ALSA: oxygen: add UART I/O functions
[firewire-audio.git] / kernel / sysctl.c
blob50ec0886fa3d355d696e9992a9057ce11a721525
1 /*
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
12 * Horn.
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
16 * Wendling.
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>
22 #include <linux/mm.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/security.h>
28 #include <linux/ctype.h>
29 #include <linux/utsname.h>
30 #include <linux/smp_lock.h>
31 #include <linux/fs.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/initrd.h>
41 #include <linux/key.h>
42 #include <linux/times.h>
43 #include <linux/limits.h>
44 #include <linux/dcache.h>
45 #include <linux/syscalls.h>
46 #include <linux/vmstat.h>
47 #include <linux/nfs_fs.h>
48 #include <linux/acpi.h>
49 #include <linux/reboot.h>
50 #include <linux/ftrace.h>
52 #include <asm/uaccess.h>
53 #include <asm/processor.h>
55 #ifdef CONFIG_X86
56 #include <asm/nmi.h>
57 #include <asm/stacktrace.h>
58 #include <asm/io.h>
59 #endif
61 static int deprecated_sysctl_warning(struct __sysctl_args *args);
63 #if defined(CONFIG_SYSCTL)
65 /* External variables not in a header file. */
66 extern int C_A_D;
67 extern int print_fatal_signals;
68 extern int sysctl_overcommit_memory;
69 extern int sysctl_overcommit_ratio;
70 extern int sysctl_panic_on_oom;
71 extern int sysctl_oom_kill_allocating_task;
72 extern int sysctl_oom_dump_tasks;
73 extern int max_threads;
74 extern int core_uses_pid;
75 extern int suid_dumpable;
76 extern char core_pattern[];
77 extern int pid_max;
78 extern int min_free_kbytes;
79 extern int pid_max_min, pid_max_max;
80 extern int sysctl_drop_caches;
81 extern int percpu_pagelist_fraction;
82 extern int compat_log;
83 extern int maps_protect;
84 extern int latencytop_enabled;
85 extern int sysctl_nr_open_min, sysctl_nr_open_max;
86 #ifdef CONFIG_RCU_TORTURE_TEST
87 extern int rcutorture_runnable;
88 #endif /* #ifdef CONFIG_RCU_TORTURE_TEST */
90 /* Constants used for minimum and maximum */
91 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP)
92 static int one = 1;
93 #endif
95 #ifdef CONFIG_DETECT_SOFTLOCKUP
96 static int sixty = 60;
97 static int neg_one = -1;
98 #endif
100 #ifdef CONFIG_MMU
101 static int two = 2;
102 #endif
104 static int zero;
105 static int one_hundred = 100;
107 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
108 static int maxolduid = 65535;
109 static int minolduid;
110 static int min_percpu_pagelist_fract = 8;
112 static int ngroups_max = NGROUPS_MAX;
114 #ifdef CONFIG_MODULES
115 extern char modprobe_path[];
116 #endif
117 #ifdef CONFIG_CHR_DEV_SG
118 extern int sg_big_buff;
119 #endif
121 #ifdef __sparc__
122 extern char reboot_command [];
123 extern int stop_a_enabled;
124 extern int scons_pwroff;
125 #endif
127 #ifdef __hppa__
128 extern int pwrsw_enabled;
129 extern int unaligned_enabled;
130 #endif
132 #ifdef CONFIG_S390
133 #ifdef CONFIG_MATHEMU
134 extern int sysctl_ieee_emulation_warnings;
135 #endif
136 extern int sysctl_userprocess_debug;
137 extern int spin_retry;
138 #endif
140 #ifdef CONFIG_BSD_PROCESS_ACCT
141 extern int acct_parm[];
142 #endif
144 #ifdef CONFIG_IA64
145 extern int no_unaligned_warning;
146 #endif
148 #ifdef CONFIG_RT_MUTEXES
149 extern int max_lock_depth;
150 #endif
152 #ifdef CONFIG_PROC_SYSCTL
153 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
154 void __user *buffer, size_t *lenp, loff_t *ppos);
155 static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
156 void __user *buffer, size_t *lenp, loff_t *ppos);
157 #endif
159 static struct ctl_table root_table[];
160 static struct ctl_table_root sysctl_table_root;
161 static struct ctl_table_header root_table_header = {
162 .count = 1,
163 .ctl_table = root_table,
164 .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),
165 .root = &sysctl_table_root,
166 .set = &sysctl_table_root.default_set,
168 static struct ctl_table_root sysctl_table_root = {
169 .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list),
170 .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry),
173 static struct ctl_table kern_table[];
174 static struct ctl_table vm_table[];
175 static struct ctl_table fs_table[];
176 static struct ctl_table debug_table[];
177 static struct ctl_table dev_table[];
178 extern struct ctl_table random_table[];
179 #ifdef CONFIG_INOTIFY_USER
180 extern struct ctl_table inotify_table[];
181 #endif
183 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
184 int sysctl_legacy_va_layout;
185 #endif
187 extern int prove_locking;
188 extern int lock_stat;
190 /* The default sysctl tables: */
192 static struct ctl_table root_table[] = {
194 .ctl_name = CTL_KERN,
195 .procname = "kernel",
196 .mode = 0555,
197 .child = kern_table,
200 .ctl_name = CTL_VM,
201 .procname = "vm",
202 .mode = 0555,
203 .child = vm_table,
206 .ctl_name = CTL_FS,
207 .procname = "fs",
208 .mode = 0555,
209 .child = fs_table,
212 .ctl_name = CTL_DEBUG,
213 .procname = "debug",
214 .mode = 0555,
215 .child = debug_table,
218 .ctl_name = CTL_DEV,
219 .procname = "dev",
220 .mode = 0555,
221 .child = dev_table,
224 * NOTE: do not add new entries to this table unless you have read
225 * Documentation/sysctl/ctl_unnumbered.txt
227 { .ctl_name = 0 }
230 #ifdef CONFIG_SCHED_DEBUG
231 static int min_sched_granularity_ns = 100000; /* 100 usecs */
232 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
233 static int min_wakeup_granularity_ns; /* 0 usecs */
234 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
235 #endif
237 static struct ctl_table kern_table[] = {
238 #ifdef CONFIG_SCHED_DEBUG
240 .ctl_name = CTL_UNNUMBERED,
241 .procname = "sched_min_granularity_ns",
242 .data = &sysctl_sched_min_granularity,
243 .maxlen = sizeof(unsigned int),
244 .mode = 0644,
245 .proc_handler = &sched_nr_latency_handler,
246 .strategy = &sysctl_intvec,
247 .extra1 = &min_sched_granularity_ns,
248 .extra2 = &max_sched_granularity_ns,
251 .ctl_name = CTL_UNNUMBERED,
252 .procname = "sched_latency_ns",
253 .data = &sysctl_sched_latency,
254 .maxlen = sizeof(unsigned int),
255 .mode = 0644,
256 .proc_handler = &sched_nr_latency_handler,
257 .strategy = &sysctl_intvec,
258 .extra1 = &min_sched_granularity_ns,
259 .extra2 = &max_sched_granularity_ns,
262 .ctl_name = CTL_UNNUMBERED,
263 .procname = "sched_wakeup_granularity_ns",
264 .data = &sysctl_sched_wakeup_granularity,
265 .maxlen = sizeof(unsigned int),
266 .mode = 0644,
267 .proc_handler = &proc_dointvec_minmax,
268 .strategy = &sysctl_intvec,
269 .extra1 = &min_wakeup_granularity_ns,
270 .extra2 = &max_wakeup_granularity_ns,
273 .ctl_name = CTL_UNNUMBERED,
274 .procname = "sched_shares_ratelimit",
275 .data = &sysctl_sched_shares_ratelimit,
276 .maxlen = sizeof(unsigned int),
277 .mode = 0644,
278 .proc_handler = &proc_dointvec,
281 .ctl_name = CTL_UNNUMBERED,
282 .procname = "sched_child_runs_first",
283 .data = &sysctl_sched_child_runs_first,
284 .maxlen = sizeof(unsigned int),
285 .mode = 0644,
286 .proc_handler = &proc_dointvec,
289 .ctl_name = CTL_UNNUMBERED,
290 .procname = "sched_features",
291 .data = &sysctl_sched_features,
292 .maxlen = sizeof(unsigned int),
293 .mode = 0644,
294 .proc_handler = &proc_dointvec,
297 .ctl_name = CTL_UNNUMBERED,
298 .procname = "sched_migration_cost",
299 .data = &sysctl_sched_migration_cost,
300 .maxlen = sizeof(unsigned int),
301 .mode = 0644,
302 .proc_handler = &proc_dointvec,
305 .ctl_name = CTL_UNNUMBERED,
306 .procname = "sched_nr_migrate",
307 .data = &sysctl_sched_nr_migrate,
308 .maxlen = sizeof(unsigned int),
309 .mode = 0644,
310 .proc_handler = &proc_dointvec,
312 #endif
314 .ctl_name = CTL_UNNUMBERED,
315 .procname = "sched_rt_period_us",
316 .data = &sysctl_sched_rt_period,
317 .maxlen = sizeof(unsigned int),
318 .mode = 0644,
319 .proc_handler = &sched_rt_handler,
322 .ctl_name = CTL_UNNUMBERED,
323 .procname = "sched_rt_runtime_us",
324 .data = &sysctl_sched_rt_runtime,
325 .maxlen = sizeof(int),
326 .mode = 0644,
327 .proc_handler = &sched_rt_handler,
330 .ctl_name = CTL_UNNUMBERED,
331 .procname = "sched_compat_yield",
332 .data = &sysctl_sched_compat_yield,
333 .maxlen = sizeof(unsigned int),
334 .mode = 0644,
335 .proc_handler = &proc_dointvec,
337 #ifdef CONFIG_PROVE_LOCKING
339 .ctl_name = CTL_UNNUMBERED,
340 .procname = "prove_locking",
341 .data = &prove_locking,
342 .maxlen = sizeof(int),
343 .mode = 0644,
344 .proc_handler = &proc_dointvec,
346 #endif
347 #ifdef CONFIG_LOCK_STAT
