[3.13.y.z extended stable] Patch "iio: adc: at91: signedness bug in at91_adc_get_trigger_value_by_name()" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    iio: adc: at91: signedness bug in at91_adc_get_trigger_value_by_name()

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.5.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 28bf2dd7c3a724840f1fd21e694b214c5c279e07 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter at oracle.com>
Date: Thu, 6 Nov 2014 09:13:00 +0000
Subject: iio: adc: at91: signedness bug in
 at91_adc_get_trigger_value_by_name()

commit 4f3bcd878f1d3c730fe00f619b7260c6125d49eb upstream.

at91_adc_get_trigger_value_by_name() was returning -ENOMEM truncated to
a positive u8 and that doesn't work.  I've changed it to int and
refactored it to preserve the error code.

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
Acked-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
Tested-by: Alexandre Belloni <alexandre.belloni at free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23 at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/iio/adc/at91_adc.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index bbba014..e6bf77d 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -322,12 +322,11 @@ static int at91_adc_channel_init(struct iio_dev *idev)
 	return idev->num_channels;
 }

-static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
+static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
 					     struct at91_adc_trigger *triggers,
 					     const char *trigger_name)
 {
 	struct at91_adc_state *st = iio_priv(idev);
-	u8 value = 0;
 	int i;

 	for (i = 0; i < st->trigger_number; i++) {
@@ -340,15 +339,16 @@ static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
 			return -ENOMEM;

 		if (strcmp(trigger_name, name) == 0) {
-			value = triggers[i].value;
 			kfree(name);
-			break;
+			if (triggers[i].value == 0)
+				return -EINVAL;
+			return triggers[i].value;
 		}

 		kfree(name);
 	}

-	return value;
+	return -EINVAL;
 }

 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
@@ -358,14 +358,14 @@ static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
 	struct iio_buffer *buffer = idev->buffer;
 	struct at91_adc_reg_desc *reg = st->registers;
 	u32 status = at91_adc_readl(st, reg->trigger_register);
-	u8 value;
+	int value;
 	u8 bit;

 	value = at91_adc_get_trigger_value_by_name(idev,
 						   st->trigger_list,
 						   idev->trig->name);
-	if (value == 0)
-		return -EINVAL;
+	if (value < 0)
+		return value;

 	if (state) {
 		st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
--
1.9.1