| From | Kamal Mostafa <> | Subject | [PATCH 047/145] timer: Fix jiffies wrap behavior of round_jiffies_common() | Date | Wed, 17 Jul 2013 15:46:19 -0700 |
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3.8.13.5 -stable review patch. If anyone has any objections, please let me know.
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From: Bart Van Assche <bart.vanassche@gmail.com>
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 <bvanassche@acm.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Link: http://lkml.kernel.org/r/519BC066.5080600@acm.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- kernel/timer.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/kernel/timer.c b/kernel/timer.c index 18f6b85..1f8a6bd 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -147,9 +147,11 @@ static unsigned long round_jiffies_common(unsigned long j, int cpu, /* 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; } /** -- 1.8.1.2
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