net/b43: don't return IRQ_HANDLED if nothing was done
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / sysctl.c
blob3dd0c46fa3bbd68d1d4774e23e0189c54508fd0b
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/printk.h>
28 #include <linux/proc_fs.h>
29 #include <linux/security.h>
30 #include <linux/ctype.h>
31 #include <linux/kmemcheck.h>
32 #include <linux/fs.h>
33 #include <linux/init.h>
34 #include <linux/kernel.h>
35 #include <linux/kobject.h>
36 #include <linux/net.h>
37 #include <linux/sysrq.h>
38 #include <linux/highuid.h>
39 #include <linux/writeback.h>
40 #include <linux/ratelimit.h>
41 #include <linux/compaction.h>
42 #include <linux/hugetlb.h>
43 #include <linux/initrd.h>
44 #include <linux/key.h>
45 #include <linux/times.h>
46 #include <linux/limits.h>
47 #include <linux/dcache.h>
48 #include <linux/dnotify.h>
49 #include <linux/syscalls.h>
50 #include <linux/vmstat.h>
51 #include <linux/nfs_fs.h>
52 #include <linux/acpi.h>
53 #include <linux/reboot.h>
54 #include <linux/ftrace.h>
55 #include <linux/perf_event.h>
56 #include <linux/kprobes.h>
57 #include <linux/pipe_fs_i.h>
58 #include <linux/oom.h>
60 #include <asm/uaccess.h>
61 #include <asm/processor.h>
63 #ifdef CONFIG_X86
64 #include <asm/nmi.h>
65 #include <asm/stacktrace.h>
66 #include <asm/io.h>
67 #endif
68 #ifdef CONFIG_BSD_PROCESS_ACCT
69 #include <linux/acct.h>
70 #endif
71 #ifdef CONFIG_RT_MUTEXES
72 #include <linux/rtmutex.h>
73 #endif
74 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
75 #include <linux/lockdep.h>
76 #endif
77 #ifdef CONFIG_CHR_DEV_SG
78 #include <scsi/sg.h>
79 #endif
81 #ifdef CONFIG_LOCKUP_DETECTOR
82 #include <linux/nmi.h>
83 #endif
86 #if defined(CONFIG_SYSCTL)
88 /* External variables not in a header file. */
89 extern int sysctl_overcommit_memory;
90 extern int sysctl_overcommit_ratio;
91 extern int max_threads;
92 extern int core_uses_pid;
93 extern int suid_dumpable;
94 extern char core_pattern[];
95 extern unsigned int core_pipe_limit;
96 extern int pid_max;
97 extern int min_free_kbytes;
98 extern int pid_max_min, pid_max_max;
99 extern int sysctl_drop_caches;
100 extern int percpu_pagelist_fraction;
101 extern int compat_log;
102 extern int latencytop_enabled;
103 extern int sysctl_nr_open_min, sysctl_nr_open_max;
104 #ifndef CONFIG_MMU
105 extern int sysctl_nr_trim_pages;
106 #endif
107 #ifdef CONFIG_BLOCK
108 extern int blk_iopoll_enabled;
109 #endif
111 /* Constants used for minimum and maximum */
112 #ifdef CONFIG_LOCKUP_DETECTOR
113 static int sixty = 60;
114 static int neg_one = -1;
115 #endif
117 static int zero;
118 static int __maybe_unused one = 1;
119 static int __maybe_unused two = 2;
120 static int __maybe_unused three = 3;
121 static unsigned long one_ul = 1;
122 static int one_hundred = 100;
123 #ifdef CONFIG_PRINTK
124 static int ten_thousand = 10000;
125 #endif
127 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
128 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
130 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
131 static int maxolduid = 65535;
132 static int minolduid;
133 static int min_percpu_pagelist_fract = 8;
135 static int ngroups_max = NGROUPS_MAX;
137 #ifdef CONFIG_INOTIFY_USER
138 #include <linux/inotify.h>
139 #endif
140 #ifdef CONFIG_SPARC
141 #include <asm/system.h>
142 #endif
144 #ifdef CONFIG_SPARC64
145 extern int sysctl_tsb_ratio;
146 #endif
148 #ifdef __hppa__
149 extern int pwrsw_enabled;
150 extern int unaligned_enabled;
151 #endif
153 #ifdef CONFIG_S390
154 #ifdef CONFIG_MATHEMU
155 extern int sysctl_ieee_emulation_warnings;
156 #endif
157 extern int sysctl_userprocess_debug;
158 extern int spin_retry;
159 #endif
161 #ifdef CONFIG_IA64
162 extern int no_unaligned_warning;
163 extern int unaligned_dump_stack;
164 #endif
166 #ifdef CONFIG_PROC_SYSCTL
167 static int proc_do_cad_pid(struct ctl_table *table, int write,
168 void __user *buffer, size_t *lenp, loff_t *ppos);
169 static int proc_taint(struct ctl_table *table, int write,
170 void __user *buffer, size_t *lenp, loff_t *ppos);
171 #endif
173 #ifdef CONFIG_PRINTK
174 static int proc_dmesg_restrict(struct ctl_table *table, int write,
175 void __user *buffer, size_t *lenp, loff_t *ppos);
176 #endif
178 #ifdef CONFIG_MAGIC_SYSRQ
179 /* Note: sysrq code uses it's own private copy */
180 static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE;
182 static int sysrq_sysctl_handler(ctl_table *table, int write,
183 void __user *buffer, size_t *lenp,
184 loff_t *ppos)
186 int error;
188 error = proc_dointvec(table, write, buffer, lenp, ppos);
189 if (error)
190 return error;
192 if (write)
193 sysrq_toggle_support(__sysrq_enabled);
195 return 0;
198 #endif
200 static struct ctl_table root_table[];
201 static struct ctl_table_root sysctl_table_root;
202 static struct ctl_table_header root_table_header = {
203 {{.count = 1,
204 .ctl_table = root_table,
205 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}},
206 .root = &sysctl_table_root,
207 .set = &sysctl_table_root.default_set,
209 static struct ctl_table_root sysctl_table_root = {
210 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
211 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
214 static struct ctl_table kern_table[];
215 static struct ctl_table vm_table[];
216 static struct ctl_table fs_table[];
217 static struct ctl_table debug_table[];
218 static struct ctl_table dev_table[];
219 extern struct ctl_table random_table[];
220 #ifdef CONFIG_EPOLL
221 extern struct ctl_table epoll_table[];
222 #endif
224 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
225 int sysctl_legacy_va_layout;
226 #endif
228 /* The default sysctl tables: */
230 static struct ctl_table root_table[] = {
232 .procname = "kernel",
233 .mode = 0555,
234 .child = kern_table,
237 .procname = "vm",
238 .mode = 0555,
239 .child = vm_table,
242 .procname = "fs",
243 .mode = 0555,
244 .child = fs_table,
247 .procname = "debug",
248 .mode = 0555,
249 .child = debug_table,
252 .procname = "dev",
253 .mode = 0555,
254 .child = dev_table,
259 #ifdef CONFIG_SCHED_DEBUG
260 static int min_sched_granularity_ns = 100000; /* 100 usecs */
261 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
262 static int min_wakeup_granularity_ns; /* 0 usecs */
263 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
264 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
265 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
266 #endif
268 #ifdef CONFIG_COMPACTION
269 static int min_extfrag_threshold;
270 static int max_extfrag_threshold = 1000;
271 #endif
273 static struct ctl_table kern_table[] = {
275 .procname = "sched_child_runs_first",
276 .data = &sysctl_sched_child_runs_first,
277 .maxlen = sizeof(unsigned int),
278 .mode = 0644,
279 .proc_handler = proc_dointvec,
281 #ifdef CONFIG_SCHED_DEBUG
283 .procname = "sched_min_granularity_ns",
284 .data = &sysctl_sched_min_granularity,
285 .maxlen = sizeof(unsigned int),
286 .mode = 0644,
287 .proc_handler = sched_proc_update_handler,
288 .extra1 = &min_sched_granularity_ns,
289 .extra2 = &max_sched_granularity_ns,
292 .procname = "sched_latency_ns",
293 .data = &sysctl_sched_latency,
294 .maxlen = sizeof(unsigned int),
295 .mode = 0644,
296 .proc_handler = sched_proc_update_handler,
297 .extra1 = &min_sched_granularity_ns,
298 .extra2 = &max_sched_granularity_ns,
301 .procname = "sched_wakeup_granularity_ns",
302 .data = &sysctl_sched_wakeup_granularity,
303 .maxlen = sizeof(unsigned int),
304 .mode = 0644,
305 .proc_handler = sched_proc_update_handler,
306 .extra1 = &min_wakeup_granularity_ns,
307 .extra2 = &max_wakeup_granularity_ns,
310 .procname = "sched_tunable_scaling",
311 .data = &sysctl_sched_tunable_scaling,
312 .maxlen = sizeof(enum sched_tunable_scaling),
313 .mode = 0644,
314 .proc_handler = sched_proc_update_handler,
315 .extra1 = &min_sched_tunable_scaling,
316 .extra2 = &max_sched_tunable_scaling,
319 .procname = "sched_migration_cost",
320 .data = &sysctl_sched_migration_cost,
321 .maxlen = sizeof(unsigned int),
322 .mode = 0644,
323 .proc_handler = proc_dointvec,
326 .procname = "sched_nr_migrate",
327 .data = &sysctl_sched_nr_migrate,
328 .maxlen = sizeof(unsigned int),
329 .mode = 0644,
330 .proc_handler = proc_dointvec,
333 .procname = "sched_time_avg",
334 .data = &sysctl_sched_time_avg,
335 .maxlen = sizeof(unsigned int),
336 .mode = 0644,
337 .proc_handler = proc_dointvec,
340 .procname = "sched_shares_window",
341 .data = &sysctl_sched_shares_window,
342 .maxlen = sizeof(unsigned int),
343 .mode = 0644,
344 .proc_handler = proc_dointvec,
347 .procname = "timer_migration",
348 .data = &sysctl_timer_migration,
349 .maxlen = sizeof(unsigned int),
350 .mode = 0644,
351 .proc_handler = proc_dointvec_minmax,
352 .extra1 = &zero,
353 .extra2 = &one,
355 #endif
357 .procname = "sched_rt_period_us",
358 .data = &sysctl_sched_rt_period,
359 .maxlen = sizeof(unsigned int),
360 .mode = 0644,
361 .proc_handler = sched_rt_handler,
364 .procname = "sched_rt_runtime_us",
365 .data = &sysctl_sched_rt_runtime,
366 .maxlen = sizeof(int),
367 .mode = 0644,
368 .proc_handler = sched_rt_handler,
370 #ifdef CONFIG_SCHED_AUTOGROUP
372 .procname = "sched_autogroup_enabled",
373 .data = &sysctl_sched_autogroup_enabled,
374 .maxlen = sizeof(unsigned int),
375 .mode = 0644,
376 .proc_handler = proc_dointvec_minmax,
377 .extra1 = &zero,
378 .extra2 = &one,
380 #endif
381 #ifdef CONFIG_PROVE_LOCKING
383 .procname = "prove_locking",
384 .data = &prove_locking,
385 .maxlen = sizeof(int),
386 .mode = 0644,
387 .proc_handler = proc_dointvec,
389 #endif
390 #ifdef CONFIG_LOCK_STAT
392 .procname = "lock_stat",
393 .data = &lock_stat,
394 .maxlen = sizeof(int),
395 .mode = 0644,
396 .proc_handler = proc_dointvec,
398 #endif
400 .procname = "panic",
401 .data = &panic_timeout,
402 .maxlen = sizeof(int),
403 .mode = 0644,
404 .proc_handler = proc_dointvec,
407 .procname = "core_uses_pid",
408 .data = &core_uses_pid,
409 .maxlen = sizeof(int),
410 .mode = 0644,
411 .proc_handler = proc_dointvec,
414 .procname = "core_pattern",
415 .data = core_pattern,
416 .maxlen = CORENAME_MAX_SIZE,
417 .mode = 0644,
418 .proc_handler = proc_dostring,
421 .procname = "core_pipe_limit",
422 .data = &core_pipe_limit,
423 .maxlen = sizeof(unsigned int),
424 .mode = 0644,
425 .proc_handler = proc_dointvec,
427 #ifdef CONFIG_PROC_SYSCTL
429 .procname = "tainted",
430 .maxlen = sizeof(long),
431 .mode = 0644,
432 .proc_handler = proc_taint,
434 #endif
435 #ifdef CONFIG_LATENCYTOP
437 .procname = "latencytop",
438 .data = &latencytop_enabled,
439 .maxlen = sizeof(int),
440 .mode = 0644,
441 .proc_handler = proc_dointvec,
443 #endif
444 #ifdef CONFIG_BLK_DEV_INITRD
446 .procname = "real-root-dev",
447 .data = &real_root_dev,
448 .maxlen = sizeof(int),
449 .mode = 0644,
450 .proc_handler = proc_dointvec,
452 #endif
454 .procname = "print-fatal-signals",
455 .data = &print_fatal_signals,
456 .maxlen = sizeof(int),
457 .mode = 0644,
458 .proc_handler = proc_dointvec,
460 #ifdef CONFIG_SPARC
462 .procname = "reboot-cmd",
463 .data = reboot_command,
464 .maxlen = 256,
465 .mode = 0644,
466 .proc_handler = proc_dostring,
469 .procname = "stop-a",
470 .data = &stop_a_enabled,
471 .maxlen = sizeof (int),
472 .mode = 0644,
473 .proc_handler = proc_dointvec,
476 .procname = "scons-poweroff",
477 .data = &scons_pwroff,
478 .maxlen = sizeof (int),
479 .mode = 0644,
480 .proc_handler = proc_dointvec,
482 #endif
483 #ifdef CONFIG_SPARC64
485 .procname = "tsb-ratio",
486 .data = &sysctl_tsb_ratio,
487 .maxlen = sizeof (int),
488 .mode = 0644,
489 .proc_handler = proc_dointvec,
491 #endif
492 #ifdef __hppa__
494 .procname = "soft-power",
495 .data = &pwrsw_enabled,
496 .maxlen = sizeof (int),
497 .mode = 0644,
498 .proc_handler = proc_dointvec,
501 .procname = "unaligned-trap",
502 .data = &unaligned_enabled,
503 .maxlen = sizeof (int),
504 .mode = 0644,
505 .proc_handler = proc_dointvec,
507 #endif
509 .procname = "ctrl-alt-del",
510 .data = &C_A_D,
511 .maxlen = sizeof(int),
512 .mode = 0644,
513 .proc_handler = proc_dointvec,
515 #ifdef CONFIG_FUNCTION_TRACER
517 .procname = "ftrace_enabled",
518 .data = &ftrace_enabled,
519 .maxlen = sizeof(int),
520 .mode = 0644,
521 .proc_handler = ftrace_enable_sysctl,
523 #endif
524 #ifdef CONFIG_STACK_TRACER
526 .procname = "stack_tracer_enabled",
527 .data = &stack_tracer_enabled,
528 .maxlen = sizeof(int),
529 .mode = 0644,
530 .proc_handler = stack_trace_sysctl,
532 #endif
533 #ifdef CONFIG_TRACING
535 .procname = "ftrace_dump_on_oops",
536 .data = &ftrace_dump_on_oops,
537 .maxlen = sizeof(int),
538 .mode = 0644,
539 .proc_handler = proc_dointvec,
541 #endif
542 #ifdef CONFIG_MODULES
544 .procname = "modprobe",
545 .data = &modprobe_path,
546 .maxlen = KMOD_PATH_LEN,
547 .mode = 0644,
548 .proc_handler = proc_dostring,
551 .procname = "modules_disabled",
552 .data = &modules_disabled,
553 .maxlen = sizeof(int),
554 .mode = 0644,
555 /* only handle a transition from default "0" to "1" */
556 .proc_handler = proc_dointvec_minmax,
557 .extra1 = &one,
558 .extra2 = &one,
560 #endif
561 #ifdef CONFIG_HOTPLUG
563 .procname = "hotplug",
564 .data = &uevent_helper,
565 .maxlen = UEVENT_HELPER_PATH_LEN,
566 .mode = 0644,
567 .proc_handler = proc_dostring,
569 #endif
570 #ifdef CONFIG_CHR_DEV_SG
572 .procname = "sg-big-buff",
573 .data = &sg_big_buff,
574 .maxlen = sizeof (int),
575 .mode = 0444,
576 .proc_handler = proc_dointvec,
578 #endif
579 #ifdef CONFIG_BSD_PROCESS_ACCT
581 .procname = "acct",
582 .data = &acct_parm,
583 .maxlen = 3*sizeof(int),
584 .mode = 0644,
585 .proc_handler = proc_dointvec,
587 #endif
588 #ifdef CONFIG_MAGIC_SYSRQ
590 .procname = "sysrq",
591 .data = &__sysrq_enabled,
592 .maxlen = sizeof (int),
593 .mode = 0644,
594 .proc_handler = sysrq_sysctl_handler,
596 #endif
597 #ifdef CONFIG_PROC_SYSCTL
599 .procname = "cad_pid",
600 .data = NULL,
601 .maxlen = sizeof (int),
602 .mode = 0600,
603 .proc_handler = proc_do_cad_pid,
605 #endif
607 .procname = "threads-max",
608 .data = &max_threads,
609 .maxlen = sizeof(int),
610 .mode = 0644,
611 .proc_handler = proc_dointvec,
614 .procname = "random",
615 .mode = 0555,
616 .child = random_table,
619 .procname = "overflowuid",
620 .data = &overflowuid,
621 .maxlen = sizeof(int),
622 .mode = 0644,
623 .proc_handler = proc_dointvec_minmax,
624 .extra1 = &minolduid,
625 .extra2 = &maxolduid,
628 .procname = "overflowgid",
629 .data = &overflowgid,
630 .maxlen = sizeof(int),
631 .mode = 0644,
632 .proc_handler = proc_dointvec_minmax,
633 .extra1 = &minolduid,
634 .extra2 = &maxolduid,
636 #ifdef CONFIG_S390
637 #ifdef CONFIG_MATHEMU
639 .procname = "ieee_emulation_warnings",
640 .data = &sysctl_ieee_emulation_warnings,
641 .maxlen = sizeof(int),
642 .mode = 0644,
643 .proc_handler = proc_dointvec,
645 #endif
647 .procname = "userprocess_debug",
648 .data = &show_unhandled_signals,
649 .maxlen = sizeof(int),
650 .mode = 0644,
651 .proc_handler = proc_dointvec,
653 #endif
655 .procname = "pid_max",
656 .data = &pid_max,
657 .maxlen = sizeof (int),
658 .mode = 0644,
659 .proc_handler = proc_dointvec_minmax,
660 .extra1 = &pid_max_min,
661 .extra2 = &pid_max_max,
664 .procname = "panic_on_oops",
665 .data = &panic_on_oops,
666 .maxlen = sizeof(int),
667 .mode = 0644,
668 .proc_handler = proc_dointvec,
670 #if defined CONFIG_PRINTK
672 .procname = "printk",
673 .data = &console_loglevel,
674 .maxlen = 4*sizeof(int),
675 .mode = 0644,
676 .proc_handler = proc_dointvec,
679 .procname = "printk_ratelimit",
680 .data = &printk_ratelimit_state.interval,
681 .maxlen = sizeof(int),
682 .mode = 0644,
683 .proc_handler = proc_dointvec_jiffies,
686 .procname = "printk_ratelimit_burst",
687 .data = &printk_ratelimit_state.burst,
688 .maxlen = sizeof(int),
689 .mode = 0644,
690 .proc_handler = proc_dointvec,
693 .procname = "printk_delay",
694 .data = &printk_delay_msec,
695 .maxlen = sizeof(int),
696 .mode = 0644,
697 .proc_handler = proc_dointvec_minmax,
698 .extra1 = &zero,
699 .extra2 = &ten_thousand,
702 .procname = "dmesg_restrict",
703 .data = &dmesg_restrict,
704 .maxlen = sizeof(int),
705 .mode = 0644,
706 .proc_handler = proc_dointvec_minmax,
707 .extra1 = &zero,
708 .extra2 = &one,
711 .procname = "kptr_restrict",
712 .data = &kptr_restrict,
713 .maxlen = sizeof(int),
714 .mode = 0644,
715 .proc_handler = proc_dmesg_restrict,
716 .extra1 = &zero,
717 .extra2 = &two,
719 #endif
721 .procname = "ngroups_max",
722 .data = &ngroups_max,
723 .maxlen = sizeof (int),
724 .mode = 0444,
725 .proc_handler = proc_dointvec,
727 #if defined(CONFIG_LOCKUP_DETECTOR)
729 .procname = "watchdog",
730 .data = &watchdog_enabled,
731 .maxlen = sizeof (int),
732 .mode = 0644,
733 .proc_handler = proc_dowatchdog,
734 .extra1 = &zero,
735 .extra2 = &one,
738 .procname = "watchdog_thresh",
739 .data = &watchdog_thresh,
740 .maxlen = sizeof(int),
741 .mode = 0644,
742 .proc_handler = proc_dowatchdog,
