Merge branch 'linux-2.6'
[linux-2.6] / kernel / sysctl.c
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
21 #include <linux/module.h>
22 #include <linux/mm.h>
23 #include <linux/swap.h>
24 #include <linux/slab.h>
25 #include <linux/sysctl.h>
26 #include <linux/proc_fs.h>
27 #include <linux/security.h>
28 #include <linux/ctype.h>
29 #include <linux/utsname.h>
30 #include <linux/smp_lock.h>
31 #include <linux/fs.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/kobject.h>
35 #include <linux/net.h>
36 #include <linux/sysrq.h>
37 #include <linux/highuid.h>
38 #include <linux/writeback.h>
39 #include <linux/hugetlb.h>
40 #include <linux/security.h>
41 #include <linux/initrd.h>
42 #include <linux/times.h>
43 #include <linux/limits.h>
44 #include <linux/dcache.h>
45 #include <linux/syscalls.h>
46 #include <linux/nfs_fs.h>
47 #include <linux/acpi.h>
48 #include <linux/reboot.h>
49
50 #include <asm/uaccess.h>
51 #include <asm/processor.h>
52
53 #ifdef CONFIG_X86
54 #include <asm/nmi.h>
55 #include <asm/stacktrace.h>
56 #endif
57
58 static int deprecated_sysctl_warning(struct __sysctl_args *args);
59
60 #if defined(CONFIG_SYSCTL)
61
62 /* External variables not in a header file. */
63 extern int C_A_D;
64 extern int print_fatal_signals;
65 extern int sysctl_overcommit_memory;
66 extern int sysctl_overcommit_ratio;
67 extern int sysctl_panic_on_oom;
68 extern int sysctl_oom_kill_allocating_task;
69 extern int max_threads;
70 extern int core_uses_pid;
71 extern int suid_dumpable;
72 extern char core_pattern[];
73 extern int pid_max;
74 extern int min_free_kbytes;
75 extern int printk_ratelimit_jiffies;
76 extern int printk_ratelimit_burst;
77 extern int pid_max_min, pid_max_max;
78 extern int sysctl_drop_caches;
79 extern int percpu_pagelist_fraction;
80 extern int compat_log;
81 extern int maps_protect;
82 extern int sysctl_stat_interval;
83 extern int audit_argv_kb;
84
85 /* Constants used for minimum and  maximum */
86 #ifdef CONFIG_DETECT_SOFTLOCKUP
87 static int one = 1;
88 static int sixty = 60;
89 #endif
90
91 #ifdef CONFIG_MMU
92 static int two = 2;
93 #endif
94
95 static int zero;
96 static int one_hundred = 100;
97
98 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
99 static int maxolduid = 65535;
100 static int minolduid;
101 static int min_percpu_pagelist_fract = 8;
102
103 static int ngroups_max = NGROUPS_MAX;
104
105 #ifdef CONFIG_KMOD
106 extern char modprobe_path[];
107 #endif
108 #ifdef CONFIG_CHR_DEV_SG
109 extern int sg_big_buff;
110 #endif
111
112 #ifdef __sparc__
113 extern char reboot_command [];
114 extern int stop_a_enabled;
115 extern int scons_pwroff;
116 #endif
117
118 #ifdef __hppa__
119 extern int pwrsw_enabled;
120 extern int unaligned_enabled;
121 #endif
122
123 #ifdef CONFIG_S390
124 #ifdef CONFIG_MATHEMU
125 extern int sysctl_ieee_emulation_warnings;
126 #endif
127 extern int sysctl_userprocess_debug;
128 extern int spin_retry;
129 #endif
130
131 extern int sysctl_hz_timer;
132
133 #ifdef CONFIG_BSD_PROCESS_ACCT
134 extern int acct_parm[];
135 #endif
136
137 #ifdef CONFIG_IA64
138 extern int no_unaligned_warning;
139 #endif
140
141 #ifdef CONFIG_RT_MUTEXES
142 extern int max_lock_depth;
143 #endif
144
145 #ifdef CONFIG_SYSCTL_SYSCALL
146 static int parse_table(int __user *, int, void __user *, size_t __user *,
147                 void __user *, size_t, struct ctl_table *);
148 #endif
149
150
151 #ifdef CONFIG_PROC_SYSCTL
152 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
153                   void __user *buffer, size_t *lenp, loff_t *ppos);
154 static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
155                                void __user *buffer, size_t *lenp, loff_t *ppos);
156 #endif
157
158 static struct ctl_table root_table[];
159 static struct ctl_table_header root_table_header =
160         { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
161
162 static struct ctl_table kern_table[];
163 static struct ctl_table vm_table[];
164 static struct ctl_table fs_table[];
165 static struct ctl_table debug_table[];
166 static struct ctl_table dev_table[];
167 extern struct ctl_table random_table[];
168 #ifdef CONFIG_INOTIFY_USER
169 extern struct ctl_table inotify_table[];
170 #endif
171
172 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
173 int sysctl_legacy_va_layout;
174 #endif
175
176 extern int prove_locking;
177 extern int lock_stat;
178
179 /* The default sysctl tables: */
180
181 static struct ctl_table root_table[] = {
182         {
183                 .ctl_name       = CTL_KERN,
184                 .procname       = "kernel",
185                 .mode           = 0555,
186                 .child          = kern_table,
187         },
188         {
189                 .ctl_name       = CTL_VM,
190                 .procname       = "vm",
191                 .mode           = 0555,
192                 .child          = vm_table,
193         },
194 #ifdef CONFIG_NET
195         {
196                 .ctl_name       = CTL_NET,
197                 .procname       = "net",
198                 .mode           = 0555,
199                 .child          = net_table,
200         },
201 #endif
202         {
203                 .ctl_name       = CTL_FS,
204                 .procname       = "fs",
205                 .mode           = 0555,
206                 .child          = fs_table,
207         },
208         {
209                 .ctl_name       = CTL_DEBUG,
210                 .procname       = "debug",
211                 .mode           = 0555,
212                 .child          = debug_table,
213         },
214         {
215                 .ctl_name       = CTL_DEV,
216                 .procname       = "dev",
217                 .mode           = 0555,
218                 .child          = dev_table,
219         },
220 /*
221  * NOTE: do not add new entries to this table unless you have read
222  * Documentation/sysctl/ctl_unnumbered.txt
223  */
224         { .ctl_name = 0 }
225 };
226
227 #ifdef CONFIG_SCHED_DEBUG
228 static unsigned long min_sched_granularity_ns = 100000;         /* 100 usecs */
229 static unsigned long max_sched_granularity_ns = NSEC_PER_SEC;   /* 1 second */
230 static unsigned long min_wakeup_granularity_ns;                 /* 0 usecs */
231 static unsigned long max_wakeup_granularity_ns = NSEC_PER_SEC;  /* 1 second */
232 #endif
233
234 static struct ctl_table kern_table[] = {
235 #ifdef CONFIG_SCHED_DEBUG
236         {
237                 .ctl_name       = CTL_UNNUMBERED,
238                 .procname       = "sched_min_granularity_ns",
239                 .data           = &sysctl_sched_min_granularity,
240                 .maxlen         = sizeof(unsigned int),
241                 .mode           = 0644,
242                 .proc_handler   = &sched_nr_latency_handler,
243                 .strategy       = &sysctl_intvec,
244                 .extra1         = &min_sched_granularity_ns,
245                 .extra2         = &max_sched_granularity_ns,
246         },
247         {
248                 .ctl_name       = CTL_UNNUMBERED,
249                 .procname       = "sched_latency_ns",
250                 .data           = &sysctl_sched_latency,
251                 .maxlen         = sizeof(unsigned int),
252                 .mode           = 0644,
253                 .proc_handler   = &sched_nr_latency_handler,
254                 .strategy       = &sysctl_intvec,
255                 .extra1         = &min_sched_granularity_ns,
256                 .extra2         = &max_sched_granularity_ns,
257         },
258         {
259                 .ctl_name       = CTL_UNNUMBERED,
260                 .procname       = "sched_wakeup_granularity_ns",
261                 .data           = &sysctl_sched_wakeup_granularity,
262                 .maxlen         = sizeof(unsigned int),
263                 .mode           = 0644,
264                 .proc_handler   = &proc_dointvec_minmax,
265                 .strategy       = &sysctl_intvec,
266                 .extra1         = &min_wakeup_granularity_ns,
267                 .extra2         = &max_wakeup_granularity_ns,
268         },
269         {
270                 .ctl_name       = CTL_UNNUMBERED,
271                 .procname       = "sched_batch_wakeup_granularity_ns",
272                 .data           = &sysctl_sched_batch_wakeup_granularity,
273                 .maxlen         = sizeof(unsigned int),
274                 .mode           = 0644,
275                 .proc_handler   = &proc_dointvec_minmax,
276                 .strategy       = &sysctl_intvec,
277                 .extra1         = &min_wakeup_granularity_ns,
278                 .extra2         = &max_wakeup_granularity_ns,
279         },
280         {
281                 .ctl_name       = CTL_UNNUMBERED,
282                 .procname       = "sched_child_runs_first",
283                 .data           = &sysctl_sched_child_runs_first,
284                 .maxlen         = sizeof(unsigned int),
285                 .mode           = 0644,
286                 .proc_handler   = &proc_dointvec,
287         },
288         {
289                 .ctl_name       = CTL_UNNUMBERED,
290                 .procname       = "sched_features",
291                 .data           = &sysctl_sched_features,
292                 .maxlen         = sizeof(unsigned int),
293                 .mode           = 0644,
294                 .proc_handler   = &proc_dointvec,
295         },
296         {
297                 .ctl_name       = CTL_UNNUMBERED,
298                 .procname       = "sched_migration_cost",
299                 .data           = &sysctl_sched_migration_cost,
300                 .maxlen         = sizeof(unsigned int),
301                 .mode           = 0644,
302                 .proc_handler   = &proc_dointvec,
303         },
304         {
305                 .ctl_name       = CTL_UNNUMBERED,
306                 .procname       = "sched_nr_migrate",
307                 .data           = &sysctl_sched_nr_migrate,
308                 .maxlen         = sizeof(unsigned int),
309                 .mode           = 644,
310                 .proc_handler   = &proc_dointvec,
311         },
312 #endif
313         {
314                 .ctl_name       = CTL_UNNUMBERED,
315                 .procname       = "sched_compat_yield",
316                 .data           = &sysctl_sched_compat_yield,
317                 .maxlen         = sizeof(unsigned int),
318                 .mode           = 0644,
319                 .proc_handler   = &proc_dointvec,
320         },
321 #ifdef CONFIG_PROVE_LOCKING
322         {
323                 .ctl_name       = CTL_UNNUMBERED,
324                 .procname       = "prove_locking",
325                 .data           = &prove_locking,
326                 .maxlen         = sizeof(int),
327                 .mode           = 0644,
328                 .proc_handler   = &proc_dointvec,
329         },
330 #endif
331 #ifdef CONFIG_LOCK_STAT
332         {
333                 .ctl_name       = CTL_UNNUMBERED,
334                 .procname       = "lock_stat",
335                 .data           = &lock_stat,
336                 .maxlen         = sizeof(int),
337                 .mode           = 0644,
338                 .proc_handler   = &proc_dointvec,
339         },
340 #endif
341         {
342                 .ctl_name       = KERN_PANIC,
343                 .procname       = "panic",
344                 .data           = &panic_timeout,
345                 .maxlen         = sizeof(int),
346                 .mode           = 0644,
347                 .proc_handler   = &proc_dointvec,
348         },
349         {
350                 .ctl_name       = KERN_CORE_USES_PID,
351                 .procname       = "core_uses_pid",
352                 .data           = &core_uses_pid,
353                 .maxlen         = sizeof(int),
354                 .mode           = 0644,
355                 .proc_handler   = &proc_dointvec,
356         },
357 #ifdef CONFIG_AUDITSYSCALL
358         {
359                 .ctl_name       = CTL_UNNUMBERED,
360                 .procname       = "audit_argv_kb",
361                 .data           = &audit_argv_kb,
362                 .maxlen         = sizeof(int),
363                 .mode           = 0644,
364                 .proc_handler   = &proc_dointvec,
365         },
366 #endif
367         {
368                 .ctl_name       = KERN_CORE_PATTERN,
369                 .procname       = "core_pattern",
370                 .data           = core_pattern,
371                 .maxlen         = CORENAME_MAX_SIZE,
372                 .mode           = 0644,
373                 .proc_handler   = &proc_dostring,
374                 .strategy       = &sysctl_string,
375         },
376 #ifdef CONFIG_PROC_SYSCTL
377         {
378                 .procname       = "tainted",
379                 .data           = &tainted,
380                 .maxlen         = sizeof(int),
381                 .mode           = 0644,
382                 .proc_handler   = &proc_dointvec_taint,
383         },
384 #endif
385 #ifdef CONFIG_SECURITY_CAPABILITIES
386         {
387                 .procname       = "cap-bound",
388                 .data           = &cap_bset,
389                 .maxlen         = sizeof(kernel_cap_t),
390                 .mode           = 0600,
391                 .proc_handler   = &proc_dointvec_bset,
392         },
393 #endif /* def CONFIG_SECURITY_CAPABILITIES */
394 #ifdef CONFIG_BLK_DEV_INITRD
395         {
396                 .ctl_name       = KERN_REALROOTDEV,
397                 .procname       = "real-root-dev",
398                 .data           = &real_root_dev,
399                 .maxlen         = sizeof(int),
400                 .mode           = 0644,
401                 .proc_handler   = &proc_dointvec,
402         },
403 #endif
404         {
405                 .ctl_name       = CTL_UNNUMBERED,
406                 .procname       = "print-fatal-signals",
407                 .data           = &print_fatal_signals,
408                 .maxlen         = sizeof(int),
409                 .mode           = 0644,
410                 .proc_handler   = &proc_dointvec,
411         },
412 #ifdef __sparc__
413         {
414                 .ctl_name       = KERN_SPARC_REBOOT,
415                 .procname       = "reboot-cmd",
416                 .data           = reboot_command,
417                 .maxlen         = 256,
418                 .mode           = 0644,
419                 .proc_handler   = &proc_dostring,
420                 .strategy       = &sysctl_string,
421         },
422         {
423                 .ctl_name       = KERN_SPARC_STOP_A,
424                 .procname       = "stop-a",
425                 .data           = &stop_a_enabled,
426                 .maxlen         = sizeof (int),
427                 .mode           = 0644,
428                 .proc_handler   = &proc_dointvec,
429         },
430         {
431                 .ctl_name       = KERN_SPARC_SCONS_PWROFF,
432                 .procname       = "scons-poweroff",
433                 .data           = &scons_pwroff,
434                 .maxlen         = sizeof (int),
435                 .mode           = 0644,
436                 .proc_handler   = &proc_dointvec,
437         },
438 #endif
439 #ifdef __hppa__
440         {
441                 .ctl_name       = KERN_HPPA_PWRSW,
442                 .procname       = "soft-power",
443                 .data           = &pwrsw_enabled,
444                 .maxlen         = sizeof (int),
445                 .mode           = 0644,
446                 .proc_handler   = &proc_dointvec,
447         },
448         {
449                 .ctl_name       = KERN_HPPA_UNALIGNED,
450                 .procname       = "unaligned-trap",
451                 .data           = &unaligned_enabled,
452                 .maxlen         = sizeof (int),
453                 .mode           = 0644,
454                 .proc_handler   = &proc_dointvec,
455         },
456 #endif
457         {
458                 .ctl_name       = KERN_CTLALTDEL,
459                 .procname       = "ctrl-alt-del",
460                 .data           = &C_A_D,
461                 .maxlen         = sizeof(int),
462                 .mode           = 0644,
463                 .proc_handler   = &proc_dointvec,
464         },
465         {
466                 .ctl_name       = KERN_PRINTK,
467                 .procname       = "printk",
468                 .data           = &console_loglevel,
469                 .maxlen         = 4*sizeof(int),
470                 .mode           = 0644,
471                 .proc_handler   = &proc_dointvec,
472         },
473 #ifdef CONFIG_KMOD
474         {
475                 .ctl_name       = KERN_MODPROBE,
476                 .procname       = "modprobe",
477                 .data           = &modprobe_path,
478                 .maxlen         = KMOD_PATH_LEN,
479                 .mode           = 0644,
480                 .proc_handler   = &proc_dostring,
481                 .strategy       = &sysctl_string,
482         },
483 #endif
484 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
485         {
486                 .ctl_name       = KERN_HOTPLUG,
487                 .procname       = "hotplug",
488                 .data           = &uevent_helper,
489                 .maxlen         = UEVENT_HELPER_PATH_LEN,
490                 .mode           = 0644,
491                 .proc_handler   = &proc_dostring,
492                 .strategy       = &sysctl_string,
493         },
494 #endif
495 #ifdef CONFIG_CHR_DEV_SG
496         {
497                 .ctl_name       = KERN_SG_BIG_BUFF,
498                 .procname       = "sg-big-buff",
499                 .data           = &sg_big_buff,
500                 .maxlen         = sizeof (int),
501                 .mode           = 0444,
502                 .proc_handler   = &proc_dointvec,
503         },
504 #endif
505 #ifdef CONFIG_BSD_PROCESS_ACCT
506         {
507                 .ctl_name       = KERN_ACCT,
508                 .procname       = "acct",
509                 .data           = &acct_parm,
510                 .maxlen         = 3*sizeof(int),
511                 .mode           = 0644,
512                 .proc_handler   = &proc_dointvec,
513         },
514 #endif
515 #ifdef CONFIG_MAGIC_SYSRQ
516         {
517                 .ctl_name       = KERN_SYSRQ,
518                 .procname       = "sysrq",
519                 .data           = &__sysrq_enabled,
520                 .maxlen         = sizeof (int),
521                 .mode           = 0644,
522                 .proc_handler   = &proc_dointvec,
523         },
524 #endif
525 #ifdef CONFIG_PROC_SYSCTL
526         {
527                 .procname       = "cad_pid",
528                 .data           = NULL,
529                 .maxlen         = sizeof (int),
530                 .mode           = 0600,
531                 .proc_handler   = &proc_do_cad_pid,
532         },
533 #endif
534         {
535                 .ctl_name       = KERN_MAX_THREADS,
536                 .procname       = "threads-max",
537                 .data           = &max_threads,
538                 .maxlen         = sizeof(int),
539                 .mode           = 0644,
540                 .proc_handler   = &proc_dointvec,
541         },
542         {
543                 .ctl_name       = KERN_RANDOM,
544                 .procname       = "random",
545                 .mode           = 0555,
546                 .child          = random_table,
547         },
548         {
549                 .ctl_name       = KERN_OVERFLOWUID,
550                 .procname       = "overflowuid",
551                 .data           = &overflowuid,
552                 .maxlen         = sizeof(int),
553                 .mode           = 0644,
554                 .proc_handler   = &proc_dointvec_minmax,
555                 .strategy       = &sysctl_intvec,
556                 .extra1         = &minolduid,
557                 .extra2         = &maxolduid,
558         },
559         {
560                 .ctl_name       = KERN_OVERFLOWGID,
561                 .procname       = "overflowgid",
562                 .data           = &overflowgid,
563                 .maxlen         = sizeof(int),
564                 .mode           = 0644,
565                 .proc_handler   = &proc_dointvec_minmax,
566                 .strategy       = &sysctl_intvec,
567                 .extra1         = &minolduid,
568                 .extra2         = &maxolduid,
569         },
570 #ifdef CONFIG_S390
571 #ifdef CONFIG_MATHEMU
572         {
573                 .ctl_name       = KERN_IEEE_EMULATION_WARNINGS,
574                 .procname       = "ieee_emulation_warnings",
575                 .data           = &sysctl_ieee_emulation_warnings,
576                 .maxlen         = sizeof(int),
577                 .mode           = 0644,
578                 .proc_handler   = &proc_dointvec,
579         },
580 #endif
581 #ifdef CONFIG_NO_IDLE_HZ
582         {
583                 .ctl_name       = KERN_HZ_TIMER,
584                 .procname       = "hz_timer",
585                 .data           = &sysctl_hz_timer,
586                 .maxlen         = sizeof(int),
587                 .mode           = 0644,
588                 .proc_handler   = &proc_dointvec,
589         },
590 #endif
591         {
592                 .ctl_name       = KERN_S390_USER_DEBUG_LOGGING,
593                 .procname       = "userprocess_debug",
594                 .data           = &sysctl_userprocess_debug,
595                 .maxlen         = sizeof(int),
596                 .mode           = 0644,
597                 .proc_handler   = &proc_dointvec,
598         },
599 #endif
600         {
601                 .ctl_name       = KERN_PIDMAX,
602                 .procname       = "pid_max",
603                 .data           = &pid_max,
604                 .maxlen         = sizeof (int),
605                 .mode           = 0644,
606                 .proc_handler   = &proc_dointvec_minmax,
607                 .strategy       = sysctl_intvec,
608                 .extra1         = &pid_max_min,
609                 .extra2         = &pid_max_max,
610         },
611         {
612                 .ctl_name       = KERN_PANIC_ON_OOPS,
613                 .procname       = "panic_on_oops",
614                 .data           = &panic_on_oops,
615                 .maxlen         = sizeof(int),
616                 .mode           = 0644,
617                 .proc_handler   = &proc_dointvec,
618         },
619         {
620                 .ctl_name       = KERN_PRINTK_RATELIMIT,
621                 .procname       = "printk_ratelimit",
622                 .data           = &printk_ratelimit_jiffies,
623                 .maxlen         = sizeof(int),
624                 .mode           = 0644,
625                 .proc_handler   = &proc_dointvec_jiffies,
626                 .strategy       = &sysctl_jiffies,
627         },
628         {
629                 .ctl_name       = KERN_PRINTK_RATELIMIT_BURST,
630                 .procname       = "printk_ratelimit_burst",
631                 .data           = &printk_ratelimit_burst,
632                 .maxlen         = sizeof(int),
633                 .mode           = 0644,
634                 .proc_handler   = &proc_dointvec,
635         },
636         {
637                 .ctl_name       = KERN_NGROUPS_MAX,
638                 .procname       = "ngroups_max",
639                 .data           = &ngroups_max,
640                 .maxlen         = sizeof (int),
641                 .mode           = 0444,
642                 .proc_handler   = &proc_dointvec,
643         },
644 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
645         {
646                 .ctl_name       = KERN_UNKNOWN_NMI_PANIC,
647                 .procname       = "unknown_nmi_panic",
648                 .data           = &unknown_nmi_panic,
649                 .maxlen         = sizeof (int),
650                 .mode           = 0644,
651                 .proc_handler   = &proc_dointvec,
652         },
653         {
654                 .procname       = "nmi_watchdog",
655                 .data           = &nmi_watchdog_enabled,
656                 .maxlen         = sizeof (int),
657                 .mode           = 0644,
658                 .proc_handler   = &proc_nmi_enabled,
659         },
660 #endif
661 #if defined(CONFIG_X86)
662         {
663                 .ctl_name       = KERN_PANIC_ON_NMI,
664                 .procname       = "panic_on_unrecovered_nmi",
665                 .data           = &panic_on_unrecovered_nmi,
666                 .maxlen         = sizeof(int),
667                 .mode           = 0644,
668                 .proc_handler   = &proc_dointvec,
669         },
670         {
671                 .ctl_name       = KERN_BOOTLOADER_TYPE,
672                 .procname       = "bootloader_type",
673                 .data           = &bootloader_type,
674                 .maxlen         = sizeof (int),
675                 .mode           = 0444,
676                 .proc_handler   = &proc_dointvec,
677         },
678         {
679                 .ctl_name       = CTL_UNNUMBERED,
680                 .procname       = "kstack_depth_to_print",
681                 .data           = &kstack_depth_to_print,
682                 .maxlen         = sizeof(int),
683                 .mode           = 0644,
684                 .proc_handler   = &proc_dointvec,
685         },
686 #endif
687 #if defined(CONFIG_MMU)
688         {
689                 .ctl_name       = KERN_RANDOMIZE,
690                 .procname       = "randomize_va_space",
691                 .data           = &randomize_va_space,
692                 .maxlen         = sizeof(int),
693                 .mode           = 0644,
694                 .proc_handler   = &proc_dointvec,
695         },
696 #endif
697 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
698         {
699                 .ctl_name       = KERN_SPIN_RETRY,
700                 .procname       = "spin_retry",
701                 .data           = &spin_retry,
702                 .maxlen         = sizeof (int),
703                 .mode           = 0644,
704                 .proc_handler   = &proc_dointvec,
705         },
706 #endif
707 #if     defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
708         {
709                 .procname       = "acpi_video_flags",
710                 .data           = &acpi_realmode_flags,
711                 .maxlen         = sizeof (unsigned long),
712                 .mode           = 0644,
713                 .proc_handler   = &proc_doulongvec_minmax,
714         },
715 #endif
716 #ifdef CONFIG_IA64
717         {
718                 .ctl_name       = KERN_IA64_UNALIGNED,
719                 .procname       = "ignore-unaligned-usertrap",
720                 .data           = &no_unaligned_warning,
721                 .maxlen         = sizeof (int),
722                 .mode           = 0644,
723                 .proc_handler   = &proc_dointvec,
724         },
725 #endif
726 #ifdef CONFIG_DETECT_SOFTLOCKUP
727         {
728                 .ctl_name       = CTL_UNNUMBERED,
729                 .procname       = "softlockup_thresh",
730                 .data           = &softlockup_thresh,
731                 .maxlen         = sizeof(int),
732                 .mode           = 0644,
733                 .proc_handler   = &proc_dointvec_minmax,
734                 .strategy       = &sysctl_intvec,
735                 .extra1         = &one,
736                 .extra2         = &sixty,
737         },
738 #endif
739 #ifdef CONFIG_COMPAT
740         {
741                 .ctl_name       = KERN_COMPAT_LOG,
742                 .procname       = "compat-log",
743                 .data           = &compat_log,
744                 .maxlen         = sizeof (int),
745                 .mode           = 0644,
746                 .proc_handler   = &proc_dointvec,
747         },
748 #endif
749 #ifdef CONFIG_RT_MUTEXES
750         {
751                 .ctl_name       = KERN_MAX_LOCK_DEPTH,
752                 .procname       = "max_lock_depth",
753                 .data           = &max_lock_depth,
754                 .maxlen         = sizeof(int),
755                 .mode           = 0644,
756                 .proc_handler   = &proc_dointvec,
757         },
758 #endif
759 #ifdef CONFIG_PROC_FS
760         {
761                 .ctl_name       = CTL_UNNUMBERED,
762                 .procname       = "maps_protect",
763                 .data           = &maps_protect,
764                 .maxlen         = sizeof(int),
765                 .mode           = 0644,
766                 .proc_handler   = &proc_dointvec,
767         },
768 #endif
769         {
770                 .ctl_name       = CTL_UNNUMBERED,
771                 .procname       = "poweroff_cmd",
772                 .data           = &poweroff_cmd,
773                 .maxlen         = POWEROFF_CMD_PATH_LEN,
774                 .mode           = 0644,
775                 .proc_handler   = &proc_dostring,
776                 .strategy       = &sysctl_string,
777         },
778 /*
779  * NOTE: do not add new entries to this table unless you have read
780  * Documentation/sysctl/ctl_unnumbered.txt
781  */
782         { .ctl_name = 0 }
783 };
784
785 static struct ctl_table vm_table[] = {
786         {
787                 .ctl_name       = VM_OVERCOMMIT_MEMORY,
788                 .procname       = "overcommit_memory",
789                 .data           = &sysctl_overcommit_memory,
790                 .maxlen         = sizeof(sysctl_overcommit_memory),
791                 .mode           = 0644,
792                 .proc_handler   = &proc_dointvec,
793         },
794         {
795                 .ctl_name       = VM_PANIC_ON_OOM,
796                 .procname       = "panic_on_oom",
797                 .data           = &sysctl_panic_on_oom,
798                 .maxlen         = sizeof(sysctl_panic_on_oom),
799                 .mode           = 0644,
800                 .proc_handler   = &proc_dointvec,
801         },
802         {
803                 .ctl_name       = CTL_UNNUMBERED,
804                 .procname       = "oom_kill_allocating_task",
805                 .data           = &sysctl_oom_kill_allocating_task,
806                 .maxlen         = sizeof(sysctl_oom_kill_allocating_task),
807                 .mode           = 0644,
808                 .proc_handler   = &proc_dointvec,
809         },
810         {
811                 .ctl_name       = VM_OVERCOMMIT_RATIO,
812                 .procname       = "overcommit_ratio",
813                 .data           = &sysctl_overcommit_ratio,
814                 .maxlen         = sizeof(sysctl_overcommit_ratio),
815                 .mode           = 0644,
816                 .proc_handler   = &proc_dointvec,
817         },
818         {
819                 .ctl_name       = VM_PAGE_CLUSTER,
820                 .procname       = "page-cluster", 
821                 .data           = &page_cluster,
822                 .maxlen         = sizeof(int),
823                 .mode           = 0644,
824                 .proc_handler   = &proc_dointvec,
825         },
826         {
827                 .ctl_name       = VM_DIRTY_BACKGROUND,
828                 .procname       = "dirty_background_ratio",
829                 .data           = &dirty_background_ratio,
830                 .maxlen         = sizeof(dirty_background_ratio),
831                 .mode           = 0644,
832                 .proc_handler   = &proc_dointvec_minmax,
833                 .strategy       = &sysctl_intvec,
834                 .extra1         = &zero,
835                 .extra2         = &one_hundred,
836         },
837         {
838                 .ctl_name       = VM_DIRTY_RATIO,
839                 .procname       = "dirty_ratio",
840                 .data           = &vm_dirty_ratio,
841                 .maxlen         = sizeof(vm_dirty_ratio),
842                 .mode           = 0644,
843                 .proc_handler   = &dirty_ratio_handler,
844                 .strategy       = &sysctl_intvec,
845                 .extra1         = &zero,
846                 .extra2         = &one_hundred,
847         },
848         {
849                 .procname       = "dirty_writeback_centisecs",
850                 .data           = &dirty_writeback_interval,
851                 .maxlen         = sizeof(dirty_writeback_interval),
852                 .mode           = 0644,
853                 .proc_handler   = &dirty_writeback_centisecs_handler,
854         },
855         {
856                 .procname       = "dirty_expire_centisecs",
857                 .data           = &dirty_expire_interval,
858                 .maxlen         = sizeof(dirty_expire_interval),
859                 .mode           = 0644,
860                 .proc_handler   = &proc_dointvec_userhz_jiffies,
861         },
862         {
863                 .ctl_name       = VM_NR_PDFLUSH_THREADS,
864                 .procname       = "nr_pdflush_threads",
865                 .data           = &nr_pdflush_threads,
866                 .maxlen         = sizeof nr_pdflush_threads,
867                 .mode           = 0444 /* read-only*/,
868                 .proc_handler   = &proc_dointvec,
869         },
870         {
871                 .ctl_name       = VM_SWAPPINESS,
872                 .procname       = "swappiness",
873                 .data           = &vm_swappiness,
874                 .maxlen         = sizeof(vm_swappiness),
875                 .mode           = 0644,
876                 .proc_handler   = &proc_dointvec_minmax,
877                 .strategy       = &sysctl_intvec,
878                 .extra1         = &zero,
879                 .extra2         = &one_hundred,
880         },
881 #ifdef CONFIG_HUGETLB_PAGE
882          {
883                 .procname       = "nr_hugepages",
884                 .data           = &max_huge_pages,
885                 .maxlen         = sizeof(unsigned long),
886                 .mode           = 0644,
887                 .proc_handler   = &hugetlb_sysctl_handler,
888                 .extra1         = (void *)&hugetlb_zero,
889                 .extra2         = (void *)&hugetlb_infinity,
890          },
891          {
892                 .ctl_name       = VM_HUGETLB_GROUP,
893                 .procname       = "hugetlb_shm_group",
894                 .data           = &sysctl_hugetlb_shm_group,
895                 .maxlen         = sizeof(gid_t),
896                 .mode           = 0644,
897                 .proc_handler   = &proc_dointvec,
898          },
899          {
900                 .ctl_name       = CTL_UNNUMBERED,
901                 .procname       = "hugepages_treat_as_movable",
902                 .data           = &hugepages_treat_as_movable,
903                 .maxlen         = sizeof(int),
904                 .mode           = 0644,
905                 .proc_handler   = &hugetlb_treat_movable_handler,
906         },
907         {
908                 .ctl_name       = CTL_UNNUMBERED,
909                 .procname       = "hugetlb_dynamic_pool",
910                 .data           = &hugetlb_dynamic_pool,
911                 .maxlen         = sizeof(hugetlb_dynamic_pool),
912                 .mode           = 0644,
913                 .proc_handler   = &proc_dointvec,
914         },
915 #endif
916         {
917                 .ctl_name       = VM_LOWMEM_RESERVE_RATIO,
918                 .procname       = "lowmem_reserve_ratio",
919                 .data           = &sysctl_lowmem_reserve_ratio,
920                 .maxlen         = sizeof(sysctl_lowmem_reserve_ratio),
921                 .mode           = 0644,
922                 .proc_handler   = &lowmem_reserve_ratio_sysctl_handler,
923                 .strategy       = &sysctl_intvec,
924         },
925         {
926                 .ctl_name       = VM_DROP_PAGECACHE,
927                 .procname       = "drop_caches",
928                 .data           = &sysctl_drop_caches,
929                 .maxlen         = sizeof(int),
930                 .mode           = 0644,
931                 .proc_handler   = drop_caches_sysctl_handler,
932                 .strategy       = &sysctl_intvec,
933         },
934         {
935                 .ctl_name       = VM_MIN_FREE_KBYTES,
936                 .procname       = "min_free_kbytes",
937                 .data           = &min_free_kbytes,
938                 .maxlen         = sizeof(min_free_kbytes),
939                 .mode           = 0644,
940                 .proc_handler   = &min_free_kbytes_sysctl_handler,
941                 .strategy       = &sysctl_intvec,
942                 .extra1         = &zero,
943         },
944         {
945                 .ctl_name       = VM_PERCPU_PAGELIST_FRACTION,
946                 .procname       = "percpu_pagelist_fraction",
947                 .data           = &percpu_pagelist_fraction,
948                 .maxlen         = sizeof(percpu_pagelist_fraction),
949                 .mode           = 0644,
950                 .proc_handler   = &percpu_pagelist_fraction_sysctl_handler,
951                 .strategy       = &sysctl_intvec,
952                 .extra1         = &min_percpu_pagelist_fract,
953         },
954 #ifdef CONFIG_MMU
955         {
956                 .ctl_name       = VM_MAX_MAP_COUNT,
957                 .procname       = "max_map_count",
958                 .data           = &sysctl_max_map_count,
959                 .maxlen         = sizeof(sysctl_max_map_count),
960                 .mode           = 0644,
961                 .proc_handler   = &proc_dointvec
962         },
963 #endif
964         {
965                 .ctl_name       = VM_LAPTOP_MODE,
966                 .procname       = "laptop_mode",
967                 .data           = &laptop_mode,
968                 .maxlen         = sizeof(laptop_mode),
969                 .mode           = 0644,
970                 .proc_handler   = &proc_dointvec_jiffies,
971                 .strategy       = &sysctl_jiffies,
972         },
973         {
974                 .ctl_name       = VM_BLOCK_DUMP,
975                 .procname       = "block_dump",
976                 .data           = &block_dump,
977                 .maxlen         = sizeof(block_dump),
978                 .mode           = 0644,
979                 .proc_handler   = &proc_dointvec,
980                 .strategy       = &sysctl_intvec,
981                 .extra1         = &zero,
982         },
983         {
984                 .ctl_name       = VM_VFS_CACHE_PRESSURE,
985                 .procname       = "vfs_cache_pressure",
986                 .data           = &sysctl_vfs_cache_pressure,
987                 .maxlen         = sizeof(sysctl_vfs_cache_pressure),
988                 .mode           = 0644,
989                 .proc_handler   = &proc_dointvec,
990                 .strategy       = &sysctl_intvec,
991                 .extra1         = &zero,
992         },
993 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
994         {
995                 .ctl_name       = VM_LEGACY_VA_LAYOUT,
996                 .procname       = "legacy_va_layout",
997                 .data           = &sysctl_legacy_va_layout,
998                 .maxlen         = sizeof(sysctl_legacy_va_layout),
999                 .mode           = 0644,
1000                 .proc_handler   = &proc_dointvec,
1001                 .strategy       = &sysctl_intvec,
1002                 .extra1         = &zero,
1003         },
1004 #endif
1005 #ifdef CONFIG_NUMA
1006         {
1007                 .ctl_name       = VM_ZONE_RECLAIM_MODE,
1008                 .procname       = "zone_reclaim_mode",
1009                 .data           = &zone_reclaim_mode,
1010                 .maxlen         = sizeof(zone_reclaim_mode),
1011                 .mode           = 0644,
1012                 .proc_handler   = &proc_dointvec,
1013                 .strategy       = &sysctl_intvec,
1014                 .extra1         = &zero,
1015         },
1016         {
1017                 .ctl_name       = VM_MIN_UNMAPPED,
1018                 .procname       = "min_unmapped_ratio",
1019                 .data           = &sysctl_min_unmapped_ratio,
1020                 .maxlen         = sizeof(sysctl_min_unmapped_ratio),
1021                 .mode           = 0644,
1022                 .proc_handler   = &sysctl_min_unmapped_ratio_sysctl_handler,
1023                 .strategy       = &sysctl_intvec,
1024                 .extra1         = &zero,
1025                 .extra2         = &one_hundred,
1026         },
1027         {
1028                 .ctl_name       = VM_MIN_SLAB,
1029                 .procname       = "min_slab_ratio",
1030                 .data           = &sysctl_min_slab_ratio,
1031                 .maxlen         = sizeof(sysctl_min_slab_ratio),
1032                 .mode           = 0644,
1033                 .proc_handler   = &sysctl_min_slab_ratio_sysctl_handler,
1034                 .strategy       = &sysctl_intvec,
1035                 .extra1         = &zero,
1036                 .extra2         = &one_hundred,
1037         },
1038 #endif
1039 #ifdef CONFIG_SMP
1040         {
1041                 .ctl_name       = CTL_UNNUMBERED,
1042                 .procname       = "stat_interval",
1043                 .data           = &sysctl_stat_interval,
1044                 .maxlen         = sizeof(sysctl_stat_interval),
1045                 .mode           = 0644,
1046                 .proc_handler   = &proc_dointvec_jiffies,
1047                 .strategy       = &sysctl_jiffies,
1048         },
1049 #endif
1050 #ifdef CONFIG_SECURITY
1051         {
1052                 .ctl_name       = CTL_UNNUMBERED,
1053                 .procname       = "mmap_min_addr",
1054                 .data           = &mmap_min_addr,
1055                 .maxlen         = sizeof(unsigned long),
1056                 .mode           = 0644,
1057                 .proc_handler   = &proc_doulongvec_minmax,
1058         },
1059 #endif
1060 #ifdef CONFIG_NUMA
1061         {
1062                 .ctl_name       = CTL_UNNUMBERED,
1063                 .procname       = "numa_zonelist_order",
1064                 .data           = &numa_zonelist_order,
1065                 .maxlen         = NUMA_ZONELIST_ORDER_LEN,
1066                 .mode           = 0644,
1067                 .proc_handler   = &numa_zonelist_order_handler,
1068                 .strategy       = &sysctl_string,
1069         },
1070 #endif
1071 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1072    (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1073         {
1074                 .ctl_name       = VM_VDSO_ENABLED,
1075                 .procname       = "vdso_enabled",
1076                 .data           = &vdso_enabled,
1077                 .maxlen         = sizeof(vdso_enabled),
1078                 .mode           = 0644,
1079                 .proc_handler   = &proc_dointvec,
1080                 .strategy       = &sysctl_intvec,
1081                 .extra1         = &zero,
1082         },
1083 #endif
1084 /*
1085  * NOTE: do not add new entries to this table unless you have read
1086  * Documentation/sysctl/ctl_unnumbered.txt
1087  */
1088         { .ctl_name = 0 }
1089 };
1090
1091 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1092 static struct ctl_table binfmt_misc_table[] = {
1093         { .ctl_name = 0 }
1094 };
1095 #endif
1096
1097 static struct ctl_table fs_table[] = {
1098         {
1099                 .ctl_name       = FS_NRINODE,
1100                 .procname       = "inode-nr",
1101                 .data           = &inodes_stat,
1102                 .maxlen         = 2*sizeof(int),
1103                 .mode           = 0444,
1104                 .proc_handler   = &proc_dointvec,
1105         },
1106         {
1107                 .ctl_name       = FS_STATINODE,
1108                 .procname       = "inode-state",
1109                 .data           = &inodes_stat,
1110                 .maxlen         = 7*sizeof(int),
1111                 .mode           = 0444,
1112                 .proc_handler   = &proc_dointvec,
1113         },
1114         {
1115                 .procname       = "file-nr",
1116                 .data           = &files_stat,
1117                 .maxlen         = 3*sizeof(int),
1118                 .mode           = 0444,
1119                 .proc_handler   = &proc_nr_files,
1120         },
1121         {
1122                 .ctl_name       = FS_MAXFILE,
1123                 .procname       = "file-max",
1124                 .data           = &files_stat.max_files,
1125                 .maxlen         = sizeof(int),
1126                 .mode           = 0644,
1127                 .proc_handler   = &proc_dointvec,
1128         },
1129         {
1130                 .ctl_name       = FS_DENTRY,
1131                 .procname       = "dentry-state",
1132                 .data           = &dentry_stat,
1133                 .maxlen         = 6*sizeof(int),
1134                 .mode           = 0444,
1135                 .proc_handler   = &proc_dointvec,
1136         },
1137         {
1138                 .ctl_name       = FS_OVERFLOWUID,
1139                 .procname       = "overflowuid",
1140                 .data           = &fs_overflowuid,
1141                 .maxlen         = sizeof(int),
1142                 .mode           = 0644,
1143                 .proc_handler   = &proc_dointvec_minmax,
1144                 .strategy       = &sysctl_intvec,
1145                 .extra1         = &minolduid,
1146                 .extra2         = &maxolduid,
1147         },
1148         {
1149                 .ctl_name       = FS_OVERFLOWGID,
1150                 .procname       = "overflowgid",
1151                 .data           = &fs_overflowgid,
1152                 .maxlen         = sizeof(int),
1153                 .mode           = 0644,
1154                 .proc_handler   = &proc_dointvec_minmax,
1155                 .strategy       = &sysctl_intvec,
1156                 .extra1         = &minolduid,
1157                 .extra2         = &maxolduid,
1158         },
1159         {
1160                 .ctl_name       = FS_LEASES,
1161                 .procname       = "leases-enable",
1162                 .data           = &leases_enable,
1163                 .maxlen         = sizeof(int),
1164                 .mode           = 0644,
1165                 .proc_handler   = &proc_dointvec,
1166         },
1167 #ifdef CONFIG_DNOTIFY
1168         {
1169                 .ctl_name       = FS_DIR_NOTIFY,
1170                 .procname       = "dir-notify-enable",
1171                 .data           = &dir_notify_enable,
1172                 .maxlen         = sizeof(int),
1173                 .mode           = 0644,
1174                 .proc_handler   = &proc_dointvec,
1175         },
1176 #endif
1177 #ifdef CONFIG_MMU
1178         {
1179                 .ctl_name       = FS_LEASE_TIME,
1180                 .procname       = "lease-break-time",
1181                 .data           = &lease_break_time,
1182                 .maxlen         = sizeof(int),
1183                 .mode           = 0644,
1184                 .proc_handler   = &proc_dointvec_minmax,
1185                 .strategy       = &sysctl_intvec,
1186                 .extra1         = &zero,
1187                 .extra2         = &two,
1188         },
1189         {
1190                 .procname       = "aio-nr",
1191                 .data           = &aio_nr,
1192                 .maxlen         = sizeof(aio_nr),
1193                 .mode           = 0444,
1194                 .proc_handler   = &proc_doulongvec_minmax,
1195         },
1196         {
1197                 .procname       = "aio-max-nr",
1198                 .data           = &aio_max_nr,
1199                 .maxlen         = sizeof(aio_max_nr),
1200                 .mode           = 0644,
1201                 .proc_handler   = &proc_doulongvec_minmax,
1202         },
1203 #ifdef CONFIG_INOTIFY_USER
1204         {
1205                 .ctl_name       = FS_INOTIFY,
1206                 .procname       = "inotify",
1207                 .mode           = 0555,
1208                 .child          = inotify_table,
1209         },
1210 #endif  
1211 #endif
1212         {
1213                 .ctl_name       = KERN_SETUID_DUMPABLE,
1214                 .procname       = "suid_dumpable",
1215                 .data           = &suid_dumpable,
1216                 .maxlen         = sizeof(int),
1217                 .mode           = 0644,
1218                 .proc_handler   = &proc_dointvec,
1219         },
1220 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1221         {
1222                 .ctl_name       = CTL_UNNUMBERED,
1223                 .procname       = "binfmt_misc",
1224                 .mode           = 0555,
1225                 .child          = binfmt_misc_table,
1226         },
1227 #endif
1228 /*
1229  * NOTE: do not add new entries to this table unless you have read
1230  * Documentation/sysctl/ctl_unnumbered.txt
1231  */
1232         { .ctl_name = 0 }
1233 };
1234
1235 static struct ctl_table debug_table[] = {
1236 #if defined(CONFIG_X86) || defined(CONFIG_PPC)
1237         {
1238                 .ctl_name       = CTL_UNNUMBERED,
1239                 .procname       = "exception-trace",
1240                 .data           = &show_unhandled_signals,
1241                 .maxlen         = sizeof(int),
1242                 .mode           = 0644,
1243                 .proc_handler   = proc_dointvec
1244         },
1245 #endif
1246         { .ctl_name = 0 }
1247 };
1248
1249 static struct ctl_table dev_table[] = {
1250         { .ctl_name = 0 }
1251 };
1252
1253 static DEFINE_SPINLOCK(sysctl_lock);
1254
1255 /* called under sysctl_lock */
1256 static int use_table(struct ctl_table_header *p)
1257 {
1258         if (unlikely(p->unregistering))
1259                 return 0;
1260         p->used++;
1261         return 1;
1262 }
1263
1264 /* called under sysctl_lock */
1265 static void unuse_table(struct ctl_table_header *p)
1266 {
1267         if (!--p->used)
1268                 if (unlikely(p->unregistering))
1269                         complete(p->unregistering);
1270 }
1271
1272 /* called under sysctl_lock, will reacquire if has to wait */
1273 static void start_unregistering(struct ctl_table_header *p)
1274 {
1275         /*
1276          * if p->used is 0, nobody will ever touch that entry again;
1277          * we'll eliminate all paths to it before dropping sysctl_lock
1278          */
1279         if (unlikely(p->used)) {
1280                 struct completion wait;
1281                 init_completion(&wait);
1282                 p->unregistering = &wait;
1283                 spin_unlock(&sysctl_lock);
1284                 wait_for_completion(&wait);
1285                 spin_lock(&sysctl_lock);
1286         }
1287         /*
1288          * do not remove from the list until nobody holds it; walking the
1289          * list in do_sysctl() relies on that.
1290          */
1291         list_del_init(&p->ctl_entry);
1292 }
1293
1294 void sysctl_head_finish(struct ctl_table_header *head)
1295 {
1296         if (!head)
1297                 return;
1298         spin_lock(&sysctl_lock);
1299         unuse_table(head);
1300         spin_unlock(&sysctl_lock);
1301 }
1302
1303 struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
1304 {
1305         struct ctl_table_header *head;
1306         struct list_head *tmp;
1307         spin_lock(&sysctl_lock);
1308         if (prev) {
1309                 tmp = &prev->ctl_entry;
1310                 unuse_table(prev);
1311                 goto next;
1312         }
1313         tmp = &root_table_header.ctl_entry;
1314         for (;;) {
1315                 head = list_entry(tmp, struct ctl_table_header, ctl_entry);
1316
1317                 if (!use_table(head))
1318                         goto next;
1319                 spin_unlock(&sysctl_lock);
1320                 return head;
1321         next:
1322                 tmp = tmp->next;
1323                 if (tmp == &root_table_header.ctl_entry)
1324                         break;
1325         }
1326         spin_unlock(&sysctl_lock);
1327         return NULL;
1328 }
1329
1330 #ifdef CONFIG_SYSCTL_SYSCALL
1331 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1332                void __user *newval, size_t newlen)
1333 {
1334         struct ctl_table_header *head;
1335         int error = -ENOTDIR;
1336
1337         if (nlen <= 0 || nlen >= CTL_MAXNAME)
1338                 return -ENOTDIR;
1339         if (oldval) {
1340                 int old_len;
1341                 if (!oldlenp || get_user(old_len, oldlenp))
1342                         return -EFAULT;
1343         }
1344
1345         for (head = sysctl_head_next(NULL); head;
1346                         head = sysctl_head_next(head)) {
1347                 error = parse_table(name, nlen, oldval, oldlenp, 
1348                                         newval, newlen, head->ctl_table);
1349                 if (error != -ENOTDIR) {
1350                         sysctl_head_finish(head);
1351                         break;
1352                 }
1353         }
1354         return error;
1355 }
1356
1357 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1358 {
1359         struct __sysctl_args tmp;
1360         int error;
1361
1362         if (copy_from_user(&tmp, args, sizeof(tmp)))
1363                 return -EFAULT;
1364
1365         error = deprecated_sysctl_warning(&tmp);
1366         if (error)
1367                 goto out;
1368
1369         lock_kernel();
1370         error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1371                           tmp.newval, tmp.newlen);
1372         unlock_kernel();
1373 out:
1374         return error;
1375 }
1376 #endif /* CONFIG_SYSCTL_SYSCALL */
1377
1378 /*
1379  * sysctl_perm does NOT grant the superuser all rights automatically, because
1380  * some sysctl variables are readonly even to root.
1381  */
1382
1383 static int test_perm(int mode, int op)
1384 {
1385         if (!current->euid)
1386                 mode >>= 6;
1387         else if (in_egroup_p(0))
1388                 mode >>= 3;
1389         if ((mode & op & 0007) == op)
1390                 return 0;
1391         return -EACCES;
1392 }
1393
1394 int sysctl_perm(struct ctl_table *table, int op)
1395 {
1396         int error;
1397         error = security_sysctl(table, op);
1398         if (error)
1399                 return error;
1400         return test_perm(table->mode, op);
1401 }
1402
1403 #ifdef CONFIG_SYSCTL_SYSCALL
1404 static int parse_table(int __user *name, int nlen,
1405                        void __user *oldval, size_t __user *oldlenp,
1406                        void __user *newval, size_t newlen,
1407                        struct ctl_table *table)
1408 {
1409         int n;
1410 repeat:
1411         if (!nlen)
1412                 return -ENOTDIR;
1413         if (get_user(n, name))
1414                 return -EFAULT;
1415         for ( ; table->ctl_name || table->procname; table++) {
1416                 if (!table->ctl_name)
1417                         continue;
1418                 if (n == table->ctl_name) {
1419                         int error;
1420                         if (table->child) {
1421                                 if (sysctl_perm(table, 001))
1422                                         return -EPERM;
1423                                 name++;
1424                                 nlen--;
1425                                 table = table->child;
1426                                 goto repeat;
1427                         }
1428                         error = do_sysctl_strategy(table, name, nlen,
1429                                                    oldval, oldlenp,
1430                                                    newval, newlen);
1431                         return error;
1432                 }
1433         }
1434         return -ENOTDIR;
1435 }
1436
1437 /* Perform the actual read/write of a sysctl table entry. */
1438 int do_sysctl_strategy (struct ctl_table *table,
1439                         int __user *name, int nlen,
1440                         void __user *oldval, size_t __user *oldlenp,
1441                         void __user *newval, size_t newlen)
1442 {
1443         int op = 0, rc;
1444
1445         if (oldval)
1446                 op |= 004;
1447         if (newval) 
1448                 op |= 002;
1449         if (sysctl_perm(table, op))
1450                 return -EPERM;
1451
1452         if (table->strategy) {
1453                 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1454                                      newval, newlen);
1455                 if (rc < 0)
1456                         return rc;
1457                 if (rc > 0)
1458                         return 0;
1459         }
1460
1461         /* If there is no strategy routine, or if the strategy returns
1462          * zero, proceed with automatic r/w */
1463         if (table->data && table->maxlen) {
1464                 rc = sysctl_data(table, name, nlen, oldval, oldlenp,
1465                                  newval, newlen);
1466                 if (rc < 0)
1467                         return rc;
1468         }
1469         return 0;
1470 }
1471 #endif /* CONFIG_SYSCTL_SYSCALL */
1472
1473 static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)
1474 {
1475         for (; table->ctl_name || table->procname; table++) {
1476                 table->parent = parent;
1477                 if (table->child)
1478                         sysctl_set_parent(table, table->child);
1479         }
1480 }
1481
1482 static __init int sysctl_init(void)
1483 {
1484         int err;
1485         sysctl_set_parent(NULL, root_table);
1486         err = sysctl_check_table(root_table);
1487         return 0;
1488 }
1489
1490 core_initcall(sysctl_init);
1491
1492 /**
1493  * register_sysctl_table - register a sysctl hierarchy
1494  * @table: the top-level table structure
1495  *
1496  * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1497  * array. An entry with a ctl_name of 0 terminates the table. 
1498  *
1499  * The members of the &struct ctl_table structure are used as follows:
1500  *
1501  * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1502  *            must be unique within that level of sysctl
1503  *
1504  * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1505  *            enter a sysctl file
1506  *
1507  * data - a pointer to data for use by proc_handler
1508  *
1509  * maxlen - the maximum size in bytes of the data
1510  *
1511  * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1512  *
1513  * child - a pointer to the child sysctl table if this entry is a directory, or
1514  *         %NULL.
1515  *
1516  * proc_handler - the text handler routine (described below)
1517  *
1518  * strategy - the strategy routine (described below)
1519  *
1520  * de - for internal use by the sysctl routines
1521  *
1522  * extra1, extra2 - extra pointers usable by the proc handler routines
1523  *
1524  * Leaf nodes in the sysctl tree will be represented by a single file
1525  * under /proc; non-leaf nodes will be represented by directories.
1526  *
1527  * sysctl(2) can automatically manage read and write requests through
1528  * the sysctl table.  The data and maxlen fields of the ctl_table
1529  * struct enable minimal validation of the values being written to be
1530  * performed, and the mode field allows minimal authentication.
1531  *
1532  * More sophisticated management can be enabled by the provision of a
1533  * strategy routine with the table entry.  This will be called before
1534  * any automatic read or write of the data is performed.
1535  *
1536  * The strategy routine may return
1537  *
1538  * < 0 - Error occurred (error is passed to user process)
1539  *
1540  * 0   - OK - proceed with automatic read or write.
1541  *
1542  * > 0 - OK - read or write has been done by the strategy routine, so
1543  *       return immediately.
1544  *
1545  * There must be a proc_handler routine for any terminal nodes
1546  * mirrored under /proc/sys (non-terminals are handled by a built-in
1547  * directory handler).  Several default handlers are available to
1548  * cover common cases -
1549  *
1550  * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1551  * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), 
1552  * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1553  *
1554  * It is the handler's job to read the input buffer from user memory
1555  * and process it. The handler should return 0 on success.
1556  *
1557  * This routine returns %NULL on a failure to register, and a pointer
1558  * to the table header on success.
1559  */
1560 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1561 {
1562         struct ctl_table_header *tmp;
1563         tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1564         if (!tmp)
1565                 return NULL;
1566         tmp->ctl_table = table;
1567         INIT_LIST_HEAD(&tmp->ctl_entry);
1568         tmp->used = 0;
1569         tmp->unregistering = NULL;
1570         sysctl_set_parent(NULL, table);
1571         if (sysctl_check_table(tmp->ctl_table)) {
1572                 kfree(tmp);
1573                 return NULL;
1574         }
1575         spin_lock(&sysctl_lock);
1576         list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1577         spin_unlock(&sysctl_lock);
1578         return tmp;
1579 }
1580
1581 /**
1582  * unregister_sysctl_table - unregister a sysctl table hierarchy
1583  * @header: the header returned from register_sysctl_table
1584  *
1585  * Unregisters the sysctl table and all children. proc entries may not
1586  * actually be removed until they are no longer used by anyone.
