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authorBastien Nocera <hadess@hadess.net>2019-06-27 09:20:45 +0200
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2019-06-27 20:38:19 +0100
commit208a68c8393d6041a90862992222f3d7943d44d6 (patch)
tree6b656dd51d2fb1178265b1820e9baf5a362a2201 /tools/iio
parentdef914a4c3899b6b3705c8ea67d29972f5652a14 (diff)
downloadlinux-208a68c8393d6041a90862992222f3d7943d44d6.tar.bz2
iio: iio-utils: Fix possible incorrect mask calculation
On some machines, iio-sensor-proxy was returning all 0's for IIO sensor values. It turns out that the bits_used for this sensor is 32, which makes the mask calculation: *mask = (1 << 32) - 1; If the compiler interprets the 1 literals as 32-bit ints, it generates undefined behavior depending on compiler version and optimization level. On my system, it optimizes out the shift, so the mask value becomes *mask = (1) - 1; With a mask value of 0, iio-sensor-proxy will always return 0 for every axis. Avoid incorrect 0 values caused by compiler optimization. See original fix by Brett Dutro <brett.dutro@gmail.com> in iio-sensor-proxy: https://github.com/hadess/iio-sensor-proxy/commit/9615ceac7c134d838660e209726cd86aa2064fd3 Signed-off-by: Bastien Nocera <hadess@hadess.net> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'tools/iio')
-rw-r--r--tools/iio/iio_utils.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c
index 7a6d61c6c012..55272fef3b50 100644
--- a/tools/iio/iio_utils.c
+++ b/tools/iio/iio_utils.c
@@ -159,9 +159,9 @@ int iioutils_get_type(unsigned *is_signed, unsigned *bytes, unsigned *bits_used,
*be = (endianchar == 'b');
*bytes = padint / 8;
if (*bits_used == 64)
- *mask = ~0;
+ *mask = ~(0ULL);
else
- *mask = (1ULL << *bits_used) - 1;
+ *mask = (1ULL << *bits_used) - 1ULL;
*is_signed = (signchar == 's');
if (fclose(sysfsfp)) {