From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751682AbXLGFIs (ORCPT ); Fri, 7 Dec 2007 00:08:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750735AbXLGFIj (ORCPT ); Fri, 7 Dec 2007 00:08:39 -0500 Received: from [222.73.24.84] ([222.73.24.84]:63835 "EHLO song.cn.fujitsu.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750779AbXLGFIj (ORCPT ); Fri, 7 Dec 2007 00:08:39 -0500 Message-ID: <4758D49A.8090908@cn.fujitsu.com> Date: Fri, 07 Dec 2007 13:05:30 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.0 (X11/20070419) MIME-Version: 1.0 To: Nick Piggin CC: paulus@samba.org, LKML , linuxppc-dev@ozlabs.org, Andrew Morton Subject: Re: [PATCH 1/3] POWERPC: don't cast a pointer to pointer of list_head References: <4757C1DA.6060603@cn.fujitsu.com> <200712071507.10161.nickpiggin@yahoo.com.au> In-Reply-To: <200712071507.10161.nickpiggin@yahoo.com.au> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nick Piggin 写道: > On Thursday 06 December 2007 20:33, Li Zefan wrote: >> The casting is safe only when the list_head member is the >> first member of the structure. > > Even so, I don't think too safe :) It might technically work, > but it could break more easily. > > So even if you find places where list_head is the first member of > a structure, it would be nice to explicitly use the list_head member > and avoid casts IMO. > This is exactly what I think. Those patches actually fix no bugs, but avoid this kind of technically and currently correct casting. > >> Signed-off-by: Li Zefan >> >> --- >> arch/ppc/syslib/ocp.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/arch/ppc/syslib/ocp.c b/arch/ppc/syslib/ocp.c >> index 3f5be2c..d42d408 100644 >> --- a/arch/ppc/syslib/ocp.c >> +++ b/arch/ppc/syslib/ocp.c >> @@ -376,7 +376,7 @@ ocp_remove_one_device(unsigned int vendor, unsigned int >> function, int index) >> >> down_write(&ocp_devices_sem); >> dev = __ocp_find_device(vendor, function, index); >> - list_del((struct list_head *)dev); >> + list_del(&dev->link); >> up_write(&ocp_devices_sem); >> >> DBG(("ocp: ocp_remove_one_device(vendor: %x, function: %x, index: %d)... >> done.\n", vendor, function, index)); > >