From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olaf Hering <olaf@aepfle.de>
Subject: ioctl handling in netbsd_privcmd_hypercall()
Date: Wed, 18 Jan 2012 17:21:22 +0100
Message-ID: <20120118162122.GA14232@aepfle.de>
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I was looking at the slightly broken error handling in the new
xc_mem_paging_load() function and stumbled over the ioctl() handling in
netbsd_privcmd_hypercall().

Is ioctl() on NetBSD special? I would have expected it returns -1 on
error and the caller can deal with errno if it actually wants to.
But instead it returns the negative errno value or what the hypervisor
returned.

static int netbsd_privcmd_hypercall(xc_interface *xch, xc_osdep_handle h, privcmd_hypercall_t *hypercall)
{   
    int fd = (int)h;
    int error = ioctl(fd, IOCTL_PRIVCMD_HYPERCALL, hypercall);

    if (error < 0)
        return -errno;
    else
        return hypercall->retval;
}

I think do_domctl() is supposed to return -1 on error and let the caller
decide what to do. At least thats how its appearently done on Linux and
Solaris.

Olaf