error::fault - Linux

Overview

error::fault is a Linux command that initializes and starts the kernel debugger, allowing you to debug kernel issues on a live system. It can be used to troubleshoot, analyze, and resolve various kernel problems.

Syntax

error::fault [OPTION]...

Options/Flags

  • -s: Silent mode. Suppress all output except error messages.
  • -t TIMEOUT: Set a timeout in seconds for the debugger to initialize. Default: 10 seconds.
  • -v: Verbose mode. Display additional debugging messages.
  • -d: Detect a kernel crash and automatically start the debugger.
  • -c COMMAND: Execute the specified COMMAND within the debugger prompt.
  • -h: Display help and usage information.

Examples

  • Start the debugger manually:
error::fault
  • Start the debugger in silent mode:
error::fault -s
  • Set a timeout of 20 seconds for debugger initialization:
error::fault -t 20
  • Execute a specific command within the debugger prompt:
error::fault -c "ps -ef"

Common Issues

  • Timeout error: If the debugger initialization takes longer than the specified timeout, the command will fail. Try increasing the timeout using the -t option.
  • No response from kernel: The debugger may not be able to communicate with the kernel if there is a communication or kernel issue. Check the system logs for any related errors.

Integration

error::fault can be used in conjunction with other tools and commands for advanced debugging scenarios. For instance, it can be combined with GDB (GNU Debugger) for more detailed debugging operations. Here’s an example of using error::fault to start GDB:

error::fault -d
gdb -ex 'target remote /proc/kcore' -ex 'set $gdb_init_file /home/user/my_gdbinit'

Related Commands

  • kgdb: Starts the kernel debugger in kgdb mode, allowing remote debugging over a serial port.
  • kdump: Creates a kernel crash dump for offline analysis.
  • oops: Dumps kernel crash information to the console.
  • dmesg: Displays kernel and driver messages, including boot messages and errors.