[PATCH] thermal: exynos_tmu: avoid uninitialized variables

[PATCH] thermal: exynos_tmu: avoid uninitialized variables

[Arnd Bergmann]

Removing the initialization in the error case introduced
a compile-time warning:

drivers/thermal/samsung/exynos_tmu.c: In function 'temp_to_code':
drivers/thermal/samsung/exynos_tmu.c:304:9: error: 'temp_code' may be used uninitialized in this function [-Werror=maybe-uninitialized]
  return temp_code;
         ^~~~~~~~~
drivers/thermal/samsung/exynos_tmu.c: In function 'exynos_get_temp':
drivers/thermal/samsung/exynos_tmu.c:931:37: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized]
   *temp = code_to_temp(data, value) * MCELSIUS;

Let's assume the runtime warning is sufficient, and make it
return a well-defined number instead of unintialized data.

Fixes: 480b5bfc16e1 ("thermal: exynos: remove parsing of samsung, tmu_default_temp_offset property")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/thermal/samsung/exynos_tmu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
index 2ec854851da1..7e351fffdaee 100644
--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -298,6 +298,7 @@ static int temp_to_code(struct exynos_tmu_data *data, u8 temp)
 		break;
 	default:
 		WARN_ON(1);
+		temp_code = 0;
 		break;
 	}
 
@@ -324,6 +325,7 @@ static int code_to_temp(struct exynos_tmu_data *data, u16 temp_code)
 		break;
 	default:
 		WARN_ON(1);
+		temp = 0;
 		break;
 	}
 
-- 
2.9.0

Re: [PATCH] thermal: exynos_tmu: avoid uninitialized variables

[Bartlomiej Zolnierkiewicz]

On Wednesday, March 28, 2018 03:44:44 PM Arnd Bergmann wrote:
> Removing the initialization in the error case introduced
> a compile-time warning:
> 
> drivers/thermal/samsung/exynos_tmu.c: In function 'temp_to_code':
> drivers/thermal/samsung/exynos_tmu.c:304:9: error: 'temp_code' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>   return temp_code;
>          ^~~~~~~~~
> drivers/thermal/samsung/exynos_tmu.c: In function 'exynos_get_temp':
> drivers/thermal/samsung/exynos_tmu.c:931:37: error: 'temp' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>    *temp = code_to_temp(data, value) * MCELSIUS;
> 
> Let's assume the runtime warning is sufficient, and make it
> return a well-defined number instead of unintialized data.
> 
> Fixes: 480b5bfc16e1 ("thermal: exynos: remove parsing of samsung, tmu_default_temp_offset property")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks Arnd!

Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics