I was following this guide to add my own custom system call inside the Linux kernel "Adding a Hello World System Call to Linux Kernel".
In Step 5, it asks to modify the system call table by going into
I looked into my system with OS version- Ubuntu 20.04.1 and then kernel version 5.4.0-42, but the specific directory had only three files
I searched online and found that the newer versions of Linux use this bash script
syscalltbl.sh to generate the desired file containing all system call numbers. So thought of running this file, but couldn't due to permission issues(I am newbie in Linux, so didn't found it a good idea to touch things much).
Then I searched for another guide, since the the guide I mentioned above was about 2 years old, and so found this video tutorial created just 4 months back, "Add your own system call to Linux Kernel".
In this the guy uses the already present
syscall_64.tbl file (the
.sh file is too present), so I thought this might be some problem with my machine only as the "Official GitHub Repository" also contains the
.tbl file along with bash script.
I upgraded my kernel to the latest version 5.9.0-050900-generic, but still the directory
has only the bash files with the Makefile.
So where exactly can I find the
syscall_64.tbl in my system?
The only thing which comes to my mind is creating
syscall_64.tbl myself in the the mentioned directory using the
syscall_64.tbl file available on the GitHub. But I believe this is a not good idea, there might be risks associated with it, which I have no clue.