lib/string.c: simplify stricmp()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / sysctl.c
blob0ef19c614f6d10cc80c08483b3b6fbaad49b56a7
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/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/ctype.h>
29 #include <linux/kmemcheck.h>
30 #include <linux/fs.h>
31 #include <linux/init.h>
32 #include <linux/kernel.h>
33 #include <linux/kobject.h>
34 #include <linux/net.h>
35 #include <linux/sysrq.h>
36 #include <linux/highuid.h>
37 #include <linux/writeback.h>
38 #include <linux/ratelimit.h>
39 #include <linux/hugetlb.h>
40 #include <linux/initrd.h>
41 #include <linux/key.h>
42 #include <linux/times.h>
43 #include <linux/limits.h>
44 #include <linux/dcache.h>
45 #include <linux/syscalls.h>
46 #include <linux/vmstat.h>
47 #include <linux/nfs_fs.h>
48 #include <linux/acpi.h>
49 #include <linux/reboot.h>
50 #include <linux/ftrace.h>
51 #include <linux/slow-work.h>
52 #include <linux/perf_event.h>
53 #include <linux/kprobes.h>
55 #include <asm/uaccess.h>
56 #include <asm/processor.h>
58 #ifdef CONFIG_X86
59 #include <asm/nmi.h>
60 #include <asm/stacktrace.h>
61 #include <asm/io.h>
62 #endif
65 #if defined(CONFIG_SYSCTL)
67 /* External variables not in a header file. */
68 extern int C_A_D;
69 extern int print_fatal_signals;
70 extern int sysctl_overcommit_memory;
71 extern int sysctl_overcommit_ratio;
72 extern int sysctl_panic_on_oom;
73 extern int sysctl_oom_kill_allocating_task;
74 extern int sysctl_oom_dump_tasks;
75 extern int max_threads;
76 extern int core_uses_pid;
77 extern int suid_dumpable;
78 extern char core_pattern[];
79 extern unsigned int core_pipe_limit;
80 extern int pid_max;
81 extern int min_free_kbytes;
82 extern int pid_max_min, pid_max_max;
83 extern int sysctl_drop_caches;
84 extern int percpu_pagelist_fraction;
85 extern int compat_log;
86 extern int latencytop_enabled;
87 extern int sysctl_nr_open_min, sysctl_nr_open_max;
88 #ifndef CONFIG_MMU
89 extern int sysctl_nr_trim_pages;
90 #endif
91 #ifdef CONFIG_RCU_TORTURE_TEST
92 extern int rcutorture_runnable;
93 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
94 #ifdef CONFIG_BLOCK
95 extern int blk_iopoll_enabled;
96 #endif
98 /* Constants used for minimum and maximum */
99 #ifdef CONFIG_DETECT_SOFTLOCKUP
100 static int sixty = 60;
101 static int neg_one = -1;
102 #endif
104 static int zero;
105 static int __maybe_unused one = 1;
106 static int __maybe_unused two = 2;
107 static unsigned long one_ul = 1;
108 static int one_hundred = 100;
109 #ifdef CONFIG_PRINTK
110 static int ten_thousand = 10000;
111 #endif
113 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
114 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
116 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
117 static int maxolduid = 65535;
118 static int minolduid;
119 static int min_percpu_pagelist_fract = 8;
121 static int ngroups_max = NGROUPS_MAX;
123 #ifdef CONFIG_MODULES
124 extern char modprobe_path[];
125 extern int modules_disabled;
126 #endif
127 #ifdef CONFIG_CHR_DEV_SG
128 extern int sg_big_buff;
129 #endif
131 #ifdef CONFIG_SPARC
132 #include <asm/system.h>
133 #endif
135 #ifdef CONFIG_SPARC64
136 extern int sysctl_tsb_ratio;
137 #endif
139 #ifdef __hppa__
140 extern int pwrsw_enabled;
141 extern int unaligned_enabled;
142 #endif
144 #ifdef CONFIG_S390
145 #ifdef CONFIG_MATHEMU
146 extern int sysctl_ieee_emulation_warnings;
147 #endif
148 extern int sysctl_userprocess_debug;
149 extern int spin_retry;
150 #endif
152 #ifdef CONFIG_BSD_PROCESS_ACCT
153 extern int acct_parm[];
154 #endif
156 #ifdef CONFIG_IA64
157 extern int no_unaligned_warning;
158 extern int unaligned_dump_stack;
159 #endif
161 extern struct ratelimit_state printk_ratelimit_state;
163 #ifdef CONFIG_RT_MUTEXES
164 extern int max_lock_depth;
165 #endif
167 #ifdef CONFIG_PROC_SYSCTL
168 static int proc_do_cad_pid(struct ctl_table *table, int write,
169 void __user *buffer, size_t *lenp, loff_t *ppos);
170 static int proc_taint(struct ctl_table *table, int write,
171 void __user *buffer, size_t *lenp, loff_t *ppos);
172 #endif
174 static struct ctl_table root_table[];
175 static struct ctl_table_root sysctl_table_root;
176 static struct ctl_table_header root_table_header = {
177 .count = 1,
178 .ctl_table = root_table,
179 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
180 .root = &sysctl_table_root,
181 .set = &sysctl_table_root.default_set,
183 static struct ctl_table_root sysctl_table_root = {
184 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
185 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
188 static struct ctl_table kern_table[];
189 static struct ctl_table vm_table[];
190 static struct ctl_table fs_table[];
191 static struct ctl_table debug_table[];
192 static struct ctl_table dev_table[];
193 extern struct ctl_table random_table[];
194 #ifdef CONFIG_INOTIFY_USER
195 extern struct ctl_table inotify_table[];
196 #endif
197 #ifdef CONFIG_EPOLL
198 extern struct ctl_table epoll_table[];
199 #endif
201 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
202 int sysctl_legacy_va_layout;
203 #endif
205 extern int prove_locking;
206 extern int lock_stat;
208 /* The default sysctl tables: */
210 static struct ctl_table root_table[] = {
212 .procname = "kernel",
213 .mode = 0555,
214 .child = kern_table,
217 .procname = "vm",
218 .mode = 0555,
219 .child = vm_table,
222 .procname = "fs",
223 .mode = 0555,
224 .child = fs_table,
227 .procname = "debug",
228 .mode = 0555,
229 .child = debug_table,
232 .procname = "dev",
233 .mode = 0555,
234 .child = dev_table,
237 * NOTE: do not add new entries to this table unless you have read
238 * Documentation/sysctl/ctl_unnumbered.txt
243 #ifdef CONFIG_SCHED_DEBUG
244 static int min_sched_granularity_ns = 100000; /* 100 usecs */
245 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
246 static int min_wakeup_granularity_ns; /* 0 usecs */
247 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
248 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
249 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
250 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
251 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
252 #endif
254 static struct ctl_table kern_table[] = {
256 .procname = "sched_child_runs_first",
257 .data = &sysctl_sched_child_runs_first,
258 .maxlen = sizeof(unsigned int),
259 .mode = 0644,
260 .proc_handler = proc_dointvec,
262 #ifdef CONFIG_SCHED_DEBUG
264 .procname = "sched_min_granularity_ns",
265 .data = &sysctl_sched_min_granularity,
266 .maxlen = sizeof(unsigned int),
267 .mode = 0644,
268 .proc_handler = sched_proc_update_handler,
269 .extra1 = &min_sched_granularity_ns,
270 .extra2 = &max_sched_granularity_ns,
273 .procname = "sched_latency_ns",
274 .data = &sysctl_sched_latency,
275 .maxlen = sizeof(unsigned int),
276 .mode = 0644,
277 .proc_handler = sched_proc_update_handler,
278 .extra1 = &min_sched_granularity_ns,
279 .extra2 = &max_sched_granularity_ns,
282 .procname = "sched_wakeup_granularity_ns",
283 .data = &sysctl_sched_wakeup_granularity,
284 .maxlen = sizeof(unsigned int),
285 .mode = 0644,
286 .proc_handler = sched_proc_update_handler,
287 .extra1 = &min_wakeup_granularity_ns,
288 .extra2 = &max_wakeup_granularity_ns,
291 .procname = "sched_shares_ratelimit",
292 .data = &sysctl_sched_shares_ratelimit,
293 .maxlen = sizeof(unsigned int),
294 .mode = 0644,
295 .proc_handler = sched_proc_update_handler,
296 .extra1 = &min_sched_shares_ratelimit,
297 .extra2 = &max_sched_shares_ratelimit,
300 .procname = "sched_tunable_scaling",
