sched: Fix user time incorrectly accounted as system time on 32-bit
authorStanislaw Gruszka <sgruszka@redhat.com>
Tue, 14 Sep 2010 14:35:14 +0000 (16:35 +0200)
committerIngo Molnar <mingo@elte.hu>
Wed, 15 Sep 2010 08:41:36 +0000 (10:41 +0200)
commite75e863dd5c7d96b91ebbd241da5328fc38a78cc
treeb7b67512b6b610c8ee90149c9b48dbaeeb1e4910
parent9c03f1622af051004416dd3e24d8a0fa31e34178
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>
kernel/sched.c