/* * sysctl.c: General linux system control interface * * Begun 24 March 1995, Stephen Tweedie * Added /proc support, Dec 1995 * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas. * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver. * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver. * Dynamic registration fixes, Stephen Tweedie. * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn. * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris * Horn. * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer. * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer. * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill * Wendling. * The list_for_each() macro wasn't appropriate for the sysctl loop. * Removed it and replaced it with older style, 03/23/00, Bill Wendling */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_X86 #include #include #include #endif #ifdef CONFIG_BSD_PROCESS_ACCT #include #endif #ifdef CONFIG_RT_MUTEXES #include #endif #if defined(CONFIG_PROVE_LOCKING) || defined(CONFIG_LOCK_STAT) #include #endif #ifdef CONFIG_CHR_DEV_SG #include #endif #ifdef CONFIG_LOCKUP_DETECTOR #include #endif #if defined(CONFIG_SYSCTL) /* External variables not in a header file. */ extern int sysctl_overcommit_memory; extern int sysctl_overcommit_ratio; extern int max_threads; extern int core_uses_pid; extern int suid_dumpable; extern char core_pattern[]; extern unsigned int core_pipe_limit; extern int pid_max; extern int min_free_kbytes; extern int pid_max_min, pid_max_max; extern int sysctl_drop_caches; extern int percpu_pagelist_fraction; extern int compat_log; extern int latencytop_enabled; extern int sysctl_nr_open_min, sysctl_nr_open_max; #ifndef CONFIG_MMU extern int sysctl_nr_trim_pages; #endif #ifdef CONFIG_BLOCK extern int blk_iopoll_enabled; #endif /* Constants used for minimum and maximum */ #ifdef CONFIG_LOCKUP_DETECTOR static int sixty = 60; static int neg_one = -1; #endif static int zero; static int __maybe_unused one = 1; static int __maybe_unused two = 2; static unsigned long one_ul = 1; static int one_hundred = 100; #ifdef CONFIG_PRINTK static int ten_thousand = 10000; #endif /* this is needed for the proc_doulongvec_minmax of vm_dirty_bytes */ static unsigned long dirty_bytes_min = 2 * PAGE_SIZE; /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */ static int maxolduid = 65535; static int minolduid; static int min_percpu_pagelist_fract = 8; static int ngroups_max = NGROUPS_MAX; #ifdef CONFIG_INOTIFY_USER #include #endif #ifdef CONFIG_SPARC #include #endif #ifdef CONFIG_SPARC64 extern int sysctl_tsb_ratio; #endif #ifdef __hppa__ extern int pwrsw_enabled; extern int unaligned_enabled; #endif #ifdef CONFIG_S390 #ifdef CONFIG_MATHEMU extern int sysctl_ieee_emulation_warnings; #endif extern int sysctl_userprocess_debug; extern int spin_retry; #endif #ifdef CONFIG_IA64 extern int no_unaligned_warning; extern int unaligned_dump_stack; #endif #ifdef CONFIG_PROC_SYSCTL static int proc_do_cad_pid(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); static int proc_taint(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos); #endif #ifdef CONFIG_MAGIC_SYSRQ /* Note: sysrq code uses it's own private copy */ static int __sysrq_enabled = SYSRQ_DEFAULT_ENABLE; static int sysrq_sysctl_handler(ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { int error; error = proc_dointvec(table, write, buffer, lenp, ppos); if (error) return error; if (write) sysrq_toggle_support(__sysrq_enabled); return 0; } #endif static struct ctl_table root_table[]; static struct ctl_table_root sysctl_table_root; static struct ctl_table_header root_table_header = { {{.count = 1, .ctl_table = root_table, .ctl_entry = LIST_HEAD_INIT(sysctl_table_root.default_set.list),}}, .root = &sysctl_table_root, .set = &sysctl_table_root.default_set, }; static struct ctl_table_root sysctl_table_root = { .root_list = LIST_HEAD_INIT(sysctl_table_root.root_list), .default_set.list = LIST_HEAD_INIT(root_table_header.ctl_entry), }; static struct ctl_table kern_table[]; static struct ctl_table vm_table[]; static struct ctl_table fs_table[]; static struct ctl_table debug_table[]; static struct ctl_table dev_table[]; extern struct ctl_table random_table[]; #ifdef CONFIG_EPOLL extern struct ctl_table epoll_table[]; #endif #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT int sysctl_legacy_va_layout; #endif /* The default sysctl tables: */ static struct ctl_table root_table[] = { { .procname = "kernel", .mode = 0555, .child = kern_table, }, { .procname = "vm", .mode = 0555, .child = vm_table, }, { .procname = "fs", .mode = 0555, .child = fs_table, }, { .procname = "debug", .mode = 0555, .child = debug_table, }, { .procname = "dev", .mode = 0555, .child = dev_table, }, { } }; #ifdef CONFIG_SCHED_DEBUG static int min_sched_granularity_ns = 100000; /* 100 usecs */ static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */ static int min_wakeup_granularity_ns; /* 0 usecs */ static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */ static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE; static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1; #endif #ifdef CONFIG_COMPACTION static int min_extfrag_threshold; static int max_extfrag_threshold = 1000; #endif static struct ctl_table kern_table[] = { { .procname = "sched_child_runs_first", .data = &sysctl_sched_child_runs_first, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec, }, #ifdef CONFIG_SCHED_DEBUG { .procname = "sched_min_granularity_ns", .data = &sysctl_sched_min_granularity, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = sched_proc_update_handler, .extra1 = &min_sched_granularity_ns, .extra2 = &max_sched_granularity_ns, }, { .procname = "sched_latency_ns", .data = &sysctl_sched_latency, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = sched_proc_update_handler, .extra1 = &min_sched_granularity_ns, .extra2 = &max_sched_granularity_ns, }, { .procname = "sched_wakeup_granularity_ns", .data = &sysctl_sched_wakeup_granularity, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = sched_proc_update_handler, .extra1 = &min_wakeup_granularity_ns, .extra2 = &max_wakeup_granularity_ns, }, { .procname = "sched_tunable_scaling", .data = &sysctl_sched_tunable_scaling, .maxlen = sizeof(enum sched_tunable_scaling), .mode = 0644, .proc_handler = sched_proc_update_handler, .extra1 = &min_sched_tunable_scaling, .extra2 = &max_sched_tunable_scaling, }, { .procname = "sched_migration_cost", .data = &sysctl_sched_migration_cost, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "sched_nr_migrate", .data = &sysctl_sched_nr_migrate, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "sched_time_avg", .data = &sysctl_sched_time_avg, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "sched_shares_window", .data = &sysctl_sched_shares_window, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "timer_migration", .data = &sysctl_timer_migration, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, #endif { .procname = "sched_rt_period_us", .data = &sysctl_sched_rt_period, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = sched_rt_handler, }, { .procname = "sched_rt_runtime_us", .data = &sysctl_sched_rt_runtime, .maxlen = sizeof(int), .mode = 0644, .proc_handler = sched_rt_handler, }, { .procname = "sched_compat_yield", .data = &sysctl_sched_compat_yield, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec, }, #ifdef CONFIG_SCHED_AUTOGROUP { .procname = "sched_autogroup_enabled", .data = &sysctl_sched_autogroup_enabled, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec, .extra1 = &zero, .extra2 = &one, }, #endif #ifdef CONFIG_PROVE_LOCKING { .procname = "prove_locking", .data = &prove_locking, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_LOCK_STAT { .procname = "lock_stat", .data = &lock_stat, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif { .procname = "panic", .data = &panic_timeout, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "core_uses_pid", .data = &core_uses_pid, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "core_pattern", .data = core_pattern, .maxlen = CORENAME_MAX_SIZE, .mode = 0644, .proc_handler = proc_dostring, }, { .procname = "core_pipe_limit", .data = &core_pipe_limit, .maxlen = sizeof(unsigned int), .mode = 0644, .proc_handler = proc_dointvec, }, #ifdef CONFIG_PROC_SYSCTL { .procname = "tainted", .maxlen = sizeof(long), .mode = 0644, .proc_handler = proc_taint, }, #endif #ifdef CONFIG_LATENCYTOP { .procname = "latencytop", .data = &latencytop_enabled, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_BLK_DEV_INITRD { .procname = "real-root-dev", .data = &real_root_dev, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif { .procname = "print-fatal-signals", .data = &print_fatal_signals, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #ifdef CONFIG_SPARC { .procname = "reboot-cmd", .data = reboot_command, .maxlen = 256, .mode = 0644, .proc_handler = proc_dostring, }, { .procname = "stop-a", .data = &stop_a_enabled, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "scons-poweroff", .data = &scons_pwroff, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_SPARC64 { .procname = "tsb-ratio", .data = &sysctl_tsb_ratio, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef __hppa__ { .procname = "soft-power", .data = &pwrsw_enabled, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "unaligned-trap", .data = &unaligned_enabled, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif { .procname = "ctrl-alt-del", .data = &C_A_D, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #ifdef CONFIG_FUNCTION_TRACER { .procname = "ftrace_enabled", .data = &ftrace_enabled, .maxlen = sizeof(int), .mode = 0644, .proc_handler = ftrace_enable_sysctl, }, #endif #ifdef CONFIG_STACK_TRACER { .procname = "stack_tracer_enabled", .data = &stack_tracer_enabled, .maxlen = sizeof(int), .mode = 0644, .proc_handler = stack_trace_sysctl, }, #endif #ifdef CONFIG_TRACING { .procname = "ftrace_dump_on_oops", .data = &ftrace_dump_on_oops, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_MODULES { .procname = "modprobe", .data = &modprobe_path, .maxlen = KMOD_PATH_LEN, .mode = 0644, .proc_handler = proc_dostring, }, { .procname = "modules_disabled", .data = &modules_disabled, .maxlen = sizeof(int), .mode = 0644, /* only handle a transition from default "0" to "1" */ .proc_handler = proc_dointvec_minmax, .extra1 = &one, .extra2 = &one, }, #endif #ifdef CONFIG_HOTPLUG { .procname = "hotplug", .data = &uevent_helper, .maxlen = UEVENT_HELPER_PATH_LEN, .mode = 0644, .proc_handler = proc_dostring, }, #endif #ifdef CONFIG_CHR_DEV_SG { .procname = "sg-big-buff", .data = &sg_big_buff, .maxlen = sizeof (int), .mode = 0444, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_BSD_PROCESS_ACCT { .procname = "acct", .data = &acct_parm, .maxlen = 3*sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_MAGIC_SYSRQ { .procname = "sysrq", .data = &__sysrq_enabled, .maxlen = sizeof (int), .mode = 0644, .proc_handler = sysrq_sysctl_handler, }, #endif #ifdef CONFIG_PROC_SYSCTL { .procname = "cad_pid", .data = NULL, .maxlen = sizeof (int), .mode = 0600, .proc_handler = proc_do_cad_pid, }, #endif { .procname = "threads-max", .data = &max_threads, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "random", .mode = 0555, .child = random_table, }, { .procname = "overflowuid", .data = &overflowuid, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &minolduid, .extra2 = &maxolduid, }, { .procname = "overflowgid", .data = &overflowgid, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &minolduid, .extra2 = &maxolduid, }, #ifdef CONFIG_S390 #ifdef CONFIG_MATHEMU { .procname = "ieee_emulation_warnings", .data = &sysctl_ieee_emulation_warnings, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif { .procname = "userprocess_debug", .data = &show_unhandled_signals, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif { .procname = "pid_max", .data = &pid_max, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &pid_max_min, .extra2 = &pid_max_max, }, { .procname = "panic_on_oops", .data = &panic_on_oops, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #if defined CONFIG_PRINTK { .procname = "printk", .data = &console_loglevel, .maxlen = 4*sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "printk_ratelimit", .data = &printk_ratelimit_state.interval, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "printk_ratelimit_burst", .data = &printk_ratelimit_state.burst, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "printk_delay", .data = &printk_delay_msec, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &ten_thousand, }, { .procname = "dmesg_restrict", .data = &dmesg_restrict, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, { .procname = "kptr_restrict", .data = &kptr_restrict, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &two, }, #endif { .procname = "ngroups_max", .data = &ngroups_max, .maxlen = sizeof (int), .mode = 0444, .proc_handler = proc_dointvec, }, #if defined(CONFIG_LOCKUP_DETECTOR) { .procname = "watchdog", .data = &watchdog_enabled, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dowatchdog_enabled, }, { .procname = "watchdog_thresh", .data = &softlockup_thresh, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dowatchdog_thresh, .extra1 = &neg_one, .extra2 = &sixty, }, { .procname = "softlockup_panic", .data = &softlockup_panic, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, { .procname = "nmi_watchdog", .data = &watchdog_enabled, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dowatchdog_enabled, }, #endif #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) { .procname = "unknown_nmi_panic", .data = &unknown_nmi_panic, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #if defined(CONFIG_X86) { .procname = "panic_on_unrecovered_nmi", .data = &panic_on_unrecovered_nmi, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "panic_on_io_nmi", .data = &panic_on_io_nmi, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "bootloader_type", .data = &bootloader_type, .maxlen = sizeof (int), .mode = 0444, .proc_handler = proc_dointvec, }, { .procname = "bootloader_version", .data = &bootloader_version, .maxlen = sizeof (int), .mode = 0444, .proc_handler = proc_dointvec, }, { .procname = "kstack_depth_to_print", .data = &kstack_depth_to_print, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "io_delay_type", .data = &io_delay_type, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #if defined(CONFIG_MMU) { .procname = "randomize_va_space", .data = &randomize_va_space, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #if defined(CONFIG_S390) && defined(CONFIG_SMP) { .procname = "spin_retry", .data = &spin_retry, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86) { .procname = "acpi_video_flags", .data = &acpi_realmode_flags, .maxlen = sizeof (unsigned long), .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, #endif #ifdef CONFIG_IA64 { .procname = "ignore-unaligned-usertrap", .data = &no_unaligned_warning, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "unaligned-dump-stack", .data = &unaligned_dump_stack, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_DETECT_HUNG_TASK { .procname = "hung_task_panic", .data = &sysctl_hung_task_panic, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, { .procname = "hung_task_check_count", .data = &sysctl_hung_task_check_count, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, { .procname = "hung_task_timeout_secs", .data = &sysctl_hung_task_timeout_secs, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = proc_dohung_task_timeout_secs, }, { .procname = "hung_task_warnings", .data = &sysctl_hung_task_warnings, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, #endif #ifdef CONFIG_COMPAT { .procname = "compat-log", .data = &compat_log, .maxlen = sizeof (int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_RT_MUTEXES { .procname = "max_lock_depth", .data = &max_lock_depth, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif { .procname = "poweroff_cmd", .data = &poweroff_cmd, .maxlen = POWEROFF_CMD_PATH_LEN, .mode = 0644, .proc_handler = proc_dostring, }, #ifdef CONFIG_KEYS { .procname = "keys", .mode = 0555, .child = key_sysctls, }, #endif #ifdef CONFIG_RCU_TORTURE_TEST { .procname = "rcutorture_runnable", .data = &rcutorture_runnable, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_PERF_EVENTS { .procname = "perf_event_paranoid", .data = &sysctl_perf_event_paranoid, .maxlen = sizeof(sysctl_perf_event_paranoid), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "perf_event_mlock_kb", .data = &sysctl_perf_event_mlock, .maxlen = sizeof(sysctl_perf_event_mlock), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "perf_event_max_sample_rate", .data = &sysctl_perf_event_sample_rate, .maxlen = sizeof(sysctl_perf_event_sample_rate), .mode = 0644, .proc_handler = perf_proc_update_handler, }, #endif #ifdef CONFIG_KMEMCHECK { .procname = "kmemcheck", .data = &kmemcheck_enabled, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_BLOCK { .procname = "blk_iopoll", .data = &blk_iopoll_enabled, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif { } }; static struct ctl_table vm_table[] = { { .procname = "overcommit_memory", .data = &sysctl_overcommit_memory, .maxlen = sizeof(sysctl_overcommit_memory), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "panic_on_oom", .data = &sysctl_panic_on_oom, .maxlen = sizeof(sysctl_panic_on_oom), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "oom_kill_allocating_task", .data = &sysctl_oom_kill_allocating_task, .maxlen = sizeof(sysctl_oom_kill_allocating_task), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "oom_dump_tasks", .data = &sysctl_oom_dump_tasks, .maxlen = sizeof(sysctl_oom_dump_tasks), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "overcommit_ratio", .data = &sysctl_overcommit_ratio, .maxlen = sizeof(sysctl_overcommit_ratio), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "page-cluster", .data = &page_cluster, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "dirty_background_ratio", .data = &dirty_background_ratio, .maxlen = sizeof(dirty_background_ratio), .mode = 0644, .proc_handler = dirty_background_ratio_handler, .extra1 = &zero, .extra2 = &one_hundred, }, { .procname = "dirty_background_bytes", .data = &dirty_background_bytes, .maxlen = sizeof(dirty_background_bytes), .mode = 0644, .proc_handler = dirty_background_bytes_handler, .extra1 = &one_ul, }, { .procname = "dirty_ratio", .data = &vm_dirty_ratio, .maxlen = sizeof(vm_dirty_ratio), .mode = 0644, .proc_handler = dirty_ratio_handler, .extra1 = &zero, .extra2 = &one_hundred, }, { .procname = "dirty_bytes", .data = &vm_dirty_bytes, .maxlen = sizeof(vm_dirty_bytes), .mode = 0644, .proc_handler = dirty_bytes_handler, .extra1 = &dirty_bytes_min, }, { .procname = "dirty_writeback_centisecs", .data = &dirty_writeback_interval, .maxlen = sizeof(dirty_writeback_interval), .mode = 0644, .proc_handler = dirty_writeback_centisecs_handler, }, { .procname = "dirty_expire_centisecs", .data = &dirty_expire_interval, .maxlen = sizeof(dirty_expire_interval), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "nr_pdflush_threads", .data = &nr_pdflush_threads, .maxlen = sizeof nr_pdflush_threads, .mode = 0444 /* read-only*/, .proc_handler = proc_dointvec, }, { .procname = "swappiness", .data = &vm_swappiness, .maxlen = sizeof(vm_swappiness), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one_hundred, }, #ifdef CONFIG_HUGETLB_PAGE { .procname = "nr_hugepages", .data = NULL, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = hugetlb_sysctl_handler, .extra1 = (void *)&hugetlb_zero, .extra2 = (void *)&hugetlb_infinity, }, #ifdef CONFIG_NUMA { .procname = "nr_hugepages_mempolicy", .data = NULL, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = &hugetlb_mempolicy_sysctl_handler, .extra1 = (void *)&hugetlb_zero, .extra2 = (void *)&hugetlb_infinity, }, #endif { .procname = "hugetlb_shm_group", .data = &sysctl_hugetlb_shm_group, .maxlen = sizeof(gid_t), .mode = 0644, .proc_handler = proc_dointvec, }, { .procname = "hugepages_treat_as_movable", .data = &hugepages_treat_as_movable, .maxlen = sizeof(int), .mode = 0644, .proc_handler = hugetlb_treat_movable_handler, }, { .procname = "nr_overcommit_hugepages", .data = NULL, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = hugetlb_overcommit_handler, .extra1 = (void *)&hugetlb_zero, .extra2 = (void *)&hugetlb_infinity, }, #endif { .procname = "lowmem_reserve_ratio", .data = &sysctl_lowmem_reserve_ratio, .maxlen = sizeof(sysctl_lowmem_reserve_ratio), .mode = 0644, .proc_handler = lowmem_reserve_ratio_sysctl_handler, }, { .procname = "drop_caches", .data = &sysctl_drop_caches, .maxlen = sizeof(int), .mode = 0644, .proc_handler = drop_caches_sysctl_handler, }, #ifdef CONFIG_COMPACTION { .procname = "compact_memory", .data = &sysctl_compact_memory, .maxlen = sizeof(int), .mode = 0200, .proc_handler = sysctl_compaction_handler, }, { .procname = "extfrag_threshold", .data = &sysctl_extfrag_threshold, .maxlen = sizeof(int), .mode = 0644, .proc_handler = sysctl_extfrag_handler, .extra1 = &min_extfrag_threshold, .extra2 = &max_extfrag_threshold, }, #endif /* CONFIG_COMPACTION */ { .procname = "min_free_kbytes", .data = &min_free_kbytes, .maxlen = sizeof(min_free_kbytes), .mode = 0644, .proc_handler = min_free_kbytes_sysctl_handler, .extra1 = &zero, }, { .procname = "percpu_pagelist_fraction", .data = &percpu_pagelist_fraction, .maxlen = sizeof(percpu_pagelist_fraction), .mode = 0644, .proc_handler = percpu_pagelist_fraction_sysctl_handler, .extra1 = &min_percpu_pagelist_fract, }, #ifdef CONFIG_MMU { .procname = "max_map_count", .data = &sysctl_max_map_count, .maxlen = sizeof(sysctl_max_map_count), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, }, #else { .procname = "nr_trim_pages", .data = &sysctl_nr_trim_pages, .maxlen = sizeof(sysctl_nr_trim_pages), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, }, #endif { .procname = "laptop_mode", .data = &laptop_mode, .maxlen = sizeof(laptop_mode), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, { .procname = "block_dump", .data = &block_dump, .maxlen = sizeof(block_dump), .mode = 0644, .proc_handler = proc_dointvec, .extra1 = &zero, }, { .procname = "vfs_cache_pressure", .data = &sysctl_vfs_cache_pressure, .maxlen = sizeof(sysctl_vfs_cache_pressure), .mode = 0644, .proc_handler = proc_dointvec, .extra1 = &zero, }, #ifdef HAVE_ARCH_PICK_MMAP_LAYOUT { .procname = "legacy_va_layout", .data = &sysctl_legacy_va_layout, .maxlen = sizeof(sysctl_legacy_va_layout), .mode = 0644, .proc_handler = proc_dointvec, .extra1 = &zero, }, #endif #ifdef CONFIG_NUMA { .procname = "zone_reclaim_mode", .data = &zone_reclaim_mode, .maxlen = sizeof(zone_reclaim_mode), .mode = 0644, .proc_handler = proc_dointvec, .extra1 = &zero, }, { .procname = "min_unmapped_ratio", .data = &sysctl_min_unmapped_ratio, .maxlen = sizeof(sysctl_min_unmapped_ratio), .mode = 0644, .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler, .extra1 = &zero, .extra2 = &one_hundred, }, { .procname = "min_slab_ratio", .data = &sysctl_min_slab_ratio, .maxlen = sizeof(sysctl_min_slab_ratio), .mode = 0644, .proc_handler = sysctl_min_slab_ratio_sysctl_handler, .extra1 = &zero, .extra2 = &one_hundred, }, #endif #ifdef CONFIG_SMP { .procname = "stat_interval", .data = &sysctl_stat_interval, .maxlen = sizeof(sysctl_stat_interval), .mode = 0644, .proc_handler = proc_dointvec_jiffies, }, #endif #ifdef CONFIG_MMU { .procname = "mmap_min_addr", .data = &dac_mmap_min_addr, .maxlen = sizeof(unsigned long), .mode = 0644, .proc_handler = mmap_min_addr_handler, }, #endif #ifdef CONFIG_NUMA { .procname = "numa_zonelist_order", .data = &numa_zonelist_order, .maxlen = NUMA_ZONELIST_ORDER_LEN, .mode = 0644, .proc_handler = numa_zonelist_order_handler, }, #endif #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \ (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL)) { .procname = "vdso_enabled", .data = &vdso_enabled, .maxlen = sizeof(vdso_enabled), .mode = 0644, .proc_handler = proc_dointvec, .extra1 = &zero, }, #endif #ifdef CONFIG_HIGHMEM { .procname = "highmem_is_dirtyable", .data = &vm_highmem_is_dirtyable, .maxlen = sizeof(vm_highmem_is_dirtyable), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, #endif { .procname = "scan_unevictable_pages", .data = &scan_unevictable_pages, .maxlen = sizeof(scan_unevictable_pages), .mode = 0644, .proc_handler = scan_unevictable_handler, }, #ifdef CONFIG_MEMORY_FAILURE { .procname = "memory_failure_early_kill", .data = &sysctl_memory_failure_early_kill, .maxlen = sizeof(sysctl_memory_failure_early_kill), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, { .procname = "memory_failure_recovery", .data = &sysctl_memory_failure_recovery, .maxlen = sizeof(sysctl_memory_failure_recovery), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &one, }, #endif { } }; #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE) static struct ctl_table binfmt_misc_table[] = { { } }; #endif static struct ctl_table fs_table[] = { { .procname = "inode-nr", .data = &inodes_stat, .maxlen = 2*sizeof(int), .mode = 0444, .proc_handler = proc_nr_inodes, }, { .procname = "inode-state", .data = &inodes_stat, .maxlen = 7*sizeof(int), .mode = 0444, .proc_handler = proc_nr_inodes, }, { .procname = "file-nr", .data = &files_stat, .maxlen = sizeof(files_stat), .mode = 0444, .proc_handler = proc_nr_files, }, { .procname = "file-max", .data = &files_stat.max_files, .maxlen = sizeof(files_stat.max_files), .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, { .procname = "nr_open", .data = &sysctl_nr_open, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &sysctl_nr_open_min, .extra2 = &sysctl_nr_open_max, }, { .procname = "dentry-state", .data = &dentry_stat, .maxlen = 6*sizeof(int), .mode = 0444, .proc_handler = proc_nr_dentry, }, { .procname = "overflowuid", .data = &fs_overflowuid, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &minolduid, .extra2 = &maxolduid, }, { .procname = "overflowgid", .data = &fs_overflowgid, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &minolduid, .extra2 = &maxolduid, }, #ifdef CONFIG_FILE_LOCKING { .procname = "leases-enable", .data = &leases_enable, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_DNOTIFY { .procname = "dir-notify-enable", .data = &dir_notify_enable, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_MMU #ifdef CONFIG_FILE_LOCKING { .procname = "lease-break-time", .data = &lease_break_time, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, #endif #ifdef CONFIG_AIO { .procname = "aio-nr", .data = &aio_nr, .maxlen = sizeof(aio_nr), .mode = 0444, .proc_handler = proc_doulongvec_minmax, }, { .procname = "aio-max-nr", .data = &aio_max_nr, .maxlen = sizeof(aio_max_nr), .mode = 0644, .proc_handler = proc_doulongvec_minmax, }, #endif /* CONFIG_AIO */ #ifdef CONFIG_INOTIFY_USER { .procname = "inotify", .mode = 0555, .child = inotify_table, }, #endif #ifdef CONFIG_EPOLL { .procname = "epoll", .mode = 0555, .child = epoll_table, }, #endif #endif { .procname = "suid_dumpable", .data = &suid_dumpable, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, .extra1 = &zero, .extra2 = &two, }, #if defined(CONFIG_BINFMT_MISC) || defined(CONFIG_BINFMT_MISC_MODULE) { .procname = "binfmt_misc", .mode = 0555, .child = binfmt_misc_table, }, #endif { .procname = "pipe-max-size", .data = &pipe_max_size, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &pipe_proc_fn, .extra1 = &pipe_min_size, }, { } }; static struct ctl_table debug_table[] = { #if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) || \ defined(CONFIG_S390) { .procname = "exception-trace", .data = &show_unhandled_signals, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec }, #endif #if defined(CONFIG_OPTPROBES) { .procname = "kprobes-optimization", .data = &sysctl_kprobes_optimization, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_kprobes_optimization_handler, .extra1 = &zero, .extra2 = &one, }, #endif { } }; static struct ctl_table dev_table[] = { { } }; static DEFINE_SPINLOCK(sysctl_lock); /* called under sysctl_lock */ static int use_table(struct ctl_table_header *p) { if (unlikely(p->unregistering)) return 0; p->used++; return 1; } /* called under sysctl_lock */ static void unuse_table(struct ctl_table_header *p) { if (!--p->used) if (unlikely(p->unregistering)) complete(p->unregistering); } /* called under sysctl_lock, will reacquire if has to wait */ static void start_unregistering(struct ctl_table_header *p) { /* * if p->used is 0, nobody will ever touch that entry again; * we'll eliminate all paths to it before dropping sysctl_lock */ if (unlikely(p->used)) { struct completion wait; init_completion(&wait); p->unregistering = &wait; spin_unlock(&sysctl_lock); wait_for_completion(&wait); spin_lock(&sysctl_lock); } else { /* anything non-NULL; we'll never dereference it */ p->unregistering = ERR_PTR(-EINVAL); } /* * do not remove from the list until nobody holds it; walking the * list in do_sysctl() relies on that. */ list_del_init(&p->ctl_entry); } void sysctl_head_get(struct ctl_table_header *head) { spin_lock(&sysctl_lock); head->count++; spin_unlock(&sysctl_lock); } static void free_head(struct rcu_head *rcu) { kfree(container_of(rcu, struct ctl_table_header, rcu)); } void sysctl_head_put(struct ctl_table_header *head) { spin_lock(&sysctl_lock); if (!--head->count) call_rcu(&head->rcu, free_head); spin_unlock(&sysctl_lock); } struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head) { if (!head) BUG(); spin_lock(&sysctl_lock); if (!use_table(head)) head = ERR_PTR(-ENOENT); spin_unlock(&sysctl_lock); return head; } void sysctl_head_finish(struct ctl_table_header *head) { if (!head) return; spin_lock(&sysctl_lock); unuse_table(head); spin_unlock(&sysctl_lock); } static struct ctl_table_set * lookup_header_set(struct ctl_table_root *root, struct nsproxy *namespaces) { struct ctl_table_set *set = &root->default_set; if (root->lookup) set = root->lookup(root, namespaces); return set; } static struct list_head * lookup_header_list(struct ctl_table_root *root, struct nsproxy *namespaces) { struct ctl_table_set *set = lookup_header_set(root, namespaces); return &set->list; } struct ctl_table_header *__sysctl_head_next(struct nsproxy *namespaces, struct ctl_table_header *prev) { struct ctl_table_root *root; struct list_head *header_list; struct ctl_table_header *head; struct list_head *tmp; spin_lock(&sysctl_lock); if (prev) { head = prev; tmp = &prev->ctl_entry; unuse_table(prev); goto next; } tmp = &root_table_header.ctl_entry; for (;;) { head = list_entry(tmp, struct ctl_table_header, ctl_entry); if (!use_table(head)) goto next; spin_unlock(&sysctl_lock); return head; next: root = head->root; tmp = tmp->next; header_list = lookup_header_list(root, namespaces); if (tmp != header_list) continue; do { root = list_entry(root->root_list.next, struct ctl_table_root, root_list); if (root == &sysctl_table_root) goto out; header_list = lookup_header_list(root, namespaces); } while (list_empty(header_list)); tmp = header_list->next; } out: spin_unlock(&sysctl_lock); return NULL; } struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev) { return __sysctl_head_next(current->nsproxy, prev); } void register_sysctl_root(struct ctl_table_root *root) { spin_lock(&sysctl_lock); list_add_tail(&root->root_list, &sysctl_table_root.root_list); spin_unlock(&sysctl_lock); } /* * sysctl_perm does NOT grant the superuser all rights automatically, because * some sysctl variables are readonly even to root. */ static int test_perm(int mode, int op) { if (!current_euid()) mode >>= 6; else if (in_egroup_p(0)) mode >>= 3; if ((op & ~mode & (MAY_READ|MAY_WRITE|MAY_EXEC)) == 0) return 0; return -EACCES; } int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op) { int error; int mode; error = security_sysctl(table, op & (MAY_READ | MAY_WRITE | MAY_EXEC)); if (error) return error; if (root->permissions) mode = root->permissions(root, current->nsproxy, table); else mode = table->mode; return test_perm(mode, op); } static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table) { for (; table->procname; table++) { table->parent = parent; if (table->child) sysctl_set_parent(table, table->child); } } static __init int sysctl_init(void) { sysctl_set_parent(NULL, root_table); #ifdef CONFIG_SYSCTL_SYSCALL_CHECK sysctl_check_table(current->nsproxy, root_table); #endif return 0; } core_initcall(sysctl_init); static struct ctl_table *is_branch_in(struct ctl_table *branch, struct ctl_table *table) { struct ctl_table *p; const char *s = branch->procname; /* branch should have named subdirectory as its first element */ if (!s || !branch->child) return NULL; /* ... and nothing else */ if (branch[1].procname) return NULL; /* table should contain subdirectory with the same name */ for (p = table; p->procname; p++) { if (!p->child) continue; if (p->procname && strcmp(p->procname, s) == 0) return p; } return NULL; } /* see if attaching q to p would be an improvement */ static void try_attach(struct ctl_table_header *p, struct ctl_table_header *q) { struct ctl_table *to = p->ctl_table, *by = q->ctl_table; struct ctl_table *next; int is_better = 0; int not_in_parent = !p->attached_by; while ((next = is_branch_in(by, to)) != NULL) { if (by == q->attached_by) is_better = 1; if (to == p->attached_by) not_in_parent = 1; by = by->child; to = next->child; } if (is_better && not_in_parent) { q->attached_by = by; q->attached_to = to; q->parent = p; } } /** * __register_sysctl_paths - register a sysctl hierarchy * @root: List of sysctl headers to register on * @namespaces: Data to compute which lists of sysctl entries are visible * @path: The path to the directory the sysctl table is in. * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. * * The members of the &struct ctl_table structure are used as follows: * * procname - the name of the sysctl file under /proc/sys. Set to %NULL to not * enter a sysctl file * * data - a pointer to data for use by proc_handler * * maxlen - the maximum size in bytes of the data * * mode - the file permissions for the /proc/sys file, and for sysctl(2) * * child - a pointer to the child sysctl table if this entry is a directory, or * %NULL. * * proc_handler - the text handler routine (described below) * * de - for internal use by the sysctl routines * * extra1, extra2 - extra pointers usable by the proc handler routines * * Leaf nodes in the sysctl tree will be represented by a single file * under /proc; non-leaf nodes will be represented by directories. * * sysctl(2) can automatically manage read and write requests through * the sysctl table. The data and maxlen fields of the ctl_table * struct enable minimal validation of the values being written to be * performed, and the mode field allows minimal authentication. * * There must be a proc_handler routine for any terminal nodes * mirrored under /proc/sys (non-terminals are handled by a built-in * directory handler). Several default handlers are available to * cover common cases - * * proc_dostring(), proc_dointvec(), proc_dointvec_jiffies(), * proc_dointvec_userhz_jiffies(), proc_dointvec_minmax(), * proc_doulongvec_ms_jiffies_minmax(), proc_doulongvec_minmax() * * It is the handler's job to read the input buffer from user memory * and process it. The handler should return 0 on success. * * This routine returns %NULL on a failure to register, and a pointer * to the table header on success. */ struct ctl_table_header *__register_sysctl_paths( struct ctl_table_root *root, struct nsproxy *namespaces, const struct ctl_path *path, struct ctl_table *table) { struct ctl_table_header *header; struct ctl_table *new, **prevp; unsigned int n, npath; struct ctl_table_set *set; /* Count the path components */ for (npath = 0; path[npath].procname; ++npath) ; /* * For each path component, allocate a 2-element ctl_table array. * The first array element will be filled with the sysctl entry * for this, the second will be the