From 22bad8bbb944a2973d3fa3581198fd67c2f40eba Mon Sep 17 00:00:00 2001 From: Stanislaw Gruszka Date: Tue, 14 Sep 2010 16:35:14 +0200 Subject: sched: Fix user time incorrectly accounted as system time on 32-bit commit e75e863dd5c7d96b91ebbd241da5328fc38a78cc upstream. We have 32-bit variable overflow possibility when multiply in task_times() and thread_group_times() functions. When the overflow happens then the scaled utime value becomes erroneously small and the scaled stime becomes i erroneously big. Reported here: https://bugzilla.redhat.com/show_bug.cgi?id=633037 https://bugzilla.kernel.org/show_bug.cgi?id=16559 Reported-by: Michael Chapman Reported-by: Ciriaco Garcia de Celis Signed-off-by: Stanislaw Gruszka Signed-off-by: Peter Zijlstra Cc: Hidetoshi Seto LKML-Reference: <20100914143513.GB8415@redhat.com> Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/sched.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 6d0dbebc2d7..4fa520b111d 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3349,9 +3349,9 @@ void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) rtime = nsecs_to_cputime(p->se.sum_exec_runtime); if (total) { - u64 temp; + u64 temp = rtime; - temp = (u64)(rtime * utime); + temp *= utime; do_div(temp, total); utime = (cputime_t)temp; } else @@ -3382,9 +3382,9 @@ void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) rtime = nsecs_to_cputime(cputime.sum_exec_runtime); if (total) { - u64 temp; + u64 temp = rtime; - temp = (u64)(rtime * cputime.utime); + temp *= cputime.utime; do_div(temp, total); utime = (cputime_t)temp; } else -- cgit v1.2.3-18-g5258