2 * sysctl.c: General linux system control interface
4 * Begun 24 March 1995, Stephen Tweedie
5 * Added /proc support, Dec 1995
6 * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
7 * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
8 * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
9 * Dynamic registration fixes, Stephen Tweedie.
10 * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
11 * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
13 * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
14 * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
15 * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
17 * The list_for_each() macro wasn't appropriate for the sysctl loop.
18 * Removed it and replaced it with older style, 03/23/00, Bill Wendling
21 #include <linux/module.h>
23 #include <linux/swap.h>
24 #include <linux/slab.h>
25 #include <linux/sysctl.h>
26 #include <linux/proc_fs.h>
27 #include <linux/capability.h>
28 #include <linux/ctype.h>
29 #include <linux/utsname.h>
30 #include <linux/capability.h>
31 #include <linux/smp_lock.h>
32 #include <linux/init.h>
33 #include <linux/kernel.h>
34 #include <linux/kobject.h>
35 #include <linux/net.h>
36 #include <linux/sysrq.h>
37 #include <linux/highuid.h>
38 #include <linux/writeback.h>
39 #include <linux/hugetlb.h>
40 #include <linux/security.h>
41 #include <linux/initrd.h>
42 #include <linux/times.h>
43 #include <linux/limits.h>
44 #include <linux/dcache.h>
45 #include <linux/syscalls.h>
46 #include <linux/nfs_fs.h>
47 #include <linux/acpi.h>
49 #include <asm/uaccess.h>
50 #include <asm/processor.h>
52 extern int proc_nr_files(ctl_table *table, int write, struct file *filp,
53 void __user *buffer, size_t *lenp, loff_t *ppos);
57 #include <asm/stacktrace.h>
60 #if defined(CONFIG_SYSCTL)
62 /* External variables not in a header file. */
64 extern int sysctl_overcommit_memory;
65 extern int sysctl_overcommit_ratio;
66 extern int sysctl_panic_on_oom;
67 extern int max_threads;
68 extern int core_uses_pid;
69 extern int suid_dumpable;
70 extern char core_pattern[];
72 extern int min_free_kbytes;
73 extern int printk_ratelimit_jiffies;
74 extern int printk_ratelimit_burst;
75 extern int pid_max_min, pid_max_max;
76 extern int sysctl_drop_caches;
77 extern int percpu_pagelist_fraction;
78 extern int compat_log;
80 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
81 static int maxolduid = 65535;
83 static int min_percpu_pagelist_fract = 8;
85 static int ngroups_max = NGROUPS_MAX;
88 extern char modprobe_path[];
90 #ifdef CONFIG_CHR_DEV_SG
91 extern int sg_big_buff;
94 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
95 void __user *buffer, size_t *lenp, loff_t *ppos);
96 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
97 void __user *buffer, size_t *lenp, loff_t *ppos);
101 extern char reboot_command [];
102 extern int stop_a_enabled;
103 extern int scons_pwroff;
107 extern int pwrsw_enabled;
108 extern int unaligned_enabled;
112 #ifdef CONFIG_MATHEMU
113 extern int sysctl_ieee_emulation_warnings;
115 extern int sysctl_userprocess_debug;
116 extern int spin_retry;
119 extern int sysctl_hz_timer;
121 #ifdef CONFIG_BSD_PROCESS_ACCT
122 extern int acct_parm[];
126 extern int no_unaligned_warning;
129 #ifdef CONFIG_RT_MUTEXES
130 extern int max_lock_depth;
133 #ifdef CONFIG_SYSCTL_SYSCALL
134 static int parse_table(int __user *, int, void __user *, size_t __user *,
135 void __user *, size_t, ctl_table *);
138 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
139 void __user *buffer, size_t *lenp, loff_t *ppos);
141 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
142 void __user *oldval, size_t __user *oldlenp,
143 void __user *newval, size_t newlen);
145 #ifdef CONFIG_SYSVIPC
146 static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
147 void __user *oldval, size_t __user *oldlenp,
148 void __user *newval, size_t newlen);
151 #ifdef CONFIG_PROC_SYSCTL
152 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
153 void __user *buffer, size_t *lenp, loff_t *ppos);
154 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
155 void __user *buffer, size_t *lenp, loff_t *ppos);
158 static ctl_table root_table[];
159 static struct ctl_table_header root_table_header =
160 { root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
162 static ctl_table kern_table[];
163 static ctl_table vm_table[];
164 static ctl_table fs_table[];
165 static ctl_table debug_table[];
166 static ctl_table dev_table[];
167 extern ctl_table random_table[];
168 #ifdef CONFIG_UNIX98_PTYS
169 extern ctl_table pty_table[];
171 #ifdef CONFIG_INOTIFY_USER
172 extern ctl_table inotify_table[];
175 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
176 int sysctl_legacy_va_layout;
180 static void *get_uts(ctl_table *table, int write)
182 char *which = table->data;
184 struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
185 which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
190 down_write(&uts_sem);
194 static void put_uts(ctl_table *table, int write, void *which)
202 #ifdef CONFIG_SYSVIPC
203 static void *get_ipc(ctl_table *table, int write)
205 char *which = table->data;
206 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
207 which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
211 #define get_ipc(T,W) ((T)->data)
214 /* /proc declarations: */
216 #ifdef CONFIG_PROC_SYSCTL
218 static ssize_t proc_readsys(struct file *, char __user *, size_t, loff_t *);
219 static ssize_t proc_writesys(struct file *, const char __user *, size_t, loff_t *);
220 static int proc_opensys(struct inode *, struct file *);
222 const struct file_operations proc_sys_file_operations = {
223 .open = proc_opensys,
224 .read = proc_readsys,
225 .write = proc_writesys,
228 extern struct proc_dir_entry *proc_sys_root;
230 static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
231 static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
234 /* The default sysctl tables: */
236 static ctl_table root_table[] = {
238 .ctl_name = CTL_KERN,
239 .procname = "kernel",
264 .ctl_name = CTL_DEBUG,
267 .child = debug_table,
279 static ctl_table kern_table[] = {
281 .ctl_name = KERN_OSTYPE,
282 .procname = "ostype",
283 .data = init_uts_ns.name.sysname,
284 .maxlen = sizeof(init_uts_ns.name.sysname),
286 .proc_handler = &proc_do_uts_string,
287 .strategy = &sysctl_uts_string,
