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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F84DC001B2 for ; Fri, 16 Dec 2022 09:33:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229782AbiLPJdQ (ORCPT ); Fri, 16 Dec 2022 04:33:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230144AbiLPJdJ (ORCPT ); Fri, 16 Dec 2022 04:33:09 -0500 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 001521B790 for ; Fri, 16 Dec 2022 01:33:07 -0800 (PST) Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8Dx_+tSO5xjexAGAA--.13875S3; Fri, 16 Dec 2022 17:33:06 +0800 (CST) Received: from [10.130.0.135] (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8AxHuRQO5xj1FwBAA--.3730S3; Fri, 16 Dec 2022 17:33:04 +0800 (CST) Subject: Re: [PATCH v10 2/4] LoongArch: Add kprobe support To: "Masami Hiramatsu (Google)" References: <1670575981-14389-1-git-send-email-yangtiezhu@loongson.cn> <1670575981-14389-3-git-send-email-yangtiezhu@loongson.cn> <20221214162847.1f9481fd2cf5212657a0fd58@kernel.org> Cc: Huacai Chen , WANG Xuerui , loongarch@lists.linux.dev, linux-kernel@vger.kernel.org From: Tiezhu Yang Message-ID: <0a135b50-ca96-8ee1-6f33-29efcdb256ed@loongson.cn> Date: Fri, 16 Dec 2022 17:33:04 +0800 User-Agent: Mozilla/5.0 (X11; Linux mips64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20221214162847.1f9481fd2cf5212657a0fd58@kernel.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID: AQAAf8AxHuRQO5xj1FwBAA--.3730S3 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBjvdXoWrtw4ruF4DGF1kZr1kGFyfWFg_yoWkKwbE93 WfJrn7G348JF4UG3WFgr4rZF1DWayUGF9Yy34FvrZ3Aa45Jw4fWrs7Cwn0yF15JrZ7CFZI krs8XF1kZryavjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8wcxFpf9Il3svdxBIdaVrn0 xqx4xG64xvF2IEw4CE5I8CrVC2j2Jv73VFW2AGmfu7bjvjm3AaLaJ3UjIYCTnIWjp_UUUY 47kC6x804xWl14x267AKxVWUJVW8JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0rVWrJVCq3w AFIxvE14AKwVWUXVWUAwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK 6xIIjxv20xvE14v26r1I6r4UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r1j6r4UM28EF7 xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Cr1j6rxdM2AI xVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12xvs2x26I8E6xACxx1l5I8CrVACY4xI64 kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVW8JVWxJwAm 72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lc7I2V7IY0VAS07AlzVAYIcxG8wCF04 k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18 MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vIr4 1lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1l IxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4 A2jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7IU83UUUUUUUU== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/14/2022 03:28 PM, Masami Hiramatsu (Google) wrote: > Hi, > > On Fri, 9 Dec 2022 16:52:59 +0800 > Tiezhu Yang wrote: > >> Kprobes allows you to trap at almost any kernel address and >> execute a callback function, this commit adds kprobe support >> for LoongArch. ... >> + case KPROBE_HIT_ACTIVE: >> + case KPROBE_HIT_SSDONE: > > Recently, I removed these cases because this page fault will be finally > handled by the generic pagefault handler. > Hi Masami, I have addressed all your comments on my local machine, the code logic looks much more clear now, thank you very much. When I test kprobe_example.ko with a C function like "kernel_clone", it works well, but the kernel hangs [1] when test with an assembler function like "__memset_fast" [2]. Just did some quick research and it seems the bug is related with kallsyms_lookup_name(), I'm looking for a solution. [1] https://lore.kernel.org/loongarch/CAEr6+EC2wPAtK8zb3=e1mUiya3gv0UhqF9J_ySYx9p_96pB+tg@mail.gmail.com/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson.git/tree/arch/loongarch/lib/memset.S?h=loongarch-next#n56 Thanks, Tiezhu