301 .data = &sysctl_sched_tunable_scaling,
302 .maxlen = sizeof(enum sched_tunable_scaling),
303 .mode = 0644,
304 .proc_handler = sched_proc_update_handler,
305 .extra1 = &min_sched_tunable_scaling,
306 .extra2 = &max_sched_tunable_scaling,
309 .procname = "sched_shares_thresh",
310 .data = &sysctl_sched_shares_thresh,
311 .maxlen = sizeof(unsigned int),
312 .mode = 0644,
313 .proc_handler = proc_dointvec_minmax,
314 .extra1 = &zero,
317 .procname = "sched_migration_cost",
318 .data = &sysctl_sched_migration_cost,
319 .maxlen = sizeof(unsigned int),
320 .mode = 0644,
321 .proc_handler = proc_dointvec,
324 .procname = "sched_nr_migrate",
325 .data = &sysctl_sched_nr_migrate,
326 .maxlen = sizeof(unsigned int),
327 .mode = 0644,
328 .proc_handler = proc_dointvec,
331 .procname = "sched_time_avg",
332 .data = &sysctl_sched_time_avg,
333 .maxlen = sizeof(unsigned int),
334 .mode = 0644,
335 .proc_handler = proc_dointvec,
338 .procname = "timer_migration",
339 .data = &sysctl_timer_migration,
340 .maxlen = sizeof(unsigned int),
341 .mode = 0644,
342 .proc_handler = proc_dointvec_minmax,
343 .extra1 = &zero,
344 .extra2 = &one,
346 #endif
348 .procname = "sched_rt_period_us",
349 .data = &sysctl_sched_rt_period,
350 .maxlen = sizeof(unsigned int),
351 .mode = 0644,
352 .proc_handler = sched_rt_handler,
355 .procname = "sched_rt_runtime_us",
356 .data = &sysctl_sched_rt_runtime,
357 .maxlen = sizeof(int),
358 .mode = 0644,
359 .proc_handler = sched_rt_handler,
362 .procname = "sched_compat_yield",
363 .data = &sysctl_sched_compat_yield,
364 .maxlen = sizeof(unsigned int),
365 .mode = 0644,
366 .proc_handler = proc_dointvec,
368 #ifdef CONFIG_PROVE_LOCKING
370 .procname = "prove_locking",
371 .data = &prove_locking,
372 .maxlen = sizeof(int),
373 .mode = 0644,
374 .proc_handler = proc_dointvec,
376 #endif
377 #ifdef CONFIG_LOCK_STAT
379 .procname = "lock_stat",
380 .data = &lock_stat,
381 .maxlen = sizeof(int),
382 .mode = 0644,
383 .proc_handler = proc_dointvec,
385 #endif
387 .procname = "panic",
388 .data = &panic_timeout,
389 .maxlen = sizeof(int),
390 .mode = 0644,
391 .proc_handler = proc_dointvec,
394 .procname = "core_uses_pid",
395 .data = &core_uses_pid,
396 .maxlen = sizeof(int),
397 .mode = 0644,
398 .proc_handler = proc_dointvec,
401 .procname = "core_pattern",
402 .data = core_pattern,
403 .maxlen = CORENAME_MAX_SIZE,
404 .mode = 0644,
405 .proc_handler = proc_dostring,
408 .procname = "core_pipe_limit",
409 .data = &core_pipe_limit,
410 .maxlen = sizeof(unsigned int),
411 .mode = 0644,
412 .proc_handler = proc_dointvec,
414 #ifdef CONFIG_PROC_SYSCTL
416 .procname = "tainted",
417 .maxlen = sizeof(long),
418 .mode = 0644,
419 .proc_handler = proc_taint,
421 #endif
422 #ifdef CONFIG_LATENCYTOP
424 .procname = "latencytop",
425 .data = &latencytop_enabled,
426 .maxlen = sizeof(int),
427 .mode = 0644,
428 .proc_handler = proc_dointvec,
430 #endif
431 #ifdef CONFIG_BLK_DEV_INITRD
433 .procname = "real-root-dev",
434 .data = &real_root_dev,
435 .maxlen = sizeof(int),
436 .mode = 0644,
437 .proc_handler = proc_dointvec,
439 #endif
441 .procname = "print-fatal-signals",
442 .data = &print_fatal_signals,
443 .maxlen = sizeof(int),
444 .mode = 0644,
445 .proc_handler = proc_dointvec,
447 #ifdef CONFIG_SPARC
449 .procname = "reboot-cmd",
450 .data = reboot_command,
451 .maxlen = 256,
452 .mode = 0644,
453 .proc_handler = proc_dostring,
456 .procname = "stop-a",
457 .data = &stop_a_enabled,
458 .maxlen = sizeof (int),
459 .mode = 0644,
460 .proc_handler = proc_dointvec,
463 .procname = "scons-poweroff",
464 .data = &scons_pwroff,
465 .maxlen = sizeof (int),
466 .mode = 0644,
467 .proc_handler = proc_dointvec,
469 #endif
470 #ifdef CONFIG_SPARC64
472 .procname = "tsb-ratio",
473 .data = &sysctl_tsb_ratio,
474 .maxlen = sizeof (int),
475 .mode = 0644,
476 .proc_handler = proc_dointvec,
478 #endif
479 #ifdef __hppa__
481 .procname = "soft-power",
482 .data = &pwrsw_enabled,
483 .maxlen = sizeof (int),
484 .mode = 0644,
485 .proc_handler = proc_dointvec,
488 .procname = "unaligned-trap",
489 .data = &unaligned_enabled,
490 .maxlen = sizeof (int),
491 .mode = 0644,
492 .proc_handler = proc_dointvec,
494 #endif
496 .procname = "ctrl-alt-del",
497 .data = &C_A_D,
498 .maxlen = sizeof(int),
499 .mode = 0644,
500 .proc_handler = proc_dointvec,
502 #ifdef CONFIG_FUNCTION_TRACER
504 .procname = "ftrace_enabled",
505 .data = &ftrace_enabled,
506 .maxlen = sizeof(int),
507 .mode = 0644,
508 .proc_handler = ftrace_enable_sysctl,
510 #endif
511 #ifdef CONFIG_STACK_TRACER
513 .procname = "stack_tracer_enabled",
514 .data = &stack_tracer_enabled,
515 .maxlen = sizeof(int),
516 .mode = 0644,
517 .proc_handler = stack_trace_sysctl,
519 #endif
520 #ifdef CONFIG_TRACING
522 .procname = "ftrace_dump_on_oops",
523 .data = &ftrace_dump_on_oops,
524 .maxlen = sizeof(int),
525 .mode = 0644,
526 .proc_handler = proc_dointvec,
528 #endif
529 #ifdef CONFIG_MODULES
531 .procname = "modprobe",
532 .data = &modprobe_path,
533 .maxlen = KMOD_PATH_LEN,
534 .mode = 0644,
535 .proc_handler = proc_dostring,
538 .procname = "modules_disabled",
539 .data = &modules_disabled,
540 .maxlen = sizeof(int),
541 .mode = 0644,
542 /* only handle a transition from default "0" to "1" */
543 .proc_handler = proc_dointvec_minmax,
544 .extra1 = &one,
545 .extra2 = &one,
547 #endif
548 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
550 .procname = "hotplug",
551 .data = &uevent_helper,
552 .maxlen = UEVENT_HELPER_PATH_LEN,
553 .mode = 0644,
554 .proc_handler = proc_dostring,
556 #endif
557 #ifdef CONFIG_CHR_DEV_SG
559 .procname = "sg-big-buff",
560 .data = &sg_big_buff,
561 .maxlen = sizeof (int),
562 .mode = 0444,
563 .proc_handler = proc_dointvec,
565 #endif
566 #ifdef CONFIG_BSD_PROCESS_ACCT
568 .procname = "acct",
569 .data = &acct_parm,
570 .maxlen = 3*sizeof(int),
571 .mode = 0644,
572 .proc_handler = proc_dointvec,
574 #endif
575 #ifdef CONFIG_MAGIC_SYSRQ
577 .procname = "sysrq",
578 .data = &__sysrq_enabled,
579 .maxlen = sizeof (int),
580 .mode = 0644,
581 .proc_handler = proc_dointvec,
583 #endif
584 #ifdef CONFIG_PROC_SYSCTL
586 .procname = "cad_pid",
587 .data = NULL,
588 .maxlen = sizeof (int),
589 .mode = 0600,
590 .proc_handler = proc_do_cad_pid,
592 #endif
594 .procname = "threads-max",
595 .data = &max_threads,
596 .maxlen = sizeof(int),
597 .mode = 0644,
598 .proc_handler = proc_dointvec,
601 .procname = "random",
602 .mode = 0555,
603 .child = random_table,
606 .procname = "overflowuid",
607 .data = &overflowuid,
608 .maxlen = sizeof(int),
609 .mode = 0644,
610 .proc_handler = proc_dointvec_minmax,
611 .extra1 = &minolduid,
612 .extra2 = &maxolduid,
615 .procname = "overflowgid",
616 .data = &overflowgid,
617 .maxlen = sizeof(int),
618 .mode = 0644,
619 .proc_handler = proc_dointvec_minmax,
620 .extra1 = &minolduid,
621 .extra2 = &maxolduid,
623 #ifdef CONFIG_S390
624 #ifdef CONFIG_MATHEMU
626 .procname = "ieee_emulation_warnings",
627 .data = &sysctl_ieee_emulation_warnings,
628 .maxlen = sizeof(int),
629 .mode = 0644,
630 .proc_handler = proc_dointvec,
632 #endif
634 .procname = "userprocess_debug",
635 .data = &sysctl_userprocess_debug,
636 .maxlen = sizeof(int),
637 .mode = 0644,
638 .proc_handler = proc_dointvec,
640 #endif
642 .procname = "pid_max",
643 .data = &pid_max,
644 .maxlen = sizeof (int),
645 .mode = 0644,
646 .proc_handler = proc_dointvec_minmax,
647 .extra1 = &pid_max_min,
648 .extra2 = &pid_max_max,
651 .procname = "panic_on_oops",
652 .data = &panic_on_oops,
653 .maxlen = sizeof(int),
654 .mode = 0644,
655 .proc_handler = proc_dointvec,
