linux-kernel - Re: [PATCH RESEND v3 09/24] ptrace: cleanup arch

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Date:	Sat, 02 Oct 2010 13:59:11 +0900
From:	Namhyung Kim <namhyung@...il.com>
To:	"Daniel K." <dk@...no>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Roland McGrath <roland@...hat.com>,
	Oleg Nesterov <oleg@...hat.com>, linux-kernel@...r.kernel.org,
	David Howells <dhowells@...hat.com>
Subject: Re: [PATCH RESEND v3 09/24] ptrace: cleanup arch_ptrace() on frv

2010-10-02 (토), 12:57 +0900, Namhyung Kim:
> 2010-10-02 (토), 03:18 +0000, Daniel K.:
> > Namhyung Kim wrote:
> > >       case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
> > >             ret = -EIO;
> > -             if ((addr & 3) || addr < 0)
> > +             if (addr & 3)
> >                     break;
> >
> > > -		ret = 0;
> > > -		switch (addr >> 2) {
> > > +		switch (regno) {
> > >  		case 0 ... PT__END - 1:
> > > -			ret = put_reg(child, addr >> 2, data);
> > > -			break;
> > > -
> > > -		default:
> > > -			ret = -EIO;
> > > +			ret = put_reg(child, regno, data);
> > >  			break;
> > >  		}
> > >  		break;
> > 
> > With this, you remove the default case, and no longer return -EIO in the
> > cases of PT__END + n, as in the PTRACE_PEEKUSR section above.
> > 
> > This is a change of behaviour as far as I can tell, and not just a cleanup.
> > 
> > 
> > Daniel K.
> 
> My bad. It should be my mistake. Will resend the fix soon.
> Thanks.
> 
> 

My mistake, again. I was bit confused.

It would not be a change of behaviour. Because 'ret' was initialized
with -EIO and only changed in the switch case. So assignment before
switch can be removed and then will return -EIO in default case.

Thanks.


-- 
Regards,
Namhyung Kim


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