Enabling -Wformat-truncation yields the following warning:
../drivers/gpu/drm/nouveau/nouveau_backlight.c: In function ‘nouveau_backlight_init’:
../drivers/gpu/drm/nouveau/nouveau_backlight.c:56:69: error: ‘%d’ directive output may be truncated writing between 1 and 10 bytes into a region of size 3 [-Werror=format-truncation=]
56 | snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
| ^~
In function ‘nouveau_get_backlight_name’,
inlined from ‘nouveau_backlight_init’ at ../drivers/gpu/drm/nouveau/nouveau_backlight.c:351:7:
../drivers/gpu/drm/nouveau/nouveau_backlight.c:56:56: note: directive argument in the range [1, 2147483647]
56 | snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
| ^~~~~~~~~~~~~~~~
../drivers/gpu/drm/nouveau/nouveau_backlight.c:56:17: note: ‘snprintf’ output between 14 and 23 bytes into a destination of size 15
56 | snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Silence the warning by checking the snprintf() return value.
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
Cc: Karol Herbst <kherbst@xxxxxxxxxx>
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: Danilo Krummrich <dakr@xxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: nouveau@xxxxxxxxxxxxxxxxxxxxx
---
drivers/gpu/drm/nouveau/nouveau_backlight.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index d47442125fa1..1d77a5f280c5 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -49,13 +49,18 @@ nouveau_get_backlight_name(char backlight_name[BL_NAME_SIZE],
struct nouveau_backlight *bl)
{
const int nb = ida_alloc_max(&bl_ida, 99, GFP_KERNEL);
+ int ret;
if (nb < 0)
return false;
if (nb > 0)
- snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
+ ret = snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight%d", nb);
else
- snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight");
+ ret = snprintf(backlight_name, BL_NAME_SIZE, "nv_backlight");
+
+ if (ret >= BL_NAME_SIZE)
+ return false;
+
bl->id = nb;
return true;
}
--
2.39.2
