linux-kernel - Re: [PATCH] xenbus: Neaten xenbus_va_dev

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Date:   Wed, 08 Feb 2017 10:20:14 -0800
From:   Joe Perches <joe@...ches.com>
To:     Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        linux-kernel@...r.kernel.org
Cc:     Juergen Gross <jgross@...e.com>, xen-devel@...ts.xenproject.org
Subject: Re: [PATCH] xenbus: Neaten xenbus_va_dev_error

On Wed, 2017-02-08 at 12:14 -0500, Boris Ostrovsky wrote:
> On 02/08/2017 11:05 AM, Joe Perches wrote:
> > On Wed, 2017-02-08 at 10:33 -0500, Boris Ostrovsky wrote:
> > > On 02/08/2017 06:33 AM, Joe Perches wrote:
> > > > This function error patch can be simplified, so do so.
> > > > 
> > > > Remove fail: label and somewhat obfuscating, used once "error_path"
> > > > function.
> > 
> > btw: I left it alone, but likely
> > 
> > #define PRINTF_BUFFER_SIZE 4096
> > 
> > is probably excessive as the maximum printk
> > buffer is 1024.
> > 
> > The xenbus_write might be longer though so
> > maybe it's OK to use 4096, but there is some
> > inequivalence there.
> > 
> 
> xenbus_write() handles writes up to 4K. However we are filling the
> buffer with sprintf() which I assume is limited to 1K too

vsnprintf is bounded only by addressable memory. ie: (void *)-1

> so it indeed
> doesn't seem useful to have PRINTF_BUFFER_SIZE set to 4.
> 
> -boris
>