From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olav Haugan Subject: Re: [PATCH v2] staging: zsmalloc: Ensure handle is never 0 on success Date: Tue, 12 Nov 2013 09:06:37 -0800 Message-ID: <5282601D.9010109@codeaurora.org> References: <1383875883-30597-1-git-send-email-ohaugan@codeaurora.org> <20131112001902.GA1043@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.codeaurora.org ([198.145.11.231]:49123 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756319Ab3KLRGj (ORCPT ); Tue, 12 Nov 2013 12:06:39 -0500 In-Reply-To: <20131112001902.GA1043@kroah.com> Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Greg KH Cc: ngupta@vflare.org, sjenning@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, minchan@kernel.org, linux-arm-msm@vger.kernel.org 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. Thanks, Olav Haugan -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation