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>
22 #include <linux/aio.h>
24 #include <linux/swap.h>
25 #include <linux/slab.h>
26 #include <linux/sysctl.h>
27 #include <linux/bitmap.h>
28 #include <linux/signal.h>
29 #include <linux/printk.h>
30 #include <linux/proc_fs.h>
31 #include <linux/security.h>
32 #include <linux/ctype.h>
33 #include <linux/kmemcheck.h>
34 #include <linux/kmemleak.h>
36 #include <linux/init.h>
37 #include <linux/kernel.h>
38 #include <linux/kobject.h>
39 #include <linux/net.h>
40 #include <linux/sysrq.h>
41 #include <linux/highuid.h>
42 #include <linux/writeback.h>
43 #include <linux/ratelimit.h>
44 #include <linux/compaction.h>
45 #include <linux/hugetlb.h>
46 #include <linux/initrd.h>
47 #include <linux/key.h>
48 #include <linux/times.h>
49 #include <linux/limits.h>
50 #include <linux/dcache.h>
51 #include <linux/dnotify.h>
52 #include <linux/syscalls.h>
53 #include <linux/vmstat.h>
54 #include <linux/nfs_fs.h>
55 #include <linux/acpi.h>
56 #include <linux/reboot.h>
57 #include <linux/ftrace.h>
58 #include <linux/perf_event.h>
59 #include <linux/kprobes.h>
60 #include <linux/pipe_fs_i.h>
61 #include <linux/oom.h>
62 #include <linux/kmod.h>
63 #include <linux/capability.h>
64 #include <linux/binfmts.h>
65 #include <linux/sched/sysctl.h>
66 #include <linux/sched/coredump.h>
67 #include <linux/kexec.h>
68 #include <linux/bpf.h>
69 #include <linux/mount.h>
71 #include <linux/uaccess.h>
72 #include <asm/processor.h>
76 #include <asm/stacktrace.h>
80 #include <asm/setup.h>
82 #ifdef CONFIG_BSD_PROCESS_ACCT
83 #include <linux/acct.h>
85 #ifdef CONFIG_RT_MUTEXES
86 #include <linux/rtmutex.h>
88 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
89 #include <linux/lockdep.h>
91 #ifdef CONFIG_CHR_DEV_SG
95 #ifdef CONFIG_LOCKUP_DETECTOR
96 #include <linux/nmi.h>
99 #if defined(CONFIG_SYSCTL)
101 /* External variables not in a header file. */
102 extern int suid_dumpable;
103 #ifdef CONFIG_COREDUMP
104 extern int core_uses_pid;
105 extern char core_pattern[];
106 extern unsigned int core_pipe_limit;
109 extern int pid_max_min, pid_max_max;
110 extern int percpu_pagelist_fraction;
111 extern int latencytop_enabled;
112 extern unsigned int sysctl_nr_open_min, sysctl_nr_open_max;
114 extern int sysctl_nr_trim_pages;
117 /* Constants used for minimum and maximum */
118 #ifdef CONFIG_LOCKUP_DETECTOR
119 static int sixty = 60;
122 static int __maybe_unused neg_one = -1;
125 static int __maybe_unused one = 1;
126 static int __maybe_unused two = 2;
127 static int __maybe_unused four = 4;
128 static unsigned long one_ul = 1;
129 static int one_hundred = 100;
130 static int one_thousand = 1000;
132 static int ten_thousand = 10000;
134 #ifdef CONFIG_PERF_EVENTS
135 static int six_hundred_forty_kb = 640 * 1024;
138 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
139 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
141 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
142 static int maxolduid = 65535;
143 static int minolduid;
145 static int ngroups_max = NGROUPS_MAX;
146 static const int cap_last_cap = CAP_LAST_CAP;
148 /*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */
149 #ifdef CONFIG_DETECT_HUNG_TASK
150 static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
153 #ifdef CONFIG_INOTIFY_USER
154 #include <linux/inotify.h>
160 extern int pwrsw_enabled;
163 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
164 extern int unaligned_enabled;
168 extern int unaligned_dump_stack;
171 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
172 extern int no_unaligned_warning;
175 #ifdef CONFIG_PROC_SYSCTL
177 #define SYSCTL_WRITES_LEGACY -1
178 #define SYSCTL_WRITES_WARN 0
179 #define SYSCTL_WRITES_STRICT 1
181 static int sysctl_writes_strict = SYSCTL_WRITES_STRICT;
183 static int proc_do_cad_pid(struct ctl_table *table, int write,
184 void __user *buffer, size_t *lenp, loff_t *ppos);
185 static int proc_taint(struct ctl_table *table, int write,
186 void __user *buffer, size_t *lenp, loff_t *ppos);
190 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
191 void __user *buffer, size_t *lenp, loff_t *ppos);
194 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
195 void __user *buffer, size_t *lenp, loff_t *ppos);
196 #ifdef CONFIG_COREDUMP
197 static int proc_dostring_coredump(struct ctl_table *table, int write,
198 void __user *buffer, size_t *lenp, loff_t *ppos);
201 #ifdef CONFIG_MAGIC_SYSRQ
202 /* Note: sysrq code uses it's own private copy */
203 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
205 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
206 void __user *buffer, size_t *lenp,
211 error = proc_dointvec(table, write, buffer, lenp, ppos);
216 sysrq_toggle_support(__sysrq_enabled);
223 static struct ctl_table kern_table[];
224 static struct ctl_table vm_table[];
225 static struct ctl_table fs_table[];
226 static struct ctl_table debug_table[];
227 static struct ctl_table dev_table[];
228 extern struct ctl_table random_table[];
230 extern struct ctl_table epoll_table[];
233 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
234 int sysctl_legacy_va_layout;
237 /* The default sysctl tables: */
239 static struct ctl_table sysctl_base_table[] = {
241 .procname = "kernel",
258 .child = debug_table,
268 #ifdef CONFIG_SCHED_DEBUG
269 static int min_sched_granularity_ns = 100000; /* 100 usecs */
270 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
271 static int min_wakeup_granularity_ns; /* 0 usecs */
272 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
274 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
275 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
276 #endif /* CONFIG_SMP */
277 #endif /* CONFIG_SCHED_DEBUG */
279 #ifdef CONFIG_COMPACTION
280 static int min_extfrag_threshold;
281 static int max_extfrag_threshold = 1000;
284 static struct ctl_table kern_table[] = {
286 .procname = "sched_child_runs_first",
287 .data = &sysctl_sched_child_runs_first,
288 .maxlen = sizeof(unsigned int),
290 .proc_handler = proc_dointvec,
292 #ifdef CONFIG_SCHED_DEBUG
294 .procname = "sched_min_granularity_ns",
295 .data = &sysctl_sched_min_granularity,
296 .maxlen = sizeof(unsigned int),
298 .proc_handler = sched_proc_update_handler,
299 .extra1 = &min_sched_granularity_ns,
300 .extra2 = &max_sched_granularity_ns,
303 .procname = "sched_latency_ns",
304 .data = &sysctl_sched_latency,
305 .maxlen = sizeof(unsigned int),
307 .proc_handler = sched_proc_update_handler,
308 .extra1 = &min_sched_granularity_ns,
309 .extra2 = &max_sched_granularity_ns,
312 .procname = "sched_wakeup_granularity_ns",
313 .data = &sysctl_sched_wakeup_granularity,
314 .maxlen = sizeof(unsigned int),
316 .proc_handler = sched_proc_update_handler,
317 .extra1 = &min_wakeup_granularity_ns,
318 .extra2 = &max_wakeup_granularity_ns,
322 .procname = "sched_tunable_scaling",
323 .data = &sysctl_sched_tunable_scaling,
324 .maxlen = sizeof(enum sched_tunable_scaling),
326 .proc_handler = sched_proc_update_handler,
327 .extra1 = &min_sched_tunable_scaling,
328 .extra2 = &max_sched_tunable_scaling,
331 .procname = "sched_migration_cost_ns",
332 .data = &sysctl_sched_migration_cost,
333 .maxlen = sizeof(unsigned int),
335 .proc_handler = proc_dointvec,
338 .procname = "sched_nr_migrate",
339 .data = &sysctl_sched_nr_migrate,
340 .maxlen = sizeof(unsigned int),
342 .proc_handler = proc_dointvec,
345 .procname = "sched_time_avg_ms",
346 .data = &sysctl_sched_time_avg,
347 .maxlen = sizeof(unsigned int),
349 .proc_handler = proc_dointvec,
351 #ifdef CONFIG_SCHEDSTATS
353 .procname = "sched_schedstats",
355 .maxlen = sizeof(unsigned int),
357 .proc_handler = sysctl_schedstats,
361 #endif /* CONFIG_SCHEDSTATS */
362 #endif /* CONFIG_SMP */
363 #ifdef CONFIG_NUMA_BALANCING
365 .procname = "numa_balancing_scan_delay_ms",
366 .data = &sysctl_numa_balancing_scan_delay,
367 .maxlen = sizeof(unsigned int),
369 .proc_handler = proc_dointvec,
372 .procname = "numa_balancing_scan_period_min_ms",
373 .data = &sysctl_numa_balancing_scan_period_min,
374 .maxlen = sizeof(unsigned int),
376 .proc_handler = proc_dointvec,
379 .procname = "numa_balancing_scan_period_max_ms",
380 .data = &sysctl_numa_balancing_scan_period_max,
381 .maxlen = sizeof(unsigned int),
383 .proc_handler = proc_dointvec,
386 .procname = "numa_balancing_scan_size_mb",
387 .data = &sysctl_numa_balancing_scan_size,
388 .maxlen = sizeof(unsigned int),
390 .proc_handler = proc_dointvec_minmax,
394 .procname = "numa_balancing",
395 .data = NULL, /* filled in by handler */
396 .maxlen = sizeof(unsigned int),
398 .proc_handler = sysctl_numa_balancing,
402 #endif /* CONFIG_NUMA_BALANCING */
403 #endif /* CONFIG_SCHED_DEBUG */
405 .procname = "sched_rt_period_us",
406 .data = &sysctl_sched_rt_period,
407 .maxlen = sizeof(unsigned int),
409 .proc_handler = sched_rt_handler,
412 .procname = "sched_rt_runtime_us",
413 .data = &sysctl_sched_rt_runtime,
414 .maxlen = sizeof(int),
416 .proc_handler = sched_rt_handler,
419 .procname = "sched_rr_timeslice_ms",
420 .data = &sysctl_sched_rr_timeslice,
421 .maxlen = sizeof(int),
423 .proc_handler = sched_rr_handler,
425 #ifdef CONFIG_SCHED_AUTOGROUP
427 .procname = "sched_autogroup_enabled",
428 .data = &sysctl_sched_autogroup_enabled,
429 .maxlen = sizeof(unsigned int),
431 .proc_handler = proc_dointvec_minmax,
436 #ifdef CONFIG_CFS_BANDWIDTH
438 .procname = "sched_cfs_bandwidth_slice_us",
439 .data = &sysctl_sched_cfs_bandwidth_slice,
440 .maxlen = sizeof(unsigned int),
442 .proc_handler = proc_dointvec_minmax,
446 #ifdef CONFIG_PROVE_LOCKING
448 .procname = "prove_locking",
449 .data = &prove_locking,
450 .maxlen = sizeof(int),
452 .proc_handler = proc_dointvec,
455 #ifdef CONFIG_LOCK_STAT
457 .procname = "lock_stat",
459 .maxlen = sizeof(int),
461 .proc_handler = proc_dointvec,
466 .data = &panic_timeout,
467 .maxlen = sizeof(int),
469 .proc_handler = proc_dointvec,
471 #ifdef CONFIG_COREDUMP
473 .procname = "core_uses_pid",
474 .data = &core_uses_pid,
475 .maxlen = sizeof(int),
477 .proc_handler = proc_dointvec,
480 .procname = "core_pattern",
481 .data = core_pattern,
482 .maxlen = CORENAME_MAX_SIZE,
484 .proc_handler = proc_dostring_coredump,
487 .procname = "core_pipe_limit",
488 .data = &core_pipe_limit,
489 .maxlen = sizeof(unsigned int),
491 .proc_handler = proc_dointvec,
494 #ifdef CONFIG_PROC_SYSCTL
496 .procname = "tainted",
497 .maxlen = sizeof(long),
499 .proc_handler = proc_taint,
502 .procname = "sysctl_writes_strict",
503 .data = &sysctl_writes_strict,
504 .maxlen = sizeof(int),
506 .proc_handler = proc_dointvec_minmax,
511 #ifdef CONFIG_LATENCYTOP
513 .procname = "latencytop",
514 .data = &latencytop_enabled,
515 .maxlen = sizeof(int),
517 .proc_handler = sysctl_latencytop,
520 #ifdef CONFIG_BLK_DEV_INITRD
522 .procname = "real-root-dev",
523 .data = &real_root_dev,
524 .maxlen = sizeof(int),
526 .proc_handler = proc_dointvec,
530 .procname = "print-fatal-signals",
531 .data = &print_fatal_signals,
532 .maxlen = sizeof(int),
534 .proc_handler = proc_dointvec,
538 .procname = "reboot-cmd",
539 .data = reboot_command,
542 .proc_handler = proc_dostring,
545 .procname = "stop-a",
546 .data = &stop_a_enabled,
547 .maxlen = sizeof (int),
549 .proc_handler = proc_dointvec,
552 .procname = "scons-poweroff",
553 .data = &scons_pwroff,
554 .maxlen = sizeof (int),
556 .proc_handler = proc_dointvec,
559 #ifdef CONFIG_SPARC64
561 .procname = "tsb-ratio",
562 .data = &sysctl_tsb_ratio,
563 .maxlen = sizeof (int),
565 .proc_handler = proc_dointvec,
570 .procname = "soft-power",
571 .data = &pwrsw_enabled,
572 .maxlen = sizeof (int),
574 .proc_handler = proc_dointvec,
577 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
579 .procname = "unaligned-trap",
580 .data = &unaligned_enabled,
581 .maxlen = sizeof (int),
583 .proc_handler = proc_dointvec,
587 .procname = "ctrl-alt-del",
589 .maxlen = sizeof(int),
591 .proc_handler = proc_dointvec,
593 #ifdef CONFIG_FUNCTION_TRACER
595 .procname = "ftrace_enabled",
596 .data = &ftrace_enabled,
597 .maxlen = sizeof(int),
599 .proc_handler = ftrace_enable_sysctl,
602 #ifdef CONFIG_STACK_TRACER
604 .procname = "stack_tracer_enabled",
605 .data = &stack_tracer_enabled,
606 .maxlen = sizeof(int),
608 .proc_handler = stack_trace_sysctl,
611 #ifdef CONFIG_TRACING
613 .procname = "ftrace_dump_on_oops",
614 .data = &ftrace_dump_on_oops,
615 .maxlen = sizeof(int),
617 .proc_handler = proc_dointvec,
620 .procname = "traceoff_on_warning",
621 .data = &__disable_trace_on_warning,
622 .maxlen = sizeof(__disable_trace_on_warning),
624 .proc_handler = proc_dointvec,
627 .procname = "tracepoint_printk",
628 .data = &tracepoint_printk,
629 .maxlen = sizeof(tracepoint_printk),
631 .proc_handler = tracepoint_printk_sysctl,
634 #ifdef CONFIG_KEXEC_CORE
636 .procname = "kexec_load_disabled",
637 .data = &kexec_load_disabled,
638 .maxlen = sizeof(int),
640 /* only handle a transition from default "0" to "1" */
641 .proc_handler = proc_dointvec_minmax,
646 #ifdef CONFIG_MODULES
648 .procname = "modprobe",
649 .data = &modprobe_path,
650 .maxlen = KMOD_PATH_LEN,
652 .proc_handler = proc_dostring,
655 .procname = "modules_disabled",
656 .data = &modules_disabled,
657 .maxlen = sizeof(int),
659 /* only handle a transition from default "0" to "1" */
660 .proc_handler = proc_dointvec_minmax,
665 #ifdef CONFIG_UEVENT_HELPER
667 .procname = "hotplug",
668 .data = &uevent_helper,
669 .maxlen = UEVENT_HELPER_PATH_LEN,
671 .proc_handler = proc_dostring,
674 #ifdef CONFIG_CHR_DEV_SG
676 .procname = "sg-big-buff",
677 .data = &sg_big_buff,
678 .maxlen = sizeof (int),
680 .proc_handler = proc_dointvec,
683 #ifdef CONFIG_BSD_PROCESS_ACCT
687 .maxlen = 3*sizeof(int),
689 .proc_handler = proc_dointvec,
692 #ifdef CONFIG_MAGIC_SYSRQ
695 .data = &__sysrq_enabled,
696 .maxlen = sizeof (int),
698 .proc_handler = sysrq_sysctl_handler,
701 #ifdef CONFIG_PROC_SYSCTL
703 .procname = "cad_pid",
705 .maxlen = sizeof (int),
707 .proc_handler = proc_do_cad_pid,
711 .procname = "threads-max",
713 .maxlen = sizeof(int),
715 .proc_handler = sysctl_max_threads,
718 .procname = "random",
720 .child = random_table,
723 .procname = "usermodehelper",
725 .child = usermodehelper_table,
728 .procname = "overflowuid",
729 .data = &overflowuid,
730 .maxlen = sizeof(int),
732 .proc_handler = proc_dointvec_minmax,
733 .extra1 = &minolduid,
734 .extra2 = &maxolduid,
737 .procname = "overflowgid",
738 .data = &overflowgid,
739 .maxlen = sizeof(int),
741 .proc_handler = proc_dointvec_minmax,
742 .extra1 = &minolduid,
743 .extra2 = &maxolduid,
746 #ifdef CONFIG_MATHEMU
748 .procname = "ieee_emulation_warnings",
749 .data = &sysctl_ieee_emulation_warnings,
750 .maxlen = sizeof(int),
752 .proc_handler = proc_dointvec,
756 .procname = "userprocess_debug",
757 .data = &show_unhandled_signals,
758 .maxlen = sizeof(int),
760 .proc_handler = proc_dointvec,
764 .procname = "pid_max",
766 .maxlen = sizeof (int),
768 .proc_handler = proc_dointvec_minmax,
769 .extra1 = &pid_max_min,
770 .extra2 = &pid_max_max,
773 .procname = "panic_on_oops",
774 .data = &panic_on_oops,
775 .maxlen = sizeof(int),
777 .proc_handler = proc_dointvec,
779 #if defined CONFIG_PRINTK
781 .procname = "printk",
782 .data = &console_loglevel,
783 .maxlen = 4*sizeof(int),
785 .proc_handler = proc_dointvec,
788 .procname = "printk_ratelimit",
789 .data = &printk_ratelimit_state.interval,
790 .maxlen = sizeof(int),
792 .proc_handler = proc_dointvec_jiffies,
795 .procname = "printk_ratelimit_burst",
796 .data = &printk_ratelimit_state.burst,
797 .maxlen = sizeof(int),
799 .proc_handler = proc_dointvec,
802 .procname = "printk_delay",
803 .data = &printk_delay_msec,
804 .maxlen = sizeof(int),
806 .proc_handler = proc_dointvec_minmax,
808 .extra2 = &ten_thousand,
811 .procname = "printk_devkmsg",
812 .data = devkmsg_log_str,
813 .maxlen = DEVKMSG_STR_MAX_SIZE,
815 .proc_handler = devkmsg_sysctl_set_loglvl,
818 .procname = "dmesg_restrict",
819 .data = &dmesg_restrict,
820 .maxlen = sizeof(int),
822 .proc_handler = proc_dointvec_minmax_sysadmin,
827 .procname = "kptr_restrict",
828 .data = &kptr_restrict,
829 .maxlen = sizeof(int),
831 .proc_handler = proc_dointvec_minmax_sysadmin,
837 .procname = "ngroups_max",
838 .data = &ngroups_max,
839 .maxlen = sizeof (int),
841 .proc_handler = proc_dointvec,
844 .procname = "cap_last_cap",
845 .data = (void *)&cap_last_cap,
846 .maxlen = sizeof(int),
848 .proc_handler = proc_dointvec,
850 #if defined(CONFIG_LOCKUP_DETECTOR)
852 .procname = "watchdog",
853 .data = &watchdog_user_enabled,
854 .maxlen = sizeof (int),
856 .proc_handler = proc_watchdog,
861 .procname = "watchdog_thresh",
862 .data = &watchdog_thresh,
863 .maxlen = sizeof(int),
865 .proc_handler = proc_watchdog_thresh,
870 .procname = "nmi_watchdog",
871 .data = &nmi_watchdog_enabled,
872 .maxlen = sizeof (int),
874 .proc_handler = proc_nmi_watchdog,
876 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
883 .procname = "soft_watchdog",
884 .data = &soft_watchdog_enabled,
885 .maxlen = sizeof (int),
887 .proc_handler = proc_soft_watchdog,
892 .procname = "watchdog_cpumask",
893 .data = &watchdog_cpumask_bits,
896 .proc_handler = proc_watchdog_cpumask,
899 .procname = "softlockup_panic",
900 .data = &softlockup_panic,
901 .maxlen = sizeof(int),
903 .proc_handler = proc_dointvec_minmax,
907 #ifdef CONFIG_HARDLOCKUP_DETECTOR
909 .procname = "hardlockup_panic",
910 .data = &hardlockup_panic,
911 .maxlen = sizeof(int),
913 .proc_handler = proc_dointvec_minmax,
920 .procname = "softlockup_all_cpu_backtrace",
921 .data = &sysctl_softlockup_all_cpu_backtrace,
922 .maxlen = sizeof(int),
924 .proc_handler = proc_dointvec_minmax,
929 .procname = "hardlockup_all_cpu_backtrace",
930 .data = &sysctl_hardlockup_all_cpu_backtrace,
931 .maxlen = sizeof(int),
933 .proc_handler = proc_dointvec_minmax,
937 #endif /* CONFIG_SMP */
939 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
941 .procname = "unknown_nmi_panic",
942 .data = &unknown_nmi_panic,
943 .maxlen = sizeof (int),
945 .proc_handler = proc_dointvec,
948 #if defined(CONFIG_X86)
950 .procname = "panic_on_unrecovered_nmi",
951 .data = &panic_on_unrecovered_nmi,
952 .maxlen = sizeof(int),
954 .proc_handler = proc_dointvec,
957 .procname = "panic_on_io_nmi",
958 .data = &panic_on_io_nmi,
959 .maxlen = sizeof(int),
961 .proc_handler = proc_dointvec,
963 #ifdef CONFIG_DEBUG_STACKOVERFLOW
965 .procname = "panic_on_stackoverflow",
966 .data = &sysctl_panic_on_stackoverflow,
967 .maxlen = sizeof(int),
969 .proc_handler = proc_dointvec,
973 .procname = "bootloader_type",
974 .data = &bootloader_type,
975 .maxlen = sizeof (int),
977 .proc_handler = proc_dointvec,
980 .procname = "bootloader_version",
981 .data = &bootloader_version,
982 .maxlen = sizeof (int),
984 .proc_handler = proc_dointvec,
987 .procname = "io_delay_type",
988 .data = &io_delay_type,
989 .maxlen = sizeof(int),
991 .proc_handler = proc_dointvec,
994 #if defined(CONFIG_MMU)
996 .procname = "randomize_va_space",
997 .data = &randomize_va_space,
998 .maxlen = sizeof(int),
1000 .proc_handler = proc_dointvec,
1003 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1005 .procname = "spin_retry",
1006 .data = &spin_retry,
1007 .maxlen = sizeof (int),
1009 .proc_handler = proc_dointvec,
1012 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1014 .procname = "acpi_video_flags",
1015 .data = &acpi_realmode_flags,
1016 .maxlen = sizeof (unsigned long),
1018 .proc_handler = proc_doulongvec_minmax,
1021 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1023 .procname = "ignore-unaligned-usertrap",
1024 .data = &no_unaligned_warning,
1025 .maxlen = sizeof (int),
1027 .proc_handler = proc_dointvec,
1032 .procname = "unaligned-dump-stack",
1033 .data = &unaligned_dump_stack,
1034 .maxlen = sizeof (int),
1036 .proc_handler = proc_dointvec,
1039 #ifdef CONFIG_DETECT_HUNG_TASK
1041 .procname = "hung_task_panic",
1042 .data = &sysctl_hung_task_panic,
1043 .maxlen = sizeof(int),
1045 .proc_handler = proc_dointvec_minmax,
1050 .procname = "hung_task_check_count",
1051 .data = &sysctl_hung_task_check_count,
1052 .maxlen = sizeof(int),
1054 .proc_handler = proc_dointvec_minmax,
1058 .procname = "hung_task_timeout_secs",
1059 .data = &sysctl_hung_task_timeout_secs,
1060 .maxlen = sizeof(unsigned long),
1062 .proc_handler = proc_dohung_task_timeout_secs,
1063 .extra2 = &hung_task_timeout_max,
1066 .procname = "hung_task_warnings",
1067 .data = &sysctl_hung_task_warnings,
1068 .maxlen = sizeof(int),
1070 .proc_handler = proc_dointvec_minmax,
1074 #ifdef CONFIG_RT_MUTEXES
1076 .procname = "max_lock_depth",
1077 .data = &max_lock_depth,
1078 .maxlen = sizeof(int),
1080 .proc_handler = proc_dointvec,
1084 .procname = "poweroff_cmd",
1085 .data = &poweroff_cmd,
1086 .maxlen = POWEROFF_CMD_PATH_LEN,
1088 .proc_handler = proc_dostring,
1094 .child = key_sysctls,
1097 #ifdef CONFIG_PERF_EVENTS
1099 * User-space scripts rely on the existence of this file
1100 * as a feature check for perf_events being enabled.
1102 * So it's an ABI, do not remove!
1105 .procname = "perf_event_paranoid",
1106 .data = &sysctl_perf_event_paranoid,
1107 .maxlen = sizeof(sysctl_perf_event_paranoid),
1109 .proc_handler = proc_dointvec,
1112 .procname = "perf_event_mlock_kb",
1113 .data = &sysctl_perf_event_mlock,
1114 .maxlen = sizeof(sysctl_perf_event_mlock),
1116 .proc_handler = proc_dointvec,
1119 .procname = "perf_event_max_sample_rate",
1120 .data = &sysctl_perf_event_sample_rate,
1121 .maxlen = sizeof(sysctl_perf_event_sample_rate),
1123 .proc_handler = perf_proc_update_handler,
1127 .procname = "perf_cpu_time_max_percent",
1128 .data = &sysctl_perf_cpu_time_max_percent,
1129 .maxlen = sizeof(sysctl_perf_cpu_time_max_percent),
1131 .proc_handler = perf_cpu_time_max_percent_handler,
1133 .extra2 = &one_hundred,
1136 .procname = "perf_event_max_stack",
1137 .data = &sysctl_perf_event_max_stack,
1138 .maxlen = sizeof(sysctl_perf_event_max_stack),
1140 .proc_handler = perf_event_max_stack_handler,
1142 .extra2 = &six_hundred_forty_kb,
1145 .procname = "perf_event_max_contexts_per_stack",
1146 .data = &sysctl_perf_event_max_contexts_per_stack,
1147 .maxlen = sizeof(sysctl_perf_event_max_contexts_per_stack),
1149 .proc_handler = perf_event_max_stack_handler,
1151 .extra2 = &one_thousand,
1154 #ifdef CONFIG_KMEMCHECK
1156 .procname = "kmemcheck",
1157 .data = &kmemcheck_enabled,
1158 .maxlen = sizeof(int),
1160 .proc_handler = proc_dointvec,
1164 .procname = "panic_on_warn",
1165 .data = &panic_on_warn,
1166 .maxlen = sizeof(int),
1168 .proc_handler = proc_dointvec_minmax,
1172 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1174 .procname = "timer_migration",
1175 .data = &sysctl_timer_migration,
1176 .maxlen = sizeof(unsigned int),
1178 .proc_handler = timer_migration_handler,
1181 #ifdef CONFIG_BPF_SYSCALL
1183 .procname = "unprivileged_bpf_disabled",
1184 .data = &sysctl_unprivileged_bpf_disabled,
1185 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
1187 /* only handle a transition from default "0" to "1" */
1188 .proc_handler = proc_dointvec_minmax,
1193 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
1195 .procname = "panic_on_rcu_stall",
1196 .data = &sysctl_panic_on_rcu_stall,
1197 .maxlen = sizeof(sysctl_panic_on_rcu_stall),
1199 .proc_handler = proc_dointvec_minmax,
1207 static struct ctl_table vm_table[] = {
1209 .procname = "overcommit_memory",
1210 .data = &sysctl_overcommit_memory,
1211 .maxlen = sizeof(sysctl_overcommit_memory),
1213 .proc_handler = proc_dointvec_minmax,
1218 .procname = "panic_on_oom",
1219 .data = &sysctl_panic_on_oom,
1220 .maxlen = sizeof(sysctl_panic_on_oom),
1222 .proc_handler = proc_dointvec_minmax,
1227 .procname = "oom_kill_allocating_task",
1228 .data = &sysctl_oom_kill_allocating_task,
1229 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
1231 .proc_handler = proc_dointvec,
1234 .procname = "oom_dump_tasks",
1235 .data = &sysctl_oom_dump_tasks,
1236 .maxlen = sizeof(sysctl_oom_dump_tasks),
1238 .proc_handler = proc_dointvec,
1241 .procname = "overcommit_ratio",
1242 .data = &sysctl_overcommit_ratio,
1243 .maxlen = sizeof(sysctl_overcommit_ratio),
1245 .proc_handler = overcommit_ratio_handler,
1248 .procname = "overcommit_kbytes",
1249 .data = &sysctl_overcommit_kbytes,
1250 .maxlen = sizeof(sysctl_overcommit_kbytes),
1252 .proc_handler = overcommit_kbytes_handler,
1255 .procname = "page-cluster",
1256 .data = &page_cluster,
1257 .maxlen = sizeof(int),
1259 .proc_handler = proc_dointvec_minmax,
1263 .procname = "dirty_background_ratio",
1264 .data = &dirty_background_ratio,
1265 .maxlen = sizeof(dirty_background_ratio),
1267 .proc_handler = dirty_background_ratio_handler,
1269 .extra2 = &one_hundred,
1272 .procname = "dirty_background_bytes",
1273 .data = &dirty_background_bytes,
1274 .maxlen = sizeof(dirty_background_bytes),
1276 .proc_handler = dirty_background_bytes_handler,
1280 .procname = "dirty_ratio",
1281 .data = &vm_dirty_ratio,
1282 .maxlen = sizeof(vm_dirty_ratio),
1284 .proc_handler = dirty_ratio_handler,
1286 .extra2 = &one_hundred,
1289 .procname = "dirty_bytes",
1290 .data = &vm_dirty_bytes,
1291 .maxlen = sizeof(vm_dirty_bytes),
1293 .proc_handler = dirty_bytes_handler,
1294 .extra1 = &dirty_bytes_min,
1297 .procname = "dirty_writeback_centisecs",
1298 .data = &dirty_writeback_interval,
1299 .maxlen = sizeof(dirty_writeback_interval),
1301 .proc_handler = dirty_writeback_centisecs_handler,
1304 .procname = "dirty_expire_centisecs",
1305 .data = &dirty_expire_interval,
1306 .maxlen = sizeof(dirty_expire_interval),
1308 .proc_handler = proc_dointvec_minmax,
1312 .procname = "dirtytime_expire_seconds",
1313 .data = &dirtytime_expire_interval,
1314 .maxlen = sizeof(dirty_expire_interval),
1316 .proc_handler = dirtytime_interval_handler,
1320 .procname = "nr_pdflush_threads",
1321 .mode = 0444 /* read-only */,
1322 .proc_handler = pdflush_proc_obsolete,
1325 .procname = "swappiness",
1326 .data = &vm_swappiness,
1327 .maxlen = sizeof(vm_swappiness),
1329 .proc_handler = proc_dointvec_minmax,
1331 .extra2 = &one_hundred,
1333 #ifdef CONFIG_HUGETLB_PAGE
1335 .procname = "nr_hugepages",
1337 .maxlen = sizeof(unsigned long),
1339 .proc_handler = hugetlb_sysctl_handler,
1343 .procname = "nr_hugepages_mempolicy",
1345 .maxlen = sizeof(unsigned long),
1347 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1351 .procname = "hugetlb_shm_group",
1352 .data = &sysctl_hugetlb_shm_group,
1353 .maxlen = sizeof(gid_t),
1355 .proc_handler = proc_dointvec,
1358 .procname = "hugepages_treat_as_movable",
1359 .data = &hugepages_treat_as_movable,
1360 .maxlen = sizeof(int),
1362 .proc_handler = proc_dointvec,
1365 .procname = "nr_overcommit_hugepages",
1367 .maxlen = sizeof(unsigned long),
1369 .proc_handler = hugetlb_overcommit_handler,
1373 .procname = "lowmem_reserve_ratio",
1374 .data = &sysctl_lowmem_reserve_ratio,
1375 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1377 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1380 .procname = "drop_caches",
1381 .data = &sysctl_drop_caches,
1382 .maxlen = sizeof(int),
1384 .proc_handler = drop_caches_sysctl_handler,
1388 #ifdef CONFIG_COMPACTION
1390 .procname = "compact_memory",
1391 .data = &sysctl_compact_memory,
1392 .maxlen = sizeof(int),
1394 .proc_handler = sysctl_compaction_handler,
1397 .procname = "extfrag_threshold",
1398 .data = &sysctl_extfrag_threshold,
1399 .maxlen = sizeof(int),
1401 .proc_handler = sysctl_extfrag_handler,
1402 .extra1 = &min_extfrag_threshold,
1403 .extra2 = &max_extfrag_threshold,
1406 .procname = "compact_unevictable_allowed",
1407 .data = &sysctl_compact_unevictable_allowed,
1408 .maxlen = sizeof(int),
1410 .proc_handler = proc_dointvec,
1415 #endif /* CONFIG_COMPACTION */
1417 .procname = "min_free_kbytes",
1418 .data = &min_free_kbytes,
1419 .maxlen = sizeof(min_free_kbytes),
1421 .proc_handler = min_free_kbytes_sysctl_handler,
1425 .procname = "watermark_scale_factor",
1426 .data = &watermark_scale_factor,
1427 .maxlen = sizeof(watermark_scale_factor),
1429 .proc_handler = watermark_scale_factor_sysctl_handler,
1431 .extra2 = &one_thousand,
1434 .procname = "percpu_pagelist_fraction",
1435 .data = &percpu_pagelist_fraction,
1436 .maxlen = sizeof(percpu_pagelist_fraction),
1438 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1443 .procname = "max_map_count",
1444 .data = &sysctl_max_map_count,
1445 .maxlen = sizeof(sysctl_max_map_count),
1447 .proc_handler = proc_dointvec_minmax,
1452 .procname = "nr_trim_pages",
1453 .data = &sysctl_nr_trim_pages,
1454 .maxlen = sizeof(sysctl_nr_trim_pages),
1456 .proc_handler = proc_dointvec_minmax,
1461 .procname = "laptop_mode",
1462 .data = &laptop_mode,
1463 .maxlen = sizeof(laptop_mode),
1465 .proc_handler = proc_dointvec_jiffies,
1468 .procname = "block_dump",
1469 .data = &block_dump,
1470 .maxlen = sizeof(block_dump),
1472 .proc_handler = proc_dointvec,
1476 .procname = "vfs_cache_pressure",
1477 .data = &sysctl_vfs_cache_pressure,
1478 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1480 .proc_handler = proc_dointvec,
1483 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1485 .procname = "legacy_va_layout",
1486 .data = &sysctl_legacy_va_layout,
1487 .maxlen = sizeof(sysctl_legacy_va_layout),
1489 .proc_handler = proc_dointvec,
1495 .procname = "zone_reclaim_mode",
1496 .data = &node_reclaim_mode,
1497 .maxlen = sizeof(node_reclaim_mode),
1499 .proc_handler = proc_dointvec,
1503 .procname = "min_unmapped_ratio",
1504 .data = &sysctl_min_unmapped_ratio,
1505 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1507 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1509 .extra2 = &one_hundred,
1512 .procname = "min_slab_ratio",
1513 .data = &sysctl_min_slab_ratio,
1514 .maxlen = sizeof(sysctl_min_slab_ratio),
1516 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1518 .extra2 = &one_hundred,
1523 .procname = "stat_interval",
1524 .data = &sysctl_stat_interval,
1525 .maxlen = sizeof(sysctl_stat_interval),
1527 .proc_handler = proc_dointvec_jiffies,
1530 .procname = "stat_refresh",
1534 .proc_handler = vmstat_refresh,
1539 .procname = "mmap_min_addr",
1540 .data = &dac_mmap_min_addr,
1541 .maxlen = sizeof(unsigned long),
1543 .proc_handler = mmap_min_addr_handler,
1548 .procname = "numa_zonelist_order",
1549 .data = &numa_zonelist_order,
1550 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1552 .proc_handler = numa_zonelist_order_handler,
1555 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1556 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1558 .procname = "vdso_enabled",
1559 #ifdef CONFIG_X86_32
1560 .data = &vdso32_enabled,
1561 .maxlen = sizeof(vdso32_enabled),
1563 .data = &vdso_enabled,
1564 .maxlen = sizeof(vdso_enabled),
1567 .proc_handler = proc_dointvec,
1571 #ifdef CONFIG_HIGHMEM
1573 .procname = "highmem_is_dirtyable",
1574 .data = &vm_highmem_is_dirtyable,
1575 .maxlen = sizeof(vm_highmem_is_dirtyable),
1577 .proc_handler = proc_dointvec_minmax,
1582 #ifdef CONFIG_MEMORY_FAILURE
1584 .procname = "memory_failure_early_kill",
1585 .data = &sysctl_memory_failure_early_kill,
1586 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1588 .proc_handler = proc_dointvec_minmax,
1593 .procname = "memory_failure_recovery",
1594 .data = &sysctl_memory_failure_recovery,
1595 .maxlen = sizeof(sysctl_memory_failure_recovery),
1597 .proc_handler = proc_dointvec_minmax,
1603 .procname = "user_reserve_kbytes",
1604 .data = &sysctl_user_reserve_kbytes,
1605 .maxlen = sizeof(sysctl_user_reserve_kbytes),
1607 .proc_handler = proc_doulongvec_minmax,
1610 .procname = "admin_reserve_kbytes",
1611 .data = &sysctl_admin_reserve_kbytes,
1612 .maxlen = sizeof(sysctl_admin_reserve_kbytes),
1614 .proc_handler = proc_doulongvec_minmax,
1616 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1618 .procname = "mmap_rnd_bits",
1619 .data = &mmap_rnd_bits,
1620 .maxlen = sizeof(mmap_rnd_bits),
1622 .proc_handler = proc_dointvec_minmax,
1623 .extra1 = (void *)&mmap_rnd_bits_min,
1624 .extra2 = (void *)&mmap_rnd_bits_max,
1627 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1629 .procname = "mmap_rnd_compat_bits",
1630 .data = &mmap_rnd_compat_bits,
1631 .maxlen = sizeof(mmap_rnd_compat_bits),
1633 .proc_handler = proc_dointvec_minmax,
1634 .extra1 = (void *)&mmap_rnd_compat_bits_min,
1635 .extra2 = (void *)&mmap_rnd_compat_bits_max,
1641 static struct ctl_table fs_table[] = {
1643 .procname = "inode-nr",
1644 .data = &inodes_stat,
1645 .maxlen = 2*sizeof(long),
1647 .proc_handler = proc_nr_inodes,
1650 .procname = "inode-state",
1651 .data = &inodes_stat,
1652 .maxlen = 7*sizeof(long),
1654 .proc_handler = proc_nr_inodes,
1657 .procname = "file-nr",
1658 .data = &files_stat,
1659 .maxlen = sizeof(files_stat),
1661 .proc_handler = proc_nr_files,
1664 .procname = "file-max",
1665 .data = &files_stat.max_files,
1666 .maxlen = sizeof(files_stat.max_files),
1668 .proc_handler = proc_doulongvec_minmax,
1671 .procname = "nr_open",
1672 .data = &sysctl_nr_open,
1673 .maxlen = sizeof(unsigned int),
1675 .proc_handler = proc_dointvec_minmax,
1676 .extra1 = &sysctl_nr_open_min,
1677 .extra2 = &sysctl_nr_open_max,
1680 .procname = "dentry-state",
1681 .data = &dentry_stat,
1682 .maxlen = 6*sizeof(long),
1684 .proc_handler = proc_nr_dentry,
1687 .procname = "overflowuid",
1688 .data = &fs_overflowuid,
1689 .maxlen = sizeof(int),
1691 .proc_handler = proc_dointvec_minmax,
1692 .extra1 = &minolduid,
1693 .extra2 = &maxolduid,
1696 .procname = "overflowgid",
1697 .data = &fs_overflowgid,
1698 .maxlen = sizeof(int),
1700 .proc_handler = proc_dointvec_minmax,
1701 .extra1 = &minolduid,
1702 .extra2 = &maxolduid,
1704 #ifdef CONFIG_FILE_LOCKING
1706 .procname = "leases-enable",
1707 .data = &leases_enable,
1708 .maxlen = sizeof(int),
1710 .proc_handler = proc_dointvec,
1713 #ifdef CONFIG_DNOTIFY
1715 .procname = "dir-notify-enable",
1716 .data = &dir_notify_enable,
1717 .maxlen = sizeof(int),
1719 .proc_handler = proc_dointvec,
1723 #ifdef CONFIG_FILE_LOCKING
1725 .procname = "lease-break-time",
1726 .data = &lease_break_time,
1727 .maxlen = sizeof(int),
1729 .proc_handler = proc_dointvec,
1734 .procname = "aio-nr",
1736 .maxlen = sizeof(aio_nr),
1738 .proc_handler = proc_doulongvec_minmax,
1741 .procname = "aio-max-nr",
1742 .data = &aio_max_nr,
1743 .maxlen = sizeof(aio_max_nr),
1745 .proc_handler = proc_doulongvec_minmax,
1747 #endif /* CONFIG_AIO */
1748 #ifdef CONFIG_INOTIFY_USER
1750 .procname = "inotify",
1752 .child = inotify_table,
1757 .procname = "epoll",
1759 .child = epoll_table,
1764 .procname = "protected_symlinks",
1765 .data = &sysctl_protected_symlinks,
1766 .maxlen = sizeof(int),
1768 .proc_handler = proc_dointvec_minmax,
1773 .procname = "protected_hardlinks",
1774 .data = &sysctl_protected_hardlinks,
1775 .maxlen = sizeof(int),
1777 .proc_handler = proc_dointvec_minmax,
1782 .procname = "suid_dumpable",
1783 .data = &suid_dumpable,
1784 .maxlen = sizeof(int),
1786 .proc_handler = proc_dointvec_minmax_coredump,
1790 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1792 .procname = "binfmt_misc",
1794 .child = sysctl_mount_point,
1798 .procname = "pipe-max-size",
1799 .data = &pipe_max_size,
1800 .maxlen = sizeof(int),
1802 .proc_handler = &pipe_proc_fn,
1803 .extra1 = &pipe_min_size,
1806 .procname = "pipe-user-pages-hard",
1807 .data = &pipe_user_pages_hard,
1808 .maxlen = sizeof(pipe_user_pages_hard),
1810 .proc_handler = proc_doulongvec_minmax,
1813 .procname = "pipe-user-pages-soft",
1814 .data = &pipe_user_pages_soft,
1815 .maxlen = sizeof(pipe_user_pages_soft),
1817 .proc_handler = proc_doulongvec_minmax,
1820 .procname = "mount-max",
1821 .data = &sysctl_mount_max,
1822 .maxlen = sizeof(unsigned int),
1824 .proc_handler = proc_dointvec_minmax,
1830 static struct ctl_table debug_table[] = {
1831 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1833 .procname = "exception-trace",
1834 .data = &show_unhandled_signals,
1835 .maxlen = sizeof(int),
1837 .proc_handler = proc_dointvec
1840 #if defined(CONFIG_OPTPROBES)
1842 .procname = "kprobes-optimization",
1843 .data = &sysctl_kprobes_optimization,
1844 .maxlen = sizeof(int),
1846 .proc_handler = proc_kprobes_optimization_handler,
1854 static struct ctl_table dev_table[] = {
1858 int __init sysctl_init(void)
1860 struct ctl_table_header *hdr;
1862 hdr = register_sysctl_table(sysctl_base_table);
1863 kmemleak_not_leak(hdr);
1867 #endif /* CONFIG_SYSCTL */
1873 #ifdef CONFIG_PROC_SYSCTL
1875 static int _proc_do_string(char *data, int maxlen, int write,
1876 char __user *buffer,
1877 size_t *lenp, loff_t *ppos)
1883 if (!data || !maxlen || !*lenp) {
1889 if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1890 /* Only continue writes not past the end of buffer. */
1892 if (len > maxlen - 1)
1899 /* Start writing from beginning of buffer. */
1905 while ((p - buffer) < *lenp && len < maxlen - 1) {
1906 if (get_user(c, p++))
1908 if (c == 0 || c == '\n')
1929 if (copy_to_user(buffer, data, len))
1932 if (put_user('\n', buffer + len))
1942 static void warn_sysctl_write(struct ctl_table *table)
1944 pr_warn_once("%s wrote to %s when file position was not 0!\n"
1945 "This will not be supported in the future. To silence this\n"
1946 "warning, set kernel.sysctl_writes_strict = -1\n",
1947 current->comm, table->procname);
1951 * proc_dostring - read a string sysctl
1952 * @table: the sysctl table
1953 * @write: %TRUE if this is a write to the sysctl file
1954 * @buffer: the user buffer
1955 * @lenp: the size of the user buffer
1956 * @ppos: file position
1958 * Reads/writes a string from/to the user buffer. If the kernel
1959 * buffer provided is not large enough to hold the string, the
1960 * string is truncated. The copied string is %NULL-terminated.
1961 * If the string is being read by the user process, it is copied
1962 * and a newline '\n' is added. It is truncated if the buffer is
1965 * Returns 0 on success.
1967 int proc_dostring(struct ctl_table *table, int write,
1968 void __user *buffer, size_t *lenp, loff_t *ppos)
1970 if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1971 warn_sysctl_write(table);
1973 return _proc_do_string((char *)(table->data), table->maxlen, write,
1974 (char __user *)buffer, lenp, ppos);
1977 static size_t proc_skip_spaces(char **buf)
1980 char *tmp = skip_spaces(*buf);
1986 static void proc_skip_char(char **buf, size_t *size, const char v)
1996 #define TMPBUFLEN 22
1998 * proc_get_long - reads an ASCII formatted integer from a user buffer
2000 * @buf: a kernel buffer
2001 * @size: size of the kernel buffer
2002 * @val: this is where the number will be stored
2003 * @neg: set to %TRUE if number is negative
2004 * @perm_tr: a vector which contains the allowed trailers
2005 * @perm_tr_len: size of the perm_tr vector
2006 * @tr: pointer to store the trailer character
2008 * In case of success %0 is returned and @buf and @size are updated with
2009 * the amount of bytes read. If @tr is non-NULL and a trailing
2010 * character exists (size is non-zero after returning from this
2011 * function), @tr is updated with the trailing character.
2013 static int proc_get_long(char **buf, size_t *size,
2014 unsigned long *val, bool *neg,
2015 const char *perm_tr, unsigned perm_tr_len, char *tr)
2018 char *p, tmp[TMPBUFLEN];
2024 if (len > TMPBUFLEN - 1)
2025 len = TMPBUFLEN - 1;
2027 memcpy(tmp, *buf, len);
2031 if (*p == '-' && *size > 1) {
2039 *val = simple_strtoul(p, &p, 0);
2043 /* We don't know if the next char is whitespace thus we may accept
2044 * invalid integers (e.g. 1234...a) or two integers instead of one
2045 * (e.g. 123...1). So lets not allow such large numbers. */
2046 if (len == TMPBUFLEN - 1)
2049 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2052 if (tr && (len < *size))
2062 * proc_put_long - converts an integer to a decimal ASCII formatted string
2064 * @buf: the user buffer
2065 * @size: the size of the user buffer
2066 * @val: the integer to be converted
2067 * @neg: sign of the number, %TRUE for negative
2069 * In case of success %0 is returned and @buf and @size are updated with
2070 * the amount of bytes written.
