Commit-ID: e75e863dd5c7d96b91ebbd241da5328fc38a78cc Gitweb: http://git.kernel.org/tip/e75e863dd5c7d96b91ebbd241da5328fc38a78cc Author: Stanislaw Gruszka <sgruszka@xxxxxxxxxx> AuthorDate: Tue, 14 Sep 2010 16:35:14 +0200 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Wed, 15 Sep 2010 10:41:36 +0200 sched: Fix user time incorrectly accounted as system time on 32-bit 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 <redhat-bugzilla@xxxxxxxxxxxxxxxxx> Reported-by: Ciriaco Garcia de Celis <sysman@xxxxxxxxxxxxxx> Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Hidetoshi Seto <seto.hidetoshi@xxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxx> # 2.6.32.19+ (partially) and 2.6.33+ LKML-Reference: <20100914143513.GB8415@xxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/sched.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index ed09d4f..dc85ceb 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3513,9 +3513,9 @@ 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 @@ -3546,9 +3546,9 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html