linux-kernel - Re: [PATCH] printf: add support for printing symbolic error codes

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Date:   Fri, 30 Aug 2019 15:21:00 -0700
From:   Joe Perches <joe@...ches.com>
To:     Rasmus Villemoes <linux@...musvillemoes.dk>,
        Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
        Uwe Kleine-König <uwe@...ine-koenig.org>,
        Petr Mladek <pmladek@...e.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Juergen Gross <jgross@...e.com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] printf: add support for printing symbolic error codes

On Sat, 2019-08-31 at 00:03 +0200, Rasmus Villemoes wrote:
> On 30/08/2019 23.53, Joe Perches wrote:
> > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> > []
> > > @@ -2178,8 +2204,6 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
> > >  		return flags_string(buf, end, ptr, spec, fmt);
> > >  	case 'O':
> > >  		return kobject_string(buf, end, ptr, spec, fmt);
> > > -	case 'x':
> > > -		return pointer_string(buf, end, ptr, spec);
> > >  	}
> > >  
> > >  	/* default is to _not_ leak addresses, hash before printing */
> > 
> > why remove this?
> > 
> 
> The handling of %px is moved above the test for ptr being an ERR_PTR, so
> that %px, ptr continues to be (roughly) equivalent to %08lx, (long)ptr.

Ah.
Pity the flow of the switch/case is disrupted.
That now deserves a separate comment.

But why not just extend check_pointer_msg?