From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Tourrilhes Subject: Re: [PATCH 1/1 v2] eal: Fix misleading error messages, errno can't be trusted. Date: Mon, 3 Oct 2016 09:07:42 -0700 Message-ID: <20161003160742.GC23662@labs.hpe.com> References: <20160921211049.GA27472@labs.hpe.com> <4a84de40-04b9-da6d-aeb9-ce661a9ebad5@intel.com> Reply-To: jean.tourrilhes@hpe.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev@dpdk.org To: Sergio Gonzalez Monroy Return-path: Received: from g4t3427.houston.hpe.com (g4t3427.houston.hpe.com [15.241.140.73]) by dpdk.org (Postfix) with ESMTP id 16BE82A5E for ; Mon, 3 Oct 2016 18:07:44 +0200 (CEST) Content-Disposition: inline In-Reply-To: <4a84de40-04b9-da6d-aeb9-ce661a9ebad5@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Mon, Oct 03, 2016 at 02:25:40PM +0100, Sergio Gonzalez Monroy wrote: > Hi Jean, > > NIT but any reason you moved the check before closing the file descriptor? > (not that it matters with current code as we panic anyway) > > Thanks, > Sergio More details, as I admit I was terse Running secondary is tricky due to the need to map the memory region at the right place, which is whatever primary has chosen. If the base address for primary happens to by already mapped in the secondary, we will hit precisely this error message (well, in a few case we might hit the other one). This is why there is already a comment about ASLR. A colleague of mine hit that message and was misled by errno claiming "permission denied", which sent him down the wrong track. It's such a common error for secondary that I feel this error message should be unambiguous and helpful. Regards, Jean