From: Mika Westerberg Date: Tue, 1 Apr 2014 10:03:00 +0000 (+0300) Subject: gpio / ACPI: Prevent potential wrap of GPIO value on OpRegion read X-Git-Tag: firefly_0821_release~176^2~4007^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b5539fa2d59d697b7b8e28b4d08da844ff60f7cf;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Mika Westerberg Signed-off-by: Linus Walleij --- diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index d5be56fe689e..401add28933f 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -451,7 +451,7 @@ acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address, 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: