Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [ 18/24] timer: Fix jiffies wrap behavior of round_jiffies_common() | Date | Thu, 18 Jul 2013 19:24:50 -0700 |
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3.4-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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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; } /**
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