[PATCH] gpu/drm: fix a -Wstringop-truncation warning

From: Qian Cai
Date: Fri Aug 23 2019 - 14:37:47 EST


In file included from ./include/linux/bitmap.h:9,
from ./include/linux/cpumask.h:12,
from ./arch/x86/include/asm/cpumask.h:5,
from ./arch/x86/include/asm/msr.h:11,
from ./arch/x86/include/asm/processor.h:21,
from ./arch/x86/include/asm/cpufeature.h:5,
from ./arch/x86/include/asm/thread_info.h:53,
from ./include/linux/thread_info.h:38,
from ./arch/x86/include/asm/preempt.h:7,
from ./include/linux/preempt.h:78,
from ./include/linux/rcupdate.h:27,
from ./include/linux/rculist.h:11,
from ./include/linux/pid.h:5,
from ./include/linux/sched.h:14,
from ./include/linux/uaccess.h:5,
from drivers/gpu/drm/drm_property.c:24:
In function 'strncpy',
inlined from 'drm_property_create' at
drivers/gpu/drm/drm_property.c:130:2:
./include/linux/string.h:305:9: warning: '__builtin_strncpy' specified
bound 32 equals destination size [-Wstringop-truncation]
return __builtin_strncpy(p, q, size);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix it by using strscpy() which will always return a valid string, and
doesn't unnecessarily force the tail of the destination buffer to be
zeroed.

Signed-off-by: Qian Cai <cai@xxxxxx>
---
drivers/gpu/drm/drm_property.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_property.c b/drivers/gpu/drm/drm_property.c
index 892ce636ef72..66ec2cc7a559 100644
--- a/drivers/gpu/drm/drm_property.c
+++ b/drivers/gpu/drm/drm_property.c
@@ -127,8 +127,7 @@ struct drm_property *drm_property_create(struct drm_device *dev,
property->num_values = num_values;
INIT_LIST_HEAD(&property->enum_list);

- strncpy(property->name, name, DRM_PROP_NAME_LEN);
- property->name[DRM_PROP_NAME_LEN-1] = '\0';
+ strscpy(property->name, name, DRM_PROP_NAME_LEN);

list_add_tail(&property->head, &dev->mode_config.property_list);

--
1.8.3.1