[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 Vlad Zahorodnii changed: What|Removed |Added CC||firef...@protonmail.com --- Comment #11 from Vlad Zahorodnii --- *** Bug 409815 has been marked as a duplicate of this bug. *** -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 Vlad Zahorodnii changed: What|Removed |Added Latest Commit|https://commits.kde.org/kwi |https://commits.kde.org/kwi |n/c438ecbb702e970004e7e97e6 |n/d948d247fe4371462f2fe6b96 |734f57caef32ea5 |b25fd8026abafb5 --- Comment #10 from Vlad Zahorodnii --- Git commit d948d247fe4371462f2fe6b96b25fd8026abafb5 by Vlad Zagorodniy. Committed on 15/07/2019 at 13:56. Pushed by vladz into branch 'Plasma/5.12'. Don't crash when highlighted tabbox client is closed Summary: The compositor tries to switch to the next tabbox client when currently highlighted client is closed. Though there is a small issue with that. Because the switch happens too late, a dangling pointer can be inserted into the unconstrained stacking order, which can lead to a crash later on. There are two cases: - compositing is on; - compositing is off. Compositing is on: TabBox will try to un-elevate currently highlighted client, though by that time the client no longer owns EffectWindow, so this is basically a no-op (that's why we haven't experienced this bug before). Compositing is off: TabBox will try to restack currently hightlighted client under the next tabbox client. Given that the restack method doesn't do any sanity checks(see Client::manage why), a client that is about to be destroyed will be re-inserted back into the unconstrained stacking order. This change ensures that the switch happens before currently highlighted client is removed from the stacking order. Test Plan: - Turn off compositing; - Follow steps to reproduce in the bug report (see comment 2). Reviewers: #kwin, davidedmundson Reviewed By: #kwin, davidedmundson Subscribers: kwin Tags: #kwin Differential Revision: https://phabricator.kde.org/D20916 M +15 -0client.cpp M +1-6workspace.cpp https://commits.kde.org/kwin/d948d247fe4371462f2fe6b96b25fd8026abafb5 -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 Nate Graham changed: What|Removed |Added Version Fixed In||5.16.0 -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 Vlad Zagorodniy changed: What|Removed |Added Latest Commit||https://commits.kde.org/kwi ||n/c438ecbb702e970004e7e97e6 ||734f57caef32ea5 Resolution|--- |FIXED Status|CONFIRMED |RESOLVED --- Comment #9 from Vlad Zagorodniy --- Git commit c438ecbb702e970004e7e97e6734f57caef32ea5 by Vlad Zagorodniy. Committed on 03/05/2019 at 18:25. Pushed by vladz into branch 'master'. Don't crash when highlighted tabbox client is closed Summary: The compositor tries to switch to the next tabbox client when currently highlighted client is closed. Though there is a small issue with that. Because the switch happens too late, a dangling pointer can be inserted into the unconstrained stacking order, which can lead to a crash later on. There are two cases: - compositing is on; - compositing is off. Compositing is on: TabBox will try to un-elevate currently highlighted client, though by that time the client no longer owns EffectWindow, so this is basically a no-op (that's why we haven't experienced this bug before). Compositing is off: TabBox will try to restack currently hightlighted client under the next tabbox client. Given that the restack method doesn't do any sanity checks(see Client::manage why), a client that is about to be destroyed will be re-inserted back into the unconstrained stacking order. This change ensures that the switch happens before currently highlighted client is removed from the stacking order. Test Plan: - Turn off compositing; - Follow steps to reproduce in the bug report (see comment 2). Reviewers: #kwin, davidedmundson Reviewed By: #kwin, davidedmundson Subscribers: kwin Tags: #kwin Differential Revision: https://phabricator.kde.org/D20916 M +15 -0client.cpp M +1-6workspace.cpp https://commits.kde.org/kwin/c438ecbb702e970004e7e97e6734f57caef32ea5 -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 Vlad Zagorodniy changed: What|Removed |Added Flags||ReviewRequest+ URL||https://phabricator.kde.org ||/D20916 --- Comment #8 from Vlad Zagorodniy --- KWin/Wayland may suffer from similar problem. -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784
--- Comment #7 from Vlad Zagorodniy ---
if (q->isKWinCompositing()) {
if (lastRaisedClient)
q->elevateClient(lastRaisedClient, w, false);
lastRaisedClient = currentClient;
if (currentClient)
q->elevateClient(currentClient, w, true);
} else {
if (lastRaisedClient) {
q->shadeClient(lastRaisedClient, true);
if (lastRaisedClientSucc)
q->restack(lastRaisedClient, lastRaisedClientSucc);
Yeah, this explains why.
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[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 --- Comment #6 from Vlad Zagorodniy --- Hmm when compositing is on, the tabbox doesn't invoke Workspace::restack() -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 --- Comment #5 from Vlad Zagorodniy --- When compositing is off, unconstrained_stacking_order contains a dangling pointer (added by Workspace::restack()): Client::destroyClient(this=0x560e5f07d1a0) Workspace::addDeleted(c=0x560e5f06e3b0, orig=0x560e5f07d1a0) Workspace::raiseClient(c=0x560e5e6cc830) Workspace::lowerClient(c=0x560e5e6cc830) Workspace::lowerClient(c=0x560e5e6cc830) Workspace::restack(c=0x560e5f07d1a0, under=0x560e5e7a2510) Workspace::raiseClient(c=0x560e5e6cc830) Workspace::constrainedStackingOrder() unconstrained_stacking_order: - 0x560e5e7824a0 - 0x560e5e795eb0 - 0x560e5e7bfba0 - 0x560e5f07d1a0 - 0x560e5e7a2510 - 0x560e5e7dcf80 - 0x560e5f06e3b0 - 0x560e5e79df70 When compositing is on, KWin doesn't crash. Investigating it further. -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 Patrick Silva changed: What|Removed |Added CC||bugsefor...@gmx.com -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 Nate Graham changed: What|Removed |Added CC||n...@kde.org -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 --- Comment #4 from Vlad Zagorodniy --- Hmm, the crash occurs only when compositing is turned off. -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 Vlad Zagorodniy changed: What|Removed |Added Status|REPORTED|CONFIRMED Ever confirmed|0 |1 -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 --- Comment #3 from Vlad Zagorodniy --- Thanks, I've managed to reproduce the crash. -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 --- Comment #2 from Stefano --- Created attachment 119573 --> https://bugs.kde.org/attachment.cgi?id=119573&action=edit screen recording I am not sure it is clear. I start the export, then I focus on Kate. Then, after pressing Alt+Tab when all the windows are present to select the one that is going to disappear, I am holding only Alt until it is closed, and soon later, when I release the key after it vanished, KWin crashes. Hope it helps. -- You are receiving this mail because: You are watching all bug changes.
[kwin] [Bug 406784] Alt-tab makes KWin crash when the window is destroyed during switch
https://bugs.kde.org/show_bug.cgi?id=406784 --- Comment #1 from Vlad Zagorodniy --- Do you think you could provide a screen recording? I wasted hours trying to reproduce this crash, screen recording would help me a lot. -- You are receiving this mail because: You are watching all bug changes.
