Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752501AbcD0CNx (ORCPT ); Tue, 26 Apr 2016 22:13:53 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:22193 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752203AbcD0CNw (ORCPT ); Tue, 26 Apr 2016 22:13:52 -0400 From: "Zengtao (B)" To: Suzuki K Poulose , Catalin Marinas CC: "will.deacon@arm.com" , "mark.rutland@arm.com" , "yang.shi@linaro.org" , "linux-kernel@vger.kernel.org" , "james.morse@arm.com" , "linux-arm-kernel@lists.infradead.org" Subject: RE: [PATCH] arm64: fix /proc/cpuinfo for elf32 Thread-Topic: [PATCH] arm64: fix /proc/cpuinfo for elf32 Thread-Index: AQHRntKs3nt0/Ucjykqwjp38/g71NZ+bhWfA///wsYCAAZ8X8A== Date: Wed, 27 Apr 2016 02:13:01 +0000 Message-ID: <678F3D1BB717D949B966B68EAEB446ED0A6E7595@SZXEMA509-MBX.china.huawei.com> References: <1461555453-60440-1-git-send-email-prime.zeng@huawei.com> <20160425091239.GB9614@e104818-lin.cambridge.arm.com> <678F3D1BB717D949B966B68EAEB446ED0A6E6FB7@SZXEMA509-MBX.china.huawei.com> <571F32F3.7080005@arm.com> In-Reply-To: <571F32F3.7080005@arm.com> Accept-Language: en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.67.233.8] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020206.57202032.0060,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=169.254.1.183, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: b754508c4bdc70e7e4b880b2a126b7eb Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id u3R2E1J3014111 Content-Length: 1076 Lines: 31 > -----Original Message----- > From: Suzuki K Poulose [mailto:Suzuki.Poulose@arm.com] > Sent: Tuesday, April 26, 2016 5:21 PM > To: Zengtao (B); Catalin Marinas > Cc: will.deacon@arm.com; mark.rutland@arm.com; yang.shi@linaro.org; > linux-kernel@vger.kernel.org; james.morse@arm.com; > linux-arm-kernel@lists.infradead.org > Subject: Re: [PATCH] arm64: fix /proc/cpuinfo for elf32 > > On 26/04/16 03:21, Zengtao (B) wrote: > > > > So you mean the 64-bit grep should see the same cpuinfo as its father process > > which is 32-bit? > > > > For 32-bit process running on 64-bit kernel, we have to explicitly call the > personality > > syscall to get the right cpuinfo, but how to deal with the old 32-bit binaries? > > Yes, you could use the syscall to switch the personality. Alternately, you could > run > "linux32" command to switch the personality to PER_LINUX32 and then > execute > 64/32 bit applications. > Any plan to place the personality syscall in libc? It is not nessary for each 32-bit process to do the personality syscall or linux32 command. > Suzuki > >