Subject: Re: [PATCH 1/4] printk: add %I4, %I6, %i4, %i6 format specifiers

From: Harvey Harrison <[email-masked]>
Date: Thu, 30 Oct 2008 16:59:59 -0700

On Thu, 2008-10-30 at 13:28 -0700, Joe Perches wrote:
> On Wed, 2008-10-29 at 11:35 -0700, Harvey Harrison wrote:
> >  		return ip6_addr_string(buf, end, ptr, field_width, precision, flags);
> > +	case 'i':
> > +		flags |= SPECIAL;
> > +		/* Fallthrough */
> > +	case 'I':
> > +		if (fmt[1] == '6')
> > +			return ip6_addr_string(buf, end, ptr, field_width, precision, flags);
> > +		if (fmt[1] == '4')
> > +			return ip4_addr_string(buf, end, ptr, field_width, precision, flags);
> > +		flags &= ~SPECIAL;
> > +		break;
> >  	}
> >  	flags |= SMALL;
> >  	if (field_width == -1) {
> 
> Hi Harvey.
> 
> I was thinking about extending %p<foo> to support
> struct task_struct * and noticed this code isn't
> really correct.
> 
> SPECIAL should be cleared from flags only when *fmt
> is 'i' not 'I' and SPECIAL wasn't previously set.
> 

SPECIAL is set when # is used with the p modifier...which warns as we've
already seen.  So the only way to set special in the %p case is to use
i.  Instead of having an if() I just unconditionally clear it (perhaps
unnecessarily).  Mind you, we only get here if you pass in %p[iI][not 4 or 6]

Cheers,

Harvey