Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1751442AbdHFWKP (ORCPT <rfc822;w@1wt.eu>);
        Sun, 6 Aug 2017 18:10:15 -0400
Received: from bedivere.hansenpartnership.com ([66.63.167.143]:37384 "EHLO
        bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK)
        by vger.kernel.org with ESMTP id S1751345AbdHFWKL (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Sun, 6 Aug 2017 18:10:11 -0400
Message-ID: <1502057361.2673.21.camel@HansenPartnership.com>
Subject: Re: [PATCH v06 04/36] uapi scsi/scsi_netlink_fc.h: use __u16, __u32
 and __u64 from linux/types.h
From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
        linux-scsi@vger.kernel.org
Date: Sun, 06 Aug 2017 15:09:21 -0700
In-Reply-To: <20170806204224.GE28459@lakka.kapsi.fi>
References: <20170806164428.2273-1-mikko.rapeli@iki.fi>
         <20170806164428.2273-5-mikko.rapeli@iki.fi>
         <1502043773.2673.9.camel@HansenPartnership.com>
         <20170806204224.GE28459@lakka.kapsi.fi>
Content-Type: text/plain; charset="UTF-8"
X-Mailer: Evolution 3.20.5 
Mime-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1402
Lines: 34

On Sun, 2017-08-06 at 23:42 +0300, Mikko Rapeli wrote:
> Hi,
> 
> On Sun, Aug 06, 2017 at 11:22:53AM -0700, James Bottomley wrote:
> > 
> > On Sun, 2017-08-06 at 18:43 +0200, Mikko Rapeli wrote:
> > > 
> > > Fixes userspace compilation errors like:
> > > 
> > > scsi/scsi_netlink_fc.h:60:2: error: expected specifier-qualifier-
> > > list  before ‘uint64_t’
> > 
> > Rather than patching the kernel, why not #include <stdint.h> in
> > your userspace programme?
> 
> The userspace program is actually a test which checks that uapi
> headers compile alone because several headers are not compiling at
> all and/or require special tricks. The test is available here:
> 
> http://marc.info/?l=linux-kernel&m=150203944104544&w=2

But you don't seem to be detecting or fixing an existing problem.
 These types are width unambiguous and all current consumers of these
headers include stdint.h so you're churning the kernel for a problem
which doesn't currently exist for any consumer of this header.

I can agree not adding any more external uint<x>_t types for newly
exported headers so new consumers don't depend on an external standard
is reasonable, so checkpatch should warn if someone tries to add them;
I just don't see the benefit of going over the whole kernel changing
stuff that has worked fine for years.  Now if you can tell me there's
an actual bug somewhere, that's different ...

James