Cannot access memory segfault in RealKMSOutput on shutdown

[Saviq]

Thread 95 (Thread 0x7f63d17fa6c0 (LWP 9883) "Mir/Workqueue"):
#0  __pthread_kill_implementation (no_tid=0, signo=6, threadid=<optimized out>) at ./nptl/pthread_kill.c:44
#1  __pthread_kill_internal (signo=6, threadid=<optimized out>) at ./nptl/pthread_kill.c:78
#2  __GI___pthread_kill (threadid=<optimized out>, signo=signo@entry=6) at ./nptl/pthread_kill.c:89
#3  0x00007f657069ec46 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#4  0x00007f65706857fc in __GI_abort () at ./stdlib/abort.c:79
#5  0x00007f6570ace803 in mir::fatal_error_abort(char const*, ...) (reason=0x7f65703d5128 "Unsupported attempt to continue after a fatal signal: %s") at /home/michal/dev/MirServer/mir/src/core/fatal.cpp:40
#6  0x00007f656ffd3f23 in (anonymous namespace)::fatal_signal_cleanup(int, siginfo_t*, void*) (sig=11, info=0x7f63d17f7b30, ucontext=0x7f63d17f7a00) at /home/michal/dev/MirServer/mir/src/server/run_mir.cpp:186
#7  0x00007f657069ecf0 in <signal handler called> () at /lib/x86_64-linux-gnu/libc.so.6
#8  0x00007f656dcd543c in mir::geometry::generic::Value<int, mir::geometry::WidthTag>::Value<unsigned short, true>(unsigned short const&) (this=0x7f63d17f87b8, value=<error reading variable: Cannot access memory at address 0x4>) at /home/michal/dev/MirServer/mir/include/core/mir/geometry/dimensions.h:79
#9  0x00007f656dcd4461 in mir::geometry::generic::Size<int>::Size<unsigned short const&, unsigned short const&>(unsigned short const&, unsigned short const&) (this=0x7f63d17f87b8, width=<error reading variable: Cannot access memory at address 0x4>, height=<error reading variable: Cannot access memory at address 0xe>) at /home/michal/dev/MirServer/mir/include/core/mir/geometry/size.h:52
#10 0x00007f656dcd0256 in mir::graphics::gbm::RealKMSOutput::size() const (this=0x5604ed65b9d0) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/real_kms_output.cpp:133
#11 0x00007f656dc8d26a in operator()(mir::graphics::gbm::KMSOutput&, mir::graphics::DisplayConfigurationOutput const&) const (__closure=0x7f63b00061c0, output=..., conf=...) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/cursor.cpp:392
#12 0x00007f656dc8f0d3 in std::__invoke_impl<void, mir::graphics::gbm::Cursor::place_cursor_at_locked(const std::lock_guard<std::mutex>&, mir::geometry::Point, ForceCursorState)::<lambda(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&)>&, mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&>(std::__invoke_other, struct {...} &) (__f=...) at /usr/include/c++/12/bits/invoke.h:61
#13 0x00007f656dc8ebd2 in std::__invoke_r<void, mir::graphics::gbm::Cursor::place_cursor_at_locked(const std::lock_guard<std::mutex>&, mir::geometry::Point, ForceCursorState)::<lambda(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&)>&, mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&>(struct {...} &) (__fn=...) at /usr/include/c++/12/bits/invoke.h:111
#14 0x00007f656dc8e340 in std::_Function_handler<void(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&), mir::graphics::gbm::Cursor::place_cursor_at_locked(const std::lock_guard<std::mutex>&, mir::geometry::Point, ForceCursorState)::<lambda(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&)> >::_M_invoke(const std::_Any_data &, mir::graphics::gbm::KMSOutput &, const mir::graphics::DisplayConfigurationOutput &) (__functor=..., __args#0=..., __args#1=...) at /usr/include/c++/12/bits/std_function.h:290
#15 0x00007f656dc933af in std::function<void (mir::graphics::gbm::KMSOutput&, mir::graphics::DisplayConfigurationOutput const&)>::operator()(mir::graphics::gbm::KMSOutput&, mir::graphics::DisplayConfigurationOutput const&) const (this=0x7f63d17f8cc0, __args#0=..., __args#1=...) at /usr/include/c++/12/bits/std_function.h:591
