linux-kernel-crash-debug

# Linux Kernel Crash Debugging

本 skill 指导如何使用 crash 工具分析 Linux 内核崩溃转储。

## 快速开始

### 启动会话

```bash
# 分析转储文件
crash vmlinux vmcore

# 调试运行中的系统
crash vmlinux

# 原始 RAM 转储
crash vmlinux ddr.bin --ram_start=0x80000000
```

### 核心调试流程

```
1. crash> sys              # 确认 panic 原因
2. crash> log              # 查看内核日志
3. crash> bt               # 分析调用栈
4. crash> struct <type>    # 检查数据结构
5. crash> kmem <addr>      # 内存分析
```

## 前置要求

| 项目 | 要求 |
|------|------|
| **vmlinux** | 必须带 debug symbols (`CONFIG_DEBUG_INFO=y`) |
| **vmcore** | kdump/netdump/diskdump/ELF 格式 |
| **版本** | vmlinux 必须与 vmcore 内核版本完全匹配 |

获取 debuginfo：
```bash
# RHEL/CentOS
yum install kernel-debuginfo

# 自编译内核
make menuconfig  # 启用 CONFIG_DEBUG_INFO
```

## 核心命令速查

### 调试分析

| 命令 | 用途 | 示例 |
|------|------|------|
| `sys` | 系统信息/panic 原因 | `sys`, `sys -i` |
| `log` | 内核消息缓冲区 | `log`, `log \| tail` |
| `bt` | 调用栈回溯 | `bt`, `bt -a`, `bt -f` |
| `struct` | 结构体查看 | `struct task_struct <addr>` |
| `p/px/pd` | 打印变量 | `p jiffies`, `px current` |
| `kmem` | 内存分析 | `kmem -i`, `kmem -S <cache>` |

### 任务和进程

| 命令 | 用途 | 示例 |
|------|------|------|
| `ps` | 进程列表 | `ps`, `ps -m \| grep UN` |
| `set` | 切换上下文 | `set <pid>`, `set -p` |
| `foreach` | 批量任务操作 | `foreach bt`, `foreach UN bt` |
| `task` | task_struct 内容 | `task <pid>` |
| `files` | 打开的文件 | `files <pid>` |

### 内存操作

| 命令 | 用途 | 示例 |
|------|------|------|
| `rd` | 读取内存 | `rd <addr>`, `rd -p <phys>` |
| `search` | 搜索内存 | `search -k deadbeef` |
| `vtop` | 地址翻译 | `vtop <addr>` |
| `list` | 遍历链表 | `list task_struct.tasks -h <addr>` |

## bt 命令详解

最重要的调试命令：

```
crash> bt              # 当前任务调用栈
crash> bt -a           # 所有 CPU 活动任务
crash> bt -f           # 展开栈帧原始数据
crash> bt -F           # 符号化栈帧数据
crash> bt -...

# Linux Kernel Crash Debug Skill

[中文文档](README_CN.md)

Welcome to **Linux Kernel Crash Debug Skill**! This is a Claude Code skill that helps you debug Linux kernel crashes using the crash utility.

## Features

- **Quick Start Guide**: Essential commands and debugging workflow
- **Complete Command Reference**: All crash utility commands with examples
- **Advanced Techniques**: Memory analysis, linked list traversal, address translation
- **Real-world Cases**: Kernel BUG, deadlock, OOM, NULL pointer, stack overflow
- **vmcore Knowledge**: ELF format, VMCOREINFO, dump file types

## Installation

```bash
# Download the skill file
git clone https://github.com/crazyss/linux-kernel-crash-debug.git

# Install in Claude Code
claude skill install linux-kernel-crash-debug.skill
```

## Quick Start

```bash
# Start crash session
crash vmlinux vmcore

# Basic debugging flow
crash> sys              # Check panic reason
crash> log              # View kernel log
crash> bt               # Backtrace
crash> struct <type>    # Inspect data structures
crash> kmem <addr>      # Memory analysis
```

## Structure

```
linux-kernel-crash-debug/
├── SKILL.md                    # Main skill file
├── README.md                   # English documentation
├── README_CN.md                # Chinese documentation
├── CONTRIBUTING.md             # Contribution guide
├── LICENSE                     # MIT License
├── linux-kernel-crash-debug.skill  # Packaged skill
└── references/                 # Detailed documentation
    ├── advanced-commands.md    # In-depth command usage
    ├── vmcore-format.md        # vmcore file format details
    └── case-studies.md         # Real-world debugging examples
```

## Usage

This skill triggers when you mention:
- kernel crash / kernel panic
- vmcore analysis
- crash utility
- kernel oops debugging

## Contributing

We welcome contributions! Please see [CONTRIBUTING.md](CONTRIBUTING.md) for details.

- Report bugs or request features via [Issues](https://gi...