From c3e0ef9a298e028a82ada28101ccd5cf64d209ee Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 15 Dec 2011 14:56:10 +0100 Subject: [S390] fix cputime overflow in uptime_proc_show For 32-bit architectures using standard jiffies the idletime calculation in uptime_proc_show will quickly overflow. It takes (2^32 / HZ) seconds of idle-time, or e.g. 12.45 days with no load on a quad-core with HZ=1000. Switch to 64-bit calculations. Cc: stable@vger.kernel.org Cc: Michael Abbott Signed-off-by: Martin Schwidefsky --- fs/proc/uptime.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c index ac52436..ab51510 100644 --- a/fs/proc/uptime.c +++ b/fs/proc/uptime.c @@ -11,15 +11,20 @@ static int uptime_proc_show(struct seq_file *m, void *v) { struct timespec uptime; struct timespec idle; + cputime64_t idletime; + u64 nsec; + u32 rem; int i; - cputime_t idletime = 0; + idletime = 0; for_each_possible_cpu(i) idletime += kstat_cpu(i).cpustat.idle; do_posix_clock_monotonic_gettime(&uptime); monotonic_to_bootbased(&uptime); - cputime_to_timespec(idletime, &idle); + nsec = cputime64_to_jiffies64(idletime) * TICK_NSEC; + idle.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem); + idle.tv_nsec = rem; seq_printf(m, "%lu.%02lu %lu.%02lu\n", (unsigned long) uptime.tv_sec, (uptime.tv_nsec / (NSEC_PER_SEC / 100)), -- cgit v1.1