79 lines
2.4 KiB
ReStructuredText
79 lines
2.4 KiB
ReStructuredText
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.. SPDX-License-Identifier: GPL-2.0
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============================================
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Debugging advice for Linux Kernel developers
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============================================
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general guides
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--------------
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.. toctree::
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:maxdepth: 1
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driver_development_debugging_guide
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userspace_debugging_guide
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.. only:: subproject and html
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subsystem specific guides
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-------------------------
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.. toctree::
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:maxdepth: 1
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media_specific_debugging_guide
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.. only:: subproject and html
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Indices
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=======
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* :ref:`genindex`
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General debugging advice
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========================
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Depending on the issue, a different set of tools is available to track down the
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problem or even to realize whether there is one in the first place.
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As a first step you have to figure out what kind of issue you want to debug.
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Depending on the answer, your methodology and choice of tools may vary.
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Do I need to debug with limited access?
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---------------------------------------
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Do you have limited access to the machine or are you unable to stop the running
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execution?
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In this case your debugging capability depends on built-in debugging support of
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provided distribution kernel.
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The :doc:`/process/debugging/userspace_debugging_guide` provides a brief
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overview over a range of possible debugging tools in that situation. You can
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check the capability of your kernel, in most cases, by looking into config file
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within the /boot directory.
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Do I have root access to the system?
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------------------------------------
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Are you easily able to replace the module in question or to install a new
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kernel?
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In that case your range of available tools is a lot bigger, you can find the
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tools in the :doc:`/process/debugging/driver_development_debugging_guide`.
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Is timing a factor?
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-------------------
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It is important to understand if the problem you want to debug manifests itself
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consistently (i.e. given a set of inputs you always get the same, incorrect
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output), or inconsistently. If it manifests itself inconsistently, some timing
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factor might be at play. If inserting delays into the code does change the
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behavior, then quite likely timing is a factor.
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When timing does alter the outcome of the code execution using a simple
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printk() for debugging purposes may not work, a similar alternative is to use
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trace_printk() , which logs the debug messages to the trace file instead of the
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kernel log.
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**Copyright** ©2024 : Collabora
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