/proc/sys/kernel/printk
/proc/sys/kernel/printkはファイルのprocfsのinod->sysctl_entryにtable["printk"]を設定し、table["printk"].proc_handlerをコール事で実装されます。引数のログレベルはスペースを区切りとし、正負および8進数/10進数/16進数の設定が可能です。/proc/sys/kernel/printkの引数は.maxlen = 4*sizeof(int)の４つですが、引数を１つとしconsole_loglevelだけ設定する事も可能で、また、syslogシステムコール様な制限はなく、minimum_console_loglevel以下のconsole_loglevelを設定でき、console_loglevel=-1とする事で、ログレベル0のKERN_EMERG等一切のシスログの画面表示を停止できます。CONFIG_PRINTKは/proc/sys/kernel/printkについてでなく、シスログその物の実装にかかるマクロです。
extern int console_printk[]; #define console_loglevel (console_printk[0]) #define default_message_loglevel (console_printk[1]) #define minimum_console_loglevel (console_printk[2]) #define default_console_loglevel (console_printk[3])
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,
},
{ }
};
[root@localhost ~]# ls -l /proc/sys
合計 0
dr-xr-xr-x 0 root root 0 7月 28 23:25 crypto
dr-xr-xr-x 0 root root 0 7月 28 23:52 debug
dr-xr-xr-x 0 root root 0 7月 28 23:52 dev
dr-xr-xr-x 0 root root 0 7月 28 23:25 fs
dr-xr-xr-x 0 root root 0 7月 28 23:25 kernel
dr-xr-xr-x 0 root root 0 7月 28 23:25 net
dr-xr-xr-x 0 root root 0 7月 28 23:52 sunrpc
dr-xr-xr-x 0 root root 0 7月 28 23:52 vm
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,
},
#ifdef CONFIG_SCHED_AUTOGROUP
{
.procname = "sched_autogroup_enabled",
.data = &sysctl_sched_autogroup_enabled,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &zero,
.extra2 = &one,
},
#endif
#ifdef CONFIG_CFS_BANDWIDTH
{
.procname = "sched_cfs_bandwidth_slice_us",
.data = &sysctl_sched_cfs_bandwidth_slice,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = &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,
.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 = "usermodehelper",
.mode = 0555,
.child = usermodehelper_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", <----------------- /proc/sys/kernel/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_sysadmin,
.extra1 = &zero,
.extra2 = &one,
},
{
.procname = "kptr_restrict",
.data = &kptr_restrict,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax_sysadmin,
.extra1 = &zero,
.extra2 = &two,
},
#endif
{
.procname = "ngroups_max",
.data = &ngroups_max,
.maxlen = sizeof (int),
.mode = 0444,
.proc_handler = proc_dointvec,
},
{
.procname = "cap_last_cap",
.data = (void *)&cap_last_cap,
.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,
.extra1 = &zero,
.extra2 = &one,
},
{
.procname = "watchdog_thresh",
.data = &watchdog_thresh,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dowatchdog,
.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,
.extra1 = &zero,
.extra2 = &one,
},
#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,
},
#ifdef CONFIG_DEBUG_STACKOVERFLOW
{
.procname = "panic_on_stackoverflow",
.data = &sysctl_panic_on_stackoverflow,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
#endif
{
.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
{ }
};
[root@localhost ~]# ls -l /proc/sys/kernel/
合計 0
-rw-r--r-- 1 root root 0 7月 28 23:52 acct
-rw-r--r-- 1 root root 0 7月 28 23:52 acpi_video_flags
-rw-r--r-- 1 root root 0 7月 28 23:52 auto_msgmni
-rw-r--r-- 1 root root 0 7月 28 23:52 blk_iopoll
-r--r--r-- 1 root root 0 7月 28 23:52 bootloader_type
-r--r--r-- 1 root root 0 7月 28 23:52 bootloader_version
-rw------- 1 root root 0 7月 28 23:52 cad_pid
-r--r--r-- 1 root root 0 7月 28 23:52 cap_last_cap
-rw-r--r-- 1 root root 0 7月 28 23:25 core_pattern
-rw-r--r-- 1 root root 0 7月 28 23:25 core_pipe_limit
-rw-r--r-- 1 root root 0 7月 28 23:25 core_uses_pid
-rw-r--r-- 1 root root 0 7月 28 23:52 ctrl-alt-del
-rw-r--r-- 1 root root 0 7月 28 23:52 dmesg_restrict
-rw-r--r-- 1 root root 0 7月 28 23:52 domainname
-rw-r--r-- 1 root root 0 7月 28 23:52 ftrace_dump_on_oops
-rw-r--r-- 1 root root 0 7月 28 23:52 ftrace_enabled
-rw-r--r-- 1 root root 0 7月 28 23:52 hostname
-rw-r--r-- 1 root root 0 7月 28 23:52 hotplug
-rw-r--r-- 1 root root 0 7月 28 23:52 io_delay_type
dr-xr-xr-x 0 root root 0 7月 28 23:52 keys
-rw-r--r-- 1 root root 0 7月 28 23:52 kptr_restrict
-rw-r--r-- 1 root root 0 7月 28 23:52 kstack_depth_to_print
-rw-r--r-- 1 root root 0 7月 28 23:52 latencytop
-rw-r--r-- 1 root root 0 7月 28 23:52 max_lock_depth
-rw-r--r-- 1 root root 0 7月 28 23:52 modprobe
-rw-r--r-- 1 root root 0 7月 28 23:52 modules_disabled
-rw-r--r-- 1 root root 0 7月 28 23:52 msgmax
-rw-r--r-- 1 root root 0 7月 28 23:52 msgmnb
-rw-r--r-- 1 root root 0 7月 28 23:52 msgmni
-r--r--r-- 1 root root 0 7月 28 23:25 ngroups_max
-rw-r--r-- 1 root root 0 7月 28 23:52 nmi_watchdog
-rw-rw-rw- 1 root root 0 7月 28 23:52 ns_last_pid
-r--r--r-- 1 root root 0 7月 28 23:52 osrelease
-r--r--r-- 1 root root 0 7月 28 23:52 ostype
-rw-r--r-- 1 root root 0 7月 28 23:52 overflowgid
-rw-r--r-- 1 root root 0 7月 28 23:52 overflowuid
-rw-r--r-- 1 root root 0 7月 28 23:52 panic
-rw-r--r-- 1 root root 0 7月 28 23:52 panic_on_io_nmi
-rw-r--r-- 1 root root 0 7月 28 23:52 panic_on_oops
-rw-r--r-- 1 root root 0 7月 28 23:52 panic_on_stackoverflow
-rw-r--r-- 1 root root 0 7月 28 23:52 panic_on_unrecovered_nmi
-rw-r--r-- 1 root root 0 7月 28 23:52 perf_event_max_sample_rate
-rw-r--r-- 1 root root 0 7月 28 23:52 perf_event_mlock_kb
-rw-r--r-- 1 root root 0 7月 28 23:52 perf_event_paranoid
-rw-r--r-- 1 root root 0 7月 28 23:52 pid_max
-rw-r--r-- 1 root root 0 7月 28 23:52 poweroff_cmd
-rw-r--r-- 1 root root 0 7月 28 23:52 print-fatal-signals
-rw-r--r-- 1 root root 0 7月 29 01:08 printk
-rw-r--r-- 1 root root 0 7月 28 23:52 printk_delay
-rw-r--r-- 1 root root 0 7月 28 23:52 printk_ratelimit
-rw-r--r-- 1 root root 0 7月 28 23:52 printk_ratelimit_burst
dr-xr-xr-x 0 root root 0 7月 28 23:52 pty
dr-xr-xr-x 0 root root 0 7月 28 23:25 random
-rw-r--r-- 1 root root 0 7月 28 23:52 randomize_va_space
-rw-r--r-- 1 root root 0 7月 28 23:52 real-root-dev
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_autogroup_enabled
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_cfs_bandwidth_slice_us
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_child_runs_first
dr-xr-xr-x 0 root root 0 7月 28 23:52 sched_domain
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_latency_ns
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_migration_cost
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_min_granularity_ns
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_nr_migrate
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_rt_period_us
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_rt_runtime_us
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_shares_window
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_time_avg
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_tunable_scaling
-rw-r--r-- 1 root root 0 7月 28 23:52 sched_wakeup_granularity_ns
-rw-r--r-- 1 root root 0 7月 28 23:52 sem
-r--r--r-- 1 root root 0 7月 28 23:52 sg-big-buff
-rw-r--r-- 1 root root 0 7月 28 23:52 shm_rmid_forced
-rw-r--r-- 1 root root 0 7月 28 23:52 shmall
-rw-r--r-- 1 root root 0 7月 28 23:52 shmmax
