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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 211D5C433DB for ; Tue, 30 Mar 2021 09:34:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0B016198F for ; Tue, 30 Mar 2021 09:34:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231708AbhC3JeI (ORCPT ); Tue, 30 Mar 2021 05:34:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:57498 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231622AbhC3Jdk (ORCPT ); Tue, 30 Mar 2021 05:33:40 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E69F06196A; Tue, 30 Mar 2021 09:33:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617096819; bh=dYLugLc2SuF0iK6NmBheI9/uixh1V9koKnsv2y5J0l0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=HZt6JV/OAnSHC4xC5UNG10NWYm4QK27EYcF4BJQorN2o003E6NyJRWEJgh/fa0Xv2 UdSOg440QgXpJ+Xk1NztoAJLtbCxlKWaJM9hIMdDpoVNju6yrGOH7xkt6Gnjova+3j 7i7IbLl2HN0+sV3x8kBDQltM4Zz1K67xS94YZyiJgcCXqTqDddD76QKTFLlRg7BvAj SST8ZD0LpKc/15Ts4NFbLiDvdy8/8TGLk8eVEtHcr2EwVG7UUwyWgUHkvMGMRTmDyf jbj8tPMUQOywNpe0/UWONHbKbr8uh+SIQz6nQx/LIRYF7q+264hpm8n/VWzopoW4Cv nFKyJSp//52+w== Date: Tue, 30 Mar 2021 18:33:16 +0900 From: Masami Hiramatsu To: Jisheng Zhang Cc: Paul Walmsley , Palmer Dabbelt , Albert Ou , Guo Ren , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] riscv: keep interrupts disabled for BREAKPOINT exception Message-Id: <20210330183316.942215efe8e6e8455ad14113@kernel.org> In-Reply-To: <20210330021624.2b776386@xhacker> References: <20210330021624.2b776386@xhacker> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jisheng, On Tue, 30 Mar 2021 02:16:24 +0800 Jisheng Zhang wrote: > From: Jisheng Zhang > > Current riscv's kprobe handlers are run with both preemption and > interrupt enabled, this violates kprobe requirements. Fix this issue > by keeping interrupts disabled for BREAKPOINT exception. Not only while the breakpoint exception but also until the end of the single step (maybe you are using __BUG_INSN_32 ??) need to be disable interrupts. Can this do that? Thank you, > > Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported") > Signed-off-by: Jisheng Zhang > --- > arch/riscv/kernel/entry.S | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S > index 744f3209c48d..4114b65698ec 100644 > --- a/arch/riscv/kernel/entry.S > +++ b/arch/riscv/kernel/entry.S > @@ -130,6 +130,8 @@ skip_context_tracking: > */ > andi t0, s1, SR_PIE > beqz t0, 1f > + li t0, EXC_BREAKPOINT > + beq s4, t0, 1f > #ifdef CONFIG_TRACE_IRQFLAGS > call trace_hardirqs_on > #endif > -- > 2.31.0 > > -- Masami Hiramatsu