How to Use Relabel in Linux to Change Process Labels

Relabel is a feature in the Linux kernel that allows you to change the label of a process. The label is a unique identifier assigned to each process when it is created, and it is used by the kernel to keep track of the process and its state.

By default, the label of a process is set to the name of the executable file that launched it. However, this can sometimes be misleading, especially if the process has been fork()ed or exec()ed multiple times. In such cases, the original label may not accurately reflect the current state of the process.

Relabel allows you to change the label of a process to a more meaningful name that describes its current state or purpose. This can be useful in situations where you need to identify a process by something other than its original name.

For example, you might use relabel to change the label of a process to indicate that it is a subprocess of another process, or to mark it as a background process that should be killed if the main process exits. You could also use relabel to assign a unique identifier to a process that is not related to its original name.

Relabel can be used in a variety of ways, including:

1. As a system call: The relabel system call allows you to change the label of a process. It takes two arguments: the old label and the new label.
2. Through the /proc file system: You can also change the label of a process by writing to the /proc//label file, where is the process ID of the process you want to relabel.
3. Through the kernel API: The kernel API provides a number of functions that allow you to manipulate the labels of processes. These functions include set_task_comm(), set_task_name(), and set_process_label().

It's important to note that changing the label of a process does not affect its behavior or state in any way. It simply changes the name by which the process is referred to in the kernel and other system components.