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/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/security.h>
41 #include <linux/initrd.h>
42 #include <linux/times.h>
43 #include <linux/limits.h>
44 #include <linux/dcache.h>
45 #include <linux/syscalls.h>
46 #include <linux/nfs_fs.h>
47 #include <linux/acpi.h>
48 #include <linux/reboot.h>
50 #include <asm/uaccess.h>
51 #include <asm/processor.h>
55 #include <asm/stacktrace.h>
58 #if defined(CONFIG_SYSCTL)
60 /* External variables not in a header file. */
62 extern int print_fatal_signals;
63 extern int sysctl_overcommit_memory;
64 extern int sysctl_overcommit_ratio;
65 extern int sysctl_panic_on_oom;
66 extern int max_threads;
67 extern int core_uses_pid;
68 extern int suid_dumpable;
69 extern char core_pattern[];
71 extern int min_free_kbytes;
72 extern int printk_ratelimit_jiffies;
73 extern int printk_ratelimit_burst;
74 extern int pid_max_min, pid_max_max;
75 extern int sysctl_drop_caches;
76 extern int percpu_pagelist_fraction;
77 extern int compat_log;
78 extern int maps_protect;
79 extern int sysctl_stat_interval;
80 extern int audit_argv_kb;
82 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
83 static int maxolduid = 65535;
85 static int min_percpu_pagelist_fract = 8;
87 static int ngroups_max = NGROUPS_MAX;
90 extern char modprobe_path[];
92 #ifdef CONFIG_CHR_DEV_SG
93 extern int sg_big_buff;
97 extern char reboot_command [];
98 extern int stop_a_enabled;
99 extern int scons_pwroff;
103 extern int pwrsw_enabled;
104 extern int unaligned_enabled;
108 #ifdef CONFIG_MATHEMU
109 extern int sysctl_ieee_emulation_warnings;
111 extern int sysctl_userprocess_debug;
112 extern int spin_retry;
115 extern int sysctl_hz_timer;
117 #ifdef CONFIG_BSD_PROCESS_ACCT
118 extern int acct_parm[];
122 extern int no_unaligned_warning;
125 #ifdef CONFIG_RT_MUTEXES
126 extern int max_lock_depth;
129 #ifdef CONFIG_SYSCTL_SYSCALL
130 static int parse_table(int __user *, int, void __user *, size_t __user *,
131 void __user *, size_t, ctl_table *);
135 #ifdef CONFIG_PROC_SYSCTL
136 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
137 void __user *buffer, size_t *lenp, loff_t *ppos);
138 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
139 void __user *buffer, size_t *lenp, loff_t *ppos);
142 static ctl_table root_table[];
143 static struct ctl_table_header root_table_header =
144 { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
146 static ctl_table kern_table[];
147 static ctl_table vm_table[];
148 static ctl_table fs_table[];
149 static ctl_table debug_table[];
150 static ctl_table dev_table[];
151 extern ctl_table random_table[];
152 #ifdef CONFIG_UNIX98_PTYS
153 extern ctl_table pty_table[];
155 #ifdef CONFIG_INOTIFY_USER
156 extern ctl_table inotify_table[];
159 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
160 int sysctl_legacy_va_layout;
163 extern int prove_locking;
164 extern int lock_stat;
166 /* The default sysctl tables: */
168 static ctl_table root_table[] = {
170 .ctl_name = CTL_KERN,
171 .procname = "kernel",
196 .ctl_name = CTL_DEBUG,
199 .child = debug_table,
208 * NOTE: do not add new entries to this table unless you have read
209 * Documentation/sysctl/ctl_unnumbered.txt
214 #ifdef CONFIG_SCHED_DEBUG
215 static unsigned long min_sched_granularity_ns = 100000; /* 100 usecs */
216 static unsigned long max_sched_granularity_ns = 1000000000; /* 1 second */
217 static unsigned long min_wakeup_granularity_ns; /* 0 usecs */
218 static unsigned long max_wakeup_granularity_ns = 1000000000; /* 1 second */
221 static ctl_table kern_table[] = {
222 #ifdef CONFIG_SCHED_DEBUG
224 .ctl_name = CTL_UNNUMBERED,
225 .procname = "sched_nr_latency",
226 .data = &sysctl_sched_nr_latency,
227 .maxlen = sizeof(unsigned int),
229 .proc_handler = &proc_dointvec,
232 .ctl_name = CTL_UNNUMBERED,
233 .procname = "sched_latency_ns",
234 .data = &sysctl_sched_latency,
235 .maxlen = sizeof(unsigned int),
237 .proc_handler = &proc_dointvec_minmax,
238 .strategy = &sysctl_intvec,
239 .extra1 = &min_sched_granularity_ns,
240 .extra2 = &max_sched_granularity_ns,
243 .ctl_name = CTL_UNNUMBERED,
244 .procname = "sched_wakeup_granularity_ns",
245 .data = &sysctl_sched_wakeup_granularity,
246 .maxlen = sizeof(unsigned int),
248 .proc_handler = &proc_dointvec_minmax,
249 .strategy = &sysctl_intvec,
250 .extra1 = &min_wakeup_granularity_ns,
251 .extra2 = &max_wakeup_granularity_ns,
254 .ctl_name = CTL_UNNUMBERED,
255 .procname = "sched_batch_wakeup_granularity_ns",
256 .data = &sysctl_sched_batch_wakeup_granularity,
257 .maxlen = sizeof(unsigned int),
259 .proc_handler = &proc_dointvec_minmax,
260 .strategy = &sysctl_intvec,
261 .extra1 = &min_wakeup_granularity_ns,
262 .extra2 = &max_wakeup_granularity_ns,
265 .ctl_name = CTL_UNNUMBERED,
266 .procname = "sched_child_runs_first",
267 .data = &sysctl_sched_child_runs_first,
268 .maxlen = sizeof(unsigned int),
270 .proc_handler = &proc_dointvec,
273 .ctl_name = CTL_UNNUMBERED,
274 .procname = "sched_features",
275 .data = &sysctl_sched_features,
276 .maxlen = sizeof(unsigned int),
278 .proc_handler = &proc_dointvec,
282 .ctl_name = CTL_UNNUMBERED,
283 .procname = "sched_compat_yield",
284 .data = &sysctl_sched_compat_yield,
285 .maxlen = sizeof(unsigned int),
287 .proc_handler = &proc_dointvec,
289 #ifdef CONFIG_PROVE_LOCKING
291 .ctl_name = CTL_UNNUMBERED,
292 .procname = "prove_locking",
293 .data = &prove_locking,
294 .maxlen = sizeof(int),
296 .proc_handler = &proc_dointvec,
299 #ifdef CONFIG_LOCK_STAT
301 .ctl_name = CTL_UNNUMBERED,
302 .procname = "lock_stat",
304 .maxlen = sizeof(int),
306 .proc_handler = &proc_dointvec,
310 .ctl_name = KERN_PANIC,
312 .data = &panic_timeout,
313 .maxlen = sizeof(int),
