2570 * @lenp: the size of the user buffer
2571 * @ppos: file position
2573 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2574 * values from/to the user buffer, treated as an ASCII string. The values
2575 * are treated as milliseconds, and converted to jiffies when they are stored.
2577 * This routine will ensure the values are within the range specified by
2578 * table->extra1 (min) and table->extra2 (max).
2580 * Returns 0 on success.
2582 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2583 void __user *buffer,
2584 size_t *lenp, loff_t *ppos)
2586 return do_proc_doulongvec_minmax(table, write, buffer,
2587 lenp, ppos, HZ, 1000l);
2591 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2592 int *valp,
2593 int write, void *data)
2595 if (write) {
2596 if (*lvalp > LONG_MAX / HZ)
2597 return 1;
2598 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2599 } else {
2600 int val = *valp;
2601 unsigned long lval;
2602 if (val < 0) {
2603 *negp = true;
2604 lval = (unsigned long)-val;
2605 } else {
2606 *negp = false;
2607 lval = (unsigned long)val;
2609 *lvalp = lval / HZ;
2611 return 0;
2614 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2615 int *valp,
2616 int write, void *data)
2618 if (write) {
2619 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2620 return 1;
2621 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2622 } else {
2623 int val = *valp;
2624 unsigned long lval;
2625 if (val < 0) {
2626 *negp = true;
2627 lval = (unsigned long)-val;
2628 } else {
2629 *negp = false;
2630 lval = (unsigned long)val;
2632 *lvalp = jiffies_to_clock_t(lval);
2634 return 0;
2637 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2638 int *valp,
2639 int write, void *data)
2641 if (write) {
2642 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2643 } else {
2644 int val = *valp;
2645 unsigned long lval;
2646 if (val < 0) {
2647 *negp = true;
2648 lval = (unsigned long)-val;
2649 } else {
2650 *negp = false;
2651 lval = (unsigned long)val;
2653 *lvalp = jiffies_to_msecs(lval);
2655 return 0;
2659 * proc_dointvec_jiffies - read a vector of integers as seconds
2660 * @table: the sysctl table
2661 * @write: %TRUE if this is a write to the sysctl file
2662 * @buffer: the user buffer
2663 * @lenp: the size of the user buffer
2664 * @ppos: file position
2666 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2667 * values from/to the user buffer, treated as an ASCII string.
2668 * The values read are assumed to be in seconds, and are converted into
2669 * jiffies.
2671 * Returns 0 on success.
2673 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2674 void __user *buffer, size_t *lenp, loff_t *ppos)
2676 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2677 do_proc_dointvec_jiffies_conv,NULL);
2681 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2682 * @table: the sysctl table
2683 * @write: %TRUE if this is a write to the sysctl file
2684 * @buffer: the user buffer
2685 * @lenp: the size of the user buffer
2686 * @ppos: pointer to the file position
2688 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2689 * values from/to the user buffer, treated as an ASCII string.
2690 * The values read are assumed to be in 1/USER_HZ seconds, and
2691 * are converted into jiffies.
2693 * Returns 0 on success.
2695 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2696 void __user *buffer, size_t *lenp, loff_t *ppos)
2698 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2699 do_proc_dointvec_userhz_jiffies_conv,NULL);
2703 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2704 * @table: the sysctl table
2705 * @write: %TRUE if this is a write to the sysctl file
2706 * @buffer: the user buffer
2707 * @lenp: the size of the user buffer
2708 * @ppos: file position
2709 * @ppos: the current position in the file
2711 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2712 * values from/to the user buffer, treated as an ASCII string.
2713 * The values read are assumed to be in 1/1000 seconds, and
2714 * are converted into jiffies.
2716 * Returns 0 on success.
2718 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2719 void __user *buffer, size_t *lenp, loff_t *ppos)
2721 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2722 do_proc_dointvec_ms_jiffies_conv, NULL);
2725 static int proc_do_cad_pid(struct ctl_table *table, int write,
2726 void __user *buffer, size_t *lenp, loff_t *ppos)
2728 struct pid *new_pid;
2729 pid_t tmp;
2730 int r;
2732 tmp = pid_vnr(cad_pid);
2734 r = __do_proc_dointvec(&tmp, table, write, buffer,
2735 lenp, ppos, NULL, NULL);
2736 if (r || !write)
2737 return r;
2739 new_pid = find_get_pid(tmp);
2740 if (!new_pid)
2741 return -ESRCH;
2743 put_pid(xchg(&cad_pid, new_pid));
2744 return 0;
2748 * proc_do_large_bitmap - read/write from/to a large bitmap
2749 * @table: the sysctl table
2750 * @write: %TRUE if this is a write to the sysctl file
2751 * @buffer: the user buffer
2752 * @lenp: the size of the user buffer
2753 * @ppos: file position
2755 * The bitmap is stored at table->data and the bitmap length (in bits)
2756 * in table->maxlen.
2758 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2759 * large bitmaps may be represented in a compact manner. Writing into
2760 * the file will clear the bitmap then update it with the given input.
2762 * Returns 0 on success.
