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 6A3BAC433FE for ; Fri, 13 May 2022 07:31:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377803AbiEMHbr (ORCPT ); Fri, 13 May 2022 03:31:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229562AbiEMHbn (ORCPT ); Fri, 13 May 2022 03:31:43 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E031354BF1; Fri, 13 May 2022 00:31:36 -0700 (PDT) Received: from kwepemi100002.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4L00gJ69DszhZ4v; Fri, 13 May 2022 15:30:52 +0800 (CST) Received: from kwepemm600018.china.huawei.com (7.193.23.140) by kwepemi100002.china.huawei.com (7.221.188.188) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 13 May 2022 15:31:34 +0800 Received: from [10.174.176.88] (10.174.176.88) by kwepemm600018.china.huawei.com (7.193.23.140) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 13 May 2022 15:31:33 +0800 Message-ID: Date: Fri, 13 May 2022 15:31:17 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [PATCH -next] docs/zh_CN: Add dev-tools/gdb-kernel-debugging.rst Chinese translation To: yanteng si CC: Alex Shi , Jonathan Corbet , "Wu XiangCheng" , Hu Haowen , Wan Jiabing , Linux Doc Mailing List , References: <20220513061035.605-1-gaochao49@huawei.com> From: "gaochao (L)" In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.176.88] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600018.china.huawei.com (7.193.23.140) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Yanteng, Thank you for the review. I will fix this and add your reviewed-by tag in the second version. 在 2022/5/13 15:11, yanteng si 写道: > gaochao 于2022年5月13日周五 14:10写道： >> >> Translate dev-tools/gdb-kernel-debugging.rst into Chinese. >> >> Signed-off-by: gaochao > Hi chao: > > If you take my suggestion below in the second version, please pick my > Reviewed-by tag. >_< > > Reviewed-by: Yanteng Si > >> --- >> .../zh_CN/dev-tools/gdb-kernel-debugging.rst | 167 ++++++++++++++++++ >> .../translations/zh_CN/dev-tools/index.rst | 2 +- >> 2 files changed, 168 insertions(+), 1 deletion(-) >> create mode 100644 Documentation/translations/zh_CN/dev-tools/gdb-kernel-debugging.rst >> >> diff --git a/Documentation/translations/zh_CN/dev-tools/gdb-kernel-debugging.rst b/Documentation/translations/zh_CN/dev-tools/gdb-kernel-debugging.rst >> new file mode 100644 >> index 000000000000..e1293176614a >> --- /dev/null >> +++ b/Documentation/translations/zh_CN/dev-tools/gdb-kernel-debugging.rst >> @@ -0,0 +1,167 @@ >> +.. highlight:: none >> + >> +.. include:: ../disclaimer-zh_CN.rst >> + >> +:Original: Documentation/dev-tools/gdb-kernel-debugging.rst >> +:Translator: 高超 gao chao >> + >> +通过gdb调试内核和模块 >> +===================== >> + >> +Kgdb内核调试器、QEMU等虚拟机管理程序或基于JTAG的硬件接口，支持在运行时使用gdb >> +调试Linux内核及其模块。Gdb提供了一个强大的python脚本接口，内核也提供了一套 >> +辅助脚本以简化典型的内核调试步骤。本文档为如何启用和使用这些脚本提供了一个简要的教程。 >> +此教程基于QEMU/KVM虚拟机，但文中示例也适用于其他gdb stub。 >> + >> + >> +环境配置要求 >> +------------ >> + >> +- gdb 7.2+ (推荐版本: 7.4+) 、使能python (通常发行版上都已支持) >> + >> +设置 >> +---- >> + >> +- 创建一个QEMU/KVM的linux虚拟机（详情请参考 www.linux-kvm.org 和 www.qemu.org ）。 >> + 对于交叉开发，https://landley.net/aboriginal/bin 提供了一些镜像和工具链， >> + 可以帮助搭建交叉开发环境。 >> + >> +- 编译内核时使能CONFIG_GDB_SCRIPTS，但关闭CONFIG_DEBUG_INFO_REDUCED。 >> + 如果架构支持CONFIG_FRAME_POINTER，请保持使能。 >> + >> +- 在guest环境上安装该内核。如有必要，通过在内核command line中添加“nokaslr”来关闭KASLR。 >> + 此外，QEMU允许通过-kernel、-append、-initrd这些命令行选项直接启动内核。 >> + 但这通常仅在不依赖内核模块时才有效。有关此模式的更多详细信息，请参阅QEMU文档。 >> + 在这种情况下，如果架构支持KASLR，应该在禁用CONFIG_RANDOMIZE_BASE的情况下构建内核。 >> + >> +- 启用QEMU/KVM的gdb stub，可以通过如下方式实现 >> + >> + - 在VM启动时，通过在QEMU命令行中添加“-s”参数 >> + >> + 或 >> + >> + - 在运行时通过从QEMU监视控制台发送“gdbserver” >> + >> +- 切换到/path/to/linux-build(内核源码编译)目录 >> + >> +- 启动gdb：gdb vmlinux >> + >> + 注意：某些发行版可能会将gdb脚本的自动加载限制在已知的安全目录中。 >> + 如果gdb报告拒绝加载vmlinux-gdb.py（相关命令找不到），请将： > The original document here is two colons, > so, Let's use :: . >> + >> + add-auto-load-safe-path /path/to/linux-build >> + >> + 添加到~/.gdbinit。更多详细信息，请参阅gdb帮助信息。 >> + >> +- 连接到已启动的guest环境： > : -> :: >> + >> + (gdb) target remote :1234 >> + >> + >> +使用Linux提供的gdb脚本的示例 >> +---------------------------- >> + >> +- 加载模块（以及主内核）符号： > : -> :: >> + >> + (gdb) lx-symbols >> + loading vmlinux >> + scanning for modules in /home/user/linux/build >> + loading @0xffffffffa0020000: /home/user/linux/build/net/netfilter/xt_tcpudp.ko >> + loading @0xffffffffa0016000: /home/user/linux/build/net/netfilter/xt_pkttype.ko >> + loading @0xffffffffa0002000: /home/user/linux/build/net/netfilter/xt_limit.ko >> + loading @0xffffffffa00ca000: /home/user/linux/build/net/packet/af_packet.ko >> + loading @0xffffffffa003c000: /home/user/linux/build/fs/fuse/fuse.ko >> + ... >> + loading @0xffffffffa0000000: /home/user/linux/build/drivers/ata/ata_generic.ko >> + >> +- 对一些尚未加载的模块中的函数函数设置断点，例如： > : -> :: >> + (gdb) b btrfs_init_sysfs >> + Function "btrfs_init_sysfs" not defined. >> + Make breakpoint pending on future shared library load? (y or [n]) y >> + Breakpoint 1 (btrfs_init_sysfs) pending. >> + >> +- 继续执行： > : -> :: >> + >> + (gdb) c >> + >> +- 加载模块并且能观察到正在加载的符号以及断点命中： > : -> :: >> + >> + loading @0xffffffffa0034000: /home/user/linux/build/lib/libcrc32c.ko >> + loading @0xffffffffa0050000: /home/user/linux/build/lib/lzo/lzo_compress.ko >> + loading @0xffffffffa006e000: /home/user/linux/build/lib/zlib_deflate/zlib_deflate.ko >> + loading @0xffffffffa01b1000: /home/user/linux/build/fs/btrfs/btrfs.ko >> + >> + Breakpoint 1, btrfs_init_sysfs () at /home/user/linux/fs/btrfs/sysfs.c:36 >> + 36 btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); >> + >> +- 查看内核的日志缓冲区： > : -> :: >> + >> + (gdb) lx-dmesg >> + [ 0.000000] Initializing cgroup subsys cpuset >> + [ 0.000000] Initializing cgroup subsys cpu >> + [ 0.000000] Linux version 3.8.0-rc4-dbg+ (... >> + [ 0.000000] Command line: root=/dev/sda2 resume=/dev/sda1 vga=0x314 >> + [ 0.000000] e820: BIOS-provided physical RAM map: >> + [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable >> + [ 0.000000] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved >> + .... >> + >> +- 查看当前task struct结构体的字段（仅x86和arm64支持） > :: >> + >> + (gdb) p $lx_current().pid >> + $1 = 4998 >> + (gdb) p $lx_current().comm >> + $2 = "modprobe\000\000\000\000\000\000\000" >> + >> +- 对当前或指定的CPU使用per-cpu函数： > : -> :: >> + >> + (gdb) p $lx_per_cpu("runqueues").nr_running >> + $3 = 1 >> + (gdb) p $lx_per_cpu("runqueues", 2).nr_running >> + $4 = 0 >> + >> +- 使用container_of查看更多hrtimers信息： > : -> :: >> + >> + (gdb) set $next = $lx_per_cpu("hrtimer_bases").clock_base[0].active.next >> + (gdb) p *$container_of($next, "struct hrtimer", "node") >> + $5 = { >> + node = { >> + node = { >> + __rb_parent_color = 18446612133355256072, >> + rb_right = 0x0 , >> + rb_left = 0x0 >> + }, >> + expires = { >> + tv64 = 1835268000000 >> + } >> + }, >> + _softexpires = { >> + tv64 = 1835268000000 >> + }, >> + function = 0xffffffff81078232 , >> + base = 0xffff88003fd0d6f0, >> + state = 1, >> + start_pid = 0, >> + start_site = 0xffffffff81055c1f , >> + start_comm = "swapper/2\000\000\000\000\000\000" >> + } >> + >> + >> +命令和辅助调试功能列表 >> +---------------------- >> + >> +命令和辅助调试功能可能会随着时间的推移而改进，此文显示的是初始版本的部分示例： > : -> :: > > > Thanks, > Yanteng >> + >> + (gdb) apropos lx >> + function lx_current -- Return current task >> + function lx_module -- Find module by name and return the module variable >> + function lx_per_cpu -- Return per-cpu variable >> + function lx_task_by_pid -- Find Linux task by PID and return the task_struct variable >> + function lx_thread_info -- Calculate Linux thread_info from task variable >> + lx-dmesg -- Print Linux kernel log buffer >> + lx-lsmod -- List currently loaded modules >> + lx-symbols -- (Re-)load symbols of Linux kernel and currently loaded modules >> + >> +可以通过“help ”或“help function ”命令 >> +获取指定命令或指定调试功能的更多详细信息。 >> diff --git a/Documentation/translations/zh_CN/dev-tools/index.rst b/Documentation/translations/zh_CN/dev-tools/index.rst >> index 77a8c44cdf49..02577c379007 100644 >> --- a/Documentation/translations/zh_CN/dev-tools/index.rst >> +++ b/Documentation/translations/zh_CN/dev-tools/index.rst >> @@ -25,6 +25,7 @@ Documentation/translations/zh_CN/dev-tools/testing-overview.rst >> sparse >> gcov >> kasan >> + gdb-kernel-debugging >> >> Todolist: >> >> @@ -34,7 +35,6 @@ Todolist: >> - kmemleak >> - kcsan >> - kfence >> - - gdb-kernel-debugging >> - kgdb >> - kselftest >> - kunit/index >> -- >> 2.17.1 >>