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;
86 extern int sysctl_nr_trim_pages;
88 #ifdef CONFIG_RCU_TORTURE_TEST
89 extern int rcutorture_runnable;
90 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
92 /* Constants used for minimum and maximum */
93 #ifdef CONFIG_DETECT_SOFTLOCKUP
94 static int sixty = 60;
95 static int neg_one = -1;
98 #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>
124 #ifdef CONFIG_SPARC64
125 extern int sysctl_tsb_ratio;
129 extern int pwrsw_enabled;
130 extern int unaligned_enabled;
134 #ifdef CONFIG_MATHEMU
135 extern int sysctl_ieee_emulation_warnings;
137 extern int sysctl_userprocess_debug;
138 extern int spin_retry;
141 #ifdef CONFIG_BSD_PROCESS_ACCT
142 extern int acct_parm[];
146 extern int no_unaligned_warning;
149 #ifdef CONFIG_RT_MUTEXES
150 extern int max_lock_depth;
153 #ifdef CONFIG_PROC_SYSCTL
154 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
155 void __user *buffer, size_t *lenp, loff_t *ppos);
156 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
157 void __user *buffer, size_t *lenp, loff_t *ppos);
160 static struct ctl_table root_table[];
161 static struct ctl_table_root sysctl_table_root;
162 static struct ctl_table_header root_table_header = {
164 .ctl_table = root_table,
165 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
166 .root = &sysctl_table_root,
167 .set = &sysctl_table_root.default_set,
169 static struct ctl_table_root sysctl_table_root = {
170 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
171 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
174 static struct ctl_table kern_table[];
175 static struct ctl_table vm_table[];
176 static struct ctl_table fs_table[];
177 static struct ctl_table debug_table[];
178 static struct ctl_table dev_table[];
179 extern struct ctl_table random_table[];
180 #ifdef CONFIG_INOTIFY_USER
181 extern struct ctl_table inotify_table[];
184 extern struct ctl_table epoll_table[];
187 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
188 int sysctl_legacy_va_layout;
191 extern int prove_locking;
192 extern int lock_stat;
194 /* The default sysctl tables: */
196 static struct ctl_table root_table[] = {
198 .ctl_name = CTL_KERN,
199 .procname = "kernel",
216 .ctl_name = CTL_DEBUG,
219 .child = debug_table,
228 * NOTE: do not add new entries to this table unless you have read
229 * Documentation/sysctl/ctl_unnumbered.txt
234 #ifdef CONFIG_SCHED_DEBUG
235 static int min_sched_granularity_ns = 100000; /* 100 usecs */
236 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
237 static int min_wakeup_granularity_ns; /* 0 usecs */
238 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
241 static struct ctl_table kern_table[] = {
242 #ifdef CONFIG_SCHED_DEBUG
244 .ctl_name = CTL_UNNUMBERED,
245 .procname = "sched_min_granularity_ns",
246 .data = &sysctl_sched_min_granularity,
247 .maxlen = sizeof(unsigned int),
249 .proc_handler = &sched_nr_latency_handler,
250 .strategy = &sysctl_intvec,
251 .extra1 = &min_sched_granularity_ns,
252 .extra2 = &max_sched_granularity_ns,
255 .ctl_name = CTL_UNNUMBERED,
256 .procname = "sched_latency_ns",
257 .data = &sysctl_sched_latency,
258 .maxlen = sizeof(unsigned int),
260 .proc_handler = &sched_nr_latency_handler,
261 .strategy = &sysctl_intvec,
262 .extra1 = &min_sched_granularity_ns,
263 .extra2 = &max_sched_granularity_ns,
266 .ctl_name = CTL_UNNUMBERED,
267 .procname = "sched_wakeup_granularity_ns",
268 .data = &sysctl_sched_wakeup_granularity,
269 .maxlen = sizeof(unsigned int),
271 .proc_handler = &proc_dointvec_minmax,
272 .strategy = &sysctl_intvec,
273 .extra1 = &min_wakeup_granularity_ns,
274 .extra2 = &max_wakeup_granularity_ns,
277 .ctl_name = CTL_UNNUMBERED,
278 .procname = "sched_shares_ratelimit",
279 .data = &sysctl_sched_shares_ratelimit,
280 .maxlen = sizeof(unsigned int),
282 .proc_handler = &proc_dointvec,
285 .ctl_name = CTL_UNNUMBERED,
286 .procname = "sched_shares_thresh",
287 .data = &sysctl_sched_shares_thresh,
288 .maxlen = sizeof(unsigned int),
290 .proc_handler = &proc_dointvec_minmax,
291 .strategy = &sysctl_intvec,
295 .ctl_name = CTL_UNNUMBERED,
296 .procname = "sched_child_runs_first",
297 .data = &sysctl_sched_child_runs_first,
298 .maxlen = sizeof(unsigned int),
300 .proc_handler = &proc_dointvec,
303 .ctl_name = CTL_UNNUMBERED,
304 .procname = "sched_features",
305 .data = &sysctl_sched_features,
306 .maxlen = sizeof(unsigned int),
308 .proc_handler = &proc_dointvec,
311 .ctl_name = CTL_UNNUMBERED,
312 .procname = "sched_migration_cost",
313 .data = &sysctl_sched_migration_cost,
314 .maxlen = sizeof(unsigned int),
316 .proc_handler = &proc_dointvec,
319 .ctl_name = CTL_UNNUMBERED,
320 .procname = "sched_nr_migrate",
321 .data = &sysctl_sched_nr_migrate,
322 .maxlen = sizeof(unsigned int),
324 .proc_handler = &proc_dointvec,
328 .ctl_name = CTL_UNNUMBERED,
329 .procname = "sched_rt_period_us",
330 .data = &sysctl_sched_rt_period,
331 .maxlen = sizeof(unsigned int),
333 .proc_handler = &sched_rt_handler,
336 .ctl_name = CTL_UNNUMBERED,
337 .procname = "sched_rt_runtime_us",
338 .data = &sysctl_sched_rt_runtime,
339 .maxlen = sizeof(int),
341 .proc_handler = &sched_rt_handler,
344 .ctl_name = CTL_UNNUMBERED,
345 .procname = "sched_compat_yield",
346 .data = &sysctl_sched_compat_yield,
347 .maxlen = sizeof(unsigned int),
349 .proc_handler = &proc_dointvec,
351 #ifdef CONFIG_PROVE_LOCKING
353 .ctl_name = CTL_UNNUMBERED,
354 .procname = "prove_locking",
355 .data = &prove_locking,
356 .maxlen = sizeof(int),
358 .proc_handler = &proc_dointvec,
361 #ifdef CONFIG_LOCK_STAT
363 .ctl_name = CTL_UNNUMBERED,
364 .procname = "lock_stat",
366 .maxlen = sizeof(int),
368 .proc_handler = &proc_dointvec,
372 .ctl_name = KERN_PANIC,
374 .data = &panic_timeout,
375 .maxlen = sizeof(int),
377 .proc_handler = &proc_dointvec,
380 .ctl_name = KERN_CORE_USES_PID,
381 .procname = "core_uses_pid",
382 .data = &core_uses_pid,
383 .maxlen = sizeof(int),
385 .proc_handler = &proc_dointvec,
388 .ctl_name = KERN_CORE_PATTERN,
389 .procname = "core_pattern",
390 .data = core_pattern,
391 .maxlen = CORENAME_MAX_SIZE,
393 .proc_handler = &proc_dostring,
394 .strategy = &sysctl_string,
396 #ifdef CONFIG_PROC_SYSCTL
398 .procname = "tainted",
399 .maxlen = sizeof(long),
401 .proc_handler = &proc_taint,
404 #ifdef CONFIG_LATENCYTOP
406 .procname = "latencytop",
407 .data = &latencytop_enabled,
408 .maxlen = sizeof(int),
410 .proc_handler = &proc_dointvec,
413 #ifdef CONFIG_BLK_DEV_INITRD
415 .ctl_name = KERN_REALROOTDEV,
416 .procname = "real-root-dev",
417 .data = &real_root_dev,
418 .maxlen = sizeof(int),
420 .proc_handler = &proc_dointvec,
424 .ctl_name = CTL_UNNUMBERED,
425 .procname = "print-fatal-signals",
426 .data = &print_fatal_signals,
427 .maxlen = sizeof(int),
429 .proc_handler = &proc_dointvec,
433 .ctl_name = KERN_SPARC_REBOOT,
434 .procname = "reboot-cmd",
435 .data = reboot_command,
438 .proc_handler = &proc_dostring,
439 .strategy = &sysctl_string,
442 .ctl_name = KERN_SPARC_STOP_A,
