[PATCH] properly stop devices before poweroff
[linux-2.6/mini2440.git] / kernel / sysctl.c
blob24a4d12d5aa9b40bc8e2ea57dde06f1075e70135
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/config.h>
22 #include <linux/module.h>
23 #include <linux/mm.h>
24 #include <linux/swap.h>
25 #include <linux/slab.h>
26 #include <linux/sysctl.h>
27 #include <linux/proc_fs.h>
28 #include <linux/ctype.h>
29 #include <linux/utsname.h>
30 #include <linux/capability.h>
31 #include <linux/smp_lock.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/sysrq.h>
35 #include <linux/highuid.h>
36 #include <linux/writeback.h>
37 #include <linux/hugetlb.h>
38 #include <linux/security.h>
39 #include <linux/initrd.h>
40 #include <linux/times.h>
41 #include <linux/limits.h>
42 #include <linux/dcache.h>
43 #include <linux/syscalls.h>
45 #include <asm/uaccess.h>
46 #include <asm/processor.h>
48 #ifdef CONFIG_ROOT_NFS
49 #include <linux/nfs_fs.h>
50 #endif
52 #if defined(CONFIG_SYSCTL)
54 /* External variables not in a header file. */
55 extern int C_A_D;
56 extern int sysctl_overcommit_memory;
57 extern int sysctl_overcommit_ratio;
58 extern int max_threads;
59 extern int sysrq_enabled;
60 extern int core_uses_pid;
61 extern int suid_dumpable;
62 extern char core_pattern[];
63 extern int cad_pid;
64 extern int pid_max;
65 extern int min_free_kbytes;
66 extern int printk_ratelimit_jiffies;
67 extern int printk_ratelimit_burst;
68 extern int pid_max_min, pid_max_max;
70 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
71 int unknown_nmi_panic;
72 extern int proc_unknown_nmi_panic(ctl_table *, int, struct file *,
73 void __user *, size_t *, loff_t *);
74 #endif
76 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
77 static int maxolduid = 65535;
78 static int minolduid;
80 static int ngroups_max = NGROUPS_MAX;
82 #ifdef CONFIG_KMOD
83 extern char modprobe_path[];
84 #endif
85 #ifdef CONFIG_HOTPLUG
86 extern char hotplug_path[];
87 #endif
88 #ifdef CONFIG_CHR_DEV_SG
89 extern int sg_big_buff;
90 #endif
91 #ifdef CONFIG_SYSVIPC
92 extern size_t shm_ctlmax;
93 extern size_t shm_ctlall;
94 extern int shm_ctlmni;
95 extern int msg_ctlmax;
96 extern int msg_ctlmnb;
97 extern int msg_ctlmni;
98 extern int sem_ctls[];
99 #endif
101 #ifdef __sparc__
102 extern char reboot_command [];
103 extern int stop_a_enabled;
104 extern int scons_pwroff;
105 #endif
107 #ifdef __hppa__
108 extern int pwrsw_enabled;
109 extern int unaligned_enabled;
110 #endif
112 #ifdef CONFIG_ARCH_S390
113 #ifdef CONFIG_MATHEMU
114 extern int sysctl_ieee_emulation_warnings;
115 #endif
116 extern int sysctl_userprocess_debug;
117 #endif
119 extern int sysctl_hz_timer;
121 #ifdef CONFIG_BSD_PROCESS_ACCT
122 extern int acct_parm[];
123 #endif
125 int randomize_va_space = 1;
127 static int parse_table(int __user *, int, void __user *, size_t __user *, void __user *, size_t,
128 ctl_table *, void **);
129 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
130 void __user *buffer, size_t *lenp, loff_t *ppos);
132 static ctl_table root_table[];
133 static struct ctl_table_header root_table_header =
134 { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
136 static ctl_table kern_table[];
137 static ctl_table vm_table[];
138 #ifdef CONFIG_NET
139 extern ctl_table net_table[];
140 #endif
141 static ctl_table proc_table[];
142 static ctl_table fs_table[];
143 static ctl_table debug_table[];
144 static ctl_table dev_table[];
145 extern ctl_table random_table[];
146 #ifdef CONFIG_UNIX98_PTYS
147 extern ctl_table pty_table[];
148 #endif
150 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
151 int sysctl_legacy_va_layout;
152 #endif
154 /* /proc declarations: */
156 #ifdef CONFIG_PROC_FS
158 static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
159 static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
160 static int proc_opensys(struct inode *, struct file *);
162 struct file_operations proc_sys_file_operations = {
163 .open = proc_opensys,
164 .read = proc_readsys,
165 .write = proc_writesys,
168 extern struct proc_dir_entry *proc_sys_root;
170 static void register_proc_table(ctl_table *, struct proc_dir_entry *);
171 static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
172 #endif
174 /* The default sysctl tables: */
176 static ctl_table root_table[] = {
178 .ctl_name = CTL_KERN,
179 .procname = "kernel",
180 .mode = 0555,
181 .child = kern_table,
184 .ctl_name = CTL_VM,
185 .procname = "vm",
186 .mode = 0555,
187 .child = vm_table,
189 #ifdef CONFIG_NET
191 .ctl_name = CTL_NET,
192 .procname = "net",
193 .mode = 0555,
194 .child = net_table,
196 #endif
198 .ctl_name = CTL_PROC,
199 .procname = "proc",
200 .mode = 0555,
201 .child = proc_table,
204 .ctl_name = CTL_FS,
205 .procname = "fs",
206 .mode = 0555,
207 .child = fs_table,
210 .ctl_name = CTL_DEBUG,
211 .procname = "debug",
212 .mode = 0555,
213 .child = debug_table,
216 .ctl_name = CTL_DEV,
217 .procname = "dev",
218 .mode = 0555,
219 .child = dev_table,
221 { .ctl_name = 0 }
224 static ctl_table kern_table[] = {
226 .ctl_name = KERN_OSTYPE,
227 .procname = "ostype",
228 .data = system_utsname.sysname,
229 .maxlen = sizeof(system_utsname.sysname),
230 .mode = 0444,
231 .proc_handler = &proc_doutsstring,
232 .strategy = &sysctl_string,
235 .ctl_name = KERN_OSRELEASE,
236 .procname = "osrelease",
237 .data = system_utsname.release,
238 .maxlen = sizeof(system_utsname.release),
239 .mode = 0444,
240 .proc_handler = &proc_doutsstring,
241 .strategy = &sysctl_string,
244 .ctl_name = KERN_VERSION,
245 .procname = "version",
246 .data = system_utsname.version,
247 .maxlen = sizeof(system_utsname.version),
248 .mode = 0444,
249 .proc_handler = &proc_doutsstring,
250 .strategy = &sysctl_string,
253 .ctl_name = KERN_NODENAME,
254 .procname = "hostname",
255 .data = system_utsname.nodename,
256 .maxlen = sizeof(system_utsname.nodename),
257 .mode = 0644,
258 .proc_handler = &proc_doutsstring,
259 .strategy = &sysctl_string,
262 .ctl_name = KERN_DOMAINNAME,
263 .procname = "domainname",
264 .data = system_utsname.domainname,
265 .maxlen = sizeof(system_utsname.domainname),
266 .mode = 0644,
267 .proc_handler = &proc_doutsstring,
268 .strategy = &sysctl_string,
271 .ctl_name = KERN_PANIC,
272 .procname = "panic",
273 .data = &panic_timeout,
274 .maxlen = sizeof(int),
275 .mode = 0644,
276 .proc_handler = &proc_dointvec,
279 .ctl_name = KERN_CORE_USES_PID,
280 .procname = "core_uses_pid",
281 .data = &core_uses_pid,
282 .maxlen = sizeof(int),
283 .mode = 0644,
284 .proc_handler = &proc_dointvec,
287 .ctl_name = KERN_CORE_PATTERN,
288 .procname = "core_pattern",
289 .data = core_pattern,
290 .maxlen = 64,
291 .mode = 0644,
292 .proc_handler = &proc_dostring,
293 .strategy = &sysctl_string,
296 .ctl_name = KERN_TAINTED,
297 .procname = "tainted",
298 .data = &tainted,
299 .maxlen = sizeof(int),
300 .mode = 0444,
301 .proc_handler = &proc_dointvec,
304 .ctl_name = KERN_CAP_BSET,
305 .procname = "cap-bound",
306 .data = &cap_bset,
307 .maxlen = sizeof(kernel_cap_t),
308 .mode = 0600,
309 .proc_handler = &proc_dointvec_bset,
311 #ifdef CONFIG_BLK_DEV_INITRD
313 .ctl_name = KERN_REALROOTDEV,
314 .procname = "real-root-dev",
315 .data = &real_root_dev,
316 .maxlen = sizeof(int),
317 .mode = 0644,
318 .proc_handler = &proc_dointvec,
320 #endif
321 #ifdef __sparc__
323 .ctl_name = KERN_SPARC_REBOOT,
324 .procname = "reboot-cmd",
325 .data = reboot_command,
326 .maxlen = 256,
327 .mode = 0644,
328 .proc_handler = &proc_dostring,
329 .strategy = &sysctl_string,
332 .ctl_name = KERN_SPARC_STOP_A,
333 .procname = "stop-a",
334 .data = &stop_a_enabled,
335 .maxlen = sizeof (int),
336 .mode = 0644,
337 .proc_handler = &proc_dointvec,
340 .ctl_name = KERN_SPARC_SCONS_PWROFF,
341 .procname = "scons-poweroff",
342 .data = &scons_pwroff,
343 .maxlen = sizeof (int),
344 .mode = 0644,
345 .proc_handler = &proc_dointvec,
347 #endif
348 #ifdef __hppa__
350 .ctl_name = KERN_HPPA_PWRSW,
351 .procname = "soft-power",
352 .data = &pwrsw_enabled,
353 .maxlen = sizeof (int),
354 .mode = 0644,
355 .proc_handler = &proc_dointvec,
358 .ctl_name = KERN_HPPA_UNALIGNED,
359 .procname = "unaligned-trap",
360 .data = &unaligned_enabled,
361 .maxlen = sizeof (int),
362 .mode = 0644,
363 .proc_handler = &proc_dointvec,
365 #endif
367 .ctl_name = KERN_CTLALTDEL,
368 .procname = "ctrl-alt-del",
369 .data = &C_A_D,
370 .maxlen = sizeof(int),
371 .mode = 0644,
372 .proc_handler = &proc_dointvec,
375 .ctl_name = KERN_PRINTK,
376 .procname = "printk",
377 .data = &console_loglevel,
378 .maxlen = 4*sizeof(int),
379 .mode = 0644,
380 .proc_handler = &proc_dointvec,
382 #ifdef CONFIG_KMOD
384 .ctl_name = KERN_MODPROBE,
385 .procname = "modprobe",
386 .data = &modprobe_path,
387 .maxlen = KMOD_PATH_LEN,
388 .mode = 0644,
389 .proc_handler = &proc_dostring,
390 .strategy = &sysctl_string,
392 #endif
393 #ifdef CONFIG_HOTPLUG
395 .ctl_name = KERN_HOTPLUG,
396 .procname = "hotplug",
397 .data = &hotplug_path,
398 .maxlen = HOTPLUG_PATH_LEN,
399 .mode = 0644,
400 .proc_handler = &proc_dostring,
401 .strategy = &sysctl_string,
403 #endif
404 #ifdef CONFIG_CHR_DEV_SG
406 .ctl_name = KERN_SG_BIG_BUFF,
407 .procname = "sg-big-buff",
408 .data = &sg_big_buff,
409 .maxlen = sizeof (int),
410 .mode = 0444,
411 .proc_handler = &proc_dointvec,
413 #endif
414 #ifdef CONFIG_BSD_PROCESS_ACCT
416 .ctl_name = KERN_ACCT,
417 .procname = "acct",
418 .data = &acct_parm,
419 .maxlen = 3*sizeof(int),
420 .mode = 0644,
421 .proc_handler = &proc_dointvec,
423 #endif
424 #ifdef CONFIG_SYSVIPC
426 .ctl_name = KERN_SHMMAX,
427 .procname = "shmmax",
428 .data = &shm_ctlmax,
429 .maxlen = sizeof (size_t),
430 .mode = 0644,
431 .proc_handler = &proc_doulongvec_minmax,
434 .ctl_name = KERN_SHMALL,
435 .procname = "shmall",
436 .data = &shm_ctlall,
437 .maxlen = sizeof (size_t),
438 .mode = 0644,
439 .proc_handler = &proc_doulongvec_minmax,
442 .ctl_name = KERN_SHMMNI,
443 .procname = "shmmni",
444 .data = &shm_ctlmni,
445 .maxlen = sizeof (int),
446 .mode = 0644,
447 .proc_handler = &proc_dointvec,
450 .ctl_name = KERN_MSGMAX,
451 .procname = "msgmax",
452 .data = &msg_ctlmax,
453 .maxlen = sizeof (int),
454 .mode = 0644,
455 .proc_handler = &proc_dointvec,
458 .ctl_name = KERN_MSGMNI,
459 .procname = "msgmni",
460 .data = &msg_ctlmni,
461 .maxlen = sizeof (int),
462 .mode = 0644,
463 .proc_handler = &proc_dointvec,
466 .ctl_name = KERN_MSGMNB,
467 .procname = "msgmnb",
468 .data = &msg_ctlmnb,
469 .maxlen = sizeof (int),
470 .mode = 0644,
471 .proc_handler = &proc_dointvec,
474 .ctl_name = KERN_SEM,
475 .procname = "sem",
476 .data = &sem_ctls,
477 .maxlen = 4*sizeof (int),
478 .mode = 0644,
479 .proc_handler = &proc_dointvec,
481 #endif
482 #ifdef CONFIG_MAGIC_SYSRQ
484 .ctl_name = KERN_SYSRQ,
485 .procname = "sysrq",
486 .data = &sysrq_enabled,
487 .maxlen = sizeof (int),
488 .mode = 0644,
489 .proc_handler = &proc_dointvec,
491 #endif
493 .ctl_name = KERN_CADPID,
494 .procname = "cad_pid",
495 .data = &cad_pid,
496 .maxlen = sizeof (int),
497 .mode = 0600,
498 .proc_handler = &proc_dointvec,
501 .ctl_name = KERN_MAX_THREADS,
502 .procname = "threads-max",
503 .data = &max_threads,
504 .maxlen = sizeof(int),
505 .mode = 0644,
506 .proc_handler = &proc_dointvec,
509 .ctl_name = KERN_RANDOM,
510 .procname = "random",
511 .mode = 0555,
512 .child = random_table,
514 #ifdef CONFIG_UNIX98_PTYS
516 .ctl_name = KERN_PTY,
517 .procname = "pty",
518 .mode = 0555,
519 .child = pty_table,
521 #endif
523 .ctl_name = KERN_OVERFLOWUID,
524 .procname = "overflowuid",
525 .data = &overflowuid,
526 .maxlen = sizeof(int),
527 .mode = 0644,
528 .proc_handler = &proc_dointvec_minmax,
529 .strategy = &sysctl_intvec,
530 .extra1 = &minolduid,
531 .extra2 = &maxolduid,
534 .ctl_name = KERN_OVERFLOWGID,
535 .procname = "overflowgid",
536 .data = &overflowgid,
537 .maxlen = sizeof(int),
538 .mode = 0644,
539 .proc_handler = &proc_dointvec_minmax,
540 .strategy = &sysctl_intvec,
541 .extra1 = &minolduid,
542 .extra2 = &maxolduid,
544 #ifdef CONFIG_ARCH_S390
545 #ifdef CONFIG_MATHEMU
547 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
548 .procname = "ieee_emulation_warnings",
549 .data = &sysctl_ieee_emulation_warnings,
550 .maxlen = sizeof(int),
551 .mode = 0644,
552 .proc_handler = &proc_dointvec,
554 #endif
555 #ifdef CONFIG_NO_IDLE_HZ
557 .ctl_name = KERN_HZ_TIMER,
558 .procname = "hz_timer",
559 .data = &sysctl_hz_timer,
560 .maxlen = sizeof(int),
561 .mode = 0644,
562 .proc_handler = &proc_dointvec,
564 #endif
566 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
567 .procname = "userprocess_debug",
568 .data = &sysctl_userprocess_debug,
569 .maxlen = sizeof(int),
570 .mode = 0644,
571 .proc_handler = &proc_dointvec,
573 #endif
575 .ctl_name = KERN_PIDMAX,
576 .procname = "pid_max",
577 .data = &pid_max,
578 .maxlen = sizeof (int),
579 .mode = 0644,
580 .proc_handler = &proc_dointvec_minmax,
581 .strategy = sysctl_intvec,
582 .extra1 = &pid_max_min,
583 .extra2 = &pid_max_max,
586 .ctl_name = KERN_PANIC_ON_OOPS,
587 .procname = "panic_on_oops",
588 .data = &panic_on_oops,
589 .maxlen = sizeof(int),
590 .mode = 0644,
591 .proc_handler = &proc_dointvec,
594 .ctl_name = KERN_PRINTK_RATELIMIT,
595 .procname = "printk_ratelimit",