290 .ctl_name = KERN_OSRELEASE,
291 .procname = "osrelease",
292 .data = init_uts_ns.name.release,
293 .maxlen = sizeof(init_uts_ns.name.release),
295 .proc_handler = &proc_do_uts_string,
296 .strategy = &sysctl_uts_string,
299 .ctl_name = KERN_VERSION,
300 .procname = "version",
301 .data = init_uts_ns.name.version,
302 .maxlen = sizeof(init_uts_ns.name.version),
304 .proc_handler = &proc_do_uts_string,
305 .strategy = &sysctl_uts_string,
308 .ctl_name = KERN_NODENAME,
309 .procname = "hostname",
310 .data = init_uts_ns.name.nodename,
311 .maxlen = sizeof(init_uts_ns.name.nodename),
313 .proc_handler = &proc_do_uts_string,
314 .strategy = &sysctl_uts_string,
317 .ctl_name = KERN_DOMAINNAME,
318 .procname = "domainname",
319 .data = init_uts_ns.name.domainname,
320 .maxlen = sizeof(init_uts_ns.name.domainname),
322 .proc_handler = &proc_do_uts_string,
323 .strategy = &sysctl_uts_string,
326 .ctl_name = KERN_PANIC,
328 .data = &panic_timeout,
329 .maxlen = sizeof(int),
331 .proc_handler = &proc_dointvec,
334 .ctl_name = KERN_CORE_USES_PID,
335 .procname = "core_uses_pid",
336 .data = &core_uses_pid,
337 .maxlen = sizeof(int),
339 .proc_handler = &proc_dointvec,
342 .ctl_name = KERN_CORE_PATTERN,
343 .procname = "core_pattern",
344 .data = core_pattern,
347 .proc_handler = &proc_dostring,
348 .strategy = &sysctl_string,
350 #ifdef CONFIG_PROC_SYSCTL
352 .ctl_name = KERN_TAINTED,
353 .procname = "tainted",
355 .maxlen = sizeof(int),
357 .proc_handler = &proc_dointvec_taint,
361 .ctl_name = KERN_CAP_BSET,
362 .procname = "cap-bound",
364 .maxlen = sizeof(kernel_cap_t),
366 .proc_handler = &proc_dointvec_bset,
368 #ifdef CONFIG_BLK_DEV_INITRD
370 .ctl_name = KERN_REALROOTDEV,
371 .procname = "real-root-dev",
372 .data = &real_root_dev,
373 .maxlen = sizeof(int),
375 .proc_handler = &proc_dointvec,
380 .ctl_name = KERN_SPARC_REBOOT,
381 .procname = "reboot-cmd",
382 .data = reboot_command,
385 .proc_handler = &proc_dostring,
386 .strategy = &sysctl_string,
389 .ctl_name = KERN_SPARC_STOP_A,
390 .procname = "stop-a",
391 .data = &stop_a_enabled,
392 .maxlen = sizeof (int),
394 .proc_handler = &proc_dointvec,
397 .ctl_name = KERN_SPARC_SCONS_PWROFF,
398 .procname = "scons-poweroff",
399 .data = &scons_pwroff,
400 .maxlen = sizeof (int),
402 .proc_handler = &proc_dointvec,
407 .ctl_name = KERN_HPPA_PWRSW,
408 .procname = "soft-power",
409 .data = &pwrsw_enabled,
410 .maxlen = sizeof (int),
412 .proc_handler = &proc_dointvec,
415 .ctl_name = KERN_HPPA_UNALIGNED,
416 .procname = "unaligned-trap",
417 .data = &unaligned_enabled,
418 .maxlen = sizeof (int),
420 .proc_handler = &proc_dointvec,
424 .ctl_name = KERN_CTLALTDEL,
425 .procname = "ctrl-alt-del",
427 .maxlen = sizeof(int),
429 .proc_handler = &proc_dointvec,
432 .ctl_name = KERN_PRINTK,
433 .procname = "printk",
434 .data = &console_loglevel,
435 .maxlen = 4*sizeof(int),
437 .proc_handler = &proc_dointvec,
441 .ctl_name = KERN_MODPROBE,
442 .procname = "modprobe",
443 .data = &modprobe_path,
444 .maxlen = KMOD_PATH_LEN,
446 .proc_handler = &proc_dostring,
447 .strategy = &sysctl_string,
450 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
452 .ctl_name = KERN_HOTPLUG,
453 .procname = "hotplug",
454 .data = &uevent_helper,
455 .maxlen = UEVENT_HELPER_PATH_LEN,
457 .proc_handler = &proc_dostring,
458 .strategy = &sysctl_string,
461 #ifdef CONFIG_CHR_DEV_SG
463 .ctl_name = KERN_SG_BIG_BUFF,
464 .procname = "sg-big-buff",
465 .data = &sg_big_buff,
466 .maxlen = sizeof (int),
468 .proc_handler = &proc_dointvec,
471 #ifdef CONFIG_BSD_PROCESS_ACCT
473 .ctl_name = KERN_ACCT,
476 .maxlen = 3*sizeof(int),
478 .proc_handler = &proc_dointvec,
481 #ifdef CONFIG_SYSVIPC
483 .ctl_name = KERN_SHMMAX,
484 .procname = "shmmax",
485 .data = &init_ipc_ns.shm_ctlmax,
486 .maxlen = sizeof (init_ipc_ns.shm_ctlmax),
488 .proc_handler = &proc_ipc_doulongvec_minmax,
489 .strategy = sysctl_ipc_data,
492 .ctl_name = KERN_SHMALL,
493 .procname = "shmall",
494 .data = &init_ipc_ns.shm_ctlall,
495 .maxlen = sizeof (init_ipc_ns.shm_ctlall),
497 .proc_handler = &proc_ipc_doulongvec_minmax,
498 .strategy = sysctl_ipc_data,
501 .ctl_name = KERN_SHMMNI,
502 .procname = "shmmni",
503 .data = &init_ipc_ns.shm_ctlmni,
504 .maxlen = sizeof (init_ipc_ns.shm_ctlmni),
506 .proc_handler = &proc_ipc_dointvec,
507 .strategy = sysctl_ipc_data,
510 .ctl_name = KERN_MSGMAX,
511 .procname = "msgmax",
512 .data = &init_ipc_ns.msg_ctlmax,
513 .maxlen = sizeof (init_ipc_ns.msg_ctlmax),
515 .proc_handler = &proc_ipc_dointvec,
516 .strategy = sysctl_ipc_data,
519 .ctl_name = KERN_MSGMNI,
520 .procname = "msgmni",
521 .data = &init_ipc_ns.msg_ctlmni,
522 .maxlen = sizeof (init_ipc_ns.msg_ctlmni),
524 .proc_handler = &proc_ipc_dointvec,
525 .strategy = sysctl_ipc_data,
528 .ctl_name = KERN_MSGMNB,
529 .procname = "msgmnb",
530 .data = &init_ipc_ns.msg_ctlmnb,
531 .maxlen = sizeof (init_ipc_ns.msg_ctlmnb),
533 .proc_handler = &proc_ipc_dointvec,
534 .strategy = sysctl_ipc_data,
537 .ctl_name = KERN_SEM,
539 .data = &init_ipc_ns.sem_ctls,
540 .maxlen = 4*sizeof (int),
542 .proc_handler = &proc_ipc_dointvec,
543 .strategy = sysctl_ipc_data,
546 #ifdef CONFIG_MAGIC_SYSRQ
548 .ctl_name = KERN_SYSRQ,
550 .data = &__sysrq_enabled,
551 .maxlen = sizeof (int),
553 .proc_handler = &proc_dointvec,
556 #ifdef CONFIG_PROC_SYSCTL
558 .ctl_name = KERN_CADPID,
559 .procname = "cad_pid",
561 .maxlen = sizeof (int),
563 .proc_handler = &proc_do_cad_pid,
567 .ctl_name = KERN_MAX_THREADS,
568 .procname = "threads-max",
569 .data = &max_threads,
570 .maxlen = sizeof(int),
572 .proc_handler = &proc_dointvec,
575 .ctl_name = KERN_RANDOM,
576 .procname = "random",
578 .child = random_table,
580 #ifdef CONFIG_UNIX98_PTYS
582 .ctl_name = KERN_PTY,
589 .ctl_name = KERN_OVERFLOWUID,
590 .procname = "overflowuid",
591 .data = &overflowuid,
592 .maxlen = sizeof(int),
594 .proc_handler = &proc_dointvec_minmax,
595 .strategy = &sysctl_intvec,
596 .extra1 = &minolduid,
597 .extra2 = &maxolduid,
600 .ctl_name = KERN_OVERFLOWGID,
601 .procname = "overflowgid",
602 .data = &overflowgid,
603 .maxlen = sizeof(int),
605 .proc_handler = &proc_dointvec_minmax,
606 .strategy = &sysctl_intvec,
607 .extra1 = &minolduid,
608 .extra2 = &maxolduid,
611 #ifdef CONFIG_MATHEMU
613 .ctl_name = KERN_IEEE_EMULATION_WARNINGS,
614 .procname = "ieee_emulation_warnings",
615 .data = &sysctl_ieee_emulation_warnings,
