From: Herve Codina <herve.codina@bootlin.com>
Date: Fri, 23 Jun 2023 08:58:20 +0000 (+0200)
Subject: iio: inkern: Check error explicitly in iio_channel_read_max()
X-Git-Tag: 6.6-rc-smb3-client-fixes-part2~25^2~3^2~217^2~10
X-Git-Url: http://git.samba.org/?a=commitdiff_plain;h=f75c544d74133278b004195220f540d8ab953e14;p=sfrench%2Fcifs-2.6.git

iio: inkern: Check error explicitly in iio_channel_read_max()

The current implementation returns the error code as part of the
default switch case.
This can lead to returning an incorrect positive value in case of
iio_avail_type enum entries evolution.

In order to avoid this case, be more strict in error checking.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/20230623085830.749991-4-herve.codina@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---

diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index 872fd5c24147..f738db9a0c04 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -858,6 +858,9 @@ static int iio_channel_read_max(struct iio_channel *chan,
 		val2 = &unused;
 
 	ret = iio_channel_read_avail(chan, &vals, type, &length, info);
+	if (ret < 0)
+		return ret;
+
 	switch (ret) {
 	case IIO_AVAIL_RANGE:
 		switch (*type) {
@@ -888,7 +891,7 @@ static int iio_channel_read_max(struct iio_channel *chan,
 		return 0;
 
 	default:
-		return ret;
+		return -EINVAL;
 	}
 }