Re: [Xen-devel] [PATCH 2/9] xen/pciback: Return proper error code from sscanf.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Fri, Sep 30, 2011 at 08:45:26AM +0100, Jan Beulich wrote:
> >>> On 29.09.11 at 21:52, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> wrote:
> > . instead of just hardcoding it to be -EINVAL.
> > 
> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> > ---
> >  drivers/xen/xen-pciback/pci_stub.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/drivers/xen/xen-pciback/pci_stub.c 
> > b/drivers/xen/xen-pciback/pci_stub.c
> > index 32d6891..d985b65 100644
> > --- a/drivers/xen/xen-pciback/pci_stub.c
> > +++ b/drivers/xen/xen-pciback/pci_stub.c
> > @@ -868,7 +868,7 @@ static inline int str_to_slot(const char *buf, int 
> > *domain, int *bus,
> >  	if (err == 4)
> >  		return 0;
> >  	else if (err < 0)
> > -		return -EINVAL;
> > +		return err;
> >  
> >  	/* try again without domain */
> >  	*domain = 0;
> 
> This should then also be done for the final return from the function:
> 
> 	return err < 0 ? err : -EINVAL;
> 
> But: Where did you read that {v,}sscanf() would return -E... values in
> hypothetical error cases? The C standard says it would return EOF
> when reaching the end of the input string before doing the first
> conversion; lib/vsprintf.c doesn't do so, and also doesn't say it might
> return -E... codes. Bottom line is that I think the code is more correct
> the way it is without this change.

will drop the patch..