616 .maxlen = sizeof(int),
618 .proc_handler = &proc_dointvec,
621 #ifdef CONFIG_NO_IDLE_HZ
623 .ctl_name = KERN_HZ_TIMER,
624 .procname = "hz_timer",
625 .data = &sysctl_hz_timer,
626 .maxlen = sizeof(int),
628 .proc_handler = &proc_dointvec,
632 .ctl_name = KERN_S390_USER_DEBUG_LOGGING,
633 .procname = "userprocess_debug",
634 .data = &sysctl_userprocess_debug,
635 .maxlen = sizeof(int),
637 .proc_handler = &proc_dointvec,
641 .ctl_name = KERN_PIDMAX,
642 .procname = "pid_max",
644 .maxlen = sizeof (int),
646 .proc_handler = &proc_dointvec_minmax,
647 .strategy = sysctl_intvec,
648 .extra1 = &pid_max_min,
649 .extra2 = &pid_max_max,
652 .ctl_name = KERN_PANIC_ON_OOPS,
653 .procname = "panic_on_oops",
654 .data = &panic_on_oops,
655 .maxlen = sizeof(int),
657 .proc_handler = &proc_dointvec,
660 .ctl_name = KERN_PRINTK_RATELIMIT,
661 .procname = "printk_ratelimit",
662 .data = &printk_ratelimit_jiffies,
663 .maxlen = sizeof(int),
665 .proc_handler = &proc_dointvec_jiffies,
666 .strategy = &sysctl_jiffies,
669 .ctl_name = KERN_PRINTK_RATELIMIT_BURST,
670 .procname = "printk_ratelimit_burst",
671 .data = &printk_ratelimit_burst,
672 .maxlen = sizeof(int),
674 .proc_handler = &proc_dointvec,
677 .ctl_name = KERN_NGROUPS_MAX,
678 .procname = "ngroups_max",
679 .data = &ngroups_max,
680 .maxlen = sizeof (int),
682 .proc_handler = &proc_dointvec,
684 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
686 .ctl_name = KERN_UNKNOWN_NMI_PANIC,
687 .procname = "unknown_nmi_panic",
688 .data = &unknown_nmi_panic,
689 .maxlen = sizeof (int),
691 .proc_handler = &proc_dointvec,
694 .ctl_name = KERN_NMI_WATCHDOG,
695 .procname = "nmi_watchdog",
696 .data = &nmi_watchdog_enabled,
697 .maxlen = sizeof (int),
699 .proc_handler = &proc_nmi_enabled,
702 #if defined(CONFIG_X86)
704 .ctl_name = KERN_PANIC_ON_NMI,
705 .procname = "panic_on_unrecovered_nmi",
706 .data = &panic_on_unrecovered_nmi,
707 .maxlen = sizeof(int),
709 .proc_handler = &proc_dointvec,
712 .ctl_name = KERN_BOOTLOADER_TYPE,
713 .procname = "bootloader_type",
714 .data = &bootloader_type,
715 .maxlen = sizeof (int),
717 .proc_handler = &proc_dointvec,
720 .ctl_name = CTL_UNNUMBERED,
721 .procname = "kstack_depth_to_print",
722 .data = &kstack_depth_to_print,
723 .maxlen = sizeof(int),
725 .proc_handler = &proc_dointvec,
728 #if defined(CONFIG_MMU)
730 .ctl_name = KERN_RANDOMIZE,
731 .procname = "randomize_va_space",
732 .data = &randomize_va_space,
733 .maxlen = sizeof(int),
735 .proc_handler = &proc_dointvec,
738 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
740 .ctl_name = KERN_SPIN_RETRY,
741 .procname = "spin_retry",
743 .maxlen = sizeof (int),
745 .proc_handler = &proc_dointvec,
748 #ifdef CONFIG_ACPI_SLEEP
750 .ctl_name = KERN_ACPI_VIDEO_FLAGS,
751 .procname = "acpi_video_flags",
752 .data = &acpi_video_flags,
753 .maxlen = sizeof (unsigned long),
755 .proc_handler = &proc_doulongvec_minmax,
760 .ctl_name = KERN_IA64_UNALIGNED,
761 .procname = "ignore-unaligned-usertrap",
762 .data = &no_unaligned_warning,
763 .maxlen = sizeof (int),
765 .proc_handler = &proc_dointvec,
770 .ctl_name = KERN_COMPAT_LOG,
771 .procname = "compat-log",
773 .maxlen = sizeof (int),
775 .proc_handler = &proc_dointvec,
778 #ifdef CONFIG_RT_MUTEXES
780 .ctl_name = KERN_MAX_LOCK_DEPTH,
781 .procname = "max_lock_depth",
782 .data = &max_lock_depth,
783 .maxlen = sizeof(int),
785 .proc_handler = &proc_dointvec,
792 /* Constants for minimum and maximum testing in vm_table.
793 We use these as one-element integer vectors. */
795 static int one_hundred = 100;
798 static ctl_table vm_table[] = {
800 .ctl_name = VM_OVERCOMMIT_MEMORY,
801 .procname = "overcommit_memory",
802 .data = &sysctl_overcommit_memory,
803 .maxlen = sizeof(sysctl_overcommit_memory),
805 .proc_handler = &proc_dointvec,
808 .ctl_name = VM_PANIC_ON_OOM,
809 .procname = "panic_on_oom",
810 .data = &sysctl_panic_on_oom,
811 .maxlen = sizeof(sysctl_panic_on_oom),
813 .proc_handler = &proc_dointvec,
816 .ctl_name = VM_OVERCOMMIT_RATIO,
817 .procname = "overcommit_ratio",
818 .data = &sysctl_overcommit_ratio,
819 .maxlen = sizeof(sysctl_overcommit_ratio),
821 .proc_handler = &proc_dointvec,
824 .ctl_name = VM_PAGE_CLUSTER,
825 .procname = "page-cluster",
826 .data = &page_cluster,
827 .maxlen = sizeof(int),
829 .proc_handler = &proc_dointvec,
832 .ctl_name = VM_DIRTY_BACKGROUND,
833 .procname = "dirty_background_ratio",
834 .data = &dirty_background_ratio,
835 .maxlen = sizeof(dirty_background_ratio),
837 .proc_handler = &proc_dointvec_minmax,
838 .strategy = &sysctl_intvec,
840 .extra2 = &one_hundred,
843 .ctl_name = VM_DIRTY_RATIO,
844 .procname = "dirty_ratio",
845 .data = &vm_dirty_ratio,
846 .maxlen = sizeof(vm_dirty_ratio),
848 .proc_handler = &proc_dointvec_minmax,
849 .strategy = &sysctl_intvec,
851 .extra2 = &one_hundred,
854 .ctl_name = VM_DIRTY_WB_CS,
855 .procname = "dirty_writeback_centisecs",
856 .data = &dirty_writeback_interval,
857 .maxlen = sizeof(dirty_writeback_interval),
859 .proc_handler = &dirty_writeback_centisecs_handler,
862 .ctl_name = VM_DIRTY_EXPIRE_CS,
863 .procname = "dirty_expire_centisecs",
864 .data = &dirty_expire_interval,
865 .maxlen = sizeof(dirty_expire_interval),
867 .proc_handler = &proc_dointvec_userhz_jiffies,
870 .ctl_name = VM_NR_PDFLUSH_THREADS,
871 .procname = "nr_pdflush_threads",
872 .data = &nr_pdflush_threads,
873 .maxlen = sizeof nr_pdflush_threads,
874 .mode = 0444 /* read-only*/,
875 .proc_handler = &proc_dointvec,
878 .ctl_name = VM_SWAPPINESS,
879 .procname = "swappiness",
880 .data = &vm_swappiness,
881 .maxlen = sizeof(vm_swappiness),
883 .proc_handler = &proc_dointvec_minmax,
884 .strategy = &sysctl_intvec,
886 .extra2 = &one_hundred,
888 #ifdef CONFIG_HUGETLB_PAGE
890 .ctl_name = VM_HUGETLB_PAGES,
891 .procname = "nr_hugepages",
892 .data = &max_huge_pages,
893 .maxlen = sizeof(unsigned long),
895 .proc_handler = &hugetlb_sysctl_handler,
896 .extra1 = (void *)&hugetlb_zero,
897 .extra2 = (void *)&hugetlb_infinity,
900 .ctl_name = VM_HUGETLB_GROUP,
901 .procname = "hugetlb_shm_group",
902 .data = &sysctl_hugetlb_shm_group,
903 .maxlen = sizeof(gid_t),
905 .proc_handler = &proc_dointvec,
909 .ctl_name = VM_LOWMEM_RESERVE_RATIO,
910 .procname = "lowmem_reserve_ratio",
911 .data = &sysctl_lowmem_reserve_ratio,
912 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
