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_min_granularity_ns",
226 .data
= &sysctl_sched_min_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
,
307 .ctl_name
= CTL_UNNUMBERED
,
308 .procname
= "sched_compat_yield",
309 .data
= &sysctl_sched_compat_yield
,
310 .maxlen
= sizeof(unsigned int),
312 .proc_handler
= &proc_dointvec
,
314 #ifdef CONFIG_PROVE_LOCKING
316 .ctl_name
= CTL_UNNUMBERED
,
317 .procname
= "prove_locking",
318 .data
= &prove_locking
,
319 .maxlen
= sizeof(int),
321 .proc_handler
= &proc_dointvec
,
324 #ifdef CONFIG_LOCK_STAT
326 .ctl_name
= CTL_UNNUMBERED
,
327 .procname
= "lock_stat",
329 .maxlen
= sizeof(int),
331 .proc_handler
= &proc_dointvec
,
335 .ctl_name
= KERN_PANIC
,
337 .data
= &panic_timeout
,
338 .maxlen
= sizeof(int),
340 .proc_handler
= &proc_dointvec
,
343 .ctl_name
= KERN_CORE_USES_PID
,
344 .procname
= "core_uses_pid",
345 .data
= &core_uses_pid
,
346 .maxlen
= sizeof(int),
348 .proc_handler
= &proc_dointvec
,
350 #ifdef CONFIG_AUDITSYSCALL
352 .ctl_name
= CTL_UNNUMBERED
,
353 .procname
= "audit_argv_kb",
354 .data
= &audit_argv_kb
,
355 .maxlen
= sizeof(int),
357 .proc_handler
= &proc_dointvec
,
361 .ctl_name
= KERN_CORE_PATTERN
,
362 .procname
= "core_pattern",
363 .data
= core_pattern
,
364 .maxlen
= CORENAME_MAX_SIZE
,
366 .proc_handler
= &proc_dostring
,
367 .strategy
= &sysctl_string
,
369 #ifdef CONFIG_PROC_SYSCTL
371 .ctl_name
= KERN_TAINTED
,
372 .procname
= "tainted",
374 .maxlen
= sizeof(int),
376 .proc_handler
= &proc_dointvec_taint
,
380 .ctl_name
= KERN_CAP_BSET
,
381 .procname
= "cap-bound",
383 .maxlen
= sizeof(kernel_cap_t
),
385 .proc_handler
= &proc_dointvec_bset
,
387 #ifdef CONFIG_BLK_DEV_INITRD
389 .ctl_name
= KERN_REALROOTDEV
,
390 .procname
= "real-root-dev",
391 .data
= &real_root_dev
,
392 .maxlen
= sizeof(int),
394 .proc_handler
= &proc_dointvec
,
398 .ctl_name
= CTL_UNNUMBERED
,
399 .procname
= "print-fatal-signals",
400 .data
= &print_fatal_signals
,
401 .maxlen
= sizeof(int),
403 .proc_handler
= &proc_dointvec
,
407 .ctl_name
= KERN_SPARC_REBOOT
,
408 .procname
= "reboot-cmd",
409 .data
= reboot_command
,
412 .proc_handler
= &proc_dostring
,
413 .strategy
= &sysctl_string
,
416 .ctl_name
= KERN_SPARC_STOP_A
,
417 .procname
= "stop-a",
418 .data
= &stop_a_enabled
,
419 .maxlen
= sizeof (int),
421 .proc_handler
= &proc_dointvec
,
424 .ctl_name
= KERN_SPARC_SCONS_PWROFF
,
425 .procname
= "scons-poweroff",
426 .data
= &scons_pwroff
,
427 .maxlen
= sizeof (int),
429 .proc_handler
= &proc_dointvec
,
434 .ctl_name
= KERN_HPPA_PWRSW
,
435 .procname
= "soft-power",
436 .data
= &pwrsw_enabled
,
437 .maxlen
= sizeof (int),
439 .proc_handler
= &proc_dointvec
,
442 .ctl_name
= KERN_HPPA_UNALIGNED
,
443 .procname
= "unaligned-trap",
444 .data
= &unaligned_enabled
,
445 .maxlen
= sizeof (int),
447 .proc_handler
= &proc_dointvec
,
451 .ctl_name
= KERN_CTLALTDEL
,
452 .procname
= "ctrl-alt-del",
454 .maxlen
= sizeof(int),
456 .proc_handler
= &proc_dointvec
,
459 .ctl_name
= KERN_PRINTK
,
460 .procname
= "printk",
461 .data
= &console_loglevel
,
462 .maxlen
= 4*sizeof(int),
464 .proc_handler
= &proc_dointvec
,
468 .ctl_name
= KERN_MODPROBE
,
469 .procname
= "modprobe",
470 .data
= &modprobe_path
,
471 .maxlen
= KMOD_PATH_LEN
,
473 .proc_handler
= &proc_dostring
,
474 .strategy
= &sysctl_string
,
477 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
479 .ctl_name
= KERN_HOTPLUG
,
480 .procname
= "hotplug",
481 .data
= &uevent_helper
,
482 .maxlen
= UEVENT_HELPER_PATH_LEN
,
484 .proc_handler
= &proc_dostring
,
485 .strategy
= &sysctl_string
,
488 #ifdef CONFIG_CHR_DEV_SG
490 .ctl_name
= KERN_SG_BIG_BUFF
,
491 .procname
= "sg-big-buff",
492 .data
= &sg_big_buff
,
493 .maxlen
= sizeof (int),
495 .proc_handler
= &proc_dointvec
,
498 #ifdef CONFIG_BSD_PROCESS_ACCT
500 .ctl_name
= KERN_ACCT
,
503 .maxlen
= 3*sizeof(int),
505 .proc_handler
= &proc_dointvec
,
508 #ifdef CONFIG_MAGIC_SYSRQ
510 .ctl_name
= KERN_SYSRQ
,
512 .data
= &__sysrq_enabled
,
513 .maxlen
= sizeof (int),
515 .proc_handler
= &proc_dointvec
,
518 #ifdef CONFIG_PROC_SYSCTL
520 .ctl_name
= KERN_CADPID
,
521 .procname
= "cad_pid",
523 .maxlen
= sizeof (int),
525 .proc_handler
= &proc_do_cad_pid
,
529 .ctl_name
= KERN_MAX_THREADS
,
530 .procname
= "threads-max",
531 .data
= &max_threads
,
532 .maxlen
= sizeof(int),
534 .proc_handler
= &proc_dointvec
,
537 .ctl_name
= KERN_RANDOM
,
538 .procname
= "random",
540 .child
= random_table
,
542 #ifdef CONFIG_UNIX98_PTYS
544 .ctl_name
= KERN_PTY
,
551 .ctl_name
= KERN_OVERFLOWUID
,
552 .procname
= "overflowuid",
553 .data
= &overflowuid
,
554 .maxlen
= sizeof(int),
556 .proc_handler
= &proc_dointvec_minmax
,
557 .strategy
= &sysctl_intvec
,
558 .extra1
= &minolduid
,
559 .extra2
= &maxolduid
,
562 .ctl_name
= KERN_OVERFLOWGID
,
563 .procname
= "overflowgid",
564 .data
= &overflowgid
,
565 .maxlen
= sizeof(int),
567 .proc_handler
= &proc_dointvec_minmax
,
568 .strategy
= &sysctl_intvec
,
569 .extra1
= &minolduid
,
570 .extra2
= &maxolduid
,
573 #ifdef CONFIG_MATHEMU
575 .ctl_name
= KERN_IEEE_EMULATION_WARNINGS
,
576 .procname
= "ieee_emulation_warnings",
577 .data
= &sysctl_ieee_emulation_warnings
,
578 .maxlen
= sizeof(int),
580 .proc_handler
= &proc_dointvec
,
583 #ifdef CONFIG_NO_IDLE_HZ
585 .ctl_name
= KERN_HZ_TIMER
,
586 .procname
= "hz_timer",
587 .data
= &sysctl_hz_timer
,
588 .maxlen
= sizeof(int),
590 .proc_handler
= &proc_dointvec
,
594 .ctl_name
= KERN_S390_USER_DEBUG_LOGGING
,
595 .procname
= "userprocess_debug",
596 .data
= &sysctl_userprocess_debug
,
597 .maxlen
= sizeof(int),
599 .proc_handler
= &proc_dointvec
,
603 .ctl_name
= KERN_PIDMAX
,
604 .procname
= "pid_max",
606 .maxlen
= sizeof (int),
608 .proc_handler
= &proc_dointvec_minmax
,
609 .strategy
= sysctl_intvec
,
610 .extra1
= &pid_max_min
,
611 .extra2
= &pid_max_max
,
614 .ctl_name
= KERN_PANIC_ON_OOPS
,
615 .procname
= "panic_on_oops",
616 .data
= &panic_on_oops
,
617 .maxlen
= sizeof(int),
619 .proc_handler
= &proc_dointvec
,
622 .ctl_name
= KERN_PRINTK_RATELIMIT
,
623 .procname
= "printk_ratelimit",
624 .data
= &printk_ratelimit_jiffies
,
625 .maxlen
= sizeof(int),
627 .proc_handler
= &proc_dointvec_jiffies
,
628 .strategy
= &sysctl_jiffies
,
631 .ctl_name
= KERN_PRINTK_RATELIMIT_BURST
,
632 .procname
= "printk_ratelimit_burst",
633 .data
= &printk_ratelimit_burst
,
634 .maxlen
= sizeof(int),
636 .proc_handler
= &proc_dointvec
,
639 .ctl_name
= KERN_NGROUPS_MAX
,
640 .procname
= "ngroups_max",
641 .data
= &ngroups_max
,
642 .maxlen
= sizeof (int),
644 .proc_handler
= &proc_dointvec
,
646 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
648 .ctl_name
= KERN_UNKNOWN_NMI_PANIC
,
649 .procname
= "unknown_nmi_panic",
650 .data
= &unknown_nmi_panic
,
651 .maxlen
= sizeof (int),
653 .proc_handler
= &proc_dointvec
,
656 .ctl_name
= KERN_NMI_WATCHDOG
,
657 .procname
= "nmi_watchdog",
658 .data
= &nmi_watchdog_enabled
,
659 .maxlen
= sizeof (int),
661 .proc_handler
= &proc_nmi_enabled
,
664 #if defined(CONFIG_X86)
666 .ctl_name
= KERN_PANIC_ON_NMI
,
667 .procname
= "panic_on_unrecovered_nmi",
668 .data
= &panic_on_unrecovered_nmi
,
669 .maxlen
= sizeof(int),
671 .proc_handler
= &proc_dointvec
,
674 .ctl_name
= KERN_BOOTLOADER_TYPE
,
675 .procname
= "bootloader_type",
676 .data
= &bootloader_type
,
677 .maxlen
= sizeof (int),
679 .proc_handler
= &proc_dointvec
,
682 .ctl_name
= CTL_UNNUMBERED
,
683 .procname
= "kstack_depth_to_print",
684 .data
= &kstack_depth_to_print
,
685 .maxlen
= sizeof(int),
687 .proc_handler
= &proc_dointvec
,
690 #if defined(CONFIG_MMU)
692 .ctl_name
= KERN_RANDOMIZE
,
693 .procname
= "randomize_va_space",
694 .data
= &randomize_va_space
,
695 .maxlen
= sizeof(int),
697 .proc_handler
= &proc_dointvec
,
700 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
702 .ctl_name
= KERN_SPIN_RETRY
,
703 .procname
= "spin_retry",
705 .maxlen
= sizeof (int),
707 .proc_handler
= &proc_dointvec
,
710 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
712 .ctl_name
= KERN_ACPI_VIDEO_FLAGS
,
713 .procname
= "acpi_video_flags",
714 .data
= &acpi_realmode_flags
,
715 .maxlen
= sizeof (unsigned long),
717 .proc_handler
= &proc_doulongvec_minmax
,
722 .ctl_name
= KERN_IA64_UNALIGNED
,
723 .procname
= "ignore-unaligned-usertrap",
724 .data
= &no_unaligned_warning
,
725 .maxlen
= sizeof (int),
727 .proc_handler
= &proc_dointvec
,
732 .ctl_name
= KERN_COMPAT_LOG
,
733 .procname
= "compat-log",
735 .maxlen
= sizeof (int),
737 .proc_handler
= &proc_dointvec
,
740 #ifdef CONFIG_RT_MUTEXES
742 .ctl_name
= KERN_MAX_LOCK_DEPTH
,
743 .procname
= "max_lock_depth",
744 .data
= &max_lock_depth
,
745 .maxlen
= sizeof(int),
747 .proc_handler
= &proc_dointvec
,
750 #ifdef CONFIG_PROC_FS
752 .ctl_name
= CTL_UNNUMBERED
,
753 .procname
= "maps_protect",
754 .data
= &maps_protect
,
755 .maxlen
= sizeof(int),
757 .proc_handler
= &proc_dointvec
,
761 .ctl_name
= CTL_UNNUMBERED
,
762 .procname
= "poweroff_cmd",
763 .data
= &poweroff_cmd
,
764 .maxlen
= POWEROFF_CMD_PATH_LEN
,
766 .proc_handler
= &proc_dostring
,
767 .strategy
= &sysctl_string
,
770 * NOTE: do not add new entries to this table unless you have read
771 * Documentation/sysctl/ctl_unnumbered.txt
776 /* Constants for minimum and maximum testing in vm_table.
