From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from szxga03-in.huawei.com ([119.145.14.66]:10176 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751861AbbLIUh3 (ORCPT ); Wed, 9 Dec 2015 15:37:29 -0500 Subject: Re: [PATCH] PCI: hisi: fix the hisi_pcie_cfg_read bug when size=4 To: Bjorn Helgaas , Dongdong Liu References: <1448600280-83695-1-git-send-email-liudongdong3@huawei.com> <20151204224334.GL20125@localhost> <20151209161643.GE31930@localhost> CC: , , , , , , From: Zhou Wang Message-ID: <566890D5.2020007@hisilicon.com> Date: Thu, 10 Dec 2015 04:36:37 +0800 MIME-Version: 1.0 In-Reply-To: <20151209161643.GE31930@localhost> Content-Type: text/plain; charset="windows-1252" Sender: linux-pci-owner@vger.kernel.org List-ID: On 2015/12/10 0:16, Bjorn Helgaas wrote: > On Fri, Dec 04, 2015 at 04:43:34PM -0600, Bjorn Helgaas wrote: >> On Fri, Nov 27, 2015 at 12:58:00PM +0800, Dongdong Liu wrote: >>> Current hisi_pcie_cfg_read code read the RC configuration space, >>> this has a problem that the output parameter "*val" have not been >>> assigned when size=4, so we fix the bug by "*val = reg_val" when size=4. >>> >>> Signed-off-by: Dongdong Liu >> >> Wow, that's a pretty egregious bug. Was the hisi driver ever tested >> at all? We use dword reads in pci_bus_read_dev_vendor_id() to >> enumerate devices, so if those didn't return valid data, nothing at >> all should have worked. >> >> I tentatively put this on my for-linus branch for v4.4, but I wonder >> whether it might be smarter to revert the driver completely until I >> have more confidence in it. >> >> What sort of testing have you done on this driver? > > Since I haven't heard anything about whether this driver was ever > tested, I dropped this patch from my for-linus branch and I reverted > the entire hisi driver. > > Let me know when you have some testing results, and I'll take another > look at it. > > Bjorn > Hi Bjorn, Very sorry for late, I am on business trip at the moment so I have restricted access to emails and my replies can be late. The driver has been tested extensively based on internal version, but I did this mistake when upstreaming :(. I will send a test log ASAP. Many Thanks, Zhou >>> --- >>> drivers/pci/host/pcie-hisi.c | 4 +++- >>> 1 file changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/pci/host/pcie-hisi.c b/drivers/pci/host/pcie-hisi.c >>> index 35457ec..da677b1 100644 >>> --- a/drivers/pci/host/pcie-hisi.c >>> +++ b/drivers/pci/host/pcie-hisi.c >>> @@ -61,7 +61,9 @@ static int hisi_pcie_cfg_read(struct pcie_port *pp, int where, int size, >>> *val = *(u8 __force *) walker; >>> else if (size == 2) >>> *val = *(u16 __force *) walker; >>> - else if (size != 4) >>> + else if (size == 4) >>> + *val = reg_val; >>> + else >>> return PCIBIOS_BAD_REGISTER_NUMBER; >>> >>> return PCIBIOS_SUCCESSFUL; >>> -- >>> 1.9.1 >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > . >