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1da177e4
LT		 1/*
2 * sysctl.c: General linux system control interface
3 *
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
19 */
20
1da177e4
LT		 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>
c59ede7b 27#include <linux/capability.h>
1da177e4
LT		 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>
0296b228 34#include <linux/kobject.h>
20380731 35#include <linux/net.h>
1da177e4
LT		 36#include <linux/sysrq.h>
37#include <linux/highuid.h>
38#include <linux/writeback.h>
39#include <linux/hugetlb.h>
40#include <linux/security.h>
41#include <linux/initrd.h>
42#include <linux/times.h>
43#include <linux/limits.h>
44#include <linux/dcache.h>
45#include <linux/syscalls.h>
c255d844
PM		 46#include <linux/nfs_fs.h>
47#include <linux/acpi.h>
1da177e4
LT		 48
49#include <asm/uaccess.h>
50#include <asm/processor.h>
51
529bf6be
DS		 52extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
53 void __user *buffer, size_t *lenp, loff_t *ppos);
54
29cbc78b
AK		 55#ifdef CONFIG_X86
56#include <asm/nmi.h>
57#endif
58
1da177e4
LT		 59#if defined(CONFIG_SYSCTL)
60
61/* External variables not in a header file. */
62extern int C_A_D;
63extern int sysctl_overcommit_memory;
64extern int sysctl_overcommit_ratio;
fadd8fbd 65extern int sysctl_panic_on_oom;
1da177e4
LT		 66extern int max_threads;
67extern int sysrq_enabled;
68extern int core_uses_pid;
d6e71144 69extern int suid_dumpable;
1da177e4
LT		 70extern char core_pattern[];
71extern int cad_pid;
72extern int pid_max;
73extern int min_free_kbytes;
74extern int printk_ratelimit_jiffies;
75extern int printk_ratelimit_burst;
76extern int pid_max_min, pid_max_max;
9d0243bc 77extern int sysctl_drop_caches;
8ad4b1fb 78extern int percpu_pagelist_fraction;
bebfa101 79extern int compat_log;
1da177e4 80
1da177e4
LT		 81/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
82static int maxolduid = 65535;
83static int minolduid;
8ad4b1fb 84static int min_percpu_pagelist_fract = 8;
1da177e4
LT		 85
86static int ngroups_max = NGROUPS_MAX;
87
88#ifdef CONFIG_KMOD
89extern char modprobe_path[];
90#endif
1da177e4
LT		 91#ifdef CONFIG_CHR_DEV_SG
92extern int sg_big_buff;
93#endif
94#ifdef CONFIG_SYSVIPC
95extern size_t shm_ctlmax;
96extern size_t shm_ctlall;
97extern int shm_ctlmni;
98extern int msg_ctlmax;
99extern int msg_ctlmnb;
100extern int msg_ctlmni;
101extern int sem_ctls[];
102#endif
103
104#ifdef __sparc__
105extern char reboot_command [];
106extern int stop_a_enabled;
107extern int scons_pwroff;
108#endif
109
110#ifdef __hppa__
111extern int pwrsw_enabled;
112extern int unaligned_enabled;
113#endif
114
347a8dc3 115#ifdef CONFIG_S390
1da177e4
LT		 116#ifdef CONFIG_MATHEMU
117extern int sysctl_ieee_emulation_warnings;
118#endif
119extern int sysctl_userprocess_debug;
951f22d5 120extern int spin_retry;
1da177e4
LT		 121#endif
122
123extern int sysctl_hz_timer;
124
125#ifdef CONFIG_BSD_PROCESS_ACCT
126extern int acct_parm[];
127#endif
128
d2b176ed
JS		 129#ifdef CONFIG_IA64
130extern int no_unaligned_warning;
131#endif
132
23f78d4a
IM		 133#ifdef CONFIG_RT_MUTEXES
134extern int max_lock_depth;
135#endif
136
b89a8171
EB		 137#ifdef CONFIG_SYSCTL_SYSCALL
138static int parse_table(int __user *, int, void __user *, size_t __user *,
139 void __user *, size_t, ctl_table *, void **);
140#endif
141
1da177e4
LT		 142static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
143 void __user *buffer, size_t *lenp, loff_t *ppos);
144
145static ctl_table root_table[];
146static struct ctl_table_header root_table_header =
147 { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
148
149static ctl_table kern_table[];
150static ctl_table vm_table[];
1da177e4
LT		 151static ctl_table fs_table[];
152static ctl_table debug_table[];
153static ctl_table dev_table[];
154extern ctl_table random_table[];
155#ifdef CONFIG_UNIX98_PTYS
156extern ctl_table pty_table[];
157#endif
2d9048e2 158#ifdef CONFIG_INOTIFY_USER
0399cb08
RL		 159extern ctl_table inotify_table[];
160#endif
1da177e4
LT		 161
162#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
163int sysctl_legacy_va_layout;
164#endif
165
166/* /proc declarations: */
167
b89a8171 168#ifdef CONFIG_PROC_SYSCTL
1da177e4
LT		 169
170static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
171static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
172static int proc_opensys(struct inode *, struct file *);
173
174struct file_operations proc_sys_file_operations = {
175 .open = proc_opensys,
176 .read = proc_readsys,
177 .write = proc_writesys,
178};
179
180extern struct proc_dir_entry *proc_sys_root;
181
330d57fb 182static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
1da177e4
LT		 183static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
184#endif
185
186/* The default sysctl tables: */
187
188static ctl_table root_table[] = {
189 {
190 .ctl_name = CTL_KERN,
191 .procname = "kernel",
192 .mode = 0555,
193 .child = kern_table,
194 },
195 {
196 .ctl_name = CTL_VM,
197 .procname = "vm",
198 .mode = 0555,
199 .child = vm_table,
200 },
201#ifdef CONFIG_NET
202 {
203 .ctl_name = CTL_NET,
204 .procname = "net",
205 .mode = 0555,
206 .child = net_table,
207 },
208#endif
1da177e4
LT		 209 {
210 .ctl_name = CTL_FS,
211 .procname = "fs",
212 .mode = 0555,
213 .child = fs_table,
214 },
215 {
216 .ctl_name = CTL_DEBUG,
217 .procname = "debug",
218 .mode = 0555,
219 .child = debug_table,
220 },
221 {
222 .ctl_name = CTL_DEV,
223 .procname = "dev",
224 .mode = 0555,
225 .child = dev_table,
226 },
0eeca283 227
1da177e4
LT		 228 { .ctl_name = 0 }
229};
230
231static ctl_table kern_table[] = {
232 {
233 .ctl_name = KERN_OSTYPE,
234 .procname = "ostype",
235 .data = system_utsname.sysname,
236 .maxlen = sizeof(system_utsname.sysname),
237 .mode = 0444,
238 .proc_handler = &proc_doutsstring,
239 .strategy = &sysctl_string,
240 },
241 {
242 .ctl_name = KERN_OSRELEASE,
243 .procname = "osrelease",
244 .data = system_utsname.release,
245 .maxlen = sizeof(system_utsname.release),
246 .mode = 0444,
247 .proc_handler = &proc_doutsstring,
248 .strategy = &sysctl_string,
249 },
250 {
251 .ctl_name = KERN_VERSION,
252 .procname = "version",
253 .data = system_utsname.version,
254 .maxlen = sizeof(system_utsname.version),
255 .mode = 0444,
256 .proc_handler = &proc_doutsstring,
257 .strategy = &sysctl_string,
258 },
259 {
260 .ctl_name = KERN_NODENAME,
261 .procname = "hostname",
262 .data = system_utsname.nodename,
263 .maxlen = sizeof(system_utsname.nodename),
264 .mode = 0644,
265 .proc_handler = &proc_doutsstring,
266 .strategy = &sysctl_string,
267 },
268 {
269 .ctl_name = KERN_DOMAINNAME,
270 .procname = "domainname",
271 .data = system_utsname.domainname,
272 .maxlen = sizeof(system_utsname.domainname),
273 .mode = 0644,
274 .proc_handler = &proc_doutsstring,
275 .strategy = &sysctl_string,
276 },
277 {
278 .ctl_name = KERN_PANIC,
279 .procname = "panic",
280 .data = &panic_timeout,
281 .maxlen = sizeof(int),
282 .mode = 0644,
283 .proc_handler = &proc_dointvec,
284 },
285 {
286 .ctl_name = KERN_CORE_USES_PID,
287 .procname = "core_uses_pid",
288 .data = &core_uses_pid,
289 .maxlen = sizeof(int),
290 .mode = 0644,
291 .proc_handler = &proc_dointvec,
292 },
293 {
294 .ctl_name = KERN_CORE_PATTERN,
295 .procname = "core_pattern",
296 .data = core_pattern,
d025c9db 297 .maxlen = 128,
1da177e4
LT		 298 .mode = 0644,
299 .proc_handler = &proc_dostring,
300 .strategy = &sysctl_string,
301 },
302 {
303 .ctl_name = KERN_TAINTED,
304 .procname = "tainted",
305 .data = &tainted,
306 .maxlen = sizeof(int),
307 .mode = 0444,
308 .proc_handler = &proc_dointvec,
309 },
310 {
311 .ctl_name = KERN_CAP_BSET,
312 .procname = "cap-bound",
313 .data = &cap_bset,
314 .maxlen = sizeof(kernel_cap_t),
315 .mode = 0600,
316 .proc_handler = &proc_dointvec_bset,
317 },
318#ifdef CONFIG_BLK_DEV_INITRD
319 {
320 .ctl_name = KERN_REALROOTDEV,
321 .procname = "real-root-dev",
322 .data = &real_root_dev,
323 .maxlen = sizeof(int),
324 .mode = 0644,
325 .proc_handler = &proc_dointvec,
326 },
327#endif
328#ifdef __sparc__
329 {
330 .ctl_name = KERN_SPARC_REBOOT,
331 .procname = "reboot-cmd",
332 .data = reboot_command,
333 .maxlen = 256,
334 .mode = 0644,
335 .proc_handler = &proc_dostring,
336 .strategy = &sysctl_string,
337 },
338 {
339 .ctl_name = KERN_SPARC_STOP_A,
340 .procname = "stop-a",
341 .data = &stop_a_enabled,
342 .maxlen = sizeof (int),
343 .mode = 0644,
344 .proc_handler = &proc_dointvec,
345 },
346 {
347 .ctl_name = KERN_SPARC_SCONS_PWROFF,
348 .procname = "scons-poweroff",
349 .data = &scons_pwroff,
350 .maxlen = sizeof (int),
351 .mode = 0644,
352 .proc_handler = &proc_dointvec,
353 },
354#endif
355#ifdef __hppa__
356 {
357 .ctl_name = KERN_HPPA_PWRSW,
358 .procname = "soft-power",
359 .data = &pwrsw_enabled,
360 .maxlen = sizeof (int),
361 .mode = 0644,
362 .proc_handler = &proc_dointvec,
363 },
364 {
365 .ctl_name = KERN_HPPA_UNALIGNED,
366 .procname = "unaligned-trap",
367 .data = &unaligned_enabled,
368 .maxlen = sizeof (int),
369 .mode = 0644,
370 .proc_handler = &proc_dointvec,
371 },
372#endif
373 {
374 .ctl_name = KERN_CTLALTDEL,
375 .procname = "ctrl-alt-del",
376 .data = &C_A_D,
377 .maxlen = sizeof(int),
378 .mode = 0644,
379 .proc_handler = &proc_dointvec,
380 },
381 {
382 .ctl_name = KERN_PRINTK,
383 .procname = "printk",
384 .data = &console_loglevel,
385 .maxlen = 4*sizeof(int),
386 .mode = 0644,
387 .proc_handler = &proc_dointvec,
388 },
389#ifdef CONFIG_KMOD
390 {
391 .ctl_name = KERN_MODPROBE,
392 .procname = "modprobe",
393 .data = &modprobe_path,
394 .maxlen = KMOD_PATH_LEN,
395 .mode = 0644,
396 .proc_handler = &proc_dostring,
397 .strategy = &sysctl_string,
398 },
399#endif
57ae2508 400#if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
1da177e4
LT		 401 {
402 .ctl_name = KERN_HOTPLUG,
403 .procname = "hotplug",
312c004d
KS		 404 .data = &uevent_helper,
405 .maxlen = UEVENT_HELPER_PATH_LEN,
1da177e4
LT		 406 .mode = 0644,
407 .proc_handler = &proc_dostring,
408 .strategy = &sysctl_string,
409 },
410#endif
411#ifdef CONFIG_CHR_DEV_SG
412 {
413 .ctl_name = KERN_SG_BIG_BUFF,
414 .procname = "sg-big-buff",
415 .data = &sg_big_buff,
416 .maxlen = sizeof (int),
417 .mode = 0444,
418 .proc_handler = &proc_dointvec,
419 },
420#endif
421#ifdef CONFIG_BSD_PROCESS_ACCT
422 {
423 .ctl_name = KERN_ACCT,
424 .procname = "acct",
425 .data = &acct_parm,
426 .maxlen = 3*sizeof(int),
427 .mode = 0644,
428 .proc_handler = &proc_dointvec,
429 },
430#endif
431#ifdef CONFIG_SYSVIPC
432 {
433 .ctl_name = KERN_SHMMAX,
434 .procname = "shmmax",
435 .data = &shm_ctlmax,
436 .maxlen = sizeof (size_t),
437 .mode = 0644,
438 .proc_handler = &proc_doulongvec_minmax,
439 },
440 {
441 .ctl_name = KERN_SHMALL,
442 .procname = "shmall",
443 .data = &shm_ctlall,
444 .maxlen = sizeof (size_t),
445 .mode = 0644,
446 .proc_handler = &proc_doulongvec_minmax,
447 },
448 {
449 .ctl_name = KERN_SHMMNI,
450 .procname = "shmmni",
451 .data = &shm_ctlmni,
452 .maxlen = sizeof (int),
453 .mode = 0644,
454 .proc_handler = &proc_dointvec,
455 },
456 {
457 .ctl_name = KERN_MSGMAX,
458 .procname = "msgmax",
459 .data = &msg_ctlmax,
460 .maxlen = sizeof (int),
461 .mode = 0644,
462 .proc_handler = &proc_dointvec,
463 },
464 {
465 .ctl_name = KERN_MSGMNI,
466 .procname = "msgmni",
467 .data = &msg_ctlmni,
468 .maxlen = sizeof (int),
469 .mode = 0644,
470 .proc_handler = &proc_dointvec,
471 },
472 {
473 .ctl_name = KERN_MSGMNB,
474 .procname = "msgmnb",
475 .data = &msg_ctlmnb,
476 .maxlen = sizeof (int),
477 .mode = 0644,
478 .proc_handler = &proc_dointvec,
479 },
480 {
481 .ctl_name = KERN_SEM,
482 .procname = "sem",
483 .data = &sem_ctls,
484 .maxlen = 4*sizeof (int),
485 .mode = 0644,
486 .proc_handler = &proc_dointvec,
487 },
488#endif
489#ifdef CONFIG_MAGIC_SYSRQ
490 {
491 .ctl_name = KERN_SYSRQ,
492 .procname = "sysrq",
493 .data = &sysrq_enabled,
494 .maxlen = sizeof (int),
495 .mode = 0644,
496 .proc_handler = &proc_dointvec,
497 },
498#endif
499 {
500 .ctl_name = KERN_CADPID,
501 .procname = "cad_pid",
502 .data = &cad_pid,
503 .maxlen = sizeof (int),
504 .mode = 0600,
505 .proc_handler = &proc_dointvec,
506 },
507 {
508 .ctl_name = KERN_MAX_THREADS,
509 .procname = "threads-max",
510 .data = &max_threads,
511 .maxlen = sizeof(int),
512 .mode = 0644,
513 .proc_handler = &proc_dointvec,
514 },
515 {
516 .ctl_name = KERN_RANDOM,
517 .procname = "random",
518 .mode = 0555,
519 .child = random_table,
520 },
521#ifdef CONFIG_UNIX98_PTYS
522 {
523 .ctl_name = KERN_PTY,
524 .procname = "pty",
525 .mode = 0555,
526 .child = pty_table,
527 },
528#endif
529 {
530 .ctl_name = KERN_OVERFLOWUID,
531 .procname = "overflowuid",
532 .data = &overflowuid,
533 .maxlen = sizeof(int),
534 .mode = 0644,
535 .proc_handler = &proc_dointvec_minmax,
536 .strategy = &sysctl_intvec,
537 .extra1 = &minolduid,
538 .extra2 = &maxolduid,
539 },
540 {
541 .ctl_name = KERN_OVERFLOWGID,
542 .procname = "overflowgid",
543 .data = &overflowgid,
544 .maxlen = sizeof(int),
545 .mode = 0644,
546 .proc_handler = &proc_dointvec_minmax,
547 .strategy = &sysctl_intvec,
548 .extra1 = &minolduid,
549 .extra2 = &maxolduid,
550 },
347a8dc3 551#ifdef CONFIG_S390
1da177e4
LT		 552#ifdef CONFIG_MATHEMU
553 {
554 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
555 .procname = "ieee_emulation_warnings",
556 .data = &sysctl_ieee_emulation_warnings,
557 .maxlen = sizeof(int),
558 .mode = 0644,
559 .proc_handler = &proc_dointvec,
560 },
561#endif
562#ifdef CONFIG_NO_IDLE_HZ
563 {
564 .ctl_name = KERN_HZ_TIMER,
565 .procname = "hz_timer",
566 .data = &sysctl_hz_timer,
567 .maxlen = sizeof(int),
568 .mode = 0644,
569 .proc_handler = &proc_dointvec,
570 },
571#endif
572 {
573 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
574 .procname = "userprocess_debug",
575 .data = &sysctl_userprocess_debug,
576 .maxlen = sizeof(int),
577 .mode = 0644,
578 .proc_handler = &proc_dointvec,
579 },
580#endif
581 {
582 .ctl_name = KERN_PIDMAX,
583 .procname = "pid_max",
584 .data = &pid_max,
585 .maxlen = sizeof (int),
586 .mode = 0644,
587 .proc_handler = &proc_dointvec_minmax,
588 .strategy = sysctl_intvec,
589 .extra1 = &pid_max_min,
590 .extra2 = &pid_max_max,
591 },
592 {
593 .ctl_name = KERN_PANIC_ON_OOPS,
594 .procname = "panic_on_oops",
595 .data = &panic_on_oops,
596 .maxlen = sizeof(int),
597 .mode = 0644,
598 .proc_handler = &proc_dointvec,
599 },
600 {
601 .ctl_name = KERN_PRINTK_RATELIMIT,
602 .procname = "printk_ratelimit",
603 .data = &printk_ratelimit_jiffies,
604 .maxlen = sizeof(int),
605 .mode = 0644,
606 .proc_handler = &proc_dointvec_jiffies,
607 .strategy = &sysctl_jiffies,
608 },
609 {
610 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
611 .procname = "printk_ratelimit_burst",
612 .data = &printk_ratelimit_burst,
613 .maxlen = sizeof(int),
614 .mode = 0644,
615 .proc_handler = &proc_dointvec,
616 },
617 {
618 .ctl_name = KERN_NGROUPS_MAX,
619 .procname = "ngroups_max",
620 .data = &ngroups_max,
621 .maxlen = sizeof (int),
622 .mode = 0444,
623 .proc_handler = &proc_dointvec,
624 },
625#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
626 {
627 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
628 .procname = "unknown_nmi_panic",
629 .data = &unknown_nmi_panic,
630 .maxlen = sizeof (int),
631 .mode = 0644,
2fbe7b25 632 .proc_handler = &proc_dointvec,
1da177e4 633 },
407984f1
DZ		 634 {
635 .ctl_name = KERN_NMI_WATCHDOG,
636 .procname = "nmi_watchdog",
637 .data = &nmi_watchdog_enabled,
638 .maxlen = sizeof (int),
639 .mode = 0644,
640 .proc_handler = &proc_nmi_enabled,
1da177e4
LT		 641 },
642#endif
643#if defined(CONFIG_X86)
8da5adda
DZ		 644 {
645 .ctl_name = KERN_PANIC_ON_NMI,
646 .procname = "panic_on_unrecovered_nmi",
647 .data = &panic_on_unrecovered_nmi,
648 .maxlen = sizeof(int),
649 .mode = 0644,
650 .proc_handler = &proc_dointvec,
651 },
1da177e4
LT		 652 {
653 .ctl_name = KERN_BOOTLOADER_TYPE,
654 .procname = "bootloader_type",
655 .data = &bootloader_type,
656 .maxlen = sizeof (int),
657 .mode = 0444,
658 .proc_handler = &proc_dointvec,
659 },
660#endif
7a9166e3 661#if defined(CONFIG_MMU)
1da177e4
LT		 662 {
663 .ctl_name = KERN_RANDOMIZE,
664 .procname = "randomize_va_space",
665 .data = &randomize_va_space,
666 .maxlen = sizeof(int),
667 .mode = 0644,
668 .proc_handler = &proc_dointvec,
669 },
7a9166e3 670#endif
0152fb37 671#if defined(CONFIG_S390) && defined(CONFIG_SMP)
951f22d5
MS		 672 {
673 .ctl_name = KERN_SPIN_RETRY,
674 .procname = "spin_retry",
675 .data = &spin_retry,
676 .maxlen = sizeof (int),
677 .mode = 0644,
678 .proc_handler = &proc_dointvec,
679 },
c255d844
PM		 680#endif
681#ifdef CONFIG_ACPI_SLEEP
682 {
683 .ctl_name = KERN_ACPI_VIDEO_FLAGS,
684 .procname = "acpi_video_flags",
685 .data = &acpi_video_flags,
686 .maxlen = sizeof (unsigned long),
687 .mode = 0644,
7f99f06f 688 .proc_handler = &proc_doulongvec_minmax,
c255d844 689 },
d2b176ed
JS		 690#endif
691#ifdef CONFIG_IA64
692 {
693 .ctl_name = KERN_IA64_UNALIGNED,
694 .procname = "ignore-unaligned-usertrap",
695 .data = &no_unaligned_warning,
696 .maxlen = sizeof (int),
697 .mode = 0644,
698 .proc_handler = &proc_dointvec,
699 },
bebfa101
AK		 700#endif
701#ifdef CONFIG_COMPAT
702 {
703 .ctl_name = KERN_COMPAT_LOG,
704 .procname = "compat-log",
705 .data = &compat_log,
706 .maxlen = sizeof (int),
707 .mode = 0644,
708 .proc_handler = &proc_dointvec,
709 },
951f22d5 710#endif
23f78d4a
IM		 711#ifdef CONFIG_RT_MUTEXES
712 {
713 .ctl_name = KERN_MAX_LOCK_DEPTH,
714 .procname = "max_lock_depth",
715 .data = &max_lock_depth,
716 .maxlen = sizeof(int),
717 .mode = 0644,
718 .proc_handler = &proc_dointvec,
719 },
720#endif
721
1da177e4
LT		 722 { .ctl_name = 0 }
723};
724
725/* Constants for minimum and maximum testing in vm_table.
726 We use these as one-element integer vectors. */
727static int zero;
728static int one_hundred = 100;
729
730
731static ctl_table vm_table[] = {
732 {
733 .ctl_name = VM_OVERCOMMIT_MEMORY,
734 .procname = "overcommit_memory",
735 .data = &sysctl_overcommit_memory,
736 .maxlen = sizeof(sysctl_overcommit_memory),
737 .mode = 0644,
738 .proc_handler = &proc_dointvec,
739 },
fadd8fbd
KH		 740 {
741 .ctl_name = VM_PANIC_ON_OOM,
742 .procname = "panic_on_oom",
743 .data = &sysctl_panic_on_oom,
744 .maxlen = sizeof(sysctl_panic_on_oom),
745 .mode = 0644,
746 .proc_handler = &proc_dointvec,
747 },
1da177e4
LT		 748 {
749 .ctl_name = VM_OVERCOMMIT_RATIO,
750 .procname = "overcommit_ratio",
751 .data = &sysctl_overcommit_ratio,
752 .maxlen = sizeof(sysctl_overcommit_ratio),
753 .mode = 0644,
754 .proc_handler = &proc_dointvec,
755 },
756 {
757 .ctl_name = VM_PAGE_CLUSTER,
758 .procname = "page-cluster",
759 .data = &page_cluster,
760 .maxlen = sizeof(int),
761 .mode = 0644,
762 .proc_handler = &proc_dointvec,
763 },
764 {
765 .ctl_name = VM_DIRTY_BACKGROUND,
766 .procname = "dirty_background_ratio",
767 .data = &dirty_background_ratio,
768 .maxlen = sizeof(dirty_background_ratio),
769 .mode = 0644,
770 .proc_handler = &proc_dointvec_minmax,
771 .strategy = &sysctl_intvec,
772 .extra1 = &zero,
773 .extra2 = &one_hundred,
774 },
775 {
776 .ctl_name = VM_DIRTY_RATIO,
777 .procname = "dirty_ratio",
778 .data = &vm_dirty_ratio,
779 .maxlen = sizeof(vm_dirty_ratio),
780 .mode = 0644,
781 .proc_handler = &proc_dointvec_minmax,
782 .strategy = &sysctl_intvec,
783 .extra1 = &zero,
784 .extra2 = &one_hundred,
785 },
786 {
787 .ctl_name = VM_DIRTY_WB_CS,
788 .procname = "dirty_writeback_centisecs",
f6ef9438
BS		 789 .data = &dirty_writeback_interval,
790 .maxlen = sizeof(dirty_writeback_interval),
1da177e4
LT		 791 .mode = 0644,
792 .proc_handler = &dirty_writeback_centisecs_handler,
793 },
794 {
795 .ctl_name = VM_DIRTY_EXPIRE_CS,
796 .procname = "dirty_expire_centisecs",
f6ef9438
BS		 797 .data = &dirty_expire_interval,
798 .maxlen = sizeof(dirty_expire_interval),
1da177e4 799 .mode = 0644,
f6ef9438 800 .proc_handler = &proc_dointvec_userhz_jiffies,
1da177e4
LT		 801 },
802 {
803 .ctl_name = VM_NR_PDFLUSH_THREADS,
804 .procname = "nr_pdflush_threads",
805 .data = &nr_pdflush_threads,
806 .maxlen = sizeof nr_pdflush_threads,
807 .mode = 0444 /* read-only*/,
808 .proc_handler = &proc_dointvec,
809 },
810 {
811 .ctl_name = VM_SWAPPINESS,
812 .procname = "swappiness",
813 .data = &vm_swappiness,
814 .maxlen = sizeof(vm_swappiness),
815 .mode = 0644,
816 .proc_handler = &proc_dointvec_minmax,
817 .strategy = &sysctl_intvec,
818 .extra1 = &zero,
819 .extra2 = &one_hundred,
820 },
821#ifdef CONFIG_HUGETLB_PAGE
822 {
823 .ctl_name = VM_HUGETLB_PAGES,
824 .procname = "nr_hugepages",
825 .data = &max_huge_pages,
826 .maxlen = sizeof(unsigned long),
827 .mode = 0644,
828 .proc_handler = &hugetlb_sysctl_handler,
829 .extra1 = (void *)&hugetlb_zero,
830 .extra2 = (void *)&hugetlb_infinity,
831 },
832 {
833 .ctl_name = VM_HUGETLB_GROUP,
834 .procname = "hugetlb_shm_group",
835 .data = &sysctl_hugetlb_shm_group,
836 .maxlen = sizeof(gid_t),
837 .mode = 0644,
838 .proc_handler = &proc_dointvec,
839 },
840#endif
841 {
842 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
843 .procname = "lowmem_reserve_ratio",
844 .data = &sysctl_lowmem_reserve_ratio,
845 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
846 .mode = 0644,
847 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
848 .strategy = &sysctl_intvec,
849 },
9d0243bc
AM		 850 {
851 .ctl_name = VM_DROP_PAGECACHE,
852 .procname = "drop_caches",
853 .data = &sysctl_drop_caches,
854 .maxlen = sizeof(int),
855 .mode = 0644,
856 .proc_handler = drop_caches_sysctl_handler,
857 .strategy = &sysctl_intvec,
858 },
1da177e4
LT		 859 {
860 .ctl_name = VM_MIN_FREE_KBYTES,
861 .procname = "min_free_kbytes",
862 .data = &min_free_kbytes,
863 .maxlen = sizeof(min_free_kbytes),
864 .mode = 0644,
865 .proc_handler = &min_free_kbytes_sysctl_handler,
866 .strategy = &sysctl_intvec,
867 .extra1 = &zero,
868 },
8ad4b1fb
RS		 869 {
870 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
871 .procname = "percpu_pagelist_fraction",
872 .data = &percpu_pagelist_fraction,
873 .maxlen = sizeof(percpu_pagelist_fraction),
874 .mode = 0644,
875 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
876 .strategy = &sysctl_intvec,
877 .extra1 = &min_percpu_pagelist_fract,
878 },
1da177e4
LT		 879#ifdef CONFIG_MMU
880 {
881 .ctl_name = VM_MAX_MAP_COUNT,
882 .procname = "max_map_count",
883 .data = &sysctl_max_map_count,
884 .maxlen = sizeof(sysctl_max_map_count),
885 .mode = 0644,
886 .proc_handler = &proc_dointvec
887 },
888#endif
889 {
890 .ctl_name = VM_LAPTOP_MODE,
891 .procname = "laptop_mode",
892 .data = &laptop_mode,
893 .maxlen = sizeof(laptop_mode),
894 .mode = 0644,
ed5b43f1
BS		 895 .proc_handler = &proc_dointvec_jiffies,
896 .strategy = &sysctl_jiffies,
1da177e4
LT		 897 },
898 {
899 .ctl_name = VM_BLOCK_DUMP,
900 .procname = "block_dump",
901 .data = &block_dump,
902 .maxlen = sizeof(block_dump),
903 .mode = 0644,
904 .proc_handler = &proc_dointvec,
905 .strategy = &sysctl_intvec,
906 .extra1 = &zero,
907 },
908 {
909 .ctl_name = VM_VFS_CACHE_PRESSURE,
910 .procname = "vfs_cache_pressure",
911 .data = &sysctl_vfs_cache_pressure,
912 .maxlen = sizeof(sysctl_vfs_cache_pressure),
913 .mode = 0644,
914 .proc_handler = &proc_dointvec,
915 .strategy = &sysctl_intvec,
916 .extra1 = &zero,
917 },
918#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
919 {
920 .ctl_name = VM_LEGACY_VA_LAYOUT,
921 .procname = "legacy_va_layout",
922 .data = &sysctl_legacy_va_layout,
923 .maxlen = sizeof(sysctl_legacy_va_layout),
924 .mode = 0644,
925 .proc_handler = &proc_dointvec,
926 .strategy = &sysctl_intvec,
927 .extra1 = &zero,
928 },
929#endif
930#ifdef CONFIG_SWAP
931 {
932 .ctl_name = VM_SWAP_TOKEN_TIMEOUT,
933 .procname = "swap_token_timeout",
934 .data = &swap_token_default_timeout,
935 .maxlen = sizeof(swap_token_default_timeout),
936 .mode = 0644,
937 .proc_handler = &proc_dointvec_jiffies,
938 .strategy = &sysctl_jiffies,
939 },
1743660b
CL		 940#endif
941#ifdef CONFIG_NUMA
942 {
943 .ctl_name = VM_ZONE_RECLAIM_MODE,
944 .procname = "zone_reclaim_mode",
945 .data = &zone_reclaim_mode,
946 .maxlen = sizeof(zone_reclaim_mode),
947 .mode = 0644,
948 .proc_handler = &proc_dointvec,
c84db23c
CL		 949 .strategy = &sysctl_intvec,
950 .extra1 = &zero,
1743660b 951 },
9614634f
CL		 952 {
953 .ctl_name = VM_MIN_UNMAPPED,
954 .procname = "min_unmapped_ratio",
955 .data = &sysctl_min_unmapped_ratio,
956 .maxlen = sizeof(sysctl_min_unmapped_ratio),
957 .mode = 0644,
958 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
959 .strategy = &sysctl_intvec,
960 .extra1 = &zero,
961 .extra2 = &one_hundred,
962 },
0ff38490
CL		 963 {
964 .ctl_name = VM_MIN_SLAB,
965 .procname = "min_slab_ratio",
966 .data = &sysctl_min_slab_ratio,
967 .maxlen = sizeof(sysctl_min_slab_ratio),
968 .mode = 0644,
969 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
970 .strategy = &sysctl_intvec,
971 .extra1 = &zero,
972 .extra2 = &one_hundred,
973 },
e6e5494c
IM		 974#endif
975#ifdef CONFIG_X86_32
976 {
977 .ctl_name = VM_VDSO_ENABLED,
978 .procname = "vdso_enabled",
979 .data = &vdso_enabled,
980 .maxlen = sizeof(vdso_enabled),
981 .mode = 0644,
982 .proc_handler = &proc_dointvec,
983 .strategy = &sysctl_intvec,
984 .extra1 = &zero,
985 },
1da177e4
LT		 986#endif
987 { .ctl_name = 0 }
988};
989
1da177e4
LT		 990static ctl_table fs_table[] = {
991 {
992 .ctl_name = FS_NRINODE,
993 .procname = "inode-nr",
994 .data = &inodes_stat,
995 .maxlen = 2*sizeof(int),
996 .mode = 0444,
997 .proc_handler = &proc_dointvec,
998 },
999 {
1000 .ctl_name = FS_STATINODE,
1001 .procname = "inode-state",
1002 .data = &inodes_stat,
1003 .maxlen = 7*sizeof(int),
1004 .mode = 0444,
1005 .proc_handler = &proc_dointvec,
1006 },
1007 {
1008 .ctl_name = FS_NRFILE,
1009 .procname = "file-nr",
1010 .data = &files_stat,
1011 .maxlen = 3*sizeof(int),
1012 .mode = 0444,
529bf6be 1013 .proc_handler = &proc_nr_files,
1da177e4
LT		 1014 },
1015 {
1016 .ctl_name = FS_MAXFILE,
1017 .procname = "file-max",
1018 .data = &files_stat.max_files,
1019 .maxlen = sizeof(int),
1020 .mode = 0644,
1021 .proc_handler = &proc_dointvec,
1022 },
1023 {
1024 .ctl_name = FS_DENTRY,
1025 .procname = "dentry-state",
1026 .data = &dentry_stat,
1027 .maxlen = 6*sizeof(int),
1028 .mode = 0444,
1029 .proc_handler = &proc_dointvec,
1030 },
1031 {
1032 .ctl_name = FS_OVERFLOWUID,
1033 .procname = "overflowuid",
1034 .data = &fs_overflowuid,
1035 .maxlen = sizeof(int),
1036 .mode = 0644,
1037 .proc_handler = &proc_dointvec_minmax,
1038 .strategy = &sysctl_intvec,
1039 .extra1 = &minolduid,
1040 .extra2 = &maxolduid,
1041 },
1042 {
1043 .ctl_name = FS_OVERFLOWGID,
1044 .procname = "overflowgid",
1045 .data = &fs_overflowgid,
1046 .maxlen = sizeof(int),
1047 .mode = 0644,
1048 .proc_handler = &proc_dointvec_minmax,
1049 .strategy = &sysctl_intvec,
1050 .extra1 = &minolduid,
1051 .extra2 = &maxolduid,
1052 },
1053 {
1054 .ctl_name = FS_LEASES,
1055 .procname = "leases-enable",
1056 .data = &leases_enable,
1057 .maxlen = sizeof(int),
1058 .mode = 0644,
1059 .proc_handler = &proc_dointvec,
1060 },
1061#ifdef CONFIG_DNOTIFY
1062 {
1063 .ctl_name = FS_DIR_NOTIFY,
1064 .procname = "dir-notify-enable",
1065 .data = &dir_notify_enable,
1066 .maxlen = sizeof(int),
1067 .mode = 0644,
1068 .proc_handler = &proc_dointvec,
1069 },
1070#endif
1071#ifdef CONFIG_MMU
1072 {
1073 .ctl_name = FS_LEASE_TIME,
1074 .procname = "lease-break-time",
1075 .data = &lease_break_time,
1076 .maxlen = sizeof(int),
1077 .mode = 0644,
1078 .proc_handler = &proc_dointvec,
1079 },
1080 {
1081 .ctl_name = FS_AIO_NR,
1082 .procname = "aio-nr",
1083 .data = &aio_nr,
1084 .maxlen = sizeof(aio_nr),
1085 .mode = 0444,
d55b5fda 1086 .proc_handler = &proc_doulongvec_minmax,
1da177e4
LT		 1087 },
1088 {
1089 .ctl_name = FS_AIO_MAX_NR,
1090 .procname = "aio-max-nr",
1091 .data = &aio_max_nr,
1092 .maxlen = sizeof(aio_max_nr),
1093 .mode = 0644,
d55b5fda 1094 .proc_handler = &proc_doulongvec_minmax,
1da177e4 1095 },
2d9048e2 1096#ifdef CONFIG_INOTIFY_USER
0399cb08
RL		 1097 {
1098 .ctl_name = FS_INOTIFY,
1099 .procname = "inotify",
1100 .mode = 0555,
1101 .child = inotify_table,
1102 },
1103#endif
1da177e4 1104#endif
d6e71144
AC		 1105 {
1106 .ctl_name = KERN_SETUID_DUMPABLE,
1107 .procname = "suid_dumpable",
1108 .data = &suid_dumpable,
1109 .maxlen = sizeof(int),
1110 .mode = 0644,
1111 .proc_handler = &proc_dointvec,
1112 },
1da177e4
LT		 1113 { .ctl_name = 0 }
1114};
1115
1116static ctl_table debug_table[] = {
1117 { .ctl_name = 0 }
1118};
1119
1120static ctl_table dev_table[] = {
1121 { .ctl_name = 0 }
0eeca283 1122};
1da177e4
LT		 1123
1124extern void init_irq_proc (void);
1125
330d57fb
AV		 1126static DEFINE_SPINLOCK(sysctl_lock);
1127
1128/* called under sysctl_lock */
1129static int use_table(struct ctl_table_header *p)
1130{
1131 if (unlikely(p->unregistering))
1132 return 0;
1133 p->used++;
1134 return 1;
1135}
1136
1137/* called under sysctl_lock */
1138static void unuse_table(struct ctl_table_header *p)
1139{
1140 if (!--p->used)
1141 if (unlikely(p->unregistering))
1142 complete(p->unregistering);
1143}
1144
1145/* called under sysctl_lock, will reacquire if has to wait */
1146static void start_unregistering(struct ctl_table_header *p)
1147{
1148 /*
1149 * if p->used is 0, nobody will ever touch that entry again;
1150 * we'll eliminate all paths to it before dropping sysctl_lock
1151 */
1152 if (unlikely(p->used)) {
1153 struct completion wait;
1154 init_completion(&wait);
1155 p->unregistering = &wait;
1156 spin_unlock(&sysctl_lock);
1157 wait_for_completion(&wait);
1158 spin_lock(&sysctl_lock);
1159 }
1160 /*
1161 * do not remove from the list until nobody holds it; walking the
1162 * list in do_sysctl() relies on that.
1163 */
1164 list_del_init(&p->ctl_entry);
1165}
1166
1da177e4
LT		 1167void __init sysctl_init(void)
1168{
b89a8171 1169#ifdef CONFIG_PROC_SYSCTL
330d57fb 1170 register_proc_table(root_table, proc_sys_root, &root_table_header);
1da177e4
LT		 1171 init_irq_proc();
1172#endif
1173}
1174
b89a8171 1175#ifdef CONFIG_SYSCTL_SYSCALL
1da177e4
LT		 1176int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1177 void __user *newval, size_t newlen)
1178{
1179 struct list_head *tmp;
330d57fb 1180 int error = -ENOTDIR;
1da177e4
LT		 1181
1182 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1183 return -ENOTDIR;
1184 if (oldval) {
1185 int old_len;
1186 if (!oldlenp || get_user(old_len, oldlenp))
1187 return -EFAULT;
1188 }
330d57fb 1189 spin_lock(&sysctl_lock);
1da177e4
LT		 1190 tmp = &root_table_header.ctl_entry;
1191 do {
1192 struct ctl_table_header *head =
1193 list_entry(tmp, struct ctl_table_header, ctl_entry);
1194 void *context = NULL;
330d57fb
AV		 1195
1196 if (!use_table(head))
1197 continue;
1198
1199 spin_unlock(&sysctl_lock);
1200
1201 error = parse_table(name, nlen, oldval, oldlenp,
1da177e4
LT		 1202 newval, newlen, head->ctl_table,
1203 &context);
5a6b454f 1204 kfree(context);
330d57fb
AV		 1205
1206 spin_lock(&sysctl_lock);
1207 unuse_table(head);
1da177e4 1208 if (error != -ENOTDIR)
330d57fb
AV		 1209 break;
1210 } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
1211 spin_unlock(&sysctl_lock);
1212 return error;
1da177e4
LT		 1213}
1214
1215asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1216{
1217 struct __sysctl_args tmp;
1218 int error;
1219
1220 if (copy_from_user(&tmp, args, sizeof(tmp)))
1221 return -EFAULT;
1222
1223 lock_kernel();
1224 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1225 tmp.newval, tmp.newlen);
1226 unlock_kernel();
1227 return error;
1228}
b89a8171 1229#endif /* CONFIG_SYSCTL_SYSCALL */
1da177e4
LT		 1230
1231/*
1232 * ctl_perm does NOT grant the superuser all rights automatically, because
1233 * some sysctl variables are readonly even to root.
1234 */
1235
1236static int test_perm(int mode, int op)
1237{
1238 if (!current->euid)
1239 mode >>= 6;
1240 else if (in_egroup_p(0))
1241 mode >>= 3;
1242 if ((mode & op & 0007) == op)
1243 return 0;
1244 return -EACCES;
1245}
1246
1247static inline int ctl_perm(ctl_table *table, int op)
1248{
1249 int error;
1250 error = security_sysctl(table, op);
1251 if (error)
1252 return error;
1253 return test_perm(table->mode, op);
1254}
1255
b89a8171 1256#ifdef CONFIG_SYSCTL_SYSCALL
1da177e4
LT		 1257static int parse_table(int __user *name, int nlen,
1258 void __user *oldval, size_t __user *oldlenp,
1259 void __user *newval, size_t newlen,
1260 ctl_table *table, void **context)
1261{
1262 int n;
1263repeat:
1264 if (!nlen)
1265 return -ENOTDIR;
1266 if (get_user(n, name))
1267 return -EFAULT;
1268 for ( ; table->ctl_name; table++) {
1269 if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
1270 int error;
1271 if (table->child) {
1272 if (ctl_perm(table, 001))
1273 return -EPERM;
1274 if (table->strategy) {
1275 error = table->strategy(
1276 table, name, nlen,
1277 oldval, oldlenp,
1278 newval, newlen, context);
1279 if (error)
1280 return error;
1281 }
1282 name++;
1283 nlen--;
1284 table = table->child;
1285 goto repeat;
1286 }
1287 error = do_sysctl_strategy(table, name, nlen,
1288 oldval, oldlenp,
1289 newval, newlen, context);
1290 return error;
1291 }
1292 }
1293 return -ENOTDIR;
1294}
1295
1296/* Perform the actual read/write of a sysctl table entry. */
1297int do_sysctl_strategy (ctl_table *table,
1298 int __user *name, int nlen,
1299 void __user *oldval, size_t __user *oldlenp,
1300 void __user *newval, size_t newlen, void **context)
1301{
1302 int op = 0, rc;
1303 size_t len;
1304
1305 if (oldval)
1306 op |= 004;
1307 if (newval)
1308 op |= 002;
1309 if (ctl_perm(table, op))
1310 return -EPERM;
1311
1312 if (table->strategy) {
1313 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1314 newval, newlen, context);
1315 if (rc < 0)
1316 return rc;
1317 if (rc > 0)
1318 return 0;
1319 }
1320
1321 /* If there is no strategy routine, or if the strategy returns
1322 * zero, proceed with automatic r/w */
1323 if (table->data && table->maxlen) {
1324 if (oldval && oldlenp) {
1325 if (get_user(len, oldlenp))
1326 return -EFAULT;
1327 if (len) {
1328 if (len > table->maxlen)
1329 len = table->maxlen;
1330 if(copy_to_user(oldval, table->data, len))
1331 return -EFAULT;
1332 if(put_user(len, oldlenp))
1333 return -EFAULT;
1334 }
1335 }
1336 if (newval && newlen) {
1337 len = newlen;
1338 if (len > table->maxlen)
1339 len = table->maxlen;
1340 if(copy_from_user(table->data, newval, len))
1341 return -EFAULT;
1342 }
1343 }
1344 return 0;
1345}
b89a8171 1346#endif /* CONFIG_SYSCTL_SYSCALL */
1da177e4
LT		 1347
1348/**
1349 * register_sysctl_table - register a sysctl hierarchy
1350 * @table: the top-level table structure
1351 * @insert_at_head: whether the entry should be inserted in front or at the end
1352 *
1353 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1354 * array. An entry with a ctl_name of 0 terminates the table.
1355 *
1356 * The members of the &ctl_table structure are used as follows:
1357 *
1358 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1359 * must be unique within that level of sysctl
1360 *
1361 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1362 * enter a sysctl file
1363 *
1364 * data - a pointer to data for use by proc_handler
1365 *
1366 * maxlen - the maximum size in bytes of the data
1367 *
1368 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1369 *
1370 * child - a pointer to the child sysctl table if this entry is a directory, or
1371 * %NULL.
1372 *
1373 * proc_handler - the text handler routine (described below)
1374 *
1375 * strategy - the strategy routine (described below)
1376 *
1377 * de - for internal use by the sysctl routines
1378 *
1379 * extra1, extra2 - extra pointers usable by the proc handler routines
1380 *
1381 * Leaf nodes in the sysctl tree will be represented by a single file
1382 * under /proc; non-leaf nodes will be represented by directories.
1383 *
1384 * sysctl(2) can automatically manage read and write requests through
1385 * the sysctl table. The data and maxlen fields of the ctl_table
1386 * struct enable minimal validation of the values being written to be
1387 * performed, and the mode field allows minimal authentication.
1388 *
1389 * More sophisticated management can be enabled by the provision of a
1390 * strategy routine with the table entry. This will be called before
1391 * any automatic read or write of the data is performed.
1392 *
1393 * The strategy routine may return
1394 *
1395 * < 0 - Error occurred (error is passed to user process)
1396 *
1397 * 0 - OK - proceed with automatic read or write.
1398 *
1399 * > 0 - OK - read or write has been done by the strategy routine, so
1400 * return immediately.
1401 *
1402 * There must be a proc_handler routine for any terminal nodes
1403 * mirrored under /proc/sys (non-terminals are handled by a built-in
1404 * directory handler). Several default handlers are available to
1405 * cover common cases -
1406 *
1407 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1408 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1409 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1410 *
1411 * It is the handler's job to read the input buffer from user memory
1412 * and process it. The handler should return 0 on success.
1413 *
1414 * This routine returns %NULL on a failure to register, and a pointer
1415 * to the table header on success.
1416 */
1417struct ctl_table_header *register_sysctl_table(ctl_table * table,
1418 int insert_at_head)
1419{
1420 struct ctl_table_header *tmp;
1421 tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1422 if (!tmp)
1423 return NULL;
1424 tmp->ctl_table = table;
1425 INIT_LIST_HEAD(&tmp->ctl_entry);
330d57fb
AV		 1426 tmp->used = 0;
1427 tmp->unregistering = NULL;
1428 spin_lock(&sysctl_lock);
1da177e4
LT		 1429 if (insert_at_head)
1430 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
1431 else
1432 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
330d57fb 1433 spin_unlock(&sysctl_lock);
b89a8171 1434#ifdef CONFIG_PROC_SYSCTL
330d57fb 1435 register_proc_table(table, proc_sys_root, tmp);
1da177e4
LT		 1436#endif
1437 return tmp;
1438}
1439
1440/**
1441 * unregister_sysctl_table - unregister a sysctl table hierarchy
1442 * @header: the header returned from register_sysctl_table
1443 *
1444 * Unregisters the sysctl table and all children. proc entries may not
1445 * actually be removed until they are no longer used by anyone.
1446 */
1447void unregister_sysctl_table(struct ctl_table_header * header)
1448{
330d57fb
AV		 1449 might_sleep();
1450 spin_lock(&sysctl_lock);
1451 start_unregistering(header);
b89a8171 1452#ifdef CONFIG_PROC_SYSCTL
1da177e4
LT		 1453 unregister_proc_table(header->ctl_table, proc_sys_root);
1454#endif
330d57fb 1455 spin_unlock(&sysctl_lock);
1da177e4
LT		 1456 kfree(header);
1457}
1458
b89a8171
EB		 1459#else /* !CONFIG_SYSCTL */
1460struct ctl_table_header * register_sysctl_table(ctl_table * table,
1461 int insert_at_head)
1462{
1463 return NULL;
1464}
1465
1466void unregister_sysctl_table(struct ctl_table_header * table)
1467{
1468}
1469
1470#endif /* CONFIG_SYSCTL */
1471
1da177e4
LT		 1472/*
1473 * /proc/sys support
1474 */
1475
b89a8171 1476#ifdef CONFIG_PROC_SYSCTL
1da177e4
LT		 1477
1478/* Scan the sysctl entries in table and add them all into /proc */
330d57fb 1479static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
1da177e4
LT		 1480{
1481 struct proc_dir_entry *de;
1482 int len;
1483 mode_t mode;
1484
1485 for (; table->ctl_name; table++) {
1486 /* Can't do anything without a proc name. */
1487 if (!table->procname)
1488 continue;
1489 /* Maybe we can't do anything with it... */
1490 if (!table->proc_handler && !table->child) {
1491 printk(KERN_WARNING "SYSCTL: Can't register %s\n",
1492 table->procname);
1493 continue;
1494 }
1495
1496 len = strlen(table->procname);
1497 mode = table->mode;
1498
1499 de = NULL;
1500 if (table->proc_handler)
1501 mode |= S_IFREG;
1502 else {
1503 mode |= S_IFDIR;
1504 for (de = root->subdir; de; de = de->next) {
1505 if (proc_match(len, table->procname, de))
1506 break;
1507 }
1508 /* If the subdir exists already, de is non-NULL */
1509 }
1510
1511 if (!de) {
1512 de = create_proc_entry(table->procname, mode, root);
1513 if (!de)
1514 continue;
330d57fb 1515 de->set = set;
1da177e4
LT		 1516 de->data = (void *) table;
1517 if (table->proc_handler)
1518 de->proc_fops = &proc_sys_file_operations;
1519 }
1520 table->de = de;
1521 if (de->mode & S_IFDIR)
330d57fb 1522 register_proc_table(table->child, de, set);
1da177e4
LT		 1523 }
1524}
1525
1526/*
1527 * Unregister a /proc sysctl table and any subdirectories.