2764 int proc_do_large_bitmap(struct ctl_table *table, int write,
2765 void __user *buffer, size_t *lenp, loff_t *ppos)
2767 int err = 0;
2768 bool first = 1;
2769 size_t left = *lenp;
2770 unsigned long bitmap_len = table->maxlen;
2771 unsigned long *bitmap = (unsigned long *) table->data;
2772 unsigned long *tmp_bitmap = NULL;
2773 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2775 if (!bitmap_len || !left || (*ppos && !write)) {
2776 *lenp = 0;
2777 return 0;
2780 if (write) {
2781 unsigned long page = 0;
2782 char *kbuf;
2784 if (left > PAGE_SIZE - 1)
2785 left = PAGE_SIZE - 1;
2787 page = __get_free_page(GFP_TEMPORARY);
2788 kbuf = (char *) page;
2789 if (!kbuf)
2790 return -ENOMEM;
2791 if (copy_from_user(kbuf, buffer, left)) {
2792 free_page(page);
2793 return -EFAULT;
2795 kbuf[left] = 0;
2797 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2798 GFP_KERNEL);
2799 if (!tmp_bitmap) {
2800 free_page(page);
2801 return -ENOMEM;
2803 proc_skip_char(&kbuf, &left, '\n');
2804 while (!err && left) {
2805 unsigned long val_a, val_b;
2806 bool neg;
2808 err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2809 sizeof(tr_a), &c);
2810 if (err)
2811 break;
2812 if (val_a >= bitmap_len || neg) {
2813 err = -EINVAL;
2814 break;
2817 val_b = val_a;
2818 if (left) {
2819 kbuf++;
2820 left--;
2823 if (c == '-') {
2824 err = proc_get_long(&kbuf, &left, &val_b,
2825 &neg, tr_b, sizeof(tr_b),
2826 &c);
2827 if (err)
2828 break;
2829 if (val_b >= bitmap_len || neg ||
2830 val_a > val_b) {
2831 err = -EINVAL;
2832 break;
2834 if (left) {
2835 kbuf++;
2836 left--;
2840 while (val_a <= val_b)
2841 set_bit(val_a++, tmp_bitmap);
2843 first = 0;
2844 proc_skip_char(&kbuf, &left, '\n');
2846 free_page(page);
2847 } else {
2848 unsigned long bit_a, bit_b = 0;
2850 while (left) {
2851 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2852 if (bit_a >= bitmap_len)
2853 break;
2854 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2855 bit_a + 1) - 1;
2857 if (!first) {
2858 err = proc_put_char(&buffer, &left, ',');
2859 if (err)
2860 break;
2862 err = proc_put_long(&buffer, &left, bit_a, false);
2863 if (err)
2864 break;
2865 if (bit_a != bit_b) {
2866 err = proc_put_char(&buffer, &left, '-');
2867 if (err)
2868 break;
2869 err = proc_put_long(&buffer, &left, bit_b, false);
2870 if (err)
2871 break;
2874 first = 0; bit_b++;
2876 if (!err)
2877 err = proc_put_char(&buffer, &left, '\n');
2880 if (!err) {
2881 if (write) {
2882 if (*ppos)
2883 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2884 else
2885 memcpy(bitmap, tmp_bitmap,
2886 BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2888 kfree(tmp_bitmap);
2889 *lenp -= left;
2890 *ppos += *lenp;
2891 return 0;
2892 } else {
2893 kfree(tmp_bitmap);
2894 return err;
2898 #else /* CONFIG_PROC_FS */
2900 int proc_dostring(struct ctl_table *table, int write,
2901 void __user *buffer, size_t *lenp, loff_t *ppos)
2903 return -ENOSYS;
2906 int proc_dointvec(struct ctl_table *table, int write,
2907 void __user *buffer, size_t *lenp, loff_t *ppos)
2909 return -ENOSYS;
2912 int proc_dointvec_minmax(struct ctl_table *table, int write,
2913 void __user *buffer, size_t *lenp, loff_t *ppos)
2915 return -ENOSYS;
2918 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2919 void __user *buffer, size_t *lenp, loff_t *ppos)
2921 return -ENOSYS;
2924 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2925 void __user *buffer, size_t *lenp, loff_t *ppos)
2927 return -ENOSYS;
2930 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2931 void __user *buffer, size_t *lenp, loff_t *ppos)
2933 return -ENOSYS;
2936 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2937 void __user *buffer, size_t *lenp, loff_t *ppos)
2939 return -ENOSYS;
2942 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2943 void __user *buffer,
2944 size_t *lenp, loff_t *ppos)
2946 return -ENOSYS;
2950 #endif /* CONFIG_PROC_FS */
2953 * No sense putting this after each symbol definition, twice,
2954 * exception granted :-)
2956 EXPORT_SYMBOL(proc_dointvec);
2957 EXPORT_SYMBOL(proc_dointvec_jiffies);
2958 EXPORT_SYMBOL(proc_dointvec_minmax);
2959 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2960 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2961 EXPORT_SYMBOL(proc_dostring);
2962 EXPORT_SYMBOL(proc_doulongvec_minmax);
2963 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2964 EXPORT_SYMBOL(register_sysctl_table);
2965 EXPORT_SYMBOL(register_sysctl_paths);
2966 EXPORT_SYMBOL(unregister_sysctl_table);