From e40a3ae1f794a35c4af3746291ed6fedc1fa0f6f Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 6 Sep 2017 17:47:45 +0200 Subject: [PATCH] gpio: acpi: work around false-positive -Wstring-overflow warning gcc-7 notices that the pin_table is an array of 16-bit numbers, but fails to take the following range check into account: drivers/gpio/gpiolib-acpi.c: In function 'acpi_gpiochip_request_interrupt': drivers/gpio/gpiolib-acpi.c:206:24: warning: '%02X' directive writing between 2 and 4 bytes into a region of size 3 [-Wformat-overflow=] sprintf(ev_name, "_%c%02X", ^~~~ drivers/gpio/gpiolib-acpi.c:206:20: note: directive argument in the range [0, 65535] sprintf(ev_name, "_%c%02X", ^~~~~~~~~ drivers/gpio/gpiolib-acpi.c:206:3: note: 'sprintf' output between 5 and 7 bytes into a destination of size 5 sprintf(ev_name, "_%c%02X", ^~~~~~~~~~~~~~~~~~~~~~~~~~~ agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L', ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ pin); ~~~~ As suggested by Andy, this changes the format string to have a fixed length. Since modifying the range check did not help, I also opened a bug against gcc, see link below. Fixes: 0d1c28a449c6 ("gpiolib-acpi: Add ACPI5 event model support to gpio.") Cc: Andy Shevchenko Link: https://patchwork.kernel.org/patch/9840801/ Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82123 Signed-off-by: Arnd Bergmann Acked-by: Mika Westerberg Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib-acpi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 4d2113530735..eb4528c87c0b 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -203,7 +203,7 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares, if (pin <= 255) { char ev_name[5]; - sprintf(ev_name, "_%c%02X", + sprintf(ev_name, "_%c%02hhX", agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L', pin); if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))