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/vmstat.h>
47 #include <linux/nfs_fs.h>
48 #include <linux/acpi.h>
49 #include <linux/reboot.h>
50 #include <linux/ftrace.h>
52 #include <asm/uaccess.h>
53 #include <asm/processor.h>
57 #include <asm/stacktrace.h>
61 static int deprecated_sysctl_warning(struct __sysctl_args *args);
63 #if defined(CONFIG_SYSCTL)
65 /* External variables not in a header file. */
67 extern int print_fatal_signals;
68 extern int sysctl_overcommit_memory;
69 extern int sysctl_overcommit_ratio;
70 extern int sysctl_panic_on_oom;
71 extern int sysctl_oom_kill_allocating_task;
72 extern int sysctl_oom_dump_tasks;
73 extern int max_threads;
74 extern int core_uses_pid;
75 extern int suid_dumpable;
76 extern char core_pattern[];
78 extern int min_free_kbytes;
79 extern int pid_max_min, pid_max_max;
80 extern int sysctl_drop_caches;
81 extern int percpu_pagelist_fraction;
82 extern int compat_log;
83 extern int latencytop_enabled;
84 extern int sysctl_nr_open_min, sysctl_nr_open_max;
85 #ifdef CONFIG_RCU_TORTURE_TEST
86 extern int rcutorture_runnable;
87 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
89 /* Constants used for minimum and maximum */
90 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP)
94 #ifdef CONFIG_DETECT_SOFTLOCKUP
95 static int sixty = 60;
96 static int neg_one = -1;
99 #if defined(CONFIG_MMU) && defined(CONFIG_FILE_LOCKING)
104 static int one_hundred = 100;
106 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
107 static int maxolduid = 65535;
108 static int minolduid;
109 static int min_percpu_pagelist_fract = 8;
111 static int ngroups_max = NGROUPS_MAX;
113 #ifdef CONFIG_MODULES
114 extern char modprobe_path[];
116 #ifdef CONFIG_CHR_DEV_SG
117 extern int sg_big_buff;
121 #include <asm/system.h>
125 extern int pwrsw_enabled;
126 extern int unaligned_enabled;
130 #ifdef CONFIG_MATHEMU
131 extern int sysctl_ieee_emulation_warnings;
133 extern int sysctl_userprocess_debug;
134 extern int spin_retry;
137 #ifdef CONFIG_BSD_PROCESS_ACCT
138 extern int acct_parm[];
142 extern int no_unaligned_warning;
145 #ifdef CONFIG_RT_MUTEXES
146 extern int max_lock_depth;
149 #ifdef CONFIG_PROC_SYSCTL
150 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
151 void __user *buffer, size_t *lenp, loff_t *ppos);
152 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
153 void __user *buffer, size_t *lenp, loff_t *ppos);
156 static struct ctl_table root_table[];
157 static struct ctl_table_root sysctl_table_root;
158 static struct ctl_table_header root_table_header = {
160 .ctl_table = root_table,
161 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
162 .root = &sysctl_table_root,
163 .set = &sysctl_table_root.default_set,
165 static struct ctl_table_root sysctl_table_root = {
166 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
167 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
170 static struct ctl_table kern_table[];
171 static struct ctl_table vm_table[];
172 static struct ctl_table fs_table[];
173 static struct ctl_table debug_table[];
174 static struct ctl_table dev_table[];
175 extern struct ctl_table random_table[];
176 #ifdef CONFIG_INOTIFY_USER
177 extern struct ctl_table inotify_table[];
180 extern struct ctl_table epoll_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_shares_ratelimit",
275 .data = &sysctl_sched_shares_ratelimit,
276 .maxlen = sizeof(unsigned int),
278 .proc_handler = &proc_dointvec,
281 .ctl_name = CTL_UNNUMBERED,
282 .procname = "sched_shares_thresh",
283 .data = &sysctl_sched_shares_thresh,
284 .maxlen = sizeof(unsigned int),
286 .proc_handler = &proc_dointvec_minmax,
287 .strategy = &sysctl_intvec,
291 .ctl_name = CTL_UNNUMBERED,
292 .procname = "sched_child_runs_first",
293 .data = &sysctl_sched_child_runs_first,
294 .maxlen = sizeof(unsigned int),
296 .proc_handler = &proc_dointvec,
299 .ctl_name = CTL_UNNUMBERED,
300 .procname = "sched_features",
301 .data = &sysctl_sched_features,
302 .maxlen = sizeof(unsigned int),
304 .proc_handler = &proc_dointvec,
307 .ctl_name = CTL_UNNUMBERED,
308 .procname = "sched_migration_cost",
309 .data = &sysctl_sched_migration_cost,
310 .maxlen = sizeof(unsigned int),
312 .proc_handler = &proc_dointvec,
315 .ctl_name = CTL_UNNUMBERED,
316 .procname = "sched_nr_migrate",
317 .data = &sysctl_sched_nr_migrate,
318 .maxlen = sizeof(unsigned int),
320 .proc_handler = &proc_dointvec,
324 .ctl_name = CTL_UNNUMBERED,
325 .procname = "sched_rt_period_us",
326 .data = &sysctl_sched_rt_period,
327 .maxlen = sizeof(unsigned int),
329 .proc_handler = &sched_rt_handler,
332 .ctl_name = CTL_UNNUMBERED,
333 .procname = "sched_rt_runtime_us",
334 .data = &sysctl_sched_rt_runtime,
335 .maxlen = sizeof(int),
337 .proc_handler = &sched_rt_handler,
340 .ctl_name = CTL_UNNUMBERED,
341 .procname = "sched_compat_yield",
342 .data = &sysctl_sched_compat_yield,
343 .maxlen = sizeof(unsigned int),
345 .proc_handler = &proc_dointvec,
347 #ifdef CONFIG_PROVE_LOCKING
349 .ctl_name = CTL_UNNUMBERED,
350 .procname = "prove_locking",
351 .data = &prove_locking,
352 .maxlen = sizeof(int),
354 .proc_handler = &proc_dointvec,
357 #ifdef CONFIG_LOCK_STAT
359 .ctl_name = CTL_UNNUMBERED,
360 .procname = "lock_stat",
362 .maxlen = sizeof(int),
364 .proc_handler = &proc_dointvec,
368 .ctl_name = KERN_PANIC,
370 .data = &panic_timeout,
371 .maxlen = sizeof(int),
373 .proc_handler = &proc_dointvec,
376 .ctl_name = KERN_CORE_USES_PID,
377 .procname = "core_uses_pid",
378 .data = &core_uses_pid,
379 .maxlen = sizeof(int),
381 .proc_handler = &proc_dointvec,
384 .ctl_name = KERN_CORE_PATTERN,
385 .procname = "core_pattern",
386 .data = core_pattern,
387 .maxlen = CORENAME_MAX_SIZE,
389 .proc_handler = &proc_dostring,
390 .strategy = &sysctl_string,
392 #ifdef CONFIG_PROC_SYSCTL
394 .procname = "tainted",
395 .maxlen = sizeof(long),
397 .proc_handler = &proc_taint,
400 #ifdef CONFIG_LATENCYTOP
402 .procname = "latencytop",
403 .data = &latencytop_enabled,
404 .maxlen = sizeof(int),
406 .proc_handler = &proc_dointvec,
409 #ifdef CONFIG_BLK_DEV_INITRD
411 .ctl_name = KERN_REALROOTDEV,
412 .procname = "real-root-dev",
413 .data = &real_root_dev,
414 .maxlen = sizeof(int),
416 .proc_handler = &proc_dointvec,
420 .ctl_name = CTL_UNNUMBERED,
421 .procname = "print-fatal-signals",
422 .data = &print_fatal_signals,
423 .maxlen = sizeof(int),
425 .proc_handler = &proc_dointvec,
429 .ctl_name = KERN_SPARC_REBOOT,
430 .procname = "reboot-cmd",
431 .data = reboot_command,
434 .proc_handler = &proc_dostring,
435 .strategy = &sysctl_string,
438 .ctl_name = KERN_SPARC_STOP_A,
439 .procname = "stop-a",
440 .data = &stop_a_enabled,
441 .maxlen = sizeof (int),
443 .proc_handler = &proc_dointvec,
446 .ctl_name = KERN_SPARC_SCONS_PWROFF,
447 .procname = "scons-poweroff",
448 .data = &scons_pwroff,
449 .maxlen = sizeof (int),
451 .proc_handler = &proc_dointvec,
456 .ctl_name = KERN_HPPA_PWRSW,
457 .procname = "soft-power",
458 .data = &pwrsw_enabled,
459 .maxlen = sizeof (int),
461 .proc_handler = &proc_dointvec,
464 .ctl_name = KERN_HPPA_UNALIGNED,
465 .procname = "unaligned-trap",
466 .data = &unaligned_enabled,
467 .maxlen = sizeof (int),
469 .proc_handler = &proc_dointvec,
473 .ctl_name = KERN_CTLALTDEL,
474 .procname = "ctrl-alt-del",
476 .maxlen = sizeof(int),
478 .proc_handler = &proc_dointvec,
480 #ifdef CONFIG_FUNCTION_TRACER
482 .ctl_name = CTL_UNNUMBERED,
483 .procname = "ftrace_enabled",
484 .data = &ftrace_enabled,
485 .maxlen = sizeof(int),
487 .proc_handler = &ftrace_enable_sysctl,
490 #ifdef CONFIG_TRACING
492 .ctl_name = CTL_UNNUMBERED,
493 .procname = "ftrace_dump_on_oops",
494 .data = &ftrace_dump_on_oops,
495 .maxlen = sizeof(int),
497 .proc_handler = &proc_dointvec,
500 #ifdef CONFIG_MODULES
502 .ctl_name = KERN_MODPROBE,
503 .procname = "modprobe",
504 .data = &modprobe_path,
505 .maxlen = KMOD_PATH_LEN,
507 .proc_handler = &proc_dostring,
508 .strategy = &sysctl_string,
511 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
513 .ctl_name = KERN_HOTPLUG,
514 .procname = "hotplug",
515 .data = &uevent_helper,
516 .maxlen = UEVENT_HELPER_PATH_LEN,
518 .proc_handler = &proc_dostring,
519 .strategy = &sysctl_string,
522 #ifdef CONFIG_CHR_DEV_SG
524 .ctl_name = KERN_SG_BIG_BUFF,
525 .procname = "sg-big-buff",
526 .data = &sg_big_buff,
527 .maxlen = sizeof (int),
529 .proc_handler = &proc_dointvec,
532 #ifdef CONFIG_BSD_PROCESS_ACCT
534 .ctl_name = KERN_ACCT,
537 .maxlen = 3*sizeof(int),
539 .proc_handler = &proc_dointvec,
542 #ifdef CONFIG_MAGIC_SYSRQ
544 .ctl_name = KERN_SYSRQ,
546 .data = &__sysrq_enabled,
547 .maxlen = sizeof (int),
549 .proc_handler = &proc_dointvec,
552 #ifdef CONFIG_PROC_SYSCTL
554 .procname = "cad_pid",
556 .maxlen = sizeof (int),
558 .proc_handler = &proc_do_cad_pid,
562 .ctl_name = KERN_MAX_THREADS,
563 .procname = "threads-max",
564 .data = &max_threads,
565 .maxlen = sizeof(int),
567 .proc_handler = &proc_dointvec,
570 .ctl_name = KERN_RANDOM,
571 .procname = "random",
573 .child = random_table,
576 .ctl_name = KERN_OVERFLOWUID,
577 .procname = "overflowuid",
578 .data = &overflowuid,
579 .maxlen = sizeof(int),
581 .proc_handler = &proc_dointvec_minmax,
582 .strategy = &sysctl_intvec,
583 .extra1 = &minolduid,
584 .extra2 = &maxolduid,
587 .ctl_name = KERN_OVERFLOWGID,
588 .procname = "overflowgid",
589 .data = &overflowgid,
590 .maxlen = sizeof(int),
592 .proc_handler = &proc_dointvec_minmax,
593 .strategy = &sysctl_intvec,
594 .extra1 = &minolduid,
595 .extra2 = &maxolduid,
598 #ifdef CONFIG_MATHEMU
600 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
601 .procname = "ieee_emulation_warnings",
602 .data = &sysctl_ieee_emulation_warnings,
603 .maxlen = sizeof(int),
605 .proc_handler = &proc_dointvec,
609 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
610 .procname = "userprocess_debug",
611 .data = &sysctl_userprocess_debug,
612 .maxlen = sizeof(int),
614 .proc_handler = &proc_dointvec,
618 .ctl_name = KERN_PIDMAX,
619 .procname = "pid_max",
621 .maxlen = sizeof (int),
623 .proc_handler = &proc_dointvec_minmax,
624 .strategy = sysctl_intvec,
625 .extra1 = &pid_max_min,
626 .extra2 = &pid_max_max,
629 .ctl_name = KERN_PANIC_ON_OOPS,
630 .procname = "panic_on_oops",
631 .data = &panic_on_oops,
632 .maxlen = sizeof(int),
634 .proc_handler = &proc_dointvec,
636 #if defined CONFIG_PRINTK
638 .ctl_name = KERN_PRINTK,
639 .procname = "printk",
640 .data = &console_loglevel,
641 .maxlen = 4*sizeof(int),
643 .proc_handler = &proc_dointvec,
646 .ctl_name = KERN_PRINTK_RATELIMIT,
647 .procname = "printk_ratelimit",
648 .data = &printk_ratelimit_state.interval,
649 .maxlen = sizeof(int),
651 .proc_handler = &proc_dointvec_jiffies,
652 .strategy = &sysctl_jiffies,
655 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
656 .procname = "printk_ratelimit_burst",
657 .data = &printk_ratelimit_state.burst,
658 .maxlen = sizeof(int),
660 .proc_handler = &proc_dointvec,
664 .ctl_name = KERN_NGROUPS_MAX,
665 .procname = "ngroups_max",
666 .data = &ngroups_max,
667 .maxlen = sizeof (int),
669 .proc_handler = &proc_dointvec,
671 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
673 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
674 .procname = "unknown_nmi_panic",
675 .data = &unknown_nmi_panic,
676 .maxlen = sizeof (int),
678 .proc_handler = &proc_dointvec,
681 .procname = "nmi_watchdog",
682 .data = &nmi_watchdog_enabled,
683 .maxlen = sizeof (int),
685 .proc_handler = &proc_nmi_enabled,
688 #if defined(CONFIG_X86)
690 .ctl_name = KERN_PANIC_ON_NMI,
691 .procname = "panic_on_unrecovered_nmi",
692 .data = &panic_on_unrecovered_nmi,
693 .maxlen = sizeof(int),
695 .proc_handler = &proc_dointvec,
698 .ctl_name = KERN_BOOTLOADER_TYPE,
699 .procname = "bootloader_type",
700 .data = &bootloader_type,
701 .maxlen = sizeof (int),
703 .proc_handler = &proc_dointvec,
706 .ctl_name = CTL_UNNUMBERED,
707 .procname = "kstack_depth_to_print",
708 .data = &kstack_depth_to_print,
709 .maxlen = sizeof(int),
711 .proc_handler = &proc_dointvec,
714 .ctl_name = CTL_UNNUMBERED,
715 .procname = "io_delay_type",
716 .data = &io_delay_type,
717 .maxlen = sizeof(int),
719 .proc_handler = &proc_dointvec,
722 #if defined(CONFIG_MMU)
724 .ctl_name = KERN_RANDOMIZE,
725 .procname = "randomize_va_space",
726 .data = &randomize_va_space,
727 .maxlen = sizeof(int),
729 .proc_handler = &proc_dointvec,
732 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
734 .ctl_name = KERN_SPIN_RETRY,
735 .procname = "spin_retry",
737 .maxlen = sizeof (int),
739 .proc_handler = &proc_dointvec,
742 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
744 .procname = "acpi_video_flags",
745 .data = &acpi_realmode_flags,
746 .maxlen = sizeof (unsigned long),
748 .proc_handler = &proc_doulongvec_minmax,
753 .ctl_name = KERN_IA64_UNALIGNED,
754 .procname = "ignore-unaligned-usertrap",
755 .data = &no_unaligned_warning,
756 .maxlen = sizeof (int),
758 .proc_handler = &proc_dointvec,
761 #ifdef CONFIG_DETECT_SOFTLOCKUP
763 .ctl_name = CTL_UNNUMBERED,
764 .procname = "softlockup_panic",
765 .data = &softlockup_panic,
766 .maxlen = sizeof(int),
768 .proc_handler = &proc_dointvec_minmax,
769 .strategy = &sysctl_intvec,
774 .ctl_name = CTL_UNNUMBERED,
775 .procname = "softlockup_thresh",
776 .data = &softlockup_thresh,
777 .maxlen = sizeof(int),
779 .proc_handler = &proc_dointvec_minmax,
780 .strategy = &sysctl_intvec,
785 .ctl_name = CTL_UNNUMBERED,
786 .procname = "hung_task_check_count",
787 .data = &sysctl_hung_task_check_count,
788 .maxlen = sizeof(unsigned long),
790 .proc_handler = &proc_doulongvec_minmax,
791 .strategy = &sysctl_intvec,
794 .ctl_name = CTL_UNNUMBERED,
795 .procname = "hung_task_timeout_secs",
796 .data = &sysctl_hung_task_timeout_secs,
797 .maxlen = sizeof(unsigned long),
799 .proc_handler = &proc_doulongvec_minmax,
800 .strategy = &sysctl_intvec,
803 .ctl_name = CTL_UNNUMBERED,
804 .procname = "hung_task_warnings",
805 .data = &sysctl_hung_task_warnings,
806 .maxlen = sizeof(unsigned long),
808 .proc_handler = &proc_doulongvec_minmax,
809 .strategy = &sysctl_intvec,
814 .ctl_name = KERN_COMPAT_LOG,
815 .procname = "compat-log",
817 .maxlen = sizeof (int),
819 .proc_handler = &proc_dointvec,
822 #ifdef CONFIG_RT_MUTEXES
824 .ctl_name = KERN_MAX_LOCK_DEPTH,
825 .procname = "max_lock_depth",
826 .data = &max_lock_depth,
827 .maxlen = sizeof(int),
829 .proc_handler = &proc_dointvec,
833 .ctl_name = CTL_UNNUMBERED,
834 .procname = "poweroff_cmd",
835 .data = &poweroff_cmd,
836 .maxlen = POWEROFF_CMD_PATH_LEN,
838 .proc_handler = &proc_dostring,
839 .strategy = &sysctl_string,
843 .ctl_name = CTL_UNNUMBERED,
846 .child = key_sysctls,
849 #ifdef CONFIG_RCU_TORTURE_TEST
851 .ctl_name = CTL_UNNUMBERED,
852 .procname = "rcutorture_runnable",
853 .data = &rcutorture_runnable,
854 .maxlen = sizeof(int),
856 .proc_handler = &proc_dointvec,
859 #ifdef CONFIG_UNEVICTABLE_LRU
861 .ctl_name = CTL_UNNUMBERED,
862 .procname = "scan_unevictable_pages",
863 .data = &scan_unevictable_pages,
864 .maxlen = sizeof(scan_unevictable_pages),
866 .proc_handler = &scan_unevictable_handler,
870 * NOTE: do not add new entries to this table unless you have read
871 * Documentation/sysctl/ctl_unnumbered.txt
876 static struct ctl_table vm_table[] = {
878 .ctl_name = VM_OVERCOMMIT_MEMORY,
879 .procname = "overcommit_memory",
880 .data = &sysctl_overcommit_memory,
881 .maxlen = sizeof(sysctl_overcommit_memory),
883 .proc_handler = &proc_dointvec,
886 .ctl_name = VM_PANIC_ON_OOM,
887 .procname = "panic_on_oom",
888 .data = &sysctl_panic_on_oom,
889 .maxlen = sizeof(sysctl_panic_on_oom),
891 .proc_handler = &proc_dointvec,
894 .ctl_name = CTL_UNNUMBERED,
895 .procname = "oom_kill_allocating_task",
896 .data = &sysctl_oom_kill_allocating_task,
897 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
899 .proc_handler = &proc_dointvec,
902 .ctl_name = CTL_UNNUMBERED,
903 .procname = "oom_dump_tasks",
904 .data = &sysctl_oom_dump_tasks,
905 .maxlen = sizeof(sysctl_oom_dump_tasks),
907 .proc_handler = &proc_dointvec,
910 .ctl_name = VM_OVERCOMMIT_RATIO,
911 .procname = "overcommit_ratio",
912 .data = &sysctl_overcommit_ratio,
913 .maxlen = sizeof(sysctl_overcommit_ratio),
915 .proc_handler = &proc_dointvec,
918 .ctl_name = VM_PAGE_CLUSTER,
919 .procname = "page-cluster",
920 .data = &page_cluster,
921 .maxlen = sizeof(int),
923 .proc_handler = &proc_dointvec,
926 .ctl_name = VM_DIRTY_BACKGROUND,
927 .procname = "dirty_background_ratio",
928 .data = &dirty_background_ratio,
929 .maxlen = sizeof(dirty_background_ratio),
931 .proc_handler = &proc_dointvec_minmax,
932 .strategy = &sysctl_intvec,
934 .extra2 = &one_hundred,
937 .ctl_name = VM_DIRTY_RATIO,
938 .procname = "dirty_ratio",
939 .data = &vm_dirty_ratio,
940 .maxlen = sizeof(vm_dirty_ratio),
942 .proc_handler = &dirty_ratio_handler,
943 .strategy = &sysctl_intvec,
945 .extra2 = &one_hundred,
948 .procname = "dirty_writeback_centisecs",
949 .data = &dirty_writeback_interval,
950 .maxlen = sizeof(dirty_writeback_interval),
952 .proc_handler = &dirty_writeback_centisecs_handler,
955 .procname = "dirty_expire_centisecs",
956 .data = &dirty_expire_interval,
957 .maxlen = sizeof(dirty_expire_interval),
959 .proc_handler = &proc_dointvec_userhz_jiffies,
962 .ctl_name = VM_NR_PDFLUSH_THREADS,
963 .procname = "nr_pdflush_threads",
964 .data = &nr_pdflush_threads,
965 .maxlen = sizeof nr_pdflush_threads,
966 .mode = 0444 /* read-only*/,
967 .proc_handler = &proc_dointvec,
970 .ctl_name = VM_SWAPPINESS,
971 .procname = "swappiness",
972 .data = &vm_swappiness,
973 .maxlen = sizeof(vm_swappiness),
975 .proc_handler = &proc_dointvec_minmax,
976 .strategy = &sysctl_intvec,
978 .extra2 = &one_hundred,
980 #ifdef CONFIG_HUGETLB_PAGE
982 .procname = "nr_hugepages",
984 .maxlen = sizeof(unsigned long),
986 .proc_handler = &hugetlb_sysctl_handler,
987 .extra1 = (void *)&hugetlb_zero,
988 .extra2 = (void *)&hugetlb_infinity,
991 .ctl_name = VM_HUGETLB_GROUP,
992 .procname = "hugetlb_shm_group",
993 .data = &sysctl_hugetlb_shm_group,
994 .maxlen = sizeof(gid_t),
996 .proc_handler = &proc_dointvec,
999 .ctl_name = CTL_UNNUMBERED,
1000 .procname = "hugepages_treat_as_movable",
1001 .data = &hugepages_treat_as_movable,
1002 .maxlen = sizeof(int),
1004 .proc_handler = &hugetlb_treat_movable_handler,
1007 .ctl_name = CTL_UNNUMBERED,
1008 .procname = "nr_overcommit_hugepages",
1010 .maxlen = sizeof(unsigned long),
1012 .proc_handler = &hugetlb_overcommit_handler,
1013 .extra1 = (void *)&hugetlb_zero,
1014 .extra2 = (void *)&hugetlb_infinity,
1018 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
1019 .procname = "lowmem_reserve_ratio",
1020 .data = &sysctl_lowmem_reserve_ratio,
1021 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1023 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
1024 .strategy = &sysctl_intvec,
1027 .ctl_name = VM_DROP_PAGECACHE,
1028 .procname = "drop_caches",
1029 .data = &sysctl_drop_caches,
1030 .maxlen = sizeof(int),
1032 .proc_handler = drop_caches_sysctl_handler,
1033 .strategy = &sysctl_intvec,
1036 .ctl_name = VM_MIN_FREE_KBYTES,
1037 .procname = "min_free_kbytes",
1038 .data = &min_free_kbytes,
1039 .maxlen = sizeof(min_free_kbytes),
1041 .proc_handler = &min_free_kbytes_sysctl_handler,
1042 .strategy = &sysctl_intvec,
1046 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
1047 .procname = "percpu_pagelist_fraction",
1048 .data = &percpu_pagelist_fraction,
1049 .maxlen = sizeof(percpu_pagelist_fraction),
1051 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
1052 .strategy = &sysctl_intvec,
1053 .extra1 = &min_percpu_pagelist_fract,
1057 .ctl_name = VM_MAX_MAP_COUNT,
1058 .procname = "max_map_count",
1059 .data = &sysctl_max_map_count,
1060 .maxlen = sizeof(sysctl_max_map_count),
1062 .proc_handler = &proc_dointvec
1066 .ctl_name = VM_LAPTOP_MODE,
1067 .procname = "laptop_mode",
1068 .data = &laptop_mode,
1069 .maxlen = sizeof(laptop_mode),
1071 .proc_handler = &proc_dointvec_jiffies,
1072 .strategy = &sysctl_jiffies,
1075 .ctl_name = VM_BLOCK_DUMP,
1076 .procname = "block_dump",
1077 .data = &block_dump,
1078 .maxlen = sizeof(block_dump),
1080 .proc_handler = &proc_dointvec,
1081 .strategy = &sysctl_intvec,
1085 .ctl_name = VM_VFS_CACHE_PRESSURE,
1086 .procname = "vfs_cache_pressure",
1087 .data = &sysctl_vfs_cache_pressure,
1088 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1090 .proc_handler = &proc_dointvec,
1091 .strategy = &sysctl_intvec,
1094 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1096 .ctl_name = VM_LEGACY_VA_LAYOUT,
1097 .procname = "legacy_va_layout",
1098 .data = &sysctl_legacy_va_layout,
1099 .maxlen = sizeof(sysctl_legacy_va_layout),
1101 .proc_handler = &proc_dointvec,
1102 .strategy = &sysctl_intvec,
1108 .ctl_name = VM_ZONE_RECLAIM_MODE,
1109 .procname = "zone_reclaim_mode",
1110 .data = &zone_reclaim_mode,
1111 .maxlen = sizeof(zone_reclaim_mode),
1113 .proc_handler = &proc_dointvec,
1114 .strategy = &sysctl_intvec,
1118 .ctl_name = VM_MIN_UNMAPPED,
1119 .procname = "min_unmapped_ratio",
1120 .data = &sysctl_min_unmapped_ratio,
1121 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1123 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1124 .strategy = &sysctl_intvec,
1126 .extra2 = &one_hundred,
1129 .ctl_name = VM_MIN_SLAB,
1130 .procname = "min_slab_ratio",
1131 .data = &sysctl_min_slab_ratio,
1132 .maxlen = sizeof(sysctl_min_slab_ratio),
1134 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1135 .strategy = &sysctl_intvec,
1137 .extra2 = &one_hundred,
1142 .ctl_name = CTL_UNNUMBERED,
1143 .procname = "stat_interval",
1144 .data = &sysctl_stat_interval,
1145 .maxlen = sizeof(sysctl_stat_interval),
1147 .proc_handler = &proc_dointvec_jiffies,
1148 .strategy = &sysctl_jiffies,
1151 #ifdef CONFIG_SECURITY
1153 .ctl_name = CTL_UNNUMBERED,
1154 .procname = "mmap_min_addr",
1155 .data = &mmap_min_addr,
1156 .maxlen = sizeof(unsigned long),
1158 .proc_handler = &proc_doulongvec_minmax,
1163 .ctl_name = CTL_UNNUMBERED,
1164 .procname = "numa_zonelist_order",
1165 .data = &numa_zonelist_order,
1166 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1168 .proc_handler = &numa_zonelist_order_handler,
1169 .strategy = &sysctl_string,
1172 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1173 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1175 .ctl_name = VM_VDSO_ENABLED,
1176 .procname = "vdso_enabled",
1177 .data = &vdso_enabled,
1178 .maxlen = sizeof(vdso_enabled),
1180 .proc_handler = &proc_dointvec,
1181 .strategy = &sysctl_intvec,
1185 #ifdef CONFIG_HIGHMEM
1187 .ctl_name = CTL_UNNUMBERED,
1188 .procname = "highmem_is_dirtyable",
1189 .data = &vm_highmem_is_dirtyable,
1190 .maxlen = sizeof(vm_highmem_is_dirtyable),
1192 .proc_handler = &proc_dointvec_minmax,
1193 .strategy = &sysctl_intvec,
1199 * NOTE: do not add new entries to this table unless you have read
1200 * Documentation/sysctl/ctl_unnumbered.txt
1205 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1206 static struct ctl_table binfmt_misc_table[] = {
1211 static struct ctl_table fs_table[] = {
1213 .ctl_name = FS_NRINODE,
1214 .procname = "inode-nr",
1215 .data = &inodes_stat,
1216 .maxlen = 2*sizeof(int),
1218 .proc_handler = &proc_dointvec,
1221 .ctl_name = FS_STATINODE,
1222 .procname = "inode-state",
1223 .data = &inodes_stat,
1224 .maxlen = 7*sizeof(int),
1226 .proc_handler = &proc_dointvec,
1229 .procname = "file-nr",
1230 .data = &files_stat,
1231 .maxlen = 3*sizeof(int),
1233 .proc_handler = &proc_nr_files,
1236 .ctl_name = FS_MAXFILE,
1237 .procname = "file-max",
1238 .data = &files_stat.max_files,
1239 .maxlen = sizeof(int),
1241 .proc_handler = &proc_dointvec,
1244 .ctl_name = CTL_UNNUMBERED,
1245 .procname = "nr_open",
1246 .data = &sysctl_nr_open,
1247 .maxlen = sizeof(int),
1249 .proc_handler = &proc_dointvec_minmax,
1250 .extra1 = &sysctl_nr_open_min,
1251 .extra2 = &sysctl_nr_open_max,
1254 .ctl_name = FS_DENTRY,
1255 .procname = "dentry-state",
1256 .data = &dentry_stat,
1257 .maxlen = 6*sizeof(int),
1259 .proc_handler = &proc_dointvec,
1262 .ctl_name = FS_OVERFLOWUID,
1263 .procname = "overflowuid",
1264 .data = &fs_overflowuid,
1265 .maxlen = sizeof(int),
1267 .proc_handler = &proc_dointvec_minmax,
1268 .strategy = &sysctl_intvec,
1269 .extra1 = &minolduid,
1270 .extra2 = &maxolduid,
1273 .ctl_name = FS_OVERFLOWGID,
1274 .procname = "overflowgid",
1275 .data = &fs_overflowgid,
1276 .maxlen = sizeof(int),
1278 .proc_handler = &proc_dointvec_minmax,
1279 .strategy = &sysctl_intvec,
1280 .extra1 = &minolduid,
1281 .extra2 = &maxolduid,
1283 #ifdef CONFIG_FILE_LOCKING
1285 .ctl_name = FS_LEASES,
1286 .procname = "leases-enable",
1287 .data = &leases_enable,
1288 .maxlen = sizeof(int),
1290 .proc_handler = &proc_dointvec,
1293 #ifdef CONFIG_DNOTIFY
1295 .ctl_name = FS_DIR_NOTIFY,
1296 .procname = "dir-notify-enable",
1297 .data = &dir_notify_enable,
1298 .maxlen = sizeof(int),
1300 .proc_handler = &proc_dointvec,
1304 #ifdef CONFIG_FILE_LOCKING
1306 .ctl_name = FS_LEASE_TIME,
1307 .procname = "lease-break-time",
1308 .data = &lease_break_time,
1309 .maxlen = sizeof(int),
1311 .proc_handler = &proc_dointvec_minmax,
1312 .strategy = &sysctl_intvec,
1319 .procname = "aio-nr",
1321 .maxlen = sizeof(aio_nr),
1323 .proc_handler = &proc_doulongvec_minmax,
1326 .procname = "aio-max-nr",
1327 .data = &aio_max_nr,
1328 .maxlen = sizeof(aio_max_nr),
1330 .proc_handler = &proc_doulongvec_minmax,
1332 #endif /* CONFIG_AIO */
1333 #ifdef CONFIG_INOTIFY_USER
1335 .ctl_name = FS_INOTIFY,
1336 .procname = "inotify",
1338 .child = inotify_table,
1343 .procname = "epoll",
1345 .child = epoll_table,
1350 .ctl_name = KERN_SETUID_DUMPABLE,
1351 .procname = "suid_dumpable",
1352 .data = &suid_dumpable,
1353 .maxlen = sizeof(int),
1355 .proc_handler = &proc_dointvec,
1357 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1359 .ctl_name = CTL_UNNUMBERED,
1360 .procname = "binfmt_misc",
1362 .child = binfmt_misc_table,
1366 * NOTE: do not add new entries to this table unless you have read
1367 * Documentation/sysctl/ctl_unnumbered.txt
1372 static struct ctl_table debug_table[] = {
1373 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1375 .ctl_name = CTL_UNNUMBERED,
1376 .procname = "exception-trace",
1377 .data = &show_unhandled_signals,
1378 .maxlen = sizeof(int),
1380 .proc_handler = proc_dointvec
1386 static struct ctl_table dev_table[] = {
1390 static DEFINE_SPINLOCK(sysctl_lock);
1392 /* called under sysctl_lock */
1393 static int use_table(struct ctl_table_header *p)
1395 if (unlikely(p->unregistering))
1401 /* called under sysctl_lock */
1402 static void unuse_table(struct ctl_table_header *p)
1405 if (unlikely(p->unregistering))
1406 complete(p->unregistering);
1409 /* called under sysctl_lock, will reacquire if has to wait */
1410 static void start_unregistering(struct ctl_table_header *p)
1413 * if p->used is 0, nobody will ever touch that entry again;
1414 * we'll eliminate all paths to it before dropping sysctl_lock
1416 if (unlikely(p->used)) {
1417 struct completion wait;
1418 init_completion(&wait);
1419 p->unregistering = &wait;
1420 spin_unlock(&sysctl_lock);
1421 wait_for_completion(&wait);
1422 spin_lock(&sysctl_lock);
1424 /* anything non-NULL; we'll never dereference it */
1425 p->unregistering = ERR_PTR(-EINVAL);
1428 * do not remove from the list until nobody holds it; walking the
1429 * list in do_sysctl() relies on that.
1431 list_del_init(&p->ctl_entry);
1434 void sysctl_head_get(struct ctl_table_header *head)
1436 spin_lock(&sysctl_lock);
1438 spin_unlock(&sysctl_lock);
1441 void sysctl_head_put(struct ctl_table_header *head)
1443 spin_lock(&sysctl_lock);
1446 spin_unlock(&sysctl_lock);
1449 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1453 spin_lock(&sysctl_lock);
1454 if (!use_table(head))
1455 head = ERR_PTR(-ENOENT);
1456 spin_unlock(&sysctl_lock);
1460 void sysctl_head_finish(struct ctl_table_header *head)
1464 spin_lock(&sysctl_lock);
1466 spin_unlock(&sysctl_lock);
1469 static struct ctl_table_set *
1470 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1472 struct ctl_table_set *set = &root->default_set;
1474 set = root->lookup(root, namespaces);
1478 static struct list_head *
1479 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1481 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1485 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1486 struct ctl_table_header *prev)
1488 struct ctl_table_root *root;
1489 struct list_head *header_list;
1490 struct ctl_table_header *head;
1491 struct list_head *tmp;
1493 spin_lock(&sysctl_lock);
1496 tmp = &prev->ctl_entry;
1500 tmp = &root_table_header.ctl_entry;
1502 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1504 if (!use_table(head))
1506 spin_unlock(&sysctl_lock);
1511 header_list = lookup_header_list(root, namespaces);
1512 if (tmp != header_list)
1516 root = list_entry(root->root_list.next,
1517 struct ctl_table_root, root_list);
1518 if (root == &sysctl_table_root)
1520 header_list = lookup_header_list(root, namespaces);
1521 } while (list_empty(header_list));
1522 tmp = header_list->next;
1525 spin_unlock(&sysctl_lock);
1529 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1531 return __sysctl_head_next(current->nsproxy, prev);
1534 void register_sysctl_root(struct ctl_table_root *root)
1536 spin_lock(&sysctl_lock);
1537 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1538 spin_unlock(&sysctl_lock);
1541 #ifdef CONFIG_SYSCTL_SYSCALL
1542 /* Perform the actual read/write of a sysctl table entry. */
1543 static int do_sysctl_strategy(struct ctl_table_root *root,
1544 struct ctl_table *table,
1545 void __user *oldval, size_t __user *oldlenp,
1546 void __user *newval, size_t newlen)
1554 if (sysctl_perm(root, table, op))
1557 if (table->strategy) {
1558 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1565 /* If there is no strategy routine, or if the strategy returns
1566 * zero, proceed with automatic r/w */
1567 if (table->data && table->maxlen) {
1568 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1575 static int parse_table(int __user *name, int nlen,
1576 void __user *oldval, size_t __user *oldlenp,
1577 void __user *newval, size_t newlen,
1578 struct ctl_table_root *root,
1579 struct ctl_table *table)
1585 if (get_user(n, name))
1587 for ( ; table->ctl_name || table->procname; table++) {
1588 if (!table->ctl_name)
1590 if (n == table->ctl_name) {
1593 if (sysctl_perm(root, table, MAY_EXEC))
1597 table = table->child;
1600 error = do_sysctl_strategy(root, table,
1609 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1610 void __user *newval, size_t newlen)
1612 struct ctl_table_header *head;
1613 int error = -ENOTDIR;
1615 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1619 if (!oldlenp || get_user(old_len, oldlenp))
1623 for (head = sysctl_head_next(NULL); head;
1624 head = sysctl_head_next(head)) {
1625 error = parse_table(name, nlen, oldval, oldlenp,
1627 head->root, head->ctl_table);
1628 if (error != -ENOTDIR) {
1629 sysctl_head_finish(head);
1636 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1638 struct __sysctl_args tmp;
1641 if (copy_from_user(&tmp, args, sizeof(tmp)))
1644 error = deprecated_sysctl_warning(&tmp);
1649 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1650 tmp.newval, tmp.newlen);
1655 #endif /* CONFIG_SYSCTL_SYSCALL */
1658 * sysctl_perm does NOT grant the superuser all rights automatically, because
1659 * some sysctl variables are readonly even to root.
1662 static int test_perm(int mode, int op)
1666 else if (in_egroup_p(0))
1668 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1673 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1678 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1682 if (root->permissions)
1683 mode = root->permissions(root, current->nsproxy, table);
1687 return test_perm(mode, op);
1690 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1692 for (; table->ctl_name || table->procname; table++) {
1693 table->parent = parent;
1695 sysctl_set_parent(table, table->child);
1699 static __init int sysctl_init(void)
1701 sysctl_set_parent(NULL, root_table);
1702 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1705 err = sysctl_check_table(current->nsproxy, root_table);
1711 core_initcall(sysctl_init);
1713 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1714 struct ctl_table *table)
1716 struct ctl_table *p;
1717 const char *s = branch->procname;
1719 /* branch should have named subdirectory as its first element */
1720 if (!s || !branch->child)
1723 /* ... and nothing else */
1724 if (branch[1].procname || branch[1].ctl_name)
1727 /* table should contain subdirectory with the same name */
1728 for (p = table; p->procname || p->ctl_name; p++) {
1731 if (p->procname && strcmp(p->procname, s) == 0)
1737 /* see if attaching q to p would be an improvement */
1738 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1740 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1741 struct ctl_table *next;
1743 int not_in_parent = !p->attached_by;
1745 while ((next = is_branch_in(by, to)) != NULL) {
1746 if (by == q->attached_by)
1748 if (to == p->attached_by)
1754 if (is_better && not_in_parent) {
1755 q->attached_by = by;
1756 q->attached_to = to;
1762 * __register_sysctl_paths - register a sysctl hierarchy
1763 * @root: List of sysctl headers to register on
1764 * @namespaces: Data to compute which lists of sysctl entries are visible
1765 * @path: The path to the directory the sysctl table is in.
1766 * @table: the top-level table structure
1768 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1769 * array. A completely 0 filled entry terminates the table.
1771 * The members of the &struct ctl_table structure are used as follows:
1773 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1774 * must be unique within that level of sysctl
1776 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1777 * enter a sysctl file
1779 * data - a pointer to data for use by proc_handler
1781 * maxlen - the maximum size in bytes of the data
1783 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1785 * child - a pointer to the child sysctl table if this entry is a directory, or
1788 * proc_handler - the text handler routine (described below)
1790 * strategy - the strategy routine (described below)
1792 * de - for internal use by the sysctl routines
1794 * extra1, extra2 - extra pointers usable by the proc handler routines
1796 * Leaf nodes in the sysctl tree will be represented by a single file
1797 * under /proc; non-leaf nodes will be represented by directories.
1799 * sysctl(2) can automatically manage read and write requests through
1800 * the sysctl table. The data and maxlen fields of the ctl_table
1801 * struct enable minimal validation of the values being written to be
1802 * performed, and the mode field allows minimal authentication.
1804 * More sophisticated management can be enabled by the provision of a
1805 * strategy routine with the table entry. This will be called before
1806 * any automatic read or write of the data is performed.
1808 * The strategy routine may return
1810 * < 0 - Error occurred (error is passed to user process)
1812 * 0 - OK - proceed with automatic read or write.
1814 * > 0 - OK - read or write has been done by the strategy routine, so
1815 * return immediately.
1817 * There must be a proc_handler routine for any terminal nodes
1818 * mirrored under /proc/sys (non-terminals are handled by a built-in
1819 * directory handler). Several default handlers are available to
1820 * cover common cases -
1822 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1823 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1824 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1826 * It is the handler's job to read the input buffer from user memory
1827 * and process it. The handler should return 0 on success.
1829 * This routine returns %NULL on a failure to register, and a pointer
1830 * to the table header on success.
1832 struct ctl_table_header *__register_sysctl_paths(
1833 struct ctl_table_root *root,
1834 struct nsproxy *namespaces,
1835 const struct ctl_path *path, struct ctl_table *table)
1837 struct ctl_table_header *header;
1838 struct ctl_table *new, **prevp;
1839 unsigned int n, npath;
1840 struct ctl_table_set *set;
1842 /* Count the path components */
1843 for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1847 * For each path component, allocate a 2-element ctl_table array.
1848 * The first array element will be filled with the sysctl entry
1849 * for this, the second will be the sentinel (ctl_name == 0).
1851 * We allocate everything in one go so that we don't have to
1852 * worry about freeing additional memory in unregister_sysctl_table.
1854 header = kzalloc(sizeof(struct ctl_table_header) +
1855 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1859 new = (struct ctl_table *) (header + 1);
1861 /* Now connect the dots */
1862 prevp = &header->ctl_table;
1863 for (n = 0; n < npath; ++n, ++path) {
1864 /* Copy the procname */
1865 new->procname = path->procname;
1866 new->ctl_name = path->ctl_name;
1870 prevp = &new->child;
1875 header->ctl_table_arg = table;
1877 INIT_LIST_HEAD(&header->ctl_entry);
1879 header->unregistering = NULL;
1880 header->root = root;
1881 sysctl_set_parent(NULL, header->ctl_table);
1883 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1884 if (sysctl_check_table(namespaces, header->ctl_table)) {
1889 spin_lock(&sysctl_lock);
1890 header->set = lookup_header_set(root, namespaces);
1891 header->attached_by = header->ctl_table;
1892 header->attached_to = root_table;
1893 header->parent = &root_table_header;
1894 for (set = header->set; set; set = set->parent) {
1895 struct ctl_table_header *p;
1896 list_for_each_entry(p, &set->list, ctl_entry) {
1897 if (p->unregistering)
1899 try_attach(p, header);
1902 header->parent->count++;
1903 list_add_tail(&header->ctl_entry, &header->set->list);
1904 spin_unlock(&sysctl_lock);
1910 * register_sysctl_table_path - register a sysctl table hierarchy
1911 * @path: The path to the directory the sysctl table is in.
1912 * @table: the top-level table structure
1914 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1915 * array. A completely 0 filled entry terminates the table.
1917 * See __register_sysctl_paths for more details.
1919 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1920 struct ctl_table *table)
1922 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1927 * register_sysctl_table - register a sysctl table hierarchy
1928 * @table: the top-level table structure
1930 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1931 * array. A completely 0 filled entry terminates the table.
1933 * See register_sysctl_paths for more details.
1935 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1937 static const struct ctl_path null_path[] = { {} };
1939 return register_sysctl_paths(null_path, table);
1943 * unregister_sysctl_table - unregister a sysctl table hierarchy
1944 * @header: the header returned from register_sysctl_table
1946 * Unregisters the sysctl table and all children. proc entries may not
1947 * actually be removed until they are no longer used by anyone.
1949 void unregister_sysctl_table(struct ctl_table_header * header)
1956 spin_lock(&sysctl_lock);
1957 start_unregistering(header);
1958 if (!--header->parent->count) {
1960 kfree(header->parent);
1962 if (!--header->count)
1964 spin_unlock(&sysctl_lock);
1967 int sysctl_is_seen(struct ctl_table_header *p)
1969 struct ctl_table_set *set = p->set;
1971 spin_lock(&sysctl_lock);
1972 if (p->unregistering)
1974 else if (!set->is_seen)
1977 res = set->is_seen(set);
1978 spin_unlock(&sysctl_lock);
1982 void setup_sysctl_set(struct ctl_table_set *p,
1983 struct ctl_table_set *parent,
1984 int (*is_seen)(struct ctl_table_set *))
1986 INIT_LIST_HEAD(&p->list);
1987 p->parent = parent ? parent : &sysctl_table_root.default_set;
1988 p->is_seen = is_seen;
1991 #else /* !CONFIG_SYSCTL */
1992 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1997 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1998 struct ctl_table *table)
2003 void unregister_sysctl_table(struct ctl_table_header * table)
2007 void setup_sysctl_set(struct ctl_table_set *p,
2008 struct ctl_table_set *parent,
2009 int (*is_seen)(struct ctl_table_set *))
2013 void sysctl_head_put(struct ctl_table_header *head)
2017 #endif /* CONFIG_SYSCTL */
2023 #ifdef CONFIG_PROC_SYSCTL
2025 static int _proc_do_string(void* data, int maxlen, int write,
2026 struct file *filp, void __user *buffer,
2027 size_t *lenp, loff_t *ppos)
2033 if (!data || !maxlen || !*lenp) {
2041 while (len < *lenp) {
2042 if (get_user(c, p++))
2044 if (c == 0 || c == '\n')
2050 if(copy_from_user(data, buffer, len))
2052 ((char *) data)[len] = 0;
2070 if(copy_to_user(buffer, data, len))
2073 if(put_user('\n', ((char __user *) buffer) + len))
2084 * proc_dostring - read a string sysctl
2085 * @table: the sysctl table
2086 * @write: %TRUE if this is a write to the sysctl file
2087 * @filp: the file structure
2088 * @buffer: the user buffer
2089 * @lenp: the size of the user buffer
2090 * @ppos: file position
2092 * Reads/writes a string from/to the user buffer. If the kernel
2093 * buffer provided is not large enough to hold the string, the
2094 * string is truncated. The copied string is %NULL-terminated.
2095 * If the string is being read by the user process, it is copied
2096 * and a newline '\n' is added. It is truncated if the buffer is
2099 * Returns 0 on success.
2101 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2102 void __user *buffer, size_t *lenp, loff_t *ppos)
2104 return _proc_do_string(table->data, table->maxlen, write, filp,
2105 buffer, lenp, ppos);
2109 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2111 int write, void *data)
2114 *valp = *negp ? -*lvalp : *lvalp;
2119 *lvalp = (unsigned long)-val;
2122 *lvalp = (unsigned long)val;
2128 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2129 int write, struct file *filp, void __user *buffer,
2130 size_t *lenp, loff_t *ppos,
2131 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2132 int write, void *data),
2135 #define TMPBUFLEN 21
2136 int *i, vleft, first=1, neg, val;
2140 char buf[TMPBUFLEN], *p;
2141 char __user *s = buffer;
2143 if (!tbl_data || !table->maxlen || !*lenp ||
2144 (*ppos && !write)) {
2149 i = (int *) tbl_data;
2150 vleft = table->maxlen / sizeof(*i);
2154 conv = do_proc_dointvec_conv;
2156 for (; left && vleft--; i++, first=0) {
2171 if (len > sizeof(buf) - 1)
2172 len = sizeof(buf) - 1;
2173 if (copy_from_user(buf, s, len))
2177 if (*p == '-' && left > 1) {
2181 if (*p < '0' || *p > '9')
2184 lval = simple_strtoul(p, &p, 0);
2187 if ((len < left) && *p && !isspace(*p))
2194 if (conv(&neg, &lval, i, 1, data))
2201 if (conv(&neg, &lval, i, 0, data))
2204 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2208 if(copy_to_user(s, buf, len))
2215 if (!write && !first && left) {
2216 if(put_user('\n', s))
2223 if (get_user(c, s++))
2238 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2239 void __user *buffer, size_t *lenp, loff_t *ppos,
2240 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2241 int write, void *data),
2244 return __do_proc_dointvec(table->data, table, write, filp,
2245 buffer, lenp, ppos, conv, data);
2249 * proc_dointvec - read a vector of integers
2250 * @table: the sysctl table
2251 * @write: %TRUE if this is a write to the sysctl file
2252 * @filp: the file structure
2253 * @buffer: the user buffer
2254 * @lenp: the size of the user buffer
2255 * @ppos: file position
2257 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2258 * values from/to the user buffer, treated as an ASCII string.
2260 * Returns 0 on success.
2262 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2263 void __user *buffer, size_t *lenp, loff_t *ppos)
2265 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2270 * Taint values can only be increased
2271 * This means we can safely use a temporary.
2273 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2274 void __user *buffer, size_t *lenp, loff_t *ppos)
2277 unsigned long tmptaint = get_taint();
2280 if (write && !capable(CAP_SYS_ADMIN))
2285 err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2291 * Poor man's atomic or. Not worth adding a primitive
2292 * to everyone's atomic.h for this
2295 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2296 if ((tmptaint >> i) & 1)
2304 struct do_proc_dointvec_minmax_conv_param {
2309 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2311 int write, void *data)
2313 struct do_proc_dointvec_minmax_conv_param *param = data;
2315 int val = *negp ? -*lvalp : *lvalp;
2316 if ((param->min && *param->min > val) ||
2317 (param->max && *param->max < val))
2324 *lvalp = (unsigned long)-val;
2327 *lvalp = (unsigned long)val;
2334 * proc_dointvec_minmax - read a vector of integers with min/max values
2335 * @table: the sysctl table
2336 * @write: %TRUE if this is a write to the sysctl file
2337 * @filp: the file structure
2338 * @buffer: the user buffer
2339 * @lenp: the size of the user buffer
2340 * @ppos: file position
2342 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2343 * values from/to the user buffer, treated as an ASCII string.
2345 * This routine will ensure the values are within the range specified by
2346 * table->extra1 (min) and table->extra2 (max).
2348 * Returns 0 on success.
2350 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2351 void __user *buffer, size_t *lenp, loff_t *ppos)
2353 struct do_proc_dointvec_minmax_conv_param param = {
2354 .min = (int *) table->extra1,
2355 .max = (int *) table->extra2,
2357 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2358 do_proc_dointvec_minmax_conv, ¶m);
2361 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2363 void __user *buffer,
2364 size_t *lenp, loff_t *ppos,
2365 unsigned long convmul,
2366 unsigned long convdiv)
2368 #define TMPBUFLEN 21
2369 unsigned long *i, *min, *max, val;
2370 int vleft, first=1, neg;
2372 char buf[TMPBUFLEN], *p;
2373 char __user *s = buffer;
2375 if (!data || !table->maxlen || !*lenp ||
2376 (*ppos && !write)) {
2381 i = (unsigned long *) data;
2382 min = (unsigned long *) table->extra1;
2383 max = (unsigned long *) table->extra2;
2384 vleft = table->maxlen / sizeof(unsigned long);
2387 for (; left && vleft--; i++, min++, max++, first=0) {
2402 if (len > TMPBUFLEN-1)
2404 if (copy_from_user(buf, s, len))
2408 if (*p == '-' && left > 1) {
2412 if (*p < '0' || *p > '9')
2414 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2416 if ((len < left) && *p && !isspace(*p))
2425 if ((min && val < *min) || (max && val > *max))
2432 sprintf(p, "%lu", convdiv * (*i) / convmul);
2436 if(copy_to_user(s, buf, len))
2443 if (!write && !first && left) {
2444 if(put_user('\n', s))
2451 if (get_user(c, s++))
2466 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2468 void __user *buffer,
2469 size_t *lenp, loff_t *ppos,
2470 unsigned long convmul,
2471 unsigned long convdiv)
2473 return __do_proc_doulongvec_minmax(table->data, table, write,
2474 filp, buffer, lenp, ppos, convmul, convdiv);
2478 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2479 * @table: the sysctl table
2480 * @write: %TRUE if this is a write to the sysctl file
2481 * @filp: the file structure
2482 * @buffer: the user buffer
2483 * @lenp: the size of the user buffer
2484 * @ppos: file position
2486 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2487 * values from/to the user buffer, treated as an ASCII string.
2489 * This routine will ensure the values are within the range specified by
2490 * table->extra1 (min) and table->extra2 (max).
2492 * Returns 0 on success.
2494 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2495 void __user *buffer, size_t *lenp, loff_t *ppos)
2497 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2501 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2502 * @table: the sysctl table
2503 * @write: %TRUE if this is a write to the sysctl file
2504 * @filp: the file structure
2505 * @buffer: the user buffer
2506 * @lenp: the size of the user buffer
2507 * @ppos: file position
2509 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2510 * values from/to the user buffer, treated as an ASCII string. The values
2511 * are treated as milliseconds, and converted to jiffies when they are stored.
2513 * This routine will ensure the values are within the range specified by
2514 * table->extra1 (min) and table->extra2 (max).
2516 * Returns 0 on success.
2518 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2520 void __user *buffer,
2521 size_t *lenp, loff_t *ppos)
2523 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2524 lenp, ppos, HZ, 1000l);
2528 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2530 int write, void *data)
2533 if (*lvalp > LONG_MAX / HZ)
2535 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2541 lval = (unsigned long)-val;
2544 lval = (unsigned long)val;
2551 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2553 int write, void *data)
2556 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2558 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2564 lval = (unsigned long)-val;
2567 lval = (unsigned long)val;
2569 *lvalp = jiffies_to_clock_t(lval);
2574 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2576 int write, void *data)
2579 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2585 lval = (unsigned long)-val;
2588 lval = (unsigned long)val;
2590 *lvalp = jiffies_to_msecs(lval);
2596 * proc_dointvec_jiffies - read a vector of integers as seconds
2597 * @table: the sysctl table
2598 * @write: %TRUE if this is a write to the sysctl file
2599 * @filp: the file structure
2600 * @buffer: the user buffer
2601 * @lenp: the size of the user buffer
2602 * @ppos: file position
2604 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2605 * values from/to the user buffer, treated as an ASCII string.
2606 * The values read are assumed to be in seconds, and are converted into
2609 * Returns 0 on success.
2611 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2612 void __user *buffer, size_t *lenp, loff_t *ppos)
2614 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2615 do_proc_dointvec_jiffies_conv,NULL);
2619 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2620 * @table: the sysctl table
2621 * @write: %TRUE if this is a write to the sysctl file
2622 * @filp: the file structure
2623 * @buffer: the user buffer
2624 * @lenp: the size of the user buffer
2625 * @ppos: pointer to the file position
2627 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2628 * values from/to the user buffer, treated as an ASCII string.
2629 * The values read are assumed to be in 1/USER_HZ seconds, and
2630 * are converted into jiffies.
2632 * Returns 0 on success.
2634 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2635 void __user *buffer, size_t *lenp, loff_t *ppos)
2637 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2638 do_proc_dointvec_userhz_jiffies_conv,NULL);
2642 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2643 * @table: the sysctl table
2644 * @write: %TRUE if this is a write to the sysctl file
2645 * @filp: the file structure
2646 * @buffer: the user buffer
2647 * @lenp: the size of the user buffer
2648 * @ppos: file position
2649 * @ppos: the current position in the file
2651 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2652 * values from/to the user buffer, treated as an ASCII string.
2653 * The values read are assumed to be in 1/1000 seconds, and
2654 * are converted into jiffies.
2656 * Returns 0 on success.
2658 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2659 void __user *buffer, size_t *lenp, loff_t *ppos)
2661 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2662 do_proc_dointvec_ms_jiffies_conv, NULL);
2665 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2666 void __user *buffer, size_t *lenp, loff_t *ppos)
2668 struct pid *new_pid;
2672 tmp = pid_vnr(cad_pid);
2674 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2675 lenp, ppos, NULL, NULL);
2679 new_pid = find_get_pid(tmp);
2683 put_pid(xchg(&cad_pid, new_pid));
2687 #else /* CONFIG_PROC_FS */
2689 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2690 void __user *buffer, size_t *lenp, loff_t *ppos)
2695 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2696 void __user *buffer, size_t *lenp, loff_t *ppos)
2701 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2702 void __user *buffer, size_t *lenp, loff_t *ppos)
2707 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2708 void __user *buffer, size_t *lenp, loff_t *ppos)
2713 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2714 void __user *buffer, size_t *lenp, loff_t *ppos)
2719 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2720 void __user *buffer, size_t *lenp, loff_t *ppos)
2725 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2726 void __user *buffer, size_t *lenp, loff_t *ppos)
2731 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2733 void __user *buffer,
2734 size_t *lenp, loff_t *ppos)
2740 #endif /* CONFIG_PROC_FS */
2743 #ifdef CONFIG_SYSCTL_SYSCALL
2745 * General sysctl support routines
2748 /* The generic sysctl data routine (used if no strategy routine supplied) */
2749 int sysctl_data(struct ctl_table *table,
2750 void __user *oldval, size_t __user *oldlenp,
2751 void __user *newval, size_t newlen)
2755 /* Get out of I don't have a variable */
2756 if (!table->data || !table->maxlen)
2759 if (oldval && oldlenp) {
2760 if (get_user(len, oldlenp))
2763 if (len > table->maxlen)
2764 len = table->maxlen;
2765 if (copy_to_user(oldval, table->data, len))
2767 if (put_user(len, oldlenp))
2772 if (newval && newlen) {
2773 if (newlen > table->maxlen)
2774 newlen = table->maxlen;
2776 if (copy_from_user(table->data, newval, newlen))
2782 /* The generic string strategy routine: */
2783 int sysctl_string(struct ctl_table *table,
2784 void __user *oldval, size_t __user *oldlenp,
2785 void __user *newval, size_t newlen)
2787 if (!table->data || !table->maxlen)
2790 if (oldval && oldlenp) {
2792 if (get_user(bufsize, oldlenp))
2795 size_t len = strlen(table->data), copied;
2797 /* This shouldn't trigger for a well-formed sysctl */
2798 if (len > table->maxlen)
2799 len = table->maxlen;
2801 /* Copy up to a max of bufsize-1 bytes of the string */
2802 copied = (len >= bufsize) ? bufsize - 1 : len;
2804 if (copy_to_user(oldval, table->data, copied) ||
2805 put_user(0, (char __user *)(oldval + copied)))
2807 if (put_user(len, oldlenp))
2811 if (newval && newlen) {
2812 size_t len = newlen;
2813 if (len > table->maxlen)
2814 len = table->maxlen;
2815 if(copy_from_user(table->data, newval, len))
2817 if (len == table->maxlen)
2819 ((char *) table->data)[len] = 0;
2825 * This function makes sure that all of the integers in the vector
2826 * are between the minimum and maximum values given in the arrays
2827 * table->extra1 and table->extra2, respectively.
2829 int sysctl_intvec(struct ctl_table *table,
2830 void __user *oldval, size_t __user *oldlenp,
2831 void __user *newval, size_t newlen)
2834 if (newval && newlen) {
2835 int __user *vec = (int __user *) newval;
2836 int *min = (int *) table->extra1;
2837 int *max = (int *) table->extra2;
2841 if (newlen % sizeof(int) != 0)
2844 if (!table->extra1 && !table->extra2)
2847 if (newlen > table->maxlen)
2848 newlen = table->maxlen;
2849 length = newlen / sizeof(int);
2851 for (i = 0; i < length; i++) {
2853 if (get_user(value, vec + i))
2855 if (min && value < min[i])
2857 if (max && value > max[i])
2864 /* Strategy function to convert jiffies to seconds */
2865 int sysctl_jiffies(struct ctl_table *table,
2866 void __user *oldval, size_t __user *oldlenp,
2867 void __user *newval, size_t newlen)
2869 if (oldval && oldlenp) {
2872 if (get_user(olen, oldlenp))
2877 if (olen < sizeof(int))
2880 val = *(int *)(table->data) / HZ;
2881 if (put_user(val, (int __user *)oldval))
2883 if (put_user(sizeof(int), oldlenp))
2887 if (newval && newlen) {
2889 if (newlen != sizeof(int))
2891 if (get_user(new, (int __user *)newval))
2893 *(int *)(table->data) = new*HZ;
2898 /* Strategy function to convert jiffies to seconds */
2899 int sysctl_ms_jiffies(struct ctl_table *table,
2900 void __user *oldval, size_t __user *oldlenp,
2901 void __user *newval, size_t newlen)
2903 if (oldval && oldlenp) {
2906 if (get_user(olen, oldlenp))
2911 if (olen < sizeof(int))
2914 val = jiffies_to_msecs(*(int *)(table->data));
2915 if (put_user(val, (int __user *)oldval))
2917 if (put_user(sizeof(int), oldlenp))
2921 if (newval && newlen) {
2923 if (newlen != sizeof(int))
2925 if (get_user(new, (int __user *)newval))
2927 *(int *)(table->data) = msecs_to_jiffies(new);
2934 #else /* CONFIG_SYSCTL_SYSCALL */
2937 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2939 struct __sysctl_args tmp;
2942 if (copy_from_user(&tmp, args, sizeof(tmp)))
2945 error = deprecated_sysctl_warning(&tmp);
2947 /* If no error reading the parameters then just -ENOSYS ... */
2954 int sysctl_data(struct ctl_table *table,
2955 void __user *oldval, size_t __user *oldlenp,
2956 void __user *newval, size_t newlen)
2961 int sysctl_string(struct ctl_table *table,
2962 void __user *oldval, size_t __user *oldlenp,
2963 void __user *newval, size_t newlen)
2968 int sysctl_intvec(struct ctl_table *table,
2969 void __user *oldval, size_t __user *oldlenp,
2970 void __user *newval, size_t newlen)
2975 int sysctl_jiffies(struct ctl_table *table,
2976 void __user *oldval, size_t __user *oldlenp,
2977 void __user *newval, size_t newlen)
2982 int sysctl_ms_jiffies(struct ctl_table *table,
2983 void __user *oldval, size_t __user *oldlenp,
2984 void __user *newval, size_t newlen)
2989 #endif /* CONFIG_SYSCTL_SYSCALL */
2991 static int deprecated_sysctl_warning(struct __sysctl_args *args)
2993 static int msg_count;
2994 int name[CTL_MAXNAME];
2997 /* Check args->nlen. */
2998 if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3001 /* Read in the sysctl name for better debug message logging */
3002 for (i = 0; i < args->nlen; i++)
3003 if (get_user(name[i], args->name + i))
3006 /* Ignore accesses to kernel.version */
3007 if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3010 if (msg_count < 5) {
3013 "warning: process `%s' used the deprecated sysctl "
3014 "system call with ", current->comm);
3015 for (i = 0; i < args->nlen; i++)
3016 printk("%d.", name[i]);
3023 * No sense putting this after each symbol definition, twice,
3024 * exception granted :-)
3026 EXPORT_SYMBOL(proc_dointvec);
3027 EXPORT_SYMBOL(proc_dointvec_jiffies);
3028 EXPORT_SYMBOL(proc_dointvec_minmax);
3029 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3030 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3031 EXPORT_SYMBOL(proc_dostring);
3032 EXPORT_SYMBOL(proc_doulongvec_minmax);
3033 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3034 EXPORT_SYMBOL(register_sysctl_table);
3035 EXPORT_SYMBOL(register_sysctl_paths);
3036 EXPORT_SYMBOL(sysctl_intvec);
3037 EXPORT_SYMBOL(sysctl_jiffies);
3038 EXPORT_SYMBOL(sysctl_ms_jiffies);
3039 EXPORT_SYMBOL(sysctl_string);
3040 EXPORT_SYMBOL(sysctl_data);
3041 EXPORT_SYMBOL(unregister_sysctl_table);