Linux内核调试工具: Crash

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Crash coding notes

1. Where could I found coding examples?

See crash whitepaper, Command Extensions section. This document also has crash command usages and a case study for kernel debugging.Please study it carefully before working on crash.

2. Public APIs defined in defs.h

Crash public APIs are defined in defs.h.

• Don not change existing APIs in defs.h
• The code changes in defs.h should not break the 3rd party crash extension source code build
• If changes can be put into private files, don not change in defs.h
• Make code changes in defs.h as simple as possible.

3. Other coding and testing guidelines

• Run “make warn” to fix all warnings.

• It would be better, if variables, APIs, and CLI output naming could reflect kernel data structure naming.

• CLI changes should also add man page changes in help.c

• Test must be done on both 32 and 64 bit kernels

• Per your code changes, need to consider the test on different kernel versions

• If you don not have enough test resources, please discuss with maintainer to leverage community test resources.

• Before sending out the patch, please make sure your changes is on top of latest upstream patch

4. Build and test environment setup

Make sure you had installed following packages. I used Fedora CLIs as examples.

• Basic development tools

  sudo yum -y groupinstall “Development Tools”

• patch

  sudo yum install -y patch

• ncurses-devel

  sudo yum install -y ncurses-devel

• zlib-devel

  sudo yum install -y zlib-devel

• bison and byacc

  yum install -y bison
  yum install –y byacc

• kernel debug info packages, if required.

  for 64 bit x86 kernel,

  debuginfo-install kernel

  for 32 bit x86 kernel,

  debuginfo-install kernel-PAE