From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758320AbdJQMyR (ORCPT ); Tue, 17 Oct 2017 08:54:17 -0400 Received: from aer-iport-1.cisco.com ([173.38.203.51]:65340 "EHLO aer-iport-1.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754636AbdJQMyP (ORCPT ); Tue, 17 Oct 2017 08:54:15 -0400 X-Greylist: delayed 591 seconds by postgrey-1.27 at vger.kernel.org; Tue, 17 Oct 2017 08:54:14 EDT X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A0ByAQBP+uVZ/xbLJq1dGQEBAQEBAQEBA?= =?us-ascii?q?QEBBwEBAQEBhENuJ4N6ixOQO5YxghQKGA2FFgKFKhcBAgEBAQEBAQFrKIUeAQE?= =?us-ascii?q?BAwEiFTwFEAsYAgImAgIoLwYBDAYCAQEQB4oCEKl7gieLOQEBAQEBAQEBAQEBA?= =?us-ascii?q?QEBAQEBAQEfgQ+CH4NYgWorgwCDCoUOgmEBBJJVjnaHX4cDhgmCcYh1hzKSS4M?= =?us-ascii?q?lgTkhAjRCgRc0IQgdFVkKgkoJFoRDPTYBiDYsghYBAQE?= X-IronPort-AV: E=Sophos;i="5.43,390,1503360000"; d="scan'208";a="698067741" Subject: Re: [PATCH] reduce the time of finding symbols for module To: Torsten Duwe , Ruslan Bilovol Cc: Li Bin , Jessica Yu , Miroslav Benes , zhouchengming , live-patching@vger.kernel.org, "linux-kernel@vger.kernel.org" , jpoimboe@redhat.com, jikos@kernel.org, pmladek@suse.com, Zefan Li , Hanjun Guo References: <1490666535-19192-1-git-send-email-zhouchengming1@huawei.com> <58DA41EE.90607@huawei.com> <20170329000333.zmafvp4uk34m3em6@jeyu> <65c261d0-1e83-8d29-899d-ec22e54a24a7@huawei.com> <20171013131841.en3yuwtl3wedei5t@suse.de> From: Ruslan Bilovol Message-ID: Date: Tue, 17 Oct 2017 15:44:21 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20171013131841.en3yuwtl3wedei5t@suse.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 10/13/2017 04:18 PM, Torsten Duwe wrote: > On Fri, Oct 13, 2017 at 03:54:46PM +0300, Ruslan Bilovol wrote: >> Hi Li, >> >> On Wed, Mar 29, 2017 at 4:50 AM, Li Bin wrote: >>> Hi, >> [snip] >>> >>> Yeah, from 2014, we started to work on livepatch support on aarch64, and >>> in May 2015, we pushed the solution to the livepatch community[1] and gcc >>> community (mfentry feature on aarch64)[2]. And then, there were an another >>> gcc solution from linaro [3], which proposes to implement a new option >>> -fprolog-pad=N that generate a pad of N nops at the beginning of each >>> function, and AFAIK, Torsten Duwe from SUSE is still discussing this method >>> with gcc community. >>> >>> At this stage, we are validating the livepatch support on aarch64 based on >>> aarch64 mfentry feature. When the community has a clear plan, we are happy >>> to make adaptation and contribute our related work to the community, including >>> the kpatch-build support :-) >>> >>> [1] livepatch: add support on arm64 >>> https://lkml.org/lkml/2015/5/28/54 >>> [2] [AArch64] support -mfentry feature for arm64 >>> https://gcc.gnu.org/ml/gcc-patches/2016-03/msg00756.html >>> [3] Kernel livepatching support in GCC >>> https://gcc.gnu.org/ml/gcc/2015-05/msg00267.html >>> [4] arm64: ftrace with regs for livepatch support >>> http://lists.infradead.org/pipermail/linux-arm-kernel/2016-January/401352.html >>> >> >> Since there is already -fpatchable-function-entry option committed by Torsten >> to gcc on 25 Jul [1], have you restarted your activities with AArch64 livepatch >> support? >> If yes, I'm interested in testing of that feature/patches on our hardware > > I also have the coresponding kernel patch(es) here. IIRC I already sent > tham to LKML. I'll re-send them once there are more gcc's with -fpatchable-function-entry > support out there. Do you mean "[PATCH v3 0/2] arm64 live patching" [1] series? I'm going to play with them and see how it works. Another question: have you tested livepatching on Big Endian systems? [1] https://lwn.net/Articles/697050 Thanks, Ruslan