349 .ctl_name = CTL_UNNUMBERED,
350 .procname = "lock_stat",
351 .data = &lock_stat,
352 .maxlen = sizeof(int),
353 .mode = 0644,
354 .proc_handler = &proc_dointvec,
356 #endif
358 .ctl_name = KERN_PANIC,
359 .procname = "panic",
360 .data = &panic_timeout,
361 .maxlen = sizeof(int),
362 .mode = 0644,
363 .proc_handler = &proc_dointvec,
366 .ctl_name = KERN_CORE_USES_PID,
367 .procname = "core_uses_pid",
368 .data = &core_uses_pid,
369 .maxlen = sizeof(int),
370 .mode = 0644,
371 .proc_handler = &proc_dointvec,
374 .ctl_name = KERN_CORE_PATTERN,
375 .procname = "core_pattern",
376 .data = core_pattern,
377 .maxlen = CORENAME_MAX_SIZE,
378 .mode = 0644,
379 .proc_handler = &proc_dostring,
380 .strategy = &sysctl_string,
382 #ifdef CONFIG_PROC_SYSCTL
384 .procname = "tainted",
385 .data = &tainted,
386 .maxlen = sizeof(int),
387 .mode = 0644,
388 .proc_handler = &proc_dointvec_taint,
390 #endif
391 #ifdef CONFIG_LATENCYTOP
393 .procname = "latencytop",
394 .data = &latencytop_enabled,
395 .maxlen = sizeof(int),
396 .mode = 0644,
397 .proc_handler = &proc_dointvec,
399 #endif
400 #ifdef CONFIG_BLK_DEV_INITRD
402 .ctl_name = KERN_REALROOTDEV,
403 .procname = "real-root-dev",
404 .data = &real_root_dev,
405 .maxlen = sizeof(int),
406 .mode = 0644,
407 .proc_handler = &proc_dointvec,
409 #endif
411 .ctl_name = CTL_UNNUMBERED,
412 .procname = "print-fatal-signals",
413 .data = &print_fatal_signals,
414 .maxlen = sizeof(int),
415 .mode = 0644,
416 .proc_handler = &proc_dointvec,
418 #ifdef __sparc__
420 .ctl_name = KERN_SPARC_REBOOT,
421 .procname = "reboot-cmd",
422 .data = reboot_command,
423 .maxlen = 256,
424 .mode = 0644,
425 .proc_handler = &proc_dostring,
426 .strategy = &sysctl_string,
429 .ctl_name = KERN_SPARC_STOP_A,
430 .procname = "stop-a",
431 .data = &stop_a_enabled,
432 .maxlen = sizeof (int),
433 .mode = 0644,
434 .proc_handler = &proc_dointvec,
437 .ctl_name = KERN_SPARC_SCONS_PWROFF,
438 .procname = "scons-poweroff",
439 .data = &scons_pwroff,
440 .maxlen = sizeof (int),
441 .mode = 0644,
442 .proc_handler = &proc_dointvec,
444 #endif
445 #ifdef __hppa__
447 .ctl_name = KERN_HPPA_PWRSW,
448 .procname = "soft-power",
449 .data = &pwrsw_enabled,
450 .maxlen = sizeof (int),
451 .mode = 0644,
452 .proc_handler = &proc_dointvec,
455 .ctl_name = KERN_HPPA_UNALIGNED,
456 .procname = "unaligned-trap",
457 .data = &unaligned_enabled,
458 .maxlen = sizeof (int),
459 .mode = 0644,
460 .proc_handler = &proc_dointvec,
462 #endif
464 .ctl_name = KERN_CTLALTDEL,
465 .procname = "ctrl-alt-del",
466 .data = &C_A_D,
467 .maxlen = sizeof(int),
468 .mode = 0644,
469 .proc_handler = &proc_dointvec,
471 #ifdef CONFIG_FTRACE
473 .ctl_name = CTL_UNNUMBERED,
474 .procname = "ftrace_enabled",
475 .data = &ftrace_enabled,
476 .maxlen = sizeof(int),
477 .mode = 0644,
478 .proc_handler = &ftrace_enable_sysctl,
480 #endif
481 #ifdef CONFIG_MODULES
483 .ctl_name = KERN_MODPROBE,
484 .procname = "modprobe",
485 .data = &modprobe_path,
486 .maxlen = KMOD_PATH_LEN,
487 .mode = 0644,
488 .proc_handler = &proc_dostring,
489 .strategy = &sysctl_string,
491 #endif
492 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
494 .ctl_name = KERN_HOTPLUG,
495 .procname = "hotplug",
496 .data = &uevent_helper,
497 .maxlen = UEVENT_HELPER_PATH_LEN,
498 .mode = 0644,
499 .proc_handler = &proc_dostring,
500 .strategy = &sysctl_string,
502 #endif
503 #ifdef CONFIG_CHR_DEV_SG
505 .ctl_name = KERN_SG_BIG_BUFF,
506 .procname = "sg-big-buff",
507 .data = &sg_big_buff,
508 .maxlen = sizeof (int),
509 .mode = 0444,
510 .proc_handler = &proc_dointvec,
512 #endif
513 #ifdef CONFIG_BSD_PROCESS_ACCT
515 .ctl_name = KERN_ACCT,
516 .procname = "acct",
517 .data = &acct_parm,
518 .maxlen = 3*sizeof(int),
519 .mode = 0644,
520 .proc_handler = &proc_dointvec,
522 #endif
523 #ifdef CONFIG_MAGIC_SYSRQ
525 .ctl_name = KERN_SYSRQ,
526 .procname = "sysrq",
527 .data = &__sysrq_enabled,
528 .maxlen = sizeof (int),
529 .mode = 0644,
530 .proc_handler = &proc_dointvec,
532 #endif
533 #ifdef CONFIG_PROC_SYSCTL
535 .procname = "cad_pid",
536 .data = NULL,
537 .maxlen = sizeof (int),
538 .mode = 0600,
539 .proc_handler = &proc_do_cad_pid,
541 #endif
543 .ctl_name = KERN_MAX_THREADS,
544 .procname = "threads-max",
545 .data = &max_threads,
546 .maxlen = sizeof(int),
547 .mode = 0644,
548 .proc_handler = &proc_dointvec,
551 .ctl_name = KERN_RANDOM,
552 .procname = "random",
553 .mode = 0555,
554 .child = random_table,
557 .ctl_name = KERN_OVERFLOWUID,
558 .procname = "overflowuid",
559 .data = &overflowuid,
560 .maxlen = sizeof(int),
561 .mode = 0644,
562 .proc_handler = &proc_dointvec_minmax,
563 .strategy = &sysctl_intvec,
564 .extra1 = &minolduid,
565 .extra2 = &maxolduid,
568 .ctl_name = KERN_OVERFLOWGID,
569 .procname = "overflowgid",
570 .data = &overflowgid,
571 .maxlen = sizeof(int),
572 .mode = 0644,
573 .proc_handler = &proc_dointvec_minmax,
574 .strategy = &sysctl_intvec,
575 .extra1 = &minolduid,
576 .extra2 = &maxolduid,
578 #ifdef CONFIG_S390
579 #ifdef CONFIG_MATHEMU
581 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
582 .procname = "ieee_emulation_warnings",
583 .data = &sysctl_ieee_emulation_warnings,
584 .maxlen = sizeof(int),
585 .mode = 0644,
586 .proc_handler = &proc_dointvec,
588 #endif
590 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
591 .procname = "userprocess_debug",
592 .data = &sysctl_userprocess_debug,
593 .maxlen = sizeof(int),
594 .mode = 0644,
595 .proc_handler = &proc_dointvec,
597 #endif
599 .ctl_name = KERN_PIDMAX,
600 .procname = "pid_max",
601 .data = &pid_max,
602 .maxlen = sizeof (int),
603 .mode = 0644,
604 .proc_handler = &proc_dointvec_minmax,
605 .strategy = sysctl_intvec,
606 .extra1 = &pid_max_min,
607 .extra2 = &pid_max_max,
610 .ctl_name = KERN_PANIC_ON_OOPS,
611 .procname = "panic_on_oops",
612 .data = &panic_on_oops,
613 .maxlen = sizeof(int),
614 .mode = 0644,
615 .proc_handler = &proc_dointvec,
617 #if defined CONFIG_PRINTK
619 .ctl_name = KERN_PRINTK,
620 .procname = "printk",
621 .data = &console_loglevel,
622 .maxlen = 4*sizeof(int),
623 .mode = 0644,
624 .proc_handler = &proc_dointvec,
627 .ctl_name = KERN_PRINTK_RATELIMIT,
628 .procname = "printk_ratelimit",
629 .data = &printk_ratelimit_state.interval,
630 .maxlen = sizeof(int),
631 .mode = 0644,
632 .proc_handler = &proc_dointvec_jiffies,
633 .strategy = &sysctl_jiffies,
636 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
637 .procname = "printk_ratelimit_burst",
638 .data = &printk_ratelimit_state.burst,
639 .maxlen = sizeof(int),
640 .mode = 0644,
641 .proc_handler = &proc_dointvec,
643 #endif
645 .ctl_name = KERN_NGROUPS_MAX,
646 .procname = "ngroups_max",
647 .data = &ngroups_max,
648 .maxlen = sizeof (int),
649 .mode = 0444,
650 .proc_handler = &proc_dointvec,
652 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
654 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
655 .procname = "unknown_nmi_panic",
656 .data = &unknown_nmi_panic,
657 .maxlen = sizeof (int),
658 .mode = 0644,
659 .proc_handler = &proc_dointvec,
662 .procname = "nmi_watchdog",
663 .data = &nmi_watchdog_enabled,
664 .maxlen = sizeof (int),
665 .mode = 0644,
666 .proc_handler = &proc_nmi_enabled,
668 #endif
669 #if defined(CONFIG_X86)
671 .ctl_name = KERN_PANIC_ON_NMI,
672 .procname = "panic_on_unrecovered_nmi",
673 .data = &panic_on_unrecovered_nmi,
674 .maxlen = sizeof(int),
675 .mode = 0644,
676 .proc_handler = &proc_dointvec,
679 .ctl_name = KERN_BOOTLOADER_TYPE,
680 .procname = "bootloader_type",
681 .data = &bootloader_type,
682 .maxlen = sizeof (int),
683 .mode = 0444,
684 .proc_handler = &proc_dointvec,
687 .ctl_name = CTL_UNNUMBERED,
688 .procname = "kstack_depth_to_print",
689 .data = &kstack_depth_to_print,
690 .maxlen = sizeof(int),
691 .mode = 0644,
692 .proc_handler = &proc_dointvec,
695 .ctl_name = CTL_UNNUMBERED,
696 .procname = "io_delay_type",
697 .data = &io_delay_type,
698 .maxlen = sizeof(int),
699 .mode = 0644,
700 .proc_handler = &proc_dointvec,
702 #endif
703 #if defined(CONFIG_MMU)
705 .ctl_name = KERN_RANDOMIZE,
706 .procname = "randomize_va_space",
707 .data = &randomize_va_space,
708 .maxlen = sizeof(int),
709 .mode = 0644,
710 .proc_handler = &proc_dointvec,
712 #endif
713 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
715 .ctl_name = KERN_SPIN_RETRY,
716 .procname = "spin_retry",
717 .data = &spin_retry,
718 .maxlen = sizeof (int),
719 .mode = 0644,
720 .proc_handler = &proc_dointvec,
722 #endif
723 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
725 .procname = "acpi_video_flags",
726 .data = &acpi_realmode_flags,
727 .maxlen = sizeof (unsigned long),
728 .mode = 0644,
729 .proc_handler = &proc_doulongvec_minmax,
731 #endif
732 #ifdef CONFIG_IA64
734 .ctl_name = KERN_IA64_UNALIGNED,
735 .procname = "ignore-unaligned-usertrap",
736 .data = &no_unaligned_warning,
737 .maxlen = sizeof (int),
738 .mode = 0644,
739 .proc_handler = &proc_dointvec,
741 #endif
742 #ifdef CONFIG_DETECT_SOFTLOCKUP
744 .ctl_name = CTL_UNNUMBERED,
745 .procname = "softlockup_panic",
746 .data = &softlockup_panic,
747 .maxlen = sizeof(int),
748 .mode = 0644,
749 .proc_handler = &proc_dointvec_minmax,
750 .strategy = &sysctl_intvec,
751 .extra1 = &zero,
752 .extra2 = &one,
755 .ctl_name = CTL_UNNUMBERED,
756 .procname = "softlockup_thresh",
757 .data = &softlockup_thresh,
758 .maxlen = sizeof(int),
759 .mode = 0644,
760 .proc_handler = &proc_dointvec_minmax,
761 .strategy = &sysctl_intvec,
762 .extra1 = &neg_one,
763 .extra2 = &sixty,
766 .ctl_name = CTL_UNNUMBERED,
767 .procname = "hung_task_check_count",
768 .data = &sysctl_hung_task_check_count,
769 .maxlen = sizeof(unsigned long),
770 .mode = 0644,
771 .proc_handler = &proc_doulongvec_minmax,
772 .strategy = &sysctl_intvec,
775 .ctl_name = CTL_UNNUMBERED,
776 .procname = "hung_task_timeout_secs",
777 .data = &sysctl_hung_task_timeout_secs,
778 .maxlen = sizeof(unsigned long),
779 .mode = 0644,
780 .proc_handler = &proc_doulongvec_minmax,
781 .strategy = &sysctl_intvec,
784 .ctl_name = CTL_UNNUMBERED,
785 .procname = "hung_task_warnings",
786 .data = &sysctl_hung_task_warnings,
787 .maxlen = sizeof(unsigned long),
788 .mode = 0644,
789 .proc_handler = &proc_doulongvec_minmax,
790 .strategy = &sysctl_intvec,
792 #endif
793 #ifdef CONFIG_COMPAT
795 .ctl_name = KERN_COMPAT_LOG,
796 .procname = "compat-log",
797 .data = &compat_log,
798 .maxlen = sizeof (int),
799 .mode = 0644,
800 .proc_handler = &proc_dointvec,
802 #endif
803 #ifdef CONFIG_RT_MUTEXES
805 .ctl_name = KERN_MAX_LOCK_DEPTH,
806 .procname = "max_lock_depth",
807 .data = &max_lock_depth,
808 .maxlen = sizeof(int),
809 .mode = 0644,
810 .proc_handler = &proc_dointvec,
812 #endif
813 #ifdef CONFIG_PROC_FS
815 .ctl_name = CTL_UNNUMBERED,
816 .procname = "maps_protect",
817 .data = &maps_protect,
818 .maxlen = sizeof(int),
819 .mode = 0644,
820 .proc_handler = &proc_dointvec,
822 #endif
824 .ctl_name = CTL_UNNUMBERED,
825 .procname = "poweroff_cmd",
826 .data = &poweroff_cmd,
827 .maxlen = POWEROFF_CMD_PATH_LEN,
828 .mode = 0644,
829 .proc_handler = &proc_dostring,
830 .strategy = &sysctl_string,
832 #ifdef CONFIG_KEYS
834 .ctl_name = CTL_UNNUMBERED,
835 .procname = "keys",
836 .mode = 0555,
837 .child = key_sysctls,
839 #endif
840 #ifdef CONFIG_RCU_TORTURE_TEST
842 .ctl_name = CTL_UNNUMBERED,
843 .procname = "rcutorture_runnable",
844 .data = &rcutorture_runnable,
845 .maxlen = sizeof(int),
846 .mode = 0644,
847 .proc_handler = &proc_dointvec,
849 #endif
851 * NOTE: do not add new entries to this table unless you have read
852 * Documentation/sysctl/ctl_unnumbered.txt
854 { .ctl_name = 0 }
857 static struct ctl_table vm_table[] = {
859 .ctl_name = VM_OVERCOMMIT_MEMORY,
860 .procname = "overcommit_memory",
861 .data = &sysctl_overcommit_memory,
862 .maxlen = sizeof(sysctl_overcommit_memory),
863 .mode = 0644,
864 .proc_handler = &proc_dointvec,
867 .ctl_name = VM_PANIC_ON_OOM,
868 .procname = "panic_on_oom",
869 .data = &sysctl_panic_on_oom,
870 .maxlen = sizeof(sysctl_panic_on_oom),
871 .mode = 0644,
872 .proc_handler = &proc_dointvec,
875 .ctl_name = CTL_UNNUMBERED,
876 .procname = "oom_kill_allocating_task",
877 .data = &sysctl_oom_kill_allocating_task,
878 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
879 .mode = 0644,
880 .proc_handler = &proc_dointvec,
883 .ctl_name = CTL_UNNUMBERED,
884 .procname = "oom_dump_tasks",
885 .data = &sysctl_oom_dump_tasks,
886 .maxlen = sizeof(sysctl_oom_dump_tasks),
887 .mode = 0644,
888 .proc_handler = &proc_dointvec,
891 .ctl_name = VM_OVERCOMMIT_RATIO,
892 .procname = "overcommit_ratio",
893 .data = &sysctl_overcommit_ratio,
894 .maxlen = sizeof(sysctl_overcommit_ratio),
895 .mode = 0644,
896 .proc_handler = &proc_dointvec,
899 .ctl_name = VM_PAGE_CLUSTER,
900 .procname = "page-cluster",
901 .data = &page_cluster,
902 .maxlen = sizeof(int),
903 .mode = 0644,
904 .proc_handler = &proc_dointvec,
907 .ctl_name = VM_DIRTY_BACKGROUND,
908 .procname = "dirty_background_ratio",
909 .data = &dirty_background_ratio,
910 .maxlen = sizeof(dirty_background_ratio),
911 .mode = 0644,
912 .proc_handler = &proc_dointvec_minmax,
913 .strategy = &sysctl_intvec,
914 .extra1 = &zero,
915 .extra2 = &one_hundred,
918 .ctl_name = VM_DIRTY_RATIO,
919 .procname = "dirty_ratio",
920 .data = &vm_dirty_ratio,
921 .maxlen = sizeof(vm_dirty_ratio),
922 .mode = 0644,
923 .proc_handler = &dirty_ratio_handler,
924 .strategy = &sysctl_intvec,
925 .extra1 = &zero,
926 .extra2 = &one_hundred,
929 .procname = "dirty_writeback_centisecs",
930 .data = &dirty_writeback_interval,
931 .maxlen = sizeof(dirty_writeback_interval),
932 .mode = 0644,
933 .proc_handler = &dirty_writeback_centisecs_handler,
936 .procname = "dirty_expire_centisecs",
937 .data = &dirty_expire_interval,
938 .maxlen = sizeof(dirty_expire_interval),
939 .mode = 0644,
940 .proc_handler = &proc_dointvec_userhz_jiffies,
943 .ctl_name = VM_NR_PDFLUSH_THREADS,
944 .procname = "nr_pdflush_threads",
945 .data = &nr_pdflush_threads,
946 .maxlen = sizeof nr_pdflush_threads,
947 .mode = 0444 /* read-only*/,
948 .proc_handler = &proc_dointvec,
951 .ctl_name = VM_SWAPPINESS,
952 .procname = "swappiness",
953 .data = &vm_swappiness,
954 .maxlen = sizeof(vm_swappiness),
955 .mode = 0644,
956 .proc_handler = &proc_dointvec_minmax,
957 .strategy = &sysctl_intvec,
958 .extra1 = &zero,
959 .extra2 = &one_hundred,
961 #ifdef CONFIG_HUGETLB_PAGE
963 .procname = "nr_hugepages",
964 .data = NULL,
965 .maxlen = sizeof(unsigned long),
966 .mode = 0644,
967 .proc_handler = &hugetlb_sysctl_handler,
968 .extra1 = (void *)&hugetlb_zero,
969 .extra2 = (void *)&hugetlb_infinity,
972 .ctl_name = VM_HUGETLB_GROUP,
973 .procname = "hugetlb_shm_group",
974 .data = &sysctl_hugetlb_shm_group,
975 .maxlen = sizeof(gid_t),
976 .mode = 0644,
977 .proc_handler = &proc_dointvec,
980 .ctl_name = CTL_UNNUMBERED,
981 .procname = "hugepages_treat_as_movable",
982 .data = &hugepages_treat_as_movable,
983 .maxlen = sizeof(int),
984 .mode = 0644,
985 .proc_handler = &hugetlb_treat_movable_handler,
988 .ctl_name = CTL_UNNUMBERED,
989 .procname = "nr_overcommit_hugepages",
990 .data = NULL,
991 .maxlen = sizeof(unsigned long),
992 .mode = 0644,
993 .proc_handler = &hugetlb_overcommit_handler,
994 .extra1 = (void *)&hugetlb_zero,
995 .extra2 = (void *)&hugetlb_infinity,
997 #endif
999 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
1000 .procname = "lowmem_reserve_ratio",
1001 .data = &sysctl_lowmem_reserve_ratio,
1002 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1003 .mode = 0644,
1004 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
1005 .strategy = &sysctl_intvec,
1008 .ctl_name = VM_DROP_PAGECACHE,
1009 .procname = "drop_caches",
1010 .data = &sysctl_drop_caches,
1011 .maxlen = sizeof(int),
1012 .mode = 0644,
1013 .proc_handler = drop_caches_sysctl_handler,
1014 .strategy = &sysctl_intvec,
1017 .ctl_name = VM_MIN_FREE_KBYTES,
1018 .procname = "min_free_kbytes",
1019 .data = &min_free_kbytes,
1020 .maxlen = sizeof(min_free_kbytes),
1021 .mode = 0644,
1022 .proc_handler = &min_free_kbytes_sysctl_handler,
1023 .strategy = &sysctl_intvec,
1024 .extra1 = &zero,
1027 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
1028 .procname = "percpu_pagelist_fraction",
1029 .data = &percpu_pagelist_fraction,
1030 .maxlen = sizeof(percpu_pagelist_fraction),
1031 .mode = 0644,
1032 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
1033 .strategy = &sysctl_intvec,
1034 .extra1 = &min_percpu_pagelist_fract,
1036 #ifdef CONFIG_MMU
1038 .ctl_name = VM_MAX_MAP_COUNT,
1039 .procname = "max_map_count",
1040 .data = &sysctl_max_map_count,
1041 .maxlen = sizeof(sysctl_max_map_count),
1042 .mode = 0644,
1043 .proc_handler = &proc_dointvec
1045 #endif
1047 .ctl_name = VM_LAPTOP_MODE,
1048 .procname = "laptop_mode",
1049 .data = &laptop_mode,
1050 .maxlen = sizeof(laptop_mode),
1051 .mode = 0644,
1052 .proc_handler = &proc_dointvec_jiffies,
1053 .strategy = &sysctl_jiffies,
1056 .ctl_name = VM_BLOCK_DUMP,
1057 .procname = "block_dump",
1058 .data = &block_dump,
1059 .maxlen = sizeof(block_dump),
1060 .mode = 0644,
1061 .proc_handler = &proc_dointvec,
1062 .strategy = &sysctl_intvec,
1063 .extra1 = &zero,
1066 .ctl_name = VM_VFS_CACHE_PRESSURE,
1067 .procname = "vfs_cache_pressure",
1068 .data = &sysctl_vfs_cache_pressure,
1069 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1070 .mode = 0644,
1071 .proc_handler = &proc_dointvec,
1072 .strategy = &sysctl_intvec,
1073 .extra1 = &zero,
1075 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1077 .ctl_name = VM_LEGACY_VA_LAYOUT,
1078 .procname = "legacy_va_layout",
1079 .data = &sysctl_legacy_va_layout,
1080 .maxlen = sizeof(sysctl_legacy_va_layout),
1081 .mode = 0644,
1082 .proc_handler = &proc_dointvec,
1083 .strategy = &sysctl_intvec,
1084 .extra1 = &zero,
1086 #endif
1087 #ifdef CONFIG_NUMA
1089 .ctl_name = VM_ZONE_RECLAIM_MODE,
1090 .procname = "zone_reclaim_mode",
1091 .data = &zone_reclaim_mode,
1092 .maxlen = sizeof(zone_reclaim_mode),
1093 .mode = 0644,
1094 .proc_handler = &proc_dointvec,
1095 .strategy = &sysctl_intvec,
1096 .extra1 = &zero,
1099 .ctl_name = VM_MIN_UNMAPPED,
1100 .procname = "min_unmapped_ratio",
1101 .data = &sysctl_min_unmapped_ratio,
1102 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1103 .mode = 0644,
1104 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1105 .strategy = &sysctl_intvec,
1106 .extra1 = &zero,
1107 .extra2 = &one_hundred,
1110 .ctl_name = VM_MIN_SLAB,
1111 .procname = "min_slab_ratio",
1112 .data = &sysctl_min_slab_ratio,
1113 .maxlen = sizeof(sysctl_min_slab_ratio),
1114 .mode = 0644,
1115 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1116 .strategy = &sysctl_intvec,
1117 .extra1 = &zero,
1118 .extra2 = &one_hundred,
1120 #endif
1121 #ifdef CONFIG_SMP
1123 .ctl_name = CTL_UNNUMBERED,
1124 .procname = "stat_interval",
1125 .data = &sysctl_stat_interval,
1126 .maxlen = sizeof(sysctl_stat_interval),
1127 .mode = 0644,
1128 .proc_handler = &proc_dointvec_jiffies,
1129 .strategy = &sysctl_jiffies,
1131 #endif
1132 #ifdef CONFIG_SECURITY
1134 .ctl_name = CTL_UNNUMBERED,
1135 .procname = "mmap_min_addr",
1136 .data = &mmap_min_addr,
1137 .maxlen = sizeof(unsigned long),
1138 .mode = 0644,
1139 .proc_handler = &proc_doulongvec_minmax,
1141 #endif
1142 #ifdef CONFIG_NUMA
1144 .ctl_name = CTL_UNNUMBERED,
1145 .procname = "numa_zonelist_order",
1146 .data = &numa_zonelist_order,
1147 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1148 .mode = 0644,
1149 .proc_handler = &numa_zonelist_order_handler,
1150 .strategy = &sysctl_string,
1152 #endif
1153 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1154 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1156 .ctl_name = VM_VDSO_ENABLED,
1157 .procname = "vdso_enabled",
1158 .data = &vdso_enabled,
1159 .maxlen = sizeof(vdso_enabled),
1160 .mode = 0644,
1161 .proc_handler = &proc_dointvec,
1162 .strategy = &sysctl_intvec,
1163 .extra1 = &zero,
1165 #endif
1166 #ifdef CONFIG_HIGHMEM
1168 .ctl_name = CTL_UNNUMBERED,
1169 .procname = "highmem_is_dirtyable",
1170 .data = &vm_highmem_is_dirtyable,
1171 .maxlen = sizeof(vm_highmem_is_dirtyable),
1172 .mode = 0644,
1173 .proc_handler = &proc_dointvec_minmax,
1174 .strategy = &sysctl_intvec,
1175 .extra1 = &zero,
1176 .extra2 = &one,
1178 #endif
1180 * NOTE: do not add new entries to this table unless you have read
1181 * Documentation/sysctl/ctl_unnumbered.txt
1183 { .ctl_name = 0 }
1186 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1187 static struct ctl_table binfmt_misc_table[] = {
1188 { .ctl_name = 0 }
1190 #endif
1192 static struct ctl_table fs_table[] = {
1194 .ctl_name = FS_NRINODE,
1195 .procname = "inode-nr",
1196 .data = &inodes_stat,
1197 .maxlen = 2*sizeof(int),
1198 .mode = 0444,
1199 .proc_handler = &proc_dointvec,
1202 .ctl_name = FS_STATINODE,
1203 .procname = "inode-state",
1204 .data = &inodes_stat,
1205 .maxlen = 7*sizeof(int),
1206 .mode = 0444,
1207 .proc_handler = &proc_dointvec,
1210 .procname = "file-nr",
1211 .data = &files_stat,
1212 .maxlen = 3*sizeof(int),
1213 .mode = 0444,
1214 .proc_handler = &proc_nr_files,
1217 .ctl_name = FS_MAXFILE,
1218 .procname = "file-max",
1219 .data = &files_stat.max_files,
1220 .maxlen = sizeof(int),
1221 .mode = 0644,
1222 .proc_handler = &proc_dointvec,
1225 .ctl_name = CTL_UNNUMBERED,
1226 .procname = "nr_open",
1227 .data = &sysctl_nr_open,
1228 .maxlen = sizeof(int),
1229 .mode = 0644,
1230 .proc_handler = &proc_dointvec_minmax,
1231 .extra1 = &sysctl_nr_open_min,
1232 .extra2 = &sysctl_nr_open_max,
1235 .ctl_name = FS_DENTRY,
1236 .procname = "dentry-state",
1237 .data = &dentry_stat,
1238 .maxlen = 6*sizeof(int),
1239 .mode = 0444,
1240 .proc_handler = &proc_dointvec,
1243 .ctl_name = FS_OVERFLOWUID,
1244 .procname = "overflowuid",
1245 .data = &fs_overflowuid,
1246 .maxlen = sizeof(int),
1247 .mode = 0644,
1248 .proc_handler = &proc_dointvec_minmax,
1249 .strategy = &sysctl_intvec,
1250 .extra1 = &minolduid,
1251 .extra2 = &maxolduid,
1254 .ctl_name = FS_OVERFLOWGID,
1255 .procname = "overflowgid",
1256 .data = &fs_overflowgid,
1257 .maxlen = sizeof(int),
1258 .mode = 0644,
1259 .proc_handler = &proc_dointvec_minmax,
1260 .strategy = &sysctl_intvec,
1261 .extra1 = &minolduid,
1262 .extra2 = &maxolduid,
1265 .ctl_name = FS_LEASES,
1266 .procname = "leases-enable",
1267 .data = &leases_enable,
1268 .maxlen = sizeof(int),
1269 .mode = 0644,
1270 .proc_handler = &proc_dointvec,
1272 #ifdef CONFIG_DNOTIFY
1274 .ctl_name = FS_DIR_NOTIFY,
1275 .procname = "dir-notify-enable",
1276 .data = &dir_notify_enable,
1277 .maxlen = sizeof(int),
1278 .mode = 0644,
1279 .proc_handler = &proc_dointvec,
1281 #endif
1282 #ifdef CONFIG_MMU
1284 .ctl_name = FS_LEASE_TIME,
1285 .procname = "lease-break-time",
1286 .data = &lease_break_time,
1287 .maxlen = sizeof(int),
1288 .mode = 0644,
1289 .proc_handler = &proc_dointvec_minmax,
1290 .strategy = &sysctl_intvec,
1291 .extra1 = &zero,
1292 .extra2 = &two,
1295 .procname = "aio-nr",
1296 .data = &aio_nr,
1297 .maxlen = sizeof(aio_nr),
1298 .mode = 0444,
1299 .proc_handler = &proc_doulongvec_minmax,
1302 .procname = "aio-max-nr",
1303 .data = &aio_max_nr,
1304 .maxlen = sizeof(aio_max_nr),
1305 .mode = 0644,
1306 .proc_handler = &proc_doulongvec_minmax,
1308 #ifdef CONFIG_INOTIFY_USER
1310 .ctl_name = FS_INOTIFY,
1311 .procname = "inotify",
1312 .mode = 0555,
1313 .child = inotify_table,
1315 #endif
1316 #endif
1318 .ctl_name = KERN_SETUID_DUMPABLE,
1319 .procname = "suid_dumpable",
1320 .data = &suid_dumpable,
1321 .maxlen = sizeof(int),
1322 .mode = 0644,
1323 .proc_handler = &proc_dointvec,
1325 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1327 .ctl_name = CTL_UNNUMBERED,
1328 .procname = "binfmt_misc",
1329 .mode = 0555,
1330 .child = binfmt_misc_table,
1332 #endif
1334 * NOTE: do not add new entries to this table unless you have read
1335 * Documentation/sysctl/ctl_unnumbered.txt
1337 { .ctl_name = 0 }
1340 static struct ctl_table debug_table[] = {
1341 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1343 .ctl_name = CTL_UNNUMBERED,
1344 .procname = "exception-trace",
1345 .data = &show_unhandled_signals,
1346 .maxlen = sizeof(int),
1347 .mode = 0644,
1348 .proc_handler = proc_dointvec
1350 #endif
1351 { .ctl_name = 0 }
1354 static struct ctl_table dev_table[] = {
1355 { .ctl_name = 0 }
1358 static DEFINE_SPINLOCK(sysctl_lock);
1360 /* called under sysctl_lock */
1361 static int use_table(struct ctl_table_header *p)
1363 if (unlikely(p->unregistering))
1364 return 0;
1365 p->used++;
1366 return 1;
1369 /* called under sysctl_lock */
1370 static void unuse_table(struct ctl_table_header *p)
1372 if (!--p->used)
1373 if (unlikely(p->unregistering))
1374 complete(p->unregistering);
1377 /* called under sysctl_lock, will reacquire if has to wait */
1378 static void start_unregistering(struct ctl_table_header *p)
1381 * if p->used is 0, nobody will ever touch that entry again;
1382 * we'll eliminate all paths to it before dropping sysctl_lock
1384 if (unlikely(p->used)) {
1385 struct completion wait;
1386 init_completion(&wait);
1387 p->unregistering = &wait;
1388 spin_unlock(&sysctl_lock);
1389 wait_for_completion(&wait);
1390 spin_lock(&sysctl_lock);
1391 } else {
1392 /* anything non-NULL; we'll never dereference it */
1393 p->unregistering = ERR_PTR(-EINVAL);
1396 * do not remove from the list until nobody holds it; walking the
1397 * list in do_sysctl() relies on that.