443 .procname = "stop-a",
444 .data = &stop_a_enabled,
445 .maxlen = sizeof (int),
447 .proc_handler = &proc_dointvec,
450 .ctl_name = KERN_SPARC_SCONS_PWROFF,
451 .procname = "scons-poweroff",
452 .data = &scons_pwroff,
453 .maxlen = sizeof (int),
455 .proc_handler = &proc_dointvec,
458 #ifdef CONFIG_SPARC64
460 .ctl_name = CTL_UNNUMBERED,
461 .procname = "tsb-ratio",
462 .data = &sysctl_tsb_ratio,
463 .maxlen = sizeof (int),
465 .proc_handler = &proc_dointvec,
470 .ctl_name = KERN_HPPA_PWRSW,
471 .procname = "soft-power",
472 .data = &pwrsw_enabled,
473 .maxlen = sizeof (int),
475 .proc_handler = &proc_dointvec,
478 .ctl_name = KERN_HPPA_UNALIGNED,
479 .procname = "unaligned-trap",
480 .data = &unaligned_enabled,
481 .maxlen = sizeof (int),
483 .proc_handler = &proc_dointvec,
487 .ctl_name = KERN_CTLALTDEL,
488 .procname = "ctrl-alt-del",
490 .maxlen = sizeof(int),
492 .proc_handler = &proc_dointvec,
494 #ifdef CONFIG_FUNCTION_TRACER
496 .ctl_name = CTL_UNNUMBERED,
497 .procname = "ftrace_enabled",
498 .data = &ftrace_enabled,
499 .maxlen = sizeof(int),
501 .proc_handler = &ftrace_enable_sysctl,
504 #ifdef CONFIG_STACK_TRACER
506 .ctl_name = CTL_UNNUMBERED,
507 .procname = "stack_tracer_enabled",
508 .data = &stack_tracer_enabled,
509 .maxlen = sizeof(int),
511 .proc_handler = &stack_trace_sysctl,
514 #ifdef CONFIG_TRACING
516 .ctl_name = CTL_UNNUMBERED,
517 .procname = "ftrace_dump_on_oops",
518 .data = &ftrace_dump_on_oops,
519 .maxlen = sizeof(int),
521 .proc_handler = &proc_dointvec,
524 #ifdef CONFIG_MODULES
526 .ctl_name = KERN_MODPROBE,
527 .procname = "modprobe",
528 .data = &modprobe_path,
529 .maxlen = KMOD_PATH_LEN,
531 .proc_handler = &proc_dostring,
532 .strategy = &sysctl_string,
535 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
537 .ctl_name = KERN_HOTPLUG,
538 .procname = "hotplug",
539 .data = &uevent_helper,
540 .maxlen = UEVENT_HELPER_PATH_LEN,
542 .proc_handler = &proc_dostring,
543 .strategy = &sysctl_string,
546 #ifdef CONFIG_CHR_DEV_SG
548 .ctl_name = KERN_SG_BIG_BUFF,
549 .procname = "sg-big-buff",
550 .data = &sg_big_buff,
551 .maxlen = sizeof (int),
553 .proc_handler = &proc_dointvec,
556 #ifdef CONFIG_BSD_PROCESS_ACCT
558 .ctl_name = KERN_ACCT,
561 .maxlen = 3*sizeof(int),
563 .proc_handler = &proc_dointvec,
566 #ifdef CONFIG_MAGIC_SYSRQ
568 .ctl_name = KERN_SYSRQ,
570 .data = &__sysrq_enabled,
571 .maxlen = sizeof (int),
573 .proc_handler = &proc_dointvec,
576 #ifdef CONFIG_PROC_SYSCTL
578 .procname = "cad_pid",
580 .maxlen = sizeof (int),
582 .proc_handler = &proc_do_cad_pid,
586 .ctl_name = KERN_MAX_THREADS,
587 .procname = "threads-max",
588 .data = &max_threads,
589 .maxlen = sizeof(int),
591 .proc_handler = &proc_dointvec,
594 .ctl_name = KERN_RANDOM,
595 .procname = "random",
597 .child = random_table,
600 .ctl_name = KERN_OVERFLOWUID,
601 .procname = "overflowuid",
602 .data = &overflowuid,
603 .maxlen = sizeof(int),
605 .proc_handler = &proc_dointvec_minmax,
606 .strategy = &sysctl_intvec,
607 .extra1 = &minolduid,
608 .extra2 = &maxolduid,
611 .ctl_name = KERN_OVERFLOWGID,
612 .procname = "overflowgid",
613 .data = &overflowgid,
614 .maxlen = sizeof(int),
616 .proc_handler = &proc_dointvec_minmax,
617 .strategy = &sysctl_intvec,
618 .extra1 = &minolduid,
619 .extra2 = &maxolduid,
622 #ifdef CONFIG_MATHEMU
624 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
625 .procname = "ieee_emulation_warnings",
626 .data = &sysctl_ieee_emulation_warnings,
627 .maxlen = sizeof(int),
629 .proc_handler = &proc_dointvec,
633 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
634 .procname = "userprocess_debug",
635 .data = &sysctl_userprocess_debug,
636 .maxlen = sizeof(int),
638 .proc_handler = &proc_dointvec,
642 .ctl_name = KERN_PIDMAX,
643 .procname = "pid_max",
645 .maxlen = sizeof (int),
647 .proc_handler = &proc_dointvec_minmax,
648 .strategy = sysctl_intvec,
649 .extra1 = &pid_max_min,
650 .extra2 = &pid_max_max,
653 .ctl_name = KERN_PANIC_ON_OOPS,
654 .procname = "panic_on_oops",
655 .data = &panic_on_oops,
656 .maxlen = sizeof(int),
658 .proc_handler = &proc_dointvec,
660 #if defined CONFIG_PRINTK
662 .ctl_name = KERN_PRINTK,
663 .procname = "printk",
664 .data = &console_loglevel,
665 .maxlen = 4*sizeof(int),
667 .proc_handler = &proc_dointvec,
670 .ctl_name = KERN_PRINTK_RATELIMIT,
671 .procname = "printk_ratelimit",
672 .data = &printk_ratelimit_state.interval,
673 .maxlen = sizeof(int),
675 .proc_handler = &proc_dointvec_jiffies,
676 .strategy = &sysctl_jiffies,
679 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
680 .procname = "printk_ratelimit_burst",
681 .data = &printk_ratelimit_state.burst,
682 .maxlen = sizeof(int),
684 .proc_handler = &proc_dointvec,
688 .ctl_name = KERN_NGROUPS_MAX,
689 .procname = "ngroups_max",
690 .data = &ngroups_max,
691 .maxlen = sizeof (int),
693 .proc_handler = &proc_dointvec,
695 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
697 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
698 .procname = "unknown_nmi_panic",
699 .data = &unknown_nmi_panic,
700 .maxlen = sizeof (int),
702 .proc_handler = &proc_dointvec,
705 .procname = "nmi_watchdog",
706 .data = &nmi_watchdog_enabled,
707 .maxlen = sizeof (int),
709 .proc_handler = &proc_nmi_enabled,
712 #if defined(CONFIG_X86)
714 .ctl_name = KERN_PANIC_ON_NMI,
715 .procname = "panic_on_unrecovered_nmi",
716 .data = &panic_on_unrecovered_nmi,
717 .maxlen = sizeof(int),
719 .proc_handler = &proc_dointvec,
722 .ctl_name = KERN_BOOTLOADER_TYPE,
723 .procname = "bootloader_type",
724 .data = &bootloader_type,
725 .maxlen = sizeof (int),
727 .proc_handler = &proc_dointvec,
730 .ctl_name = CTL_UNNUMBERED,
731 .procname = "kstack_depth_to_print",
732 .data = &kstack_depth_to_print,
733 .maxlen = sizeof(int),
735 .proc_handler = &proc_dointvec,
738 .ctl_name = CTL_UNNUMBERED,
739 .procname = "io_delay_type",
740 .data = &io_delay_type,
741 .maxlen = sizeof(int),
743 .proc_handler = &proc_dointvec,
746 #if defined(CONFIG_MMU)
748 .ctl_name = KERN_RANDOMIZE,
749 .procname = "randomize_va_space",
750 .data = &randomize_va_space,
751 .maxlen = sizeof(int),
753 .proc_handler = &proc_dointvec,
756 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
758 .ctl_name = KERN_SPIN_RETRY,
759 .procname = "spin_retry",
761 .maxlen = sizeof (int),
763 .proc_handler = &proc_dointvec,
766 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
768 .procname = "acpi_video_flags",
769 .data = &acpi_realmode_flags,
770 .maxlen = sizeof (unsigned long),
772 .proc_handler = &proc_doulongvec_minmax,
777 .ctl_name = KERN_IA64_UNALIGNED,
778 .procname = "ignore-unaligned-usertrap",
779 .data = &no_unaligned_warning,
780 .maxlen = sizeof (int),
782 .proc_handler = &proc_dointvec,
785 #ifdef CONFIG_DETECT_SOFTLOCKUP
787 .ctl_name = CTL_UNNUMBERED,
788 .procname = "softlockup_panic",
789 .data = &softlockup_panic,
790 .maxlen = sizeof(int),
792 .proc_handler = &proc_dointvec_minmax,
793 .strategy = &sysctl_intvec,
798 .ctl_name = CTL_UNNUMBERED,
799 .procname = "softlockup_thresh",
800 .data = &softlockup_thresh,
801 .maxlen = sizeof(int),
803 .proc_handler = &proc_dointvec_minmax,
804 .strategy = &sysctl_intvec,
809 .ctl_name = CTL_UNNUMBERED,
810 .procname = "hung_task_check_count",
811 .data = &sysctl_hung_task_check_count,
812 .maxlen = sizeof(unsigned long),
814 .proc_handler = &proc_doulongvec_minmax,
815 .strategy = &sysctl_intvec,
818 .ctl_name = CTL_UNNUMBERED,
819 .procname = "hung_task_timeout_secs",
820 .data = &sysctl_hung_task_timeout_secs,
821 .maxlen = sizeof(unsigned long),
823 .proc_handler = &proc_doulongvec_minmax,
824 .strategy = &sysctl_intvec,
827 .ctl_name = CTL_UNNUMBERED,
828 .procname = "hung_task_warnings",
829 .data = &sysctl_hung_task_warnings,
830 .maxlen = sizeof(unsigned long),
832 .proc_handler = &proc_doulongvec_minmax,
833 .strategy = &sysctl_intvec,
838 .ctl_name = KERN_COMPAT_LOG,
839 .procname = "compat-log",
841 .maxlen = sizeof (int),
843 .proc_handler = &proc_dointvec,
846 #ifdef CONFIG_RT_MUTEXES
848 .ctl_name = KERN_MAX_LOCK_DEPTH,
849 .procname = "max_lock_depth",
850 .data = &max_lock_depth,
851 .maxlen = sizeof(int),
853 .proc_handler = &proc_dointvec,
857 .ctl_name = CTL_UNNUMBERED,
858 .procname = "poweroff_cmd",
859 .data = &poweroff_cmd,
860 .maxlen = POWEROFF_CMD_PATH_LEN,
862 .proc_handler = &proc_dostring,
863 .strategy = &sysctl_string,
867 .ctl_name = CTL_UNNUMBERED,
870 .child = key_sysctls,
873 #ifdef CONFIG_RCU_TORTURE_TEST
875 .ctl_name = CTL_UNNUMBERED,
876 .procname = "rcutorture_runnable",
877 .data = &rcutorture_runnable,
878 .maxlen = sizeof(int),
880 .proc_handler = &proc_dointvec,
883 #ifdef CONFIG_UNEVICTABLE_LRU
885 .ctl_name = CTL_UNNUMBERED,
886 .procname = "scan_unevictable_pages",
887 .data = &scan_unevictable_pages,
888 .maxlen = sizeof(scan_unevictable_pages),
890 .proc_handler = &scan_unevictable_handler,
894 * NOTE: do not add new entries to this table unless you have read
895 * Documentation/sysctl/ctl_unnumbered.txt
900 static struct ctl_table vm_table[] = {
902 .ctl_name = VM_OVERCOMMIT_MEMORY,
903 .procname = "overcommit_memory",
904 .data = &sysctl_overcommit_memory,
905 .maxlen = sizeof(sysctl_overcommit_memory),
907 .proc_handler = &proc_dointvec,
910 .ctl_name = VM_PANIC_ON_OOM,
911 .procname = "panic_on_oom",
912 .data = &sysctl_panic_on_oom,
913 .maxlen = sizeof(sysctl_panic_on_oom),
915 .proc_handler = &proc_dointvec,
918 .ctl_name = CTL_UNNUMBERED,
919 .procname = "oom_kill_allocating_task",
920 .data = &sysctl_oom_kill_allocating_task,
921 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
923 .proc_handler = &proc_dointvec,
926 .ctl_name = CTL_UNNUMBERED,
927 .procname = "oom_dump_tasks",
928 .data = &sysctl_oom_dump_tasks,
929 .maxlen = sizeof(sysctl_oom_dump_tasks),
931 .proc_handler = &proc_dointvec,
934 .ctl_name = VM_OVERCOMMIT_RATIO,
935 .procname = "overcommit_ratio",
936 .data = &sysctl_overcommit_ratio,
937 .maxlen = sizeof(sysctl_overcommit_ratio),
939 .proc_handler = &proc_dointvec,
942 .ctl_name = VM_PAGE_CLUSTER,
943 .procname = "page-cluster",
944 .data = &page_cluster,
945 .maxlen = sizeof(int),
947 .proc_handler = &proc_dointvec,
950 .ctl_name = VM_DIRTY_BACKGROUND,
951 .procname = "dirty_background_ratio",
952 .data = &dirty_background_ratio,
953 .maxlen = sizeof(dirty_background_ratio),
955 .proc_handler = &dirty_background_ratio_handler,
956 .strategy = &sysctl_intvec,
958 .extra2 = &one_hundred,
961 .ctl_name = CTL_UNNUMBERED,
962 .procname = "dirty_background_bytes",
963 .data = &dirty_background_bytes,
964 .maxlen = sizeof(dirty_background_bytes),
966 .proc_handler = &dirty_background_bytes_handler,
967 .strategy = &sysctl_intvec,
971 .ctl_name = VM_DIRTY_RATIO,
972 .procname = "dirty_ratio",
973 .data = &vm_dirty_ratio,
974 .maxlen = sizeof(vm_dirty_ratio),
976 .proc_handler = &dirty_ratio_handler,
977 .strategy = &sysctl_intvec,
979 .extra2 = &one_hundred,
982 .ctl_name = CTL_UNNUMBERED,
983 .procname = "dirty_bytes",
984 .data = &vm_dirty_bytes,
985 .maxlen = sizeof(vm_dirty_bytes),
987 .proc_handler = &dirty_bytes_handler,
988 .strategy = &sysctl_intvec,
992 .procname = "dirty_writeback_centisecs",
993 .data = &dirty_writeback_interval,
994 .maxlen = sizeof(dirty_writeback_interval),
996 .proc_handler = &dirty_writeback_centisecs_handler,
999 .procname = "dirty_expire_centisecs",
1000 .data = &dirty_expire_interval,
1001 .maxlen = sizeof(dirty_expire_interval),
1003 .proc_handler = &proc_dointvec_userhz_jiffies,
1006 .ctl_name = VM_NR_PDFLUSH_THREADS,
1007 .procname = "nr_pdflush_threads",
1008 .data = &nr_pdflush_threads,
1009 .maxlen = sizeof nr_pdflush_threads,
1010 .mode = 0444 /* read-only*/,
1011 .proc_handler = &proc_dointvec,
1014 .ctl_name = VM_SWAPPINESS,
1015 .procname = "swappiness",
1016 .data = &vm_swappiness,
1017 .maxlen = sizeof(vm_swappiness),
1019 .proc_handler = &proc_dointvec_minmax,
1020 .strategy = &sysctl_intvec,
1022 .extra2 = &one_hundred,
1024 #ifdef CONFIG_HUGETLB_PAGE
1026 .procname = "nr_hugepages",
1028 .maxlen = sizeof(unsigned long),
1030 .proc_handler = &hugetlb_sysctl_handler,
1031 .extra1 = (void *)&hugetlb_zero,
1032 .extra2 = (void *)&hugetlb_infinity,
1035 .ctl_name = VM_HUGETLB_GROUP,
1036 .procname = "hugetlb_shm_group",
1037 .data = &sysctl_hugetlb_shm_group,
1038 .maxlen = sizeof(gid_t),
1040 .proc_handler = &proc_dointvec,
1043 .ctl_name = CTL_UNNUMBERED,
1044 .procname = "hugepages_treat_as_movable",
1045 .data = &hugepages_treat_as_movable,
1046 .maxlen = sizeof(int),
1048 .proc_handler = &hugetlb_treat_movable_handler,
1051 .ctl_name = CTL_UNNUMBERED,
1052 .procname = "nr_overcommit_hugepages",
1054 .maxlen = sizeof(unsigned long),
1056 .proc_handler = &hugetlb_overcommit_handler,
1057 .extra1 = (void *)&hugetlb_zero,
1058 .extra2 = (void *)&hugetlb_infinity,
1062 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
1063 .procname = "lowmem_reserve_ratio",
1064 .data = &sysctl_lowmem_reserve_ratio,
1065 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1067 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
1068 .strategy = &sysctl_intvec,
1071 .ctl_name = VM_DROP_PAGECACHE,
1072 .procname = "drop_caches",
1073 .data = &sysctl_drop_caches,
1074 .maxlen = sizeof(int),
1076 .proc_handler = drop_caches_sysctl_handler,
1077 .strategy = &sysctl_intvec,
1080 .ctl_name = VM_MIN_FREE_KBYTES,
1081 .procname = "min_free_kbytes",
1082 .data = &min_free_kbytes,
1083 .maxlen = sizeof(min_free_kbytes),
1085 .proc_handler = &min_free_kbytes_sysctl_handler,
1086 .strategy = &sysctl_intvec,
1090 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
1091 .procname = "percpu_pagelist_fraction",
1092 .data = &percpu_pagelist_fraction,
1093 .maxlen = sizeof(percpu_pagelist_fraction),
1095 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
1096 .strategy = &sysctl_intvec,
1097 .extra1 = &min_percpu_pagelist_fract,
1101 .ctl_name = VM_MAX_MAP_COUNT,
1102 .procname = "max_map_count",
1103 .data = &sysctl_max_map_count,
1104 .maxlen = sizeof(sysctl_max_map_count),
1106 .proc_handler = &proc_dointvec
1110 .ctl_name = CTL_UNNUMBERED,
1111 .procname = "nr_trim_pages",
1112 .data = &sysctl_nr_trim_pages,
1113 .maxlen = sizeof(sysctl_nr_trim_pages),
1115 .proc_handler = &proc_dointvec_minmax,
1116 .strategy = &sysctl_intvec,
1121 .ctl_name = VM_LAPTOP_MODE,
1122 .procname = "laptop_mode",
1123 .data = &laptop_mode,
1124 .maxlen = sizeof(laptop_mode),
1126 .proc_handler = &proc_dointvec_jiffies,
1127 .strategy = &sysctl_jiffies,
1130 .ctl_name = VM_BLOCK_DUMP,
1131 .procname = "block_dump",
1132 .data = &block_dump,
1133 .maxlen = sizeof(block_dump),
1135 .proc_handler = &proc_dointvec,
1136 .strategy = &sysctl_intvec,
1140 .ctl_name = VM_VFS_CACHE_PRESSURE,
1141 .procname = "vfs_cache_pressure",
1142 .data = &sysctl_vfs_cache_pressure,
1143 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1145 .proc_handler = &proc_dointvec,
1146 .strategy = &sysctl_intvec,
1149 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1151 .ctl_name = VM_LEGACY_VA_LAYOUT,
1152 .procname = "legacy_va_layout",
1153 .data = &sysctl_legacy_va_layout,
1154 .maxlen = sizeof(sysctl_legacy_va_layout),
1156 .proc_handler = &proc_dointvec,
1157 .strategy = &sysctl_intvec,
1163 .ctl_name = VM_ZONE_RECLAIM_MODE,
1164 .procname = "zone_reclaim_mode",
1165 .data = &zone_reclaim_mode,
1166 .maxlen = sizeof(zone_reclaim_mode),
1168 .proc_handler = &proc_dointvec,
1169 .strategy = &sysctl_intvec,
1173 .ctl_name = VM_MIN_UNMAPPED,
1174 .procname = "min_unmapped_ratio",
1175 .data = &sysctl_min_unmapped_ratio,
1176 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1178 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1179 .strategy = &sysctl_intvec,
1181 .extra2 = &one_hundred,
1184 .ctl_name = VM_MIN_SLAB,
1185 .procname = "min_slab_ratio",
1186 .data = &sysctl_min_slab_ratio,
1187 .maxlen = sizeof(sysctl_min_slab_ratio),
1189 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1190 .strategy = &sysctl_intvec,
1192 .extra2 = &one_hundred,
1197 .ctl_name = CTL_UNNUMBERED,
1198 .procname = "stat_interval",
1199 .data = &sysctl_stat_interval,
1200 .maxlen = sizeof(sysctl_stat_interval),
1202 .proc_handler = &proc_dointvec_jiffies,
1203 .strategy = &sysctl_jiffies,
1206 #ifdef CONFIG_SECURITY
1208 .ctl_name = CTL_UNNUMBERED,
1209 .procname = "mmap_min_addr",
1210 .data = &mmap_min_addr,
1211 .maxlen = sizeof(unsigned long),
1213 .proc_handler = &proc_doulongvec_minmax,
1218 .ctl_name = CTL_UNNUMBERED,
1219 .procname = "numa_zonelist_order",
1220 .data = &numa_zonelist_order,
1221 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1223 .proc_handler = &numa_zonelist_order_handler,
1224 .strategy = &sysctl_string,
1227 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1228 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1230 .ctl_name = VM_VDSO_ENABLED,
1231 .procname = "vdso_enabled",
1232 .data = &vdso_enabled,
1233 .maxlen = sizeof(vdso_enabled),
1235 .proc_handler = &proc_dointvec,
1236 .strategy = &sysctl_intvec,
1240 #ifdef CONFIG_HIGHMEM
1242 .ctl_name = CTL_UNNUMBERED,
1243 .procname = "highmem_is_dirtyable",
1244 .data = &vm_highmem_is_dirtyable,
1245 .maxlen = sizeof(vm_highmem_is_dirtyable),
1247 .proc_handler = &proc_dointvec_minmax,
1248 .strategy = &sysctl_intvec,
1254 * NOTE: do not add new entries to this table unless you have read
1255 * Documentation/sysctl/ctl_unnumbered.txt
1260 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1261 static struct ctl_table binfmt_misc_table[] = {
1266 static struct ctl_table fs_table[] = {
1268 .ctl_name = FS_NRINODE,
1269 .procname = "inode-nr",
1270 .data = &inodes_stat,
1271 .maxlen = 2*sizeof(int),
1273 .proc_handler = &proc_dointvec,
1276 .ctl_name = FS_STATINODE,
1277 .procname = "inode-state",
1278 .data = &inodes_stat,
1279 .maxlen = 7*sizeof(int),
1281 .proc_handler = &proc_dointvec,
1284 .procname = "file-nr",
1285 .data = &files_stat,
1286 .maxlen = 3*sizeof(int),
1288 .proc_handler = &proc_nr_files,
1291 .ctl_name = FS_MAXFILE,
1292 .procname = "file-max",
1293 .data = &files_stat.max_files,
1294 .maxlen = sizeof(int),
1296 .proc_handler = &proc_dointvec,
1299 .ctl_name = CTL_UNNUMBERED,
1300 .procname = "nr_open",
1301 .data = &sysctl_nr_open,
1302 .maxlen = sizeof(int),
1304 .proc_handler = &proc_dointvec_minmax,
1305 .extra1 = &sysctl_nr_open_min,
1306 .extra2 = &sysctl_nr_open_max,
1309 .ctl_name = FS_DENTRY,
1310 .procname = "dentry-state",
1311 .data = &dentry_stat,
1312 .maxlen = 6*sizeof(int),
1314 .proc_handler = &proc_dointvec,
1317 .ctl_name = FS_OVERFLOWUID,
1318 .procname = "overflowuid",
1319 .data = &fs_overflowuid,
1320 .maxlen = sizeof(int),
1322 .proc_handler = &proc_dointvec_minmax,
1323 .strategy = &sysctl_intvec,
1324 .extra1 = &minolduid,
1325 .extra2 = &maxolduid,
1328 .ctl_name = FS_OVERFLOWGID,
1329 .procname = "overflowgid",
1330 .data = &fs_overflowgid,
1331 .maxlen = sizeof(int),
1333 .proc_handler = &proc_dointvec_minmax,
1334 .strategy = &sysctl_intvec,
1335 .extra1 = &minolduid,
1336 .extra2 = &maxolduid,
1338 #ifdef CONFIG_FILE_LOCKING
1340 .ctl_name = FS_LEASES,
1341 .procname = "leases-enable",
1342 .data = &leases_enable,
1343 .maxlen = sizeof(int),
1345 .proc_handler = &proc_dointvec,
1348 #ifdef CONFIG_DNOTIFY
1350 .ctl_name = FS_DIR_NOTIFY,
1351 .procname = "dir-notify-enable",
1352 .data = &dir_notify_enable,
1353 .maxlen = sizeof(int),
1355 .proc_handler = &proc_dointvec,
1359 #ifdef CONFIG_FILE_LOCKING
1361 .ctl_name = FS_LEASE_TIME,
1362 .procname = "lease-break-time",
1363 .data = &lease_break_time,
1364 .maxlen = sizeof(int),
1366 .proc_handler = &proc_dointvec_minmax,
1367 .strategy = &sysctl_intvec,
1374 .procname = "aio-nr",
1376 .maxlen = sizeof(aio_nr),
1378 .proc_handler = &proc_doulongvec_minmax,
1381 .procname = "aio-max-nr",
1382 .data = &aio_max_nr,
1383 .maxlen = sizeof(aio_max_nr),
1385 .proc_handler = &proc_doulongvec_minmax,
1387 #endif /* CONFIG_AIO */
1388 #ifdef CONFIG_INOTIFY_USER
1390 .ctl_name = FS_INOTIFY,
1391 .procname = "inotify",
1393 .child = inotify_table,
1398 .procname = "epoll",
1400 .child = epoll_table,
1405 .ctl_name = KERN_SETUID_DUMPABLE,
1406 .procname = "suid_dumpable",
1407 .data = &suid_dumpable,
1408 .maxlen = sizeof(int),
1410 .proc_handler = &proc_dointvec,
1412 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1414 .ctl_name = CTL_UNNUMBERED,
1415 .procname = "binfmt_misc",
1417 .child = binfmt_misc_table,
1421 * NOTE: do not add new entries to this table unless you have read
1422 * Documentation/sysctl/ctl_unnumbered.txt
1427 static struct ctl_table debug_table[] = {
1428 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1430 .ctl_name = CTL_UNNUMBERED,
1431 .procname = "exception-trace",
1432 .data = &show_unhandled_signals,
1433 .maxlen = sizeof(int),
1435 .proc_handler = proc_dointvec
1441 static struct ctl_table dev_table[] = {
1445 static DEFINE_SPINLOCK(sysctl_lock);
1447 /* called under sysctl_lock */
1448 static int use_table(struct ctl_table_header *p)
1450 if (unlikely(p->unregistering))
1456 /* called under sysctl_lock */
1457 static void unuse_table(struct ctl_table_header *p)
1460 if (unlikely(p->unregistering))
1461 complete(p->unregistering);
1464 /* called under sysctl_lock, will reacquire if has to wait */
1465 static void start_unregistering(struct ctl_table_header *p)
1468 * if p->used is 0, nobody will ever touch that entry again;
1469 * we'll eliminate all paths to it before dropping sysctl_lock
1471 if (unlikely(p->used)) {
1472 struct completion wait;
1473 init_completion(&wait);
1474 p->unregistering = &wait;
1475 spin_unlock(&sysctl_lock);
1476 wait_for_completion(&wait);
1477 spin_lock(&sysctl_lock);
1479 /* anything non-NULL; we'll never dereference it */
1480 p->unregistering = ERR_PTR(-EINVAL);
1483 * do not remove from the list until nobody holds it; walking the
1484 * list in do_sysctl() relies on that.
1486 list_del_init(&p->ctl_entry);
1489 void sysctl_head_get(struct ctl_table_header *head)
1491 spin_lock(&sysctl_lock);
1493 spin_unlock(&sysctl_lock);
1496 void sysctl_head_put(struct ctl_table_header *head)
1498 spin_lock(&sysctl_lock);
1501 spin_unlock(&sysctl_lock);
1504 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1508 spin_lock(&sysctl_lock);
1509 if (!use_table(head))
1510 head = ERR_PTR(-ENOENT);
1511 spin_unlock(&sysctl_lock);
1515 void sysctl_head_finish(struct ctl_table_header *head)
1519 spin_lock(&sysctl_lock);
1521 spin_unlock(&sysctl_lock);
1524 static struct ctl_table_set *
1525 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1527 struct ctl_table_set *set = &root->default_set;
1529 set = root->lookup(root, namespaces);
1533 static struct list_head *
1534 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1536 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1540 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1541 struct ctl_table_header *prev)
1543 struct ctl_table_root *root;
1544 struct list_head *header_list;
1545 struct ctl_table_header *head;
1546 struct list_head *tmp;
1548 spin_lock(&sysctl_lock);
1551 tmp = &prev->ctl_entry;
1555 tmp = &root_table_header.ctl_entry;
1557 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1559 if (!use_table(head))
1561 spin_unlock(&sysctl_lock);
1566 header_list = lookup_header_list(root, namespaces);
1567 if (tmp != header_list)
1571 root = list_entry(root->root_list.next,
1572 struct ctl_table_root, root_list);
1573 if (root == &sysctl_table_root)
1575 header_list = lookup_header_list(root, namespaces);
1576 } while (list_empty(header_list));
1577 tmp = header_list->next;
1580 spin_unlock(&sysctl_lock);
1584 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1586 return __sysctl_head_next(current->nsproxy, prev);
1589 void register_sysctl_root(struct ctl_table_root *root)
1591 spin_lock(&sysctl_lock);
1592 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1593 spin_unlock(&sysctl_lock);
1596 #ifdef CONFIG_SYSCTL_SYSCALL
1597 /* Perform the actual read/write of a sysctl table entry. */
1598 static int do_sysctl_strategy(struct ctl_table_root *root,
1599 struct ctl_table *table,
1600 void __user *oldval, size_t __user *oldlenp,
1601 void __user *newval, size_t newlen)
1609 if (sysctl_perm(root, table, op))
1612 if (table->strategy) {
1613 rc = table->strategy(table, oldval, oldlenp, newval, newlen);
1620 /* If there is no strategy routine, or if the strategy returns
1621 * zero, proceed with automatic r/w */
1622 if (table->data && table->maxlen) {
1623 rc = sysctl_data(table, oldval, oldlenp, newval, newlen);
1630 static int parse_table(int __user *name, int nlen,
1631 void __user *oldval, size_t __user *oldlenp,
1632 void __user *newval, size_t newlen,
1633 struct ctl_table_root *root,
1634 struct ctl_table *table)
1640 if (get_user(n, name))
1642 for ( ; table->ctl_name || table->procname; table++) {
1643 if (!table->ctl_name)
1645 if (n == table->ctl_name) {
1648 if (sysctl_perm(root, table, MAY_EXEC))
1652 table = table->child;
1655 error = do_sysctl_strategy(root, table,
1664 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1665 void __user *newval, size_t newlen)
1667 struct ctl_table_header *head;
1668 int error = -ENOTDIR;
1670 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1674 if (!oldlenp || get_user(old_len, oldlenp))
1678 for (head = sysctl_head_next(NULL); head;
1679 head = sysctl_head_next(head)) {
1680 error = parse_table(name, nlen, oldval, oldlenp,
1682 head->root, head->ctl_table);
1683 if (error != -ENOTDIR) {
1684 sysctl_head_finish(head);
1691 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
1693 struct __sysctl_args tmp;
1696 if (copy_from_user(&tmp, args, sizeof(tmp)))
1699 error = deprecated_sysctl_warning(&tmp);
1704 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1705 tmp.newval, tmp.newlen);
1710 #endif /* CONFIG_SYSCTL_SYSCALL */
1713 * sysctl_perm does NOT grant the superuser all rights automatically, because
1714 * some sysctl variables are readonly even to root.
1717 static int test_perm(int mode, int op)
1719 if (!current_euid())
1721 else if (in_egroup_p(0))
1723 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1728 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1733 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1737 if (root->permissions)
1738 mode = root->permissions(root, current->nsproxy, table);
1742 return test_perm(mode, op);
1745 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1747 for (; table->ctl_name || table->procname; table++) {
1748 table->parent = parent;
1750 sysctl_set_parent(table, table->child);
1754 static __init int sysctl_init(void)
1756 sysctl_set_parent(NULL, root_table);
1757 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1760 err = sysctl_check_table(current->nsproxy, root_table);
1766 core_initcall(sysctl_init);
1768 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1769 struct ctl_table *table)
1771 struct ctl_table *p;
1772 const char *s = branch->procname;
1774 /* branch should have named subdirectory as its first element */
1775 if (!s || !branch->child)
1778 /* ... and nothing else */
1779 if (branch[1].procname || branch[1].ctl_name)
1782 /* table should contain subdirectory with the same name */
1783 for (p = table; p->procname || p->ctl_name; p++) {
1786 if (p->procname && strcmp(p->procname, s) == 0)
1792 /* see if attaching q to p would be an improvement */
1793 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1795 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1796 struct ctl_table *next;
1798 int not_in_parent = !p->attached_by;
1800 while ((next = is_branch_in(by, to)) != NULL) {
1801 if (by == q->attached_by)
1803 if (to == p->attached_by)
1809 if (is_better && not_in_parent) {
1810 q->attached_by = by;
1811 q->attached_to = to;
1817 * __register_sysctl_paths - register a sysctl hierarchy
1818 * @root: List of sysctl headers to register on
1819 * @namespaces: Data to compute which lists of sysctl entries are visible
1820 * @path: The path to the directory the sysctl table is in.
1821 * @table: the top-level table structure
1823 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1824 * array. A completely 0 filled entry terminates the table.
1826 * The members of the &struct ctl_table structure are used as follows:
1828 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1829 * must be unique within that level of sysctl
1831 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1832 * enter a sysctl file
1834 * data - a pointer to data for use by proc_handler
1836 * maxlen - the maximum size in bytes of the data
1838 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1840 * child - a pointer to the child sysctl table if this entry is a directory, or
1843 * proc_handler - the text handler routine (described below)
1845 * strategy - the strategy routine (described below)
1847 * de - for internal use by the sysctl routines
1849 * extra1, extra2 - extra pointers usable by the proc handler routines
1851 * Leaf nodes in the sysctl tree will be represented by a single file
1852 * under /proc; non-leaf nodes will be represented by directories.
1854 * sysctl(2) can automatically manage read and write requests through
1855 * the sysctl table. The data and maxlen fields of the ctl_table
1856 * struct enable minimal validation of the values being written to be
1857 * performed, and the mode field allows minimal authentication.
1859 * More sophisticated management can be enabled by the provision of a
1860 * strategy routine with the table entry. This will be called before
1861 * any automatic read or write of the data is performed.
1863 * The strategy routine may return
1865 * < 0 - Error occurred (error is passed to user process)
1867 * 0 - OK - proceed with automatic read or write.
1869 * > 0 - OK - read or write has been done by the strategy routine, so
1870 * return immediately.
1872 * There must be a proc_handler routine for any terminal nodes
1873 * mirrored under /proc/sys (non-terminals are handled by a built-in
1874 * directory handler). Several default handlers are available to
1875 * cover common cases -
1877 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1878 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1879 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1881 * It is the handler's job to read the input buffer from user memory
1882 * and process it. The handler should return 0 on success.
1884 * This routine returns %NULL on a failure to register, and a pointer
1885 * to the table header on success.
1887 struct ctl_table_header *__register_sysctl_paths(
1888 struct ctl_table_root *root,
1889 struct nsproxy *namespaces,
1890 const struct ctl_path *path, struct ctl_table *table)
1892 struct ctl_table_header *header;
1893 struct ctl_table *new, **prevp;
1894 unsigned int n, npath;
1895 struct ctl_table_set *set;
1897 /* Count the path components */
1898 for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1902 * For each path component, allocate a 2-element ctl_table array.
1903 * The first array element will be filled with the sysctl entry
1904 * for this, the second will be the sentinel (ctl_name == 0).
1906 * We allocate everything in one go so that we don't have to
1907 * worry about freeing additional memory in unregister_sysctl_table.
1909 header = kzalloc(sizeof(struct ctl_table_header) +
1910 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1914 new = (struct ctl_table *) (header + 1);
1916 /* Now connect the dots */
1917 prevp = &header->ctl_table;
1918 for (n = 0; n < npath; ++n, ++path) {
1919 /* Copy the procname */
1920 new->procname = path->procname;
1921 new->ctl_name = path->ctl_name;
1925 prevp = &new->child;
1930 header->ctl_table_arg = table;
1932 INIT_LIST_HEAD(&header->ctl_entry);
1934 header->unregistering = NULL;
1935 header->root = root;
1936 sysctl_set_parent(NULL, header->ctl_table);
1938 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1939 if (sysctl_check_table(namespaces, header->ctl_table)) {
1944 spin_lock(&sysctl_lock);
1945 header->set = lookup_header_set(root, namespaces);
1946 header->attached_by = header->ctl_table;
1947 header->attached_to = root_table;
1948 header->parent = &root_table_header;
1949 for (set = header->set; set; set = set->parent) {
1950 struct ctl_table_header *p;
1951 list_for_each_entry(p, &set->list, ctl_entry) {
1952 if (p->unregistering)
1954 try_attach(p, header);
1957 header->parent->count++;
1958 list_add_tail(&header->ctl_entry, &header->set->list);
1959 spin_unlock(&sysctl_lock);
1965 * register_sysctl_table_path - register a sysctl table hierarchy
1966 * @path: The path to the directory the sysctl table is in.
1967 * @table: the top-level table structure
1969 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1970 * array. A completely 0 filled entry terminates the table.
1972 * See __register_sysctl_paths for more details.
1974 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1975 struct ctl_table *table)
1977 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1982 * register_sysctl_table - register a sysctl table hierarchy
1983 * @table: the top-level table structure
1985 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1986 * array. A completely 0 filled entry terminates the table.
1988 * See register_sysctl_paths for more details.
1990 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1992 static const struct ctl_path null_path[] = { {} };
1994 return register_sysctl_paths(null_path, table);
1998 * unregister_sysctl_table - unregister a sysctl table hierarchy
1999 * @header: the header returned from register_sysctl_table
2001 * Unregisters the sysctl table and all children. proc entries may not
2002 * actually be removed until they are no longer used by anyone.
2004 void unregister_sysctl_table(struct ctl_table_header * header)
2011 spin_lock(&sysctl_lock);
2012 start_unregistering(header);
2013 if (!--header->parent->count) {
2015 kfree(header->parent);
2017 if (!--header->count)
2019 spin_unlock(&sysctl_lock);
2022 int sysctl_is_seen(struct ctl_table_header *p)
2024 struct ctl_table_set *set = p->set;
2026 spin_lock(&sysctl_lock);
2027 if (p->unregistering)
2029 else if (!set->is_seen)
2032 res = set->is_seen(set);
2033 spin_unlock(&sysctl_lock);
2037 void setup_sysctl_set(struct ctl_table_set *p,
2038 struct ctl_table_set *parent,
2039 int (*is_seen)(struct ctl_table_set *))
2041 INIT_LIST_HEAD(&p->list);
2042 p->parent = parent ? parent : &sysctl_table_root.default_set;
2043 p->is_seen = is_seen;
2046 #else /* !CONFIG_SYSCTL */
2047 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
2052 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
2053 struct ctl_table *table)
2058 void unregister_sysctl_table(struct ctl_table_header * table)
2062 void setup_sysctl_set(struct ctl_table_set *p,
2063 struct ctl_table_set *parent,
2064 int (*is_seen)(struct ctl_table_set *))
2068 void sysctl_head_put(struct ctl_table_header *head)
2072 #endif /* CONFIG_SYSCTL */
2078 #ifdef CONFIG_PROC_SYSCTL
2080 static int _proc_do_string(void* data, int maxlen, int write,
2081 struct file *filp, void __user *buffer,
2082 size_t *lenp, loff_t *ppos)
2088 if (!data || !maxlen || !*lenp) {
2096 while (len < *lenp) {
2097 if (get_user(c, p++))
2099 if (c == 0 || c == '\n')
2105 if(copy_from_user(data, buffer, len))
2107 ((char *) data)[len] = 0;
2125 if(copy_to_user(buffer, data, len))
2128 if(put_user('\n', ((char __user *) buffer) + len))
2139 * proc_dostring - read a string sysctl
2140 * @table: the sysctl table
2141 * @write: %TRUE if this is a write to the sysctl file
2142 * @filp: the file structure
2143 * @buffer: the user buffer
2144 * @lenp: the size of the user buffer
2145 * @ppos: file position
2147 * Reads/writes a string from/to the user buffer. If the kernel
2148 * buffer provided is not large enough to hold the string, the
2149 * string is truncated. The copied string is %NULL-terminated.
2150 * If the string is being read by the user process, it is copied
2151 * and a newline '\n' is added. It is truncated if the buffer is
2154 * Returns 0 on success.
2156 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2157 void __user *buffer, size_t *lenp, loff_t *ppos)
2159 return _proc_do_string(table->data, table->maxlen, write, filp,
2160 buffer, lenp, ppos);
2164 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2166 int write, void *data)
2169 *valp = *negp ? -*lvalp : *lvalp;
2174 *lvalp = (unsigned long)-val;
2177 *lvalp = (unsigned long)val;
2183 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2184 int write, struct file *filp, void __user *buffer,
2185 size_t *lenp, loff_t *ppos,
2186 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2187 int write, void *data),
2190 #define TMPBUFLEN 21
2191 int *i, vleft, first=1, neg, val;
2195 char buf[TMPBUFLEN], *p;
2196 char __user *s = buffer;
2198 if (!tbl_data || !table->maxlen || !*lenp ||
2199 (*ppos && !write)) {
2204 i = (int *) tbl_data;
2205 vleft = table->maxlen / sizeof(*i);
2209 conv = do_proc_dointvec_conv;
2211 for (; left && vleft--; i++, first=0) {
2226 if (len > sizeof(buf) - 1)
2227 len = sizeof(buf) - 1;
2228 if (copy_from_user(buf, s, len))
2232 if (*p == '-' && left > 1) {
2236 if (*p < '0' || *p > '9')
2239 lval = simple_strtoul(p, &p, 0);
2242 if ((len < left) && *p && !isspace(*p))
2249 if (conv(&neg, &lval, i, 1, data))
2256 if (conv(&neg, &lval, i, 0, data))
2259 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2263 if(copy_to_user(s, buf, len))
2270 if (!write && !first && left) {
2271 if(put_user('\n', s))
2278 if (get_user(c, s++))
2293 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2294 void __user *buffer, size_t *lenp, loff_t *ppos,
2295 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2296 int write, void *data),
2299 return __do_proc_dointvec(table->data, table, write, filp,
2300 buffer, lenp, ppos, conv, data);
2304 * proc_dointvec - read a vector of integers
2305 * @table: the sysctl table
2306 * @write: %TRUE if this is a write to the sysctl file
2307 * @filp: the file structure
2308 * @buffer: the user buffer
2309 * @lenp: the size of the user buffer
2310 * @ppos: file position
2312 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2313 * values from/to the user buffer, treated as an ASCII string.
2315 * Returns 0 on success.
2317 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2318 void __user *buffer, size_t *lenp, loff_t *ppos)
2320 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2325 * Taint values can only be increased
2326 * This means we can safely use a temporary.
2328 static int proc_taint(struct ctl_table *table, int write, struct file *filp,
2329 void __user *buffer, size_t *lenp, loff_t *ppos)
2332 unsigned long tmptaint = get_taint();
2335 if (write && !capable(CAP_SYS_ADMIN))
2340 err = proc_doulongvec_minmax(&t, write, filp, buffer, lenp, ppos);
2346 * Poor man's atomic or. Not worth adding a primitive
2347 * to everyone's atomic.h for this
2350 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2351 if ((tmptaint >> i) & 1)
2359 struct do_proc_dointvec_minmax_conv_param {
2364 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2366 int write, void *data)
2368 struct do_proc_dointvec_minmax_conv_param *param = data;
2370 int val = *negp ? -*lvalp : *lvalp;
2371 if ((param->min && *param->min > val) ||
2372 (param->max && *param->max < val))
2379 *lvalp = (unsigned long)-val;
2382 *lvalp = (unsigned long)val;
2389 * proc_dointvec_minmax - read a vector of integers with min/max values
2390 * @table: the sysctl table
2391 * @write: %TRUE if this is a write to the sysctl file
2392 * @filp: the file structure
2393 * @buffer: the user buffer
2394 * @lenp: the size of the user buffer
2395 * @ppos: file position
2397 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2398 * values from/to the user buffer, treated as an ASCII string.
2400 * This routine will ensure the values are within the range specified by
2401 * table->extra1 (min) and table->extra2 (max).
2403 * Returns 0 on success.
2405 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2406 void __user *buffer, size_t *lenp, loff_t *ppos)
2408 struct do_proc_dointvec_minmax_conv_param param = {
2409 .min = (int *) table->extra1,
2410 .max = (int *) table->extra2,
2412 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2413 do_proc_dointvec_minmax_conv, ¶m);
2416 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2418 void __user *buffer,
2419 size_t *lenp, loff_t *ppos,
2420 unsigned long convmul,
2421 unsigned long convdiv)
2423 #define TMPBUFLEN 21
2424 unsigned long *i, *min, *max, val;
2425 int vleft, first=1, neg;
2427 char buf[TMPBUFLEN], *p;
2428 char __user *s = buffer;
2430 if (!data || !table->maxlen || !*lenp ||
2431 (*ppos && !write)) {
2436 i = (unsigned long *) data;
2437 min = (unsigned long *) table->extra1;
2438 max = (unsigned long *) table->extra2;
2439 vleft = table->maxlen / sizeof(unsigned long);
2442 for (; left && vleft--; i++, min++, max++, first=0) {
2457 if (len > TMPBUFLEN-1)
2459 if (copy_from_user(buf, s, len))
2463 if (*p == '-' && left > 1) {
2467 if (*p < '0' || *p > '9')
2469 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2471 if ((len < left) && *p && !isspace(*p))
2480 if ((min && val < *min) || (max && val > *max))
2487 sprintf(p, "%lu", convdiv * (*i) / convmul);
2491 if(copy_to_user(s, buf, len))
2498 if (!write && !first && left) {
2499 if(put_user('\n', s))
2506 if (get_user(c, s++))
2521 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2523 void __user *buffer,
2524 size_t *lenp, loff_t *ppos,
2525 unsigned long convmul,
2526 unsigned long convdiv)
2528 return __do_proc_doulongvec_minmax(table->data, table, write,
2529 filp, buffer, lenp, ppos, convmul, convdiv);
2533 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2534 * @table: the sysctl table
2535 * @write: %TRUE if this is a write to the sysctl file
2536 * @filp: the file structure
2537 * @buffer: the user buffer
2538 * @lenp: the size of the user buffer
2539 * @ppos: file position
2541 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2542 * values from/to the user buffer, treated as an ASCII string.
2544 * This routine will ensure the values are within the range specified by
2545 * table->extra1 (min) and table->extra2 (max).
2547 * Returns 0 on success.
2549 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2550 void __user *buffer, size_t *lenp, loff_t *ppos)
2552 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2556 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2557 * @table: the sysctl table
2558 * @write: %TRUE if this is a write to the sysctl file
2559 * @filp: the file structure
2560 * @buffer: the user buffer
2561 * @lenp: the size of the user buffer
2562 * @ppos: file position
2564 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2565 * values from/to the user buffer, treated as an ASCII string. The values
2566 * are treated as milliseconds, and converted to jiffies when they are stored.
2568 * This routine will ensure the values are within the range specified by
2569 * table->extra1 (min) and table->extra2 (max).
2571 * Returns 0 on success.
2573 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2575 void __user *buffer,
2576 size_t *lenp, loff_t *ppos)
2578 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2579 lenp, ppos, HZ, 1000l);
2583 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2585 int write, void *data)
2588 if (*lvalp > LONG_MAX / HZ)
2590 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2596 lval = (unsigned long)-val;
2599 lval = (unsigned long)val;
2606 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2608 int write, void *data)
2611 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2613 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2619 lval = (unsigned long)-val;
2622 lval = (unsigned long)val;
2624 *lvalp = jiffies_to_clock_t(lval);
2629 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2631 int write, void *data)
2634 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2640 lval = (unsigned long)-val;
2643 lval = (unsigned long)val;
2645 *lvalp = jiffies_to_msecs(lval);
2651 * proc_dointvec_jiffies - read a vector of integers as seconds
2652 * @table: the sysctl table
2653 * @write: %TRUE if this is a write to the sysctl file
2654 * @filp: the file structure
2655 * @buffer: the user buffer
2656 * @lenp: the size of the user buffer
2657 * @ppos: file position
2659 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2660 * values from/to the user buffer, treated as an ASCII string.
2661 * The values read are assumed to be in seconds, and are converted into
2664 * Returns 0 on success.
2666 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2667 void __user *buffer, size_t *lenp, loff_t *ppos)
2669 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2670 do_proc_dointvec_jiffies_conv,NULL);
2674 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2675 * @table: the sysctl table
2676 * @write: %TRUE if this is a write to the sysctl file
2677 * @filp: the file structure
2678 * @buffer: the user buffer
2679 * @lenp: the size of the user buffer
2680 * @ppos: pointer to the file position
2682 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2683 * values from/to the user buffer, treated as an ASCII string.
2684 * The values read are assumed to be in 1/USER_HZ seconds, and
2685 * are converted into jiffies.
2687 * Returns 0 on success.
2689 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2690 void __user *buffer, size_t *lenp, loff_t *ppos)
2692 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2693 do_proc_dointvec_userhz_jiffies_conv,NULL);
2697 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2698 * @table: the sysctl table
2699 * @write: %TRUE if this is a write to the sysctl file
2700 * @filp: the file structure
2701 * @buffer: the user buffer
2702 * @lenp: the size of the user buffer
2703 * @ppos: file position
2704 * @ppos: the current position in the file
2706 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2707 * values from/to the user buffer, treated as an ASCII string.
2708 * The values read are assumed to be in 1/1000 seconds, and
2709 * are converted into jiffies.
2711 * Returns 0 on success.
2713 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2714 void __user *buffer, size_t *lenp, loff_t *ppos)
2716 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2717 do_proc_dointvec_ms_jiffies_conv, NULL);
2720 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2721 void __user *buffer, size_t *lenp, loff_t *ppos)
2723 struct pid *new_pid;
2727 tmp = pid_vnr(cad_pid);
2729 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2730 lenp, ppos, NULL, NULL);
2734 new_pid = find_get_pid(tmp);
2738 put_pid(xchg(&cad_pid, new_pid));
2742 #else /* CONFIG_PROC_FS */
2744 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2745 void __user *buffer, size_t *lenp, loff_t *ppos)
2750 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2751 void __user *buffer, size_t *lenp, loff_t *ppos)
2756 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2757 void __user *buffer, size_t *lenp, loff_t *ppos)
2762 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2763 void __user *buffer, size_t *lenp, loff_t *ppos)
2768 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2769 void __user *buffer, size_t *lenp, loff_t *ppos)
2774 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2775 void __user *buffer, size_t *lenp, loff_t *ppos)
2780 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2781 void __user *buffer, size_t *lenp, loff_t *ppos)
2786 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2788 void __user *buffer,
2789 size_t *lenp, loff_t *ppos)
2795 #endif /* CONFIG_PROC_FS */
2798 #ifdef CONFIG_SYSCTL_SYSCALL
2800 * General sysctl support routines
2803 /* The generic sysctl data routine (used if no strategy routine supplied) */
2804 int sysctl_data(struct ctl_table *table,
2805 void __user *oldval, size_t __user *oldlenp,
2806 void __user *newval, size_t newlen)
2810 /* Get out of I don't have a variable */
2811 if (!table->data || !table->maxlen)
2814 if (oldval && oldlenp) {
2815 if (get_user(len, oldlenp))
2818 if (len > table->maxlen)
2819 len = table->maxlen;
2820 if (copy_to_user(oldval, table->data, len))
2822 if (put_user(len, oldlenp))
2827 if (newval && newlen) {
2828 if (newlen > table->maxlen)
2829 newlen = table->maxlen;
2831 if (copy_from_user(table->data, newval, newlen))
2837 /* The generic string strategy routine: */
2838 int sysctl_string(struct ctl_table *table,
2839 void __user *oldval, size_t __user *oldlenp,
2840 void __user *newval, size_t newlen)
2842 if (!table->data || !table->maxlen)
2845 if (oldval && oldlenp) {
2847 if (get_user(bufsize, oldlenp))
2850 size_t len = strlen(table->data), copied;
2852 /* This shouldn't trigger for a well-formed sysctl */
2853 if (len > table->maxlen)
2854 len = table->maxlen;
2856 /* Copy up to a max of bufsize-1 bytes of the string */
2857 copied = (len >= bufsize) ? bufsize - 1 : len;
2859 if (copy_to_user(oldval, table->data, copied) ||
2860 put_user(0, (char __user *)(oldval + copied)))
2862 if (put_user(len, oldlenp))
2866 if (newval && newlen) {
2867 size_t len = newlen;
2868 if (len > table->maxlen)
2869 len = table->maxlen;
2870 if(copy_from_user(table->data, newval, len))
2872 if (len == table->maxlen)
2874 ((char *) table->data)[len] = 0;
2880 * This function makes sure that all of the integers in the vector
2881 * are between the minimum and maximum values given in the arrays
2882 * table->extra1 and table->extra2, respectively.
2884 int sysctl_intvec(struct ctl_table *table,
2885 void __user *oldval, size_t __user *oldlenp,
2886 void __user *newval, size_t newlen)
2889 if (newval && newlen) {
2890 int __user *vec = (int __user *) newval;
2891 int *min = (int *) table->extra1;
2892 int *max = (int *) table->extra2;
2896 if (newlen % sizeof(int) != 0)
2899 if (!table->extra1 && !table->extra2)
2902 if (newlen > table->maxlen)
2903 newlen = table->maxlen;
2904 length = newlen / sizeof(int);
2906 for (i = 0; i < length; i++) {
2908 if (get_user(value, vec + i))
2910 if (min && value < min[i])
2912 if (max && value > max[i])
2919 /* Strategy function to convert jiffies to seconds */
2920 int sysctl_jiffies(struct ctl_table *table,
2921 void __user *oldval, size_t __user *oldlenp,
2922 void __user *newval, size_t newlen)
2924 if (oldval && oldlenp) {
2927 if (get_user(olen, oldlenp))
2932 if (olen < sizeof(int))
2935 val = *(int *)(table->data) / HZ;
2936 if (put_user(val, (int __user *)oldval))
2938 if (put_user(sizeof(int), oldlenp))
2942 if (newval && newlen) {
2944 if (newlen != sizeof(int))
2946 if (get_user(new, (int __user *)newval))
2948 *(int *)(table->data) = new*HZ;
2953 /* Strategy function to convert jiffies to seconds */
2954 int sysctl_ms_jiffies(struct ctl_table *table,
2955 void __user *oldval, size_t __user *oldlenp,
2956 void __user *newval, size_t newlen)
2958 if (oldval && oldlenp) {
2961 if (get_user(olen, oldlenp))
2966 if (olen < sizeof(int))
2969 val = jiffies_to_msecs(*(int *)(table->data));
2970 if (put_user(val, (int __user *)oldval))
2972 if (put_user(sizeof(int), oldlenp))
2976 if (newval && newlen) {
2978 if (newlen != sizeof(int))
2980 if (get_user(new, (int __user *)newval))
2982 *(int *)(table->data) = msecs_to_jiffies(new);
2989 #else /* CONFIG_SYSCTL_SYSCALL */
2992 SYSCALL_DEFINE1(sysctl, struct __sysctl_args __user *, args)
2994 struct __sysctl_args tmp;
2997 if (copy_from_user(&tmp, args, sizeof(tmp)))
3000 error = deprecated_sysctl_warning(&tmp);
3002 /* If no error reading the parameters then just -ENOSYS ... */
3009 int sysctl_data(struct ctl_table *table,
3010 void __user *oldval, size_t __user *oldlenp,
3011 void __user *newval, size_t newlen)
3016 int sysctl_string(struct ctl_table *table,
3017 void __user *oldval, size_t __user *oldlenp,
3018 void __user *newval, size_t newlen)
3023 int sysctl_intvec(struct ctl_table *table,
3024 void __user *oldval, size_t __user *oldlenp,
3025 void __user *newval, size_t newlen)
3030 int sysctl_jiffies(struct ctl_table *table,
3031 void __user *oldval, size_t __user *oldlenp,
3032 void __user *newval, size_t newlen)
3037 int sysctl_ms_jiffies(struct ctl_table *table,
3038 void __user *oldval, size_t __user *oldlenp,
3039 void __user *newval, size_t newlen)
3044 #endif /* CONFIG_SYSCTL_SYSCALL */
3046 static int deprecated_sysctl_warning(struct __sysctl_args *args)
3048 static int msg_count;
3049 int name[CTL_MAXNAME];
3052 /* Check args->nlen. */
3053 if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
3056 /* Read in the sysctl name for better debug message logging */
3057 for (i = 0; i < args->nlen; i++)
3058 if (get_user(name[i], args->name + i))
3061 /* Ignore accesses to kernel.version */
3062 if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
3065 if (msg_count < 5) {
3068 "warning: process `%s' used the deprecated sysctl "
3069 "system call with ", current->comm);
3070 for (i = 0; i < args->nlen; i++)
3071 printk("%d.", name[i]);
3078 * No sense putting this after each symbol definition, twice,
3079 * exception granted :-)
3081 EXPORT_SYMBOL(proc_dointvec);
3082 EXPORT_SYMBOL(proc_dointvec_jiffies);
3083 EXPORT_SYMBOL(proc_dointvec_minmax);
3084 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3085 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3086 EXPORT_SYMBOL(proc_dostring);
3087 EXPORT_SYMBOL(proc_doulongvec_minmax);
3088 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3089 EXPORT_SYMBOL(register_sysctl_table);
3090 EXPORT_SYMBOL(register_sysctl_paths);
3091 EXPORT_SYMBOL(sysctl_intvec);
3092 EXPORT_SYMBOL(sysctl_jiffies);
3093 EXPORT_SYMBOL(sysctl_ms_jiffies);
3094 EXPORT_SYMBOL(sysctl_string);
3095 EXPORT_SYMBOL(sysctl_data);
3096 EXPORT_SYMBOL(unregister_sysctl_table);