From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 395A1C2BA1A for ; Tue, 7 Apr 2020 16:02:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A1232075E for ; Tue, 7 Apr 2020 16:02:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586275344; bh=3VjqdLa0s70r8aebZrWtJwDbgUgBPZ4Fn9cPzsn7F8c=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=nhSpTlDoaiHfIhQkGjaFjspiRMA/Il6ix+yyV1IyXvO8JBbtBEmyNm7Rg1/YVv7/z ir598cBIhV7H2yZDvoRa+NDGju/v5wtJ2HaK1TeA4lNhrOjEsqoNd1TuqBza0qFNYb j6Tm0MCwzvWp0BP1CZnq81UifrA7DnMF0SD9tCgc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727806AbgDGQCX (ORCPT ); Tue, 7 Apr 2020 12:02:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:39860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726889AbgDGQCX (ORCPT ); Tue, 7 Apr 2020 12:02:23 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C7CBB2075E; Tue, 7 Apr 2020 16:02:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586275342; bh=3VjqdLa0s70r8aebZrWtJwDbgUgBPZ4Fn9cPzsn7F8c=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Gw12nJpwBaICSNfCelcRlTky9psIctNfr5AJaqWmlY49ejsFHlL99qIPglWjGUE6g lt8XQXYKRg8vkMPGLFA45y42nwSgDMDSWpCJnWHPa0OORNCkXAgpnZMm3xhLDod8Xu 5vmKwu/nNjeR6eTeVFO7ruZlDGkVoOk0ro2Istk8= Date: Wed, 8 Apr 2020 01:02:18 +0900 From: Masami Hiramatsu To: Zong Li Cc: palmer@dabbelt.com, paul.walmsley@sifive.com, aou@eecs.berkeley.edu, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 3/9] riscv: patch code by fixmap mapping Message-Id: <20200408010218.c601beb496712a1251e2c9a0@kernel.org> In-Reply-To: <0b6ad2759b47731a83008b46dbbed7c92e68cae2.1586265122.git.zong.li@sifive.com> References: <0b6ad2759b47731a83008b46dbbed7c92e68cae2.1586265122.git.zong.li@sifive.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 7 Apr 2020 22:46:48 +0800 Zong Li wrote: > On strict kernel memory permission, the ftrace have to change the > permission of text for dynamic patching the intructions. Use > riscv_patch_text_nosync() to patch code instead of probe_kernel_write. > > Signed-off-by: Zong Li > Suggested-by: Masami Hiramatsu Looks good to me. Reviewed-by: Masami Hiramatsu Thanks! > --- > arch/riscv/kernel/ftrace.c | 26 +++++++++++++++++--------- > 1 file changed, 17 insertions(+), 9 deletions(-) > > diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c > index c40fdcdeb950..08396614d6f4 100644 > --- a/arch/riscv/kernel/ftrace.c > +++ b/arch/riscv/kernel/ftrace.c > @@ -7,9 +7,23 @@ > > #include > #include > +#include > #include > +#include > > #ifdef CONFIG_DYNAMIC_FTRACE > +int ftrace_arch_code_modify_prepare(void) __acquires(&text_mutex) > +{ > + mutex_lock(&text_mutex); > + return 0; > +} > + > +int ftrace_arch_code_modify_post_process(void) __releases(&text_mutex) > +{ > + mutex_unlock(&text_mutex); > + return 0; > +} > + > static int ftrace_check_current_call(unsigned long hook_pos, > unsigned int *expected) > { > @@ -46,20 +60,14 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target, > { > unsigned int call[2]; > unsigned int nops[2] = {NOP4, NOP4}; > - int ret = 0; > > make_call(hook_pos, target, call); > > - /* replace the auipc-jalr pair at once */ > - ret = probe_kernel_write((void *)hook_pos, enable ? call : nops, > - MCOUNT_INSN_SIZE); > - /* return must be -EPERM on write error */ > - if (ret) > + /* Replace the auipc-jalr pair at once. Return -EPERM on write error. */ > + if (patch_text_nosync > + ((void *)hook_pos, enable ? call : nops, MCOUNT_INSN_SIZE)) > return -EPERM; > > - smp_mb(); > - flush_icache_range((void *)hook_pos, (void *)hook_pos + MCOUNT_INSN_SIZE); > - > return 0; > } > > -- > 2.26.0 > -- Masami Hiramatsu