Re: [PATCH] conf, tap: Silence two false positive invalidFunctionArg from cppcheck

[David Gibson <david@gibson.dropbear.id.au>]

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On Thu, Feb 16, 2023 at 07:22:10PM +0100, Stefano Brivio wrote:
> The newly introduced die() calls exit(), but cppcheck doesn't see it
> and warns about possibly invalid arguments used after the check which
> triggers die(). Add return statements to silence the warnings.
> 
> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Oof, that's super ugly.  Any chance that cppcheck will recognize the
((noreturn)) attribute if we added it to die()?

> ---
>  conf.c | 3 +++
>  tap.c  | 6 +++++-
>  2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/conf.c b/conf.c
> index 675d961..5426c9b 100644
> --- a/conf.c
> +++ b/conf.c
> @@ -1036,6 +1036,9 @@ static void conf_ugid(char *runas, uid_t *uid, gid_t *gid)
>  	if ((fd = open("/proc/self/uid_map", O_RDONLY | O_CLOEXEC)) < 0) {
>  		die("Can't determine if we're in init namespace: %s",
>  		    strerror(errno));
> +
> +		/* Silence cppcheck's invalidFunctionArg for 'fd' in read() */
> +		return;
>  	}
>  
>  	if (read(fd, buf, BUFSIZ) != sizeof(root_uid_map) ||
> diff --git a/tap.c b/tap.c
> index 88eed88..d6f962e 100644
> --- a/tap.c
> +++ b/tap.c
> @@ -1037,9 +1037,13 @@ static void tap_sock_unix_init(struct ctx *c)
>  			snprintf(path, UNIX_PATH_MAX - 1, UNIX_SOCK_PATH, i);
>  
>  		ex = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK, 0);
> -		if (ex < 0)
> +		if (ex < 0) {
>  			die("UNIX domain socket check: %s", strerror(errno));
>  
> +			/* Silence cppcheck's invalidFunctionArg for 'ex' */
> +			return;
> +		}
> +
>  		ret = connect(ex, (const struct sockaddr *)&addr, sizeof(addr));
>  		if (!ret || (errno != ENOENT && errno != ECONNREFUSED &&
>  			     errno != EACCES)) {

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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