libobs/util: Prevent locking mutex in child process when checking Qt5 #12018
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The frontend has set a log handler which locks the mutex in `LogString`. If `os_dlopen` fails in the child process, it calls `blog` and attempted to lock the mutex that may have already been locked by another thread before `fork()`. This change prevents the child process from locking the mutex, resolving the potential deadlock.
kkartaltepe
approved these changes
Apr 2, 2025
I think so, too. It's much better to remove the Qt5 check in the next major release or the next. |
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Description
In
has_qt5_dependency, revert the log handler to the default just after the fork.This change assumes that
base_set_log_handleranddef_log_handlerdo not use any locks.Motivation and Context
The frontend has set a log handler which locks a mutex in
LogString.If
os_dlopenfails in the child process, it callsblogand attempts to lock the mutex that another thread may have already locked beforefork().Though I never encountered the deadlock, it's better to fix it.
How Has This Been Tested?
OS: Fedora 40
Added a plugin binary file which causes an error during
os_dlopen.Ran OBS and checked the log file contains only one error message of the plugin.
Types of changes
Checklist: