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Diffstat (limited to 'doc/troubleshooting.rst')
| -rw-r--r-- | doc/troubleshooting.rst | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/doc/troubleshooting.rst b/doc/troubleshooting.rst index 3d7c359..5bd1d90 100644 --- a/doc/troubleshooting.rst +++ b/doc/troubleshooting.rst @@ -9,7 +9,7 @@ First of all, check the logs. Enabling at least the ``warning`` message severity may help you to identify some problems. See the :ref:`log section` for details. -.. _Submitting a bugreport: +.. _Submitting a bugreport: Reporting bugs ============== @@ -46,7 +46,7 @@ addition at least the following information: If possible, please provide a minimal configuration file and zone files which can be used to reproduce the bug. -.. _Generating backtrace: +.. _Generating backtrace: Generating backtrace ==================== @@ -108,3 +108,16 @@ If you fail to get a backtrace of a running process using the previous method, you may try the single-purpose ``pstack`` utility:: $ pstack $(pidof knotd) > backtrace.txt + +.. _Bus error: + +Crash caused by a Bus error +=========================== + +Zone files and a configuration file are usually accessed as +`mmaped <https://pubs.opengroup.org/onlinepubs/9699919799/functions/mmap.html>`_ +files. If such files are changed or truncated at the same time when those files +are being loaded/reloaded by the program, it may result in `Bus error +(SIGBUS) <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/signal.h.html>`_ +and a program crash. If you encounter a Bus error, first check that there isn't +a concurrent write access from an external program to the respective files. |