657 #if defined CONFIG_PRINTK
659 .procname = "printk",
660 .data = &console_loglevel,
661 .maxlen = 4*sizeof(int),
662 .mode = 0644,
663 .proc_handler = proc_dointvec,
666 .procname = "printk_ratelimit",
667 .data = &printk_ratelimit_state.interval,
668 .maxlen = sizeof(int),
669 .mode = 0644,
670 .proc_handler = proc_dointvec_jiffies,
673 .procname = "printk_ratelimit_burst",
674 .data = &printk_ratelimit_state.burst,
675 .maxlen = sizeof(int),
676 .mode = 0644,
677 .proc_handler = proc_dointvec,
680 .procname = "printk_delay",
681 .data = &printk_delay_msec,
682 .maxlen = sizeof(int),
683 .mode = 0644,
684 .proc_handler = proc_dointvec_minmax,
685 .extra1 = &zero,
686 .extra2 = &ten_thousand,
688 #endif
690 .procname = "ngroups_max",
691 .data = &ngroups_max,
692 .maxlen = sizeof (int),
693 .mode = 0444,
694 .proc_handler = proc_dointvec,
696 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
698 .procname = "unknown_nmi_panic",
699 .data = &unknown_nmi_panic,
700 .maxlen = sizeof (int),
701 .mode = 0644,
702 .proc_handler = proc_dointvec,
705 .procname = "nmi_watchdog",
706 .data = &nmi_watchdog_enabled,
707 .maxlen = sizeof (int),
708 .mode = 0644,
709 .proc_handler = proc_nmi_enabled,
711 #endif
712 #if defined(CONFIG_X86)
714 .procname = "panic_on_unrecovered_nmi",
715 .data = &panic_on_unrecovered_nmi,
716 .maxlen = sizeof(int),
717 .mode = 0644,
718 .proc_handler = proc_dointvec,
721 .procname = "panic_on_io_nmi",
722 .data = &panic_on_io_nmi,
723 .maxlen = sizeof(int),
724 .mode = 0644,
725 .proc_handler = proc_dointvec,
728 .procname = "bootloader_type",
729 .data = &bootloader_type,
730 .maxlen = sizeof (int),
731 .mode = 0444,
732 .proc_handler = proc_dointvec,
735 .procname = "bootloader_version",
736 .data = &bootloader_version,
737 .maxlen = sizeof (int),
738 .mode = 0444,
739 .proc_handler = proc_dointvec,
742 .procname = "kstack_depth_to_print",
743 .data = &kstack_depth_to_print,
744 .maxlen = sizeof(int),
745 .mode = 0644,
746 .proc_handler = proc_dointvec,
749 .procname = "io_delay_type",
750 .data = &io_delay_type,
751 .maxlen = sizeof(int),
752 .mode = 0644,
753 .proc_handler = proc_dointvec,
755 #endif
756 #if defined(CONFIG_MMU)
758 .procname = "randomize_va_space",
759 .data = &randomize_va_space,
760 .maxlen = sizeof(int),
761 .mode = 0644,
762 .proc_handler = proc_dointvec,
764 #endif
765 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
767 .procname = "spin_retry",
768 .data = &spin_retry,
769 .maxlen = sizeof (int),
770 .mode = 0644,
771 .proc_handler = proc_dointvec,
773 #endif
774 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
776 .procname = "acpi_video_flags",
777 .data = &acpi_realmode_flags,
778 .maxlen = sizeof (unsigned long),
779 .mode = 0644,
780 .proc_handler = proc_doulongvec_minmax,
782 #endif
783 #ifdef CONFIG_IA64
785 .procname = "ignore-unaligned-usertrap",
786 .data = &no_unaligned_warning,
787 .maxlen = sizeof (int),
788 .mode = 0644,
789 .proc_handler = proc_dointvec,
792 .procname = "unaligned-dump-stack",
793 .data = &unaligned_dump_stack,
794 .maxlen = sizeof (int),
795 .mode = 0644,
796 .proc_handler = proc_dointvec,
798 #endif
799 #ifdef CONFIG_DETECT_SOFTLOCKUP
801 .procname = "softlockup_panic",
802 .data = &softlockup_panic,
803 .maxlen = sizeof(int),
804 .mode = 0644,
805 .proc_handler = proc_dointvec_minmax,
806 .extra1 = &zero,
807 .extra2 = &one,
810 .procname = "softlockup_thresh",
811 .data = &softlockup_thresh,
812 .maxlen = sizeof(int),
813 .mode = 0644,
814 .proc_handler = proc_dosoftlockup_thresh,
815 .extra1 = &neg_one,
816 .extra2 = &sixty,
818 #endif
819 #ifdef CONFIG_DETECT_HUNG_TASK
821 .procname = "hung_task_panic",
822 .data = &sysctl_hung_task_panic,
823 .maxlen = sizeof(int),
824 .mode = 0644,
825 .proc_handler = proc_dointvec_minmax,
826 .extra1 = &zero,
827 .extra2 = &one,
830 .procname = "hung_task_check_count",
831 .data = &sysctl_hung_task_check_count,
832 .maxlen = sizeof(unsigned long),
833 .mode = 0644,
834 .proc_handler = proc_doulongvec_minmax,
837 .procname = "hung_task_timeout_secs",
838 .data = &sysctl_hung_task_timeout_secs,
839 .maxlen = sizeof(unsigned long),
840 .mode = 0644,
841 .proc_handler = proc_dohung_task_timeout_secs,
844 .procname = "hung_task_warnings",
845 .data = &sysctl_hung_task_warnings,
846 .maxlen = sizeof(unsigned long),
847 .mode = 0644,
848 .proc_handler = proc_doulongvec_minmax,
850 #endif
851 #ifdef CONFIG_COMPAT
853 .procname = "compat-log",
854 .data = &compat_log,
855 .maxlen = sizeof (int),
856 .mode = 0644,
857 .proc_handler = proc_dointvec,
859 #endif
860 #ifdef CONFIG_RT_MUTEXES
862 .procname = "max_lock_depth",
863 .data = &max_lock_depth,
864 .maxlen = sizeof(int),
865 .mode = 0644,
866 .proc_handler = proc_dointvec,
868 #endif
870 .procname = "poweroff_cmd",
871 .data = &poweroff_cmd,
872 .maxlen = POWEROFF_CMD_PATH_LEN,
873 .mode = 0644,
874 .proc_handler = proc_dostring,
876 #ifdef CONFIG_KEYS
878 .procname = "keys",
879 .mode = 0555,
880 .child = key_sysctls,
882 #endif
883 #ifdef CONFIG_RCU_TORTURE_TEST
885 .procname = "rcutorture_runnable",
886 .data = &rcutorture_runnable,
887 .maxlen = sizeof(int),
888 .mode = 0644,
889 .proc_handler = proc_dointvec,
891 #endif
892 #ifdef CONFIG_SLOW_WORK
894 .procname = "slow-work",
895 .mode = 0555,
896 .child = slow_work_sysctls,
898 #endif
899 #ifdef CONFIG_PERF_EVENTS
901 .procname = "perf_event_paranoid",
902 .data = &sysctl_perf_event_paranoid,
903 .maxlen = sizeof(sysctl_perf_event_paranoid),
904 .mode = 0644,
905 .proc_handler = proc_dointvec,
908 .procname = "perf_event_mlock_kb",
909 .data = &sysctl_perf_event_mlock,
910 .maxlen = sizeof(sysctl_perf_event_mlock),
911 .mode = 0644,
912 .proc_handler = proc_dointvec,
915 .procname = "perf_event_max_sample_rate",
916 .data = &sysctl_perf_event_sample_rate,
917 .maxlen = sizeof(sysctl_perf_event_sample_rate),
918 .mode = 0644,
919 .proc_handler = proc_dointvec,
921 #endif
922 #ifdef CONFIG_KMEMCHECK
924 .procname = "kmemcheck",
925 .data = &kmemcheck_enabled,
926 .maxlen = sizeof(int),
927 .mode = 0644,
928 .proc_handler = proc_dointvec,
930 #endif
931 #ifdef CONFIG_BLOCK
933 .procname = "blk_iopoll",
934 .data = &blk_iopoll_enabled,
935 .maxlen = sizeof(int),
936 .mode = 0644,
937 .proc_handler = proc_dointvec,
939 #endif
941 * NOTE: do not add new entries to this table unless you have read
942 * Documentation/sysctl/ctl_unnumbered.txt
947 static struct ctl_table vm_table[] = {
949 .procname = "overcommit_memory",
950 .data = &sysctl_overcommit_memory,
951 .maxlen = sizeof(sysctl_overcommit_memory),
952 .mode = 0644,
953 .proc_handler = proc_dointvec,
956 .procname = "panic_on_oom",
957 .data = &sysctl_panic_on_oom,
958 .maxlen = sizeof(sysctl_panic_on_oom),
959 .mode = 0644,
960 .proc_handler = proc_dointvec,
963 .procname = "oom_kill_allocating_task",
964 .data = &sysctl_oom_kill_allocating_task,
965 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
966 .mode = 0644,
967 .proc_handler = proc_dointvec,
970 .procname = "oom_dump_tasks",
971 .data = &sysctl_oom_dump_tasks,
972 .maxlen = sizeof(sysctl_oom_dump_tasks),
973 .mode = 0644,
974 .proc_handler = proc_dointvec,
977 .procname = "overcommit_ratio",
978 .data = &sysctl_overcommit_ratio,
979 .maxlen = sizeof(sysctl_overcommit_ratio),
980 .mode = 0644,
981 .proc_handler = proc_dointvec,
984 .procname = "page-cluster",
985 .data = &page_cluster,
986 .maxlen = sizeof(int),
987 .mode = 0644,
988 .proc_handler = proc_dointvec,
991 .procname = "dirty_background_ratio",
992 .data = &dirty_background_ratio,
993 .maxlen = sizeof(dirty_background_ratio),
