From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bart Van Assche , Arjan van de Ven , Stephen Rothwell , Thomas Gleixner Subject: [ 18/24] timer: Fix jiffies wrap behavior of round_jiffies_common() Date: Thu, 18 Jul 2013 19:24:50 -0700 Message-Id: <20130719022405.268285428@linuxfoundation.org> In-Reply-To: <20130719022404.015008451@linuxfoundation.org> References: <20130719022404.015008451@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bart Van Assche commit 9e04d3804d3ac97d8c03a41d78d0f0674b5d01e1 upstream. Direct compare of jiffies related values does not work in the wrap around case. Replace it with time_is_after_jiffies(). Signed-off-by: Bart Van Assche Cc: Arjan van de Ven Cc: Stephen Rothwell Link: http://lkml.kernel.org/r/519BC066.5080600@acm.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- kernel/timer.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/kernel/timer.c +++ b/kernel/timer.c @@ -145,9 +145,11 @@ static unsigned long round_jiffies_commo /* now that we have rounded, subtract the extra skew again */ j -= cpu * 3; - if (j <= jiffies) /* rounding ate our timeout entirely; */ - return original; - return j; + /* + * Make sure j is still in the future. Otherwise return the + * unmodified value. + */ + return time_is_after_jiffies(j) ? j : original; } /**