gpio / ACPI: Prevent potential wrap of GPIO value on OpRegion read
Dan Carpenter's static code checker reports:
The patch 473ed7be0da0: "gpio / ACPI: Add support for ACPI GPIO
operation regions" from Mar 14, 2014, leads to the following static
checker warning:
drivers/gpio/gpiolib-acpi.c:454 acpi_gpio_adr_space_handler()
warn: should 'gpiod_get_raw_value(desc) << i' be a 64 bit type?
This is due the fact that *value is of type u64 and gpiod_get_raw_value()
returns int. Since i can be larger than 31, it is possible that the value
returned gets wrapped.
Fix this by casting the return of gpiod_get_raw_value() to u64 first before
shift.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index d5be56f..401add2 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -451,7 +451,7 @@
if (function == ACPI_WRITE)
gpiod_set_raw_value(desc, !!((1 << i) & *value));
else
- *value |= gpiod_get_raw_value(desc) << i;
+ *value |= (u64)gpiod_get_raw_value(desc) << i;
}
out:
