Re: [PATCH v3 1/2] net: tap: check if the file descriptor is valid before using it

[Jason Wang <jasowang@redhat.com>]

On 2020/7/2 上午3:39, Laurent Vivier wrote:
> +void qemu_set_nonblock(int fd)
> +{
> +    int f;
> +    f = qemu_try_set_nonblock(fd);
> +    assert(f == 0);
>   }


So we keep this assert which means it can still be triggered from monitor?

I don't check all the callers, but I got:

in tap_init_one() we had:

         if (vhostfdname) {
             vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
             if (vhostfd == -1) {
                 if (tap->has_vhostforce && tap->vhostforce) {
                     error_propagate(errp, err);
                 } else {
                     warn_report_err(err);
                 }
                 return;
             }
             qemu_set_nonblock(vhostfd);
         } else {

and in net_init_socket() we had:

     if (sock->has_fd) {
         int fd;

         fd = monitor_fd_param(cur_mon, sock->fd, errp);
         if (fd == -1) {
             return -1;
         }
         qemu_set_nonblock(fd);
         if (!net_socket_fd_init(peer, "socket", name, fd, 1, sock->mcast,
                                 errp)) {
             return -1;
         }
         return 0;
     }

Thanks