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/capability.h>
28 #include <linux/ctype.h>
29 #include <linux/utsname.h>
30 #include <linux/capability.h>
31 #include <linux/smp_lock.h>
33 #include <linux/init.h>
34 #include <linux/kernel.h>
35 #include <linux/kobject.h>
36 #include <linux/net.h>
37 #include <linux/sysrq.h>
38 #include <linux/highuid.h>
39 #include <linux/writeback.h>
40 #include <linux/hugetlb.h>
41 #include <linux/security.h>
42 #include <linux/initrd.h>
43 #include <linux/times.h>
44 #include <linux/limits.h>
45 #include <linux/dcache.h>
46 #include <linux/syscalls.h>
47 #include <linux/nfs_fs.h>
48 #include <linux/acpi.h>
49 #include <linux/reboot.h>
51 #include <asm/uaccess.h>
52 #include <asm/processor.h>
56 #include <asm/stacktrace.h>
59 #if defined(CONFIG_SYSCTL)
61 /* External variables not in a header file. */
63 extern int print_fatal_signals;
64 extern int sysctl_overcommit_memory;
65 extern int sysctl_overcommit_ratio;
66 extern int sysctl_panic_on_oom;
67 extern int max_threads;
68 extern int core_uses_pid;
69 extern int suid_dumpable;
70 extern char core_pattern[];
72 extern int min_free_kbytes;
73 extern int printk_ratelimit_jiffies;
74 extern int printk_ratelimit_burst;
75 extern int pid_max_min, pid_max_max;
76 extern int sysctl_drop_caches;
77 extern int percpu_pagelist_fraction;
78 extern int compat_log;
79 extern int maps_protect;
80 extern int sysctl_stat_interval;
81 extern int audit_argv_kb;
83 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
84 static int maxolduid = 65535;
86 static int min_percpu_pagelist_fract = 8;
88 static int ngroups_max = NGROUPS_MAX;
91 extern char modprobe_path[];
93 #ifdef CONFIG_CHR_DEV_SG
94 extern int sg_big_buff;
98 extern char reboot_command [];
99 extern int stop_a_enabled;
100 extern int scons_pwroff;
104 extern int pwrsw_enabled;
105 extern int unaligned_enabled;
109 #ifdef CONFIG_MATHEMU
110 extern int sysctl_ieee_emulation_warnings;
112 extern int sysctl_userprocess_debug;
113 extern int spin_retry;
116 extern int sysctl_hz_timer;
118 #ifdef CONFIG_BSD_PROCESS_ACCT
119 extern int acct_parm[];
123 extern int no_unaligned_warning;
126 #ifdef CONFIG_RT_MUTEXES
127 extern int max_lock_depth;
130 #ifdef CONFIG_SYSCTL_SYSCALL
131 static int parse_table(int __user *, int, void __user *, size_t __user *,
132 void __user *, size_t, ctl_table *);
136 #ifdef CONFIG_PROC_SYSCTL
137 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
138 void __user *buffer, size_t *lenp, loff_t *ppos);
139 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
140 void __user *buffer, size_t *lenp, loff_t *ppos);
143 static ctl_table root_table[];
144 static struct ctl_table_header root_table_header =
145 { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
147 static ctl_table kern_table[];
148 static ctl_table vm_table[];
149 static ctl_table fs_table[];
150 static ctl_table debug_table[];
151 static ctl_table dev_table[];
152 extern ctl_table random_table[];
153 #ifdef CONFIG_UNIX98_PTYS
154 extern ctl_table pty_table[];
156 #ifdef CONFIG_INOTIFY_USER
157 extern ctl_table inotify_table[];
160 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
161 int sysctl_legacy_va_layout;
164 extern int prove_locking;
165 extern int lock_stat;
167 /* The default sysctl tables: */
169 static ctl_table root_table[] = {
171 .ctl_name = CTL_KERN,
172 .procname = "kernel",
197 .ctl_name = CTL_DEBUG,
200 .child = debug_table,
209 * NOTE: do not add new entries to this table unless you have read
210 * Documentation/sysctl/ctl_unnumbered.txt
215 #ifdef CONFIG_SCHED_DEBUG
216 static unsigned long min_sched_granularity_ns = 100000; /* 100 usecs */
217 static unsigned long max_sched_granularity_ns = 1000000000; /* 1 second */
218 static unsigned long min_wakeup_granularity_ns; /* 0 usecs */
219 static unsigned long max_wakeup_granularity_ns = 1000000000; /* 1 second */
222 static ctl_table kern_table[] = {
223 #ifdef CONFIG_SCHED_DEBUG
225 .ctl_name = CTL_UNNUMBERED,
226 .procname = "sched_granularity_ns",
227 .data = &sysctl_sched_granularity,
228 .maxlen = sizeof(unsigned int),
230 .proc_handler = &proc_dointvec_minmax,
231 .strategy = &sysctl_intvec,
232 .extra1 = &min_sched_granularity_ns,
233 .extra2 = &max_sched_granularity_ns,
236 .ctl_name = CTL_UNNUMBERED,
237 .procname = "sched_wakeup_granularity_ns",
238 .data = &sysctl_sched_wakeup_granularity,
239 .maxlen = sizeof(unsigned int),
241 .proc_handler = &proc_dointvec_minmax,
242 .strategy = &sysctl_intvec,
243 .extra1 = &min_wakeup_granularity_ns,
244 .extra2 = &max_wakeup_granularity_ns,
247 .ctl_name = CTL_UNNUMBERED,
248 .procname = "sched_batch_wakeup_granularity_ns",
249 .data = &sysctl_sched_batch_wakeup_granularity,
250 .maxlen = sizeof(unsigned int),
252 .proc_handler = &proc_dointvec_minmax,
253 .strategy = &sysctl_intvec,
254 .extra1 = &min_wakeup_granularity_ns,
255 .extra2 = &max_wakeup_granularity_ns,
258 .ctl_name = CTL_UNNUMBERED,
259 .procname = "sched_stat_granularity_ns",
260 .data = &sysctl_sched_stat_granularity,
261 .maxlen = sizeof(unsigned int),
263 .proc_handler = &proc_dointvec_minmax,
264 .strategy = &sysctl_intvec,
265 .extra1 = &min_wakeup_granularity_ns,
266 .extra2 = &max_wakeup_granularity_ns,
269 .ctl_name = CTL_UNNUMBERED,
270 .procname = "sched_runtime_limit_ns",
271 .data = &sysctl_sched_runtime_limit,
272 .maxlen = sizeof(unsigned int),
274 .proc_handler = &proc_dointvec_minmax,
275 .strategy = &sysctl_intvec,
276 .extra1 = &min_sched_granularity_ns,
277 .extra2 = &max_sched_granularity_ns,
280 .ctl_name = CTL_UNNUMBERED,
281 .procname = "sched_child_runs_first",
282 .data = &sysctl_sched_child_runs_first,
283 .maxlen = sizeof(unsigned int),
285 .proc_handler = &proc_dointvec,
287 #ifdef CONFIG_PROVE_LOCKING
289 .ctl_name = CTL_UNNUMBERED,
290 .procname = "prove_locking",
291 .data = &prove_locking,
292 .maxlen = sizeof(int),
294 .proc_handler = &proc_dointvec,
297 #ifdef CONFIG_LOCK_STAT
299 .ctl_name = CTL_UNNUMBERED,
300 .procname = "lock_stat",
302 .maxlen = sizeof(int),
304 .proc_handler = &proc_dointvec,
308 .ctl_name = CTL_UNNUMBERED,
309 .procname = "sched_features",
310 .data = &sysctl_sched_features,
311 .maxlen = sizeof(unsigned int),
313 .proc_handler = &proc_dointvec,
317 .ctl_name = KERN_PANIC,
319 .data = &panic_timeout,
320 .maxlen = sizeof(int),
322 .proc_handler = &proc_dointvec,
325 .ctl_name = KERN_CORE_USES_PID,
326 .procname = "core_uses_pid",
327 .data = &core_uses_pid,
328 .maxlen = sizeof(int),
330 .proc_handler = &proc_dointvec,
332 #ifdef CONFIG_AUDITSYSCALL
334 .ctl_name = CTL_UNNUMBERED,
335 .procname = "audit_argv_kb",
336 .data = &audit_argv_kb,
337 .maxlen = sizeof(int),
339 .proc_handler = &proc_dointvec,
343 .ctl_name = KERN_CORE_PATTERN,
344 .procname = "core_pattern",
345 .data = core_pattern,
346 .maxlen = CORENAME_MAX_SIZE,
348 .proc_handler = &proc_dostring,
349 .strategy = &sysctl_string,
351 #ifdef CONFIG_PROC_SYSCTL
353 .ctl_name = KERN_TAINTED,
354 .procname = "tainted",
356 .maxlen = sizeof(int),
358 .proc_handler = &proc_dointvec_taint,
362 .ctl_name = KERN_CAP_BSET,
363 .procname = "cap-bound",
365 .maxlen = sizeof(kernel_cap_t),
367 .proc_handler = &proc_dointvec_bset,
369 #ifdef CONFIG_BLK_DEV_INITRD
371 .ctl_name = KERN_REALROOTDEV,
372 .procname = "real-root-dev",
373 .data = &real_root_dev,
374 .maxlen = sizeof(int),
376 .proc_handler = &proc_dointvec,
380 .ctl_name = CTL_UNNUMBERED,
381 .procname = "print-fatal-signals",
382 .data = &print_fatal_signals,
383 .maxlen = sizeof(int),
385 .proc_handler = &proc_dointvec,
389 .ctl_name = KERN_SPARC_REBOOT,
390 .procname = "reboot-cmd",
391 .data = reboot_command,
394 .proc_handler = &proc_dostring,
395 .strategy = &sysctl_string,
398 .ctl_name = KERN_SPARC_STOP_A,
399 .procname = "stop-a",
400 .data = &stop_a_enabled,
401 .maxlen = sizeof (int),
403 .proc_handler = &proc_dointvec,
406 .ctl_name = KERN_SPARC_SCONS_PWROFF,
407 .procname = "scons-poweroff",
408 .data = &scons_pwroff,
409 .maxlen = sizeof (int),
411 .proc_handler = &proc_dointvec,
416 .ctl_name = KERN_HPPA_PWRSW,
417 .procname = "soft-power",
418 .data = &pwrsw_enabled,
419 .maxlen = sizeof (int),
421 .proc_handler = &proc_dointvec,
424 .ctl_name = KERN_HPPA_UNALIGNED,
425 .procname = "unaligned-trap",
426 .data = &unaligned_enabled,
427 .maxlen = sizeof (int),
429 .proc_handler = &proc_dointvec,
433 .ctl_name = KERN_CTLALTDEL,
434 .procname = "ctrl-alt-del",
436 .maxlen = sizeof(int),
438 .proc_handler = &proc_dointvec,
441 .ctl_name = KERN_PRINTK,
442 .procname = "printk",
443 .data = &console_loglevel,
444 .maxlen = 4*sizeof(int),
446 .proc_handler = &proc_dointvec,
450 .ctl_name = KERN_MODPROBE,
451 .procname = "modprobe",
452 .data = &modprobe_path,
453 .maxlen = KMOD_PATH_LEN,
455 .proc_handler = &proc_dostring,
456 .strategy = &sysctl_string,
459 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
461 .ctl_name = KERN_HOTPLUG,
462 .procname = "hotplug",
463 .data = &uevent_helper,
464 .maxlen = UEVENT_HELPER_PATH_LEN,
466 .proc_handler = &proc_dostring,
467 .strategy = &sysctl_string,
470 #ifdef CONFIG_CHR_DEV_SG
472 .ctl_name = KERN_SG_BIG_BUFF,
473 .procname = "sg-big-buff",
474 .data = &sg_big_buff,
475 .maxlen = sizeof (int),
477 .proc_handler = &proc_dointvec,
480 #ifdef CONFIG_BSD_PROCESS_ACCT
482 .ctl_name = KERN_ACCT,
485 .maxlen = 3*sizeof(int),
487 .proc_handler = &proc_dointvec,
490 #ifdef CONFIG_MAGIC_SYSRQ
492 .ctl_name = KERN_SYSRQ,
494 .data = &__sysrq_enabled,
495 .maxlen = sizeof (int),
497 .proc_handler = &proc_dointvec,
500 #ifdef CONFIG_PROC_SYSCTL
502 .ctl_name = KERN_CADPID,
503 .procname = "cad_pid",
505 .maxlen = sizeof (int),
507 .proc_handler = &proc_do_cad_pid,
511 .ctl_name = KERN_MAX_THREADS,
512 .procname = "threads-max",
513 .data = &max_threads,
514 .maxlen = sizeof(int),
516 .proc_handler = &proc_dointvec,
519 .ctl_name = KERN_RANDOM,
520 .procname = "random",
522 .child = random_table,
524 #ifdef CONFIG_UNIX98_PTYS
526 .ctl_name = KERN_PTY,
533 .ctl_name = KERN_OVERFLOWUID,
534 .procname = "overflowuid",
535 .data = &overflowuid,
536 .maxlen = sizeof(int),
538 .proc_handler = &proc_dointvec_minmax,
539 .strategy = &sysctl_intvec,
540 .extra1 = &minolduid,
541 .extra2 = &maxolduid,
544 .ctl_name = KERN_OVERFLOWGID,
545 .procname = "overflowgid",
546 .data = &overflowgid,
547 .maxlen = sizeof(int),
549 .proc_handler = &proc_dointvec_minmax,
550 .strategy = &sysctl_intvec,
551 .extra1 = &minolduid,
552 .extra2 = &maxolduid,
555 #ifdef CONFIG_MATHEMU
557 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
558 .procname = "ieee_emulation_warnings",
559 .data = &sysctl_ieee_emulation_warnings,
560 .maxlen = sizeof(int),
562 .proc_handler = &proc_dointvec,
565 #ifdef CONFIG_NO_IDLE_HZ
567 .ctl_name = KERN_HZ_TIMER,
568 .procname = "hz_timer",
569 .data = &sysctl_hz_timer,
570 .maxlen = sizeof(int),
572 .proc_handler = &proc_dointvec,
576 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
577 .procname = "userprocess_debug",
578 .data = &sysctl_userprocess_debug,
579 .maxlen = sizeof(int),
581 .proc_handler = &proc_dointvec,
585 .ctl_name = KERN_PIDMAX,
586 .procname = "pid_max",
588 .maxlen = sizeof (int),
590 .proc_handler = &proc_dointvec_minmax,
591 .strategy = sysctl_intvec,
592 .extra1 = &pid_max_min,
593 .extra2 = &pid_max_max,
596 .ctl_name = KERN_PANIC_ON_OOPS,
597 .procname = "panic_on_oops",
598 .data = &panic_on_oops,
599 .maxlen = sizeof(int),
601 .proc_handler = &proc_dointvec,
604 .ctl_name = KERN_PRINTK_RATELIMIT,
605 .procname = "printk_ratelimit",
606 .data = &printk_ratelimit_jiffies,
607 .maxlen = sizeof(int),