2072 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2076 char tmp[TMPBUFLEN], *p = tmp;
2078 sprintf(p, "%s%lu", neg ? "-" : "", val);
2082 if (copy_to_user(*buf, tmp, len))
2090 static int proc_put_char(void __user **buf, size_t *size, char c)
2093 char __user **buffer = (char __user **)buf;
2094 if (put_user(c, *buffer))
2096 (*size)--, (*buffer)++;
2102 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2104 int write, void *data)
2108 if (*lvalp > (unsigned long) INT_MAX + 1)
2112 if (*lvalp > (unsigned long) INT_MAX)
2120 *lvalp = -(unsigned long)val;
2123 *lvalp = (unsigned long)val;
2129 static int do_proc_douintvec_conv(bool *negp, unsigned long *lvalp,
2131 int write, void *data)
2138 unsigned int val = *valp;
2139 *lvalp = (unsigned long)val;
2144 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2146 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2147 int write, void __user *buffer,
2148 size_t *lenp, loff_t *ppos,
2149 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2150 int write, void *data),
2153 int *i, vleft, first = 1, err = 0;
2155 char *kbuf = NULL, *p;
2157 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2162 i = (int *) tbl_data;
2163 vleft = table->maxlen / sizeof(*i);
2167 conv = do_proc_dointvec_conv;
2171 switch (sysctl_writes_strict) {
2172 case SYSCTL_WRITES_STRICT:
2174 case SYSCTL_WRITES_WARN:
2175 warn_sysctl_write(table);
2182 if (left > PAGE_SIZE - 1)
2183 left = PAGE_SIZE - 1;
2184 p = kbuf = memdup_user_nul(buffer, left);
2186 return PTR_ERR(kbuf);
2189 for (; left && vleft--; i++, first=0) {
2194 left -= proc_skip_spaces(&p);
2198 err = proc_get_long(&p, &left, &lval, &neg,
2200 sizeof(proc_wspace_sep), NULL);
2203 if (conv(&neg, &lval, i, 1, data)) {
2208 if (conv(&neg, &lval, i, 0, data)) {
2213 err = proc_put_char(&buffer, &left, '\t');
2216 err = proc_put_long(&buffer, &left, lval, neg);
2222 if (!write && !first && left && !err)
2223 err = proc_put_char(&buffer, &left, '\n');
2224 if (write && !err && left)
2225 left -= proc_skip_spaces(&p);
2229 return err ? : -EINVAL;
2237 static int do_proc_dointvec(struct ctl_table *table, int write,
2238 void __user *buffer, size_t *lenp, loff_t *ppos,
2239 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2240 int write, void *data),
2243 return __do_proc_dointvec(table->data, table, write,
2244 buffer, lenp, ppos, conv, data);
2248 * proc_dointvec - read a vector of integers
2249 * @table: the sysctl table
2250 * @write: %TRUE if this is a write to the sysctl file
2251 * @buffer: the user buffer
2252 * @lenp: the size of the user buffer
2253 * @ppos: file position
2255 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2256 * values from/to the user buffer, treated as an ASCII string.
2258 * Returns 0 on success.
2260 int proc_dointvec(struct ctl_table *table, int write,
2261 void __user *buffer, size_t *lenp, loff_t *ppos)
2263 return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
2267 * proc_douintvec - read a vector of unsigned integers
2268 * @table: the sysctl table
2269 * @write: %TRUE if this is a write to the sysctl file
2270 * @buffer: the user buffer
2271 * @lenp: the size of the user buffer
2272 * @ppos: file position
2274 * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
2275 * values from/to the user buffer, treated as an ASCII string.
2277 * Returns 0 on success.
2279 int proc_douintvec(struct ctl_table *table, int write,
2280 void __user *buffer, size_t *lenp, loff_t *ppos)
2282 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2283 do_proc_douintvec_conv, NULL);
2287 * Taint values can only be increased
2288 * This means we can safely use a temporary.
2290 static int proc_taint(struct ctl_table *table, int write,
2291 void __user *buffer, size_t *lenp, loff_t *ppos)
2294 unsigned long tmptaint = get_taint();
2297 if (write && !capable(CAP_SYS_ADMIN))
2302 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2308 * Poor man's atomic or. Not worth adding a primitive
2309 * to everyone's atomic.h for this
2312 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2313 if ((tmptaint >> i) & 1)
2314 add_taint(i, LOCKDEP_STILL_OK);
2321 #ifdef CONFIG_PRINTK
2322 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2323 void __user *buffer, size_t *lenp, loff_t *ppos)
2325 if (write && !capable(CAP_SYS_ADMIN))
2328 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2332 struct do_proc_dointvec_minmax_conv_param {
2337 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2339 int write, void *data)
2341 struct do_proc_dointvec_minmax_conv_param *param = data;
2343 int val = *negp ? -*lvalp : *lvalp;
2344 if ((param->min && *param->min > val) ||
2345 (param->max && *param->max < val))
2352 *lvalp = -(unsigned long)val;
2355 *lvalp = (unsigned long)val;
2362 * proc_dointvec_minmax - read a vector of integers with min/max values
2363 * @table: the sysctl table
2364 * @write: %TRUE if this is a write to the sysctl file
2365 * @buffer: the user buffer
2366 * @lenp: the size of the user buffer
2367 * @ppos: file position
2369 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2370 * values from/to the user buffer, treated as an ASCII string.
2372 * This routine will ensure the values are within the range specified by
2373 * table->extra1 (min) and table->extra2 (max).
2375 * Returns 0 on success.
2377 int proc_dointvec_minmax(struct ctl_table *table, int write,
2378 void __user *buffer, size_t *lenp, loff_t *ppos)
2380 struct do_proc_dointvec_minmax_conv_param param = {
2381 .min = (int *) table->extra1,
2382 .max = (int *) table->extra2,
2384 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2385 do_proc_dointvec_minmax_conv, ¶m);
2388 static void validate_coredump_safety(void)
2390 #ifdef CONFIG_COREDUMP
2391 if (suid_dumpable == SUID_DUMP_ROOT &&
2392 core_pattern[0] != '/' && core_pattern[0] != '|') {
2394 "Unsafe core_pattern used with fs.suid_dumpable=2.\n"
2395 "Pipe handler or fully qualified core dump path required.\n"
2396 "Set kernel.core_pattern before fs.suid_dumpable.\n"
2402 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2403 void __user *buffer, size_t *lenp, loff_t *ppos)
2405 int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2407 validate_coredump_safety();
2411 #ifdef CONFIG_COREDUMP
2412 static int proc_dostring_coredump(struct ctl_table *table, int write,
2413 void __user *buffer, size_t *lenp, loff_t *ppos)
2415 int error = proc_dostring(table, write, buffer, lenp, ppos);
2417 validate_coredump_safety();
2422 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2423 void __user *buffer,
2424 size_t *lenp, loff_t *ppos,
2425 unsigned long convmul,
2426 unsigned long convdiv)
2428 unsigned long *i, *min, *max;
2429 int vleft, first = 1, err = 0;
2431 char *kbuf = NULL, *p;
2433 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2438 i = (unsigned long *) data;
2439 min = (unsigned long *) table->extra1;
2440 max = (unsigned long *) table->extra2;
2441 vleft = table->maxlen / sizeof(unsigned long);
2446 switch (sysctl_writes_strict) {
2447 case SYSCTL_WRITES_STRICT:
2449 case SYSCTL_WRITES_WARN:
2450 warn_sysctl_write(table);
2457 if (left > PAGE_SIZE - 1)
2458 left = PAGE_SIZE - 1;
2459 p = kbuf = memdup_user_nul(buffer, left);
2461 return PTR_ERR(kbuf);
2464 for (; left && vleft--; i++, first = 0) {
2470 left -= proc_skip_spaces(&p);
2472 err = proc_get_long(&p, &left, &val, &neg,
2474 sizeof(proc_wspace_sep), NULL);
2479 val = convmul * val / convdiv;
2480 if ((min && val < *min) || (max && val > *max))
2484 val = convdiv * (*i) / convmul;
2486 err = proc_put_char(&buffer, &left, '\t');
2490 err = proc_put_long(&buffer, &left, val, false);
2496 if (!write && !first && left && !err)
2497 err = proc_put_char(&buffer, &left, '\n');
2499 left -= proc_skip_spaces(&p);
2503 return err ? : -EINVAL;
2511 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2512 void __user *buffer,
2513 size_t *lenp, loff_t *ppos,
2514 unsigned long convmul,
2515 unsigned long convdiv)
2517 return __do_proc_doulongvec_minmax(table->data, table, write,
2518 buffer, lenp, ppos, convmul, convdiv);
2522 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2523 * @table: the sysctl table
2524 * @write: %TRUE if this is a write to the sysctl file
2525 * @buffer: the user buffer
2526 * @lenp: the size of the user buffer
2527 * @ppos: file position
2529 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2530 * values from/to the user buffer, treated as an ASCII string.
2532 * This routine will ensure the values are within the range specified by
2533 * table->extra1 (min) and table->extra2 (max).
2535 * Returns 0 on success.
2537 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2538 void __user *buffer, size_t *lenp, loff_t *ppos)
2540 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2544 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2545 * @table: the sysctl table
2546 * @write: %TRUE if this is a write to the sysctl file
2547 * @buffer: the user buffer
2548 * @lenp: the size of the user buffer
2549 * @ppos: file position
2551 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2552 * values from/to the user buffer, treated as an ASCII string. The values
2553 * are treated as milliseconds, and converted to jiffies when they are stored.
2555 * This routine will ensure the values are within the range specified by
2556 * table->extra1 (min) and table->extra2 (max).
2558 * Returns 0 on success.
2560 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2561 void __user *buffer,
2562 size_t *lenp, loff_t *ppos)
2564 return do_proc_doulongvec_minmax(table, write, buffer,
2565 lenp, ppos, HZ, 1000l);
2569 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2571 int write, void *data)
2574 if (*lvalp > LONG_MAX / HZ)
2576 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2582 lval = -(unsigned long)val;
2585 lval = (unsigned long)val;
2592 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2594 int write, void *data)
2597 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2599 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2605 lval = -(unsigned long)val;
2608 lval = (unsigned long)val;
2610 *lvalp = jiffies_to_clock_t(lval);
2615 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2617 int write, void *data)
2620 unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2630 lval = -(unsigned long)val;
2633 lval = (unsigned long)val;
2635 *lvalp = jiffies_to_msecs(lval);
2641 * proc_dointvec_jiffies - read a vector of integers as seconds
2642 * @table: the sysctl table
2643 * @write: %TRUE if this is a write to the sysctl file
2644 * @buffer: the user buffer
2645 * @lenp: the size of the user buffer
2646 * @ppos: file position
2648 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2649 * values from/to the user buffer, treated as an ASCII string.
2650 * The values read are assumed to be in seconds, and are converted into
2653 * Returns 0 on success.
2655 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2656 void __user *buffer, size_t *lenp, loff_t *ppos)
2658 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2659 do_proc_dointvec_jiffies_conv,NULL);
2663 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2664 * @table: the sysctl table
2665 * @write: %TRUE if this is a write to the sysctl file
2666 * @buffer: the user buffer
2667 * @lenp: the size of the user buffer
2668 * @ppos: pointer to the file position
2670 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2671 * values from/to the user buffer, treated as an ASCII string.
2672 * The values read are assumed to be in 1/USER_HZ seconds, and
2673 * are converted into jiffies.
2675 * Returns 0 on success.
2677 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2678 void __user *buffer, size_t *lenp, loff_t *ppos)
2680 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2681 do_proc_dointvec_userhz_jiffies_conv,NULL);
2685 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2686 * @table: the sysctl table
2687 * @write: %TRUE if this is a write to the sysctl file
2688 * @buffer: the user buffer
2689 * @lenp: the size of the user buffer
2690 * @ppos: file position
2691 * @ppos: the current position in the file
2693 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2694 * values from/to the user buffer, treated as an ASCII string.
2695 * The values read are assumed to be in 1/1000 seconds, and
2696 * are converted into jiffies.
2698 * Returns 0 on success.
2700 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2701 void __user *buffer, size_t *lenp, loff_t *ppos)
2703 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2704 do_proc_dointvec_ms_jiffies_conv, NULL);
2707 static int proc_do_cad_pid(struct ctl_table *table, int write,
2708 void __user *buffer, size_t *lenp, loff_t *ppos)
2710 struct pid *new_pid;
2714 tmp = pid_vnr(cad_pid);
2716 r = __do_proc_dointvec(&tmp, table, write, buffer,
2717 lenp, ppos, NULL, NULL);
2721 new_pid = find_get_pid(tmp);
2725 put_pid(xchg(&cad_pid, new_pid));
2730 * proc_do_large_bitmap - read/write from/to a large bitmap
2731 * @table: the sysctl table
2732 * @write: %TRUE if this is a write to the sysctl file
2733 * @buffer: the user buffer
2734 * @lenp: the size of the user buffer
2735 * @ppos: file position
2737 * The bitmap is stored at table->data and the bitmap length (in bits)
2740 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2741 * large bitmaps may be represented in a compact manner. Writing into
2742 * the file will clear the bitmap then update it with the given input.
2744 * Returns 0 on success.
2746 int proc_do_large_bitmap(struct ctl_table *table, int write,
2747 void __user *buffer, size_t *lenp, loff_t *ppos)
2751 size_t left = *lenp;
2752 unsigned long bitmap_len = table->maxlen;
2753 unsigned long *bitmap = *(unsigned long **) table->data;
2754 unsigned long *tmp_bitmap = NULL;
2755 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2757 if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2765 if (left > PAGE_SIZE - 1)
2766 left = PAGE_SIZE - 1;
2768 p = kbuf = memdup_user_nul(buffer, left);
2770 return PTR_ERR(kbuf);
2772 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2778 proc_skip_char(&p, &left, '\n');
2779 while (!err && left) {
2780 unsigned long val_a, val_b;
2783 err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2787 if (val_a >= bitmap_len || neg) {
2799 err = proc_get_long(&p, &left, &val_b,
2800 &neg, tr_b, sizeof(tr_b),
2804 if (val_b >= bitmap_len || neg ||
2815 bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2817 proc_skip_char(&p, &left, '\n');
2821 unsigned long bit_a, bit_b = 0;
2824 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2825 if (bit_a >= bitmap_len)
2827 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2831 err = proc_put_char(&buffer, &left, ',');
2835 err = proc_put_long(&buffer, &left, bit_a, false);
2838 if (bit_a != bit_b) {
2839 err = proc_put_char(&buffer, &left, '-');
2842 err = proc_put_long(&buffer, &left, bit_b, false);
2850 err = proc_put_char(&buffer, &left, '\n');
2856 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2858 bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2870 #else /* CONFIG_PROC_SYSCTL */
2872 int proc_dostring(struct ctl_table *table, int write,
2873 void __user *buffer, size_t *lenp, loff_t *ppos)
2878 int proc_dointvec(struct ctl_table *table, int write,
2879 void __user *buffer, size_t *lenp, loff_t *ppos)
2884 int proc_douintvec(struct ctl_table *table, int write,
2885 void __user *buffer, size_t *lenp, loff_t *ppos)
2890 int proc_dointvec_minmax(struct ctl_table *table, int write,
2891 void __user *buffer, size_t *lenp, loff_t *ppos)
2896 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2897 void __user *buffer, size_t *lenp, loff_t *ppos)
2902 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2903 void __user *buffer, size_t *lenp, loff_t *ppos)
2908 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2909 void __user *buffer, size_t *lenp, loff_t *ppos)
2914 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2915 void __user *buffer, size_t *lenp, loff_t *ppos)
2920 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2921 void __user *buffer,
2922 size_t *lenp, loff_t *ppos)
2928 #endif /* CONFIG_PROC_SYSCTL */
2931 * No sense putting this after each symbol definition, twice,
2932 * exception granted :-)
2934 EXPORT_SYMBOL(proc_dointvec);
2935 EXPORT_SYMBOL(proc_douintvec);
2936 EXPORT_SYMBOL(proc_dointvec_jiffies);
2937 EXPORT_SYMBOL(proc_dointvec_minmax);
2938 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2939 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2940 EXPORT_SYMBOL(proc_dostring);
2941 EXPORT_SYMBOL(proc_doulongvec_minmax);
2942 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);