diff mbox

HID: uhid: use strlcpy() instead of strncpy()

Message ID 1515500612-191425-1-git-send-email-wangxiongfeng2@huawei.com (mailing list archive)
State New, archived
Headers show

Commit Message

Xiongfeng Wang Jan. 9, 2018, 12:23 p.m. UTC 
From: Xiongfeng Wang <xiongfeng.wang@linaro.org>

gcc-8 reports

drivers/hid/uhid.c: In function 'uhid_dev_create2':
./include/linux/string.h:245:9: warning: '__builtin_strncpy' output may
be truncated copying 127 bytes from a string of length 127
[-Wstringop-truncation]

The compiler require that the input param 'len' of strncpy() should be
greater than the length of the src string, so that '\0' is copied as
well. We can just use strlcpy() to avoid this warning.

Signed-off-by: Xiongfeng Wang <xiongfeng.wang@linaro.org>
---
 drivers/hid/uhid.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Jiri Kosina Feb. 16, 2018, 12:37 p.m. UTC | #1 
On Tue, 9 Jan 2018, Xiongfeng Wang wrote:

> From: Xiongfeng Wang <xiongfeng.wang@linaro.org>
> 
> gcc-8 reports
> 
> drivers/hid/uhid.c: In function 'uhid_dev_create2':
> ./include/linux/string.h:245:9: warning: '__builtin_strncpy' output may
> be truncated copying 127 bytes from a string of length 127
> [-Wstringop-truncation]
> 
> The compiler require that the input param 'len' of strncpy() should be
> greater than the length of the src string, so that '\0' is copied as
> well. We can just use strlcpy() to avoid this warning.

Applied to for-4.17/upstream.
diff mbox

Patch

diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index 6f819f1..0315ddd 100644
--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -496,12 +496,12 @@  static int uhid_dev_create2(struct uhid_device *uhid,
 		goto err_free;
 	}
 
-	len = min(sizeof(hid->name), sizeof(ev->u.create2.name)) - 1;
-	strncpy(hid->name, ev->u.create2.name, len);
-	len = min(sizeof(hid->phys), sizeof(ev->u.create2.phys)) - 1;
-	strncpy(hid->phys, ev->u.create2.phys, len);
-	len = min(sizeof(hid->uniq), sizeof(ev->u.create2.uniq)) - 1;
-	strncpy(hid->uniq, ev->u.create2.uniq, len);
+	len = min(sizeof(hid->name), sizeof(ev->u.create2.name));
+	strlcpy(hid->name, ev->u.create2.name, len);
+	len = min(sizeof(hid->phys), sizeof(ev->u.create2.phys));
+	strlcpy(hid->phys, ev->u.create2.phys, len);
+	len = min(sizeof(hid->uniq), sizeof(ev->u.create2.uniq));
+	strlcpy(hid->uniq, ev->u.create2.uniq, len);
 
 	hid->ll_driver = &uhid_hid_driver;
 	hid->bus = ev->u.create2.bus;