[PATCH 1/2] platform/x86: peaq-wmi: select INPUT_POLLDEV

[PATCH 1/2] platform/x86: peaq-wmi: select INPUT_POLLDEV

[Arnd Bergmann]

The new driver fails to build without INPUT_POLLDEV

drivers/platform/x86/peaq-wmi.o: In function `peaq_wmi_exit':
peaq-wmi.c:(.exit.text+0x1c): undefined reference to `input_unregister_polled_device'
drivers/platform/x86/peaq-wmi.o: In function `peaq_wmi_init':
peaq-wmi.c:(.init.text+0x23): undefined reference to `input_allocate_polled_device'
peaq-wmi.c:(.init.text+0x18e): undefined reference to `input_register_polled_device'

For some reason, all other drivers that need this use 'select'
here rather than 'depends on', so I'm doing the same.

Fixes: 13bb0fd5519d ("platform/x86: peaq-wmi: Add new peaq-wmi driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/platform/x86/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 2b209f5d42ff..d9238e9ff54a 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -672,6 +672,7 @@ config PEAQ_WMI
 	tristate "PEAQ 2-in-1 WMI hotkey driver"
 	depends on ACPI_WMI
 	depends on INPUT
+	select INPUT_POLLDEV
 	help
 	 Say Y here if you want to support WMI-based hotkeys on PEAQ 2-in-1s.
 
-- 
2.9.0

[PATCH 2/2] platform/x86: alienware-wmi: fix format string overflow warning

[Arnd Bergmann]

gcc points out a possible format string overflow for a large value of 'zone':

drivers/platform/x86/alienware-wmi.c: In function 'alienware_wmi_init':
drivers/platform/x86/alienware-wmi.c:461:24: error: '%02X' directive writing between 2 and 8 bytes into a region of size 6 [-Werror=format-overflow=]
   sprintf(buffer, "zone%02X", i);
                        ^~~~
drivers/platform/x86/alienware-wmi.c:461:19: note: directive argument in the range [0, 2147483646]
   sprintf(buffer, "zone%02X", i);
                   ^~~~~~~~~~
drivers/platform/x86/alienware-wmi.c:461:3: note: 'sprintf' output between 7 and 13 bytes into a destination of size 10

This replaces the 'int' variable with an 'u8' to make sure
it always fits, renaming the variable to 'zone' for clarity.

Unfortunately, gcc-7.1.1 still warns about it with that change, which
seems to be unintended by the gcc developers. I have opened a bug
against gcc with a reduced test case. As a workaround, I also
change the format string to use "%02hhX", which shuts up the
warning in that version.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81483
Link: https://patchwork.ozlabs.org/patch/788415/
Suggested-by: Andy Shevchenko <andy@infradead.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2: completely rewrite the patch after discussing with Andy
---
 drivers/platform/x86/alienware-wmi.c | 38 ++++++++++++++++++------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/platform/x86/alienware-wmi.c b/drivers/platform/x86/alienware-wmi.c
index 0831b428c217..c56a9ecba959 100644
--- a/drivers/platform/x86/alienware-wmi.c
+++ b/drivers/platform/x86/alienware-wmi.c
@@ -255,12 +255,12 @@ static int parse_rgb(const char *buf, struct platform_zone *zone)
 
 static struct platform_zone *match_zone(struct device_attribute *attr)
 {
-	int i;
-	for (i = 0; i < quirks->num_zones; i++) {
-		if ((struct device_attribute *)zone_data[i].attr == attr) {
+	u8 zone;
+	for (zone = 0; zone < quirks->num_zones; zone++) {
+		if ((struct device_attribute *)zone_data[zone].attr == attr) {
 			pr_debug("alienware-wmi: matched zone location: %d\n",
-				 zone_data[i].location);
-			return &zone_data[i];
+				 zone_data[zone].location);
+			return &zone_data[zone];
 		}
 	}
 	return NULL;
@@ -420,7 +420,7 @@ static DEVICE_ATTR(lighting_control_state, 0644, show_control_state,
 
 static int alienware_zone_init(struct platform_device *dev)
 {
-	int i;
+	u8 zone;
 	char buffer[10];
 	char *name;
 
@@ -457,19 +457,19 @@ static int alienware_zone_init(struct platform_device *dev)
 	if (!zone_data)
 		return -ENOMEM;
 
-	for (i = 0; i < quirks->num_zones; i++) {
-		sprintf(buffer, "zone%02X", i);
+	for (zone = 0; zone < quirks->num_zones; zone++) {
+		sprintf(buffer, "zone%02hhX", zone);
 		name = kstrdup(buffer, GFP_KERNEL);
 		if (name == NULL)
 			return 1;
-		sysfs_attr_init(&zone_dev_attrs[i].attr);
-		zone_dev_attrs[i].attr.name = name;
-		zone_dev_attrs[i].attr.mode = 0644;
-		zone_dev_attrs[i].show = zone_show;
-		zone_dev_attrs[i].store = zone_set;
-		zone_data[i].location = i;
-		zone_attrs[i] = &zone_dev_attrs[i].attr;
-		zone_data[i].attr = &zone_dev_attrs[i];
+		sysfs_attr_init(&zone_dev_attrs[zone].attr);
+		zone_dev_attrs[zone].attr.name = name;
+		zone_dev_attrs[zone].attr.mode = 0644;
+		zone_dev_attrs[zone].show = zone_show;
+		zone_dev_attrs[zone].store = zone_set;
+		zone_data[zone].location = zone;
+		zone_attrs[zone] = &zone_dev_attrs[zone].attr;
+		zone_data[zone].attr = &zone_dev_attrs[zone];
 	}
 	zone_attrs[quirks->num_zones] = &dev_attr_lighting_control_state.attr;
 	zone_attribute_group.attrs = zone_attrs;
@@ -484,9 +484,9 @@ static void alienware_zone_exit(struct platform_device *dev)
 	sysfs_remove_group(&dev->dev.kobj, &zone_attribute_group);
 	led_classdev_unregister(&global_led);
 	if (zone_dev_attrs) {
-		int i;
-		for (i = 0; i < quirks->num_zones; i++)
-			kfree(zone_dev_attrs[i].attr.name);
+		u8 zone;
+		for (zone = 0; zone < quirks->num_zones; zone++)
+			kfree(zone_dev_attrs[zone].attr.name);
 	}
 	kfree(zone_dev_attrs);
 	kfree(zone_data);
-- 
2.9.0

Re: [PATCH 1/2] platform/x86: peaq-wmi: select INPUT_POLLDEV

[Darren Hart]

On Thu, Jul 20, 2017 at 06:00:50PM +0200, Arnd Bergmann wrote:
> The new driver fails to build without INPUT_POLLDEV
> 
> drivers/platform/x86/peaq-wmi.o: In function `peaq_wmi_exit':
> peaq-wmi.c:(.exit.text+0x1c): undefined reference to `input_unregister_polled_device'
> drivers/platform/x86/peaq-wmi.o: In function `peaq_wmi_init':
> peaq-wmi.c:(.init.text+0x23): undefined reference to `input_allocate_polled_device'
> peaq-wmi.c:(.init.text+0x18e): undefined reference to `input_register_polled_device'
> 
> For some reason, all other drivers that need this use 'select'
> here rather than 'depends on', so I'm doing the same.
> 
> Fixes: 13bb0fd5519d ("platform/x86: peaq-wmi: Add new peaq-wmi driver")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Queued to fixes branch for 4.13-rcX. I'll leave patch 2/2 to andy since you
worked that one together already.

-- 
Darren Hart
VMware Open Source Technology Center

Re: [PATCH 2/2] platform/x86: alienware-wmi: fix format string overflow warning

[Andy Shevchenko]

On Thu, Jul 20, 2017 at 7:00 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> gcc points out a possible format string overflow for a large value of 'zone':
>
> drivers/platform/x86/alienware-wmi.c: In function 'alienware_wmi_init':
> drivers/platform/x86/alienware-wmi.c:461:24: error: '%02X' directive writing between 2 and 8 bytes into a region of size 6 [-Werror=format-overflow=]
>    sprintf(buffer, "zone%02X", i);
>                         ^~~~
> drivers/platform/x86/alienware-wmi.c:461:19: note: directive argument in the range [0, 2147483646]
>    sprintf(buffer, "zone%02X", i);
>                    ^~~~~~~~~~
> drivers/platform/x86/alienware-wmi.c:461:3: note: 'sprintf' output between 7 and 13 bytes into a destination of size 10
>
> This replaces the 'int' variable with an 'u8' to make sure
> it always fits, renaming the variable to 'zone' for clarity.
>
> Unfortunately, gcc-7.1.1 still warns about it with that change, which
> seems to be unintended by the gcc developers. I have opened a bug
> against gcc with a reduced test case. As a workaround, I also
> change the format string to use "%02hhX", which shuts up the
> warning in that version.
>

Thanks, pushed to testing with slight change (+ empty lines after u8
zone; where it's applicable).
I'm not going to move this to fixes queue since it looks to me not
critical at all. Drop me a message if you think otherwise.

> Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81483
> Link: https://patchwork.ozlabs.org/patch/788415/
> Suggested-by: Andy Shevchenko <andy@infradead.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> v2: completely rewrite the patch after discussing with Andy
> ---
>  drivers/platform/x86/alienware-wmi.c | 38 ++++++++++++++++++------------------
>  1 file changed, 19 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/platform/x86/alienware-wmi.c b/drivers/platform/x86/alienware-wmi.c
> index 0831b428c217..c56a9ecba959 100644
> --- a/drivers/platform/x86/alienware-wmi.c
> +++ b/drivers/platform/x86/alienware-wmi.c
> @@ -255,12 +255,12 @@ static int parse_rgb(const char *buf, struct platform_zone *zone)
>
>  static struct platform_zone *match_zone(struct device_attribute *attr)
>  {
> -       int i;
> -       for (i = 0; i < quirks->num_zones; i++) {
> -               if ((struct device_attribute *)zone_data[i].attr == attr) {
> +       u8 zone;
> +       for (zone = 0; zone < quirks->num_zones; zone++) {
> +               if ((struct device_attribute *)zone_data[zone].attr == attr) {
>                         pr_debug("alienware-wmi: matched zone location: %d\n",
> -                                zone_data[i].location);
> -                       return &zone_data[i];
> +                                zone_data[zone].location);
> +                       return &zone_data[zone];
>                 }
>         }
>         return NULL;
> @@ -420,7 +420,7 @@ static DEVICE_ATTR(lighting_control_state, 0644, show_control_state,
>
>  static int alienware_zone_init(struct platform_device *dev)
>  {
> -       int i;
> +       u8 zone;
>         char buffer[10];
>         char *name;
>
> @@ -457,19 +457,19 @@ static int alienware_zone_init(struct platform_device *dev)
>         if (!zone_data)
>                 return -ENOMEM;
>
> -       for (i = 0; i < quirks->num_zones; i++) {
> -               sprintf(buffer, "zone%02X", i);
> +       for (zone = 0; zone < quirks->num_zones; zone++) {
> +               sprintf(buffer, "zone%02hhX", zone);
>                 name = kstrdup(buffer, GFP_KERNEL);
>                 if (name == NULL)
>                         return 1;
> -               sysfs_attr_init(&zone_dev_attrs[i].attr);
> -               zone_dev_attrs[i].attr.name = name;
> -               zone_dev_attrs[i].attr.mode = 0644;
> -               zone_dev_attrs[i].show = zone_show;
> -               zone_dev_attrs[i].store = zone_set;
> -               zone_data[i].location = i;
> -               zone_attrs[i] = &zone_dev_attrs[i].attr;
> -               zone_data[i].attr = &zone_dev_attrs[i];
> +               sysfs_attr_init(&zone_dev_attrs[zone].attr);
> +               zone_dev_attrs[zone].attr.name = name;
> +               zone_dev_attrs[zone].attr.mode = 0644;
> +               zone_dev_attrs[zone].show = zone_show;
> +               zone_dev_attrs[zone].store = zone_set;
> +               zone_data[zone].location = zone;
> +               zone_attrs[zone] = &zone_dev_attrs[zone].attr;
> +               zone_data[zone].attr = &zone_dev_attrs[zone];
>         }
>         zone_attrs[quirks->num_zones] = &dev_attr_lighting_control_state.attr;
>         zone_attribute_group.attrs = zone_attrs;
> @@ -484,9 +484,9 @@ static void alienware_zone_exit(struct platform_device *dev)
>         sysfs_remove_group(&dev->dev.kobj, &zone_attribute_group);
>         led_classdev_unregister(&global_led);
>         if (zone_dev_attrs) {
> -               int i;
> -               for (i = 0; i < quirks->num_zones; i++)
> -                       kfree(zone_dev_attrs[i].attr.name);
> +               u8 zone;
> +               for (zone = 0; zone < quirks->num_zones; zone++)
> +                       kfree(zone_dev_attrs[zone].attr.name);
>         }
>         kfree(zone_dev_attrs);
>         kfree(zone_data);
> --
> 2.9.0
>



-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH 2/2] platform/x86: alienware-wmi: fix format string overflow warning

[Arnd Bergmann]

On Mon, Jul 24, 2017 at 11:22 AM, Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Thu, Jul 20, 2017 at 7:00 PM, Arnd Bergmann <arnd@arndb.de> wrote:
>> gcc points out a possible format string overflow for a large value of 'zone':
>>
>> drivers/platform/x86/alienware-wmi.c: In function 'alienware_wmi_init':
>> drivers/platform/x86/alienware-wmi.c:461:24: error: '%02X' directive writing between 2 and 8 bytes into a region of size 6 [-Werror=format-overflow=]
>>    sprintf(buffer, "zone%02X", i);
>>                         ^~~~
>> drivers/platform/x86/alienware-wmi.c:461:19: note: directive argument in the range [0, 2147483646]
>>    sprintf(buffer, "zone%02X", i);
>>                    ^~~~~~~~~~
>> drivers/platform/x86/alienware-wmi.c:461:3: note: 'sprintf' output between 7 and 13 bytes into a destination of size 10
>>
>> This replaces the 'int' variable with an 'u8' to make sure
>> it always fits, renaming the variable to 'zone' for clarity.
>>
>> Unfortunately, gcc-7.1.1 still warns about it with that change, which
>> seems to be unintended by the gcc developers. I have opened a bug
>> against gcc with a reduced test case. As a workaround, I also
>> change the format string to use "%02hhX", which shuts up the
>> warning in that version.
>>
>
> Thanks, pushed to testing with slight change (+ empty lines after u8
> zone; where it's applicable).
> I'm not going to move this to fixes queue since it looks to me not
> critical at all. Drop me a message if you think otherwise.

Sounds good, thanks! This instance is harmless, and the warning is now
globally disabled in stable kernels (and in mainline). I plan to send a patch
to re-enable the warning in mainline once all the other instances are
addressed.  I don't think that Greg will backport that patch, but if he does,
then he may need some additional 30 patches besides this one.

          Arnd