1528 */
1529static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
1530{
1531 struct proc_dir_entry *de;
1532 for (; table->ctl_name; table++) {
1533 if (!(de = table->de))
1534 continue;
1535 if (de->mode & S_IFDIR) {
1536 if (!table->child) {
1537 printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
1538 continue;
1539 }
1540 unregister_proc_table(table->child, de);
1541
1542 /* Don't unregister directories which still have entries.. */
1543 if (de->subdir)
1544 continue;
1545 }
1546
330d57fb
AV		 1547 /*
1548 * In any case, mark the entry as goner; we'll keep it
1549 * around if it's busy, but we'll know to do nothing with
1550 * its fields. We are under sysctl_lock here.
1551 */
1552 de->data = NULL;
1553
1da177e4
LT		 1554 /* Don't unregister proc entries that are still being used.. */
1555 if (atomic_read(&de->count))
1556 continue;
1557
1558 table->de = NULL;
1559 remove_proc_entry(table->procname, root);
1560 }
1561}
1562
1563static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
1564 size_t count, loff_t *ppos)
1565{
1566 int op;
330d57fb 1567 struct proc_dir_entry *de = PDE(file->f_dentry->d_inode);
1da177e4
LT		 1568 struct ctl_table *table;
1569 size_t res;
330d57fb 1570 ssize_t error = -ENOTDIR;
1da177e4 1571
330d57fb
AV		 1572 spin_lock(&sysctl_lock);
1573 if (de && de->data && use_table(de->set)) {
1574 /*
1575 * at that point we know that sysctl was not unregistered
1576 * and won't be until we finish
1577 */
1578 spin_unlock(&sysctl_lock);
1579 table = (struct ctl_table *) de->data;
1580 if (!table || !table->proc_handler)
1581 goto out;
1582 error = -EPERM;
1583 op = (write ? 002 : 004);
1584 if (ctl_perm(table, op))
1585 goto out;
1586
1587 /* careful: calling conventions are nasty here */
1588 res = count;
1589 error = (*table->proc_handler)(table, write, file,
1590 buf, &res, ppos);
1591 if (!error)
1592 error = res;
1593 out:
1594 spin_lock(&sysctl_lock);
1595 unuse_table(de->set);
1596 }
1597 spin_unlock(&sysctl_lock);
1598 return error;
1da177e4
LT		 1599}
1600
1601static int proc_opensys(struct inode *inode, struct file *file)
1602{
1603 if (file->f_mode & FMODE_WRITE) {
1604 /*
1605 * sysctl entries that are not writable,
1606 * are _NOT_ writable, capabilities or not.
1607 */
1608 if (!(inode->i_mode & S_IWUSR))
1609 return -EPERM;
1610 }
1611
1612 return 0;
1613}
1614
1615static ssize_t proc_readsys(struct file * file, char __user * buf,
1616 size_t count, loff_t *ppos)
1617{
1618 return do_rw_proc(0, file, buf, count, ppos);
1619}
1620
1621static ssize_t proc_writesys(struct file * file, const char __user * buf,
1622 size_t count, loff_t *ppos)
1623{
1624 return do_rw_proc(1, file, (char __user *) buf, count, ppos);
1625}
1626
1627/**
1628 * proc_dostring - read a string sysctl
1629 * @table: the sysctl table
1630 * @write: %TRUE if this is a write to the sysctl file
1631 * @filp: the file structure
1632 * @buffer: the user buffer
1633 * @lenp: the size of the user buffer
1634 * @ppos: file position
1635 *
1636 * Reads/writes a string from/to the user buffer. If the kernel
1637 * buffer provided is not large enough to hold the string, the
1638 * string is truncated. The copied string is %NULL-terminated.
1639 * If the string is being read by the user process, it is copied
1640 * and a newline '\n' is added. It is truncated if the buffer is
1641 * not large enough.
1642 *
1643 * Returns 0 on success.
1644 */
1645int proc_dostring(ctl_table *table, int write, struct file *filp,
1646 void __user *buffer, size_t *lenp, loff_t *ppos)
1647{
1648 size_t len;
1649 char __user *p;
1650 char c;
1651
1652 if (!table->data || !table->maxlen || !*lenp ||
1653 (*ppos && !write)) {
1654 *lenp = 0;
1655 return 0;
1656 }
1657
1658 if (write) {
1659 len = 0;
1660 p = buffer;
1661 while (len < *lenp) {
1662 if (get_user(c, p++))
1663 return -EFAULT;
1664 if (c == 0 || c == '\n')
1665 break;
1666 len++;
1667 }
1668 if (len >= table->maxlen)
1669 len = table->maxlen-1;
1670 if(copy_from_user(table->data, buffer, len))
1671 return -EFAULT;
1672 ((char *) table->data)[len] = 0;
1673 *ppos += *lenp;
1674 } else {
1675 len = strlen(table->data);
1676 if (len > table->maxlen)
1677 len = table->maxlen;
1678 if (len > *lenp)
1679 len = *lenp;
1680 if (len)
1681 if(copy_to_user(buffer, table->data, len))
1682 return -EFAULT;
1683 if (len < *lenp) {
1684 if(put_user('\n', ((char __user *) buffer) + len))
1685 return -EFAULT;
1686 len++;
1687 }
1688 *lenp = len;
1689 *ppos += len;
1690 }
1691 return 0;
1692}
1693
1694/*
1695 * Special case of dostring for the UTS structure. This has locks
1696 * to observe. Should this be in kernel/sys.c ????
1697 */
1698
1699static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
1700 void __user *buffer, size_t *lenp, loff_t *ppos)
1701{
1702 int r;
1703
1704 if (!write) {
1705 down_read(&uts_sem);
1706 r=proc_dostring(table,0,filp,buffer,lenp, ppos);
1707 up_read(&uts_sem);
1708 } else {
1709 down_write(&uts_sem);
1710 r=proc_dostring(table,1,filp,buffer,lenp, ppos);
1711 up_write(&uts_sem);
1712 }
1713 return r;
1714}
1715
1716static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1717 int *valp,
1718 int write, void *data)
1719{
1720 if (write) {
1721 *valp = *negp ? -*lvalp : *lvalp;
1722 } else {
1723 int val = *valp;
1724 if (val < 0) {
1725 *negp = -1;
1726 *lvalp = (unsigned long)-val;
1727 } else {
1728 *negp = 0;
1729 *lvalp = (unsigned long)val;
1730 }
1731 }
1732 return 0;
1733}
1734
1735static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1736 void __user *buffer, size_t *lenp, loff_t *ppos,
1737 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1738 int write, void *data),
1739 void *data)
1740{
1741#define TMPBUFLEN 21
1742 int *i, vleft, first=1, neg, val;
1743 unsigned long lval;
1744 size_t left, len;
1745
1746 char buf[TMPBUFLEN], *p;
1747 char __user *s = buffer;
1748
1749 if (!table->data || !table->maxlen || !*lenp ||
1750 (*ppos && !write)) {
1751 *lenp = 0;
1752 return 0;
1753 }
1754
1755 i = (int *) table->data;
1756 vleft = table->maxlen / sizeof(*i);
1757 left = *lenp;
1758
1759 if (!conv)
1760 conv = do_proc_dointvec_conv;
1761
1762 for (; left && vleft--; i++, first=0) {
1763 if (write) {
1764 while (left) {
1765 char c;
1766 if (get_user(c, s))
1767 return -EFAULT;
1768 if (!isspace(c))
1769 break;
1770 left--;
1771 s++;
1772 }
1773 if (!left)
1774 break;
1775 neg = 0;
1776 len = left;
1777 if (len > sizeof(buf) - 1)
1778 len = sizeof(buf) - 1;
1779 if (copy_from_user(buf, s, len))
1780 return -EFAULT;
1781 buf[len] = 0;
1782 p = buf;
1783 if (*p == '-' && left > 1) {
1784 neg = 1;
1785 left--, p++;
1786 }
1787 if (*p < '0' || *p > '9')
1788 break;
1789
1790 lval = simple_strtoul(p, &p, 0);
1791
1792 len = p-buf;
1793 if ((len < left) && *p && !isspace(*p))
1794 break;
1795 if (neg)
1796 val = -val;
1797 s += len;
1798 left -= len;
1799
1800 if (conv(&neg, &lval, i, 1, data))
1801 break;
1802 } else {
1803 p = buf;
1804 if (!first)
1805 *p++ = '\t';
1806
1807 if (conv(&neg, &lval, i, 0, data))
1808 break;
1809
1810 sprintf(p, "%s%lu", neg ? "-" : "", lval);
1811 len = strlen(buf);
1812 if (len > left)
1813 len = left;
1814 if(copy_to_user(s, buf, len))
1815 return -EFAULT;
1816 left -= len;
1817 s += len;
1818 }
1819 }
1820
1821 if (!write && !first && left) {
1822 if(put_user('\n', s))
1823 return -EFAULT;
1824 left--, s++;
1825 }
1826 if (write) {
1827 while (left) {
1828 char c;
1829 if (get_user(c, s++))
1830 return -EFAULT;
1831 if (!isspace(c))
1832 break;
1833 left--;
1834 }
1835 }
1836 if (write && first)
1837 return -EINVAL;
1838 *lenp -= left;
1839 *ppos += *lenp;
1840 return 0;
1841#undef TMPBUFLEN
1842}
1843
1844/**
1845 * proc_dointvec - read a vector of integers
1846 * @table: the sysctl table
1847 * @write: %TRUE if this is a write to the sysctl file
1848 * @filp: the file structure
1849 * @buffer: the user buffer
1850 * @lenp: the size of the user buffer
1851 * @ppos: file position
1852 *
1853 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1854 * values from/to the user buffer, treated as an ASCII string.
1855 *
1856 * Returns 0 on success.