609 .proc_handler = &proc_dointvec_jiffies,
610 .strategy = &sysctl_jiffies,
613 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
614 .procname = "printk_ratelimit_burst",
615 .data = &printk_ratelimit_burst,
616 .maxlen = sizeof(int),
618 .proc_handler = &proc_dointvec,
621 .ctl_name = KERN_NGROUPS_MAX,
622 .procname = "ngroups_max",
623 .data = &ngroups_max,
624 .maxlen = sizeof (int),
626 .proc_handler = &proc_dointvec,
628 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
630 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
631 .procname = "unknown_nmi_panic",
632 .data = &unknown_nmi_panic,
633 .maxlen = sizeof (int),
635 .proc_handler = &proc_dointvec,
638 .ctl_name = KERN_NMI_WATCHDOG,
639 .procname = "nmi_watchdog",
640 .data = &nmi_watchdog_enabled,
641 .maxlen = sizeof (int),
643 .proc_handler = &proc_nmi_enabled,
646 #if defined(CONFIG_X86)
648 .ctl_name = KERN_PANIC_ON_NMI,
649 .procname = "panic_on_unrecovered_nmi",
650 .data = &panic_on_unrecovered_nmi,
651 .maxlen = sizeof(int),
653 .proc_handler = &proc_dointvec,
656 .ctl_name = KERN_BOOTLOADER_TYPE,
657 .procname = "bootloader_type",
658 .data = &bootloader_type,
659 .maxlen = sizeof (int),
661 .proc_handler = &proc_dointvec,
664 .ctl_name = CTL_UNNUMBERED,
665 .procname = "kstack_depth_to_print",
666 .data = &kstack_depth_to_print,
667 .maxlen = sizeof(int),
669 .proc_handler = &proc_dointvec,
672 #if defined(CONFIG_MMU)
674 .ctl_name = KERN_RANDOMIZE,
675 .procname = "randomize_va_space",
676 .data = &randomize_va_space,
677 .maxlen = sizeof(int),
679 .proc_handler = &proc_dointvec,
682 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
684 .ctl_name = KERN_SPIN_RETRY,
685 .procname = "spin_retry",
687 .maxlen = sizeof (int),
689 .proc_handler = &proc_dointvec,
692 #ifdef CONFIG_ACPI_SLEEP
694 .ctl_name = KERN_ACPI_VIDEO_FLAGS,
695 .procname = "acpi_video_flags",
696 .data = &acpi_realmode_flags,
697 .maxlen = sizeof (unsigned long),
699 .proc_handler = &proc_doulongvec_minmax,
704 .ctl_name = KERN_IA64_UNALIGNED,
705 .procname = "ignore-unaligned-usertrap",
706 .data = &no_unaligned_warning,
707 .maxlen = sizeof (int),
709 .proc_handler = &proc_dointvec,
714 .ctl_name = KERN_COMPAT_LOG,
715 .procname = "compat-log",
717 .maxlen = sizeof (int),
719 .proc_handler = &proc_dointvec,
722 #ifdef CONFIG_RT_MUTEXES
724 .ctl_name = KERN_MAX_LOCK_DEPTH,
725 .procname = "max_lock_depth",
726 .data = &max_lock_depth,
727 .maxlen = sizeof(int),
729 .proc_handler = &proc_dointvec,
732 #ifdef CONFIG_PROC_FS
734 .ctl_name = CTL_UNNUMBERED,
735 .procname = "maps_protect",
736 .data = &maps_protect,
737 .maxlen = sizeof(int),
739 .proc_handler = &proc_dointvec,
743 .ctl_name = CTL_UNNUMBERED,
744 .procname = "poweroff_cmd",
745 .data = &poweroff_cmd,
746 .maxlen = POWEROFF_CMD_PATH_LEN,
748 .proc_handler = &proc_dostring,
749 .strategy = &sysctl_string,
752 * NOTE: do not add new entries to this table unless you have read
753 * Documentation/sysctl/ctl_unnumbered.txt
758 /* Constants for minimum and maximum testing in vm_table.
759 We use these as one-element integer vectors. */
762 static int one_hundred = 100;
765 static ctl_table vm_table[] = {
767 .ctl_name = VM_OVERCOMMIT_MEMORY,
768 .procname = "overcommit_memory",
769 .data = &sysctl_overcommit_memory,
770 .maxlen = sizeof(sysctl_overcommit_memory),
772 .proc_handler = &proc_dointvec,
775 .ctl_name = VM_PANIC_ON_OOM,
776 .procname = "panic_on_oom",
777 .data = &sysctl_panic_on_oom,
778 .maxlen = sizeof(sysctl_panic_on_oom),
780 .proc_handler = &proc_dointvec,
783 .ctl_name = VM_OVERCOMMIT_RATIO,
784 .procname = "overcommit_ratio",
785 .data = &sysctl_overcommit_ratio,
786 .maxlen = sizeof(sysctl_overcommit_ratio),
788 .proc_handler = &proc_dointvec,
791 .ctl_name = VM_PAGE_CLUSTER,
792 .procname = "page-cluster",
793 .data = &page_cluster,
794 .maxlen = sizeof(int),
796 .proc_handler = &proc_dointvec,
799 .ctl_name = VM_DIRTY_BACKGROUND,
800 .procname = "dirty_background_ratio",
801 .data = &dirty_background_ratio,
802 .maxlen = sizeof(dirty_background_ratio),
804 .proc_handler = &proc_dointvec_minmax,
805 .strategy = &sysctl_intvec,
807 .extra2 = &one_hundred,
810 .ctl_name = VM_DIRTY_RATIO,
811 .procname = "dirty_ratio",
812 .data = &vm_dirty_ratio,
813 .maxlen = sizeof(vm_dirty_ratio),
815 .proc_handler = &proc_dointvec_minmax,
816 .strategy = &sysctl_intvec,
818 .extra2 = &one_hundred,
821 .ctl_name = VM_DIRTY_WB_CS,
822 .procname = "dirty_writeback_centisecs",
823 .data = &dirty_writeback_interval,
824 .maxlen = sizeof(dirty_writeback_interval),
826 .proc_handler = &dirty_writeback_centisecs_handler,
829 .ctl_name = VM_DIRTY_EXPIRE_CS,
830 .procname = "dirty_expire_centisecs",
831 .data = &dirty_expire_interval,
832 .maxlen = sizeof(dirty_expire_interval),
834 .proc_handler = &proc_dointvec_userhz_jiffies,
837 .ctl_name = VM_NR_PDFLUSH_THREADS,
838 .procname = "nr_pdflush_threads",
839 .data = &nr_pdflush_threads,
840 .maxlen = sizeof nr_pdflush_threads,
841 .mode = 0444 /* read-only*/,
842 .proc_handler = &proc_dointvec,
845 .ctl_name = VM_SWAPPINESS,
846 .procname = "swappiness",
847 .data = &vm_swappiness,
848 .maxlen = sizeof(vm_swappiness),
850 .proc_handler = &proc_dointvec_minmax,
851 .strategy = &sysctl_intvec,
853 .extra2 = &one_hundred,
855 #ifdef CONFIG_HUGETLB_PAGE
857 .ctl_name = VM_HUGETLB_PAGES,
858 .procname = "nr_hugepages",
859 .data = &max_huge_pages,
860 .maxlen = sizeof(unsigned long),
862 .proc_handler = &hugetlb_sysctl_handler,
863 .extra1 = (void *)&hugetlb_zero,
864 .extra2 = (void *)&hugetlb_infinity,
867 .ctl_name = VM_HUGETLB_GROUP,
868 .procname = "hugetlb_shm_group",
869 .data = &sysctl_hugetlb_shm_group,
870 .maxlen = sizeof(gid_t),
872 .proc_handler = &proc_dointvec,
875 .ctl_name = CTL_UNNUMBERED,
876 .procname = "hugepages_treat_as_movable",
877 .data = &hugepages_treat_as_movable,
878 .maxlen = sizeof(int),
880 .proc_handler = &hugetlb_treat_movable_handler,
884 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
885 .procname = "lowmem_reserve_ratio",
886 .data = &sysctl_lowmem_reserve_ratio,
887 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
889 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
890 .strategy = &sysctl_intvec,
893 .ctl_name = VM_DROP_PAGECACHE,
894 .procname = "drop_caches",
895 .data = &sysctl_drop_caches,
896 .maxlen = sizeof(int),
898 .proc_handler = drop_caches_sysctl_handler,
899 .strategy = &sysctl_intvec,
902 .ctl_name = VM_MIN_FREE_KBYTES,
903 .procname = "min_free_kbytes",
904 .data = &min_free_kbytes,
905 .maxlen = sizeof(min_free_kbytes),
907 .proc_handler = &min_free_kbytes_sysctl_handler,
908 .strategy = &sysctl_intvec,
912 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
913 .procname = "percpu_pagelist_fraction",
914 .data = &percpu_pagelist_fraction,
915 .maxlen = sizeof(percpu_pagelist_fraction),
917 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
918 .strategy = &sysctl_intvec,
919 .extra1 = &min_percpu_pagelist_fract,
923 .ctl_name = VM_MAX_MAP_COUNT,
924 .procname = "max_map_count",
925 .data = &sysctl_max_map_count,
926 .maxlen = sizeof(sysctl_max_map_count),
928 .proc_handler = &proc_dointvec
932 .ctl_name = VM_LAPTOP_MODE,
933 .procname = "laptop_mode",
934 .data = &laptop_mode,
935 .maxlen = sizeof(laptop_mode),
937 .proc_handler = &proc_dointvec_jiffies,
938 .strategy = &sysctl_jiffies,
941 .ctl_name = VM_BLOCK_DUMP,
942 .procname = "block_dump",
944 .maxlen = sizeof(block_dump),
946 .proc_handler = &proc_dointvec,
947 .strategy = &sysctl_intvec,
951 .ctl_name = VM_VFS_CACHE_PRESSURE,
952 .procname = "vfs_cache_pressure",
953 .data = &sysctl_vfs_cache_pressure,
954 .maxlen = sizeof(sysctl_vfs_cache_pressure),
956 .proc_handler = &proc_dointvec,
957 .strategy = &sysctl_intvec,
960 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
962 .ctl_name = VM_LEGACY_VA_LAYOUT,
963 .procname = "legacy_va_layout",
964 .data = &sysctl_legacy_va_layout,
965 .maxlen = sizeof(sysctl_legacy_va_layout),
967 .proc_handler = &proc_dointvec,
968 .strategy = &sysctl_intvec,
974 .ctl_name = VM_ZONE_RECLAIM_MODE,
975 .procname = "zone_reclaim_mode",
976 .data = &zone_reclaim_mode,
977 .maxlen = sizeof(zone_reclaim_mode),
979 .proc_handler = &proc_dointvec,
980 .strategy = &sysctl_intvec,
984 .ctl_name = VM_MIN_UNMAPPED,
985 .procname = "min_unmapped_ratio",
986 .data = &sysctl_min_unmapped_ratio,
987 .maxlen = sizeof(sysctl_min_unmapped_ratio),
989 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
990 .strategy = &sysctl_intvec,
992 .extra2 = &one_hundred,
995 .ctl_name = VM_MIN_SLAB,
996 .procname = "min_slab_ratio",
997 .data = &sysctl_min_slab_ratio,
998 .maxlen = sizeof(sysctl_min_slab_ratio),
1000 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1001 .strategy = &sysctl_intvec,
1003 .extra2 = &one_hundred,
1008 .ctl_name = CTL_UNNUMBERED,
1009 .procname = "stat_interval",
1010 .data = &sysctl_stat_interval,
1011 .maxlen = sizeof(sysctl_stat_interval),
1013 .proc_handler = &proc_dointvec_jiffies,
1014 .strategy = &sysctl_jiffies,
1017 #ifdef CONFIG_SECURITY
1019 .ctl_name = CTL_UNNUMBERED,
1020 .procname = "mmap_min_addr",
1021 .data = &mmap_min_addr,
1022 .maxlen = sizeof(unsigned long),
1024 .proc_handler = &proc_doulongvec_minmax,
1028 .ctl_name = CTL_UNNUMBERED,
1029 .procname = "numa_zonelist_order",
1030 .data = &numa_zonelist_order,
1031 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1033 .proc_handler = &numa_zonelist_order_handler,
1034 .strategy = &sysctl_string,
1038 #if defined(CONFIG_X86_32) || \
1039 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1041 .ctl_name = VM_VDSO_ENABLED,
1042 .procname = "vdso_enabled",
1043 .data = &vdso_enabled,
1044 .maxlen = sizeof(vdso_enabled),
1046 .proc_handler = &proc_dointvec,
1047 .strategy = &sysctl_intvec,
1052 * NOTE: do not add new entries to this table unless you have read
1053 * Documentation/sysctl/ctl_unnumbered.txt
1058 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1059 static ctl_table binfmt_misc_table[] = {
1064 static ctl_table fs_table[] = {
1066 .ctl_name = FS_NRINODE,
1067 .procname = "inode-nr",
1068 .data = &inodes_stat,
1069 .maxlen = 2*sizeof(int),
1071 .proc_handler = &proc_dointvec,
1074 .ctl_name = FS_STATINODE,
1075 .procname = "inode-state",
1076 .data = &inodes_stat,
1077 .maxlen = 7*sizeof(int),
1079 .proc_handler = &proc_dointvec,
1082 .ctl_name = FS_NRFILE,
1083 .procname = "file-nr",
1084 .data = &files_stat,
1085 .maxlen = 3*sizeof(int),
1087 .proc_handler = &proc_nr_files,
1090 .ctl_name = FS_MAXFILE,
1091 .procname = "file-max",
1092 .data = &files_stat.max_files,
1093 .maxlen = sizeof(int),
1095 .proc_handler = &proc_dointvec,
1098 .ctl_name = FS_DENTRY,
1099 .procname = "dentry-state",
1100 .data = &dentry_stat,
1101 .maxlen = 6*sizeof(int),
1103 .proc_handler = &proc_dointvec,
1106 .ctl_name = FS_OVERFLOWUID,
1107 .procname = "overflowuid",
1108 .data = &fs_overflowuid,
1109 .maxlen = sizeof(int),
1111 .proc_handler = &proc_dointvec_minmax,
1112 .strategy = &sysctl_intvec,
1113 .extra1 = &minolduid,
1114 .extra2 = &maxolduid,
1117 .ctl_name = FS_OVERFLOWGID,
1118 .procname = "overflowgid",
1119 .data = &fs_overflowgid,
1120 .maxlen = sizeof(int),
1122 .proc_handler = &proc_dointvec_minmax,
1123 .strategy = &sysctl_intvec,
1124 .extra1 = &minolduid,
1125 .extra2 = &maxolduid,
1128 .ctl_name = FS_LEASES,
1129 .procname = "leases-enable",
1130 .data = &leases_enable,
1131 .maxlen = sizeof(int),
1133 .proc_handler = &proc_dointvec,
1135 #ifdef CONFIG_DNOTIFY
1137 .ctl_name = FS_DIR_NOTIFY,
1138 .procname = "dir-notify-enable",
