Re: [PATCH v3 net-next 9/9] selftest: af_unix: Test SO_PASSRIGHTS.

[Kuniyuki Iwashima <kuniyu@amazon.com>]

From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: Thu, 15 May 2025 15:27:22 -0400
> > @@ -227,10 +297,18 @@ void __send_fd(struct __test_metadata *_metadata,
> >  		.msg_control = &cmsg,
> >  		.msg_controllen = CMSG_SPACE(sizeof(cmsg.fd)),
> >  	};
> > -	int ret;
> > +	int ret, saved_errno;
> >  
> > +	errno = 0;
> >  	ret = sendmsg(self->fd[receiver * 2 + 1], &msg, variant->flags);
> > -	ASSERT_EQ(MSGLEN, ret);
> > +	saved_errno = errno;
> > +
> > +	if (variant->disabled) {
> > +		ASSERT_EQ(-1, ret);
> > +		ASSERT_EQ(-EPERM, -saved_errno);
> > +	} else {
> > +		ASSERT_EQ(MSGLEN, ret);
> > +	}
> 
> Why is this errno complexity needed?
> 
> It should never be needed to manually reset errno.
> 
> Is the saved_errno there because ASSERT_EQ on ret could call a libc
> function that resets errno?

I guess it's paranoid here.

When ASSERT_EQ() calls TH_LOG(), it always fails and does
not reach the 2nd ASSERT_EQ().

Will remove them.

Thanks!