Received-SPF: pass (google.com: domain of linux-kernel+bounces-70560-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
From: Rodrigo Campos <rodrigo@sdfg.com.ar>
To: Willy Tarreau <w@1wt.eu>,
	=?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>
Cc: linux-kernel@vger.kernel.org,
	Rodrigo Campos <rodrigo@sdfg.com.ar>
Subject: [PATCH v3 3/4] tools/nolibc: Fix strlcpy() return code and size usage
Date: Sun, 18 Feb 2024 16:51:05 -0300
Message-ID: <20240218195110.1386840-4-rodrigo@sdfg.com.ar>
In-Reply-To: <20240218195110.1386840-1-rodrigo@sdfg.com.ar>
References: <20240218195110.1386840-1-rodrigo@sdfg.com.ar>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

The return code should always be strlen(src), and we should copy at most
size-1 bytes.

While we are there, make sure to null-terminate the dst buffer if we
copied something.

Signed-off-by: Rodrigo Campos <rodrigo@sdfg.com.ar>
---
 tools/include/nolibc/string.h | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/tools/include/nolibc/string.h b/tools/include/nolibc/string.h
index cc51fd6b63d0..565230a4ad47 100644
--- a/tools/include/nolibc/string.h
+++ b/tools/include/nolibc/string.h
@@ -219,16 +219,18 @@ static __attribute__((unused))
 size_t strlcpy(char *dst, const char *src, size_t size)
 {
 	size_t len;
-	char c;
 
-	for (len = 0;;) {
-		c = src[len];
-		if (len < size)
-			dst[len] = c;
-		if (!c)
-			break;
-		len++;
+	for (len = 0; len < size; len++) {
+		dst[len] = src[len];
+		if (!dst[len])
+			return len;
 	}
+	if (size)
+		dst[size-1] = '\0';
+
+	while (src[len])
+		len++;
+
 	return len;
 }
 
-- 
2.43.0