From owner-freebsd-arch@FreeBSD.ORG  Wed Jul  9 11:06:35 2014
Return-Path: <owner-freebsd-arch@FreeBSD.ORG>
Delivered-To: arch@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id 814D569D;
 Wed,  9 Jul 2014 11:06:35 +0000 (UTC)
Received: from mail110.syd.optusnet.com.au (mail110.syd.optusnet.com.au
 [211.29.132.97])
 by mx1.freebsd.org (Postfix) with ESMTP id 018252EAD;
 Wed,  9 Jul 2014 11:06:34 +0000 (UTC)
Received: from c122-106-147-133.carlnfd1.nsw.optusnet.com.au
 (c122-106-147-133.carlnfd1.nsw.optusnet.com.au [122.106.147.133])
 by mail110.syd.optusnet.com.au (Postfix) with ESMTPS id BEA66780D56;
 Wed,  9 Jul 2014 21:06:31 +1000 (EST)
Date: Wed, 9 Jul 2014 21:06:31 +1000 (EST)
From: Bruce Evans <brde@optusnet.com.au>
X-X-Sender: bde@besplex.bde.org
To: Bruce Evans <brde@optusnet.com.au>
Subject: Re: sys/proc.h inclusion of sys/time.h
In-Reply-To: <20140709201148.W1201@besplex.bde.org>
Message-ID: <20140709205126.V1201@besplex.bde.org>
References: <53BC4F49.7000903@FreeBSD.org>
 <20140709201148.W1201@besplex.bde.org>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
X-Optus-CM-Score: 0
X-Optus-CM-Analysis: v=2.1 cv=U6SrU4bu c=1 sm=1 tr=0
 a=7NqvjVvQucbO2RlWB8PEog==:117 a=PO7r1zJSAAAA:8 a=z5S34nFNDvQA:10
 a=kj9zAlcOel0A:10 a=JzwRw_2MAAAA:8 a=M9_dusmLnZ1afHhWExwA:9
 a=CjuIK1q_8ugA:10
Cc: arch@freebsd.org, Bryan Drewery <bdrewery@freebsd.org>
X-BeenThere: freebsd-arch@freebsd.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: Discussion related to FreeBSD architecture <freebsd-arch.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-arch>,
 <mailto:freebsd-arch-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arch/>
List-Post: <mailto:freebsd-arch@freebsd.org>
List-Help: <mailto:freebsd-arch-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
 <mailto:freebsd-arch-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 09 Jul 2014 11:06:35 -0000

On Wed, 9 Jul 2014, Bruce Evans wrote:

> On Tue, 8 Jul 2014, Bryan Drewery wrote:
>
>> In r34924 sys/proc.h was changed to only include sys/time.h if not building 
>> in kernel.
> ...
>> struct proc {
>> ..
>> struct itimerval p_realtimer;   /* (c) Alarm timer. */
>> 
>> This manifests when (hackishly) including sys/proc.h with _KERNEL defined:
>> 
>>> In file included from 
>>> /root/svn/base/usr.sbin/tcpdump/tcpdump/../../../contrib/tcpdump/print-pflog.c:37:
>>> /usr/include/sys/proc.h:524:19: error: field has incomplete type 'struct 
>>> itimerval'
>>>         struct itimerval p_realtimer;   /* (c) Alarm timer. */
>> 
>> (Why am I doing this? I need PID_MAX and NO_PID for a tcpdump change I am 
>> testing that is intended for upstreaming. Perhaps I can use kern.pid_max in 
>> __FreeBSD__ and other hacks on other platforms, I have not yet decided on 
>> this.)
>
> Ah, you were chummy with the implementation, but not chummy enough to
> know all the details of the kernel environment that must be duplicated
> to use the hack of defining _KERNEL.  It seems to be necessary to include
> sys/param.h and define _KERNEL before that.  There may be collateral
> pollution and further chumminess to avoid problems with it.

PS: in some old cleanups, proc.h caused similar problems but I was
able to avoid them by not including it at all.  It is less needed for
abuse outside the kernel than most kernel headers.

% diff -u2 ./kvm.c~ ./kvm.c
% --- ./kvm.c~	Wed Jun  9 06:13:50 2004
% +++ ./kvm.c	Wed Jun  9 06:13:51 2004
% @@ -46,10 +46,10 @@
% 
%  #include <sys/param.h>
% -#include <sys/user.h>
% -#include <sys/proc.h>

These cleanups are mainly to combine with ones for sys/user.h.  Here I
mainly just wanted to sort it. but sys/proc.h dependend on the sys/time.h
pollution in it.

% +#include <sys/errno.h>
%  #include <sys/ioctl.h>
% +#include <sys/linker.h>
%  #include <sys/stat.h>
%  #include <sys/sysctl.h>
% -#include <sys/linker.h>
% +#include <sys/user.h>
% 
%  #include <vm/vm.h>
% diff -u2 ./kvm_file.c~ ./kvm_file.c
% --- ./kvm_file.c~	Fri Aug  1 21:47:20 2003
% +++ ./kvm_file.c	Fri Aug  1 21:47:53 2003
% @@ -48,23 +48,14 @@
%   */
% 
% -#include <sys/param.h>
% -#include <sys/user.h>
% -#include <sys/proc.h>
% +#include <sys/types.h>
%  #define _KERNEL
%  #include <sys/file.h>
%  #undef _KERNEL

sys/param.h turns out to be mustly unnecessary here.  Defining _KERNEL
before including it was not needed partly because including it at all
is not needed, except possibly for other things that are not needed.

% -#include <sys/stat.h>
% -#include <sys/ioctl.h>
% -#include <nlist.h>
% -#include <kvm.h>
% -
% -#include <vm/vm.h>
% -#include <vm/vm_param.h>
% -
%  #include <sys/sysctl.h>
% 
% +#include <kvm.h>
%  #include <limits.h>
% -#include <ndbm.h>
% -#include <paths.h>
% +#include <nlist.h>
% +#include <stddef.h>
% 
%  #include "kvm_private.h"
% diff -u2 ./kvm_i386.c~ ./kvm_i386.c
% --- ./kvm_i386.c~	Thu Oct 11 20:18:31 2001
% +++ ./kvm_i386.c	Sun Sep  8 01:05:29 2002
% @@ -52,5 +52,4 @@
%  #include <sys/param.h>
%  #include <sys/user.h>
% -#include <sys/proc.h>
%  #include <sys/stat.h>
%  #include <stdlib.h>
% @@ -60,4 +59,5 @@
% 
%  #include <vm/vm.h>
% +#include <vm/pmap.h>
%  #include <vm/vm_param.h>
%

PS2: grepping for PID_MAX shows that ps used to use BSD_PID_MAX (defined
as 99999.  That was supposed to be a copy of the kernel PID_MAX, perhaps
to avoid the namespace problem.  It now uses kern.pid_max with a
fallback to 99999.

Bruce