914 .proc_handler = &lowmem_reserve_ratio_sysctl_handler,
915 .strategy = &sysctl_intvec,
918 .ctl_name = VM_DROP_PAGECACHE,
919 .procname = "drop_caches",
920 .data = &sysctl_drop_caches,
921 .maxlen = sizeof(int),
923 .proc_handler = drop_caches_sysctl_handler,
924 .strategy = &sysctl_intvec,
927 .ctl_name = VM_MIN_FREE_KBYTES,
928 .procname = "min_free_kbytes",
929 .data = &min_free_kbytes,
930 .maxlen = sizeof(min_free_kbytes),
932 .proc_handler = &min_free_kbytes_sysctl_handler,
933 .strategy = &sysctl_intvec,
937 .ctl_name = VM_PERCPU_PAGELIST_FRACTION,
938 .procname = "percpu_pagelist_fraction",
939 .data = &percpu_pagelist_fraction,
940 .maxlen = sizeof(percpu_pagelist_fraction),
942 .proc_handler = &percpu_pagelist_fraction_sysctl_handler,
943 .strategy = &sysctl_intvec,
944 .extra1 = &min_percpu_pagelist_fract,
948 .ctl_name = VM_MAX_MAP_COUNT,
949 .procname = "max_map_count",
950 .data = &sysctl_max_map_count,
951 .maxlen = sizeof(sysctl_max_map_count),
953 .proc_handler = &proc_dointvec
957 .ctl_name = VM_LAPTOP_MODE,
958 .procname = "laptop_mode",
959 .data = &laptop_mode,
960 .maxlen = sizeof(laptop_mode),
962 .proc_handler = &proc_dointvec_jiffies,
963 .strategy = &sysctl_jiffies,
966 .ctl_name = VM_BLOCK_DUMP,
967 .procname = "block_dump",
969 .maxlen = sizeof(block_dump),
971 .proc_handler = &proc_dointvec,
972 .strategy = &sysctl_intvec,
976 .ctl_name = VM_VFS_CACHE_PRESSURE,
977 .procname = "vfs_cache_pressure",
978 .data = &sysctl_vfs_cache_pressure,
979 .maxlen = sizeof(sysctl_vfs_cache_pressure),
981 .proc_handler = &proc_dointvec,
982 .strategy = &sysctl_intvec,
985 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
987 .ctl_name = VM_LEGACY_VA_LAYOUT,
988 .procname = "legacy_va_layout",
989 .data = &sysctl_legacy_va_layout,
990 .maxlen = sizeof(sysctl_legacy_va_layout),
992 .proc_handler = &proc_dointvec,
993 .strategy = &sysctl_intvec,
999 .ctl_name = VM_ZONE_RECLAIM_MODE,
1000 .procname = "zone_reclaim_mode",
1001 .data = &zone_reclaim_mode,
1002 .maxlen = sizeof(zone_reclaim_mode),
1004 .proc_handler = &proc_dointvec,
1005 .strategy = &sysctl_intvec,
1009 .ctl_name = VM_MIN_UNMAPPED,
1010 .procname = "min_unmapped_ratio",
1011 .data = &sysctl_min_unmapped_ratio,
1012 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1014 .proc_handler = &sysctl_min_unmapped_ratio_sysctl_handler,
1015 .strategy = &sysctl_intvec,
1017 .extra2 = &one_hundred,
1020 .ctl_name = VM_MIN_SLAB,
1021 .procname = "min_slab_ratio",
1022 .data = &sysctl_min_slab_ratio,
1023 .maxlen = sizeof(sysctl_min_slab_ratio),
1025 .proc_handler = &sysctl_min_slab_ratio_sysctl_handler,
1026 .strategy = &sysctl_intvec,
1028 .extra2 = &one_hundred,
1031 #ifdef CONFIG_X86_32
1033 .ctl_name = VM_VDSO_ENABLED,
1034 .procname = "vdso_enabled",
1035 .data = &vdso_enabled,
1036 .maxlen = sizeof(vdso_enabled),
1038 .proc_handler = &proc_dointvec,
1039 .strategy = &sysctl_intvec,
1046 static ctl_table fs_table[] = {
1048 .ctl_name = FS_NRINODE,
1049 .procname = "inode-nr",
1050 .data = &inodes_stat,
1051 .maxlen = 2*sizeof(int),
1053 .proc_handler = &proc_dointvec,
1056 .ctl_name = FS_STATINODE,
1057 .procname = "inode-state",
1058 .data = &inodes_stat,
1059 .maxlen = 7*sizeof(int),
1061 .proc_handler = &proc_dointvec,
1064 .ctl_name = FS_NRFILE,
1065 .procname = "file-nr",
1066 .data = &files_stat,
1067 .maxlen = 3*sizeof(int),
1069 .proc_handler = &proc_nr_files,
1072 .ctl_name = FS_MAXFILE,
1073 .procname = "file-max",
1074 .data = &files_stat.max_files,
1075 .maxlen = sizeof(int),
1077 .proc_handler = &proc_dointvec,
1080 .ctl_name = FS_DENTRY,
1081 .procname = "dentry-state",
1082 .data = &dentry_stat,
1083 .maxlen = 6*sizeof(int),
1085 .proc_handler = &proc_dointvec,
1088 .ctl_name = FS_OVERFLOWUID,
1089 .procname = "overflowuid",
1090 .data = &fs_overflowuid,
1091 .maxlen = sizeof(int),
1093 .proc_handler = &proc_dointvec_minmax,
1094 .strategy = &sysctl_intvec,
1095 .extra1 = &minolduid,
1096 .extra2 = &maxolduid,
1099 .ctl_name = FS_OVERFLOWGID,
1100 .procname = "overflowgid",
1101 .data = &fs_overflowgid,
1102 .maxlen = sizeof(int),
1104 .proc_handler = &proc_dointvec_minmax,
1105 .strategy = &sysctl_intvec,
1106 .extra1 = &minolduid,
1107 .extra2 = &maxolduid,
1110 .ctl_name = FS_LEASES,
1111 .procname = "leases-enable",
1112 .data = &leases_enable,
1113 .maxlen = sizeof(int),
1115 .proc_handler = &proc_dointvec,
1117 #ifdef CONFIG_DNOTIFY
1119 .ctl_name = FS_DIR_NOTIFY,
1120 .procname = "dir-notify-enable",
1121 .data = &dir_notify_enable,
1122 .maxlen = sizeof(int),
1124 .proc_handler = &proc_dointvec,
1129 .ctl_name = FS_LEASE_TIME,
1130 .procname = "lease-break-time",
1131 .data = &lease_break_time,
1132 .maxlen = sizeof(int),
1134 .proc_handler = &proc_dointvec,
1137 .ctl_name = FS_AIO_NR,
1138 .procname = "aio-nr",
1140 .maxlen = sizeof(aio_nr),
1142 .proc_handler = &proc_doulongvec_minmax,
1145 .ctl_name = FS_AIO_MAX_NR,
1146 .procname = "aio-max-nr",
1147 .data = &aio_max_nr,
1148 .maxlen = sizeof(aio_max_nr),
1150 .proc_handler = &proc_doulongvec_minmax,
1152 #ifdef CONFIG_INOTIFY_USER
1154 .ctl_name = FS_INOTIFY,
1155 .procname = "inotify",
1157 .child = inotify_table,
1162 .ctl_name = KERN_SETUID_DUMPABLE,
1163 .procname = "suid_dumpable",
1164 .data = &suid_dumpable,
1165 .maxlen = sizeof(int),
1167 .proc_handler = &proc_dointvec,
1172 static ctl_table debug_table[] = {
1176 static ctl_table dev_table[] = {
1180 extern void init_irq_proc (void);
1182 static DEFINE_SPINLOCK(sysctl_lock);
1184 /* called under sysctl_lock */
1185 static int use_table(struct ctl_table_header *p)
1187 if (unlikely(p->unregistering))
1193 /* called under sysctl_lock */
1194 static void unuse_table(struct ctl_table_header *p)
1197 if (unlikely(p->unregistering))
1198 complete(p->unregistering);
1201 /* called under sysctl_lock, will reacquire if has to wait */
1202 static void start_unregistering(struct ctl_table_header *p)
1205 * if p->used is 0, nobody will ever touch that entry again;
1206 * we'll eliminate all paths to it before dropping sysctl_lock
1208 if (unlikely(p->used)) {
1209 struct completion wait;
1210 init_completion(&wait);
1211 p->unregistering = &wait;
1212 spin_unlock(&sysctl_lock);
1213 wait_for_completion(&wait);
1214 spin_lock(&sysctl_lock);
1217 * do not remove from the list until nobody holds it; walking the
1218 * list in do_sysctl() relies on that.
