1// SPDX-License-Identifier: GPL-2.0 2#include <linux/fs.h> 3#include <linux/init.h> 4#include <linux/proc_fs.h> 5#include <linux/sched.h> 6#include <linux/seq_file.h> 7#include <linux/time.h> 8#include <linux/time_namespace.h> 9#include <linux/kernel_stat.h> 10 11static int uptime_proc_show(struct seq_file *m, void *v) 12{ 13 struct timespec64 uptime; 14 struct timespec64 idle; 15 u64 idle_nsec; 16 u32 rem; 17 int i; 18 19 idle_nsec = 0; 20 for_each_possible_cpu(i) { 21 struct kernel_cpustat kcs; 22 23 kcpustat_cpu_fetch(&kcs, i); 24 idle_nsec += get_idle_time(&kcs, i); 25 } 26 27 ktime_get_boottime_ts64(&uptime); 28 timens_add_boottime(&uptime); 29 30 idle.tv_sec = div_u64_rem(idle_nsec, NSEC_PER_SEC, &rem); 31 idle.tv_nsec = rem; 32 seq_printf(m, "%lu.%02lu %lu.%02lu\n", 33 (unsigned long) uptime.tv_sec, 34 (uptime.tv_nsec / (NSEC_PER_SEC / 100)), 35 (unsigned long) idle.tv_sec, 36 (idle.tv_nsec / (NSEC_PER_SEC / 100))); 37 return 0; 38} 39 40static int __init proc_uptime_init(void) 41{ 42 proc_create_single("uptime", 0, NULL, uptime_proc_show); 43 return 0; 44} 45fs_initcall(proc_uptime_init); 46