1399 list_del_init(&p->ctl_entry);
1402 void sysctl_head_get(struct ctl_table_header *head)
1404 spin_lock(&sysctl_lock);
1405 head->count++;
1406 spin_unlock(&sysctl_lock);
1409 void sysctl_head_put(struct ctl_table_header *head)
1411 spin_lock(&sysctl_lock);
1412 if (!--head->count)
1413 kfree(head);
1414 spin_unlock(&sysctl_lock);
1417 struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)
1419 if (!head)
1420 BUG();
1421 spin_lock(&sysctl_lock);
1422 if (!use_table(head))
1423 head = ERR_PTR(-ENOENT);
1424 spin_unlock(&sysctl_lock);
1425 return head;
1428 void sysctl_head_finish(struct ctl_table_header *head)
1430 if (!head)
1431 return;
1432 spin_lock(&sysctl_lock);
1433 unuse_table(head);
1434 spin_unlock(&sysctl_lock);
1437 static struct ctl_table_set *
1438 lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces)
1440 struct ctl_table_set *set = &root->default_set;
1441 if (root->lookup)
1442 set = root->lookup(root, namespaces);
1443 return set;
1446 static struct list_head *
1447 lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces)
1449 struct ctl_table_set *set = lookup_header_set(root, namespaces);
1450 return &set->list;
1453 struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces,
1454 struct ctl_table_header *prev)
1456 struct ctl_table_root *root;
1457 struct list_head *header_list;
1458 struct ctl_table_header *head;
1459 struct list_head *tmp;
1461 spin_lock(&sysctl_lock);
1462 if (prev) {
1463 head = prev;
1464 tmp = &prev->ctl_entry;
1465 unuse_table(prev);
1466 goto next;
1468 tmp = &root_table_header.ctl_entry;
1469 for (;;) {
1470 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1472 if (!use_table(head))
1473 goto next;
1474 spin_unlock(&sysctl_lock);
1475 return head;
1476 next:
1477 root = head->root;
1478 tmp = tmp->next;
1479 header_list = lookup_header_list(root, namespaces);
1480 if (tmp != header_list)
1481 continue;
1483 do {
1484 root = list_entry(root->root_list.next,
1485 struct ctl_table_root, root_list);
1486 if (root == &sysctl_table_root)
1487 goto out;
1488 header_list = lookup_header_list(root, namespaces);
1489 } while (list_empty(header_list));
1490 tmp = header_list->next;
1492 out:
1493 spin_unlock(&sysctl_lock);
1494 return NULL;
1497 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1499 return __sysctl_head_next(current->nsproxy, prev);
1502 void register_sysctl_root(struct ctl_table_root *root)
1504 spin_lock(&sysctl_lock);
1505 list_add_tail(&root->root_list, &sysctl_table_root.root_list);
1506 spin_unlock(&sysctl_lock);
1509 #ifdef CONFIG_SYSCTL_SYSCALL
1510 /* Perform the actual read/write of a sysctl table entry. */
1511 static int do_sysctl_strategy(struct ctl_table_root *root,
1512 struct ctl_table *table,
1513 int __user *name, int nlen,
1514 void __user *oldval, size_t __user *oldlenp,
1515 void __user *newval, size_t newlen)
1517 int op = 0, rc;
1519 if (oldval)
1520 op |= MAY_READ;
1521 if (newval)
1522 op |= MAY_WRITE;
1523 if (sysctl_perm(root, table, op))
1524 return -EPERM;
1526 if (table->strategy) {
1527 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1528 newval, newlen);
1529 if (rc < 0)
1530 return rc;
1531 if (rc > 0)
1532 return 0;
1535 /* If there is no strategy routine, or if the strategy returns
1536 * zero, proceed with automatic r/w */
1537 if (table->data && table->maxlen) {
1538 rc = sysctl_data(table, name, nlen, oldval, oldlenp,
1539 newval, newlen);
1540 if (rc < 0)
1541 return rc;
1543 return 0;
1546 static int parse_table(int __user *name, int nlen,
1547 void __user *oldval, size_t __user *oldlenp,
1548 void __user *newval, size_t newlen,
1549 struct ctl_table_root *root,
1550 struct ctl_table *table)
1552 int n;
1553 repeat:
1554 if (!nlen)
1555 return -ENOTDIR;
1556 if (get_user(n, name))
1557 return -EFAULT;
1558 for ( ; table->ctl_name || table->procname; table++) {
1559 if (!table->ctl_name)
1560 continue;
1561 if (n == table->ctl_name) {
1562 int error;
1563 if (table->child) {
1564 if (sysctl_perm(root, table, MAY_EXEC))
1565 return -EPERM;
1566 name++;
1567 nlen--;
1568 table = table->child;
1569 goto repeat;
1571 error = do_sysctl_strategy(root, table, name, nlen,
1572 oldval, oldlenp,
1573 newval, newlen);
1574 return error;
1577 return -ENOTDIR;
1580 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1581 void __user *newval, size_t newlen)
1583 struct ctl_table_header *head;
1584 int error = -ENOTDIR;
1586 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1587 return -ENOTDIR;
1588 if (oldval) {
1589 int old_len;
1590 if (!oldlenp || get_user(old_len, oldlenp))
1591 return -EFAULT;
1594 for (head = sysctl_head_next(NULL); head;
1595 head = sysctl_head_next(head)) {
1596 error = parse_table(name, nlen, oldval, oldlenp,
1597 newval, newlen,
1598 head->root, head->ctl_table);
1599 if (error != -ENOTDIR) {
1600 sysctl_head_finish(head);
1601 break;
1604 return error;
1607 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1609 struct __sysctl_args tmp;
1610 int error;
1612 if (copy_from_user(&tmp, args, sizeof(tmp)))
1613 return -EFAULT;
1615 error = deprecated_sysctl_warning(&tmp);
1616 if (error)
1617 goto out;
1619 lock_kernel();
1620 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1621 tmp.newval, tmp.newlen);
1622 unlock_kernel();
1623 out:
1624 return error;
1626 #endif /* CONFIG_SYSCTL_SYSCALL */
1629 * sysctl_perm does NOT grant the superuser all rights automatically, because
1630 * some sysctl variables are readonly even to root.
1633 static int test_perm(int mode, int op)
1635 if (!current->euid)
1636 mode >>= 6;
1637 else if (in_egroup_p(0))
1638 mode >>= 3;
1639 if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0)
1640 return 0;
1641 return -EACCES;
1644 int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
1646 int error;
1647 int mode;
1649 error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC));
1650 if (error)
1651 return error;
1653 if (root->permissions)
1654 mode = root->permissions(root, current->nsproxy, table);
1655 else
1656 mode = table->mode;
1658 return test_perm(mode, op);
1661 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1663 for (; table->ctl_name || table->procname; table++) {
1664 table->parent = parent;
1665 if (table->child)
1666 sysctl_set_parent(table, table->child);
1670 static __init int sysctl_init(void)
1672 sysctl_set_parent(NULL, root_table);
1673 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1675 int err;
1676 err = sysctl_check_table(current->nsproxy, root_table);
1678 #endif
1679 return 0;
1682 core_initcall(sysctl_init);
1684 static struct ctl_table *is_branch_in(struct ctl_table *branch,
1685 struct ctl_table *table)
1687 struct ctl_table *p;
1688 const char *s = branch->procname;
1690 /* branch should have named subdirectory as its first element */
1691 if (!s || !branch->child)
1692 return NULL;
1694 /* ... and nothing else */
1695 if (branch[1].procname || branch[1].ctl_name)
1696 return NULL;
1698 /* table should contain subdirectory with the same name */
1699 for (p = table; p->procname || p->ctl_name; p++) {
1700 if (!p->child)
1701 continue;
1702 if (p->procname && strcmp(p->procname, s) == 0)
1703 return p;
1705 return NULL;
1708 /* see if attaching q to p would be an improvement */
1709 static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q)
1711 struct ctl_table *to = p->ctl_table, *by = q->ctl_table;
1712 struct ctl_table *next;
1713 int is_better = 0;
1714 int not_in_parent = !p->attached_by;
1716 while ((next = is_branch_in(by, to)) != NULL) {
1717 if (by == q->attached_by)
1718 is_better = 1;
1719 if (to == p->attached_by)
1720 not_in_parent = 1;
1721 by = by->child;
1722 to = next->child;
1725 if (is_better && not_in_parent) {
1726 q->attached_by = by;
1727 q->attached_to = to;
1728 q->parent = p;
1733 * __register_sysctl_paths - register a sysctl hierarchy
1734 * @root: List of sysctl headers to register on
1735 * @namespaces: Data to compute which lists of sysctl entries are visible
1736 * @path: The path to the directory the sysctl table is in.
1737 * @table: the top-level table structure
1739 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1740 * array. A completely 0 filled entry terminates the table.
1742 * The members of the &struct ctl_table structure are used as follows:
1744 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1745 * must be unique within that level of sysctl
1747 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1748 * enter a sysctl file
1750 * data - a pointer to data for use by proc_handler
1752 * maxlen - the maximum size in bytes of the data
1754 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1756 * child - a pointer to the child sysctl table if this entry is a directory, or
1757 * %NULL.
1759 * proc_handler - the text handler routine (described below)
1761 * strategy - the strategy routine (described below)
1763 * de - for internal use by the sysctl routines
1765 * extra1, extra2 - extra pointers usable by the proc handler routines
1767 * Leaf nodes in the sysctl tree will be represented by a single file
1768 * under /proc; non-leaf nodes will be represented by directories.
1770 * sysctl(2) can automatically manage read and write requests through
1771 * the sysctl table. The data and maxlen fields of the ctl_table
1772 * struct enable minimal validation of the values being written to be
1773 * performed, and the mode field allows minimal authentication.
1775 * More sophisticated management can be enabled by the provision of a
1776 * strategy routine with the table entry. This will be called before
1777 * any automatic read or write of the data is performed.
1779 * The strategy routine may return
1781 * < 0 - Error occurred (error is passed to user process)
1783 * 0 - OK - proceed with automatic read or write.
1785 * > 0 - OK - read or write has been done by the strategy routine, so
1786 * return immediately.
1788 * There must be a proc_handler routine for any terminal nodes
1789 * mirrored under /proc/sys (non-terminals are handled by a built-in
1790 * directory handler). Several default handlers are available to
1791 * cover common cases -
1793 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1794 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1795 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1797 * It is the handler's job to read the input buffer from user memory
1798 * and process it. The handler should return 0 on success.
1800 * This routine returns %NULL on a failure to register, and a pointer
1801 * to the table header on success.
1803 struct ctl_table_header *__register_sysctl_paths(
1804 struct ctl_table_root *root,
1805 struct nsproxy *namespaces,
1806 const struct ctl_path *path, struct ctl_table *table)
1808 struct ctl_table_header *header;
1809 struct ctl_table *new, **prevp;
1810 unsigned int n, npath;
1811 struct ctl_table_set *set;
1813 /* Count the path components */
1814 for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath)
1818 * For each path component, allocate a 2-element ctl_table array.
1819 * The first array element will be filled with the sysctl entry
1820 * for this, the second will be the sentinel (ctl_name == 0).
1822 * We allocate everything in one go so that we don't have to
1823 * worry about freeing additional memory in unregister_sysctl_table.
1825 header = kzalloc(sizeof(struct ctl_table_header) +
1826 (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL);
1827 if (!header)
1828 return NULL;
1830 new = (struct ctl_table *) (header + 1);
1832 /* Now connect the dots */
1833 prevp = &header->ctl_table;
1834 for (n = 0; n < npath; ++n, ++path) {
1835 /* Copy the procname */
1836 new->procname = path->procname;
1837 new->ctl_name = path->ctl_name;
1838 new->mode = 0555;
1840 *prevp = new;
1841 prevp = &new->child;
1843 new += 2;
1845 *prevp = table;
1846 header->ctl_table_arg = table;
1848 INIT_LIST_HEAD(&header->ctl_entry);
1849 header->used = 0;
1850 header->unregistering = NULL;
1851 header->root = root;
1852 sysctl_set_parent(NULL, header->ctl_table);
1853 header->count = 1;
1854 #ifdef CONFIG_SYSCTL_SYSCALL_CHECK
1855 if (sysctl_check_table(namespaces, header->ctl_table)) {
1856 kfree(header);
1857 return NULL;
1859 #endif
1860 spin_lock(&sysctl_lock);
1861 header->set = lookup_header_set(root, namespaces);
1862 header->attached_by = header->ctl_table;
1863 header->attached_to = root_table;
1864 header->parent = &root_table_header;
1865 for (set = header->set; set; set = set->parent) {
1866 struct ctl_table_header *p;
1867 list_for_each_entry(p, &set->list, ctl_entry) {
1868 if (p->unregistering)
1869 continue;
1870 try_attach(p, header);
1873 header->parent->count++;
1874 list_add_tail(&header->ctl_entry, &header->set->list);
1875 spin_unlock(&sysctl_lock);
1877 return header;
1881 * register_sysctl_table_path - register a sysctl table hierarchy
1882 * @path: The path to the directory the sysctl table is in.
1883 * @table: the top-level table structure
1885 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1886 * array. A completely 0 filled entry terminates the table.
1888 * See __register_sysctl_paths for more details.
1890 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1891 struct ctl_table *table)
1893 return __register_sysctl_paths(&sysctl_table_root, current->nsproxy,
1894 path, table);
1898 * register_sysctl_table - register a sysctl table hierarchy
1899 * @table: the top-level table structure
1901 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1902 * array. A completely 0 filled entry terminates the table.
1904 * See register_sysctl_paths for more details.
1906 struct ctl_table_header *register_sysctl_table(struct ctl_table *table)
1908 static const struct ctl_path null_path[] = { {} };
1910 return register_sysctl_paths(null_path, table);
1914 * unregister_sysctl_table - unregister a sysctl table hierarchy
1915 * @header: the header returned from register_sysctl_table
1917 * Unregisters the sysctl table and all children. proc entries may not
1918 * actually be removed until they are no longer used by anyone.
1920 void unregister_sysctl_table(struct ctl_table_header * header)
1922 might_sleep();
1924 if (header == NULL)
1925 return;
1927 spin_lock(&sysctl_lock);
1928 start_unregistering(header);
1929 if (!--header->parent->count) {
1930 WARN_ON(1);
1931 kfree(header->parent);
1933 if (!--header->count)
1934 kfree(header);
1935 spin_unlock(&sysctl_lock);
1938 int sysctl_is_seen(struct ctl_table_header *p)
1940 struct ctl_table_set *set = p->set;
1941 int res;
1942 spin_lock(&sysctl_lock);
1943 if (p->unregistering)
1944 res = 0;
1945 else if (!set->is_seen)
1946 res = 1;
1947 else
1948 res = set->is_seen(set);
1949 spin_unlock(&sysctl_lock);
1950 return res;
1953 void setup_sysctl_set(struct ctl_table_set *p,
1954 struct ctl_table_set *parent,
1955 int (*is_seen)(struct ctl_table_set *))
1957 INIT_LIST_HEAD(&p->list);
1958 p->parent = parent ? parent : &sysctl_table_root.default_set;
1959 p->is_seen = is_seen;
1962 #else /* !CONFIG_SYSCTL */
1963 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1965 return NULL;
1968 struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path,
1969 struct ctl_table *table)
1971 return NULL;
1974 void unregister_sysctl_table(struct ctl_table_header * table)
1978 void setup_sysctl_set(struct ctl_table_set *p,
1979 struct ctl_table_set *parent,
1980 int (*is_seen)(struct ctl_table_set *))
1984 void sysctl_head_put(struct ctl_table_header *head)
1988 #endif /* CONFIG_SYSCTL */
1991 * /proc/sys support
1994 #ifdef CONFIG_PROC_SYSCTL
1996 static int _proc_do_string(void* data, int maxlen, int write,
1997 struct file *filp, void __user *buffer,
1998 size_t *lenp, loff_t *ppos)
2000 size_t len;
2001 char __user *p;
2002 char c;
2004 if (!data || !maxlen || !*lenp) {
2005 *lenp = 0;
2006 return 0;
2009 if (write) {
2010 len = 0;
2011 p = buffer;
2012 while (len < *lenp) {
2013 if (get_user(c, p++))
2014 return -EFAULT;
2015 if (c == 0 || c == '\n')
2016 break;
2017 len++;
2019 if (len >= maxlen)
2020 len = maxlen-1;
2021 if(copy_from_user(data, buffer, len))
2022 return -EFAULT;
2023 ((char *) data)[len] = 0;
2024 *ppos += *lenp;
2025 } else {
2026 len = strlen(data);
2027 if (len > maxlen)
2028 len = maxlen;
2030 if (*ppos > len) {
2031 *lenp = 0;
2032 return 0;
2035 data += *ppos;
2036 len -= *ppos;
2038 if (len > *lenp)
2039 len = *lenp;
2040 if (len)
2041 if(copy_to_user(buffer, data, len))
2042 return -EFAULT;
2043 if (len < *lenp) {
2044 if(put_user('\n', ((char __user *) buffer) + len))
2045 return -EFAULT;
2046 len++;
2048 *lenp = len;
2049 *ppos += len;
2051 return 0;
2055 * proc_dostring - read a string sysctl
2056 * @table: the sysctl table
2057 * @write: %TRUE if this is a write to the sysctl file
2058 * @filp: the file structure
2059 * @buffer: the user buffer
2060 * @lenp: the size of the user buffer
2061 * @ppos: file position
2063 * Reads/writes a string from/to the user buffer. If the kernel
2064 * buffer provided is not large enough to hold the string, the
2065 * string is truncated. The copied string is %NULL-terminated.
2066 * If the string is being read by the user process, it is copied
2067 * and a newline '\n' is added. It is truncated if the buffer is
2068 * not large enough.
2070 * Returns 0 on success.
2072 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2073 void __user *buffer, size_t *lenp, loff_t *ppos)
2075 return _proc_do_string(table->data, table->maxlen, write, filp,
2076 buffer, lenp, ppos);
2080 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
2081 int *valp,
2082 int write, void *data)
2084 if (write) {
2085 *valp = *negp ? -*lvalp : *lvalp;
2086 } else {
2087 int val = *valp;
2088 if (val < 0) {
2089 *negp = -1;
2090 *lvalp = (unsigned long)-val;
2091 } else {
2092 *negp = 0;
2093 *lvalp = (unsigned long)val;
2096 return 0;
2099 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2100 int write, struct file *filp, void __user *buffer,
2101 size_t *lenp, loff_t *ppos,
2102 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2103 int write, void *data),
2104 void *data)
2106 #define TMPBUFLEN 21
2107 int *i, vleft, first=1, neg, val;
2108 unsigned long lval;
2109 size_t left, len;
2111 char buf[TMPBUFLEN], *p;
2112 char __user *s = buffer;
2114 if (!tbl_data || !table->maxlen || !*lenp ||
2115 (*ppos && !write)) {
2116 *lenp = 0;
2117 return 0;
2120 i = (int *) tbl_data;
2121 vleft = table->maxlen / sizeof(*i);
2122 left = *lenp;
2124 if (!conv)
2125 conv = do_proc_dointvec_conv;
2127 for (; left && vleft--; i++, first=0) {
2128 if (write) {
2129 while (left) {
2130 char c;
2131 if (get_user(c, s))
2132 return -EFAULT;
2133 if (!isspace(c))
2134 break;
2135 left--;
2136 s++;
2138 if (!left)
2139 break;
2140 neg = 0;
2141 len = left;
2142 if (len > sizeof(buf) - 1)
2143 len = sizeof(buf) - 1;
2144 if (copy_from_user(buf, s, len))
2145 return -EFAULT;
2146 buf[len] = 0;
2147 p = buf;
2148 if (*p == '-' && left > 1) {
2149 neg = 1;
2150 p++;
2152 if (*p < '0' || *p > '9')
2153 break;
2155 lval = simple_strtoul(p, &p, 0);
2157 len = p-buf;
2158 if ((len < left) && *p && !isspace(*p))
2159 break;
2160 if (neg)
2161 val = -val;
2162 s += len;
2163 left -= len;
2165 if (conv(&neg, &lval, i, 1, data))
2166 break;
2167 } else {
2168 p = buf;
2169 if (!first)
2170 *p++ = '\t';
2172 if (conv(&neg, &lval, i, 0, data))
2173 break;
2175 sprintf(p, "%s%lu", neg ? "-" : "", lval);
2176 len = strlen(buf);
2177 if (len > left)
2178 len = left;
2179 if(copy_to_user(s, buf, len))
2180 return -EFAULT;
2181 left -= len;
2182 s += len;
2186 if (!write && !first && left) {
2187 if(put_user('\n', s))
2188 return -EFAULT;
2189 left--, s++;
2191 if (write) {
2192 while (left) {
2193 char c;
2194 if (get_user(c, s++))
2195 return -EFAULT;
2196 if (!isspace(c))
2197 break;
2198 left--;
2201 if (write && first)
2202 return -EINVAL;
2203 *lenp -= left;
2204 *ppos += *lenp;
2205 return 0;
2206 #undef TMPBUFLEN
2209 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2210 void __user *buffer, size_t *lenp, loff_t *ppos,
2211 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
2212 int write, void *data),
2213 void *data)
2215 return __do_proc_dointvec(table->data, table, write, filp,
2216 buffer, lenp, ppos, conv, data);
2220 * proc_dointvec - read a vector of integers
2221 * @table: the sysctl table
2222 * @write: %TRUE if this is a write to the sysctl file
2223 * @filp: the file structure
2224 * @buffer: the user buffer
2225 * @lenp: the size of the user buffer
2226 * @ppos: file position
2228 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2229 * values from/to the user buffer, treated as an ASCII string.