777 We use these as one-element integer vectors. */
780 static int one_hundred
= 100;
783 static ctl_table vm_table
[] = {
785 .ctl_name
= VM_OVERCOMMIT_MEMORY
,
786 .procname
= "overcommit_memory",
787 .data
= &sysctl_overcommit_memory
,
788 .maxlen
= sizeof(sysctl_overcommit_memory
),
790 .proc_handler
= &proc_dointvec
,
793 .ctl_name
= VM_PANIC_ON_OOM
,
794 .procname
= "panic_on_oom",
795 .data
= &sysctl_panic_on_oom
,
796 .maxlen
= sizeof(sysctl_panic_on_oom
),
798 .proc_handler
= &proc_dointvec
,
801 .ctl_name
= VM_OVERCOMMIT_RATIO
,
802 .procname
= "overcommit_ratio",
803 .data
= &sysctl_overcommit_ratio
,
804 .maxlen
= sizeof(sysctl_overcommit_ratio
),
806 .proc_handler
= &proc_dointvec
,
809 .ctl_name
= VM_PAGE_CLUSTER
,
810 .procname
= "page-cluster",
811 .data
= &page_cluster
,
812 .maxlen
= sizeof(int),
814 .proc_handler
= &proc_dointvec
,
817 .ctl_name
= VM_DIRTY_BACKGROUND
,
818 .procname
= "dirty_background_ratio",
819 .data
= &dirty_background_ratio
,
820 .maxlen
= sizeof(dirty_background_ratio
),
822 .proc_handler
= &proc_dointvec_minmax
,
823 .strategy
= &sysctl_intvec
,
825 .extra2
= &one_hundred
,
828 .ctl_name
= VM_DIRTY_RATIO
,
829 .procname
= "dirty_ratio",
830 .data
= &vm_dirty_ratio
,
831 .maxlen
= sizeof(vm_dirty_ratio
),
833 .proc_handler
= &proc_dointvec_minmax
,
834 .strategy
= &sysctl_intvec
,
836 .extra2
= &one_hundred
,
839 .ctl_name
= VM_DIRTY_WB_CS
,
840 .procname
= "dirty_writeback_centisecs",
841 .data
= &dirty_writeback_interval
,
842 .maxlen
= sizeof(dirty_writeback_interval
),
844 .proc_handler
= &dirty_writeback_centisecs_handler
,
847 .ctl_name
= VM_DIRTY_EXPIRE_CS
,
848 .procname
= "dirty_expire_centisecs",
849 .data
= &dirty_expire_interval
,
850 .maxlen
= sizeof(dirty_expire_interval
),
852 .proc_handler
= &proc_dointvec_userhz_jiffies
,
855 .ctl_name
= VM_NR_PDFLUSH_THREADS
,
856 .procname
= "nr_pdflush_threads",
857 .data
= &nr_pdflush_threads
,
858 .maxlen
= sizeof nr_pdflush_threads
,
859 .mode
= 0444 /* read-only*/,
860 .proc_handler
= &proc_dointvec
,
863 .ctl_name
= VM_SWAPPINESS
,
864 .procname
= "swappiness",
865 .data
= &vm_swappiness
,
866 .maxlen
= sizeof(vm_swappiness
),
868 .proc_handler
= &proc_dointvec_minmax
,
869 .strategy
= &sysctl_intvec
,
871 .extra2
= &one_hundred
,
873 #ifdef CONFIG_HUGETLB_PAGE
875 .ctl_name
= VM_HUGETLB_PAGES
,
876 .procname
= "nr_hugepages",
877 .data
= &max_huge_pages
,
878 .maxlen
= sizeof(unsigned long),
880 .proc_handler
= &hugetlb_sysctl_handler
,
881 .extra1
= (void *)&hugetlb_zero
,
882 .extra2
= (void *)&hugetlb_infinity
,
885 .ctl_name
= VM_HUGETLB_GROUP
,
886 .procname
= "hugetlb_shm_group",
887 .data
= &sysctl_hugetlb_shm_group
,
888 .maxlen
= sizeof(gid_t
),
890 .proc_handler
= &proc_dointvec
,
893 .ctl_name
= CTL_UNNUMBERED
,
894 .procname
= "hugepages_treat_as_movable",
895 .data
= &hugepages_treat_as_movable
,
896 .maxlen
= sizeof(int),
898 .proc_handler
= &hugetlb_treat_movable_handler
,
902 .ctl_name
= VM_LOWMEM_RESERVE_RATIO
,
903 .procname
= "lowmem_reserve_ratio",
904 .data
= &sysctl_lowmem_reserve_ratio
,
905 .maxlen
= sizeof(sysctl_lowmem_reserve_ratio
),
907 .proc_handler
= &lowmem_reserve_ratio_sysctl_handler
,
908 .strategy
= &sysctl_intvec
,
911 .ctl_name
= VM_DROP_PAGECACHE
,
912 .procname
= "drop_caches",
913 .data
= &sysctl_drop_caches
,
914 .maxlen
= sizeof(int),
916 .proc_handler
= drop_caches_sysctl_handler
,
917 .strategy
= &sysctl_intvec
,
920 .ctl_name
= VM_MIN_FREE_KBYTES
,
921 .procname
= "min_free_kbytes",
922 .data
= &min_free_kbytes
,
923 .maxlen
= sizeof(min_free_kbytes
),
925 .proc_handler
= &min_free_kbytes_sysctl_handler
,
926 .strategy
= &sysctl_intvec
,
930 .ctl_name
= VM_PERCPU_PAGELIST_FRACTION
,
931 .procname
= "percpu_pagelist_fraction",
932 .data
= &percpu_pagelist_fraction
,
933 .maxlen
= sizeof(percpu_pagelist_fraction
),
935 .proc_handler
= &percpu_pagelist_fraction_sysctl_handler
,
936 .strategy
= &sysctl_intvec
,
937 .extra1
= &min_percpu_pagelist_fract
,
941 .ctl_name
= VM_MAX_MAP_COUNT
,
942 .procname
= "max_map_count",
943 .data
= &sysctl_max_map_count
,
944 .maxlen
= sizeof(sysctl_max_map_count
),
946 .proc_handler
= &proc_dointvec
950 .ctl_name
= VM_LAPTOP_MODE
,
951 .procname
= "laptop_mode",
952 .data
= &laptop_mode
,
953 .maxlen
= sizeof(laptop_mode
),
955 .proc_handler
= &proc_dointvec_jiffies
,
956 .strategy
= &sysctl_jiffies
,
959 .ctl_name
= VM_BLOCK_DUMP
,
960 .procname
= "block_dump",
962 .maxlen
= sizeof(block_dump
),
964 .proc_handler
= &proc_dointvec
,
965 .strategy
= &sysctl_intvec
,
969 .ctl_name
= VM_VFS_CACHE_PRESSURE
,
970 .procname
= "vfs_cache_pressure",
971 .data
= &sysctl_vfs_cache_pressure
,
972 .maxlen
= sizeof(sysctl_vfs_cache_pressure
),
974 .proc_handler
= &proc_dointvec
,
975 .strategy
= &sysctl_intvec
,
978 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
980 .ctl_name
= VM_LEGACY_VA_LAYOUT
,
981 .procname
= "legacy_va_layout",
982 .data
= &sysctl_legacy_va_layout
,
983 .maxlen
= sizeof(sysctl_legacy_va_layout
),
985 .proc_handler
= &proc_dointvec
,
986 .strategy
= &sysctl_intvec
,
992 .ctl_name
= VM_ZONE_RECLAIM_MODE
,
993 .procname
= "zone_reclaim_mode",
994 .data
= &zone_reclaim_mode
,
995 .maxlen
= sizeof(zone_reclaim_mode
),
997 .proc_handler
= &proc_dointvec
,
998 .strategy
= &sysctl_intvec
,
1002 .ctl_name
= VM_MIN_UNMAPPED
,
1003 .procname
= "min_unmapped_ratio",
1004 .data
= &sysctl_min_unmapped_ratio
,
1005 .maxlen
= sizeof(sysctl_min_unmapped_ratio
),
1007 .proc_handler
= &sysctl_min_unmapped_ratio_sysctl_handler
,
1008 .strategy
= &sysctl_intvec
,
1010 .extra2
= &one_hundred
,
1013 .ctl_name
= VM_MIN_SLAB
,
1014 .procname
= "min_slab_ratio",
1015 .data
= &sysctl_min_slab_ratio
,
1016 .maxlen
= sizeof(sysctl_min_slab_ratio
),
1018 .proc_handler
= &sysctl_min_slab_ratio_sysctl_handler
,
1019 .strategy
= &sysctl_intvec
,
1021 .extra2
= &one_hundred
,
1026 .ctl_name
= CTL_UNNUMBERED
,
1027 .procname
= "stat_interval",
1028 .data
= &sysctl_stat_interval
,
1029 .maxlen
= sizeof(sysctl_stat_interval
),
1031 .proc_handler
= &proc_dointvec_jiffies
,
1032 .strategy
= &sysctl_jiffies
,
1035 #ifdef CONFIG_SECURITY
1037 .ctl_name
= CTL_UNNUMBERED
,
1038 .procname
= "mmap_min_addr",
1039 .data
= &mmap_min_addr
,
1040 .maxlen
= sizeof(unsigned long),
1042 .proc_handler
= &proc_doulongvec_minmax
,
1047 .ctl_name
= CTL_UNNUMBERED
,
1048 .procname
= "numa_zonelist_order",
1049 .data
= &numa_zonelist_order
,
1050 .maxlen
= NUMA_ZONELIST_ORDER_LEN
,
1052 .proc_handler
= &numa_zonelist_order_handler
,
1053 .strategy
= &sysctl_string
,
1056 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1057 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1059 .ctl_name
= VM_VDSO_ENABLED
,
1060 .procname
= "vdso_enabled",
1061 .data
= &vdso_enabled
,
1062 .maxlen
= sizeof(vdso_enabled
),
1064 .proc_handler
= &proc_dointvec
,
1065 .strategy
= &sysctl_intvec
,
1070 * NOTE: do not add new entries to this table unless you have read
1071 * Documentation/sysctl/ctl_unnumbered.txt
1076 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1077 static ctl_table binfmt_misc_table
[] = {
1082 static ctl_table fs_table
[] = {
1084 .ctl_name
= FS_NRINODE
,
1085 .procname
= "inode-nr",
1086 .data
= &inodes_stat
,
1087 .maxlen
= 2*sizeof(int),
1089 .proc_handler
= &proc_dointvec
,
1092 .ctl_name
= FS_STATINODE
,
1093 .procname
= "inode-state",
1094 .data
= &inodes_stat
,
1095 .maxlen
= 7*sizeof(int),
1097 .proc_handler
= &proc_dointvec
,
1100 .ctl_name
= FS_NRFILE
,
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 .ctl_name
= FS_AIO_NR
,
1177 .procname
= "aio-nr",
1179 .maxlen
= sizeof(aio_nr
),
1181 .proc_handler
= &proc_doulongvec_minmax
,
1184 .ctl_name
= FS_AIO_MAX_NR
,
1185 .procname
= "aio-max-nr",
1186 .data
= &aio_max_nr
,
1187 .maxlen
= sizeof(aio_max_nr
),
1189 .proc_handler
= &proc_doulongvec_minmax
,
1191 #ifdef CONFIG_INOTIFY_USER
1193 .ctl_name
= FS_INOTIFY
,
1194 .procname
= "inotify",
1196 .child
= inotify_table
,
1201 .ctl_name
= KERN_SETUID_DUMPABLE
,
1202 .procname
= "suid_dumpable",
1203 .data
= &suid_dumpable
,
1204 .maxlen
= sizeof(int),
1206 .proc_handler
= &proc_dointvec
,
1208 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1210 .ctl_name
= CTL_UNNUMBERED
,
1211 .procname
= "binfmt_misc",
1213 .child
= binfmt_misc_table
,
1217 * NOTE: do not add new entries to this table unless you have read
1218 * Documentation/sysctl/ctl_unnumbered.txt
1223 static ctl_table debug_table
[] = {
1224 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1226 .ctl_name
= CTL_UNNUMBERED
,
1227 .procname
= "exception-trace",
1228 .data
= &show_unhandled_signals
,
1229 .maxlen
= sizeof(int),
1231 .proc_handler
= proc_dointvec
1237 static ctl_table dev_table
[] = {
1241 static DEFINE_SPINLOCK(sysctl_lock
);
1243 /* called under sysctl_lock */
1244 static int use_table(struct ctl_table_header
*p
)
1246 if (unlikely(p
->unregistering
))
1252 /* called under sysctl_lock */
1253 static void unuse_table(struct ctl_table_header
*p
)
1256 if (unlikely(p
->unregistering
))
1257 complete(p
->unregistering
);
1260 /* called under sysctl_lock, will reacquire if has to wait */
1261 static void start_unregistering(struct ctl_table_header
*p
)
1264 * if p->used is 0, nobody will ever touch that entry again;
1265 * we'll eliminate all paths to it before dropping sysctl_lock
1267 if (unlikely(p
->used
)) {
1268 struct completion wait
;
1269 init_completion(&wait
);
1270 p
->unregistering
= &wait
;
1271 spin_unlock(&sysctl_lock
);
1272 wait_for_completion(&wait
);
1273 spin_lock(&sysctl_lock
);
1276 * do not remove from the list until nobody holds it; walking the
1277 * list in do_sysctl() relies on that.
1279 list_del_init(&p
->ctl_entry
);
1282 void sysctl_head_finish(struct ctl_table_header
*head
)
1286 spin_lock(&sysctl_lock
);
1288 spin_unlock(&sysctl_lock
);
1291 struct ctl_table_header
*sysctl_head_next(struct ctl_table_header
*prev
)
1293 struct ctl_table_header
*head
;
1294 struct list_head
*tmp
;
1295 spin_lock(&sysctl_lock
);
1297 tmp
= &prev
->ctl_entry
;
1301 tmp
= &root_table_header
.ctl_entry
;
1303 head
= list_entry(tmp
, struct ctl_table_header
, ctl_entry
);
1305 if (!use_table(head
))
1307 spin_unlock(&sysctl_lock
);
1311 if (tmp
== &root_table_header
.ctl_entry
)
1314 spin_unlock(&sysctl_lock
);
1318 #ifdef CONFIG_SYSCTL_SYSCALL
1319 int do_sysctl(int __user
*name
, int nlen
, void __user
*oldval
, size_t __user
*oldlenp
,
1320 void __user
*newval
, size_t newlen
)
1322 struct ctl_table_header
*head
;
1323 int error
= -ENOTDIR
;
1325 if (nlen
<= 0 || nlen
>= CTL_MAXNAME
)
1329 if (!oldlenp
|| get_user(old_len
, oldlenp
))
1333 for (head
= sysctl_head_next(NULL
); head
;
1334 head
= sysctl_head_next(head
)) {
1335 error
= parse_table(name
, nlen
, oldval
, oldlenp
,
1336 newval
, newlen
, head
->ctl_table
);
1337 if (error
!= -ENOTDIR
) {
1338 sysctl_head_finish(head
);
1345 asmlinkage
long sys_sysctl(struct __sysctl_args __user
*args
)
1347 struct __sysctl_args tmp
;
1350 if (copy_from_user(&tmp
, args
, sizeof(tmp
)))
1354 error
= do_sysctl(tmp
.name
, tmp
.nlen
, tmp
.oldval
, tmp
.oldlenp
,
1355 tmp
.newval
, tmp
.newlen
);
1359 #endif /* CONFIG_SYSCTL_SYSCALL */
1362 * sysctl_perm does NOT grant the superuser all rights automatically, because
1363 * some sysctl variables are readonly even to root.
1366 static int test_perm(int mode
, int op
)
1370 else if (in_egroup_p(0))
1372 if ((mode
& op
& 0007) == op
)
1377 int sysctl_perm(ctl_table
*table
, int op
)
1380 error
= security_sysctl(table
, op
);
1383 return test_perm(table
->mode
, op
);
1386 #ifdef CONFIG_SYSCTL_SYSCALL
1387 static int parse_table(int __user
*name
, int nlen
,
1388 void __user
*oldval
, size_t __user
*oldlenp
,
1389 void __user
*newval
, size_t newlen
,
1396 if (get_user(n
, name
))
1398 for ( ; table
->ctl_name
|| table
->procname
; table
++) {
1399 if (!table
->ctl_name
)
1401 if (n
== table
->ctl_name
) {
1404 if (sysctl_perm(table
, 001))
1408 table
= table
->child
;
1411 error
= do_sysctl_strategy(table
, name
, nlen
,
1420 /* Perform the actual read/write of a sysctl table entry. */
1421 int do_sysctl_strategy (ctl_table
*table
,
1422 int __user
*name
, int nlen
,
1423 void __user
*oldval
, size_t __user
*oldlenp
,
1424 void __user
*newval
, size_t newlen
)
1433 if (sysctl_perm(table
, op
))
1436 if (table
->strategy
) {
1437 rc
= table
->strategy(table
, name
, nlen
, oldval
, oldlenp
,
1445 /* If there is no strategy routine, or if the strategy returns
1446 * zero, proceed with automatic r/w */
1447 if (table
->data
&& table
->maxlen
) {
1448 if (oldval
&& oldlenp
) {
1449 if (get_user(len
, oldlenp
))
1452 if (len
> table
->maxlen
)
1453 len
= table
->maxlen
;
1454 if(copy_to_user(oldval
, table
->data
, len
))
1456 if(put_user(len
, oldlenp
))
1460 if (newval
&& newlen
) {
1462 if (len
> table
->maxlen
)
1463 len
= table
->maxlen
;
1464 if(copy_from_user(table
->data
, newval
, len
))
1470 #endif /* CONFIG_SYSCTL_SYSCALL */
1472 static void sysctl_set_parent(struct ctl_table
*parent
, struct ctl_table
*table
)
1474 for (; table
->ctl_name
|| table
->procname
; table
++) {
1475 table
->parent
= parent
;
1477 sysctl_set_parent(table
, table
->child
);
1481 static __init
int sysctl_init(void)
1483 sysctl_set_parent(NULL
, root_table
);
1487 core_initcall(sysctl_init
);
1490 * register_sysctl_table - register a sysctl hierarchy
1491 * @table: the top-level table structure
1493 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1494 * array. An entry with a ctl_name of 0 terminates the table.
1496 * The members of the &ctl_table structure are used as follows:
1498 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1499 * must be unique within that level of sysctl
1501 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1502 * enter a sysctl file
1504 * data - a pointer to data for use by proc_handler
1506 * maxlen - the maximum size in bytes of the data
1508 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1510 * child - a pointer to the child sysctl table if this entry is a directory, or
1513 * proc_handler - the text handler routine (described below)
1515 * strategy - the strategy routine (described below)
1517 * de - for internal use by the sysctl routines
1519 * extra1, extra2 - extra pointers usable by the proc handler routines
1521 * Leaf nodes in the sysctl tree will be represented by a single file
1522 * under /proc; non-leaf nodes will be represented by directories.
1524 * sysctl(2) can automatically manage read and write requests through
1525 * the sysctl table. The data and maxlen fields of the ctl_table
1526 * struct enable minimal validation of the values being written to be
1527 * performed, and the mode field allows minimal authentication.
1529 * More sophisticated management can be enabled by the provision of a
1530 * strategy routine with the table entry. This will be called before
1531 * any automatic read or write of the data is performed.
1533 * The strategy routine may return
1535 * < 0 - Error occurred (error is passed to user process)
1537 * 0 - OK - proceed with automatic read or write.
1539 * > 0 - OK - read or write has been done by the strategy routine, so
1540 * return immediately.
1542 * There must be a proc_handler routine for any terminal nodes
1543 * mirrored under /proc/sys (non-terminals are handled by a built-in
1544 * directory handler). Several default handlers are available to
1545 * cover common cases -
1547 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1548 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1549 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1551 * It is the handler's job to read the input buffer from user memory
1552 * and process it. The handler should return 0 on success.
1554 * This routine returns %NULL on a failure to register, and a pointer
1555 * to the table header on success.
1557 struct ctl_table_header
*register_sysctl_table(ctl_table
* table
)
1559 struct ctl_table_header
*tmp
;
1560 tmp
= kmalloc(sizeof(struct ctl_table_header
), GFP_KERNEL
);
1563 tmp
->ctl_table
= table
;
1564 INIT_LIST_HEAD(&tmp
->ctl_entry
);
1566 tmp
->unregistering
= NULL
;
1567 sysctl_set_parent(NULL
, table
);
1568 spin_lock(&sysctl_lock
);
1569 list_add_tail(&tmp
->ctl_entry
, &root_table_header
.ctl_entry
);
1570 spin_unlock(&sysctl_lock
);
1575 * unregister_sysctl_table - unregister a sysctl table hierarchy
1576 * @header: the header returned from register_sysctl_table
1578 * Unregisters the sysctl table and all children. proc entries may not
1579 * actually be removed until they are no longer used by anyone.
1581 void unregister_sysctl_table(struct ctl_table_header
* header
)
1584 spin_lock(&sysctl_lock
);
1585 start_unregistering(header
);
1586 spin_unlock(&sysctl_lock
);
1590 #else /* !CONFIG_SYSCTL */
1591 struct ctl_table_header
*register_sysctl_table(ctl_table
* table
)
1596 void unregister_sysctl_table(struct ctl_table_header
* table
)
1600 #endif /* CONFIG_SYSCTL */
1606 #ifdef CONFIG_PROC_SYSCTL
1608 static int _proc_do_string(void* data
, int maxlen
, int write
,
1609 struct file
*filp
, void __user
*buffer
,
1610 size_t *lenp
, loff_t
*ppos
)
1616 if (!data
|| !maxlen
|| !*lenp
) {
1624 while (len
< *lenp
) {
1625 if (get_user(c
, p
++))
1627 if (c
== 0 || c
== '\n')
1633 if(copy_from_user(data
, buffer
, len
))
1635 ((char *) data
)[len
] = 0;
1653 if(copy_to_user(buffer
, data
, len
))
1656 if(put_user('\n', ((char __user
*) buffer
) + len
))
1667 * proc_dostring - read a string sysctl
1668 * @table: the sysctl table
1669 * @write: %TRUE if this is a write to the sysctl file
1670 * @filp: the file structure
1671 * @buffer: the user buffer
1672 * @lenp: the size of the user buffer
1673 * @ppos: file position
1675 * Reads/writes a string from/to the user buffer. If the kernel
1676 * buffer provided is not large enough to hold the string, the
1677 * string is truncated. The copied string is %NULL-terminated.
1678 * If the string is being read by the user process, it is copied
1679 * and a newline '\n' is added. It is truncated if the buffer is
1682 * Returns 0 on success.
1684 int proc_dostring(ctl_table
*table
, int write
, struct file
*filp
,
1685 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1687 return _proc_do_string(table
->data
, table
->maxlen
, write
, filp
,
1688 buffer
, lenp
, ppos
);
1692 static int do_proc_dointvec_conv(int *negp
, unsigned long *lvalp
,
1694 int write
, void *data
)
1697 *valp
= *negp
? -*lvalp
: *lvalp
;
1702 *lvalp
= (unsigned long)-val
;
1705 *lvalp
= (unsigned long)val
;
1711 static int __do_proc_dointvec(void *tbl_data
, ctl_table
*table
,
1712 int write
, struct file
*filp
, void __user
*buffer
,
1713 size_t *lenp
, loff_t
*ppos
,
1714 int (*conv
)(int *negp
, unsigned long *lvalp
, int *valp
,
1715 int write
, void *data
),
1718 #define TMPBUFLEN 21
1719 int *i
, vleft
, first
=1, neg
, val
;
1723 char buf
[TMPBUFLEN
], *p
;
1724 char __user
*s
= buffer
;
1726 if (!tbl_data
|| !table
->maxlen
|| !*lenp
||
1727 (*ppos
&& !write
)) {
1732 i
= (int *) tbl_data
;
1733 vleft
= table
->maxlen
/ sizeof(*i
);
1737 conv
= do_proc_dointvec_conv
;
1739 for (; left
&& vleft
--; i
++, first
=0) {
1754 if (len
> sizeof(buf
) - 1)
1755 len
= sizeof(buf
) - 1;
1756 if (copy_from_user(buf
, s
, len
))
1760 if (*p
== '-' && left
> 1) {
1764 if (*p
< '0' || *p
> '9')
1767 lval
= simple_strtoul(p
, &p
, 0);
1770 if ((len
< left
) && *p
&& !isspace(*p
))
1777 if (conv(&neg
, &lval
, i
, 1, data
))
1784 if (conv(&neg
, &lval
, i
, 0, data
))
1787 sprintf(p
, "%s%lu", neg
? "-" : "", lval
);
1791 if(copy_to_user(s
, buf
, len
))
1798 if (!write
&& !first
&& left
) {
1799 if(put_user('\n', s
))
1806 if (get_user(c
, s
++))
1821 static int do_proc_dointvec(ctl_table
*table
, int write
, struct file
*filp
,
1822 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
,
1823 int (*conv
)(int *negp
, unsigned long *lvalp
, int *valp
,
1824 int write
, void *data
),
1827 return __do_proc_dointvec(table
->data
, table
, write
, filp
,
1828 buffer
, lenp
, ppos
, conv
, data
);
1832 * proc_dointvec - read a vector of integers
1833 * @table: the sysctl table
1834 * @write: %TRUE if this is a write to the sysctl file
1835 * @filp: the file structure
1836 * @buffer: the user buffer
1837 * @lenp: the size of the user buffer
1838 * @ppos: file position
1840 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1841 * values from/to the user buffer, treated as an ASCII string.
1843 * Returns 0 on success.
1845 int proc_dointvec(ctl_table
*table
, int write
, struct file
*filp
,
1846 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1848 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
1856 static int do_proc_dointvec_bset_conv(int *negp
, unsigned long *lvalp
,
1858 int write
, void *data
)
1860 int op
= *(int *)data
;
1862 int val
= *negp
? -*lvalp
: *lvalp
;
1864 case OP_SET
: *valp
= val
; break;
1865 case OP_AND
: *valp
&= val
; break;
1866 case OP_OR
: *valp
|= val
; break;
1872 *lvalp
= (unsigned long)-val
;
1875 *lvalp
= (unsigned long)val
;
1882 * init may raise the set.
1885 int proc_dointvec_bset(ctl_table
*table
, int write
, struct file
*filp
,
1886 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1890 if (write
&& !capable(CAP_SYS_MODULE
)) {
1894 op
= is_init(current
) ? OP_SET
: OP_AND
;
1895 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
1896 do_proc_dointvec_bset_conv
,&op
);
1900 * Taint values can only be increased
1902 static int proc_dointvec_taint(ctl_table
*table
, int write
, struct file
*filp
,
1903 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1907 if (write
&& !capable(CAP_SYS_ADMIN
))
1911 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
1912 do_proc_dointvec_bset_conv
,&op
);
1915 struct do_proc_dointvec_minmax_conv_param
{
1920 static int do_proc_dointvec_minmax_conv(int *negp
, unsigned long *lvalp
,
1922 int write
, void *data
)
1924 struct do_proc_dointvec_minmax_conv_param
*param
= data
;
1926 int val
= *negp
? -*lvalp
: *lvalp
;
1927 if ((param
->min
&& *param
->min
> val
) ||
1928 (param
->max
&& *param
->max
< val
))
1935 *lvalp
= (unsigned long)-val
;
1938 *lvalp
= (unsigned long)val
;
1945 * proc_dointvec_minmax - read a vector of integers with min/max values
1946 * @table: the sysctl table
1947 * @write: %TRUE if this is a write to the sysctl file
1948 * @filp: the file structure
1949 * @buffer: the user buffer
1950 * @lenp: the size of the user buffer
1951 * @ppos: file position
1953 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1954 * values from/to the user buffer, treated as an ASCII string.
1956 * This routine will ensure the values are within the range specified by
1957 * table->extra1 (min) and table->extra2 (max).
1959 * Returns 0 on success.
1961 int proc_dointvec_minmax(ctl_table
*table
, int write
, struct file
*filp
,
1962 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
1964 struct do_proc_dointvec_minmax_conv_param param
= {
1965 .min
= (int *) table
->extra1
,
1966 .max
= (int *) table
->extra2
,
1968 return do_proc_dointvec(table
, write
, filp
, buffer
, lenp
, ppos
,
1969 do_proc_dointvec_minmax_conv
, ¶m
);
1972 static int __do_proc_doulongvec_minmax(void *data
, ctl_table
*table
, int write
,
1974 void __user
*buffer
,
1975 size_t *lenp
, loff_t
*ppos
,
1976 unsigned long convmul
,
1977 unsigned long convdiv
)
1979 #define TMPBUFLEN 21
1980 unsigned long *i
, *min
, *max
, val
;
1981 int vleft
, first
=1, neg
;
1983 char buf
[TMPBUFLEN
], *p
;
1984 char __user
*s
= buffer
;
1986 if (!data
|| !table
->maxlen
|| !*lenp
||
1987 (*ppos
&& !write
)) {
1992 i
= (unsigned long *) data
;
1993 min
= (unsigned long *) table
->extra1
;
1994 max
= (unsigned long *) table
->extra2
;
1995 vleft
= table
->maxlen
/ sizeof(unsigned long);
1998 for (; left
&& vleft
--; i
++, min
++, max
++, first
=0) {
2013 if (len
> TMPBUFLEN
-1)
2015 if (copy_from_user(buf
, s
, len
))
2019 if (*p
== '-' && left
> 1) {
2023 if (*p
< '0' || *p
> '9')
2025 val
= simple_strtoul(p
, &p
, 0) * convmul
/ convdiv
;
2027 if ((len
< left
) && *p
&& !isspace(*p
))
2036 if ((min
&& val
< *min
) || (max
&& val
> *max
))
2043 sprintf(p
, "%lu", convdiv
* (*i
) / convmul
);
2047 if(copy_to_user(s
, buf
, len
))
2054 if (!write
&& !first
&& left
) {
2055 if(put_user('\n', s
))
2062 if (get_user(c
, s
++))
2077 static int do_proc_doulongvec_minmax(ctl_table
*table
, int write
,
2079 void __user
*buffer
,
2080 size_t *lenp
, loff_t
*ppos
,
2081 unsigned long convmul
,
2082 unsigned long convdiv
)
2084 return __do_proc_doulongvec_minmax(table
->data
, table
, write
,
2085 filp
, buffer
, lenp
, ppos
, convmul
, convdiv
);
2089 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2090 * @table: the sysctl table
2091 * @write: %TRUE if this is a write to the sysctl file
2092 * @filp: the file structure
2093 * @buffer: the user buffer
2094 * @lenp: the size of the user buffer
2095 * @ppos: file position
2097 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2098 * values from/to the user buffer, treated as an ASCII string.
