From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [PATCH v6 1/2] arm64: Define Documentation/arm64/tagged-address-abi.rst Date: Wed, 31 Jul 2019 09:43:46 -0700 Message-ID: References: <20190725135044.24381-1-vincenzo.frascino@arm.com> <20190725135044.24381-2-vincenzo.frascino@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190725135044.24381-2-vincenzo.frascino@arm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Vincenzo Frascino , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Andrey Konovalov , Szabolcs Nagy List-Id: linux-arch.vger.kernel.org On 7/25/19 6:50 AM, Vincenzo Frascino wrote: > With the relaxed ABI proposed through this document, it is now possible > to pass tagged pointers to the syscalls, when these pointers are in > memory ranges obtained by an anonymous (MAP_ANONYMOUS) mmap(). I don't see a lot of description of why this restriction is necessary. What's the problem with supporting MAP_SHARED? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com ([192.55.52.120]:30347 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730367AbfGaQnr (ORCPT ); Wed, 31 Jul 2019 12:43:47 -0400 Subject: Re: [PATCH v6 1/2] arm64: Define Documentation/arm64/tagged-address-abi.rst References: <20190725135044.24381-1-vincenzo.frascino@arm.com> <20190725135044.24381-2-vincenzo.frascino@arm.com> From: Dave Hansen Message-ID: Date: Wed, 31 Jul 2019 09:43:46 -0700 MIME-Version: 1.0 In-Reply-To: <20190725135044.24381-2-vincenzo.frascino@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Vincenzo Frascino , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Andrey Konovalov , Szabolcs Nagy Message-ID: <20190731164346.MQ9Ykx2pUTJdfJceLK3GfEomv7zL1KSpq6fN_nsaCDI@z> On 7/25/19 6:50 AM, Vincenzo Frascino wrote: > With the relaxed ABI proposed through this document, it is now possible > to pass tagged pointers to the syscalls, when these pointers are in > memory ranges obtained by an anonymous (MAP_ANONYMOUS) mmap(). I don't see a lot of description of why this restriction is necessary. What's the problem with supporting MAP_SHARED?