linux-kernel - Re: [PATCH] bcachefs: Use snprintf() instead of scnprintf() when appropriate

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Message-ID: <20230920003847.nus6l45zqhv5hseb@moria.home.lan>
Date:   Tue, 19 Sep 2023 20:38:47 -0400
From:   Kent Overstreet <kent.overstreet@...ux.dev>
To:     Christophe JAILLET <christophe.jaillet@...adoo.fr>
Cc:     Brian Foster <bfoster@...hat.com>, linux-kernel@...r.kernel.org,
        kernel-janitors@...r.kernel.org, linux-bcachefs@...r.kernel.org
Subject: Re: [PATCH] bcachefs: Use snprintf() instead of scnprintf() when
 appropriate

On Tue, Sep 19, 2023 at 09:23:47PM +0200, Christophe JAILLET wrote:
> Le 19/09/2023 à 21:02, Kent Overstreet a écrit :
> > On Tue, Sep 19, 2023 at 09:17:27AM -0400, Brian Foster wrote:
> > > On Sat, Sep 16, 2023 at 09:30:19AM +0200, Christophe JAILLET wrote:
> > > > snprintf() and scnprintf() are the same, except for the returned value.
> > > > When this value is not used, it is more logical to use snprintf() which is
> > > > slightly simpler.
> > > > 
> > > > Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
> > > > ---
> > > 
> > > Seems reasonable:
> > > 
> > > Reviewed-by: Brian Foster <bfoster@...hat.com>
> > 
> > No, let's stay with scnprintf as the default - snprintf should be
> > deprecated except for when its return value is actually needed, using it
> > incorrectly has been a source of buffer overruns in the past.
> > 
> 
> Ok, I was not aware of it.
> 
> In this case, there are also some s/snprintf/scnprintf/ opportunities in
> fs/bcachefs
> 
> Does it make sense to update them or is it too low value changes?

Not terribly important - long term, I want to depracate both snprintf
and scnprintf and convert everything to printbufs.