Re: [Qemu-devel] [PATCH v2 2/2] ivshmem: add missing error exit(2)

[Stefan Hajnoczi <stefanha@redhat.com>]

On Mon, Jun 03, 2013 at 06:26:22AM -0600, Eric Blake wrote:
> On 06/03/2013 02:58 AM, Stefan Hajnoczi wrote:
> > If the user fails to specify 'chardev' or 'shm' then we cannot continue.
> > Exit right away so that we don't invoke shm_open(3) with a NULL pointer.
> > 
> > It would be nice to replace exit(1) with error returns in the PCI device
> > .init() function, but leave that for another patch since exit(1) is
> > currently used elsewhere.
> > 
> > Spotted by Coverity.
> > 
> > Cc: Cam Macdonell <cam@cs.ualberta.ca>
> > Cc: qemu-stable@nongnu.org
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> >  hw/misc/ivshmem.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> > index a19a6d6..5658f73 100644
> > --- a/hw/misc/ivshmem.c
> > +++ b/hw/misc/ivshmem.c
> > @@ -735,6 +735,7 @@ static int pci_ivshmem_init(PCIDevice *dev)
> >  
> >          if (s->shmobj == NULL) {
> >              fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
> > +            exit(1);
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>
> 
> However, I prefer exit(EXIT_FAILURE) rather than exit(1), to make it a
> bit easier to grep for known failure exits.  Libvirt has a syntax
> checker (taken from gnulib) that enforces such a style, if qemu would
> like to adopt that style.

I like EXIT_FAILURE too but the rest of the file inconsistently uses
exit(1) and exit(-1).  I decided exit(1) was the least evil but the
longer term fix is to return instead of exiting.