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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 A0ABEC433B4 for ; Wed, 31 Mar 2021 14:29:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 78D7D60FF3 for ; Wed, 31 Mar 2021 14:29:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236122AbhCaO2m (ORCPT ); Wed, 31 Mar 2021 10:28:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235951AbhCaO2Q (ORCPT ); Wed, 31 Mar 2021 10:28:16 -0400 Received: from ustc.edu.cn (email6.ustc.edu.cn [IPv6:2001:da8:d800::8]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 50314C061574 for ; Wed, 31 Mar 2021 07:28:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mail.ustc.edu.cn; s=dkim; h=Received:Date:From:To:Cc:Subject: Message-ID:In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=/USMBB5tdJb798E3Ew+mE5e8OfVTFhQ2z3 foDoJoUxw=; b=V03ymP6pvnQl1qX46eZ14aIGakYtv+5IJZNJFW6EIktV+S3RsY VleDki0NiBju0UdGeqd3BUNwj1vMSZ8Gq0TkabCTbxr1jUaIbdASKkZOj/YxNUbp eKBkCS8WNWB+xOEEHI+lg3cbEOuZ5/+JF6q4AXlovSfZq1OCftnYMSBXg= Received: from xhacker (unknown [101.86.19.180]) by newmailweb.ustc.edu.cn (Coremail) with SMTP id LkAmygCXOpnohmRg0xh6AA--.15607S2; Wed, 31 Mar 2021 22:27:53 +0800 (CST) Date: Wed, 31 Mar 2021 22:22:44 +0800 From: Jisheng Zhang To: Masami Hiramatsu 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: <20210331222244.45a5807c@xhacker> In-Reply-To: <20210330183316.942215efe8e6e8455ad14113@kernel.org> References: <20210330021624.2b776386@xhacker> <20210330183316.942215efe8e6e8455ad14113@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-CM-TRANSID: LkAmygCXOpnohmRg0xh6AA--.15607S2 X-Coremail-Antispam: 1UD129KBjvdXoWrKFWrGryrJF1kAry8Aw1rCrg_yoWDWrg_Ww 1jvrZxG3yYyr4Ikan2qrn7ArZF9r17WFWxXw1fKFWDKa4Ut3yYqFsavFy5JrZ7tF4ftFZx uFy7XrZ0qry7WjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbrAYjsxI4VWDJwAYFVCjjxCrM7AC8VAFwI0_Gr0_Xr1l1xkIjI8I 6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM2 8CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0 cI8IcVCY1x0267AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4 A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IE w4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMc vjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvEwIxGrwCF04k20xvY0x0EwIxGrwCFx2IqxVCF s4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r 1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWU JVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVCF04k26cxKx2IYs7xG6r W3Jr0E3s1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8 JbIYCTnIWIevJa73UjIFyTuYvjxU2rcTDUUUU X-CM-SenderInfo: xmv2xttqjtqzxdloh3xvwfhvlgxou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 30 Mar 2021 18:33:16 +0900 Masami Hiramatsu wrote: > Hi Jisheng, Hi Masami, > > 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? > interrupt is disabled during "single step" by kprobes_save_local_irqflag() and kprobes_restore_local_irqflag(). The code flow looks like: do_trap_break() // for bp kprobe_breakpoint_handler() setup_singlestep() kprobes_restore_local_irqflag() do_trap_break() // for ss kprobe_single_step_handler() kprobes_restore_local_irqflag() Thanks