lkml.org 
[lkml]   [2017]   [Sep]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] gpio: acpi: work around false-positive -Wstring-overflow warning
Date
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 <andriy.shevchenko@linux.intel.com>
Link: https://patchwork.kernel.org/patch/9840801/
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82123
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
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)))
--
2.9.0
\
 
 \ /
  Last update: 2017-09-06 17:48    [W:0.065 / U:0.252 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site