1587  */
1588 void unregister_sysctl_table(struct ctl_table_header * header)
1589 {
1590         might_sleep();
1591
1592         if (header == NULL)
1593                 return;
1594
1595         spin_lock(&sysctl_lock);
1596         start_unregistering(header);
1597         spin_unlock(&sysctl_lock);
1598         kfree(header);
1599 }
1600
1601 #else /* !CONFIG_SYSCTL */
1602 struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
1603 {
1604         return NULL;
1605 }
1606
1607 void unregister_sysctl_table(struct ctl_table_header * table)
1608 {
1609 }
1610
1611 #endif /* CONFIG_SYSCTL */
1612
1613 /*
1614  * /proc/sys support
1615  */
1616
1617 #ifdef CONFIG_PROC_SYSCTL
1618
1619 static int _proc_do_string(void* data, int maxlen, int write,
1620                            struct file *filp, void __user *buffer,
1621                            size_t *lenp, loff_t *ppos)
1622 {
1623         size_t len;
1624         char __user *p;
1625         char c;
1626
1627         if (!data || !maxlen || !*lenp) {
1628                 *lenp = 0;
1629                 return 0;
1630         }
1631
1632         if (write) {
1633                 len = 0;
1634                 p = buffer;
1635                 while (len < *lenp) {
1636                         if (get_user(c, p++))
1637                                 return -EFAULT;
1638                         if (c == 0 || c == '\n')
1639                                 break;
1640                         len++;
1641                 }
1642                 if (len >= maxlen)
1643                         len = maxlen-1;
1644                 if(copy_from_user(data, buffer, len))
1645                         return -EFAULT;
1646                 ((char *) data)[len] = 0;
1647                 *ppos += *lenp;
1648         } else {
1649                 len = strlen(data);
1650                 if (len > maxlen)
1651                         len = maxlen;
1652
1653                 if (*ppos > len) {
1654                         *lenp = 0;
1655                         return 0;
1656                 }
1657
1658                 data += *ppos;
1659                 len  -= *ppos;
1660
1661                 if (len > *lenp)
1662                         len = *lenp;
1663                 if (len)
1664                         if(copy_to_user(buffer, data, len))
1665                                 return -EFAULT;
1666                 if (len < *lenp) {
1667                         if(put_user('\n', ((char __user *) buffer) + len))
1668                                 return -EFAULT;
1669                         len++;
1670                 }
1671                 *lenp = len;
1672                 *ppos += len;
1673         }
1674         return 0;
1675 }
1676
1677 /**
1678  * proc_dostring - read a string sysctl
1679  * @table: the sysctl table
1680  * @write: %TRUE if this is a write to the sysctl file
1681  * @filp: the file structure
1682  * @buffer: the user buffer
1683  * @lenp: the size of the user buffer
1684  * @ppos: file position
1685  *
1686  * Reads/writes a string from/to the user buffer. If the kernel
1687  * buffer provided is not large enough to hold the string, the
1688  * string is truncated. The copied string is %NULL-terminated.
1689  * If the string is being read by the user process, it is copied
1690  * and a newline '\n' is added. It is truncated if the buffer is
1691  * not large enough.
1692  *
1693  * Returns 0 on success.
1694  */
1695 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
1696                   void __user *buffer, size_t *lenp, loff_t *ppos)
1697 {
1698         return _proc_do_string(table->data, table->maxlen, write, filp,
1699                                buffer, lenp, ppos);
1700 }
1701
1702
1703 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1704                                  int *valp,
1705                                  int write, void *data)
1706 {
1707         if (write) {
1708                 *valp = *negp ? -*lvalp : *lvalp;
1709         } else {
1710                 int val = *valp;
1711                 if (val < 0) {
1712                         *negp = -1;
1713                         *lvalp = (unsigned long)-val;
1714                 } else {
1715                         *negp = 0;
1716                         *lvalp = (unsigned long)val;
1717                 }
1718         }
1719         return 0;
1720 }
1721
1722 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
1723                   int write, struct file *filp, void __user *buffer,
1724                   size_t *lenp, loff_t *ppos,
1725                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1726                               int write, void *data),
1727                   void *data)
1728 {
1729 #define TMPBUFLEN 21
1730         int *i, vleft, first=1, neg, val;
1731         unsigned long lval;
1732         size_t left, len;
1733         
1734         char buf[TMPBUFLEN], *p;
1735         char __user *s = buffer;
1736         
1737         if (!tbl_data || !table->maxlen || !*lenp ||
1738             (*ppos && !write)) {
1739                 *lenp = 0;
1740                 return 0;
1741         }
1742         
1743         i = (int *) tbl_data;
1744         vleft = table->maxlen / sizeof(*i);
1745         left = *lenp;
1746
1747         if (!conv)
1748                 conv = do_proc_dointvec_conv;
1749
1750         for (; left && vleft--; i++, first=0) {
1751                 if (write) {
1752                         while (left) {
1753                                 char c;
1754                                 if (get_user(c, s))
1755                                         return -EFAULT;
1756                                 if (!isspace(c))
1757                                         break;
1758                                 left--;
1759                                 s++;
1760                         }
1761                         if (!left)
1762                                 break;
1763                         neg = 0;
1764                         len = left;
1765                         if (len > sizeof(buf) - 1)
1766                                 len = sizeof(buf) - 1;
1767                         if (copy_from_user(buf, s, len))
1768                                 return -EFAULT;
1769                         buf[len] = 0;
1770                         p = buf;
1771                         if (*p == '-' && left > 1) {
1772                                 neg = 1;
1773                                 p++;
1774                         }
1775                         if (*p < '0' || *p > '9')
1776                                 break;
1777
1778                         lval = simple_strtoul(p, &p, 0);
1779
1780                         len = p-buf;
1781                         if ((len < left) && *p && !isspace(*p))
1782                                 break;
1783                         if (neg)
1784                                 val = -val;
1785                         s += len;
1786                         left -= len;
1787
1788                         if (conv(&neg, &lval, i, 1, data))
1789                                 break;
1790                 } else {
1791                         p = buf;
1792                         if (!first)
1793                                 *p++ = '\t';
1794         
1795                         if (conv(&neg, &lval, i, 0, data))
1796                                 break;
1797
1798                         sprintf(p, "%s%lu", neg ? "-" : "", lval);
1799                         len = strlen(buf);
1800                         if (len > left)
1801                                 len = left;
1802                         if(copy_to_user(s, buf, len))
1803                                 return -EFAULT;
1804                         left -= len;
1805                         s += len;
1806                 }
1807         }
1808
1809         if (!write && !first && left) {
1810                 if(put_user('\n', s))
1811                         return -EFAULT;
1812                 left--, s++;
1813         }
1814         if (write) {
1815                 while (left) {
1816                         char c;
1817                         if (get_user(c, s++))
1818                                 return -EFAULT;
1819                         if (!isspace(c))
1820                                 break;
1821                         left--;
1822                 }
1823         }
1824         if (write && first)
1825                 return -EINVAL;
1826         *lenp -= left;
1827         *ppos += *lenp;
1828         return 0;
1829 #undef TMPBUFLEN
1830 }
1831
1832 static int do_proc_dointvec(struct ctl_table *table, int write, struct file *filp,
1833                   void __user *buffer, size_t *lenp, loff_t *ppos,
1834                   int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1835                               int write, void *data),
1836                   void *data)
1837 {
1838         return __do_proc_dointvec(table->data, table, write, filp,
1839                         buffer, lenp, ppos, conv, data);
1840 }
1841
1842 /**
1843  * proc_dointvec - read a vector of integers
1844  * @table: the sysctl table
1845  * @write: %TRUE if this is a write to the sysctl file
1846  * @filp: the file structure
1847  * @buffer: the user buffer
1848  * @lenp: the size of the user buffer
1849  * @ppos: file position
1850  *
1851  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1852  * values from/to the user buffer, treated as an ASCII string. 
1853  *
1854  * Returns 0 on success.
1855  */
1856 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
1857                      void __user *buffer, size_t *lenp, loff_t *ppos)
1858 {
1859     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1860                             NULL,NULL);
1861 }
1862
1863 #define OP_SET  0
1864 #define OP_AND  1
1865 #define OP_OR   2
1866
1867 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1868                                       int *valp,
1869                                       int write, void *data)
1870 {
1871         int op = *(int *)data;
1872         if (write) {
1873                 int val = *negp ? -*lvalp : *lvalp;
1874                 switch(op) {
1875                 case OP_SET:    *valp = val; break;
1876                 case OP_AND:    *valp &= val; break;
1877                 case OP_OR:     *valp |= val; break;
1878                 }
1879         } else {
1880                 int val = *valp;
1881                 if (val < 0) {
1882                         *negp = -1;
1883                         *lvalp = (unsigned long)-val;
1884                 } else {
1885                         *negp = 0;
1886                         *lvalp = (unsigned long)val;
1887                 }
1888         }
1889         return 0;
1890 }
1891
1892 #ifdef CONFIG_SECURITY_CAPABILITIES
1893 /*
1894  *      init may raise the set.
1895  */
1896
1897 int proc_dointvec_bset(struct ctl_table *table, int write, struct file *filp,
1898                         void __user *buffer, size_t *lenp, loff_t *ppos)
1899 {
1900         int op;
1901
1902         if (write && !capable(CAP_SYS_MODULE)) {
1903                 return -EPERM;
1904         }
1905
1906         op = is_global_init(current) ? OP_SET : OP_AND;
1907         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1908                                 do_proc_dointvec_bset_conv,&op);
1909 }
1910 #endif /* def CONFIG_SECURITY_CAPABILITIES */
1911
1912 /*
1913  *      Taint values can only be increased
1914  */
1915 static int proc_dointvec_taint(struct ctl_table *table, int write, struct file *filp,
1916                                void __user *buffer, size_t *lenp, loff_t *ppos)
1917 {
1918         int op;
1919
1920         if (write && !capable(CAP_SYS_ADMIN))
1921                 return -EPERM;
1922
1923         op = OP_OR;
1924         return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1925                                 do_proc_dointvec_bset_conv,&op);
1926 }
1927
1928 struct do_proc_dointvec_minmax_conv_param {
1929         int *min;
1930         int *max;
1931 };
1932
1933 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp, 
1934                                         int *valp, 
1935                                         int write, void *data)
1936 {
1937         struct do_proc_dointvec_minmax_conv_param *param = data;
1938         if (write) {
1939                 int val = *negp ? -*lvalp : *lvalp;
1940                 if ((param->min && *param->min > val) ||
1941                     (param->max && *param->max < val))
1942                         return -EINVAL;
1943                 *valp = val;
1944         } else {
1945                 int val = *valp;
1946                 if (val < 0) {
1947                         *negp = -1;
1948                         *lvalp = (unsigned long)-val;
1949                 } else {
1950                         *negp = 0;
1951                         *lvalp = (unsigned long)val;
1952                 }
1953         }
1954         return 0;
1955 }
1956
1957 /**
1958  * proc_dointvec_minmax - read a vector of integers with min/max values
1959  * @table: the sysctl table
1960  * @write: %TRUE if this is a write to the sysctl file
1961  * @filp: the file structure
1962  * @buffer: the user buffer
1963  * @lenp: the size of the user buffer
1964  * @ppos: file position
1965  *
1966  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1967  * values from/to the user buffer, treated as an ASCII string.
1968  *
1969  * This routine will ensure the values are within the range specified by
1970  * table->extra1 (min) and table->extra2 (max).
1971  *
1972  * Returns 0 on success.
1973  */
1974 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
1975                   void __user *buffer, size_t *lenp, loff_t *ppos)
1976 {
1977         struct do_proc_dointvec_minmax_conv_param param = {
1978                 .min = (int *) table->extra1,
1979                 .max = (int *) table->extra2,
1980         };
1981         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
1982                                 do_proc_dointvec_minmax_conv, &param);
1983 }
1984
1985 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
1986                                      struct file *filp,
1987                                      void __user *buffer,
1988                                      size_t *lenp, loff_t *ppos,
1989                                      unsigned long convmul,
1990                                      unsigned long convdiv)
1991 {
1992 #define TMPBUFLEN 21
1993         unsigned long *i, *min, *max, val;
1994         int vleft, first=1, neg;
1995         size_t len, left;
1996         char buf[TMPBUFLEN], *p;
1997         char __user *s = buffer;
1998         
1999         if (!data || !table->maxlen || !*lenp ||
2000             (*ppos && !write)) {
2001                 *lenp = 0;
2002                 return 0;
2003         }
2004         
2005         i = (unsigned long *) data;
2006         min = (unsigned long *) table->extra1;
2007         max = (unsigned long *) table->extra2;
2008         vleft = table->maxlen / sizeof(unsigned long);
2009         left = *lenp;
2010         
2011         for (; left && vleft--; i++, min++, max++, first=0) {
2012                 if (write) {
2013                         while (left) {
2014                                 char c;
2015                                 if (get_user(c, s))
2016                                         return -EFAULT;
2017                                 if (!isspace(c))
2018                                         break;
2019                                 left--;
2020                                 s++;
2021                         }
2022                         if (!left)
2023                                 break;
2024                         neg = 0;
2025                         len = left;
2026                         if (len > TMPBUFLEN-1)
2027                                 len = TMPBUFLEN-1;
2028                         if (copy_from_user(buf, s, len))
2029                                 return -EFAULT;
2030                         buf[len] = 0;
2031                         p = buf;
2032                         if (*p == '-' && left > 1) {
2033                                 neg = 1;
2034                                 p++;
2035                         }
2036                         if (*p < '0' || *p > '9')
2037                                 break;
2038                         val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2039                         len = p-buf;
2040                         if ((len < left) && *p && !isspace(*p))
2041                                 break;
2042                         if (neg)
2043                                 val = -val;
2044                         s += len;
2045                         left -= len;
2046
2047                         if(neg)
2048                                 continue;
2049                         if ((min && val < *min) || (max && val > *max))
2050                                 continue;
2051                         *i = val;
2052                 } else {
2053                         p = buf;
2054                         if (!first)
2055                                 *p++ = '\t';
2056                         sprintf(p, "%lu", convdiv * (*i) / convmul);
2057                         len = strlen(buf);
2058                         if (len > left)
2059                                 len = left;
2060                         if(copy_to_user(s, buf, len))
2061                                 return -EFAULT;
2062                         left -= len;
2063                         s += len;
2064                 }
2065         }
2066
2067         if (!write && !first && left) {
2068                 if(put_user('\n', s))
2069                         return -EFAULT;
2070                 left--, s++;
2071         }
2072         if (write) {
2073                 while (left) {
2074                         char c;
2075                         if (get_user(c, s++))
2076                                 return -EFAULT;
2077                         if (!isspace(c))
2078                                 break;
2079                         left--;
2080                 }
2081         }
2082         if (write && first)
2083                 return -EINVAL;
2084         *lenp -= left;
2085         *ppos += *lenp;
2086         return 0;
2087 #undef TMPBUFLEN
2088 }
2089
2090 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2091                                      struct file *filp,
2092                                      void __user *buffer,
2093                                      size_t *lenp, loff_t *ppos,
2094                                      unsigned long convmul,
2095                                      unsigned long convdiv)
2096 {
2097         return __do_proc_doulongvec_minmax(table->data, table, write,
2098                         filp, buffer, lenp, ppos, convmul, convdiv);
2099 }
2100
2101 /**
2102  * proc_doulongvec_minmax - read a vector of long integers with min/max values
2103  * @table: the sysctl table
2104  * @write: %TRUE if this is a write to the sysctl file
2105  * @filp: the file structure
2106  * @buffer: the user buffer
2107  * @lenp: the size of the user buffer
2108  * @ppos: file position
2109  *
2110  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2111  * values from/to the user buffer, treated as an ASCII string.
2112  *
2113  * This routine will ensure the values are within the range specified by
2114  * table->extra1 (min) and table->extra2 (max).
2115  *
2116  * Returns 0 on success.
2117  */
2118 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2119                            void __user *buffer, size_t *lenp, loff_t *ppos)
2120 {
2121     return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2122 }
2123
2124 /**
2125  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2126  * @table: the sysctl table
2127  * @write: %TRUE if this is a write to the sysctl file
2128  * @filp: the file structure
2129  * @buffer: the user buffer
2130  * @lenp: the size of the user buffer
2131  * @ppos: file position
2132  *
2133  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2134  * values from/to the user buffer, treated as an ASCII string. The values
2135  * are treated as milliseconds, and converted to jiffies when they are stored.
2136  *
2137  * This routine will ensure the values are within the range specified by
2138  * table->extra1 (min) and table->extra2 (max).
2139  *
2140  * Returns 0 on success.
2141  */
2142 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2143                                       struct file *filp,
2144                                       void __user *buffer,
2145                                       size_t *lenp, loff_t *ppos)
2146 {
2147     return do_proc_doulongvec_minmax(table, write, filp, buffer,
2148                                      lenp, ppos, HZ, 1000l);
2149 }
2150
2151
2152 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2153                                          int *valp,
2154                                          int write, void *data)
2155 {
2156         if (write) {
2157                 if (*lvalp > LONG_MAX / HZ)
2158                         return 1;
2159                 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2160         } else {
2161                 int val = *valp;
2162                 unsigned long lval;
2163                 if (val < 0) {
2164                         *negp = -1;
2165                         lval = (unsigned long)-val;
2166                 } else {
2167                         *negp = 0;
2168                         lval = (unsigned long)val;
2169                 }
2170                 *lvalp = lval / HZ;
2171         }
2172         return 0;
2173 }
2174
2175 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2176                                                 int *valp,
2177                                                 int write, void *data)
2178 {
2179         if (write) {
2180                 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2181                         return 1;
2182                 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2183         } else {
2184                 int val = *valp;
2185                 unsigned long lval;
2186                 if (val < 0) {
2187                         *negp = -1;
2188                         lval = (unsigned long)-val;
2189                 } else {
2190                         *negp = 0;
2191                         lval = (unsigned long)val;
2192                 }
2193                 *lvalp = jiffies_to_clock_t(lval);
2194         }
2195         return 0;
2196 }
2197
2198 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2199                                             int *valp,
2200                                             int write, void *data)
2201 {
2202         if (write) {
2203                 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2204         } else {
2205                 int val = *valp;
2206                 unsigned long lval;
2207                 if (val < 0) {
2208                         *negp = -1;
2209                         lval = (unsigned long)-val;
2210                 } else {
2211                         *negp = 0;
2212                         lval = (unsigned long)val;
2213                 }
2214                 *lvalp = jiffies_to_msecs(lval);
2215         }
2216         return 0;
2217 }
2218
2219 /**
2220  * proc_dointvec_jiffies - read a vector of integers as seconds
2221  * @table: the sysctl table
2222  * @write: %TRUE if this is a write to the sysctl file
2223  * @filp: the file structure
2224  * @buffer: the user buffer
2225  * @lenp: the size of the user buffer
2226  * @ppos: file position
2227  *
2228  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2229  * values from/to the user buffer, treated as an ASCII string. 
2230  * The values read are assumed to be in seconds, and are converted into
2231  * jiffies.
2232  *
2233  * Returns 0 on success.
2234  */
2235 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2236                           void __user *buffer, size_t *lenp, loff_t *ppos)
2237 {
2238     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2239                             do_proc_dointvec_jiffies_conv,NULL);
2240 }
2241
2242 /**
2243  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2244  * @table: the sysctl table
2245  * @write: %TRUE if this is a write to the sysctl file
2246  * @filp: the file structure
2247  * @buffer: the user buffer
2248  * @lenp: the size of the user buffer
2249  * @ppos: pointer to the file position
2250  *
2251  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2252  * values from/to the user buffer, treated as an ASCII string. 
2253  * The values read are assumed to be in 1/USER_HZ seconds, and 
2254  * are converted into jiffies.
2255  *
2256  * Returns 0 on success.
2257  */
2258 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2259                                  void __user *buffer, size_t *lenp, loff_t *ppos)
2260 {
2261     return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2262                             do_proc_dointvec_userhz_jiffies_conv,NULL);
2263 }
2264
2265 /**
2266  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2267  * @table: the sysctl table
2268  * @write: %TRUE if this is a write to the sysctl file
2269  * @filp: the file structure
2270  * @buffer: the user buffer
2271  * @lenp: the size of the user buffer
2272  * @ppos: file position
2273  * @ppos: the current position in the file
2274  *
2275  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2276  * values from/to the user buffer, treated as an ASCII string. 
2277  * The values read are assumed to be in 1/1000 seconds, and 
2278  * are converted into jiffies.
2279  *
2280  * Returns 0 on success.