1139 .data = &dir_notify_enable,
1140 .maxlen = sizeof(int),
1142 .proc_handler = &proc_dointvec,
1147 .ctl_name = FS_LEASE_TIME,
1148 .procname = "lease-break-time",
1149 .data = &lease_break_time,
1150 .maxlen = sizeof(int),
1152 .proc_handler = &proc_dointvec_minmax,
1153 .strategy = &sysctl_intvec,
1158 .ctl_name = FS_AIO_NR,
1159 .procname = "aio-nr",
1161 .maxlen = sizeof(aio_nr),
1163 .proc_handler = &proc_doulongvec_minmax,
1166 .ctl_name = FS_AIO_MAX_NR,
1167 .procname = "aio-max-nr",
1168 .data = &aio_max_nr,
1169 .maxlen = sizeof(aio_max_nr),
1171 .proc_handler = &proc_doulongvec_minmax,
1173 #ifdef CONFIG_INOTIFY_USER
1175 .ctl_name = FS_INOTIFY,
1176 .procname = "inotify",
1178 .child = inotify_table,
1183 .ctl_name = KERN_SETUID_DUMPABLE,
1184 .procname = "suid_dumpable",
1185 .data = &suid_dumpable,
1186 .maxlen = sizeof(int),
1188 .proc_handler = &proc_dointvec,
1190 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1192 .ctl_name = CTL_UNNUMBERED,
1193 .procname = "binfmt_misc",
1195 .child = binfmt_misc_table,
1199 * NOTE: do not add new entries to this table unless you have read
1200 * Documentation/sysctl/ctl_unnumbered.txt
1205 static ctl_table debug_table[] = {
1209 static ctl_table dev_table[] = {
1213 static DEFINE_SPINLOCK(sysctl_lock);
1215 /* called under sysctl_lock */
1216 static int use_table(struct ctl_table_header *p)
1218 if (unlikely(p->unregistering))
1224 /* called under sysctl_lock */
1225 static void unuse_table(struct ctl_table_header *p)
1228 if (unlikely(p->unregistering))
1229 complete(p->unregistering);
1232 /* called under sysctl_lock, will reacquire if has to wait */
1233 static void start_unregistering(struct ctl_table_header *p)
1236 * if p->used is 0, nobody will ever touch that entry again;
1237 * we'll eliminate all paths to it before dropping sysctl_lock
1239 if (unlikely(p->used)) {
1240 struct completion wait;
1241 init_completion(&wait);
1242 p->unregistering = &wait;
1243 spin_unlock(&sysctl_lock);
1244 wait_for_completion(&wait);
1245 spin_lock(&sysctl_lock);
1248 * do not remove from the list until nobody holds it; walking the
1249 * list in do_sysctl() relies on that.
1251 list_del_init(&p->ctl_entry);
1254 void sysctl_head_finish(struct ctl_table_header *head)
1258 spin_lock(&sysctl_lock);
1260 spin_unlock(&sysctl_lock);
1263 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1265 struct ctl_table_header *head;
1266 struct list_head *tmp;
1267 spin_lock(&sysctl_lock);
1269 tmp = &prev->ctl_entry;
1273 tmp = &root_table_header.ctl_entry;
1275 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1277 if (!use_table(head))
1279 spin_unlock(&sysctl_lock);
1283 if (tmp == &root_table_header.ctl_entry)
1286 spin_unlock(&sysctl_lock);
1290 #ifdef CONFIG_SYSCTL_SYSCALL
1291 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1292 void __user *newval, size_t newlen)
1294 struct ctl_table_header *head;
1295 int error = -ENOTDIR;
1297 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1301 if (!oldlenp || get_user(old_len, oldlenp))
1305 for (head = sysctl_head_next(NULL); head;
1306 head = sysctl_head_next(head)) {
1307 error = parse_table(name, nlen, oldval, oldlenp,
1308 newval, newlen, head->ctl_table);
1309 if (error != -ENOTDIR) {
1310 sysctl_head_finish(head);
1317 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1319 struct __sysctl_args tmp;
1322 if (copy_from_user(&tmp, args, sizeof(tmp)))
1326 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1327 tmp.newval, tmp.newlen);
1331 #endif /* CONFIG_SYSCTL_SYSCALL */
1334 * sysctl_perm does NOT grant the superuser all rights automatically, because
1335 * some sysctl variables are readonly even to root.
1338 static int test_perm(int mode, int op)
1342 else if (in_egroup_p(0))
1344 if ((mode & op & 0007) == op)
1349 int sysctl_perm(ctl_table *table, int op)
1352 error = security_sysctl(table, op);
1355 return test_perm(table->mode, op);
1358 #ifdef CONFIG_SYSCTL_SYSCALL
1359 static int parse_table(int __user *name, int nlen,
1360 void __user *oldval, size_t __user *oldlenp,
1361 void __user *newval, size_t newlen,
1368 if (get_user(n, name))
1370 for ( ; table->ctl_name || table->procname; table++) {
1371 if (!table->ctl_name)
1373 if (n == table->ctl_name) {
1376 if (sysctl_perm(table, 001))
1380 table = table->child;
1383 error = do_sysctl_strategy(table, name, nlen,
1392 /* Perform the actual read/write of a sysctl table entry. */
1393 int do_sysctl_strategy (ctl_table *table,
1394 int __user *name, int nlen,
1395 void __user *oldval, size_t __user *oldlenp,
1396 void __user *newval, size_t newlen)
1405 if (sysctl_perm(table, op))
1408 if (table->strategy) {
1409 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1417 /* If there is no strategy routine, or if the strategy returns
1418 * zero, proceed with automatic r/w */
1419 if (table->data && table->maxlen) {
1420 if (oldval && oldlenp) {
1421 if (get_user(len, oldlenp))
1424 if (len > table->maxlen)
1425 len = table->maxlen;
1426 if(copy_to_user(oldval, table->data, len))
1428 if(put_user(len, oldlenp))
1432 if (newval && newlen) {
1434 if (len > table->maxlen)
1435 len = table->maxlen;
1436 if(copy_from_user(table->data, newval, len))
1442 #endif /* CONFIG_SYSCTL_SYSCALL */
1444 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1446 for (; table->ctl_name || table->procname; table++) {
1447 table->parent = parent;
1449 sysctl_set_parent(table, table->child);
1453 static __init int sysctl_init(void)
1455 sysctl_set_parent(NULL, root_table);
1459 core_initcall(sysctl_init);
1462 * register_sysctl_table - register a sysctl hierarchy
1463 * @table: the top-level table structure
1465 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1466 * array. An entry with a ctl_name of 0 terminates the table.
1468 * The members of the &ctl_table structure are used as follows:
1470 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1471 * must be unique within that level of sysctl
1473 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1474 * enter a sysctl file
1476 * data - a pointer to data for use by proc_handler
1478 * maxlen - the maximum size in bytes of the data
1480 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1482 * child - a pointer to the child sysctl table if this entry is a directory, or
1485 * proc_handler - the text handler routine (described below)
1487 * strategy - the strategy routine (described below)
1489 * de - for internal use by the sysctl routines
1491 * extra1, extra2 - extra pointers usable by the proc handler routines
1493 * Leaf nodes in the sysctl tree will be represented by a single file
1494 * under /proc; non-leaf nodes will be represented by directories.
1496 * sysctl(2) can automatically manage read and write requests through
1497 * the sysctl table. The data and maxlen fields of the ctl_table
1498 * struct enable minimal validation of the values being written to be
1499 * performed, and the mode field allows minimal authentication.
1501 * More sophisticated management can be enabled by the provision of a
1502 * strategy routine with the table entry. This will be called before
1503 * any automatic read or write of the data is performed.
1505 * The strategy routine may return
1507 * < 0 - Error occurred (error is passed to user process)
1509 * 0 - OK - proceed with automatic read or write.
1511 * > 0 - OK - read or write has been done by the strategy routine, so
1512 * return immediately.
1514 * There must be a proc_handler routine for any terminal nodes
1515 * mirrored under /proc/sys (non-terminals are handled by a built-in
1516 * directory handler). Several default handlers are available to
1517 * cover common cases -
1519 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1520 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1521 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1523 * It is the handler's job to read the input buffer from user memory
1524 * and process it. The handler should return 0 on success.
1526 * This routine returns %NULL on a failure to register, and a pointer
1527 * to the table header on success.
1529 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1531 struct ctl_table_header *tmp;
1532 tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1535 tmp->ctl_table = table;
1536 INIT_LIST_HEAD(&tmp->ctl_entry);
1538 tmp->unregistering = NULL;
1539 sysctl_set_parent(NULL, table);
1540 spin_lock(&sysctl_lock);
1541 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1542 spin_unlock(&sysctl_lock);
1547 * unregister_sysctl_table - unregister a sysctl table hierarchy
1548 * @header: the header returned from register_sysctl_table
1550 * Unregisters the sysctl table and all children. proc entries may not
1551 * actually be removed until they are no longer used by anyone.
1553 void unregister_sysctl_table(struct ctl_table_header * header)
1556 spin_lock(&sysctl_lock);
1557 start_unregistering(header);
1558 spin_unlock(&sysctl_lock);
1562 #else /* !CONFIG_SYSCTL */
1563 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1568 void unregister_sysctl_table(struct ctl_table_header * table)
1572 #endif /* CONFIG_SYSCTL */
1578 #ifdef CONFIG_PROC_SYSCTL
1580 static int _proc_do_string(void* data, int maxlen, int write,
1581 struct file *filp, void __user *buffer,
1582 size_t *lenp, loff_t *ppos)
1588 if (!data || !maxlen || !*lenp) {
1596 while (len < *lenp) {
1597 if (get_user(c, p++))
1599 if (c == 0 || c == '\n')
1605 if(copy_from_user(data, buffer, len))
1607 ((char *) data)[len] = 0;
1625 if(copy_to_user(buffer, data, len))
1628 if(put_user('\n', ((char __user *) buffer) + len))
1639 * proc_dostring - read a string sysctl
1640 * @table: the sysctl table
1641 * @write: %TRUE if this is a write to the sysctl file
1642 * @filp: the file structure
1643 * @buffer: the user buffer
1644 * @lenp: the size of the user buffer
1645 * @ppos: file position
1647 * Reads/writes a string from/to the user buffer. If the kernel
1648 * buffer provided is not large enough to hold the string, the
1649 * string is truncated. The copied string is %NULL-terminated.
1650 * If the string is being read by the user process, it is copied
1651 * and a newline '\n' is added. It is truncated if the buffer is
1654 * Returns 0 on success.
1656 int proc_dostring(ctl_table *table, int write, struct file *filp,
1657 void __user *buffer, size_t *lenp, loff_t *ppos)
1659 return _proc_do_string(table->data, table->maxlen, write, filp,
1660 buffer, lenp, ppos);
1664 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1666 int write, void *data)
1669 *valp = *negp ? -*lvalp : *lvalp;
1674 *lvalp = (unsigned long)-val;
1677 *lvalp = (unsigned long)val;
1683 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1684 int write, struct file *filp, void __user *buffer,
1685 size_t *lenp, loff_t *ppos,
1686 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1687 int write, void *data),
1690 #define TMPBUFLEN 21
1691 int *i, vleft, first=1, neg, val;
1695 char buf[TMPBUFLEN], *p;
1696 char __user *s = buffer;
1698 if (!tbl_data || !table->maxlen || !*lenp ||
1699 (*ppos && !write)) {
1704 i = (int *) tbl_data;
1705 vleft = table->maxlen / sizeof(*i);
1709 conv = do_proc_dointvec_conv;
1711 for (; left && vleft--; i++, first=0) {
1726 if (len > sizeof(buf) - 1)
1727 len = sizeof(buf) - 1;
1728 if (copy_from_user(buf, s, len))
1732 if (*p == '-' && left > 1) {
1736 if (*p < '0' || *p > '9')
1739 lval = simple_strtoul(p, &p, 0);
1742 if ((len < left) && *p && !isspace(*p))
1749 if (conv(&neg, &lval, i, 1, data))
1756 if (conv(&neg, &lval, i, 0, data))
1759 sprintf(p, "%s%lu", neg ? "-" : "", lval);
1763 if(copy_to_user(s, buf, len))
1770 if (!write && !first && left) {
1771 if(put_user('\n', s))
1778 if (get_user(c, s++))
1793 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1794 void __user *buffer, size_t *lenp, loff_t *ppos,
1795 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1796 int write, void *data),
1799 return __do_proc_dointvec(table->data, table, write, filp,
1800 buffer, lenp, ppos, conv, data);
1804 * proc_dointvec - read a vector of integers
1805 * @table: the sysctl table
1806 * @write: %TRUE if this is a write to the sysctl file
1807 * @filp: the file structure
1808 * @buffer: the user buffer
1809 * @lenp: the size of the user buffer
1810 * @ppos: file position
1812 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1813 * values from/to the user buffer, treated as an ASCII string.
