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>
68 #include <linux/mount.h>
70 #include <linux/uaccess.h>
71 #include <asm/processor.h>
75 #include <asm/stacktrace.h>
79 #include <asm/setup.h>
81 #ifdef CONFIG_BSD_PROCESS_ACCT
82 #include <linux/acct.h>
84 #ifdef CONFIG_RT_MUTEXES
85 #include <linux/rtmutex.h>
87 #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT)
88 #include <linux/lockdep.h>
90 #ifdef CONFIG_CHR_DEV_SG
94 #ifdef CONFIG_LOCKUP_DETECTOR
95 #include <linux/nmi.h>
98 #if defined(CONFIG_SYSCTL)
100 /* External variables not in a header file. */
101 extern int suid_dumpable;
102 #ifdef CONFIG_COREDUMP
103 extern int core_uses_pid;
104 extern char core_pattern[];
105 extern unsigned int core_pipe_limit;
108 extern int pid_max_min, pid_max_max;
109 extern int percpu_pagelist_fraction;
110 extern int latencytop_enabled;
111 extern unsigned 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,
350 #ifdef CONFIG_SCHEDSTATS
352 .procname = "sched_schedstats",
354 .maxlen = sizeof(unsigned int),
356 .proc_handler = sysctl_schedstats,
360 #endif /* CONFIG_SCHEDSTATS */
361 #endif /* CONFIG_SMP */
362 #ifdef CONFIG_NUMA_BALANCING
364 .procname = "numa_balancing_scan_delay_ms",
365 .data = &sysctl_numa_balancing_scan_delay,
366 .maxlen = sizeof(unsigned int),
368 .proc_handler = proc_dointvec,
371 .procname = "numa_balancing_scan_period_min_ms",
372 .data = &sysctl_numa_balancing_scan_period_min,
373 .maxlen = sizeof(unsigned int),
375 .proc_handler = proc_dointvec,
378 .procname = "numa_balancing_scan_period_max_ms",
379 .data = &sysctl_numa_balancing_scan_period_max,
380 .maxlen = sizeof(unsigned int),
382 .proc_handler = proc_dointvec,
385 .procname = "numa_balancing_scan_size_mb",
386 .data = &sysctl_numa_balancing_scan_size,
387 .maxlen = sizeof(unsigned int),
389 .proc_handler = proc_dointvec_minmax,
393 .procname = "numa_balancing",
394 .data = NULL, /* filled in by handler */
395 .maxlen = sizeof(unsigned int),
397 .proc_handler = sysctl_numa_balancing,
401 #endif /* CONFIG_NUMA_BALANCING */
402 #endif /* CONFIG_SCHED_DEBUG */
404 .procname = "sched_rt_period_us",
405 .data = &sysctl_sched_rt_period,
406 .maxlen = sizeof(unsigned int),
408 .proc_handler = sched_rt_handler,
411 .procname = "sched_rt_runtime_us",
412 .data = &sysctl_sched_rt_runtime,
413 .maxlen = sizeof(int),
415 .proc_handler = sched_rt_handler,
418 .procname = "sched_rr_timeslice_ms",
419 .data = &sysctl_sched_rr_timeslice,
420 .maxlen = sizeof(int),
422 .proc_handler = sched_rr_handler,
424 #ifdef CONFIG_SCHED_AUTOGROUP
426 .procname = "sched_autogroup_enabled",
427 .data = &sysctl_sched_autogroup_enabled,
428 .maxlen = sizeof(unsigned int),
430 .proc_handler = proc_dointvec_minmax,
435 #ifdef CONFIG_CFS_BANDWIDTH
437 .procname = "sched_cfs_bandwidth_slice_us",
438 .data = &sysctl_sched_cfs_bandwidth_slice,
439 .maxlen = sizeof(unsigned int),
441 .proc_handler = proc_dointvec_minmax,
445 #ifdef CONFIG_PROVE_LOCKING
447 .procname = "prove_locking",
448 .data = &prove_locking,
449 .maxlen = sizeof(int),
451 .proc_handler = proc_dointvec,
454 #ifdef CONFIG_LOCK_STAT
456 .procname = "lock_stat",
458 .maxlen = sizeof(int),
460 .proc_handler = proc_dointvec,
465 .data = &panic_timeout,
466 .maxlen = sizeof(int),
468 .proc_handler = proc_dointvec,
470 #ifdef CONFIG_COREDUMP
472 .procname = "core_uses_pid",
473 .data = &core_uses_pid,
474 .maxlen = sizeof(int),
476 .proc_handler = proc_dointvec,
479 .procname = "core_pattern",
480 .data = core_pattern,
481 .maxlen = CORENAME_MAX_SIZE,
483 .proc_handler = proc_dostring_coredump,
486 .procname = "core_pipe_limit",
487 .data = &core_pipe_limit,
488 .maxlen = sizeof(unsigned int),
490 .proc_handler = proc_dointvec,
493 #ifdef CONFIG_PROC_SYSCTL
495 .procname = "tainted",
496 .maxlen = sizeof(long),
498 .proc_handler = proc_taint,
501 .procname = "sysctl_writes_strict",
502 .data = &sysctl_writes_strict,
503 .maxlen = sizeof(int),
505 .proc_handler = proc_dointvec_minmax,
510 #ifdef CONFIG_LATENCYTOP
512 .procname = "latencytop",
513 .data = &latencytop_enabled,
514 .maxlen = sizeof(int),
516 .proc_handler = sysctl_latencytop,
519 #ifdef CONFIG_BLK_DEV_INITRD
521 .procname = "real-root-dev",
522 .data = &real_root_dev,
523 .maxlen = sizeof(int),
525 .proc_handler = proc_dointvec,
529 .procname = "print-fatal-signals",
530 .data = &print_fatal_signals,
531 .maxlen = sizeof(int),
533 .proc_handler = proc_dointvec,
537 .procname = "reboot-cmd",
538 .data = reboot_command,
541 .proc_handler = proc_dostring,
544 .procname = "stop-a",
545 .data = &stop_a_enabled,
546 .maxlen = sizeof (int),
548 .proc_handler = proc_dointvec,
551 .procname = "scons-poweroff",
552 .data = &scons_pwroff,
553 .maxlen = sizeof (int),
555 .proc_handler = proc_dointvec,
558 #ifdef CONFIG_SPARC64
560 .procname = "tsb-ratio",
561 .data = &sysctl_tsb_ratio,
562 .maxlen = sizeof (int),
564 .proc_handler = proc_dointvec,
569 .procname = "soft-power",
570 .data = &pwrsw_enabled,
571 .maxlen = sizeof (int),
573 .proc_handler = proc_dointvec,
576 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
578 .procname = "unaligned-trap",
579 .data = &unaligned_enabled,
580 .maxlen = sizeof (int),
582 .proc_handler = proc_dointvec,
586 .procname = "ctrl-alt-del",
588 .maxlen = sizeof(int),
590 .proc_handler = proc_dointvec,
592 #ifdef CONFIG_FUNCTION_TRACER
594 .procname = "ftrace_enabled",
595 .data = &ftrace_enabled,
596 .maxlen = sizeof(int),
598 .proc_handler = ftrace_enable_sysctl,
601 #ifdef CONFIG_STACK_TRACER
603 .procname = "stack_tracer_enabled",
604 .data = &stack_tracer_enabled,
605 .maxlen = sizeof(int),
607 .proc_handler = stack_trace_sysctl,
610 #ifdef CONFIG_TRACING
612 .procname = "ftrace_dump_on_oops",
613 .data = &ftrace_dump_on_oops,
614 .maxlen = sizeof(int),
616 .proc_handler = proc_dointvec,
619 .procname = "traceoff_on_warning",
620 .data = &__disable_trace_on_warning,
621 .maxlen = sizeof(__disable_trace_on_warning),
623 .proc_handler = proc_dointvec,
626 .procname = "tracepoint_printk",
627 .data = &tracepoint_printk,
628 .maxlen = sizeof(tracepoint_printk),
630 .proc_handler = tracepoint_printk_sysctl,
633 #ifdef CONFIG_KEXEC_CORE
635 .procname = "kexec_load_disabled",
636 .data = &kexec_load_disabled,
637 .maxlen = sizeof(int),
639 /* only handle a transition from default "0" to "1" */
640 .proc_handler = proc_dointvec_minmax,
645 #ifdef CONFIG_MODULES
647 .procname = "modprobe",
648 .data = &modprobe_path,
649 .maxlen = KMOD_PATH_LEN,
651 .proc_handler = proc_dostring,
654 .procname = "modules_disabled",
655 .data = &modules_disabled,
656 .maxlen = sizeof(int),
658 /* only handle a transition from default "0" to "1" */
659 .proc_handler = proc_dointvec_minmax,
664 #ifdef CONFIG_UEVENT_HELPER
666 .procname = "hotplug",
667 .data = &uevent_helper,
668 .maxlen = UEVENT_HELPER_PATH_LEN,
670 .proc_handler = proc_dostring,
673 #ifdef CONFIG_CHR_DEV_SG
675 .procname = "sg-big-buff",
676 .data = &sg_big_buff,
677 .maxlen = sizeof (int),
679 .proc_handler = proc_dointvec,
682 #ifdef CONFIG_BSD_PROCESS_ACCT
686 .maxlen = 3*sizeof(int),
688 .proc_handler = proc_dointvec,
691 #ifdef CONFIG_MAGIC_SYSRQ
694 .data = &__sysrq_enabled,
695 .maxlen = sizeof (int),
697 .proc_handler = sysrq_sysctl_handler,
700 #ifdef CONFIG_PROC_SYSCTL
702 .procname = "cad_pid",
704 .maxlen = sizeof (int),
706 .proc_handler = proc_do_cad_pid,
710 .procname = "threads-max",
712 .maxlen = sizeof(int),
714 .proc_handler = sysctl_max_threads,
717 .procname = "random",
719 .child = random_table,
722 .procname = "usermodehelper",
724 .child = usermodehelper_table,
727 .procname = "overflowuid",
728 .data = &overflowuid,
729 .maxlen = sizeof(int),
731 .proc_handler = proc_dointvec_minmax,
732 .extra1 = &minolduid,
733 .extra2 = &maxolduid,
736 .procname = "overflowgid",
737 .data = &overflowgid,
738 .maxlen = sizeof(int),
740 .proc_handler = proc_dointvec_minmax,
741 .extra1 = &minolduid,
742 .extra2 = &maxolduid,
745 #ifdef CONFIG_MATHEMU
747 .procname = "ieee_emulation_warnings",
748 .data = &sysctl_ieee_emulation_warnings,
749 .maxlen = sizeof(int),
751 .proc_handler = proc_dointvec,
755 .procname = "userprocess_debug",
756 .data = &show_unhandled_signals,
757 .maxlen = sizeof(int),
759 .proc_handler = proc_dointvec,
763 .procname = "pid_max",
765 .maxlen = sizeof (int),
767 .proc_handler = proc_dointvec_minmax,
768 .extra1 = &pid_max_min,
769 .extra2 = &pid_max_max,
772 .procname = "panic_on_oops",
773 .data = &panic_on_oops,
774 .maxlen = sizeof(int),
776 .proc_handler = proc_dointvec,
778 #if defined CONFIG_PRINTK
780 .procname = "printk",
781 .data = &console_loglevel,
782 .maxlen = 4*sizeof(int),
784 .proc_handler = proc_dointvec,
787 .procname = "printk_ratelimit",
788 .data = &printk_ratelimit_state.interval,
789 .maxlen = sizeof(int),
791 .proc_handler = proc_dointvec_jiffies,
794 .procname = "printk_ratelimit_burst",
795 .data = &printk_ratelimit_state.burst,
796 .maxlen = sizeof(int),
798 .proc_handler = proc_dointvec,
801 .procname = "printk_delay",
802 .data = &printk_delay_msec,
803 .maxlen = sizeof(int),
805 .proc_handler = proc_dointvec_minmax,
807 .extra2 = &ten_thousand,
810 .procname = "printk_devkmsg",
811 .data = devkmsg_log_str,
812 .maxlen = DEVKMSG_STR_MAX_SIZE,
814 .proc_handler = devkmsg_sysctl_set_loglvl,
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 = "io_delay_type",
987 .data = &io_delay_type,
988 .maxlen = sizeof(int),
990 .proc_handler = proc_dointvec,
993 #if defined(CONFIG_MMU)
995 .procname = "randomize_va_space",
996 .data = &randomize_va_space,
997 .maxlen = sizeof(int),
999 .proc_handler = proc_dointvec,
1002 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1004 .procname = "spin_retry",
1005 .data = &spin_retry,
1006 .maxlen = sizeof (int),
1008 .proc_handler = proc_dointvec,
1011 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1013 .procname = "acpi_video_flags",
1014 .data = &acpi_realmode_flags,
1015 .maxlen = sizeof (unsigned long),
1017 .proc_handler = proc_doulongvec_minmax,
1020 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1022 .procname = "ignore-unaligned-usertrap",
1023 .data = &no_unaligned_warning,
1024 .maxlen = sizeof (int),
1026 .proc_handler = proc_dointvec,
1031 .procname = "unaligned-dump-stack",
1032 .data = &unaligned_dump_stack,
1033 .maxlen = sizeof (int),
1035 .proc_handler = proc_dointvec,
1038 #ifdef CONFIG_DETECT_HUNG_TASK
1040 .procname = "hung_task_panic",
1041 .data = &sysctl_hung_task_panic,
1042 .maxlen = sizeof(int),
1044 .proc_handler = proc_dointvec_minmax,
1049 .procname = "hung_task_check_count",
1050 .data = &sysctl_hung_task_check_count,
1051 .maxlen = sizeof(int),
1053 .proc_handler = proc_dointvec_minmax,
1057 .procname = "hung_task_timeout_secs",
1058 .data = &sysctl_hung_task_timeout_secs,
1059 .maxlen = sizeof(unsigned long),
1061 .proc_handler = proc_dohung_task_timeout_secs,
1062 .extra2 = &hung_task_timeout_max,
1065 .procname = "hung_task_warnings",
1066 .data = &sysctl_hung_task_warnings,
1067 .maxlen = sizeof(int),
1069 .proc_handler = proc_dointvec_minmax,
1073 #ifdef CONFIG_RT_MUTEXES
1075 .procname = "max_lock_depth",
1076 .data = &max_lock_depth,
1077 .maxlen = sizeof(int),
1079 .proc_handler = proc_dointvec,
1083 .procname = "poweroff_cmd",
1084 .data = &poweroff_cmd,
1085 .maxlen = POWEROFF_CMD_PATH_LEN,
1087 .proc_handler = proc_dostring,
1093 .child = key_sysctls,
1096 #ifdef CONFIG_PERF_EVENTS
1098 * User-space scripts rely on the existence of this file
1099 * as a feature check for perf_events being enabled.
1101 * So it's an ABI, do not remove!
1104 .procname = "perf_event_paranoid",
1105 .data = &sysctl_perf_event_paranoid,
1106 .maxlen = sizeof(sysctl_perf_event_paranoid),
1108 .proc_handler = proc_dointvec,
1111 .procname = "perf_event_mlock_kb",
1112 .data = &sysctl_perf_event_mlock,
1113 .maxlen = sizeof(sysctl_perf_event_mlock),
1115 .proc_handler = proc_dointvec,
1118 .procname = "perf_event_max_sample_rate",
1119 .data = &sysctl_perf_event_sample_rate,
1120 .maxlen = sizeof(sysctl_perf_event_sample_rate),
1122 .proc_handler = perf_proc_update_handler,
1126 .procname = "perf_cpu_time_max_percent",
1127 .data = &sysctl_perf_cpu_time_max_percent,
1128 .maxlen = sizeof(sysctl_perf_cpu_time_max_percent),
1130 .proc_handler = perf_cpu_time_max_percent_handler,
1132 .extra2 = &one_hundred,
1135 .procname = "perf_event_max_stack",
1136 .data = &sysctl_perf_event_max_stack,
1137 .maxlen = sizeof(sysctl_perf_event_max_stack),
1139 .proc_handler = perf_event_max_stack_handler,
1141 .extra2 = &six_hundred_forty_kb,
1144 .procname = "perf_event_max_contexts_per_stack",
1145 .data = &sysctl_perf_event_max_contexts_per_stack,
1146 .maxlen = sizeof(sysctl_perf_event_max_contexts_per_stack),
1148 .proc_handler = perf_event_max_stack_handler,
1150 .extra2 = &one_thousand,
1153 #ifdef CONFIG_KMEMCHECK
1155 .procname = "kmemcheck",
1156 .data = &kmemcheck_enabled,
1157 .maxlen = sizeof(int),
1159 .proc_handler = proc_dointvec,
1163 .procname = "panic_on_warn",
1164 .data = &panic_on_warn,
1165 .maxlen = sizeof(int),
1167 .proc_handler = proc_dointvec_minmax,
1171 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
1173 .procname = "timer_migration",
1174 .data = &sysctl_timer_migration,
1175 .maxlen = sizeof(unsigned int),
1177 .proc_handler = timer_migration_handler,
1180 #ifdef CONFIG_BPF_SYSCALL
1182 .procname = "unprivileged_bpf_disabled",
1183 .data = &sysctl_unprivileged_bpf_disabled,
1184 .maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
1186 /* only handle a transition from default "0" to "1" */
1187 .proc_handler = proc_dointvec_minmax,
1192 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
1194 .procname = "panic_on_rcu_stall",
1195 .data = &sysctl_panic_on_rcu_stall,
1196 .maxlen = sizeof(sysctl_panic_on_rcu_stall),
1198 .proc_handler = proc_dointvec_minmax,
1206 static struct ctl_table vm_table[] = {
1208 .procname = "overcommit_memory",
1209 .data = &sysctl_overcommit_memory,
1210 .maxlen = sizeof(sysctl_overcommit_memory),
1212 .proc_handler = proc_dointvec_minmax,
1217 .procname = "panic_on_oom",
1218 .data = &sysctl_panic_on_oom,
1219 .maxlen = sizeof(sysctl_panic_on_oom),
1221 .proc_handler = proc_dointvec_minmax,
1226 .procname = "oom_kill_allocating_task",
1227 .data = &sysctl_oom_kill_allocating_task,
1228 .maxlen = sizeof(sysctl_oom_kill_allocating_task),
1230 .proc_handler = proc_dointvec,
1233 .procname = "oom_dump_tasks",
1234 .data = &sysctl_oom_dump_tasks,
1235 .maxlen = sizeof(sysctl_oom_dump_tasks),
1237 .proc_handler = proc_dointvec,
1240 .procname = "overcommit_ratio",
1241 .data = &sysctl_overcommit_ratio,
1242 .maxlen = sizeof(sysctl_overcommit_ratio),
1244 .proc_handler = overcommit_ratio_handler,
1247 .procname = "overcommit_kbytes",
1248 .data = &sysctl_overcommit_kbytes,
1249 .maxlen = sizeof(sysctl_overcommit_kbytes),
1251 .proc_handler = overcommit_kbytes_handler,
1254 .procname = "page-cluster",
1255 .data = &page_cluster,
1256 .maxlen = sizeof(int),
1258 .proc_handler = proc_dointvec_minmax,
1262 .procname = "dirty_background_ratio",
1263 .data = &dirty_background_ratio,
1264 .maxlen = sizeof(dirty_background_ratio),
1266 .proc_handler = dirty_background_ratio_handler,
1268 .extra2 = &one_hundred,
1271 .procname = "dirty_background_bytes",
1272 .data = &dirty_background_bytes,
1273 .maxlen = sizeof(dirty_background_bytes),
1275 .proc_handler = dirty_background_bytes_handler,
1279 .procname = "dirty_ratio",
1280 .data = &vm_dirty_ratio,
1281 .maxlen = sizeof(vm_dirty_ratio),
1283 .proc_handler = dirty_ratio_handler,
1285 .extra2 = &one_hundred,
1288 .procname = "dirty_bytes",
1289 .data = &vm_dirty_bytes,
1290 .maxlen = sizeof(vm_dirty_bytes),
1292 .proc_handler = dirty_bytes_handler,
1293 .extra1 = &dirty_bytes_min,
1296 .procname = "dirty_writeback_centisecs",
1297 .data = &dirty_writeback_interval,
1298 .maxlen = sizeof(dirty_writeback_interval),
1300 .proc_handler = dirty_writeback_centisecs_handler,
1303 .procname = "dirty_expire_centisecs",
1304 .data = &dirty_expire_interval,
1305 .maxlen = sizeof(dirty_expire_interval),
1307 .proc_handler = proc_dointvec_minmax,
1311 .procname = "dirtytime_expire_seconds",
1312 .data = &dirtytime_expire_interval,
1313 .maxlen = sizeof(dirty_expire_interval),
1315 .proc_handler = dirtytime_interval_handler,
1319 .procname = "nr_pdflush_threads",
1320 .mode = 0444 /* read-only */,
1321 .proc_handler = pdflush_proc_obsolete,
1324 .procname = "swappiness",
1325 .data = &vm_swappiness,
1326 .maxlen = sizeof(vm_swappiness),
1328 .proc_handler = proc_dointvec_minmax,
1330 .extra2 = &one_hundred,
1332 #ifdef CONFIG_HUGETLB_PAGE
1334 .procname = "nr_hugepages",
1336 .maxlen = sizeof(unsigned long),
1338 .proc_handler = hugetlb_sysctl_handler,
1342 .procname = "nr_hugepages_mempolicy",
1344 .maxlen = sizeof(unsigned long),
1346 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
1350 .procname = "hugetlb_shm_group",
1351 .data = &sysctl_hugetlb_shm_group,
1352 .maxlen = sizeof(gid_t),
1354 .proc_handler = proc_dointvec,
1357 .procname = "hugepages_treat_as_movable",
1358 .data = &hugepages_treat_as_movable,
1359 .maxlen = sizeof(int),
1361 .proc_handler = proc_dointvec,
1364 .procname = "nr_overcommit_hugepages",
1366 .maxlen = sizeof(unsigned long),
1368 .proc_handler = hugetlb_overcommit_handler,
1372 .procname = "lowmem_reserve_ratio",
1373 .data = &sysctl_lowmem_reserve_ratio,
1374 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
1376 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
1379 .procname = "drop_caches",
1380 .data = &sysctl_drop_caches,
1381 .maxlen = sizeof(int),
1383 .proc_handler = drop_caches_sysctl_handler,
1387 #ifdef CONFIG_COMPACTION
1389 .procname = "compact_memory",
1390 .data = &sysctl_compact_memory,
1391 .maxlen = sizeof(int),
1393 .proc_handler = sysctl_compaction_handler,
1396 .procname = "extfrag_threshold",
1397 .data = &sysctl_extfrag_threshold,
1398 .maxlen = sizeof(int),
1400 .proc_handler = sysctl_extfrag_handler,
1401 .extra1 = &min_extfrag_threshold,
1402 .extra2 = &max_extfrag_threshold,
1405 .procname = "compact_unevictable_allowed",
1406 .data = &sysctl_compact_unevictable_allowed,
1407 .maxlen = sizeof(int),
1409 .proc_handler = proc_dointvec,
1414 #endif /* CONFIG_COMPACTION */
1416 .procname = "min_free_kbytes",
1417 .data = &min_free_kbytes,
1418 .maxlen = sizeof(min_free_kbytes),
1420 .proc_handler = min_free_kbytes_sysctl_handler,
1424 .procname = "watermark_scale_factor",
1425 .data = &watermark_scale_factor,
1426 .maxlen = sizeof(watermark_scale_factor),
1428 .proc_handler = watermark_scale_factor_sysctl_handler,
1430 .extra2 = &one_thousand,
1433 .procname = "percpu_pagelist_fraction",
1434 .data = &percpu_pagelist_fraction,
1435 .maxlen = sizeof(percpu_pagelist_fraction),
1437 .proc_handler = percpu_pagelist_fraction_sysctl_handler,
1442 .procname = "max_map_count",
1443 .data = &sysctl_max_map_count,
1444 .maxlen = sizeof(sysctl_max_map_count),
1446 .proc_handler = proc_dointvec_minmax,
1451 .procname = "nr_trim_pages",
1452 .data = &sysctl_nr_trim_pages,
1453 .maxlen = sizeof(sysctl_nr_trim_pages),
1455 .proc_handler = proc_dointvec_minmax,
1460 .procname = "laptop_mode",
1461 .data = &laptop_mode,
1462 .maxlen = sizeof(laptop_mode),
1464 .proc_handler = proc_dointvec_jiffies,
1467 .procname = "block_dump",
1468 .data = &block_dump,
1469 .maxlen = sizeof(block_dump),
1471 .proc_handler = proc_dointvec,
1475 .procname = "vfs_cache_pressure",
1476 .data = &sysctl_vfs_cache_pressure,
1477 .maxlen = sizeof(sysctl_vfs_cache_pressure),
1479 .proc_handler = proc_dointvec,
1482 #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
1484 .procname = "legacy_va_layout",
1485 .data = &sysctl_legacy_va_layout,
1486 .maxlen = sizeof(sysctl_legacy_va_layout),
1488 .proc_handler = proc_dointvec,
1494 .procname = "zone_reclaim_mode",
1495 .data = &node_reclaim_mode,
1496 .maxlen = sizeof(node_reclaim_mode),
1498 .proc_handler = proc_dointvec,
1502 .procname = "min_unmapped_ratio",
1503 .data = &sysctl_min_unmapped_ratio,
1504 .maxlen = sizeof(sysctl_min_unmapped_ratio),
1506 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
1508 .extra2 = &one_hundred,
1511 .procname = "min_slab_ratio",
1512 .data = &sysctl_min_slab_ratio,
1513 .maxlen = sizeof(sysctl_min_slab_ratio),
1515 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
1517 .extra2 = &one_hundred,
1522 .procname = "stat_interval",
1523 .data = &sysctl_stat_interval,
1524 .maxlen = sizeof(sysctl_stat_interval),
1526 .proc_handler = proc_dointvec_jiffies,
1529 .procname = "stat_refresh",
1533 .proc_handler = vmstat_refresh,
1538 .procname = "mmap_min_addr",
1539 .data = &dac_mmap_min_addr,
1540 .maxlen = sizeof(unsigned long),
1542 .proc_handler = mmap_min_addr_handler,
1547 .procname = "numa_zonelist_order",
1548 .data = &numa_zonelist_order,
1549 .maxlen = NUMA_ZONELIST_ORDER_LEN,
1551 .proc_handler = numa_zonelist_order_handler,
1554 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
1555 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
1557 .procname = "vdso_enabled",
1558 #ifdef CONFIG_X86_32
1559 .data = &vdso32_enabled,
1560 .maxlen = sizeof(vdso32_enabled),
1562 .data = &vdso_enabled,
1563 .maxlen = sizeof(vdso_enabled),
1566 .proc_handler = proc_dointvec,
1570 #ifdef CONFIG_HIGHMEM
1572 .procname = "highmem_is_dirtyable",
1573 .data = &vm_highmem_is_dirtyable,
1574 .maxlen = sizeof(vm_highmem_is_dirtyable),
1576 .proc_handler = proc_dointvec_minmax,
1581 #ifdef CONFIG_MEMORY_FAILURE
1583 .procname = "memory_failure_early_kill",
1584 .data = &sysctl_memory_failure_early_kill,
1585 .maxlen = sizeof(sysctl_memory_failure_early_kill),
1587 .proc_handler = proc_dointvec_minmax,
1592 .procname = "memory_failure_recovery",
1593 .data = &sysctl_memory_failure_recovery,
1594 .maxlen = sizeof(sysctl_memory_failure_recovery),
1596 .proc_handler = proc_dointvec_minmax,
1602 .procname = "user_reserve_kbytes",
1603 .data = &sysctl_user_reserve_kbytes,
1604 .maxlen = sizeof(sysctl_user_reserve_kbytes),
1606 .proc_handler = proc_doulongvec_minmax,
1609 .procname = "admin_reserve_kbytes",
1610 .data = &sysctl_admin_reserve_kbytes,
1611 .maxlen = sizeof(sysctl_admin_reserve_kbytes),
1613 .proc_handler = proc_doulongvec_minmax,
1615 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
1617 .procname = "mmap_rnd_bits",
1618 .data = &mmap_rnd_bits,
1619 .maxlen = sizeof(mmap_rnd_bits),
1621 .proc_handler = proc_dointvec_minmax,
1622 .extra1 = (void *)&mmap_rnd_bits_min,
1623 .extra2 = (void *)&mmap_rnd_bits_max,
1626 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
1628 .procname = "mmap_rnd_compat_bits",
1629 .data = &mmap_rnd_compat_bits,
1630 .maxlen = sizeof(mmap_rnd_compat_bits),
1632 .proc_handler = proc_dointvec_minmax,
1633 .extra1 = (void *)&mmap_rnd_compat_bits_min,
1634 .extra2 = (void *)&mmap_rnd_compat_bits_max,
1640 static struct ctl_table fs_table[] = {
1642 .procname = "inode-nr",
1643 .data = &inodes_stat,
1644 .maxlen = 2*sizeof(long),
1646 .proc_handler = proc_nr_inodes,
1649 .procname = "inode-state",
1650 .data = &inodes_stat,
1651 .maxlen = 7*sizeof(long),
1653 .proc_handler = proc_nr_inodes,
1656 .procname = "file-nr",
1657 .data = &files_stat,
1658 .maxlen = sizeof(files_stat),
1660 .proc_handler = proc_nr_files,
1663 .procname = "file-max",
1664 .data = &files_stat.max_files,
1665 .maxlen = sizeof(files_stat.max_files),
1667 .proc_handler = proc_doulongvec_minmax,
1670 .procname = "nr_open",
1671 .data = &sysctl_nr_open,
1672 .maxlen = sizeof(unsigned int),
1674 .proc_handler = proc_dointvec_minmax,
1675 .extra1 = &sysctl_nr_open_min,
1676 .extra2 = &sysctl_nr_open_max,
1679 .procname = "dentry-state",
1680 .data = &dentry_stat,
1681 .maxlen = 6*sizeof(long),
1683 .proc_handler = proc_nr_dentry,
1686 .procname = "overflowuid",
1687 .data = &fs_overflowuid,
1688 .maxlen = sizeof(int),
1690 .proc_handler = proc_dointvec_minmax,
1691 .extra1 = &minolduid,
1692 .extra2 = &maxolduid,
1695 .procname = "overflowgid",
1696 .data = &fs_overflowgid,
1697 .maxlen = sizeof(int),
1699 .proc_handler = proc_dointvec_minmax,
1700 .extra1 = &minolduid,
1701 .extra2 = &maxolduid,
1703 #ifdef CONFIG_FILE_LOCKING
1705 .procname = "leases-enable",
1706 .data = &leases_enable,
1707 .maxlen = sizeof(int),
1709 .proc_handler = proc_dointvec,
1712 #ifdef CONFIG_DNOTIFY
1714 .procname = "dir-notify-enable",
1715 .data = &dir_notify_enable,
1716 .maxlen = sizeof(int),
1718 .proc_handler = proc_dointvec,
1722 #ifdef CONFIG_FILE_LOCKING
1724 .procname = "lease-break-time",
1725 .data = &lease_break_time,
1726 .maxlen = sizeof(int),
1728 .proc_handler = proc_dointvec,
1733 .procname = "aio-nr",
1735 .maxlen = sizeof(aio_nr),
1737 .proc_handler = proc_doulongvec_minmax,
1740 .procname = "aio-max-nr",
1741 .data = &aio_max_nr,
1742 .maxlen = sizeof(aio_max_nr),
1744 .proc_handler = proc_doulongvec_minmax,
1746 #endif /* CONFIG_AIO */
1747 #ifdef CONFIG_INOTIFY_USER
1749 .procname = "inotify",
1751 .child = inotify_table,
1756 .procname = "epoll",
1758 .child = epoll_table,
1763 .procname = "protected_symlinks",
1764 .data = &sysctl_protected_symlinks,
1765 .maxlen = sizeof(int),
1767 .proc_handler = proc_dointvec_minmax,
1772 .procname = "protected_hardlinks",
1773 .data = &sysctl_protected_hardlinks,
1774 .maxlen = sizeof(int),
1776 .proc_handler = proc_dointvec_minmax,
1781 .procname = "suid_dumpable",
1782 .data = &suid_dumpable,
1783 .maxlen = sizeof(int),
1785 .proc_handler = proc_dointvec_minmax_coredump,
1789 #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE)
1791 .procname = "binfmt_misc",
1793 .child = sysctl_mount_point,
1797 .procname = "pipe-max-size",
1798 .data = &pipe_max_size,
1799 .maxlen = sizeof(int),
1801 .proc_handler = &pipe_proc_fn,
1802 .extra1 = &pipe_min_size,
1805 .procname = "pipe-user-pages-hard",
1806 .data = &pipe_user_pages_hard,
1807 .maxlen = sizeof(pipe_user_pages_hard),
1809 .proc_handler = proc_doulongvec_minmax,
1812 .procname = "pipe-user-pages-soft",
1813 .data = &pipe_user_pages_soft,
1814 .maxlen = sizeof(pipe_user_pages_soft),
1816 .proc_handler = proc_doulongvec_minmax,
1819 .procname = "mount-max",
1820 .data = &sysctl_mount_max,
1821 .maxlen = sizeof(unsigned int),
1823 .proc_handler = proc_dointvec_minmax,
1829 static struct ctl_table debug_table[] = {
1830 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
1832 .procname = "exception-trace",
1833 .data = &show_unhandled_signals,
1834 .maxlen = sizeof(int),
1836 .proc_handler = proc_dointvec
1839 #if defined(CONFIG_OPTPROBES)
1841 .procname = "kprobes-optimization",
1842 .data = &sysctl_kprobes_optimization,
1843 .maxlen = sizeof(int),
1845 .proc_handler = proc_kprobes_optimization_handler,
1853 static struct ctl_table dev_table[] = {
1857 int __init sysctl_init(void)
1859 struct ctl_table_header *hdr;
1861 hdr = register_sysctl_table(sysctl_base_table);
1862 kmemleak_not_leak(hdr);
1866 #endif /* CONFIG_SYSCTL */
1872 #ifdef CONFIG_PROC_SYSCTL
1874 static int _proc_do_string(char *data, int maxlen, int write,
1875 char __user *buffer,
1876 size_t *lenp, loff_t *ppos)
1882 if (!data || !maxlen || !*lenp) {
1888 if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
1889 /* Only continue writes not past the end of buffer. */
1891 if (len > maxlen - 1)
1898 /* Start writing from beginning of buffer. */
1904 while ((p - buffer) < *lenp && len < maxlen - 1) {
1905 if (get_user(c, p++))
1907 if (c == 0 || c == '\n')
1928 if (copy_to_user(buffer, data, len))
1931 if (put_user('\n', buffer + len))
1941 static void warn_sysctl_write(struct ctl_table *table)
1943 pr_warn_once("%s wrote to %s when file position was not 0!\n"
1944 "This will not be supported in the future. To silence this\n"
1945 "warning, set kernel.sysctl_writes_strict = -1\n",
1946 current->comm, table->procname);
1950 * proc_dostring - read a string sysctl
1951 * @table: the sysctl table
1952 * @write: %TRUE if this is a write to the sysctl file
1953 * @buffer: the user buffer
1954 * @lenp: the size of the user buffer
1955 * @ppos: file position
1957 * Reads/writes a string from/to the user buffer. If the kernel
1958 * buffer provided is not large enough to hold the string, the
1959 * string is truncated. The copied string is %NULL-terminated.
