1 files changed, 45 insertions, 0 deletions
diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c
new file mode 100644
index 000000000000..df26aa88fa47
--- /dev/null
+++ b/fs/proc/uptime.c
@@ -0,0 +1,45 @@
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <asm/cputime.h>
+
+static int proc_calc_metrics(char *page, char **start, off_t off,
+				 int count, int *eof, int len)
+{
+	if (len <= off + count)
+		*eof = 1;
+	*start = page + off;
+	len -= off;
+	if (len > count)
+		len = count;
+	if (len < 0)
+		len = 0;
+	return len;
+}
+
+static int uptime_read_proc(char *page, char **start, off_t off, int count,
+			    int *eof, void *data)
+{
+	struct timespec uptime;
+	struct timespec idle;
+	int len;
+	cputime_t idletime = cputime_add(init_task.utime, init_task.stime);
+
+	do_posix_clock_monotonic_gettime(&uptime);
+	monotonic_to_bootbased(&uptime);
+	cputime_to_timespec(idletime, &idle);
+	len = sprintf(page, "%lu.%02lu %lu.%02lu\n",
+			(unsigned long) uptime.tv_sec,
+			(uptime.tv_nsec / (NSEC_PER_SEC / 100)),
+			(unsigned long) idle.tv_sec,
+			(idle.tv_nsec / (NSEC_PER_SEC / 100)));
+	return proc_calc_metrics(page, start, off, count, eof, len);
+}
+
+static int __init proc_uptime_init(void)
+{
+	create_proc_read_entry("uptime", 0, NULL, uptime_read_proc, NULL);
+	return 0;
+}
+module_init(proc_uptime_init);