1815 * Returns 0 on success.
1817 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1818 void __user *buffer, size_t *lenp, loff_t *ppos)
1820 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1828 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1830 int write, void *data)
1832 int op = *(int *)data;
1834 int val = *negp ? -*lvalp : *lvalp;
1836 case OP_SET: *valp = val; break;
1837 case OP_AND: *valp &= val; break;
1838 case OP_OR: *valp |= val; break;
1844 *lvalp = (unsigned long)-val;
1847 *lvalp = (unsigned long)val;
1854 * init may raise the set.
1857 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1858 void __user *buffer, size_t *lenp, loff_t *ppos)
1862 if (write && !capable(CAP_SYS_MODULE)) {
1866 op = is_init(current) ? OP_SET : OP_AND;
1867 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1868 do_proc_dointvec_bset_conv,&op);
1872 * Taint values can only be increased
1874 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1875 void __user *buffer, size_t *lenp, loff_t *ppos)
1879 if (write && !capable(CAP_SYS_ADMIN))
1883 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1884 do_proc_dointvec_bset_conv,&op);
1887 struct do_proc_dointvec_minmax_conv_param {
1892 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1894 int write, void *data)
1896 struct do_proc_dointvec_minmax_conv_param *param = data;
1898 int val = *negp ? -*lvalp : *lvalp;
1899 if ((param->min && *param->min > val) ||
1900 (param->max && *param->max < val))
1907 *lvalp = (unsigned long)-val;
1910 *lvalp = (unsigned long)val;
1917 * proc_dointvec_minmax - read a vector of integers with min/max values
1918 * @table: the sysctl table
1919 * @write: %TRUE if this is a write to the sysctl file
1920 * @filp: the file structure
1921 * @buffer: the user buffer
1922 * @lenp: the size of the user buffer
1923 * @ppos: file position
1925 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1926 * values from/to the user buffer, treated as an ASCII string.
1928 * This routine will ensure the values are within the range specified by
1929 * table->extra1 (min) and table->extra2 (max).
1931 * Returns 0 on success.
1933 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1934 void __user *buffer, size_t *lenp, loff_t *ppos)
1936 struct do_proc_dointvec_minmax_conv_param param = {
1937 .min = (int *) table->extra1,
1938 .max = (int *) table->extra2,
1940 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1941 do_proc_dointvec_minmax_conv, ¶m);
1944 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1946 void __user *buffer,
1947 size_t *lenp, loff_t *ppos,
1948 unsigned long convmul,
1949 unsigned long convdiv)
1951 #define TMPBUFLEN 21
1952 unsigned long *i, *min, *max, val;
1953 int vleft, first=1, neg;
1955 char buf[TMPBUFLEN], *p;
1956 char __user *s = buffer;
1958 if (!data || !table->maxlen || !*lenp ||
1959 (*ppos && !write)) {
1964 i = (unsigned long *) data;
1965 min = (unsigned long *) table->extra1;
1966 max = (unsigned long *) table->extra2;
1967 vleft = table->maxlen / sizeof(unsigned long);
1970 for (; left && vleft--; i++, min++, max++, first=0) {
1985 if (len > TMPBUFLEN-1)
1987 if (copy_from_user(buf, s, len))
1991 if (*p == '-' && left > 1) {
1995 if (*p < '0' || *p > '9')
1997 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1999 if ((len < left) && *p && !isspace(*p))
2008 if ((min && val < *min) || (max && val > *max))
2015 sprintf(p, "%lu", convdiv * (*i) / convmul);
2019 if(copy_to_user(s, buf, len))
2026 if (!write && !first && left) {
2027 if(put_user('\n', s))
2034 if (get_user(c, s++))
2049 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
2051 void __user *buffer,
2052 size_t *lenp, loff_t *ppos,
2053 unsigned long convmul,
2054 unsigned long convdiv)
2056 return __do_proc_doulongvec_minmax(table->data, table, write,
2057 filp, buffer, lenp, ppos, convmul, convdiv);
2061 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2062 * @table: the sysctl table
2063 * @write: %TRUE if this is a write to the sysctl file
2064 * @filp: the file structure
2065 * @buffer: the user buffer
2066 * @lenp: the size of the user buffer
2067 * @ppos: file position
2069 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2070 * values from/to the user buffer, treated as an ASCII string.
2072 * This routine will ensure the values are within the range specified by
2073 * table->extra1 (min) and table->extra2 (max).
2075 * Returns 0 on success.
2077 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2078 void __user *buffer, size_t *lenp, loff_t *ppos)
2080 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2084 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2085 * @table: the sysctl table
2086 * @write: %TRUE if this is a write to the sysctl file
2087 * @filp: the file structure
2088 * @buffer: the user buffer
2089 * @lenp: the size of the user buffer
2090 * @ppos: file position
2092 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2093 * values from/to the user buffer, treated as an ASCII string. The values
2094 * are treated as milliseconds, and converted to jiffies when they are stored.
2096 * This routine will ensure the values are within the range specified by
2097 * table->extra1 (min) and table->extra2 (max).
2099 * Returns 0 on success.
2101 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2103 void __user *buffer,
2104 size_t *lenp, loff_t *ppos)
2106 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2107 lenp, ppos, HZ, 1000l);
2111 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2113 int write, void *data)
2116 if (*lvalp > LONG_MAX / HZ)
2118 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2124 lval = (unsigned long)-val;
2127 lval = (unsigned long)val;
2134 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2136 int write, void *data)
2139 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2141 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2147 lval = (unsigned long)-val;
2150 lval = (unsigned long)val;
2152 *lvalp = jiffies_to_clock_t(lval);
2157 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2159 int write, void *data)
2162 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2168 lval = (unsigned long)-val;
2171 lval = (unsigned long)val;
2173 *lvalp = jiffies_to_msecs(lval);
2179 * proc_dointvec_jiffies - read a vector of integers as seconds
2180 * @table: the sysctl table
2181 * @write: %TRUE if this is a write to the sysctl file
2182 * @filp: the file structure
2183 * @buffer: the user buffer
2184 * @lenp: the size of the user buffer
2185 * @ppos: file position
2187 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2188 * values from/to the user buffer, treated as an ASCII string.
2189 * The values read are assumed to be in seconds, and are converted into
2192 * Returns 0 on success.
2194 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2195 void __user *buffer, size_t *lenp, loff_t *ppos)
2197 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2198 do_proc_dointvec_jiffies_conv,NULL);
2202 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2203 * @table: the sysctl table
2204 * @write: %TRUE if this is a write to the sysctl file
2205 * @filp: the file structure
2206 * @buffer: the user buffer
2207 * @lenp: the size of the user buffer
2208 * @ppos: pointer to the file position
2210 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2211 * values from/to the user buffer, treated as an ASCII string.
2212 * The values read are assumed to be in 1/USER_HZ seconds, and
2213 * are converted into jiffies.
2215 * Returns 0 on success.
2217 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2218 void __user *buffer, size_t *lenp, loff_t *ppos)
2220 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2221 do_proc_dointvec_userhz_jiffies_conv,NULL);
2225 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2226 * @table: the sysctl table
2227 * @write: %TRUE if this is a write to the sysctl file
2228 * @filp: the file structure
2229 * @buffer: the user buffer
2230 * @lenp: the size of the user buffer
2231 * @ppos: file position
2232 * @ppos: the current position in the file
2234 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2235 * values from/to the user buffer, treated as an ASCII string.
2236 * The values read are assumed to be in 1/1000 seconds, and
2237 * are converted into jiffies.
2239 * Returns 0 on success.
2241 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2242 void __user *buffer, size_t *lenp, loff_t *ppos)
2244 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2245 do_proc_dointvec_ms_jiffies_conv, NULL);
2248 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2249 void __user *buffer, size_t *lenp, loff_t *ppos)
2251 struct pid *new_pid;
2255 tmp = pid_nr(cad_pid);
2257 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2258 lenp, ppos, NULL, NULL);
2262 new_pid = find_get_pid(tmp);
2266 put_pid(xchg(&cad_pid, new_pid));
2270 #else /* CONFIG_PROC_FS */
2272 int proc_dostring(ctl_table *table, int write, struct file *filp,
2273 void __user *buffer, size_t *lenp, loff_t *ppos)
2278 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2279 void __user *buffer, size_t *lenp, loff_t *ppos)
2284 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2285 void __user *buffer, size_t *lenp, loff_t *ppos)
2290 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2291 void __user *buffer, size_t *lenp, loff_t *ppos)
2296 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2297 void __user *buffer, size_t *lenp, loff_t *ppos)
2302 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2303 void __user *buffer, size_t *lenp, loff_t *ppos)
2308 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2309 void __user *buffer, size_t *lenp, loff_t *ppos)
2314 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2315 void __user *buffer, size_t *lenp, loff_t *ppos)
2320 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2322 void __user *buffer,
2323 size_t *lenp, loff_t *ppos)
2329 #endif /* CONFIG_PROC_FS */
2332 #ifdef CONFIG_SYSCTL_SYSCALL
2334 * General sysctl support routines
2337 /* The generic string strategy routine: */
2338 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2339 void __user *oldval, size_t __user *oldlenp,
2340 void __user *newval, size_t newlen)
2342 if (!table->data || !table->maxlen)
2345 if (oldval && oldlenp) {
2347 if (get_user(bufsize, oldlenp))
2350 size_t len = strlen(table->data), copied;
2352 /* This shouldn't trigger for a well-formed sysctl */
2353 if (len > table->maxlen)
2354 len = table->maxlen;
2356 /* Copy up to a max of bufsize-1 bytes of the string */
2357 copied = (len >= bufsize) ? bufsize - 1 : len;
2359 if (copy_to_user(oldval, table->data, copied) ||
2360 put_user(0, (char __user *)(oldval + copied)))
2362 if (put_user(len, oldlenp))
2366 if (newval && newlen) {
2367 size_t len = newlen;
2368 if (len > table->maxlen)
2369 len = table->maxlen;
2370 if(copy_from_user(table->data, newval, len))
2372 if (len == table->maxlen)
2374 ((char *) table->data)[len] = 0;
2380 * This function makes sure that all of the integers in the vector
2381 * are between the minimum and maximum values given in the arrays
2382 * table->extra1 and table->extra2, respectively.
2384 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2385 void __user *oldval, size_t __user *oldlenp,
2386 void __user *newval, size_t newlen)
2389 if (newval && newlen) {
2390 int __user *vec = (int __user *) newval;
2391 int *min = (int *) table->extra1;
2392 int *max = (int *) table->extra2;
2396 if (newlen % sizeof(int) != 0)
2399 if (!table->extra1 && !table->extra2)
2402 if (newlen > table->maxlen)
2403 newlen = table->maxlen;
2404 length = newlen / sizeof(int);
2406 for (i = 0; i < length; i++) {
2408 if (get_user(value, vec + i))
2410 if (min && value < min[i])
2412 if (max && value > max[i])
2419 /* Strategy function to convert jiffies to seconds */
2420 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2421 void __user *oldval, size_t __user *oldlenp,
2422 void __user *newval, size_t newlen)
2424 if (oldval && oldlenp) {
2427 if (get_user(olen, oldlenp))
2432 if (olen < sizeof(int))
2435 val = *(int *)(table->data) / HZ;
2436 if (put_user(val, (int __user *)oldval))
2438 if (put_user(sizeof(int), oldlenp))
2442 if (newval && newlen) {
2444 if (newlen != sizeof(int))
2446 if (get_user(new, (int __user *)newval))
2448 *(int *)(table->data) = new*HZ;
2453 /* Strategy function to convert jiffies to seconds */
2454 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2455 void __user *oldval, size_t __user *oldlenp,
2456 void __user *newval, size_t newlen)
2458 if (oldval && oldlenp) {
2461 if (get_user(olen, oldlenp))
2466 if (olen < sizeof(int))
2469 val = jiffies_to_msecs(*(int *)(table->data));
2470 if (put_user(val, (int __user *)oldval))
2472 if (put_user(sizeof(int), oldlenp))
2476 if (newval && newlen) {
2478 if (newlen != sizeof(int))
2480 if (get_user(new, (int __user *)newval))
2482 *(int *)(table->data) = msecs_to_jiffies(new);
2489 #else /* CONFIG_SYSCTL_SYSCALL */
2492 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2494 static int msg_count;
2495 struct __sysctl_args tmp;
2496 int name[CTL_MAXNAME];
2499 /* Read in the sysctl name for better debug message logging */
2500 if (copy_from_user(&tmp, args, sizeof(tmp)))
2502 if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2504 for (i = 0; i < tmp.nlen; i++)
2505 if (get_user(name[i], tmp.name + i))
2508 /* Ignore accesses to kernel.version */
2509 if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2512 if (msg_count < 5) {
2515 "warning: process `%s' used the removed sysctl "
2516 "system call with ", current->comm);
2517 for (i = 0; i < tmp.nlen; i++)
2518 printk("%d.", name[i]);
2525 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2526 void __user *oldval, size_t __user *oldlenp,
2527 void __user *newval, size_t newlen)
2532 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2533 void __user *oldval, size_t __user *oldlenp,
2534 void __user *newval, size_t newlen)
2539 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2540 void __user *oldval, size_t __user *oldlenp,
2541 void __user *newval, size_t newlen)
2546 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2547 void __user *oldval, size_t __user *oldlenp,
2548 void __user *newval, size_t newlen)
2553 #endif /* CONFIG_SYSCTL_SYSCALL */
2556 * No sense putting this after each symbol definition, twice,
2557 * exception granted :-)
2559 EXPORT_SYMBOL(proc_dointvec);
2560 EXPORT_SYMBOL(proc_dointvec_jiffies);
2561 EXPORT_SYMBOL(proc_dointvec_minmax);
2562 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2563 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2564 EXPORT_SYMBOL(proc_dostring);
2565 EXPORT_SYMBOL(proc_doulongvec_minmax);
2566 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2567 EXPORT_SYMBOL(register_sysctl_table);
2568 EXPORT_SYMBOL(sysctl_intvec);
2569 EXPORT_SYMBOL(sysctl_jiffies);
2570 EXPORT_SYMBOL(sysctl_ms_jiffies);
2571 EXPORT_SYMBOL(sysctl_string);
2572 EXPORT_SYMBOL(unregister_sysctl_table);