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
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
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>
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/utsname.h>
30 #include <linux/smp_lock.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/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/nfs_fs.h>
47 #include <linux/acpi.h>
48 #include <linux/reboot.h>
50 #include <asm/uaccess.h>
51 #include <asm/processor.h>
55 #include <asm/stacktrace.h>
59 static int deprecated_sysctl_warning(struct __sysctl_args *args);
61 #if defined(CONFIG_SYSCTL)
63 /* External variables not in a header file. */
65 extern int print_fatal_signals;
66 extern int sysctl_overcommit_memory;
67 extern int sysctl_overcommit_ratio;
68 extern int sysctl_panic_on_oom;
69 extern int sysctl_oom_kill_allocating_task;
70 extern int sysctl_oom_dump_tasks;
71 extern int max_threads;
72 extern int core_uses_pid;
73 extern int suid_dumpable;
74 extern char core_pattern[];
76 extern int min_free_kbytes;
77 extern int pid_max_min, pid_max_max;
78 extern int sysctl_drop_caches;
79 extern int percpu_pagelist_fraction;
80 extern int compat_log;
81 extern int maps_protect;
82 extern int sysctl_stat_interval;
83 extern int latencytop_enabled;
85 /* Constants used for minimum and maximum */
86 #if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM)
90 #ifdef CONFIG_DETECT_SOFTLOCKUP
91 static int sixty = 60;
99 static int one_hundred = 100;
101 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
102 static int maxolduid = 65535;
103 static int minolduid;
104 static int min_percpu_pagelist_fract = 8;
106 static int ngroups_max = NGROUPS_MAX;
109 extern char modprobe_path[];
111 #ifdef CONFIG_CHR_DEV_SG
112 extern int sg_big_buff;
116 extern char reboot_command [];
117 extern int stop_a_enabled;
118 extern int scons_pwroff;
122 extern int pwrsw_enabled;
123 extern int unaligned_enabled;
127 #ifdef CONFIG_MATHEMU
128 extern int sysctl_ieee_emulation_warnings;
130 extern int sysctl_userprocess_debug;
131 extern int spin_retry;
134 extern int sysctl_hz_timer;
136 #ifdef CONFIG_BSD_PROCESS_ACCT
137 extern int acct_parm[];
141 extern int no_unaligned_warning;
144 #ifdef CONFIG_RT_MUTEXES
145 extern int max_lock_depth;
148 #ifdef CONFIG_SYSCTL_SYSCALL
149 static int parse_table(int __user *, int, void __user *, size_t __user *,
150 void __user *, size_t, struct ctl_table *);
154 #ifdef CONFIG_PROC_SYSCTL
155 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
156 void __user *buffer, size_t *lenp, loff_t *ppos);
157 static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
158 void __user *buffer, size_t *lenp, loff_t *ppos);
161 static struct ctl_table root_table[];
162 static struct ctl_table_root sysctl_table_root;
163 static struct ctl_table_header root_table_header = {
164 .ctl_table = root_table,
165 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.header_list),
166 .root = &sysctl_table_root,
168 static struct ctl_table_root sysctl_table_root = {
169 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
170 .header_list = LIST_HEAD_INIT(root_table_header.ctl_entry),
173 static struct ctl_table kern_table[];
174 static struct ctl_table vm_table[];
175 static struct ctl_table fs_table[];
176 static struct ctl_table debug_table[];
177 static struct ctl_table dev_table[];
178 extern struct ctl_table random_table[];
179 #ifdef CONFIG_INOTIFY_USER
180 extern struct ctl_table inotify_table[];
183 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
184 int sysctl_legacy_va_layout;
187 extern int prove_locking;
188 extern int lock_stat;
190 /* The default sysctl tables: */
192 static struct ctl_table root_table[] = {
194 .ctl_name = CTL_KERN,
195 .procname = "kernel",
212 .ctl_name = CTL_DEBUG,
215 .child = debug_table,
224 * NOTE: do not add new entries to this table unless you have read
225 * Documentation/sysctl/ctl_unnumbered.txt
230 #ifdef CONFIG_SCHED_DEBUG
231 static int min_sched_granularity_ns = 100000; /* 100 usecs */
232 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
233 static int min_wakeup_granularity_ns; /* 0 usecs */
234 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
237 static struct ctl_table kern_table[] = {
238 #ifdef CONFIG_SCHED_DEBUG
240 .ctl_name = CTL_UNNUMBERED,
241 .procname = "sched_min_granularity_ns",
242 .data = &sysctl_sched_min_granularity,
243 .maxlen = sizeof(unsigned int),
245 .proc_handler = &sched_nr_latency_handler,
246 .strategy = &sysctl_intvec,
247 .extra1 = &min_sched_granularity_ns,
248 .extra2 = &max_sched_granularity_ns,
251 .ctl_name = CTL_UNNUMBERED,
252 .procname = "sched_latency_ns",
253 .data = &sysctl_sched_latency,
254 .maxlen = sizeof(unsigned int),
256 .proc_handler = &sched_nr_latency_handler,
257 .strategy = &sysctl_intvec,
258 .extra1 = &min_sched_granularity_ns,
259 .extra2 = &max_sched_granularity_ns,
262 .ctl_name = CTL_UNNUMBERED,
263 .procname = "sched_wakeup_granularity_ns",
264 .data = &sysctl_sched_wakeup_granularity,
265 .maxlen = sizeof(unsigned int),
267 .proc_handler = &proc_dointvec_minmax,
268 .strategy = &sysctl_intvec,
269 .extra1 = &min_wakeup_granularity_ns,
270 .extra2 = &max_wakeup_granularity_ns,
273 .ctl_name = CTL_UNNUMBERED,
274 .procname = "sched_child_runs_first",
275 .data = &sysctl_sched_child_runs_first,
276 .maxlen = sizeof(unsigned int),
278 .proc_handler = &proc_dointvec,
281 .ctl_name = CTL_UNNUMBERED,
282 .procname = "sched_features",
283 .data = &sysctl_sched_features,
284 .maxlen = sizeof(unsigned int),
286 .proc_handler = &proc_dointvec,
289 .ctl_name = CTL_UNNUMBERED,
290 .procname = "sched_migration_cost",
291 .data = &sysctl_sched_migration_cost,
292 .maxlen = sizeof(unsigned int),
294 .proc_handler = &proc_dointvec,
297 .ctl_name = CTL_UNNUMBERED,
298 .procname = "sched_nr_migrate",
299 .data = &sysctl_sched_nr_migrate,
300 .maxlen = sizeof(unsigned int),
302 .proc_handler = &proc_dointvec,
306 .ctl_name = CTL_UNNUMBERED,
307 .procname = "sched_rt_period_us",
308 .data = &sysctl_sched_rt_period,
309 .maxlen = sizeof(unsigned int),
311 .proc_handler = &sched_rt_handler,
314 .ctl_name = CTL_UNNUMBERED,
315 .procname = "sched_rt_runtime_us",
316 .data = &sysctl_sched_rt_runtime,
317 .maxlen = sizeof(int),
319 .proc_handler = &sched_rt_handler,
322 .ctl_name = CTL_UNNUMBERED,
323 .procname = "sched_compat_yield",
324 .data = &sysctl_sched_compat_yield,
325 .maxlen = sizeof(unsigned int),
327 .proc_handler = &proc_dointvec,
