Installation

The first step in the systemtap journey is to INSTALL it, otherwise how to play with it?

After I struggled a while and when I look back, this is really an easy step. While I faced some trouble at the very beginning. First I didn't have a clear concept about systemtap and second there is some problems for systemtap on Ubuntu 16.04. So I met a lot of frustrated error messages and had no idea what should I do.

Finally, I managed to install and run it on Ubuntu 18.04. So I list the complete steps of installation here. Hope this information would help you overcome the first obstacle.

What to install

Basically, to use systemtap we need to install not only the systemtap itself but also

• linux-headers and

• linux-image-debug

systemtap is the magic tool itself. It is obvious to be necessary to install this. While to make systemtap help us exploring kernel, we need the other two packages. linux-headers is necessary to build the proper kernel module and linux-image-debug is necessary to locate where to insert the probe function.

By knowing this, it would be more clear about what we should do.

Install systemtap

That's easy and obvious.

sudo apt-get install systemtap
sudo apt-get install gcc

Well, gcc is necessary to build systemtap script. So you need to install it, if you didn't.

Install linux-headers and linux-image-debug

Usually, the installation could be accomplished by apt.

Use "uname -r" and "aptitude search" to get the proper package name.

$aptitude search linux-headers-`uname -r`
i A linux-headers-4.15.0-33-generic                                                                 - Linux kernel headers for version 4.15.0 on 64 bit x86 SMP                                                
p   linux-headers-4.15.0-33-generic:i386                                                            - Linux kernel headers for version 4.15.0 on 32 bit x86 SMP

$aptitude search linux-image | grep `uname -r` | grep dbg
i  linux-image-unsigned-4.15.0-33-generic-dbgsym - Linux kernel debug image for version 4.15.0 on 64 bit x86 SMP

Then install them.

In case you can't find the linux-image-debug package, refer to Install debug file part in this post.

Verify the installation

After installation and before further investigation, let's see whether the tool could work properly.

Run the following commands in console:

sudo stap -v -e 'probe begin { printf("Hello, World!\n"); exit() }'

sudo stap -v -e 'probe vfs.read {printf("read performed\n"); exit()}'

If both of them works fine, congratulations!

HelloWorld

HelloWorld is the classical example in programming. Let's make a HelloWorld~

$cat helloworld.stp
probe begin
{ 
    printf("HelloWorld\n");
    exit(); 
}

Then run this script with this command.

sudo stap -v helloworld.stp

If you see the "HelloWorld" is printed, you can start your journey now~

Install SystemTap in Ubuntu 14.04

Ubuntu wiki -- Systemtap