Date: Sat, 5 Mar 2016 17:52:34 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, Peter Anvin <hpa@zytor.com>,
        Dave Hansen <dave@sr71.net>, Andrew Morton <akpm@linux-foundation.org>,
        Helge Deller <deller@gmx.de>, Stephen Rothwell <sfr@canb.auug.org.au>,
        "linux-tip-commits@vger.kernel.org" 
	<linux-tip-commits@vger.kernel.org>
Subject: Re: [tip:mm/pkeys] mm/pkeys: Fix siginfo ABI breakage caused by new
 u64 field
Message-ID: <20160305165234.GY6356@twins.programming.kicks-ass.net>
References: <20160301125451.02C7426D@viggo.jf.intel.com>
 <tip-16bc7477807393efb5b81f875888ee9221ead3a1@git.kernel.org>
 <CA+55aFweet30JmSc8zx1+vKGCPADuKFsMBi4CETeF9w4tfi5XA@mail.gmail.com>
 <20160305135006.GA15928@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20160305135006.GA15928@gmail.com>
User-Agent: Mutt/1.5.21 (2012-12-30)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 533
Lines: 9

On Sat, Mar 05, 2016 at 02:50:06PM +0100, Ingo Molnar wrote:
> A more workable method would be to have a test .c file that includes all UAPI 
> structures in existence and defines a variable out of every single one, and then 
> generates a list of sizeof() values or so. But even that isn't perfect: a 
> structure might shift some fields forward, into a pre-existing hole, without 
> changing the sizeof? We'd need a list of all field offsets in all structures to be 
> really sure, and that's nasty.

pahole has such logic, right?