From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: [PATCH v2] staging: zsmalloc: Ensure handle is never 0 on success Date: Tue, 19 Nov 2013 15:26:47 -0800 Message-ID: <20131119232647.GE24947@kroah.com> References: <1383875883-30597-1-git-send-email-ohaugan@codeaurora.org> <20131112001902.GA1043@kroah.com> <5282601D.9010109@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42591 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751421Ab3KSX0Z (ORCPT ); Tue, 19 Nov 2013 18:26:25 -0500 Content-Disposition: inline In-Reply-To: <5282601D.9010109@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Olav Haugan Cc: ngupta@vflare.org, sjenning@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, minchan@kernel.org, linux-arm-msm@vger.kernel.org On Tue, Nov 12, 2013 at 09:06:37AM -0800, Olav Haugan wrote: > Hi Greg, > > On 11/11/2013 4:19 PM, Greg KH wrote: > > On Thu, Nov 07, 2013 at 05:58:03PM -0800, Olav Haugan wrote: > >> zsmalloc encodes a handle using the pfn and an object > >> index. On hardware platforms with physical memory starting > >> at 0x0 the pfn can be 0. This causes the encoded handle to be > >> 0 and is incorrectly interpreted as an allocation failure. > > > > Please list the known hardware platforms that have this issue, so that > > people have a chance to know if this patch is relevant for them or not. > > > > For example, should I include this in the stable releases because it > > affects systems that are shipping? Or is it just in "future" chips and > > it doesn't need to go there or not? > > > > Please make it easy for me to do this type of determination, I already > > asked you this question before, why didn't you include the information > > here as well (hint, that is why I asked you...) > > I don't think it would be the best to mention specific hardware > platforms in the commit text. If I saw this patch listing specific > hardware platforms I would have made the wrong decision (I would look at > the list and decide that I am not running on those platforms so I don't > need this patch). The problem could happen on any hardware platform. It > just depends on how the memory map of the platform is configured. Hence, > I re-worded the commit text to make it clear that this will happen when > you have memory starting at 0x0. > > If I list out specific hardware platforms it would be only a sample (I > do not know all hardware platforms and their memory maps). However, > having said that there are products already shipping with physical > address starting at 0. Having something in there is better than nothing... So, care to try it again?