994 .mode = 0644,
995 .proc_handler = dirty_background_ratio_handler,
996 .extra1 = &zero,
997 .extra2 = &one_hundred,
1000 .procname = "dirty_background_bytes",
1001 .data = &dirty_background_bytes,
1002 .maxlen = sizeof(dirty_background_bytes),
1003 .mode = 0644,
1004 .proc_handler = dirty_background_bytes_handler,
1005 .extra1 = &one_ul,
1008 .procname = "dirty_ratio",
1009 .data = &vm_dirty_ratio,
1010 .maxlen = sizeof(vm_dirty_ratio),
1011 .mode = 0644,
1012 .proc_handler = dirty_ratio_handler,
1013 .extra1 = &zero,
1014 .extra2 = &one_hundred,
1017 .procname = "dirty_bytes",
1018 .data = &vm_dirty_bytes,
1019 .maxlen = sizeof(vm_dirty_bytes),
1020 .mode = 0644,
1021 .proc_handler = dirty_bytes_handler,
1022 .extra1 = &dirty_bytes_min,
1025 .procname = "dirty_writeback_centisecs",
1026 .data = &dirty_writeback_interval,
1027 .maxlen = sizeof(dirty_writeback_interval),
1028 .mode = 0644,
1029 .proc_handler = dirty_writeback_centisecs_handler,
1032 .procname = "dirty_expire_centisecs",
1033 .data = &dirty_expire_interval,
1034 .maxlen = sizeof(dirty_expire_interval),
1035 .mode = 0644,
1036 .proc_handler = proc_dointvec,
1039 .procname = "nr_pdflush_threads",
1040 .data = &nr_pdflush_threads,
1041 .maxlen = sizeof nr_pdflush_threads,
1042 .mode = 0444 /* read-only*/,
1043 .proc_handler = proc_dointvec,
1046 .procname = "swappiness",
1047 .data = &vm_swappiness,
1048 .maxlen = sizeof(vm_swappiness),
1049 .mode = 0644,
1050 .proc_handler = proc_dointvec_minmax,
1051 .extra1 = &zero,
1052 .extra2 = &one_hundred,
1054 #ifdef CONFIG_HUGETLB_PAGE
1056 .procname = "nr_hugepages",
1057 .data = NULL,
1058 .maxlen = sizeof(unsigned long),
1059 .mode = 0644,
1060 .proc_handler = hugetlb_sysctl_handler,
1061 .extra1 = (void *)&hugetlb_zero,
1062 .extra2 = (void *)&hugetlb_infinity,
1064 #ifdef CONFIG_NUMA
1066 .procname = "nr_hugepages_mempolicy",
1067 .data = NULL,
1068 .maxlen = sizeof(unsigned long),
1069 .mode = 0644,
1070 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1071 .extra1 = (void *)&hugetlb_zero,
1072 .extra2 = (void *)&hugetlb_infinity,
1074 #endif
1076 .procname = "hugetlb_shm_group",
1077 .data = &sysctl_hugetlb_shm_group,
1078 .maxlen = sizeof(gid_t),
1079 .mode = 0644,
1080 .proc_handler = proc_dointvec,
1083 .procname = "hugepages_treat_as_movable",
1084 .data = &hugepages_treat_as_movable,
1085 .maxlen = sizeof(int),
1086 .mode = 0644,
1087 .proc_handler = hugetlb_treat_movable_handler,
1090 .procname = "nr_overcommit_hugepages",
1091 .data = NULL,
1092 .maxlen = sizeof(unsigned long),
1093 .mode = 0644,
1094 .proc_handler = hugetlb_overcommit_handler,
1095 .extra1 = (void *)&hugetlb_zero,
1096 .extra2 = (void *)&hugetlb_infinity,
1098 #endif
1100 .procname = "lowmem_reserve_ratio",
1101 .data = &sysctl_lowmem_reserve_ratio,
1102 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1103 .mode = 0644,
1104 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1107 .procname = "drop_caches",
1108 .data = &sysctl_drop_caches,
1109 .maxlen = sizeof(int),
1110 .mode = 0644,
1111 .proc_handler = drop_caches_sysctl_handler,
1114 .procname = "min_free_kbytes",
1115 .data = &min_free_kbytes,
1116 .maxlen = sizeof(min_free_kbytes),
1117 .mode = 0644,
1118 .proc_handler = min_free_kbytes_sysctl_handler,
1119 .extra1 = &zero,
1122 .procname = "percpu_pagelist_fraction",
1123 .data = &percpu_pagelist_fraction,
1124 .maxlen = sizeof(percpu_pagelist_fraction),
1125 .mode = 0644,
1126 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1127 .extra1 = &min_percpu_pagelist_fract,
1129 #ifdef CONFIG_MMU
1131 .procname = "max_map_count",
1132 .data = &sysctl_max_map_count,
1133 .maxlen = sizeof(sysctl_max_map_count),
1134 .mode = 0644,
1135 .proc_handler = proc_dointvec_minmax,
1136 .extra1 = &zero,
1138 #else
1140 .procname = "nr_trim_pages",
1141 .data = &sysctl_nr_trim_pages,
1142 .maxlen = sizeof(sysctl_nr_trim_pages),
1143 .mode = 0644,
1144 .proc_handler = proc_dointvec_minmax,
1145 .extra1 = &zero,
1147 #endif
1149 .procname = "laptop_mode",
1150 .data = &laptop_mode,
1151 .maxlen = sizeof(laptop_mode),
1152 .mode = 0644,
1153 .proc_handler = proc_dointvec_jiffies,
1156 .procname = "block_dump",
1157 .data = &block_dump,
1158 .maxlen = sizeof(block_dump),
1159 .mode = 0644,
1160 .proc_handler = proc_dointvec,
1161 .extra1 = &zero,
1164 .procname = "vfs_cache_pressure",
1165 .data = &sysctl_vfs_cache_pressure,
1166 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1167 .mode = 0644,
1168 .proc_handler = proc_dointvec,
1169 .extra1 = &zero,
1171 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1173 .procname = "legacy_va_layout",
1174 .data = &sysctl_legacy_va_layout,
1175 .maxlen = sizeof(sysctl_legacy_va_layout),
1176 .mode = 0644,
1177 .proc_handler = proc_dointvec,
1178 .extra1 = &zero,
1180 #endif
1181 #ifdef CONFIG_NUMA
1183 .procname = "zone_reclaim_mode",
1184 .data = &zone_reclaim_mode,
1185 .maxlen = sizeof(zone_reclaim_mode),
1186 .mode = 0644,
1187 .proc_handler = proc_dointvec,
1188 .extra1 = &zero,
1191 .procname = "min_unmapped_ratio",
1192 .data = &sysctl_min_unmapped_ratio,
1193 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1194 .mode = 0644,
1195 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1196 .extra1 = &zero,
1197 .extra2 = &one_hundred,
1200 .procname = "min_slab_ratio",
1201 .data = &sysctl_min_slab_ratio,
1202 .maxlen = sizeof(sysctl_min_slab_ratio),
1203 .mode = 0644,
1204 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1205 .extra1 = &zero,
1206 .extra2 = &one_hundred,
1208 #endif
1209 #ifdef CONFIG_SMP
1211 .procname = "stat_interval",
1212 .data = &sysctl_stat_interval,
1213 .maxlen = sizeof(sysctl_stat_interval),
1214 .mode = 0644,
1215 .proc_handler = proc_dointvec_jiffies,
1217 #endif
1218 #ifdef CONFIG_MMU
1220 .procname = "mmap_min_addr",
1221 .data = &dac_mmap_min_addr,
1222 .maxlen = sizeof(unsigned long),
1223 .mode = 0644,
1224 .proc_handler = mmap_min_addr_handler,
1226 #endif
1227 #ifdef CONFIG_NUMA
1229 .procname = "numa_zonelist_order",
1230 .data = &numa_zonelist_order,
1231 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1232 .mode = 0644,
1233 .proc_handler = numa_zonelist_order_handler,
1235 #endif
1236 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1237 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1239 .procname = "vdso_enabled",
1240 .data = &vdso_enabled,
1241 .maxlen = sizeof(vdso_enabled),
1242 .mode = 0644,
1243 .proc_handler = proc_dointvec,
1244 .extra1 = &zero,
1246 #endif
1247 #ifdef CONFIG_HIGHMEM
1249 .procname = "highmem_is_dirtyable",
1250 .data = &vm_highmem_is_dirtyable,
1251 .maxlen = sizeof(vm_highmem_is_dirtyable),
1252 .mode = 0644,
1253 .proc_handler = proc_dointvec_minmax,
1254 .extra1 = &zero,
1255 .extra2 = &one,
1257 #endif
1259 .procname = "scan_unevictable_pages",
1260 .data = &scan_unevictable_pages,
1261 .maxlen = sizeof(scan_unevictable_pages),
1262 .mode = 0644,
1263 .proc_handler = scan_unevictable_handler,
1265 #ifdef CONFIG_MEMORY_FAILURE
1267 .procname = "memory_failure_early_kill",
1268 .data = &sysctl_memory_failure_early_kill,
1269 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1270 .mode = 0644,
1271 .proc_handler = proc_dointvec_minmax,
1272 .extra1 = &zero,
1273 .extra2 = &one,
1276 .procname = "memory_failure_recovery",
1277 .data = &sysctl_memory_failure_recovery,
1278 .maxlen = sizeof(sysctl_memory_failure_recovery),
1279 .mode = 0644,
1280 .proc_handler = proc_dointvec_minmax,
1281 .extra1 = &zero,
1282 .extra2 = &one,
1284 #endif
1287 * NOTE: do not add new entries to this table unless you have read
1288 * Documentation/sysctl/ctl_unnumbered.txt
1293 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1294 static struct ctl_table binfmt_misc_table[] = {
1297 #endif
1299 static struct ctl_table fs_table[] = {
1301 .procname = "inode-nr",
1302 .data = &inodes_stat,
1303 .maxlen = 2*sizeof(int),
1304 .mode = 0444,
1305 .proc_handler = proc_dointvec,
1308 .procname = "inode-state",
1309 .data = &inodes_stat,
1310 .maxlen = 7*sizeof(int),
1311 .mode = 0444,
1312 .proc_handler = proc_dointvec,
1315 .procname = "file-nr",
1316 .data = &files_stat,
1317 .maxlen = 3*sizeof(int),
1318 .mode = 0444,
1319 .proc_handler = proc_nr_files,
1322 .procname = "file-max",
1323 .data = &files_stat.max_files,
1324 .maxlen = sizeof(int),
1325 .mode = 0644,
1326 .proc_handler = proc_dointvec,
1329 .procname = "nr_open",
1330 .data = &sysctl_nr_open,
1331 .maxlen = sizeof(int),
1332 .mode = 0644,
1333 .proc_handler = proc_dointvec_minmax,
1334 .extra1 = &sysctl_nr_open_min,
1335 .extra2 = &sysctl_nr_open_max,
1338 .procname = "dentry-state",
1339 .data = &dentry_stat,
1340 .maxlen = 6*sizeof(int),
1341 .mode = 0444,
1342 .proc_handler = proc_dointvec,
1345 .procname = "overflowuid",
1346 .data = &fs_overflowuid,
1347 .maxlen = sizeof(int),
1348 .mode = 0644,
1349 .proc_handler = proc_dointvec_minmax,
1350 .extra1 = &minolduid,
1351 .extra2 = &maxolduid,
1354 .procname = "overflowgid",
1355 .data = &fs_overflowgid,
1356 .maxlen = sizeof(int),
1357 .mode = 0644,
1358 .proc_handler = proc_dointvec_minmax,
1359 .extra1 = &minolduid,
1360 .extra2 = &maxolduid,
1362 #ifdef CONFIG_FILE_LOCKING
1364 .procname = "leases-enable",
1365 .data = &leases_enable,
1366 .maxlen = sizeof(int),
1367 .mode = 0644,
1368 .proc_handler = proc_dointvec,
1370 #endif
1371 #ifdef CONFIG_DNOTIFY
1373 .procname = "dir-notify-enable",
1374 .data = &dir_notify_enable,
1375 .maxlen = sizeof(int),
1376 .mode = 0644,
1377 .proc_handler = proc_dointvec,
1379 #endif
1380 #ifdef CONFIG_MMU
1381 #ifdef CONFIG_FILE_LOCKING
1383 .procname = "lease-break-time",
1384 .data = &lease_break_time,
1385 .maxlen = sizeof(int),
1386 .mode = 0644,
1387 .proc_handler = proc_dointvec,
1389 #endif
1390 #ifdef CONFIG_AIO
1392 .procname = "aio-nr",
1393 .data = &aio_nr,
1394 .maxlen = sizeof(aio_nr),
1395 .mode = 0444,
1396 .proc_handler = proc_doulongvec_minmax,
1399 .procname = "aio-max-nr",
1400 .data = &aio_max_nr,
1401 .maxlen = sizeof(aio_max_nr),
1402 .mode = 0644,
1403 .proc_handler = proc_doulongvec_minmax,
1405 #endif /* CONFIG_AIO */
1406 #ifdef CONFIG_INOTIFY_USER
1408 .procname = "inotify",
1409 .mode = 0555,
1410 .child = inotify_table,
1412 #endif
1413 #ifdef CONFIG_EPOLL
1415 .procname = "epoll",
1416 .mode = 0555,
1417 .child = epoll_table,
1419 #endif
1420 #endif
1422 .procname = "suid_dumpable",
1423 .data = &suid_dumpable,
1424 .maxlen = sizeof(int),
1425 .mode = 0644,
1426 .proc_handler = proc_dointvec_minmax,
1427 .extra1 = &zero,
1428 .extra2 = &two,
1430 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1432 .procname = "binfmt_misc",
1433 .mode = 0555,
1434 .child = binfmt_misc_table,
1436 #endif
1438 * NOTE: do not add new entries to this table unless you have read
1439 * Documentation/sysctl/ctl_unnumbered.txt
1444 static struct ctl_table debug_table[] = {
1445 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC)
1447 .procname = "exception-trace",
1448 .data = &show_unhandled_signals,
1449 .maxlen = sizeof(int),
1450 .mode = 0644,
1451 .proc_handler = proc_dointvec
1453 #endif
1454 #if defined(CONFIG_OPTPROBES)
1456 .procname = "kprobes-optimization",
1457 .data = &sysctl_kprobes_optimization,
1458 .maxlen = sizeof(int),
1459 .mode = 0644,
1460 .proc_handler = proc_kprobes_optimization_handler,
1461 .extra1 = &zero,
1462 .extra2 = &one,
1464 #endif
1468 static struct ctl_table dev_table[] = {
1472 static DEFINE_SPINLOCK(sysctl_lock);
1474 /* called under sysctl_lock */
1475 static int use_table(struct ctl_table_header *p)
1477 if (unlikely(p->unregistering))
1478 return 0;
1479 p->used++;
1480 return 1;
1483 /* called under sysctl_lock */
1484 static void unuse_table(struct ctl_table_header *p)
1486 if (!--p->used)
1487 if (unlikely(p->unregistering))
1488 complete(p->unregistering);
1491 /* called under sysctl_lock, will reacquire if has to wait */
1492 static void start_unregistering(struct ctl_table_header *p)
1495 * if p->used is 0, nobody will ever touch that entry again;
1496 * we'll eliminate all paths to it before dropping sysctl_lock
1498 if (unlikely(p->used)) {
1499 struct completion wait;
1500 init_completion(&wait);
1501 p->unregistering = &wait;
1502 spin_unlock(&sysctl_lock);
1503 wait_for_completion(&wait);
1504 spin_lock(&sysctl_lock);
1505 } else {
1506 /* anything non-NULL; we'll never dereference it */
1507 p->unregistering = ERR_PTR(-EINVAL);
1510 * do not remove from the list until nobody holds it; walking the
1511 * list in do_sysctl() relies on that.
1513 list_del_init(&p->ctl_entry);
1516 void sysctl_head_get(struct ctl_table_header *head)
1518 spin_lock(&sysctl_lock);
1519 head->count++;
1520 spin_unlock(&sysctl_lock);
1523 void sysctl_head_put(struct ctl_table_header *head)
1525 spin_lock(&sysctl_lock);
1526 if (!--head->count)
1527 kfree(head);
1528 spin_unlock(&sysctl_lock);
1531 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1533 if (!head)
1534 BUG();
1535 spin_lock(&sysctl_lock);
1536 if (!use_table(head))
1537 head = ERR_PTR(-ENOENT);
1538 spin_unlock(&sysctl_lock);
1539 return head;
1542 void sysctl_head_finish(struct ctl_table_header *head)
1544 if (!head)
1545 return;
1546 spin_lock(&sysctl_lock);
1547 unuse_table(head);
1548 spin_unlock(&sysctl_lock);
1551 static struct ctl_table_set *
1552 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1554 struct ctl_table_set *set = &root->default_set;
1555 if (root->lookup)
1556 set = root->lookup(root, namespaces);
1557 return set;
1560 static struct list_head *
1561 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1563 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1564 return &set->list;
1567 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1568 struct ctl_table_header *prev)
1570 struct ctl_table_root *root;
1571 struct list_head *header_list;
1572 struct ctl_table_header *head;
1573 struct list_head *tmp;
1575 spin_lock(&sysctl_lock);
1576 if (prev) {
1577 head = prev;
1578 tmp = &prev->ctl_entry;
1579 unuse_table(prev);
1580 goto next;
1582 tmp = &root_table_header.ctl_entry;
1583 for (;;) {
1584 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1586 if (!use_table(head))
1587 goto next;
1588 spin_unlock(&sysctl_lock);
1589 return head;
1590 next:
1591 root = head->root;
1592 tmp = tmp->next;
1593 header_list = lookup_header_list(root, namespaces);
1594 if (tmp != header_list)
1595 continue;
1597 do {
1598 root = list_entry(root->root_list.next,
1599 struct ctl_table_root, root_list);
1600 if (root == &sysctl_table_root)
1601 goto out;
1602 header_list = lookup_header_list(root, namespaces);
1603 } while (list_empty(header_list));
1604 tmp = header_list->next;
1606 out:
1607 spin_unlock(&sysctl_lock);
1608 return NULL;
1611 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1613 return __sysctl_head_next(current->nsproxy, prev);
1616 void register_sysctl_root(struct ctl_table_root *root)
1618 spin_lock(&sysctl_lock);
1619 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1620 spin_unlock(&sysctl_lock);
1624 * sysctl_perm does NOT grant the superuser all rights automatically, because
1625 * some sysctl variables are readonly even to root.
1628 static int test_perm(int mode, int op)
1630 if (!current_euid())
1631 mode >>= 6;
1632 else if (in_egroup_p(0))
1633 mode >>= 3;
1634 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1635 return 0;
1636 return -EACCES;
1639 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1641 int error;
1642 int mode;
1644 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1645 if (error)
1646 return error;
1648 if (root->permissions)
1649 mode = root->permissions(root, current->nsproxy, table);
1650 else
1651 mode = table->mode;
1653 return test_perm(mode, op);
1656 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1658 for (; table->procname; table++) {
1659 table->parent = parent;
1660 if (table->child)
1661 sysctl_set_parent(table, table->child);
1665 static __init int sysctl_init(void)
1667 sysctl_set_parent(NULL, root_table);
1668 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1670 int err;
1671 err = sysctl_check_table(current->nsproxy, root_table);
1673 #endif
1674 return 0;
1677 core_initcall(sysctl_init);
1679 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1680 struct ctl_table *table)
1682 struct ctl_table *p;
1683 const char *s = branch->procname;
1685 /* branch should have named subdirectory as its first element */
1686 if (!s || !branch->child)
1687 return NULL;
1689 /* ... and nothing else */
1690 if (branch[1].procname)
1691 return NULL;
1693 /* table should contain subdirectory with the same name */
1694 for (p = table; p->procname; p++) {
1695 if (!p->child)
1696 continue;
1697 if (p->procname && strcmp(p->procname, s) == 0)
1698 return p;
1700 return NULL;
1703 /* see if attaching q to p would be an improvement */
1704 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1706 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1707 struct ctl_table *next;
1708 int is_better = 0;
1709 int not_in_parent = !p->attached_by;
1711 while ((next = is_branch_in(by, to)) != NULL) {
1712 if (by == q->attached_by)
1713 is_better = 1;
1714 if (to == p->attached_by)
1715 not_in_parent = 1;
1716 by = by->child;
1717 to = next->child;
1720 if (is_better && not_in_parent) {
1721 q->attached_by = by;
1722 q->attached_to = to;
1723 q->parent = p;
1728 * __register_sysctl_paths - register a sysctl hierarchy
1729 * @root: List of sysctl headers to register on
1730 * @namespaces: Data to compute which lists of sysctl entries are visible
1731 * @path: The path to the directory the sysctl table is in.
1732 * @table: the top-level table structure
1734 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1735 * array. A completely 0 filled entry terminates the table.
1737 * The members of the &struct ctl_table structure are used as follows:
1739 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1740 * enter a sysctl file
1742 * data - a pointer to data for use by proc_handler
1744 * maxlen - the maximum size in bytes of the data
1746 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1748 * child - a pointer to the child sysctl table if this entry is a directory, or
1749 * %NULL.
1751 * proc_handler - the text handler routine (described below)
1753 * de - for internal use by the sysctl routines
1755 * extra1, extra2 - extra pointers usable by the proc handler routines
1757 * Leaf nodes in the sysctl tree will be represented by a single file
1758 * under /proc; non-leaf nodes will be represented by directories.
1760 * sysctl(2) can automatically manage read and write requests through
1761 * the sysctl table. The data and maxlen fields of the ctl_table
1762 * struct enable minimal validation of the values being written to be
1763 * performed, and the mode field allows minimal authentication.
1765 * There must be a proc_handler routine for any terminal nodes
1766 * mirrored under /proc/sys (non-terminals are handled by a built-in
1767 * directory handler). Several default handlers are available to
1768 * cover common cases -
1770 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1771 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1772 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1774 * It is the handler's job to read the input buffer from user memory
1775 * and process it. The handler should return 0 on success.
1777 * This routine returns %NULL on a failure to register, and a pointer
1778 * to the table header on success.
1780 struct ctl_table_header *__register_sysctl_paths(
1781 struct ctl_table_root *root,
1782 struct nsproxy *namespaces,
1783 const struct ctl_path *path, struct ctl_table *table)
1785 struct ctl_table_header *header;
1786 struct ctl_table *new, **prevp;
1787 unsigned int n, npath;
1788 struct ctl_table_set *set;
1790 /* Count the path components */
1791 for (npath = 0; path[npath].procname; ++npath)
1795 * For each path component, allocate a 2-element ctl_table array.
1796 * The first array element will be filled with the sysctl entry
1797 * for this, the second will be the sentinel (procname == 0).
1799 * We allocate everything in one go so that we don't have to
1800 * worry about freeing additional memory in unregister_sysctl_table.
1802 header = kzalloc(sizeof(struct ctl_table_header) +
1803 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1804 if (!header)
1805 return NULL;
1807 new = (struct ctl_table *) (header + 1);
1809 /* Now connect the dots */
1810 prevp = &header->ctl_table;
1811 for (n = 0; n < npath; ++n, ++path) {
1812 /* Copy the procname */
1813 new->procname = path->procname;
1814 new->mode = 0555;
1816 *prevp = new;
1817 prevp = &new->child;
1819 new += 2;
1821 *prevp = table;
1822 header->ctl_table_arg = table;
1824 INIT_LIST_HEAD(&header->ctl_entry);
1825 header->used = 0;
1826 header->unregistering = NULL;
1827 header->root = root;
1828 sysctl_set_parent(NULL, header->ctl_table);
1829 header->count = 1;
1830 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1831 if (sysctl_check_table(namespaces, header->ctl_table)) {
1832 kfree(header);
1833 return NULL;
1835 #endif
1836 spin_lock(&sysctl_lock);
1837 header->set = lookup_header_set(root, namespaces);
1838 header->attached_by = header->ctl_table;
1839 header->attached_to = root_table;
1840 header->parent = &root_table_header;
1841 for (set = header->set; set; set = set->parent) {
1842 struct ctl_table_header *p;
1843 list_for_each_entry(p, &set->list, ctl_entry) {
1844 if (p->unregistering)
1845 continue;
1846 try_attach(p, header);
1849 header->parent->count++;
1850 list_add_tail(&header->ctl_entry, &header->set->list);
1851 spin_unlock(&sysctl_lock);
1853 return header;
1857 * register_sysctl_table_path - register a sysctl table hierarchy
1858 * @path: The path to the directory the sysctl table is in.
1859 * @table: the top-level table structure
1861 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1862 * array. A completely 0 filled entry terminates the table.
1864 * See __register_sysctl_paths for more details.
1866 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1867 struct ctl_table *table)
1869 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1870 path, table);
1874 * register_sysctl_table - register a sysctl table hierarchy
1875 * @table: the top-level table structure
1877 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1878 * array. A completely 0 filled entry terminates the table.
1880 * See register_sysctl_paths for more details.
1882 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1884 static const struct ctl_path null_path[] = { {} };
1886 return register_sysctl_paths(null_path, table);
1890 * unregister_sysctl_table - unregister a sysctl table hierarchy
1891 * @header: the header returned from register_sysctl_table
1893 * Unregisters the sysctl table and all children. proc entries may not
1894 * actually be removed until they are no longer used by anyone.
1896 void unregister_sysctl_table(struct ctl_table_header * header)
1898 might_sleep();
1900 if (header == NULL)
1901 return;
1903 spin_lock(&sysctl_lock);
1904 start_unregistering(header);
1905 if (!--header->parent->count) {
1906 WARN_ON(1);
1907 kfree(header->parent);
1909 if (!--header->count)
1910 kfree(header);
1911 spin_unlock(&sysctl_lock);
1914 int sysctl_is_seen(struct ctl_table_header *p)
1916 struct ctl_table_set *set = p->set;
1917 int res;
1918 spin_lock(&sysctl_lock);
1919 if (p->unregistering)
1920 res = 0;
1921 else if (!set->is_seen)
1922 res = 1;
1923 else
1924 res = set->is_seen(set);
1925 spin_unlock(&sysctl_lock);
1926 return res;
1929 void setup_sysctl_set(struct ctl_table_set *p,
1930 struct ctl_table_set *parent,
1931 int (*is_seen)(struct ctl_table_set *))
1933 INIT_LIST_HEAD(&p->list);
1934 p->parent = parent ? parent : &sysctl_table_root.default_set;
1935 p->is_seen = is_seen;
1938 #else /* !CONFIG_SYSCTL */
1939 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1941 return NULL;
1944 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1945 struct ctl_table *table)
1947 return NULL;
1950 void unregister_sysctl_table(struct ctl_table_header * table)
1954 void setup_sysctl_set(struct ctl_table_set *p,
1955 struct ctl_table_set *parent,
1956 int (*is_seen)(struct ctl_table_set *))
1960 void sysctl_head_put(struct ctl_table_header *head)
1964 #endif /* CONFIG_SYSCTL */
1967 * /proc/sys support
1970 #ifdef CONFIG_PROC_SYSCTL
1972 static int _proc_do_string(void* data, int maxlen, int write,
1973 void __user *buffer,
1974 size_t *lenp, loff_t *ppos)
1976 size_t len;
1977 char __user *p;
1978 char c;
1980 if (!data || !maxlen || !*lenp) {
1981 *lenp = 0;
1982 return 0;
1985 if (write) {
1986 len = 0;
1987 p = buffer;
1988 while (len < *lenp) {
1989 if (get_user(c, p++))
1990 return -EFAULT;
1991 if (c == 0 || c == '\n')
1992 break;
1993 len++;
1995 if (len >= maxlen)
1996 len = maxlen-1;
1997 if(copy_from_user(data, buffer, len))
1998 return -EFAULT;
1999 ((char *) data)[len] = 0;
2000 *ppos += *lenp;
2001 } else {
2002 len = strlen(data);
2003 if (len > maxlen)
2004 len = maxlen;
2006 if (*ppos > len) {
2007 *lenp = 0;
2008 return 0;
2011 data += *ppos;
2012 len -= *ppos;
2014 if (len > *lenp)
2015 len = *lenp;
2016 if (len)
2017 if(copy_to_user(buffer, data, len))
2018 return -EFAULT;
2019 if (len < *lenp) {
2020 if(put_user('\n', ((char __user *) buffer) + len))
2021 return -EFAULT;
2022 len++;
2024 *lenp = len;
2025 *ppos += len;
2027 return 0;
2031 * proc_dostring - read a string sysctl
2032 * @table: the sysctl table
2033 * @write: %TRUE if this is a write to the sysctl file
2034 * @buffer: the user buffer
2035 * @lenp: the size of the user buffer
2036 * @ppos: file position
2038 * Reads/writes a string from/to the user buffer. If the kernel
2039 * buffer provided is not large enough to hold the string, the
2040 * string is truncated. The copied string is %NULL-terminated.
2041 * If the string is being read by the user process, it is copied
2042 * and a newline '\n' is added. It is truncated if the buffer is
2043 * not large enough.
2045 * Returns 0 on success.
2047 int proc_dostring(struct ctl_table *table, int write,
2048 void __user *buffer, size_t *lenp, loff_t *ppos)
2050 return _proc_do_string(table->data, table->maxlen, write,
2051 buffer, lenp, ppos);
2055 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2056 int *valp,
2057 int write, void *data)
2059 if (write) {
2060 *valp = *negp ? -*lvalp : *lvalp;
2061 } else {
2062 int val = *valp;
2063 if (val < 0) {
2064 *negp = -1;
2065 *lvalp = (unsigned long)-val;
2066 } else {
2067 *negp = 0;
2068 *lvalp = (unsigned long)val;
2071 return 0;
2074 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2075 int write, void __user *buffer,
2076 size_t *lenp, loff_t *ppos,
2077 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2078 int write, void *data),
2079 void *data)
2081 #define TMPBUFLEN 21
2082 int *i, vleft, first = 1, neg;
2083 unsigned long lval;
2084 size_t left, len;
2086 char buf[TMPBUFLEN], *p;
2087 char __user *s = buffer;
2089 if (!tbl_data || !table->maxlen || !*lenp ||
2090 (*ppos && !write)) {
2091 *lenp = 0;
2092 return 0;
2095 i = (int *) tbl_data;
2096 vleft = table->maxlen / sizeof(*i);
2097 left = *lenp;
2099 if (!conv)
2100 conv = do_proc_dointvec_conv;
2102 for (; left && vleft--; i++, first=0) {
2103 if (write) {
2104 while (left) {
2105 char c;
2106 if (get_user(c, s))
2107 return -EFAULT;
2108 if (!isspace(c))
2109 break;
2110 left--;
2111 s++;
2113 if (!left)
2114 break;
2115 neg = 0;
2116 len = left;
2117 if (len > sizeof(buf) - 1)
2118 len = sizeof(buf) - 1;
2119 if (copy_from_user(buf, s, len))
2120 return -EFAULT;
2121 buf[len] = 0;
2122 p = buf;
2123 if (*p == '-' && left > 1) {
2124 neg = 1;
2125 p++;
2127 if (*p < '0' || *p > '9')
2128 break;
2130 lval = simple_strtoul(p, &p, 0);
2132 len = p-buf;
2133 if ((len < left) && *p && !isspace(*p))
2134 break;
2135 s += len;
2136 left -= len;
2138 if (conv(&neg, &lval, i, 1, data))
2139 break;
2140 } else {
2141 p = buf;
2142 if (!first)
2143 *p++ = '\t';
2145 if (conv(&neg, &lval, i, 0, data))
2146 break;
2148 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2149 len = strlen(buf);
2150 if (len > left)
2151 len = left;
2152 if(copy_to_user(s, buf, len))
2153 return -EFAULT;
2154 left -= len;
2155 s += len;
2159 if (!write && !first && left) {
2160 if(put_user('\n', s))
2161 return -EFAULT;
2162 left--, s++;
2164 if (write) {
2165 while (left) {
2166 char c;
2167 if (get_user(c, s++))
2168 return -EFAULT;
2169 if (!isspace(c))
2170 break;
2171 left--;
2174 if (write && first)
2175 return -EINVAL;
2176 *lenp -= left;
2177 *ppos += *lenp;
2178 return 0;
2179 #undef TMPBUFLEN
2182 static int do_proc_dointvec(struct ctl_table *table, int write,
2183 void __user *buffer, size_t *lenp, loff_t *ppos,
2184 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2185 int write, void *data),
2186 void *data)
2188 return __do_proc_dointvec(table->data, table, write,
2189 buffer, lenp, ppos, conv, data);
2193 * proc_dointvec - read a vector of integers
2194 * @table: the sysctl table
2195 * @write: %TRUE if this is a write to the sysctl file
2196 * @buffer: the user buffer
2197 * @lenp: the size of the user buffer
2198 * @ppos: file position
2200 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2201 * values from/to the user buffer, treated as an ASCII string.
2203 * Returns 0 on success.
2205 int proc_dointvec(struct ctl_table *table, int write,
2206 void __user *buffer, size_t *lenp, loff_t *ppos)
2208 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2209 NULL,NULL);
2213 * Taint values can only be increased
2214 * This means we can safely use a temporary.
2216 static int proc_taint(struct ctl_table *table, int write,
2217 void __user *buffer, size_t *lenp, loff_t *ppos)
2219 struct ctl_table t;
2220 unsigned long tmptaint = get_taint();
2221 int err;
2223 if (write && !capable(CAP_SYS_ADMIN))
2224 return -EPERM;
2226 t = *table;
2227 t.data = &tmptaint;
2228 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2229 if (err < 0)
2230 return err;
2232 if (write) {
2234 * Poor man's atomic or. Not worth adding a primitive
2235 * to everyone's atomic.h for this
2237 int i;
2238 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2239 if ((tmptaint >> i) & 1)
2240 add_taint(i);
2244 return err;
2247 struct do_proc_dointvec_minmax_conv_param {
2248 int *min;
2249 int *max;
2252 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2253 int *valp,
2254 int write, void *data)
2256 struct do_proc_dointvec_minmax_conv_param *param = data;
2257 if (write) {
2258 int val = *negp ? -*lvalp : *lvalp;
2259 if ((param->min && *param->min > val) ||
2260 (param->max && *param->max < val))
2261 return -EINVAL;
2262 *valp = val;
2263 } else {
2264 int val = *valp;
2265 if (val < 0) {
2266 *negp = -1;
2267 *lvalp = (unsigned long)-val;
2268 } else {
2269 *negp = 0;
2270 *lvalp = (unsigned long)val;
2273 return 0;
2277 * proc_dointvec_minmax - read a vector of integers with min/max values
2278 * @table: the sysctl table
2279 * @write: %TRUE if this is a write to the sysctl file
2280 * @buffer: the user buffer
2281 * @lenp: the size of the user buffer
2282 * @ppos: file position
2284 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2285 * values from/to the user buffer, treated as an ASCII string.
2287 * This routine will ensure the values are within the range specified by
2288 * table->extra1 (min) and table->extra2 (max).
2290 * Returns 0 on success.
2292 int proc_dointvec_minmax(struct ctl_table *table, int write,
2293 void __user *buffer, size_t *lenp, loff_t *ppos)
2295 struct do_proc_dointvec_minmax_conv_param param = {
2296 .min = (int *) table->extra1,
2297 .max = (int *) table->extra2,
2299 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2300 do_proc_dointvec_minmax_conv, &param);
2303 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2304 void __user *buffer,
2305 size_t *lenp, loff_t *ppos,
2306 unsigned long convmul,
2307 unsigned long convdiv)
2309 #define TMPBUFLEN 21
2310 unsigned long *i, *min, *max, val;
2311 int vleft, first=1, neg;
2312 size_t len, left;
2313 char buf[TMPBUFLEN], *p;
2314 char __user *s = buffer;
2316 if (!data || !table->maxlen || !*lenp ||
2317 (*ppos && !write)) {
2318 *lenp = 0;
2319 return 0;
2322 i = (unsigned long *) data;
2323 min = (unsigned long *) table->extra1;
2324 max = (unsigned long *) table->extra2;
2325 vleft = table->maxlen / sizeof(unsigned long);
2326 left = *lenp;
2328 for (; left && vleft--; i++, min++, max++, first=0) {
2329 if (write) {
2330 while (left) {
2331 char c;
2332 if (get_user(c, s))
2333 return -EFAULT;
2334 if (!isspace(c))
2335 break;
2336 left--;
2337 s++;
2339 if (!left)
2340 break;
2341 neg = 0;
2342 len = left;
2343 if (len > TMPBUFLEN-1)
2344 len = TMPBUFLEN-1;
2345 if (copy_from_user(buf, s, len))
2346 return -EFAULT;
2347 buf[len] = 0;
2348 p = buf;
2349 if (*p == '-' && left > 1) {
2350 neg = 1;
2351 p++;
2353 if (*p < '0' || *p > '9')
2354 break;
2355 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2356 len = p-buf;
2357 if ((len < left) && *p && !isspace(*p))
2358 break;
2359 if (neg)
2360 val = -val;
2361 s += len;
2362 left -= len;
2364 if(neg)
2365 continue;
2366 if ((min && val < *min) || (max && val > *max))
2367 continue;
2368 *i = val;
2369 } else {
2370 p = buf;
2371 if (!first)
2372 *p++ = '\t';
2373 sprintf(p, "%lu", convdiv * (*i) / convmul);
2374 len = strlen(buf);
2375 if (len > left)
2376 len = left;
2377 if(copy_to_user(s, buf, len))
2378 return -EFAULT;
2379 left -= len;
2380 s += len;
2384 if (!write && !first && left) {
2385 if(put_user('\n', s))
2386 return -EFAULT;
2387 left--, s++;
2389 if (write) {
2390 while (left) {
2391 char c;
2392 if (get_user(c, s++))
2393 return -EFAULT;
2394 if (!isspace(c))
2395 break;
2396 left--;
2399 if (write && first)
2400 return -EINVAL;
2401 *lenp -= left;
2402 *ppos += *lenp;
2403 return 0;
2404 #undef TMPBUFLEN
2407 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2408 void __user *buffer,
2409 size_t *lenp, loff_t *ppos,
2410 unsigned long convmul,
2411 unsigned long convdiv)
2413 return __do_proc_doulongvec_minmax(table->data, table, write,
2414 buffer, lenp, ppos, convmul, convdiv);
2418 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2419 * @table: the sysctl table
2420 * @write: %TRUE if this is a write to the sysctl file
2421 * @buffer: the user buffer
2422 * @lenp: the size of the user buffer
2423 * @ppos: file position
2425 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2426 * values from/to the user buffer, treated as an ASCII string.
2428 * This routine will ensure the values are within the range specified by
2429 * table->extra1 (min) and table->extra2 (max).
2431 * Returns 0 on success.
2433 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2434 void __user *buffer, size_t *lenp, loff_t *ppos)
2436 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2440 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2441 * @table: the sysctl table
2442 * @write: %TRUE if this is a write to the sysctl file
2443 * @buffer: the user buffer
2444 * @lenp: the size of the user buffer
2445 * @ppos: file position
2447 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2448 * values from/to the user buffer, treated as an ASCII string. The values
2449 * are treated as milliseconds, and converted to jiffies when they are stored.
2451 * This routine will ensure the values are within the range specified by
2452 * table->extra1 (min) and table->extra2 (max).
2454 * Returns 0 on success.
2456 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2457 void __user *buffer,
2458 size_t *lenp, loff_t *ppos)
2460 return do_proc_doulongvec_minmax(table, write, buffer,
2461 lenp, ppos, HZ, 1000l);
2465 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2466 int *valp,
2467 int write, void *data)
2469 if (write) {
2470 if (*lvalp > LONG_MAX / HZ)
2471 return 1;
2472 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2473 } else {
2474 int val = *valp;
2475 unsigned long lval;
2476 if (val < 0) {
2477 *negp = -1;
2478 lval = (unsigned long)-val;
2479 } else {
2480 *negp = 0;
2481 lval = (unsigned long)val;
2483 *lvalp = lval / HZ;
2485 return 0;
2488 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2489 int *valp,
2490 int write, void *data)
2492 if (write) {
2493 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2494 return 1;
2495 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2496 } else {
2497 int val = *valp;
2498 unsigned long lval;
2499 if (val < 0) {
2500 *negp = -1;
2501 lval = (unsigned long)-val;
2502 } else {
2503 *negp = 0;
2504 lval = (unsigned long)val;
2506 *lvalp = jiffies_to_clock_t(lval);
2508 return 0;
2511 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2512 int *valp,
2513 int write, void *data)
2515 if (write) {
2516 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2517 } else {
2518 int val = *valp;
2519 unsigned long lval;
2520 if (val < 0) {
2521 *negp = -1;
2522 lval = (unsigned long)-val;
2523 } else {
2524 *negp = 0;
2525 lval = (unsigned long)val;
2527 *lvalp = jiffies_to_msecs(lval);
2529 return 0;
2533 * proc_dointvec_jiffies - read a vector of integers as seconds
2534 * @table: the sysctl table
2535 * @write: %TRUE if this is a write to the sysctl file
2536 * @buffer: the user buffer
2537 * @lenp: the size of the user buffer
2538 * @ppos: file position
2540 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2541 * values from/to the user buffer, treated as an ASCII string.
2542 * The values read are assumed to be in seconds, and are converted into
2543 * jiffies.
2545 * Returns 0 on success.
2547 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2548 void __user *buffer, size_t *lenp, loff_t *ppos)
2550 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2551 do_proc_dointvec_jiffies_conv,NULL);
2555 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2556 * @table: the sysctl table
2557 * @write: %TRUE if this is a write to the sysctl file
2558 * @buffer: the user buffer
2559 * @lenp: the size of the user buffer
2560 * @ppos: pointer to the file position
2562 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2563 * values from/to the user buffer, treated as an ASCII string.
2564 * The values read are assumed to be in 1/USER_HZ seconds, and
2565 * are converted into jiffies.
2567 * Returns 0 on success.
2569 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2570 void __user *buffer, size_t *lenp, loff_t *ppos)
2572 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2573 do_proc_dointvec_userhz_jiffies_conv,NULL);
2577 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2578 * @table: the sysctl table
2579 * @write: %TRUE if this is a write to the sysctl file
2580 * @buffer: the user buffer
2581 * @lenp: the size of the user buffer
2582 * @ppos: file position
2583 * @ppos: the current position in the file
2585 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2586 * values from/to the user buffer, treated as an ASCII string.
2587 * The values read are assumed to be in 1/1000 seconds, and
2588 * are converted into jiffies.
2590 * Returns 0 on success.
2592 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2593 void __user *buffer, size_t *lenp, loff_t *ppos)
2595 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2596 do_proc_dointvec_ms_jiffies_conv, NULL);
2599 static int proc_do_cad_pid(struct ctl_table *table, int write,
2600 void __user *buffer, size_t *lenp, loff_t *ppos)
2602 struct pid *new_pid;
2603 pid_t tmp;
2604 int r;
2606 tmp = pid_vnr(cad_pid);
2608 r = __do_proc_dointvec(&tmp, table, write, buffer,
2609 lenp, ppos, NULL, NULL);
2610 if (r || !write)
2611 return r;
2613 new_pid = find_get_pid(tmp);
2614 if (!new_pid)
2615 return -ESRCH;
2617 put_pid(xchg(&cad_pid, new_pid));
2618 return 0;
2621 #else /* CONFIG_PROC_FS */
2623 int proc_dostring(struct ctl_table *table, int write,
2624 void __user *buffer, size_t *lenp, loff_t *ppos)
2626 return -ENOSYS;
2629 int proc_dointvec(struct ctl_table *table, int write,
2630 void __user *buffer, size_t *lenp, loff_t *ppos)
2632 return -ENOSYS;
2635 int proc_dointvec_minmax(struct ctl_table *table, int write,
2636 void __user *buffer, size_t *lenp, loff_t *ppos)
2638 return -ENOSYS;
2641 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2642 void __user *buffer, size_t *lenp, loff_t *ppos)
2644 return -ENOSYS;
2647 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2648 void __user *buffer, size_t *lenp, loff_t *ppos)
2650 return -ENOSYS;
2653 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2654 void __user *buffer, size_t *lenp, loff_t *ppos)
2656 return -ENOSYS;
2659 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2660 void __user *buffer, size_t *lenp, loff_t *ppos)
2662 return -ENOSYS;
2665 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2666 void __user *buffer,
2667 size_t *lenp, loff_t *ppos)
2669 return -ENOSYS;
2673 #endif /* CONFIG_PROC_FS */
2676 * No sense putting this after each symbol definition, twice,
2677 * exception granted :-)
2679 EXPORT_SYMBOL(proc_dointvec);
2680 EXPORT_SYMBOL(proc_dointvec_jiffies);
2681 EXPORT_SYMBOL(proc_dointvec_minmax);
2682 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2683 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2684 EXPORT_SYMBOL(proc_dostring);
2685 EXPORT_SYMBOL(proc_doulongvec_minmax);
2686 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2687 EXPORT_SYMBOL(register_sysctl_table);
2688 EXPORT_SYMBOL(register_sysctl_paths);
2689 EXPORT_SYMBOL(unregister_sysctl_table);