2231 * Returns 0 on success.
2233 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2234 void __user *buffer, size_t *lenp, loff_t *ppos)
2236 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2237 NULL,NULL);
2240 #define OP_SET 0
2241 #define OP_AND 1
2242 #define OP_OR 2
2244 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
2245 int *valp,
2246 int write, void *data)
2248 int op = *(int *)data;
2249 if (write) {
2250 int val = *negp ? -*lvalp : *lvalp;
2251 switch(op) {
2252 case OP_SET: *valp = val; break;
2253 case OP_AND: *valp &= val; break;
2254 case OP_OR: *valp |= val; break;
2256 } else {
2257 int val = *valp;
2258 if (val < 0) {
2259 *negp = -1;
2260 *lvalp = (unsigned long)-val;
2261 } else {
2262 *negp = 0;
2263 *lvalp = (unsigned long)val;
2266 return 0;
2270 * Taint values can only be increased
2272 static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
2273 void __user *buffer, size_t *lenp, loff_t *ppos)
2275 int op;
2277 if (write && !capable(CAP_SYS_ADMIN))
2278 return -EPERM;
2280 op = OP_OR;
2281 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2282 do_proc_dointvec_bset_conv,&op);
2285 struct do_proc_dointvec_minmax_conv_param {
2286 int *min;
2287 int *max;
2290 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2291 int *valp,
2292 int write, void *data)
2294 struct do_proc_dointvec_minmax_conv_param *param = data;
2295 if (write) {
2296 int val = *negp ? -*lvalp : *lvalp;
2297 if ((param->min && *param->min > val) ||
2298 (param->max && *param->max < val))
2299 return -EINVAL;
2300 *valp = val;
2301 } else {
2302 int val = *valp;
2303 if (val < 0) {
2304 *negp = -1;
2305 *lvalp = (unsigned long)-val;
2306 } else {
2307 *negp = 0;
2308 *lvalp = (unsigned long)val;
2311 return 0;
2315 * proc_dointvec_minmax - read a vector of integers with min/max values
2316 * @table: the sysctl table
2317 * @write: %TRUE if this is a write to the sysctl file
2318 * @filp: the file structure
2319 * @buffer: the user buffer
2320 * @lenp: the size of the user buffer
2321 * @ppos: file position
2323 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2324 * values from/to the user buffer, treated as an ASCII string.
2326 * This routine will ensure the values are within the range specified by
2327 * table->extra1 (min) and table->extra2 (max).
2329 * Returns 0 on success.
2331 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2332 void __user *buffer, size_t *lenp, loff_t *ppos)
2334 struct do_proc_dointvec_minmax_conv_param param = {
2335 .min = (int *) table->extra1,
2336 .max = (int *) table->extra2,
2338 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2339 do_proc_dointvec_minmax_conv, &param);
2342 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2343 struct file *filp,
2344 void __user *buffer,
2345 size_t *lenp, loff_t *ppos,
2346 unsigned long convmul,
2347 unsigned long convdiv)
2349 #define TMPBUFLEN 21
2350 unsigned long *i, *min, *max, val;
2351 int vleft, first=1, neg;
2352 size_t len, left;
2353 char buf[TMPBUFLEN], *p;
2354 char __user *s = buffer;
2356 if (!data || !table->maxlen || !*lenp ||
2357 (*ppos && !write)) {
2358 *lenp = 0;
2359 return 0;
2362 i = (unsigned long *) data;
2363 min = (unsigned long *) table->extra1;
2364 max = (unsigned long *) table->extra2;
2365 vleft = table->maxlen / sizeof(unsigned long);
2366 left = *lenp;
2368 for (; left && vleft--; i++, min++, max++, first=0) {
2369 if (write) {
2370 while (left) {
2371 char c;
2372 if (get_user(c, s))
2373 return -EFAULT;
2374 if (!isspace(c))
2375 break;
2376 left--;
2377 s++;
2379 if (!left)
2380 break;
2381 neg = 0;
2382 len = left;
2383 if (len > TMPBUFLEN-1)
2384 len = TMPBUFLEN-1;
2385 if (copy_from_user(buf, s, len))
2386 return -EFAULT;
2387 buf[len] = 0;
2388 p = buf;
2389 if (*p == '-' && left > 1) {
2390 neg = 1;
2391 p++;
2393 if (*p < '0' || *p > '9')
2394 break;
2395 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2396 len = p-buf;
2397 if ((len < left) && *p && !isspace(*p))
2398 break;
2399 if (neg)
2400 val = -val;
2401 s += len;
2402 left -= len;
2404 if(neg)
2405 continue;
2406 if ((min && val < *min) || (max && val > *max))
2407 continue;
2408 *i = val;
2409 } else {
2410 p = buf;
2411 if (!first)
2412 *p++ = '\t';
2413 sprintf(p, "%lu", convdiv * (*i) / convmul);
2414 len = strlen(buf);
2415 if (len > left)
2416 len = left;
2417 if(copy_to_user(s, buf, len))
2418 return -EFAULT;
2419 left -= len;
2420 s += len;
2424 if (!write && !first && left) {
2425 if(put_user('\n', s))
2426 return -EFAULT;
2427 left--, s++;
2429 if (write) {
2430 while (left) {
2431 char c;
2432 if (get_user(c, s++))
2433 return -EFAULT;
2434 if (!isspace(c))
2435 break;
2436 left--;
2439 if (write && first)
2440 return -EINVAL;
2441 *lenp -= left;
2442 *ppos += *lenp;
2443 return 0;
2444 #undef TMPBUFLEN
2447 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2448 struct file *filp,
2449 void __user *buffer,
2450 size_t *lenp, loff_t *ppos,
2451 unsigned long convmul,
2452 unsigned long convdiv)
2454 return __do_proc_doulongvec_minmax(table->data, table, write,
2455 filp, buffer, lenp, ppos, convmul, convdiv);
2459 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2460 * @table: the sysctl table
2461 * @write: %TRUE if this is a write to the sysctl file
2462 * @filp: the file structure
2463 * @buffer: the user buffer
2464 * @lenp: the size of the user buffer
2465 * @ppos: file position
2467 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2468 * values from/to the user buffer, treated as an ASCII string.
2470 * This routine will ensure the values are within the range specified by
2471 * table->extra1 (min) and table->extra2 (max).
2473 * Returns 0 on success.
2475 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2476 void __user *buffer, size_t *lenp, loff_t *ppos)
2478 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2482 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2483 * @table: the sysctl table
2484 * @write: %TRUE if this is a write to the sysctl file
2485 * @filp: the file structure
2486 * @buffer: the user buffer
2487 * @lenp: the size of the user buffer
2488 * @ppos: file position
2490 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2491 * values from/to the user buffer, treated as an ASCII string. The values
2492 * are treated as milliseconds, and converted to jiffies when they are stored.
2494 * This routine will ensure the values are within the range specified by
2495 * table->extra1 (min) and table->extra2 (max).
2497 * Returns 0 on success.
2499 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2500 struct file *filp,
2501 void __user *buffer,
2502 size_t *lenp, loff_t *ppos)
2504 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2505 lenp, ppos, HZ, 1000l);
2509 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2510 int *valp,
2511 int write, void *data)
2513 if (write) {
2514 if (*lvalp > LONG_MAX / HZ)
2515 return 1;
2516 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2517 } else {
2518 int val = *valp;
2519 unsigned long lval;
2520 if (val < 0) {
2521 *negp = -1;
2522 lval = (unsigned long)-val;
2523 } else {
2524 *negp = 0;
2525 lval = (unsigned long)val;
2527 *lvalp = lval / HZ;
2529 return 0;
2532 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2533 int *valp,
2534 int write, void *data)
2536 if (write) {
2537 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2538 return 1;
2539 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2540 } else {
2541 int val = *valp;
2542 unsigned long lval;
2543 if (val < 0) {
2544 *negp = -1;
2545 lval = (unsigned long)-val;
2546 } else {
2547 *negp = 0;
2548 lval = (unsigned long)val;
2550 *lvalp = jiffies_to_clock_t(lval);
2552 return 0;
2555 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2556 int *valp,
2557 int write, void *data)
2559 if (write) {
2560 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2561 } else {
2562 int val = *valp;
2563 unsigned long lval;
2564 if (val < 0) {
2565 *negp = -1;
2566 lval = (unsigned long)-val;
2567 } else {
2568 *negp = 0;
2569 lval = (unsigned long)val;
2571 *lvalp = jiffies_to_msecs(lval);
2573 return 0;
2577 * proc_dointvec_jiffies - read a vector of integers as seconds
2578 * @table: the sysctl table
2579 * @write: %TRUE if this is a write to the sysctl file
2580 * @filp: the file structure
2581 * @buffer: the user buffer
2582 * @lenp: the size of the user buffer
2583 * @ppos: file position
2585 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2586 * values from/to the user buffer, treated as an ASCII string.
2587 * The values read are assumed to be in seconds, and are converted into
2588 * jiffies.
2590 * Returns 0 on success.
2592 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2593 void __user *buffer, size_t *lenp, loff_t *ppos)
2595 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2596 do_proc_dointvec_jiffies_conv,NULL);
2600 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2601 * @table: the sysctl table
2602 * @write: %TRUE if this is a write to the sysctl file
2603 * @filp: the file structure
2604 * @buffer: the user buffer
2605 * @lenp: the size of the user buffer
2606 * @ppos: pointer to the file position
2608 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2609 * values from/to the user buffer, treated as an ASCII string.
2610 * The values read are assumed to be in 1/USER_HZ seconds, and
2611 * are converted into jiffies.
2613 * Returns 0 on success.
2615 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2616 void __user *buffer, size_t *lenp, loff_t *ppos)
2618 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2619 do_proc_dointvec_userhz_jiffies_conv,NULL);
2623 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2624 * @table: the sysctl table
2625 * @write: %TRUE if this is a write to the sysctl file
2626 * @filp: the file structure
2627 * @buffer: the user buffer
2628 * @lenp: the size of the user buffer
2629 * @ppos: file position
2630 * @ppos: the current position in the file
2632 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2633 * values from/to the user buffer, treated as an ASCII string.
2634 * The values read are assumed to be in 1/1000 seconds, and
2635 * are converted into jiffies.
2637 * Returns 0 on success.
2639 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2640 void __user *buffer, size_t *lenp, loff_t *ppos)
2642 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2643 do_proc_dointvec_ms_jiffies_conv, NULL);
2646 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2647 void __user *buffer, size_t *lenp, loff_t *ppos)
2649 struct pid *new_pid;
2650 pid_t tmp;
2651 int r;
2653 tmp = pid_vnr(cad_pid);
2655 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2656 lenp, ppos, NULL, NULL);
2657 if (r || !write)
2658 return r;
2660 new_pid = find_get_pid(tmp);
2661 if (!new_pid)
2662 return -ESRCH;
2664 put_pid(xchg(&cad_pid, new_pid));
2665 return 0;
2668 #else /* CONFIG_PROC_FS */
2670 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2671 void __user *buffer, size_t *lenp, loff_t *ppos)
2673 return -ENOSYS;
2676 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2677 void __user *buffer, size_t *lenp, loff_t *ppos)
2679 return -ENOSYS;
2682 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2683 void __user *buffer, size_t *lenp, loff_t *ppos)
2685 return -ENOSYS;
2688 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2689 void __user *buffer, size_t *lenp, loff_t *ppos)
2691 return -ENOSYS;
2694 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2695 void __user *buffer, size_t *lenp, loff_t *ppos)
2697 return -ENOSYS;
2700 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2701 void __user *buffer, size_t *lenp, loff_t *ppos)
2703 return -ENOSYS;
2706 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2707 void __user *buffer, size_t *lenp, loff_t *ppos)
2709 return -ENOSYS;
2712 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2713 struct file *filp,
2714 void __user *buffer,
2715 size_t *lenp, loff_t *ppos)
2717 return -ENOSYS;
2721 #endif /* CONFIG_PROC_FS */
2724 #ifdef CONFIG_SYSCTL_SYSCALL
2726 * General sysctl support routines
2729 /* The generic sysctl data routine (used if no strategy routine supplied) */
2730 int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2731 void __user *oldval, size_t __user *oldlenp,
2732 void __user *newval, size_t newlen)
2734 size_t len;
2736 /* Get out of I don't have a variable */
2737 if (!table->data || !table->maxlen)
2738 return -ENOTDIR;
2740 if (oldval && oldlenp) {
2741 if (get_user(len, oldlenp))
2742 return -EFAULT;
2743 if (len) {
2744 if (len > table->maxlen)
2745 len = table->maxlen;
2746 if (copy_to_user(oldval, table->data, len))
2747 return -EFAULT;
2748 if (put_user(len, oldlenp))
2749 return -EFAULT;
2753 if (newval && newlen) {
2754 if (newlen > table->maxlen)
2755 newlen = table->maxlen;
2757 if (copy_from_user(table->data, newval, newlen))
2758 return -EFAULT;
2760 return 1;
2763 /* The generic string strategy routine: */
2764 int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2765 void __user *oldval, size_t __user *oldlenp,
2766 void __user *newval, size_t newlen)
2768 if (!table->data || !table->maxlen)
2769 return -ENOTDIR;
2771 if (oldval && oldlenp) {
2772 size_t bufsize;
2773 if (get_user(bufsize, oldlenp))
2774 return -EFAULT;
2775 if (bufsize) {
2776 size_t len = strlen(table->data), copied;
2778 /* This shouldn't trigger for a well-formed sysctl */
2779 if (len > table->maxlen)
2780 len = table->maxlen;
2782 /* Copy up to a max of bufsize-1 bytes of the string */
2783 copied = (len >= bufsize) ? bufsize - 1 : len;
2785 if (copy_to_user(oldval, table->data, copied) ||
2786 put_user(0, (char __user *)(oldval + copied)))
2787 return -EFAULT;
2788 if (put_user(len, oldlenp))
2789 return -EFAULT;
2792 if (newval && newlen) {
2793 size_t len = newlen;
2794 if (len > table->maxlen)
2795 len = table->maxlen;
2796 if(copy_from_user(table->data, newval, len))
2797 return -EFAULT;
2798 if (len == table->maxlen)
2799 len--;
2800 ((char *) table->data)[len] = 0;
2802 return 1;
2806 * This function makes sure that all of the integers in the vector
2807 * are between the minimum and maximum values given in the arrays
2808 * table->extra1 and table->extra2, respectively.
2810 int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2811 void __user *oldval, size_t __user *oldlenp,
2812 void __user *newval, size_t newlen)
2815 if (newval && newlen) {
2816 int __user *vec = (int __user *) newval;
2817 int *min = (int *) table->extra1;
2818 int *max = (int *) table->extra2;
2819 size_t length;
2820 int i;
2822 if (newlen % sizeof(int) != 0)
2823 return -EINVAL;
2825 if (!table->extra1 && !table->extra2)
2826 return 0;
2828 if (newlen > table->maxlen)
2829 newlen = table->maxlen;
2830 length = newlen / sizeof(int);
2832 for (i = 0; i < length; i++) {
2833 int value;
2834 if (get_user(value, vec + i))
2835 return -EFAULT;
2836 if (min && value < min[i])
2837 return -EINVAL;
2838 if (max && value > max[i])
2839 return -EINVAL;
2842 return 0;
2845 /* Strategy function to convert jiffies to seconds */
2846 int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2847 void __user *oldval, size_t __user *oldlenp,
2848 void __user *newval, size_t newlen)
2850 if (oldval && oldlenp) {
2851 size_t olen;
2853 if (get_user(olen, oldlenp))
2854 return -EFAULT;
2855 if (olen) {
2856 int val;
2858 if (olen < sizeof(int))
2859 return -EINVAL;
2861 val = *(int *)(table->data) / HZ;
2862 if (put_user(val, (int __user *)oldval))
2863 return -EFAULT;
2864 if (put_user(sizeof(int), oldlenp))
2865 return -EFAULT;
2868 if (newval && newlen) {
2869 int new;
2870 if (newlen != sizeof(int))
2871 return -EINVAL;
2872 if (get_user(new, (int __user *)newval))
2873 return -EFAULT;
2874 *(int *)(table->data) = new*HZ;
2876 return 1;
2879 /* Strategy function to convert jiffies to seconds */
2880 int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2881 void __user *oldval, size_t __user *oldlenp,
2882 void __user *newval, size_t newlen)
2884 if (oldval && oldlenp) {
2885 size_t olen;
2887 if (get_user(olen, oldlenp))
2888 return -EFAULT;
2889 if (olen) {
2890 int val;
2892 if (olen < sizeof(int))
2893 return -EINVAL;
2895 val = jiffies_to_msecs(*(int *)(table->data));
2896 if (put_user(val, (int __user *)oldval))
2897 return -EFAULT;
2898 if (put_user(sizeof(int), oldlenp))
2899 return -EFAULT;
2902 if (newval && newlen) {
2903 int new;
2904 if (newlen != sizeof(int))
2905 return -EINVAL;
2906 if (get_user(new, (int __user *)newval))
2907 return -EFAULT;
2908 *(int *)(table->data) = msecs_to_jiffies(new);
2910 return 1;
2915 #else /* CONFIG_SYSCTL_SYSCALL */
2918 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2920 struct __sysctl_args tmp;
2921 int error;
2923 if (copy_from_user(&tmp, args, sizeof(tmp)))
2924 return -EFAULT;
2926 error = deprecated_sysctl_warning(&tmp);
2928 /* If no error reading the parameters then just -ENOSYS ... */
2929 if (!error)
2930 error = -ENOSYS;
2932 return error;
2935 int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2936 void __user *oldval, size_t __user *oldlenp,
2937 void __user *newval, size_t newlen)
2939 return -ENOSYS;
2942 int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2943 void __user *oldval, size_t __user *oldlenp,
2944 void __user *newval, size_t newlen)
2946 return -ENOSYS;
2949 int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2950 void __user *oldval, size_t __user *oldlenp,
2951 void __user *newval, size_t newlen)
2953 return -ENOSYS;
2956 int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2957 void __user *oldval, size_t __user *oldlenp,
2958 void __user *newval, size_t newlen)
2960 return -ENOSYS;
2963 int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2964 void __user *oldval, size_t __user *oldlenp,
2965 void __user *newval, size_t newlen)
2967 return -ENOSYS;
2970 #endif /* CONFIG_SYSCTL_SYSCALL */
2972 static int deprecated_sysctl_warning(struct __sysctl_args *args)
2974 static int msg_count;
2975 int name[CTL_MAXNAME];
2976 int i;
2978 /* Check args->nlen. */
2979 if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
2980 return -ENOTDIR;
2982 /* Read in the sysctl name for better debug message logging */
2983 for (i = 0; i < args->nlen; i++)
2984 if (get_user(name[i], args->name + i))
2985 return -EFAULT;
2987 /* Ignore accesses to kernel.version */
2988 if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2989 return 0;
2991 if (msg_count < 5) {
2992 msg_count++;
2993 printk(KERN_INFO
2994 "warning: process `%s' used the deprecated sysctl "
2995 "system call with ", current->comm);
2996 for (i = 0; i < args->nlen; i++)
2997 printk("%d.", name[i]);
2998 printk("\n");
3000 return 0;
3004 * No sense putting this after each symbol definition, twice,
3005 * exception granted :-)
3007 EXPORT_SYMBOL(proc_dointvec);
3008 EXPORT_SYMBOL(proc_dointvec_jiffies);
3009 EXPORT_SYMBOL(proc_dointvec_minmax);
3010 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
3011 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
3012 EXPORT_SYMBOL(proc_dostring);
3013 EXPORT_SYMBOL(proc_doulongvec_minmax);
3014 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
3015 EXPORT_SYMBOL(register_sysctl_table);
3016 EXPORT_SYMBOL(register_sysctl_paths);
3017 EXPORT_SYMBOL(sysctl_intvec);
3018 EXPORT_SYMBOL(sysctl_jiffies);
3019 EXPORT_SYMBOL(sysctl_ms_jiffies);
3020 EXPORT_SYMBOL(sysctl_string);
3021 EXPORT_SYMBOL(sysctl_data);
3022 EXPORT_SYMBOL(unregister_sysctl_table);