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 sysctl_oom_kill_allocating_task
;
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 /* Constants used for minimum and maximum */
84 #ifdef CONFIG_DETECT_SOFTLOCKUP
86 static int sixty
= 60;
94 static int one_hundred
= 100;
96 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
97 static int maxolduid
= 65535;
99 static int min_percpu_pagelist_fract
= 8;
101 static int ngroups_max
= NGROUPS_MAX
;
104 extern char modprobe_path
[];
106 #ifdef CONFIG_CHR_DEV_SG
107 extern int sg_big_buff
;
111 extern char reboot_command
[];
112 extern int stop_a_enabled
;
113 extern int scons_pwroff
;
117 extern int pwrsw_enabled
;
118 extern int unaligned_enabled
;
122 #ifdef CONFIG_MATHEMU
123 extern int sysctl_ieee_emulation_warnings
;
125 extern int sysctl_userprocess_debug
;
126 extern int spin_retry
;
129 extern int sysctl_hz_timer
;
131 #ifdef CONFIG_BSD_PROCESS_ACCT
132 extern int acct_parm
[];
136 extern int no_unaligned_warning
;
139 #ifdef CONFIG_RT_MUTEXES
140 extern int max_lock_depth
;
143 #ifdef CONFIG_SYSCTL_SYSCALL
144 static int parse_table(int __user
*, int, void __user
*, size_t __user
*,
145 void __user
*, size_t, struct ctl_table
*);
149 #ifdef CONFIG_PROC_SYSCTL
150 static int proc_do_cad_pid(struct ctl_table
*table
, int write
, struct file
*filp
,
151 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
152 static int proc_dointvec_taint(struct ctl_table
*table
, int write
, struct file
*filp
,
153 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
);
156 static struct ctl_table root_table
[];
157 static struct ctl_table_header root_table_header
=
158 { root_table
, LIST_HEAD_INIT(root_table_header
.ctl_entry
) };
160 static struct ctl_table kern_table
[];
161 static struct ctl_table vm_table
[];
162 static struct ctl_table fs_table
[];
163 static struct ctl_table debug_table
[];
164 static struct ctl_table dev_table
[];
165 extern struct ctl_table random_table
[];
166 #ifdef CONFIG_INOTIFY_USER
167 extern struct ctl_table inotify_table
[];
170 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
171 int sysctl_legacy_va_layout
;
174 extern int prove_locking
;
175 extern int lock_stat
;
177 /* The default sysctl tables: */
179 static struct ctl_table root_table
[] = {
181 .ctl_name
= CTL_KERN
,
182 .procname
= "kernel",
207 .ctl_name
= CTL_DEBUG
,
210 .child
= debug_table
,
219 * NOTE: do not add new entries to this table unless you have read
220 * Documentation/sysctl/ctl_unnumbered.txt
225 #ifdef CONFIG_SCHED_DEBUG
226 static unsigned long min_sched_granularity_ns
= 100000; /* 100 usecs */
227 static unsigned long max_sched_granularity_ns
= 1000000000; /* 1 second */
228 static unsigned long min_wakeup_granularity_ns
; /* 0 usecs */
229 static unsigned long max_wakeup_granularity_ns
= 1000000000; /* 1 second */
232 static struct ctl_table kern_table
[] = {
233 #ifdef CONFIG_SCHED_DEBUG
235 .ctl_name
= CTL_UNNUMBERED
,
236 .procname
= "sched_nr_latency",
237 .data
= &sysctl_sched_nr_latency
,
238 .maxlen
= sizeof(unsigned int),
240 .proc_handler
= &proc_dointvec
,
243 .ctl_name
= CTL_UNNUMBERED
,
244 .procname
= "sched_latency_ns",
245 .data
= &sysctl_sched_latency
,
246 .maxlen
= sizeof(unsigned int),
248 .proc_handler
= &proc_dointvec_minmax
,
249 .strategy
= &sysctl_intvec
,
250 .extra1
= &min_sched_granularity_ns
,
251 .extra2
= &max_sched_granularity_ns
,
254 .ctl_name
= CTL_UNNUMBERED
,
255 .procname
= "sched_wakeup_granularity_ns",
256 .data
= &sysctl_sched_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_batch_wakeup_granularity_ns",
267 .data
= &sysctl_sched_batch_wakeup_granularity
,
268 .maxlen
= sizeof(unsigned int),
270 .proc_handler
= &proc_dointvec_minmax
,
271 .strategy
= &sysctl_intvec
,
272 .extra1
= &min_wakeup_granularity_ns
,
273 .extra2
= &max_wakeup_granularity_ns
,
276 .ctl_name
= CTL_UNNUMBERED
,
277 .procname
= "sched_child_runs_first",
278 .data
= &sysctl_sched_child_runs_first
,
279 .maxlen
= sizeof(unsigned int),
281 .proc_handler
= &proc_dointvec
,
284 .ctl_name
= CTL_UNNUMBERED
,
285 .procname
= "sched_features",
286 .data
= &sysctl_sched_features
,
287 .maxlen
= sizeof(unsigned int),
289 .proc_handler
= &proc_dointvec
,
292 .ctl_name
= CTL_UNNUMBERED
,
293 .procname
= "sched_migration_cost",
294 .data
= &sysctl_sched_migration_cost
,
295 .maxlen
= sizeof(unsigned int),
297 .proc_handler
= &proc_dointvec
,
301 .ctl_name
= CTL_UNNUMBERED
,
302 .procname
= "sched_compat_yield",
303 .data
= &sysctl_sched_compat_yield
,
304 .maxlen
= sizeof(unsigned int),
306 .proc_handler
= &proc_dointvec
,
308 #ifdef CONFIG_PROVE_LOCKING
310 .ctl_name
= CTL_UNNUMBERED
,
311 .procname
= "prove_locking",
312 .data
= &prove_locking
,
313 .maxlen
= sizeof(int),
315 .proc_handler
= &proc_dointvec
,
318 #ifdef CONFIG_LOCK_STAT
320 .ctl_name
= CTL_UNNUMBERED
,
321 .procname
= "lock_stat",
323 .maxlen
= sizeof(int),
325 .proc_handler
= &proc_dointvec
,
329 .ctl_name
= KERN_PANIC
,
331 .data
= &panic_timeout
,
332 .maxlen
= sizeof(int),
334 .proc_handler
= &proc_dointvec
,
337 .ctl_name
= KERN_CORE_USES_PID
,
338 .procname
= "core_uses_pid",
339 .data
= &core_uses_pid
,
340 .maxlen
= sizeof(int),
342 .proc_handler
= &proc_dointvec
,
344 #ifdef CONFIG_AUDITSYSCALL
346 .ctl_name
= CTL_UNNUMBERED
,
347 .procname
= "audit_argv_kb",
348 .data
= &audit_argv_kb
,
349 .maxlen
= sizeof(int),
351 .proc_handler
= &proc_dointvec
,
355 .ctl_name
= KERN_CORE_PATTERN
,
356 .procname
= "core_pattern",
357 .data
= core_pattern
,
358 .maxlen
= CORENAME_MAX_SIZE
,
360 .proc_handler
= &proc_dostring
,
361 .strategy
= &sysctl_string
,
363 #ifdef CONFIG_PROC_SYSCTL
365 .procname
= "tainted",
367 .maxlen
= sizeof(int),
369 .proc_handler
= &proc_dointvec_taint
,
373 .procname
= "cap-bound",
375 .maxlen
= sizeof(kernel_cap_t
),
377 .proc_handler
= &proc_dointvec_bset
,
379 #ifdef CONFIG_BLK_DEV_INITRD
381 .ctl_name
= KERN_REALROOTDEV
,
382 .procname
= "real-root-dev",
383 .data
= &real_root_dev
,
384 .maxlen
= sizeof(int),
386 .proc_handler
= &proc_dointvec
,
390 .ctl_name
= CTL_UNNUMBERED
,
391 .procname
= "print-fatal-signals",
392 .data
