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 11 static int uptime_proc_show(struct seq_file *m, void *v) 12 { 13 struct timespec64 uptime; 14 struct timespec64 idle; 15 u64 nsec; 16 u32 rem; 17 int i; 18 19 nsec = 0; 20 for_each_possible_cpu(i) 21 nsec += (__force u64) kcpustat_cpu(i).cpustat[CPUTIME_IDLE]; 22 23 ktime_get_boottime_ts64(&uptime); 24 timens_add_boottime(&uptime); 25 26 idle.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem); 27 idle.tv_nsec = rem; 28 seq_printf(m, "%lu.%02lu %lu.%02lu\n", 29 (unsigned long) uptime.tv_sec, 30 (uptime.tv_nsec / (NSEC_PER_SEC / 100)), 31 (unsigned long) idle.tv_sec, 32 (idle.tv_nsec / (NSEC_PER_SEC / 100))); 33 return 0; 34 } 35 36 static int __init proc_uptime_init(void) 37 { 38 proc_create_single("uptime", 0, NULL, uptime_proc_show); 39 return 0; 40 } 41 fs_initcall(proc_uptime_init); 42