1220 list_del_init(&p->ctl_entry);
1223 void __init sysctl_init(void)
1225 #ifdef CONFIG_PROC_SYSCTL
1226 register_proc_table(root_table, proc_sys_root, &root_table_header);
1231 #ifdef CONFIG_SYSCTL_SYSCALL
1232 int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp,
1233 void __user *newval, size_t newlen)
1235 struct list_head *tmp;
1236 int error = -ENOTDIR;
1238 if (nlen <= 0 || nlen >= CTL_MAXNAME)
1242 if (!oldlenp || get_user(old_len, oldlenp))
1245 spin_lock(&sysctl_lock);
1246 tmp = &root_table_header.ctl_entry;
1248 struct ctl_table_header *head =
1249 list_entry(tmp, struct ctl_table_header, ctl_entry);
1251 if (!use_table(head))
1254 spin_unlock(&sysctl_lock);
1256 error = parse_table(name, nlen, oldval, oldlenp,
1257 newval, newlen, head->ctl_table);
1259 spin_lock(&sysctl_lock);
1261 if (error != -ENOTDIR)
1263 } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
1264 spin_unlock(&sysctl_lock);
1268 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
1270 struct __sysctl_args tmp;
1273 if (copy_from_user(&tmp, args, sizeof(tmp)))
1277 error = do_sysctl(tmp.name, tmp.nlen, tmp.oldval, tmp.oldlenp,
1278 tmp.newval, tmp.newlen);
1282 #endif /* CONFIG_SYSCTL_SYSCALL */
1285 * ctl_perm does NOT grant the superuser all rights automatically, because
1286 * some sysctl variables are readonly even to root.
1289 static int test_perm(int mode, int op)
1293 else if (in_egroup_p(0))
1295 if ((mode & op & 0007) == op)
1300 static inline int ctl_perm(ctl_table *table, int op)
1303 error = security_sysctl(table, op);
1306 return test_perm(table->mode, op);
1309 #ifdef CONFIG_SYSCTL_SYSCALL
1310 static int parse_table(int __user *name, int nlen,
1311 void __user *oldval, size_t __user *oldlenp,
1312 void __user *newval, size_t newlen,
1319 if (get_user(n, name))
1321 for ( ; table->ctl_name || table->procname; table++) {
1322 if (!table->ctl_name)
1324 if (n == table->ctl_name || table->ctl_name == CTL_ANY) {
1327 if (ctl_perm(table, 001))
1329 if (table->strategy) {
1330 error = table->strategy(
1339 table = table->child;
1342 error = do_sysctl_strategy(table, name, nlen,
1351 /* Perform the actual read/write of a sysctl table entry. */
1352 int do_sysctl_strategy (ctl_table *table,
1353 int __user *name, int nlen,
1354 void __user *oldval, size_t __user *oldlenp,
1355 void __user *newval, size_t newlen)
1364 if (ctl_perm(table, op))
1367 if (table->strategy) {
1368 rc = table->strategy(table, name, nlen, oldval, oldlenp,
1376 /* If there is no strategy routine, or if the strategy returns
1377 * zero, proceed with automatic r/w */
1378 if (table->data && table->maxlen) {
1379 if (oldval && oldlenp) {
1380 if (get_user(len, oldlenp))
1383 if (len > table->maxlen)
1384 len = table->maxlen;
1385 if(copy_to_user(oldval, table->data, len))
1387 if(put_user(len, oldlenp))
1391 if (newval && newlen) {
1393 if (len > table->maxlen)
1394 len = table->maxlen;
1395 if(copy_from_user(table->data, newval, len))
1401 #endif /* CONFIG_SYSCTL_SYSCALL */
1404 * register_sysctl_table - register a sysctl hierarchy
1405 * @table: the top-level table structure
1406 * @insert_at_head: whether the entry should be inserted in front or at the end
1408 * Register a sysctl table hierarchy. @table should be a filled in ctl_table
1409 * array. An entry with a ctl_name of 0 terminates the table.
1411 * The members of the &ctl_table structure are used as follows:
1413 * ctl_name - This is the numeric sysctl value used by sysctl(2). The number
1414 * must be unique within that level of sysctl
1416 * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not
1417 * enter a sysctl file
1419 * data - a pointer to data for use by proc_handler
1421 * maxlen - the maximum size in bytes of the data
1423 * mode - the file permissions for the /proc/sys file, and for sysctl(2)
1425 * child - a pointer to the child sysctl table if this entry is a directory, or
1428 * proc_handler - the text handler routine (described below)
1430 * strategy - the strategy routine (described below)
1432 * de - for internal use by the sysctl routines
1434 * extra1, extra2 - extra pointers usable by the proc handler routines
1436 * Leaf nodes in the sysctl tree will be represented by a single file
1437 * under /proc; non-leaf nodes will be represented by directories.
1439 * sysctl(2) can automatically manage read and write requests through
1440 * the sysctl table. The data and maxlen fields of the ctl_table
1441 * struct enable minimal validation of the values being written to be
1442 * performed, and the mode field allows minimal authentication.
1444 * More sophisticated management can be enabled by the provision of a
1445 * strategy routine with the table entry. This will be called before
1446 * any automatic read or write of the data is performed.
1448 * The strategy routine may return
1450 * < 0 - Error occurred (error is passed to user process)
1452 * 0 - OK - proceed with automatic read or write.
1454 * > 0 - OK - read or write has been done by the strategy routine, so
1455 * return immediately.
1457 * There must be a proc_handler routine for any terminal nodes
1458 * mirrored under /proc/sys (non-terminals are handled by a built-in
1459 * directory handler). Several default handlers are available to
1460 * cover common cases -
1462 * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(),
1463 * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(),
1464 * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax()
1466 * It is the handler's job to read the input buffer from user memory
1467 * and process it. The handler should return 0 on success.
1469 * This routine returns %NULL on a failure to register, and a pointer
1470 * to the table header on success.
1472 struct ctl_table_header *register_sysctl_table(ctl_table * table,
1475 struct ctl_table_header *tmp;
1476 tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
1479 tmp->ctl_table = table;
1480 INIT_LIST_HEAD(&tmp->ctl_entry);
1482 tmp->unregistering = NULL;
1483 spin_lock(&sysctl_lock);
1485 list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
1487 list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
1488 spin_unlock(&sysctl_lock);
1489 #ifdef CONFIG_PROC_SYSCTL
1490 register_proc_table(table, proc_sys_root, tmp);
1496 * unregister_sysctl_table - unregister a sysctl table hierarchy
1497 * @header: the header returned from register_sysctl_table
1499 * Unregisters the sysctl table and all children. proc entries may not
1500 * actually be removed until they are no longer used by anyone.
1502 void unregister_sysctl_table(struct ctl_table_header * header)
1505 spin_lock(&sysctl_lock);
1506 start_unregistering(header);
1507 #ifdef CONFIG_PROC_SYSCTL
1508 unregister_proc_table(header->ctl_table, proc_sys_root);
1510 spin_unlock(&sysctl_lock);
1514 #else /* !CONFIG_SYSCTL */
1515 struct ctl_table_header * register_sysctl_table(ctl_table * table,
1521 void unregister_sysctl_table(struct ctl_table_header * table)
1525 #endif /* CONFIG_SYSCTL */
1531 #ifdef CONFIG_PROC_SYSCTL
1533 /* Scan the sysctl entries in table and add them all into /proc */
1534 static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
1536 struct proc_dir_entry *de;
1540 for (; table->ctl_name || table->procname; table++) {
1541 /* Can't do anything without a proc name. */
1542 if (!table->procname)
1544 /* Maybe we can't do anything with it... */
1545 if (!table->proc_handler && !table->child) {
1546 printk(KERN_WARNING "SYSCTL: Can't register %s\n",
1551 len = strlen(table->procname);
1555 if (table->proc_handler)
1559 for (de = root->subdir; de; de = de->next) {
1560 if (proc_match(len, table->procname, de))
1563 /* If the subdir exists already, de is non-NULL */
1567 de = create_proc_entry(table->procname, mode, root);
1571 de->data = (void *) table;
1572 if (table->proc_handler)
1573 de->proc_fops = &proc_sys_file_operations;
1576 if (de->mode & S_IFDIR)
1577 register_proc_table(table->child, de, set);
1582 * Unregister a /proc sysctl table and any subdirectories.
1584 static void unregister_proc_table(ctl_table * table, struct proc_dir_entry *root)
1586 struct proc_dir_entry *de;
1587 for (; table->ctl_name || table->procname; table++) {
1588 if (!(de = table->de))
1590 if (de->mode & S_IFDIR) {
1591 if (!table->child) {
1592 printk (KERN_ALERT "Help - malformed sysctl tree on free\n");
1595 unregister_proc_table(table->child, de);
1597 /* Don't unregister directories which still have entries.. */
1603 * In any case, mark the entry as goner; we'll keep it
1604 * around if it's busy, but we'll know to do nothing with
1605 * its fields. We are under sysctl_lock here.
