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>
51 #include <linux/slow-work.h>
53 #include <asm/uaccess.h>
54 #include <asm/processor.h>
58 #include <asm/stacktrace.h>
62 static int deprecated_sysctl_warning(struct __sysctl_args *args);
64 #if defined(CONFIG_SYSCTL)
66 /* External variables not in a header file. */
68 extern int print_fatal_signals;
69 extern int sysctl_overcommit_memory;
70 extern int sysctl_overcommit_ratio;
71 extern int sysctl_panic_on_oom;
72 extern int sysctl_oom_kill_allocating_task;
73 extern int sysctl_oom_dump_tasks;
74 extern int max_threads;
75 extern int core_uses_pid;
76 extern int suid_dumpable;
77 extern char core_pattern[];
79 extern int min_free_kbytes;
80 extern int pid_max_min, pid_max_max;
81 extern int sysctl_drop_caches;
82 extern int percpu_pagelist_fraction;
83 extern int compat_log;
84 extern int latencytop_enabled;
85 extern int sysctl_nr_open_min, sysctl_nr_open_max;
87 extern int sysctl_nr_trim_pages;
89 #ifdef CONFIG_RCU_TORTURE_TEST
90 extern int rcutorture_runnable;
91 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
93 /* Constants used for minimum and maximum */
94 #ifdef CONFIG_DETECT_SOFTLOCKUP
95 static int sixty = 60;
96 static int neg_one = -1;
100 static int __maybe_unused one = 1;
101 static int __maybe_unused two = 2;
102 static unsigned long one_ul = 1;
103 static int one_hundred = 100;
105 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
106 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
108 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
109 static int maxolduid = 65535;
110 static int minolduid;
111 static int min_percpu_pagelist_fract = 8;
113 static int ngroups_max = NGROUPS_MAX;
115 #ifdef CONFIG_MODULES
116 extern char modprobe_path[];
117 extern int modules_disabled;
119 #ifdef CONFIG_CHR_DEV_SG
120 extern int sg_big_buff;
124 #include <asm/system.h>
127 #ifdef CONFIG_SPARC64
128 extern int sysctl_tsb_ratio;
132 extern int pwrsw_enabled;
133 extern int unaligned_enabled;
137 #ifdef CONFIG_MATHEMU
138 extern int sysctl_ieee_emulation_warnings;
140 extern int sysctl_userprocess_debug;
141 extern int spin_retry;
144 #ifdef CONFIG_BSD_PROCESS_ACCT
145 extern int acct_parm[];
149 extern int no_unaligned_warning;
150 extern int unaligned_dump_stack;
153 #ifdef CONFIG_RT_MUTEXES
154 extern int max_lock_depth;
157 #ifdef CONFIG_PROC_SYSCTL
158 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
159 void __user *buffer, size_t *lenp, loff_t *ppos);
160 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
161 void __user *buffer, size_t *lenp, loff_t *ppos);
164 static struct ctl_table root_table[];
165 static struct ctl_table_root sysctl_table_root;
166 static struct ctl_table_header root_table_header = {
168 .ctl_table = root_table,
169 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
170 .root = &sysctl_table_root,
171 .set = &sysctl_table_root.default_set,
173 static struct ctl_table_root sysctl_table_root = {
174 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
175 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
178 static struct ctl_table kern_table[];
179 static struct ctl_table vm_table[];
180 static struct ctl_table fs_table[];
181 static struct ctl_table debug_table[];
182 static struct ctl_table dev_table[];
183 extern struct ctl_table random_table[];
184 #ifdef CONFIG_INOTIFY_USER
185 extern struct ctl_table inotify_table[];
188 extern struct ctl_table epoll_table[];
191 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
192 int sysctl_legacy_va_layout;
195 extern int prove_locking;
196 extern int lock_stat;
198 /* The default sysctl tables: */
200 static struct ctl_table root_table[] = {
202 .ctl_name = CTL_KERN,
203 .procname = "kernel",
220 .ctl_name = CTL_DEBUG,
223 .child = debug_table,
232 * NOTE: do not add new entries to this table unless you have read
233 * Documentation/sysctl/ctl_unnumbered.txt
238 #ifdef CONFIG_SCHED_DEBUG
239 static int min_sched_granularity_ns = 100000; /* 100 usecs */
240 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
241 static int min_wakeup_granularity_ns; /* 0 usecs */
242 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
245 static struct ctl_table kern_table[] = {
246 #ifdef CONFIG_SCHED_DEBUG
248 .ctl_name = CTL_UNNUMBERED,
249 .procname = "sched_min_granularity_ns",
250 .data = &sysctl_sched_min_granularity,
251 .maxlen = sizeof(unsigned int),
253 .proc_handler = &sched_nr_latency_handler,
254 .strategy = &sysctl_intvec,
255 .extra1 = &min_sched_granularity_ns,
256 .extra2 = &max_sched_granularity_ns,
259 .ctl_name = CTL_UNNUMBERED,
260 .procname = "sched_latency_ns",
261 .data = &sysctl_sched_latency,
262 .maxlen = sizeof(unsigned int),
264 .proc_handler = &sched_nr_latency_handler,
265 .strategy = &sysctl_intvec,
266 .extra1 = &min_sched_granularity_ns,
267 .extra2 = &max_sched_granularity_ns,
270 .ctl_name = CTL_UNNUMBERED,
271 .procname = "sched_wakeup_granularity_ns",
272 .data = &sysctl_sched_wakeup_granularity,
273 .maxlen = sizeof(unsigned int),
275 .proc_handler = &proc_dointvec_minmax,
276 .strategy = &sysctl_intvec,
277 .extra1 = &min_wakeup_granularity_ns,
278 .extra2 = &max_wakeup_granularity_ns,
281 .ctl_name = CTL_UNNUMBERED,
282 .procname = "sched_shares_ratelimit",
283 .data = &sysctl_sched_shares_ratelimit,
284 .maxlen = sizeof(unsigned int),
286 .proc_handler = &proc_dointvec,
289 .ctl_name = CTL_UNNUMBERED,
290 .procname = "sched_shares_thresh",
291 .data = &sysctl_sched_shares_thresh,
292 .maxlen = sizeof(unsigned int),
294 .proc_handler = &proc_dointvec_minmax,
295 .strategy = &sysctl_intvec,
299 .ctl_name = CTL_UNNUMBERED,
300 .procname = "sched_child_runs_first",
301 .data = &sysctl_sched_child_runs_first,
302 .maxlen = sizeof(unsigned int),
304 .proc_handler = &proc_dointvec,
307 .ctl_name = CTL_UNNUMBERED,
308 .procname = "sched_features",
309 .data = &sysctl_sched_features,
310 .maxlen = sizeof(unsigned int),
312 .proc_handler = &proc_dointvec,
315 .ctl_name = CTL_UNNUMBERED,
316 .procname = "sched_migration_cost",
317 .data = &sysctl_sched_migration_cost,
318 .maxlen = sizeof(unsigned int),
320 .proc_handler = &proc_dointvec,
323 .ctl_name = CTL_UNNUMBERED,
324 .procname = "sched_nr_migrate",
325 .data = &sysctl_sched_nr_migrate,
326 .maxlen = sizeof(unsigned int),
328 .proc_handler = &proc_dointvec,
332 .ctl_name = CTL_UNNUMBERED,
333 .procname = "sched_rt_period_us",
334 .data = &sysctl_sched_rt_period,
335 .maxlen = sizeof(unsigned int),
337 .proc_handler = &sched_rt_handler,
340 .ctl_name = CTL_UNNUMBERED,
341 .procname = "sched_rt_runtime_us",
342 .data = &sysctl_sched_rt_runtime,
343 .maxlen = sizeof(int),
345 .proc_handler = &sched_rt_handler,
348 .ctl_name = CTL_UNNUMBERED,
349 .procname = "sched_compat_yield",
350 .data = &sysctl_sched_compat_yield,
351 .maxlen = sizeof(unsigned int),
353 .proc_handler = &proc_dointvec,
355 #ifdef CONFIG_PROVE_LOCKING
357 .ctl_name = CTL_UNNUMBERED,
358 .procname = "prove_locking",
359 .data = &prove_locking,
360 .maxlen = sizeof(int),
362 .proc_handler = &proc_dointvec,
365 #ifdef CONFIG_LOCK_STAT
367 .ctl_name = CTL_UNNUMBERED,
368 .procname = "lock_stat",
370 .maxlen = sizeof(int),
372 .proc_handler = &proc_dointvec,
376 .ctl_name = KERN_PANIC,
378 .data = &panic_timeout,
379 .maxlen = sizeof(int),
381 .proc_handler = &proc_dointvec,
384 .ctl_name = KERN_CORE_USES_PID,
385 .procname = "core_uses_pid",
386 .data = &core_uses_pid,
387 .maxlen = sizeof(int),
389 .proc_handler = &proc_dointvec,
392 .ctl_name = KERN_CORE_PATTERN,
393 .procname = "core_pattern",
394 .data = core_pattern,
395 .maxlen = CORENAME_MAX_SIZE,
397 .proc_handler = &proc_dostring,
398 .strategy = &sysctl_string,
400 #ifdef CONFIG_PROC_SYSCTL
402 .procname = "tainted",
403 .maxlen = sizeof(long),
405 .proc_handler = &proc_taint,
408 #ifdef CONFIG_LATENCYTOP
410 .procname = "latencytop",
411 .data = &latencytop_enabled,
412 .maxlen = sizeof(int),
414 .proc_handler = &proc_dointvec,
417 #ifdef CONFIG_BLK_DEV_INITRD
419 .ctl_name = KERN_REALROOTDEV,
420 .procname = "real-root-dev",
421 .data = &real_root_dev,
422 .maxlen = sizeof(int),
424 .proc_handler = &proc_dointvec,
428 .ctl_name = CTL_UNNUMBERED,
429 .procname = "print-fatal-signals",
430 .data = &print_fatal_signals,
431 .maxlen = sizeof(int),
433 .proc_handler = &proc_dointvec,
437 .ctl_name = KERN_SPARC_REBOOT,
438 .procname = "reboot-cmd",
439 .data = reboot_command,
442 .proc_handler = &proc_dostring,
443 .strategy = &sysctl_string,
446 .ctl_name = KERN_SPARC_STOP_A,
447 .procname = "stop-a",
448 .data = &stop_a_enabled,
449 .maxlen = sizeof (int),
451 .proc_handler = &proc_dointvec,
454 .ctl_name = KERN_SPARC_SCONS_PWROFF,
455 .procname = "scons-poweroff",
456 .data = &scons_pwroff,
457 .maxlen = sizeof (int),
459 .proc_handler = &proc_dointvec,
462 #ifdef CONFIG_SPARC64
464 .ctl_name = CTL_UNNUMBERED,
465 .procname = "tsb-ratio",
466 .data = &sysctl_tsb_ratio,
467 .maxlen = sizeof (int),
469 .proc_handler = &proc_dointvec,
474 .ctl_name = KERN_HPPA_PWRSW,
475 .procname = "soft-power",
476 .data = &pwrsw_enabled,
477 .maxlen = sizeof (int),
479 .proc_handler = &proc_dointvec,
482 .ctl_name = KERN_HPPA_UNALIGNED,
483 .procname = "unaligned-trap",
484 .data = &unaligned_enabled,
485 .maxlen = sizeof (int),
487 .proc_handler = &proc_dointvec,
491 .ctl_name = KERN_CTLALTDEL,
492 .procname = "ctrl-alt-del",
494 .maxlen = sizeof(int),
496 .proc_handler = &proc_dointvec,
498 #ifdef CONFIG_FUNCTION_TRACER
500 .ctl_name = CTL_UNNUMBERED,
501 .procname = "ftrace_enabled",
502 .data = &ftrace_enabled,
503 .maxlen = sizeof(int),
505 .proc_handler = &ftrace_enable_sysctl,
508 #ifdef CONFIG_STACK_TRACER
510 .ctl_name = CTL_UNNUMBERED,
511 .procname = "stack_tracer_enabled",
512 .data = &stack_tracer_enabled,
513 .maxlen = sizeof(int),
515 .proc_handler = &stack_trace_sysctl,
518 #ifdef CONFIG_TRACING
520 .ctl_name = CTL_UNNUMBERED,
521 .procname = "ftrace_dump_on_oops",
522 .data = &ftrace_dump_on_oops,
523 .maxlen = sizeof(int),
525 .proc_handler = &proc_dointvec,
528 #ifdef CONFIG_MODULES
530 .ctl_name = KERN_MODPROBE,
531 .procname = "modprobe",
532 .data = &modprobe_path,
533 .maxlen = KMOD_PATH_LEN,
535 .proc_handler = &proc_dostring,
536 .strategy = &sysctl_string,
539 .ctl_name = CTL_UNNUMBERED,
540 .procname = "modules_disabled",
541 .data = &modules_disabled,
542 .maxlen = sizeof(int),
544 /* only handle a transition from default "0" to "1" */
545 .proc_handler = &proc_dointvec_minmax,
550 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
552 .ctl_name = KERN_HOTPLUG,
553 .procname = "hotplug",
554 .data = &uevent_helper,
555 .maxlen = UEVENT_HELPER_PATH_LEN,
557 .proc_handler = &proc_dostring,
558 .strategy = &sysctl_string,
561 #ifdef CONFIG_CHR_DEV_SG
563 .ctl_name = KERN_SG_BIG_BUFF,
564 .procname = "sg-big-buff",
565 .data = &sg_big_buff,
566 .maxlen = sizeof (int),
568 .proc_handler = &proc_dointvec,
571 #ifdef CONFIG_BSD_PROCESS_ACCT
573 .ctl_name = KERN_ACCT,
576 .maxlen = 3*sizeof(int),
578 .proc_handler = &proc_dointvec,
581 #ifdef CONFIG_MAGIC_SYSRQ
583 .ctl_name = KERN_SYSRQ,
585 .data = &__sysrq_enabled,
586 .maxlen = sizeof (int),
588 .proc_handler = &proc_dointvec,
591 #ifdef CONFIG_PROC_SYSCTL
593 .procname = "cad_pid",
595 .maxlen = sizeof (int),
597 .proc_handler = &proc_do_cad_pid,
601 .ctl_name = KERN_MAX_THREADS,
602 .procname = "threads-max",
603 .data = &max_threads,
604 .maxlen = sizeof(int),
606 .proc_handler = &proc_dointvec,
609 .ctl_name = KERN_RANDOM,
610 .procname = "random",
612 .child = random_table,
615 .ctl_name = KERN_OVERFLOWUID,
616 .procname = "overflowuid",
617 .data = &overflowuid,
618 .maxlen = sizeof(int),
620 .proc_handler = &proc_dointvec_minmax,
621 .strategy = &sysctl_intvec,
622 .extra1 = &minolduid,
623 .extra2 = &maxolduid,
626 .ctl_name = KERN_OVERFLOWGID,
627 .procname = "overflowgid",
628 .data = &overflowgid,
629 .maxlen = sizeof(int),
631 .proc_handler = &proc_dointvec_minmax,
632 .strategy = &sysctl_intvec,
633 .extra1 = &minolduid,
634 .extra2 = &maxolduid,
637 #ifdef CONFIG_MATHEMU
639 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
640 .procname = "ieee_emulation_warnings",
641 .data = &sysctl_ieee_emulation_warnings,
642 .maxlen = sizeof(int),
644 .proc_handler = &proc_dointvec,
648 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
649 .procname = "userprocess_debug",
650 .data = &sysctl_userprocess_debug,
651 .maxlen = sizeof(int),
653 .proc_handler = &proc_dointvec,
657 .ctl_name = KERN_PIDMAX,
658 .procname = "pid_max",
660 .maxlen = sizeof (int),
662 .proc_handler = &proc_dointvec_minmax,
663 .strategy = sysctl_intvec,
664 .extra1 = &pid_max_min,
665 .extra2 = &pid_max_max,
668 .ctl_name = KERN_PANIC_ON_OOPS,
669 .procname = "panic_on_oops",
670 .data = &panic_on_oops,
671 .maxlen = sizeof(int),
673 .proc_handler = &proc_dointvec,
675 #if defined CONFIG_PRINTK
677 .ctl_name = KERN_PRINTK,
678 .procname = "printk",
679 .data = &console_loglevel,
680 .maxlen = 4*sizeof(int),
682 .proc_handler = &proc_dointvec,
685 .ctl_name = KERN_PRINTK_RATELIMIT,
686 .procname = "printk_ratelimit",
687 .data = &printk_ratelimit_state.interval,
688 .maxlen = sizeof(int),
690 .proc_handler = &proc_dointvec_jiffies,
691 .strategy = &sysctl_jiffies,
694 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
695 .procname = "printk_ratelimit_burst",
696 .data = &printk_ratelimit_state.burst,
697 .maxlen = sizeof(int),
699 .proc_handler = &proc_dointvec,
703 .ctl_name = KERN_NGROUPS_MAX,
704 .procname = "ngroups_max",
705 .data = &ngroups_max,
706 .maxlen = sizeof (int),
708 .proc_handler = &proc_dointvec,
710 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
712 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
713 .procname = "unknown_nmi_panic",
714 .data = &unknown_nmi_panic,
715 .maxlen = sizeof (int),
717 .proc_handler = &proc_dointvec,
720 .procname = "nmi_watchdog",
721 .data = &nmi_watchdog_enabled,
722 .maxlen = sizeof (int),
724 .proc_handler = &proc_nmi_enabled,
727 #if defined(CONFIG_X86)
729 .ctl_name = KERN_PANIC_ON_NMI,
730 .procname = "panic_on_unrecovered_nmi",
731 .data = &panic_on_unrecovered_nmi,
732 .maxlen = sizeof(int),
734 .proc_handler = &proc_dointvec,
737 .ctl_name = KERN_BOOTLOADER_TYPE,
738 .procname = "bootloader_type",
739 .data = &bootloader_type,
740 .maxlen = sizeof (int),
742 .proc_handler = &proc_dointvec,
745 .ctl_name = CTL_UNNUMBERED,
746 .procname = "bootloader_version",
747 .data = &bootloader_version,
748 .maxlen = sizeof (int),
750 .proc_handler = &proc_dointvec,
753 .ctl_name = CTL_UNNUMBERED,
754 .procname = "kstack_depth_to_print",
755 .data = &kstack_depth_to_print,
756 .maxlen = sizeof(int),
758 .proc_handler = &proc_dointvec,
761 .ctl_name = CTL_UNNUMBERED,
762 .procname = "io_delay_type",
763 .data = &io_delay_type,
764 .maxlen = sizeof(int),
766 .proc_handler = &proc_dointvec,
769 #if defined(CONFIG_MMU)
771 .ctl_name = KERN_RANDOMIZE,
772 .procname = "randomize_va_space",
773 .data = &randomize_va_space,
774 .maxlen = sizeof(int),
776 .proc_handler = &proc_dointvec,
779 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
781 .ctl_name = KERN_SPIN_RETRY,
782 .procname = "spin_retry",
784 .maxlen = sizeof (int),
786 .proc_handler = &proc_dointvec,
789 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
791 .procname = "acpi_video_flags",
792 .data = &acpi_realmode_flags,
793 .maxlen = sizeof (unsigned long),
795 .proc_handler = &proc_doulongvec_minmax,
800 .ctl_name = KERN_IA64_UNALIGNED,
801 .procname = "ignore-unaligned-usertrap",
802 .data = &no_unaligned_warning,
803 .maxlen = sizeof (int),
805 .proc_handler = &proc_dointvec,
808 .ctl_name = CTL_UNNUMBERED,
809 .procname = "unaligned-dump-stack",
810 .data = &unaligned_dump_stack,
811 .maxlen = sizeof (int),
813 .proc_handler = &proc_dointvec,
816 #ifdef CONFIG_DETECT_SOFTLOCKUP
818 .ctl_name = CTL_UNNUMBERED,
819 .procname = "softlockup_panic",
820 .data = &softlockup_panic,
821 .maxlen = sizeof(int),
823 .proc_handler = &proc_dointvec_minmax,
824 .strategy = &sysctl_intvec,
829 .ctl_name = CTL_UNNUMBERED,
830 .procname = "softlockup_thresh",
831 .data = &softlockup_thresh,
832 .maxlen = sizeof(int),
834 .proc_handler = &proc_dosoftlockup_thresh,
835 .strategy = &sysctl_intvec,
840 #ifdef CONFIG_DETECT_HUNG_TASK
842 .ctl_name = CTL_UNNUMBERED,
843 .procname = "hung_task_panic",
844 .data = &sysctl_hung_task_panic,
845 .maxlen = sizeof(int),
847 .proc_handler = &proc_dointvec_minmax,
848 .strategy = &sysctl_intvec,
853 .ctl_name = CTL_UNNUMBERED,
854 .procname = "hung_task_check_count",
855 .data = &sysctl_hung_task_check_count,
856 .maxlen = sizeof(unsigned long),
858 .proc_handler = &proc_doulongvec_minmax,
859 .strategy = &sysctl_intvec,
862 .ctl_name = CTL_UNNUMBERED,
863 .procname = "hung_task_timeout_secs",
864 .data = &sysctl_hung_task_timeout_secs,
865 .maxlen = sizeof(unsigned long),
867 .proc_handler = &proc_dohung_task_timeout_secs,
868 .strategy = &sysctl_intvec,
871 .ctl_name = CTL_UNNUMBERED,
872 .procname = "hung_task_warnings",
873 .data = &sysctl_hung_task_warnings,
874 .maxlen = sizeof(unsigned long),
876 .proc_handler = &proc_doulongvec_minmax,
877 .strategy = &sysctl_intvec,
882 .ctl_name = KERN_COMPAT_LOG,
883 .procname = "compat-log",
885 .maxlen = sizeof (int),
887 .proc_handler = &proc_dointvec,
890 #ifdef CONFIG_RT_MUTEXES
892 .ctl_name = KERN_MAX_LOCK_DEPTH,
893 .procname = "max_lock_depth",
894 .data = &max_lock_depth,
895 .maxlen = sizeof(int),
897 .proc_handler = &proc_dointvec,
901 .ctl_name = CTL_UNNUMBERED,
902 .procname = "poweroff_cmd",
903 .data = &poweroff_cmd,
904 .maxlen = POWEROFF_CMD_PATH_LEN,
906 .proc_handler = &proc_dostring,
907 .strategy = &sysctl_string,
911 .ctl_name = CTL_UNNUMBERED,
914 .child = key_sysctls,
917 #ifdef CONFIG_RCU_TORTURE_TEST
919 .ctl_name = CTL_UNNUMBERED,
920 .procname = "rcutorture_runnable",
921 .data = &rcutorture_runnable,
922 .maxlen = sizeof(int),
924 .proc_handler = &proc_dointvec,
927 #ifdef CONFIG_SLOW_WORK
929 .ctl_name = CTL_UNNUMBERED,
930 .procname = "slow-work",
932 .child = slow_work_sysctls,
936 * NOTE: do not add new entries to this table unless you have read
937 * Documentation/sysctl/ctl_unnumbered.txt
942 static struct ctl_table vm_table[] = {
944 .ctl_name = VM_OVERCOMMIT_MEMORY,
945 .procname = "overcommit_memory",
946 .data = &sysctl_overcommit_memory,
947 .maxlen = sizeof(sysctl_overcommit_memory),
949 .proc_handler = &proc_dointvec,
952 .ctl_name = VM_PANIC_ON_OOM,
953 .procname = "panic_on_oom",
954 .data = &sysctl_panic_on_oom,
955 .maxlen = sizeof(sysctl_panic_on_oom),
957 .proc_handler = &proc_dointvec,
960 .ctl_name = CTL_UNNUMBERED,
961 .procname = "oom_kill_allocating_task",
962 .data = &sysctl_oom_kill_allocating_task,
963 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
965 .proc_handler = &proc_dointvec,
968 .ctl_name = CTL_UNNUMBERED,
969 .procname = "oom_dump_tasks",
970 .data = &sysctl_oom_dump_tasks,
971 .maxlen = sizeof(sysctl_oom_dump_tasks),
973 .proc_handler = &proc_dointvec,
976 .ctl_name = VM_OVERCOMMIT_RATIO,
977 .procname = "overcommit_ratio",
978 .data = &sysctl_overcommit_ratio,
979 .maxlen = sizeof(sysctl_overcommit_ratio),
981 .proc_handler = &proc_dointvec,
984 .ctl_name = VM_PAGE_CLUSTER,
985 .procname = "page-cluster",
986 .data = &page_cluster,
987 .maxlen = sizeof(int),
989 .proc_handler = &proc_dointvec,
992 .ctl_name = VM_DIRTY_BACKGROUND,
993 .procname = "dirty_background_ratio",
994 .data = &dirty_background_ratio,
995 .maxlen = sizeof(dirty_background_ratio),
997 .proc_handler = &dirty_background_ratio_handler,
998 .strategy = &sysctl_intvec,
1000 .extra2 = &one_hundred,
1003 .ctl_name = CTL_UNNUMBERED,
1004 .procname = "dirty_background_bytes",
1005 .data = &dirty_background_bytes,
1006 .maxlen = sizeof(dirty_background_bytes),
1008 .proc_handler = &dirty_background_bytes_handler,
1009 .strategy = &sysctl_intvec,
1013 .ctl_name = VM_DIRTY_RATIO,
1014 .procname = "dirty_ratio",
1015 .data = &vm_dirty_ratio,
1016 .maxlen = sizeof(vm_dirty_ratio),
1018 .proc_handler = &dirty_ratio_handler,
1019 .strategy = &sysctl_intvec,
1021 .extra2 = &one_hundred,
1024 .ctl_name = CTL_UNNUMBERED,
1025 .procname = "dirty_bytes",
1026 .data = &vm_dirty_bytes,
1027 .maxlen = sizeof(vm_dirty_bytes),
1029 .proc_handler = &dirty_bytes_handler,
1030 .strategy = &sysctl_intvec,
1031 .extra1 = &dirty_bytes_min,
1034 .procname = "dirty_writeback_centisecs",
1035 .data = &dirty_writeback_interval,
1036 .maxlen = sizeof(dirty_writeback_interval),
1038 .proc_handler = &dirty_writeback_centisecs_handler,
1041 .procname = "dirty_expire_centisecs",
1042 .data = &dirty_expire_interval,
1043 .maxlen = sizeof(dirty_expire_interval),
1045 .proc_handler = &proc_dointvec,
1048 .ctl_name = VM_NR_PDFLUSH_THREADS,
1049 .procname = "nr_pdflush_threads",
1050 .data = &nr_pdflush_threads,
1051 .maxlen = sizeof nr_pdflush_threads,
1052 .mode = 0444 /* read-only*/,
1053 .proc_handler = &proc_dointvec,
1056 .ctl_name = VM_SWAPPINESS,
1057 .procname = "swappiness",
1058 .data = &vm_swappiness,
1059 .maxlen = sizeof(vm_swappiness),
1061 .proc_handler = &proc_dointvec_minmax,
1062 .strategy = &sysctl_intvec,
1064 .extra2 = &one_hundred,
1066 #ifdef CONFIG_HUGETLB_PAGE
1068 .procname = "nr_hugepages",
