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[linux-2.6.34.14-moxart.git] / kernel / sysctl.c
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1 /*
2 * sysctl.c: General linux system control interface
4 * Begun 24 March 1995, Stephen Tweedie
5 * Added /proc support, Dec 1995
6 * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
7 * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
8 * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
9 * Dynamic registration fixes, Stephen Tweedie.
10 * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
11 * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
12 * Horn.
13 * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
14 * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
15 * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
16 * Wendling.
17 * The list_for_each() macro wasn't appropriate for the sysctl loop.
18 * Removed it and replaced it with older style, 03/23/00, Bill Wendling
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/swap.h>
24 #include <linux/slab.h>
25 #include <linux/sysctl.h>
26 #include <linux/signal.h>
27 #include <linux/proc_fs.h>
28 #include <linux/security.h>
29 #include <linux/ctype.h>
30 #include <linux/kmemcheck.h>
31 #include <linux/fs.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/kobject.h>
35 #include <linux/net.h>
36 #include <linux/sysrq.h>
37 #include <linux/highuid.h>
38 #include <linux/writeback.h>
39 #include <linux/ratelimit.h>
40 #include <linux/hugetlb.h>
41 #include <linux/initrd.h>
42 #include <linux/key.h>
43 #include <linux/times.h>
44 #include <linux/limits.h>
45 #include <linux/dcache.h>
46 #include <linux/syscalls.h>
47 #include <linux/vmstat.h>
48 #include <linux/nfs_fs.h>
49 #include <linux/acpi.h>
50 #include <linux/reboot.h>
51 #include <linux/ftrace.h>
52 #include <linux/slow-work.h>
53 #include <linux/perf_event.h>
54 #include <linux/kprobes.h>
56 #include <asm/uaccess.h>
57 #include <asm/processor.h>
59 #ifdef CONFIG_X86
60 #include <asm/nmi.h>
61 #include <asm/stacktrace.h>
62 #include <asm/io.h>
63 #endif
64 #ifdef CONFIG_BSD_PROCESS_ACCT
65 #include <linux/acct.h>
66 #endif
67 #ifdef CONFIG_RT_MUTEXES
68 #include <linux/rtmutex.h>
69 #endif
70 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
71 #include <linux/lockdep.h>
72 #endif
73 #ifdef CONFIG_CHR_DEV_SG
74 #include <scsi/sg.h>
75 #endif
78 #if defined(CONFIG_SYSCTL)
80 /* External variables not in a header file. */
81 extern int sysctl_overcommit_memory;
82 extern int sysctl_overcommit_ratio;
83 extern int sysctl_panic_on_oom;
84 extern int sysctl_oom_kill_allocating_task;
85 extern int sysctl_oom_dump_tasks;
86 extern int max_threads;
87 extern int core_uses_pid;
88 extern int suid_dumpable;
89 extern char core_pattern[];
90 extern unsigned int core_pipe_limit;
91 extern int pid_max;
92 extern int min_free_kbytes;
93 extern int pid_max_min, pid_max_max;
94 extern int sysctl_drop_caches;
95 extern int percpu_pagelist_fraction;
96 extern int compat_log;
97 extern int latencytop_enabled;
98 extern int sysctl_nr_open_min, sysctl_nr_open_max;
99 #ifndef CONFIG_MMU
100 extern int sysctl_nr_trim_pages;
101 #endif
102 #ifdef CONFIG_BLOCK
103 extern int blk_iopoll_enabled;
104 #endif
106 /* Constants used for minimum and maximum */
107 #ifdef CONFIG_DETECT_SOFTLOCKUP
108 static int sixty = 60;
109 static int neg_one = -1;
110 #endif
112 static int zero;
113 static int __maybe_unused one = 1;
114 static int __maybe_unused two = 2;
115 static unsigned long one_ul = 1;
116 static int one_hundred = 100;
117 #ifdef CONFIG_PRINTK
118 static int ten_thousand = 10000;
119 #endif
121 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
122 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
124 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
125 static int maxolduid = 65535;
126 static int minolduid;
127 static int min_percpu_pagelist_fract = 8;
129 static int ngroups_max = NGROUPS_MAX;
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_IA64
153 extern int no_unaligned_warning;
154 extern int unaligned_dump_stack;
155 #endif
157 extern struct ratelimit_state printk_ratelimit_state;
159 #ifdef CONFIG_PROC_SYSCTL
160 static int proc_do_cad_pid(struct ctl_table *table, int write,
161 void __user *buffer, size_t *lenp, loff_t *ppos);
162 static int proc_taint(struct ctl_table *table, int write,
163 void __user *buffer, size_t *lenp, loff_t *ppos);
164 #endif
166 static struct ctl_table root_table[];
167 static struct ctl_table_root sysctl_table_root;
168 static struct ctl_table_header root_table_header = {
169 .count = 1,
170 .ctl_table = root_table,
171 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
172 .root = &sysctl_table_root,
173 .set = &sysctl_table_root.default_set,
175 static struct ctl_table_root sysctl_table_root = {
176 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
177 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
180 static struct ctl_table kern_table[];
181 static struct ctl_table vm_table[];
182 static struct ctl_table fs_table[];
183 static struct ctl_table debug_table[];
184 static struct ctl_table dev_table[];
185 extern struct ctl_table random_table[];
186 #ifdef CONFIG_INOTIFY_USER
187 extern struct ctl_table inotify_table[];
188 #endif
189 #ifdef CONFIG_EPOLL
190 extern struct ctl_table epoll_table[];
191 #endif
193 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
194 int sysctl_legacy_va_layout;
195 #endif
197 /* The default sysctl tables: */
199 static struct ctl_table root_table[] = {
201 .procname = "kernel",
202 .mode = 0555,
203 .child = kern_table,
206 .procname = "vm",
207 .mode = 0555,
208 .child = vm_table,
211 .procname = "fs",
212 .mode = 0555,
213 .child = fs_table,
216 .procname = "debug",
217 .mode = 0555,
218 .child = debug_table,
221 .procname = "dev",
222 .mode = 0555,
223 .child = dev_table,
226 * NOTE: do not add new entries to this table unless you have read
227 * Documentation/sysctl/ctl_unnumbered.txt
232 #ifdef CONFIG_SCHED_DEBUG
233 static int min_sched_granularity_ns = 100000; /* 100 usecs */
234 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
235 static int min_wakeup_granularity_ns; /* 0 usecs */
236 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
237 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
238 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
239 static int min_sched_shares_ratelimit = 100000; /* 100 usec */
240 static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
241 #endif
243 static struct ctl_table kern_table[] = {
245 .procname = "sched_child_runs_first",
246 .data = &sysctl_sched_child_runs_first,
247 .maxlen = sizeof(unsigned int),
248 .mode = 0644,
249 .proc_handler = proc_dointvec,
251 #ifdef CONFIG_SCHED_DEBUG
253 .procname = "sched_min_granularity_ns",
254 .data = &sysctl_sched_min_granularity,
255 .maxlen = sizeof(unsigned int),
256 .mode = 0644,
257 .proc_handler = sched_proc_update_handler,
258 .extra1 = &min_sched_granularity_ns,
259 .extra2 = &max_sched_granularity_ns,
262 .procname = "sched_latency_ns",
263 .data = &sysctl_sched_latency,
264 .maxlen = sizeof(unsigned int),
265 .mode = 0644,
266 .proc_handler = sched_proc_update_handler,
267 .extra1 = &min_sched_granularity_ns,
268 .extra2 = &max_sched_granularity_ns,
271 .procname = "sched_wakeup_granularity_ns",
272 .data = &sysctl_sched_wakeup_granularity,
273 .maxlen = sizeof(unsigned int),
274 .mode = 0644,
275 .proc_handler = sched_proc_update_handler,
276 .extra1 = &min_wakeup_granularity_ns,
277 .extra2 = &max_wakeup_granularity_ns,
280 .procname = "sched_shares_ratelimit",
281 .data = &sysctl_sched_shares_ratelimit,
282 .maxlen = sizeof(unsigned int),
283 .mode = 0644,
284 .proc_handler = sched_proc_update_handler,
285 .extra1 = &min_sched_shares_ratelimit,
286 .extra2 = &max_sched_shares_ratelimit,
289 .procname = "sched_tunable_scaling",
290 .data = &sysctl_sched_tunable_scaling,
291 .maxlen = sizeof(enum sched_tunable_scaling),
292 .mode = 0644,
293 .proc_handler = sched_proc_update_handler,
294 .extra1 = &min_sched_tunable_scaling,
295 .extra2 = &max_sched_tunable_scaling,
298 .procname = "sched_shares_thresh",
299 .data = &sysctl_sched_shares_thresh,
300 .maxlen = sizeof(unsigned int),
301 .mode = 0644,
302 .proc_handler = proc_dointvec_minmax,
303 .extra1 = &zero,
306 .procname = "sched_migration_cost",
307 .data = &sysctl_sched_migration_cost,
308 .maxlen = sizeof(unsigned int),
309 .mode = 0644,
310 .proc_handler = proc_dointvec,
313 .procname = "sched_nr_migrate",
314 .data = &sysctl_sched_nr_migrate,
315 .maxlen = sizeof(unsigned int),
316 .mode = 0644,
317 .proc_handler = proc_dointvec,
320 .procname = "sched_time_avg",
321 .data = &sysctl_sched_time_avg,
322 .maxlen = sizeof(unsigned int),
323 .mode = 0644,
324 .proc_handler = proc_dointvec,
327 .procname = "timer_migration",
328 .data = &sysctl_timer_migration,
329 .maxlen = sizeof(unsigned int),
330 .mode = 0644,
331 .proc_handler = proc_dointvec_minmax,
332 .extra1 = &zero,
333 .extra2 = &one,
335 #endif
337 .procname = "sched_rt_period_us",
338 .data = &sysctl_sched_rt_period,
339 .maxlen = sizeof(unsigned int),
340 .mode = 0644,
341 .proc_handler = sched_rt_handler,
344 .procname = "sched_rt_runtime_us",
345 .data = &sysctl_sched_rt_runtime,
346 .maxlen = sizeof(int),
347 .mode = 0644,
348 .proc_handler = sched_rt_handler,
351 .procname = "sched_compat_yield",
352 .data = &sysctl_sched_compat_yield,
353 .maxlen = sizeof(unsigned int),
354 .mode = 0644,
355 .proc_handler = proc_dointvec,
357 #ifdef CONFIG_PROVE_LOCKING
359 .procname = "prove_locking",
360 .data = &prove_locking,
361 .maxlen = sizeof(int),
362 .mode = 0644,
363 .proc_handler = proc_dointvec,
365 #endif
366 #ifdef CONFIG_LOCK_STAT
368 .procname = "lock_stat",
369 .data = &lock_stat,
370 .maxlen = sizeof(int),
371 .mode = 0644,
372 .proc_handler = proc_dointvec,
374 #endif
376 .procname = "panic",
377 .data = &panic_timeout,
378 .maxlen = sizeof(int),
379 .mode = 0644,
380 .proc_handler = proc_dointvec,
383 .procname = "core_uses_pid",
384 .data = &core_uses_pid,
385 .maxlen = sizeof(int),
386 .mode = 0644,
387 .proc_handler = proc_dointvec,
390 .procname = "core_pattern",
391 .data = core_pattern,
392 .maxlen = CORENAME_MAX_SIZE,
393 .mode = 0644,
394 .proc_handler = proc_dostring,
397 .procname = "core_pipe_limit",
398 .data = &core_pipe_limit,
399 .maxlen = sizeof(unsigned int),
400 .mode = 0644,
401 .proc_handler = proc_dointvec,
403 #ifdef CONFIG_PROC_SYSCTL
405 .procname = "tainted",
406 .maxlen = sizeof(long),
407 .mode = 0644,
408 .proc_handler = proc_taint,
410 #endif
411 #ifdef CONFIG_LATENCYTOP
413 .procname = "latencytop",
414 .data = &latencytop_enabled,
415 .maxlen = sizeof(int),
416 .mode = 0644,
417 .proc_handler = proc_dointvec,
419 #endif
420 #ifdef CONFIG_BLK_DEV_INITRD
422 .procname = "real-root-dev",
423 .data = &real_root_dev,
424 .maxlen = sizeof(int),
425 .mode = 0644,
426 .proc_handler = proc_dointvec,
428 #endif
430 .procname = "print-fatal-signals",
431 .data = &print_fatal_signals,
432 .maxlen = sizeof(int),
433 .mode = 0644,
434 .proc_handler = proc_dointvec,
436 #ifdef CONFIG_SPARC
438 .procname = "reboot-cmd",
439 .data = reboot_command,
440 .maxlen = 256,
441 .mode = 0644,
442 .proc_handler = proc_dostring,
445 .procname = "stop-a",
446 .data = &stop_a_enabled,
447 .maxlen = sizeof (int),
448 .mode = 0644,
449 .proc_handler = proc_dointvec,
452 .procname = "scons-poweroff",
453 .data = &scons_pwroff,
454 .maxlen = sizeof (int),
455 .mode = 0644,
456 .proc_handler = proc_dointvec,
458 #endif
459 #ifdef CONFIG_SPARC64
461 .procname = "tsb-ratio",
462 .data = &sysctl_tsb_ratio,
463 .maxlen = sizeof (int),
464 .mode = 0644,
465 .proc_handler = proc_dointvec,
467 #endif
468 #ifdef __hppa__
470 .procname = "soft-power",
471 .data = &pwrsw_enabled,
472 .maxlen = sizeof (int),
473 .mode = 0644,
474 .proc_handler = proc_dointvec,
477 .procname = "unaligned-trap",
478 .data = &unaligned_enabled,
479 .maxlen = sizeof (int),
480 .mode = 0644,
481 .proc_handler = proc_dointvec,
483 #endif
485 .procname = "ctrl-alt-del",
486 .data = &C_A_D,
487 .maxlen = sizeof(int),
488 .mode = 0644,
489 .proc_handler = proc_dointvec,
491 #ifdef CONFIG_FUNCTION_TRACER
493 .procname = "ftrace_enabled",
494 .data = &ftrace_enabled,
495 .maxlen = sizeof(int),
496 .mode = 0644,
497 .proc_handler = ftrace_enable_sysctl,
499 #endif
500 #ifdef CONFIG_STACK_TRACER
502 .procname = "stack_tracer_enabled",
503 .data = &stack_tracer_enabled,
504 .maxlen = sizeof(int),
505 .mode = 0644,
506 .proc_handler = stack_trace_sysctl,
508 #endif
509 #ifdef CONFIG_TRACING
511 .procname = "ftrace_dump_on_oops",
512 .data = &ftrace_dump_on_oops,
513 .maxlen = sizeof(int),
514 .mode = 0644,
515 .proc_handler = proc_dointvec,
517 #endif
518 #ifdef CONFIG_MODULES
520 .procname = "modprobe",
521 .data = &modprobe_path,
522 .maxlen = KMOD_PATH_LEN,
523 .mode = 0644,
524 .proc_handler = proc_dostring,
527 .procname = "modules_disabled",
528 .data = &modules_disabled,
529 .maxlen = sizeof(int),
530 .mode = 0644,
531 /* only handle a transition from default "0" to "1" */
532 .proc_handler = proc_dointvec_minmax,
533 .extra1 = &one,
534 .extra2 = &one,
536 #endif
537 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
539 .procname = "hotplug",
540 .data = &uevent_helper,
541 .maxlen = UEVENT_HELPER_PATH_LEN,
542 .mode = 0644,
543 .proc_handler = proc_dostring,
545 #endif
546 #ifdef CONFIG_CHR_DEV_SG
548 .procname = "sg-big-buff",
549 .data = &sg_big_buff,
550 .maxlen = sizeof (int),
551 .mode = 0444,
552 .proc_handler = proc_dointvec,
554 #endif
555 #ifdef CONFIG_BSD_PROCESS_ACCT
557 .procname = "acct",
558 .data = &acct_parm,
559 .maxlen = 3*sizeof(int),
560 .mode = 0644,
561 .proc_handler = proc_dointvec,
563 #endif
564 #ifdef CONFIG_MAGIC_SYSRQ
566 .procname = "sysrq",
567 .data = &__sysrq_enabled,
568 .maxlen = sizeof (int),
569 .mode = 0644,
570 .proc_handler = proc_dointvec,
572 #endif
573 #ifdef CONFIG_PROC_SYSCTL
575 .procname = "cad_pid",
576 .data = NULL,
577 .maxlen = sizeof (int),
578 .mode = 0600,
579 .proc_handler = proc_do_cad_pid,
581 #endif
583 .procname = "threads-max",
584 .data = &max_threads,
585 .maxlen = sizeof(int),
586 .mode = 0644,
587 .proc_handler = proc_dointvec,
590 .procname = "random",
591 .mode = 0555,
592 .child = random_table,
595 .procname = "overflowuid",
596 .data = &overflowuid,
597 .maxlen = sizeof(int),
598 .mode = 0644,
599 .proc_handler = proc_dointvec_minmax,
600 .extra1 = &minolduid,
601 .extra2 = &maxolduid,
604 .procname = "overflowgid",
605 .data = &overflowgid,
606 .maxlen = sizeof(int),
607 .mode = 0644,
608 .proc_handler = proc_dointvec_minmax,
609 .extra1 = &minolduid,
610 .extra2 = &maxolduid,
612 #ifdef CONFIG_S390
613 #ifdef CONFIG_MATHEMU
615 .procname = "ieee_emulation_warnings",
616 .data = &sysctl_ieee_emulation_warnings,
617 .maxlen = sizeof(int),
618 .mode = 0644,
619 .proc_handler = proc_dointvec,
621 #endif
623 .procname = "userprocess_debug",
624 .data = &sysctl_userprocess_debug,
625 .maxlen = sizeof(int),
626 .mode = 0644,
627 .proc_handler = proc_dointvec,
629 #endif
631 .procname = "pid_max",
632 .data = &pid_max,
633 .maxlen = sizeof (int),
634 .mode = 0644,
635 .proc_handler = proc_dointvec_minmax,
636 .extra1 = &pid_max_min,
637 .extra2 = &pid_max_max,
640 .procname = "panic_on_oops",
641 .data = &panic_on_oops,
642 .maxlen = sizeof(int),
643 .mode = 0644,
644 .proc_handler = proc_dointvec,
646 #if defined CONFIG_PRINTK
648 .procname = "printk",
649 .data = &console_loglevel,
650 .maxlen = 4*sizeof(int),
651 .mode = 0644,
652 .proc_handler = proc_dointvec,
655 .procname = "printk_ratelimit",
656 .data = &printk_ratelimit_state.interval,
657 .maxlen = sizeof(int),
658 .mode = 0644,
659 .proc_handler = proc_dointvec_jiffies,
662 .procname = "printk_ratelimit_burst",
663 .data = &printk_ratelimit_state.burst,
664 .maxlen = sizeof(int),
665 .mode = 0644,
666 .proc_handler = proc_dointvec,
669 .procname = "printk_delay",
670 .data = &printk_delay_msec,
671 .maxlen = sizeof(int),
672 .mode = 0644,
673 .proc_handler = proc_dointvec_minmax,
674 .extra1 = &zero,
675 .extra2 = &ten_thousand,
677 #endif
679 .procname = "ngroups_max",
680 .data = &ngroups_max,
681 .maxlen = sizeof (int),
682 .mode = 0444,
683 .proc_handler = proc_dointvec,
685 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
687 .procname = "unknown_nmi_panic",
688 .data = &unknown_nmi_panic,
689 .maxlen = sizeof (int),
690 .mode = 0644,
691 .proc_handler = proc_dointvec,
694 .procname = "nmi_watchdog",
695 .data = &nmi_watchdog_enabled,
696 .maxlen = sizeof (int),
697 .mode = 0644,
698 .proc_handler = proc_nmi_enabled,
700 #endif
701 #if defined(CONFIG_X86)
703 .procname = "panic_on_unrecovered_nmi",
704 .data = &panic_on_unrecovered_nmi,
705 .maxlen = sizeof(int),
706 .mode = 0644,
707 .proc_handler = proc_dointvec,
710 .procname = "panic_on_io_nmi",
711 .data = &panic_on_io_nmi,
712 .maxlen = sizeof(int),
713 .mode = 0644,
714 .proc_handler = proc_dointvec,
717 .procname = "bootloader_type",
718 .data = &bootloader_type,
719 .maxlen = sizeof (int),
720 .mode = 0444,
721 .proc_handler = proc_dointvec,
724 .procname = "bootloader_version",
725 .data = &bootloader_version,
726 .maxlen = sizeof (int),
727 .mode = 0444,
728 .proc_handler = proc_dointvec,
731 .procname = "kstack_depth_to_print",
732 .data = &kstack_depth_to_print,
733 .maxlen = sizeof(int),
734 .mode = 0644,
735 .proc_handler = proc_dointvec,
738 .procname = "io_delay_type",
739 .data = &io_delay_type,
740 .maxlen = sizeof(int),
741 .mode = 0644,
742 .proc_handler = proc_dointvec,
744 #endif
745 #if defined(CONFIG_MMU)
747 .procname = "randomize_va_space",
748 .data = &randomize_va_space,
749 .maxlen = sizeof(int),
750 .mode = 0644,
751 .proc_handler = proc_dointvec,
753 #endif
754 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
756 .procname = "spin_retry",
757 .data = &spin_retry,
758 .maxlen = sizeof (int),
759 .mode = 0644,
760 .proc_handler = proc_dointvec,
762 #endif
763 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
765 .procname = "acpi_video_flags",
766 .data = &acpi_realmode_flags,
767 .maxlen = sizeof (unsigned long),
768 .mode = 0644,
769 .proc_handler = proc_doulongvec_minmax,
771 #endif
772 #ifdef CONFIG_IA64
774 .procname = "ignore-unaligned-usertrap",
775 .data = &no_unaligned_warning,
776 .maxlen = sizeof (int),
777 .mode = 0644,
778 .proc_handler = proc_dointvec,
781 .procname = "unaligned-dump-stack",
782 .data = &unaligned_dump_stack,
783 .maxlen = sizeof (int),
784 .mode = 0644,
785 .proc_handler = proc_dointvec,
787 #endif
788 #ifdef CONFIG_DETECT_SOFTLOCKUP
790 .procname = "softlockup_panic",
791 .data = &softlockup_panic,
792 .maxlen = sizeof(int),
793 .mode = 0644,
794 .proc_handler = proc_dointvec_minmax,
795 .extra1 = &zero,
796 .extra2 = &one,
799 .procname = "softlockup_thresh",
800 .data = &softlockup_thresh,
801 .maxlen = sizeof(int),
802 .mode = 0644,
803 .proc_handler = proc_dosoftlockup_thresh,
804 .extra1 = &neg_one,
805 .extra2 = &sixty,
807 #endif
808 #ifdef CONFIG_DETECT_HUNG_TASK
810 .procname = "hung_task_panic",
811 .data = &sysctl_hung_task_panic,
812 .maxlen = sizeof(int),
813 .mode = 0644,
814 .proc_handler = proc_dointvec_minmax,
815 .extra1 = &zero,
816 .extra2 = &one,
819 .procname = "hung_task_check_count",
820 .data = &sysctl_hung_task_check_count,
821 .maxlen = sizeof(unsigned long),
822 .mode = 0644,
823 .proc_handler = proc_doulongvec_minmax,
826 .procname = "hung_task_timeout_secs",
827 .data = &sysctl_hung_task_timeout_secs,
828 .maxlen = sizeof(unsigned long),
829 .mode = 0644,
830 .proc_handler = proc_dohung_task_timeout_secs,
833 .procname = "hung_task_warnings",
834 .data = &sysctl_hung_task_warnings,
835 .maxlen = sizeof(unsigned long),
836 .mode = 0644,
837 .proc_handler = proc_doulongvec_minmax,
839 #endif
840 #ifdef CONFIG_COMPAT
842 .procname = "compat-log",
843 .data = &compat_log,
844 .maxlen = sizeof (int),
845 .mode = 0644,
846 .proc_handler = proc_dointvec,
848 #endif
849 #ifdef CONFIG_RT_MUTEXES
851 .procname = "max_lock_depth",
852 .data = &max_lock_depth,
853 .maxlen = sizeof(int),
854 .mode = 0644,
855 .proc_handler = proc_dointvec,
857 #endif
859 .procname = "poweroff_cmd",
860 .data = &poweroff_cmd,
861 .maxlen = POWEROFF_CMD_PATH_LEN,
862 .mode = 0644,
863 .proc_handler = proc_dostring,
865 #ifdef CONFIG_KEYS
867 .procname = "keys",
868 .mode = 0555,
869 .child = key_sysctls,
871 #endif
872 #ifdef CONFIG_RCU_TORTURE_TEST
874 .procname = "rcutorture_runnable",
875 .data = &rcutorture_runnable,
876 .maxlen = sizeof(int),
877 .mode = 0644,
878 .proc_handler = proc_dointvec,
880 #endif
881 #ifdef CONFIG_SLOW_WORK
883 .procname = "slow-work",
884 .mode = 0555,
885 .child = slow_work_sysctls,
887 #endif
888 #ifdef CONFIG_PERF_EVENTS
890 .procname = "perf_event_paranoid",
891 .data = &sysctl_perf_event_paranoid,
892 .maxlen = sizeof(sysctl_perf_event_paranoid),
893 .mode = 0644,
894 .proc_handler = proc_dointvec,
897 .procname = "perf_event_mlock_kb",
898 .data = &sysctl_perf_event_mlock,
899 .maxlen = sizeof(sysctl_perf_event_mlock),
900 .mode = 0644,
901 .proc_handler = proc_dointvec,
904 .procname = "perf_event_max_sample_rate",
905 .data = &sysctl_perf_event_sample_rate,
906 .maxlen = sizeof(sysctl_perf_event_sample_rate),
907 .mode = 0644,
908 .proc_handler = proc_dointvec,
910 #endif
911 #ifdef CONFIG_KMEMCHECK
913 .procname = "kmemcheck",
914 .data = &kmemcheck_enabled,
915 .maxlen = sizeof(int),
916 .mode = 0644,
917 .proc_handler = proc_dointvec,
919 #endif
920 #ifdef CONFIG_BLOCK
922 .procname = "blk_iopoll",
923 .data = &blk_iopoll_enabled,
924 .maxlen = sizeof(int),
925 .mode = 0644,
926 .proc_handler = proc_dointvec,
928 #endif
930 * NOTE: do not add new entries to this table unless you have read
931 * Documentation/sysctl/ctl_unnumbered.txt
936 static struct ctl_table vm_table[] = {
938 .procname = "overcommit_memory",
939 .data = &sysctl_overcommit_memory,
940 .maxlen = sizeof(sysctl_overcommit_memory),
941 .mode = 0644,
942 .proc_handler = proc_dointvec,
945 .procname = "panic_on_oom",
946 .data = &sysctl_panic_on_oom,
947 .maxlen = sizeof(sysctl_panic_on_oom),
948 .mode = 0644,
949 .proc_handler = proc_dointvec,
952 .procname = "oom_kill_allocating_task",
953 .data = &sysctl_oom_kill_allocating_task,
954 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
955 .mode = 0644,
956 .proc_handler = proc_dointvec,
959 .procname = "oom_dump_tasks",
960 .data = &sysctl_oom_dump_tasks,
961 .maxlen = sizeof(sysctl_oom_dump_tasks),
962 .mode = 0644,
963 .proc_handler = proc_dointvec,
966 .procname = "overcommit_ratio",
967 .data = &sysctl_overcommit_ratio,
968 .maxlen = sizeof(sysctl_overcommit_ratio),
969 .mode = 0644,
970 .proc_handler = proc_dointvec,
973 .procname = "page-cluster",
974 .data = &page_cluster,
975 .maxlen = sizeof(int),
976 .mode = 0644,
977 .proc_handler = proc_dointvec,
980 .procname = "dirty_background_ratio",
981 .data = &dirty_background_ratio,
982 .maxlen = sizeof(dirty_background_ratio),
983 .mode = 0644,
984 .proc_handler = dirty_background_ratio_handler,
985 .extra1 = &zero,
986 .extra2 = &one_hundred,
989 .procname = "dirty_background_bytes",
990 .data = &dirty_background_bytes,
991 .maxlen = sizeof(dirty_background_bytes),
992 .mode = 0644,
993 .proc_handler = dirty_background_bytes_handler,
994 .extra1 = &one_ul,
997 .procname = "dirty_ratio",
998 .data = &vm_dirty_ratio,
999 .maxlen = sizeof(vm_dirty_ratio),
1000 .mode = 0644,
1001 .proc_handler = dirty_ratio_handler,
1002 .extra1 = &zero,
1003 .extra2 = &one_hundred,
1006 .procname = "dirty_bytes",
1007 .data = &vm_dirty_bytes,
1008 .maxlen = sizeof(vm_dirty_bytes),
1009 .mode = 0644,
1010 .proc_handler = dirty_bytes_handler,
1011 .extra1 = &dirty_bytes_min,
1014 .procname = "dirty_writeback_centisecs",
1015 .data = &dirty_writeback_interval,
1016 .maxlen = sizeof(dirty_writeback_interval),
1017 .mode = 0644,
1018 .proc_handler = dirty_writeback_centisecs_handler,
1021 .procname = "dirty_expire_centisecs",
1022 .data = &dirty_expire_interval,
1023 .maxlen = sizeof(dirty_expire_interval),
1024 .mode = 0644,
1025 .proc_handler = proc_dointvec,
1028 .procname = "nr_pdflush_threads",
1029 .data = &nr_pdflush_threads,
1030 .maxlen = sizeof nr_pdflush_threads,
1031 .mode = 0444 /* read-only*/,
1032 .proc_handler = proc_dointvec,
1035 .procname = "swappiness",
1036 .data = &vm_swappiness,
1037 .maxlen = sizeof(vm_swappiness),
1038 .mode = 0644,
1039 .proc_handler = proc_dointvec_minmax,
1040 .extra1 = &zero,
1041 .extra2 = &one_hundred,
1043 #ifdef CONFIG_HUGETLB_PAGE
1045 .procname = "nr_hugepages",
1046 .data = NULL,
1047 .maxlen = sizeof(unsigned long),
1048 .mode = 0644,
1049 .proc_handler = hugetlb_sysctl_handler,
1050 .extra1 = (void *)&hugetlb_zero,
1051 .extra2 = (void *)&hugetlb_infinity,
1053 #ifdef CONFIG_NUMA
1055 .procname = "nr_hugepages_mempolicy",
1056 .data = NULL,
1057 .maxlen = sizeof(unsigned long),
1058 .mode = 0644,
1059 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1060 .extra1 = (void *)&hugetlb_zero,
1061 .extra2 = (void *)&hugetlb_infinity,
1063 #endif
1065 .procname = "hugetlb_shm_group",
1066 .data = &sysctl_hugetlb_shm_group,
1067 .maxlen = sizeof(gid_t),
1068 .mode = 0644,
1069 .proc_handler = proc_dointvec,
1072 .procname = "hugepages_treat_as_movable",
1073 .data = &hugepages_treat_as_movable,
1074 .maxlen = sizeof(int),
1075 .mode = 0644,
1076 .proc_handler = hugetlb_treat_movable_handler,
1079 .procname = "nr_overcommit_hugepages",
1080 .data = NULL,
1081 .maxlen = sizeof(unsigned long),
1082 .mode = 0644,
1083 .proc_handler = hugetlb_overcommit_handler,
1084 .extra1 = (void *)&hugetlb_zero,
1085 .extra2 = (void *)&hugetlb_infinity,
1087 #endif
1089 .procname = "lowmem_reserve_ratio",
1090 .data = &sysctl_lowmem_reserve_ratio,
1091 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1092 .mode = 0644,
1093 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1096 .procname = "drop_caches",
1097 .data = &sysctl_drop_caches,
1098 .maxlen = sizeof(int),
1099 .mode = 0644,
1100 .proc_handler = drop_caches_sysctl_handler,
1103 .procname = "min_free_kbytes",
1104 .data = &min_free_kbytes,
1105 .maxlen = sizeof(min_free_kbytes),
1106 .mode = 0644,
1107 .proc_handler = min_free_kbytes_sysctl_handler,
1108 .extra1 = &zero,
1111 .procname = "percpu_pagelist_fraction",
1112 .data = &percpu_pagelist_fraction,
1113 .maxlen = sizeof(percpu_pagelist_fraction),
1114 .mode = 0644,
1115 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1116 .extra1 = &min_percpu_pagelist_fract,
1118 #ifdef CONFIG_MMU
1120 .procname = "max_map_count",
1121 .data = &sysctl_max_map_count,
1122 .maxlen = sizeof(sysctl_max_map_count),
1123 .mode = 0644,
1124 .proc_handler = proc_dointvec_minmax,
1125 .extra1 = &zero,
1127 #else
1129 .procname = "nr_trim_pages",
1130 .data = &sysctl_nr_trim_pages,
1131 .maxlen = sizeof(sysctl_nr_trim_pages),
1132 .mode = 0644,
1133 .proc_handler = proc_dointvec_minmax,
1134 .extra1 = &zero,
1136 #endif
1138 .procname = "laptop_mode",
1139 .data = &laptop_mode,
1140 .maxlen = sizeof(laptop_mode),
1141 .mode = 0644,
1142 .proc_handler = proc_dointvec_jiffies,
1145 .procname = "block_dump",
1146 .data = &block_dump,
1147 .maxlen = sizeof(block_dump),
1148 .mode = 0644,
1149 .proc_handler = proc_dointvec,
1150 .extra1 = &zero,
1153 .procname = "vfs_cache_pressure",
1154 .data = &sysctl_vfs_cache_pressure,
1155 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1156 .mode = 0644,
1157 .proc_handler = proc_dointvec,
1158 .extra1 = &zero,
1160 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1162 .procname = "legacy_va_layout",
1163 .data = &sysctl_legacy_va_layout,
1164 .maxlen = sizeof(sysctl_legacy_va_layout),
1165 .mode = 0644,
1166 .proc_handler = proc_dointvec,
1167 .extra1 = &zero,
1169 #endif
1170 #ifdef CONFIG_NUMA
1172 .procname = "zone_reclaim_mode",
1173 .data = &zone_reclaim_mode,
1174 .maxlen = sizeof(zone_reclaim_mode),
1175 .mode = 0644,
1176 .proc_handler = proc_dointvec,
1177 .extra1 = &zero,
1180 .procname = "min_unmapped_ratio",
1181 .data = &sysctl_min_unmapped_ratio,
1182 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1183 .mode = 0644,
1184 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1185 .extra1 = &zero,
1186 .extra2 = &one_hundred,
1189 .procname = "min_slab_ratio",
1190 .data = &sysctl_min_slab_ratio,
1191 .maxlen = sizeof(sysctl_min_slab_ratio),
1192 .mode = 0644,
1193 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1194 .extra1 = &zero,
1195 .extra2 = &one_hundred,
1197 #endif
1198 #ifdef CONFIG_SMP
1200 .procname = "stat_interval",
1201 .data = &sysctl_stat_interval,
1202 .maxlen = sizeof(sysctl_stat_interval),
1203 .mode = 0644,
1204 .proc_handler = proc_dointvec_jiffies,
1206 #endif
1207 #ifdef CONFIG_MMU
1209 .procname = "mmap_min_addr",
1210 .data = &dac_mmap_min_addr,
1211 .maxlen = sizeof(unsigned long),
1212 .mode = 0644,
1213 .proc_handler = mmap_min_addr_handler,
1215 #endif
1216 #ifdef CONFIG_NUMA
1218 .procname = "numa_zonelist_order",
1219 .data = &numa_zonelist_order,
1220 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1221 .mode = 0644,
1222 .proc_handler = numa_zonelist_order_handler,
1224 #endif
1225 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1226 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1228 .procname = "vdso_enabled",
1229 .data = &vdso_enabled,
1230 .maxlen = sizeof(vdso_enabled),
1231 .mode = 0644,
1232 .proc_handler = proc_dointvec,
1233 .extra1 = &zero,
1235 #endif
1236 #ifdef CONFIG_HIGHMEM
1238 .procname = "highmem_is_dirtyable",
1239 .data = &vm_highmem_is_dirtyable,
1240 .maxlen = sizeof(vm_highmem_is_dirtyable),
1241 .mode = 0644,
1242 .proc_handler = proc_dointvec_minmax,
1243 .extra1 = &zero,
1244 .extra2 = &one,
1246 #endif
1248 .procname = "scan_unevictable_pages",
1249 .data = &scan_unevictable_pages,
1250 .maxlen = sizeof(scan_unevictable_pages),
1251 .mode = 0644,
1252 .proc_handler = scan_unevictable_handler,
1254 #ifdef CONFIG_MEMORY_FAILURE
1256 .procname = "memory_failure_early_kill",
1257 .data = &sysctl_memory_failure_early_kill,
1258 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1259 .mode = 0644,
1260 .proc_handler = proc_dointvec_minmax,
1261 .extra1 = &zero,
1262 .extra2 = &one,
1265 .procname = "memory_failure_recovery",
1266 .data = &sysctl_memory_failure_recovery,
1267 .maxlen = sizeof(sysctl_memory_failure_recovery),
1268 .mode = 0644,
1269 .proc_handler = proc_dointvec_minmax,
1270 .extra1 = &zero,
1271 .extra2 = &one,
1273 #endif
1276 * NOTE: do not add new entries to this table unless you have read
1277 * Documentation/sysctl/ctl_unnumbered.txt
1282 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1283 static struct ctl_table binfmt_misc_table[] = {
1286 #endif
1288 static struct ctl_table fs_table[] = {
1290 .procname = "inode-nr",
1291 .data = &inodes_stat,
1292 .maxlen = 2*sizeof(int),
1293 .mode = 0444,
1294 .proc_handler = proc_dointvec,
1297 .procname = "inode-state",
1298 .data = &inodes_stat,
1299 .maxlen = 7*sizeof(int),
1300 .mode = 0444,
1301 .proc_handler = proc_dointvec,
1304 .procname = "file-nr",
1305 .data = &files_stat,
1306 .maxlen = 3*sizeof(int),
1307 .mode = 0444,
1308 .proc_handler = proc_nr_files,
1311 .procname = "file-max",
1312 .data = &files_stat.max_files,
1313 .maxlen = sizeof(int),
1314 .mode = 0644,
1315 .proc_handler = proc_dointvec,
1318 .procname = "nr_open",
1319 .data = &sysctl_nr_open,
1320 .maxlen = sizeof(int),
1321 .mode = 0644,
1322 .proc_handler = proc_dointvec_minmax,
1323 .extra1 = &sysctl_nr_open_min,
1324 .extra2 = &sysctl_nr_open_max,
1327 .procname = "dentry-state",
1328 .data = &dentry_stat,
1329 .maxlen = 6*sizeof(int),
1330 .mode = 0444,
1331 .proc_handler = proc_dointvec,
1334 .procname = "overflowuid",
1335 .data = &fs_overflowuid,
1336 .maxlen = sizeof(int),
1337 .mode = 0644,
1338 .proc_handler = proc_dointvec_minmax,
1339 .extra1 = &minolduid,
1340 .extra2 = &maxolduid,
1343 .procname = "overflowgid",
1344 .data = &fs_overflowgid,
1345 .maxlen = sizeof(int),
1346 .mode = 0644,
1347 .proc_handler = proc_dointvec_minmax,
1348 .extra1 = &minolduid,
1349 .extra2 = &maxolduid,
1351 #ifdef CONFIG_FILE_LOCKING
1353 .procname = "leases-enable",
1354 .data = &leases_enable,
1355 .maxlen = sizeof(int),
1356 .mode = 0644,
1357 .proc_handler = proc_dointvec,
1359 #endif
1360 #ifdef CONFIG_DNOTIFY
1362 .procname = "dir-notify-enable",
1363 .data = &dir_notify_enable,
1364 .maxlen = sizeof(int),
1365 .mode = 0644,
1366 .proc_handler = proc_dointvec,
1368 #endif
1369 #ifdef CONFIG_MMU
1370 #ifdef CONFIG_FILE_LOCKING
1372 .procname = "lease-break-time",
1373 .data = &lease_break_time,
1374 .maxlen = sizeof(int),
1375 .mode = 0644,
1376 .proc_handler = proc_dointvec,
1378 #endif
1379 #ifdef CONFIG_AIO
1381 .procname = "aio-nr",
1382 .data = &aio_nr,
1383 .maxlen = sizeof(aio_nr),
1384 .mode = 0444,
1385 .proc_handler = proc_doulongvec_minmax,
1388 .procname = "aio-max-nr",
1389 .data = &aio_max_nr,
1390 .maxlen = sizeof(aio_max_nr),
1391 .mode = 0644,
1392 .proc_handler = proc_doulongvec_minmax,
1394 #endif /* CONFIG_AIO */
1395 #ifdef CONFIG_INOTIFY_USER
1397 .procname = "inotify",
1398 .mode = 0555,
1399 .child = inotify_table,
1401 #endif
1402 #ifdef CONFIG_EPOLL
1404 .procname = "epoll",
1405 .mode = 0555,
1406 .child = epoll_table,
1408 #endif
1409 #endif
1411 .procname = "suid_dumpable",
1412 .data = &suid_dumpable,
1413 .maxlen = sizeof(int),
1414 .mode = 0644,
1415 .proc_handler = proc_dointvec_minmax,
1416 .extra1 = &zero,
1417 .extra2 = &two,
1419 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1421 .procname = "binfmt_misc",
1422 .mode = 0555,
1423 .child = binfmt_misc_table,
1425 #endif
1427 * NOTE: do not add new entries to this table unless you have read
1428 * Documentation/sysctl/ctl_unnumbered.txt
1433 static struct ctl_table debug_table[] = {
1434 #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC)
1436 .procname = "exception-trace",
1437 .data = &show_unhandled_signals,
1438 .maxlen = sizeof(int),
1439 .mode = 0644,
1440 .proc_handler = proc_dointvec
1442 #endif
1443 #if defined(CONFIG_OPTPROBES)
1445 .procname = "kprobes-optimization",
1446 .data = &sysctl_kprobes_optimization,
1447 .maxlen = sizeof(int),
1448 .mode = 0644,
1449 .proc_handler = proc_kprobes_optimization_handler,
1450 .extra1 = &zero,
1451 .extra2 = &one,
1453 #endif
1457 static struct ctl_table dev_table[] = {
1461 static DEFINE_SPINLOCK(sysctl_lock);
1463 /* called under sysctl_lock */
1464 static int use_table(struct ctl_table_header *p)
1466 if (unlikely(p->unregistering))
1467 return 0;
1468 p->used++;
1469 return 1;
1472 /* called under sysctl_lock */
1473 static void unuse_table(struct ctl_table_header *p)
1475 if (!--p->used)
1476 if (unlikely(p->unregistering))
1477 complete(p->unregistering);
1480 /* called under sysctl_lock, will reacquire if has to wait */
1481 static void start_unregistering(struct ctl_table_header *p)
1484 * if p->used is 0, nobody will ever touch that entry again;
1485 * we'll eliminate all paths to it before dropping sysctl_lock
1487 if (unlikely(p->used)) {
1488 struct completion wait;
1489 init_completion(&wait);
1490 p->unregistering = &wait;
1491 spin_unlock(&sysctl_lock);
1492 wait_for_completion(&wait);
1493 spin_lock(&sysctl_lock);
1494 } else {
1495 /* anything non-NULL; we'll never dereference it */
1496 p->unregistering = ERR_PTR(-EINVAL);
1499 * do not remove from the list until nobody holds it; walking the
1500 * list in do_sysctl() relies on that.
1502 list_del_init(&p->ctl_entry);
1505 void sysctl_head_get(struct ctl_table_header *head)
1507 spin_lock(&sysctl_lock);
1508 head->count++;
1509 spin_unlock(&sysctl_lock);
1512 void sysctl_head_put(struct ctl_table_header *head)
1514 spin_lock(&sysctl_lock);
1515 if (!--head->count)
1516 kfree(head);
1517 spin_unlock(&sysctl_lock);
1520 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1522 if (!head)
1523 BUG();
1524 spin_lock(&sysctl_lock);
1525 if (!use_table(head))
1526 head = ERR_PTR(-ENOENT);
1527 spin_unlock(&sysctl_lock);
1528 return head;
1531 void sysctl_head_finish(struct ctl_table_header *head)
1533 if (!head)
1534 return;
1535 spin_lock(&sysctl_lock);
1536 unuse_table(head);
1537 spin_unlock(&sysctl_lock);
1540 static struct ctl_table_set *
1541 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1543 struct ctl_table_set *set = &root->default_set;
1544 if (root->lookup)
1545 set = root->lookup(root, namespaces);
1546 return set;
1549 static struct list_head *
1550 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1552 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1553 return &set->list;
1556 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1557 struct ctl_table_header *prev)
1559 struct ctl_table_root *root;
1560 struct list_head *header_list;
1561 struct ctl_table_header *head;
1562 struct list_head *tmp;
1564 spin_lock(&sysctl_lock);
1565 if (prev) {
1566 head = prev;
1567 tmp = &prev->ctl_entry;
1568 unuse_table(prev);
1569 goto next;
1571 tmp = &root_table_header.ctl_entry;
1572 for (;;) {
1573 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1575 if (!use_table(head))
1576 goto next;
1577 spin_unlock(&sysctl_lock);
1578 return head;
1579 next:
1580 root = head->root;
1581 tmp = tmp->next;
1582 header_list = lookup_header_list(root, namespaces);
1583 if (tmp != header_list)
1584 continue;
1586 do {
1587 root = list_entry(root->root_list.next,
1588 struct ctl_table_root, root_list);
1589 if (root == &sysctl_table_root)
1590 goto out;
1591 header_list = lookup_header_list(root, namespaces);
1592 } while (list_empty(header_list));
1593 tmp = header_list->next;
1595 out:
1596 spin_unlock(&sysctl_lock);
1597 return NULL;
1600 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1602 return __sysctl_head_next(current->nsproxy, prev);
1605 void register_sysctl_root(struct ctl_table_root *root)
1607 spin_lock(&sysctl_lock);
1608 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1609 spin_unlock(&sysctl_lock);
1613 * sysctl_perm does NOT grant the superuser all rights automatically, because
1614 * some sysctl variables are readonly even to root.
1617 static int test_perm(int mode, int op)
1619 if (!current_euid())
1620 mode >>= 6;
1621 else if (in_egroup_p(0))
1622 mode >>= 3;
1623 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1624 return 0;
1625 return -EACCES;
1628 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1630 int error;
1631 int mode;
1633 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1634 if (error)
1635 return error;
1637 if (root->permissions)
1638 mode = root->permissions(root, current->nsproxy, table);
1639 else
1640 mode = table->mode;
1642 return test_perm(mode, op);
1645 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1647 for (; table->procname; table++) {
1648 table->parent = parent;
1649 if (table->child)
1650 sysctl_set_parent(table, table->child);
1654 static __init int sysctl_init(void)
1656 sysctl_set_parent(NULL, root_table);
1657 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1659 int err;
1660 err = sysctl_check_table(current->nsproxy, root_table);
1662 #endif
1663 return 0;
1666 core_initcall(sysctl_init);
1668 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1669 struct ctl_table *table)
1671 struct ctl_table *p;
1672 const char *s = branch->procname;
1674 /* branch should have named subdirectory as its first element */
1675 if (!s || !branch->child)
1676 return NULL;
1678 /* ... and nothing else */
1679 if (branch[1].procname)
1680 return NULL;
1682 /* table should contain subdirectory with the same name */
1683 for (p = table; p->procname; p++) {
1684 if (!p->child)
1685 continue;
1686 if (p->procname && strcmp(p->procname, s) == 0)
1687 return p;
1689 return NULL;
1692 /* see if attaching q to p would be an improvement */
1693 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1695 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1696 struct ctl_table *next;
1697 int is_better = 0;
1698 int not_in_parent = !p->attached_by;
1700 while ((next = is_branch_in(by, to)) != NULL) {
1701 if (by == q->attached_by)
1702 is_better = 1;
1703 if (to == p->attached_by)
1704 not_in_parent = 1;
1705 by = by->child;
1706 to = next->child;
1709 if (is_better && not_in_parent) {
1710 q->attached_by = by;
1711 q->attached_to = to;
1712 q->parent = p;
1717 * __register_sysctl_paths - register a sysctl hierarchy
1718 * @root: List of sysctl headers to register on
1719 * @namespaces: Data to compute which lists of sysctl entries are visible
1720 * @path: The path to the directory the sysctl table is in.
1721 * @table: the top-level table structure
1723 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1724 * array. A completely 0 filled entry terminates the table.
1726 * The members of the &struct ctl_table structure are used as follows:
1728 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1729 * enter a sysctl file
1731 * data - a pointer to data for use by proc_handler
1733 * maxlen - the maximum size in bytes of the data
1735 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1737 * child - a pointer to the child sysctl table if this entry is a directory, or
1738 * %NULL.
1740 * proc_handler - the text handler routine (described below)
1742 * de - for internal use by the sysctl routines
1744 * extra1, extra2 - extra pointers usable by the proc handler routines
1746 * Leaf nodes in the sysctl tree will be represented by a single file
1747 * under /proc; non-leaf nodes will be represented by directories.
1749 * sysctl(2) can automatically manage read and write requests through
1750 * the sysctl table. The data and maxlen fields of the ctl_table
1751 * struct enable minimal validation of the values being written to be
1752 * performed, and the mode field allows minimal authentication.
1754 * There must be a proc_handler routine for any terminal nodes
1755 * mirrored under /proc/sys (non-terminals are handled by a built-in
1756 * directory handler). Several default handlers are available to
1757 * cover common cases -
1759 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1760 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1761 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1763 * It is the handler's job to read the input buffer from user memory
1764 * and process it. The handler should return 0 on success.
1766 * This routine returns %NULL on a failure to register, and a pointer
1767 * to the table header on success.
1769 struct ctl_table_header *__register_sysctl_paths(
1770 struct ctl_table_root *root,
1771 struct nsproxy *namespaces,
1772 const struct ctl_path *path, struct ctl_table *table)
1774 struct ctl_table_header *header;
1775 struct ctl_table *new, **prevp;
1776 unsigned int n, npath;
1777 struct ctl_table_set *set;
1779 /* Count the path components */
1780 for (npath = 0; path[npath].procname; ++npath)
1784 * For each path component, allocate a 2-element ctl_table array.
1785 * The first array element will be filled with the sysctl entry
1786 * for this, the second will be the sentinel (procname == 0).
1788 * We allocate everything in one go so that we don't have to
1789 * worry about freeing additional memory in unregister_sysctl_table.
1791 header = kzalloc(sizeof(struct ctl_table_header) +
1792 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1793 if (!header)
1794 return NULL;
1796 new = (struct ctl_table *) (header + 1);
1798 /* Now connect the dots */
1799 prevp = &header->ctl_table;
1800 for (n = 0; n < npath; ++n, ++path) {
1801 /* Copy the procname */
1802 new->procname = path->procname;
1803 new->mode = 0555;
1805 *prevp = new;
1806 prevp = &new->child;
1808 new += 2;
1810 *prevp = table;
1811 header->ctl_table_arg = table;
1813 INIT_LIST_HEAD(&header->ctl_entry);
1814 header->used = 0;
1815 header->unregistering = NULL;
1816 header->root = root;
1817 sysctl_set_parent(NULL, header->ctl_table);
1818 header->count = 1;
1819 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1820 if (sysctl_check_table(namespaces, header->ctl_table)) {
1821 kfree(header);
1822 return NULL;
1824 #endif
1825 spin_lock(&sysctl_lock);
1826 header->set = lookup_header_set(root, namespaces);
1827 header->attached_by = header->ctl_table;
1828 header->attached_to = root_table;
1829 header->parent = &root_table_header;
1830 for (set = header->set; set; set = set->parent) {
1831 struct ctl_table_header *p;
1832 list_for_each_entry(p, &set->list, ctl_entry) {
1833 if (p->unregistering)
1834 continue;
1835 try_attach(p, header);
1838 header->parent->count++;
1839 list_add_tail(&header->ctl_entry, &header->set->list);
1840 spin_unlock(&sysctl_lock);
1842 return header;
1846 * register_sysctl_table_path - register a sysctl table hierarchy
1847 * @path: The path to the directory the sysctl table is in.
1848 * @table: the top-level table structure
1850 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1851 * array. A completely 0 filled entry terminates the table.
1853 * See __register_sysctl_paths for more details.
1855 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1856 struct ctl_table *table)
1858 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1859 path, table);
1863 * register_sysctl_table - register a sysctl table hierarchy
1864 * @table: the top-level table structure
1866 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1867 * array. A completely 0 filled entry terminates the table.
1869 * See register_sysctl_paths for more details.
1871 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1873 static const struct ctl_path null_path[] = { {} };
1875 return register_sysctl_paths(null_path, table);
1879 * unregister_sysctl_table - unregister a sysctl table hierarchy
1880 * @header: the header returned from register_sysctl_table
1882 * Unregisters the sysctl table and all children. proc entries may not
1883 * actually be removed until they are no longer used by anyone.
1885 void unregister_sysctl_table(struct ctl_table_header * header)
1887 might_sleep();
1889 if (header == NULL)
1890 return;
1892 spin_lock(&sysctl_lock);
1893 start_unregistering(header);
1894 if (!--header->parent->count) {
1895 WARN_ON(1);
1896 kfree(header->parent);
1898 if (!--header->count)
1899 kfree(header);
1900 spin_unlock(&sysctl_lock);
1903 int sysctl_is_seen(struct ctl_table_header *p)
1905 struct ctl_table_set *set = p->set;
1906 int res;
1907 spin_lock(&sysctl_lock);
1908 if (p->unregistering)
1909 res = 0;
1910 else if (!set->is_seen)
1911 res = 1;
1912 else
1913 res = set->is_seen(set);
1914 spin_unlock(&sysctl_lock);
1915 return res;
1918 void setup_sysctl_set(struct ctl_table_set *p,
1919 struct ctl_table_set *parent,
1920 int (*is_seen)(struct ctl_table_set *))
1922 INIT_LIST_HEAD(&p->list);
1923 p->parent = parent ? parent : &sysctl_table_root.default_set;
1924 p->is_seen = is_seen;
1927 #else /* !CONFIG_SYSCTL */
1928 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1930 return NULL;
1933 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1934 struct ctl_table *table)
1936 return NULL;
1939 void unregister_sysctl_table(struct ctl_table_header * table)
1943 void setup_sysctl_set(struct ctl_table_set *p,
1944 struct ctl_table_set *parent,
1945 int (*is_seen)(struct ctl_table_set *))
1949 void sysctl_head_put(struct ctl_table_header *head)
1953 #endif /* CONFIG_SYSCTL */
1956 * /proc/sys support
1959 #ifdef CONFIG_PROC_SYSCTL
1961 static int _proc_do_string(void* data, int maxlen, int write,
1962 void __user *buffer,
1963 size_t *lenp, loff_t *ppos)
1965 size_t len;
1966 char __user *p;
1967 char c;
1969 if (!data || !maxlen || !*lenp) {
1970 *lenp = 0;
1971 return 0;
1974 if (write) {
1975 len = 0;
1976 p = buffer;
1977 while (len < *lenp) {
1978 if (get_user(c, p++))
1979 return -EFAULT;
1980 if (c == 0 || c == '\n')
1981 break;
1982 len++;
1984 if (len >= maxlen)
1985 len = maxlen-1;
1986 if(copy_from_user(data, buffer, len))
1987 return -EFAULT;
1988 ((char *) data)[len] = 0;
1989 *ppos += *lenp;
1990 } else {
1991 len = strlen(data);
1992 if (len > maxlen)
1993 len = maxlen;
1995 if (*ppos > len) {
1996 *lenp = 0;
1997 return 0;
2000 data += *ppos;
2001 len -= *ppos;
2003 if (len > *lenp)
2004 len = *lenp;
2005 if (len)
2006 if(copy_to_user(buffer, data, len))
2007 return -EFAULT;
2008 if (len < *lenp) {
2009 if(put_user('\n', ((char __user *) buffer) + len))
2010 return -EFAULT;
2011 len++;
2013 *lenp = len;
2014 *ppos += len;
2016 return 0;
2020 * proc_dostring - read a string sysctl
2021 * @table: the sysctl table
2022 * @write: %TRUE if this is a write to the sysctl file
2023 * @buffer: the user buffer
2024 * @lenp: the size of the user buffer
2025 * @ppos: file position
2027 * Reads/writes a string from/to the user buffer. If the kernel
2028 * buffer provided is not large enough to hold the string, the
2029 * string is truncated. The copied string is %NULL-terminated.
2030 * If the string is being read by the user process, it is copied
2031 * and a newline '\n' is added. It is truncated if the buffer is
2032 * not large enough.
2034 * Returns 0 on success.
2036 int proc_dostring(struct ctl_table *table, int write,
2037 void __user *buffer, size_t *lenp, loff_t *ppos)
2039 return _proc_do_string(table->data, table->maxlen, write,
2040 buffer, lenp, ppos);
2044 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2045 int *valp,
2046 int write, void *data)
2048 if (write) {
2049 *valp = *negp ? -*lvalp : *lvalp;
2050 } else {
2051 int val = *valp;
2052 if (val < 0) {
2053 *negp = -1;
2054 *lvalp = (unsigned long)-val;
2055 } else {
2056 *negp = 0;
2057 *lvalp = (unsigned long)val;
2060 return 0;
2063 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2064 int write, void __user *buffer,
2065 size_t *lenp, loff_t *ppos,
2066 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2067 int write, void *data),
2068 void *data)
2070 #define TMPBUFLEN 21
2071 int *i, vleft, first = 1, neg;
2072 unsigned long lval;
2073 size_t left, len;
2075 char buf[TMPBUFLEN], *p;
2076 char __user *s = buffer;
2078 if (!tbl_data || !table->maxlen || !*lenp ||
2079 (*ppos && !write)) {
2080 *lenp = 0;
2081 return 0;
2084 i = (int *) tbl_data;
2085 vleft = table->maxlen / sizeof(*i);
2086 left = *lenp;
2088 if (!conv)
2089 conv = do_proc_dointvec_conv;
2091 for (; left && vleft--; i++, first=0) {
2092 if (write) {
2093 while (left) {
2094 char c;
2095 if (get_user(c, s))
2096 return -EFAULT;
2097 if (!isspace(c))
2098 break;
2099 left--;
2100 s++;
2102 if (!left)
2103 break;
2104 neg = 0;
2105 len = left;
2106 if (len > sizeof(buf) - 1)
2107 len = sizeof(buf) - 1;
2108 if (copy_from_user(buf, s, len))
2109 return -EFAULT;
2110 buf[len] = 0;
2111 p = buf;
2112 if (*p == '-' && left > 1) {
2113 neg = 1;
2114 p++;
2116 if (*p < '0' || *p > '9')
2117 break;
2119 lval = simple_strtoul(p, &p, 0);
2121 len = p-buf;
2122 if ((len < left) && *p && !isspace(*p))
2123 break;
2124 s += len;
2125 left -= len;
2127 if (conv(&neg, &lval, i, 1, data))
2128 break;
2129 } else {
2130 p = buf;
2131 if (!first)
2132 *p++ = '\t';
2134 if (conv(&neg, &lval, i, 0, data))
2135 break;
2137 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2138 len = strlen(buf);
2139 if (len > left)
2140 len = left;
2141 if(copy_to_user(s, buf, len))
2142 return -EFAULT;
2143 left -= len;
2144 s += len;
2148 if (!write && !first && left) {
2149 if(put_user('\n', s))
2150 return -EFAULT;
2151 left--, s++;
2153 if (write) {
2154 while (left) {
2155 char c;
2156 if (get_user(c, s++))
2157 return -EFAULT;
2158 if (!isspace(c))
2159 break;
2160 left--;
2163 if (write && first)
2164 return -EINVAL;
2165 *lenp -= left;
2166 *ppos += *lenp;
2167 return 0;
2168 #undef TMPBUFLEN
2171 static int do_proc_dointvec(struct ctl_table *table, int write,
2172 void __user *buffer, size_t *lenp, loff_t *ppos,
2173 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2174 int write, void *data),
2175 void *data)
2177 return __do_proc_dointvec(table->data, table, write,
2178 buffer, lenp, ppos, conv, data);
2182 * proc_dointvec - read a vector of integers
2183 * @table: the sysctl table
2184 * @write: %TRUE if this is a write to the sysctl file
2185 * @buffer: the user buffer
2186 * @lenp: the size of the user buffer
2187 * @ppos: file position
2189 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2190 * values from/to the user buffer, treated as an ASCII string.
2192 * Returns 0 on success.
2194 int proc_dointvec(struct ctl_table *table, int write,
2195 void __user *buffer, size_t *lenp, loff_t *ppos)
2197 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2198 NULL,NULL);
2202 * Taint values can only be increased
2203 * This means we can safely use a temporary.
2205 static int proc_taint(struct ctl_table *table, int write,
2206 void __user *buffer, size_t *lenp, loff_t *ppos)
2208 struct ctl_table t;
2209 unsigned long tmptaint = get_taint();
2210 int err;
2212 if (write && !capable(CAP_SYS_ADMIN))
2213 return -EPERM;
2215 t = *table;
2216 t.data = &tmptaint;
2217 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2218 if (err < 0)
2219 return err;
2221 if (write) {
2223 * Poor man's atomic or. Not worth adding a primitive
2224 * to everyone's atomic.h for this
2226 int i;
2227 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2228 if ((tmptaint >> i) & 1)
2229 add_taint(i);
2233 return err;
2236 struct do_proc_dointvec_minmax_conv_param {
2237 int *min;
2238 int *max;
2241 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2242 int *valp,
2243 int write, void *data)
2245 struct do_proc_dointvec_minmax_conv_param *param = data;
2246 if (write) {
2247 int val = *negp ? -*lvalp : *lvalp;
2248 if ((param->min && *param->min > val) ||
2249 (param->max && *param->max < val))
2250 return -EINVAL;
2251 *valp = val;
2252 } else {
2253 int val = *valp;
2254 if (val < 0) {
2255 *negp = -1;
2256 *lvalp = (unsigned long)-val;
2257 } else {
2258 *negp = 0;
2259 *lvalp = (unsigned long)val;
2262 return 0;
2266 * proc_dointvec_minmax - read a vector of integers with min/max values
2267 * @table: the sysctl table
2268 * @write: %TRUE if this is a write to the sysctl file
2269 * @buffer: the user buffer
2270 * @lenp: the size of the user buffer
2271 * @ppos: file position
2273 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2274 * values from/to the user buffer, treated as an ASCII string.
2276 * This routine will ensure the values are within the range specified by
2277 * table->extra1 (min) and table->extra2 (max).
2279 * Returns 0 on success.
2281 int proc_dointvec_minmax(struct ctl_table *table, int write,
2282 void __user *buffer, size_t *lenp, loff_t *ppos)
2284 struct do_proc_dointvec_minmax_conv_param param = {
2285 .min = (int *) table->extra1,
2286 .max = (int *) table->extra2,
2288 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2289 do_proc_dointvec_minmax_conv, &param);
2292 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2293 void __user *buffer,
2294 size_t *lenp, loff_t *ppos,
2295 unsigned long convmul,
2296 unsigned long convdiv)
2298 #define TMPBUFLEN 21
2299 unsigned long *i, *min, *max, val;
2300 int vleft, first=1, neg;
2301 size_t len, left;
2302 char buf[TMPBUFLEN], *p;
2303 char __user *s = buffer;
2305 if (!data || !table->maxlen || !*lenp ||
2306 (*ppos && !write)) {
2307 *lenp = 0;
2308 return 0;
2311 i = (unsigned long *) data;
2312 min = (unsigned long *) table->extra1;
2313 max = (unsigned long *) table->extra2;
2314 vleft = table->maxlen / sizeof(unsigned long);
2315 left = *lenp;
2317 for (; left && vleft--; i++, first = 0) {
2318 if (write) {
2319 while (left) {
2320 char c;
2321 if (get_user(c, s))
2322 return -EFAULT;
2323 if (!isspace(c))
2324 break;
2325 left--;
2326 s++;
2328 if (!left)
2329 break;
2330 neg = 0;
2331 len = left;
2332 if (len > TMPBUFLEN-1)
2333 len = TMPBUFLEN-1;
2334 if (copy_from_user(buf, s, len))
2335 return -EFAULT;
2336 buf[len] = 0;
2337 p = buf;
2338 if (*p == '-' && left > 1) {
2339 neg = 1;
2340 p++;
2342 if (*p < '0' || *p > '9')
2343 break;
2344 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2345 len = p-buf;
2346 if ((len < left) && *p && !isspace(*p))
2347 break;
2348 if (neg)
2349 val = -val;
2350 s += len;
2351 left -= len;
2353 if(neg)
2354 continue;
2355 if ((min && val < *min) || (max && val > *max))
2356 continue;
2357 *i = val;
2358 } else {
2359 p = buf;
2360 if (!first)
2361 *p++ = '\t';
2362 sprintf(p, "%lu", convdiv * (*i) / convmul);
2363 len = strlen(buf);
2364 if (len > left)
2365 len = left;
2366 if(copy_to_user(s, buf, len))
2367 return -EFAULT;
2368 left -= len;
2369 s += len;
2373 if (!write && !first && left) {
2374 if(put_user('\n', s))
2375 return -EFAULT;
2376 left--, s++;
2378 if (write) {
2379 while (left) {
2380 char c;
2381 if (get_user(c, s++))
2382 return -EFAULT;
2383 if (!isspace(c))
2384 break;
2385 left--;
2388 if (write && first)
2389 return -EINVAL;
2390 *lenp -= left;
2391 *ppos += *lenp;
2392 return 0;
2393 #undef TMPBUFLEN
2396 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2397 void __user *buffer,
2398 size_t *lenp, loff_t *ppos,
2399 unsigned long convmul,
2400 unsigned long convdiv)
2402 return __do_proc_doulongvec_minmax(table->data, table, write,
2403 buffer, lenp, ppos, convmul, convdiv);
2407 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2408 * @table: the sysctl table
2409 * @write: %TRUE if this is a write to the sysctl file
2410 * @buffer: the user buffer
2411 * @lenp: the size of the user buffer
2412 * @ppos: file position
2414 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2415 * values from/to the user buffer, treated as an ASCII string.
2417 * This routine will ensure the values are within the range specified by
2418 * table->extra1 (min) and table->extra2 (max).
2420 * Returns 0 on success.
2422 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2423 void __user *buffer, size_t *lenp, loff_t *ppos)
2425 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2429 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2430 * @table: the sysctl table
2431 * @write: %TRUE if this is a write to the sysctl file
2432 * @buffer: the user buffer
2433 * @lenp: the size of the user buffer
2434 * @ppos: file position
2436 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2437 * values from/to the user buffer, treated as an ASCII string. The values
2438 * are treated as milliseconds, and converted to jiffies when they are stored.
2440 * This routine will ensure the values are within the range specified by
2441 * table->extra1 (min) and table->extra2 (max).
2443 * Returns 0 on success.
2445 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2446 void __user *buffer,
2447 size_t *lenp, loff_t *ppos)
2449 return do_proc_doulongvec_minmax(table, write, buffer,
2450 lenp, ppos, HZ, 1000l);
2454 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2455 int *valp,
2456 int write, void *data)
2458 if (write) {
2459 if (*lvalp > LONG_MAX / HZ)
2460 return 1;
2461 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2462 } else {
2463 int val = *valp;
2464 unsigned long lval;
2465 if (val < 0) {
2466 *negp = -1;
2467 lval = (unsigned long)-val;
2468 } else {
2469 *negp = 0;
2470 lval = (unsigned long)val;
2472 *lvalp = lval / HZ;
2474 return 0;
2477 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2478 int *valp,
2479 int write, void *data)
2481 if (write) {
2482 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2483 return 1;
2484 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2485 } else {
2486 int val = *valp;
2487 unsigned long lval;
2488 if (val < 0) {
2489 *negp = -1;
2490 lval = (unsigned long)-val;
2491 } else {
2492 *negp = 0;
2493 lval = (unsigned long)val;
2495 *lvalp = jiffies_to_clock_t(lval);
2497 return 0;
2500 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2501 int *valp,
2502 int write, void *data)
2504 if (write) {
2505 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2506 } else {
2507 int val = *valp;
2508 unsigned long lval;
2509 if (val < 0) {
2510 *negp = -1;
2511 lval = (unsigned long)-val;
2512 } else {
2513 *negp = 0;
2514 lval = (unsigned long)val;
2516 *lvalp = jiffies_to_msecs(lval);
2518 return 0;
2522 * proc_dointvec_jiffies - read a vector of integers as seconds
2523 * @table: the sysctl table
2524 * @write: %TRUE if this is a write to the sysctl file
2525 * @buffer: the user buffer
2526 * @lenp: the size of the user buffer
2527 * @ppos: file position
2529 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2530 * values from/to the user buffer, treated as an ASCII string.
2531 * The values read are assumed to be in seconds, and are converted into
2532 * jiffies.
2534 * Returns 0 on success.
2536 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2537 void __user *buffer, size_t *lenp, loff_t *ppos)
2539 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2540 do_proc_dointvec_jiffies_conv,NULL);
2544 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2545 * @table: the sysctl table
2546 * @write: %TRUE if this is a write to the sysctl file
2547 * @buffer: the user buffer
2548 * @lenp: the size of the user buffer
2549 * @ppos: pointer to the file position
2551 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2552 * values from/to the user buffer, treated as an ASCII string.
2553 * The values read are assumed to be in 1/USER_HZ seconds, and
2554 * are converted into jiffies.
2556 * Returns 0 on success.
2558 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2559 void __user *buffer, size_t *lenp, loff_t *ppos)
2561 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2562 do_proc_dointvec_userhz_jiffies_conv,NULL);
2566 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2567 * @table: the sysctl table
2568 * @write: %TRUE if this is a write to the sysctl file
2569 * @buffer: the user buffer
2570 * @lenp: the size of the user buffer
2571 * @ppos: file position
2572 * @ppos: the current position in the file
2574 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2575 * values from/to the user buffer, treated as an ASCII string.
2576 * The values read are assumed to be in 1/1000 seconds, and
2577 * are converted into jiffies.
2579 * Returns 0 on success.
2581 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2582 void __user *buffer, size_t *lenp, loff_t *ppos)
2584 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2585 do_proc_dointvec_ms_jiffies_conv, NULL);
2588 static int proc_do_cad_pid(struct ctl_table *table, int write,
2589 void __user *buffer, size_t *lenp, loff_t *ppos)
2591 struct pid *new_pid;
2592 pid_t tmp;
2593 int r;
2595 tmp = pid_vnr(cad_pid);
2597 r = __do_proc_dointvec(&tmp, table, write, buffer,
2598 lenp, ppos, NULL, NULL);
2599 if (r || !write)
2600 return r;
2602 new_pid = find_get_pid(tmp);
2603 if (!new_pid)
2604 return -ESRCH;
2606 put_pid(xchg(&cad_pid, new_pid));
2607 return 0;
2610 #else /* CONFIG_PROC_FS */
2612 int proc_dostring(struct ctl_table *table, int write,
2613 void __user *buffer, size_t *lenp, loff_t *ppos)
2615 return -ENOSYS;
2618 int proc_dointvec(struct ctl_table *table, int write,
2619 void __user *buffer, size_t *lenp, loff_t *ppos)
2621 return -ENOSYS;
2624 int proc_dointvec_minmax(struct ctl_table *table, int write,
2625 void __user *buffer, size_t *lenp, loff_t *ppos)
2627 return -ENOSYS;
2630 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2631 void __user *buffer, size_t *lenp, loff_t *ppos)
2633 return -ENOSYS;
2636 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2637 void __user *buffer, size_t *lenp, loff_t *ppos)
2639 return -ENOSYS;
2642 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2643 void __user *buffer, size_t *lenp, loff_t *ppos)
2645 return -ENOSYS;
2648 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2649 void __user *buffer, size_t *lenp, loff_t *ppos)
2651 return -ENOSYS;
2654 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2655 void __user *buffer,
2656 size_t *lenp, loff_t *ppos)
2658 return -ENOSYS;
2662 #endif /* CONFIG_PROC_FS */
2665 * No sense putting this after each symbol definition, twice,
2666 * exception granted :-)
2668 EXPORT_SYMBOL(proc_dointvec);
2669 EXPORT_SYMBOL(proc_dointvec_jiffies);
2670 EXPORT_SYMBOL(proc_dointvec_minmax);
2671 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2672 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2673 EXPORT_SYMBOL(proc_dostring);
2674 EXPORT_SYMBOL(proc_doulongvec_minmax);
2675 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2676 EXPORT_SYMBOL(register_sysctl_table);
2677 EXPORT_SYMBOL(register_sysctl_paths);
2678 EXPORT_SYMBOL(unregister_sysctl_table);