1609 /* Don't unregister proc entries that are still being used.. */
1610 if (atomic_read(&de->count))
1614 remove_proc_entry(table->procname, root);
1618 static ssize_t do_rw_proc(int write, struct file * file, char __user * buf,
1619 size_t count, loff_t *ppos)
1622 struct proc_dir_entry *de = PDE(file->f_path.dentry->d_inode);
1623 struct ctl_table *table;
1625 ssize_t error = -ENOTDIR;
1627 spin_lock(&sysctl_lock);
1628 if (de && de->data && use_table(de->set)) {
1630 * at that point we know that sysctl was not unregistered
1631 * and won't be until we finish
1633 spin_unlock(&sysctl_lock);
1634 table = (struct ctl_table *) de->data;
1635 if (!table || !table->proc_handler)
1638 op = (write ? 002 : 004);
1639 if (ctl_perm(table, op))
1642 /* careful: calling conventions are nasty here */
1644 error = (*table->proc_handler)(table, write, file,
1649 spin_lock(&sysctl_lock);
1650 unuse_table(de->set);
1652 spin_unlock(&sysctl_lock);
1656 static int proc_opensys(struct inode *inode, struct file *file)
1658 if (file->f_mode & FMODE_WRITE) {
1660 * sysctl entries that are not writable,
1661 * are _NOT_ writable, capabilities or not.
1663 if (!(inode->i_mode & S_IWUSR))
1670 static ssize_t proc_readsys(struct file * file, char __user * buf,
1671 size_t count, loff_t *ppos)
1673 return do_rw_proc(0, file, buf, count, ppos);
1676 static ssize_t proc_writesys(struct file * file, const char __user * buf,
1677 size_t count, loff_t *ppos)
1679 return do_rw_proc(1, file, (char __user *) buf, count, ppos);
1682 static int _proc_do_string(void* data, int maxlen, int write,
1683 struct file *filp, void __user *buffer,
1684 size_t *lenp, loff_t *ppos)
1690 if (!data || !maxlen || !*lenp) {
1698 while (len < *lenp) {
1699 if (get_user(c, p++))
1701 if (c == 0 || c == '\n')
1707 if(copy_from_user(data, buffer, len))
1709 ((char *) data)[len] = 0;
1727 if(copy_to_user(buffer, data, len))
1730 if(put_user('\n', ((char __user *) buffer) + len))
1741 * proc_dostring - read a string sysctl
1742 * @table: the sysctl table
1743 * @write: %TRUE if this is a write to the sysctl file
1744 * @filp: the file structure
1745 * @buffer: the user buffer
1746 * @lenp: the size of the user buffer
1747 * @ppos: file position
1749 * Reads/writes a string from/to the user buffer. If the kernel
1750 * buffer provided is not large enough to hold the string, the
1751 * string is truncated. The copied string is %NULL-terminated.
1752 * If the string is being read by the user process, it is copied
1753 * and a newline '\n' is added. It is truncated if the buffer is
1756 * Returns 0 on success.
1758 int proc_dostring(ctl_table *table, int write, struct file *filp,
1759 void __user *buffer, size_t *lenp, loff_t *ppos)
1761 return _proc_do_string(table->data, table->maxlen, write, filp,
1762 buffer, lenp, ppos);
1766 * Special case of dostring for the UTS structure. This has locks
1767 * to observe. Should this be in kernel/sys.c ????
1770 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
1771 void __user *buffer, size_t *lenp, loff_t *ppos)
1775 which = get_uts(table, write);
1776 r = _proc_do_string(which, table->maxlen,write,filp,buffer,lenp, ppos);
1777 put_uts(table, write, which);
1781 static int do_proc_dointvec_conv(int *negp, unsigned long *lvalp,
1783 int write, void *data)
1786 *valp = *negp ? -*lvalp : *lvalp;
1791 *lvalp = (unsigned long)-val;
1794 *lvalp = (unsigned long)val;
1800 static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
1801 int write, struct file *filp, void __user *buffer,
1802 size_t *lenp, loff_t *ppos,
1803 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1804 int write, void *data),
1807 #define TMPBUFLEN 21
1808 int *i, vleft, first=1, neg, val;
1812 char buf[TMPBUFLEN], *p;
1813 char __user *s = buffer;
1815 if (!tbl_data || !table->maxlen || !*lenp ||
1816 (*ppos && !write)) {
1821 i = (int *) tbl_data;
1822 vleft = table->maxlen / sizeof(*i);
1826 conv = do_proc_dointvec_conv;
1828 for (; left && vleft--; i++, first=0) {
1843 if (len > sizeof(buf) - 1)
1844 len = sizeof(buf) - 1;
1845 if (copy_from_user(buf, s, len))
1849 if (*p == '-' && left > 1) {
1853 if (*p < '0' || *p > '9')
1856 lval = simple_strtoul(p, &p, 0);
1859 if ((len < left) && *p && !isspace(*p))
1866 if (conv(&neg, &lval, i, 1, data))
1873 if (conv(&neg, &lval, i, 0, data))
1876 sprintf(p, "%s%lu", neg ? "-" : "", lval);
1880 if(copy_to_user(s, buf, len))
1887 if (!write && !first && left) {
1888 if(put_user('\n', s))
1895 if (get_user(c, s++))
1910 static int do_proc_dointvec(ctl_table *table, int write, struct file *filp,
1911 void __user *buffer, size_t *lenp, loff_t *ppos,
1912 int (*conv)(int *negp, unsigned long *lvalp, int *valp,
1913 int write, void *data),
1916 return __do_proc_dointvec(table->data, table, write, filp,
1917 buffer, lenp, ppos, conv, data);
1921 * proc_dointvec - read a vector of integers
1922 * @table: the sysctl table
1923 * @write: %TRUE if this is a write to the sysctl file
1924 * @filp: the file structure
1925 * @buffer: the user buffer
1926 * @lenp: the size of the user buffer
1927 * @ppos: file position
1929 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1930 * values from/to the user buffer, treated as an ASCII string.
1932 * Returns 0 on success.
1934 int proc_dointvec(ctl_table *table, int write, struct file *filp,
1935 void __user *buffer, size_t *lenp, loff_t *ppos)
1937 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1945 static int do_proc_dointvec_bset_conv(int *negp, unsigned long *lvalp,
1947 int write, void *data)
1949 int op = *(int *)data;
1951 int val = *negp ? -*lvalp : *lvalp;
1953 case OP_SET: *valp = val; break;
1954 case OP_AND: *valp &= val; break;
1955 case OP_OR: *valp |= val; break;
1961 *lvalp = (unsigned long)-val;
1964 *lvalp = (unsigned long)val;
1971 * init may raise the set.
1974 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
1975 void __user *buffer, size_t *lenp, loff_t *ppos)
1979 if (write && !capable(CAP_SYS_MODULE)) {
1983 op = is_init(current) ? OP_SET : OP_AND;
1984 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
1985 do_proc_dointvec_bset_conv,&op);
1989 * Taint values can only be increased
1991 static int proc_dointvec_taint(ctl_table *table, int write, struct file *filp,
1992 void __user *buffer, size_t *lenp, loff_t *ppos)
1996 if (!capable(CAP_SYS_ADMIN))
2000 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2001 do_proc_dointvec_bset_conv,&op);
2004 struct do_proc_dointvec_minmax_conv_param {
2009 static int do_proc_dointvec_minmax_conv(int *negp, unsigned long *lvalp,
2011 int write, void *data)
2013 struct do_proc_dointvec_minmax_conv_param *param = data;
2015 int val = *negp ? -*lvalp : *lvalp;
2016 if ((param->min && *param->min > val) ||
2017 (param->max && *param->max < val))
2024 *lvalp = (unsigned long)-val;
2027 *lvalp = (unsigned long)val;
2034 * proc_dointvec_minmax - read a vector of integers with min/max values
2035 * @table: the sysctl table
2036 * @write: %TRUE if this is a write to the sysctl file
2037 * @filp: the file structure
2038 * @buffer: the user buffer
2039 * @lenp: the size of the user buffer
2040 * @ppos: file position
2042 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2043 * values from/to the user buffer, treated as an ASCII string.
2045 * This routine will ensure the values are within the range specified by
2046 * table->extra1 (min) and table->extra2 (max).
2048 * Returns 0 on success.
