* [PATCH] HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled
@ 2018-11-02 15:14 Arnd Bergmann
2018-11-03 22:16 ` Geert Uytterhoeven
2018-11-06 12:58 ` Jiri Kosina
0 siblings, 2 replies; 3+ messages in thread
From: Arnd Bergmann @ 2018-11-02 15:14 UTC (permalink / raw)
To: Jiri Kosina
Cc: Arnd Bergmann, Benjamin Tissoires, Hans de Goede, Colin Ian King,
Peter Hutterer, Mustafa Kuscu, Daniel Drake, linux-input,
linux-kernel
asus_wmi_evaluate_method() is an empty dummy function when CONFIG_ASUS_WMI
is disabled, or not reachable from a built-in device driver. This leads to
a theoretical evaluation of an uninitialized variable that the compiler
complains about, failing to check that the hardcoded return value makes
this an unreachable code path:
In file included from include/linux/printk.h:336,
from include/linux/kernel.h:14,
from include/linux/list.h:9,
from include/linux/dmi.h:5,
from drivers/hid/hid-asus.c:29:
drivers/hid/hid-asus.c: In function 'asus_input_configured':
include/linux/dynamic_debug.h:135:3: error: 'value' may be used uninitialized in this function [-Werror=maybe-uninitialized]
__dynamic_dev_dbg(&descriptor, dev, fmt, \
^~~~~~~~~~~~~~~~~
drivers/hid/hid-asus.c:359:6: note: 'value' was declared here
u32 value;
^~~~~
With an extra IS_ENABLED() check, the warning goes away.
Fixes: 3b692c55e58d ("HID: asus: only support backlight when it's not driven by WMI")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/hid/hid-asus.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index dc6d6477e961..a1fa2fc8c9b5 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -359,6 +359,9 @@ static bool asus_kbd_wmi_led_control_present(struct hid_device *hdev)
u32 value;
int ret;
+ if (!IS_ENABLED(CONFIG_ASUS_WMI))
+ return false;
+
ret = asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS2,
ASUS_WMI_DEVID_KBD_BACKLIGHT, 0, &value);
hid_dbg(hdev, "WMI backlight check: rc %d value %x", ret, value);
--
2.18.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled
2018-11-02 15:14 [PATCH] HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled Arnd Bergmann
@ 2018-11-03 22:16 ` Geert Uytterhoeven
2018-11-06 12:58 ` Jiri Kosina
1 sibling, 0 replies; 3+ messages in thread
From: Geert Uytterhoeven @ 2018-11-03 22:16 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Jiri Kosina, benjamin.tissoires, Hans de Goede, Colin King,
peter.hutterer, mustafakuscu, Daniel Drake, linux-input,
Linux Kernel Mailing List
On Fri, Nov 2, 2018 at 4:16 PM Arnd Bergmann <arnd@arndb.de> wrote:
> asus_wmi_evaluate_method() is an empty dummy function when CONFIG_ASUS_WMI
> is disabled, or not reachable from a built-in device driver. This leads to
> a theoretical evaluation of an uninitialized variable that the compiler
> complains about, failing to check that the hardcoded return value makes
> this an unreachable code path:
>
> In file included from include/linux/printk.h:336,
> from include/linux/kernel.h:14,
> from include/linux/list.h:9,
> from include/linux/dmi.h:5,
> from drivers/hid/hid-asus.c:29:
> drivers/hid/hid-asus.c: In function 'asus_input_configured':
> include/linux/dynamic_debug.h:135:3: error: 'value' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> __dynamic_dev_dbg(&descriptor, dev, fmt, \
> ^~~~~~~~~~~~~~~~~
> drivers/hid/hid-asus.c:359:6: note: 'value' was declared here
> u32 value;
> ^~~~~
>
> With an extra IS_ENABLED() check, the warning goes away.
>
> Fixes: 3b692c55e58d ("HID: asus: only support backlight when it's not driven by WMI")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled
2018-11-02 15:14 [PATCH] HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled Arnd Bergmann
2018-11-03 22:16 ` Geert Uytterhoeven
@ 2018-11-06 12:58 ` Jiri Kosina
1 sibling, 0 replies; 3+ messages in thread
From: Jiri Kosina @ 2018-11-06 12:58 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Benjamin Tissoires, Hans de Goede, Colin Ian King,
Peter Hutterer, Mustafa Kuscu, Daniel Drake, linux-input,
linux-kernel
On Fri, 2 Nov 2018, Arnd Bergmann wrote:
> asus_wmi_evaluate_method() is an empty dummy function when CONFIG_ASUS_WMI
> is disabled, or not reachable from a built-in device driver. This leads to
> a theoretical evaluation of an uninitialized variable that the compiler
> complains about, failing to check that the hardcoded return value makes
> this an unreachable code path:
>
> In file included from include/linux/printk.h:336,
> from include/linux/kernel.h:14,
> from include/linux/list.h:9,
> from include/linux/dmi.h:5,
> from drivers/hid/hid-asus.c:29:
> drivers/hid/hid-asus.c: In function 'asus_input_configured':
> include/linux/dynamic_debug.h:135:3: error: 'value' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> __dynamic_dev_dbg(&descriptor, dev, fmt, \
> ^~~~~~~~~~~~~~~~~
> drivers/hid/hid-asus.c:359:6: note: 'value' was declared here
> u32 value;
> ^~~~~
>
> With an extra IS_ENABLED() check, the warning goes away.
>
> Fixes: 3b692c55e58d ("HID: asus: only support backlight when it's not driven by WMI")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Applied to for-4.20/upstream-fixes. Thanks,
--
Jiri Kosina
SUSE Labs
^ permalink raw reply [flat|nested] 3+ messages in thread
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2018-11-02 15:14 [PATCH] HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled Arnd Bergmann
2018-11-03 22:16 ` Geert Uytterhoeven
2018-11-06 12:58 ` Jiri Kosina
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