1857 */
1858int proc_dointvec(ctl_table *table, int write, struct file *filp,
1859 void __user *buffer, size_t *lenp, loff_t *ppos)
1860{
1861 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1862 NULL,NULL);
1863}
1864
1865#define OP_SET 0
1866#define OP_AND 1
1867#define OP_OR 2
1868#define OP_MAX 3
1869#define OP_MIN 4
1870
1871static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1872 int *valp,
1873 int write, void *data)
1874{
1875 int op = *(int *)data;
1876 if (write) {
1877 int val = *negp ? -*lvalp : *lvalp;
1878 switch(op) {
1879 case OP_SET: *valp = val; break;
1880 case OP_AND: *valp &= val; break;
1881 case OP_OR: *valp |= val; break;
1882 case OP_MAX: if(*valp < val)
1883 *valp = val;
1884 break;
1885 case OP_MIN: if(*valp > val)
1886 *valp = val;
1887 break;
1888 }
1889 } else {
1890 int val = *valp;
1891 if (val < 0) {
1892 *negp = -1;
1893 *lvalp = (unsigned long)-val;
1894 } else {
1895 *negp = 0;
1896 *lvalp = (unsigned long)val;
1897 }
1898 }
1899 return 0;
1900}
1901
1902/*
1903 * init may raise the set.
1904 */
1905
1906int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1907 void __user *buffer, size_t *lenp, loff_t *ppos)
1908{
1909 int op;
1910
1911 if (!capable(CAP_SYS_MODULE)) {
1912 return -EPERM;
1913 }
1914
f400e198 1915 op = is_init(current) ? OP_SET : OP_AND;
1da177e4
LT		 1916 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1917 do_proc_dointvec_bset_conv,&op);
1918}
1919
1920struct do_proc_dointvec_minmax_conv_param {
1921 int *min;
1922 int *max;
1923};
1924
1925static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
1926 int *valp,
1927 int write, void *data)
1928{
1929 struct do_proc_dointvec_minmax_conv_param *param = data;
1930 if (write) {
1931 int val = *negp ? -*lvalp : *lvalp;
1932 if ((param->min && *param->min > val) ||
1933 (param->max && *param->max < val))
1934 return -EINVAL;
1935 *valp = val;
1936 } else {
1937 int val = *valp;
1938 if (val < 0) {
1939 *negp = -1;
1940 *lvalp = (unsigned long)-val;
1941 } else {
1942 *negp = 0;
1943 *lvalp = (unsigned long)val;
1944 }
1945 }
1946 return 0;
1947}
1948
1949/**
1950 * proc_dointvec_minmax - read a vector of integers with min/max values
1951 * @table: the sysctl table
1952 * @write: %TRUE if this is a write to the sysctl file
1953 * @filp: the file structure
1954 * @buffer: the user buffer
1955 * @lenp: the size of the user buffer
1956 * @ppos: file position
1957 *
1958 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1959 * values from/to the user buffer, treated as an ASCII string.
1960 *
1961 * This routine will ensure the values are within the range specified by
1962 * table->extra1 (min) and table->extra2 (max).
1963 *
1964 * Returns 0 on success.
1965 */
1966int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
1967 void __user *buffer, size_t *lenp, loff_t *ppos)
1968{
1969 struct do_proc_dointvec_minmax_conv_param param = {
1970 .min = (int *) table->extra1,
1971 .max = (int *) table->extra2,
1972 };
1973 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1974 do_proc_dointvec_minmax_conv, &param);
1975}
1976
1977static int do_proc_doulongvec_minmax(ctl_table *table, int write,
1978 struct file *filp,
1979 void __user *buffer,
1980 size_t *lenp, loff_t *ppos,
1981 unsigned long convmul,
1982 unsigned long convdiv)
1983{
1984#define TMPBUFLEN 21
1985 unsigned long *i, *min, *max, val;
1986 int vleft, first=1, neg;
1987 size_t len, left;
1988 char buf[TMPBUFLEN], *p;
1989 char __user *s = buffer;
1990
1991 if (!table->data || !table->maxlen || !*lenp ||
1992 (*ppos && !write)) {
1993 *lenp = 0;
1994 return 0;
1995 }
1996
1997 i = (unsigned long *) table->data;
1998 min = (unsigned long *) table->extra1;
1999 max = (unsigned long *) table->extra2;
2000 vleft = table->maxlen / sizeof(unsigned long);
2001 left = *lenp;
2002
2003 for (; left && vleft--; i++, min++, max++, first=0) {
2004 if (write) {
2005 while (left) {
2006 char c;
2007 if (get_user(c, s))
2008 return -EFAULT;
2009 if (!isspace(c))
2010 break;
2011 left--;
2012 s++;
2013 }
2014 if (!left)
2015 break;
2016 neg = 0;
2017 len = left;
2018 if (len > TMPBUFLEN-1)
2019 len = TMPBUFLEN-1;
2020 if (copy_from_user(buf, s, len))
2021 return -EFAULT;
2022 buf[len] = 0;
2023 p = buf;
2024 if (*p == '-' && left > 1) {
2025 neg = 1;
2026 left--, p++;
2027 }
2028 if (*p < '0' || *p > '9')
2029 break;
2030 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2031 len = p-buf;
2032 if ((len < left) && *p && !isspace(*p))
2033 break;
2034 if (neg)
2035 val = -val;
2036 s += len;
2037 left -= len;
2038
2039 if(neg)
2040 continue;
2041 if ((min && val < *min) || (max && val > *max))
2042 continue;
2043 *i = val;
2044 } else {
2045 p = buf;
2046 if (!first)
2047 *p++ = '\t';
2048 sprintf(p, "%lu", convdiv * (*i) / convmul);
2049 len = strlen(buf);
2050 if (len > left)
2051 len = left;
2052 if(copy_to_user(s, buf, len))
2053 return -EFAULT;
2054 left -= len;
2055 s += len;
2056 }
2057 }
2058
2059 if (!write && !first && left) {
2060 if(put_user('\n', s))
2061 return -EFAULT;
2062 left--, s++;
2063 }
2064 if (write) {
2065 while (left) {
2066 char c;
2067 if (get_user(c, s++))
2068 return -EFAULT;
2069 if (!isspace(c))
2070 break;
2071 left--;
2072 }
2073 }
2074 if (write && first)
2075 return -EINVAL;
2076 *lenp -= left;
2077 *ppos += *lenp;
2078 return 0;
2079#undef TMPBUFLEN
2080}
2081
2082/**
2083 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2084 * @table: the sysctl table
2085 * @write: %TRUE if this is a write to the sysctl file
2086 * @filp: the file structure
2087 * @buffer: the user buffer
2088 * @lenp: the size of the user buffer
2089 * @ppos: file position
2090 *
2091 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2092 * values from/to the user buffer, treated as an ASCII string.
2093 *
2094 * This routine will ensure the values are within the range specified by
2095 * table->extra1 (min) and table->extra2 (max).
2096 *
2097 * Returns 0 on success.
2098 */
2099int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2100 void __user *buffer, size_t *lenp, loff_t *ppos)
2101{
2102 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2103}
2104
2105/**
2106 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2107 * @table: the sysctl table
2108 * @write: %TRUE if this is a write to the sysctl file
2109 * @filp: the file structure
2110 * @buffer: the user buffer
2111 * @lenp: the size of the user buffer
2112 * @ppos: file position
2113 *
2114 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2115 * values from/to the user buffer, treated as an ASCII string. The values
2116 * are treated as milliseconds, and converted to jiffies when they are stored.
2117 *
2118 * This routine will ensure the values are within the range specified by
2119 * table->extra1 (min) and table->extra2 (max).
2120 *
2121 * Returns 0 on success.
2122 */
2123int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2124 struct file *filp,
2125 void __user *buffer,
2126 size_t *lenp, loff_t *ppos)
2127{
2128 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2129 lenp, ppos, HZ, 1000l);
2130}
2131
2132
2133static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2134 int *valp,
2135 int write, void *data)
2136{
2137 if (write) {
cba9f33d
BS		 2138 if (*lvalp > LONG_MAX / HZ)
2139 return 1;
1da177e4
LT		 2140 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2141 } else {
2142 int val = *valp;
2143 unsigned long lval;
2144 if (val < 0) {
2145 *negp = -1;
2146 lval = (unsigned long)-val;
2147 } else {
2148 *negp = 0;
2149 lval = (unsigned long)val;
2150 }
2151 *lvalp = lval / HZ;
2152 }
2153 return 0;
2154}
2155
2156static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2157 int *valp,
2158 int write, void *data)
2159{
2160 if (write) {
cba9f33d
BS		 2161 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2162 return 1;
1da177e4
LT		 2163 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2164 } else {
2165 int val = *valp;
2166 unsigned long lval;
2167 if (val < 0) {
2168 *negp = -1;
2169 lval = (unsigned long)-val;
2170 } else {
2171 *negp = 0;
2172 lval = (unsigned long)val;
2173 }
2174 *lvalp = jiffies_to_clock_t(lval);
2175 }
2176 return 0;
2177}
2178
2179static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2180 int *valp,
2181 int write, void *data)
2182{
2183 if (write) {
2184 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2185 } else {
2186 int val = *valp;
2187 unsigned long lval;
2188 if (val < 0) {
2189 *negp = -1;
2190 lval = (unsigned long)-val;
2191 } else {
2192 *negp = 0;
2193 lval = (unsigned long)val;
2194 }
2195 *lvalp = jiffies_to_msecs(lval);
2196 }
2197 return 0;
2198}
2199
2200/**
2201 * proc_dointvec_jiffies - read a vector of integers as seconds
2202 * @table: the sysctl table
2203 * @write: %TRUE if this is a write to the sysctl file
2204 * @filp: the file structure
2205 * @buffer: the user buffer
2206 * @lenp: the size of the user buffer
2207 * @ppos: file position
2208 *
2209 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2210 * values from/to the user buffer, treated as an ASCII string.
2211 * The values read are assumed to be in seconds, and are converted into
2212 * jiffies.
2213 *
2214 * Returns 0 on success.
2215 */
2216int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2217 void __user *buffer, size_t *lenp, loff_t *ppos)
2218{
2219 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2220 do_proc_dointvec_jiffies_conv,NULL);
2221}
2222
2223/**
2224 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2225 * @table: the sysctl table
2226 * @write: %TRUE if this is a write to the sysctl file
2227 * @filp: the file structure
2228 * @buffer: the user buffer
2229 * @lenp: the size of the user buffer
1e5d5331 2230 * @ppos: pointer to the file position
1da177e4
LT		 2231 *
2232 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2233 * values from/to the user buffer, treated as an ASCII string.
2234 * The values read are assumed to be in 1/USER_HZ seconds, and
2235 * are converted into jiffies.
2236 *
2237 * Returns 0 on success.
2238 */
2239int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2240 void __user *buffer, size_t *lenp, loff_t *ppos)
2241{
2242 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2243 do_proc_dointvec_userhz_jiffies_conv,NULL);
2244}
2245
2246/**
2247 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2248 * @table: the sysctl table
2249 * @write: %TRUE if this is a write to the sysctl file
2250 * @filp: the file structure
2251 * @buffer: the user buffer
2252 * @lenp: the size of the user buffer
67be2dd1
MW		 2253 * @ppos: file position
2254 * @ppos: the current position in the file
1da177e4
LT		 2255 *
2256 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2257 * values from/to the user buffer, treated as an ASCII string.
2258 * The values read are assumed to be in 1/1000 seconds, and
2259 * are converted into jiffies.
2260 *
2261 * Returns 0 on success.
2262 */
2263int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2264 void __user *buffer, size_t *lenp, loff_t *ppos)
2265{
2266 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2267 do_proc_dointvec_ms_jiffies_conv, NULL);
2268}
2269
2270#else /* CONFIG_PROC_FS */
2271
2272int proc_dostring(ctl_table *table, int write, struct file *filp,
2273 void __user *buffer, size_t *lenp, loff_t *ppos)
2274{
2275 return -ENOSYS;
2276}
2277
2278static int proc_doutsstring(ctl_table *table, int write, struct file *filp,
2279 void __user *buffer, size_t *lenp, loff_t *ppos)
2280{
2281 return -ENOSYS;
2282}
2283
2284int proc_dointvec(ctl_table *table, int write, struct file *filp,
2285 void __user *buffer, size_t *lenp, loff_t *ppos)
2286{
2287 return -ENOSYS;
2288}
2289
2290int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2291 void __user *buffer, size_t *lenp, loff_t *ppos)
2292{
2293 return -ENOSYS;
2294}
2295
2296int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2297 void __user *buffer, size_t *lenp, loff_t *ppos)
2298{
2299 return -ENOSYS;
2300}
2301
2302int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2303 void __user *buffer, size_t *lenp, loff_t *ppos)
2304{
2305 return -ENOSYS;
2306}
2307
2308int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2309 void __user *buffer, size_t *lenp, loff_t *ppos)
2310{
2311 return -ENOSYS;
2312}
2313
2314int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2315 void __user *buffer, size_t *lenp, loff_t *ppos)
2316{
2317 return -ENOSYS;
2318}
2319
2320int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2321 void __user *buffer, size_t *lenp, loff_t *ppos)
2322{
2323 return -ENOSYS;
2324}
2325
2326int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2327 struct file *filp,
2328 void __user *buffer,
2329 size_t *lenp, loff_t *ppos)
2330{
2331 return -ENOSYS;
2332}
2333
2334
2335#endif /* CONFIG_PROC_FS */
2336
2337
b89a8171 2338#ifdef CONFIG_SYSCTL_SYSCALL
1da177e4
LT		 2339/*
2340 * General sysctl support routines
2341 */
2342
2343/* The generic string strategy routine: */
2344int sysctl_string(ctl_table *table, int __user *name, int nlen,
2345 void __user *oldval, size_t __user *oldlenp,
2346 void __user *newval, size_t newlen, void **context)
2347{
1da177e4
LT		 2348 if (!table->data || !table->maxlen)
2349 return -ENOTDIR;
2350
2351 if (oldval && oldlenp) {
de9e007d
LT		 2352 size_t bufsize;
2353 if (get_user(bufsize, oldlenp))
1da177e4 2354 return -EFAULT;
de9e007d
LT		 2355 if (bufsize) {
2356 size_t len = strlen(table->data), copied;
2357
2358 /* This shouldn't trigger for a well-formed sysctl */
2359 if (len > table->maxlen)
1da177e4 2360 len = table->maxlen;
de9e007d
LT		 2361
2362 /* Copy up to a max of bufsize-1 bytes of the string */
2363 copied = (len >= bufsize) ? bufsize - 1 : len;
2364
2365 if (copy_to_user(oldval, table->data, copied) ||
2366 put_user(0, (char __user *)(oldval + copied)))
1da177e4 2367 return -EFAULT;
de9e007d 2368 if (put_user(len, oldlenp))
1da177e4
LT		 2369 return -EFAULT;
2370 }
2371 }
2372 if (newval && newlen) {
de9e007d 2373 size_t len = newlen;
1da177e4
LT		 2374 if (len > table->maxlen)
2375 len = table->maxlen;
2376 if(copy_from_user(table->data, newval, len))
2377 return -EFAULT;
2378 if (len == table->maxlen)
2379 len--;
2380 ((char *) table->data)[len] = 0;
2381 }
82c9df82 2382 return 1;
1da177e4
LT		 2383}
2384
2385/*
2386 * This function makes sure that all of the integers in the vector
2387 * are between the minimum and maximum values given in the arrays
2388 * table->extra1 and table->extra2, respectively.
2389 */
2390int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2391 void __user *oldval, size_t __user *oldlenp,
2392 void __user *newval, size_t newlen, void **context)
2393{
2394
2395 if (newval && newlen) {
2396 int __user *vec = (int __user *) newval;
2397 int *min = (int *) table->extra1;
2398 int *max = (int *) table->extra2;
2399 size_t length;
2400 int i;
2401
2402 if (newlen % sizeof(int) != 0)
2403 return -EINVAL;
2404
2405 if (!table->extra1 && !table->extra2)
2406 return 0;
2407
2408 if (newlen > table->maxlen)
2409 newlen = table->maxlen;
2410 length = newlen / sizeof(int);
2411
2412 for (i = 0; i < length; i++) {
2413 int value;
2414 if (get_user(value, vec + i))
2415 return -EFAULT;
2416 if (min && value < min[i])
2417 return -EINVAL;
2418 if (max && value > max[i])
2419 return -EINVAL;
2420 }
2421 }
2422 return 0;
2423}
2424
2425/* Strategy function to convert jiffies to seconds */
2426int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2427 void __user *oldval, size_t __user *oldlenp,
2428 void __user *newval, size_t newlen, void **context)
2429{
2430 if (oldval) {
2431 size_t olen;
2432 if (oldlenp) {
2433 if (get_user(olen, oldlenp))
2434 return -EFAULT;
2435 if (olen!=sizeof(int))
2436 return -EINVAL;
2437 }
2438 if (put_user(*(int *)(table->data)/HZ, (int __user *)oldval) ||
2439 (oldlenp && put_user(sizeof(int),oldlenp)))
2440 return -EFAULT;
2441 }
2442 if (newval && newlen) {
2443 int new;
2444 if (newlen != sizeof(int))
2445 return -EINVAL;
2446 if (get_user(new, (int __user *)newval))
2447 return -EFAULT;
2448 *(int *)(table->data) = new*HZ;
2449 }
2450 return 1;
2451}
2452
2453/* Strategy function to convert jiffies to seconds */
2454int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2455 void __user *oldval, size_t __user *oldlenp,
2456 void __user *newval, size_t newlen, void **context)
2457{
2458 if (oldval) {
2459 size_t olen;
2460 if (oldlenp) {
2461 if (get_user(olen, oldlenp))
2462 return -EFAULT;
2463 if (olen!=sizeof(int))
2464 return -EINVAL;
2465 }
2466 if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
2467 (oldlenp && put_user(sizeof(int),oldlenp)))
2468 return -EFAULT;
2469 }
2470 if (newval && newlen) {
2471 int new;
2472 if (newlen != sizeof(int))
2473 return -EINVAL;
2474 if (get_user(new, (int __user *)newval))
2475 return -EFAULT;
2476 *(int *)(table->data) = msecs_to_jiffies(new);
2477 }
2478 return 1;
2479}
2480
b89a8171 2481#else /* CONFIG_SYSCTL_SYSCALL */
1da177e4
LT		 2482
2483
2484asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2485{
b89a8171
EB		 2486 static int msg_count;
2487
2488 if (msg_count < 5) {
2489 msg_count++;
2490 printk(KERN_INFO
2491 "warning: process `%s' used the removed sysctl "
2492 "system call\n", current->comm);
2493 }
1da177e4
LT		 2494 return -ENOSYS;
2495}
2496
2497int sysctl_string(ctl_table *table, int __user *name, int nlen,
2498 void __user *oldval, size_t __user *oldlenp,
2499 void __user *newval, size_t newlen, void **context)
2500{
2501 return -ENOSYS;
2502}
2503
2504int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2505 void __user *oldval, size_t __user *oldlenp,
2506 void __user *newval, size_t newlen, void **context)
2507{
2508 return -ENOSYS;
2509}
2510
2511int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2512 void __user *oldval, size_t __user *oldlenp,
2513 void __user *newval, size_t newlen, void **context)
2514{
2515 return -ENOSYS;
2516}
2517
2518int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2519 void __user *oldval, size_t __user *oldlenp,
2520 void __user *newval, size_t newlen, void **context)
2521{
2522 return -ENOSYS;
2523}
2524
b89a8171 2525#endif /* CONFIG_SYSCTL_SYSCALL */
1da177e4
LT		 2526
2527/*
2528 * No sense putting this after each symbol definition, twice,
2529 * exception granted :-)
2530 */
2531EXPORT_SYMBOL(proc_dointvec);
2532EXPORT_SYMBOL(proc_dointvec_jiffies);
2533EXPORT_SYMBOL(proc_dointvec_minmax);
2534EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2535EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2536EXPORT_SYMBOL(proc_dostring);
2537EXPORT_SYMBOL(proc_doulongvec_minmax);
2538EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2539EXPORT_SYMBOL(register_sysctl_table);
2540EXPORT_SYMBOL(sysctl_intvec);
2541EXPORT_SYMBOL(sysctl_jiffies);
2542EXPORT_SYMBOL(sysctl_ms_jiffies);
2543EXPORT_SYMBOL(sysctl_string);
2544EXPORT_SYMBOL(unregister_sysctl_table);
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