From: Pablo Neira Ayuso <pablo@netfilter.org>
To: Phil Sutter <phil@nwl.cc>, netfilter-devel@vger.kernel.org
Subject: Re: [nf-next PATCH] netfilter: include: uapi: Use C99 flexible array member
Date: Fri, 17 Jul 2020 12:20:56 +0200 [thread overview]
Message-ID: <20200717102056.GA18560@salvia> (raw)
In-Reply-To: <20200717100648.GE23632@orbyte.nwl.cc>
On Fri, Jul 17, 2020 at 12:06:48PM +0200, Phil Sutter wrote:
> Hi Pablo,
>
> On Wed, Jul 15, 2020 at 08:14:33PM +0200, Pablo Neira Ayuso wrote:
> > On Mon, Jul 13, 2020 at 01:15:52PM +0200, Phil Sutter wrote:
> > [...]
> > > Avoid this warning by declaring 'entries' as an ISO C99 flexible array
> > > member. This makes gcc aware of the intended use and enables sanity
> > > checking as described in:
> > > https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
> > >
> > > Signed-off-by: Phil Sutter <phil@nwl.cc>
> > > ---
> > > include/uapi/linux/netfilter_ipv4/ip_tables.h | 2 +-
> > > include/uapi/linux/netfilter_ipv6/ip6_tables.h | 2 +-
> > > 2 files changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/include/uapi/linux/netfilter_ipv4/ip_tables.h b/include/uapi/linux/netfilter_ipv4/ip_tables.h
> > > index 50c7fee625ae9..1a298cc7a29c1 100644
> > > --- a/include/uapi/linux/netfilter_ipv4/ip_tables.h
> > > +++ b/include/uapi/linux/netfilter_ipv4/ip_tables.h
> > > @@ -203,7 +203,7 @@ struct ipt_replace {
> > > struct xt_counters __user *counters;
> > >
> > > /* The entries (hang off end: not really an array). */
> > > - struct ipt_entry entries[0];
> > > + struct ipt_entry entries[];
> >
> > arpt_replace uses this idiom too.
>
> Oh, indeed. I focussed on those cases gcc complained about when
> compiling iptables. Grepping for '\[0\]' in all of
> include/uapi/linux/netfilter* reveals a few more cases. Do you think
> it's worth "fixing" those as well?
It seems this patch was missing a few spots, right?
commit 6daf14140129d30207ed6a0a69851fa6a3636bda
Author: Gustavo A. R. Silva <gustavo@embeddedor.com>
Date: Thu Feb 20 07:59:14 2020 -0600
netfilter: Replace zero-length array with flexible-array member
Probably Cc: Gustavo to confirm this.
prev parent reply other threads:[~2020-07-17 10:21 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-13 11:15 [nf-next PATCH] netfilter: include: uapi: Use C99 flexible array member Phil Sutter
2020-07-15 18:14 ` Pablo Neira Ayuso
2020-07-17 10:06 ` Phil Sutter
2020-07-17 10:20 ` Pablo Neira Ayuso [this message]
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