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authorStanislaw Gruszka <sgruszka@redhat.com>2010-09-14 16:35:14 +0200
committerIngo Molnar <mingo@elte.hu>2010-09-15 10:41:36 +0200
commite75e863dd5c7d96b91ebbd241da5328fc38a78cc (patch)
treeb7b67512b6b610c8ee90149c9b48dbaeeb1e4910
parent9c03f1622af051004416dd3e24d8a0fa31e34178 (diff)
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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@very.puzzling.org> Reported-by: Ciriaco Garcia de Celis <sysman@etherpilot.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: <stable@kernel.org> # 2.6.32.19+ (partially) and 2.6.33+ LKML-Reference: <20100914143513.GB8415@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/sched.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index ed09d4f2a69..dc85ceb9083 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