How do I debug Linux kernel modules?

Setup

Table of Contents

Build the kernel with CONFIG_GDB_SCRIPTS enabled, but leave CONFIG_DEBUG_INFO_REDUCED off.
Install that kernel on the guest, turn off KASLR if necessary by adding “nokaslr” to the kernel command line.
Enable the gdb stub of QEMU/KVM, either.
cd /path/to/linux-build.
Start gdb: gdb vmlinux.
Attach to the booted guest:

What is KDB in Linux?

The Linux kernel debugger (KDB) allows you to debug the Linux kernel. This aptly named tool is essentially a patch to the kernel code that lets hackers access kernel memory and data structures.

How do I list all modules in Linux?

To list all currently loaded modules in Linux, we can use the lsmod (list modules) command which reads the contents of /proc/modules like this.

What is the difference between user mode and kernel mode debugging?

When debugging in user mode, you are debugging a single executable, which is separated from other executables by the OS. Kernel debugging is performed on two systems because there is only one kernel; if the kernel is at a breakpoint, no applications can be running on the system.

What is global debug settings?

Advanced>Global debug settings – Specifies the debugger connection settings on this computer for a kernel debugger to communicate with a debugger host. The debugger connection between the host and target computers can be Serial, IEEE 1394, or USB 2.0.

How do I install Q?

Installing a Standard License

Visit your Customer Page in your web browser.
Click Install Q Professional.
On the following screen, click Install Q Professional.
When the installation file has downloaded, find it in the location where it saved and double-click to run/open it.

How do I see modules in Linux?

How do I debug a PS script?

To start debugging Press F5 or, on the toolbar, click the Run Script icon, or on the Debug menu click Run/Continue. The script runs until it encounters the first breakpoint.