1960 * If the string is being read by the user process, it is copied
1961 * and a newline '\n' is added. It is truncated if the buffer is
1964 * Returns 0 on success.
1966 int proc_dostring(struct ctl_table *table, int write,
1967 void __user *buffer, size_t *lenp, loff_t *ppos)
1969 if (write && *ppos && sysctl_writes_strict == SYSCTL_WRITES_WARN)
1970 warn_sysctl_write(table);
1972 return _proc_do_string((char *)(table->data), table->maxlen, write,
1973 (char __user *)buffer, lenp, ppos);
1976 static size_t proc_skip_spaces(char **buf)
1979 char *tmp = skip_spaces(*buf);
1985 static void proc_skip_char(char **buf, size_t *size, const char v)
1995 #define TMPBUFLEN 22
1997 * proc_get_long - reads an ASCII formatted integer from a user buffer
1999 * @buf: a kernel buffer
2000 * @size: size of the kernel buffer
2001 * @val: this is where the number will be stored
2002 * @neg: set to %TRUE if number is negative
2003 * @perm_tr: a vector which contains the allowed trailers
2004 * @perm_tr_len: size of the perm_tr vector
2005 * @tr: pointer to store the trailer character
2007 * In case of success %0 is returned and @buf and @size are updated with
2008 * the amount of bytes read. If @tr is non-NULL and a trailing
2009 * character exists (size is non-zero after returning from this
2010 * function), @tr is updated with the trailing character.
2012 static int proc_get_long(char **buf, size_t *size,
2013 unsigned long *val, bool *neg,
2014 const char *perm_tr, unsigned perm_tr_len, char *tr)
2017 char *p, tmp[TMPBUFLEN];
2023 if (len > TMPBUFLEN - 1)
2024 len = TMPBUFLEN - 1;
2026 memcpy(tmp, *buf, len);
2030 if (*p == '-' && *size > 1) {
2038 *val = simple_strtoul(p, &p, 0);
2042 /* We don't know if the next char is whitespace thus we may accept
2043 * invalid integers (e.g. 1234...a) or two integers instead of one
2044 * (e.g. 123...1). So lets not allow such large numbers. */
2045 if (len == TMPBUFLEN - 1)
2048 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
2051 if (tr && (len < *size))
2061 * proc_put_long - converts an integer to a decimal ASCII formatted string
2063 * @buf: the user buffer
2064 * @size: the size of the user buffer
2065 * @val: the integer to be converted
2066 * @neg: sign of the number, %TRUE for negative
2068 * In case of success %0 is returned and @buf and @size are updated with
2069 * the amount of bytes written.
2071 static int proc_put_long(void __user **buf, size_t *size, unsigned long val,
2075 char tmp[TMPBUFLEN], *p = tmp;
2077 sprintf(p, "%s%lu", neg ? "-" : "", val);
2081 if (copy_to_user(*buf, tmp, len))
2089 static int proc_put_char(void __user **buf, size_t *size, char c)
2092 char __user **buffer = (char __user **)buf;
2093 if (put_user(c, *buffer))
2095 (*size)--, (*buffer)++;
2101 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
2103 int write, void *data)
2107 if (*lvalp > (unsigned long) INT_MAX + 1)
2111 if (*lvalp > (unsigned long) INT_MAX)
2119 *lvalp = -(unsigned long)val;
2122 *lvalp = (unsigned long)val;
2128 static int do_proc_douintvec_conv(bool *negp, unsigned long *lvalp,
2130 int write, void *data)
2137 unsigned int val = *valp;
2138 *lvalp = (unsigned long)val;
2143 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
2145 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
2146 int write, void __user *buffer,
2147 size_t *lenp, loff_t *ppos,
2148 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2149 int write, void *data),
2152 int *i, vleft, first = 1, err = 0;
2154 char *kbuf = NULL, *p;
2156 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
2161 i = (int *) tbl_data;
2162 vleft = table->maxlen / sizeof(*i);
2166 conv = do_proc_dointvec_conv;
2170 switch (sysctl_writes_strict) {
2171 case SYSCTL_WRITES_STRICT:
2173 case SYSCTL_WRITES_WARN:
2174 warn_sysctl_write(table);
2181 if (left > PAGE_SIZE - 1)
2182 left = PAGE_SIZE - 1;
2183 p = kbuf = memdup_user_nul(buffer, left);
2185 return PTR_ERR(kbuf);
2188 for (; left && vleft--; i++, first=0) {
2193 left -= proc_skip_spaces(&p);
2197 err = proc_get_long(&p, &left, &lval, &neg,
2199 sizeof(proc_wspace_sep), NULL);
2202 if (conv(&neg, &lval, i, 1, data)) {
2207 if (conv(&neg, &lval, i, 0, data)) {
2212 err = proc_put_char(&buffer, &left, '\t');
2215 err = proc_put_long(&buffer, &left, lval, neg);
2221 if (!write && !first && left && !err)
2222 err = proc_put_char(&buffer, &left, '\n');
2223 if (write && !err && left)
2224 left -= proc_skip_spaces(&p);
2228 return err ? : -EINVAL;
2236 static int do_proc_dointvec(struct ctl_table *table, int write,
2237 void __user *buffer, size_t *lenp, loff_t *ppos,
2238 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
2239 int write, void *data),
2242 return __do_proc_dointvec(table->data, table, write,
2243 buffer, lenp, ppos, conv, data);
2247 * proc_dointvec - read a vector of integers
2248 * @table: the sysctl table
2249 * @write: %TRUE if this is a write to the sysctl file
2250 * @buffer: the user buffer
2251 * @lenp: the size of the user buffer
2252 * @ppos: file position
2254 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2255 * values from/to the user buffer, treated as an ASCII string.
2257 * Returns 0 on success.
2259 int proc_dointvec(struct ctl_table *table, int write,
2260 void __user *buffer, size_t *lenp, loff_t *ppos)
2262 return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
2266 * proc_douintvec - read a vector of unsigned integers
2267 * @table: the sysctl table
2268 * @write: %TRUE if this is a write to the sysctl file
2269 * @buffer: the user buffer
2270 * @lenp: the size of the user buffer
2271 * @ppos: file position
2273 * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
2274 * values from/to the user buffer, treated as an ASCII string.
2276 * Returns 0 on success.
2278 int proc_douintvec(struct ctl_table *table, int write,
2279 void __user *buffer, size_t *lenp, loff_t *ppos)
2281 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2282 do_proc_douintvec_conv, NULL);
2286 * Taint values can only be increased
2287 * This means we can safely use a temporary.
2289 static int proc_taint(struct ctl_table *table, int write,
2290 void __user *buffer, size_t *lenp, loff_t *ppos)
2293 unsigned long tmptaint = get_taint();
2296 if (write && !capable(CAP_SYS_ADMIN))
2301 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
2307 * Poor man's atomic or. Not worth adding a primitive
2308 * to everyone's atomic.h for this
2311 for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) {
2312 if ((tmptaint >> i) & 1)
2313 add_taint(i, LOCKDEP_STILL_OK);
2320 #ifdef CONFIG_PRINTK
2321 static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
2322 void __user *buffer, size_t *lenp, loff_t *ppos)
2324 if (write && !capable(CAP_SYS_ADMIN))
2327 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2331 struct do_proc_dointvec_minmax_conv_param {
2336 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
2338 int write, void *data)
2340 struct do_proc_dointvec_minmax_conv_param *param = data;
2342 int val = *negp ? -*lvalp : *lvalp;
2343 if ((param->min && *param->min > val) ||
2344 (param->max && *param->max < val))
2351 *lvalp = -(unsigned long)val;
2354 *lvalp = (unsigned long)val;
2361 * proc_dointvec_minmax - read a vector of integers with min/max values
2362 * @table: the sysctl table
2363 * @write: %TRUE if this is a write to the sysctl file
2364 * @buffer: the user buffer
2365 * @lenp: the size of the user buffer
2366 * @ppos: file position
2368 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2369 * values from/to the user buffer, treated as an ASCII string.
2371 * This routine will ensure the values are within the range specified by
2372 * table->extra1 (min) and table->extra2 (max).
2374 * Returns 0 on success.
2376 int proc_dointvec_minmax(struct ctl_table *table, int write,
2377 void __user *buffer, size_t *lenp, loff_t *ppos)
2379 struct do_proc_dointvec_minmax_conv_param param = {
2380 .min = (int *) table->extra1,
2381 .max = (int *) table->extra2,
2383 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2384 do_proc_dointvec_minmax_conv, ¶m);
2387 static void validate_coredump_safety(void)
2389 #ifdef CONFIG_COREDUMP
2390 if (suid_dumpable == SUID_DUMP_ROOT &&
2391 core_pattern[0] != '/' && core_pattern[0] != '|') {
2393 "Unsafe core_pattern used with fs.suid_dumpable=2.\n"
2394 "Pipe handler or fully qualified core dump path required.\n"
2395 "Set kernel.core_pattern before fs.suid_dumpable.\n"
2401 static int proc_dointvec_minmax_coredump(struct ctl_table *table, int write,
2402 void __user *buffer, size_t *lenp, loff_t *ppos)
2404 int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2406 validate_coredump_safety();
2410 #ifdef CONFIG_COREDUMP
2411 static int proc_dostring_coredump(struct ctl_table *table, int write,
2412 void __user *buffer, size_t *lenp, loff_t *ppos)
2414 int error = proc_dostring(table, write, buffer, lenp, ppos);
2416 validate_coredump_safety();
2421 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write,
2422 void __user *buffer,
2423 size_t *lenp, loff_t *ppos,
2424 unsigned long convmul,
2425 unsigned long convdiv)
2427 unsigned long *i, *min, *max;
2428 int vleft, first = 1, err = 0;
2430 char *kbuf = NULL, *p;
2432 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
2437 i = (unsigned long *) data;
2438 min = (unsigned long *) table->extra1;
2439 max = (unsigned long *) table->extra2;
2440 vleft = table->maxlen / sizeof(unsigned long);
2445 switch (sysctl_writes_strict) {
2446 case SYSCTL_WRITES_STRICT:
2448 case SYSCTL_WRITES_WARN:
2449 warn_sysctl_write(table);
2456 if (left > PAGE_SIZE - 1)
2457 left = PAGE_SIZE - 1;
2458 p = kbuf = memdup_user_nul(buffer, left);
2460 return PTR_ERR(kbuf);
2463 for (; left && vleft--; i++, first = 0) {
2469 left -= proc_skip_spaces(&p);
2471 err = proc_get_long(&p, &left, &val, &neg,
2473 sizeof(proc_wspace_sep), NULL);
2478 val = convmul * val / convdiv;
2479 if ((min && val < *min) || (max && val > *max))
2483 val = convdiv * (*i) / convmul;
2485 err = proc_put_char(&buffer, &left, '\t');
2489 err = proc_put_long(&buffer, &left, val, false);
2495 if (!write && !first && left && !err)
2496 err = proc_put_char(&buffer, &left, '\n');
2498 left -= proc_skip_spaces(&p);
2502 return err ? : -EINVAL;
2510 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
2511 void __user *buffer,
2512 size_t *lenp, loff_t *ppos,
2513 unsigned long convmul,
2514 unsigned long convdiv)
2516 return __do_proc_doulongvec_minmax(table->data, table, write,
2517 buffer, lenp, ppos, convmul, convdiv);
2521 * proc_doulongvec_minmax - read a vector of long integers with min/max values
2522 * @table: the sysctl table
2523 * @write: %TRUE if this is a write to the sysctl file
2524 * @buffer: the user buffer
2525 * @lenp: the size of the user buffer
2526 * @ppos: file position
2528 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2529 * values from/to the user buffer, treated as an ASCII string.
2531 * This routine will ensure the values are within the range specified by
2532 * table->extra1 (min) and table->extra2 (max).
2534 * Returns 0 on success.
2536 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2537 void __user *buffer, size_t *lenp, loff_t *ppos)
2539 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
2543 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
2544 * @table: the sysctl table
2545 * @write: %TRUE if this is a write to the sysctl file
2546 * @buffer: the user buffer
2547 * @lenp: the size of the user buffer
2548 * @ppos: file position
2550 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
2551 * values from/to the user buffer, treated as an ASCII string. The values
2552 * are treated as milliseconds, and converted to jiffies when they are stored.
2554 * This routine will ensure the values are within the range specified by
2555 * table->extra1 (min) and table->extra2 (max).
2557 * Returns 0 on success.
2559 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2560 void __user *buffer,
2561 size_t *lenp, loff_t *ppos)
2563 return do_proc_doulongvec_minmax(table, write, buffer,
2564 lenp, ppos, HZ, 1000l);
2568 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
2570 int write, void *data)
2573 if (*lvalp > LONG_MAX / HZ)
2575 *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
2581 lval = -(unsigned long)val;
2584 lval = (unsigned long)val;
2591 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
2593 int write, void *data)
2596 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
2598 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
2604 lval = -(unsigned long)val;
2607 lval = (unsigned long)val;
2609 *lvalp = jiffies_to_clock_t(lval);
2614 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
2616 int write, void *data)
2619 unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
2629 lval = -(unsigned long)val;
2632 lval = (unsigned long)val;
2634 *lvalp = jiffies_to_msecs(lval);
2640 * proc_dointvec_jiffies - read a vector of integers as seconds
2641 * @table: the sysctl table
2642 * @write: %TRUE if this is a write to the sysctl file
2643 * @buffer: the user buffer
2644 * @lenp: the size of the user buffer
2645 * @ppos: file position
2647 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2648 * values from/to the user buffer, treated as an ASCII string.
2649 * The values read are assumed to be in seconds, and are converted into
2652 * Returns 0 on success.
2654 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2655 void __user *buffer, size_t *lenp, loff_t *ppos)
2657 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2658 do_proc_dointvec_jiffies_conv,NULL);
2662 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
2663 * @table: the sysctl table
2664 * @write: %TRUE if this is a write to the sysctl file
2665 * @buffer: the user buffer
2666 * @lenp: the size of the user buffer
2667 * @ppos: pointer to the file position
2669 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2670 * values from/to the user buffer, treated as an ASCII string.
2671 * The values read are assumed to be in 1/USER_HZ seconds, and
2672 * are converted into jiffies.
2674 * Returns 0 on success.
2676 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2677 void __user *buffer, size_t *lenp, loff_t *ppos)
2679 return do_proc_dointvec(table,write,buffer,lenp,ppos,
2680 do_proc_dointvec_userhz_jiffies_conv,NULL);
2684 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
2685 * @table: the sysctl table
2686 * @write: %TRUE if this is a write to the sysctl file
2687 * @buffer: the user buffer
2688 * @lenp: the size of the user buffer
2689 * @ppos: file position
2690 * @ppos: the current position in the file
2692 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
2693 * values from/to the user buffer, treated as an ASCII string.
2694 * The values read are assumed to be in 1/1000 seconds, and
2695 * are converted into jiffies.
2697 * Returns 0 on success.
2699 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2700 void __user *buffer, size_t *lenp, loff_t *ppos)
2702 return do_proc_dointvec(table, write, buffer, lenp, ppos,
2703 do_proc_dointvec_ms_jiffies_conv, NULL);
2706 static int proc_do_cad_pid(struct ctl_table *table, int write,
2707 void __user *buffer, size_t *lenp, loff_t *ppos)
2709 struct pid *new_pid;
2713 tmp = pid_vnr(cad_pid);
2715 r = __do_proc_dointvec(&tmp, table, write, buffer,
2716 lenp, ppos, NULL, NULL);
2720 new_pid = find_get_pid(tmp);
2724 put_pid(xchg(&cad_pid, new_pid));
2729 * proc_do_large_bitmap - read/write from/to a large bitmap
2730 * @table: the sysctl table
2731 * @write: %TRUE if this is a write to the sysctl file
2732 * @buffer: the user buffer
2733 * @lenp: the size of the user buffer
2734 * @ppos: file position
2736 * The bitmap is stored at table->data and the bitmap length (in bits)
2739 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
2740 * large bitmaps may be represented in a compact manner. Writing into
2741 * the file will clear the bitmap then update it with the given input.
2743 * Returns 0 on success.
2745 int proc_do_large_bitmap(struct ctl_table *table, int write,
2746 void __user *buffer, size_t *lenp, loff_t *ppos)
2750 size_t left = *lenp;
2751 unsigned long bitmap_len = table->maxlen;
2752 unsigned long *bitmap = *(unsigned long **) table->data;
2753 unsigned long *tmp_bitmap = NULL;
2754 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
2756 if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
2764 if (left > PAGE_SIZE - 1)
2765 left = PAGE_SIZE - 1;
2767 p = kbuf = memdup_user_nul(buffer, left);
2769 return PTR_ERR(kbuf);
2771 tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
2777 proc_skip_char(&p, &left, '\n');
2778 while (!err && left) {
2779 unsigned long val_a, val_b;
2782 err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
2786 if (val_a >= bitmap_len || neg) {
2798 err = proc_get_long(&p, &left, &val_b,
2799 &neg, tr_b, sizeof(tr_b),
2803 if (val_b >= bitmap_len || neg ||
2814 bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
2816 proc_skip_char(&p, &left, '\n');
2820 unsigned long bit_a, bit_b = 0;
2823 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
2824 if (bit_a >= bitmap_len)
2826 bit_b = find_next_zero_bit(bitmap, bitmap_len,
2830 err = proc_put_char(&buffer, &left, ',');
2834 err = proc_put_long(&buffer, &left, bit_a, false);
2837 if (bit_a != bit_b) {
2838 err = proc_put_char(&buffer, &left, '-');
2841 err = proc_put_long(&buffer, &left, bit_b, false);
2849 err = proc_put_char(&buffer, &left, '\n');
2855 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
2857 bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
2869 #else /* CONFIG_PROC_SYSCTL */
2871 int proc_dostring(struct ctl_table *table, int write,
2872 void __user *buffer, size_t *lenp, loff_t *ppos)
2877 int proc_dointvec(struct ctl_table *table, int write,
2878 void __user *buffer, size_t *lenp, loff_t *ppos)
2883 int proc_douintvec(struct ctl_table *table, int write,
2884 void __user *buffer, size_t *lenp, loff_t *ppos)
2889 int proc_dointvec_minmax(struct ctl_table *table, int write,
2890 void __user *buffer, size_t *lenp, loff_t *ppos)
2895 int proc_dointvec_jiffies(struct ctl_table *table, int write,
2896 void __user *buffer, size_t *lenp, loff_t *ppos)
2901 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
2902 void __user *buffer, size_t *lenp, loff_t *ppos)
2907 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
2908 void __user *buffer, size_t *lenp, loff_t *ppos)
2913 int proc_doulongvec_minmax(struct ctl_table *table, int write,
2914 void __user *buffer, size_t *lenp, loff_t *ppos)
2919 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
2920 void __user *buffer,
2921 size_t *lenp, loff_t *ppos)
2927 #endif /* CONFIG_PROC_SYSCTL */
2930 * No sense putting this after each symbol definition, twice,
2931 * exception granted :-)
2933 EXPORT_SYMBOL(proc_dointvec);
2934 EXPORT_SYMBOL(proc_douintvec);
2935 EXPORT_SYMBOL(proc_dointvec_jiffies);
2936 EXPORT_SYMBOL(proc_dointvec_minmax);
2937 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2938 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2939 EXPORT_SYMBOL(proc_dostring);
2940 EXPORT_SYMBOL(proc_doulongvec_minmax);
2941 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);