From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 107755 invoked by alias); 19 Sep 2019 05:17:28 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 107747 invoked by uid 89); 19 Sep 2019 05:17:27 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-3.5 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,KAM_SHORT,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.1 spammy=HTo:U*pinskia X-HELO: mail-io1-f65.google.com Received: from mail-io1-f65.google.com (HELO mail-io1-f65.google.com) (209.85.166.65) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 19 Sep 2019 05:17:26 +0000 Received: by mail-io1-f65.google.com with SMTP id r26so4701196ioh.8 for ; Wed, 18 Sep 2019 22:17:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=U+Lszj3OxVKPsIPHFMf36WUmcNjwRUtuaEqOgQ8KcJQ=; b=G4nr7ugCsSF542bqfhtiAi8gtYPg5bhqDropJwwAK/IjndVF5V7NLB/327hXYs8dxo 2RVdVozgfnzIjvtZphQDneWbTE126eNtRe+oufMeZ7XCau3903kxKH5Udjczs7zZ8d3b WO35msq+aVYYVpR99Pk8EJtVbk6BJ2dW12Vzr7d7lF6lxhv6DF6i81hW914G80qCmngR V1Yjf3VSsMcdntEFIp+Q1nKsX1xDkXAMNpmqs7ostHeERfiXYztQgrhozq4P6g/i3/LV cVfMSez7xs+cdODGqabsrMklCkWFUbk6tJ3QGnMEqFd/RtXA55pF4ibwLZokQetG1ixS hJxg== MIME-Version: 1.0 References: In-Reply-To: From: "Bin.Cheng" Date: Thu, 19 Sep 2019 05:17:00 -0000 Message-ID: Subject: Re: Any future plan supporting livepatching in kernel for AArch64? To: Andrew Pinski Cc: GCC Development , Maxim Kuvyrkov , Li Bin , duwe@suse.de, Szabolcs Nagy , Richard Earnshaw , "takahiro.akashi@linaro.org" Content-Type: text/plain; charset="UTF-8" X-IsSubscribed: yes X-SW-Source: 2019-09/txt/msg00138.txt.bz2 On Thu, Sep 19, 2019 at 1:02 PM Andrew Pinski wrote: > > On Wed, Sep 18, 2019 at 9:56 PM Andrew Pinski wrote: > > > > On Wed, Sep 18, 2019 at 9:24 PM Bin.Cheng wrote: > > > > > > Hi, > > > I read through previous messages which tried to support livepatching > > > in kernel for AArch64. > > > Following is the patch supporting mfentry: > > > https://gcc.gnu.org/ml/gcc-patches/2016-03/msg00756.html > > > And this is the last message about above thread: > > > https://gcc.gnu.org/ml/gcc-patches/2016-04/msg01093.html > > > > > > Here is another patch trying to support a general option, however. it > > > was not merged either. > > > https://gcc.gnu.org/ml/gcc-patches/2016-12/msg01791.html > > > > > > If I read messages correctly, kernel part is not merged (partly) > > > because of waiting for GCC. As a result, we have to apply local > > > patches, I am wondering if there is any future plan to support it on > > > AArch64, or no one really uses it? > > > > A GCC patch was merged for this already and is included in GCC 9.1.0 and above. > > See https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/Common-Function-Attributes.html#index-patchable_005ffunction_005fentry-function-attribute > > And > > https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/Instrumentation-Options.html#index-fpatchable-function-entry > > > > Someone did not add it to the GCC 9 release notes though to highlight it. > Note I Mean GCC 8 release notes as it was included in GCC 8.1.0 and above :). > > Also see https://lkml.org/lkml/2017/10/13/340 for the Linux side of > discussion about this option :). Thank you very much, the option name changed several times and I missed this one! Thanks, bin > > > > > > Thanks, > > Andrew Pinski > > > > > > > > I CCed patch authors as well as who joined previous discussions, > > > please let me know if you don't want to be cced in this thread. > > > > > > Thanks, > > > bin