329 #ifdef CONFIG_PROVE_LOCKING
331 .ctl_name = CTL_UNNUMBERED,
332 .procname = "prove_locking",
333 .data = &prove_locking,
334 .maxlen = sizeof(int),
336 .proc_handler = &proc_dointvec,
339 #ifdef CONFIG_LOCK_STAT
341 .ctl_name = CTL_UNNUMBERED,
342 .procname = "lock_stat",
344 .maxlen = sizeof(int),
346 .proc_handler = &proc_dointvec,
350 .ctl_name = KERN_PANIC,
352 .data = &panic_timeout,
353 .maxlen = sizeof(int),
355 .proc_handler = &proc_dointvec,
358 .ctl_name = KERN_CORE_USES_PID,
359 .procname = "core_uses_pid",
360 .data = &core_uses_pid,
361 .maxlen = sizeof(int),
363 .proc_handler = &proc_dointvec,
366 .ctl_name = KERN_CORE_PATTERN,
367 .procname = "core_pattern",
368 .data = core_pattern,
369 .maxlen = CORENAME_MAX_SIZE,
371 .proc_handler = &proc_dostring,
372 .strategy = &sysctl_string,
374 #ifdef CONFIG_PROC_SYSCTL
376 .procname = "tainted",
378 .maxlen = sizeof(int),
380 .proc_handler = &proc_dointvec_taint,
383 #ifdef CONFIG_LATENCYTOP
385 .procname = "latencytop",
386 .data = &latencytop_enabled,
387 .maxlen = sizeof(int),
389 .proc_handler = &proc_dointvec,
392 #ifdef CONFIG_BLK_DEV_INITRD
394 .ctl_name = KERN_REALROOTDEV,
395 .procname = "real-root-dev",
396 .data = &real_root_dev,
397 .maxlen = sizeof(int),
399 .proc_handler = &proc_dointvec,
403 .ctl_name = CTL_UNNUMBERED,
404 .procname = "print-fatal-signals",
405 .data = &print_fatal_signals,
406 .maxlen = sizeof(int),
408 .proc_handler = &proc_dointvec,
412 .ctl_name = KERN_SPARC_REBOOT,
413 .procname = "reboot-cmd",
414 .data = reboot_command,
417 .proc_handler = &proc_dostring,
418 .strategy = &sysctl_string,
421 .ctl_name = KERN_SPARC_STOP_A,
422 .procname = "stop-a",
423 .data = &stop_a_enabled,
424 .maxlen = sizeof (int),
426 .proc_handler = &proc_dointvec,
429 .ctl_name = KERN_SPARC_SCONS_PWROFF,
430 .procname = "scons-poweroff",
431 .data = &scons_pwroff,
432 .maxlen = sizeof (int),
434 .proc_handler = &proc_dointvec,
439 .ctl_name = KERN_HPPA_PWRSW,
440 .procname = "soft-power",
441 .data = &pwrsw_enabled,
442 .maxlen = sizeof (int),
444 .proc_handler = &proc_dointvec,
447 .ctl_name = KERN_HPPA_UNALIGNED,
448 .procname = "unaligned-trap",
449 .data = &unaligned_enabled,
450 .maxlen = sizeof (int),
452 .proc_handler = &proc_dointvec,
456 .ctl_name = KERN_CTLALTDEL,
457 .procname = "ctrl-alt-del",
459 .maxlen = sizeof(int),
461 .proc_handler = &proc_dointvec,
465 .ctl_name = KERN_MODPROBE,
466 .procname = "modprobe",
467 .data = &modprobe_path,
468 .maxlen = KMOD_PATH_LEN,
470 .proc_handler = &proc_dostring,
471 .strategy = &sysctl_string,
474 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
476 .ctl_name = KERN_HOTPLUG,
477 .procname = "hotplug",
478 .data = &uevent_helper,
479 .maxlen = UEVENT_HELPER_PATH_LEN,
481 .proc_handler = &proc_dostring,
482 .strategy = &sysctl_string,
485 #ifdef CONFIG_CHR_DEV_SG
487 .ctl_name = KERN_SG_BIG_BUFF,
488 .procname = "sg-big-buff",
489 .data = &sg_big_buff,
490 .maxlen = sizeof (int),
492 .proc_handler = &proc_dointvec,
495 #ifdef CONFIG_BSD_PROCESS_ACCT
497 .ctl_name = KERN_ACCT,
500 .maxlen = 3*sizeof(int),
502 .proc_handler = &proc_dointvec,
505 #ifdef CONFIG_MAGIC_SYSRQ
507 .ctl_name = KERN_SYSRQ,
509 .data = &__sysrq_enabled,
510 .maxlen = sizeof (int),
512 .proc_handler = &proc_dointvec,
515 #ifdef CONFIG_PROC_SYSCTL
517 .procname = "cad_pid",
519 .maxlen = sizeof (int),
521 .proc_handler = &proc_do_cad_pid,
525 .ctl_name = KERN_MAX_THREADS,
526 .procname = "threads-max",
527 .data = &max_threads,
528 .maxlen = sizeof(int),
530 .proc_handler = &proc_dointvec,
533 .ctl_name = KERN_RANDOM,
534 .procname = "random",
536 .child = random_table,
539 .ctl_name = KERN_OVERFLOWUID,
540 .procname = "overflowuid",
541 .data = &overflowuid,
542 .maxlen = sizeof(int),
544 .proc_handler = &proc_dointvec_minmax,
545 .strategy = &sysctl_intvec,
546 .extra1 = &minolduid,
547 .extra2 = &maxolduid,
550 .ctl_name = KERN_OVERFLOWGID,
551 .procname = "overflowgid",
552 .data = &overflowgid,
553 .maxlen = sizeof(int),
555 .proc_handler = &proc_dointvec_minmax,
556 .strategy = &sysctl_intvec,
557 .extra1 = &minolduid,
558 .extra2 = &maxolduid,
561 #ifdef CONFIG_MATHEMU
563 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
564 .procname = "ieee_emulation_warnings",
565 .data = &sysctl_ieee_emulation_warnings,
566 .maxlen = sizeof(int),
568 .proc_handler = &proc_dointvec,
571 #ifdef CONFIG_NO_IDLE_HZ
573 .ctl_name = KERN_HZ_TIMER,
574 .procname = "hz_timer",
575 .data = &sysctl_hz_timer,
576 .maxlen = sizeof(int),
578 .proc_handler = &proc_dointvec,
582 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
583 .procname = "userprocess_debug",
584 .data = &sysctl_userprocess_debug,
585 .maxlen = sizeof(int),
587 .proc_handler = &proc_dointvec,
591 .ctl_name = KERN_PIDMAX,
592 .procname = "pid_max",
594 .maxlen = sizeof (int),
596 .proc_handler = &proc_dointvec_minmax,
597 .strategy = sysctl_intvec,
598 .extra1 = &pid_max_min,
599 .extra2 = &pid_max_max,
602 .ctl_name = KERN_PANIC_ON_OOPS,
603 .procname = "panic_on_oops",
604 .data = &panic_on_oops,
605 .maxlen = sizeof(int),
607 .proc_handler = &proc_dointvec,
609 #if defined CONFIG_PRINTK
611 .ctl_name = KERN_PRINTK,
612 .procname = "printk",
613 .data = &console_loglevel,
614 .maxlen = 4*sizeof(int),
616 .proc_handler = &proc_dointvec,
619 .ctl_name = KERN_PRINTK_RATELIMIT,
620 .procname = "printk_ratelimit",
621 .data = &printk_ratelimit_jiffies,
622 .maxlen = sizeof(int),
624 .proc_handler = &proc_dointvec_jiffies,
625 .strategy = &sysctl_jiffies,
628 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
629 .procname = "printk_ratelimit_burst",
630 .data = &printk_ratelimit_burst,
631 .maxlen = sizeof(int),
633 .proc_handler = &proc_dointvec,
637 .ctl_name = KERN_NGROUPS_MAX,
638 .procname = "ngroups_max",
639 .data = &ngroups_max,
640 .maxlen = sizeof (int),
642 .proc_handler = &proc_dointvec,
644 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
646 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
647 .procname = "unknown_nmi_panic",
648 .data = &unknown_nmi_panic,
649 .maxlen = sizeof (int),
651 .proc_handler = &proc_dointvec,
654 .procname = "nmi_watchdog",
655 .data = &nmi_watchdog_enabled,
656 .maxlen = sizeof (int),
658 .proc_handler = &proc_nmi_enabled,
661 #if defined(CONFIG_X86)
663 .ctl_name = KERN_PANIC_ON_NMI,
664 .procname = "panic_on_unrecovered_nmi",
665 .data = &panic_on_unrecovered_nmi,
666 .maxlen = sizeof(int),
668 .proc_handler = &proc_dointvec,
671 .ctl_name = KERN_BOOTLOADER_TYPE,
672 .procname = "bootloader_type",
673 .data = &bootloader_type,
674 .maxlen = sizeof (int),
676 .proc_handler = &proc_dointvec,
679 .ctl_name = CTL_UNNUMBERED,
680 .procname = "kstack_depth_to_print",
681 .data = &kstack_depth_to_print,
682 .maxlen = sizeof(int),
684 .proc_handler = &proc_dointvec,
687 .ctl_name = CTL_UNNUMBERED,
688 .procname = "io_delay_type",
689 .data = &io_delay_type,
690 .maxlen = sizeof(int),
692 .proc_handler = &proc_dointvec,
695 #if defined(CONFIG_MMU)
697 .ctl_name = KERN_RANDOMIZE,
698 .procname = "randomize_va_space",
699 .data = &randomize_va_space,
700 .maxlen = sizeof(int),
702 .proc_handler = &proc_dointvec,
705 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
707 .ctl_name = KERN_SPIN_RETRY,
708 .procname = "spin_retry",
710 .maxlen = sizeof (int),
712 .proc_handler = &proc_dointvec,
715 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
717 .procname = "acpi_video_flags",
718 .data = &acpi_realmode_flags,
719 .maxlen = sizeof (unsigned long),
721 .proc_handler = &proc_doulongvec_minmax,
726 .ctl_name = KERN_IA64_UNALIGNED,
727 .procname = "ignore-unaligned-usertrap",
728 .data = &no_unaligned_warning,
729 .maxlen = sizeof (int),
731 .proc_handler = &proc_dointvec,
734 #ifdef CONFIG_DETECT_SOFTLOCKUP
736 .ctl_name = CTL_UNNUMBERED,
737 .procname = "softlockup_thresh",
738 .data = &softlockup_thresh,
739 .maxlen = sizeof(unsigned long),
741 .proc_handler = &proc_doulongvec_minmax,
742 .strategy = &sysctl_intvec,
747 .ctl_name = CTL_UNNUMBERED,
748 .procname = "hung_task_check_count",
749 .data = &sysctl_hung_task_check_count,
750 .maxlen = sizeof(unsigned long),
752 .proc_handler = &proc_doulongvec_minmax,
753 .strategy = &sysctl_intvec,
756 .ctl_name = CTL_UNNUMBERED,
757 .procname = "hung_task_timeout_secs",
758 .data = &sysctl_hung_task_timeout_secs,
759 .maxlen = sizeof(unsigned long),
761 .proc_handler = &proc_doulongvec_minmax,
762 .strategy = &sysctl_intvec,
765 .ctl_name = CTL_UNNUMBERED,
766 .procname = "hung_task_warnings",
767 .data = &sysctl_hung_task_warnings,
768 .maxlen = sizeof(unsigned long),
770 .proc_handler = &proc_doulongvec_minmax,
771 .strategy = &sysctl_intvec,
776 .ctl_name = KERN_COMPAT_LOG,
777 .procname = "compat-log",
779 .maxlen = sizeof (int),
781 .proc_handler = &proc_dointvec,
784 #ifdef CONFIG_RT_MUTEXES
786 .ctl_name = KERN_MAX_LOCK_DEPTH,
787 .procname = "max_lock_depth",
788 .data = &max_lock_depth,
789 .maxlen = sizeof(int),
791 .proc_handler = &proc_dointvec,
794 #ifdef CONFIG_PROC_FS
796 .ctl_name = CTL_UNNUMBERED,
797 .procname = "maps_protect",
798 .data = &maps_protect,
799 .maxlen = sizeof(int),
801 .proc_handler = &proc_dointvec,
805 .ctl_name = CTL_UNNUMBERED,
806 .procname = "poweroff_cmd",
807 .data = &poweroff_cmd,
808 .maxlen = POWEROFF_CMD_PATH_LEN,
810 .proc_handler = &proc_dostring,
811 .strategy = &sysctl_string,
815 .ctl_name = CTL_UNNUMBERED,
818 .child = key_sysctls,
822 * NOTE: do not add new entries to this table unless you have read
823 * Documentation/sysctl/ctl_unnumbered.txt
828 static struct ctl_table vm_table[] = {
830 .ctl_name = VM_OVERCOMMIT_MEMORY,
831 .procname = "overcommit_memory",
832 .data = &sysctl_overcommit_memory,
833 .maxlen = sizeof(sysctl_overcommit_memory),
835 .proc_handler = &proc_dointvec,
838 .ctl_name = VM_PANIC_ON_OOM,
839 .procname = "panic_on_oom",
840 .data = &sysctl_panic_on_oom,
841 .maxlen = sizeof(sysctl_panic_on_oom),
843 .proc_handler = &proc_dointvec,
846 .ctl_name = CTL_UNNUMBERED,
847 .procname = "oom_kill_allocating_task",
848 .data = &sysctl_oom_kill_allocating_task,
849 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
851 .proc_handler = &proc_dointvec,
854 .ctl_name = CTL_UNNUMBERED,
855 .procname = "oom_dump_tasks",
856 .data = &sysctl_oom_dump_tasks,
857 .maxlen = sizeof(sysctl_oom_dump_tasks),
859 .proc_handler = &proc_dointvec,
862 .ctl_name = VM_OVERCOMMIT_RATIO,
863 .procname = "overcommit_ratio",
864 .data = &sysctl_overcommit_ratio,
865 .maxlen = sizeof(sysctl_overcommit_ratio),
867 .proc_handler = &proc_dointvec,
870 .ctl_name = VM_PAGE_CLUSTER,
871 .procname = "page-cluster",
872 .data = &page_cluster,
873 .maxlen = sizeof(int),
875 .proc_handler = &proc_dointvec,
878 .ctl_name = VM_DIRTY_BACKGROUND,
879 .procname = "dirty_background_ratio",
880 .data = &dirty_background_ratio,
881 .maxlen = sizeof(dirty_background_ratio),
883 .proc_handler = &proc_dointvec_minmax,
884 .strategy = &sysctl_intvec,
886 .extra2 = &one_hundred,
889 .ctl_name = VM_DIRTY_RATIO,
890 .procname = "dirty_ratio",
891 .data = &vm_dirty_ratio,
892 .maxlen = sizeof(vm_dirty_ratio),
894 .proc_handler = &dirty_ratio_handler,
895 .strategy = &sysctl_intvec,
897 .extra2 = &one_hundred,
900 .procname = "dirty_writeback_centisecs",
901 .data = &dirty_writeback_interval,
902 .maxlen = sizeof(dirty_writeback_interval),
904 .proc_handler = &dirty_writeback_centisecs_handler,
907 .procname = "dirty_expire_centisecs",
908 .data = &dirty_expire_interval,
909 .maxlen = sizeof(dirty_expire_interval),
911 .proc_handler = &proc_dointvec_userhz_jiffies,
914 .ctl_name = VM_NR_PDFLUSH_THREADS,
915 .procname = "nr_pdflush_threads",
916 .data = &nr_pdflush_threads,
917 .maxlen = sizeof nr_pdflush_threads,
918 .mode = 0444 /* read-only*/,
919 .proc_handler = &proc_dointvec,
922 .ctl_name = VM_SWAPPINESS,
923 .procname = "swappiness",
924 .data = &vm_swappiness,
925 .maxlen = sizeof(vm_swappiness),
927 .proc_handler = &proc_dointvec_minmax,
928 .strategy = &sysctl_intvec,
930 .extra2 = &one_hundred,
932 #ifdef CONFIG_HUGETLB_PAGE
934 .procname = "nr_hugepages",
935 .data = &max_huge_pages,
936 .maxlen = sizeof(unsigned long),
938 .proc_handler = &hugetlb_sysctl_handler,
939 .extra1 = (void *)&hugetlb_zero,
940 .extra2 = (void *)&hugetlb_infinity,
943 .ctl_name = VM_HUGETLB_GROUP,
944 .procname = "hugetlb_shm_group",
945 .data = &sysctl_hugetlb_shm_group,
946 .maxlen = sizeof(gid_t),
948 .proc_handler = &proc_dointvec,
951 .ctl_name = CTL_UNNUMBERED,
952 .procname = "hugepages_treat_as_movable",
953 .data = &hugepages_treat_as_movable,
954 .maxlen = sizeof(int),
956 .proc_handler = &hugetlb_treat_movable_handler,
959 .ctl_name = CTL_UNNUMBERED,
960 .procname = "nr_overcommit_hugepages",
961 .data = &sysctl_overcommit_huge_pages,
962 .maxlen = sizeof(sysctl_overcommit_huge_pages),
964 .proc_handler = &hugetlb_overcommit_handler,
968 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
969 .procname = "lowmem_reserve_ratio",
970 .data = &sysctl_lowmem_reserve_ratio,
971 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
973 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
974 .strategy = &sysctl_intvec,
977 .ctl_name = VM_DROP_PAGECACHE,
978 .procname = "drop_caches",
979 .data = &sysctl_drop_caches,
980 .maxlen = sizeof(int),
982 .proc_handler = drop_caches_sysctl_handler,
983 .strategy = &sysctl_intvec,
986 .ctl_name = VM_MIN_FREE_KBYTES,
987 .procname = "min_free_kbytes",
988 .data = &min_free_kbytes,
989 .maxlen = sizeof(min_free_kbytes),
991 .proc_handler = &min_free_kbytes_sysctl_handler,
992 .strategy = &sysctl_intvec,
996 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
997 .procname = "percpu_pagelist_fraction",
998 .data = &percpu_pagelist_fraction,
999 .maxlen = sizeof(percpu_pagelist_fraction),
1001 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
1002 .strategy = &sysctl_intvec,
1003 .extra1 = &min_percpu_pagelist_fract,
1007 .ctl_name = VM_MAX_MAP_COUNT,
1008 .procname = "max_map_count",
1009 .data = &sysctl_max_map_count,
1010 .maxlen = sizeof(sysctl_max_map_count),
1012 .proc_handler = &proc_dointvec
1016 .ctl_name = VM_LAPTOP_MODE,
1017 .procname = "laptop_mode",
1018 .data = &laptop_mode,
1019 .maxlen = sizeof(laptop_mode),
1021 .proc_handler = &proc_dointvec_jiffies,
1022 .strategy = &sysctl_jiffies,
1025 .ctl_name = VM_BLOCK_DUMP,
1026 .procname = "block_dump",
1027 .data = &block_dump,
1028 .maxlen = sizeof(block_dump),
1030 .proc_handler = &proc_dointvec,
1031 .strategy = &sysctl_intvec,
1035 .ctl_name = VM_VFS_CACHE_PRESSURE,
1036 .procname = "vfs_cache_pressure",
1037 .data = &sysctl_vfs_cache_pressure,
1038 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1040 .proc_handler = &proc_dointvec,
1041 .strategy = &sysctl_intvec,
1044 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1046 .ctl_name = VM_LEGACY_VA_LAYOUT,
1047 .procname = "legacy_va_layout",
1048 .data = &sysctl_legacy_va_layout,
1049 .maxlen = sizeof(sysctl_legacy_va_layout),
1051 .proc_handler = &proc_dointvec,
1052 .strategy = &sysctl_intvec,
1058 .ctl_name = VM_ZONE_RECLAIM_MODE,
1059 .procname = "zone_reclaim_mode",
1060 .data = &zone_reclaim_mode,
1061 .maxlen = sizeof(zone_reclaim_mode),
1063 .proc_handler = &proc_dointvec,
1064 .strategy = &sysctl_intvec,
1068 .ctl_name = VM_MIN_UNMAPPED,
1069 .procname = "min_unmapped_ratio",
1070 .data = &sysctl_min_unmapped_ratio,
1071 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1073 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1074 .strategy = &sysctl_intvec,
1076 .extra2 = &one_hundred,
1079 .ctl_name = VM_MIN_SLAB,
1080 .procname = "min_slab_ratio",
1081 .data = &sysctl_min_slab_ratio,
1082 .maxlen = sizeof(sysctl_min_slab_ratio),
1084 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1085 .strategy = &sysctl_intvec,
1087 .extra2 = &one_hundred,
1092 .ctl_name = CTL_UNNUMBERED,
1093 .procname = "stat_interval",
1094 .data = &sysctl_stat_interval,
1095 .maxlen = sizeof(sysctl_stat_interval),
1097 .proc_handler = &proc_dointvec_jiffies,
1098 .strategy = &sysctl_jiffies,
1101 #ifdef CONFIG_SECURITY
1103 .ctl_name = CTL_UNNUMBERED,
1104 .procname = "mmap_min_addr",
1105 .data = &mmap_min_addr,
1106 .maxlen = sizeof(unsigned long),
1108 .proc_handler = &proc_doulongvec_minmax,
1113 .ctl_name = CTL_UNNUMBERED,
1114 .procname = "numa_zonelist_order",
1115 .data = &numa_zonelist_order,
1116 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1118 .proc_handler = &numa_zonelist_order_handler,
1119 .strategy = &sysctl_string,
1122 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1123 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1125 .ctl_name = VM_VDSO_ENABLED,
1126 .procname = "vdso_enabled",
1127 .data = &vdso_enabled,
1128 .maxlen = sizeof(vdso_enabled),
1130 .proc_handler = &proc_dointvec,
1131 .strategy = &sysctl_intvec,
1135 #ifdef CONFIG_HIGHMEM
1137 .ctl_name = CTL_UNNUMBERED,
1138 .procname = "highmem_is_dirtyable",
1139 .data = &vm_highmem_is_dirtyable,
1140 .maxlen = sizeof(vm_highmem_is_dirtyable),
1142 .proc_handler = &proc_dointvec_minmax,
1143 .strategy = &sysctl_intvec,
1149 * NOTE: do not add new entries to this table unless you have read
1150 * Documentation/sysctl/ctl_unnumbered.txt
1155 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1156 static struct ctl_table binfmt_misc_table[] = {
1161 static struct ctl_table fs_table[] = {
1163 .ctl_name = FS_NRINODE,
1164 .procname = "inode-nr",
1165 .data = &inodes_stat,
1166 .maxlen = 2*sizeof(int),
1168 .proc_handler = &proc_dointvec,
1171 .ctl_name = FS_STATINODE,
1172 .procname = "inode-state",
1173 .data = &inodes_stat,
1174 .maxlen = 7*sizeof(int),
1176 .proc_handler = &proc_dointvec,
1179 .procname = "file-nr",
1180 .data = &files_stat,
1181 .maxlen = 3*sizeof(int),
1183 .proc_handler = &proc_nr_files,
1186 .ctl_name = FS_MAXFILE,
1187 .procname = "file-max",
1188 .data = &files_stat.max_files,
1189 .maxlen = sizeof(int),
1191 .proc_handler = &proc_dointvec,
1194 .ctl_name = CTL_UNNUMBERED,
1195 .procname = "nr_open",
1196 .data = &sysctl_nr_open,
1197 .maxlen = sizeof(int),
1199 .proc_handler = &proc_dointvec,
1202 .ctl_name = FS_DENTRY,
1203 .procname = "dentry-state",
1204 .data = &dentry_stat,
1205 .maxlen = 6*sizeof(int),
1207 .proc_handler = &proc_dointvec,
1210 .ctl_name = FS_OVERFLOWUID,
1211 .procname = "overflowuid",
1212 .data = &fs_overflowuid,
1213 .maxlen = sizeof(int),
1215 .proc_handler = &proc_dointvec_minmax,
1216 .strategy = &sysctl_intvec,
1217 .extra1 = &minolduid,
1218 .extra2 = &maxolduid,
1221 .ctl_name = FS_OVERFLOWGID,
1222 .procname = "overflowgid",
1223 .data = &fs_overflowgid,
1224 .maxlen = sizeof(int),
1226 .proc_handler = &proc_dointvec_minmax,
1227 .strategy = &sysctl_intvec,
1228 .extra1 = &minolduid,
1229 .extra2 = &maxolduid,
1232 .ctl_name = FS_LEASES,
1233 .procname = "leases-enable",
1234 .data = &leases_enable,
1235 .maxlen = sizeof(int),
1237 .proc_handler = &proc_dointvec,
1239 #ifdef CONFIG_DNOTIFY
1241 .ctl_name = FS_DIR_NOTIFY,
1242 .procname = "dir-notify-enable",
1243 .data = &dir_notify_enable,
1244 .maxlen = sizeof(int),
1246 .proc_handler = &proc_dointvec,
1251 .ctl_name = FS_LEASE_TIME,
1252 .procname = "lease-break-time",
1253 .data = &lease_break_time,
1254 .maxlen = sizeof(int),
1256 .proc_handler = &proc_dointvec_minmax,
1257 .strategy = &sysctl_intvec,
1262 .procname = "aio-nr",
1264 .maxlen = sizeof(aio_nr),
1266 .proc_handler = &proc_doulongvec_minmax,
1269 .procname = "aio-max-nr",
1270 .data = &aio_max_nr,
1271 .maxlen = sizeof(aio_max_nr),
1273 .proc_handler = &proc_doulongvec_minmax,
1275 #ifdef CONFIG_INOTIFY_USER
1277 .ctl_name = FS_INOTIFY,
1278 .procname = "inotify",
1280 .child = inotify_table,
1285 .ctl_name = KERN_SETUID_DUMPABLE,
1286 .procname = "suid_dumpable",
1287 .data = &suid_dumpable,
1288 .maxlen = sizeof(int),
1290 .proc_handler = &proc_dointvec,
1292 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1294 .ctl_name = CTL_UNNUMBERED,
1295 .procname = "binfmt_misc",
1297 .child = binfmt_misc_table,
1301 * NOTE: do not add new entries to this table unless you have read
1302 * Documentation/sysctl/ctl_unnumbered.txt
1307 static struct ctl_table debug_table[] = {
1308 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1310 .ctl_name = CTL_UNNUMBERED,
1311 .procname = "exception-trace",
1312 .data = &show_unhandled_signals,
1313 .maxlen = sizeof(int),
1315 .proc_handler = proc_dointvec
1321 static struct ctl_table dev_table[] = {
1325 static DEFINE_SPINLOCK(sysctl_lock);
1327 /* called under sysctl_lock */
1328 static int use_table(struct ctl_table_header *p)
1330 if (unlikely(p->unregistering))
1336 /* called under sysctl_lock */
1337 static void unuse_table(struct ctl_table_header *p)
1340 if (unlikely(p->unregistering))
1341 complete(p->unregistering);
1344 /* called under sysctl_lock, will reacquire if has to wait */
1345 static void start_unregistering(struct ctl_table_header *p)
1348 * if p->used is 0, nobody will ever touch that entry again;
1349 * we'll eliminate all paths to it before dropping sysctl_lock
1351 if (unlikely(p->used)) {
1352 struct completion wait;
1353 init_completion(&wait);
1354 p->unregistering = &wait;
1355 spin_unlock(&sysctl_lock);
1356 wait_for_completion(&wait);
1357 spin_lock(&sysctl_lock);
1360 * do not remove from the list until nobody holds it; walking the
1361 * list in do_sysctl() relies on that.
1363 list_del_init(&p->ctl_entry);
1366 void sysctl_head_finish(struct ctl_table_header *head)
1370 spin_lock(&sysctl_lock);
1372 spin_unlock(&sysctl_lock);
1375 static struct list_head *
1376 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1378 struct list_head *header_list;
1379 header_list = &root->header_list;
1381 header_list = root->lookup(root, namespaces);
1385 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1386 struct ctl_table_header *prev)
1388 struct ctl_table_root *root;
1389 struct list_head *header_list;
1390 struct ctl_table_header *head;
1391 struct list_head *tmp;
1393 spin_lock(&sysctl_lock);
1396 tmp = &prev->ctl_entry;
1400 tmp = &root_table_header.ctl_entry;
1402 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1404 if (!use_table(head))
1406 spin_unlock(&sysctl_lock);
1411 header_list = lookup_header_list(root, namespaces);
1412 if (tmp != header_list)
1416 root = list_entry(root->root_list.next,
1417 struct ctl_table_root, root_list);
1418 if (root == &sysctl_table_root)
1420 header_list = lookup_header_list(root, namespaces);
1421 } while (list_empty(header_list));
1422 tmp = header_list->next;
1425 spin_unlock(&sysctl_lock);
1429 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1431 return __sysctl_head_next(current->nsproxy, prev);
1434 void register_sysctl_root(struct ctl_table_root *root)
1436 spin_lock(&sysctl_lock);
1437 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1438 spin_unlock(&sysctl_lock);
1441 #ifdef CONFIG_SYSCTL_SYSCALL
1442 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1443 void __user *newval, size_t newlen)
1445 struct ctl_table_header *head;
1446 int error = -ENOTDIR;
1448 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1452 if (!oldlenp || get_user(old_len, oldlenp))
1456 for (head = sysctl_head_next(NULL); head;
1457 head = sysctl_head_next(head)) {
1458 error = parse_table(name, nlen, oldval, oldlenp,
1459 newval, newlen, head->ctl_table);
1460 if (error != -ENOTDIR) {
1461 sysctl_head_finish(head);
1468 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1470 struct __sysctl_args tmp;
1473 if (copy_from_user(&tmp, args, sizeof(tmp)))
1476 error = deprecated_sysctl_warning(&tmp);
1481 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1482 tmp.newval, tmp.newlen);
1487 #endif /* CONFIG_SYSCTL_SYSCALL */
1490 * sysctl_perm does NOT grant the superuser all rights automatically, because
1491 * some sysctl variables are readonly even to root.
1494 static int test_perm(int mode, int op)
1498 else if (in_egroup_p(0))
1500 if ((mode & op & 0007) == op)
1505 int sysctl_perm(struct ctl_table *table, int op)
1508 error = security_sysctl(table, op);
1511 return test_perm(table->mode, op);
1514 #ifdef CONFIG_SYSCTL_SYSCALL
1515 static int parse_table(int __user *name, int nlen,
1516 void __user *oldval, size_t __user *oldlenp,
1517 void __user *newval, size_t newlen,
1518 struct ctl_table *table)
1524 if (get_user(n, name))
1526 for ( ; table->ctl_name || table->procname; table++) {
1527 if (!table->ctl_name)
1529 if (n == table->ctl_name) {
1532 if (sysctl_perm(table, 001))
1536 table = table->child;
1539 error = do_sysctl_strategy(table, name, nlen,
1548 /* Perform the actual read/write of a sysctl table entry. */
1549 int do_sysctl_strategy (struct ctl_table *table,
1550 int __user *name, int nlen,
1551 void __user *oldval, size_t __user *oldlenp,
1552 void __user *newval, size_t newlen)
1560 if (sysctl_perm(table, op))
1563 if (table->strategy) {
1564 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1572 /* If there is no strategy routine, or if the strategy returns
1573 * zero, proceed with automatic r/w */
1574 if (table->data && table->maxlen) {
1575 rc = sysctl_data(table, name, nlen, oldval, oldlenp,
1582 #endif /* CONFIG_SYSCTL_SYSCALL */
1584 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1586 for (; table->ctl_name || table->procname; table++) {
1587 table->parent = parent;
1589 sysctl_set_parent(table, table->child);
1593 static __init int sysctl_init(void)
1595 sysctl_set_parent(NULL, root_table);
1596 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1599 err = sysctl_check_table(current->nsproxy, root_table);
1605 core_initcall(sysctl_init);
1608 * __register_sysctl_paths - register a sysctl hierarchy
1609 * @root: List of sysctl headers to register on
1610 * @namespaces: Data to compute which lists of sysctl entries are visible
1611 * @path: The path to the directory the sysctl table is in.
