netdev - Re: may I ignore "net/core/rtnetlink.c:3156:1: warning: the frame size of 1280 bytes ..."?

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Date:   Sun, 04 Nov 2018 09:15:45 -0800
From:   Joe Perches <joe@...ches.com>
To:     Toralf Förster <toralf.foerster@....de>,
        netdev@...r.kernel.org, Kees Cook <kees.cook@...onical.com>
Cc:     Linux Kernel <linux-kernel@...r.kernel.org>
Subject: Re: may I ignore "net/core/rtnetlink.c:3156:1: warning: the frame
 size of 1280 bytes ..."?

On Sun, 2018-11-04 at 17:14 +0100, Toralf Förster wrote:
> compiling recent kernel (4.18.x, 4.19.1) at my server I do still get :
> 
> 
> net/core/rtnetlink.c: In function ‘rtnl_newlink’:
> net/core/rtnetlink.c:3156:1: warning: the frame size of 1280 bytes is larger than 1024 bytes [-Wframe-larger-than=]
> 
> 
> with "gcc version 7.3.0 (Gentoo Hardened 7.3.0-r3 p1.4) " and do wonder whether it is safe to ignore it?
> 

This was introduce by a desire to eliminate variable length array
declarations by

commit ccf8dbcd062a930e64741c939ca784d15316aa0c
Author: Kees Cook <
keescook@...omium.org>
Date:   Wed May 30 15:20:52 2018 -0700

    rtnetlink: Remove VLA usage

It does make the stack use here unfortunately obviously large, but
it could have been this large, just unreported.

Perhaps no obvious solution here as an alloc instead of stack use
may be costly.