This is a note to let you know that I've just added the patch titled iio:core: fix IIO_VAL_FRACTIONAL sign handling to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: iio-core-fix-iio_val_fractional-sign-handling.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 171c0091837c81ed5c949fec6966bb5afff2d1cf Mon Sep 17 00:00:00 2001 From: Gregor Boirie <gregor.boirie@xxxxxxxxxx> Date: Fri, 2 Sep 2016 20:27:46 +0200 Subject: iio:core: fix IIO_VAL_FRACTIONAL sign handling From: Gregor Boirie <gregor.boirie@xxxxxxxxxx> commit 171c0091837c81ed5c949fec6966bb5afff2d1cf upstream. 7985e7c100 ("iio: Introduce a new fractional value type") introduced a new IIO_VAL_FRACTIONAL value type meant to represent rational type numbers expressed by a numerator and denominator combination. Formating of IIO_VAL_FRACTIONAL values relies upon do_div() usage. This fails handling negative values properly since parameters are reevaluated as unsigned values. Fix this by using div_s64_rem() instead. Computed integer part will carry properly signed value. Formatted fractional part will always be positive. Fixes: 7985e7c100 ("iio: Introduce a new fractional value type") Signed-off-by: Gregor Boirie <gregor.boirie@xxxxxxxxxx> Reviewed-by: Lars-Peter Clausen <lars@xxxxxxxxxx> Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iio/industrialio-core.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/drivers/iio/industrialio-core.c +++ b/drivers/iio/industrialio-core.c @@ -447,9 +447,8 @@ ssize_t iio_format_value(char *buf, unsi return sprintf(buf, "%d.%09u\n", vals[0], vals[1]); case IIO_VAL_FRACTIONAL: tmp = div_s64((s64)vals[0] * 1000000000LL, vals[1]); - vals[1] = do_div(tmp, 1000000000LL); - vals[0] = tmp; - return sprintf(buf, "%d.%09u\n", vals[0], vals[1]); + vals[0] = (int)div_s64_rem(tmp, 1000000000, &vals[1]); + return sprintf(buf, "%d.%09u\n", vals[0], abs(vals[1])); case IIO_VAL_FRACTIONAL_LOG2: tmp = (s64)vals[0] * 1000000000LL >> vals[1]; vals[1] = do_div(tmp, 1000000000LL); Patches currently in stable-queue which might be from gregor.boirie@xxxxxxxxxx are queue-4.4/iio-core-fix-iio_val_fractional-sign-handling.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html