From: Eddie James <eajames@linux.vnet.ibm.com>
To: openbmc@lists.ozlabs.org
Cc: joel@jms.id.au, Eddie James <eajames@linux.vnet.ibm.com>,
 "Edward A. James" <eajames@us.ibm.com>
Subject: [PATCH linux dev-4.10 v3] hwmon (occ): Fix integer overflow in
 multiplication
Date: Tue, 19 Dec 2017 13:56:33 -0600
Message-Id: <1513713393-10030-1-git-send-email-eajames@linux.vnet.ibm.com>
Precedence: list

Power values were overflowing INT_MAX when being converted to
microwatts, even though the storage was sufficiently large (unsigned 64
bit). Change literals to unsigned long long. Also change tmep storage to u32
to avoid overflows at 65000 millidegrees.

Signed-off-by: Edward A. James <eajames@us.ibm.com>
---
 drivers/hwmon/occ/common.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index 3175e7b..2e188d5 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -353,7 +353,7 @@ static ssize_t occ_show_temp_1(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	int rc;
-	u16 val = 0;
+	u32 val = 0;
 	struct temp_sensor_1 *temp;
 	struct occ *occ = dev_get_drvdata(dev);
 	struct occ_sensors *sensors = &occ->sensors;
@@ -468,7 +468,7 @@ static ssize_t occ_show_power_1(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	int rc;
-	u32 val = 0;
+	u64 val = 0;
 	struct power_sensor_1 *power;
 	struct occ *occ = dev_get_drvdata(dev);
 	struct occ_sensors *sensors = &occ->sensors;
@@ -491,11 +491,11 @@ static ssize_t occ_show_power_1(struct device *dev,
 		val = get_unaligned_be32(&power->accumulator);
 		break;
 	case 3:
-		val = get_unaligned_be16(&power->value) * 1000000;
+		val = get_unaligned_be16(&power->value) * 1000000ULL;
 		break;
 	}
 
-	return snprintf(buf, PAGE_SIZE - 1, "%u\n", val);
+	return snprintf(buf, PAGE_SIZE - 1, "%llu\n", val);
 }
 
 static ssize_t occ_show_power_2(struct device *dev,
@@ -525,7 +525,7 @@ static ssize_t occ_show_power_2(struct device *dev,
 		val = get_unaligned_be64(&power->accumulator);
 		break;
 	case 3:
-		val = get_unaligned_be16(&power->value) * 1000000;
+		val = get_unaligned_be16(&power->value) * 1000000ULL;
 		break;
 	case 4:
 		val = power->function_id;
@@ -562,7 +562,7 @@ static ssize_t occ_show_power_a0(struct device *dev,
 		val = get_unaligned_be16(&power->system.update_time);
 		break;
 	case 2:
-		val = get_unaligned_be16(&power->system.value) * 1000000;
+		val = get_unaligned_be16(&power->system.value) * 1000000ULL;
 		break;
 	case 3:
 		val = get_unaligned_be32(&power->system.update_tag);
@@ -574,7 +574,7 @@ static ssize_t occ_show_power_a0(struct device *dev,
 		val = get_unaligned_be16(&power->proc.update_time);
 		break;
 	case 6:
-		val = get_unaligned_be16(&power->proc.value) * 1000000;
+		val = get_unaligned_be16(&power->proc.value) * 1000000ULL;
 		break;
 	case 7:
 		val = get_unaligned_be32(&power->proc.update_tag);
@@ -583,7 +583,7 @@ static ssize_t occ_show_power_a0(struct device *dev,
 		val = get_unaligned_be64(&power->proc.accumulator);
 		break;
 	case 9:
-		val = get_unaligned_be16(&power->vdd.value) * 1000000;
+		val = get_unaligned_be16(&power->vdd.value) * 1000000ULL;
 		break;
 	case 10:
 		val = get_unaligned_be32(&power->vdd.update_tag);
@@ -592,7 +592,7 @@ static ssize_t occ_show_power_a0(struct device *dev,
 		val = get_unaligned_be64(&power->vdd.accumulator);
 		break;
 	case 12:
-		val = get_unaligned_be16(&power->vdn.value) * 1000000;
+		val = get_unaligned_be16(&power->vdn.value) * 1000000ULL;
 		break;
 	case 13:
 		val = get_unaligned_be32(&power->vdn.update_tag);
-- 
1.8.3.1