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/kexec.h>
67 #include <linux/bpf.h>
69 #include <asm/uaccess.h>
70 #include <asm/processor.h>
74 #include <asm/stacktrace.h>
78 #include <asm/setup.h>
80 #ifdef CONFIG_BSD_PROCESS_ACCT
81 #include <linux/acct.h>
83 #ifdef CONFIG_RT_MUTEXES
84 #include <linux/rtmutex.h>
86 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
87 #include <linux/lockdep.h>
89 #ifdef CONFIG_CHR_DEV_SG
93 #ifdef CONFIG_LOCKUP_DETECTOR
94 #include <linux/nmi.h>
97 #if defined(CONFIG_SYSCTL)
99 /* External variables not in a header file. */
100 extern int suid_dumpable;
101 #ifdef CONFIG_COREDUMP
102 extern int core_uses_pid;
103 extern char core_pattern[];
104 extern unsigned int core_pipe_limit;
107 extern int pid_max_min, pid_max_max;
108 extern int percpu_pagelist_fraction;
109 extern int compat_log;
110 extern int latencytop_enabled;
111 extern int sysctl_nr_open_min, sysctl_nr_open_max;
113 extern int sysctl_nr_trim_pages;
116 /* Constants used for minimum and maximum */
117 #ifdef CONFIG_LOCKUP_DETECTOR
118 static int sixty = 60;
121 static int __maybe_unused neg_one = -1;
124 static int __maybe_unused one = 1;
125 static int __maybe_unused two = 2;
126 static int __maybe_unused four = 4;
127 static unsigned long one_ul = 1;
128 static int one_hundred = 100;
129 static int one_thousand = 1000;
131 static int ten_thousand = 10000;
133 #ifdef CONFIG_PERF_EVENTS
134 static int six_hundred_forty_kb = 640 * 1024;
137 /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */
138 static unsigned long dirty_bytes_min = 2 * PAGE_SIZE;
140 /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
141 static int maxolduid = 65535;
142 static int minolduid;
144 static int ngroups_max = NGROUPS_MAX;
145 static const int cap_last_cap = CAP_LAST_CAP;
147 /*this is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs */
148 #ifdef CONFIG_DETECT_HUNG_TASK
149 static unsigned long hung_task_timeout_max = (LONG_MAX/HZ);
152 #ifdef CONFIG_INOTIFY_USER
153 #include <linux/inotify.h>
159 extern int pwrsw_enabled;
162 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
163 extern int unaligned_enabled;
167 extern int unaligned_dump_stack;
170 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
171 extern int no_unaligned_warning;
174 #ifdef CONFIG_PROC_SYSCTL
176 #define SYSCTL_WRITES_LEGACY -1
177 #define SYSCTL_WRITES_WARN 0
178 #define SYSCTL_WRITES_STRICT 1
180 static int sysctl_writes_strict = SYSCTL_WRITES_STRICT;
182 static int proc_do_cad_pid(struct ctl_table *table, int write,
183 void __user *buffer, size_t *lenp, loff_t *ppos);
184 static int proc_taint(struct ctl_table *table, int write,
185 void __user *buffer, size_t *lenp, loff_t *ppos);
189 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
190 void __user *buffer, size_t *lenp, loff_t *ppos);
193 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
194 void __user *buffer, size_t *lenp, loff_t *ppos);
195 #ifdef CONFIG_COREDUMP
196 static int proc_dostring_coredump(struct ctl_table *table, int write,
197 void __user *buffer, size_t *lenp, loff_t *ppos);
200 #ifdef CONFIG_MAGIC_SYSRQ
201 /* Note: sysrq code uses it's own private copy */
202 static int __sysrq_enabled = CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE;
204 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
205 void __user *buffer, size_t *lenp,
210 error = proc_dointvec(table, write, buffer, lenp, ppos);
215 sysrq_toggle_support(__sysrq_enabled);
222 static struct ctl_table kern_table[];
223 static struct ctl_table vm_table[];
224 static struct ctl_table fs_table[];
225 static struct ctl_table debug_table[];
226 static struct ctl_table dev_table[];
227 extern struct ctl_table random_table[];
229 extern struct ctl_table epoll_table[];
232 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
233 int sysctl_legacy_va_layout;
236 /* The default sysctl tables: */
238 static struct ctl_table sysctl_base_table[] = {
240 .procname = "kernel",
257 .child = debug_table,
267 #ifdef CONFIG_SCHED_DEBUG
268 static int min_sched_granularity_ns = 100000; /* 100 usecs */
269 static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
270 static int min_wakeup_granularity_ns; /* 0 usecs */
271 static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
273 static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
274 static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
275 #endif /* CONFIG_SMP */
276 #endif /* CONFIG_SCHED_DEBUG */
278 #ifdef CONFIG_COMPACTION
279 static int min_extfrag_threshold;
280 static int max_extfrag_threshold = 1000;
283 static struct ctl_table kern_table[] = {
285 .procname = "sched_child_runs_first",
286 .data = &sysctl_sched_child_runs_first,
287 .maxlen = sizeof(unsigned int),
289 .proc_handler = proc_dointvec,
291 #ifdef CONFIG_SCHED_DEBUG
293 .procname = "sched_min_granularity_ns",
294 .data = &sysctl_sched_min_granularity,
295 .maxlen = sizeof(unsigned int),
297 .proc_handler = sched_proc_update_handler,
298 .extra1 = &min_sched_granularity_ns,
299 .extra2 = &max_sched_granularity_ns,
302 .procname = "sched_latency_ns",
303 .data = &sysctl_sched_latency,
304 .maxlen = sizeof(unsigned int),
306 .proc_handler = sched_proc_update_handler,
307 .extra1 = &min_sched_granularity_ns,
308 .extra2 = &max_sched_granularity_ns,
311 .procname = "sched_wakeup_granularity_ns",
312 .data = &sysctl_sched_wakeup_granularity,
313 .maxlen = sizeof(unsigned int),
315 .proc_handler = sched_proc_update_handler,
316 .extra1 = &min_wakeup_granularity_ns,
317 .extra2 = &max_wakeup_granularity_ns,
321 .procname = "sched_tunable_scaling",
322 .data = &sysctl_sched_tunable_scaling,
323 .maxlen = sizeof(enum sched_tunable_scaling),
325 .proc_handler = sched_proc_update_handler,
326 .extra1 = &min_sched_tunable_scaling,
327 .extra2 = &max_sched_tunable_scaling,
330 .procname = "sched_migration_cost_ns",
331 .data = &sysctl_sched_migration_cost,
332 .maxlen = sizeof(unsigned int),
334 .proc_handler = proc_dointvec,
337 .procname = "sched_nr_migrate",
338 .data = &sysctl_sched_nr_migrate,
339 .maxlen = sizeof(unsigned int),
341 .proc_handler = proc_dointvec,
344 .procname = "sched_time_avg_ms",
345 .data = &sysctl_sched_time_avg,
346 .maxlen = sizeof(unsigned int),
348 .proc_handler = proc_dointvec,
351 .procname = "sched_shares_window_ns",
352 .data = &sysctl_sched_shares_window,
353 .maxlen = sizeof(unsigned int),
355 .proc_handler = proc_dointvec,
357 #ifdef CONFIG_SCHEDSTATS
359 .procname = "sched_schedstats",
361 .maxlen = sizeof(unsigned int),
363 .proc_handler = sysctl_schedstats,
367 #endif /* CONFIG_SCHEDSTATS */
368 #endif /* CONFIG_SMP */
369 #ifdef CONFIG_NUMA_BALANCING
371 .procname = "numa_balancing_scan_delay_ms",
372 .data = &sysctl_numa_balancing_scan_delay,
373 .maxlen = sizeof(unsigned int),
375 .proc_handler = proc_dointvec,
378 .procname = "numa_balancing_scan_period_min_ms",
379 .data = &sysctl_numa_balancing_scan_period_min,
380 .maxlen = sizeof(unsigned int),
382 .proc_handler = proc_dointvec,
385 .procname = "numa_balancing_scan_period_max_ms",
386 .data = &sysctl_numa_balancing_scan_period_max,
387 .maxlen = sizeof(unsigned int),
389 .proc_handler = proc_dointvec,
392 .procname = "numa_balancing_scan_size_mb",
393 .data = &sysctl_numa_balancing_scan_size,
394 .maxlen = sizeof(unsigned int),
396 .proc_handler = proc_dointvec_minmax,
400 .procname = "numa_balancing",
401 .data = NULL, /* filled in by handler */
402 .maxlen = sizeof(unsigned int),
404 .proc_handler = sysctl_numa_balancing,
408 #endif /* CONFIG_NUMA_BALANCING */
409 #endif /* CONFIG_SCHED_DEBUG */
411 .procname = "sched_rt_period_us",
412 .data = &sysctl_sched_rt_period,
413 .maxlen = sizeof(unsigned int),
415 .proc_handler = sched_rt_handler,
418 .procname = "sched_rt_runtime_us",
419 .data = &sysctl_sched_rt_runtime,
420 .maxlen = sizeof(int),
422 .proc_handler = sched_rt_handler,
425 .procname = "sched_rr_timeslice_ms",
426 .data = &sched_rr_timeslice,
427 .maxlen = sizeof(int),
429 .proc_handler = sched_rr_handler,
431 #ifdef CONFIG_SCHED_AUTOGROUP
433 .procname = "sched_autogroup_enabled",
434 .data = &sysctl_sched_autogroup_enabled,
435 .maxlen = sizeof(unsigned int),
437 .proc_handler = proc_dointvec_minmax,
442 #ifdef CONFIG_CFS_BANDWIDTH
444 .procname = "sched_cfs_bandwidth_slice_us",
445 .data = &sysctl_sched_cfs_bandwidth_slice,
446 .maxlen = sizeof(unsigned int),
448 .proc_handler = proc_dointvec_minmax,
452 #ifdef CONFIG_PROVE_LOCKING
454 .procname = "prove_locking",
455 .data = &prove_locking,
456 .maxlen = sizeof(int),
458 .proc_handler = proc_dointvec,
461 #ifdef CONFIG_LOCK_STAT
463 .procname = "lock_stat",
465 .maxlen = sizeof(int),
467 .proc_handler = proc_dointvec,
472 .data = &panic_timeout,
473 .maxlen = sizeof(int),
475 .proc_handler = proc_dointvec,
477 #ifdef CONFIG_COREDUMP
479 .procname = "core_uses_pid",
480 .data = &core_uses_pid,
481 .maxlen = sizeof(int),
483 .proc_handler = proc_dointvec,
486 .procname = "core_pattern",
487 .data = core_pattern,
488 .maxlen = CORENAME_MAX_SIZE,
490 .proc_handler = proc_dostring_coredump,
493 .procname = "core_pipe_limit",
494 .data = &core_pipe_limit,
495 .maxlen = sizeof(unsigned int),
497 .proc_handler = proc_dointvec,
500 #ifdef CONFIG_PROC_SYSCTL
502 .procname = "tainted",
503 .maxlen = sizeof(long),
505 .proc_handler = proc_taint,
508 .procname = "sysctl_writes_strict",
509 .data = &sysctl_writes_strict,
510 .maxlen = sizeof(int),
512 .proc_handler = proc_dointvec_minmax,
517 #ifdef CONFIG_LATENCYTOP
519 .procname = "latencytop",
520 .data = &latencytop_enabled,
521 .maxlen = sizeof(int),
523 .proc_handler = sysctl_latencytop,
526 #ifdef CONFIG_BLK_DEV_INITRD
528 .procname = "real-root-dev",
529 .data = &real_root_dev,
530 .maxlen = sizeof(int),
532 .proc_handler = proc_dointvec,
536 .procname = "print-fatal-signals",
537 .data = &print_fatal_signals,
538 .maxlen = sizeof(int),
540 .proc_handler = proc_dointvec,
544 .procname = "reboot-cmd",
545 .data = reboot_command,
548 .proc_handler = proc_dostring,
551 .procname = "stop-a",
552 .data = &stop_a_enabled,
553 .maxlen = sizeof (int),
555 .proc_handler = proc_dointvec,
558 .procname = "scons-poweroff",
559 .data = &scons_pwroff,
560 .maxlen = sizeof (int),
562 .proc_handler = proc_dointvec,
565 #ifdef CONFIG_SPARC64
567 .procname = "tsb-ratio",
568 .data = &sysctl_tsb_ratio,
569 .maxlen = sizeof (int),
571 .proc_handler = proc_dointvec,
576 .procname = "soft-power",
577 .data = &pwrsw_enabled,
578 .maxlen = sizeof (int),
580 .proc_handler = proc_dointvec,
583 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
585 .procname = "unaligned-trap",
586 .data = &unaligned_enabled,
587 .maxlen = sizeof (int),
589 .proc_handler = proc_dointvec,
593 .procname = "ctrl-alt-del",
595 .maxlen = sizeof(int),
597 .proc_handler = proc_dointvec,
599 #ifdef CONFIG_FUNCTION_TRACER
601 .procname = "ftrace_enabled",
602 .data = &ftrace_enabled,
603 .maxlen = sizeof(int),
605 .proc_handler = ftrace_enable_sysctl,
608 #ifdef CONFIG_STACK_TRACER
610 .procname = "stack_tracer_enabled",
611 .data = &stack_tracer_enabled,
612 .maxlen = sizeof(int),
614 .proc_handler = stack_trace_sysctl,
617 #ifdef CONFIG_TRACING
619 .procname = "ftrace_dump_on_oops",
620 .data = &ftrace_dump_on_oops,
621 .maxlen = sizeof(int),
623 .proc_handler = proc_dointvec,
626 .procname = "traceoff_on_warning",
627 .data = &__disable_trace_on_warning,
628 .maxlen = sizeof(__disable_trace_on_warning),
630 .proc_handler = proc_dointvec,
633 .procname = "tracepoint_printk",
634 .data = &tracepoint_printk,
635 .maxlen = sizeof(tracepoint_printk),
637 .proc_handler = proc_dointvec,
640 #ifdef CONFIG_KEXEC_CORE
642 .procname = "kexec_load_disabled",
643 .data = &kexec_load_disabled,
644 .maxlen = sizeof(int),
646 /* only handle a transition from default "0" to "1" */
647 .proc_handler = proc_dointvec_minmax,
652 #ifdef CONFIG_MODULES
654 .procname = "modprobe",
655 .data = &modprobe_path,
656 .maxlen = KMOD_PATH_LEN,
658 .proc_handler = proc_dostring,
661 .procname = "modules_disabled",
662 .data = &modules_disabled,
663 .maxlen = sizeof(int),
665 /* only handle a transition from default "0" to "1" */
666 .proc_handler = proc_dointvec_minmax,
671 #ifdef CONFIG_UEVENT_HELPER
673 .procname = "hotplug",
674 .data = &uevent_helper,
675 .maxlen = UEVENT_HELPER_PATH_LEN,
677 .proc_handler = proc_dostring,
680 #ifdef CONFIG_CHR_DEV_SG
682 .procname = "sg-big-buff",
683 .data = &sg_big_buff,
684 .maxlen = sizeof (int),
686 .proc_handler = proc_dointvec,
689 #ifdef CONFIG_BSD_PROCESS_ACCT
693 .maxlen = 3*sizeof(int),
695 .proc_handler = proc_dointvec,
698 #ifdef CONFIG_MAGIC_SYSRQ
701 .data = &__sysrq_enabled,
702 .maxlen = sizeof (int),
704 .proc_handler = sysrq_sysctl_handler,
707 #ifdef CONFIG_PROC_SYSCTL
709 .procname = "cad_pid",
711 .maxlen = sizeof (int),
713 .proc_handler = proc_do_cad_pid,
717 .procname = "threads-max",
719 .maxlen = sizeof(int),
721 .proc_handler = sysctl_max_threads,
724 .procname = "random",
726 .child = random_table,
729 .procname = "usermodehelper",
731 .child = usermodehelper_table,
734 .procname = "overflowuid",
735 .data = &overflowuid,
736 .maxlen = sizeof(int),
738 .proc_handler = proc_dointvec_minmax,
739 .extra1 = &minolduid,
740 .extra2 = &maxolduid,
743 .procname = "overflowgid",
744 .data = &overflowgid,
745 .maxlen = sizeof(int),
747 .proc_handler = proc_dointvec_minmax,
748 .extra1 = &minolduid,
749 .extra2 = &maxolduid,
752 #ifdef CONFIG_MATHEMU
754 .procname = "ieee_emulation_warnings",
755 .data = &sysctl_ieee_emulation_warnings,
756 .maxlen = sizeof(int),
758 .proc_handler = proc_dointvec,
762 .procname = "userprocess_debug",
763 .data = &show_unhandled_signals,
764 .maxlen = sizeof(int),
766 .proc_handler = proc_dointvec,
770 .procname = "pid_max",
772 .maxlen = sizeof (int),
774 .proc_handler = proc_dointvec_minmax,
775 .extra1 = &pid_max_min,
776 .extra2 = &pid_max_max,
779 .procname = "panic_on_oops",
780 .data = &panic_on_oops,
781 .maxlen = sizeof(int),
783 .proc_handler = proc_dointvec,
785 #if defined CONFIG_PRINTK
787 .procname = "printk",
788 .data = &console_loglevel,
789 .maxlen = 4*sizeof(int),
791 .proc_handler = proc_dointvec,
794 .procname = "printk_ratelimit",
795 .data = &printk_ratelimit_state.interval,
796 .maxlen = sizeof(int),
798 .proc_handler = proc_dointvec_jiffies,
801 .procname = "printk_ratelimit_burst",
802 .data = &printk_ratelimit_state.burst,
803 .maxlen = sizeof(int),
805 .proc_handler = proc_dointvec,
808 .procname = "printk_delay",
809 .data = &printk_delay_msec,
810 .maxlen = sizeof(int),
812 .proc_handler = proc_dointvec_minmax,
814 .extra2 = &ten_thousand,
817 .procname = "dmesg_restrict",
818 .data = &dmesg_restrict,
819 .maxlen = sizeof(int),
821 .proc_handler = proc_dointvec_minmax_sysadmin,
826 .procname = "kptr_restrict",
827 .data = &kptr_restrict,
828 .maxlen = sizeof(int),
830 .proc_handler = proc_dointvec_minmax_sysadmin,
836 .procname = "ngroups_max",
837 .data = &ngroups_max,
838 .maxlen = sizeof (int),
840 .proc_handler = proc_dointvec,
843 .procname = "cap_last_cap",
844 .data = (void *)&cap_last_cap,
845 .maxlen = sizeof(int),
847 .proc_handler = proc_dointvec,
849 #if defined(CONFIG_LOCKUP_DETECTOR)
851 .procname = "watchdog",
852 .data = &watchdog_user_enabled,
853 .maxlen = sizeof (int),
855 .proc_handler = proc_watchdog,
860 .procname = "watchdog_thresh",
861 .data = &watchdog_thresh,
862 .maxlen = sizeof(int),
864 .proc_handler = proc_watchdog_thresh,
869 .procname = "nmi_watchdog",
870 .data = &nmi_watchdog_enabled,
871 .maxlen = sizeof (int),
873 .proc_handler = proc_nmi_watchdog,
875 #if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR)
882 .procname = "soft_watchdog",
883 .data = &soft_watchdog_enabled,
884 .maxlen = sizeof (int),
886 .proc_handler = proc_soft_watchdog,
891 .procname = "watchdog_cpumask",
892 .data = &watchdog_cpumask_bits,
895 .proc_handler = proc_watchdog_cpumask,
898 .procname = "softlockup_panic",
899 .data = &softlockup_panic,
900 .maxlen = sizeof(int),
902 .proc_handler = proc_dointvec_minmax,
906 #ifdef CONFIG_HARDLOCKUP_DETECTOR
908 .procname = "hardlockup_panic",
909 .data = &hardlockup_panic,
910 .maxlen = sizeof(int),
912 .proc_handler = proc_dointvec_minmax,
919 .procname = "softlockup_all_cpu_backtrace",
920 .data = &sysctl_softlockup_all_cpu_backtrace,
921 .maxlen = sizeof(int),
923 .proc_handler = proc_dointvec_minmax,
928 .procname = "hardlockup_all_cpu_backtrace",
929 .data = &sysctl_hardlockup_all_cpu_backtrace,
930 .maxlen = sizeof(int),
932 .proc_handler = proc_dointvec_minmax,
936 #endif /* CONFIG_SMP */
938 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
940 .procname = "unknown_nmi_panic",
941 .data = &unknown_nmi_panic,
942 .maxlen = sizeof (int),
944 .proc_handler = proc_dointvec,
947 #if defined(CONFIG_X86)
949 .procname = "panic_on_unrecovered_nmi",
950 .data = &panic_on_unrecovered_nmi,
951 .maxlen = sizeof(int),
953 .proc_handler = proc_dointvec,
956 .procname = "panic_on_io_nmi",
957 .data = &panic_on_io_nmi,
958 .maxlen = sizeof(int),
960 .proc_handler = proc_dointvec,
962 #ifdef CONFIG_DEBUG_STACKOVERFLOW
964 .procname = "panic_on_stackoverflow",
965 .data = &sysctl_panic_on_stackoverflow,
966 .maxlen = sizeof(int),
968 .proc_handler = proc_dointvec,
972 .procname = "bootloader_type",
973 .data = &bootloader_type,
974 .maxlen = sizeof (int),
976 .proc_handler = proc_dointvec,
979 .procname = "bootloader_version",
980 .data = &bootloader_version,
981 .maxlen = sizeof (int),
983 .proc_handler = proc_dointvec,
986 .procname = "kstack_depth_to_print",
987 .data = &kstack_depth_to_print,
988 .maxlen = sizeof(int),
990 .proc_handler = proc_dointvec,
993 .procname = "io_delay_type",
994 .data = &io_delay_type,
995 .maxlen = sizeof(int),
997 .proc_handler = proc_dointvec,
1000 #if defined(CONFIG_MMU)
1002 .procname = "randomize_va_space",
1003 .data = &randomize_va_space,
1004 .maxlen = sizeof(int),
1006 .proc_handler = proc_dointvec,
1009 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1011 .procname = "spin_retry",
1012 .data = &spin_retry,
1013 .maxlen = sizeof (int),
1015 .proc_handler = proc_dointvec,
1018 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1020 .procname = "acpi_video_flags",
1021 .data = &acpi_realmode_flags,
1022 .maxlen = sizeof (unsigned long),
1024 .proc_handler = proc_doulongvec_minmax,
1027 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1029 .procname = "ignore-unaligned-usertrap",
1030 .data = &no_unaligned_warning,
1031 .maxlen = sizeof (int),
1033 .proc_handler = proc_dointvec,
1038 .procname = "unaligned-dump-stack",
1039 .data = &unaligned_dump_stack,
1040 .maxlen = sizeof (int),
1042 .proc_handler = proc_dointvec,
1045 #ifdef CONFIG_DETECT_HUNG_TASK
1047 .procname = "hung_task_panic",
1048 .data = &sysctl_hung_task_panic,
1049 .maxlen = sizeof(int),
1051 .proc_handler = proc_dointvec_minmax,
1056 .procname = "hung_task_check_count",
1057 .data = &sysctl_hung_task_check_count,
1058 .maxlen = sizeof(int),
1060 .proc_handler = proc_dointvec_minmax,
1064 .procname = "hung_task_timeout_secs",
1065 .data = &sysctl_hung_task_timeout_secs,
1066 .maxlen = sizeof(unsigned long),
1068 .proc_handler = proc_dohung_task_timeout_secs,
1069 .extra2 = &hung_task_timeout_max,
1072 .procname = "hung_task_warnings",
1073 .data = &sysctl_hung_task_warnings,
1074 .maxlen = sizeof(int),
1076 .proc_handler = proc_dointvec_minmax,
1080 #ifdef CONFIG_COMPAT
1082 .procname = "compat-log",
1083 .data = &compat_log,
1084 .maxlen = sizeof (int),
1086 .proc_handler = proc_dointvec,
1089 #ifdef CONFIG_RT_MUTEXES
1091 .procname = "max_lock_depth",
1092 .data = &max_lock_depth,
1093 .maxlen = sizeof(int),
1095 .proc_handler = proc_dointvec,
1099 .procname = "poweroff_cmd",
1100 .data = &poweroff_cmd,
1101 .maxlen = POWEROFF_CMD_PATH_LEN,
1103 .proc_handler = proc_dostring,
1109 .child = key_sysctls,
1112 #ifdef CONFIG_PERF_EVENTS
1114 * User-space scripts rely on the existence of this file
1115 * as a feature check for perf_events being enabled.
1117 * So it's an ABI, do not remove!
1120 .procname = "perf_event_paranoid",
1121 .data = &sysctl_perf_event_paranoid,
1122 .maxlen = sizeof(sysctl_perf_event_paranoid),
1124 .proc_handler = proc_dointvec,
1127 .procname = "perf_event_mlock_kb",
1128 .data = &sysctl_perf_event_mlock,
1129 .maxlen = sizeof(sysctl_perf_event_mlock),
1131 .proc_handler = proc_dointvec,
1134 .procname = "perf_event_max_sample_rate",
1135 .data = &sysctl_perf_event_sample_rate,
1136 .maxlen = sizeof(sysctl_perf_event_sample_rate),
1138 .proc_handler = perf_proc_update_handler,
1142 .procname = "perf_cpu_time_max_percent",
1143 .data = &sysctl_perf_cpu_time_max_percent,
1144 .maxlen = sizeof(sysctl_perf_cpu_time_max_percent),
1146 .proc_handler = perf_cpu_time_max_percent_handler,
1148 .extra2 = &one_hundred,
1151 .procname = "perf_event_max_stack",
1152 .data = NULL, /* filled in by handler */
1153 .maxlen = sizeof(sysctl_perf_event_max_stack),
1155 .proc_handler = perf_event_max_stack_handler,
1157 .extra2 = &six_hundred_forty_kb,
1160 #ifdef CONFIG_KMEMCHECK
1162 .procname = "kmemcheck",
1163 .data = &kmemcheck_enabled,
1164 .maxlen = sizeof(int),
1166 .proc_handler = proc_dointvec,
1170 .procname = "panic_on_warn",
1171 .data = &panic_on_warn,
1172 .maxlen = sizeof(int),
1174 .proc_handler = proc_dointvec_minmax,
1178 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1180 .procname = "timer_migration",
1181 .data = &sysctl_timer_migration,
1182 .maxlen = sizeof(unsigned int),
1184 .proc_handler = timer_migration_handler,
1187 #ifdef CONFIG_BPF_SYSCALL
1189 .procname = "unprivileged_bpf_disabled",
1190 .data = &sysctl_unprivileged_bpf_disabled,
1191 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
1193 /* only handle a transition from default "0" to "1" */
1194 .proc_handler = proc_dointvec_minmax,
1202 static struct ctl_table vm_table[] = {
1204 .procname = "overcommit_memory",
1205 .data = &sysctl_overcommit_memory,
1206 .maxlen = sizeof(sysctl_overcommit_memory),
1208 .proc_handler = proc_dointvec_minmax,
1213 .procname = "panic_on_oom",
1214 .data = &sysctl_panic_on_oom,
1215 .maxlen = sizeof(sysctl_panic_on_oom),
1217 .proc_handler = proc_dointvec_minmax,
1222 .procname = "oom_kill_allocating_task",
1223 .data = &sysctl_oom_kill_allocating_task,
1224 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
1226 .proc_handler = proc_dointvec,
1229 .procname = "oom_dump_tasks",
1230 .data = &sysctl_oom_dump_tasks,
1231 .maxlen = sizeof(sysctl_oom_dump_tasks),
1233 .proc_handler = proc_dointvec,
1236 .procname = "overcommit_ratio",
1237 .data = &sysctl_overcommit_ratio,
1238 .maxlen = sizeof(sysctl_overcommit_ratio),
1240 .proc_handler = overcommit_ratio_handler,
1243 .procname = "overcommit_kbytes",
1244 .data = &sysctl_overcommit_kbytes,
1245 .maxlen = sizeof(sysctl_overcommit_kbytes),
1247 .proc_handler = overcommit_kbytes_handler,
1250 .procname = "page-cluster",
1251 .data = &page_cluster,
1252 .maxlen = sizeof(int),
1254 .proc_handler = proc_dointvec_minmax,
1258 .procname = "dirty_background_ratio",
1259 .data = &dirty_background_ratio,
1260 .maxlen = sizeof(dirty_background_ratio),
1262 .proc_handler = dirty_background_ratio_handler,
1264 .extra2 = &one_hundred,
1267 .procname = "dirty_background_bytes",
1268 .data = &dirty_background_bytes,
1269 .maxlen = sizeof(dirty_background_bytes),
1271 .proc_handler = dirty_background_bytes_handler,
1275 .procname = "dirty_ratio",
1276 .data = &vm_dirty_ratio,
1277 .maxlen = sizeof(vm_dirty_ratio),
1279 .proc_handler = dirty_ratio_handler,
1281 .extra2 = &one_hundred,
1284 .procname = "dirty_bytes",
1285 .data = &vm_dirty_bytes,
1286 .maxlen = sizeof(vm_dirty_bytes),
1288 .proc_handler = dirty_bytes_handler,
1289 .extra1 = &dirty_bytes_min,
1292 .procname = "dirty_writeback_centisecs",
1293 .data = &dirty_writeback_interval,
1294 .maxlen = sizeof(dirty_writeback_interval),
1296 .proc_handler = dirty_writeback_centisecs_handler,
1299 .procname = "dirty_expire_centisecs",
1300 .data = &dirty_expire_interval,
1301 .maxlen = sizeof(dirty_expire_interval),
1303 .proc_handler = proc_dointvec_minmax,
1307 .procname = "dirtytime_expire_seconds",
1308 .data = &dirtytime_expire_interval,
1309 .maxlen = sizeof(dirty_expire_interval),
1311 .proc_handler = dirtytime_interval_handler,
1315 .procname = "nr_pdflush_threads",
1316 .mode = 0444 /* read-only */,
1317 .proc_handler = pdflush_proc_obsolete,
1320 .procname = "swappiness",
1321 .data = &vm_swappiness,
1322 .maxlen = sizeof(vm_swappiness),
1324 .proc_handler = proc_dointvec_minmax,
1326 .extra2 = &one_hundred,
1328 #ifdef CONFIG_HUGETLB_PAGE
1330 .procname = "nr_hugepages",
1332 .maxlen = sizeof(unsigned long),
1334 .proc_handler = hugetlb_sysctl_handler,
1338 .procname = "nr_hugepages_mempolicy",
1340 .maxlen = sizeof(unsigned long),
1342 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1346 .procname = "hugetlb_shm_group",
1347 .data = &sysctl_hugetlb_shm_group,
1348 .maxlen = sizeof(gid_t),
1350 .proc_handler = proc_dointvec,
1353 .procname = "hugepages_treat_as_movable",
1354 .data = &hugepages_treat_as_movable,
1355 .maxlen = sizeof(int),
1357 .proc_handler = proc_dointvec,
1360 .procname = "nr_overcommit_hugepages",
1362 .maxlen = sizeof(unsigned long),
1364 .proc_handler = hugetlb_overcommit_handler,
1368 .procname = "lowmem_reserve_ratio",
1369 .data = &sysctl_lowmem_reserve_ratio,
1370 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1372 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1375 .procname = "drop_caches",
1376 .data = &sysctl_drop_caches,
1377 .maxlen = sizeof(int),
1379 .proc_handler = drop_caches_sysctl_handler,
1383 #ifdef CONFIG_COMPACTION
1385 .procname = "compact_memory",
1386 .data = &sysctl_compact_memory,
1387 .maxlen = sizeof(int),
1389 .proc_handler = sysctl_compaction_handler,
1392 .procname = "extfrag_threshold",
1393 .data = &sysctl_extfrag_threshold,
1394 .maxlen = sizeof(int),
1396 .proc_handler = sysctl_extfrag_handler,
1397 .extra1 = &min_extfrag_threshold,
1398 .extra2 = &max_extfrag_threshold,
1401 .procname = "compact_unevictable_allowed",
1402 .data = &sysctl_compact_unevictable_allowed,
1403 .maxlen = sizeof(int),
1405 .proc_handler = proc_dointvec,
1410 #endif /* CONFIG_COMPACTION */
1412 .procname = "min_free_kbytes",
1413 .data = &min_free_kbytes,
1414 .maxlen = sizeof(min_free_kbytes),
1416 .proc_handler = min_free_kbytes_sysctl_handler,
1420 .procname = "watermark_scale_factor",
1421 .data = &watermark_scale_factor,
1422 .maxlen = sizeof(watermark_scale_factor),
1424 .proc_handler = watermark_scale_factor_sysctl_handler,
1426 .extra2 = &one_thousand,
1429 .procname = "percpu_pagelist_fraction",
1430 .data = &percpu_pagelist_fraction,
1431 .maxlen = sizeof(percpu_pagelist_fraction),
1433 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1438 .procname = "max_map_count",
1439 .data = &sysctl_max_map_count,
1440 .maxlen = sizeof(sysctl_max_map_count),
1442 .proc_handler = proc_dointvec_minmax,
1447 .procname = "nr_trim_pages",
1448 .data = &sysctl_nr_trim_pages,
1449 .maxlen = sizeof(sysctl_nr_trim_pages),
1451 .proc_handler = proc_dointvec_minmax,
1456 .procname = "laptop_mode",
1457 .data = &laptop_mode,
1458 .maxlen = sizeof(laptop_mode),
1460 .proc_handler = proc_dointvec_jiffies,
1463 .procname = "block_dump",
1464 .data = &block_dump,
1465 .maxlen = sizeof(block_dump),
1467 .proc_handler = proc_dointvec,
1471 .procname = "vfs_cache_pressure",
1472 .data = &sysctl_vfs_cache_pressure,
1473 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1475 .proc_handler = proc_dointvec,
1478 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1480 .procname = "legacy_va_layout",
1481 .data = &sysctl_legacy_va_layout,
1482 .maxlen = sizeof(sysctl_legacy_va_layout),
1484 .proc_handler = proc_dointvec,
1490 .procname = "zone_reclaim_mode",
1491 .data = &zone_reclaim_mode,
1492 .maxlen = sizeof(zone_reclaim_mode),
1494 .proc_handler = proc_dointvec,
1498 .procname = "min_unmapped_ratio",
1499 .data = &sysctl_min_unmapped_ratio,
1500 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1502 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1504 .extra2 = &one_hundred,
1507 .procname = "min_slab_ratio",
1508 .data = &sysctl_min_slab_ratio,
1509 .maxlen = sizeof(sysctl_min_slab_ratio),
1511 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1513 .extra2 = &one_hundred,
1518 .procname = "stat_interval",
1519 .data = &sysctl_stat_interval,
1520 .maxlen = sizeof(sysctl_stat_interval),
1522 .proc_handler = proc_dointvec_jiffies,
1527 .procname = "mmap_min_addr",
1528 .data = &dac_mmap_min_addr,
1529 .maxlen = sizeof(unsigned long),
1531 .proc_handler = mmap_min_addr_handler,
1536 .procname = "numa_zonelist_order",
1537 .data = &numa_zonelist_order,
1538 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1540 .proc_handler = numa_zonelist_order_handler,
1543 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1544 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1546 .procname = "vdso_enabled",
1547 #ifdef CONFIG_X86_32
1548 .data = &vdso32_enabled,
1549 .maxlen = sizeof(vdso32_enabled),
1551 .data = &vdso_enabled,
1552 .maxlen = sizeof(vdso_enabled),
1555 .proc_handler = proc_dointvec,
1559 #ifdef CONFIG_HIGHMEM
1561 .procname = "highmem_is_dirtyable",
1562 .data = &vm_highmem_is_dirtyable,
1563 .maxlen = sizeof(vm_highmem_is_dirtyable),
1565 .proc_handler = proc_dointvec_minmax,
1570 #ifdef CONFIG_MEMORY_FAILURE
1572 .procname = "memory_failure_early_kill",
1573 .data = &sysctl_memory_failure_early_kill,
1574 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1576 .proc_handler = proc_dointvec_minmax,
1581 .procname = "memory_failure_recovery",
1582 .data = &sysctl_memory_failure_recovery,
1583 .maxlen = sizeof(sysctl_memory_failure_recovery),
1585 .proc_handler = proc_dointvec_minmax,
1591 .procname = "user_reserve_kbytes",
1592 .data = &sysctl_user_reserve_kbytes,
1593 .maxlen = sizeof(sysctl_user_reserve_kbytes),
1595 .proc_handler = proc_doulongvec_minmax,
1598 .procname = "admin_reserve_kbytes",
1599 .data = &sysctl_admin_reserve_kbytes,
1600 .maxlen = sizeof(sysctl_admin_reserve_kbytes),
1602 .proc_handler = proc_doulongvec_minmax,
1604 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1606 .procname = "mmap_rnd_bits",
1607 .data = &mmap_rnd_bits,
1608 .maxlen = sizeof(mmap_rnd_bits),
1610 .proc_handler = proc_dointvec_minmax,
1611 .extra1 = (void *)&mmap_rnd_bits_min,
1612 .extra2 = (void *)&mmap_rnd_bits_max,
1615 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1617 .procname = "mmap_rnd_compat_bits",
1618 .data = &mmap_rnd_compat_bits,
1619 .maxlen = sizeof(mmap_rnd_compat_bits),
1621 .proc_handler = proc_dointvec_minmax,
1622 .extra1 = (void *)&mmap_rnd_compat_bits_min,
1623 .extra2 = (void *)&mmap_rnd_compat_bits_max,
1629 static struct ctl_table fs_table[] = {
1631 .procname = "inode-nr",
1632 .data = &inodes_stat,
1633 .maxlen = 2*sizeof(long),
1635 .proc_handler = proc_nr_inodes,
1638 .procname = "inode-state",
1639 .data = &inodes_stat,
1640 .maxlen = 7*sizeof(long),
1642 .proc_handler = proc_nr_inodes,
1645 .procname = "file-nr",
1646 .data = &files_stat,
1647 .maxlen = sizeof(files_stat),
1649 .proc_handler = proc_nr_files,
1652 .procname = "file-max",
1653 .data = &files_stat.max_files,
1654 .maxlen = sizeof(files_stat.max_files),
1656 .proc_handler = proc_doulongvec_minmax,
1659 .procname = "nr_open",
1660 .data = &sysctl_nr_open,
1661 .maxlen = sizeof(int),
1663 .proc_handler = proc_dointvec_minmax,
1664 .extra1 = &sysctl_nr_open_min,
1665 .extra2 = &sysctl_nr_open_max,
1668 .procname = "dentry-state",
1669 .data = &dentry_stat,
1670 .maxlen = 6*sizeof(long),
1672 .proc_handler = proc_nr_dentry,
1675 .procname = "overflowuid",
1676 .data = &fs_overflowuid,
1677 .maxlen = sizeof(int),
1679 .proc_handler = proc_dointvec_minmax,
1680 .extra1 = &minolduid,
1681 .extra2 = &maxolduid,
1684 .procname = "overflowgid",
1685 .data = &fs_overflowgid,
1686 .maxlen = sizeof(int),
1688 .proc_handler = proc_dointvec_minmax,
1689 .extra1 = &minolduid,
1690 .extra2 = &maxolduid,
1692 #ifdef CONFIG_FILE_LOCKING
1694 .procname = "leases-enable",
1695 .data = &leases_enable,
1696 .maxlen = sizeof(int),
1698 .proc_handler = proc_dointvec,
1701 #ifdef CONFIG_DNOTIFY
1703 .procname = "dir-notify-enable",
1704 .data = &dir_notify_enable,
1705 .maxlen = sizeof(int),
1707 .proc_handler = proc_dointvec,
1711 #ifdef CONFIG_FILE_LOCKING
1713 .procname = "lease-break-time",
1714 .data = &lease_break_time,
1715 .maxlen = sizeof(int),
1717 .proc_handler = proc_dointvec,
1722 .procname = "aio-nr",
1724 .maxlen = sizeof(aio_nr),
1726 .proc_handler = proc_doulongvec_minmax,
1729 .procname = "aio-max-nr",
1730 .data = &aio_max_nr,
1731 .maxlen = sizeof(aio_max_nr),
1733 .proc_handler = proc_doulongvec_minmax,
1735 #endif /* CONFIG_AIO */
1736 #ifdef CONFIG_INOTIFY_USER
1738 .procname = "inotify",
1740 .child = inotify_table,
1745 .procname = "epoll",
1747 .child = epoll_table,
1752 .procname = "protected_symlinks",
1753 .data = &sysctl_protected_symlinks,
1754 .maxlen = sizeof(int),
1756 .proc_handler = proc_dointvec_minmax,
1761 .procname = "protected_hardlinks",
1762 .data = &sysctl_protected_hardlinks,
1763 .maxlen = sizeof(int),
1765 .proc_handler = proc_dointvec_minmax,
1770 .procname = "suid_dumpable",
1771 .data = &suid_dumpable,
1772 .maxlen = sizeof(int),
1774 .proc_handler = proc_dointvec_minmax_coredump,
1778 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1780 .procname = "binfmt_misc",
1782 .child = sysctl_mount_point,
1786 .procname = "pipe-max-size",
1787 .data = &pipe_max_size,
1788 .maxlen = sizeof(int),
1790 .proc_handler = &pipe_proc_fn,
1791 .extra1 = &pipe_min_size,
1794 .procname = "pipe-user-pages-hard",
1795 .data = &pipe_user_pages_hard,
1796 .maxlen = sizeof(pipe_user_pages_hard),
1798 .proc_handler = proc_doulongvec_minmax,
1801 .procname = "pipe-user-pages-soft",
1802 .data = &pipe_user_pages_soft,
1803 .maxlen = sizeof(pipe_user_pages_soft),
1805 .proc_handler = proc_doulongvec_minmax,
1810 static struct ctl_table debug_table[] = {
1811 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1813 .procname = "exception-trace",
1814 .data = &show_unhandled_signals,
1815 .maxlen = sizeof(int),
1817 .proc_handler = proc_dointvec
1820 #if defined(CONFIG_OPTPROBES)
1822 .procname = "kprobes-optimization",
1823 .data = &sysctl_kprobes_optimization,
1824 .maxlen = sizeof(int),
1826 .proc_handler = proc_kprobes_optimization_handler,
1834 static struct ctl_table dev_table[] = {
1838 int __init sysctl_init(void)
1840 struct ctl_table_header *hdr;
1842 hdr = register_sysctl_table(sysctl_base_table);
1843 kmemleak_not_leak(hdr);
1847 #endif /* CONFIG_SYSCTL */
1853 #ifdef CONFIG_PROC_SYSCTL
1855 static int _proc_do_string(char *data, int maxlen, int write,
1856 char __user *buffer,
1857 size_t *lenp, loff_t *ppos)
1863 if (!data || !maxlen || !*lenp) {
1869 if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1870 /* Only continue writes not past the end of buffer. */
1872 if (len > maxlen - 1)
1879 /* Start writing from beginning of buffer. */
1885 while ((p - buffer) < *lenp && len < maxlen - 1) {
1886 if (get_user(c, p++))
1888 if (c == 0 || c == '\n')
1909 if (copy_to_user(buffer, data, len))
1912 if (put_user('\n', buffer + len))
1922 static void warn_sysctl_write(struct ctl_table *table)
1924 pr_warn_once("%s wrote to %s when file position was not 0!\n"
1925 "This will not be supported in the future. To silence this\n"
1926 "warning, set kernel.sysctl_writes_strict = -1\n",
1927 current->comm, table->procname);
1931 * proc_dostring - read a string sysctl
1932 * @table: the sysctl table
1933 * @write: %TRUE if this is a write to the sysctl file
1934 * @buffer: the user buffer
1935 * @lenp: the size of the user buffer
1936 * @ppos: file position
1938 * Reads/writes a string from/to the user buffer. If the kernel
1939 * buffer provided is not large enough to hold the string, the
1940 * string is truncated. The copied string is %NULL-terminated.
1941 * If the string is being read by the user process, it is copied
1942 * and a newline '\n' is added. It is truncated if the buffer is
1945 * Returns 0 on success.
1947 int proc_dostring(struct ctl_table *table, int write,
1948 void __user *buffer, size_t *lenp, loff_t *ppos)
1950 if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1951 warn_sysctl_write(table);
1953 return _proc_do_string((char *)(table->data), table->maxlen, write,
1954 (char __user *)buffer, lenp, ppos);
1957 static size_t proc_skip_spaces(char **buf)
1960 char *tmp = skip_spaces(*buf);
1966 static void proc_skip_char(char **buf, size_t *size, const char v)
1976 #define TMPBUFLEN 22
1978 * proc_get_long - reads an ASCII formatted integer from a user buffer
1980 * @buf: a kernel buffer
1981 * @size: size of the kernel buffer
1982 * @val: this is where the number will be stored
1983 * @neg: set to %TRUE if number is negative
1984 * @perm_tr: a vector which contains the allowed trailers
1985 * @perm_tr_len: size of the perm_tr vector
1986 * @tr: pointer to store the trailer character
1988 * In case of success %0 is returned and @buf and @size are updated with
1989 * the amount of bytes read. If @tr is non-NULL and a trailing
1990 * character exists (size is non-zero after returning from this
1991 * function), @tr is updated with the trailing character.
1993 static int proc_get_long(char **buf, size_t *size,
1994 unsigned long *val, bool *neg,
1995 const char *perm_tr, unsigned perm_tr_len, char *tr)
1998 char *p, tmp[TMPBUFLEN];
2004 if (len > TMPBUFLEN - 1)
2005 len = TMPBUFLEN - 1;
2007 memcpy(tmp, *buf, len);
2011 if (*p == '-' && *size > 1) {
2019 *val = simple_strtoul(p, &p, 0);
2023 /* We don't know if the next char is whitespace thus we may accept
2024 * invalid integers (e.g. 1234...a) or two integers instead of one
2025 * (e.g. 123...1). So lets not allow such large numbers. */
2026 if (len == TMPBUFLEN - 1)
2029 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2032 if (tr && (len < *size))
2042 * proc_put_long - converts an integer to a decimal ASCII formatted string
2044 * @buf: the user buffer
2045 * @size: the size of the user buffer
2046 * @val: the integer to be converted
2047 * @neg: sign of the number, %TRUE for negative
2049 * In case of success %0 is returned and @buf and @size are updated with
2050 * the amount of bytes written.
2052 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2056 char tmp[TMPBUFLEN], *p = tmp;
2058 sprintf(p, "%s%lu", neg ? "-" : "", val);
2062 if (copy_to_user(*buf, tmp, len))
2070 static int proc_put_char(void __user **buf, size_t *size, char c)
2073 char __user **buffer = (char __user **)buf;
2074 if (put_user(c, *buffer))
2076 (*size)--, (*buffer)++;
2082 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2084 int write, void *data)
2088 if (*lvalp > (unsigned long) INT_MAX + 1)
2092 if (*lvalp > (unsigned long) INT_MAX)
2100 *lvalp = -(unsigned long)val;
2103 *lvalp = (unsigned long)val;
2109 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2111 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2112 int write, void __user *buffer,
2113 size_t *lenp, loff_t *ppos,
2114 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2115 int write, void *data),
2118 int *i, vleft, first = 1, err = 0;
2120 char *kbuf = NULL, *p;
2122 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2127 i = (int *) tbl_data;
2128 vleft = table->maxlen / sizeof(*i);
2132 conv = do_proc_dointvec_conv;
2136 switch (sysctl_writes_strict) {
2137 case SYSCTL_WRITES_STRICT:
2139 case SYSCTL_WRITES_WARN:
2140 warn_sysctl_write(table);
2147 if (left > PAGE_SIZE - 1)
2148 left = PAGE_SIZE - 1;
2149 p = kbuf = memdup_user_nul(buffer, left);
2151 return PTR_ERR(kbuf);
2154 for (; left && vleft--; i++, first=0) {
2159 left -= proc_skip_spaces(&p);
2163 err = proc_get_long(&p, &left, &lval, &neg,
2165 sizeof(proc_wspace_sep), NULL);
2168 if (conv(&neg, &lval, i, 1, data)) {
2173 if (conv(&neg, &lval, i, 0, data)) {
2178 err = proc_put_char(&buffer, &left, '\t');
2181 err = proc_put_long(&buffer, &left, lval, neg);
2187 if (!write && !first && left && !err)
2188 err = proc_put_char(&buffer, &left, '\n');
2189 if (write && !err && left)
2190 left -= proc_skip_spaces(&p);
2194 return err ? : -EINVAL;
2202 static int do_proc_dointvec(struct ctl_table *table, int write,
2203 void __user *buffer, size_t *lenp, loff_t *ppos,
2204 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2205 int write, void *data),
2208 return __do_proc_dointvec(table->data, table, write,
2209 buffer, lenp, ppos, conv, data);
2213 * proc_dointvec - read a vector of integers
2214 * @table: the sysctl table
2215 * @write: %TRUE if this is a write to the sysctl file
2216 * @buffer: the user buffer
2217 * @lenp: the size of the user buffer
2218 * @ppos: file position
2220 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2221 * values from/to the user buffer, treated as an ASCII string.
2223 * Returns 0 on success.
2225 int proc_dointvec(struct ctl_table *table, int write,
2226 void __user *buffer, size_t *lenp, loff_t *ppos)
2228 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2233 * Taint values can only be increased
2234 * This means we can safely use a temporary.
2236 static int proc_taint(struct ctl_table *table, int write,
2237 void __user *buffer, size_t *lenp, loff_t *ppos)
2240 unsigned long tmptaint = get_taint();
2243 if (write && !capable(CAP_SYS_ADMIN))
2248 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2254 * Poor man's atomic or. Not worth adding a primitive
2255 * to everyone's atomic.h for this
2258 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2259 if ((tmptaint >> i) & 1)
2260 add_taint(i, LOCKDEP_STILL_OK);
2267 #ifdef CONFIG_PRINTK
2268 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2269 void __user *buffer, size_t *lenp, loff_t *ppos)
2271 if (write && !capable(CAP_SYS_ADMIN))
2274 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2278 struct do_proc_dointvec_minmax_conv_param {
2283 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2285 int write, void *data)
2287 struct do_proc_dointvec_minmax_conv_param *param = data;
2289 int val = *negp ? -*lvalp : *lvalp;
2290 if ((param->min && *param->min > val) ||
2291 (param->max && *param->max < val))
2298 *lvalp = -(unsigned long)val;
2301 *lvalp = (unsigned long)val;
2308 * proc_dointvec_minmax - read a vector of integers with min/max values
2309 * @table: the sysctl table
2310 * @write: %TRUE if this is a write to the sysctl file
2311 * @buffer: the user buffer
2312 * @lenp: the size of the user buffer
2313 * @ppos: file position
2315 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2316 * values from/to the user buffer, treated as an ASCII string.
2318 * This routine will ensure the values are within the range specified by
2319 * table->extra1 (min) and table->extra2 (max).
2321 * Returns 0 on success.
2323 int proc_dointvec_minmax(struct ctl_table *table, int write,
2324 void __user *buffer, size_t *lenp, loff_t *ppos)
2326 struct do_proc_dointvec_minmax_conv_param param = {
2327 .min = (int *) table->extra1,
2328 .max = (int *) table->extra2,
2330 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2331 do_proc_dointvec_minmax_conv, ¶m);
2334 static void validate_coredump_safety(void)
2336 #ifdef CONFIG_COREDUMP
2337 if (suid_dumpable == SUID_DUMP_ROOT &&
2338 core_pattern[0] != '/' && core_pattern[0] != '|') {
2339 printk(KERN_WARNING "Unsafe core_pattern used with "\
2340 "suid_dumpable=2. Pipe handler or fully qualified "\
2341 "core dump path required.\n");
2346 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2347 void __user *buffer, size_t *lenp, loff_t *ppos)
2349 int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2351 validate_coredump_safety();
2355 #ifdef CONFIG_COREDUMP
2356 static int proc_dostring_coredump(struct ctl_table *table, int write,
2357 void __user *buffer, size_t *lenp, loff_t *ppos)
2359 int error = proc_dostring(table, write, buffer, lenp, ppos);
2361 validate_coredump_safety();
2366 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2367 void __user *buffer,
2368 size_t *lenp, loff_t *ppos,
2369 unsigned long convmul,
2370 unsigned long convdiv)
2372 unsigned long *i, *min, *max;
2373 int vleft, first = 1, err = 0;
2375 char *kbuf = NULL, *p;
2377 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2382 i = (unsigned long *) data;
2383 min = (unsigned long *) table->extra1;
2384 max = (unsigned long *) table->extra2;
2385 vleft = table->maxlen / sizeof(unsigned long);
2390 switch (sysctl_writes_strict) {
2391 case SYSCTL_WRITES_STRICT:
2393 case SYSCTL_WRITES_WARN:
2394 warn_sysctl_write(table);
2401 if (left > PAGE_SIZE - 1)
2402 left = PAGE_SIZE - 1;
2403 p = kbuf = memdup_user_nul(buffer, left);
2405 return PTR_ERR(kbuf);
2408 for (; left && vleft--; i++, first = 0) {
2414 left -= proc_skip_spaces(&p);
2416 err = proc_get_long(&p, &left, &val, &neg,
2418 sizeof(proc_wspace_sep), NULL);
2423 if ((min && val < *min) || (max && val > *max))
2427 val = convdiv * (*i) / convmul;
2429 err = proc_put_char(&buffer, &left, '\t');
2433 err = proc_put_long(&buffer, &left, val, false);
2439 if (!write && !first && left && !err)
2440 err = proc_put_char(&buffer, &left, '\n');
2442 left -= proc_skip_spaces(&p);
2446 return err ? : -EINVAL;
2454 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2455 void __user *buffer,
2456 size_t *lenp, loff_t *ppos,
2457 unsigned long convmul,
2458 unsigned long convdiv)
2460 return __do_proc_doulongvec_minmax(table->data, table, write,
2461 buffer, lenp, ppos, convmul, convdiv);
2465 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2466 * @table: the sysctl table
2467 * @write: %TRUE if this is a write to the sysctl file
2468 * @buffer: the user buffer
2469 * @lenp: the size of the user buffer
2470 * @ppos: file position
2472 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2473 * values from/to the user buffer, treated as an ASCII string.
