Ubuntu 11.10 (Oneiric)上编译带utrace补丁的内核

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. > /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..tar.bz2

cd linux-source-3.0./

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 # succeeded at  (offset  lines).

Hunk # succeeded at  (offset  lines).

Hunk # succeeded at  with fuzz  (offset  lines).

patching file include/linux/signal.h

patching file include/linux/tracehook.h

patching file include/linux/utrace.h

patching file init/Kconfig

Hunk # succeeded at  (offset  lines).

patching file kernel/Makefile

patching file kernel/fork.c

Hunk # FAILED at .

Hunk # succeeded at  (offset  lines).

 out of  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 # succeeded at  (offset - lines).

Hunk # succeeded at  (offset - lines).

Hunk # succeeded at  (offset - lines).

Hunk # succeeded at  (offset - 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

@@ -, +, @@

    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= ，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./ 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：

https://help.ubuntu.com/community/Kernel/Compile#Alternate_Build_Method:_The_Old-Fashioned_Debian_Way