diff options
authorArnd Bergmann <arnd@arndb.de>2018-02-22 16:55:34 +0100
committerDavid S. Miller <davem@davemloft.net>2018-02-23 10:53:26 -0500
commitca79bec237f5809a7c3c59bd41cd0880aa889966 (patch)
parent4e14bf4236490306004782813b8b4494b18f5e60 (diff)
ipv6 sit: work around bogus gcc-8 -Wrestrict warning
gcc-8 has a new warning that detects overlapping input and output arguments in memcpy(). It triggers for sit_init_net() calling ipip6_tunnel_clone_6rd(), which is actually correct: net/ipv6/sit.c: In function 'sit_init_net': net/ipv6/sit.c:192:3: error: 'memcpy' source argument is the same as destination [-Werror=restrict] The problem here is that the logic detecting the memcpy() arguments finds them to be the same, but the conditional that tests for the input and output of ipip6_tunnel_clone_6rd() to be identical is not a compile-time constant. We know that netdev_priv(t->dev) is the same as t for a tunnel device, and comparing "dev" directly here lets the compiler figure out as well that 'dev == sitn->fb_tunnel_dev' when called from sit_init_net(), so it no longer warns. This code is old, so Cc stable to make sure that we don't get the warning for older kernels built with new gcc. Cc: Martin Sebor <msebor@gmail.com> Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83456 Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 3873d3877135..3a1775a62973 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -182,7 +182,7 @@ static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
struct ip_tunnel *t = netdev_priv(dev);
- if (t->dev == sitn->fb_tunnel_dev) {
+ if (dev == sitn->fb_tunnel_dev) {
ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
t->ip6rd.relay_prefix = 0;
t->ip6rd.prefixlen = 16;