1612 * @table: the top-level table structure
1614 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1615 * array. A completely 0 filled entry terminates the table.
1617 * The members of the &struct ctl_table structure are used as follows:
1619 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1620 * must be unique within that level of sysctl
1622 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1623 * enter a sysctl file
1625 * data - a pointer to data for use by proc_handler
1627 * maxlen - the maximum size in bytes of the data
1629 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1631 * child - a pointer to the child sysctl table if this entry is a directory, or
1634 * proc_handler - the text handler routine (described below)
1636 * strategy - the strategy routine (described below)
1638 * de - for internal use by the sysctl routines
1640 * extra1, extra2 - extra pointers usable by the proc handler routines
1642 * Leaf nodes in the sysctl tree will be represented by a single file
1643 * under /proc; non-leaf nodes will be represented by directories.
1645 * sysctl(2) can automatically manage read and write requests through
1646 * the sysctl table. The data and maxlen fields of the ctl_table
1647 * struct enable minimal validation of the values being written to be
1648 * performed, and the mode field allows minimal authentication.
1650 * More sophisticated management can be enabled by the provision of a
1651 * strategy routine with the table entry. This will be called before
1652 * any automatic read or write of the data is performed.
1654 * The strategy routine may return
1656 * < 0 - Error occurred (error is passed to user process)
1658 * 0 - OK - proceed with automatic read or write.
1660 * > 0 - OK - read or write has been done by the strategy routine, so
1661 * return immediately.
1663 * There must be a proc_handler routine for any terminal nodes
1664 * mirrored under /proc/sys (non-terminals are handled by a built-in
1665 * directory handler). Several default handlers are available to
1666 * cover common cases -
1668 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1669 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1670 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1672 * It is the handler's job to read the input buffer from user memory
1673 * and process it. The handler should return 0 on success.
1675 * This routine returns %NULL on a failure to register, and a pointer
1676 * to the table header on success.
1678 struct ctl_table_header *__register_sysctl_paths(
1679 struct ctl_table_root *root,
1680 struct nsproxy *namespaces,
1681 const struct ctl_path *path, struct ctl_table *table)
1683 struct list_head *header_list;
1684 struct ctl_table_header *header;
1685 struct ctl_table *new, **prevp;
1686 unsigned int n, npath;
1688 /* Count the path components */
1689 for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1693 * For each path component, allocate a 2-element ctl_table array.
1694 * The first array element will be filled with the sysctl entry
1695 * for this, the second will be the sentinel (ctl_name == 0).
1697 * We allocate everything in one go so that we don't have to
1698 * worry about freeing additional memory in unregister_sysctl_table.
1700 header = kzalloc(sizeof(struct ctl_table_header) +
1701 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1705 new = (struct ctl_table *) (header + 1);
1707 /* Now connect the dots */
1708 prevp = &header->ctl_table;
1709 for (n = 0; n < npath; ++n, ++path) {
1710 /* Copy the procname */
1711 new->procname = path->procname;
1712 new->ctl_name = path->ctl_name;
1716 prevp = &new->child;
1721 header->ctl_table_arg = table;
1723 INIT_LIST_HEAD(&header->ctl_entry);
1725 header->unregistering = NULL;
1726 header->root = root;
1727 sysctl_set_parent(NULL, header->ctl_table);
1728 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1729 if (sysctl_check_table(namespaces, header->ctl_table)) {
1734 spin_lock(&sysctl_lock);
1735 header_list = lookup_header_list(root, namespaces);
1736 list_add_tail(&header->ctl_entry, header_list);
1737 spin_unlock(&sysctl_lock);
1743 * register_sysctl_table_path - register a sysctl table hierarchy
1744 * @path: The path to the directory the sysctl table is in.
1745 * @table: the top-level table structure
1747 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1748 * array. A completely 0 filled entry terminates the table.
1750 * See __register_sysctl_paths for more details.
1752 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1753 struct ctl_table *table)
1755 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1760 * register_sysctl_table - register a sysctl table hierarchy
1761 * @table: the top-level table structure
1763 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1764 * array. A completely 0 filled entry terminates the table.
1766 * See register_sysctl_paths for more details.
1768 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1770 static const struct ctl_path null_path[] = { {} };
1772 return register_sysctl_paths(null_path, table);
1776 * unregister_sysctl_table - unregister a sysctl table hierarchy
1777 * @header: the header returned from register_sysctl_table
1779 * Unregisters the sysctl table and all children. proc entries may not
1780 * actually be removed until they are no longer used by anyone.
1782 void unregister_sysctl_table(struct ctl_table_header * header)
1789 spin_lock(&sysctl_lock);
1790 start_unregistering(header);
1791 spin_unlock(&sysctl_lock);
1795 #else /* !CONFIG_SYSCTL */
1796 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1801 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1802 struct ctl_table *table)
1807 void unregister_sysctl_table(struct ctl_table_header * table)
1811 #endif /* CONFIG_SYSCTL */
1817 #ifdef CONFIG_PROC_SYSCTL
1819 static int _proc_do_string(void* data, int maxlen, int write,
1820 struct file *filp, void __user *buffer,
1821 size_t *lenp, loff_t *ppos)
1827 if (!data || !maxlen || !*lenp) {
1835 while (len < *lenp) {
1836 if (get_user(c, p++))
1838 if (c == 0 || c == '\n')
1844 if(copy_from_user(data, buffer, len))
1846 ((char *) data)[len] = 0;
1864 if(copy_to_user(buffer, data, len))
1867 if(put_user('\n', ((char __user *) buffer) + len))
1878 * proc_dostring - read a string sysctl
1879 * @table: the sysctl table
1880 * @write: %TRUE if this is a write to the sysctl file
1881 * @filp: the file structure
1882 * @buffer: the user buffer
1883 * @lenp: the size of the user buffer
1884 * @ppos: file position
1886 * Reads/writes a string from/to the user buffer. If the kernel
1887 * buffer provided is not large enough to hold the string, the
1888 * string is truncated. The copied string is %NULL-terminated.
1889 * If the string is being read by the user process, it is copied
1890 * and a newline '\n' is added. It is truncated if the buffer is
1893 * Returns 0 on success.
1895 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
1896 void __user *buffer, size_t *lenp, loff_t *ppos)
1898 return _proc_do_string(table->data, table->maxlen, write, filp,
1899 buffer, lenp, ppos);
1903 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1905 int write, void *data)
1908 *valp = *negp ? -*lvalp : *lvalp;
1913 *lvalp = (unsigned long)-val;
1916 *lvalp = (unsigned long)val;
1922 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
1923 int write, struct file *filp, void __user *buffer,
1924 size_t *lenp, loff_t *ppos,
1925 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1926 int write, void *data),
1929 #define TMPBUFLEN 21
1930 int *i, vleft, first=1, neg, val;
1934 char buf[TMPBUFLEN], *p;
1935 char __user *s = buffer;
1937 if (!tbl_data || !table->maxlen || !*lenp ||
1938 (*ppos && !write)) {
1943 i = (int *) tbl_data;
1944 vleft = table->maxlen / sizeof(*i);
1948 conv = do_proc_dointvec_conv;
1950 for (; left && vleft--; i++, first=0) {
1965 if (len > sizeof(buf) - 1)
1966 len = sizeof(buf) - 1;
1967 if (copy_from_user(buf, s, len))
1971 if (*p == '-' && left > 1) {
1975 if (*p < '0' || *p > '9')
1978 lval = simple_strtoul(p, &p, 0);
1981 if ((len < left) && *p && !isspace(*p))
1988 if (conv(&neg, &lval, i, 1, data))
1995 if (conv(&neg, &lval, i, 0, data))
1998 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2002 if(copy_to_user(s, buf, len))
2009 if (!write && !first && left) {
2010 if(put_user('\n', s))
2017 if (get_user(c, s++))
2032 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2033 void __user *buffer, size_t *lenp, loff_t *ppos,
2034 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2035 int write, void *data),
2038 return __do_proc_dointvec(table->data, table, write, filp,
2039 buffer, lenp, ppos, conv, data);
2043 * proc_dointvec - read a vector of integers
2044 * @table: the sysctl table
2045 * @write: %TRUE if this is a write to the sysctl file
2046 * @filp: the file structure
2047 * @buffer: the user buffer
2048 * @lenp: the size of the user buffer
2049 * @ppos: file position
2051 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2052 * values from/to the user buffer, treated as an ASCII string.
2054 * Returns 0 on success.
2056 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2057 void __user *buffer, size_t *lenp, loff_t *ppos)
2059 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2067 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
2069 int write, void *data)
2071 int op = *(int *)data;
2073 int val = *negp ? -*lvalp : *lvalp;
2075 case OP_SET: *valp = val; break;
2076 case OP_AND: *valp &= val; break;
2077 case OP_OR: *valp |= val; break;
2083 *lvalp = (unsigned long)-val;
2086 *lvalp = (unsigned long)val;
2093 * Taint values can only be increased
2095 static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
2096 void __user *buffer, size_t *lenp, loff_t *ppos)
2100 if (write && !capable(CAP_SYS_ADMIN))
2104 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2105 do_proc_dointvec_bset_conv,&op);
2108 struct do_proc_dointvec_minmax_conv_param {
2113 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2115 int write, void *data)
2117 struct do_proc_dointvec_minmax_conv_param *param = data;
2119 int val = *negp ? -*lvalp : *lvalp;
2120 if ((param->min && *param->min > val) ||
2121 (param->max && *param->max < val))
2128 *lvalp = (unsigned long)-val;
2131 *lvalp = (unsigned long)val;
2138 * proc_dointvec_minmax - read a vector of integers with min/max values
2139 * @table: the sysctl table
2140 * @write: %TRUE if this is a write to the sysctl file
2141 * @filp: the file structure
2142 * @buffer: the user buffer
2143 * @lenp: the size of the user buffer
2144 * @ppos: file position
2146 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2147 * values from/to the user buffer, treated as an ASCII string.
2149 * This routine will ensure the values are within the range specified by
2150 * table->extra1 (min) and table->extra2 (max).
2152 * Returns 0 on success.
2154 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2155 void __user *buffer, size_t *lenp, loff_t *ppos)
2157 struct do_proc_dointvec_minmax_conv_param param = {
2158 .min = (int *) table->extra1,
2159 .max = (int *) table->extra2,
2161 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2162 do_proc_dointvec_minmax_conv, ¶m);
2165 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2167 void __user *buffer,
2168 size_t *lenp, loff_t *ppos,
2169 unsigned long convmul,
2170 unsigned long convdiv)
2172 #define TMPBUFLEN 21
2173 unsigned long *i, *min, *max, val;
2174 int vleft, first=1, neg;
2176 char buf[TMPBUFLEN], *p;
2177 char __user *s = buffer;
2179 if (!data || !table->maxlen || !*lenp ||
2180 (*ppos && !write)) {
2185 i = (unsigned long *) data;
2186 min = (unsigned long *) table->extra1;
2187 max = (unsigned long *) table->extra2;
2188 vleft = table->maxlen / sizeof(unsigned long);
2191 for (; left && vleft--; i++, min++, max++, first=0) {
2206 if (len > TMPBUFLEN-1)
2208 if (copy_from_user(buf, s, len))
2212 if (*p == '-' && left > 1) {
2216 if (*p < '0' || *p > '9')
2218 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2220 if ((len < left) && *p && !isspace(*p))
2229 if ((min && val < *min) || (max && val > *max))
2236 sprintf(p, "%lu", convdiv * (*i) / convmul);
2240 if(copy_to_user(s, buf, len))
2247 if (!write && !first && left) {
2248 if(put_user('\n', s))
2255 if (get_user(c, s++))
2270 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2272 void __user *buffer,
2273 size_t *lenp, loff_t *ppos,
2274 unsigned long convmul,
2275 unsigned long convdiv)
2277 return __do_proc_doulongvec_minmax(table->data, table, write,
2278 filp, buffer, lenp, ppos, convmul, convdiv);
2282 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2283 * @table: the sysctl table
2284 * @write: %TRUE if this is a write to the sysctl file
2285 * @filp: the file structure
2286 * @buffer: the user buffer
2287 * @lenp: the size of the user buffer
2288 * @ppos: file position
2290 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2291 * values from/to the user buffer, treated as an ASCII string.
2293 * This routine will ensure the values are within the range specified by
2294 * table->extra1 (min) and table->extra2 (max).
2296 * Returns 0 on success.
2298 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2299 void __user *buffer, size_t *lenp, loff_t *ppos)
2301 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2305 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2306 * @table: the sysctl table
2307 * @write: %TRUE if this is a write to the sysctl file
2308 * @filp: the file structure
2309 * @buffer: the user buffer
2310 * @lenp: the size of the user buffer
2311 * @ppos: file position
2313 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2314 * values from/to the user buffer, treated as an ASCII string. The values
2315 * are treated as milliseconds, and converted to jiffies when they are stored.
2317 * This routine will ensure the values are within the range specified by
2318 * table->extra1 (min) and table->extra2 (max).
2320 * Returns 0 on success.
2322 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2324 void __user *buffer,
2325 size_t *lenp, loff_t *ppos)
2327 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2328 lenp, ppos, HZ, 1000l);
2332 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2334 int write, void *data)
2337 if (*lvalp > LONG_MAX / HZ)
2339 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2345 lval = (unsigned long)-val;
2348 lval = (unsigned long)val;
2355 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2357 int write, void *data)
2360 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2362 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2368 lval = (unsigned long)-val;
2371 lval = (unsigned long)val;
2373 *lvalp = jiffies_to_clock_t(lval);
2378 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2380 int write, void *data)
2383 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2389 lval = (unsigned long)-val;
2392 lval = (unsigned long)val;
2394 *lvalp = jiffies_to_msecs(lval);
2400 * proc_dointvec_jiffies - read a vector of integers as seconds
2401 * @table: the sysctl table
2402 * @write: %TRUE if this is a write to the sysctl file
2403 * @filp: the file structure
2404 * @buffer: the user buffer
2405 * @lenp: the size of the user buffer
2406 * @ppos: file position
2408 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2409 * values from/to the user buffer, treated as an ASCII string.
2410 * The values read are assumed to be in seconds, and are converted into
2413 * Returns 0 on success.
2415 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2416 void __user *buffer, size_t *lenp, loff_t *ppos)
2418 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2419 do_proc_dointvec_jiffies_conv,NULL);
2423 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2424 * @table: the sysctl table
2425 * @write: %TRUE if this is a write to the sysctl file
2426 * @filp: the file structure
2427 * @buffer: the user buffer
2428 * @lenp: the size of the user buffer
2429 * @ppos: pointer to the file position
2431 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2432 * values from/to the user buffer, treated as an ASCII string.
2433 * The values read are assumed to be in 1/USER_HZ seconds, and
2434 * are converted into jiffies.
2436 * Returns 0 on success.
2438 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2439 void __user *buffer, size_t *lenp, loff_t *ppos)
2441 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2442 do_proc_dointvec_userhz_jiffies_conv,NULL);
2446 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2447 * @table: the sysctl table
2448 * @write: %TRUE if this is a write to the sysctl file
2449 * @filp: the file structure
2450 * @buffer: the user buffer
2451 * @lenp: the size of the user buffer
2452 * @ppos: file position
2453 * @ppos: the current position in the file
2455 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2456 * values from/to the user buffer, treated as an ASCII string.
2457 * The values read are assumed to be in 1/1000 seconds, and
2458 * are converted into jiffies.
2460 * Returns 0 on success.
2462 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2463 void __user *buffer, size_t *lenp, loff_t *ppos)
2465 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2466 do_proc_dointvec_ms_jiffies_conv, NULL);
2469 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2470 void __user *buffer, size_t *lenp, loff_t *ppos)
2472 struct pid *new_pid;
2476 tmp = pid_vnr(cad_pid);
2478 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2479 lenp, ppos, NULL, NULL);
2483 new_pid = find_get_pid(tmp);
2487 put_pid(xchg(&cad_pid, new_pid));
2491 #else /* CONFIG_PROC_FS */
2493 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2494 void __user *buffer, size_t *lenp, loff_t *ppos)
2499 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2500 void __user *buffer, size_t *lenp, loff_t *ppos)
2505 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2506 void __user *buffer, size_t *lenp, loff_t *ppos)
2511 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2512 void __user *buffer, size_t *lenp, loff_t *ppos)
2517 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2518 void __user *buffer, size_t *lenp, loff_t *ppos)
2523 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2524 void __user *buffer, size_t *lenp, loff_t *ppos)
2529 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2530 void __user *buffer, size_t *lenp, loff_t *ppos)
2535 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2537 void __user *buffer,
2538 size_t *lenp, loff_t *ppos)
2544 #endif /* CONFIG_PROC_FS */
2547 #ifdef CONFIG_SYSCTL_SYSCALL
2549 * General sysctl support routines
2552 /* The generic sysctl data routine (used if no strategy routine supplied) */
2553 int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2554 void __user *oldval, size_t __user *oldlenp,
2555 void __user *newval, size_t newlen)
2559 /* Get out of I don't have a variable */
2560 if (!table->data || !table->maxlen)
2563 if (oldval && oldlenp) {
2564 if (get_user(len, oldlenp))
2567 if (len > table->maxlen)
2568 len = table->maxlen;
2569 if (copy_to_user(oldval, table->data, len))
2571 if (put_user(len, oldlenp))
2576 if (newval && newlen) {
2577 if (newlen > table->maxlen)
2578 newlen = table->maxlen;
2580 if (copy_from_user(table->data, newval, newlen))
2586 /* The generic string strategy routine: */
2587 int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2588 void __user *oldval, size_t __user *oldlenp,
2589 void __user *newval, size_t newlen)
2591 if (!table->data || !table->maxlen)
2594 if (oldval && oldlenp) {
2596 if (get_user(bufsize, oldlenp))
2599 size_t len = strlen(table->data), copied;
2601 /* This shouldn't trigger for a well-formed sysctl */
2602 if (len > table->maxlen)
2603 len = table->maxlen;
2605 /* Copy up to a max of bufsize-1 bytes of the string */
2606 copied = (len >= bufsize) ? bufsize - 1 : len;
2608 if (copy_to_user(oldval, table->data, copied) ||
2609 put_user(0, (char __user *)(oldval + copied)))
2611 if (put_user(len, oldlenp))
2615 if (newval && newlen) {
2616 size_t len = newlen;
2617 if (len > table->maxlen)
2618 len = table->maxlen;
2619 if(copy_from_user(table->data, newval, len))
2621 if (len == table->maxlen)
2623 ((char *) table->data)[len] = 0;
2629 * This function makes sure that all of the integers in the vector
2630 * are between the minimum and maximum values given in the arrays
2631 * table->extra1 and table->extra2, respectively.
2633 int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2634 void __user *oldval, size_t __user *oldlenp,
2635 void __user *newval, size_t newlen)
2638 if (newval && newlen) {
2639 int __user *vec = (int __user *) newval;
2640 int *min = (int *) table->extra1;
2641 int *max = (int *) table->extra2;
2645 if (newlen % sizeof(int) != 0)
2648 if (!table->extra1 && !table->extra2)
2651 if (newlen > table->maxlen)
2652 newlen = table->maxlen;
2653 length = newlen / sizeof(int);
2655 for (i = 0; i < length; i++) {
2657 if (get_user(value, vec + i))
2659 if (min && value < min[i])
2661 if (max && value > max[i])
2668 /* Strategy function to convert jiffies to seconds */
2669 int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2670 void __user *oldval, size_t __user *oldlenp,
2671 void __user *newval, size_t newlen)
2673 if (oldval && oldlenp) {
2676 if (get_user(olen, oldlenp))
2681 if (olen < sizeof(int))
2684 val = *(int *)(table->data) / HZ;
2685 if (put_user(val, (int __user *)oldval))
2687 if (put_user(sizeof(int), oldlenp))
2691 if (newval && newlen) {
2693 if (newlen != sizeof(int))
2695 if (get_user(new, (int __user *)newval))
2697 *(int *)(table->data) = new*HZ;
2702 /* Strategy function to convert jiffies to seconds */
2703 int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2704 void __user *oldval, size_t __user *oldlenp,
2705 void __user *newval, size_t newlen)
2707 if (oldval && oldlenp) {
2710 if (get_user(olen, oldlenp))
2715 if (olen < sizeof(int))
2718 val = jiffies_to_msecs(*(int *)(table->data));
2719 if (put_user(val, (int __user *)oldval))
2721 if (put_user(sizeof(int), oldlenp))
2725 if (newval && newlen) {
2727 if (newlen != sizeof(int))
2729 if (get_user(new, (int __user *)newval))
2731 *(int *)(table->data) = msecs_to_jiffies(new);
2738 #else /* CONFIG_SYSCTL_SYSCALL */
2741 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2743 struct __sysctl_args tmp;
2746 if (copy_from_user(&tmp, args, sizeof(tmp)))
2749 error = deprecated_sysctl_warning(&tmp);
2751 /* If no error reading the parameters then just -ENOSYS ... */
2758 int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2759 void __user *oldval, size_t __user *oldlenp,
2760 void __user *newval, size_t newlen)
2765 int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2766 void __user *oldval, size_t __user *oldlenp,
2767 void __user *newval, size_t newlen)
2772 int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2773 void __user *oldval, size_t __user *oldlenp,
2774 void __user *newval, size_t newlen)
2779 int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2780 void __user *oldval, size_t __user *oldlenp,
2781 void __user *newval, size_t newlen)
2786 int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2787 void __user *oldval, size_t __user *oldlenp,
2788 void __user *newval, size_t newlen)
2793 #endif /* CONFIG_SYSCTL_SYSCALL */
2795 static int deprecated_sysctl_warning(struct __sysctl_args *args)
2797 static int msg_count;
2798 int name[CTL_MAXNAME];
2801 /* Check args->nlen. */
2802 if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
2805 /* Read in the sysctl name for better debug message logging */
2806 for (i = 0; i < args->nlen; i++)
2807 if (get_user(name[i], args->name + i))
2810 /* Ignore accesses to kernel.version */
2811 if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2814 if (msg_count < 5) {
2817 "warning: process `%s' used the deprecated sysctl "
2818 "system call with ", current->comm);
2819 for (i = 0; i < args->nlen; i++)
2820 printk("%d.", name[i]);
2827 * No sense putting this after each symbol definition, twice,
2828 * exception granted :-)
2830 EXPORT_SYMBOL(proc_dointvec);
2831 EXPORT_SYMBOL(proc_dointvec_jiffies);
2832 EXPORT_SYMBOL(proc_dointvec_minmax);
2833 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2834 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2835 EXPORT_SYMBOL(proc_dostring);
2836 EXPORT_SYMBOL(proc_doulongvec_minmax);
2837 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2838 EXPORT_SYMBOL(register_sysctl_table);
2839 EXPORT_SYMBOL(register_sysctl_paths);
2840 EXPORT_SYMBOL(sysctl_intvec);
2841 EXPORT_SYMBOL(sysctl_jiffies);
2842 EXPORT_SYMBOL(sysctl_ms_jiffies);
2843 EXPORT_SYMBOL(sysctl_string);
2844 EXPORT_SYMBOL(sysctl_data);
2845 EXPORT_SYMBOL(unregister_sysctl_table);