[PATCH 5.15 110/121] hwmon: (mr75203) fix VM sensor allocation when "intel,vm-map" not defined

Greg Kroah-Hartman
2022-09-13T15:00:39Z

From: Eliav Farber <farbere@amazon.com>

[ Upstream commit 81114fc3d27bf5b06b2137d2fd2b63da656a8b90 ]

Bug - in case "intel,vm-map" is missing in device-tree ,'num' is set
to 0, and no voltage channel infos are allocated.

The reason num is set to 0 when "intel,vm-map" is missing is to set the
entire pvt->vm_idx[] with incremental channel numbers, but it didn't
take into consideration that same num is used later in devm_kcalloc().

If "intel,vm-map" does exist there is no need to set the unspecified
channels with incremental numbers, because the unspecified channels
can't be accessed in pvt_read_in() which is the only other place besides
the probe functions that uses pvt->vm_idx[].

This change fixes the bug by moving the incremental channel numbers
setting to be done only if "intel,vm-map" property is defined (starting
loop from 0), and removing 'num = 0'.

Fixes: 9d823351a337 ("hwmon: Add hardware monitoring driver for Moortec MR75203 PVT controller")
Signed-off-by: Eliav Farber <farbere@amazon.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220908152449.35457-3-farbere@amazon.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hwmon/mr75203.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c
index 1ba1e31459690..36cbc86033ce9 100644
--- a/drivers/hwmon/mr75203.c
+++ b/drivers/hwmon/mr75203.c
@@ -594,7 +594,12 @@ static int mr75203_probe(struct platform_device *pdev)
ret = device_property_read_u8_array(dev, "intel,vm-map",
pvt->vm_idx, vm_num);
if (ret) {
- num = 0;
+ /*
+ * Incase intel,vm-map property is not defined, we
+ * assume incremental channel numbers.
+ */
+ for (i = 0; i < vm_num; i++)
+ pvt->vm_idx[i] = i;
} else {
for (i = 0; i < vm_num; i++)
if (pvt->vm_idx[i] >= vm_num ||
@@ -604,13 +609,6 @@ static int mr75203_probe(struct platform_device *pdev)
}
}

- /*
- * Incase intel,vm-map property is not defined, we assume
- * incremental channel numbers.
- */
- for (i = num; i < vm_num; i++)
- pvt->vm_idx[i] = i;
-
in_config = devm_kcalloc(dev, num + 1,
sizeof(*in_config), GFP_KERNEL);
if (!in_config)
--
2.35.1