google break pad 使用

Linux，今天你的C挂挂程序 挂了没有？

Linux本地程序crash定位处理，发送到服务端以后在介绍。

还是来自Google：http://code.google.com/p/google-breakpad/wiki/LinuxStarterGuide

由于有代码等原因，本人直接按自己理解，白话，E文好的直接点链接看。

怎样把Breakpad加入你的程序呢,E文是母语的直接点连接。

 

• How To Add Breakpad To Your Linux Application
  • Building the Breakpad libraries
  • Integrating Breakpad into your Application
  • Sending the minidump file
  • Producing symbols for your application
  • Processing the minidump to produce a stack trace

 

This document is an overview of using the Breakpad client libraries on Linux.

先编译库

源码目录下运行 

./configure && make

 生成 src/client/linux/libbreakpad_client.a

把Breakpad整合进程序

首先，把libbreakpad_client.a链接进你的程序，把src目录include进去，诸如：（g++ -g test.cc -I. -L./client/linux/ -lbreakpad_client -lpthread -o test）。

#include"client/linux/handler/exception_handler.h"

在程序刚开始的时候实例化google_breakpad::MinidumpDescriptor和google_breakpad::ExceptionHandler 这两个东东。dump目录可改，dump时可设回调来获取dump信息，示例代码如下：

staticbool dumpCallback(const google_breakpad::MinidumpDescriptor& descriptor,void* context,bool succeeded){
  printf("Dump path: %sn", descriptor.path());return succeeded;}void crash(){volatileint* a =(int*)(NULL);*a =1;}int main(int argc,char* argv[]){
  google_breakpad::MinidumpDescriptor descriptor("/tmp");
  google_breakpad::ExceptionHandler eh(descriptor,
                                       NULL,
                                       dumpCallback,
                                       NULL,true,-1);
  crash();return0;}

编译运行会产生dmp在/tmp下，ExceptionHandler 结构的信息参考 
in the exception_handler.h source file.

回调做的工作越少越好，因为crash的程序本身就不安全，分配内存或调用另一个库里的函数都是不安全的，使用fork另起个进程来做事才是最安全的. 如果必须在crash时使用回调参考some simple reimplementations
of libc functions,避免直接调用libc, 比如a header file for making Linux system calls(insrc/third_party/lss) 避免使用动态库.(其实就是提倡使用系统调用system call而已，原理就是使用子进程来do something)

如何发送dump文件

参考 some HTTP upload sourcea
minidump upload tool.

处理符号文件

为了产生有用的堆栈跟踪, Breakpad需要你把二进制中的调试符号转成text-format symbol files. 首先，编译时必须用-g 包含调试符号。其次编译这个工具
dump_syms ，这个在上边make的时候一起生成好了。

$ google-breakpad/src/tools/linux/dump_syms/dump_syms ./test > test.sym

像下面这样搞，就是搞出个特定的目录来，目录名是head命令 查看 test.sym第一行得出来的，然后把test.sym搞进去，最好复制。

$ head -n1 test.sym
MODULE Linux x86_64 6EDC6ACDB282125843FD59DA9C81BD830 test
$ mkdir -p ./symbols/test/6EDC6ACDB282125843FD59DA9C81BD830
$ mv test.sym ./symbols/test/6EDC6ACDB282125843FD59DA9C81BD830

symbolstore.py 这个 Mozilla 的脚本貌似能搞定上边几步。

处理minidump来生成堆栈信息

还是用工具minidump_stackwalk 来搞

google-breakpad/src/processor/minidump_stackwalk minidump.dmp ./symbols

在 stderr输出了很长的输出信息，在stdout输出了堆栈信息，然后你就可以定位挂在哪里了。

示例：

[root@CentOS src]# ./processor/minidump_stackwalk 5ee28168-f798-caba-749b962b-312eaf19.dmp ./symbols/
2012-12-13 17:15:29: minidump_processor.cc:281: INFO: Processing minidump in file 5ee28168-f798-caba-749b962b-312eaf19.dmp
2012-12-13 17:15:29: minidump.cc:3832: INFO: Minidump opened minidump 5ee28168-f798-caba-749b962b-312eaf19.dmp
2012-12-13 17:15:29: minidump.cc:3943: INFO: Minidump not byte-swapping minidump
2012-12-13 17:15:29: minidump.cc:4309: INFO: GetStream: type 1197932545 not present
2012-12-13 17:15:29: minidump.cc:4309: INFO: GetStream: type 1197932546 not present
2012-12-13 17:15:29: minidump.cc:2011: INFO: MinidumpModule could not determine version for /workspace/Breakpad/trunk/src/test
2012-12-13 17:15:29: minidump.cc:2011: INFO: MinidumpModule could not determine version for /lib64/ld-2.12.so
2012-12-13 17:15:29: minidump.cc:2011: INFO: MinidumpModule could not determine version for /lib64/libc-2.12.so
2012-12-13 17:15:29: minidump.cc:2011: INFO: MinidumpModule could not determine version for /lib64/libpthread-2.12.so
2012-12-13 17:15:29: minidump.cc:2011: INFO: MinidumpModule could not determine version for /lib64/libm-2.12.so
2012-12-13 17:15:29: minidump.cc:2011: INFO: MinidumpModule could not determine version for /lib64/libgcc_s-4.4.6-20120305.so.1
2012-12-13 17:15:29: minidump.cc:2011: INFO: MinidumpModule could not determine version for /usr/lib64/libstdc++.so.6.0.13
2012-12-13 17:15:29: minidump.cc:2011: INFO: MinidumpModule could not determine version for linux-gate.so
2012-12-13 17:15:29: minidump_processor.cc:128: INFO: Minidump 5ee28168-f798-caba-749b962b-312eaf19.dmp has CPU info, OS info, no Breakpad info, exception, module list, thread list, no dump thread, and requesting thread
2012-12-13 17:15:29: minidump_processor.cc:166: INFO: Looking at thread 5ee28168-f798-caba-749b962b-312eaf19.dmp:0/1 id 0x38f5
2012-12-13 17:15:29: minidump.cc:308: INFO: MinidumpContext: looks like AMD64 context
2012-12-13 17:15:29: minidump.cc:308: INFO: MinidumpContext: looks like AMD64 context
2012-12-13 17:15:29: source_line_resolver_base.cc:220: INFO: Loading symbols for module /workspace/Breakpad/trunk/src/test from memory buffer
2012-12-13 17:15:29: simple_symbol_supplier.cc:193: INFO: No symbol file at ./symbols//libc-2.12.so/77DDBBF2BF8AFBECA0C59BBCBA94D1150/libc-2.12.so.sym
2012-12-13 17:15:29: basic_code_modules.cc:88: INFO: No module at 0×0
2012-12-13 17:15:29: basic_code_modules.cc:88: INFO: No module at 0x7fff6c4b8bc8
2012-12-13 17:15:29: basic_code_modules.cc:88: INFO: No module at 0×100000000
2012-12-13 17:15:29: minidump_processor.cc:275: INFO: Processed 5ee28168-f798-caba-749b962b-312eaf19.dmp
2012-12-13 17:15:29: minidump.cc:3804: INFO: Minidump closing minidump
Operating system: Linux
                  0.0.0 Linux 2.6.32-279.11.1.el6.x86_64 #1 SMP Tue Oct 16 15:57:10 UTC 2012 x86_64
CPU: amd64
     family 6 model 42 stepping 7
     1 CPU

Crash reason:  SIGSEGV//挂掉类型
Crash address: 0×0

Thread 0 (crashed)//挂掉线程id
 0  test!crash() [test.cc : 10 + 0x4]//代码：   *a = 1; //a是一个int*的指针，值为NULL，给NULL赋值1，必须挂，源码的第10行，从左到右第四个字符的位置挂了，即a。
    rbx = 0x00007fff6c4b8a90   r12 = 0x0000000000401a00
    r13 = 0x00007fff6c4b8bc0   r14 = 0×0000000000000000
    r15 = 0×0000000000000000   rip = 0x0000000000401b2d
    rsp = 0x00007fff6c4b89e0   rbp = 0x00007fff6c4b89e0
    Found by: given as instruction pointer in context
 1  test!main [test.cc : 16 + 0x4]
    rbx = 0x00007fff6c4b8a90   r12 = 0x0000000000401a00
    r13 = 0x00007fff6c4b8bc0   r14 = 0×0000000000000000
    r15 = 0×0000000000000000   rip = 0x0000000000401c29
    rsp = 0x00007fff6c4b89f0   rbp = 0x00007fff6c4b8ae0
    Found by: call frame info
 2  libc-2.12.so + 0x1ecdc
    rbx = 0×0000000000000000   r12 = 0x0000000000401a00
    r13 = 0x00007fff6c4b8bc0   r14 = 0×0000000000000000
    r15 = 0×0000000000000000   rip = 0x0000003d64e1ecdd
    rsp = 0x00007fff6c4b8af0   rbp = 0×0000000000000000
    Found by: call frame info
 3  test!crash() [test.cc : 11 + 0x1]
    rip = 0x0000000000401b35   rsp = 0x00007fff6c4b8b10
    Found by: stack scanning

Loaded modules:
0×00400000 – 0x00412fff  test  ???  (main)
0x3d64a00000 – 0x3d64a1ffff  ld-2.12.so  ???
0x3d64e00000 – 0x3d6518dfff  libc-2.12.so  ???
0x3d65600000 – 0x3d65818fff  libpthread-2.12.so  ???
0x3d65a00000 – 0x3d65c83fff  libm-2.12.so  ???
0x3d6a600000 – 0x3d6a815fff  libgcc_s-4.4.6-20120305.so.1  ???
0x3d6c600000 – 0x3d6c8f0fff  libstdc++.so.6.0.13  ???
0x7fff6c4f9000 – 0x7fff6c4f9fff  linux-gate.so  ???