Bug#1122641: Data Race in QReadWriteLock

[Miao Wang <shankerwangmiao@gmail.com>]

Source: qtbase-opensource-src
Version: 5.15.17+dfsg-4
Severity: important
Tags: patch, upstream, fixed-upstream, ftbfs
Control: found -1 5.15.15+dfsg-6
Control: affects -1 + qt3d-opensource-src

Dear maintainer,

I recently discovered a data race in QReadWriteLock which can cause 
programs hang on weakly ordering architectures. This bug was reported 
to the upstream [1] and the fix is available in commit 4fd88011fa79 
("QReadWriteLock: fix data race on weakly-ordered memory
architectures") [2]. This can cause qt3d-opensource-src FTBFS on
such architectures, reporting heavyDutyMultiThreadedAccess or
heavyDutyMultiThreadedAccessRelease from the test suite 
tst_qresourcemanager time out.


Grateful if you can integrate the commit and the commit 80d01c4ccb69
("QReadWriteLock: fix data race on the d_ptr members") into the
current Debian source package and also fix this in stable-pu.

Cheers,

Miao Wang

[1]: https://qt-project.atlassian.net/browse/QTBUG-142321
[2]: https://codereview.qt-project.org/gitweb?p=qt/qtbase.git;a=commit;h=4fd88011fa7975ce64d5648698a234f85bac359c