From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758790Ab2CFIuQ (ORCPT ); Tue, 6 Mar 2012 03:50:16 -0500 Received: from mx01.sz.bfs.de ([194.94.69.103]:1949 "EHLO mx01.sz.bfs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758365Ab2CFIuP (ORCPT ); Tue, 6 Mar 2012 03:50:15 -0500 Message-ID: <4F55CFC4.3020100@bfs.de> Date: Tue, 06 Mar 2012 09:50:12 +0100 From: walter harms Reply-To: wharms@bfs.de User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; de; rv:1.9.1.16) Gecko/20101125 SUSE/3.0.11 Thunderbird/3.0.11 MIME-Version: 1.0 To: Dan Carpenter CC: Eric Wollesen , Doug Thompson , list-edac@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [patch v3] edac i5000, i5400: fix pointer math in i5000_get_mc_regs() References: <20120306063859.GA3324@elgon.mountain> In-Reply-To: <20120306063859.GA3324@elgon.mountain> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 06.03.2012 07:38, schrieb Dan Carpenter: > "pvt->ambase" is a u64 datatype. The intent here is to fill the first > half in the first call to pci_read_config_dword() and the other half in > the second. Unfortunately the pointer math is wrong so we set the wrong > data. > > Signed-off-by: Dan Carpenter > --- > v2: Redid it as with a union as Walter Harms suggested. > Fixed the same bug in i5400_edac.c as well. > v3: Make the struct __packed just in case. > > I don't have this hardware, so please review carefully. > > diff --git a/drivers/edac/i5400_edac.c b/drivers/edac/i5400_edac.c > index 74d6ec34..083e80a 100644 > --- a/drivers/edac/i5400_edac.c > +++ b/drivers/edac/i5400_edac.c > @@ -343,7 +343,13 @@ struct i5400_pvt { > struct pci_dev *branch_1; /* 22.0 */ > > u16 tolm; /* top of low memory */ > - u64 ambase; /* AMB BAR */ > + union { > + u64 ambase; /* AMB BAR */ > + struct { > + u32 ambase_bottom; > + u32 ambase_top; > + } u __packed; > + }; > > u16 mir0, mir1; > > @@ -1024,9 +1030,9 @@ static void i5400_get_mc_regs(struct mem_ctl_info *mci) > pvt = mci->pvt_info; > > pci_read_config_dword(pvt->system_address, AMBASE, > - (u32 *) &pvt->ambase); > + &pvt->u.ambase_bottom); > pci_read_config_dword(pvt->system_address, AMBASE + sizeof(u32), > - ((u32 *) &pvt->ambase) + sizeof(u32)); > + &pvt->u.ambase_top); > > maxdimmperch = pvt->maxdimmperch; > maxch = pvt->maxch; > diff --git a/drivers/edac/i5000_edac.c b/drivers/edac/i5000_edac.c > index 4dc3ac2..ecc2401 100644 > --- a/drivers/edac/i5000_edac.c > +++ b/drivers/edac/i5000_edac.c > @@ -343,7 +343,13 @@ struct i5000_pvt { > struct pci_dev *branch_1; /* 22.0 */ > > u16 tolm; /* top of low memory */ > - u64 ambase; /* AMB BAR */ > + union { > + u64 ambase; /* AMB BAR */ > + struct { > + u32 ambase_bottom; > + u32 ambase_top; > + } u __packed; > + }; > > u16 mir0, mir1, mir2; > > @@ -1128,9 +1134,9 @@ static void i5000_get_mc_regs(struct mem_ctl_info *mci) > pvt = mci->pvt_info; > > pci_read_config_dword(pvt->system_address, AMBASE, > - (u32 *) & pvt->ambase); > + &pvt->u.ambase_bottom); > pci_read_config_dword(pvt->system_address, AMBASE + sizeof(u32), > - ((u32 *) & pvt->ambase) + sizeof(u32)); > + &pvt->u.ambase_top); > > maxdimmperch = pvt->maxdimmperch; > maxch = pvt->maxch; > nice work dan, i can not find anything to worry about. Acked-by: walter harms