315 .proc_handler = &proc_dointvec,
318 .ctl_name = KERN_CORE_USES_PID,
319 .procname = "core_uses_pid",
320 .data = &core_uses_pid,
321 .maxlen = sizeof(int),
323 .proc_handler = &proc_dointvec,
325 #ifdef CONFIG_AUDITSYSCALL
327 .ctl_name = CTL_UNNUMBERED,
328 .procname = "audit_argv_kb",
329 .data = &audit_argv_kb,
330 .maxlen = sizeof(int),
332 .proc_handler = &proc_dointvec,
336 .ctl_name = KERN_CORE_PATTERN,
337 .procname = "core_pattern",
338 .data = core_pattern,
339 .maxlen = CORENAME_MAX_SIZE,
341 .proc_handler = &proc_dostring,
342 .strategy = &sysctl_string,
344 #ifdef CONFIG_PROC_SYSCTL
346 .ctl_name = KERN_TAINTED,
347 .procname = "tainted",
349 .maxlen = sizeof(int),
351 .proc_handler = &proc_dointvec_taint,
355 .ctl_name = KERN_CAP_BSET,
356 .procname = "cap-bound",
358 .maxlen = sizeof(kernel_cap_t),
360 .proc_handler = &proc_dointvec_bset,
362 #ifdef CONFIG_BLK_DEV_INITRD
364 .ctl_name = KERN_REALROOTDEV,
365 .procname = "real-root-dev",
366 .data = &real_root_dev,
367 .maxlen = sizeof(int),
369 .proc_handler = &proc_dointvec,
373 .ctl_name = CTL_UNNUMBERED,
374 .procname = "print-fatal-signals",
375 .data = &print_fatal_signals,
376 .maxlen = sizeof(int),
378 .proc_handler = &proc_dointvec,
382 .ctl_name = KERN_SPARC_REBOOT,
383 .procname = "reboot-cmd",
384 .data = reboot_command,
387 .proc_handler = &proc_dostring,
388 .strategy = &sysctl_string,
391 .ctl_name = KERN_SPARC_STOP_A,
392 .procname = "stop-a",
393 .data = &stop_a_enabled,
394 .maxlen = sizeof (int),
396 .proc_handler = &proc_dointvec,
399 .ctl_name = KERN_SPARC_SCONS_PWROFF,
400 .procname = "scons-poweroff",
401 .data = &scons_pwroff,
402 .maxlen = sizeof (int),
404 .proc_handler = &proc_dointvec,
409 .ctl_name = KERN_HPPA_PWRSW,
410 .procname = "soft-power",
411 .data = &pwrsw_enabled,
412 .maxlen = sizeof (int),
414 .proc_handler = &proc_dointvec,
417 .ctl_name = KERN_HPPA_UNALIGNED,
418 .procname = "unaligned-trap",
419 .data = &unaligned_enabled,
420 .maxlen = sizeof (int),
422 .proc_handler = &proc_dointvec,
426 .ctl_name = KERN_CTLALTDEL,
427 .procname = "ctrl-alt-del",
429 .maxlen = sizeof(int),
431 .proc_handler = &proc_dointvec,
434 .ctl_name = KERN_PRINTK,
435 .procname = "printk",
436 .data = &console_loglevel,
437 .maxlen = 4*sizeof(int),
439 .proc_handler = &proc_dointvec,
443 .ctl_name = KERN_MODPROBE,
444 .procname = "modprobe",
445 .data = &modprobe_path,
446 .maxlen = KMOD_PATH_LEN,
448 .proc_handler = &proc_dostring,
449 .strategy = &sysctl_string,
452 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
454 .ctl_name = KERN_HOTPLUG,
455 .procname = "hotplug",
456 .data = &uevent_helper,
457 .maxlen = UEVENT_HELPER_PATH_LEN,
459 .proc_handler = &proc_dostring,
460 .strategy = &sysctl_string,
463 #ifdef CONFIG_CHR_DEV_SG
465 .ctl_name = KERN_SG_BIG_BUFF,
466 .procname = "sg-big-buff",
467 .data = &sg_big_buff,
468 .maxlen = sizeof (int),
470 .proc_handler = &proc_dointvec,
473 #ifdef CONFIG_BSD_PROCESS_ACCT
475 .ctl_name = KERN_ACCT,
478 .maxlen = 3*sizeof(int),
480 .proc_handler = &proc_dointvec,
483 #ifdef CONFIG_MAGIC_SYSRQ
485 .ctl_name = KERN_SYSRQ,
487 .data = &__sysrq_enabled,
488 .maxlen = sizeof (int),
490 .proc_handler = &proc_dointvec,
493 #ifdef CONFIG_PROC_SYSCTL
495 .ctl_name = KERN_CADPID,
496 .procname = "cad_pid",
498 .maxlen = sizeof (int),
500 .proc_handler = &proc_do_cad_pid,
504 .ctl_name = KERN_MAX_THREADS,
505 .procname = "threads-max",
506 .data = &max_threads,
507 .maxlen = sizeof(int),
509 .proc_handler = &proc_dointvec,
512 .ctl_name = KERN_RANDOM,
513 .procname = "random",
515 .child = random_table,
517 #ifdef CONFIG_UNIX98_PTYS
519 .ctl_name = KERN_PTY,
526 .ctl_name = KERN_OVERFLOWUID,
527 .procname = "overflowuid",
528 .data = &overflowuid,
529 .maxlen = sizeof(int),
531 .proc_handler = &proc_dointvec_minmax,
532 .strategy = &sysctl_intvec,
533 .extra1 = &minolduid,
534 .extra2 = &maxolduid,
537 .ctl_name = KERN_OVERFLOWGID,
538 .procname = "overflowgid",
539 .data = &overflowgid,
540 .maxlen = sizeof(int),
542 .proc_handler = &proc_dointvec_minmax,
543 .strategy = &sysctl_intvec,
544 .extra1 = &minolduid,
545 .extra2 = &maxolduid,
548 #ifdef CONFIG_MATHEMU
550 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
551 .procname = "ieee_emulation_warnings",
552 .data = &sysctl_ieee_emulation_warnings,
553 .maxlen = sizeof(int),
555 .proc_handler = &proc_dointvec,
558 #ifdef CONFIG_NO_IDLE_HZ
560 .ctl_name = KERN_HZ_TIMER,
561 .procname = "hz_timer",
562 .data = &sysctl_hz_timer,
563 .maxlen = sizeof(int),
565 .proc_handler = &proc_dointvec,
569 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
570 .procname = "userprocess_debug",
571 .data = &sysctl_userprocess_debug,
572 .maxlen = sizeof(int),
574 .proc_handler = &proc_dointvec,
578 .ctl_name = KERN_PIDMAX,
579 .procname = "pid_max",
581 .maxlen = sizeof (int),
583 .proc_handler = &proc_dointvec_minmax,
584 .strategy = sysctl_intvec,
585 .extra1 = &pid_max_min,
586 .extra2 = &pid_max_max,
589 .ctl_name = KERN_PANIC_ON_OOPS,
590 .procname = "panic_on_oops",
591 .data = &panic_on_oops,
592 .maxlen = sizeof(int),
594 .proc_handler = &proc_dointvec,
597 .ctl_name = KERN_PRINTK_RATELIMIT,
598 .procname = "printk_ratelimit",
599 .data = &printk_ratelimit_jiffies,
600 .maxlen = sizeof(int),
602 .proc_handler = &proc_dointvec_jiffies,
603 .strategy = &sysctl_jiffies,
606 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
607 .procname = "printk_ratelimit_burst",
608 .data = &printk_ratelimit_burst,
609 .maxlen = sizeof(int),
611 .proc_handler = &proc_dointvec,
614 .ctl_name = KERN_NGROUPS_MAX,
615 .procname = "ngroups_max",
616 .data = &ngroups_max,
617 .maxlen = sizeof (int),
619 .proc_handler = &proc_dointvec,
621 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
623 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
624 .procname = "unknown_nmi_panic",
625 .data = &unknown_nmi_panic,
626 .maxlen = sizeof (int),
628 .proc_handler = &proc_dointvec,
631 .ctl_name = KERN_NMI_WATCHDOG,
632 .procname = "nmi_watchdog",
633 .data = &nmi_watchdog_enabled,
634 .maxlen = sizeof (int),
636 .proc_handler = &proc_nmi_enabled,
639 #if defined(CONFIG_X86)
641 .ctl_name = KERN_PANIC_ON_NMI,
642 .procname = "panic_on_unrecovered_nmi",
643 .data = &panic_on_unrecovered_nmi,
644 .maxlen = sizeof(int),
646 .proc_handler = &proc_dointvec,
649 .ctl_name = KERN_BOOTLOADER_TYPE,
650 .procname = "bootloader_type",
651 .data = &bootloader_type,
652 .maxlen = sizeof (int),
654 .proc_handler = &proc_dointvec,
657 .ctl_name = CTL_UNNUMBERED,
658 .procname = "kstack_depth_to_print",
659 .data = &kstack_depth_to_print,
660 .maxlen = sizeof(int),
662 .proc_handler = &proc_dointvec,
665 #if defined(CONFIG_MMU)
667 .ctl_name = KERN_RANDOMIZE,
668 .procname = "randomize_va_space",
669 .data = &randomize_va_space,
670 .maxlen = sizeof(int),
672 .proc_handler = &proc_dointvec,
675 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
677 .ctl_name = KERN_SPIN_RETRY,
678 .procname = "spin_retry",
680 .maxlen = sizeof (int),
682 .proc_handler = &proc_dointvec,
685 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
687 .ctl_name = KERN_ACPI_VIDEO_FLAGS,
688 .procname = "acpi_video_flags",
689 .data = &acpi_realmode_flags,
690 .maxlen = sizeof (unsigned long),
692 .proc_handler = &proc_doulongvec_minmax,
697 .ctl_name = KERN_IA64_UNALIGNED,
698 .procname = "ignore-unaligned-usertrap",
699 .data = &no_unaligned_warning,
700 .maxlen = sizeof (int),
702 .proc_handler = &proc_dointvec,
707 .ctl_name = KERN_COMPAT_LOG,
708 .procname = "compat-log",
710 .maxlen = sizeof (int),
712 .proc_handler = &proc_dointvec,
715 #ifdef CONFIG_RT_MUTEXES
717 .ctl_name = KERN_MAX_LOCK_DEPTH,
718 .procname = "max_lock_depth",
719 .data = &max_lock_depth,
720 .maxlen = sizeof(int),
722 .proc_handler = &proc_dointvec,
725 #ifdef CONFIG_PROC_FS
727 .ctl_name = CTL_UNNUMBERED,
728 .procname = "maps_protect",
729 .data = &maps_protect,
730 .maxlen = sizeof(int),
732 .proc_handler = &proc_dointvec,
736 .ctl_name = CTL_UNNUMBERED,
737 .procname = "poweroff_cmd",
738 .data = &poweroff_cmd,
739 .maxlen = POWEROFF_CMD_PATH_LEN,
741 .proc_handler = &proc_dostring,
742 .strategy = &sysctl_string,
745 * NOTE: do not add new entries to this table unless you have read
746 * Documentation/sysctl/ctl_unnumbered.txt
751 /* Constants for minimum and maximum testing in vm_table.
752 We use these as one-element integer vectors. */
755 static int one_hundred = 100;
758 static ctl_table vm_table[] = {
760 .ctl_name = VM_OVERCOMMIT_MEMORY,
761 .procname = "overcommit_memory",
762 .data = &sysctl_overcommit_memory,
763 .maxlen = sizeof(sysctl_overcommit_memory),
765 .proc_handler = &proc_dointvec,
768 .ctl_name = VM_PANIC_ON_OOM,
769 .procname = "panic_on_oom",
770 .data = &sysctl_panic_on_oom,
771 .maxlen = sizeof(sysctl_panic_on_oom),
773 .proc_handler = &proc_dointvec,
776 .ctl_name = VM_OVERCOMMIT_RATIO,
777 .procname = "overcommit_ratio",
778 .data = &sysctl_overcommit_ratio,
779 .maxlen = sizeof(sysctl_overcommit_ratio),
781 .proc_handler = &proc_dointvec,
784 .ctl_name = VM_PAGE_CLUSTER,
785 .procname = "page-cluster",
786 .data = &page_cluster,
787 .maxlen = sizeof(int),
789 .proc_handler = &proc_dointvec,
792 .ctl_name = VM_DIRTY_BACKGROUND,
793 .procname = "dirty_background_ratio",
794 .data = &dirty_background_ratio,
795 .maxlen = sizeof(dirty_background_ratio),
797 .proc_handler = &proc_dointvec_minmax,
798 .strategy = &sysctl_intvec,
800 .extra2 = &one_hundred,
803 .ctl_name = VM_DIRTY_RATIO,
804 .procname = "dirty_ratio",
805 .data = &vm_dirty_ratio,
806 .maxlen = sizeof(vm_dirty_ratio),
808 .proc_handler = &proc_dointvec_minmax,
809 .strategy = &sysctl_intvec,
811 .extra2 = &one_hundred,
814 .ctl_name = VM_DIRTY_WB_CS,
815 .procname = "dirty_writeback_centisecs",
816 .data = &dirty_writeback_interval,
817 .maxlen = sizeof(dirty_writeback_interval),
819 .proc_handler = &dirty_writeback_centisecs_handler,
822 .ctl_name = VM_DIRTY_EXPIRE_CS,
823 .procname = "dirty_expire_centisecs",
824 .data = &dirty_expire_interval,
825 .maxlen = sizeof(dirty_expire_interval),
827 .proc_handler = &proc_dointvec_userhz_jiffies,
830 .ctl_name = VM_NR_PDFLUSH_THREADS,
831 .procname = "nr_pdflush_threads",
832 .data = &nr_pdflush_threads,
833 .maxlen = sizeof nr_pdflush_threads,
834 .mode = 0444 /* read-only*/,
835 .proc_handler = &proc_dointvec,
838 .ctl_name = VM_SWAPPINESS,
839 .procname = "swappiness",
840 .data = &vm_swappiness,
841 .maxlen = sizeof(vm_swappiness),
843 .proc_handler = &proc_dointvec_minmax,
844 .strategy = &sysctl_intvec,
846 .extra2 = &one_hundred,
848 #ifdef CONFIG_HUGETLB_PAGE
850 .ctl_name = VM_HUGETLB_PAGES,
851 .procname = "nr_hugepages",
852 .data = &max_huge_pages,
853 .maxlen = sizeof(unsigned long),
855 .proc_handler = &hugetlb_sysctl_handler,
856 .extra1 = (void *)&hugetlb_zero,
857 .extra2 = (void *)&hugetlb_infinity,
860 .ctl_name = VM_HUGETLB_GROUP,
861 .procname = "hugetlb_shm_group",
862 .data = &sysctl_hugetlb_shm_group,
863 .maxlen = sizeof(gid_t),
865 .proc_handler = &proc_dointvec,
868 .ctl_name = CTL_UNNUMBERED,
869 .procname = "hugepages_treat_as_movable",
870 .data = &hugepages_treat_as_movable,
871 .maxlen = sizeof(int),
873 .proc_handler = &hugetlb_treat_movable_handler,
877 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
878 .procname = "lowmem_reserve_ratio",
879 .data = &sysctl_lowmem_reserve_ratio,
880 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
882 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
883 .strategy = &sysctl_intvec,
886 .ctl_name = VM_DROP_PAGECACHE,
887 .procname = "drop_caches",
888 .data = &sysctl_drop_caches,
889 .maxlen = sizeof(int),
891 .proc_handler = drop_caches_sysctl_handler,
892 .strategy = &sysctl_intvec,
895 .ctl_name = VM_MIN_FREE_KBYTES,
896 .procname = "min_free_kbytes",
897 .data = &min_free_kbytes,
898 .maxlen = sizeof(min_free_kbytes),
900 .proc_handler = &min_free_kbytes_sysctl_handler,
901 .strategy = &sysctl_intvec,
905 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
906 .procname = "percpu_pagelist_fraction",
907 .data = &percpu_pagelist_fraction,
908 .maxlen = sizeof(percpu_pagelist_fraction),
910 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
911 .strategy = &sysctl_intvec,
912 .extra1 = &min_percpu_pagelist_fract,
916 .ctl_name = VM_MAX_MAP_COUNT,
917 .procname = "max_map_count",
918 .data = &sysctl_max_map_count,
919 .maxlen = sizeof(sysctl_max_map_count),
921 .proc_handler = &proc_dointvec
925 .ctl_name = VM_LAPTOP_MODE,
926 .procname = "laptop_mode",
927 .data = &laptop_mode,
928 .maxlen = sizeof(laptop_mode),
930 .proc_handler = &proc_dointvec_jiffies,
931 .strategy = &sysctl_jiffies,
934 .ctl_name = VM_BLOCK_DUMP,
935 .procname = "block_dump",
937 .maxlen = sizeof(block_dump),
939 .proc_handler = &proc_dointvec,
940 .strategy = &sysctl_intvec,
944 .ctl_name = VM_VFS_CACHE_PRESSURE,
945 .procname = "vfs_cache_pressure",
946 .data = &sysctl_vfs_cache_pressure,
947 .maxlen = sizeof(sysctl_vfs_cache_pressure),
949 .proc_handler = &proc_dointvec,
950 .strategy = &sysctl_intvec,
953 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
955 .ctl_name = VM_LEGACY_VA_LAYOUT,
956 .procname = "legacy_va_layout",
957 .data = &sysctl_legacy_va_layout,
958 .maxlen = sizeof(sysctl_legacy_va_layout),
960 .proc_handler = &proc_dointvec,
961 .strategy = &sysctl_intvec,
967 .ctl_name = VM_ZONE_RECLAIM_MODE,
968 .procname = "zone_reclaim_mode",
969 .data = &zone_reclaim_mode,
970 .maxlen = sizeof(zone_reclaim_mode),
972 .proc_handler = &proc_dointvec,
973 .strategy = &sysctl_intvec,
977 .ctl_name = VM_MIN_UNMAPPED,
978 .procname = "min_unmapped_ratio",
979 .data = &sysctl_min_unmapped_ratio,
980 .maxlen = sizeof(sysctl_min_unmapped_ratio),
982 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
983 .strategy = &sysctl_intvec,
985 .extra2 = &one_hundred,
988 .ctl_name = VM_MIN_SLAB,
989 .procname = "min_slab_ratio",
990 .data = &sysctl_min_slab_ratio,
991 .maxlen = sizeof(sysctl_min_slab_ratio),
993 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
994 .strategy = &sysctl_intvec,
996 .extra2 = &one_hundred,
1001 .ctl_name = CTL_UNNUMBERED,
1002 .procname = "stat_interval",
1003 .data = &sysctl_stat_interval,
1004 .maxlen = sizeof(sysctl_stat_interval),
1006 .proc_handler = &proc_dointvec_jiffies,
1007 .strategy = &sysctl_jiffies,
1010 #ifdef CONFIG_SECURITY
1012 .ctl_name = CTL_UNNUMBERED,
1013 .procname = "mmap_min_addr",
1014 .data = &mmap_min_addr,
1015 .maxlen = sizeof(unsigned long),
1017 .proc_handler = &proc_doulongvec_minmax,
1022 .ctl_name = CTL_UNNUMBERED,
1023 .procname = "numa_zonelist_order",
1024 .data = &numa_zonelist_order,
1025 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1027 .proc_handler = &numa_zonelist_order_handler,
1028 .strategy = &sysctl_string,
1031 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1032 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1034 .ctl_name = VM_VDSO_ENABLED,
1035 .procname = "vdso_enabled",
1036 .data = &vdso_enabled,
1037 .maxlen = sizeof(vdso_enabled),
1039 .proc_handler = &proc_dointvec,
1040 .strategy = &sysctl_intvec,
1045 * NOTE: do not add new entries to this table unless you have read
1046 * Documentation/sysctl/ctl_unnumbered.txt
1051 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1052 static ctl_table binfmt_misc_table[] = {
1057 static ctl_table fs_table[] = {
1059 .ctl_name = FS_NRINODE,
1060 .procname = "inode-nr",
1061 .data = &inodes_stat,
1062 .maxlen = 2*sizeof(int),
1064 .proc_handler = &proc_dointvec,
1067 .ctl_name = FS_STATINODE,
1068 .procname = "inode-state",
1069 .data = &inodes_stat,
1070 .maxlen = 7*sizeof(int),
1072 .proc_handler = &proc_dointvec,
1075 .ctl_name = FS_NRFILE,
1076 .procname = "file-nr",
1077 .data = &files_stat,
1078 .maxlen = 3*sizeof(int),
1080 .proc_handler = &proc_nr_files,
1083 .ctl_name = FS_MAXFILE,
1084 .procname = "file-max",
1085 .data = &files_stat.max_files,
1086 .maxlen = sizeof(int),
1088 .proc_handler = &proc_dointvec,
1091 .ctl_name = FS_DENTRY,
1092 .procname = "dentry-state",
1093 .data = &dentry_stat,
1094 .maxlen = 6*sizeof(int),
1096 .proc_handler = &proc_dointvec,
1099 .ctl_name = FS_OVERFLOWUID,
1100 .procname = "overflowuid",
1101 .data = &fs_overflowuid,
1102 .maxlen = sizeof(int),
1104 .proc_handler = &proc_dointvec_minmax,
1105 .strategy = &sysctl_intvec,
1106 .extra1 = &minolduid,
1107 .extra2 = &maxolduid,
1110 .ctl_name = FS_OVERFLOWGID,
1111 .procname = "overflowgid",
1112 .data = &fs_overflowgid,
1113 .maxlen = sizeof(int),
1115 .proc_handler = &proc_dointvec_minmax,
1116 .strategy = &sysctl_intvec,
1117 .extra1 = &minolduid,
1118 .extra2 = &maxolduid,
1121 .ctl_name = FS_LEASES,
1122 .procname = "leases-enable",
1123 .data = &leases_enable,
1124 .maxlen = sizeof(int),
1126 .proc_handler = &proc_dointvec,
1128 #ifdef CONFIG_DNOTIFY
1130 .ctl_name = FS_DIR_NOTIFY,
1131 .procname = "dir-notify-enable",
1132 .data = &dir_notify_enable,
1133 .maxlen = sizeof(int),
1135 .proc_handler = &proc_dointvec,
1140 .ctl_name = FS_LEASE_TIME,
1141 .procname = "lease-break-time",
1142 .data = &lease_break_time,
1143 .maxlen = sizeof(int),
1145 .proc_handler = &proc_dointvec_minmax,
1146 .strategy = &sysctl_intvec,
1151 .ctl_name = FS_AIO_NR,
1152 .procname = "aio-nr",
1154 .maxlen = sizeof(aio_nr),
1156 .proc_handler = &proc_doulongvec_minmax,
1159 .ctl_name = FS_AIO_MAX_NR,
1160 .procname = "aio-max-nr",
1161 .data = &aio_max_nr,
1162 .maxlen = sizeof(aio_max_nr),
1164 .proc_handler = &proc_doulongvec_minmax,
1166 #ifdef CONFIG_INOTIFY_USER
1168 .ctl_name = FS_INOTIFY,
1169 .procname = "inotify",
1171 .child = inotify_table,
1176 .ctl_name = KERN_SETUID_DUMPABLE,
1177 .procname = "suid_dumpable",
1178 .data = &suid_dumpable,
1179 .maxlen = sizeof(int),
1181 .proc_handler = &proc_dointvec,
1183 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1185 .ctl_name = CTL_UNNUMBERED,
1186 .procname = "binfmt_misc",
1188 .child = binfmt_misc_table,
1192 * NOTE: do not add new entries to this table unless you have read
1193 * Documentation/sysctl/ctl_unnumbered.txt
1198 static ctl_table debug_table[] = {
1199 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1201 .ctl_name = CTL_UNNUMBERED,
1202 .procname = "exception-trace",
1203 .data = &show_unhandled_signals,
1204 .maxlen = sizeof(int),
1206 .proc_handler = proc_dointvec
1212 static ctl_table dev_table[] = {
1216 static DEFINE_SPINLOCK(sysctl_lock);
1218 /* called under sysctl_lock */
1219 static int use_table(struct ctl_table_header *p)
1221 if (unlikely(p->unregistering))
1227 /* called under sysctl_lock */
1228 static void unuse_table(struct ctl_table_header *p)
1231 if (unlikely(p->unregistering))
1232 complete(p->unregistering);
1235 /* called under sysctl_lock, will reacquire if has to wait */
1236 static void start_unregistering(struct ctl_table_header *p)
1239 * if p->used is 0, nobody will ever touch that entry again;
1240 * we'll eliminate all paths to it before dropping sysctl_lock
1242 if (unlikely(p->used)) {
1243 struct completion wait;
1244 init_completion(&wait);
1245 p->unregistering = &wait;
1246 spin_unlock(&sysctl_lock);
1247 wait_for_completion(&wait);
1248 spin_lock(&sysctl_lock);
1251 * do not remove from the list until nobody holds it; walking the
1252 * list in do_sysctl() relies on that.
1254 list_del_init(&p->ctl_entry);
1257 void sysctl_head_finish(struct ctl_table_header *head)
1261 spin_lock(&sysctl_lock);
1263 spin_unlock(&sysctl_lock);
1266 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1268 struct ctl_table_header *head;
1269 struct list_head *tmp;
1270 spin_lock(&sysctl_lock);
1272 tmp = &prev->ctl_entry;
1276 tmp = &root_table_header.ctl_entry;
1278 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1280 if (!use_table(head))
1282 spin_unlock(&sysctl_lock);
1286 if (tmp == &root_table_header.ctl_entry)
1289 spin_unlock(&sysctl_lock);
1293 #ifdef CONFIG_SYSCTL_SYSCALL
1294 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1295 void __user *newval, size_t newlen)
1297 struct ctl_table_header *head;
1298 int error = -ENOTDIR;
1300 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1304 if (!oldlenp || get_user(old_len, oldlenp))
1308 for (head = sysctl_head_next(NULL); head;
1309 head = sysctl_head_next(head)) {
1310 error = parse_table(name, nlen, oldval, oldlenp,
1311 newval, newlen, head->ctl_table);
1312 if (error != -ENOTDIR) {
1313 sysctl_head_finish(head);
1320 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1322 struct __sysctl_args tmp;
1325 if (copy_from_user(&tmp, args, sizeof(tmp)))
1329 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1330 tmp.newval, tmp.newlen);
1334 #endif /* CONFIG_SYSCTL_SYSCALL */
1337 * sysctl_perm does NOT grant the superuser all rights automatically, because
1338 * some sysctl variables are readonly even to root.
1341 static int test_perm(int mode, int op)
1345 else if (in_egroup_p(0))
1347 if ((mode & op & 0007) == op)
1352 int sysctl_perm(ctl_table *table, int op)
1355 error = security_sysctl(table, op);
1358 return test_perm(table->mode, op);
1361 #ifdef CONFIG_SYSCTL_SYSCALL
1362 static int parse_table(int __user *name, int nlen,
1363 void __user *oldval, size_t __user *oldlenp,
1364 void __user *newval, size_t newlen,
1371 if (get_user(n, name))
1373 for ( ; table->ctl_name || table->procname; table++) {
1374 if (!table->ctl_name)
1376 if (n == table->ctl_name) {
1379 if (sysctl_perm(table, 001))
1383 table = table->child;
1386 error = do_sysctl_strategy(table, name, nlen,
1395 /* Perform the actual read/write of a sysctl table entry. */
1396 int do_sysctl_strategy (ctl_table *table,
1397 int __user *name, int nlen,
1398 void __user *oldval, size_t __user *oldlenp,
1399 void __user *newval, size_t newlen)
1408 if (sysctl_perm(table, op))
1411 if (table->strategy) {
1412 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1420 /* If there is no strategy routine, or if the strategy returns
1421 * zero, proceed with automatic r/w */
1422 if (table->data && table->maxlen) {
1423 if (oldval && oldlenp) {
1424 if (get_user(len, oldlenp))
1427 if (len > table->maxlen)
1428 len = table->maxlen;
1429 if(copy_to_user(oldval, table->data, len))
1431 if(put_user(len, oldlenp))
1435 if (newval && newlen) {
1437 if (len > table->maxlen)
1438 len = table->maxlen;
1439 if(copy_from_user(table->data, newval, len))
1445 #endif /* CONFIG_SYSCTL_SYSCALL */
1447 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1449 for (; table->ctl_name || table->procname; table++) {
1450 table->parent = parent;
1452 sysctl_set_parent(table, table->child);
1456 static __init int sysctl_init(void)
1458 sysctl_set_parent(NULL, root_table);
1462 core_initcall(sysctl_init);
1465 * register_sysctl_table - register a sysctl hierarchy
1466 * @table: the top-level table structure
1468 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1469 * array. An entry with a ctl_name of 0 terminates the table.
1471 * The members of the &ctl_table structure are used as follows:
1473 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1474 * must be unique within that level of sysctl
1476 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1477 * enter a sysctl file
1479 * data - a pointer to data for use by proc_handler
1481 * maxlen - the maximum size in bytes of the data
1483 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1485 * child - a pointer to the child sysctl table if this entry is a directory, or
1488 * proc_handler - the text handler routine (described below)
1490 * strategy - the strategy routine (described below)
1492 * de - for internal use by the sysctl routines
1494 * extra1, extra2 - extra pointers usable by the proc handler routines
1496 * Leaf nodes in the sysctl tree will be represented by a single file
1497 * under /proc; non-leaf nodes will be represented by directories.
1499 * sysctl(2) can automatically manage read and write requests through
1500 * the sysctl table. The data and maxlen fields of the ctl_table
1501 * struct enable minimal validation of the values being written to be
1502 * performed, and the mode field allows minimal authentication.
1504 * More sophisticated management can be enabled by the provision of a
1505 * strategy routine with the table entry. This will be called before
1506 * any automatic read or write of the data is performed.
1508 * The strategy routine may return
1510 * < 0 - Error occurred (error is passed to user process)
1512 * 0 - OK - proceed with automatic read or write.
1514 * > 0 - OK - read or write has been done by the strategy routine, so
1515 * return immediately.
1517 * There must be a proc_handler routine for any terminal nodes
1518 * mirrored under /proc/sys (non-terminals are handled by a built-in
1519 * directory handler). Several default handlers are available to
1520 * cover common cases -
1522 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1523 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1524 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1526 * It is the handler's job to read the input buffer from user memory
1527 * and process it. The handler should return 0 on success.
1529 * This routine returns %NULL on a failure to register, and a pointer
1530 * to the table header on success.
1532 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1534 struct ctl_table_header *tmp;
1535 tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1538 tmp->ctl_table = table;
1539 INIT_LIST_HEAD(&tmp->ctl_entry);
1541 tmp->unregistering = NULL;
1542 sysctl_set_parent(NULL, table);
1543 spin_lock(&sysctl_lock);
1544 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1545 spin_unlock(&sysctl_lock);
1550 * unregister_sysctl_table - unregister a sysctl table hierarchy
1551 * @header: the header returned from register_sysctl_table
1553 * Unregisters the sysctl table and all children. proc entries may not
1554 * actually be removed until they are no longer used by anyone.
1556 void unregister_sysctl_table(struct ctl_table_header * header)
1559 spin_lock(&sysctl_lock);
1560 start_unregistering(header);
1561 spin_unlock(&sysctl_lock);
1565 #else /* !CONFIG_SYSCTL */
1566 struct ctl_table_header *register_sysctl_table(ctl_table * table)
1571 void unregister_sysctl_table(struct ctl_table_header * table)
1575 #endif /* CONFIG_SYSCTL */
1581 #ifdef CONFIG_PROC_SYSCTL
1583 static int _proc_do_string(void* data, int maxlen, int write,
1584 struct file *filp, void __user *buffer,
1585 size_t *lenp, loff_t *ppos)
1591 if (!data || !maxlen || !*lenp) {
1599 while (len < *lenp) {
1600 if (get_user(c, p++))
1602 if (c == 0 || c == '\n')
1608 if(copy_from_user(data, buffer, len))
1610 ((char *) data)[len] = 0;
1628 if(copy_to_user(buffer, data, len))
1631 if(put_user('\n', ((char __user *) buffer) + len))
1642 * proc_dostring - read a string sysctl
1643 * @table: the sysctl table
1644 * @write: %TRUE if this is a write to the sysctl file
1645 * @filp: the file structure
1646 * @buffer: the user buffer
1647 * @lenp: the size of the user buffer
1648 * @ppos: file position
1650 * Reads/writes a string from/to the user buffer. If the kernel
1651 * buffer provided is not large enough to hold the string, the
1652 * string is truncated. The copied string is %NULL-terminated.
1653 * If the string is being read by the user process, it is copied
1654 * and a newline '\n' is added. It is truncated if the buffer is
1657 * Returns 0 on success.
1659 int proc_dostring(ctl_table *table, int write, struct file *filp,
1660 void __user *buffer, size_t *lenp, loff_t *ppos)
1662 return _proc_do_string(table->data, table->maxlen, write, filp,
1663 buffer, lenp, ppos);
1667 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1669 int write, void *data)
1672 *valp = *negp ? -*lvalp : *lvalp;
1677 *lvalp = (unsigned long)-val;
1680 *lvalp = (unsigned long)val;
1686 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1687 int write, struct file *filp, void __user *buffer,
1688 size_t *lenp, loff_t *ppos,
1689 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1690 int write, void *data),
1693 #define TMPBUFLEN 21
1694 int *i, vleft, first=1, neg, val;
1698 char buf[TMPBUFLEN], *p;
1699 char __user *s = buffer;
1701 if (!tbl_data || !table->maxlen || !*lenp ||
1702 (*ppos && !write)) {
1707 i = (int *) tbl_data;
1708 vleft = table->maxlen / sizeof(*i);
1712 conv = do_proc_dointvec_conv;
1714 for (; left && vleft--; i++, first=0) {
1729 if (len > sizeof(buf) - 1)
1730 len = sizeof(buf) - 1;
1731 if (copy_from_user(buf, s, len))
1735 if (*p == '-' && left > 1) {
1739 if (*p < '0' || *p > '9')
1742 lval = simple_strtoul(p, &p, 0);
1745 if ((len < left) && *p && !isspace(*p))
1752 if (conv(&neg, &lval, i, 1, data))
1759 if (conv(&neg, &lval, i, 0, data))
1762 sprintf(p, "%s%lu", neg ? "-" : "", lval);
1766 if(copy_to_user(s, buf, len))
1773 if (!write && !first && left) {
1774 if(put_user('\n', s))
1781 if (get_user(c, s++))
1796 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1797 void __user *buffer, size_t *lenp, loff_t *ppos,
1798 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1799 int write, void *data),
1802 return __do_proc_dointvec(table->data, table, write, filp,
1803 buffer, lenp, ppos, conv, data);
1807 * proc_dointvec - read a vector of integers
1808 * @table: the sysctl table
1809 * @write: %TRUE if this is a write to the sysctl file
1810 * @filp: the file structure
1811 * @buffer: the user buffer
1812 * @lenp: the size of the user buffer
1813 * @ppos: file position
1815 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1816 * values from/to the user buffer, treated as an ASCII string.
1818 * Returns 0 on success.
1820 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1821 void __user *buffer, size_t *lenp, loff_t *ppos)
1823 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1831 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1833 int write, void *data)
1835 int op = *(int *)data;
1837 int val = *negp ? -*lvalp : *lvalp;
1839 case OP_SET: *valp = val; break;
1840 case OP_AND: *valp &= val; break;
1841 case OP_OR: *valp |= val; break;
1847 *lvalp = (unsigned long)-val;
1850 *lvalp = (unsigned long)val;
1857 * init may raise the set.
1860 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1861 void __user *buffer, size_t *lenp, loff_t *ppos)
1865 if (write && !capable(CAP_SYS_MODULE)) {
1869 op = is_init(current) ? OP_SET : OP_AND;
1870 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1871 do_proc_dointvec_bset_conv,&op);
1875 * Taint values can only be increased
1877 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1878 void __user *buffer, size_t *lenp, loff_t *ppos)
1882 if (write && !capable(CAP_SYS_ADMIN))
1886 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1887 do_proc_dointvec_bset_conv,&op);
1890 struct do_proc_dointvec_minmax_conv_param {
1895 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1897 int write, void *data)
1899 struct do_proc_dointvec_minmax_conv_param *param = data;
1901 int val = *negp ? -*lvalp : *lvalp;
1902 if ((param->min && *param->min > val) ||
1903 (param->max && *param->max < val))
1910 *lvalp = (unsigned long)-val;
1913 *lvalp = (unsigned long)val;
1920 * proc_dointvec_minmax - read a vector of integers with min/max values
1921 * @table: the sysctl table
1922 * @write: %TRUE if this is a write to the sysctl file
1923 * @filp: the file structure
1924 * @buffer: the user buffer
1925 * @lenp: the size of the user buffer
1926 * @ppos: file position
1928 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1929 * values from/to the user buffer, treated as an ASCII string.
1931 * This routine will ensure the values are within the range specified by
1932 * table->extra1 (min) and table->extra2 (max).
1934 * Returns 0 on success.
1936 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1937 void __user *buffer, size_t *lenp, loff_t *ppos)
1939 struct do_proc_dointvec_minmax_conv_param param = {
1940 .min = (int *) table->extra1,
1941 .max = (int *) table->extra2,
1943 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1944 do_proc_dointvec_minmax_conv, ¶m);
1947 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
1949 void __user *buffer,
1950 size_t *lenp, loff_t *ppos,
1951 unsigned long convmul,
1952 unsigned long convdiv)
1954 #define TMPBUFLEN 21
1955 unsigned long *i, *min, *max, val;
1956 int vleft, first=1, neg;
1958 char buf[TMPBUFLEN], *p;
1959 char __user *s = buffer;
1961 if (!data || !table->maxlen || !*lenp ||
1962 (*ppos && !write)) {
1967 i = (unsigned long *) data;
1968 min = (unsigned long *) table->extra1;
1969 max = (unsigned long *) table->extra2;
1970 vleft = table->maxlen / sizeof(unsigned long);
1973 for (; left && vleft--; i++, min++, max++, first=0) {
1988 if (len > TMPBUFLEN-1)
1990 if (copy_from_user(buf, s, len))
1994 if (*p == '-' && left > 1) {
1998 if (*p < '0' || *p > '9')
2000 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2002 if ((len < left) && *p && !isspace(*p))
2011 if ((min && val < *min) || (max && val > *max))
2018 sprintf(p, "%lu", convdiv * (*i) / convmul);
2022 if(copy_to_user(s, buf, len))
2029 if (!write && !first && left) {
2030 if(put_user('\n', s))
2037 if (get_user(c, s++))
2052 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
2054 void __user *buffer,
2055 size_t *lenp, loff_t *ppos,
2056 unsigned long convmul,
2057 unsigned long convdiv)
2059 return __do_proc_doulongvec_minmax(table->data, table, write,
2060 filp, buffer, lenp, ppos, convmul, convdiv);
2064 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2065 * @table: the sysctl table
2066 * @write: %TRUE if this is a write to the sysctl file
2067 * @filp: the file structure
2068 * @buffer: the user buffer
2069 * @lenp: the size of the user buffer
2070 * @ppos: file position
2072 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2073 * values from/to the user buffer, treated as an ASCII string.
2075 * This routine will ensure the values are within the range specified by
2076 * table->extra1 (min) and table->extra2 (max).
2078 * Returns 0 on success.
2080 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2081 void __user *buffer, size_t *lenp, loff_t *ppos)
2083 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2087 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2088 * @table: the sysctl table
2089 * @write: %TRUE if this is a write to the sysctl file
2090 * @filp: the file structure
2091 * @buffer: the user buffer
2092 * @lenp: the size of the user buffer
2093 * @ppos: file position
2095 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2096 * values from/to the user buffer, treated as an ASCII string. The values
2097 * are treated as milliseconds, and converted to jiffies when they are stored.
2099 * This routine will ensure the values are within the range specified by
2100 * table->extra1 (min) and table->extra2 (max).
2102 * Returns 0 on success.
2104 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2106 void __user *buffer,
2107 size_t *lenp, loff_t *ppos)
2109 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2110 lenp, ppos, HZ, 1000l);
2114 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2116 int write, void *data)
2119 if (*lvalp > LONG_MAX / HZ)
2121 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2127 lval = (unsigned long)-val;
2130 lval = (unsigned long)val;
2137 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2139 int write, void *data)
2142 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2144 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2150 lval = (unsigned long)-val;
2153 lval = (unsigned long)val;
2155 *lvalp = jiffies_to_clock_t(lval);
2160 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2162 int write, void *data)
2165 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2171 lval = (unsigned long)-val;
2174 lval = (unsigned long)val;
2176 *lvalp = jiffies_to_msecs(lval);
2182 * proc_dointvec_jiffies - read a vector of integers as seconds
2183 * @table: the sysctl table
2184 * @write: %TRUE if this is a write to the sysctl file
2185 * @filp: the file structure
2186 * @buffer: the user buffer
2187 * @lenp: the size of the user buffer
2188 * @ppos: file position
2190 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2191 * values from/to the user buffer, treated as an ASCII string.
2192 * The values read are assumed to be in seconds, and are converted into
2195 * Returns 0 on success.
2197 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2198 void __user *buffer, size_t *lenp, loff_t *ppos)
2200 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2201 do_proc_dointvec_jiffies_conv,NULL);
2205 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2206 * @table: the sysctl table
2207 * @write: %TRUE if this is a write to the sysctl file
2208 * @filp: the file structure
2209 * @buffer: the user buffer
2210 * @lenp: the size of the user buffer
2211 * @ppos: pointer to the file position
2213 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2214 * values from/to the user buffer, treated as an ASCII string.
2215 * The values read are assumed to be in 1/USER_HZ seconds, and
2216 * are converted into jiffies.
2218 * Returns 0 on success.
2220 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2221 void __user *buffer, size_t *lenp, loff_t *ppos)
2223 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2224 do_proc_dointvec_userhz_jiffies_conv,NULL);
2228 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2229 * @table: the sysctl table
2230 * @write: %TRUE if this is a write to the sysctl file
2231 * @filp: the file structure
2232 * @buffer: the user buffer
2233 * @lenp: the size of the user buffer
2234 * @ppos: file position
2235 * @ppos: the current position in the file
2237 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2238 * values from/to the user buffer, treated as an ASCII string.
2239 * The values read are assumed to be in 1/1000 seconds, and
2240 * are converted into jiffies.
2242 * Returns 0 on success.
2244 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2245 void __user *buffer, size_t *lenp, loff_t *ppos)
2247 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2248 do_proc_dointvec_ms_jiffies_conv, NULL);
2251 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2252 void __user *buffer, size_t *lenp, loff_t *ppos)
2254 struct pid *new_pid;
2258 tmp = pid_nr(cad_pid);
2260 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2261 lenp, ppos, NULL, NULL);
2265 new_pid = find_get_pid(tmp);
2269 put_pid(xchg(&cad_pid, new_pid));
2273 #else /* CONFIG_PROC_FS */
2275 int proc_dostring(ctl_table *table, int write, struct file *filp,
2276 void __user *buffer, size_t *lenp, loff_t *ppos)
2281 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2282 void __user *buffer, size_t *lenp, loff_t *ppos)
2287 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2288 void __user *buffer, size_t *lenp, loff_t *ppos)
2293 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2294 void __user *buffer, size_t *lenp, loff_t *ppos)
2299 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2300 void __user *buffer, size_t *lenp, loff_t *ppos)
2305 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2306 void __user *buffer, size_t *lenp, loff_t *ppos)
2311 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2312 void __user *buffer, size_t *lenp, loff_t *ppos)
2317 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2318 void __user *buffer, size_t *lenp, loff_t *ppos)
2323 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2325 void __user *buffer,
2326 size_t *lenp, loff_t *ppos)
2332 #endif /* CONFIG_PROC_FS */
2335 #ifdef CONFIG_SYSCTL_SYSCALL
2337 * General sysctl support routines
2340 /* The generic string strategy routine: */
2341 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2342 void __user *oldval, size_t __user *oldlenp,
2343 void __user *newval, size_t newlen)
2345 if (!table->data || !table->maxlen)
2348 if (oldval && oldlenp) {
2350 if (get_user(bufsize, oldlenp))
2353 size_t len = strlen(table->data), copied;
2355 /* This shouldn't trigger for a well-formed sysctl */
2356 if (len > table->maxlen)
2357 len = table->maxlen;
2359 /* Copy up to a max of bufsize-1 bytes of the string */
2360 copied = (len >= bufsize) ? bufsize - 1 : len;
2362 if (copy_to_user(oldval, table->data, copied) ||
2363 put_user(0, (char __user *)(oldval + copied)))
2365 if (put_user(len, oldlenp))
2369 if (newval && newlen) {
2370 size_t len = newlen;
2371 if (len > table->maxlen)
2372 len = table->maxlen;
2373 if(copy_from_user(table->data, newval, len))
2375 if (len == table->maxlen)
2377 ((char *) table->data)[len] = 0;
2383 * This function makes sure that all of the integers in the vector
2384 * are between the minimum and maximum values given in the arrays
2385 * table->extra1 and table->extra2, respectively.
2387 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2388 void __user *oldval, size_t __user *oldlenp,
2389 void __user *newval, size_t newlen)
2392 if (newval && newlen) {
2393 int __user *vec = (int __user *) newval;
2394 int *min = (int *) table->extra1;
2395 int *max = (int *) table->extra2;
2399 if (newlen % sizeof(int) != 0)
2402 if (!table->extra1 && !table->extra2)
2405 if (newlen > table->maxlen)
2406 newlen = table->maxlen;
2407 length = newlen / sizeof(int);
2409 for (i = 0; i < length; i++) {
2411 if (get_user(value, vec + i))
2413 if (min && value < min[i])
2415 if (max && value > max[i])
2422 /* Strategy function to convert jiffies to seconds */
2423 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2424 void __user *oldval, size_t __user *oldlenp,
2425 void __user *newval, size_t newlen)
2427 if (oldval && oldlenp) {
2430 if (get_user(olen, oldlenp))
2435 if (olen < sizeof(int))
2438 val = *(int *)(table->data) / HZ;
2439 if (put_user(val, (int __user *)oldval))
2441 if (put_user(sizeof(int), oldlenp))
2445 if (newval && newlen) {
2447 if (newlen != sizeof(int))
2449 if (get_user(new, (int __user *)newval))
2451 *(int *)(table->data) = new*HZ;
2456 /* Strategy function to convert jiffies to seconds */
2457 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2458 void __user *oldval, size_t __user *oldlenp,
2459 void __user *newval, size_t newlen)
2461 if (oldval && oldlenp) {
2464 if (get_user(olen, oldlenp))
2469 if (olen < sizeof(int))
2472 val = jiffies_to_msecs(*(int *)(table->data));
2473 if (put_user(val, (int __user *)oldval))
2475 if (put_user(sizeof(int), oldlenp))
2479 if (newval && newlen) {
2481 if (newlen != sizeof(int))
2483 if (get_user(new, (int __user *)newval))
2485 *(int *)(table->data) = msecs_to_jiffies(new);
2492 #else /* CONFIG_SYSCTL_SYSCALL */
2495 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2497 static int msg_count;
2498 struct __sysctl_args tmp;
2499 int name[CTL_MAXNAME];
2502 /* Read in the sysctl name for better debug message logging */
2503 if (copy_from_user(&tmp, args, sizeof(tmp)))
2505 if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2507 for (i = 0; i < tmp.nlen; i++)
2508 if (get_user(name[i], tmp.name + i))
2511 /* Ignore accesses to kernel.version */
2512 if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2515 if (msg_count < 5) {
2518 "warning: process `%s' used the removed sysctl "
2519 "system call with ", current->comm);
2520 for (i = 0; i < tmp.nlen; i++)
2521 printk("%d.", name[i]);
2528 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2529 void __user *oldval, size_t __user *oldlenp,
2530 void __user *newval, size_t newlen)
2535 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2536 void __user *oldval, size_t __user *oldlenp,
2537 void __user *newval, size_t newlen)
2542 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2543 void __user *oldval, size_t __user *oldlenp,
2544 void __user *newval, size_t newlen)
2549 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2550 void __user *oldval, size_t __user *oldlenp,
2551 void __user *newval, size_t newlen)
2556 #endif /* CONFIG_SYSCTL_SYSCALL */
2559 * No sense putting this after each symbol definition, twice,
2560 * exception granted :-)
2562 EXPORT_SYMBOL(proc_dointvec);
2563 EXPORT_SYMBOL(proc_dointvec_jiffies);
2564 EXPORT_SYMBOL(proc_dointvec_minmax);
2565 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2566 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2567 EXPORT_SYMBOL(proc_dostring);
2568 EXPORT_SYMBOL(proc_doulongvec_minmax);
2569 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2570 EXPORT_SYMBOL(register_sysctl_table);
2571 EXPORT_SYMBOL(sysctl_intvec);
2572 EXPORT_SYMBOL(sysctl_jiffies);
2573 EXPORT_SYMBOL(sysctl_ms_jiffies);
2574 EXPORT_SYMBOL(sysctl_string);
2575 EXPORT_SYMBOL(unregister_sysctl_table);