= &print_fatal_signals
,
393 .maxlen
= sizeof(int),
395 .proc_handler
= &proc_dointvec
,
399 .ctl_name
= KERN_SPARC_REBOOT
,
400 .procname
= "reboot-cmd",
401 .data
= reboot_command
,
404 .proc_handler
= &proc_dostring
,
405 .strategy
= &sysctl_string
,
408 .ctl_name
= KERN_SPARC_STOP_A
,
409 .procname
= "stop-a",
410 .data
= &stop_a_enabled
,
411 .maxlen
= sizeof (int),
413 .proc_handler
= &proc_dointvec
,
416 .ctl_name
= KERN_SPARC_SCONS_PWROFF
,
417 .procname
= "scons-poweroff",
418 .data
= &scons_pwroff
,
419 .maxlen
= sizeof (int),
421 .proc_handler
= &proc_dointvec
,
426 .ctl_name
= KERN_HPPA_PWRSW
,
427 .procname
= "soft-power",
428 .data
= &pwrsw_enabled
,
429 .maxlen
= sizeof (int),
431 .proc_handler
= &proc_dointvec
,
434 .ctl_name
= KERN_HPPA_UNALIGNED
,
435 .procname
= "unaligned-trap",
436 .data
= &unaligned_enabled
,
437 .maxlen
= sizeof (int),
439 .proc_handler
= &proc_dointvec
,
443 .ctl_name
= KERN_CTLALTDEL
,
444 .procname
= "ctrl-alt-del",
446 .maxlen
= sizeof(int),
448 .proc_handler
= &proc_dointvec
,
451 .ctl_name
= KERN_PRINTK
,
452 .procname
= "printk",
453 .data
= &console_loglevel
,
454 .maxlen
= 4*sizeof(int),
456 .proc_handler
= &proc_dointvec
,
460 .ctl_name
= KERN_MODPROBE
,
461 .procname
= "modprobe",
462 .data
= &modprobe_path
,
463 .maxlen
= KMOD_PATH_LEN
,
465 .proc_handler
= &proc_dostring
,
466 .strategy
= &sysctl_string
,
469 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
471 .ctl_name
= KERN_HOTPLUG
,
472 .procname
= "hotplug",
473 .data
= &uevent_helper
,
474 .maxlen
= UEVENT_HELPER_PATH_LEN
,
476 .proc_handler
= &proc_dostring
,
477 .strategy
= &sysctl_string
,
480 #ifdef CONFIG_CHR_DEV_SG
482 .ctl_name
= KERN_SG_BIG_BUFF
,
483 .procname
= "sg-big-buff",
484 .data
= &sg_big_buff
,
485 .maxlen
= sizeof (int),
487 .proc_handler
= &proc_dointvec
,
490 #ifdef CONFIG_BSD_PROCESS_ACCT
492 .ctl_name
= KERN_ACCT
,
495 .maxlen
= 3*sizeof(int),
497 .proc_handler
= &proc_dointvec
,
500 #ifdef CONFIG_MAGIC_SYSRQ
502 .ctl_name
= KERN_SYSRQ
,
504 .data
= &__sysrq_enabled
,
505 .maxlen
= sizeof (int),
507 .proc_handler
= &proc_dointvec
,
510 #ifdef CONFIG_PROC_SYSCTL
512 .ctl_name
= KERN_CADPID
,
513 .procname
= "cad_pid",
515 .maxlen
= sizeof (int),
517 .proc_handler
= &proc_do_cad_pid
,
521 .ctl_name
= KERN_MAX_THREADS
,
522 .procname
= "threads-max",
523 .data
= &max_threads
,
524 .maxlen
= sizeof(int),
526 .proc_handler
= &proc_dointvec
,
529 .ctl_name
= KERN_RANDOM
,
530 .procname
= "random",
532 .child
= random_table
,
535 .ctl_name
= KERN_OVERFLOWUID
,
536 .procname
= "overflowuid",
537 .data
= &overflowuid
,
538 .maxlen
= sizeof(int),
540 .proc_handler
= &proc_dointvec_minmax
,
541 .strategy
= &sysctl_intvec
,
542 .extra1
= &minolduid
,
543 .extra2
= &maxolduid
,
546 .ctl_name
= KERN_OVERFLOWGID
,
547 .procname
= "overflowgid",
548 .data
= &overflowgid
,
549 .maxlen
= sizeof(int),
551 .proc_handler
= &proc_dointvec_minmax
,
552 .strategy
= &sysctl_intvec
,
553 .extra1
= &minolduid
,
554 .extra2
= &maxolduid
,
557 #ifdef CONFIG_MATHEMU
559 .ctl_name
= KERN_IEEE_EMULATION_WARNINGS
,
560 .procname
= "ieee_emulation_warnings",
561 .data
= &sysctl_ieee_emulation_warnings
,
562 .maxlen
= sizeof(int),
564 .proc_handler
= &proc_dointvec
,
567 #ifdef CONFIG_NO_IDLE_HZ
569 .ctl_name
= KERN_HZ_TIMER
,
570 .procname
= "hz_timer",
571 .data
= &sysctl_hz_timer
,
572 .maxlen
= sizeof(int),
574 .proc_handler
= &proc_dointvec
,
578 .ctl_name
= KERN_S390_USER_DEBUG_LOGGING
,
579 .procname
= "userprocess_debug",
580 .data
= &sysctl_userprocess_debug
,
581 .maxlen
= sizeof(int),
583 .proc_handler
= &proc_dointvec
,
587 .ctl_name
= KERN_PIDMAX
,
588 .procname
= "pid_max",
590 .maxlen
= sizeof (int),
592 .proc_handler
= &proc_dointvec_minmax
,
593 .strategy
= sysctl_intvec
,
594 .extra1
= &pid_max_min
,
595 .extra2
= &pid_max_max
,
598 .ctl_name
= KERN_PANIC_ON_OOPS
,
599 .procname
= "panic_on_oops",
600 .data
= &panic_on_oops
,
601 .maxlen
= sizeof(int),
603 .proc_handler
= &proc_dointvec
,
606 .ctl_name
= KERN_PRINTK_RATELIMIT
,
607 .procname
= "printk_ratelimit",
608 .data
= &printk_ratelimit_jiffies
,
609 .maxlen
= sizeof(int),
611 .proc_handler
= &proc_dointvec_jiffies
,
612 .strategy
= &sysctl_jiffies
,
615 .ctl_name
= KERN_PRINTK_RATELIMIT_BURST
,
616 .procname
= "printk_ratelimit_burst",
617 .data
= &printk_ratelimit_burst
,
618 .maxlen
= sizeof(int),
620 .proc_handler
= &proc_dointvec
,
623 .ctl_name
= KERN_NGROUPS_MAX
,
624 .procname
= "ngroups_max",
625 .data
= &ngroups_max
,
626 .maxlen
= sizeof (int),
628 .proc_handler
= &proc_dointvec
,
630 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
632 .ctl_name
= KERN_UNKNOWN_NMI_PANIC
,
633 .procname
= "unknown_nmi_panic",
634 .data
= &unknown_nmi_panic
,
635 .maxlen
= sizeof (int),
637 .proc_handler
= &proc_dointvec
,
640 .procname
= "nmi_watchdog",
641 .data
= &nmi_watchdog_enabled
,
642 .maxlen
= sizeof (int),
644 .proc_handler
= &proc_nmi_enabled
,
647 #if defined(CONFIG_X86)
649 .ctl_name
= KERN_PANIC_ON_NMI
,
650 .procname
= "panic_on_unrecovered_nmi",
651 .data
= &panic_on_unrecovered_nmi
,
652 .maxlen
= sizeof(int),
654 .proc_handler
= &proc_dointvec
,
657 .ctl_name
= KERN_BOOTLOADER_TYPE
,
658 .procname
= "bootloader_type",
659 .data
= &bootloader_type
,
660 .maxlen
= sizeof (int),
662 .proc_handler
= &proc_dointvec
,
665 .ctl_name
= CTL_UNNUMBERED
,
666 .procname
= "kstack_depth_to_print",
667 .data
= &kstack_depth_to_print
,
668 .maxlen
= sizeof(int),
670 .proc_handler
= &proc_dointvec
,
673 #if defined(CONFIG_MMU)
675 .ctl_name
= KERN_RANDOMIZE
,
676 .procname
= "randomize_va_space",
677 .data
= &randomize_va_space
,
678 .maxlen
= sizeof(int),
680 .proc_handler
= &proc_dointvec
,
683 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
685 .ctl_name
= KERN_SPIN_RETRY
,
686 .procname
= "spin_retry",
688 .maxlen
= sizeof (int),
690 .proc_handler
= &proc_dointvec
,
693 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
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
,
712 #ifdef CONFIG_DETECT_SOFTLOCKUP
714 .ctl_name
= CTL_UNNUMBERED
,
715 .procname
= "softlockup_thresh",
716 .data
= &softlockup_thresh
,
717 .maxlen
= sizeof(int),
719 .proc_handler
= &proc_dointvec_minmax
,
720 .strategy
= &sysctl_intvec
,
727 .ctl_name
= KERN_COMPAT_LOG
,
728 .procname
= "compat-log",
730 .maxlen
= sizeof (int),
732 .proc_handler
= &proc_dointvec
,
735 #ifdef CONFIG_RT_MUTEXES
737 .ctl_name
= KERN_MAX_LOCK_DEPTH
,
738 .procname
= "max_lock_depth",
739 .data
= &max_lock_depth
,
740 .maxlen
= sizeof(int),
742 .proc_handler
= &proc_dointvec
,
745 #ifdef CONFIG_PROC_FS
747 .ctl_name
= CTL_UNNUMBERED
,
748 .procname
= "maps_protect",
749 .data
= &maps_protect
,
750 .maxlen
= sizeof(int),
752 .proc_handler
= &proc_dointvec
,
756 .ctl_name
= CTL_UNNUMBERED
,
757 .procname
= "poweroff_cmd",
758 .data
= &poweroff_cmd
,
759 .maxlen
= POWEROFF_CMD_PATH_LEN
,
761 .proc_handler
= &proc_dostring
,
762 .strategy
= &sysctl_string
,
765 * NOTE: do not add new entries to this table unless you have read
766 * Documentation/sysctl/ctl_unnumbered.txt
771 static struct ctl_table vm_table
[] = {
773 .ctl_name
= VM_OVERCOMMIT_MEMORY
,
774 .procname
= "overcommit_memory",
775 .data
= &sysctl_overcommit_memory
,
776 .maxlen
= sizeof(sysctl_overcommit_memory
),
778 .proc_handler
= &proc_dointvec
,
781 .ctl_name
= VM_PANIC_ON_OOM
,
782 .procname
= "panic_on_oom",
783 .data
= &sysctl_panic_on_oom
,
784 .maxlen
= sizeof(sysctl_panic_on_oom
),
786 .proc_handler
= &proc_dointvec
,
789 .ctl_name
= CTL_UNNUMBERED
,
790 .procname
= "oom_kill_allocating_task",
791 .data
= &sysctl_oom_kill_allocating_task
,
792 .maxlen
= sizeof(sysctl_oom_kill_allocating_task
),
794 .proc_handler
= &proc_dointvec
,
797 .ctl_name
= VM_OVERCOMMIT_RATIO
,
798 .procname
= "overcommit_ratio",
799 .data
= &sysctl_overcommit_ratio
,
800 .maxlen
= sizeof(sysctl_overcommit_ratio
),
802 .proc_handler
= &proc_dointvec
,
805 .ctl_name
= VM_PAGE_CLUSTER
,
806 .procname
= "page-cluster",
807 .data
= &page_cluster
,
808 .maxlen
= sizeof(int),
810 .proc_handler
= &proc_dointvec
,
813 .ctl_name
= VM_DIRTY_BACKGROUND
,
814 .procname
= "dirty_background_ratio",
815 .data
= &dirty_background_ratio
,
816 .maxlen
= sizeof(dirty_background_ratio
),
818 .proc_handler
= &proc_dointvec_minmax
,
819 .strategy
= &sysctl_intvec
,
821 .extra2
= &one_hundred
,
824 .ctl_name
= VM_DIRTY_RATIO
,
825 .procname
= "dirty_ratio",
826 .data
= &vm_dirty_ratio
,
827 .maxlen
= sizeof(vm_dirty_ratio
),
829 .proc_handler
= &dirty_ratio_handler
,
830 .strategy
= &sysctl_intvec
,
832 .extra2
= &one_hundred
,
835 .procname
= "dirty_writeback_centisecs",
836 .data
= &dirty_writeback_interval
,
837 .maxlen
= sizeof(dirty_writeback_interval
),
839 .proc_handler
= &dirty_writeback_centisecs_handler
,
842 .procname
= "dirty_expire_centisecs",
843 .data
= &dirty_expire_interval
,
844 .maxlen
= sizeof(dirty_expire_interval
),
846 .proc_handler
= &proc_dointvec_userhz_jiffies
,
849 .ctl_name
= VM_NR_PDFLUSH_THREADS
,
850 .procname
= "nr_pdflush_threads",
851 .data
= &nr_pdflush_threads
,
852 .maxlen
= sizeof nr_pdflush_threads
,
853 .mode
= 0444 /* read-only*/,
854 .proc_handler
= &proc_dointvec
,
857 .ctl_name
= VM_SWAPPINESS
,
858 .procname
= "swappiness",
859 .data
= &vm_swappiness
,
860 .maxlen
= sizeof(vm_swappiness
),
862 .proc_handler
= &proc_dointvec_minmax
,
863 .strategy
= &sysctl_intvec
,
865 .extra2
= &one_hundred
,
867 #ifdef CONFIG_HUGETLB_PAGE
869 .procname
= "nr_hugepages",
870 .data
= &max_huge_pages
,
871 .maxlen
= sizeof(unsigned long),
873 .proc_handler
= &hugetlb_sysctl_handler
,
874 .extra1
= (void *)&hugetlb_zero
,
875 .extra2
= (void *)&hugetlb_infinity
,
878 .ctl_name
= VM_HUGETLB_GROUP
,
879 .procname
= "hugetlb_shm_group",
880 .data
= &sysctl_hugetlb_shm_group
,
881 .maxlen
= sizeof(gid_t
),
883 .proc_handler
= &proc_dointvec
,
886 .ctl_name
= CTL_UNNUMBERED
,
887 .procname
= "hugepages_treat_as_movable",
888 .data
= &hugepages_treat_as_movable
,
889 .maxlen
= sizeof(int),
891 .proc_handler
= &hugetlb_treat_movable_handler
,
894 .ctl_name
= CTL_UNNUMBERED
,
895 .procname
= "hugetlb_dynamic_pool",
896 .data
= &hugetlb_dynamic_pool
,
897 .maxlen
= sizeof(hugetlb_dynamic_pool
),
899 .proc_handler
= &proc_dointvec
,
903 .ctl_name
= VM_LOWMEM_RESERVE_RATIO
,
904 .procname
= "lowmem_reserve_ratio",
905 .data
= &sysctl_lowmem_reserve_ratio
,
906 .maxlen
= sizeof(sysctl_lowmem_reserve_ratio
),
908 .proc_handler
= &lowmem_reserve_ratio_sysctl_handler
,
909 .strategy
= &sysctl_intvec
,
912 .ctl_name
= VM_DROP_PAGECACHE
,
913 .procname
= "drop_caches",
914 .data
= &sysctl_drop_caches
,
915 .maxlen
= sizeof(int),
917 .proc_handler
= drop_caches_sysctl_handler
,
918 .strategy
= &sysctl_intvec
,
921 .ctl_name
= VM_MIN_FREE_KBYTES
,
922 .procname
= "min_free_kbytes",
923 .data
= &min_free_kbytes
,
924 .maxlen
= sizeof(min_free_kbytes
),
926 .proc_handler
= &min_free_kbytes_sysctl_handler
,
927 .strategy
= &sysctl_intvec
,
931 .ctl_name
= VM_PERCPU_PAGELIST_FRACTION
,
932 .procname
= "percpu_pagelist_fraction",
933 .data
= &percpu_pagelist_fraction
,
934 .maxlen
= sizeof(percpu_pagelist_fraction
),
936 .proc_handler
= &percpu_pagelist_fraction_sysctl_handler
,
937 .strategy
= &sysctl_intvec
,
938 .extra1
= &min_percpu_pagelist_fract
,
942 .ctl_name
= VM_MAX_MAP_COUNT
,
943 .procname
= "max_map_count",
944 .data
= &sysctl_max_map_count
,
945 .maxlen
= sizeof(sysctl_max_map_count
),
947 .proc_handler
= &proc_dointvec
951 .ctl_name
= VM_LAPTOP_MODE
,
952 .procname
= "laptop_mode",
953 .data
= &laptop_mode
,
954 .maxlen
= sizeof(laptop_mode
),
956 .proc_handler
= &proc_dointvec_jiffies
,
957 .strategy
= &sysctl_jiffies
,
960 .ctl_name
= VM_BLOCK_DUMP
,
961 .procname
= "block_dump",
963 .maxlen
= sizeof(block_dump
),
965 .proc_handler
= &proc_dointvec
,
966 .strategy
= &sysctl_intvec
,
970 .ctl_name
= VM_VFS_CACHE_PRESSURE
,
971 .procname
= "vfs_cache_pressure",
972 .data
= &sysctl_vfs_cache_pressure
,
973 .maxlen
= sizeof(sysctl_vfs_cache_pressure
),
975 .proc_handler
= &proc_dointvec
,
976 .strategy
= &sysctl_intvec
,
979 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
981 .ctl_name
= VM_LEGACY_VA_LAYOUT
,
982 .procname
= "legacy_va_layout",
983 .data
= &sysctl_legacy_va_layout
,
984 .maxlen
= sizeof(sysctl_legacy_va_layout
),
986 .proc_handler
= &proc_dointvec
,
987 .strategy
= &sysctl_intvec
,
993 .ctl_name
= VM_ZONE_RECLAIM_MODE
,
994 .procname
= "zone_reclaim_mode",
995 .data
= &zone_reclaim_mode
,
996 .maxlen
= sizeof(zone_reclaim_mode
),
998 .proc_handler
= &proc_dointvec
,
999 .strategy
= &sysctl_intvec
,
1003 .ctl_name
= VM_MIN_UNMAPPED
,
1004 .procname
= "min_unmapped_ratio",
1005 .data
= &sysctl_min_unmapped_ratio
,
1006 .maxlen
= sizeof(sysctl_min_unmapped_ratio
),
1008 .proc_handler
= &sysctl_min_unmapped_ratio_sysctl_handler
,
1009 .strategy
= &sysctl_intvec
,
1011 .extra2
= &one_hundred
,
1014 .ctl_name
= VM_MIN_SLAB
,
1015 .procname
= "min_slab_ratio",
1016 .data
= &sysctl_min_slab_ratio
,
1017 .maxlen
= sizeof(sysctl_min_slab_ratio
),
1019 .proc_handler
= &sysctl_min_slab_ratio_sysctl_handler
,
1020 .strategy
= &sysctl_intvec
,
1022 .extra2
= &one_hundred
,
1027 .ctl_name
= CTL_UNNUMBERED
,
1028 .procname
= "stat_interval",
1029 .data
= &sysctl_stat_interval
,
1030 .maxlen
= sizeof(sysctl_stat_interval
),
1032 .proc_handler
= &proc_dointvec_jiffies
,
1033 .strategy
= &sysctl_jiffies
,
1036 #ifdef CONFIG_SECURITY
1038 .ctl_name
= CTL_UNNUMBERED
,
1039 .procname
= "mmap_min_addr",
1040 .data
= &mmap_min_addr
,
1041 .maxlen
= sizeof(unsigned long),
1043 .proc_handler
= &proc_doulongvec_minmax
,
1048 .ctl_name
= CTL_UNNUMBERED
,
1049 .procname
= "numa_zonelist_order",
1050 .data
= &numa_zonelist_order
,
1051 .maxlen
= NUMA_ZONELIST_ORDER_LEN
,
1053 .proc_handler
= &numa_zonelist_order_handler
,
1054 .strategy
= &sysctl_string
,
1057 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1058 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1060 .ctl_name
= VM_VDSO_ENABLED
,
1061 .procname
= "vdso_enabled",
1062 .data
= &vdso_enabled
,
1063 .maxlen
= sizeof(vdso_enabled
),
1065 .proc_handler
= &proc_dointvec
,
1066 .strategy
= &sysctl_intvec
,
1071 * NOTE: do not add new entries to this table unless you have read
1072 * Documentation/sysctl/ctl_unnumbered.txt
1077 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1078 static struct ctl_table binfmt_misc_table
[] = {
1083 static struct ctl_table fs_table
[] = {
1085 .ctl_name
= FS_NRINODE
,
1086 .procname
= "inode-nr",
1087 .data
= &inodes_stat
,
1088 .maxlen
= 2*sizeof(int),
1090 .proc_handler
= &proc_dointvec
,
1093 .ctl_name
= FS_STATINODE
,
1094 .procname
= "inode-state",
1095 .data
= &inodes_stat
,
1096 .maxlen
= 7*sizeof(int),
1098 .proc_handler
= &proc_dointvec
,
1101 .procname
= "file-nr",
1102 .data
= &files_stat
,
1103 .maxlen
= 3*sizeof(int),
1105 .proc_handler
= &proc_nr_files
,
1108 .ctl_name
= FS_MAXFILE
,
1109 .procname
= "file-max",
1110 .data
= &files_stat
.max_files
,
1111 .maxlen
= sizeof(int),
1113 .proc_handler
= &proc_dointvec
,
1116 .ctl_name
= FS_DENTRY
,
1117 .procname
= "dentry-state",
1118 .data
= &dentry_stat
,
1119 .maxlen
= 6*sizeof(int),
1121 .proc_handler
= &proc_dointvec
,
1124 .ctl_name
= FS_OVERFLOWUID
,
1125 .procname
= "overflowuid",
1126 .data
= &fs_overflowuid
,
1127 .maxlen
= sizeof(int),
1129 .proc_handler
= &proc_dointvec_minmax
,
1130 .strategy
= &sysctl_intvec
,
1131 .extra1
= &minolduid
,
1132 .extra2
= &maxolduid
,
1135 .ctl_name
= FS_OVERFLOWGID
,
1136 .procname
= "overflowgid",
1137 .data
= &fs_overflowgid
,
1138 .maxlen
= sizeof(int),
1140 .proc_handler
= &proc_dointvec_minmax
,
1141 .strategy
= &sysctl_intvec
,
1142 .extra1
= &minolduid
,
1143 .extra2
= &maxolduid
,
1146 .ctl_name
= FS_LEASES
,
1147 .procname
= "leases-enable",
1148 .data
= &leases_enable
,
1149 .maxlen
= sizeof(int),
1151 .proc_handler
= &proc_dointvec
,
1153 #ifdef CONFIG_DNOTIFY
1155 .ctl_name
= FS_DIR_NOTIFY
,
1156 .procname
= "dir-notify-enable",
1157 .data
= &dir_notify_enable
,
1158 .maxlen
= sizeof(int),
1160 .proc_handler
= &proc_dointvec
,
1165 .ctl_name
= FS_LEASE_TIME
,
1166 .procname
= "lease-break-time",
1167 .data
= &lease_break_time
,
1168 .maxlen
= sizeof(int),
1170 .proc_handler
= &proc_dointvec_minmax
,
1171 .strategy
= &sysctl_intvec
,
1176 .procname
= "aio-nr",
1178 .maxlen
= sizeof(aio_nr
),
1180 .proc_handler
= &proc_doulongvec_minmax
,
1183 .procname
= "aio-max-nr",
1184 .data
= &aio_max_nr
,
1185 .maxlen
= sizeof(aio_max_nr
),
1187 .proc_handler
= &proc_doulongvec_minmax
,
1189 #ifdef CONFIG_INOTIFY_USER
1191 .ctl_name
= FS_INOTIFY
,
1192 .procname
= "inotify",
1194 .child
= inotify_table
,
1199 .ctl_name
= KERN_SETUID_DUMPABLE
,
1200 .procname
= "suid_dumpable",
1201 .data
= &suid_dumpable
,
1202 .maxlen
= sizeof(int),
1204 .proc_handler
= &proc_dointvec
,
1206 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1208 .ctl_name
= CTL_UNNUMBERED
,
1209 .procname
= "binfmt_misc",
1211 .child
= binfmt_misc_table
,
1215 * NOTE: do not add new entries to this table unless you have read
1216 * Documentation/sysctl/ctl_unnumbered.txt
1221 static struct ctl_table debug_table
[] = {
1222 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1224 .ctl_name
= CTL_UNNUMBERED
,
1225 .procname
= "exception-trace",
1226 .data
= &show_unhandled_signals
,
1227 .maxlen
= sizeof(int),
1229 .proc_handler
= proc_dointvec
1235 static struct ctl_table dev_table
[] = {
1239 static DEFINE_SPINLOCK(sysctl_lock
);
1241 /* called under sysctl_lock */
1242 static int use_table(struct ctl_table_header
*p
)
1244 if (unlikely(p
->unregistering
))
1250 /* called under sysctl_lock */
1251 static void unuse_table(struct ctl_table_header
*p
)
1254 if (unlikely(p
->unregistering
))
1255 complete(p
->unregistering
);
1258 /* called under sysctl_lock, will reacquire if has to wait */
1259 static void start_unregistering(struct ctl_table_header
*p
)
1262 * if p->used is 0, nobody will ever touch that entry again;
1263 * we'll eliminate all paths to it before dropping sysctl_lock
1265 if (unlikely(p
->used
)) {
1266 struct completion wait
;
1267 init_completion(&wait
);
1268 p
->unregistering
= &wait
;
1269 spin_unlock(&sysctl_lock
);
1270 wait_for_completion(&wait
);
1271 spin_lock(&sysctl_lock
);
1274 * do not remove from the list until nobody holds it; walking the
1275 * list in do_sysctl() relies on that.
1277 list_del_init(&p
->ctl_entry
);
1280 void sysctl_head_finish(struct ctl_table_header
*head
)
1284 spin_lock(&sysctl_lock
);
1286 spin_unlock(&sysctl_lock
);
1289 struct ctl_table_header
*sysctl_head_next(struct ctl_table_header
*prev
)
1291 struct ctl_table_header
*head
;
1292 struct list_head
*tmp
;
1293 spin_lock(&sysctl_lock
);
1295 tmp
= &prev
->ctl_entry
;
1299 tmp
= &root_table_header
.ctl_entry
;
1301 head
= list_entry(tmp
, struct ctl_table_header
, ctl_entry
);
1303 if (!use_table(head
))
1305 spin_unlock(&sysctl_lock
);
1309 if (tmp
== &root_table_header
.ctl_entry
)
1312 spin_unlock(&sysctl_lock
);
1316 #ifdef CONFIG_SYSCTL_SYSCALL
1317 int do_sysctl(int __user
*name
, int nlen
, void __user
*oldval
, size_t __user
*oldlenp
,
1318 void __user
*newval
, size_t newlen
)
1320 struct ctl_table_header
*head
;
1321 int error
= -ENOTDIR
;
1323 if (nlen
<= 0 || nlen
>= CTL_MAXNAME
)
1327 if (!oldlenp
|| get_user(old_len
, oldlenp
))
1331 for (head
= sysctl_head_next(NULL
); head
;
1332 head
= sysctl_head_next(head
)) {
1333 error
= parse_table(name
, nlen
, oldval
, oldlenp
,
1334 newval
, newlen
, head
->ctl_table
);
1335 if (error
!= -ENOTDIR
) {
1336 sysctl_head_finish(head
);
1343 asmlinkage
long sys_sysctl(struct __sysctl_args __user
*args
)
1345 struct __sysctl_args tmp
;
1348 if (copy_from_user(&tmp
, args
, sizeof(tmp
)))
1352 error
= do_sysctl(tmp
.name
, tmp
.nlen
, tmp
.oldval
, tmp
.oldlenp
,
1353 tmp
.newval
, tmp
.newlen
);
1357 #endif /* CONFIG_SYSCTL_SYSCALL */
1360 * sysctl_perm does NOT grant the superuser all rights automatically, because
1361 * some sysctl variables are readonly even to root.
1364 static int test_perm(int mode
, int op
)
1368 else if (in_egroup_p(0))
1370 if ((mode
& op
& 0007) == op
)
1375 int sysctl_perm(struct ctl_table
*table
, int op
)
1378 error
= security_sysctl(table
, op
);
1381 return test_perm(table
->mode
, op
);
1384 #ifdef CONFIG_SYSCTL_SYSCALL
1385 static int parse_table(int __user
*name
, int nlen
,
1386 void __user
*oldval
, size_t __user
*oldlenp
,
1387 void __user
*newval
, size_t newlen
,
1388 struct ctl_table
*table
)
1394 if (get_user(n
, name
))
1396 for ( ; table
->ctl_name
|| table
->procname
; table
++) {
1397 if (!table
->ctl_name
)
1399 if (n
== table
->ctl_name
) {
1402 if (sysctl_perm(table
, 001))
1406 table
= table
->child
;
1409 error
= do_sysctl_strategy(table
, name
, nlen
,
1418 /* Perform the actual read/write of a sysctl table entry. */
1419 int do_sysctl_strategy (struct ctl_table
*table
,
1420 int __user
*name
, int nlen
,
1421 void __user
*oldval
, size_t __user
*oldlenp
,
1422 void __user
*newval
, size_t newlen
)
1430 if (sysctl_perm(table
, op
))
1433 if (table
->strategy
) {
1434 rc
= table
->strategy(table
, name
, nlen
, oldval
, oldlenp
,
1442 /* If there is no strategy routine, or if the strategy returns
1443 * zero, proceed with automatic r/w */
1444 if (table
->data
&& table
->maxlen
) {
1445 rc
= sysctl_data(table
, name
, nlen
, oldval
, oldlenp
,
1452 #endif /* CONFIG_SYSCTL_SYSCALL */
1454 static void sysctl_set_parent(struct ctl_table
*parent
, struct ctl_table
*table
)
1456 for (; table
->ctl_name
|| table
->procname
; table
++) {
1457 table
->parent
= parent
;
1459 sysctl_set_parent(table
, table
->child
);
1463 static __init
int sysctl_init(void)
1465 sysctl_set_parent(NULL
, root_table
);
1469 core_initcall(sysctl_init
);
1472 * register_sysctl_table - register a sysctl hierarchy
1473 * @table: the top-level table structure
1475 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1476 * array. An entry with a ctl_name of 0 terminates the table.
1478 * The members of the &struct ctl_table structure are used as follows:
1480 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1481 * must be unique within that level of sysctl
1483 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1484 * enter a sysctl file
1486 * data - a pointer to data for use by proc_handler
1488 * maxlen - the maximum size in bytes of the data
1490 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1492 * child - a pointer to the child sysctl table if this entry is a directory, or
1495 * proc_handler - the text handler routine (described below)
1497 * strategy - the strategy routine (described below)
1499 * de - for internal use by the sysctl routines
1501 * extra1, extra2 - extra pointers usable by the proc handler routines
1503 * Leaf nodes in the sysctl tree will be represented by a single file
1504 * under /proc; non-leaf nodes will be represented by directories.
1506 * sysctl(2) can automatically manage read and write requests through
1507 * the sysctl table. The data and maxlen fields of the ctl_table
1508 * struct enable minimal validation of the values being written to be
1509 * performed, and the mode field allows minimal authentication.
1511 * More sophisticated management can be enabled by the provision of a
1512 * strategy routine with the table entry. This will be called before
1513 * any automatic read or write of the data is performed.
1515 * The strategy routine may return
1517 * < 0 - Error occurred (error is passed to user process)
1519 * 0 - OK - proceed with automatic read or write.
1521 * > 0 - OK - read or write has been done by the strategy routine, so
1522 * return immediately.
1524 * There must be a proc_handler routine for any terminal nodes
1525 * mirrored under /proc/sys (non-terminals are handled by a built-in
1526 * directory handler). Several default handlers are available to
1527 * cover common cases -
1529 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1530 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1531 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1533 * It is the handler's job to read the input buffer from user memory
1534 * and process it. The handler should return 0 on success.
1536 * This routine returns %NULL on a failure to register, and a pointer
1537 * to the table header on success.
1539 struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
)
1541 struct ctl_table_header
*tmp
;
1542 tmp
= kmalloc(sizeof(struct ctl_table_header
), GFP_KERNEL
);
1545 tmp
->ctl_table
= table
;
1546 INIT_LIST_HEAD(&tmp
->ctl_entry
);
1548 tmp
->unregistering
= NULL
;
1549 sysctl_set_parent(NULL
, table
);
1550 spin_lock(&sysctl_lock
);
1551 list_add_tail(&tmp
->ctl_entry
, &root_table_header
.ctl_entry
);
1552 spin_unlock(&sysctl_lock
);
1557 * unregister_sysctl_table - unregister a sysctl table hierarchy
1558 * @header: the header returned from register_sysctl_table
1560 * Unregisters the sysctl table and all children. proc entries may not
1561 * actually be removed until they are no longer used by anyone.
1563 void unregister_sysctl_table(struct ctl_table_header
* header
)
1566 spin_lock(&sysctl_lock
);
1567 start_unregistering(header
);
1568 spin_unlock(&sysctl_lock
);
1572 #else /* !CONFIG_SYSCTL */
1573 struct ctl_table_header
*register_sysctl_table(struct ctl_table
* table
)
1578 void unregister_sysctl_table(struct ctl_table_header
* table
)
1582 #endif /* CONFIG_SYSCTL */
1588 #ifdef CONFIG_PROC_SYSCTL
1590 static int _proc_do_string(void* data
, int maxlen
, int write
,
1591 struct file
*filp
, void __user
*buffer
,
1592 size_t *lenp
, loff_t
*ppos
)
1598 if (!data
|| !maxlen
|| !*lenp
) {
1606 while (len
< *lenp
) {
1607 if (get_user(c
, p
++))
1609 if (c
== 0 || c
== '\n')
1615 if(copy_from_user(data
, buffer
, len
))
1617 ((char *) data
)[len
] = 0;
1635 if(copy_to_user(buffer
, data
, len
))
1638 if(put_user('\n', ((char __user
*) buffer
) + len
))
1649 * proc_dostring - read a string sysctl
1650 * @table: the sysctl table
1651 * @write: %TRUE if this is a write to the sysctl file
1652 * @filp: the file structure
1653 * @buffer: the user buffer
1654 * @lenp: the size of the user buffer
1655 * @ppos: file position
1657 * Reads/writes a string from/to the user buffer. If the kernel
1658 * buffer provided is not large enough to hold the string, the
1659 * string is truncated. The copied string is %NULL-terminated.
1660 * If the string is being read by the user process, it is copied
1661 * and a newline '\n' is added. It is truncated if the buffer is
1664 * Returns 0 on success.
1666 int proc_dostring(struct ctl_table
*table
, int write
, struct file
*filp
,
1667 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1669 return _proc_do_string(table
->data
, table
->maxlen
, write
, filp
,
1670 buffer
, lenp
, ppos
);
1674 static int do_proc_dointvec_conv(int *negp
, unsigned long *lvalp
,
1676 int write
, void *data
)
1679 *valp
= *negp
? -*lvalp
: *lvalp
;
1684 *lvalp
= (unsigned long)-val
;
1687 *lvalp
= (unsigned long)val
;
1693 static int __do_proc_dointvec(void *tbl_data
, struct ctl_table
*table
,
1694 int write
, struct file
*filp
, void __user
*buffer
,
1695 size_t *lenp
, loff_t
*ppos
,
1696 int (*conv
)(int *negp
, unsigned long *lvalp
, int *valp
,
1697 int write
, void *data
),
1700 #define TMPBUFLEN 21
1701 int *i
, vleft
, first
=1, neg
, val
;
1705 char buf
[TMPBUFLEN
], *p
;
1706 char __user
*s
= buffer
;
1708 if (!tbl_data
|| !table
->maxlen
|| !*lenp
||
1709 (*ppos
&& !write
)) {
1714 i
= (int *) tbl_data
;
1715 vleft
= table
->maxlen
/ sizeof(*i
);
1719 conv
= do_proc_dointvec_conv
;
1721 for (; left
&& vleft
--; i
++, first
=0) {
1736 if (len
> sizeof(buf
) - 1)
1737 len
= sizeof(buf
) - 1;
1738 if (copy_from_user(buf
, s
, len
))
1742 if (*p
== '-' && left
> 1) {
1746 if (*p
< '0' || *p
> '9')
1749 lval
= simple_strtoul(p
, &p
, 0);
1752 if ((len
< left
) && *p
&& !isspace(*p
))
1759 if (conv(&neg
, &lval
, i
, 1, data
))
1766 if (conv(&neg
, &lval
, i
, 0, data
))
1769 sprintf(p
, "%s%lu", neg
? "-" : "", lval
);
1773 if(copy_to_user(s
, buf
, len
))
1780 if (!write
&& !first
&& left
) {
1781 if(put_user('\n', s
))
1788 if (get_user(c
, s
++))
1803 static int do_proc_dointvec(struct ctl_table
*table
, int write
, struct file
*filp
,
1804 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
,
1805 int (*conv
)(int *negp
, unsigned long *lvalp
, int *valp
,
1806 int write
, void *data
),
1809 return __do_proc_dointvec(table
->data
, table
, write
, filp
,
1810 buffer
, lenp
, ppos
, conv
, data
);
1814 * proc_dointvec - read a vector of integers
1815 * @table: the sysctl table
1816 * @write: %TRUE if this is a write to the sysctl file
1817 * @filp: the file structure
1818 * @buffer: the user buffer
1819 * @lenp: the size of the user buffer
1820 * @ppos: file position
1822 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1823 * values from/to the user buffer, treated as an ASCII string.
1825 * Returns 0 on success.
1827 int proc_dointvec(struct ctl_table
*table
, int write
, struct file
*filp
,
1828 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1830 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
1838 static int do_proc_dointvec_bset_conv(int *negp
, unsigned long *lvalp
,
1840 int write
, void *data
)
1842 int op
= *(int *)data
;
1844 int val
= *negp
? -*lvalp
: *lvalp
;
1846 case OP_SET
: *valp
= val
; break;
1847 case OP_AND
: *valp
&= val
; break;
1848 case OP_OR
: *valp
|= val
; break;
1854 *lvalp
= (unsigned long)-val
;
1857 *lvalp
= (unsigned long)val
;
1864 * init may raise the set.
1867 int proc_dointvec_bset(struct ctl_table
*table
, int write
, struct file
*filp
,
1868 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1872 if (write
&& !capable(CAP_SYS_MODULE
)) {
1876 op
= is_init(current
) ? OP_SET
: OP_AND
;
1877 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
1878 do_proc_dointvec_bset_conv
,&op
);
1882 * Taint values can only be increased
1884 static int proc_dointvec_taint(struct ctl_table
*table
, int write
, struct file
*filp
,
1885 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1889 if (write
&& !capable(CAP_SYS_ADMIN
))
1893 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
1894 do_proc_dointvec_bset_conv
,&op
);
1897 struct do_proc_dointvec_minmax_conv_param
{
1902 static int do_proc_dointvec_minmax_conv(int *negp
, unsigned long *lvalp
,
1904 int write
, void *data
)
1906 struct do_proc_dointvec_minmax_conv_param
*param
= data
;
1908 int val
= *negp
? -*lvalp
: *lvalp
;
1909 if ((param
->min
&& *param
->min
> val
) ||
1910 (param
->max
&& *param
->max
< val
))
1917 *lvalp
= (unsigned long)-val
;
1920 *lvalp
= (unsigned long)val
;
1927 * proc_dointvec_minmax - read a vector of integers with min/max values
1928 * @table: the sysctl table
1929 * @write: %TRUE if this is a write to the sysctl file
1930 * @filp: the file structure
1931 * @buffer: the user buffer
1932 * @lenp: the size of the user buffer
1933 * @ppos: file position
1935 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1936 * values from/to the user buffer, treated as an ASCII string.
1938 * This routine will ensure the values are within the range specified by
1939 * table->extra1 (min) and table->extra2 (max).
1941 * Returns 0 on success.
1943 int proc_dointvec_minmax(struct ctl_table
*table
, int write
, struct file
*filp
,
1944 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1946 struct do_proc_dointvec_minmax_conv_param param
= {
1947 .min
= (int *) table
->extra1
,
1948 .max
= (int *) table
->extra2
,
1950 return do_proc_dointvec(table
, write
, filp
, buffer
, lenp
, ppos
,
1951 do_proc_dointvec_minmax_conv
, ¶m
);
1954 static int __do_proc_doulongvec_minmax(void *data
, struct ctl_table
*table
, int write
,
1956 void __user
*buffer
,
1957 size_t *lenp
, loff_t
*ppos
,
1958 unsigned long convmul
,
1959 unsigned long convdiv
)
1961 #define TMPBUFLEN 21
1962 unsigned long *i
, *min
, *max
, val
;
1963 int vleft
, first
=1, neg
;
1965 char buf
[TMPBUFLEN
], *p
;
1966 char __user
*s
= buffer
;
1968 if (!data
|| !table
->maxlen
|| !*lenp
||
1969 (*ppos
&& !write
)) {
1974 i
= (unsigned long *) data
;
1975 min
= (unsigned long *) table
->extra1
;
1976 max
= (unsigned long *) table
->extra2
;
1977 vleft
= table
->maxlen
/ sizeof(unsigned long);
1980 for (; left
&& vleft
--; i
++, min
++, max
++, first
=0) {
1995 if (len
> TMPBUFLEN
-1)
1997 if (copy_from_user(buf
, s
, len
))
2001 if (*p
== '-' && left
> 1) {
2005 if (*p
< '0' || *p
> '9')
2007 val
= simple_strtoul(p
, &p
, 0) * convmul
/ convdiv
;
2009 if ((len
< left
) && *p
&& !isspace(*p
))
2018 if ((min
&& val
< *min
) || (max
&& val
> *max
))
2025 sprintf(p
, "%lu", convdiv
* (*i
) / convmul
);
2029 if(copy_to_user(s
, buf
, len
))
2036 if (!write
&& !first
&& left
) {
2037 if(put_user('\n', s
))
2044 if (get_user(c
, s
++))
2059 static int do_proc_doulongvec_minmax(struct ctl_table
*table
, int write
,
2061 void __user
*buffer
,
2062 size_t *lenp
, loff_t
*ppos
,
2063 unsigned long convmul
,
2064 unsigned long convdiv
)
2066 return __do_proc_doulongvec_minmax(table
->data
, table
, write
,
2067 filp
, buffer
, lenp
, ppos
, convmul
, convdiv
);
2071 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2072 * @table: the sysctl table
2073 * @write: %TRUE if this is a write to the sysctl file
2074 * @filp: the file structure
2075 * @buffer: the user buffer
2076 * @lenp: the size of the user buffer
2077 * @ppos: file position
2079 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2080 * values from/to the user buffer, treated as an ASCII string.
2082 * This routine will ensure the values are within the range specified by
2083 * table->extra1 (min) and table->extra2 (max).
2085 * Returns 0 on success.
2087 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
, struct file
*filp
,
2088 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2090 return do_proc_doulongvec_minmax(table
, write
, filp
, buffer
, lenp
, ppos
, 1l, 1l);
2094 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2095 * @table: the sysctl table
2096 * @write: %TRUE if this is a write to the sysctl file
2097 * @filp: the file structure
2098 * @buffer: the user buffer
2099 * @lenp: the size of the user buffer
2100 * @ppos: file position
2102 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2103 * values from/to the user buffer, treated as an ASCII string. The values
2104 * are treated as milliseconds, and converted to jiffies when they are stored.
2106 * This routine will ensure the values are within the range specified by
2107 * table->extra1 (min) and table->extra2 (max).
2109 * Returns 0 on success.
2111 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2113 void __user
*buffer
,
2114 size_t *lenp
, loff_t
*ppos
)
2116 return do_proc_doulongvec_minmax(table
, write
, filp
, buffer
,
2117 lenp
, ppos
, HZ
, 1000l);
2121 static int do_proc_dointvec_jiffies_conv(int *negp
, unsigned long *lvalp
,
2123 int write
, void *data
)
2126 if (*lvalp
> LONG_MAX
/ HZ
)
2128 *valp
= *negp
? -(*lvalp
*HZ
) : (*lvalp
*HZ
);
2134 lval
= (unsigned long)-val
;
2137 lval
= (unsigned long)val
;
2144 static int do_proc_dointvec_userhz_jiffies_conv(int *negp
, unsigned long *lvalp
,
2146 int write
, void *data
)
2149 if (USER_HZ
< HZ
&& *lvalp
> (LONG_MAX
/ HZ
) * USER_HZ
)
2151 *valp
= clock_t_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2157 lval
= (unsigned long)-val
;
2160 lval
= (unsigned long)val
;
2162 *lvalp
= jiffies_to_clock_t(lval
);
2167 static int do_proc_dointvec_ms_jiffies_conv(int *negp
, unsigned long *lvalp
,
2169 int write
, void *data
)
2172 *valp
= msecs_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2178 lval
= (unsigned long)-val
;
2181 lval
= (unsigned long)val
;
2183 *lvalp
= jiffies_to_msecs(lval
);
2189 * proc_dointvec_jiffies - read a vector of integers as seconds
2190 * @table: the sysctl table
2191 * @write: %TRUE if this is a write to the sysctl file
2192 * @filp: the file structure
2193 * @buffer: the user buffer
2194 * @lenp: the size of the user buffer
2195 * @ppos: file position
2197 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2198 * values from/to the user buffer, treated as an ASCII string.
2199 * The values read are assumed to be in seconds, and are converted into
2202 * Returns 0 on success.
2204 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2205 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2207 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2208 do_proc_dointvec_jiffies_conv
,NULL
);
2212 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2213 * @table: the sysctl table
2214 * @write: %TRUE if this is a write to the sysctl file
2215 * @filp: the file structure
2216 * @buffer: the user buffer
2217 * @lenp: the size of the user buffer
2218 * @ppos: pointer to the file position
2220 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2221 * values from/to the user buffer, treated as an ASCII string.
2222 * The values read are assumed to be in 1/USER_HZ seconds, and
2223 * are converted into jiffies.
2225 * Returns 0 on success.
2227 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2228 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2230 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2231 do_proc_dointvec_userhz_jiffies_conv
,NULL
);
2235 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2236 * @table: the sysctl table
2237 * @write: %TRUE if this is a write to the sysctl file
2238 * @filp: the file structure
2239 * @buffer: the user buffer
2240 * @lenp: the size of the user buffer
2241 * @ppos: file position
2242 * @ppos: the current position in the file
2244 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2245 * values from/to the user buffer, treated as an ASCII string.
2246 * The values read are assumed to be in 1/1000 seconds, and
2247 * are converted into jiffies.
2249 * Returns 0 on success.
2251 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2252 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2254 return do_proc_dointvec(table
, write
, filp
, buffer
, lenp
, ppos
,
2255 do_proc_dointvec_ms_jiffies_conv
, NULL
);
2258 static int proc_do_cad_pid(struct ctl_table
*table
, int write
, struct file
*filp
,
2259 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2261 struct pid
*new_pid
;
2265 tmp
= pid_nr(cad_pid
);
2267 r
= __do_proc_dointvec(&tmp
, table
, write
, filp
, buffer
,
2268 lenp
, ppos
, NULL
, NULL
);
2272 new_pid
= find_get_pid(tmp
);
2276 put_pid(xchg(&cad_pid
, new_pid
));
2280 #else /* CONFIG_PROC_FS */
2282 int proc_dostring(struct ctl_table
*table
, int write
, struct file
*filp
,
2283 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2288 int proc_dointvec(struct ctl_table
*table
, int write
, struct file
*filp
,
2289 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2294 int proc_dointvec_bset(struct ctl_table
*table
, int write
, struct file
*filp
,
2295 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2300 int proc_dointvec_minmax(struct ctl_table
*table
, int write
, struct file
*filp
,
2301 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2306 int proc_dointvec_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2307 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2312 int proc_dointvec_userhz_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2313 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2318 int proc_dointvec_ms_jiffies(struct ctl_table
*table
, int write
, struct file
*filp
,
2319 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2324 int proc_doulongvec_minmax(struct ctl_table
*table
, int write
, struct file
*filp
,
2325 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2330 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table
*table
, int write
,
2332 void __user
*buffer
,
2333 size_t *lenp
, loff_t
*ppos
)
2339 #endif /* CONFIG_PROC_FS */
2342 #ifdef CONFIG_SYSCTL_SYSCALL
2344 * General sysctl support routines
2347 /* The generic sysctl data routine (used if no strategy routine supplied) */
2348 int sysctl_data(struct ctl_table
*table
, int __user
*name
, int nlen
,
2349 void __user
*oldval
, size_t __user
*oldlenp
,
2350 void __user
*newval
, size_t newlen
)
2354 /* Get out of I don't have a variable */
2355 if (!table
->data
|| !table
->maxlen
)
2358 if (oldval
&& oldlenp
) {
2359 if (get_user(len
, oldlenp
))
2362 if (len
> table
->maxlen
)
2363 len
= table
->maxlen
;
2364 if (copy_to_user(oldval
, table
->data
, len
))
2366 if (put_user(len
, oldlenp
))
2371 if (newval
&& newlen
) {
2372 if (newlen
> table
->maxlen
)
2373 newlen
= table
->maxlen
;
2375 if (copy_from_user(table
->data
, newval
, newlen
))
2381 /* The generic string strategy routine: */
2382 int sysctl_string(struct ctl_table
*table
, int __user
*name
, int nlen
,
2383 void __user
*oldval
, size_t __user
*oldlenp
,
2384 void __user
*newval
, size_t newlen
)
2386 if (!table
->data
|| !table
->maxlen
)
2389 if (oldval
&& oldlenp
) {
2391 if (get_user(bufsize
, oldlenp
))
2394 size_t len
= strlen(table
->data
), copied
;
2396 /* This shouldn't trigger for a well-formed sysctl */
2397 if (len
> table
->maxlen
)
2398 len
= table
->maxlen
;
2400 /* Copy up to a max of bufsize-1 bytes of the string */
2401 copied
= (len
>= bufsize
) ? bufsize
- 1 : len
;
2403 if (copy_to_user(oldval
, table
->data
, copied
) ||
2404 put_user(0, (char __user
*)(oldval
+ copied
)))
2406 if (put_user(len
, oldlenp
))
2410 if (newval
&& newlen
) {
2411 size_t len
= newlen
;
2412 if (len
> table
->maxlen
)
2413 len
= table
->maxlen
;
2414 if(copy_from_user(table
->data
, newval
, len
))
2416 if (len
== table
->maxlen
)
2418 ((char *) table
->data
)[len
] = 0;
2424 * This function makes sure that all of the integers in the vector
2425 * are between the minimum and maximum values given in the arrays
2426 * table->extra1 and table->extra2, respectively.
2428 int sysctl_intvec(struct ctl_table
*table
, int __user
*name
, int nlen
,
2429 void __user
*oldval
, size_t __user
*oldlenp
,
2430 void __user
*newval
, size_t newlen
)
2433 if (newval
&& newlen
) {
2434 int __user
*vec
= (int __user
*) newval
;
2435 int *min
= (int *) table
->extra1
;
2436 int *max
= (int *) table
->extra2
;
2440 if (newlen
% sizeof(int) != 0)
2443 if (!table
->extra1
&& !table
->extra2
)
2446 if (newlen
> table
->maxlen
)
2447 newlen
= table
->maxlen
;
2448 length
= newlen
/ sizeof(int);
2450 for (i
= 0; i
< length
; i
++) {
2452 if (get_user(value
, vec
+ i
))
2454 if (min
&& value
< min
[i
])
2456 if (max
&& value
> max
[i
])
2463 /* Strategy function to convert jiffies to seconds */
2464 int sysctl_jiffies(struct ctl_table
*table
, int __user
*name
, int nlen
,
2465 void __user
*oldval
, size_t __user
*oldlenp
,
2466 void __user
*newval
, size_t newlen
)
2468 if (oldval
&& oldlenp
) {
2471 if (get_user(olen
, oldlenp
))
2476 if (olen
< sizeof(int))
2479 val
= *(int *)(table
->data
) / HZ
;
2480 if (put_user(val
, (int __user
*)oldval
))
2482 if (put_user(sizeof(int), oldlenp
))
2486 if (newval
&& newlen
) {
2488 if (newlen
!= sizeof(int))
2490 if (get_user(new, (int __user
*)newval
))
2492 *(int *)(table
->data
) = new*HZ
;
2497 /* Strategy function to convert jiffies to seconds */
2498 int sysctl_ms_jiffies(struct ctl_table
*table
, int __user
*name
, int nlen
,
2499 void __user
*oldval
, size_t __user
*oldlenp
,
2500 void __user
*newval
, size_t newlen
)
2502 if (oldval
&& oldlenp
) {
2505 if (get_user(olen
, oldlenp
))
2510 if (olen
< sizeof(int))
2513 val
= jiffies_to_msecs(*(int *)(table
->data
));
2514 if (put_user(val
, (int __user
*)oldval
))
2516 if (put_user(sizeof(int), oldlenp
))
2520 if (newval
&& newlen
) {
2522 if (newlen
!= sizeof(int))
2524 if (get_user(new, (int __user
*)newval
))
2526 *(int *)(table
->data
) = msecs_to_jiffies(new);
2533 #else /* CONFIG_SYSCTL_SYSCALL */
2536 asmlinkage
long sys_sysctl(struct __sysctl_args __user
*args
)
2538 static int msg_count
;
2539 struct __sysctl_args tmp
;
2540 int name
[CTL_MAXNAME
];
2543 /* Read in the sysctl name for better debug message logging */
2544 if (copy_from_user(&tmp
, args
, sizeof(tmp
)))
2546 if (tmp
.nlen
<= 0 || tmp
.nlen
>= CTL_MAXNAME
)
2548 for (i
= 0; i
< tmp
.nlen
; i
++)
2549 if (get_user(name
[i
], tmp
.name
+ i
))
2552 /* Ignore accesses to kernel.version */
2553 if ((tmp
.nlen
== 2) && (name
[0] == CTL_KERN
) && (name
[1] == KERN_VERSION
))
2556 if (msg_count
< 5) {
2559 "warning: process `%s' used the removed sysctl "
2560 "system call with ", current
->comm
);
2561 for (i
= 0; i
< tmp
.nlen
; i
++)
2562 printk("%d.", name
[i
]);
2569 int sysctl_data(struct ctl_table
*table
, int __user
*name
, int nlen
,
2570 void __user
*oldval
, size_t __user
*oldlenp
,
2571 void __user
*newval
, size_t newlen
)
2576 int sysctl_string(struct ctl_table
*table
, int __user
*name
, int nlen
,
2577 void __user
*oldval
, size_t __user
*oldlenp
,
2578 void __user
*newval
, size_t newlen
)
2583 int sysctl_intvec(struct ctl_table
*table
, int __user
*name
, int nlen
,
2584 void __user
*oldval
, size_t __user
*oldlenp
,
2585 void __user
*newval
, size_t newlen
)
2590 int sysctl_jiffies(struct ctl_table
*table
, int __user
*name
, int nlen
,
2591 void __user
*oldval
, size_t __user
*oldlenp
,
2592 void __user
*newval
, size_t newlen
)
2597 int sysctl_ms_jiffies(struct ctl_table
*table
, int __user
*name
, int nlen
,
2598 void __user
*oldval
, size_t __user
*oldlenp
,
2599 void __user
*newval
, size_t newlen
)
2604 #endif /* CONFIG_SYSCTL_SYSCALL */
2607 * No sense putting this after each symbol definition, twice,
2608 * exception granted :-)
2610 EXPORT_SYMBOL(proc_dointvec
);
2611 EXPORT_SYMBOL(proc_dointvec_jiffies
);
2612 EXPORT_SYMBOL(proc_dointvec_minmax
);
2613 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies
);
2614 EXPORT_SYMBOL(proc_dointvec_ms_jiffies
);
2615 EXPORT_SYMBOL(proc_dostring
);
2616 EXPORT_SYMBOL(proc_doulongvec_minmax
);
2617 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax
);
2618 EXPORT_SYMBOL(register_sysctl_table
);
2619 EXPORT_SYMBOL(sysctl_intvec
);
2620 EXPORT_SYMBOL(sysctl_jiffies
);
2621 EXPORT_SYMBOL(sysctl_ms_jiffies
);
2622 EXPORT_SYMBOL(sysctl_string
);
2623 EXPORT_SYMBOL(sysctl_data
);
2624 EXPORT_SYMBOL(unregister_sysctl_table
);