[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 2/3] Don't exit() in config_error()
From: |
Mark McLoughlin |
Subject: |
Re: [Qemu-devel] [PATCH 2/3] Don't exit() in config_error() |
Date: |
Wed, 30 Sep 2009 11:27:42 +0100 |
On Mon, 2009-09-28 at 21:11 +0200, Markus Armbruster wrote:
> Propagating errors up the call chain is tedious. In startup code, we
> can take a shortcut: terminate the program. This is wrong elsewhere,
> the monitor in particular.
>
> config_error() tries to cater for both customers: it terminates the
> program unless its mon parameter tells it it's working for the
> monitor.
>
> Its users need to return status anyway (unless passing a null mon
> argument, which none do), which their users need to check. So this
> automatic exit buys us exactly nothing useful. Only the dangerous
> delusion that we can get away without returning status. Some of its
> users fell for that. Their callers continue executing after failure
> when working for the monitor.
>
> This bites monitor command host_net_add in two places:
>
> * net_slirp_init() continues after slirp_hostfwd(), slirp_guestfwd(),
> or slirp_smb() failed, and may end up reporting success. This
> happens for "host_net_add user guestfwd=foo": it complains about the
> invalid guest forwarding rule, then happily creates the user network
> without guest forwarding.
>
> * net_client_init() can't detect slirp_guestfwd() failure, and gets
> fooled by net_slirp_init() lying about success. Suppresses its
> "Could not initialize device" message.
>
> Add the missing error reporting, make sure errors are checked, and
> drop the exit() from config_error().
>
> Signed-off-by: Markus Armbruster <address@hidden>
> ---
> net.c | 83 ++++++++++++++++++++++++++++++++++++----------------------------
> net.h | 4 +-
> vl.c | 9 ++++--
> 3 files changed, 55 insertions(+), 41 deletions(-)
>
...
> diff --git a/vl.c b/vl.c
> index 7bfd415..96e4312 100644
> --- a/vl.c
> +++ b/vl.c
...
> @@ -5766,7 +5768,8 @@ int main(int argc, char **argv, char **envp)
>
> /* init USB devices */
> if (usb_enabled) {
> - foreach_device_config(DEV_USB, usb_parse);
> + if (foreach_device_config(DEV_USB, usb_parse) < 0)
> + exit(1);
> }
>
> /* init generic devices */
This hunk appears to be unrelated
Cheers,
Mark.