linux-kernel - [PATCH] kernfs: Replace strncpy with memcpy

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Date:   Sun,  1 Jul 2018 13:57:13 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     linux-kernel@...r.kernel.org, Tejun Heo <tj@...nel.org>,
        Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH] kernfs: Replace strncpy with memcpy

gcc 8.1.0 complains:

fs/kernfs/symlink.c:91:3: warning:
	'strncpy' output truncated before terminating nul copying
	as many bytes from a string as its length
fs/kernfs/symlink.c: In function 'kernfs_iop_get_link':
fs/kernfs/symlink.c:88:14: note: length computed here

Using strncpy() is indeed less than perfect since the length of data to
be copied has already been determined with strlen(). Replace strncpy()
with memcpy() to address the warning and optimize the code a little.

Signed-off-by: Guenter Roeck <linux@...ck-us.net>
---
 fs/kernfs/symlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index 08ccabd7047f..5145ae2f0572 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -88,7 +88,7 @@ static int kernfs_get_target_path(struct kernfs_node *parent,
 		int slen = strlen(kn->name);
 
 		len -= slen;
-		strncpy(s + len, kn->name, slen);
+		memcpy(s + len, kn->name, slen);
 		if (len)
 			s[--len] = '/';
 
-- 
2.7.4