From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754175Ab1ABHte (ORCPT ); Sun, 2 Jan 2011 02:49:34 -0500 Received: from mail.windriver.com ([147.11.1.11]:35870 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754074Ab1ABHXt (ORCPT ); Sun, 2 Jan 2011 02:23:49 -0500 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Stanislaw Gruszka , Peter Zijlstra , Hidetoshi Seto , Ingo Molnar , Paul Gortmaker Subject: [34-longterm 129/260] sched: Fix user time incorrectly accounted as system time on 32-bit Date: Sun, 2 Jan 2011 02:17:05 -0500 Message-Id: <1293952756-15010-130-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.3.3 In-Reply-To: <1293952756-15010-1-git-send-email-paul.gortmaker@windriver.com> References: <1293952756-15010-1-git-send-email-paul.gortmaker@windriver.com> X-OriginalArrivalTime: 02 Jan 2011 07:22:31.0087 (UTC) FILETIME=[D14CDBF0:01CBAA4D] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stanislaw Gruszka 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: Paul Gortmaker --- kernel/sched.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/sched.c b/kernel/sched.c index b741de5..dd7c170 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -3428,9 +3428,9 @@ 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 @@ -3461,9 +3461,9 @@ 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 -- 1.7.3.3