743 .extra1 = &neg_one,
744 .extra2 = &sixty,
747 .procname = "softlockup_panic",
748 .data = &softlockup_panic,
749 .maxlen = sizeof(int),
750 .mode = 0644,
751 .proc_handler = proc_dointvec_minmax,
752 .extra1 = &zero,
753 .extra2 = &one,
756 .procname = "nmi_watchdog",
757 .data = &watchdog_enabled,
758 .maxlen = sizeof (int),
759 .mode = 0644,
760 .proc_handler = proc_dowatchdog,
761 .extra1 = &zero,
762 .extra2 = &one,
764 #endif
765 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
767 .procname = "unknown_nmi_panic",
768 .data = &unknown_nmi_panic,
769 .maxlen = sizeof (int),
770 .mode = 0644,
771 .proc_handler = proc_dointvec,
773 #endif
774 #if defined(CONFIG_X86)
776 .procname = "panic_on_unrecovered_nmi",
777 .data = &panic_on_unrecovered_nmi,
778 .maxlen = sizeof(int),
779 .mode = 0644,
780 .proc_handler = proc_dointvec,
783 .procname = "panic_on_io_nmi",
784 .data = &panic_on_io_nmi,
785 .maxlen = sizeof(int),
786 .mode = 0644,
787 .proc_handler = proc_dointvec,
790 .procname = "bootloader_type",
791 .data = &bootloader_type,
792 .maxlen = sizeof (int),
793 .mode = 0444,
794 .proc_handler = proc_dointvec,
797 .procname = "bootloader_version",
798 .data = &bootloader_version,
799 .maxlen = sizeof (int),
800 .mode = 0444,
801 .proc_handler = proc_dointvec,
804 .procname = "kstack_depth_to_print",
805 .data = &kstack_depth_to_print,
806 .maxlen = sizeof(int),
807 .mode = 0644,
808 .proc_handler = proc_dointvec,
811 .procname = "io_delay_type",
812 .data = &io_delay_type,
813 .maxlen = sizeof(int),
814 .mode = 0644,
815 .proc_handler = proc_dointvec,
817 #endif
818 #if defined(CONFIG_MMU)
820 .procname = "randomize_va_space",
821 .data = &randomize_va_space,
822 .maxlen = sizeof(int),
823 .mode = 0644,
824 .proc_handler = proc_dointvec,
826 #endif
827 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
829 .procname = "spin_retry",
830 .data = &spin_retry,
831 .maxlen = sizeof (int),
832 .mode = 0644,
833 .proc_handler = proc_dointvec,
835 #endif
836 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
838 .procname = "acpi_video_flags",
839 .data = &acpi_realmode_flags,
840 .maxlen = sizeof (unsigned long),
841 .mode = 0644,
842 .proc_handler = proc_doulongvec_minmax,
844 #endif
845 #ifdef CONFIG_IA64
847 .procname = "ignore-unaligned-usertrap",
848 .data = &no_unaligned_warning,
849 .maxlen = sizeof (int),
850 .mode = 0644,
851 .proc_handler = proc_dointvec,
854 .procname = "unaligned-dump-stack",
855 .data = &unaligned_dump_stack,
856 .maxlen = sizeof (int),
857 .mode = 0644,
858 .proc_handler = proc_dointvec,
860 #endif
861 #ifdef CONFIG_DETECT_HUNG_TASK
863 .procname = "hung_task_panic",
864 .data = &sysctl_hung_task_panic,
865 .maxlen = sizeof(int),
866 .mode = 0644,
867 .proc_handler = proc_dointvec_minmax,
868 .extra1 = &zero,
869 .extra2 = &one,
872 .procname = "hung_task_check_count",
873 .data = &sysctl_hung_task_check_count,
874 .maxlen = sizeof(unsigned long),
875 .mode = 0644,
876 .proc_handler = proc_doulongvec_minmax,
879 .procname = "hung_task_timeout_secs",
880 .data = &sysctl_hung_task_timeout_secs,
881 .maxlen = sizeof(unsigned long),
882 .mode = 0644,
883 .proc_handler = proc_dohung_task_timeout_secs,
886 .procname = "hung_task_warnings",
887 .data = &sysctl_hung_task_warnings,
888 .maxlen = sizeof(unsigned long),
889 .mode = 0644,
890 .proc_handler = proc_doulongvec_minmax,
892 #endif
893 #ifdef CONFIG_COMPAT
895 .procname = "compat-log",
896 .data = &compat_log,
897 .maxlen = sizeof (int),
898 .mode = 0644,
899 .proc_handler = proc_dointvec,
901 #endif
902 #ifdef CONFIG_RT_MUTEXES
904 .procname = "max_lock_depth",
905 .data = &max_lock_depth,
906 .maxlen = sizeof(int),
907 .mode = 0644,
908 .proc_handler = proc_dointvec,
910 #endif
912 .procname = "poweroff_cmd",
913 .data = &poweroff_cmd,
914 .maxlen = POWEROFF_CMD_PATH_LEN,
915 .mode = 0644,
916 .proc_handler = proc_dostring,
918 #ifdef CONFIG_KEYS
920 .procname = "keys",
921 .mode = 0555,
922 .child = key_sysctls,
924 #endif
925 #ifdef CONFIG_RCU_TORTURE_TEST
927 .procname = "rcutorture_runnable",
928 .data = &rcutorture_runnable,
929 .maxlen = sizeof(int),
930 .mode = 0644,
931 .proc_handler = proc_dointvec,
933 #endif
934 #ifdef CONFIG_PERF_EVENTS
936 .procname = "perf_event_paranoid",
937 .data = &sysctl_perf_event_paranoid,
938 .maxlen = sizeof(sysctl_perf_event_paranoid),
939 .mode = 0644,
940 .proc_handler = proc_dointvec,
943 .procname = "perf_event_mlock_kb",
944 .data = &sysctl_perf_event_mlock,
945 .maxlen = sizeof(sysctl_perf_event_mlock),
946 .mode = 0644,
947 .proc_handler = proc_dointvec,
950 .procname = "perf_event_max_sample_rate",
951 .data = &sysctl_perf_event_sample_rate,
952 .maxlen = sizeof(sysctl_perf_event_sample_rate),
953 .mode = 0644,
954 .proc_handler = perf_proc_update_handler,
956 #endif
957 #ifdef CONFIG_KMEMCHECK
959 .procname = "kmemcheck",
960 .data = &kmemcheck_enabled,
961 .maxlen = sizeof(int),
962 .mode = 0644,
963 .proc_handler = proc_dointvec,
965 #endif
966 #ifdef CONFIG_BLOCK
968 .procname = "blk_iopoll",
969 .data = &blk_iopoll_enabled,
970 .maxlen = sizeof(int),
971 .mode = 0644,
972 .proc_handler = proc_dointvec,
974 #endif
978 static struct ctl_table vm_table[] = {
980 .procname = "overcommit_memory",
981 .data = &sysctl_overcommit_memory,
982 .maxlen = sizeof(sysctl_overcommit_memory),
983 .mode = 0644,
984 .proc_handler = proc_dointvec_minmax,
985 .extra1 = &zero,
986 .extra2 = &two,
989 .procname = "panic_on_oom",
990 .data = &sysctl_panic_on_oom,
991 .maxlen = sizeof(sysctl_panic_on_oom),
992 .mode = 0644,
993 .proc_handler = proc_dointvec_minmax,
994 .extra1 = &zero,
995 .extra2 = &two,
998 .procname = "oom_kill_allocating_task",
999 .data = &sysctl_oom_kill_allocating_task,
1000 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
1001 .mode = 0644,
1002 .proc_handler = proc_dointvec,
1005 .procname = "oom_dump_tasks",
1006 .data = &sysctl_oom_dump_tasks,
1007 .maxlen = sizeof(sysctl_oom_dump_tasks),
1008 .mode = 0644,
1009 .proc_handler = proc_dointvec,
1012 .procname = "overcommit_ratio",
1013 .data = &sysctl_overcommit_ratio,
1014 .maxlen = sizeof(sysctl_overcommit_ratio),
1015 .mode = 0644,
1016 .proc_handler = proc_dointvec,
1019 .procname = "page-cluster",
1020 .data = &page_cluster,
1021 .maxlen = sizeof(int),
1022 .mode = 0644,
1023 .proc_handler = proc_dointvec_minmax,
1024 .extra1 = &zero,
1027 .procname = "dirty_background_ratio",
1028 .data = &dirty_background_ratio,
1029 .maxlen = sizeof(dirty_background_ratio),
1030 .mode = 0644,
1031 .proc_handler = dirty_background_ratio_handler,
1032 .extra1 = &zero,
1033 .extra2 = &one_hundred,
1036 .procname = "dirty_background_bytes",
1037 .data = &dirty_background_bytes,
1038 .maxlen = sizeof(dirty_background_bytes),
1039 .mode = 0644,
1040 .proc_handler = dirty_background_bytes_handler,
1041 .extra1 = &one_ul,
1044 .procname = "dirty_ratio",
1045 .data = &vm_dirty_ratio,
1046 .maxlen = sizeof(vm_dirty_ratio),
1047 .mode = 0644,
1048 .proc_handler = dirty_ratio_handler,
1049 .extra1 = &zero,
1050 .extra2 = &one_hundred,
1053 .procname = "dirty_bytes",
1054 .data = &vm_dirty_bytes,
1055 .maxlen = sizeof(vm_dirty_bytes),
1056 .mode = 0644,
1057 .proc_handler = dirty_bytes_handler,
1058 .extra1 = &dirty_bytes_min,
1061 .procname = "dirty_writeback_centisecs",
1062 .data = &dirty_writeback_interval,
1063 .maxlen = sizeof(dirty_writeback_interval),
1064 .mode = 0644,
1065 .proc_handler = dirty_writeback_centisecs_handler,
1068 .procname = "dirty_expire_centisecs",
1069 .data = &dirty_expire_interval,
1070 .maxlen = sizeof(dirty_expire_interval),
1071 .mode = 0644,
1072 .proc_handler = proc_dointvec_minmax,
1073 .extra1 = &zero,
1076 .procname = "nr_pdflush_threads",
1077 .data = &nr_pdflush_threads,
1078 .maxlen = sizeof nr_pdflush_threads,
1079 .mode = 0444 /* read-only*/,
1080 .proc_handler = proc_dointvec,
1083 .procname = "swappiness",
1084 .data = &vm_swappiness,
1085 .maxlen = sizeof(vm_swappiness),
1086 .mode = 0644,
1087 .proc_handler = proc_dointvec_minmax,
1088 .extra1 = &zero,
1089 .extra2 = &one_hundred,
1091 #ifdef CONFIG_HUGETLB_PAGE
1093 .procname = "nr_hugepages",
1094 .data = NULL,
1095 .maxlen = sizeof(unsigned long),
1096 .mode = 0644,
1097 .proc_handler = hugetlb_sysctl_handler,
1098 .extra1 = (void *)&hugetlb_zero,
1099 .extra2 = (void *)&hugetlb_infinity,
1101 #ifdef CONFIG_NUMA
1103 .procname = "nr_hugepages_mempolicy",
1104 .data = NULL,
1105 .maxlen = sizeof(unsigned long),
1106 .mode = 0644,
1107 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1108 .extra1 = (void *)&hugetlb_zero,
1109 .extra2 = (void *)&hugetlb_infinity,
1111 #endif
1113 .procname = "hugetlb_shm_group",
1114 .data = &sysctl_hugetlb_shm_group,
1115 .maxlen = sizeof(gid_t),
1116 .mode = 0644,
1117 .proc_handler = proc_dointvec,
1120 .procname = "hugepages_treat_as_movable",
1121 .data = &hugepages_treat_as_movable,
1122 .maxlen = sizeof(int),
1123 .mode = 0644,
1124 .proc_handler = hugetlb_treat_movable_handler,
1127 .procname = "nr_overcommit_hugepages",
1128 .data = NULL,
1129 .maxlen = sizeof(unsigned long),
1130 .mode = 0644,
1131 .proc_handler = hugetlb_overcommit_handler,
1132 .extra1 = (void *)&hugetlb_zero,
1133 .extra2 = (void *)&hugetlb_infinity,
1135 #endif
1137 .procname = "lowmem_reserve_ratio",
1138 .data = &sysctl_lowmem_reserve_ratio,
1139 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1140 .mode = 0644,
1141 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1144 .procname = "drop_caches",
1145 .data = &sysctl_drop_caches,
1146 .maxlen = sizeof(int),
1147 .mode = 0644,
1148 .proc_handler = drop_caches_sysctl_handler,
1149 .extra1 = &one,
1150 .extra2 = &three,
1152 #ifdef CONFIG_COMPACTION
1154 .procname = "compact_memory",
1155 .data = &sysctl_compact_memory,
1156 .maxlen = sizeof(int),
1157 .mode = 0200,
1158 .proc_handler = sysctl_compaction_handler,
1161 .procname = "extfrag_threshold",
1162 .data = &sysctl_extfrag_threshold,
1163 .maxlen = sizeof(int),
1164 .mode = 0644,
1165 .proc_handler = sysctl_extfrag_handler,
1166 .extra1 = &min_extfrag_threshold,
1167 .extra2 = &max_extfrag_threshold,
1170 #endif /* CONFIG_COMPACTION */
1172 .procname = "min_free_kbytes",
1173 .data = &min_free_kbytes,
1174 .maxlen = sizeof(min_free_kbytes),
1175 .mode = 0644,
1176 .proc_handler = min_free_kbytes_sysctl_handler,
1177 .extra1 = &zero,
1180 .procname = "percpu_pagelist_fraction",
1181 .data = &percpu_pagelist_fraction,
1182 .maxlen = sizeof(percpu_pagelist_fraction),
1183 .mode = 0644,
1184 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1185 .extra1 = &min_percpu_pagelist_fract,
1187 #ifdef CONFIG_MMU
1189 .procname = "max_map_count",
1190 .data = &sysctl_max_map_count,
1191 .maxlen = sizeof(sysctl_max_map_count),
1192 .mode = 0644,
1193 .proc_handler = proc_dointvec_minmax,
1194 .extra1 = &zero,
1196 #else
1198 .procname = "nr_trim_pages",
1199 .data = &sysctl_nr_trim_pages,
1200 .maxlen = sizeof(sysctl_nr_trim_pages),
1201 .mode = 0644,
1202 .proc_handler = proc_dointvec_minmax,
1203 .extra1 = &zero,
1205 #endif
1207 .procname = "laptop_mode",
1208 .data = &laptop_mode,
1209 .maxlen = sizeof(laptop_mode),
1210 .mode = 0644,
1211 .proc_handler = proc_dointvec_jiffies,
1214 .procname = "block_dump",
1215 .data = &block_dump,
1216 .maxlen = sizeof(block_dump),
1217 .mode = 0644,
1218 .proc_handler = proc_dointvec,
1219 .extra1 = &zero,
1222 .procname = "vfs_cache_pressure",
1223 .data = &sysctl_vfs_cache_pressure,
1224 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1225 .mode = 0644,
1226 .proc_handler = proc_dointvec,
1227 .extra1 = &zero,
1229 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1231 .procname = "legacy_va_layout",
1232 .data = &sysctl_legacy_va_layout,
1233 .maxlen = sizeof(sysctl_legacy_va_layout),
1234 .mode = 0644,
1235 .proc_handler = proc_dointvec,
1236 .extra1 = &zero,
1238 #endif
1239 #ifdef CONFIG_NUMA
1241 .procname = "zone_reclaim_mode",
1242 .data = &zone_reclaim_mode,
1243 .maxlen = sizeof(zone_reclaim_mode),
1244 .mode = 0644,
1245 .proc_handler = proc_dointvec,
1246 .extra1 = &zero,
1249 .procname = "min_unmapped_ratio",
1250 .data = &sysctl_min_unmapped_ratio,
1251 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1252 .mode = 0644,
1253 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1254 .extra1 = &zero,
1255 .extra2 = &one_hundred,
1258 .procname = "min_slab_ratio",
1259 .data = &sysctl_min_slab_ratio,
1260 .maxlen = sizeof(sysctl_min_slab_ratio),
1261 .mode = 0644,
1262 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1263 .extra1 = &zero,
1264 .extra2 = &one_hundred,
1266 #endif
1267 #ifdef CONFIG_SMP
1269 .procname = "stat_interval",
1270 .data = &sysctl_stat_interval,
1271 .maxlen = sizeof(sysctl_stat_interval),
1272 .mode = 0644,
1273 .proc_handler = proc_dointvec_jiffies,
1275 #endif
1276 #ifdef CONFIG_MMU
1278 .procname = "mmap_min_addr",
1279 .data = &dac_mmap_min_addr,
1280 .maxlen = sizeof(unsigned long),
1281 .mode = 0644,
1282 .proc_handler = mmap_min_addr_handler,
1284 #endif
1285 #ifdef CONFIG_NUMA
1287 .procname = "numa_zonelist_order",
1288 .data = &numa_zonelist_order,
1289 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1290 .mode = 0644,
1291 .proc_handler = numa_zonelist_order_handler,
1293 #endif
1294 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1295 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1297 .procname = "vdso_enabled",
1298 .data = &vdso_enabled,
1299 .maxlen = sizeof(vdso_enabled),
1300 .mode = 0644,
1301 .proc_handler = proc_dointvec,
1302 .extra1 = &zero,
1304 #endif
1305 #ifdef CONFIG_HIGHMEM
1307 .procname = "highmem_is_dirtyable",
1308 .data = &vm_highmem_is_dirtyable,
1309 .maxlen = sizeof(vm_highmem_is_dirtyable),
1310 .mode = 0644,
1311 .proc_handler = proc_dointvec_minmax,
1312 .extra1 = &zero,
1313 .extra2 = &one,
1315 #endif
1317 .procname = "scan_unevictable_pages",
1318 .data = &scan_unevictable_pages,
1319 .maxlen = sizeof(scan_unevictable_pages),
1320 .mode = 0644,
1321 .proc_handler = scan_unevictable_handler,
1323 #ifdef CONFIG_MEMORY_FAILURE
1325 .procname = "memory_failure_early_kill",
1326 .data = &sysctl_memory_failure_early_kill,
1327 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1328 .mode = 0644,
1329 .proc_handler = proc_dointvec_minmax,
1330 .extra1 = &zero,
1331 .extra2 = &one,
1334 .procname = "memory_failure_recovery",
1335 .data = &sysctl_memory_failure_recovery,
1336 .maxlen = sizeof(sysctl_memory_failure_recovery),
1337 .mode = 0644,
1338 .proc_handler = proc_dointvec_minmax,
1339 .extra1 = &zero,
1340 .extra2 = &one,
1342 #endif
1346 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1347 static struct ctl_table binfmt_misc_table[] = {
1350 #endif
1352 static struct ctl_table fs_table[] = {
1354 .procname = "inode-nr",
1355 .data = &inodes_stat,
1356 .maxlen = 2*sizeof(int),
1357 .mode = 0444,
1358 .proc_handler = proc_nr_inodes,
1361 .procname = "inode-state",
1362 .data = &inodes_stat,
1363 .maxlen = 7*sizeof(int),
1364 .mode = 0444,
1365 .proc_handler = proc_nr_inodes,
1368 .procname = "file-nr",
1369 .data = &files_stat,
1370 .maxlen = sizeof(files_stat),
1371 .mode = 0444,
1372 .proc_handler = proc_nr_files,
1375 .procname = "file-max",
1376 .data = &files_stat.max_files,
1377 .maxlen = sizeof(files_stat.max_files),
1378 .mode = 0644,
1379 .proc_handler = proc_doulongvec_minmax,
1382 .procname = "nr_open",
1383 .data = &sysctl_nr_open,
1384 .maxlen = sizeof(int),
1385 .mode = 0644,
1386 .proc_handler = proc_dointvec_minmax,
1387 .extra1 = &sysctl_nr_open_min,
1388 .extra2 = &sysctl_nr_open_max,
1391 .procname = "dentry-state",
1392 .data = &dentry_stat,
1393 .maxlen = 6*sizeof(int),
1394 .mode = 0444,
1395 .proc_handler = proc_nr_dentry,
1398 .procname = "overflowuid",
1399 .data = &fs_overflowuid,
1400 .maxlen = sizeof(int),
1401 .mode = 0644,
1402 .proc_handler = proc_dointvec_minmax,
1403 .extra1 = &minolduid,
1404 .extra2 = &maxolduid,
1407 .procname = "overflowgid",
1408 .data = &fs_overflowgid,
1409 .maxlen = sizeof(int),
1410 .mode = 0644,
1411 .proc_handler = proc_dointvec_minmax,
1412 .extra1 = &minolduid,
1413 .extra2 = &maxolduid,
1415 #ifdef CONFIG_FILE_LOCKING
1417 .procname = "leases-enable",
1418 .data = &leases_enable,
1419 .maxlen = sizeof(int),
1420 .mode = 0644,
1421 .proc_handler = proc_dointvec,
1423 #endif
1424 #ifdef CONFIG_DNOTIFY
1426 .procname = "dir-notify-enable",
1427 .data = &dir_notify_enable,
1428 .maxlen = sizeof(int),
1429 .mode = 0644,
1430 .proc_handler = proc_dointvec,
1432 #endif
1433 #ifdef CONFIG_MMU
1434 #ifdef CONFIG_FILE_LOCKING
1436 .procname = "lease-break-time",
1437 .data = &lease_break_time,
1438 .maxlen = sizeof(int),
1439 .mode = 0644,
1440 .proc_handler = proc_dointvec,
1442 #endif
1443 #ifdef CONFIG_AIO
1445 .procname = "aio-nr",
1446 .data = &aio_nr,
1447 .maxlen = sizeof(aio_nr),
