Re: [PATCH 1/3] vxlan: silence one build warning

[Stephen Hemminger <stephen@networkplumber.org>]

On Sat, 26 Oct 2013 15:06:04 +0800
Zhi Yong Wu <zwu.kernel@gmail.com> wrote:

> On Fri, Oct 25, 2013 at 11:41 PM, Stephen Hemminger
> <stephen@networkplumber.org> wrote:
> > On Fri, 25 Oct 2013 15:49:18 +0800
> > Zhi Yong Wu <zwu.kernel@gmail.com> wrote:
> >
> >> From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
> >>
> >> drivers/net/vxlan.c: In function ‘vxlan_sock_add’:
> >> drivers/net/vxlan.c:2298:11: warning: ‘sock’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> >> drivers/net/vxlan.c:2275:17: note: ‘sock’ was declared here
> >>   LD      drivers/net/built-in.o
> >>
> >> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
> >> ---
> >>  drivers/net/vxlan.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
> >> index 2ef5b62..e15f1af 100644
> >> --- a/drivers/net/vxlan.c
> >> +++ b/drivers/net/vxlan.c
> >> @@ -2272,7 +2272,7 @@ static struct vxlan_sock *vxlan_socket_create(struct net *net, __be16 port,
> >>  {
> >>       struct vxlan_net *vn = net_generic(net, vxlan_net_id);
> >>       struct vxlan_sock *vs;
> >> -     struct socket *sock;
> >> +     struct socket *sock = NULL;
> >>       struct sock *sk;
> >>       int rc = 0;
> >>       unsigned int h;
> >
> > This only happens with certain versions of Gcc which have buggy dependency
> > analysis. It doesn't happen with Gcc 4.7, think it only shows up in 4.4.
> > I would rather not fix the warning this way since it risks masking later bugs if this code ever changes.
> Gcc version is 4.7.2 on my box, this warning took palce.
> # gcc -v
> Using built-in specs.
> COLLECT_GCC=gcc
> ...
> gcc version 4.7.2 20120921 (Red Hat 4.7.2-2) (GCC)
> 
> 

I dont see it on Debian 7.
$ gcc -v
Using built-in specs.
COLLECT_GCC=/usr/bin/gcc-4.7.real
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.7.2-5' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --with-arch-32=i586 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.2 (Debian 4.7.2-5)