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_granularity_ns",
226 .data
= &sysctl_sched_granularity
,
227 .maxlen
= sizeof(unsigned int),
229 .proc_handler
= &proc_dointvec_minmax
,
230 .strategy
= &sysctl_intvec
,
231 .extra1
= &min_sched_granularity_ns
,
232 .extra2
= &max_sched_granularity_ns
,
235 .ctl_name
= CTL_UNNUMBERED
,
236 .procname
= "sched_latency_ns",
237 .data
= &sysctl_sched_latency
,
238 .maxlen
= sizeof(unsigned int),
240 .proc_handler
= &proc_dointvec_minmax
,
241 .strategy
= &sysctl_intvec
,
242 .extra1
= &min_sched_granularity_ns
,
243 .extra2
= &max_sched_granularity_ns
,
246 .ctl_name
= CTL_UNNUMBERED
,
247 .procname
= "sched_wakeup_granularity_ns",
248 .data
= &sysctl_sched_wakeup_granularity
,
249 .maxlen
= sizeof(unsigned int),
251 .proc_handler
= &proc_dointvec_minmax
,
252 .strategy
= &sysctl_intvec
,
253 .extra1
= &min_wakeup_granularity_ns
,
254 .extra2
= &max_wakeup_granularity_ns
,
257 .ctl_name
= CTL_UNNUMBERED
,
258 .procname
= "sched_batch_wakeup_granularity_ns",
259 .data
= &sysctl_sched_batch_wakeup_granularity
,
260 .maxlen
= sizeof(unsigned int),
262 .proc_handler
= &proc_dointvec_minmax
,
263 .strategy
= &sysctl_intvec
,
264 .extra1
= &min_wakeup_granularity_ns
,
265 .extra2
= &max_wakeup_granularity_ns
,
268 .ctl_name
= CTL_UNNUMBERED
,
269 .procname
= "sched_stat_granularity_ns",
270 .data
= &sysctl_sched_stat_granularity
,
271 .maxlen
= sizeof(unsigned int),
273 .proc_handler
= &proc_dointvec_minmax
,
274 .strategy
= &sysctl_intvec
,
275 .extra1
= &min_wakeup_granularity_ns
,
276 .extra2
= &max_wakeup_granularity_ns
,
279 .ctl_name
= CTL_UNNUMBERED
,
280 .procname
= "sched_runtime_limit_ns",
281 .data
= &sysctl_sched_runtime_limit
,
282 .maxlen
= sizeof(unsigned int),
284 .proc_handler
= &proc_dointvec_minmax
,
285 .strategy
= &sysctl_intvec
,
286 .extra1
= &min_sched_granularity_ns
,
287 .extra2
= &max_sched_granularity_ns
,
290 .ctl_name
= CTL_UNNUMBERED
,
291 .procname
= "sched_child_runs_first",
292 .data
= &sysctl_sched_child_runs_first
,
293 .maxlen
= sizeof(unsigned int),
295 .proc_handler
= &proc_dointvec
,
298 .ctl_name
= CTL_UNNUMBERED
,
299 .procname
= "sched_features",
300 .data
= &sysctl_sched_features
,
301 .maxlen
= sizeof(unsigned int),
303 .proc_handler
= &proc_dointvec
,
306 #ifdef CONFIG_PROVE_LOCKING
308 .ctl_name
= CTL_UNNUMBERED
,
309 .procname
= "prove_locking",
310 .data
= &prove_locking
,
311 .maxlen
= sizeof(int),
313 .proc_handler
= &proc_dointvec
,
316 #ifdef CONFIG_LOCK_STAT
318 .ctl_name
= CTL_UNNUMBERED
,
319 .procname
= "lock_stat",
321 .maxlen
= sizeof(int),
323 .proc_handler
= &proc_dointvec
,
327 .ctl_name
= KERN_PANIC
,
329 .data
= &panic_timeout
,
330 .maxlen
= sizeof(int),
332 .proc_handler
= &proc_dointvec
,
335 .ctl_name
= KERN_CORE_USES_PID
,
336 .procname
= "core_uses_pid",
337 .data
= &core_uses_pid
,
338 .maxlen
= sizeof(int),
340 .proc_handler
= &proc_dointvec
,
342 #ifdef CONFIG_AUDITSYSCALL
344 .ctl_name
= CTL_UNNUMBERED
,
345 .procname
= "audit_argv_kb",
346 .data
= &audit_argv_kb
,
347 .maxlen
= sizeof(int),
349 .proc_handler
= &proc_dointvec
,
353 .ctl_name
= KERN_CORE_PATTERN
,
354 .procname
= "core_pattern",
355 .data
= core_pattern
,
356 .maxlen
= CORENAME_MAX_SIZE
,
358 .proc_handler
= &proc_dostring
,
359 .strategy
= &sysctl_string
,
361 #ifdef CONFIG_PROC_SYSCTL
363 .ctl_name
= KERN_TAINTED
,
364 .procname
= "tainted",
366 .maxlen
= sizeof(int),
368 .proc_handler
= &proc_dointvec_taint
,
372 .ctl_name
= KERN_CAP_BSET
,
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
,
534 #ifdef CONFIG_UNIX98_PTYS
536 .ctl_name
= KERN_PTY
,
543 .ctl_name
= KERN_OVERFLOWUID
,
544 .procname
= "overflowuid",
545 .data
= &overflowuid
,
546 .maxlen
= sizeof(int),
548 .proc_handler
= &proc_dointvec_minmax
,
549 .strategy
= &sysctl_intvec
,
550 .extra1
= &minolduid
,
551 .extra2
= &maxolduid
,
554 .ctl_name
= KERN_OVERFLOWGID
,
555 .procname
= "overflowgid",
556 .data
= &overflowgid
,
557 .maxlen
= sizeof(int),
559 .proc_handler
= &proc_dointvec_minmax
,
560 .strategy
= &sysctl_intvec
,
561 .extra1
= &minolduid
,
562 .extra2
= &maxolduid
,
565 #ifdef CONFIG_MATHEMU
567 .ctl_name
= KERN_IEEE_EMULATION_WARNINGS
,
568 .procname
= "ieee_emulation_warnings",
569 .data
= &sysctl_ieee_emulation_warnings
,
570 .maxlen
= sizeof(int),
572 .proc_handler
= &proc_dointvec
,
575 #ifdef CONFIG_NO_IDLE_HZ
577 .ctl_name
= KERN_HZ_TIMER
,
578 .procname
= "hz_timer",
579 .data
= &sysctl_hz_timer
,
580 .maxlen
= sizeof(int),
582 .proc_handler
= &proc_dointvec
,
586 .ctl_name
= KERN_S390_USER_DEBUG_LOGGING
,
587 .procname
= "userprocess_debug",
588 .data
= &sysctl_userprocess_debug
,
589 .maxlen
= sizeof(int),
591 .proc_handler
= &proc_dointvec
,
595 .ctl_name
= KERN_PIDMAX
,
596 .procname
= "pid_max",
598 .maxlen
= sizeof (int),
600 .proc_handler
= &proc_dointvec_minmax
,
601 .strategy
= sysctl_intvec
,
602 .extra1
= &pid_max_min
,
603 .extra2
= &pid_max_max
,
606 .ctl_name
= KERN_PANIC_ON_OOPS
,
607 .procname
= "panic_on_oops",
608 .data
= &panic_on_oops
,
609 .maxlen
= sizeof(int),
611 .proc_handler
= &proc_dointvec
,
614 .ctl_name
= KERN_PRINTK_RATELIMIT
,
615 .procname
= "printk_ratelimit",
616 .data
= &printk_ratelimit_jiffies
,
617 .maxlen
= sizeof(int),
619 .proc_handler
= &proc_dointvec_jiffies
,
620 .strategy
= &sysctl_jiffies
,
623 .ctl_name
= KERN_PRINTK_RATELIMIT_BURST
,
624 .procname
= "printk_ratelimit_burst",
625 .data
= &printk_ratelimit_burst
,
626 .maxlen
= sizeof(int),
628 .proc_handler
= &proc_dointvec
,
631 .ctl_name
= KERN_NGROUPS_MAX
,
632 .procname
= "ngroups_max",
633 .data
= &ngroups_max
,
634 .maxlen
= sizeof (int),
636 .proc_handler
= &proc_dointvec
,
638 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
640 .ctl_name
= KERN_UNKNOWN_NMI_PANIC
,
641 .procname
= "unknown_nmi_panic",
642 .data
= &unknown_nmi_panic
,
643 .maxlen
= sizeof (int),
645 .proc_handler
= &proc_dointvec
,
648 .ctl_name
= KERN_NMI_WATCHDOG
,
649 .procname
= "nmi_watchdog",
650 .data
= &nmi_watchdog_enabled
,
651 .maxlen
= sizeof (int),
653 .proc_handler
= &proc_nmi_enabled
,
656 #if defined(CONFIG_X86)
658 .ctl_name
= KERN_PANIC_ON_NMI
,
659 .procname
= "panic_on_unrecovered_nmi",
660 .data
= &panic_on_unrecovered_nmi
,
661 .maxlen
= sizeof(int),
663 .proc_handler
= &proc_dointvec
,
666 .ctl_name
= KERN_BOOTLOADER_TYPE
,
667 .procname
= "bootloader_type",
668 .data
= &bootloader_type
,
669 .maxlen
= sizeof (int),
671 .proc_handler
= &proc_dointvec
,
674 .ctl_name
= CTL_UNNUMBERED
,
675 .procname
= "kstack_depth_to_print",
676 .data
= &kstack_depth_to_print
,
677 .maxlen
= sizeof(int),
679 .proc_handler
= &proc_dointvec
,
682 #if defined(CONFIG_MMU)
684 .ctl_name
= KERN_RANDOMIZE
,
685 .procname
= "randomize_va_space",
686 .data
= &randomize_va_space
,
687 .maxlen
= sizeof(int),
689 .proc_handler
= &proc_dointvec
,
692 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
694 .ctl_name
= KERN_SPIN_RETRY
,
695 .procname
= "spin_retry",
697 .maxlen
= sizeof (int),
699 .proc_handler
= &proc_dointvec
,
702 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
704 .ctl_name
= KERN_ACPI_VIDEO_FLAGS
,
705 .procname
= "acpi_video_flags",
706 .data
= &acpi_realmode_flags
,
707 .maxlen
= sizeof (unsigned long),
709 .proc_handler
= &proc_doulongvec_minmax
,
714 .ctl_name
= KERN_IA64_UNALIGNED
,
715 .procname
= "ignore-unaligned-usertrap",
716 .data
= &no_unaligned_warning
,
717 .maxlen
= sizeof (int),
719 .proc_handler
= &proc_dointvec
,
724 .ctl_name
= KERN_COMPAT_LOG
,
725 .procname
= "compat-log",
727 .maxlen
= sizeof (int),
729 .proc_handler
= &proc_dointvec
,
732 #ifdef CONFIG_RT_MUTEXES
734 .ctl_name
= KERN_MAX_LOCK_DEPTH
,
735 .procname
= "max_lock_depth",
736 .data
= &max_lock_depth
,
737 .maxlen
= sizeof(int),
739 .proc_handler
= &proc_dointvec
,
742 #ifdef CONFIG_PROC_FS
744 .ctl_name
= CTL_UNNUMBERED
,
745 .procname
= "maps_protect",
746 .data
= &maps_protect
,
747 .maxlen
= sizeof(int),
749 .proc_handler
= &proc_dointvec
,
753 .ctl_name
= CTL_UNNUMBERED
,
754 .procname
= "poweroff_cmd",
755 .data
= &poweroff_cmd
,
756 .maxlen
= POWEROFF_CMD_PATH_LEN
,
758 .proc_handler
= &proc_dostring
,
759 .strategy
= &sysctl_string
,
762 * NOTE: do not add new entries to this table unless you have read
763 * Documentation/sysctl/ctl_unnumbered.txt
768 /* Constants for minimum and maximum testing in vm_table.
769 We use these as one-element integer vectors. */
772 static int one_hundred
= 100;
775 static ctl_table vm_table
[] = {
777 .ctl_name
= VM_OVERCOMMIT_MEMORY
,
778 .procname
= "overcommit_memory",
779 .data
= &sysctl_overcommit_memory
,
780 .maxlen
= sizeof(sysctl_overcommit_memory
),
782 .proc_handler
= &proc_dointvec
,
785 .ctl_name
= VM_PANIC_ON_OOM
,
786 .procname
= "panic_on_oom",
787 .data
= &sysctl_panic_on_oom
,
788 .maxlen
= sizeof(sysctl_panic_on_oom
),
790 .proc_handler
= &proc_dointvec
,
793 .ctl_name
= VM_OVERCOMMIT_RATIO
,
794 .procname
= "overcommit_ratio",
795 .data
= &sysctl_overcommit_ratio
,
796 .maxlen
= sizeof(sysctl_overcommit_ratio
),
798 .proc_handler
= &proc_dointvec
,
801 .ctl_name
= VM_PAGE_CLUSTER
,
802 .procname
= "page-cluster",
803 .data
= &page_cluster
,
804 .maxlen
= sizeof(int),
806 .proc_handler
= &proc_dointvec
,
809 .ctl_name
= VM_DIRTY_BACKGROUND
,
810 .procname
= "dirty_background_ratio",
811 .data
= &dirty_background_ratio
,
812 .maxlen
= sizeof(dirty_background_ratio
),
814 .proc_handler
= &proc_dointvec_minmax
,
815 .strategy
= &sysctl_intvec
,
817 .extra2
= &one_hundred
,
820 .ctl_name
= VM_DIRTY_RATIO
,
821 .procname
= "dirty_ratio",
822 .data
= &vm_dirty_ratio
,
823 .maxlen
= sizeof(vm_dirty_ratio
),
825 .proc_handler
= &proc_dointvec_minmax
,
826 .strategy
= &sysctl_intvec
,
828 .extra2
= &one_hundred
,
831 .ctl_name
= VM_DIRTY_WB_CS
,
832 .procname
= "dirty_writeback_centisecs",
833 .data
= &dirty_writeback_interval
,
834 .maxlen
= sizeof(dirty_writeback_interval
),
836 .proc_handler
= &dirty_writeback_centisecs_handler
,
839 .ctl_name
= VM_DIRTY_EXPIRE_CS
,
840 .procname
= "dirty_expire_centisecs",
841 .data
= &dirty_expire_interval
,
842 .maxlen
= sizeof(dirty_expire_interval
),
844 .proc_handler
= &proc_dointvec_userhz_jiffies
,
847 .ctl_name
= VM_NR_PDFLUSH_THREADS
,
848 .procname
= "nr_pdflush_threads",
849 .data
= &nr_pdflush_threads
,
850 .maxlen
= sizeof nr_pdflush_threads
,
851 .mode
= 0444 /* read-only*/,
852 .proc_handler
= &proc_dointvec
,
855 .ctl_name
= VM_SWAPPINESS
,
856 .procname
= "swappiness",
857 .data
= &vm_swappiness
,
858 .maxlen
= sizeof(vm_swappiness
),
860 .proc_handler
= &proc_dointvec_minmax
,
861 .strategy
= &sysctl_intvec
,
863 .extra2
= &one_hundred
,
865 #ifdef CONFIG_HUGETLB_PAGE
867 .ctl_name
= VM_HUGETLB_PAGES
,
868 .procname
= "nr_hugepages",
869 .data
= &max_huge_pages
,
870 .maxlen
= sizeof(unsigned long),
872 .proc_handler
= &hugetlb_sysctl_handler
,
873 .extra1
= (void *)&hugetlb_zero
,
874 .extra2
= (void *)&hugetlb_infinity
,
877 .ctl_name
= VM_HUGETLB_GROUP
,
878 .procname
= "hugetlb_shm_group",
879 .data
= &sysctl_hugetlb_shm_group
,
880 .maxlen
= sizeof(gid_t
),
882 .proc_handler
= &proc_dointvec
,
885 .ctl_name
= CTL_UNNUMBERED
,
886 .procname
= "hugepages_treat_as_movable",
887 .data
= &hugepages_treat_as_movable
,
888 .maxlen
= sizeof(int),
890 .proc_handler
= &hugetlb_treat_movable_handler
,
894 .ctl_name
= VM_LOWMEM_RESERVE_RATIO
,
895 .procname
= "lowmem_reserve_ratio",
896 .data
= &sysctl_lowmem_reserve_ratio
,
897 .maxlen
= sizeof(sysctl_lowmem_reserve_ratio
),
899 .proc_handler
= &lowmem_reserve_ratio_sysctl_handler
,
900 .strategy
= &sysctl_intvec
,
903 .ctl_name
= VM_DROP_PAGECACHE
,
904 .procname
= "drop_caches",
905 .data
= &sysctl_drop_caches
,
906 .maxlen
= sizeof(int),
908 .proc_handler
= drop_caches_sysctl_handler
,
909 .strategy
= &sysctl_intvec
,
912 .ctl_name
= VM_MIN_FREE_KBYTES
,
913 .procname
= "min_free_kbytes",
914 .data
= &min_free_kbytes
,
915 .maxlen
= sizeof(min_free_kbytes
),
917 .proc_handler
= &min_free_kbytes_sysctl_handler
,
918 .strategy
= &sysctl_intvec
,
922 .ctl_name
= VM_PERCPU_PAGELIST_FRACTION
,
923 .procname
= "percpu_pagelist_fraction",
924 .data
= &percpu_pagelist_fraction
,
925 .maxlen
= sizeof(percpu_pagelist_fraction
),
927 .proc_handler
= &percpu_pagelist_fraction_sysctl_handler
,
928 .strategy
= &sysctl_intvec
,
929 .extra1
= &min_percpu_pagelist_fract
,
933 .ctl_name
= VM_MAX_MAP_COUNT
,
934 .procname
= "max_map_count",
935 .data
= &sysctl_max_map_count
,
936 .maxlen
= sizeof(sysctl_max_map_count
),
938 .proc_handler
= &proc_dointvec
942 .ctl_name
= VM_LAPTOP_MODE
,
943 .procname
= "laptop_mode",
944 .data
= &laptop_mode
,
945 .maxlen
= sizeof(laptop_mode
),
947 .proc_handler
= &proc_dointvec_jiffies
,
948 .strategy
= &sysctl_jiffies
,
951 .ctl_name
= VM_BLOCK_DUMP
,
952 .procname
= "block_dump",
954 .maxlen
= sizeof(block_dump
),
956 .proc_handler
= &proc_dointvec
,
957 .strategy
= &sysctl_intvec
,
961 .ctl_name
= VM_VFS_CACHE_PRESSURE
,
962 .procname
= "vfs_cache_pressure",
963 .data
= &sysctl_vfs_cache_pressure
,
964 .maxlen
= sizeof(sysctl_vfs_cache_pressure
),
966 .proc_handler
= &proc_dointvec
,
967 .strategy
= &sysctl_intvec
,
970 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
972 .ctl_name
= VM_LEGACY_VA_LAYOUT
,
973 .procname
= "legacy_va_layout",
974 .data
= &sysctl_legacy_va_layout
,
975 .maxlen
= sizeof(sysctl_legacy_va_layout
),
977 .proc_handler
= &proc_dointvec
,
978 .strategy
= &sysctl_intvec
,
984 .ctl_name
= VM_ZONE_RECLAIM_MODE
,
985 .procname
= "zone_reclaim_mode",
986 .data
= &zone_reclaim_mode
,
987 .maxlen
= sizeof(zone_reclaim_mode
),
989 .proc_handler
= &proc_dointvec
,
990 .strategy
= &sysctl_intvec
,
994 .ctl_name
= VM_MIN_UNMAPPED
,
995 .procname
= "min_unmapped_ratio",
996 .data
= &sysctl_min_unmapped_ratio
,
997 .maxlen
= sizeof(sysctl_min_unmapped_ratio
),
999 .proc_handler
= &sysctl_min_unmapped_ratio_sysctl_handler
,
1000 .strategy
= &sysctl_intvec
,
1002 .extra2
= &one_hundred
,
1005 .ctl_name
= VM_MIN_SLAB
,
1006 .procname
= "min_slab_ratio",
1007 .data
= &sysctl_min_slab_ratio
,
1008 .maxlen
= sizeof(sysctl_min_slab_ratio
),
1010 .proc_handler
= &sysctl_min_slab_ratio_sysctl_handler
,
1011 .strategy
= &sysctl_intvec
,
1013 .extra2
= &one_hundred
,
1018 .ctl_name
= CTL_UNNUMBERED
,
1019 .procname
= "stat_interval",
1020 .data
= &sysctl_stat_interval
,
1021 .maxlen
= sizeof(sysctl_stat_interval
),
1023 .proc_handler
= &proc_dointvec_jiffies
,
1024 .strategy
= &sysctl_jiffies
,
1027 #ifdef CONFIG_SECURITY
1029 .ctl_name
= CTL_UNNUMBERED
,
1030 .procname
= "mmap_min_addr",
1031 .data
= &mmap_min_addr
,
1032 .maxlen
= sizeof(unsigned long),
1034 .proc_handler
= &proc_doulongvec_minmax
,
1039 .ctl_name
= CTL_UNNUMBERED
,
1040 .procname
= "numa_zonelist_order",
1041 .data
= &numa_zonelist_order
,
1042 .maxlen
= NUMA_ZONELIST_ORDER_LEN
,
1044 .proc_handler
= &numa_zonelist_order_handler
,
1045 .strategy
= &sysctl_string
,
1048 #if defined(CONFIG_X86_32) || \
1049 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1051 .ctl_name
= VM_VDSO_ENABLED
,
1052 .procname
= "vdso_enabled",
1053 .data
= &vdso_enabled
,
1054 .maxlen
= sizeof(vdso_enabled
),
1056 .proc_handler
= &proc_dointvec
,
1057 .strategy
= &sysctl_intvec
,
1062 * NOTE: do not add new entries to this table unless you have read
1063 * Documentation/sysctl/ctl_unnumbered.txt
1068 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1069 static ctl_table binfmt_misc_table
[] = {
1074 static ctl_table fs_table
[] = {
1076 .ctl_name
= FS_NRINODE
,
1077 .procname
= "inode-nr",
1078 .data
= &inodes_stat
,
1079 .maxlen
= 2*sizeof(int),
1081 .proc_handler
= &proc_dointvec
,
1084 .ctl_name
= FS_STATINODE
,
1085 .procname
= "inode-state",
1086 .data
= &inodes_stat
,
1087 .maxlen
= 7*sizeof(int),
1089 .proc_handler
= &proc_dointvec
,
1092 .ctl_name
= FS_NRFILE
,
1093 .procname
= "file-nr",
1094 .data
= &files_stat
,
1095 .maxlen
= 3*sizeof(int),
1097 .proc_handler
= &proc_nr_files
,
1100 .ctl_name
= FS_MAXFILE
,
1101 .procname
= "file-max",
1102 .data
= &files_stat
.max_files
,
1103 .maxlen
= sizeof(int),
1105 .proc_handler
= &proc_dointvec
,
1108 .ctl_name
= FS_DENTRY
,
1109 .procname
= "dentry-state",
1110 .data
= &dentry_stat
,
1111 .maxlen
= 6*sizeof(int),
1113 .proc_handler
= &proc_dointvec
,
1116 .ctl_name
= FS_OVERFLOWUID
,
1117 .procname
= "overflowuid",
1118 .data
= &fs_overflowuid
,
1119 .maxlen
= sizeof(int),
1121 .proc_handler
= &proc_dointvec_minmax
,
1122 .strategy
= &sysctl_intvec
,
1123 .extra1
= &minolduid
,
1124 .extra2
= &maxolduid
,
1127 .ctl_name
= FS_OVERFLOWGID
,
1128 .procname
= "overflowgid",
1129 .data
= &fs_overflowgid
,
1130 .maxlen
= sizeof(int),
1132 .proc_handler
= &proc_dointvec_minmax
,
1133 .strategy
= &sysctl_intvec
,
1134 .extra1
= &minolduid
,
1135 .extra2
= &maxolduid
,
1138 .ctl_name
= FS_LEASES
,
1139 .procname
= "leases-enable",
1140 .data
= &leases_enable
,
1141 .maxlen
= sizeof(int),
1143 .proc_handler
= &proc_dointvec
,
1145 #ifdef CONFIG_DNOTIFY
1147 .ctl_name
= FS_DIR_NOTIFY
,
1148 .procname
= "dir-notify-enable",
1149 .data
= &dir_notify_enable
,
1150 .maxlen
= sizeof(int),
1152 .proc_handler
= &proc_dointvec
,
1157 .ctl_name
= FS_LEASE_TIME
,
1158 .procname
= "lease-break-time",
1159 .data
= &lease_break_time
,
1160 .maxlen
= sizeof(int),
1162 .proc_handler
= &proc_dointvec_minmax
,
1163 .strategy
= &sysctl_intvec
,
1168 .ctl_name
= FS_AIO_NR
,
1169 .procname
= "aio-nr",
1171 .maxlen
= sizeof(aio_nr
),
1173 .proc_handler
= &proc_doulongvec_minmax
,
1176 .ctl_name
= FS_AIO_MAX_NR
,
1177 .procname
= "aio-max-nr",
1178 .data
= &aio_max_nr
,
1179 .maxlen
= sizeof(aio_max_nr
),
1181 .proc_handler
= &proc_doulongvec_minmax
,
1183 #ifdef CONFIG_INOTIFY_USER
1185 .ctl_name
= FS_INOTIFY
,
1186 .procname
= "inotify",
1188 .child
= inotify_table
,
1193 .ctl_name
= KERN_SETUID_DUMPABLE
,
1194 .procname
= "suid_dumpable",
1195 .data
= &suid_dumpable
,
1196 .maxlen
= sizeof(int),
1198 .proc_handler
= &proc_dointvec
,
1200 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1202 .ctl_name
= CTL_UNNUMBERED
,
1203 .procname
= "binfmt_misc",
1205 .child
= binfmt_misc_table
,
1209 * NOTE: do not add new entries to this table unless you have read
1210 * Documentation/sysctl/ctl_unnumbered.txt
1215 static ctl_table debug_table
[] = {
1218 .ctl_name
= CTL_UNNUMBERED
,
1219 .procname
= "exception-trace",
1220 .data
= &show_unhandled_signals
,
1221 .maxlen
= sizeof(int),
1223 .proc_handler
= proc_dointvec
1229 static ctl_table dev_table
[] = {
1233 static DEFINE_SPINLOCK(sysctl_lock
);
1235 /* called under sysctl_lock */
1236 static int use_table(struct ctl_table_header
*p
)
1238 if (unlikely(p
->unregistering
))
1244 /* called under sysctl_lock */
1245 static void unuse_table(struct ctl_table_header
*p
)
1248 if (unlikely(p
->unregistering
))
1249 complete(p
->unregistering
);
1252 /* called under sysctl_lock, will reacquire if has to wait */
1253 static void start_unregistering(struct ctl_table_header
*p
)
1256 * if p->used is 0, nobody will ever touch that entry again;
1257 * we'll eliminate all paths to it before dropping sysctl_lock
1259 if (unlikely(p
->used
)) {
1260 struct completion wait
;
1261 init_completion(&wait
);
1262 p
->unregistering
= &wait
;
1263 spin_unlock(&sysctl_lock
);
1264 wait_for_completion(&wait
);
1265 spin_lock(&sysctl_lock
);
1268 * do not remove from the list until nobody holds it; walking the
1269 * list in do_sysctl() relies on that.
1271 list_del_init(&p
->ctl_entry
);
1274 void sysctl_head_finish(struct ctl_table_header
*head
)
1278 spin_lock(&sysctl_lock
);
1280 spin_unlock(&sysctl_lock
);
1283 struct ctl_table_header
*sysctl_head_next(struct ctl_table_header
*prev
)
1285 struct ctl_table_header
*head
;
1286 struct list_head
*tmp
;
1287 spin_lock(&sysctl_lock
);
1289 tmp
= &prev
->ctl_entry
;
1293 tmp
= &root_table_header
.ctl_entry
;
1295 head
= list_entry(tmp
, struct ctl_table_header
, ctl_entry
);
1297 if (!use_table(head
))
1299 spin_unlock(&sysctl_lock
);
1303 if (tmp
== &root_table_header
.ctl_entry
)
1306 spin_unlock(&sysctl_lock
);
1310 #ifdef CONFIG_SYSCTL_SYSCALL
1311 int do_sysctl(int __user
*name
, int nlen
, void __user
*oldval
, size_t __user
*oldlenp
,
1312 void __user
*newval
, size_t newlen
)
1314 struct ctl_table_header
*head
;
1315 int error
= -ENOTDIR
;
1317 if (nlen
<= 0 || nlen
>= CTL_MAXNAME
)
1321 if (!oldlenp
|| get_user(old_len
, oldlenp
))
1325 for (head
= sysctl_head_next(NULL
); head
;
1326 head
= sysctl_head_next(head
)) {
1327 error
= parse_table(name
, nlen
, oldval
, oldlenp
,
1328 newval
, newlen
, head
->ctl_table
);
1329 if (error
!= -ENOTDIR
) {
1330 sysctl_head_finish(head
);
1337 asmlinkage
long sys_sysctl(struct __sysctl_args __user
*args
)
1339 struct __sysctl_args tmp
;
1342 if (copy_from_user(&tmp
, args
, sizeof(tmp
)))
1346 error
= do_sysctl(tmp
.name
, tmp
.nlen
, tmp
.oldval
, tmp
.oldlenp
,
1347 tmp
.newval
, tmp
.newlen
);
1351 #endif /* CONFIG_SYSCTL_SYSCALL */
1354 * sysctl_perm does NOT grant the superuser all rights automatically, because
1355 * some sysctl variables are readonly even to root.
1358 static int test_perm(int mode
, int op
)
1362 else if (in_egroup_p(0))
1364 if ((mode
& op
& 0007) == op
)
1369 int sysctl_perm(ctl_table
*table
, int op
)
1372 error
= security_sysctl(table
, op
);
1375 return test_perm(table
->mode
, op
);
1378 #ifdef CONFIG_SYSCTL_SYSCALL
1379 static int parse_table(int __user
*name
, int nlen
,
1380 void __user
*oldval
, size_t __user
*oldlenp
,
1381 void __user
*newval
, size_t newlen
,
1388 if (get_user(n
, name
))
1390 for ( ; table
->ctl_name
|| table
->procname
; table
++) {
1391 if (!table
->ctl_name
)
1393 if (n
== table
->ctl_name
) {
1396 if (sysctl_perm(table
, 001))
1400 table
= table
->child
;
1403 error
= do_sysctl_strategy(table
, name
, nlen
,
1412 /* Perform the actual read/write of a sysctl table entry. */
1413 int do_sysctl_strategy (ctl_table
*table
,
1414 int __user
*name
, int nlen
,
1415 void __user
*oldval
, size_t __user
*oldlenp
,
1416 void __user
*newval
, size_t newlen
)
1425 if (sysctl_perm(table
, op
))
1428 if (table
->strategy
) {
1429 rc
= table
->strategy(table
, name
, nlen
, oldval
, oldlenp
,
1437 /* If there is no strategy routine, or if the strategy returns
1438 * zero, proceed with automatic r/w */
1439 if (table
->data
&& table
->maxlen
) {
1440 if (oldval
&& oldlenp
) {
1441 if (get_user(len
, oldlenp
))
1444 if (len
> table
->maxlen
)
1445 len
= table
->maxlen
;
1446 if(copy_to_user(oldval
, table
->data
, len
))
1448 if(put_user(len
, oldlenp
))
1452 if (newval
&& newlen
) {
1454 if (len
> table
->maxlen
)
1455 len
= table
->maxlen
;
1456 if(copy_from_user(table
->data
, newval
, len
))
1462 #endif /* CONFIG_SYSCTL_SYSCALL */
1464 static void sysctl_set_parent(struct ctl_table
*parent
, struct ctl_table
*table
)
1466 for (; table
->ctl_name
|| table
->procname
; table
++) {
1467 table
->parent
= parent
;
1469 sysctl_set_parent(table
, table
->child
);
1473 static __init
int sysctl_init(void)
1475 sysctl_set_parent(NULL
, root_table
);
1479 core_initcall(sysctl_init
);
1482 * register_sysctl_table - register a sysctl hierarchy
1483 * @table: the top-level table structure
1485 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1486 * array. An entry with a ctl_name of 0 terminates the table.
1488 * The members of the &ctl_table structure are used as follows:
1490 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1491 * must be unique within that level of sysctl
1493 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1494 * enter a sysctl file
1496 * data - a pointer to data for use by proc_handler
1498 * maxlen - the maximum size in bytes of the data
1500 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1502 * child - a pointer to the child sysctl table if this entry is a directory, or
1505 * proc_handler - the text handler routine (described below)
1507 * strategy - the strategy routine (described below)
1509 * de - for internal use by the sysctl routines
1511 * extra1, extra2 - extra pointers usable by the proc handler routines
1513 * Leaf nodes in the sysctl tree will be represented by a single file
1514 * under /proc; non-leaf nodes will be represented by directories.
1516 * sysctl(2) can automatically manage read and write requests through
1517 * the sysctl table. The data and maxlen fields of the ctl_table
1518 * struct enable minimal validation of the values being written to be
1519 * performed, and the mode field allows minimal authentication.
1521 * More sophisticated management can be enabled by the provision of a
1522 * strategy routine with the table entry. This will be called before
1523 * any automatic read or write of the data is performed.
1525 * The strategy routine may return
1527 * < 0 - Error occurred (error is passed to user process)
1529 * 0 - OK - proceed with automatic read or write.
1531 * > 0 - OK - read or write has been done by the strategy routine, so
1532 * return immediately.
1534 * There must be a proc_handler routine for any terminal nodes
1535 * mirrored under /proc/sys (non-terminals are handled by a built-in
1536 * directory handler). Several default handlers are available to
1537 * cover common cases -
1539 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1540 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1541 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1543 * It is the handler's job to read the input buffer from user memory
1544 * and process it. The handler should return 0 on success.
1546 * This routine returns %NULL on a failure to register, and a pointer
1547 * to the table header on success.
1549 struct ctl_table_header
*register_sysctl_table(ctl_table
* table
)
1551 struct ctl_table_header
*tmp
;
1552 tmp
= kmalloc(sizeof(struct ctl_table_header
), GFP_KERNEL
);
1555 tmp
->ctl_table
= table
;
1556 INIT_LIST_HEAD(&tmp
->ctl_entry
);
1558 tmp
->unregistering
= NULL
;
1559 sysctl_set_parent(NULL
, table
);
1560 spin_lock(&sysctl_lock
);
1561 list_add_tail(&tmp
->ctl_entry
, &root_table_header
.ctl_entry
);
1562 spin_unlock(&sysctl_lock
);
1567 * unregister_sysctl_table - unregister a sysctl table hierarchy
1568 * @header: the header returned from register_sysctl_table
1570 * Unregisters the sysctl table and all children. proc entries may not
1571 * actually be removed until they are no longer used by anyone.
1573 void unregister_sysctl_table(struct ctl_table_header
* header
)
1576 spin_lock(&sysctl_lock
);
1577 start_unregistering(header
);
1578 spin_unlock(&sysctl_lock
);
1582 #else /* !CONFIG_SYSCTL */
1583 struct ctl_table_header
*register_sysctl_table(ctl_table
* table
)
1588 void unregister_sysctl_table(struct ctl_table_header
* table
)
1592 #endif /* CONFIG_SYSCTL */
1598 #ifdef CONFIG_PROC_SYSCTL
1600 static int _proc_do_string(void* data
, int maxlen
, int write
,
1601 struct file
*filp
, void __user
*buffer
,
1602 size_t *lenp
, loff_t
*ppos
)
1608 if (!data
|| !maxlen
|| !*lenp
) {
1616 while (len
< *lenp
) {
1617 if (get_user(c
, p
++))
1619 if (c
== 0 || c
== '\n')
1625 if(copy_from_user(data
, buffer
, len
))
1627 ((char *) data
)[len
] = 0;
1645 if(copy_to_user(buffer
, data
, len
))
1648 if(put_user('\n', ((char __user
*) buffer
) + len
))
1659 * proc_dostring - read a string sysctl
1660 * @table: the sysctl table
1661 * @write: %TRUE if this is a write to the sysctl file
1662 * @filp: the file structure
1663 * @buffer: the user buffer
1664 * @lenp: the size of the user buffer
1665 * @ppos: file position
1667 * Reads/writes a string from/to the user buffer. If the kernel
1668 * buffer provided is not large enough to hold the string, the
1669 * string is truncated. The copied string is %NULL-terminated.
1670 * If the string is being read by the user process, it is copied
1671 * and a newline '\n' is added. It is truncated if the buffer is
1674 * Returns 0 on success.
1676 int proc_dostring(ctl_table
*table
, int write
, struct file
*filp
,
1677 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1679 return _proc_do_string(table
->data
, table
->maxlen
, write
, filp
,
1680 buffer
, lenp
, ppos
);
1684 static int do_proc_dointvec_conv(int *negp
, unsigned long *lvalp
,
1686 int write
, void *data
)
1689 *valp
= *negp
? -*lvalp
: *lvalp
;
1694 *lvalp
= (unsigned long)-val
;
1697 *lvalp
= (unsigned long)val
;
1703 static int __do_proc_dointvec(void *tbl_data
, ctl_table
*table
,
1704 int write
, struct file
*filp
, void __user
*buffer
,
1705 size_t *lenp
, loff_t
*ppos
,
1706 int (*conv
)(int *negp
, unsigned long *lvalp
, int *valp
,
1707 int write
, void *data
),
1710 #define TMPBUFLEN 21
1711 int *i
, vleft
, first
=1, neg
, val
;
1715 char buf
[TMPBUFLEN
], *p
;
1716 char __user
*s
= buffer
;
1718 if (!tbl_data
|| !table
->maxlen
|| !*lenp
||
1719 (*ppos
&& !write
)) {
1724 i
= (int *) tbl_data
;
1725 vleft
= table
->maxlen
/ sizeof(*i
);
1729 conv
= do_proc_dointvec_conv
;
1731 for (; left
&& vleft
--; i
++, first
=0) {
1746 if (len
> sizeof(buf
) - 1)
1747 len
= sizeof(buf
) - 1;
1748 if (copy_from_user(buf
, s
, len
))
1752 if (*p
== '-' && left
> 1) {
1756 if (*p
< '0' || *p
> '9')
1759 lval
= simple_strtoul(p
, &p
, 0);
1762 if ((len
< left
) && *p
&& !isspace(*p
))
1769 if (conv(&neg
, &lval
, i
, 1, data
))
1776 if (conv(&neg
, &lval
, i
, 0, data
))
1779 sprintf(p
, "%s%lu", neg
? "-" : "", lval
);
1783 if(copy_to_user(s
, buf
, len
))
1790 if (!write
&& !first
&& left
) {
1791 if(put_user('\n', s
))
1798 if (get_user(c
, s
++))
1813 static int do_proc_dointvec(ctl_table
*table
, int write
, struct file
*filp
,
1814 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
,
1815 int (*conv
)(int *negp
, unsigned long *lvalp
, int *valp
,
1816 int write
, void *data
),
1819 return __do_proc_dointvec(table
->data
, table
, write
, filp
,
1820 buffer
, lenp
, ppos
, conv
, data
);
1824 * proc_dointvec - read a vector of integers
1825 * @table: the sysctl table
1826 * @write: %TRUE if this is a write to the sysctl file
1827 * @filp: the file structure
1828 * @buffer: the user buffer
1829 * @lenp: the size of the user buffer
1830 * @ppos: file position
1832 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1833 * values from/to the user buffer, treated as an ASCII string.
1835 * Returns 0 on success.
1837 int proc_dointvec(ctl_table
*table
, int write
, struct file
*filp
,
1838 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1840 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
1848 static int do_proc_dointvec_bset_conv(int *negp
, unsigned long *lvalp
,
1850 int write
, void *data
)
1852 int op
= *(int *)data
;
1854 int val
= *negp
? -*lvalp
: *lvalp
;
1856 case OP_SET
: *valp
= val
; break;
1857 case OP_AND
: *valp
&= val
; break;
1858 case OP_OR
: *valp
|= val
; break;
1864 *lvalp
= (unsigned long)-val
;
1867 *lvalp
= (unsigned long)val
;
1874 * init may raise the set.
1877 int proc_dointvec_bset(ctl_table
*table
, int write
, struct file
*filp
,
1878 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1882 if (write
&& !capable(CAP_SYS_MODULE
)) {
1886 op
= is_init(current
) ? OP_SET
: OP_AND
;
1887 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
1888 do_proc_dointvec_bset_conv
,&op
);
1892 * Taint values can only be increased
1894 static int proc_dointvec_taint(ctl_table
*table
, int write
, struct file
*filp
,
1895 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1899 if (write
&& !capable(CAP_SYS_ADMIN
))
1903 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
1904 do_proc_dointvec_bset_conv
,&op
);
1907 struct do_proc_dointvec_minmax_conv_param
{
1912 static int do_proc_dointvec_minmax_conv(int *negp
, unsigned long *lvalp
,
1914 int write
, void *data
)
1916 struct do_proc_dointvec_minmax_conv_param
*param
= data
;
1918 int val
= *negp
? -*lvalp
: *lvalp
;
1919 if ((param
->min
&& *param
->min
> val
) ||
1920 (param
->max
&& *param
->max
< val
))
1927 *lvalp
= (unsigned long)-val
;
1930 *lvalp
= (unsigned long)val
;
1937 * proc_dointvec_minmax - read a vector of integers with min/max values
1938 * @table: the sysctl table
1939 * @write: %TRUE if this is a write to the sysctl file
1940 * @filp: the file structure
1941 * @buffer: the user buffer
1942 * @lenp: the size of the user buffer
1943 * @ppos: file position
1945 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1946 * values from/to the user buffer, treated as an ASCII string.
1948 * This routine will ensure the values are within the range specified by
1949 * table->extra1 (min) and table->extra2 (max).
1951 * Returns 0 on success.