-rw-r--r-- 1 root root 0 7月 28 23:52 shmmni
-rw-r--r-- 1 root root 0 7月 28 23:52 softlockup_panic
-rw-r--r-- 1 root root 0 7月 28 23:52 stack_tracer_enabled
-rw-r--r-- 1 root root 0 7月 28 23:25 sysrq
-rw-r--r-- 1 root root 0 7月 28 23:52 tainted
-rw-r--r-- 1 root root 0 7月 28 23:52 threads-max
-rw-r--r-- 1 root root 0 7月 28 23:52 timer_migration
-rw-r--r-- 1 root root 0 7月 28 23:52 unknown_nmi_panic
dr-xr-xr-x 0 root root 0 7月 28 23:52 usermodehelper
-r--r--r-- 1 root root 0 7月 28 23:52 version
-rw-r--r-- 1 root root 0 7月 28 23:52 watchdog
-rw-r--r-- 1 root root 0 7月 28 23:52 watchdog_thresh
static const struct file_operations proc_sys_file_operations = {
.open = proc_sys_open,
.poll = proc_sys_poll,
.read = proc_sys_read,
.write = proc_sys_write,
.llseek = default_llseek,
};
static ssize_t proc_sys_read(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0);
}
static ssize_t proc_sys_write(struct file *filp, const char __user *buf,
size_t count, loff_t *ppos)
{
return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1);
}
static ssize_t proc_sys_call_handler(struct file *filp, void __user *buf,
size_t count, loff_t *ppos, int write)
{
struct inode *inode = filp->f_path.dentry->d_inode;
struct ctl_table_header *head = grab_header(inode);
struct ctl_table *table = PROC_I(inode)->sysctl_entry;
ssize_t error;
size_t res;
if (IS_ERR(head))
return PTR_ERR(head);
error = -EPERM;
if (sysctl_perm(head->root, table, write ? MAY_WRITE : MAY_READ))
goto out;
error = -EINVAL;
if (!table->proc_handler)
goto out;
res = count;
error = table->proc_handler(table, write, buf, &res, ppos);
if (!error)
error = res;
out:
sysctl_head_finish(head);
return error;
}
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);
}
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);
}
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;
}
正負および8進数/10進数/16進数の取得。
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;
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;
}
unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
{
return simple_strtoull(cp, endp, base);
}
unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
{
unsigned long long result;
unsigned int rv;
cp = _parse_integer_fixup_radix(cp, &base);
rv = _parse_integer(cp, base, &result);
cp += (rv & ~KSTRTOX_OVERFLOW);
if (endp)
*endp = (char *)cp;
return result;
}
const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
{
if (*base == 0) {
if (s[0] == '0') {
if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
*base = 16;
else
*base = 8;
} else
*base = 10;
}
if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
s += 2;
return s;
}
補足
/proc/sys下の struct ctl_table kern_table[]等のinodeを作成時、struct proc_inode *ei->sysctl_entry = tableで、掛かるファイルinodeからの参照領域の取得を実装します。
static struct inode *proc_sys_make_inode(struct super_block *sb,
struct ctl_table_header *head, struct ctl_table *table)
{
struct inode *inode;
struct proc_inode *ei;
inode = new_inode(sb);
if (!inode)
goto out;
inode->i_ino = get_next_ino();
sysctl_head_get(head);
ei = PROC_I(inode);
ei->sysctl = head;
ei->sysctl_entry = table;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->i_mode = table->mode;
if (!table->child) {
inode->i_mode |= S_IFREG;
inode->i_op = &proc_sys_inode_operations;
inode->i_fop = &proc_sys_file_operations;
} else {
inode->i_mode |= S_IFDIR;
clear_nlink(inode);
inode->i_op = &proc_sys_dir_operations;
inode->i_fop = &proc_sys_dir_file_operations;
}
out:
return inode;
}
static const struct file_operations proc_sys_dir_file_operations = {
.read = generic_read_dir,
.readdir = proc_sys_readdir,
.llseek = generic_file_llseek,
};
static int proc_sys_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct dentry *dentry = filp->f_path.dentry;
struct inode *inode = dentry->d_inode;
struct ctl_table_header *head = grab_header(inode);
struct ctl_table *table = PROC_I(inode)->sysctl_entry;
struct ctl_table_header *h = NULL;
unsigned long pos;
int ret = -EINVAL;
if (IS_ERR(head))
return PTR_ERR(head);
if (table && !table->child) {
WARN_ON(1);
goto out;
}
table = table ? table->child : head->ctl_table;
ret = 0;
if (filp->f_pos == 0) {
if (filldir(dirent, ".", 1, filp->f_pos,
inode->i_ino, DT_DIR) < 0)
goto out;
filp->f_pos++;
}
if (filp->f_pos == 1) {
if (filldir(dirent, "..", 2, filp->f_pos,
parent_ino(dentry), DT_DIR) < 0)
goto out;
filp->f_pos++;
}
pos = 2;
ret = scan(head, table, &pos, filp, dirent, filldir);
if (ret)
goto out;
for (h = sysctl_head_next(NULL); h; h = sysctl_head_next(h)) {
if (h->attached_to != table)
continue;
ret = scan(h, h->attached_by, &pos, filp, dirent, filldir);
if (ret) {
sysctl_head_finish(h);
break;
}
}
ret = 1;
out:
sysctl_head_finish(head);
return ret;
}
static int scan(struct ctl_table_header *head, ctl_table *table,
unsigned long *pos, struct file *file,
void *dirent, filldir_t filldir)
{
for (; table->procname; table++, (*pos)++) {
int res;
if (!table->procname)
continue;
if (*pos < file->f_pos)
continue;
res = proc_sys_fill_cache(file, dirent, filldir, head, table);
if (res)
return res;
file->f_pos = *pos + 1;
}
return 0;
}
static int proc_sys_fill_cache(struct file *filp, void *dirent,
filldir_t filldir,
struct ctl_table_header *head,
struct ctl_table *table)
{
struct dentry *child, *dir = filp->f_path.dentry;
struct inode *inode;
struct qstr qname;
ino_t ino = 0;
unsigned type = DT_UNKNOWN;
qname.name = table->procname;
qname.len = strlen(table->procname);
qname.hash = full_name_hash(qname.name, qname.len);
child = d_lookup(dir, &qname);
if (!child) {
child = d_alloc(dir, &qname);
if (child) {
inode = proc_sys_make_inode(dir->d_sb, head, table);
if (!inode) {
dput(child);
return -ENOMEM;
} else {
d_set_d_op(child, &proc_sys_dentry_operations);
d_add(child, inode);
}
} else {
return -ENOMEM;
}
}
inode = child->d_inode;
ino = inode->i_ino;
type = inode->i_mode >> 12;
dput(child);
return !!filldir(dirent, qname.name, qname.len, filp->f_pos, ino, type);
}
static struct inode *proc_sys_make_inode(struct super_block *sb,
struct ctl_table_header *head, struct ctl_table *table)
{
struct inode *inode;
struct proc_inode *ei;
inode = new_inode(sb);
if (!inode)
goto out;
inode->i_ino = get_next_ino();
sysctl_head_get(head);
ei = PROC_I(inode);
ei->sysctl = head;
ei->sysctl_entry = table;
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode->i_mode = table->mode;
if (!table->child) {
inode->i_mode |= S_IFREG;
inode->i_op = &proc_sys_inode_operations;
inode->i_fop = &proc_sys_file_operations;
} else {
inode->i_mode |= S_IFDIR;
clear_nlink(inode);
inode->i_op = &proc_sys_dir_operations;
inode->i_fop = &proc_sys_dir_file_operations;
}
out:
return inode;
}
補足
proc_dointvec_minmax()はdo_proc_dointvec()でのvoid *data=NULLでなく、struct ctl_table *table->extra1/extra2の最大値/最小値をチェックするdo_proc_dointvec_minmax_convをコールバックにします。
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_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;
}
