[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Nate Graham changed: What|Removed |Added Version Fixed In||5.97 -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Michael Pyne changed: What|Removed |Added Latest Commit|https://invent.kde.org/fram |https://invent.kde.org/fram |eworks/kjobwidgets/commit/b |eworks/kjobwidgets/commit/5 |8752085d2a480dfc93d2d422c46 |aeba3f01ef8cdf723813cacdd29 |3a59d46af5ee|945328288663 Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #27 from Michael Pyne --- Git commit 5aeba3f01ef8cdf723813cacdd29945328288663 by Michael Pyne. Committed on 09/07/2022 at 18:42. Pushed by mpyne into branch 'master'. ui-server: Fix crash by only re-registering live KJobs. This addresses a frequently-reported crash in the job tracker for KUiServerV2 that occurs when attempting to re-register new job views for active KJobs after a new UI server comes online. Although I have not been able to reproduce the crash myself, (by attempting to use both long-lived and short-lived file transfers from Dolphin and restarting plasmashell), inspection of the code shows that it is possible for there to be deleted KJobs pointing to JobView objects during some portions of the job tracker's lifetime. The current code deals with this in situations including DBus calls to create a U/I view for a KJob (the KJob may terminate before the DBus reply is received) and even a short delay that can be optionally introduced (the KJob may terminate before the delay elapses). A QPointer is used as a guard in these situations, but there is no similar guard for the re-registration code. In this case we cannot use QPointer to guard the job's lifetime because the KJob must be alive when the QPointer is created, and this crash occurs when the KJob is terminated. However the KJob's destruction should lead to the unregisterJob() function being called, which handles removing the terminated KJob from the map of job views with only one exception, where instead the job view for the KJob has its "terminated" pending status set. So the fix here checks for the "terminated" state in the same way as performed in requestView(), and if the KJob is terminated, handles requesting the job view to terminate the U/I and finally removing the terminated KJob from the map of job views. By doing this, we avoid passing a deleted KJob to the registerJob() function, which will attempt to dereference it and crash the application. See also merge request !22 M +16 -4src/kuiserverv2jobtracker.cpp https://invent.kde.org/frameworks/kjobwidgets/commit/5aeba3f01ef8cdf723813cacdd29945328288663 -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 --- Comment #26 from Nate Graham --- That's correct, yeah. It's also requires for other people to be able to rebase your MRs. -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 --- Comment #25 from Christoph Cullmann --- I think the branch must be names work/ to avoid the hooks. -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Bug Janitor Service changed: What|Removed |Added Status|REOPENED|ASSIGNED --- Comment #24 from Bug Janitor Service --- A possibly relevant merge request was started @ https://invent.kde.org/frameworks/kjobwidgets/-/merge_requests/22 -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Michael Pyne changed: What|Removed |Added Ever confirmed|0 |1 Resolution|FIXED |--- Status|RESOLVED|REOPENED --- Comment #23 from Michael Pyne --- I thought that a MR needed to be merged to master to have its BUG: close a bug, reopening until a fix is merged. -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Michael Pyne changed: What|Removed |Added Resolution|--- |FIXED Latest Commit||https://invent.kde.org/fram ||eworks/kjobwidgets/commit/b ||8752085d2a480dfc93d2d422c46 ||3a59d46af5ee Status|REPORTED|RESOLVED --- Comment #22 from Michael Pyne --- Git commit b8752085d2a480dfc93d2d422c463a59d46af5ee by Michael Pyne. Committed on 02/07/2022 at 22:13. Pushed by mpyne into branch 'work-bug-450325-fix-crash'. ui-server: Fix crash by only re-registering live KJobs. This addresses a frequently-reported crash in the job tracker for KUiServerV2 that occurs when attempting to re-register new job views for active KJobs after a new UI server comes online. Although I have not been able to reproduce the crash myself, (by attempting to use both long-lived and short-lived file transfers from Dolphin and restarting plasmashell), inspection of the code shows that it is possible for there to be deleted KJobs pointing to JobView objects during some portions of the job tracker's lifetime. The current code deals with this in situations including DBus calls to create a U/I view for a KJob (the KJob may terminate before the DBus reply is received) and even a short delay that can be optionally introduced (the KJob may terminate before the delay elapses). A QPointer is used as a guard in these situations, but there is no similar guard for the re-registration code. In this case we cannot use QPointer to guard the job's lifetime because the KJob must be alive when the QPointer is created, and this crash occurs when the KJob is terminated. However the KJob's destruction should lead to the unregisterJob() function being called, which handles removing the terminated KJob from the map of job views with only one exception, where instead the job view for the KJob has its "terminated" pending status set. So the fix here checks for the "terminated" state in the same way as performed in requestView(), and if the KJob is terminated, handles requesting the job view to terminate the U/I and finally removing the terminated KJob from the map of job views. By doing this, we avoid passing a deleted KJob to the registerJob() function, which will attempt to dereference it and crash the application. M +16 -4src/kuiserverv2jobtracker.cpp https://invent.kde.org/frameworks/kjobwidgets/commit/b8752085d2a480dfc93d2d422c463a59d46af5ee -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325
--- Comment #21 from Michael Pyne ---
(In reply to Christoph Cullmann from comment #20)
> Sounds like a reasonable explanation.
well, maybe. I did find the code meant to update the jobView structure when the
KJob is finished, but it is a) called indirectly (from
KUiServerV2JobTracker::unregisterJob), and b) has a weird special case to
handle terminated KJobs that don't have an existing view (presumably because
the signal that would create it being later in the event loop):
// Remember that the job finished in the meantime and
// terminate the JobView once it arrives
d->scheduleUpdate(job, QStringLiteral("terminated"), true);
if (job->error()) {
d->scheduleUpdate(job, QStringLiteral("errorCode"),
static_cast(job->error()));
d->scheduleUpdate(job, QStringLiteral("errorMessage"),
job->errorText());
}
But scheduleUpdate() simply recreates the jobView mapping to the soon-to-be
dead KJob and if the re-registration happens before the "terminate the JobView
once it arrives" occurs we're in for a bad time, as the re-registration code
assumes all entries in the map of jobs to jobViews have valid KJobs.
I'll take a look at how best to handle the weird lifetimes here and try to open
the MR tonight.
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[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 --- Comment #20 from Christoph Cullmann --- Sounds like a reasonable explanation. -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325
Michael Pyne changed:
What|Removed |Added
CC||mp...@kde.org
--- Comment #19 from Michael Pyne ---
I suspect the issue is in using a deleted KJob when re-registering a job view
(kuiserverv2jobtracker.cpp:197)
// Watch the server registering/unregistering and re-register the jobs as
needed
if (!d->serverRegisteredConnection) {
d->serverRegisteredConnection = connect(serverProxy(),
&KSharedUiServerV2Proxy::serverRegistered, this, [this]() {
const auto staleViews = d->jobViews;
// elided
for (auto it = staleViews.begin(), end = staleViews.end(); it !=
end; ++it) {
KJob *job = it.key();
const JobView &view = it.value();
// elided
registerJob(job);
In the section of code right after this in registerJob, the code is careful to
ensure that a QPointer is used in order to verify that the KJob being
registered won't have been deleted in the functor to be added to the event loop
by QTimer (kuiserverv2jobtracker.cpp:248):
QPointer jobGuard = job;
QTimer *delayTimer = new QTimer();
delayTimer->setSingleShot(true);
connect(delayTimer, &QTimer::timeout, this, [this, job, jobGuard,
desktopEntry] {
// elided
});
This part of the code also references the d->jobViews the re-registration code
uses earlier, so if it were possible to assume that a KJob* held in d->jobViews
was enough to guarantee the KJob were still valid, the later delay timer could
have done the same thing. It would take more code to do this so that's not
airtight evidence, but I can't find anywhere else that guarantees a KJob ending
also removes its JobView (the re-registration code as much as calls it a
"stale" job view...) so I suspect this is the cause of this crash.
I'll put together a patch that uses the same QPointer jobGuard trick and
open an MR.
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[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Christoph Cullmann changed: What|Removed |Added CC||hsuship...@gmail.com --- Comment #16 from Christoph Cullmann --- *** Bug 455696 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 --- Comment #17 from Christoph Cullmann --- *** Bug 455658 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Christoph Cullmann changed: What|Removed |Added CC||toralf.foers...@gmx.de --- Comment #15 from Christoph Cullmann --- *** Bug 456175 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Christoph Cullmann changed: What|Removed |Added Priority|NOR |HI --- Comment #18 from Christoph Cullmann --- Seems this crash is not that uncommon :( -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Christoph Cullmann changed: What|Removed |Added CC||cullm...@kde.org --- Comment #14 from Christoph Cullmann --- I collected all other bugs with the same backtrace now here. -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Christoph Cullmann changed: What|Removed |Added CC||jda...@redhat.com --- Comment #13 from Christoph Cullmann --- *** Bug 453377 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Christoph Cullmann changed: What|Removed |Added CC||dabiswas...@gmail.com --- Comment #12 from Christoph Cullmann --- *** Bug 452167 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Christoph Cullmann changed: What|Removed |Added CC||torokat...@gmail.com --- Comment #11 from Christoph Cullmann --- *** Bug 451855 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Christoph Cullmann changed: What|Removed |Added CC||justin.zo...@gmail.com --- Comment #10 from Christoph Cullmann --- *** Bug 451474 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Christoph Cullmann changed: What|Removed |Added CC||and...@cavallium.it --- Comment #9 from Christoph Cullmann --- *** Bug 452808 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 --- Comment #8 from Kai Uwe Broulik --- I unfortunately cannot reproduce the Ark crash when restarting plasma while extracting a file. The crash could occur if Plasma restarts, thus our jobtracker re-registers the job, but the job is already gone or something. But I failed to reproduce it by extracting a file or manually using kjobcreator. -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 --- Comment #7 from hbr --- I have since switched some hardware and am now running Fedora 36 pre-release. The crash still happens there but in a much more graceful way (e.g. the restart of Plasma Shell is not delayed by about 30s + but pretty much happens instantly). I will check and report again once Fedora 36 is properly released, so this can be closed. -- You are receiving this mail because: You are watching all bug changes.
[frameworks-kjobwidgets] [Bug 450325] Ark crashes in KUiServerV2JobTracker::registerJob() when turning on second monitor
https://bugs.kde.org/show_bug.cgi?id=450325 Nate Graham changed: What|Removed |Added CC||n...@kde.org Component|generic-crash |general Target Milestone|1.0 |--- Product|plasmashell |frameworks-kjobwidgets Assignee|plasma-b...@kde.org |kdelibs-b...@kde.org Summary|Plasmashell / KDE apps |Ark crashes in |crash when turning on |KUiServerV2JobTracker::regi |second monitor |sterJob() when turning on ||second monitor Version|5.24.2 |5.91.0 --- Comment #6 from Nate Graham --- #7 0x7f47359d47b5 in KUiServerV2JobTracker::registerJob (this=0x555e082d4200, job=) at /usr/src/debug/kjobwidgets-5.91.0/src/kuiserverv2jobtracker.cpp:187 Can you file a new bug report for the Plasma crash, and attach a backtrace of Plasma crashing? Thanks! -- You are receiving this mail because: You are watching all bug changes.
