Stanislaw Gruszka 58d5e43422 sched: Fix user time incorrectly accounted as system time on 32-bit ...

commit e75e863dd5 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 <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>
LKML-Reference: <20100914143513.GB8415@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2010-09-26 17:21:25 -07:00

272 KiB

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