sentinel (procname == 0). * * We allocate everything in one go so that we don't have to * worry about freeing additional memory in unregister_sysctl_table. */ header = kzalloc(sizeof(struct ctl_table_header) + (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL); if (!header) return NULL; new = (struct ctl_table *) (header + 1); /* Now connect the dots */ prevp = &header->ctl_table; for (n = 0; n < npath; ++n, ++path) { /* Copy the procname */ new->procname = path->procname; new->mode = 0555; *prevp = new; prevp = &new->child; new += 2; } *prevp = table; header->ctl_table_arg = table; INIT_LIST_HEAD(&header->ctl_entry); header->used = 0; header->unregistering = NULL; header->root = root; sysctl_set_parent(NULL, header->ctl_table); header->count = 1; #ifdef CONFIG_SYSCTL_SYSCALL_CHECK if (sysctl_check_table(namespaces, header->ctl_table)) { kfree(header); return NULL; } #endif spin_lock(&sysctl_lock); header->set = lookup_header_set(root, namespaces); header->attached_by = header->ctl_table; header->attached_to = root_table; header->parent = &root_table_header; for (set = header->set; set; set = set->parent) { struct ctl_table_header *p; list_for_each_entry(p, &set->list, ctl_entry) { if (p->unregistering) continue; try_attach(p, header); } } header->parent->count++; list_add_tail(&header->ctl_entry, &header->set->list); spin_unlock(&sysctl_lock); return header; } /** * register_sysctl_table_path - register a sysctl table hierarchy * @path: The path to the directory the sysctl table is in. * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. * * See __register_sysctl_paths for more details. */ struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, struct ctl_table *table) { return __register_sysctl_paths(&sysctl_table_root, current->nsproxy, path, table); } /** * register_sysctl_table - register a sysctl table hierarchy * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table * array. A completely 0 filled entry terminates the table. * * See register_sysctl_paths for more details. */ struct ctl_table_header *register_sysctl_table(struct ctl_table *table) { static const struct ctl_path null_path[] = { {} }; return register_sysctl_paths(null_path, table); } /** * unregister_sysctl_table - unregister a sysctl table hierarchy * @header: the header returned from register_sysctl_table * * Unregisters the sysctl table and all children. proc entries may not * actually be removed until they are no longer used by anyone. */ void unregister_sysctl_table(struct ctl_table_header * header) { might_sleep(); if (header == NULL) return; spin_lock(&sysctl_lock); start_unregistering(header); if (!--header->parent->count) { WARN_ON(1); call_rcu(&header->parent->rcu, free_head); } if (!--header->count) call_rcu(&header->rcu, free_head); spin_unlock(&sysctl_lock); } int sysctl_is_seen(struct ctl_table_header *p) { struct ctl_table_set *set = p->set; int res; spin_lock(&sysctl_lock); if (p->unregistering) res = 0; else if (!set->is_seen) res = 1; else res = set->is_seen(set); spin_unlock(&sysctl_lock); return res; } void setup_sysctl_set(struct ctl_table_set *p, struct ctl_table_set *parent, int (*is_seen)(struct ctl_table_set *)) { INIT_LIST_HEAD(&p->list); p->parent = parent ? parent : &sysctl_table_root.default_set; p->is_seen = is_seen; } #else /* !CONFIG_SYSCTL */ struct ctl_table_header *register_sysctl_table(struct ctl_table * table) { return NULL; } struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, struct ctl_table *table) { return NULL; } void unregister_sysctl_table(struct ctl_table_header * table) { } void setup_sysctl_set(struct ctl_table_set *p, struct ctl_table_set *parent, int (*is_seen)(struct ctl_table_set *)) { } void sysctl_head_put(struct ctl_table_header *head) { } #endif /* CONFIG_SYSCTL */ /* * /proc/sys support */ #ifdef CONFIG_PROC_SYSCTL static int _proc_do_string(void* data, int maxlen, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { size_t len; char __user *p; char c; if (!data || !maxlen || !*lenp) { *lenp = 0; return 0; } if (write) { len = 0; p = buffer; while (len < *lenp) { if (get_user(c, p++)) return -EFAULT; if (c == 0 || c == '\n') break; len++; } if (len >= maxlen) len = maxlen-1; if(copy_from_user(data, buffer, len)) return -EFAULT; ((char *) data)[len] = 0; *ppos += *lenp; } else { len = strlen(data); if (len > maxlen) len = maxlen; if (*ppos > len) { *lenp = 0; return 0; } data += *ppos; len -= *ppos; if (len > *lenp) len = *lenp; if (len) if(copy_to_user(buffer, data, len)) return -EFAULT; if (len < *lenp) { if(put_user('\n', ((char __user *) buffer) + len)) return -EFAULT; len++; } *lenp = len; *ppos += len; } return 0; } /** * proc_dostring - read a string sysctl * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position * * Reads/writes a string from/to the user buffer. If the kernel * buffer provided is not large enough to hold the string, the * string is truncated. The copied string is %NULL-terminated. * If the string is being read by the user process, it is copied * and a newline '\n' is added. It is truncated if the buffer is * not large enough. * * Returns 0 on success. */ int proc_dostring(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return _proc_do_string(table->data, table->maxlen, write, buffer, lenp, ppos); } static size_t proc_skip_spaces(char **buf) { size_t ret; char *tmp = skip_spaces(*buf); ret = tmp - *buf; *buf = tmp; return ret; } static void proc_skip_char(char **buf, size_t *size, const char v) { while (*size) { if (**buf != v) break; (*size)--; (*buf)++; } } #define TMPBUFLEN 22 /** * proc_get_long - reads an ASCII formatted integer from a user buffer * * @buf: a kernel buffer * @size: size of the kernel buffer * @val: this is where the number will be stored * @neg: set to %TRUE if number is negative * @perm_tr: a vector which contains the allowed trailers * @perm_tr_len: size of the perm_tr vector * @tr: pointer to store the trailer character * * In case of success %0 is returned and @buf and @size are updated with * the amount of bytes read. If @tr is non-NULL and a trailing * character exists (size is non-zero after returning from this * function), @tr is updated with the trailing character. */ static int proc_get_long(char **buf, size_t *size, unsigned long *val, bool *neg, const char *perm_tr, unsigned perm_tr_len, char *tr) { int len; char *p, tmp[TMPBUFLEN]; if (!*size) return -EINVAL; len = *size; if (len > TMPBUFLEN - 1) len = TMPBUFLEN - 1; memcpy(tmp, *buf, len); tmp[len] = 0; p = tmp; if (*p == '-' && *size > 1) { *neg = true; p++; } else *neg = false; if (!isdigit(*p)) return -EINVAL; *val = simple_strtoul(p, &p, 0); len = p - tmp; /* We don't know if the next char is whitespace thus we may accept * invalid integers (e.g. 1234...a) or two integers instead of one * (e.g. 123...1). So lets not allow such large numbers. */ if (len == TMPBUFLEN - 1) return -EINVAL; if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len)) return -EINVAL; if (tr && (len < *size)) *tr = *p; *buf += len; *size -= len; return 0; } /** * proc_put_long - converts an integer to a decimal ASCII formatted string * * @buf: the user buffer * @size: the size of the user buffer * @val: the integer to be converted * @neg: sign of the number, %TRUE for negative * * In case of success %0 is returned and @buf and @size are updated with * the amount of bytes written. */ static int proc_put_long(void __user **buf, size_t *size, unsigned long val, bool neg) { int len; char tmp[TMPBUFLEN], *p = tmp; sprintf(p, "%s%lu", neg ? "-" : "", val); len = strlen(tmp); if (len > *size) len = *size; if (copy_to_user(*buf, tmp, len)) return -EFAULT; *size -= len; *buf += len; return 0; } #undef TMPBUFLEN static int proc_put_char(void __user **buf, size_t *size, char c) { if (*size) { char __user **buffer = (char __user **)buf; if (put_user(c, *buffer)) return -EFAULT; (*size)--, (*buffer)++; *buf = *buffer; } return 0; } static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { if (write) { *valp = *negp ? -*lvalp : *lvalp; } else { int val = *valp; if (val < 0) { *negp = true; *lvalp = (unsigned long)-val; } else { *negp = false; *lvalp = (unsigned long)val; } } return 0; } static const char proc_wspace_sep[] = { ' ', '\t', '\n' }; static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos, int (*conv)(bool *negp, unsigned long *lvalp, int *valp, int write, void *data), void *data) { int *i, vleft, first = 1, err = 0; unsigned long page = 0; size_t left; char *kbuf; if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) { *lenp = 0; return 0; } i = (int *) tbl_data; vleft = table->maxlen / sizeof(*i); left = *lenp; if (!conv) conv = do_proc_dointvec_conv; if (write) { if (left > PAGE_SIZE - 1) left = PAGE_SIZE - 1; page = __get_free_page(GFP_TEMPORARY); kbuf = (char *) page; if (!kbuf) return -ENOMEM; if (copy_from_user(kbuf, buffer, left)) { err = -EFAULT; goto free; } kbuf[left] = 0; } for (; left && vleft--; i++, first=0) { unsigned long lval; bool neg; if (write) { left -= proc_skip_spaces(&kbuf); if (!left) break; err = proc_get_long(&kbuf, &left, &lval, &neg, proc_wspace_sep, sizeof(proc_wspace_sep), NULL); if (err) break; if (conv(&neg, &lval, i, 1, data)) { err = -EINVAL; break; } } else { if (conv(&neg, &lval, i, 0, data)) { err = -EINVAL; break; } if (!first) err = proc_put_char(&buffer, &left, '\t'); if (err) break; err = proc_put_long(&buffer, &left, lval, neg); if (err) break; } } if (!write && !first && left && !err) err = proc_put_char(&buffer, &left, '\n'); if (write && !err && left) left -= proc_skip_spaces(&kbuf); free: if (write) { free_page(page); if (first) return err ? : -EINVAL; } *lenp -= left; *ppos += *lenp; return err; } static int do_proc_dointvec(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos, int (*conv)(bool *negp, unsigned long *lvalp, int *valp, int write, void *data), void *data) { return __do_proc_dointvec(table->data, table, write, buffer, lenp, ppos, conv, data); } /** * proc_dointvec - read a vector of integers * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position * * Reads/writes up to table->maxlen/sizeof(unsigned int) integer * values from/to the user buffer, treated as an ASCII string. * * Returns 0 on success. */ int proc_dointvec(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return do_proc_dointvec(table,write,buffer,lenp,ppos, NULL,NULL); } /* * Taint values can only be increased * This means we can safely use a temporary. */ static int proc_taint(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct ctl_table t; unsigned long tmptaint = get_taint(); int err; if (write && !capable(CAP_SYS_ADMIN)) return -EPERM; t = *table; t.data = &tmptaint; err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos); if (err < 0) return err; if (write) { /* * Poor man's atomic or. Not worth adding a primitive * to everyone's atomic.h for this */ int i; for (i = 0; i < BITS_PER_LONG && tmptaint >> i; i++) { if ((tmptaint >> i) & 1) add_taint(i); } } return err; } struct do_proc_dointvec_minmax_conv_param { int *min; int *max; }; static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { struct do_proc_dointvec_minmax_conv_param *param = data; if (write) { int val = *negp ? -*lvalp : *lvalp; if ((param->min && *param->min > val) || (param->max && *param->max < val)) return -EINVAL; *valp = val; } else { int val = *valp; if (val < 0) { *negp = true; *lvalp = (unsigned long)-val; } else { *negp = false; *lvalp = (unsigned long)val; } } return 0; } /** * proc_dointvec_minmax - read a vector of integers with min/max values * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position * * Reads/writes up to table->maxlen/sizeof(unsigned int) integer * values from/to the user buffer, treated as an ASCII string. * * This routine will ensure the values are within the range specified by * table->extra1 (min) and table->extra2 (max). * * Returns 0 on success. */ int proc_dointvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct do_proc_dointvec_minmax_conv_param param = { .min = (int *) table->extra1, .max = (int *) table->extra2, }; return do_proc_dointvec(table, write, buffer, lenp, ppos, do_proc_dointvec_minmax_conv, ¶m); } static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul, unsigned long convdiv) { unsigned long *i, *min, *max; int vleft, first = 1, err = 0; unsigned long page = 0; size_t left; char *kbuf; if (!data || !table->maxlen || !*lenp || (*ppos && !write)) { *lenp = 0; return 0; } i = (unsigned long *) data; min = (unsigned long *) table->extra1; max = (unsigned long *) table->extra2; vleft = table->maxlen / sizeof(unsigned long); left = *lenp; if (write) { if (left > PAGE_SIZE - 1) left = PAGE_SIZE - 1; page = __get_free_page(GFP_TEMPORARY); kbuf = (char *) page; if (!kbuf) return -ENOMEM; if (copy_from_user(kbuf, buffer, left)) { err = -EFAULT; goto free; } kbuf[left] = 0; } for (; left && vleft--; i++, first = 0) { unsigned long val; if (write) { bool neg; left -= proc_skip_spaces(&kbuf); err = proc_get_long(&kbuf, &left, &val, &neg, proc_wspace_sep, sizeof(proc_wspace_sep), NULL); if (err) break; if (neg) continue; if ((min && val < *min) || (max && val > *max)) continue; *i = val; } else { val = convdiv * (*i) / convmul; if (!first) err = proc_put_char(&buffer, &left, '\t'); err = proc_put_long(&buffer, &left, val, false); if (err) break; } } if (!write && !first && left && !err) err = proc_put_char(&buffer, &left, '\n'); if (write && !err) left -= proc_skip_spaces(&kbuf); free: if (write) { free_page(page); if (first) return err ? : -EINVAL; } *lenp -= left; *ppos += *lenp; return err; } static int do_proc_doulongvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul, unsigned long convdiv) { return __do_proc_doulongvec_minmax(table->data, table, write, buffer, lenp, ppos, convmul, convdiv); } /** * proc_doulongvec_minmax - read a vector of long integers with min/max values * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position * * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long * values from/to the user buffer, treated as an ASCII string. * * This routine will ensure the values are within the range specified by * table->extra1 (min) and table->extra2 (max). * * Returns 0 on success. */ int proc_doulongvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l); } /** * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position * * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long * values from/to the user buffer, treated as an ASCII string. The values * are treated as milliseconds, and converted to jiffies when they are stored. * * This routine will ensure the values are within the range specified by * table->extra1 (min) and table->extra2 (max). * * Returns 0 on success. */ int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, HZ, 1000l); } static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { if (write) { if (*lvalp > LONG_MAX / HZ) return 1; *valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ); } else { int val = *valp; unsigned long lval; if (val < 0) { *negp = true; lval = (unsigned long)-val; } else { *negp = false; lval = (unsigned long)val; } *lvalp = lval / HZ; } return 0; } static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { if (write) { if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ) return 1; *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp); } else { int val = *valp; unsigned long lval; if (val < 0) { *negp = true; lval = (unsigned long)-val; } else { *negp = false; lval = (unsigned long)val; } *lvalp = jiffies_to_clock_t(lval); } return 0; } static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp, int *valp, int write, void *data) { if (write) { *valp = msecs_to_jiffies(*negp ? -*lvalp : *lvalp); } else { int val = *valp; unsigned long lval; if (val < 0) { *negp = true; lval = (unsigned long)-val; } else { *negp = false; lval = (unsigned long)val; } *lvalp = jiffies_to_msecs(lval); } return 0; } /** * proc_dointvec_jiffies - read a vector of integers as seconds * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position * * Reads/writes up to table->maxlen/sizeof(unsigned int) integer * values from/to the user buffer, treated as an ASCII string. * The values read are assumed to be in seconds, and are converted into * jiffies. * * Returns 0 on success. */ int proc_dointvec_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return do_proc_dointvec(table,write,buffer,lenp,ppos, do_proc_dointvec_jiffies_conv,NULL); } /** * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: pointer to the file position * * Reads/writes up to table->maxlen/sizeof(unsigned int) integer * values from/to the user buffer, treated as an ASCII string. * The values read are assumed to be in 1/USER_HZ seconds, and * are converted into jiffies. * * Returns 0 on success. */ int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return do_proc_dointvec(table,write,buffer,lenp,ppos, do_proc_dointvec_userhz_jiffies_conv,NULL); } /** * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position * @ppos: the current position in the file * * Reads/writes up to table->maxlen/sizeof(unsigned int) integer * values from/to the user buffer, treated as an ASCII string. * The values read are assumed to be in 1/1000 seconds, and * are converted into jiffies. * * Returns 0 on success. */ int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return do_proc_dointvec(table, write, buffer, lenp, ppos, do_proc_dointvec_ms_jiffies_conv, NULL); } static int proc_do_cad_pid(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { struct pid *new_pid; pid_t tmp; int r; tmp = pid_vnr(cad_pid); r = __do_proc_dointvec(&tmp, table, write, buffer, lenp, ppos, NULL, NULL); if (r || !write) return r; new_pid = find_get_pid(tmp); if (!new_pid) return -ESRCH; put_pid(xchg(&cad_pid, new_pid)); return 0; } /** * proc_do_large_bitmap - read/write from/to a large bitmap * @table: the sysctl table * @write: %TRUE if this is a write to the sysctl file * @buffer: the user buffer * @lenp: the size of the user buffer * @ppos: file position * * The bitmap is stored at table->data and the bitmap length (in bits) * in table->maxlen. * * We use a range comma separated format (e.g. 1,3-4,10-10) so that * large bitmaps may be represented in a compact manner. Writing into * the file will clear the bitmap then update it with the given input. * * Returns 0 on success. */ int proc_do_large_bitmap(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { int err = 0; bool first = 1; size_t left = *lenp; unsigned long bitmap_len = table->maxlen; unsigned long *bitmap = (unsigned long *) table->data; unsigned long *tmp_bitmap = NULL; char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c; if (!bitmap_len || !left || (*ppos && !write)) { *lenp = 0; return 0; } if (write) { unsigned long page = 0; char *kbuf; if (left > PAGE_SIZE - 1) left = PAGE_SIZE - 1; page = __get_free_page(GFP_TEMPORARY); kbuf = (char *) page; if (!kbuf) return -ENOMEM; if (copy_from_user(kbuf, buffer, left)) { free_page(page); return -EFAULT; } kbuf[left] = 0; tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long), GFP_KERNEL); if (!tmp_bitmap) { free_page(page); return -ENOMEM; } proc_skip_char(&kbuf, &left, '\n'); while (!err && left) { unsigned long val_a, val_b; bool neg; err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a, sizeof(tr_a), &c); if (err) break; if (val_a >= bitmap_len || neg) { err = -EINVAL; break; } val_b = val_a; if (left) { kbuf++; left--; } if (c == '-') { err = proc_get_long(&kbuf, &left, &val_b, &neg, tr_b, sizeof(tr_b), &c); if (err) break; if (val_b >= bitmap_len || neg || val_a > val_b) { err = -EINVAL; break; } if (left) { kbuf++; left--; } } while (val_a <= val_b) set_bit(val_a++, tmp_bitmap); first = 0; proc_skip_char(&kbuf, &left, '\n'); } free_page(page); } else { unsigned long bit_a, bit_b = 0; while (left) { bit_a = find_next_bit(bitmap, bitmap_len, bit_b); if (bit_a >= bitmap_len) break; bit_b = find_next_zero_bit(bitmap, bitmap_len, bit_a + 1) - 1; if (!first) { err = proc_put_char(&buffer, &left, ','); if (err) break; } err = proc_put_long(&buffer, &left, bit_a, false); if (err) break; if (bit_a != bit_b) { err = proc_put_char(&buffer, &left, '-'); if (err) break; err = proc_put_long(&buffer, &left, bit_b, false); if (err) break; } first = 0; bit_b++; } if (!err) err = proc_put_char(&buffer, &left, '\n'); } if (!err) { if (write) { if (*ppos) bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len); else memcpy(bitmap, tmp_bitmap, BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long)); } kfree(tmp_bitmap); *lenp -= left; *ppos += *lenp; return 0; } else { kfree(tmp_bitmap); return err; } } #else /* CONFIG_PROC_SYSCTL */ int proc_dostring(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } int proc_dointvec(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } int proc_dointvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } int proc_dointvec_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } int proc_doulongvec_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { return -ENOSYS; } #endif /* CONFIG_PROC_SYSCTL */ /* * No sense putting this after each symbol definition, twice, * exception granted :-) */ EXPORT_SYMBOL(proc_dointvec); EXPORT_SYMBOL(proc_dointvec_jiffies); EXPORT_SYMBOL(proc_dointvec_minmax); EXPORT_SYMBOL(proc_dointvec_userhz_jiffies); EXPORT_SYMBOL(proc_dointvec_ms_jiffies); EXPORT_SYMBOL(proc_dostring); EXPORT_SYMBOL(proc_doulongvec_minmax); EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax); EXPORT_SYMBOL(register_sysctl_table); EXPORT_SYMBOL(register_sysctl_paths); EXPORT_SYMBOL(unregister_sysctl_table);