Re: net/sunrpc/svcsock.c:527:32: warning: Variable 'uninitialized_var' is assigned a value that is never used. [unreadVariable]

[Chuck Lever]

> On Apr 8, 2020, at 5:32 PM, kbuild test robot <lkp@xxxxxxxxx> wrote:
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   f5e94d10e4c468357019e5c28d48499f677b284f
> commit: da1661b93bf489cdbc8bcea919b165d31b4810bf SUNRPC: Teach server to use xprt_sock_sendmsg for socket sends
> date:   3 weeks ago
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> 
> 
> cppcheck warnings: (new ones prefixed by >>)
> 
>   net/sunrpc/svcsock.c:405:9: warning: union member 'Anonymous0::all' is never used. [unusedStructMember]
>     long  all[SVC_PKTINFO_SPACE / sizeof(long)];
>           ^
>   net/sunrpc/svcsock.c:518:9: warning: union member 'Anonymous1::all' is never used. [unusedStructMember]
>     long  all[SVC_PKTINFO_SPACE / sizeof(long)];
>           ^
>>> net/sunrpc/svcsock.c:527:32: warning: Variable 'uninitialized_var' is assigned a value that is never used. [unreadVariable]
>    unsigned int uninitialized_var(sent);
>                                  ^
> 
> vim +/uninitialized_var +527 net/sunrpc/svcsock.c
> 
>   504	
>   505	/**
>   506	 * svc_udp_sendto - Send out a reply on a UDP socket
>   507	 * @rqstp: completed svc_rqst
>   508	 *
>   509	 * Returns the number of bytes sent, or a negative errno.
>   510	 */
>   511	static int svc_udp_sendto(struct svc_rqst *rqstp)
>   512	{
>   513		struct svc_xprt *xprt = rqstp->rq_xprt;
>   514		struct svc_sock	*svsk = container_of(xprt, struct svc_sock, sk_xprt);
>   515		struct xdr_buf *xdr = &rqstp->rq_res;
>   516		union {
>   517			struct cmsghdr	hdr;
>   518			long		all[SVC_PKTINFO_SPACE / sizeof(long)];
>   519		} buffer;
>   520		struct cmsghdr *cmh = &buffer.hdr;
>   521		struct msghdr msg = {
>   522			.msg_name	= &rqstp->rq_addr,
>   523			.msg_namelen	= rqstp->rq_addrlen,
>   524			.msg_control	= cmh,
>   525			.msg_controllen	= sizeof(buffer),
>   526		};
>> 527		unsigned int uninitialized_var(sent);
>   528		int err;
>   529	
>   530		svc_set_cmsg_data(rqstp, cmh);
>   531	
>   532		err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
>   533		xdr_free_bvec(xdr);
>   534		if (err == -ECONNREFUSED) {
>   535			/* ICMP error on earlier request. */
>   536			err = xprt_sock_sendmsg(svsk->sk_sock, &msg, xdr, 0, 0, &sent);
>   537			xdr_free_bvec(xdr);
>   538		}
>   539		if (err < 0)
>   540			return err;
>   541		return sent;

Wha? "sent" is used right here. Can someone explain this warning?


>   542	}
>   543	
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

--
Chuck Lever