2050 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2051 void __user *buffer, size_t *lenp, loff_t *ppos)
2053 struct do_proc_dointvec_minmax_conv_param param = {
2054 .min = (int *) table->extra1,
2055 .max = (int *) table->extra2,
2057 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2058 do_proc_dointvec_minmax_conv, ¶m);
2061 static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
2063 void __user *buffer,
2064 size_t *lenp, loff_t *ppos,
2065 unsigned long convmul,
2066 unsigned long convdiv)
2068 #define TMPBUFLEN 21
2069 unsigned long *i, *min, *max, val;
2070 int vleft, first=1, neg;
2072 char buf[TMPBUFLEN], *p;
2073 char __user *s = buffer;
2075 if (!data || !table->maxlen || !*lenp ||
2076 (*ppos && !write)) {
2081 i = (unsigned long *) data;
2082 min = (unsigned long *) table->extra1;
2083 max = (unsigned long *) table->extra2;
2084 vleft = table->maxlen / sizeof(unsigned long);
2087 for (; left && vleft--; i++, min++, max++, first=0) {
2102 if (len > TMPBUFLEN-1)
2104 if (copy_from_user(buf, s, len))
2108 if (*p == '-' && left > 1) {
2112 if (*p < '0' || *p > '9')
2114 val = simple_strtoul(p, &p, 0) * convmul / convdiv ;
2116 if ((len < left) && *p && !isspace(*p))
2125 if ((min && val < *min) || (max && val > *max))
2132 sprintf(p, "%lu", convdiv * (*i) / convmul);
2136 if(copy_to_user(s, buf, len))
2143 if (!write && !first && left) {
2144 if(put_user('\n', s))
2151 if (get_user(c, s++))
2166 static int do_proc_doulongvec_minmax(ctl_table *table, int write,
2168 void __user *buffer,
2169 size_t *lenp, loff_t *ppos,
2170 unsigned long convmul,
2171 unsigned long convdiv)
2173 return __do_proc_doulongvec_minmax(table->data, table, write,
2174 filp, buffer, lenp, ppos, convmul, convdiv);
2178 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2179 * @table: the sysctl table
2180 * @write: %TRUE if this is a write to the sysctl file
2181 * @filp: the file structure
2182 * @buffer: the user buffer
2183 * @lenp: the size of the user buffer
2184 * @ppos: file position
2186 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2187 * values from/to the user buffer, treated as an ASCII string.
2189 * This routine will ensure the values are within the range specified by
2190 * table->extra1 (min) and table->extra2 (max).
2192 * Returns 0 on success.
2194 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2195 void __user *buffer, size_t *lenp, loff_t *ppos)
2197 return do_proc_doulongvec_minmax(table, write, filp, buffer, lenp, ppos, 1l, 1l);
2201 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2202 * @table: the sysctl table
2203 * @write: %TRUE if this is a write to the sysctl file
2204 * @filp: the file structure
2205 * @buffer: the user buffer
2206 * @lenp: the size of the user buffer
2207 * @ppos: file position
2209 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2210 * values from/to the user buffer, treated as an ASCII string. The values
2211 * are treated as milliseconds, and converted to jiffies when they are stored.
2213 * This routine will ensure the values are within the range specified by
2214 * table->extra1 (min) and table->extra2 (max).
2216 * Returns 0 on success.
2218 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2220 void __user *buffer,
2221 size_t *lenp, loff_t *ppos)
2223 return do_proc_doulongvec_minmax(table, write, filp, buffer,
2224 lenp, ppos, HZ, 1000l);
2228 static int do_proc_dointvec_jiffies_conv(int *negp, unsigned long *lvalp,
2230 int write, void *data)
2233 if (*lvalp > LONG_MAX / HZ)
2235 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2241 lval = (unsigned long)-val;
2244 lval = (unsigned long)val;
2251 static int do_proc_dointvec_userhz_jiffies_conv(int *negp, unsigned long *lvalp,
2253 int write, void *data)
2256 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2258 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2264 lval = (unsigned long)-val;
2267 lval = (unsigned long)val;
2269 *lvalp = jiffies_to_clock_t(lval);
2274 static int do_proc_dointvec_ms_jiffies_conv(int *negp, unsigned long *lvalp,
2276 int write, void *data)
2279 *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2285 lval = (unsigned long)-val;
2288 lval = (unsigned long)val;
2290 *lvalp = jiffies_to_msecs(lval);
2296 * proc_dointvec_jiffies - read a vector of integers as seconds
2297 * @table: the sysctl table
2298 * @write: %TRUE if this is a write to the sysctl file
2299 * @filp: the file structure
2300 * @buffer: the user buffer
2301 * @lenp: the size of the user buffer
2302 * @ppos: file position
2304 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2305 * values from/to the user buffer, treated as an ASCII string.
2306 * The values read are assumed to be in seconds, and are converted into
2309 * Returns 0 on success.
2311 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2312 void __user *buffer, size_t *lenp, loff_t *ppos)
2314 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2315 do_proc_dointvec_jiffies_conv,NULL);
2319 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2320 * @table: the sysctl table
2321 * @write: %TRUE if this is a write to the sysctl file
2322 * @filp: the file structure
2323 * @buffer: the user buffer
2324 * @lenp: the size of the user buffer
2325 * @ppos: pointer to the file position
2327 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2328 * values from/to the user buffer, treated as an ASCII string.
2329 * The values read are assumed to be in 1/USER_HZ seconds, and
2330 * are converted into jiffies.
2332 * Returns 0 on success.
2334 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2335 void __user *buffer, size_t *lenp, loff_t *ppos)
2337 return do_proc_dointvec(table,write,filp,buffer,lenp,ppos,
2338 do_proc_dointvec_userhz_jiffies_conv,NULL);
2342 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2343 * @table: the sysctl table
2344 * @write: %TRUE if this is a write to the sysctl file
2345 * @filp: the file structure
2346 * @buffer: the user buffer
2347 * @lenp: the size of the user buffer
2348 * @ppos: file position
2349 * @ppos: the current position in the file
2351 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2352 * values from/to the user buffer, treated as an ASCII string.
2353 * The values read are assumed to be in 1/1000 seconds, and
2354 * are converted into jiffies.
2356 * Returns 0 on success.
2358 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2359 void __user *buffer, size_t *lenp, loff_t *ppos)
2361 return do_proc_dointvec(table, write, filp, buffer, lenp, ppos,
2362 do_proc_dointvec_ms_jiffies_conv, NULL);
2365 #ifdef CONFIG_SYSVIPC
2366 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
2367 void __user *buffer, size_t *lenp, loff_t *ppos)
2370 which = get_ipc(table, write);
2371 return __do_proc_dointvec(which, table, write, filp, buffer,
2372 lenp, ppos, NULL, NULL);
2375 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
2376 struct file *filp, void __user *buffer, size_t *lenp, loff_t *ppos)
2379 which = get_ipc(table, write);
2380 return __do_proc_doulongvec_minmax(which, table, write, filp, buffer,
2381 lenp, ppos, 1l, 1l);
2386 static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
2387 void __user *buffer, size_t *lenp, loff_t *ppos)
2389 struct pid *new_pid;
2393 tmp = pid_nr(cad_pid);
2395 r = __do_proc_dointvec(&tmp, table, write, filp, buffer,
2396 lenp, ppos, NULL, NULL);
2400 new_pid = find_get_pid(tmp);
2404 put_pid(xchg(&cad_pid, new_pid));
2408 #else /* CONFIG_PROC_FS */
2410 int proc_dostring(ctl_table *table, int write, struct file *filp,
2411 void __user *buffer, size_t *lenp, loff_t *ppos)
2416 static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
2417 void __user *buffer, size_t *lenp, loff_t *ppos)
2422 #ifdef CONFIG_SYSVIPC
2423 static int proc_do_ipc_string(ctl_table *table, int write, struct file *filp,
2424 void __user *buffer, size_t *lenp, loff_t *ppos)
2428 static int proc_ipc_dointvec(ctl_table *table, int write, struct file *filp,
2429 void __user *buffer, size_t *lenp, loff_t *ppos)
2433 static int proc_ipc_doulongvec_minmax(ctl_table *table, int write,
2434 struct file *filp, void __user *buffer,
2435 size_t *lenp, loff_t *ppos)
2441 int proc_dointvec(ctl_table *table, int write, struct file *filp,
2442 void __user *buffer, size_t *lenp, loff_t *ppos)
2447 int proc_dointvec_bset(ctl_table *table, int write, struct file *filp,
2448 void __user *buffer, size_t *lenp, loff_t *ppos)
2453 int proc_dointvec_minmax(ctl_table *table, int write, struct file *filp,
2454 void __user *buffer, size_t *lenp, loff_t *ppos)
2459 int proc_dointvec_jiffies(ctl_table *table, int write, struct file *filp,
2460 void __user *buffer, size_t *lenp, loff_t *ppos)
2465 int proc_dointvec_userhz_jiffies(ctl_table *table, int write, struct file *filp,
2466 void __user *buffer, size_t *lenp, loff_t *ppos)
2471 int proc_dointvec_ms_jiffies(ctl_table *table, int write, struct file *filp,
2472 void __user *buffer, size_t *lenp, loff_t *ppos)
2477 int proc_doulongvec_minmax(ctl_table *table, int write, struct file *filp,
2478 void __user *buffer, size_t *lenp, loff_t *ppos)
2483 int proc_doulongvec_ms_jiffies_minmax(ctl_table *table, int write,
2485 void __user *buffer,
2486 size_t *lenp, loff_t *ppos)
2492 #endif /* CONFIG_PROC_FS */
2495 #ifdef CONFIG_SYSCTL_SYSCALL
2497 * General sysctl support routines
2500 /* The generic string strategy routine: */
2501 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2502 void __user *oldval, size_t __user *oldlenp,
2503 void __user *newval, size_t newlen)
2505 if (!table->data || !table->maxlen)
2508 if (oldval && oldlenp) {
2510 if (get_user(bufsize, oldlenp))
2513 size_t len = strlen(table->data), copied;
2515 /* This shouldn't trigger for a well-formed sysctl */
2516 if (len > table->maxlen)
2517 len = table->maxlen;
2519 /* Copy up to a max of bufsize-1 bytes of the string */
2520 copied = (len >= bufsize) ? bufsize - 1 : len;
2522 if (copy_to_user(oldval, table->data, copied) ||
2523 put_user(0, (char __user *)(oldval + copied)))
2525 if (put_user(len, oldlenp))
2529 if (newval && newlen) {
2530 size_t len = newlen;
2531 if (len > table->maxlen)
2532 len = table->maxlen;
2533 if(copy_from_user(table->data, newval, len))
2535 if (len == table->maxlen)
2537 ((char *) table->data)[len] = 0;
2543 * This function makes sure that all of the integers in the vector
2544 * are between the minimum and maximum values given in the arrays
2545 * table->extra1 and table->extra2, respectively.