2475 * This routine will ensure the values are within the range specified by
2476 * table->extra1 (min) and table->extra2 (max).
2478 * Returns 0 on success.
2480 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2481 void __user *buffer, size_t *lenp, loff_t *ppos)
2483 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2487 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2488 * @table: the sysctl table
2489 * @write: %TRUE if this is a write to the sysctl file
2490 * @buffer: the user buffer
2491 * @lenp: the size of the user buffer
2492 * @ppos: file position
2494 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2495 * values from/to the user buffer, treated as an ASCII string. The values
2496 * are treated as milliseconds, and converted to jiffies when they are stored.
2498 * This routine will ensure the values are within the range specified by
2499 * table->extra1 (min) and table->extra2 (max).
2501 * Returns 0 on success.
2503 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2504 void __user *buffer,
2505 size_t *lenp, loff_t *ppos)
2507 return do_proc_doulongvec_minmax(table, write, buffer,
2508 lenp, ppos, HZ, 1000l);
2512 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2514 int write, void *data)
2517 if (*lvalp > LONG_MAX / HZ)
2519 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2525 lval = -(unsigned long)val;
2528 lval = (unsigned long)val;
2535 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2537 int write, void *data)
2540 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2542 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2548 lval = -(unsigned long)val;
2551 lval = (unsigned long)val;
2553 *lvalp = jiffies_to_clock_t(lval);
2558 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2560 int write, void *data)
2563 unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2573 lval = -(unsigned long)val;
2576 lval = (unsigned long)val;
2578 *lvalp = jiffies_to_msecs(lval);
2584 * proc_dointvec_jiffies - read a vector of integers as seconds
2585 * @table: the sysctl table
2586 * @write: %TRUE if this is a write to the sysctl file
2587 * @buffer: the user buffer
2588 * @lenp: the size of the user buffer
2589 * @ppos: file position
2591 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2592 * values from/to the user buffer, treated as an ASCII string.
2593 * The values read are assumed to be in seconds, and are converted into
2596 * Returns 0 on success.
2598 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2599 void __user *buffer, size_t *lenp, loff_t *ppos)
2601 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2602 do_proc_dointvec_jiffies_conv,NULL);
2606 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2607 * @table: the sysctl table
2608 * @write: %TRUE if this is a write to the sysctl file
2609 * @buffer: the user buffer
2610 * @lenp: the size of the user buffer
2611 * @ppos: pointer to the file position
2613 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2614 * values from/to the user buffer, treated as an ASCII string.
2615 * The values read are assumed to be in 1/USER_HZ seconds, and
2616 * are converted into jiffies.
2618 * Returns 0 on success.
2620 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2621 void __user *buffer, size_t *lenp, loff_t *ppos)
2623 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2624 do_proc_dointvec_userhz_jiffies_conv,NULL);
2628 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2629 * @table: the sysctl table
2630 * @write: %TRUE if this is a write to the sysctl file
2631 * @buffer: the user buffer
2632 * @lenp: the size of the user buffer
2633 * @ppos: file position
2634 * @ppos: the current position in the file
2636 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2637 * values from/to the user buffer, treated as an ASCII string.
2638 * The values read are assumed to be in 1/1000 seconds, and
2639 * are converted into jiffies.
2641 * Returns 0 on success.
2643 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2644 void __user *buffer, size_t *lenp, loff_t *ppos)
2646 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2647 do_proc_dointvec_ms_jiffies_conv, NULL);
2650 static int proc_do_cad_pid(struct ctl_table *table, int write,
2651 void __user *buffer, size_t *lenp, loff_t *ppos)
2653 struct pid *new_pid;
2657 tmp = pid_vnr(cad_pid);
2659 r = __do_proc_dointvec(&tmp, table, write, buffer,
2660 lenp, ppos, NULL, NULL);
2664 new_pid = find_get_pid(tmp);
2668 put_pid(xchg(&cad_pid, new_pid));
2673 * proc_do_large_bitmap - read/write from/to a large bitmap
2674 * @table: the sysctl table
2675 * @write: %TRUE if this is a write to the sysctl file
2676 * @buffer: the user buffer
2677 * @lenp: the size of the user buffer
2678 * @ppos: file position
2680 * The bitmap is stored at table->data and the bitmap length (in bits)
2683 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2684 * large bitmaps may be represented in a compact manner. Writing into
2685 * the file will clear the bitmap then update it with the given input.
2687 * Returns 0 on success.
2689 int proc_do_large_bitmap(struct ctl_table *table, int write,
2690 void __user *buffer, size_t *lenp, loff_t *ppos)
2694 size_t left = *lenp;
2695 unsigned long bitmap_len = table->maxlen;
2696 unsigned long *bitmap = *(unsigned long **) table->data;
2697 unsigned long *tmp_bitmap = NULL;
2698 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2700 if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2708 if (left > PAGE_SIZE - 1)
2709 left = PAGE_SIZE - 1;
2711 p = kbuf = memdup_user_nul(buffer, left);
2713 return PTR_ERR(kbuf);
2715 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2721 proc_skip_char(&p, &left, '\n');
2722 while (!err && left) {
2723 unsigned long val_a, val_b;
2726 err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2730 if (val_a >= bitmap_len || neg) {
2742 err = proc_get_long(&p, &left, &val_b,
2743 &neg, tr_b, sizeof(tr_b),
2747 if (val_b >= bitmap_len || neg ||
2758 bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2760 proc_skip_char(&p, &left, '\n');
2764 unsigned long bit_a, bit_b = 0;
2767 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2768 if (bit_a >= bitmap_len)
2770 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2774 err = proc_put_char(&buffer, &left, ',');
2778 err = proc_put_long(&buffer, &left, bit_a, false);
2781 if (bit_a != bit_b) {
2782 err = proc_put_char(&buffer, &left, '-');
2785 err = proc_put_long(&buffer, &left, bit_b, false);
2793 err = proc_put_char(&buffer, &left, '\n');
2799 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2801 bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2813 #else /* CONFIG_PROC_SYSCTL */
2815 int proc_dostring(struct ctl_table *table, int write,
2816 void __user *buffer, size_t *lenp, loff_t *ppos)
2821 int proc_dointvec(struct ctl_table *table, int write,
2822 void __user *buffer, size_t *lenp, loff_t *ppos)
2827 int proc_dointvec_minmax(struct ctl_table *table, int write,
2828 void __user *buffer, size_t *lenp, loff_t *ppos)
2833 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2834 void __user *buffer, size_t *lenp, loff_t *ppos)
2839 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2840 void __user *buffer, size_t *lenp, loff_t *ppos)
2845 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2846 void __user *buffer, size_t *lenp, loff_t *ppos)
2851 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2852 void __user *buffer, size_t *lenp, loff_t *ppos)
2857 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2858 void __user *buffer,
2859 size_t *lenp, loff_t *ppos)
2865 #endif /* CONFIG_PROC_SYSCTL */
2868 * No sense putting this after each symbol definition, twice,
2869 * exception granted :-)
2871 EXPORT_SYMBOL(proc_dointvec);
2872 EXPORT_SYMBOL(proc_dointvec_jiffies);
2873 EXPORT_SYMBOL(proc_dointvec_minmax);
2874 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2875 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2876 EXPORT_SYMBOL(proc_dostring);
2877 EXPORT_SYMBOL(proc_doulongvec_minmax);
2878 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);