Re: [PATCH] selftest:net: Fix uninit pointers and return values

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

[PATCH net]

and a Fixes tag

Sidharth Seela wrote:
> Fix uninitialized character pointers, and functions that return
> undefined values. These issues were caught by running clang using LLVM=1
> option; and are as follows:
> --
> ovpn-cli.c:1587:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
>  1587 |         if (!sock) {
>       |             ^~~~~
> ovpn-cli.c:1635:9: note: uninitialized use occurs here
>  1635 |         return ret;
>       |                ^~~
> ovpn-cli.c:1587:2: note: remove the 'if' if its condition is always false
>  1587 |         if (!sock) {
>       |         ^~~~~~~~~~~~
>  1588 |                 fprintf(stderr, "cannot allocate netlink socket\n");
>       |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>  1589 |                 goto err_free;
>       |                 ~~~~~~~~~~~~~~
>  1590 |         }
>       |         ~
> ovpn-cli.c:1584:15: note: initialize the variable 'ret' to silence this warning
>  1584 |         int mcid, ret;
>       |                      ^
>       |                       = 0
> ovpn-cli.c:2107:7: warning: variable 'ret' is used uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
>  2107 |         case CMD_INVALID:
>       |              ^~~~~~~~~~~
> ovpn-cli.c:2111:9: note: uninitialized use occurs here
>  2111 |         return ret;
>       |                ^~~
> ovpn-cli.c:1939:12: note: initialize the variable 'ret' to silence this warning
>  1939 |         int n, ret;
>       |                   ^

These two look legitimate.

>       |
> --
> txtimestamp.c:240:2: warning: variable 'tsname' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
>   240 |         default:

Does not need a fix. The default statement calls error() which exits the program.

>       |         ^~~~~~~
> txtimestamp.c:244:20: note: uninitialized use occurs here
>   244 |         __print_timestamp(tsname, &tss->ts[0], tskey, payload_len);
>       |                           ^~~~~~
> txtimestamp.c:220:20: note: initialize the variable 'tsname' to silence this warning
>   220 |         const char *tsname;
>       |                           ^
>       |                            = NULL
> --
> so_txtime.c:210:3: warning: variable 'reason' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
>   210 |                 default:
>       |                 ^~~~~~~

Same.

> so_txtime.c:219:27: note: uninitialized use occurs here
>   219 |                         data[ret - 1], tstamp, reason);
>       |                                                ^~~~~~
> so_txtime.c:177:21: note: initialize the variable 'reason' to silence this warning
>   177 |                 const char *reason;
>       |                                   ^
>       |
> --
> 
> Signed-off-by: Sidharth Seela <sidharthseela@gmail.com>

Agreed on all the occurrences and the ovpn fixes.

> ---
> 
> diff --git a/tools/testing/selftests/net/ovpn/ovpn-cli.c b/tools/testing/selftests/net/ovpn/ovpn-cli.c
> index 9201f2905f2c..20d00378f34a 100644
> --- a/tools/testing/selftests/net/ovpn/ovpn-cli.c
> +++ b/tools/testing/selftests/net/ovpn/ovpn-cli.c
> @@ -1581,7 +1581,7 @@ static int ovpn_listen_mcast(void)
>  {
>  	struct nl_sock *sock;
>  	struct nl_cb *cb;
> -	int mcid, ret;
> +	int mcid, ret = -1;
>  
>  	sock = nl_socket_alloc();
>  	if (!sock) {
> @@ -1936,7 +1936,7 @@ static int ovpn_run_cmd(struct ovpn_ctx *ovpn)
>  {
>  	char peer_id[10], vpnip[INET6_ADDRSTRLEN], laddr[128], lport[10];
>  	char raddr[128], rport[10];
> -	int n, ret;
> +	int n, ret = -1;
>  	FILE *fp;
>  
>  	switch (ovpn->cmd) {
> diff --git a/tools/testing/selftests/net/so_txtime.c b/tools/testing/selftests/net/so_txtime.c
> index 8457b7ccbc09..b76df1efc2ef 100644
> --- a/tools/testing/selftests/net/so_txtime.c
> +++ b/tools/testing/selftests/net/so_txtime.c
> @@ -174,7 +174,7 @@ static int do_recv_errqueue_timeout(int fdt)
>  	msg.msg_controllen = sizeof(control);
>  
>  	while (1) {
> -		const char *reason;
> +		const char *reason = NULL;

Since reason is a string that's printed, better to initialize it to a
string. Preferably in the case statement, e.g., "unknown errno".

>  
>  		ret = recvmsg(fdt, &msg, MSG_ERRQUEUE);
>  		if (ret == -1 && errno == EAGAIN)
> diff --git a/tools/testing/selftests/net/txtimestamp.c b/tools/testing/selftests/net/txtimestamp.c
> index dae91eb97d69..bcc14688661d 100644
> --- a/tools/testing/selftests/net/txtimestamp.c
> +++ b/tools/testing/selftests/net/txtimestamp.c
> @@ -217,7 +217,7 @@ static void print_timestamp_usr(void)
>  static void print_timestamp(struct scm_timestamping *tss, int tstype,
>  			    int tskey, int payload_len)
>  {
> -	const char *tsname;
> +	const char *tsname = NULL;
>  
>  	validate_key(tskey, tstype);
>  
> -- 
> 2.47.3
>