2547 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2548 void __user *oldval, size_t __user *oldlenp,
2549 void __user *newval, size_t newlen)
2552 if (newval && newlen) {
2553 int __user *vec = (int __user *) newval;
2554 int *min = (int *) table->extra1;
2555 int *max = (int *) table->extra2;
2559 if (newlen % sizeof(int) != 0)
2562 if (!table->extra1 && !table->extra2)
2565 if (newlen > table->maxlen)
2566 newlen = table->maxlen;
2567 length = newlen / sizeof(int);
2569 for (i = 0; i < length; i++) {
2571 if (get_user(value, vec + i))
2573 if (min && value < min[i])
2575 if (max && value > max[i])
2582 /* Strategy function to convert jiffies to seconds */
2583 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2584 void __user *oldval, size_t __user *oldlenp,
2585 void __user *newval, size_t newlen)
2587 if (oldval && oldlenp) {
2590 if (get_user(olen, oldlenp))
2595 if (olen < sizeof(int))
2598 val = *(int *)(table->data) / HZ;
2599 if (put_user(val, (int __user *)oldval))
2601 if (put_user(sizeof(int), oldlenp))
2605 if (newval && newlen) {
2607 if (newlen != sizeof(int))
2609 if (get_user(new, (int __user *)newval))
2611 *(int *)(table->data) = new*HZ;
2616 /* Strategy function to convert jiffies to seconds */
2617 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2618 void __user *oldval, size_t __user *oldlenp,
2619 void __user *newval, size_t newlen)
2621 if (oldval && oldlenp) {
2624 if (get_user(olen, oldlenp))
2629 if (olen < sizeof(int))
2632 val = jiffies_to_msecs(*(int *)(table->data));
2633 if (put_user(val, (int __user *)oldval))
2635 if (put_user(sizeof(int), oldlenp))
2639 if (newval && newlen) {
2641 if (newlen != sizeof(int))
2643 if (get_user(new, (int __user *)newval))
2645 *(int *)(table->data) = msecs_to_jiffies(new);
2651 /* The generic string strategy routine: */
2652 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
2653 void __user *oldval, size_t __user *oldlenp,
2654 void __user *newval, size_t newlen)
2656 struct ctl_table uts_table;
2658 write = newval && newlen;
2659 memcpy(&uts_table, table, sizeof(uts_table));
2660 uts_table.data = get_uts(table, write);
2661 r = sysctl_string(&uts_table, name, nlen,
2662 oldval, oldlenp, newval, newlen);
2663 put_uts(table, write, uts_table.data);
2667 #ifdef CONFIG_SYSVIPC
2668 /* The generic sysctl ipc data routine. */
2669 static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
2670 void __user *oldval, size_t __user *oldlenp,
2671 void __user *newval, size_t newlen)
2676 /* Get out of I don't have a variable */
2677 if (!table->data || !table->maxlen)
2680 data = get_ipc(table, 1);
2684 if (oldval && oldlenp) {
2685 if (get_user(len, oldlenp))
2688 if (len > table->maxlen)
2689 len = table->maxlen;
2690 if (copy_to_user(oldval, data, len))
2692 if (put_user(len, oldlenp))
2697 if (newval && newlen) {
2698 if (newlen > table->maxlen)
2699 newlen = table->maxlen;
2701 if (copy_from_user(data, newval, newlen))
2708 #else /* CONFIG_SYSCTL_SYSCALL */
2711 asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
2713 static int msg_count;
2714 struct __sysctl_args tmp;
2715 int name[CTL_MAXNAME];
2718 /* Read in the sysctl name for better debug message logging */
2719 if (copy_from_user(&tmp, args, sizeof(tmp)))
2721 if (tmp.nlen <= 0 || tmp.nlen >= CTL_MAXNAME)
2723 for (i = 0; i < tmp.nlen; i++)
2724 if (get_user(name[i], tmp.name + i))
2727 /* Ignore accesses to kernel.version */
2728 if ((tmp.nlen == 2) && (name[0] == CTL_KERN) && (name[1] == KERN_VERSION))
2731 if (msg_count < 5) {
2734 "warning: process `%s' used the removed sysctl "
2735 "system call with ", current->comm);
2736 for (i = 0; i < tmp.nlen; i++)
2737 printk("%d.", name[i]);
2744 int sysctl_string(ctl_table *table, int __user *name, int nlen,
2745 void __user *oldval, size_t __user *oldlenp,
2746 void __user *newval, size_t newlen)
2751 int sysctl_intvec(ctl_table *table, int __user *name, int nlen,
2752 void __user *oldval, size_t __user *oldlenp,
2753 void __user *newval, size_t newlen)
2758 int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
2759 void __user *oldval, size_t __user *oldlenp,
2760 void __user *newval, size_t newlen)
2765 int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
2766 void __user *oldval, size_t __user *oldlenp,
2767 void __user *newval, size_t newlen)
2772 static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
2773 void __user *oldval, size_t __user *oldlenp,
2774 void __user *newval, size_t newlen)
2778 #ifdef CONFIG_SYSVIPC
2779 static int sysctl_ipc_data(ctl_table *table, int __user *name, int nlen,
2780 void __user *oldval, size_t __user *oldlenp,
2781 void __user *newval, size_t newlen)
2786 #endif /* CONFIG_SYSCTL_SYSCALL */
2789 * No sense putting this after each symbol definition, twice,
2790 * exception granted :-)
2792 EXPORT_SYMBOL(proc_dointvec);
2793 EXPORT_SYMBOL(proc_dointvec_jiffies);
2794 EXPORT_SYMBOL(proc_dointvec_minmax);
2795 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2796 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2797 EXPORT_SYMBOL(proc_dostring);
2798 EXPORT_SYMBOL(proc_doulongvec_minmax);
2799 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2800 EXPORT_SYMBOL(register_sysctl_table);
2801 EXPORT_SYMBOL(sysctl_intvec);
2802 EXPORT_SYMBOL(sysctl_jiffies);
2803 EXPORT_SYMBOL(sysctl_ms_jiffies);
2804 EXPORT_SYMBOL(sysctl_string);
2805 EXPORT_SYMBOL(unregister_sysctl_table);