596 .data = &printk_ratelimit_jiffies,
597 .maxlen = sizeof(int),
598 .mode = 0644,
599 .proc_handler = &proc_dointvec_jiffies,
600 .strategy = &sysctl_jiffies,
603 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
604 .procname = "printk_ratelimit_burst",
605 .data = &printk_ratelimit_burst,
606 .maxlen = sizeof(int),
607 .mode = 0644,
608 .proc_handler = &proc_dointvec,
611 .ctl_name = KERN_NGROUPS_MAX,
612 .procname = "ngroups_max",
613 .data = &ngroups_max,
614 .maxlen = sizeof (int),
615 .mode = 0444,
616 .proc_handler = &proc_dointvec,
618 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
620 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
621 .procname = "unknown_nmi_panic",
622 .data = &unknown_nmi_panic,
623 .maxlen = sizeof (int),
624 .mode = 0644,
625 .proc_handler = &proc_unknown_nmi_panic,
627 #endif
628 #if defined(CONFIG_X86)
630 .ctl_name = KERN_BOOTLOADER_TYPE,
631 .procname = "bootloader_type",
632 .data = &bootloader_type,
633 .maxlen = sizeof (int),
634 .mode = 0444,
635 .proc_handler = &proc_dointvec,
637 #endif
639 .ctl_name = KERN_RANDOMIZE,
640 .procname = "randomize_va_space",
641 .data = &randomize_va_space,
642 .maxlen = sizeof(int),
643 .mode = 0644,
644 .proc_handler = &proc_dointvec,
647 { .ctl_name = 0 }
650 /* Constants for minimum and maximum testing in vm_table.
651 We use these as one-element integer vectors. */
652 static int zero;
653 static int one_hundred = 100;
656 static ctl_table vm_table[] = {
658 .ctl_name = VM_OVERCOMMIT_MEMORY,
659 .procname = "overcommit_memory",
660 .data = &sysctl_overcommit_memory,
661 .maxlen = sizeof(sysctl_overcommit_memory),
662 .mode = 0644,
663 .proc_handler = &proc_dointvec,
666 .ctl_name = VM_OVERCOMMIT_RATIO,
667 .procname = "overcommit_ratio",
668 .data = &sysctl_overcommit_ratio,
669 .maxlen = sizeof(sysctl_overcommit_ratio),
670 .mode = 0644,
671 .proc_handler = &proc_dointvec,
674 .ctl_name = VM_PAGE_CLUSTER,
675 .procname = "page-cluster",
676 .data = &page_cluster,
677 .maxlen = sizeof(int),
678 .mode = 0644,
679 .proc_handler = &proc_dointvec,
682 .ctl_name = VM_DIRTY_BACKGROUND,
683 .procname = "dirty_background_ratio",
684 .data = &dirty_background_ratio,
685 .maxlen = sizeof(dirty_background_ratio),
686 .mode = 0644,
687 .proc_handler = &proc_dointvec_minmax,
688 .strategy = &sysctl_intvec,
689 .extra1 = &zero,
690 .extra2 = &one_hundred,
693 .ctl_name = VM_DIRTY_RATIO,
694 .procname = "dirty_ratio",
695 .data = &vm_dirty_ratio,
696 .maxlen = sizeof(vm_dirty_ratio),
697 .mode = 0644,
698 .proc_handler = &proc_dointvec_minmax,
699 .strategy = &sysctl_intvec,
700 .extra1 = &zero,
701 .extra2 = &one_hundred,
704 .ctl_name = VM_DIRTY_WB_CS,
705 .procname = "dirty_writeback_centisecs",
706 .data = &dirty_writeback_centisecs,
707 .maxlen = sizeof(dirty_writeback_centisecs),
708 .mode = 0644,
709 .proc_handler = &dirty_writeback_centisecs_handler,
712 .ctl_name = VM_DIRTY_EXPIRE_CS,
713 .procname = "dirty_expire_centisecs",
714 .data = &dirty_expire_centisecs,
715 .maxlen = sizeof(dirty_expire_centisecs),
716 .mode = 0644,
717 .proc_handler = &proc_dointvec,
720 .ctl_name = VM_NR_PDFLUSH_THREADS,
721 .procname = "nr_pdflush_threads",
722 .data = &nr_pdflush_threads,
723 .maxlen = sizeof nr_pdflush_threads,
724 .mode = 0444 /* read-only*/,
725 .proc_handler = &proc_dointvec,
728 .ctl_name = VM_SWAPPINESS,
729 .procname = "swappiness",
730 .data = &vm_swappiness,
731 .maxlen = sizeof(vm_swappiness),
732 .mode = 0644,
733 .proc_handler = &proc_dointvec_minmax,
734 .strategy = &sysctl_intvec,
735 .extra1 = &zero,
736 .extra2 = &one_hundred,
738 #ifdef CONFIG_HUGETLB_PAGE
740 .ctl_name = VM_HUGETLB_PAGES,
741 .procname = "nr_hugepages",
742 .data = &max_huge_pages,
743 .maxlen = sizeof(unsigned long),
744 .mode = 0644,
745 .proc_handler = &hugetlb_sysctl_handler,
746 .extra1 = (void *)&hugetlb_zero,
747 .extra2 = (void *)&hugetlb_infinity,
750 .ctl_name = VM_HUGETLB_GROUP,
751 .procname = "hugetlb_shm_group",
752 .data = &sysctl_hugetlb_shm_group,
753 .maxlen = sizeof(gid_t),
754 .mode = 0644,
755 .proc_handler = &proc_dointvec,
757 #endif
759 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
760 .procname = "lowmem_reserve_ratio",
761 .data = &sysctl_lowmem_reserve_ratio,
762 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
763 .mode = 0644,
764 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
765 .strategy = &sysctl_intvec,
768 .ctl_name = VM_MIN_FREE_KBYTES,
769 .procname = "min_free_kbytes",
770 .data = &min_free_kbytes,
771 .maxlen = sizeof(min_free_kbytes),
772 .mode = 0644,
773 .proc_handler = &min_free_kbytes_sysctl_handler,
774 .strategy = &sysctl_intvec,
775 .extra1 = &zero,
777 #ifdef CONFIG_MMU
779 .ctl_name = VM_MAX_MAP_COUNT,
780 .procname = "max_map_count",
781 .data = &sysctl_max_map_count,
782 .maxlen = sizeof(sysctl_max_map_count),
783 .mode = 0644,
784 .proc_handler = &proc_dointvec
786 #endif
788 .ctl_name = VM_LAPTOP_MODE,
789 .procname = "laptop_mode",
790 .data = &laptop_mode,
791 .maxlen = sizeof(laptop_mode),
792 .mode = 0644,
793 .proc_handler = &proc_dointvec,
794 .strategy = &sysctl_intvec,
795 .extra1 = &zero,
798 .ctl_name = VM_BLOCK_DUMP,
799 .procname = "block_dump",
800 .data = &block_dump,
801 .maxlen = sizeof(block_dump),
802 .mode = 0644,
803 .proc_handler = &proc_dointvec,
804 .strategy = &sysctl_intvec,
805 .extra1 = &zero,
808 .ctl_name = VM_VFS_CACHE_PRESSURE,
809 .procname = "vfs_cache_pressure",
810 .data = &sysctl_vfs_cache_pressure,
811 .maxlen = sizeof(sysctl_vfs_cache_pressure),
812 .mode = 0644,
813 .proc_handler = &proc_dointvec,
814 .strategy = &sysctl_intvec,
815 .extra1 = &zero,
817 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
819 .ctl_name = VM_LEGACY_VA_LAYOUT,
820 .procname = "legacy_va_layout",
821 .data = &sysctl_legacy_va_layout,
822 .maxlen = sizeof(sysctl_legacy_va_layout),
823 .mode = 0644,
824 .proc_handler = &proc_dointvec,
825 .strategy = &sysctl_intvec,
826 .extra1 = &zero,
828 #endif
829 #ifdef CONFIG_SWAP
831 .ctl_name = VM_SWAP_TOKEN_TIMEOUT,
832 .procname = "swap_token_timeout",
833 .data = &swap_token_default_timeout,
834 .maxlen = sizeof(swap_token_default_timeout),
835 .mode = 0644,
836 .proc_handler = &proc_dointvec_jiffies,
837 .strategy = &sysctl_jiffies,
839 #endif
840 { .ctl_name = 0 }
843 static ctl_table proc_table[] = {
844 { .ctl_name = 0 }
847 static ctl_table fs_table[] = {
849 .ctl_name = FS_NRINODE,
850 .procname = "inode-nr",
851 .data = &inodes_stat,
852 .maxlen = 2*sizeof(int),
853 .mode = 0444,
854 .proc_handler = &proc_dointvec,
857 .ctl_name = FS_STATINODE,
858 .procname = "inode-state",
859 .data = &inodes_stat,
860 .maxlen = 7*sizeof(int),
861 .mode = 0444,
862 .proc_handler = &proc_dointvec,
865 .ctl_name = FS_NRFILE,
866 .procname = "file-nr",
867 .data = &files_stat,
868 .maxlen = 3*sizeof(int),
869 .mode = 0444,
870 .proc_handler = &proc_dointvec,
873 .ctl_name = FS_MAXFILE,
874 .procname = "file-max",
875 .data = &files_stat.max_files,
876 .maxlen = sizeof(int),
877 .mode = 0644,
878 .proc_handler = &proc_dointvec,
881 .ctl_name = FS_DENTRY,
882 .procname = "dentry-state",
883 .data = &dentry_stat,
884 .maxlen = 6*sizeof(int),
885 .mode = 0444,
886 .proc_handler = &proc_dointvec,
889 .ctl_name = FS_OVERFLOWUID,
890 .procname = "overflowuid",
891 .data = &fs_overflowuid,
892 .maxlen = sizeof(int),
893 .mode = 0644,
894 .proc_handler = &proc_dointvec_minmax,
895 .strategy = &sysctl_intvec,
896 .extra1 = &minolduid,
897 .extra2 = &maxolduid,
900 .ctl_name = FS_OVERFLOWGID,
901 .procname = "overflowgid",
902 .data = &fs_overflowgid,
903 .maxlen = sizeof(int),
904 .mode = 0644,
905 .proc_handler = &proc_dointvec_minmax,
906 .strategy = &sysctl_intvec,
907 .extra1 = &minolduid,
908 .extra2 = &maxolduid,
911 .ctl_name = FS_LEASES,
912 .procname = "leases-enable",
913 .data = &leases_enable,
914 .maxlen = sizeof(int),
915 .mode = 0644,
916 .proc_handler = &proc_dointvec,
918 #ifdef CONFIG_DNOTIFY
920 .ctl_name = FS_DIR_NOTIFY,
921 .procname = "dir-notify-enable",
922 .data = &dir_notify_enable,
923 .maxlen = sizeof(int),
924 .mode = 0644,
925 .proc_handler = &proc_dointvec,
927 #endif
928 #ifdef CONFIG_MMU
930 .ctl_name = FS_LEASE_TIME,
931 .procname = "lease-break-time",
932 .data = &lease_break_time,
933 .maxlen = sizeof(int),
934 .mode = 0644,
935 .proc_handler = &proc_dointvec,
938 .ctl_name = FS_AIO_NR,
939 .procname = "aio-nr",
940 .data = &aio_nr,
941 .maxlen = sizeof(aio_nr),
942 .mode = 0444,
943 .proc_handler = &proc_dointvec,
946 .ctl_name = FS_AIO_MAX_NR,
947 .procname = "aio-max-nr",
948 .data = &aio_max_nr,
949 .maxlen = sizeof(aio_max_nr),
950 .mode = 0644,
951 .proc_handler = &proc_dointvec,
953 #endif
955 .ctl_name = KERN_SETUID_DUMPABLE,
956 .procname = "suid_dumpable",
957 .data = &suid_dumpable,
958 .maxlen = sizeof(int),
959 .mode = 0644,
960 .proc_handler = &proc_dointvec,
962 { .ctl_name = 0 }
965 static ctl_table debug_table[] = {
966 { .ctl_name = 0 }
969 static ctl_table dev_table[] = {
970 { .ctl_name = 0 }
973 extern void init_irq_proc (void);
975 void __init sysctl_init(void)
977 #ifdef CONFIG_PROC_FS
978 register_proc_table(root_table, proc_sys_root);
979 init_irq_proc();
980 #endif
983 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
984 void __user *newval, size_t newlen)
986 struct list_head *tmp;
988 if (nlen <= 0 || nlen >= CTL_MAXNAME)
989 return -ENOTDIR;
990 if (oldval) {
991 int old_len;
992 if (!oldlenp || get_user(old_len, oldlenp))
993 return -EFAULT;
995 tmp = &root_table_header.ctl_entry;
996 do {
997 struct ctl_table_header *head =
998 list_entry(tmp, struct ctl_table_header, ctl_entry);
999 void *context = NULL;
1000 int error = parse_table(name, nlen, oldval, oldlenp,
1001 newval, newlen, head->ctl_table,
1002 &context);
1003 if (context)
1004 kfree(context);
1005 if (error != -ENOTDIR)
1006 return error;
1007 tmp = tmp->next;
1008 } while (tmp != &root_table_header.ctl_entry);
1009 return -ENOTDIR;
1012 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1014 struct __sysctl_args tmp;
1015 int error;
1017 if (copy_from_user(&tmp, args, sizeof(tmp)))
1018 return -EFAULT;
1020 lock_kernel();
1021 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1022 tmp.newval, tmp.newlen);
1023 unlock_kernel();
1024 return error;
1028 * ctl_perm does NOT grant the superuser all rights automatically, because
1029 * some sysctl variables are readonly even to root.
1032 static int test_perm(int mode, int op)
1034 if (!current->euid)
1035 mode >>= 6;
1036 else if (in_egroup_p(0))
1037 mode >>= 3;
1038 if ((mode & op & 0007) == op)
1039 return 0;
1040 return -EACCES;
1043 static inline int ctl_perm(ctl_table *table, int op)
1045 int error;
1046 error = security_sysctl(table, op);
1047 if (error)
1048 return error;
1049 return test_perm(table->mode, op);
1052 static int parse_table(int __user *name, int nlen,
1053 void __user *oldval, size_t __user *oldlenp,
1054 void __user *newval, size_t newlen,
1055 ctl_table *table, void **context)
1057 int n;
1058 repeat:
1059 if (!nlen)
1060 return -ENOTDIR;
1061 if (get_user(n, name))
1062 return -EFAULT;
1063 for ( ; table->ctl_name; table++) {
1064 if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
1065 int error;
1066 if (table->child) {
1067 if (ctl_perm(table, 001))
1068 return -EPERM;
1069 if (table->strategy) {
1070 error = table->strategy(
1071 table, name, nlen,
1072 oldval, oldlenp,
1073 newval, newlen, context);
1074 if (error)
1075 return error;
1077 name++;
1078 nlen--;
1079 table = table->child;
1080 goto repeat;
1082 error = do_sysctl_strategy(table, name, nlen,
1083 oldval, oldlenp,
1084 newval, newlen, context);
1085 return error;
1088 return -ENOTDIR;
1091 /* Perform the actual read/write of a sysctl table entry. */
1092 int do_sysctl_strategy (ctl_table *table,
1093 int __user *name, int nlen,
1094 void __user *oldval, size_t __user *oldlenp,
1095 void __user *newval, size_t newlen, void **context)
1097 int op = 0, rc;
1098 size_t len;
1100 if (oldval)
1101 op |= 004;
1102 if (newval)
1103 op |= 002;
1104 if (ctl_perm(table, op))
1105 return -EPERM;
1107 if (table->strategy) {
1108 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1109 newval, newlen, context);
1110 if (rc < 0)
1111 return rc;
1112 if (rc > 0)
1113 return 0;
1116 /* If there is no strategy routine, or if the strategy returns
1117 * zero, proceed with automatic r/w */
1118 if (table->data && table->maxlen) {
1119 if (oldval && oldlenp) {
1120 if (get_user(len, oldlenp))
1121 return -EFAULT;
1122 if (len) {
1123 if (len > table->maxlen)
1124 len = table->maxlen;
1125 if(copy_to_user(oldval, table->data, len))
1126 return -EFAULT;
1127 if(put_user(len, oldlenp))
1128 return -EFAULT;
1131 if (newval && newlen) {
1132 len = newlen;
1133 if (len > table->maxlen)
1134 len = table->maxlen;
1135 if(copy_from_user(table->data, newval, len))
1136 return -EFAULT;
1139 return 0;
1143 * register_sysctl_table - register a sysctl hierarchy
1144 * @table: the top-level table structure
1145 * @insert_at_head: whether the entry should be inserted in front or at the end
1147 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1148 * array. An entry with a ctl_name of 0 terminates the table.
1150 * The members of the &ctl_table structure are used as follows:
1152 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1153 * must be unique within that level of sysctl
1155 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1156 * enter a sysctl file
1158 * data - a pointer to data for use by proc_handler
1160 * maxlen - the maximum size in bytes of the data
1162 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1164 * child - a pointer to the child sysctl table if this entry is a directory, or
1165 * %NULL.
1167 * proc_handler - the text handler routine (described below)
1169 * strategy - the strategy routine (described below)
1171 * de - for internal use by the sysctl routines
1173 * extra1, extra2 - extra pointers usable by the proc handler routines
1175 * Leaf nodes in the sysctl tree will be represented by a single file
1176 * under /proc; non-leaf nodes will be represented by directories.
1178 * sysctl(2) can automatically manage read and write requests through
1179 * the sysctl table. The data and maxlen fields of the ctl_table
1180 * struct enable minimal validation of the values being written to be
1181 * performed, and the mode field allows minimal authentication.
1183 * More sophisticated management can be enabled by the provision of a
1184 * strategy routine with the table entry. This will be called before
1185 * any automatic read or write of the data is performed.
1187 * The strategy routine may return
1189 * < 0 - Error occurred (error is passed to user process)
1191 * 0 - OK - proceed with automatic read or write.
1193 * > 0 - OK - read or write has been done by the strategy routine, so
1194 * return immediately.
1196 * There must be a proc_handler routine for any terminal nodes
1197 * mirrored under /proc/sys (non-terminals are handled by a built-in
1198 * directory handler). Several default handlers are available to
1199 * cover common cases -
1201 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1202 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1203 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1205 * It is the handler's job to read the input buffer from user memory
1206 * and process it. The handler should return 0 on success.
1208 * This routine returns %NULL on a failure to register, and a pointer
1209 * to the table header on success.
1211 struct ctl_table_header *register_sysctl_table(ctl_table * table,
1212 int insert_at_head)
1214 struct ctl_table_header *tmp;
1215 tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1216 if (!tmp)
1217 return NULL;
1218 tmp->ctl_table = table;
1219 INIT_LIST_HEAD(&tmp->ctl_entry);
1220 if (insert_at_head)
1221 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
1222 else
1223 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1224 #ifdef CONFIG_PROC_FS
1225 register_proc_table(table, proc_sys_root);
1226 #endif
1227 return tmp;
1231 * unregister_sysctl_table - unregister a sysctl table hierarchy
1232 * @header: the header returned from register_sysctl_table
1234 * Unregisters the sysctl table and all children. proc entries may not
1235 * actually be removed until they are no longer used by anyone.
1237 void unregister_sysctl_table(struct ctl_table_header * header)
1239 list_del(&header->ctl_entry);
1240 #ifdef CONFIG_PROC_FS
1241 unregister_proc_table(header->ctl_table, proc_sys_root);
1242 #endif
1243 kfree(header);
1247 * /proc/sys support
1250 #ifdef CONFIG_PROC_FS
1252 /* Scan the sysctl entries in table and add them all into /proc */
1253 static void register_proc_table(ctl_table * table, struct proc_dir_entry *root)
1255 struct proc_dir_entry *de;
1256 int len;
1257 mode_t mode;
1259 for (; table->ctl_name; table++) {
1260 /* Can't do anything without a proc name. */
1261 if (!table->procname)
1262 continue;
1263 /* Maybe we can't do anything with it... */
1264 if (!table->proc_handler && !table->child) {
1265 printk(KERN_WARNING "SYSCTL: Can't register %s\n",
1266 table->procname);
1267 continue;
1270 len = strlen(table->procname);
1271 mode = table->mode;
1273 de = NULL;
1274 if (table->proc_handler)
1275 mode |= S_IFREG;
1276 else {
1277 mode |= S_IFDIR;
1278 for (de = root->subdir; de; de = de->next) {
1279 if (proc_match(len, table->procname, de))
1280 break;
1282 /* If the subdir exists already, de is non-NULL */
1285 if (!de) {
1286 de = create_proc_entry(table->procname, mode, root);
1287 if (!de)
1288 continue;
1289 de->data = (void *) table;
1290 if (table->proc_handler)
1291 de->proc_fops = &proc_sys_file_operations;
1293 table->de = de;
1294 if (de->mode & S_IFDIR)
1295 register_proc_table(table->child, de);
1300 * Unregister a /proc sysctl table and any subdirectories.
1302 static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
1304 struct proc_dir_entry *de;
1305 for (; table->ctl_name; table++) {
1306 if (!(de = table->de))
1307 continue;
1308 if (de->mode & S_IFDIR) {
1309 if (!table->child) {
1310 printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
1311 continue;
1313 unregister_proc_table(table->child, de);
1315 /* Don't unregister directories which still have entries.. */
1316 if (de->subdir)
1317 continue;
1320 /* Don't unregister proc entries that are still being used.. */
1321 if (atomic_read(&de->count))
1322 continue;
1324 table->de = NULL;
1325 remove_proc_entry(table->procname, root);
1329 static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
1330 size_t count, loff_t *ppos)
1332 int op;
1333 struct proc_dir_entry *de;
1334 struct ctl_table *table;
1335 size_t res;
1336 ssize_t error;
1338 de = PDE(file->f_dentry->d_inode);
1339 if (!de || !de->data)
1340 return -ENOTDIR;
1341 table = (struct ctl_table *) de->data;
1342 if (!table || !table->proc_handler)
1343 return -ENOTDIR;
1344 op = (write ? 002 : 004);
1345 if (ctl_perm(table, op))
1346 return -EPERM;
1348 res = count;
1350 error = (*table->proc_handler) (table, write, file, buf, &res, ppos);
1351 if (error)
1352 return error;
1353 return res;
1356 static int proc_opensys(struct inode *inode, struct file *file)
1358 if (file->f_mode & FMODE_WRITE) {
1360 * sysctl entries that are not writable,
1361 * are _NOT_ writable, capabilities or not.
1363 if (!(inode->i_mode & S_IWUSR))
1364 return -EPERM;
1367 return 0;
1370 static ssize_t proc_readsys(struct file * file, char __user * buf,
1371 size_t count, loff_t *ppos)
1373 return do_rw_proc(0, file, buf, count, ppos);
1376 static ssize_t proc_writesys(struct file * file, const char __user * buf,
1377 size_t count, loff_t *ppos)
1379 return do_rw_proc(1, file, (char __user *) buf, count, ppos);
1383 * proc_dostring - read a string sysctl
1384 * @table: the sysctl table
1385 * @write: %TRUE if this is a write to the sysctl file
1386 * @filp: the file structure
1387 * @buffer: the user buffer
1388 * @lenp: the size of the user buffer
1389 * @ppos: file position
1391 * Reads/writes a string from/to the user buffer. If the kernel
1392 * buffer provided is not large enough to hold the string, the
1393 * string is truncated. The copied string is %NULL-terminated.
1394 * If the string is being read by the user process, it is copied
1395 * and a newline '\n' is added. It is truncated if the buffer is
1396 * not large enough.
1398 * Returns 0 on success.
1400 int proc_dostring(ctl_table *table, int write, struct file *filp,
1401 void __user *buffer, size_t *lenp, loff_t *ppos)
1403 size_t len;
1404 char __user *p;
1405 char c;
1407 if (!table->data || !table->maxlen || !*lenp ||
1408 (*ppos && !write)) {
1409 *lenp = 0;
1410 return 0;
1413 if (write) {
1414 len = 0;
1415 p = buffer;
1416 while (len < *lenp) {
1417 if (get_user(c, p++))
1418 return -EFAULT;
1419 if (c == 0 || c == '\n')
1420 break;
1421 len++;
1423 if (len >= table->maxlen)
1424 len = table->maxlen-1;
1425 if(copy_from_user(table->data, buffer, len))
1426 return -EFAULT;
1427 ((char *) table->data)[len] = 0;
1428 *ppos += *lenp;
1429 } else {
1430 len = strlen(table->data);
1431 if (len > table->maxlen)
1432 len = table->maxlen;
1433 if (len > *lenp)
1434 len = *lenp;
1435 if (len)
1436 if(copy_to_user(buffer, table->data, len))
1437 return -EFAULT;
1438 if (len < *lenp) {
1439 if(put_user('\n', ((char __user *) buffer) + len))
1440 return -EFAULT;
1441 len++;
1443 *lenp = len;
1444 *ppos += len;
1446 return 0;
1450 * Special case of dostring for the UTS structure. This has locks
1451 * to observe. Should this be in kernel/sys.c ????
1454 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
1455 void __user *buffer, size_t *lenp, loff_t *ppos)
1457 int r;
1459 if (!write) {
1460 down_read(&uts_sem);
1461 r=proc_dostring(table,0,filp,buffer,lenp, ppos);
1462 up_read(&uts_sem);
1463 } else {
1464 down_write(&uts_sem);
1465 r=proc_dostring(table,1,filp,buffer,lenp, ppos);
1466 up_write(&uts_sem);
1468 return r;
1471 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1472 int *valp,
1473 int write, void *data)
1475 if (write) {
1476 *valp = *negp ? -*lvalp : *lvalp;
1477 } else {
1478 int val = *valp;
1479 if (val < 0) {
1480 *negp = -1;
1481 *lvalp = (unsigned long)-val;
1482 } else {
1483 *negp = 0;
1484 *lvalp = (unsigned long)val;
1487 return 0;
1490 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1491 void __user *buffer, size_t *lenp, loff_t *ppos,
1492 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1493 int write, void *data),
1494 void *data)
1496 #define TMPBUFLEN 21
1497 int *i, vleft, first=1, neg, val;
1498 unsigned long lval;
1499 size_t left, len;
1501 char buf[TMPBUFLEN], *p;
1502 char __user *s = buffer;
1504 if (!table->data || !table->maxlen || !*lenp ||
1505 (*ppos && !write)) {
1506 *lenp = 0;
1507 return 0;
1510 i = (int *) table->data;
1511 vleft = table->maxlen / sizeof(*i);
1512 left = *lenp;
1514 if (!conv)
1515 conv = do_proc_dointvec_conv;
1517 for (; left && vleft--; i++, first=0) {
1518 if (write) {
1519 while (left) {
1520 char c;
1521 if (get_user(c, s))
1522 return -EFAULT;
1523 if (!isspace(c))
1524 break;
1525 left--;
1526 s++;
1528 if (!left)
1529 break;
1530 neg = 0;
1531 len = left;
1532 if (len > sizeof(buf) - 1)
1533 len = sizeof(buf) - 1;
1534 if (copy_from_user(buf, s, len))
1535 return -EFAULT;
1536 buf[len] = 0;
1537 p = buf;
1538 if (*p == '-' && left > 1) {
1539 neg = 1;
1540 left--, p++;
1542 if (*p < '0' || *p > '9')
1543 break;
1545 lval = simple_strtoul(p, &p, 0);
1547 len = p-buf;
1548 if ((len < left) && *p && !isspace(*p))
1549 break;
1550 if (neg)
1551 val = -val;
1552 s += len;
1553 left -= len;
1555 if (conv(&neg, &lval, i, 1, data))
1556 break;
1557 } else {
1558 p = buf;
1559 if (!first)
1560 *p++ = '\t';
1562 if (conv(&neg, &lval, i, 0, data))
1563 break;
1565 sprintf(p, "%s%lu", neg ? "-" : "", lval);
1566 len = strlen(buf);
1567 if (len > left)
1568 len = left;
1569 if(copy_to_user(s, buf, len))
1570 return -EFAULT;
1571 left -= len;
1572 s += len;
1576 if (!write && !first && left) {
1577 if(put_user('\n', s))
1578 return -EFAULT;
1579 left--, s++;
1581 if (write) {
1582 while (left) {
1583 char c;
1584 if (get_user(c, s++))
1585 return -EFAULT;
1586 if (!isspace(c))
1587 break;
1588 left--;
1591 if (write && first)
1592 return -EINVAL;
1593 *lenp -= left;
1594 *ppos += *lenp;
1595 return 0;
1596 #undef TMPBUFLEN
1600 * proc_dointvec - read a vector of integers
1601 * @table: the sysctl table
1602 * @write: %TRUE if this is a write to the sysctl file
1603 * @filp: the file structure
1604 * @buffer: the user buffer
1605 * @lenp: the size of the user buffer
1606 * @ppos: file position
1608 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1609 * values from/to the user buffer, treated as an ASCII string.
1611 * Returns 0 on success.
1613 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1614 void __user *buffer, size_t *lenp, loff_t *ppos)
1616 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1617 NULL,NULL);
1620 #define OP_SET 0
1621 #define OP_AND 1
1622 #define OP_OR 2
1623 #define OP_MAX 3
1624 #define OP_MIN 4
1626 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1627 int *valp,
1628 int write, void *data)
1630 int op = *(int *)data;
1631 if (write) {
1632 int val = *negp ? -*lvalp : *lvalp;
1633 switch(op) {
1634 case OP_SET: *valp = val; break;
1635 case OP_AND: *valp &= val; break;
1636 case OP_OR: *valp |= val; break;
1637 case OP_MAX: if(*valp < val)
1638 *valp = val;
1639 break;
1640 case OP_MIN: if(*valp > val)
1641 *valp = val;
1642 break;
1644 } else {
1645 int val = *valp;
1646 if (val < 0) {
1647 *negp = -1;
1648 *lvalp = (unsigned long)-val;
1649 } else {
1650 *negp = 0;
1651 *lvalp = (unsigned long)val;
1654 return 0;
1658 * init may raise the set.
1661 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1662 void __user *buffer, size_t *lenp, loff_t *ppos)
1664 int op;
1666 if (!capable(CAP_SYS_MODULE)) {
1667 return -EPERM;
1670 op = (current->pid == 1) ? OP_SET : OP_AND;
1671 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1672 do_proc_dointvec_bset_conv,&op);
1675 struct do_proc_dointvec_minmax_conv_param {
1676 int *min;
1677 int *max;
1680 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1681 int *valp,
1682 int write, void *data)
1684 struct do_proc_dointvec_minmax_conv_param *param = data;
1685 if (write) {
1686 int val = *negp ? -*lvalp : *lvalp;
1687 if ((param->min && *param->min > val) ||
1688 (param->max && *param->max < val))
1689 return -EINVAL;
1690 *valp = val;
1691 } else {
1692 int val = *valp;
1693 if (val < 0) {
1694 *negp = -1;
1695 *lvalp = (unsigned long)-val;
1696 } else {
1697 *negp = 0;
1698 *lvalp = (unsigned long)val;
1701 return 0;
1705 * proc_dointvec_minmax - read a vector of integers with min/max values
1706 * @table: the sysctl table
1707 * @write: %TRUE if this is a write to the sysctl file
1708 * @filp: the file structure
1709 * @buffer: the user buffer
1710 * @lenp: the size of the user buffer
1711 * @ppos: file position
1713 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1714 * values from/to the user buffer, treated as an ASCII string.
1716 * This routine will ensure the values are within the range specified by
1717 * table->extra1 (min) and table->extra2 (max).
1719 * Returns 0 on success.
1721 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1722 void __user *buffer, size_t *lenp, loff_t *ppos)
1724 struct do_proc_dointvec_minmax_conv_param param = {
1725 .min = (int *) table->extra1,
1726 .max = (int *) table->extra2,
1728 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1729 do_proc_dointvec_minmax_conv, &param);
1732 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1733 struct file *filp,
1734 void __user *buffer,
1735 size_t *lenp, loff_t *ppos,
1736 unsigned long convmul,
1737 unsigned long convdiv)
1739 #define TMPBUFLEN 21
1740 unsigned long *i, *min, *max, val;
1741 int vleft, first=1, neg;
1742 size_t len, left;
1743 char buf[TMPBUFLEN], *p;
1744 char __user *s = buffer;
1746 if (!table->data || !table->maxlen || !*lenp ||
1747 (*ppos && !write)) {
1748 *lenp = 0;
1749 return 0;
1752 i = (unsigned long *) table->data;
1753 min = (unsigned long *) table->extra1;
1754 max = (unsigned long *) table->extra2;
1755 vleft = table->maxlen / sizeof(unsigned long);
1756 left = *lenp;
1758 for (; left && vleft--; i++, min++, max++, first=0) {
1759 if (write) {
1760 while (left) {
1761 char c;
1762 if (get_user(c, s))
1763 return -EFAULT;
1764 if (!isspace(c))
1765 break;
1766 left--;
1767 s++;
1769 if (!left)
1770 break;
1771 neg = 0;
1772 len = left;
1773 if (len > TMPBUFLEN-1)
1774 len = TMPBUFLEN-1;
1775 if (copy_from_user(buf, s, len))
1776 return -EFAULT;
1777 buf[len] = 0;
1778 p = buf;
1779 if (*p == '-' && left > 1) {
1780 neg = 1;
1781 left--, p++;
1783 if (*p < '0' || *p > '9')
1784 break;
1785 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
1786 len = p-buf;
1787 if ((len < left) && *p && !isspace(*p))
1788 break;
1789 if (neg)
1790 val = -val;
1791 s += len;
1792 left -= len;
1794 if(neg)
1795 continue;
1796 if ((min && val < *min) || (max && val > *max))
1797 continue;
1798 *i = val;
1799 } else {
1800 p = buf;
1801 if (!first)
1802 *p++ = '\t';
1803 sprintf(p, "%lu", convdiv * (*i) / convmul);
1804 len = strlen(buf);
1805 if (len > left)
1806 len = left;
1807 if(copy_to_user(s, buf, len))
1808 return -EFAULT;
1809 left -= len;
1810 s += len;
1814 if (!write && !first && left) {
1815 if(put_user('\n', s))
1816 return -EFAULT;
1817 left--, s++;
1819 if (write) {
1820 while (left) {
1821 char c;
1822 if (get_user(c, s++))
1823 return -EFAULT;
1824 if (!isspace(c))
1825 break;
1826 left--;
1829 if (write && first)
1830 return -EINVAL;
1831 *lenp -= left;
1832 *ppos += *lenp;
1833 return 0;
1834 #undef TMPBUFLEN
1838 * proc_doulongvec_minmax - read a vector of long integers with min/max values
1839 * @table: the sysctl table
1840 * @write: %TRUE if this is a write to the sysctl file
1841 * @filp: the file structure
1842 * @buffer: the user buffer
1843 * @lenp: the size of the user buffer
1844 * @ppos: file position
1846 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1847 * values from/to the user buffer, treated as an ASCII string.
1849 * This routine will ensure the values are within the range specified by
1850 * table->extra1 (min) and table->extra2 (max).
1852 * Returns 0 on success.
1854 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
1855 void __user *buffer, size_t *lenp, loff_t *ppos)
1857 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
1861 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
1862 * @table: the sysctl table
1863 * @write: %TRUE if this is a write to the sysctl file
1864 * @filp: the file structure
1865 * @buffer: the user buffer
1866 * @lenp: the size of the user buffer
1867 * @ppos: file position
1869 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1870 * values from/to the user buffer, treated as an ASCII string. The values
1871 * are treated as milliseconds, and converted to jiffies when they are stored.
1873 * This routine will ensure the values are within the range specified by
1874 * table->extra1 (min) and table->extra2 (max).
1876 * Returns 0 on success.
1878 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
1879 struct file *filp,
1880 void __user *buffer,
1881 size_t *lenp, loff_t *ppos)
1883 return do_proc_doulongvec_minmax(table, write, filp, buffer,
1884 lenp, ppos, HZ, 1000l);
1888 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
1889 int *valp,
1890 int write, void *data)
1892 if (write) {
1893 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
1894 } else {
1895 int val = *valp;
1896 unsigned long lval;
1897 if (val < 0) {
1898 *negp = -1;
1899 lval = (unsigned long)-val;
1900 } else {
1901 *negp = 0;
1902 lval = (unsigned long)val;
1904 *lvalp = lval / HZ;
1906 return 0;
1909 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
1910 int *valp,
1911 int write, void *data)
1913 if (write) {
1914 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
1915 } else {
1916 int val = *valp;
1917 unsigned long lval;
1918 if (val < 0) {
1919 *negp = -1;
1920 lval = (unsigned long)-val;
1921 } else {
1922 *negp = 0;
1923 lval = (unsigned long)val;
1925 *lvalp = jiffies_to_clock_t(lval);
1927 return 0;
1930 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
1931 int *valp,
1932 int write, void *data)
1934 if (write) {
1935 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
1936 } else {
1937 int val = *valp;
1938 unsigned long lval;
1939 if (val < 0) {
1940 *negp = -1;
1941 lval = (unsigned long)-val;
1942 } else {
1943 *negp = 0;
1944 lval = (unsigned long)val;
1946 *lvalp = jiffies_to_msecs(lval);
1948 return 0;
1952 * proc_dointvec_jiffies - read a vector of integers as seconds
1953 * @table: the sysctl table
1954 * @write: %TRUE if this is a write to the sysctl file
1955 * @filp: the file structure
1956 * @buffer: the user buffer
1957 * @lenp: the size of the user buffer
1958 * @ppos: file position
1960 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1961 * values from/to the user buffer, treated as an ASCII string.
1962 * The values read are assumed to be in seconds, and are converted into
1963 * jiffies.
1965 * Returns 0 on success.
1967 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
1968 void __user *buffer, size_t *lenp, loff_t *ppos)
1970 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1971 do_proc_dointvec_jiffies_conv,NULL);
1975 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
1976 * @table: the sysctl table
1977 * @write: %TRUE if this is a write to the sysctl file
1978 * @filp: the file structure
1979 * @buffer: the user buffer
1980 * @lenp: the size of the user buffer
1982 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1983 * values from/to the user buffer, treated as an ASCII string.
1984 * The values read are assumed to be in 1/USER_HZ seconds, and
1985 * are converted into jiffies.
1987 * Returns 0 on success.
1989 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
1990 void __user *buffer, size_t *lenp, loff_t *ppos)
1992 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1993 do_proc_dointvec_userhz_jiffies_conv,NULL);
1997 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
1998 * @table: the sysctl table
1999 * @write: %TRUE if this is a write to the sysctl file
2000 * @filp: the file structure
2001 * @buffer: the user buffer
2002 * @lenp: the size of the user buffer
2003 * @ppos: file position
2004 * @ppos: the current position in the file
2006 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2007 * values from/to the user buffer, treated as an ASCII string.
2008 * The values read are assumed to be in 1/1000 seconds, and
2009 * are converted into jiffies.
2011 * Returns 0 on success.
2013 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2014 void __user *buffer, size_t *lenp, loff_t *ppos)
2016 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2017 do_proc_dointvec_ms_jiffies_conv, NULL);
2020 #else /* CONFIG_PROC_FS */
2022 int proc_dostring(ctl_table *table, int write, struct file *filp,
2023 void __user *buffer, size_t *lenp, loff_t *ppos)
2025 return -ENOSYS;
2028 static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
2029 void __user *buffer, size_t *lenp, loff_t *ppos)
2031 return -ENOSYS;
2034 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2035 void __user *buffer, size_t *lenp, loff_t *ppos)
2037 return -ENOSYS;
2040 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2041 void __user *buffer, size_t *lenp, loff_t *ppos)
2043 return -ENOSYS;
2046 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2047 void __user *buffer, size_t *lenp, loff_t *ppos)
2049 return -ENOSYS;
2052 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2053 void __user *buffer, size_t *lenp, loff_t *ppos)
2055 return -ENOSYS;
2058 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2059 void __user *buffer, size_t *lenp, loff_t *ppos)
2061 return -ENOSYS;
2064 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2065 void __user *buffer, size_t *lenp, loff_t *ppos)
2067 return -ENOSYS;
2070 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2071 void __user *buffer, size_t *lenp, loff_t *ppos)
2073 return -ENOSYS;
2076 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2077 struct file *filp,
2078 void __user *buffer,
2079 size_t *lenp, loff_t *ppos)
2081 return -ENOSYS;
2085 #endif /* CONFIG_PROC_FS */
2089 * General sysctl support routines
2092 /* The generic string strategy routine: */
2093 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2094 void __user *oldval, size_t __user *oldlenp,
2095 void __user *newval, size_t newlen, void **context)
2097 size_t l, len;
2099 if (!table->data || !table->maxlen)
2100 return -ENOTDIR;
2102 if (oldval && oldlenp) {
2103 if (get_user(len, oldlenp))
2104 return -EFAULT;
2105 if (len) {
2106 l = strlen(table->data);
2107 if (len > l) len = l;
2108 if (len >= table->maxlen)
2109 len = table->maxlen;
2110 if(copy_to_user(oldval, table->data, len))
2111 return -EFAULT;
2112 if(put_user(0, ((char __user *) oldval) + len))
2113 return -EFAULT;
2114 if(put_user(len, oldlenp))
2115 return -EFAULT;
2118 if (newval && newlen) {
2119 len = newlen;
2120 if (len > table->maxlen)
2121 len = table->maxlen;
2122 if(copy_from_user(table->data, newval, len))
2123 return -EFAULT;
2124 if (len == table->maxlen)
2125 len--;
2126 ((char *) table->data)[len] = 0;
2128 return 0;
2132 * This function makes sure that all of the integers in the vector
2133 * are between the minimum and maximum values given in the arrays
2134 * table->extra1 and table->extra2, respectively.
2136 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2137 void __user *oldval, size_t __user *oldlenp,
2138 void __user *newval, size_t newlen, void **context)
2141 if (newval && newlen) {
2142 int __user *vec = (int __user *) newval;
2143 int *min = (int *) table->extra1;
2144 int *max = (int *) table->extra2;
2145 size_t length;
2146 int i;
2148 if (newlen % sizeof(int) != 0)
2149 return -EINVAL;
2151 if (!table->extra1 && !table->extra2)
2152 return 0;
2154 if (newlen > table->maxlen)
2155 newlen = table->maxlen;
2156 length = newlen / sizeof(int);
2158 for (i = 0; i < length; i++) {
2159 int value;
2160 if (get_user(value, vec + i))
2161 return -EFAULT;
2162 if (min && value < min[i])
2163 return -EINVAL;
2164 if (max && value > max[i])
2165 return -EINVAL;
2168 return 0;
2171 /* Strategy function to convert jiffies to seconds */
2172 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2173 void __user *oldval, size_t __user *oldlenp,
2174 void __user *newval, size_t newlen, void **context)
2176 if (oldval) {
2177 size_t olen;
2178 if (oldlenp) {
2179 if (get_user(olen, oldlenp))
2180 return -EFAULT;
2181 if (olen!=sizeof(int))
2182 return -EINVAL;
2184 if (put_user(*(int *)(table->data)/HZ, (int __user *)oldval) ||
2185 (oldlenp && put_user(sizeof(int),oldlenp)))
2186 return -EFAULT;
2188 if (newval && newlen) {
2189 int new;
2190 if (newlen != sizeof(int))
2191 return -EINVAL;
2192 if (get_user(new, (int __user *)newval))
2193 return -EFAULT;
2194 *(int *)(table->data) = new*HZ;
2196 return 1;
2199 /* Strategy function to convert jiffies to seconds */
2200 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2201 void __user *oldval, size_t __user *oldlenp,
2202 void __user *newval, size_t newlen, void **context)
2204 if (oldval) {
2205 size_t olen;
2206 if (oldlenp) {
2207 if (get_user(olen, oldlenp))
2208 return -EFAULT;
2209 if (olen!=sizeof(int))
2210 return -EINVAL;
2212 if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
2213 (oldlenp && put_user(sizeof(int),oldlenp)))
2214 return -EFAULT;
2216 if (newval && newlen) {
2217 int new;
2218 if (newlen != sizeof(int))
2219 return -EINVAL;
2220 if (get_user(new, (int __user *)newval))
2221 return -EFAULT;
2222 *(int *)(table->data) = msecs_to_jiffies(new);
2224 return 1;
2227 #else /* CONFIG_SYSCTL */
2230 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2232 return -ENOSYS;
2235 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2236 void __user *oldval, size_t __user *oldlenp,
2237 void __user *newval, size_t newlen, void **context)
2239 return -ENOSYS;
2242 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2243 void __user *oldval, size_t __user *oldlenp,
2244 void __user *newval, size_t newlen, void **context)
2246 return -ENOSYS;
2249 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2250 void __user *oldval, size_t __user *oldlenp,
2251 void __user *newval, size_t newlen, void **context)
2253 return -ENOSYS;
2256 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2257 void __user *oldval, size_t __user *oldlenp,
2258 void __user *newval, size_t newlen, void **context)
2260 return -ENOSYS;
2263 int proc_dostring(ctl_table *table, int write, struct file *filp,
2264 void __user *buffer, size_t *lenp, loff_t *ppos)
2266 return -ENOSYS;
2269 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2270 void __user *buffer, size_t *lenp, loff_t *ppos)
2272 return -ENOSYS;
2275 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2276 void __user *buffer, size_t *lenp, loff_t *ppos)
2278 return -ENOSYS;
2281 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2282 void __user *buffer, size_t *lenp, loff_t *ppos)
2284 return -ENOSYS;
2287 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2288 void __user *buffer, size_t *lenp, loff_t *ppos)
2290 return -ENOSYS;
2293 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2294 void __user *buffer, size_t *lenp, loff_t *ppos)
2296 return -ENOSYS;
2299 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2300 void __user *buffer, size_t *lenp, loff_t *ppos)
2302 return -ENOSYS;
2305 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2306 void __user *buffer, size_t *lenp, loff_t *ppos)
2308 return -ENOSYS;
2311 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2312 struct file *filp,
2313 void __user *buffer,
2314 size_t *lenp, loff_t *ppos)
2316 return -ENOSYS;
2319 struct ctl_table_header * register_sysctl_table(ctl_table * table,
2320 int insert_at_head)
2322 return NULL;
2325 void unregister_sysctl_table(struct ctl_table_header * table)
2329 #endif /* CONFIG_SYSCTL */
2332 * No sense putting this after each symbol definition, twice,
2333 * exception granted :-)
2335 EXPORT_SYMBOL(proc_dointvec);
2336 EXPORT_SYMBOL(proc_dointvec_jiffies);
2337 EXPORT_SYMBOL(proc_dointvec_minmax);
2338 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2339 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2340 EXPORT_SYMBOL(proc_dostring);
2341 EXPORT_SYMBOL(proc_doulongvec_minmax);
2342 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2343 EXPORT_SYMBOL(register_sysctl_table);
2344 EXPORT_SYMBOL(sysctl_intvec);
2345 EXPORT_SYMBOL(sysctl_jiffies);
2346 EXPORT_SYMBOL(sysctl_ms_jiffies);
2347 EXPORT_SYMBOL(sysctl_string);
2348 EXPORT_SYMBOL(unregister_sysctl_table);