1448 .mode = 0444,
1449 .proc_handler = proc_doulongvec_minmax,
1452 .procname = "aio-max-nr",
1453 .data = &aio_max_nr,
1454 .maxlen = sizeof(aio_max_nr),
1455 .mode = 0644,
1456 .proc_handler = proc_doulongvec_minmax,
1458 #endif /* CONFIG_AIO */
1459 #ifdef CONFIG_INOTIFY_USER
1461 .procname = "inotify",
1462 .mode = 0555,
1463 .child = inotify_table,
1465 #endif
1466 #ifdef CONFIG_EPOLL
1468 .procname = "epoll",
1469 .mode = 0555,
1470 .child = epoll_table,
1472 #endif
1473 #endif
1475 .procname = "suid_dumpable",
1476 .data = &suid_dumpable,
1477 .maxlen = sizeof(int),
1478 .mode = 0644,
1479 .proc_handler = proc_dointvec_minmax,
1480 .extra1 = &zero,
1481 .extra2 = &two,
1483 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1485 .procname = "binfmt_misc",
1486 .mode = 0555,
1487 .child = binfmt_misc_table,
1489 #endif
1491 .procname = "pipe-max-size",
1492 .data = &pipe_max_size,
1493 .maxlen = sizeof(int),
1494 .mode = 0644,
1495 .proc_handler = &pipe_proc_fn,
1496 .extra1 = &pipe_min_size,
1501 static struct ctl_table debug_table[] = {
1502 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \
1503 defined(CONFIG_S390)
1505 .procname = "exception-trace",
1506 .data = &show_unhandled_signals,
1507 .maxlen = sizeof(int),
1508 .mode = 0644,
1509 .proc_handler = proc_dointvec
1511 #endif
1512 #if defined(CONFIG_OPTPROBES)
1514 .procname = "kprobes-optimization",
1515 .data = &sysctl_kprobes_optimization,
1516 .maxlen = sizeof(int),
1517 .mode = 0644,
1518 .proc_handler = proc_kprobes_optimization_handler,
1519 .extra1 = &zero,
1520 .extra2 = &one,
1522 #endif
1526 static struct ctl_table dev_table[] = {
1530 static DEFINE_SPINLOCK(sysctl_lock);
1532 /* called under sysctl_lock */
1533 static int use_table(struct ctl_table_header *p)
1535 if (unlikely(p->unregistering))
1536 return 0;
1537 p->used++;
1538 return 1;
1541 /* called under sysctl_lock */
1542 static void unuse_table(struct ctl_table_header *p)
1544 if (!--p->used)
1545 if (unlikely(p->unregistering))
1546 complete(p->unregistering);
1549 /* called under sysctl_lock, will reacquire if has to wait */
1550 static void start_unregistering(struct ctl_table_header *p)
1553 * if p->used is 0, nobody will ever touch that entry again;
1554 * we'll eliminate all paths to it before dropping sysctl_lock
1556 if (unlikely(p->used)) {
1557 struct completion wait;
1558 init_completion(&wait);
1559 p->unregistering = &wait;
1560 spin_unlock(&sysctl_lock);
1561 wait_for_completion(&wait);
1562 spin_lock(&sysctl_lock);
1563 } else {
1564 /* anything non-NULL; we'll never dereference it */
1565 p->unregistering = ERR_PTR(-EINVAL);
1568 * do not remove from the list until nobody holds it; walking the
1569 * list in do_sysctl() relies on that.
1571 list_del_init(&p->ctl_entry);
1574 void sysctl_head_get(struct ctl_table_header *head)
1576 spin_lock(&sysctl_lock);
1577 head->count++;
1578 spin_unlock(&sysctl_lock);
1581 static void free_head(struct rcu_head *rcu)
1583 kfree(container_of(rcu, struct ctl_table_header, rcu));
1586 void sysctl_head_put(struct ctl_table_header *head)
1588 spin_lock(&sysctl_lock);
1589 if (!--head->count)
1590 call_rcu(&head->rcu, free_head);
1591 spin_unlock(&sysctl_lock);
1594 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1596 if (!head)
1597 BUG();
1598 spin_lock(&sysctl_lock);
1599 if (!use_table(head))
1600 head = ERR_PTR(-ENOENT);
1601 spin_unlock(&sysctl_lock);
1602 return head;
1605 void sysctl_head_finish(struct ctl_table_header *head)
1607 if (!head)
1608 return;
1609 spin_lock(&sysctl_lock);
1610 unuse_table(head);
1611 spin_unlock(&sysctl_lock);
1614 static struct ctl_table_set *
1615 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1617 struct ctl_table_set *set = &root->default_set;
1618 if (root->lookup)
1619 set = root->lookup(root, namespaces);
1620 return set;
1623 static struct list_head *
1624 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1626 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1627 return &set->list;
1630 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1631 struct ctl_table_header *prev)
1633 struct ctl_table_root *root;
1634 struct list_head *header_list;
1635 struct ctl_table_header *head;
1636 struct list_head *tmp;
1638 spin_lock(&sysctl_lock);
1639 if (prev) {
1640 head = prev;
1641 tmp = &prev->ctl_entry;
1642 unuse_table(prev);
1643 goto next;
1645 tmp = &root_table_header.ctl_entry;
1646 for (;;) {
1647 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1649 if (!use_table(head))
1650 goto next;
1651 spin_unlock(&sysctl_lock);
1652 return head;
1653 next:
1654 root = head->root;
1655 tmp = tmp->next;
1656 header_list = lookup_header_list(root, namespaces);
1657 if (tmp != header_list)
1658 continue;
1660 do {
1661 root = list_entry(root->root_list.next,
1662 struct ctl_table_root, root_list);
1663 if (root == &sysctl_table_root)
1664 goto out;
1665 header_list = lookup_header_list(root, namespaces);
1666 } while (list_empty(header_list));
1667 tmp = header_list->next;
1669 out:
1670 spin_unlock(&sysctl_lock);
1671 return NULL;
1674 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1676 return __sysctl_head_next(current->nsproxy, prev);
1679 void register_sysctl_root(struct ctl_table_root *root)
1681 spin_lock(&sysctl_lock);
1682 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1683 spin_unlock(&sysctl_lock);
1687 * sysctl_perm does NOT grant the superuser all rights automatically, because
1688 * some sysctl variables are readonly even to root.
1691 static int test_perm(int mode, int op)
1693 if (!current_euid())
1694 mode >>= 6;
1695 else if (in_egroup_p(0))
1696 mode >>= 3;
1697 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1698 return 0;
1699 return -EACCES;
1702 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1704 int mode;
1706 if (root->permissions)
1707 mode = root->permissions(root, current->nsproxy, table);
1708 else
1709 mode = table->mode;
1711 return test_perm(mode, op);
1714 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1716 for (; table->procname; table++) {
1717 table->parent = parent;
1718 if (table->child)
1719 sysctl_set_parent(table, table->child);
1723 static __init int sysctl_init(void)
1725 sysctl_set_parent(NULL, root_table);
1726 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1727 sysctl_check_table(current->nsproxy, root_table);
1728 #endif
1729 return 0;
1732 core_initcall(sysctl_init);
1734 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1735 struct ctl_table *table)
1737 struct ctl_table *p;
1738 const char *s = branch->procname;
1740 /* branch should have named subdirectory as its first element */
1741 if (!s || !branch->child)
1742 return NULL;
1744 /* ... and nothing else */
1745 if (branch[1].procname)
1746 return NULL;
1748 /* table should contain subdirectory with the same name */
1749 for (p = table; p->procname; p++) {
1750 if (!p->child)
1751 continue;
1752 if (p->procname && strcmp(p->procname, s) == 0)
1753 return p;
1755 return NULL;
1758 /* see if attaching q to p would be an improvement */
1759 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1761 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1762 struct ctl_table *next;
1763 int is_better = 0;
1764 int not_in_parent = !p->attached_by;
1766 while ((next = is_branch_in(by, to)) != NULL) {
1767 if (by == q->attached_by)
1768 is_better = 1;
1769 if (to == p->attached_by)
1770 not_in_parent = 1;
1771 by = by->child;
1772 to = next->child;
1775 if (is_better && not_in_parent) {
1776 q->attached_by = by;
1777 q->attached_to = to;
1778 q->parent = p;
1783 * __register_sysctl_paths - register a sysctl hierarchy
1784 * @root: List of sysctl headers to register on
1785 * @namespaces: Data to compute which lists of sysctl entries are visible
1786 * @path: The path to the directory the sysctl table is in.
1787 * @table: the top-level table structure
1789 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1790 * array. A completely 0 filled entry terminates the table.
1792 * The members of the &struct ctl_table structure are used as follows:
1794 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1795 * enter a sysctl file
1797 * data - a pointer to data for use by proc_handler
1799 * maxlen - the maximum size in bytes of the data
1801 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1803 * child - a pointer to the child sysctl table if this entry is a directory, or
1804 * %NULL.
1806 * proc_handler - the text handler routine (described below)
1808 * de - for internal use by the sysctl routines
1810 * extra1, extra2 - extra pointers usable by the proc handler routines
1812 * Leaf nodes in the sysctl tree will be represented by a single file
1813 * under /proc; non-leaf nodes will be represented by directories.
1815 * sysctl(2) can automatically manage read and write requests through
1816 * the sysctl table. The data and maxlen fields of the ctl_table
1817 * struct enable minimal validation of the values being written to be
1818 * performed, and the mode field allows minimal authentication.
1820 * There must be a proc_handler routine for any terminal nodes
1821 * mirrored under /proc/sys (non-terminals are handled by a built-in
1822 * directory handler). Several default handlers are available to
1823 * cover common cases -
1825 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1826 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1827 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1829 * It is the handler's job to read the input buffer from user memory
1830 * and process it. The handler should return 0 on success.
1832 * This routine returns %NULL on a failure to register, and a pointer
1833 * to the table header on success.
1835 struct ctl_table_header *__register_sysctl_paths(
1836 struct ctl_table_root *root,
1837 struct nsproxy *namespaces,
1838 const struct ctl_path *path, struct ctl_table *table)
1840 struct ctl_table_header *header;
1841 struct ctl_table *new, **prevp;
1842 unsigned int n, npath;
1843 struct ctl_table_set *set;
1845 /* Count the path components */
1846 for (npath = 0; path[npath].procname; ++npath)
1850 * For each path component, allocate a 2-element ctl_table array.
1851 * The first array element will be filled with the sysctl entry
1852 * for this, the second will be the sentinel (procname == 0).
1854 * We allocate everything in one go so that we don't have to
1855 * worry about freeing additional memory in unregister_sysctl_table.
1857 header = kzalloc(sizeof(struct ctl_table_header) +
1858 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1859 if (!header)
1860 return NULL;
1862 new = (struct ctl_table *) (header + 1);
1864 /* Now connect the dots */
1865 prevp = &header->ctl_table;
1866 for (n = 0; n < npath; ++n, ++path) {
1867 /* Copy the procname */
1868 new->procname = path->procname;
1869 new->mode = 0555;
1871 *prevp = new;
1872 prevp = &new->child;
1874 new += 2;
1876 *prevp = table;
1877 header->ctl_table_arg = table;
1879 INIT_LIST_HEAD(&header->ctl_entry);
1880 header->used = 0;
1881 header->unregistering = NULL;
1882 header->root = root;
1883 sysctl_set_parent(NULL, header->ctl_table);
1884 header->count = 1;
1885 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1886 if (sysctl_check_table(namespaces, header->ctl_table)) {
1887 kfree(header);
1888 return NULL;
1890 #endif
1891 spin_lock(&sysctl_lock);
1892 header->set = lookup_header_set(root, namespaces);
1893 header->attached_by = header->ctl_table;
1894 header->attached_to = root_table;
1895 header->parent = &root_table_header;
1896 for (set = header->set; set; set = set->parent) {
1897 struct ctl_table_header *p;
1898 list_for_each_entry(p, &set->list, ctl_entry) {
1899 if (p->unregistering)
1900 continue;
1901 try_attach(p, header);
1904 header->parent->count++;
1905 list_add_tail(&header->ctl_entry, &header->set->list);
1906 spin_unlock(&sysctl_lock);
1908 return header;
1912 * register_sysctl_table_path - register a sysctl table hierarchy
1913 * @path: The path to the directory the sysctl table is in.
1914 * @table: the top-level table structure
1916 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1917 * array. A completely 0 filled entry terminates the table.
1919 * See __register_sysctl_paths for more details.
1921 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1922 struct ctl_table *table)
1924 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1925 path, table);
1929 * register_sysctl_table - register a sysctl table hierarchy
1930 * @table: the top-level table structure
1932 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1933 * array. A completely 0 filled entry terminates the table.
1935 * See register_sysctl_paths for more details.
1937 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1939 static const struct ctl_path null_path[] = { {} };
1941 return register_sysctl_paths(null_path, table);
1945 * unregister_sysctl_table - unregister a sysctl table hierarchy
1946 * @header: the header returned from register_sysctl_table
1948 * Unregisters the sysctl table and all children. proc entries may not
1949 * actually be removed until they are no longer used by anyone.
1951 void unregister_sysctl_table(struct ctl_table_header * header)
1953 might_sleep();
1955 if (header == NULL)
1956 return;
1958 spin_lock(&sysctl_lock);
1959 start_unregistering(header);
1960 if (!--header->parent->count) {
1961 WARN_ON(1);
1962 call_rcu(&header->parent->rcu, free_head);
1964 if (!--header->count)
1965 call_rcu(&header->rcu, free_head);
1966 spin_unlock(&sysctl_lock);
1969 int sysctl_is_seen(struct ctl_table_header *p)
1971 struct ctl_table_set *set = p->set;
1972 int res;
1973 spin_lock(&sysctl_lock);
1974 if (p->unregistering)
1975 res = 0;
1976 else if (!set->is_seen)
1977 res = 1;
1978 else
1979 res = set->is_seen(set);
1980 spin_unlock(&sysctl_lock);
1981 return res;
1984 void setup_sysctl_set(struct ctl_table_set *p,
1985 struct ctl_table_set *parent,
1986 int (*is_seen)(struct ctl_table_set *))
1988 INIT_LIST_HEAD(&p->list);
1989 p->parent = parent ? parent : &sysctl_table_root.default_set;
1990 p->is_seen = is_seen;
1993 #else /* !CONFIG_SYSCTL */
1994 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1996 return NULL;
1999 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2000 struct ctl_table *table)
2002 return NULL;
2005 void unregister_sysctl_table(struct ctl_table_header * table)
2009 void setup_sysctl_set(struct ctl_table_set *p,
2010 struct ctl_table_set *parent,
2011 int (*is_seen)(struct ctl_table_set *))
2015 void sysctl_head_put(struct ctl_table_header *head)
2019 #endif /* CONFIG_SYSCTL */
2022 * /proc/sys support
2025 #ifdef CONFIG_PROC_SYSCTL
2027 static int _proc_do_string(void* data, int maxlen, int write,
2028 void __user *buffer,
2029 size_t *lenp, loff_t *ppos)
2031 size_t len;
2032 char __user *p;
2033 char c;
2035 if (!data || !maxlen || !*lenp) {
2036 *lenp = 0;
2037 return 0;
2040 if (write) {
2041 len = 0;
2042 p = buffer;
2043 while (len < *lenp) {
2044 if (get_user(c, p++))
2045 return -EFAULT;
2046 if (c == 0 || c == '\n')
2047 break;
2048 len++;
2050 if (len >= maxlen)
2051 len = maxlen-1;
2052 if(copy_from_user(data, buffer, len))
2053 return -EFAULT;
2054 ((char *) data)[len] = 0;
2055 *ppos += *lenp;
2056 } else {
2057 len = strlen(data);
2058 if (len > maxlen)
2059 len = maxlen;
2061 if (*ppos > len) {
2062 *lenp = 0;
2063 return 0;
2066 data += *ppos;
2067 len -= *ppos;
2069 if (len > *lenp)
2070 len = *lenp;
2071 if (len)
2072 if(copy_to_user(buffer, data, len))
2073 return -EFAULT;
2074 if (len < *lenp) {
2075 if(put_user('\n', ((char __user *) buffer) + len))
2076 return -EFAULT;
2077 len++;
2079 *lenp = len;
2080 *ppos += len;
2082 return 0;
2086 * proc_dostring - read a string sysctl
2087 * @table: the sysctl table
2088 * @write: %TRUE if this is a write to the sysctl file
2089 * @buffer: the user buffer
2090 * @lenp: the size of the user buffer
2091 * @ppos: file position
2093 * Reads/writes a string from/to the user buffer. If the kernel
2094 * buffer provided is not large enough to hold the string, the
2095 * string is truncated. The copied string is %NULL-terminated.
2096 * If the string is being read by the user process, it is copied
2097 * and a newline '\n' is added. It is truncated if the buffer is
2098 * not large enough.
2100 * Returns 0 on success.
2102 int proc_dostring(struct ctl_table *table, int write,
2103 void __user *buffer, size_t *lenp, loff_t *ppos)
2105 return _proc_do_string(table->data, table->maxlen, write,
2106 buffer, lenp, ppos);
2109 static size_t proc_skip_spaces(char **buf)
2111 size_t ret;
2112 char *tmp = skip_spaces(*buf);
2113 ret = tmp - *buf;
2114 *buf = tmp;
2115 return ret;
2118 static void proc_skip_char(char **buf, size_t *size, const char v)
2120 while (*size) {
2121 if (**buf != v)
2122 break;
2123 (*size)--;
2124 (*buf)++;
2128 #define TMPBUFLEN 22
2130 * proc_get_long - reads an ASCII formatted integer from a user buffer
2132 * @buf: a kernel buffer
2133 * @size: size of the kernel buffer
2134 * @val: this is where the number will be stored
2135 * @neg: set to %TRUE if number is negative
2136 * @perm_tr: a vector which contains the allowed trailers
2137 * @perm_tr_len: size of the perm_tr vector
2138 * @tr: pointer to store the trailer character
2140 * In case of success %0 is returned and @buf and @size are updated with
2141 * the amount of bytes read. If @tr is non-NULL and a trailing
2142 * character exists (size is non-zero after returning from this
2143 * function), @tr is updated with the trailing character.
2145 static int proc_get_long(char **buf, size_t *size,
2146 unsigned long *val, bool *neg,
2147 const char *perm_tr, unsigned perm_tr_len, char *tr)
2149 int len;
2150 char *p, tmp[TMPBUFLEN];
2152 if (!*size)
2153 return -EINVAL;
2155 len = *size;
2156 if (len > TMPBUFLEN - 1)
2157 len = TMPBUFLEN - 1;
2159 memcpy(tmp, *buf, len);
2161 tmp[len] = 0;
2162 p = tmp;
2163 if (*p == '-' && *size > 1) {
2164 *neg = true;
2165 p++;
2166 } else
2167 *neg = false;
2168 if (!isdigit(*p))
2169 return -EINVAL;
2171 *val = simple_strtoul(p, &p, 0);
2173 len = p - tmp;
2175 /* We don't know if the next char is whitespace thus we may accept
2176 * invalid integers (e.g. 1234...a) or two integers instead of one
2177 * (e.g. 123...1). So lets not allow such large numbers. */
2178 if (len == TMPBUFLEN - 1)
2179 return -EINVAL;
2181 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2182 return -EINVAL;
2184 if (tr && (len < *size))
2185 *tr = *p;
2187 *buf += len;
2188 *size -= len;
2190 return 0;
2194 * proc_put_long - converts an integer to a decimal ASCII formatted string
2196 * @buf: the user buffer
2197 * @size: the size of the user buffer
2198 * @val: the integer to be converted
2199 * @neg: sign of the number, %TRUE for negative
2201 * In case of success %0 is returned and @buf and @size are updated with
2202 * the amount of bytes written.
2204 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2205 bool neg)
2207 int len;
2208 char tmp[TMPBUFLEN], *p = tmp;
2210 sprintf(p, "%s%lu", neg ? "-" : "", val);
2211 len = strlen(tmp);
2212 if (len > *size)
2213 len = *size;
2214 if (copy_to_user(*buf, tmp, len))
2215 return -EFAULT;
2216 *size -= len;
2217 *buf += len;
2218 return 0;
2220 #undef TMPBUFLEN
2222 static int proc_put_char(void __user **buf, size_t *size, char c)
2224 if (*size) {
2225 char __user **buffer = (char __user **)buf;
2226 if (put_user(c, *buffer))
2227 return -EFAULT;
2228 (*size)--, (*buffer)++;
2229 *buf = *buffer;
2231 return 0;
2234 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2235 int *valp,
2236 int write, void *data)
2238 if (write) {
2239 *valp = *negp ? -*lvalp : *lvalp;
2240 } else {
2241 int val = *valp;
2242 if (val < 0) {
2243 *negp = true;
2244 *lvalp = (unsigned long)-val;
2245 } else {
2246 *negp = false;
2247 *lvalp = (unsigned long)val;
2250 return 0;
2253 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2255 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2256 int write, void __user *buffer,
2257 size_t *lenp, loff_t *ppos,
2258 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2259 int write, void *data),
2260 void *data)
2262 int *i, vleft, first = 1, err = 0;
2263 unsigned long page = 0;
2264 size_t left;
2265 char *kbuf;
2267 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2268 *lenp = 0;
2269 return 0;
2272 i = (int *) tbl_data;
2273 vleft = table->maxlen / sizeof(*i);
2274 left = *lenp;
2276 if (!conv)
2277 conv = do_proc_dointvec_conv;
2279 if (write) {
2280 if (left > PAGE_SIZE - 1)
2281 left = PAGE_SIZE - 1;
2282 page = __get_free_page(GFP_TEMPORARY);
2283 kbuf = (char *) page;
2284 if (!kbuf)
2285 return -ENOMEM;
2286 if (copy_from_user(kbuf, buffer, left)) {
2287 err = -EFAULT;
2288 goto free;
2290 kbuf[left] = 0;
2293 for (; left && vleft--; i++, first=0) {
2294 unsigned long lval;
2295 bool neg;
2297 if (write) {
2298 left -= proc_skip_spaces(&kbuf);
2300 if (!left)
2301 break;
2302 err = proc_get_long(&kbuf, &left, &lval, &neg,
2303 proc_wspace_sep,
2304 sizeof(proc_wspace_sep), NULL);
2305 if (err)
2306 break;
2307 if (conv(&neg, &lval, i, 1, data)) {
2308 err = -EINVAL;
2309 break;
2311 } else {
2312 if (conv(&neg, &lval, i, 0, data)) {
2313 err = -EINVAL;
2314 break;
2316 if (!first)
2317 err = proc_put_char(&buffer, &left, '\t');
2318 if (err)
2319 break;
2320 err = proc_put_long(&buffer, &left, lval, neg);
2321 if (err)
2322 break;
2326 if (!write && !first && left && !err)
2327 err = proc_put_char(&buffer, &left, '\n');
2328 if (write && !err && left)
2329 left -= proc_skip_spaces(&kbuf);
2330 free:
2331 if (write) {
2332 free_page(page);
2333 if (first)
2334 return err ? : -EINVAL;
2336 *lenp -= left;
2337 *ppos += *lenp;
2338 return err;
2341 static int do_proc_dointvec(struct ctl_table *table, int write,
2342 void __user *buffer, size_t *lenp, loff_t *ppos,
2343 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2344 int write, void *data),
2345 void *data)
2347 return __do_proc_dointvec(table->data, table, write,
2348 buffer, lenp, ppos, conv, data);
2352 * proc_dointvec - read a vector of integers
2353 * @table: the sysctl table
2354 * @write: %TRUE if this is a write to the sysctl file
2355 * @buffer: the user buffer
2356 * @lenp: the size of the user buffer
2357 * @ppos: file position
2359 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2360 * values from/to the user buffer, treated as an ASCII string.
2362 * Returns 0 on success.
2364 int proc_dointvec(struct ctl_table *table, int write,
2365 void __user *buffer, size_t *lenp, loff_t *ppos)
2367 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2368 NULL,NULL);
2372 * Taint values can only be increased
2373 * This means we can safely use a temporary.
2375 static int proc_taint(struct ctl_table *table, int write,
2376 void __user *buffer, size_t *lenp, loff_t *ppos)
2378 struct ctl_table t;
2379 unsigned long tmptaint = get_taint();
2380 int err;
2382 if (write && !capable(CAP_SYS_ADMIN))
2383 return -EPERM;
2385 t = *table;
2386 t.data = &tmptaint;
2387 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2388 if (err < 0)
2389 return err;
2391 if (write) {
2393 * Poor man's atomic or. Not worth adding a primitive
2394 * to everyone's atomic.h for this
2396 int i;
2397 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2398 if ((tmptaint >> i) & 1)
2399 add_taint(i);
2403 return err;
2406 #ifdef CONFIG_PRINTK
2407 static int proc_dmesg_restrict(struct ctl_table *table, int write,
2408 void __user *buffer, size_t *lenp, loff_t *ppos)
2410 if (write && !capable(CAP_SYS_ADMIN))
2411 return -EPERM;
2413 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2415 #endif
2417 struct do_proc_dointvec_minmax_conv_param {
2418 int *min;
2419 int *max;
2422 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2423 int *valp,
2424 int write, void *data)
2426 struct do_proc_dointvec_minmax_conv_param *param = data;
2427 if (write) {
2428 int val = *negp ? -*lvalp : *lvalp;
2429 if ((param->min && *param->min > val) ||
2430 (param->max && *param->max < val))
2431 return -EINVAL;
2432 *valp = val;
2433 } else {
2434 int val = *valp;
2435 if (val < 0) {
2436 *negp = true;
2437 *lvalp = (unsigned long)-val;
2438 } else {
2439 *negp = false;
2440 *lvalp = (unsigned long)val;
2443 return 0;
2447 * proc_dointvec_minmax - read a vector of integers with min/max values
2448 * @table: the sysctl table
2449 * @write: %TRUE if this is a write to the sysctl file
2450 * @buffer: the user buffer
2451 * @lenp: the size of the user buffer
2452 * @ppos: file position
2454 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2455 * values from/to the user buffer, treated as an ASCII string.
2457 * This routine will ensure the values are within the range specified by
2458 * table->extra1 (min) and table->extra2 (max).
2460 * Returns 0 on success.
2462 int proc_dointvec_minmax(struct ctl_table *table, int write,
2463 void __user *buffer, size_t *lenp, loff_t *ppos)
2465 struct do_proc_dointvec_minmax_conv_param param = {
2466 .min = (int *) table->extra1,
2467 .max = (int *) table->extra2,
2469 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2470 do_proc_dointvec_minmax_conv, &param);
2473 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2474 void __user *buffer,
2475 size_t *lenp, loff_t *ppos,
2476 unsigned long convmul,
2477 unsigned long convdiv)
2479 unsigned long *i, *min, *max;
2480 int vleft, first = 1, err = 0;
2481 unsigned long page = 0;
2482 size_t left;
2483 char *kbuf;
2485 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2486 *lenp = 0;
2487 return 0;
2490 i = (unsigned long *) data;
2491 min = (unsigned long *) table->extra1;
2492 max = (unsigned long *) table->extra2;
2493 vleft = table->maxlen / sizeof(unsigned long);
2494 left = *lenp;
2496 if (write) {
2497 if (left > PAGE_SIZE - 1)
2498 left = PAGE_SIZE - 1;
2499 page = __get_free_page(GFP_TEMPORARY);
2500 kbuf = (char *) page;
2501 if (!kbuf)
2502 return -ENOMEM;
2503 if (copy_from_user(kbuf, buffer, left)) {
2504 err = -EFAULT;
2505 goto free;
2507 kbuf[left] = 0;
2510 for (; left && vleft--; i++, first = 0) {
2511 unsigned long val;
2513 if (write) {
2514 bool neg;
2516 left -= proc_skip_spaces(&kbuf);
2518 err = proc_get_long(&kbuf, &left, &val, &neg,
2519 proc_wspace_sep,
2520 sizeof(proc_wspace_sep), NULL);
2521 if (err)
2522 break;
2523 if (neg)
2524 continue;
2525 if ((min && val < *min) || (max && val > *max))
2526 continue;
2527 *i = val;
2528 } else {
2529 val = convdiv * (*i) / convmul;
2530 if (!first)
2531 err = proc_put_char(&buffer, &left, '\t');
2532 err = proc_put_long(&buffer, &left, val, false);
2533 if (err)
2534 break;
2538 if (!write && !first && left && !err)
2539 err = proc_put_char(&buffer, &left, '\n');
2540 if (write && !err)
2541 left -= proc_skip_spaces(&kbuf);
2542 free:
2543 if (write) {
2544 free_page(page);
2545 if (first)
2546 return err ? : -EINVAL;
2548 *lenp -= left;
2549 *ppos += *lenp;
2550 return err;
2553 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2554 void __user *buffer,
2555 size_t *lenp, loff_t *ppos,
2556 unsigned long convmul,
2557 unsigned long convdiv)
2559 return __do_proc_doulongvec_minmax(table->data, table, write,
2560 buffer, lenp, ppos, convmul, convdiv);
2564 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2565 * @table: the sysctl table
2566 * @write: %TRUE if this is a write to the sysctl file
2567 * @buffer: the user buffer
2568 * @lenp: the size of the user buffer
2569 * @ppos: file position
2571 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2572 * values from/to the user buffer, treated as an ASCII string.
2574 * This routine will ensure the values are within the range specified by
2575 * table->extra1 (min) and table->extra2 (max).
2577 * Returns 0 on success.
