首先准备linux内核编译环境:
- sudo apt-get install fakeroot build-essential crash kexec-tools makedumpfile kernel-wedge kernel-package
- sudo apt-get build-dep linux
- sudo apt-get install git-core libncurses5 libncurses5-dev libelf-dev asciidoc binutils-dev
检出带有utrace补丁的官方内核代码,并生成对应Ubuntu当前版本内核(3.0)的补丁:
- git clone https://github.com/utrace/linux.git utrace-linux-git
- cd utrace-linux-git/
- git checkout -b utrace-3.0 origin/utrace-3.0
- git diff v3.0 > /tmp/utrace.patch
获得Ubuntu定制内核代码,并打上utrace补丁
- sudo apt-get install linux-source
- tar xjf /usr/src/linux-source-3.0.0.tar.bz2
- cd linux-source-3.0.0/
- patch -p1 < /tmp/utrace.patch
输出为:
patching file Documentation/DocBook/Makefile patching file Documentation/DocBook/utrace.tmpl patching file arch/x86/kernel/ptrace.c patching file fs/proc/array.c patching file include/linux/ptrace.h patching file include/linux/sched.h Hunk #1 succeeded at 187 (offset 3 lines). Hunk #2 succeeded at 206 (offset 3 lines). Hunk #3 succeeded at 1415 with fuzz 2 (offset 7 lines). patching file include/linux/signal.h patching file include/linux/tracehook.h patching file include/linux/utrace.h patching file init/Kconfig Hunk #1 succeeded at 388 (offset 16 lines). patching file kernel/Makefile patching file kernel/fork.c Hunk #1 FAILED at 168. Hunk #2 succeeded at 1098 (offset 3 lines). 1 out of 2 hunks FAILED -- saving rejects to file kernel/fork.c.rej patching file kernel/ptrace.c patching file kernel/sched.c patching file kernel/signal.c Hunk #4 succeeded at 1993 (offset -2 lines). Hunk #5 succeeded at 2017 (offset -2 lines). Hunk #6 succeeded at 2124 (offset -2 lines). Hunk #7 succeeded at 2132 (offset -2 lines). patching file kernel/utrace.c
注意 kernel/fork.c 的补丁失败了,看看 kernel/fork.c.rej:
--- kernel/fork.c +++ kernel/fork.c @@ -168,6 +168,7 @@ free_thread_info(tsk->stack); rt_mutex_debug_task_free(tsk); ftrace_graph_exit_task(tsk); + tracehook_free_task(tsk); free_task_struct(tsk); } EXPORT_SYMBOL(free_task);
修改 kernel/fork.c,在 free_task 函数的 ftrace_graph_exit_task(tsk); 之后手工加上这行 tracehook_free_task 调用即可。
编译新的内核,使用当前系统内核的配置参数作为基准,开启 utrace 补丁提供的 CONFIG_UTRACE 功能即可:
- cp /boot/config-`uname -r` .config
- make oldconfig ,出现如下提示时回答 y:Infrastructure for tracing and debugging user processes (UTRACE) [N/y/?] (NEW)
- make-kpkg clean
- export CONCURRENCY_LEVEL=9 ,这里指定编译内核时的并发任务数,设置为核数+1即可
- fakeroot make-kpkg --initrd --append-to-version=-utrace binary-arch
编译完成后,在 linux-source-3.0.0/ 的上级目录会生成 linux-headers/image/debug-symbol 的 deb 安装包,直接用 sudo dpkg -i *.deb 安装即可。重启后选择新内核进入即可用 systemtap 进行用户态程序跟踪。
参考: