From mboxrd@z Thu Jan 1 00:00:00 1970 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) Received: from g4t3433.houston.hpecorp.net (g4t3433.houston.hpecorp.net [16.208.49.245]) by g4t3427.houston.hpe.com (Postfix) with ESMTP id 39BAE5C; Mon, 3 Oct 2016 16:07:43 +0000 (UTC) Received: from postal.labs.hpecorp.net (postal.labs.hpecorp.net [16.111.35.25]) by g4t3433.houston.hpecorp.net (Postfix) with ESMTP id 1758046; Mon, 3 Oct 2016 16:07:42 +0000 (UTC) Received: from bougret.labs.hpecorp.net (bougret.labs.hpecorp.net [16.111.8.16]) by postal.labs.hpecorp.net (8.14.4/8.14.4/HPL-PA Hub) with ESMTP id u93G7gll023912 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Mon, 3 Oct 2016 09:07:42 -0700 Received: from jt by bougret.labs.hpecorp.net with local (Exim 4.84_2) (envelope-from ) id 1br5mI-0006Lv-7G; Mon, 03 Oct 2016 09:07:42 -0700 Date: Mon, 3 Oct 2016 09:07:42 -0700 From: Jean Tourrilhes To: Sergio Gonzalez Monroy Cc: dev@dpdk.org Message-ID: <20161003160742.GC23662@labs.hpe.com> References: <20160921211049.GA27472@labs.hpe.com> <4a84de40-04b9-da6d-aeb9-ce661a9ebad5@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4a84de40-04b9-da6d-aeb9-ce661a9ebad5@intel.com> Organisation: HP Labs Palo Alto Address: HP Labs, MS1184, 1501 Page Mill road, Palo Alto, CA 94304, USA. E-mail: jean.tourrilhes@hpe.com User-Agent: Mutt/1.5.23 (2014-03-12) Subject: Re: [dpdk-dev] [PATCH 1/1 v2] eal: Fix misleading error messages, errno can't be trusted. X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list Reply-To: jean.tourrilhes@hpe.com List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 03 Oct 2016 16:07:44 -0000 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