2100 * This routine will ensure the values are within the range specified by
2101 * table->extra1 (min) and table->extra2 (max).
2103 * Returns 0 on success.
2105 int proc_doulongvec_minmax(ctl_table
*table
, int write
, struct file
*filp
,
2106 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2108 return do_proc_doulongvec_minmax(table
, write
, filp
, buffer
, lenp
, ppos
, 1l, 1l);
2112 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2113 * @table: the sysctl table
2114 * @write: %TRUE if this is a write to the sysctl file
2115 * @filp: the file structure
2116 * @buffer: the user buffer
2117 * @lenp: the size of the user buffer
2118 * @ppos: file position
2120 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2121 * values from/to the user buffer, treated as an ASCII string. The values
2122 * are treated as milliseconds, and converted to jiffies when they are stored.
2124 * This routine will ensure the values are within the range specified by
2125 * table->extra1 (min) and table->extra2 (max).
2127 * Returns 0 on success.
2129 int proc_doulongvec_ms_jiffies_minmax(ctl_table
*table
, int write
,
2131 void __user
*buffer
,
2132 size_t *lenp
, loff_t
*ppos
)
2134 return do_proc_doulongvec_minmax(table
, write
, filp
, buffer
,
2135 lenp
, ppos
, HZ
, 1000l);
2139 static int do_proc_dointvec_jiffies_conv(int *negp
, unsigned long *lvalp
,
2141 int write
, void *data
)
2144 if (*lvalp
> LONG_MAX
/ HZ
)
2146 *valp
= *negp
? -(*lvalp
*HZ
) : (*lvalp
*HZ
);
2152 lval
= (unsigned long)-val
;
2155 lval
= (unsigned long)val
;
2162 static int do_proc_dointvec_userhz_jiffies_conv(int *negp
, unsigned long *lvalp
,
2164 int write
, void *data
)
2167 if (USER_HZ
< HZ
&& *lvalp
> (LONG_MAX
/ HZ
) * USER_HZ
)
2169 *valp
= clock_t_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2175 lval
= (unsigned long)-val
;
2178 lval
= (unsigned long)val
;
2180 *lvalp
= jiffies_to_clock_t(lval
);
2185 static int do_proc_dointvec_ms_jiffies_conv(int *negp
, unsigned long *lvalp
,
2187 int write
, void *data
)
2190 *valp
= msecs_to_jiffies(*negp
? -*lvalp
: *lvalp
);
2196 lval
= (unsigned long)-val
;
2199 lval
= (unsigned long)val
;
2201 *lvalp
= jiffies_to_msecs(lval
);
2207 * proc_dointvec_jiffies - read a vector of integers as seconds
2208 * @table: the sysctl table
2209 * @write: %TRUE if this is a write to the sysctl file
2210 * @filp: the file structure
2211 * @buffer: the user buffer
2212 * @lenp: the size of the user buffer
2213 * @ppos: file position
2215 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2216 * values from/to the user buffer, treated as an ASCII string.
2217 * The values read are assumed to be in seconds, and are converted into
2220 * Returns 0 on success.
2222 int proc_dointvec_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2223 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2225 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2226 do_proc_dointvec_jiffies_conv
,NULL
);
2230 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2231 * @table: the sysctl table
2232 * @write: %TRUE if this is a write to the sysctl file
2233 * @filp: the file structure
2234 * @buffer: the user buffer
2235 * @lenp: the size of the user buffer
2236 * @ppos: pointer to the file position
2238 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2239 * values from/to the user buffer, treated as an ASCII string.
2240 * The values read are assumed to be in 1/USER_HZ seconds, and
2241 * are converted into jiffies.
2243 * Returns 0 on success.
2245 int proc_dointvec_userhz_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2246 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2248 return do_proc_dointvec(table
,write
,filp
,buffer
,lenp
,ppos
,
2249 do_proc_dointvec_userhz_jiffies_conv
,NULL
);
2253 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2254 * @table: the sysctl table
2255 * @write: %TRUE if this is a write to the sysctl file
2256 * @filp: the file structure
2257 * @buffer: the user buffer
2258 * @lenp: the size of the user buffer
2259 * @ppos: file position
2260 * @ppos: the current position in the file
2262 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2263 * values from/to the user buffer, treated as an ASCII string.
2264 * The values read are assumed to be in 1/1000 seconds, and
2265 * are converted into jiffies.
2267 * Returns 0 on success.
2269 int proc_dointvec_ms_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2270 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2272 return do_proc_dointvec(table
, write
, filp
, buffer
, lenp
, ppos
,
2273 do_proc_dointvec_ms_jiffies_conv
, NULL
);
2276 static int proc_do_cad_pid(ctl_table
*table
, int write
, struct file
*filp
,
2277 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2279 struct pid
*new_pid
;
2283 tmp
= pid_nr(cad_pid
);
2285 r
= __do_proc_dointvec(&tmp
, table
, write
, filp
, buffer
,
2286 lenp
, ppos
, NULL
, NULL
);
2290 new_pid
= find_get_pid(tmp
);
2294 put_pid(xchg(&cad_pid
, new_pid
));
2298 #else /* CONFIG_PROC_FS */
2300 int proc_dostring(ctl_table
*table
, int write
, struct file
*filp
,
2301 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2306 int proc_dointvec(ctl_table
*table
, int write
, struct file
*filp
,
2307 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2312 int proc_dointvec_bset(ctl_table
*table
, int write
, struct file
*filp
,
2313 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2318 int proc_dointvec_minmax(ctl_table
*table
, int write
, struct file
*filp
,
2319 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2324 int proc_dointvec_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2325 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2330 int proc_dointvec_userhz_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2331 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2336 int proc_dointvec_ms_jiffies(ctl_table
*table
, int write
, struct file
*filp
,
2337 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2342 int proc_doulongvec_minmax(ctl_table
*table
, int write
, struct file
*filp
,
2343 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
2348 int proc_doulongvec_ms_jiffies_minmax(ctl_table
*table
, int write
,
2350 void __user
*buffer
,
2351 size_t *lenp
, loff_t
*ppos
)
2357 #endif /* CONFIG_PROC_FS */
2360 #ifdef CONFIG_SYSCTL_SYSCALL
2362 * General sysctl support routines
2365 /* The generic string strategy routine: */
2366 int sysctl_string(ctl_table
*table
, int __user
*name
, int nlen
,
2367 void __user
*oldval
, size_t __user
*oldlenp
,
2368 void __user
*newval
, size_t newlen
)
2370 if (!table
->data
|| !table
->maxlen
)
2373 if (oldval
&& oldlenp
) {
2375 if (get_user(bufsize
, oldlenp
))
2378 size_t len
= strlen(table
->data
), copied
;
2380 /* This shouldn't trigger for a well-formed sysctl */
2381 if (len
> table
->maxlen
)
2382 len
= table
->maxlen
;
2384 /* Copy up to a max of bufsize-1 bytes of the string */
2385 copied
= (len
>= bufsize
) ? bufsize
- 1 : len
;
2387 if (copy_to_user(oldval
, table
->data
, copied
) ||
2388 put_user(0, (char __user
*)(oldval
+ copied
)))
2390 if (put_user(len
, oldlenp
))
2394 if (newval
&& newlen
) {
2395 size_t len
= newlen
;
2396 if (len
> table
->maxlen
)
2397 len
= table
->maxlen
;
2398 if(copy_from_user(table
->data
, newval
, len
))
2400 if (len
== table
->maxlen
)
2402 ((char *) table
->data
)[len
] = 0;
2408 * This function makes sure that all of the integers in the vector
2409 * are between the minimum and maximum values given in the arrays
2410 * table->extra1 and table->extra2, respectively.
2412 int sysctl_intvec(ctl_table
*table
, int __user
*name
, int nlen
,
2413 void __user
*oldval
, size_t __user
*oldlenp
,
2414 void __user
*newval
, size_t newlen
)
2417 if (newval
&& newlen
) {
2418 int __user
*vec
= (int __user
*) newval
;
2419 int *min
= (int *) table
->extra1
;
2420 int *max
= (int *) table
->extra2
;
2424 if (newlen
% sizeof(int) != 0)
2427 if (!table
->extra1
&& !table
->extra2
)
2430 if (newlen
> table
->maxlen
)
2431 newlen
= table
->maxlen
;
2432 length
= newlen
/ sizeof(int);
2434 for (i
= 0; i
< length
; i
++) {
2436 if (get_user(value
, vec
+ i
))
2438 if (min
&& value
< min
[i
])
2440 if (max
&& value
> max
[i
])
2447 /* Strategy function to convert jiffies to seconds */
2448 int sysctl_jiffies(ctl_table
*table
, int __user
*name
, int nlen
,
2449 void __user
*oldval
, size_t __user
*oldlenp
,
2450 void __user
*newval
, size_t newlen
)
2452 if (oldval
&& oldlenp
) {
2455 if (get_user(olen
, oldlenp
))
2460 if (olen
< sizeof(int))
2463 val
= *(int *)(table
->data
) / HZ
;
2464 if (put_user(val
, (int __user
*)oldval
))
2466 if (put_user(sizeof(int), oldlenp
))
2470 if (newval
&& newlen
) {
2472 if (newlen
!= sizeof(int))
2474 if (get_user(new, (int __user
*)newval
))
2476 *(int *)(table
->data
) = new*HZ
;
2481 /* Strategy function to convert jiffies to seconds */
2482 int sysctl_ms_jiffies(ctl_table
*table
, int __user
*name
, int nlen
,
2483 void __user
*oldval
, size_t __user
*oldlenp
,
2484 void __user
*newval
, size_t newlen
)
2486 if (oldval
&& oldlenp
) {
2489 if (get_user(olen
, oldlenp
))
2494 if (olen
< sizeof(int))
2497 val
= jiffies_to_msecs(*(int *)(table
->data
));
2498 if (put_user(val
, (int __user
*)oldval
))
2500 if (put_user(sizeof(int), oldlenp
))
2504 if (newval
&& newlen
) {
2506 if (newlen
!= sizeof(int))
2508 if (get_user(new, (int __user
*)newval
))
2510 *(int *)(table
->data
) = msecs_to_jiffies(new);
2517 #else /* CONFIG_SYSCTL_SYSCALL */
2520 asmlinkage
long sys_sysctl(struct __sysctl_args __user
*args
)
2522 static int msg_count
;
2523 struct __sysctl_args tmp
;
2524 int name
[CTL_MAXNAME
];
2527 /* Read in the sysctl name for better debug message logging */
2528 if (copy_from_user(&tmp
, args
, sizeof(tmp
)))
2530 if (tmp
.nlen
<= 0 || tmp
.nlen
>= CTL_MAXNAME
)
2532 for (i
= 0; i
< tmp
.nlen
; i
++)
2533 if (get_user(name
[i
], tmp
.name
+ i
))
2536 /* Ignore accesses to kernel.version */
2537 if ((tmp
.nlen
== 2) && (name
[0] == CTL_KERN
) && (name
[1] == KERN_VERSION
))
2540 if (msg_count
< 5) {
2543 "warning: process `%s' used the removed sysctl "
2544 "system call with ", current
->comm
);
2545 for (i
= 0; i
< tmp
.nlen
; i
++)
2546 printk("%d.", name
[i
]);
2553 int sysctl_string(ctl_table
*table
, int __user
*name
, int nlen
,
2554 void __user
*oldval
, size_t __user
*oldlenp
,
2555 void __user
*newval
, size_t newlen
)
2560 int sysctl_intvec(ctl_table
*table
, int __user
*name
, int nlen
,
2561 void __user
*oldval
, size_t __user
*oldlenp
,
2562 void __user
*newval
, size_t newlen
)
2567 int sysctl_jiffies(ctl_table
*table
, int __user
*name
, int nlen
,
2568 void __user
*oldval
, size_t __user
*oldlenp
,
2569 void __user
*newval
, size_t newlen
)
2574 int sysctl_ms_jiffies(ctl_table
*table
, int __user
*name
, int nlen
,
2575 void __user
*oldval
, size_t __user
*oldlenp
,
2576 void __user
*newval
, size_t newlen
)
2581 #endif /* CONFIG_SYSCTL_SYSCALL */
2584 * No sense putting this after each symbol definition, twice,
2585 * exception granted :-)
2587 EXPORT_SYMBOL(proc_dointvec
);
2588 EXPORT_SYMBOL(proc_dointvec_jiffies
);
2589 EXPORT_SYMBOL(proc_dointvec_minmax
);
2590 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies
);
2591 EXPORT_SYMBOL(proc_dointvec_ms_jiffies
);
2592 EXPORT_SYMBOL(proc_dostring
);
2593 EXPORT_SYMBOL(proc_doulongvec_minmax
);
2594 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax
);
2595 EXPORT_SYMBOL(register_sysctl_table
);
2596 EXPORT_SYMBOL(sysctl_intvec
);
2597 EXPORT_SYMBOL(sysctl_jiffies
);
2598 EXPORT_SYMBOL(sysctl_ms_jiffies
);
2599 EXPORT_SYMBOL(sysctl_string
);
2600 EXPORT_SYMBOL(unregister_sysctl_table
);