2579 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2580 void __user *buffer, size_t *lenp, loff_t *ppos)
2582 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2586 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2587 * @table: the sysctl table
2588 * @write: %TRUE if this is a write to the sysctl file
2589 * @buffer: the user buffer
2590 * @lenp: the size of the user buffer
2591 * @ppos: file position
2593 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2594 * values from/to the user buffer, treated as an ASCII string. The values
2595 * are treated as milliseconds, and converted to jiffies when they are stored.
2597 * This routine will ensure the values are within the range specified by
2598 * table->extra1 (min) and table->extra2 (max).
2600 * Returns 0 on success.
2602 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2603 void __user *buffer,
2604 size_t *lenp, loff_t *ppos)
2606 return do_proc_doulongvec_minmax(table, write, buffer,
2607 lenp, ppos, HZ, 1000l);
2611 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2612 int *valp,
2613 int write, void *data)
2615 if (write) {
2616 if (*lvalp > LONG_MAX / HZ)
2617 return 1;
2618 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2619 } else {
2620 int val = *valp;
2621 unsigned long lval;
2622 if (val < 0) {
2623 *negp = true;
2624 lval = (unsigned long)-val;
2625 } else {
2626 *negp = false;
2627 lval = (unsigned long)val;
2629 *lvalp = lval / HZ;
2631 return 0;
2634 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2635 int *valp,
2636 int write, void *data)
2638 if (write) {
2639 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2640 return 1;
2641 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2642 } else {
2643 int val = *valp;
2644 unsigned long lval;
2645 if (val < 0) {
2646 *negp = true;
2647 lval = (unsigned long)-val;
2648 } else {
2649 *negp = false;
2650 lval = (unsigned long)val;
2652 *lvalp = jiffies_to_clock_t(lval);
2654 return 0;
2657 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2658 int *valp,
2659 int write, void *data)
2661 if (write) {
2662 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2663 } else {
2664 int val = *valp;
2665 unsigned long lval;
2666 if (val < 0) {
2667 *negp = true;
2668 lval = (unsigned long)-val;
2669 } else {
2670 *negp = false;
2671 lval = (unsigned long)val;
2673 *lvalp = jiffies_to_msecs(lval);
2675 return 0;
2679 * proc_dointvec_jiffies - read a vector of integers as seconds
2680 * @table: the sysctl table
2681 * @write: %TRUE if this is a write to the sysctl file
2682 * @buffer: the user buffer
2683 * @lenp: the size of the user buffer
2684 * @ppos: file position
2686 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2687 * values from/to the user buffer, treated as an ASCII string.
2688 * The values read are assumed to be in seconds, and are converted into
2689 * jiffies.
2691 * Returns 0 on success.
2693 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2694 void __user *buffer, size_t *lenp, loff_t *ppos)
2696 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2697 do_proc_dointvec_jiffies_conv,NULL);
2701 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2702 * @table: the sysctl table
2703 * @write: %TRUE if this is a write to the sysctl file
2704 * @buffer: the user buffer
2705 * @lenp: the size of the user buffer
2706 * @ppos: pointer to the file position
2708 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2709 * values from/to the user buffer, treated as an ASCII string.
2710 * The values read are assumed to be in 1/USER_HZ seconds, and
2711 * are converted into jiffies.
2713 * Returns 0 on success.
2715 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2716 void __user *buffer, size_t *lenp, loff_t *ppos)
2718 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2719 do_proc_dointvec_userhz_jiffies_conv,NULL);
2723 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2724 * @table: the sysctl table
2725 * @write: %TRUE if this is a write to the sysctl file
2726 * @buffer: the user buffer
2727 * @lenp: the size of the user buffer
2728 * @ppos: file position
2729 * @ppos: the current position in the file
2731 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2732 * values from/to the user buffer, treated as an ASCII string.
2733 * The values read are assumed to be in 1/1000 seconds, and
2734 * are converted into jiffies.
2736 * Returns 0 on success.
2738 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2739 void __user *buffer, size_t *lenp, loff_t *ppos)
2741 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2742 do_proc_dointvec_ms_jiffies_conv, NULL);
2745 static int proc_do_cad_pid(struct ctl_table *table, int write,
2746 void __user *buffer, size_t *lenp, loff_t *ppos)
2748 struct pid *new_pid;
2749 pid_t tmp;
2750 int r;
2752 tmp = pid_vnr(cad_pid);
2754 r = __do_proc_dointvec(&tmp, table, write, buffer,
2755 lenp, ppos, NULL, NULL);
2756 if (r || !write)
2757 return r;
2759 new_pid = find_get_pid(tmp);
2760 if (!new_pid)
2761 return -ESRCH;
2763 put_pid(xchg(&cad_pid, new_pid));
2764 return 0;
2768 * proc_do_large_bitmap - read/write from/to a large bitmap
2769 * @table: the sysctl table
2770 * @write: %TRUE if this is a write to the sysctl file
2771 * @buffer: the user buffer
2772 * @lenp: the size of the user buffer
2773 * @ppos: file position
2775 * The bitmap is stored at table->data and the bitmap length (in bits)
2776 * in table->maxlen.
2778 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2779 * large bitmaps may be represented in a compact manner. Writing into
2780 * the file will clear the bitmap then update it with the given input.
2782 * Returns 0 on success.
2784 int proc_do_large_bitmap(struct ctl_table *table, int write,
2785 void __user *buffer, size_t *lenp, loff_t *ppos)
2787 int err = 0;
2788 bool first = 1;
2789 size_t left = *lenp;
2790 unsigned long bitmap_len = table->maxlen;
2791 unsigned long *bitmap = (unsigned long *) table->data;
2792 unsigned long *tmp_bitmap = NULL;
2793 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2795 if (!bitmap_len || !left || (*ppos && !write)) {
2796 *lenp = 0;
2797 return 0;
2800 if (write) {
2801 unsigned long page = 0;
2802 char *kbuf;
2804 if (left > PAGE_SIZE - 1)
2805 left = PAGE_SIZE - 1;
2807 page = __get_free_page(GFP_TEMPORARY);
2808 kbuf = (char *) page;
2809 if (!kbuf)
2810 return -ENOMEM;
2811 if (copy_from_user(kbuf, buffer, left)) {
2812 free_page(page);
2813 return -EFAULT;
2815 kbuf[left] = 0;
2817 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2818 GFP_KERNEL);
2819 if (!tmp_bitmap) {
2820 free_page(page);
2821 return -ENOMEM;
2823 proc_skip_char(&kbuf, &left, '\n');
2824 while (!err && left) {
2825 unsigned long val_a, val_b;
2826 bool neg;
2828 err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
2829 sizeof(tr_a), &c);
2830 if (err)
2831 break;
2832 if (val_a >= bitmap_len || neg) {
2833 err = -EINVAL;
2834 break;
2837 val_b = val_a;
2838 if (left) {
2839 kbuf++;
2840 left--;
2843 if (c == '-') {
2844 err = proc_get_long(&kbuf, &left, &val_b,
2845 &neg, tr_b, sizeof(tr_b),
2846 &c);
2847 if (err)
2848 break;
2849 if (val_b >= bitmap_len || neg ||
2850 val_a > val_b) {
2851 err = -EINVAL;
2852 break;
2854 if (left) {
2855 kbuf++;
2856 left--;
2860 while (val_a <= val_b)
2861 set_bit(val_a++, tmp_bitmap);
2863 first = 0;
2864 proc_skip_char(&kbuf, &left, '\n');
2866 free_page(page);
2867 } else {
2868 unsigned long bit_a, bit_b = 0;
2870 while (left) {
2871 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2872 if (bit_a >= bitmap_len)
2873 break;
2874 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2875 bit_a + 1) - 1;
2877 if (!first) {
2878 err = proc_put_char(&buffer, &left, ',');
2879 if (err)
2880 break;
2882 err = proc_put_long(&buffer, &left, bit_a, false);
2883 if (err)
2884 break;
2885 if (bit_a != bit_b) {
2886 err = proc_put_char(&buffer, &left, '-');
2887 if (err)
2888 break;
2889 err = proc_put_long(&buffer, &left, bit_b, false);
2890 if (err)
2891 break;
2894 first = 0; bit_b++;
2896 if (!err)
2897 err = proc_put_char(&buffer, &left, '\n');
2900 if (!err) {
2901 if (write) {
2902 if (*ppos)
2903 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2904 else
2905 memcpy(bitmap, tmp_bitmap,
2906 BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long));
2908 kfree(tmp_bitmap);
2909 *lenp -= left;
2910 *ppos += *lenp;
2911 return 0;
2912 } else {
2913 kfree(tmp_bitmap);
2914 return err;
2918 #else /* CONFIG_PROC_SYSCTL */
2920 int proc_dostring(struct ctl_table *table, int write,
2921 void __user *buffer, size_t *lenp, loff_t *ppos)
2923 return -ENOSYS;
2926 int proc_dointvec(struct ctl_table *table, int write,
2927 void __user *buffer, size_t *lenp, loff_t *ppos)
2929 return -ENOSYS;
2932 int proc_dointvec_minmax(struct ctl_table *table, int write,
2933 void __user *buffer, size_t *lenp, loff_t *ppos)
2935 return -ENOSYS;
2938 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2939 void __user *buffer, size_t *lenp, loff_t *ppos)
2941 return -ENOSYS;
2944 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2945 void __user *buffer, size_t *lenp, loff_t *ppos)
2947 return -ENOSYS;
2950 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2951 void __user *buffer, size_t *lenp, loff_t *ppos)
2953 return -ENOSYS;
2956 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2957 void __user *buffer, size_t *lenp, loff_t *ppos)
2959 return -ENOSYS;
2962 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2963 void __user *buffer,
2964 size_t *lenp, loff_t *ppos)
2966 return -ENOSYS;
2970 #endif /* CONFIG_PROC_SYSCTL */
2973 * No sense putting this after each symbol definition, twice,
2974 * exception granted :-)
2976 EXPORT_SYMBOL(proc_dointvec);
2977 EXPORT_SYMBOL(proc_dointvec_jiffies);
2978 EXPORT_SYMBOL(proc_dointvec_minmax);
2979 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2980 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2981 EXPORT_SYMBOL(proc_dostring);
2982 EXPORT_SYMBOL(proc_doulongvec_minmax);
2983 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2984 EXPORT_SYMBOL(register_sysctl_table);
2985 EXPORT_SYMBOL(register_sysctl_paths);
2986 EXPORT_SYMBOL(unregister_sysctl_table);