1953 int proc_dointvec_minmax(ctl_table
*table
, int write
, struct file
*filp
,
1954 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1956 struct do_proc_dointvec_minmax_conv_param param
= {
1957 .min
= (int *) table
->extra1
,
1958 .max
= (int *) table
->extra2
,
1960 return do_proc_dointvec(table
, write
, filp
, buffer
, lenp
, ppos
,
1961 do_proc_dointvec_minmax_conv
, ¶m
);
1964 static int __do_proc_doulongvec_minmax(void *data
, ctl_table
*table
, int write
,
1966 void __user
*buffer
,
1967 size_t *lenp
, loff_t
*ppos
,
1968 unsigned long convmul
,
1969 unsigned long convdiv
)
1971 #define TMPBUFLEN 21
1972 unsigned long *i
, *min
, *max
, val
;
1973 int vleft
, first
=1, neg
;
1975 char buf
[TMPBUFLEN
], *p
;
1976 char __user
*s
= buffer
;
1978 if (!data
|| !table
->maxlen
|| !*lenp
||
1979 (*ppos
&& !write
)) {
1984 i
= (unsigned long *) data
;
1985 min
= (unsigned long *) table
->extra1
;
1986 max
= (unsigned long *) table
->extra2
;
1987 vleft
= table
->maxlen
/ sizeof(unsigned long);
1990 for (; left
&& vleft
--; i
++, min
++, max
++, first
=0) {
2005 if (len
> TMPBUFLEN
-1)
2007 if (copy_from_user(buf
, s
, len
))
2011 if (*p
== '-' && left
> 1) {
2015 if (*p
< '0' || *p
> '9')
2017 val
= simple_strtoul(p
, &p
, 0) * convmul
/ convdiv
;
2019 if ((len
< left
) && *p
&& !isspace(*p
))
2028 if ((min
&& val
< *min
) || (max
&& val
> *max
))
2035 sprintf(p
, "%lu", convdiv
* (*i
) / convmul
);
2039 if(copy_to_user(s
, buf
, len
))
2046 if (!write
&& !first
&& left
) {
2047 if(put_user('\n', s
))
2054 if (get_user(c
, s
++))
2069 static int do_proc_doulongvec_minmax(ctl_table
*table
, int write
,
2071 void __user
*buffer
,
2072 size_t *lenp
, loff_t
*ppos
,
2073 unsigned long convmul
,
2074 unsigned long convdiv
)
2076 return __do_proc_doulongvec_minmax(table
->data
, table
, write
,
2077 filp
, buffer
, lenp
, ppos
, convmul
, convdiv
);
2081 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2082 * @table: the sysctl table
2083 * @write: %TRUE if this is a write to the sysctl file
2084 * @filp: the file structure
2085 * @buffer: the user buffer
2086 * @lenp: the size of the user buffer
2087 * @ppos: file position
2089 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2090 * values from/to the user buffer, treated as an ASCII string.
2092 * This routine will ensure the values are within the range specified by
2093 * table->extra1 (min) and table->extra2 (max).
2095 * Returns 0 on success.
2097 int proc_doulongvec_minmax(ctl_table
*table
, int write
, struct file
*filp
,
2098 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2100 return do_proc_doulongvec_minmax(table
, write
, filp
, buffer
, lenp
, ppos
, 1l, 1l);
2104 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2105 * @table: the sysctl table
2106 * @write: %TRUE if this is a write to the sysctl file
2107 * @filp: the file structure
2108 * @buffer: the user buffer
2109 * @lenp: the size of the user buffer
2110 * @ppos: file position
2112 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2113 * values from/to the user buffer, treated as an ASCII string. The values
2114 * are treated as milliseconds, and converted to jiffies when they are stored.
2116 * This routine will ensure the values are within the range specified by
2117 * table->extra1 (min) and table->extra2 (max).
2119 * Returns 0 on success.
2121 int proc_doulongvec_ms_jiffies_minmax(ctl_table
*table
, int write
,
2123 void __user
*buffer
,
2124 size_t *lenp
, loff_t
*ppos
)
2126 return do_proc_doulongvec_minmax(table
, write
, filp
, buffer
,
2127 lenp
, ppos
, HZ
, 1000l);
2131 static int do_proc_dointvec_jiffies_conv(int *negp
, unsigned long *lvalp
,
2133 int write
, void *data
)
2136 if (*lvalp
> LONG_MAX
/ HZ
)
2138 *valp
= *negp
? -(*lvalp
*HZ
) : (*lvalp
*HZ
);
2144 lval
= (unsigned long)-val
;
2147 lval
= (unsigned long)val
;
2154 static int do_proc_dointvec_userhz_jiffies_conv(int *negp
, unsigned long *lvalp
,
2156 int write
, void *data
)
2159 if (USER_HZ
< HZ
&& *lvalp
> (LONG_MAX
/ HZ
) * USER_HZ
)
2161 *valp
= clock_t_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2167 lval
= (unsigned long)-val
;
2170 lval
= (unsigned long)val
;
2172 *lvalp
= jiffies_to_clock_t(lval
);
2177 static int do_proc_dointvec_ms_jiffies_conv(int *negp
, unsigned long *lvalp
,
2179 int write
, void *data
)
2182 *valp
= msecs_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2188 lval
= (unsigned long)-val
;
2191 lval
= (unsigned long)val
;
2193 *lvalp
= jiffies_to_msecs(lval
);
2199 * proc_dointvec_jiffies - read a vector of integers as seconds
2200 * @table: the sysctl table
2201 * @write: %TRUE if this is a write to the sysctl file
2202 * @filp: the file structure
2203 * @buffer: the user buffer
2204 * @lenp: the size of the user buffer
2205 * @ppos: file position
2207 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2208 * values from/to the user buffer, treated as an ASCII string.
2209 * The values read are assumed to be in seconds, and are converted into
2212 * Returns 0 on success.
2214 int proc_dointvec_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2215 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2217 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2218 do_proc_dointvec_jiffies_conv
,NULL
);
2222 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2223 * @table: the sysctl table
2224 * @write: %TRUE if this is a write to the sysctl file
2225 * @filp: the file structure
2226 * @buffer: the user buffer
2227 * @lenp: the size of the user buffer
2228 * @ppos: pointer to the file position
2230 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2231 * values from/to the user buffer, treated as an ASCII string.
2232 * The values read are assumed to be in 1/USER_HZ seconds, and
2233 * are converted into jiffies.
2235 * Returns 0 on success.
2237 int proc_dointvec_userhz_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2238 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2240 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2241 do_proc_dointvec_userhz_jiffies_conv
,NULL
);
2245 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2246 * @table: the sysctl table
2247 * @write: %TRUE if this is a write to the sysctl file
2248 * @filp: the file structure
2249 * @buffer: the user buffer
2250 * @lenp: the size of the user buffer
2251 * @ppos: file position
2252 * @ppos: the current position in the file
2254 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2255 * values from/to the user buffer, treated as an ASCII string.
2256 * The values read are assumed to be in 1/1000 seconds, and
2257 * are converted into jiffies.
2259 * Returns 0 on success.
2261 int proc_dointvec_ms_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2262 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2264 return do_proc_dointvec(table
, write
, filp
, buffer
, lenp
, ppos
,
2265 do_proc_dointvec_ms_jiffies_conv
, NULL
);
2268 static int proc_do_cad_pid(ctl_table
*table
, int write
, struct file
*filp
,
2269 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2271 struct pid
*new_pid
;
2275 tmp
= pid_nr(cad_pid
);
2277 r
= __do_proc_dointvec(&tmp
, table
, write
, filp
, buffer
,
2278 lenp
, ppos
, NULL
, NULL
);
2282 new_pid
= find_get_pid(tmp
);
2286 put_pid(xchg(&cad_pid
, new_pid
));
2290 #else /* CONFIG_PROC_FS */
2292 int proc_dostring(ctl_table
*table
, int write
, struct file
*filp
,
2293 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2298 int proc_dointvec(ctl_table
*table
, int write
, struct file
*filp
,
2299 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2304 int proc_dointvec_bset(ctl_table
*table
, int write
, struct file
*filp
,
2305 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2310 int proc_dointvec_minmax(ctl_table
*table
, int write
, struct file
*filp
,
2311 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2316 int proc_dointvec_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2317 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2322 int proc_dointvec_userhz_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2323 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2328 int proc_dointvec_ms_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2329 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2334 int proc_doulongvec_minmax(ctl_table
*table
, int write
, struct file
*filp
,
2335 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2340 int proc_doulongvec_ms_jiffies_minmax(ctl_table
*table
, int write
,
2342 void __user
*buffer
,
2343 size_t *lenp
, loff_t
*ppos
)
2349 #endif /* CONFIG_PROC_FS */
2352 #ifdef CONFIG_SYSCTL_SYSCALL
2354 * General sysctl support routines
2357 /* The generic string strategy routine: */
2358 int sysctl_string(ctl_table
*table
, int __user
*name
, int nlen
,
2359 void __user
*oldval
, size_t __user
*oldlenp
,
2360 void __user
*newval
, size_t newlen
)
2362 if (!table
->data
|| !table
->maxlen
)
2365 if (oldval
&& oldlenp
) {
2367 if (get_user(bufsize
, oldlenp
))
2370 size_t len
= strlen(table
->data
), copied
;
2372 /* This shouldn't trigger for a well-formed sysctl */
2373 if (len
> table
->maxlen
)
2374 len
= table
->maxlen
;
2376 /* Copy up to a max of bufsize-1 bytes of the string */
2377 copied
= (len
>= bufsize
) ? bufsize
- 1 : len
;
2379 if (copy_to_user(oldval
, table
->data
, copied
) ||
2380 put_user(0, (char __user
*)(oldval
+ copied
)))
2382 if (put_user(len
, oldlenp
))
2386 if (newval
&& newlen
) {
2387 size_t len
= newlen
;
2388 if (len
> table
->maxlen
)
2389 len
= table
->maxlen
;
2390 if(copy_from_user(table
->data
, newval
, len
))
2392 if (len
== table
->maxlen
)
2394 ((char *) table
->data
)[len
] = 0;
2400 * This function makes sure that all of the integers in the vector
2401 * are between the minimum and maximum values given in the arrays
2402 * table->extra1 and table->extra2, respectively.
2404 int sysctl_intvec(ctl_table
*table
, int __user
*name
, int nlen
,
2405 void __user
*oldval
, size_t __user
*oldlenp
,
2406 void __user
*newval
, size_t newlen
)
2409 if (newval
&& newlen
) {
2410 int __user
*vec
= (int __user
*) newval
;
2411 int *min
= (int *) table
->extra1
;
2412 int *max
= (int *) table
->extra2
;
2416 if (newlen
% sizeof(int) != 0)
2419 if (!table
->extra1
&& !table
->extra2
)
2422 if (newlen
> table
->maxlen
)
2423 newlen
= table
->maxlen
;
2424 length
= newlen
/ sizeof(int);
2426 for (i
= 0; i
< length
; i
++) {
2428 if (get_user(value
, vec
+ i
))
2430 if (min
&& value
< min
[i
])
2432 if (max
&& value
> max
[i
])
2439 /* Strategy function to convert jiffies to seconds */
2440 int sysctl_jiffies(ctl_table
*table
, int __user
*name
, int nlen
,
2441 void __user
*oldval
, size_t __user
*oldlenp
,
2442 void __user
*newval
, size_t newlen
)
2444 if (oldval
&& oldlenp
) {
2447 if (get_user(olen
, oldlenp
))
2452 if (olen
< sizeof(int))
2455 val
= *(int *)(table
->data
) / HZ
;
2456 if (put_user(val
, (int __user
*)oldval
))
2458 if (put_user(sizeof(int), oldlenp
))
2462 if (newval
&& newlen
) {
2464 if (newlen
!= sizeof(int))
2466 if (get_user(new, (int __user
*)newval
))
2468 *(int *)(table
->data
) = new*HZ
;
2473 /* Strategy function to convert jiffies to seconds */
2474 int sysctl_ms_jiffies(ctl_table
*table
, int __user
*name
, int nlen
,
2475 void __user
*oldval
, size_t __user
*oldlenp
,
2476 void __user
*newval
, size_t newlen
)
2478 if (oldval
&& oldlenp
) {
2481 if (get_user(olen
, oldlenp
))
2486 if (olen
< sizeof(int))
2489 val
= jiffies_to_msecs(*(int *)(table
->data
));
2490 if (put_user(val
, (int __user
*)oldval
))
2492 if (put_user(sizeof(int), oldlenp
))
2496 if (newval
&& newlen
) {
2498 if (newlen
!= sizeof(int))
2500 if (get_user(new, (int __user
*)newval
))
2502 *(int *)(table
->data
) = msecs_to_jiffies(new);
2509 #else /* CONFIG_SYSCTL_SYSCALL */
2512 asmlinkage
long sys_sysctl(struct __sysctl_args __user
*args
)
2514 static int msg_count
;
2515 struct __sysctl_args tmp
;
2516 int name
[CTL_MAXNAME
];
2519 /* Read in the sysctl name for better debug message logging */
2520 if (copy_from_user(&tmp
, args
, sizeof(tmp
)))
2522 if (tmp
.nlen
<= 0 || tmp
.nlen
>= CTL_MAXNAME
)
2524 for (i
= 0; i
< tmp
.nlen
; i
++)
2525 if (get_user(name
[i
], tmp
.name
+ i
))
2528 /* Ignore accesses to kernel.version */
2529 if ((tmp
.nlen
== 2) && (name
[0] == CTL_KERN
) && (name
[1] == KERN_VERSION
))
2532 if (msg_count
< 5) {
2535 "warning: process `%s' used the removed sysctl "
2536 "system call with ", current
->comm
);
2537 for (i
= 0; i
< tmp
.nlen
; i
++)
2538 printk("%d.", name
[i
]);
2545 int sysctl_string(ctl_table
*table
, int __user
*name
, int nlen
,
2546 void __user
*oldval
, size_t __user
*oldlenp
,
2547 void __user
*newval
, size_t newlen
)
2552 int sysctl_intvec(ctl_table
*table
, int __user
*name
, int nlen
,
2553 void __user
*oldval
, size_t __user
*oldlenp
,
2554 void __user
*newval
, size_t newlen
)
2559 int sysctl_jiffies(ctl_table
*table
, int __user
*name
, int nlen
,
2560 void __user
*oldval
, size_t __user
*oldlenp
,
2561 void __user
*newval
, size_t newlen
)
2566 int sysctl_ms_jiffies(ctl_table
*table
, int __user
*name
, int nlen
,
2567 void __user
*oldval
, size_t __user
*oldlenp
,
2568 void __user
*newval
, size_t newlen
)
2573 #endif /* CONFIG_SYSCTL_SYSCALL */
2576 * No sense putting this after each symbol definition, twice,
2577 * exception granted :-)
2579 EXPORT_SYMBOL(proc_dointvec
);
2580 EXPORT_SYMBOL(proc_dointvec_jiffies
);
2581 EXPORT_SYMBOL(proc_dointvec_minmax
);
2582 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies
);
2583 EXPORT_SYMBOL(proc_dointvec_ms_jiffies
);
2584 EXPORT_SYMBOL(proc_dostring
);
2585 EXPORT_SYMBOL(proc_doulongvec_minmax
);
2586 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax
);
2587 EXPORT_SYMBOL(register_sysctl_table
);
2588 EXPORT_SYMBOL(sysctl_intvec
);
2589 EXPORT_SYMBOL(sysctl_jiffies
);
2590 EXPORT_SYMBOL(sysctl_ms_jiffies
);
2591 EXPORT_SYMBOL(sysctl_string
);
2592 EXPORT_SYMBOL(unregister_sysctl_table
);