From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757386AbbE3ABg (ORCPT ); Fri, 29 May 2015 20:01:36 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:48387 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753951AbbE3ABa (ORCPT ); Fri, 29 May 2015 20:01:30 -0400 Message-ID: <5568FDD2.2040005@hitachi.com> Date: Sat, 30 May 2015 09:01:22 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Li Bin , rostedt@goodmis.org, mingo@kernel.org, jpoimboe@redhat.com, sjenning@redhat.com, jkosina@suse.cz, vojtech@suse.cz, catalin.marinas@arm.com, will.deacon@arm.com CC: live-patching@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, lizefan@huawei.com, felix.yang@huawei.com, guohanjun@huawei.com, xiexiuqi@huawei.com, takahiro.akashi@linaro.org, David Long Subject: Re: [RFC PATCH 0/5] livepatch: add support on arm64 References: <1432792265-24076-1-git-send-email-huawei.libin@huawei.com> In-Reply-To: <1432792265-24076-1-git-send-email-huawei.libin@huawei.com> Content-Type: text/plain; charset=iso-2022-jp Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2015/05/28 14:51, Li Bin wrote: > This patchset propose a method for gcc -mfentry feature(profile > before prologue) implementation for arm64, and propose the livepatch > implementation for arm64 based on this feature. > The gcc implementation about this feature will be post to the gcc > community soon. > > With this -mfentry feature, the entry of each function like: > > foo: > mov x9, x30 > bl __fentry__ > mov x30, x9 > [prologue] > ... > > The x9 is a callee corruptible register, and the __fentry__ function > is responsible to protect all registers, so it can be used to protect > the x30. And the added two instructions which is register mov operation > have ralatively small impact on performance. Hm, this implementation looks good to me :) This also enables us to KPROBES_ON_FTRACE too. Thanks, > > This patchset has been tested on arm64 platform. > > Li Bin (4): > livepatch: ftrace: arm64: Add support for DYNAMIC_FTRACE_WITH_REGS > livepatch: ftrace: add ftrace_function_stub_ip function > livepatch: ftrace: arm64: Add support for -mfentry on arm64 > livepatch: arm64: add support for livepatch on arm64 > > Xie XiuQi (1): > livepatch: arm64: support relocation in a module > > arch/arm64/Kconfig | 5 + > arch/arm64/include/asm/ftrace.h | 9 + > arch/arm64/include/asm/livepatch.h | 45 +++++ > arch/arm64/kernel/Makefile | 1 + > arch/arm64/kernel/arm64ksyms.c | 4 + > arch/arm64/kernel/entry-ftrace.S | 154 +++++++++++++++- > arch/arm64/kernel/ftrace.c | 28 +++- > arch/arm64/kernel/livepatch.c | 41 ++++ > arch/arm64/kernel/module.c | 355 ++++++++++++++++++------------------ > include/linux/ftrace.h | 1 + > kernel/livepatch/core.c | 17 ++- > kernel/trace/ftrace.c | 32 ++++ > scripts/recordmcount.pl | 2 +- > 13 files changed, 508 insertions(+), 186 deletions(-) > create mode 100644 arch/arm64/include/asm/livepatch.h > create mode 100644 arch/arm64/kernel/livepatch.c > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu.pt@hitachi.com