2281  */
2282 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2283                              void __user *buffer, size_t *lenp, loff_t *ppos)
2284 {
2285         return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2286                                 do_proc_dointvec_ms_jiffies_conv, NULL);
2287 }
2288
2289 static int proc_do_cad_pid(struct ctl_table *table, int write, struct file *filp,
2290                            void __user *buffer, size_t *lenp, loff_t *ppos)
2291 {
2292         struct pid *new_pid;
2293         pid_t tmp;
2294         int r;
2295
2296         tmp = pid_nr_ns(cad_pid, current->nsproxy->pid_ns);
2297
2298         r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2299                                lenp, ppos, NULL, NULL);
2300         if (r || !write)
2301                 return r;
2302
2303         new_pid = find_get_pid(tmp);
2304         if (!new_pid)
2305                 return -ESRCH;
2306
2307         put_pid(xchg(&cad_pid, new_pid));
2308         return 0;
2309 }
2310
2311 #else /* CONFIG_PROC_FS */
2312
2313 int proc_dostring(struct ctl_table *table, int write, struct file *filp,
2314                   void __user *buffer, size_t *lenp, loff_t *ppos)
2315 {
2316         return -ENOSYS;
2317 }
2318
2319 int proc_dointvec(struct ctl_table *table, int write, struct file *filp,
2320                   void __user *buffer, size_t *lenp, loff_t *ppos)
2321 {
2322         return -ENOSYS;
2323 }
2324
2325 int proc_dointvec_bset(struct ctl_table *table, int write, struct file *filp,
2326                         void __user *buffer, size_t *lenp, loff_t *ppos)
2327 {
2328         return -ENOSYS;
2329 }
2330
2331 int proc_dointvec_minmax(struct ctl_table *table, int write, struct file *filp,
2332                     void __user *buffer, size_t *lenp, loff_t *ppos)
2333 {
2334         return -ENOSYS;
2335 }
2336
2337 int proc_dointvec_jiffies(struct ctl_table *table, int write, struct file *filp,
2338                     void __user *buffer, size_t *lenp, loff_t *ppos)
2339 {
2340         return -ENOSYS;
2341 }
2342
2343 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, struct file *filp,
2344                     void __user *buffer, size_t *lenp, loff_t *ppos)
2345 {
2346         return -ENOSYS;
2347 }
2348
2349 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, struct file *filp,
2350                              void __user *buffer, size_t *lenp, loff_t *ppos)
2351 {
2352         return -ENOSYS;
2353 }
2354
2355 int proc_doulongvec_minmax(struct ctl_table *table, int write, struct file *filp,
2356                     void __user *buffer, size_t *lenp, loff_t *ppos)
2357 {
2358         return -ENOSYS;
2359 }
2360
2361 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2362                                       struct file *filp,
2363                                       void __user *buffer,
2364                                       size_t *lenp, loff_t *ppos)
2365 {
2366     return -ENOSYS;
2367 }
2368
2369
2370 #endif /* CONFIG_PROC_FS */
2371
2372
2373 #ifdef CONFIG_SYSCTL_SYSCALL
2374 /*
2375  * General sysctl support routines 
2376  */
2377
2378 /* The generic sysctl data routine (used if no strategy routine supplied) */
2379 int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2380                 void __user *oldval, size_t __user *oldlenp,
2381                 void __user *newval, size_t newlen)
2382 {
2383         size_t len;
2384
2385         /* Get out of I don't have a variable */
2386         if (!table->data || !table->maxlen)
2387                 return -ENOTDIR;
2388
2389         if (oldval && oldlenp) {
2390                 if (get_user(len, oldlenp))
2391                         return -EFAULT;
2392                 if (len) {
2393                         if (len > table->maxlen)
2394                                 len = table->maxlen;
2395                         if (copy_to_user(oldval, table->data, len))
2396                                 return -EFAULT;
2397                         if (put_user(len, oldlenp))
2398                                 return -EFAULT;
2399                 }
2400         }
2401
2402         if (newval && newlen) {
2403                 if (newlen > table->maxlen)
2404                         newlen = table->maxlen;
2405
2406                 if (copy_from_user(table->data, newval, newlen))
2407                         return -EFAULT;
2408         }
2409         return 1;
2410 }
2411
2412 /* The generic string strategy routine: */
2413 int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2414                   void __user *oldval, size_t __user *oldlenp,
2415                   void __user *newval, size_t newlen)
2416 {
2417         if (!table->data || !table->maxlen) 
2418                 return -ENOTDIR;
2419         
2420         if (oldval && oldlenp) {
2421                 size_t bufsize;
2422                 if (get_user(bufsize, oldlenp))
2423                         return -EFAULT;
2424                 if (bufsize) {
2425                         size_t len = strlen(table->data), copied;
2426
2427                         /* This shouldn't trigger for a well-formed sysctl */
2428                         if (len > table->maxlen)
2429                                 len = table->maxlen;
2430
2431                         /* Copy up to a max of bufsize-1 bytes of the string */
2432                         copied = (len >= bufsize) ? bufsize - 1 : len;
2433
2434                         if (copy_to_user(oldval, table->data, copied) ||
2435                             put_user(0, (char __user *)(oldval + copied)))
2436                                 return -EFAULT;
2437                         if (put_user(len, oldlenp))
2438                                 return -EFAULT;
2439                 }
2440         }
2441         if (newval && newlen) {
2442                 size_t len = newlen;
2443                 if (len > table->maxlen)
2444                         len = table->maxlen;
2445                 if(copy_from_user(table->data, newval, len))
2446                         return -EFAULT;
2447                 if (len == table->maxlen)
2448                         len--;
2449                 ((char *) table->data)[len] = 0;
2450         }
2451         return 1;
2452 }
2453
2454 /*
2455  * This function makes sure that all of the integers in the vector
2456  * are between the minimum and maximum values given in the arrays
2457  * table->extra1 and table->extra2, respectively.
2458  */
2459 int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2460                 void __user *oldval, size_t __user *oldlenp,
2461                 void __user *newval, size_t newlen)
2462 {
2463
2464         if (newval && newlen) {
2465                 int __user *vec = (int __user *) newval;
2466                 int *min = (int *) table->extra1;
2467                 int *max = (int *) table->extra2;
2468                 size_t length;
2469                 int i;
2470
2471                 if (newlen % sizeof(int) != 0)
2472                         return -EINVAL;
2473
2474                 if (!table->extra1 && !table->extra2)
2475                         return 0;
2476
2477                 if (newlen > table->maxlen)
2478                         newlen = table->maxlen;
2479                 length = newlen / sizeof(int);
2480
2481                 for (i = 0; i < length; i++) {
2482                         int value;
2483                         if (get_user(value, vec + i))
2484                                 return -EFAULT;
2485                         if (min && value < min[i])
2486                                 return -EINVAL;
2487                         if (max && value > max[i])
2488                                 return -EINVAL;
2489                 }
2490         }
2491         return 0;
2492 }
2493
2494 /* Strategy function to convert jiffies to seconds */ 
2495 int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2496                 void __user *oldval, size_t __user *oldlenp,
2497                 void __user *newval, size_t newlen)
2498 {
2499         if (oldval && oldlenp) {
2500                 size_t olen;
2501
2502                 if (get_user(olen, oldlenp))
2503                         return -EFAULT;
2504                 if (olen) {
2505                         int val;
2506
2507                         if (olen < sizeof(int))
2508                                 return -EINVAL;
2509
2510                         val = *(int *)(table->data) / HZ;
2511                         if (put_user(val, (int __user *)oldval))
2512                                 return -EFAULT;
2513                         if (put_user(sizeof(int), oldlenp))
2514                                 return -EFAULT;
2515                 }
2516         }
2517         if (newval && newlen) { 
2518                 int new;
2519                 if (newlen != sizeof(int))
2520                         return -EINVAL; 
2521                 if (get_user(new, (int __user *)newval))
2522                         return -EFAULT;
2523                 *(int *)(table->data) = new*HZ; 
2524         }
2525         return 1;
2526 }
2527
2528 /* Strategy function to convert jiffies to seconds */ 
2529 int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2530                 void __user *oldval, size_t __user *oldlenp,
2531                 void __user *newval, size_t newlen)
2532 {
2533         if (oldval && oldlenp) {
2534                 size_t olen;
2535
2536                 if (get_user(olen, oldlenp))
2537                         return -EFAULT;
2538                 if (olen) {
2539                         int val;
2540
2541                         if (olen < sizeof(int))
2542                                 return -EINVAL;
2543
2544                         val = jiffies_to_msecs(*(int *)(table->data));
2545                         if (put_user(val, (int __user *)oldval))
2546                                 return -EFAULT;
2547                         if (put_user(sizeof(int), oldlenp))
2548                                 return -EFAULT;
2549                 }
2550         }
2551         if (newval && newlen) { 
2552                 int new;
2553                 if (newlen != sizeof(int))
2554                         return -EINVAL; 
2555                 if (get_user(new, (int __user *)newval))
2556                         return -EFAULT;
2557                 *(int *)(table->data) = msecs_to_jiffies(new);
2558         }
2559         return 1;
2560 }
2561
2562
2563
2564 #else /* CONFIG_SYSCTL_SYSCALL */
2565
2566
2567 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2568 {
2569         struct __sysctl_args tmp;
2570         int error;
2571
2572         if (copy_from_user(&tmp, args, sizeof(tmp)))
2573                 return -EFAULT;
2574
2575         error = deprecated_sysctl_warning(&tmp);
2576
2577         /* If no error reading the parameters then just -ENOSYS ... */
2578         if (!error)
2579                 error = -ENOSYS;
2580
2581         return error;
2582 }
2583
2584 int sysctl_data(struct ctl_table *table, int __user *name, int nlen,
2585                   void __user *oldval, size_t __user *oldlenp,
2586                   void __user *newval, size_t newlen)
2587 {
2588         return -ENOSYS;
2589 }
2590
2591 int sysctl_string(struct ctl_table *table, int __user *name, int nlen,
2592                   void __user *oldval, size_t __user *oldlenp,
2593                   void __user *newval, size_t newlen)
2594 {
2595         return -ENOSYS;
2596 }
2597
2598 int sysctl_intvec(struct ctl_table *table, int __user *name, int nlen,
2599                 void __user *oldval, size_t __user *oldlenp,
2600                 void __user *newval, size_t newlen)
2601 {
2602         return -ENOSYS;
2603 }
2604
2605 int sysctl_jiffies(struct ctl_table *table, int __user *name, int nlen,
2606                 void __user *oldval, size_t __user *oldlenp,
2607                 void __user *newval, size_t newlen)
2608 {
2609         return -ENOSYS;
2610 }
2611
2612 int sysctl_ms_jiffies(struct ctl_table *table, int __user *name, int nlen,
2613                 void __user *oldval, size_t __user *oldlenp,
2614                 void __user *newval, size_t newlen)
2615 {
2616         return -ENOSYS;
2617 }
2618
2619 #endif /* CONFIG_SYSCTL_SYSCALL */
2620
2621 static int deprecated_sysctl_warning(struct __sysctl_args *args)
2622 {
2623         static int msg_count;
2624         int name[CTL_MAXNAME];
2625         int i;
2626
2627         /* Check args->nlen. */
2628         if (args->nlen < 0 || args->nlen > CTL_MAXNAME)
2629                 return -ENOTDIR;
2630
2631         /* Read in the sysctl name for better debug message logging */
2632         for (i = 0; i < args->nlen; i++)
2633                 if (get_user(name[i], args->name + i))
2634                         return -EFAULT;
2635
2636         /* Ignore accesses to kernel.version */
2637         if ((args->nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2638                 return 0;
2639
2640         if (msg_count < 5) {
2641                 msg_count++;
2642                 printk(KERN_INFO
2643                         "warning: process `%s' used the deprecated sysctl "
2644                         "system call with ", current->comm);
2645                 for (i = 0; i < args->nlen; i++)
2646                         printk("%d.", name[i]);
2647                 printk("\n");
2648         }
2649         return 0;
2650 }
2651
2652 /*
2653  * No sense putting this after each symbol definition, twice,
2654  * exception granted :-)
2655  */
2656 EXPORT_SYMBOL(proc_dointvec);
2657 EXPORT_SYMBOL(proc_dointvec_jiffies);
2658 EXPORT_SYMBOL(proc_dointvec_minmax);
2659 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2660 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2661 EXPORT_SYMBOL(proc_dostring);
2662 EXPORT_SYMBOL(proc_doulongvec_minmax);
2663 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2664 EXPORT_SYMBOL(register_sysctl_table);
2665 EXPORT_SYMBOL(sysctl_intvec);
2666 EXPORT_SYMBOL(sysctl_jiffies);
2667 EXPORT_SYMBOL(sysctl_ms_jiffies);
2668 EXPORT_SYMBOL(sysctl_string);
2669 EXPORT_SYMBOL(sysctl_data);
2670 EXPORT_SYMBOL(unregister_sysctl_table);