From: Dmitry V. Levin <ldv@altlinux.org>
Date: Wed, 7 Feb 2018 12:32:57 +0000 (+0000)
Subject: tests: rewrite net-accept-connect.c without strncpy
X-Git-Tag: v4.21~55
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=85bd0dcea1a72ce4f1d4a247682155b0246a3ab9;p=strace

tests: rewrite net-accept-connect.c without strncpy

gcc8 -Wall -Werror rejects our method of struct sockaddr_un.sun_path
initialization because the field lacks __nonstring__ attribute.

As we calculate the length of the string being copied anyway,
workaround this gcc+glibc bug by changing the code to use this
pre-calculated length and get rid of strncpy completely.

* tests/net-accept-connect.c (main): Use memcpy to initialize sun_path.
---

diff --git a/tests/net-accept-connect.c b/tests/net-accept-connect.c
index 4045e056..64a5fcdf 100644
--- a/tests/net-accept-connect.c
+++ b/tests/net-accept-connect.c
@@ -49,15 +49,16 @@ main(int ac, const char **av)
 	struct sockaddr_un addr = {
 		.sun_family = AF_UNIX,
 	};
-	socklen_t len;
 
 	assert(ac == 2);
-	assert(strlen(av[1]) > 0);
+	socklen_t len = strlen(av[1]);
+	assert(len > 0 && len <= sizeof(addr.sun_path));
 
-	strncpy(addr.sun_path, av[1], sizeof(addr.sun_path));
-	len = offsetof(struct sockaddr_un, sun_path) + strlen(av[1]) + 1;
-	if (len > sizeof(addr))
-		len = sizeof(addr);
+	if (++len > sizeof(addr.sun_path))
+		len = sizeof(addr.sun_path);
+
+	memcpy(addr.sun_path, av[1], len);
+	len += offsetof(struct sockaddr_un, sun_path);
 
 	unlink(av[1]);
 	close(0);