1070 .maxlen = sizeof(unsigned long),
1072 .proc_handler = &hugetlb_sysctl_handler,
1073 .extra1 = (void *)&hugetlb_zero,
1074 .extra2 = (void *)&hugetlb_infinity,
1077 .ctl_name = VM_HUGETLB_GROUP,
1078 .procname = "hugetlb_shm_group",
1079 .data = &sysctl_hugetlb_shm_group,
1080 .maxlen = sizeof(gid_t),
1082 .proc_handler = &proc_dointvec,
1085 .ctl_name = CTL_UNNUMBERED,
1086 .procname = "hugepages_treat_as_movable",
1087 .data = &hugepages_treat_as_movable,
1088 .maxlen = sizeof(int),
1090 .proc_handler = &hugetlb_treat_movable_handler,
1093 .ctl_name = CTL_UNNUMBERED,
1094 .procname = "nr_overcommit_hugepages",
1096 .maxlen = sizeof(unsigned long),
1098 .proc_handler = &hugetlb_overcommit_handler,
1099 .extra1 = (void *)&hugetlb_zero,
1100 .extra2 = (void *)&hugetlb_infinity,
1104 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
1105 .procname = "lowmem_reserve_ratio",
1106 .data = &sysctl_lowmem_reserve_ratio,
1107 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1109 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
1110 .strategy = &sysctl_intvec,
1113 .ctl_name = VM_DROP_PAGECACHE,
1114 .procname = "drop_caches",
1115 .data = &sysctl_drop_caches,
1116 .maxlen = sizeof(int),
1118 .proc_handler = drop_caches_sysctl_handler,
1119 .strategy = &sysctl_intvec,
1122 .ctl_name = VM_MIN_FREE_KBYTES,
1123 .procname = "min_free_kbytes",
1124 .data = &min_free_kbytes,
1125 .maxlen = sizeof(min_free_kbytes),
1127 .proc_handler = &min_free_kbytes_sysctl_handler,
1128 .strategy = &sysctl_intvec,
1132 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
1133 .procname = "percpu_pagelist_fraction",
1134 .data = &percpu_pagelist_fraction,
1135 .maxlen = sizeof(percpu_pagelist_fraction),
1137 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
1138 .strategy = &sysctl_intvec,
1139 .extra1 = &min_percpu_pagelist_fract,
1143 .ctl_name = VM_MAX_MAP_COUNT,
1144 .procname = "max_map_count",
1145 .data = &sysctl_max_map_count,
1146 .maxlen = sizeof(sysctl_max_map_count),
1148 .proc_handler = &proc_dointvec
1152 .ctl_name = CTL_UNNUMBERED,
1153 .procname = "nr_trim_pages",
1154 .data = &sysctl_nr_trim_pages,
1155 .maxlen = sizeof(sysctl_nr_trim_pages),
1157 .proc_handler = &proc_dointvec_minmax,
1158 .strategy = &sysctl_intvec,
1163 .ctl_name = VM_LAPTOP_MODE,
1164 .procname = "laptop_mode",
1165 .data = &laptop_mode,
1166 .maxlen = sizeof(laptop_mode),
1168 .proc_handler = &proc_dointvec_jiffies,
1169 .strategy = &sysctl_jiffies,
1172 .ctl_name = VM_BLOCK_DUMP,
1173 .procname = "block_dump",
1174 .data = &block_dump,
1175 .maxlen = sizeof(block_dump),
1177 .proc_handler = &proc_dointvec,
1178 .strategy = &sysctl_intvec,
1182 .ctl_name = VM_VFS_CACHE_PRESSURE,
1183 .procname = "vfs_cache_pressure",
1184 .data = &sysctl_vfs_cache_pressure,
1185 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1187 .proc_handler = &proc_dointvec,
1188 .strategy = &sysctl_intvec,
1191 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1193 .ctl_name = VM_LEGACY_VA_LAYOUT,
1194 .procname = "legacy_va_layout",
1195 .data = &sysctl_legacy_va_layout,
1196 .maxlen = sizeof(sysctl_legacy_va_layout),
1198 .proc_handler = &proc_dointvec,
1199 .strategy = &sysctl_intvec,
1205 .ctl_name = VM_ZONE_RECLAIM_MODE,
1206 .procname = "zone_reclaim_mode",
1207 .data = &zone_reclaim_mode,
1208 .maxlen = sizeof(zone_reclaim_mode),
1210 .proc_handler = &proc_dointvec,
1211 .strategy = &sysctl_intvec,
1215 .ctl_name = VM_MIN_UNMAPPED,
1216 .procname = "min_unmapped_ratio",
1217 .data = &sysctl_min_unmapped_ratio,
1218 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1220 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1221 .strategy = &sysctl_intvec,
1223 .extra2 = &one_hundred,
1226 .ctl_name = VM_MIN_SLAB,
1227 .procname = "min_slab_ratio",
1228 .data = &sysctl_min_slab_ratio,
1229 .maxlen = sizeof(sysctl_min_slab_ratio),
1231 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1232 .strategy = &sysctl_intvec,
1234 .extra2 = &one_hundred,
1239 .ctl_name = CTL_UNNUMBERED,
1240 .procname = "stat_interval",
1241 .data = &sysctl_stat_interval,
1242 .maxlen = sizeof(sysctl_stat_interval),
1244 .proc_handler = &proc_dointvec_jiffies,
1245 .strategy = &sysctl_jiffies,
1249 .ctl_name = CTL_UNNUMBERED,
1250 .procname = "mmap_min_addr",
1251 .data = &mmap_min_addr,
1252 .maxlen = sizeof(unsigned long),
1254 .proc_handler = &proc_doulongvec_minmax,
1258 .ctl_name = CTL_UNNUMBERED,
1259 .procname = "numa_zonelist_order",
1260 .data = &numa_zonelist_order,
1261 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1263 .proc_handler = &numa_zonelist_order_handler,
1264 .strategy = &sysctl_string,
1267 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1268 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1270 .ctl_name = VM_VDSO_ENABLED,
1271 .procname = "vdso_enabled",
1272 .data = &vdso_enabled,
1273 .maxlen = sizeof(vdso_enabled),
1275 .proc_handler = &proc_dointvec,
1276 .strategy = &sysctl_intvec,
1280 #ifdef CONFIG_HIGHMEM
1282 .ctl_name = CTL_UNNUMBERED,
1283 .procname = "highmem_is_dirtyable",
1284 .data = &vm_highmem_is_dirtyable,
1285 .maxlen = sizeof(vm_highmem_is_dirtyable),
1287 .proc_handler = &proc_dointvec_minmax,
1288 .strategy = &sysctl_intvec,
1293 #ifdef CONFIG_UNEVICTABLE_LRU
1295 .ctl_name = CTL_UNNUMBERED,
1296 .procname = "scan_unevictable_pages",
1297 .data = &scan_unevictable_pages,
1298 .maxlen = sizeof(scan_unevictable_pages),
1300 .proc_handler = &scan_unevictable_handler,
1304 * NOTE: do not add new entries to this table unless you have read
1305 * Documentation/sysctl/ctl_unnumbered.txt
1310 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1311 static struct ctl_table binfmt_misc_table[] = {
1316 static struct ctl_table fs_table[] = {
1318 .ctl_name = FS_NRINODE,
1319 .procname = "inode-nr",
1320 .data = &inodes_stat,
1321 .maxlen = 2*sizeof(int),
1323 .proc_handler = &proc_dointvec,
1326 .ctl_name = FS_STATINODE,
1327 .procname = "inode-state",
1328 .data = &inodes_stat,
1329 .maxlen = 7*sizeof(int),
1331 .proc_handler = &proc_dointvec,
1334 .procname = "file-nr",
1335 .data = &files_stat,
1336 .maxlen = 3*sizeof(int),
1338 .proc_handler = &proc_nr_files,
1341 .ctl_name = FS_MAXFILE,
1342 .procname = "file-max",
1343 .data = &files_stat.max_files,
1344 .maxlen = sizeof(int),
1346 .proc_handler = &proc_dointvec,
1349 .ctl_name = CTL_UNNUMBERED,
1350 .procname = "nr_open",
1351 .data = &sysctl_nr_open,
1352 .maxlen = sizeof(int),
1354 .proc_handler = &proc_dointvec_minmax,
1355 .extra1 = &sysctl_nr_open_min,
1356 .extra2 = &sysctl_nr_open_max,
1359 .ctl_name = FS_DENTRY,
1360 .procname = "dentry-state",
1361 .data = &dentry_stat,
1362 .maxlen = 6*sizeof(int),
1364 .proc_handler = &proc_dointvec,
1367 .ctl_name = FS_OVERFLOWUID,
1368 .procname = "overflowuid",
1369 .data = &fs_overflowuid,
1370 .maxlen = sizeof(int),
1372 .proc_handler = &proc_dointvec_minmax,
1373 .strategy = &sysctl_intvec,
1374 .extra1 = &minolduid,
1375 .extra2 = &maxolduid,
1378 .ctl_name = FS_OVERFLOWGID,
1379 .procname = "overflowgid",
1380 .data = &fs_overflowgid,
1381 .maxlen = sizeof(int),
1383 .proc_handler = &proc_dointvec_minmax,
1384 .strategy = &sysctl_intvec,
1385 .extra1 = &minolduid,
1386 .extra2 = &maxolduid,
1388 #ifdef CONFIG_FILE_LOCKING
1390 .ctl_name = FS_LEASES,
1391 .procname = "leases-enable",
1392 .data = &leases_enable,
1393 .maxlen = sizeof(int),
1395 .proc_handler = &proc_dointvec,
1398 #ifdef CONFIG_DNOTIFY
1400 .ctl_name = FS_DIR_NOTIFY,
1401 .procname = "dir-notify-enable",
1402 .data = &dir_notify_enable,
1403 .maxlen = sizeof(int),
1405 .proc_handler = &proc_dointvec,
1409 #ifdef CONFIG_FILE_LOCKING
1411 .ctl_name = FS_LEASE_TIME,
1412 .procname = "lease-break-time",
1413 .data = &lease_break_time,
1414 .maxlen = sizeof(int),
1416 .proc_handler = &proc_dointvec,
1421 .procname = "aio-nr",
1423 .maxlen = sizeof(aio_nr),
1425 .proc_handler = &proc_doulongvec_minmax,
1428 .procname = "aio-max-nr",
1429 .data = &aio_max_nr,
1430 .maxlen = sizeof(aio_max_nr),
1432 .proc_handler = &proc_doulongvec_minmax,
1434 #endif /* CONFIG_AIO */
1435 #ifdef CONFIG_INOTIFY_USER
1437 .ctl_name = FS_INOTIFY,
1438 .procname = "inotify",
1440 .child = inotify_table,
1445 .procname = "epoll",
1447 .child = epoll_table,
1452 .ctl_name = KERN_SETUID_DUMPABLE,
1453 .procname = "suid_dumpable",
1454 .data = &suid_dumpable,
1455 .maxlen = sizeof(int),
1457 .proc_handler = &proc_dointvec_minmax,
1458 .strategy = &sysctl_intvec,
1462 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1464 .ctl_name = CTL_UNNUMBERED,
1465 .procname = "binfmt_misc",
1467 .child = binfmt_misc_table,
1471 * NOTE: do not add new entries to this table unless you have read
1472 * Documentation/sysctl/ctl_unnumbered.txt
1477 static struct ctl_table debug_table[] = {
1478 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1480 .ctl_name = CTL_UNNUMBERED,
1481 .procname = "exception-trace",
1482 .data = &show_unhandled_signals,
1483 .maxlen = sizeof(int),
1485 .proc_handler = proc_dointvec
1491 static struct ctl_table dev_table[] = {
1495 static DEFINE_SPINLOCK(sysctl_lock);
1497 /* called under sysctl_lock */
1498 static int use_table(struct ctl_table_header *p)
1500 if (unlikely(p->unregistering))
1506 /* called under sysctl_lock */
1507 static void unuse_table(struct ctl_table_header *p)
1510 if (unlikely(p->unregistering))
1511 complete(p->unregistering);
1514 /* called under sysctl_lock, will reacquire if has to wait */
1515 static void start_unregistering(struct ctl_table_header *p)
1518 * if p->used is 0, nobody will ever touch that entry again;
1519 * we'll eliminate all paths to it before dropping sysctl_lock
1521 if (unlikely(p->used)) {
1522 struct completion wait;
1523 init_completion(&wait);
1524 p->unregistering = &wait;
1525 spin_unlock(&sysctl_lock);
1526 wait_for_completion(&wait);
1527 spin_lock(&sysctl_lock);
1529 /* anything non-NULL; we'll never dereference it */
1530 p->unregistering = ERR_PTR(-EINVAL);
1533 * do not remove from the list until nobody holds it; walking the
1534 * list in do_sysctl() relies on that.
1536 list_del_init(&p->ctl_entry);
1539 void sysctl_head_get(struct ctl_table_header *head)
1541 spin_lock(&sysctl_lock);
1543 spin_unlock(&sysctl_lock);
1546 void sysctl_head_put(struct ctl_table_header *head)
1548 spin_lock(&sysctl_lock);
1551 spin_unlock(&sysctl_lock);
1554 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1558 spin_lock(&sysctl_lock);
1559 if (!use_table(head))
1560 head = ERR_PTR(-ENOENT);
1561 spin_unlock(&sysctl_lock);
1565 void sysctl_head_finish(struct ctl_table_header *head)
1569 spin_lock(&sysctl_lock);
1571 spin_unlock(&sysctl_lock);
1574 static struct ctl_table_set *
1575 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1577 struct ctl_table_set *set = &root->default_set;
1579 set = root->lookup(root, namespaces);
1583 static struct list_head *
1584 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1586 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1590 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1591 struct ctl_table_header *prev)
1593 struct ctl_table_root *root;
1594 struct list_head *header_list;
1595 struct ctl_table_header *head;
1596 struct list_head *tmp;
1598 spin_lock(&sysctl_lock);
1601 tmp = &prev->ctl_entry;
1605 tmp = &root_table_header.ctl_entry;
1607 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1609 if (!use_table(head))
1611 spin_unlock(&sysctl_lock);
1616 header_list = lookup_header_list(root, namespaces);
1617 if (tmp != header_list)
1621 root = list_entry(root->root_list.next,
1622 struct ctl_table_root, root_list);
1623 if (root == &sysctl_table_root)
1625 header_list = lookup_header_list(root, namespaces);
1626 } while (list_empty(header_list));
1627 tmp = header_list->next;
1630 spin_unlock(&sysctl_lock);
1634 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1636 return __sysctl_head_next(current->nsproxy, prev);
1639 void register_sysctl_root(struct ctl_table_root *root)
1641 spin_lock(&sysctl_lock);
1642 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1643 spin_unlock(&sysctl_lock);
1646 #ifdef CONFIG_SYSCTL_SYSCALL
1647 /* Perform the actual read/write of a sysctl table entry. */
1648 static int do_sysctl_strategy(struct ctl_table_root *root,
1649 struct ctl_table *table,
1650 void __user *oldval, size_t __user *oldlenp,
1651 void __user *newval, size_t newlen)
1659 if (sysctl_perm(root, table, op))
1662 if (table->strategy) {
1663 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1670 /* If there is no strategy routine, or if the strategy returns
1671 * zero, proceed with automatic r/w */
1672 if (table->data && table->maxlen) {
1673 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1680 static int parse_table(int __user *name, int nlen,
1681 void __user *oldval, size_t __user *oldlenp,
1682 void __user *newval, size_t newlen,
1683 struct ctl_table_root *root,
1684 struct ctl_table *table)
1690 if (get_user(n, name))
1692 for ( ; table->ctl_name || table->procname; table++) {
1693 if (!table->ctl_name)
1695 if (n == table->ctl_name) {
1698 if (sysctl_perm(root, table, MAY_EXEC))
1702 table = table->child;
1705 error = do_sysctl_strategy(root, table,
1714 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1715 void __user *newval, size_t newlen)
1717 struct ctl_table_header *head;
1718 int error = -ENOTDIR;
1720 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1724 if (!oldlenp || get_user(old_len, oldlenp))
1728 for (head = sysctl_head_next(NULL); head;
1729 head = sysctl_head_next(head)) {
1730 error = parse_table(name, nlen, oldval, oldlenp,
1732 head->root, head->ctl_table);
1733 if (error != -ENOTDIR) {
1734 sysctl_head_finish(head);
1741 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1743 struct __sysctl_args tmp;
1746 if (copy_from_user(&tmp, args, sizeof(tmp)))
1749 error = deprecated_sysctl_warning(&tmp);
1754 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1755 tmp.newval, tmp.newlen);
1760 #endif /* CONFIG_SYSCTL_SYSCALL */
1763 * sysctl_perm does NOT grant the superuser all rights automatically, because
1764 * some sysctl variables are readonly even to root.
1767 static int test_perm(int mode, int op)
1769 if (!current_euid())
1771 else if (in_egroup_p(0))
1773 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1778 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1783 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1787 if (root->permissions)
1788 mode = root->permissions(root, current->nsproxy, table);
1792 return test_perm(mode, op);
1795 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1797 for (; table->ctl_name || table->procname; table++) {
1798 table->parent = parent;
1800 sysctl_set_parent(table, table->child);
1804 static __init int sysctl_init(void)
1806 sysctl_set_parent(NULL, root_table);
1807 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1810 err = sysctl_check_table(current->nsproxy, root_table);
1816 core_initcall(sysctl_init);
1818 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1819 struct ctl_table *table)
1821 struct ctl_table *p;
1822 const char *s = branch->procname;
1824 /* branch should have named subdirectory as its first element */
1825 if (!s || !branch->child)
1828 /* ... and nothing else */
1829 if (branch[1].procname || branch[1].ctl_name)
1832 /* table should contain subdirectory with the same name */
1833 for (p = table; p->procname || p->ctl_name; p++) {
1836 if (p->procname && strcmp(p->procname, s) == 0)
1842 /* see if attaching q to p would be an improvement */
1843 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1845 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1846 struct ctl_table *next;
1848 int not_in_parent = !p->attached_by;
1850 while ((next = is_branch_in(by, to)) != NULL) {
1851 if (by == q->attached_by)
1853 if (to == p->attached_by)
1859 if (is_better && not_in_parent) {
1860 q->attached_by = by;
1861 q->attached_to = to;
1867 * __register_sysctl_paths - register a sysctl hierarchy
1868 * @root: List of sysctl headers to register on
1869 * @namespaces: Data to compute which lists of sysctl entries are visible
1870 * @path: The path to the directory the sysctl table is in.
1871 * @table: the top-level table structure
1873 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1874 * array. A completely 0 filled entry terminates the table.
1876 * The members of the &struct ctl_table structure are used as follows:
1878 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1879 * must be unique within that level of sysctl
1881 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1882 * enter a sysctl file
1884 * data - a pointer to data for use by proc_handler
1886 * maxlen - the maximum size in bytes of the data
1888 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1890 * child - a pointer to the child sysctl table if this entry is a directory, or
1893 * proc_handler - the text handler routine (described below)
1895 * strategy - the strategy routine (described below)
1897 * de - for internal use by the sysctl routines
1899 * extra1, extra2 - extra pointers usable by the proc handler routines
1901 * Leaf nodes in the sysctl tree will be represented by a single file
1902 * under /proc; non-leaf nodes will be represented by directories.
1904 * sysctl(2) can automatically manage read and write requests through
1905 * the sysctl table. The data and maxlen fields of the ctl_table
1906 * struct enable minimal validation of the values being written to be
1907 * performed, and the mode field allows minimal authentication.
1909 * More sophisticated management can be enabled by the provision of a
1910 * strategy routine with the table entry. This will be called before
1911 * any automatic read or write of the data is performed.
1913 * The strategy routine may return
1915 * < 0 - Error occurred (error is passed to user process)
1917 * 0 - OK - proceed with automatic read or write.
1919 * > 0 - OK - read or write has been done by the strategy routine, so
1920 * return immediately.
1922 * There must be a proc_handler routine for any terminal nodes
1923 * mirrored under /proc/sys (non-terminals are handled by a built-in
1924 * directory handler). Several default handlers are available to
1925 * cover common cases -
1927 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1928 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1929 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1931 * It is the handler's job to read the input buffer from user memory
1932 * and process it. The handler should return 0 on success.
1934 * This routine returns %NULL on a failure to register, and a pointer
1935 * to the table header on success.
1937 struct ctl_table_header *__register_sysctl_paths(
1938 struct ctl_table_root *root,
1939 struct nsproxy *namespaces,
1940 const struct ctl_path *path, struct ctl_table *table)
1942 struct ctl_table_header *header;
1943 struct ctl_table *new, **prevp;
1944 unsigned int n, npath;
1945 struct ctl_table_set *set;
1947 /* Count the path components */
1948 for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1952 * For each path component, allocate a 2-element ctl_table array.
1953 * The first array element will be filled with the sysctl entry
1954 * for this, the second will be the sentinel (ctl_name == 0).
1956 * We allocate everything in one go so that we don't have to
1957 * worry about freeing additional memory in unregister_sysctl_table.
1959 header = kzalloc(sizeof(struct ctl_table_header) +
1960 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1964 new = (struct ctl_table *) (header + 1);
1966 /* Now connect the dots */
1967 prevp = &header->ctl_table;
1968 for (n = 0; n < npath; ++n, ++path) {
1969 /* Copy the procname */
1970 new->procname = path->procname;
1971 new->ctl_name = path->ctl_name;
1975 prevp = &new->child;
1980 header->ctl_table_arg = table;
1982 INIT_LIST_HEAD(&header->ctl_entry);
1984 header->unregistering = NULL;
1985 header->root = root;
1986 sysctl_set_parent(NULL, header->ctl_table);
1988 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1989 if (sysctl_check_table(namespaces, header->ctl_table)) {
1994 spin_lock(&sysctl_lock);
1995 header->set = lookup_header_set(root, namespaces);
1996 header->attached_by = header->ctl_table;
1997 header->attached_to = root_table;
1998 header->parent = &root_table_header;
1999 for (set = header->set; set; set = set->parent) {
2000 struct ctl_table_header *p;
2001 list_for_each_entry(p, &set->list, ctl_entry) {
2002 if (p->unregistering)
2004 try_attach(p, header);
2007 header->parent->count++;
2008 list_add_tail(&header->ctl_entry, &header->set->list);
2009 spin_unlock(&sysctl_lock);
2015 * register_sysctl_table_path - register a sysctl table hierarchy
2016 * @path: The path to the directory the sysctl table is in.
2017 * @table: the top-level table structure
2019 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2020 * array. A completely 0 filled entry terminates the table.
2022 * See __register_sysctl_paths for more details.
2024 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2025 struct ctl_table *table)
2027 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
2032 * register_sysctl_table - register a sysctl table hierarchy
2033 * @table: the top-level table structure
2035 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
2036 * array. A completely 0 filled entry terminates the table.
2038 * See register_sysctl_paths for more details.
2040 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
2042 static const struct ctl_path null_path[] = { {} };
2044 return register_sysctl_paths(null_path, table);
2048 * unregister_sysctl_table - unregister a sysctl table hierarchy
2049 * @header: the header returned from register_sysctl_table
2051 * Unregisters the sysctl table and all children. proc entries may not
2052 * actually be removed until they are no longer used by anyone.
2054 void unregister_sysctl_table(struct ctl_table_header * header)
2061 spin_lock(&sysctl_lock);
2062 start_unregistering(header);
2063 if (!--header->parent->count) {
2065 kfree(header->parent);
2067 if (!--header->count)
2069 spin_unlock(&sysctl_lock);
2072 int sysctl_is_seen(struct ctl_table_header *p)
2074 struct ctl_table_set *set = p->set;
2076 spin_lock(&sysctl_lock);
2077 if (p->unregistering)
2079 else if (!set->is_seen)
2082 res = set->is_seen(set);
2083 spin_unlock(&sysctl_lock);
2087 void setup_sysctl_set(struct ctl_table_set *p,
2088 struct ctl_table_set *parent,
2089 int (*is_seen)(struct ctl_table_set *))
2091 INIT_LIST_HEAD(&p->list);
2092 p->parent = parent ? parent : &sysctl_table_root.default_set;
2093 p->is_seen = is_seen;
2096 #else /* !CONFIG_SYSCTL */
2097 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2102 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2103 struct ctl_table *table)
2108 void unregister_sysctl_table(struct ctl_table_header * table)
2112 void setup_sysctl_set(struct ctl_table_set *p,
2113 struct ctl_table_set *parent,
2114 int (*is_seen)(struct ctl_table_set *))
2118 void sysctl_head_put(struct ctl_table_header *head)
2122 #endif /* CONFIG_SYSCTL */
2128 #ifdef CONFIG_PROC_SYSCTL
2130 static int _proc_do_string(void* data, int maxlen, int write,
2131 struct file *filp, void __user *buffer,
2132 size_t *lenp, loff_t *ppos)
2138 if (!data || !maxlen || !*lenp) {
2146 while (len < *lenp) {
2147 if (get_user(c, p++))
2149 if (c == 0 || c == '\n')
2155 if(copy_from_user(data, buffer, len))
2157 ((char *) data)[len] = 0;
2175 if(copy_to_user(buffer, data, len))
2178 if(put_user('\n', ((char __user *) buffer) + len))
2189 * proc_dostring - read a string sysctl
2190 * @table: the sysctl table
2191 * @write: %TRUE if this is a write to the sysctl file
2192 * @filp: the file structure
2193 * @buffer: the user buffer
2194 * @lenp: the size of the user buffer
2195 * @ppos: file position
2197 * Reads/writes a string from/to the user buffer. If the kernel
2198 * buffer provided is not large enough to hold the string, the
2199 * string is truncated. The copied string is %NULL-terminated.
2200 * If the string is being read by the user process, it is copied
2201 * and a newline '\n' is added. It is truncated if the buffer is
2204 * Returns 0 on success.
2206 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2207 void __user *buffer, size_t *lenp, loff_t *ppos)
2209 return _proc_do_string(table->data, table->maxlen, write, filp,
2210 buffer, lenp, ppos);
2214 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2216 int write, void *data)
2219 *valp = *negp ? -*lvalp : *lvalp;
2224 *lvalp = (unsigned long)-val;
2227 *lvalp = (unsigned long)val;
2233 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2234 int write, struct file *filp, void __user *buffer,
2235 size_t *lenp, loff_t *ppos,
2236 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2237 int write, void *data),
2240 #define TMPBUFLEN 21
2241 int *i, vleft, first=1, neg, val;
2245 char buf[TMPBUFLEN], *p;
2246 char __user *s = buffer;
2248 if (!tbl_data || !table->maxlen || !*lenp ||
2249 (*ppos && !write)) {
2254 i = (int *) tbl_data;
2255 vleft = table->maxlen / sizeof(*i);
2259 conv = do_proc_dointvec_conv;
2261 for (; left && vleft--; i++, first=0) {
2276 if (len > sizeof(buf) - 1)
2277 len = sizeof(buf) - 1;
2278 if (copy_from_user(buf, s, len))
2282 if (*p == '-' && left > 1) {
2286 if (*p < '0' || *p > '9')
2289 lval = simple_strtoul(p, &p, 0);
2292 if ((len < left) && *p && !isspace(*p))
2299 if (conv(&neg, &lval, i, 1, data))
2306 if (conv(&neg, &lval, i, 0, data))
2309 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2313 if(copy_to_user(s, buf, len))
2320 if (!write && !first && left) {
2321 if(put_user('\n', s))
2328 if (get_user(c, s++))
2343 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2344 void __user *buffer, size_t *lenp, loff_t *ppos,
2345 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2346 int write, void *data),
2349 return __do_proc_dointvec(table->data, table, write, filp,
2350 buffer, lenp, ppos, conv, data);
2354 * proc_dointvec - read a vector of integers
2355 * @table: the sysctl table
2356 * @write: %TRUE if this is a write to the sysctl file
2357 * @filp: the file structure
2358 * @buffer: the user buffer
2359 * @lenp: the size of the user buffer
2360 * @ppos: file position
2362 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2363 * values from/to the user buffer, treated as an ASCII string.
2365 * Returns 0 on success.
2367 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2368 void __user *buffer, size_t *lenp, loff_t *ppos)
2370 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2375 * Taint values can only be increased
2376 * This means we can safely use a temporary.
2378 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2379 void __user *buffer, size_t *lenp, loff_t *ppos)
2382 unsigned long tmptaint = get_taint();
2385 if (write && !capable(CAP_SYS_ADMIN))
2390 err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2396 * Poor man's atomic or. Not worth adding a primitive
2397 * to everyone's atomic.h for this
2400 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2401 if ((tmptaint >> i) & 1)
2409 struct do_proc_dointvec_minmax_conv_param {
2414 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2416 int write, void *data)
2418 struct do_proc_dointvec_minmax_conv_param *param = data;
2420 int val = *negp ? -*lvalp : *lvalp;
2421 if ((param->min && *param->min > val) ||
2422 (param->max && *param->max < val))
2429 *lvalp = (unsigned long)-val;
2432 *lvalp = (unsigned long)val;
2439 * proc_dointvec_minmax - read a vector of integers with min/max values
2440 * @table: the sysctl table
2441 * @write: %TRUE if this is a write to the sysctl file
2442 * @filp: the file structure
2443 * @buffer: the user buffer
2444 * @lenp: the size of the user buffer
2445 * @ppos: file position
2447 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2448 * values from/to the user buffer, treated as an ASCII string.
2450 * This routine will ensure the values are within the range specified by
2451 * table->extra1 (min) and table->extra2 (max).
2453 * Returns 0 on success.
2455 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2456 void __user *buffer, size_t *lenp, loff_t *ppos)
2458 struct do_proc_dointvec_minmax_conv_param param = {
2459 .min = (int *) table->extra1,
2460 .max = (int *) table->extra2,
2462 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2463 do_proc_dointvec_minmax_conv, ¶m);
2466 static int __do_proc_doulongvec_minmax(void *data, 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 #define TMPBUFLEN 21
2474 unsigned long *i, *min, *max, val;
2475 int vleft, first=1, neg;
2477 char buf[TMPBUFLEN], *p;
2478 char __user *s = buffer;
2480 if (!data || !table->maxlen || !*lenp ||
2481 (*ppos && !write)) {
2486 i = (unsigned long *) data;
2487 min = (unsigned long *) table->extra1;
2488 max = (unsigned long *) table->extra2;
2489 vleft = table->maxlen / sizeof(unsigned long);
2492 for (; left && vleft--; i++, min++, max++, first=0) {
2507 if (len > TMPBUFLEN-1)
2509 if (copy_from_user(buf, s, len))
2513 if (*p == '-' && left > 1) {
2517 if (*p < '0' || *p > '9')
2519 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2521 if ((len < left) && *p && !isspace(*p))
2530 if ((min && val < *min) || (max && val > *max))
2537 sprintf(p, "%lu", convdiv * (*i) / convmul);
2541 if(copy_to_user(s, buf, len))
2548 if (!write && !first && left) {
2549 if(put_user('\n', s))
2556 if (get_user(c, s++))
2571 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2573 void __user *buffer,
2574 size_t *lenp, loff_t *ppos,
2575 unsigned long convmul,
2576 unsigned long convdiv)
2578 return __do_proc_doulongvec_minmax(table->data, table, write,
2579 filp, buffer, lenp, ppos, convmul, convdiv);
2583 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2584 * @table: the sysctl table
2585 * @write: %TRUE if this is a write to the sysctl file
2586 * @filp: the file structure
2587 * @buffer: the user buffer
2588 * @lenp: the size of the user buffer
2589 * @ppos: file position
2591 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2592 * values from/to the user buffer, treated as an ASCII string.
2594 * This routine will ensure the values are within the range specified by
2595 * table->extra1 (min) and table->extra2 (max).
2597 * Returns 0 on success.
2599 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2600 void __user *buffer, size_t *lenp, loff_t *ppos)
2602 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2606 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2607 * @table: the sysctl table
2608 * @write: %TRUE if this is a write to the sysctl file
2609 * @filp: the file structure
2610 * @buffer: the user buffer
2611 * @lenp: the size of the user buffer
2612 * @ppos: file position
2614 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2615 * values from/to the user buffer, treated as an ASCII string. The values
2616 * are treated as milliseconds, and converted to jiffies when they are stored.
2618 * This routine will ensure the values are within the range specified by
2619 * table->extra1 (min) and table->extra2 (max).
2621 * Returns 0 on success.
2623 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2625 void __user *buffer,
2626 size_t *lenp, loff_t *ppos)
2628 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2629 lenp, ppos, HZ, 1000l);
2633 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2635 int write, void *data)
2638 if (*lvalp > LONG_MAX / HZ)
2640 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2646 lval = (unsigned long)-val;
2649 lval = (unsigned long)val;
2656 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2658 int write, void *data)
2661 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2663 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2669 lval = (unsigned long)-val;
2672 lval = (unsigned long)val;
2674 *lvalp = jiffies_to_clock_t(lval);
2679 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2681 int write, void *data)
2684 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2690 lval = (unsigned long)-val;
2693 lval = (unsigned long)val;
2695 *lvalp = jiffies_to_msecs(lval);
2701 * proc_dointvec_jiffies - read a vector of integers as seconds
2702 * @table: the sysctl table
2703 * @write: %TRUE if this is a write to the sysctl file
2704 * @filp: the file structure
2705 * @buffer: the user buffer
2706 * @lenp: the size of the user buffer
2707 * @ppos: file position
2709 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2710 * values from/to the user buffer, treated as an ASCII string.
2711 * The values read are assumed to be in seconds, and are converted into
2714 * Returns 0 on success.
2716 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2717 void __user *buffer, size_t *lenp, loff_t *ppos)
2719 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2720 do_proc_dointvec_jiffies_conv,NULL);
2724 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2725 * @table: the sysctl table
2726 * @write: %TRUE if this is a write to the sysctl file
2727 * @filp: the file structure
2728 * @buffer: the user buffer
2729 * @lenp: the size of the user buffer
2730 * @ppos: pointer to the file position
2732 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2733 * values from/to the user buffer, treated as an ASCII string.
2734 * The values read are assumed to be in 1/USER_HZ seconds, and
2735 * are converted into jiffies.
2737 * Returns 0 on success.
2739 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2740 void __user *buffer, size_t *lenp, loff_t *ppos)
2742 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2743 do_proc_dointvec_userhz_jiffies_conv,NULL);
2747 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2748 * @table: the sysctl table
2749 * @write: %TRUE if this is a write to the sysctl file
2750 * @filp: the file structure
2751 * @buffer: the user buffer
2752 * @lenp: the size of the user buffer
2753 * @ppos: file position
2754 * @ppos: the current position in the file
2756 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2757 * values from/to the user buffer, treated as an ASCII string.
2758 * The values read are assumed to be in 1/1000 seconds, and
2759 * are converted into jiffies.
2761 * Returns 0 on success.
2763 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2764 void __user *buffer, size_t *lenp, loff_t *ppos)
2766 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2767 do_proc_dointvec_ms_jiffies_conv, NULL);
2770 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2771 void __user *buffer, size_t *lenp, loff_t *ppos)
2773 struct pid *new_pid;
2777 tmp = pid_vnr(cad_pid);
2779 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2780 lenp, ppos, NULL, NULL);
2784 new_pid = find_get_pid(tmp);
2788 put_pid(xchg(&cad_pid, new_pid));
2792 #else /* CONFIG_PROC_FS */
2794 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2795 void __user *buffer, size_t *lenp, loff_t *ppos)
2800 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2801 void __user *buffer, size_t *lenp, loff_t *ppos)
2806 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2807 void __user *buffer, size_t *lenp, loff_t *ppos)
2812 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2813 void __user *buffer, size_t *lenp, loff_t *ppos)
2818 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2819 void __user *buffer, size_t *lenp, loff_t *ppos)
2824 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2825 void __user *buffer, size_t *lenp, loff_t *ppos)
2830 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2831 void __user *buffer, size_t *lenp, loff_t *ppos)
2836 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2838 void __user *buffer,
2839 size_t *lenp, loff_t *ppos)
2845 #endif /* CONFIG_PROC_FS */
2848 #ifdef CONFIG_SYSCTL_SYSCALL
2850 * General sysctl support routines
2853 /* The generic sysctl data routine (used if no strategy routine supplied) */
2854 int sysctl_data(struct ctl_table *table,
2855 void __user *oldval, size_t __user *oldlenp,
2856 void __user *newval, size_t newlen)
2860 /* Get out of I don't have a variable */
2861 if (!table->data || !table->maxlen)
2864 if (oldval && oldlenp) {
2865 if (get_user(len, oldlenp))
2868 if (len > table->maxlen)
2869 len = table->maxlen;
2870 if (copy_to_user(oldval, table->data, len))
2872 if (put_user(len, oldlenp))
2877 if (newval && newlen) {
2878 if (newlen > table->maxlen)
2879 newlen = table->maxlen;
2881 if (copy_from_user(table->data, newval, newlen))
2887 /* The generic string strategy routine: */
2888 int sysctl_string(struct ctl_table *table,
2889 void __user *oldval, size_t __user *oldlenp,
2890 void __user *newval, size_t newlen)
2892 if (!table->data || !table->maxlen)
2895 if (oldval && oldlenp) {
2897 if (get_user(bufsize, oldlenp))
2900 size_t len = strlen(table->data), copied;
2902 /* This shouldn't trigger for a well-formed sysctl */
2903 if (len > table->maxlen)
2904 len = table->maxlen;
2906 /* Copy up to a max of bufsize-1 bytes of the string */
2907 copied = (len >= bufsize) ? bufsize - 1 : len;
2909 if (copy_to_user(oldval, table->data, copied) ||
2910 put_user(0, (char __user *)(oldval + copied)))
2912 if (put_user(len, oldlenp))
2916 if (newval && newlen) {
2917 size_t len = newlen;
2918 if (len > table->maxlen)
2919 len = table->maxlen;
2920 if(copy_from_user(table->data, newval, len))
2922 if (len == table->maxlen)
2924 ((char *) table->data)[len] = 0;
2930 * This function makes sure that all of the integers in the vector
2931 * are between the minimum and maximum values given in the arrays
2932 * table->extra1 and table->extra2, respectively.
2934 int sysctl_intvec(struct ctl_table *table,
2935 void __user *oldval, size_t __user *oldlenp,
2936 void __user *newval, size_t newlen)
2939 if (newval && newlen) {
2940 int __user *vec = (int __user *) newval;
2941 int *min = (int *) table->extra1;
2942 int *max = (int *) table->extra2;
2946 if (newlen % sizeof(int) != 0)
2949 if (!table->extra1 && !table->extra2)
2952 if (newlen > table->maxlen)
2953 newlen = table->maxlen;
2954 length = newlen / sizeof(int);
2956 for (i = 0; i < length; i++) {
2958 if (get_user(value, vec + i))
2960 if (min && value < min[i])
2962 if (max && value > max[i])
2969 /* Strategy function to convert jiffies to seconds */
2970 int sysctl_jiffies(struct ctl_table *table,
2971 void __user *oldval, size_t __user *oldlenp,
2972 void __user *newval, size_t newlen)
2974 if (oldval && oldlenp) {
2977 if (get_user(olen, oldlenp))
2982 if (olen < sizeof(int))
2985 val = *(int *)(table->data) / HZ;
2986 if (put_user(val, (int __user *)oldval))
2988 if (put_user(sizeof(int), oldlenp))
2992 if (newval && newlen) {
2994 if (newlen != sizeof(int))
2996 if (get_user(new, (int __user *)newval))
2998 *(int *)(table->data) = new*HZ;
3003 /* Strategy function to convert jiffies to seconds */
3004 int sysctl_ms_jiffies(struct ctl_table *table,
3005 void __user *oldval, size_t __user *oldlenp,
3006 void __user *newval, size_t newlen)
3008 if (oldval && oldlenp) {
3011 if (get_user(olen, oldlenp))
3016 if (olen < sizeof(int))
3019 val = jiffies_to_msecs(*(int *)(table->data));
3020 if (put_user(val, (int __user *)oldval))
3022 if (put_user(sizeof(int), oldlenp))
3026 if (newval && newlen) {
3028 if (newlen != sizeof(int))
3030 if (get_user(new, (int __user *)newval))
3032 *(int *)(table->data) = msecs_to_jiffies(new);
3039 #else /* CONFIG_SYSCTL_SYSCALL */
3042 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
3044 struct __sysctl_args tmp;
3047 if (copy_from_user(&tmp, args, sizeof(tmp)))
3050 error = deprecated_sysctl_warning(&tmp);
3052 /* If no error reading the parameters then just -ENOSYS ... */
3059 int sysctl_data(struct ctl_table *table,
3060 void __user *oldval, size_t __user *oldlenp,
3061 void __user *newval, size_t newlen)
3066 int sysctl_string(struct ctl_table *table,
3067 void __user *oldval, size_t __user *oldlenp,
3068 void __user *newval, size_t newlen)
3073 int sysctl_intvec(struct ctl_table *table,
3074 void __user *oldval, size_t __user *oldlenp,
3075 void __user *newval, size_t newlen)
3080 int sysctl_jiffies(struct ctl_table *table,
3081 void __user *oldval, size_t __user *oldlenp,
3082 void __user *newval, size_t newlen)
3087 int sysctl_ms_jiffies(struct ctl_table *table,
3088 void __user *oldval, size_t __user *oldlenp,
3089 void __user *newval, size_t newlen)
3094 #endif /* CONFIG_SYSCTL_SYSCALL */
3096 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3098 static int msg_count;
3099 int name[CTL_MAXNAME];
3102 /* Check args->nlen. */
3103 if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3106 /* Read in the sysctl name for better debug message logging */
3107 for (i = 0; i < args->nlen; i++)
3108 if (get_user(name[i], args->name + i))
3111 /* Ignore accesses to kernel.version */
3112 if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3115 if (msg_count < 5) {
3118 "warning: process `%s' used the deprecated sysctl "
3119 "system call with ", current->comm);
3120 for (i = 0; i < args->nlen; i++)
3121 printk("%d.", name[i]);
3128 * No sense putting this after each symbol definition, twice,
3129 * exception granted :-)
3131 EXPORT_SYMBOL(proc_dointvec);
3132 EXPORT_SYMBOL(proc_dointvec_jiffies);
3133 EXPORT_SYMBOL(proc_dointvec_minmax);
3134 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3135 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3136 EXPORT_SYMBOL(proc_dostring);
3137 EXPORT_SYMBOL(proc_doulongvec_minmax);
3138 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3139 EXPORT_SYMBOL(register_sysctl_table);
3140 EXPORT_SYMBOL(register_sysctl_paths);
3141 EXPORT_SYMBOL(sysctl_intvec);
3142 EXPORT_SYMBOL(sysctl_jiffies);
3143 EXPORT_SYMBOL(sysctl_ms_jiffies);
3144 EXPORT_SYMBOL(sysctl_string);
3145 EXPORT_SYMBOL(sysctl_data);
3146 EXPORT_SYMBOL(unregister_sysctl_table);