#16 0x00007f656dc8ce08 in operator()(mir::graphics::DisplayConfigurationOutput const&) const (__closure=0x7f63d17f8aa0, conf_output=...) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/cursor.cpp:344
#17 0x00007f656dc8ef49 in std::__invoke_impl<void, mir::graphics::gbm::Cursor::for_each_used_output(const std::function<void(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&)>&)::<lambda(const mir::graphics::gbm::KMSDisplayConfiguration&)>::<lambda(const mir::graphics::DisplayConfigurationOutput&)>&, const mir::graphics::DisplayConfigurationOutput&>(std::__invoke_other, struct {...} &) (__f=...) at /usr/include/c++/12/bits/invoke.h:61
#18 0x00007f656dc8e8cb in std::__invoke_r<void, mir::graphics::gbm::Cursor::for_each_used_output(const std::function<void(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&)>&)::<lambda(const mir::graphics::gbm::KMSDisplayConfiguration&)>::<lambda(const mir::graphics::DisplayConfigurationOutput&)>&, const mir::graphics::DisplayConfigurationOutput&>(struct {...} &) (__fn=...) at /usr/include/c++/12/bits/invoke.h:111
#19 0x00007f656dc8e10a in std::_Function_handler<void(const mir::graphics::DisplayConfigurationOutput&), mir::graphics::gbm::Cursor::for_each_used_output(const std::function<void(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&)>&)::<lambda(const mir::graphics::gbm::KMSDisplayConfiguration&)>::<lambda(const mir::graphics::DisplayConfigurationOutput&)> >::_M_invoke(const std::_Any_data &, const mir::graphics::DisplayConfigurationOutput &) (__functor=..., __args#0=...) at /usr/include/c++/12/bits/std_function.h:290
#20 0x00007f656dcc70f3 in std::function<void (mir::graphics::DisplayConfigurationOutput const&)>::operator()(mir::graphics::DisplayConfigurationOutput const&) const (this=0x7f63d17f8aa0, __args#0=...) at /usr/include/c++/12/bits/std_function.h:591
#21 0x00007f656dcc4c14 in mir::graphics::gbm::RealKMSDisplayConfiguration::for_each_output(std::function<void (mir::graphics::DisplayConfigurationOutput const&)>) const (this=0x5604ed6385d0, f=...) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/real_kms_display_configuration.cpp:70
#22 0x00007f656dc8ceb7 in operator()(mir::graphics::gbm::KMSDisplayConfiguration const&) const (__closure=0x7f63d17f8c10, kms_conf=...) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/cursor.cpp:339
#23 0x00007f656dc8f009 in std::__invoke_impl<void, mir::graphics::gbm::Cursor::for_each_used_output(const std::function<void(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&)>&)::<lambda(const mir::graphics::gbm::KMSDisplayConfiguration&)>&, const mir::graphics::gbm::KMSDisplayConfiguration&>(std::__invoke_other, struct {...} &) (__f=...) at /usr/include/c++/12/bits/invoke.h:61
#24 0x00007f656dc8ea39 in std::__invoke_r<void, mir::graphics::gbm::Cursor::for_each_used_output(const std::function<void(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&)>&)::<lambda(const mir::graphics::gbm::KMSDisplayConfiguration&)>&, const mir::graphics::gbm::KMSDisplayConfiguration&>(struct {...} &) (__fn=...) at /usr/include/c++/12/bits/invoke.h:111
#25 0x00007f656dc8e219 in std::_Function_handler<void(const mir::graphics::gbm::KMSDisplayConfiguration&), mir::graphics::gbm::Cursor::for_each_used_output(const std::function<void(mir::graphics::gbm::KMSOutput&, const mir::graphics::DisplayConfigurationOutput&)>&)::<lambda(const mir::graphics::gbm::KMSDisplayConfiguration&)> >::_M_invoke(const std::_Any_data &, const mir::graphics::gbm::KMSDisplayConfiguration &) (__functor=..., __args#0=...) at /usr/include/c++/12/bits/std_function.h:290
#26 0x00007f656dca5013 in std::function<void (mir::graphics::gbm::KMSDisplayConfiguration const&)>::operator()(mir::graphics::gbm::KMSDisplayConfiguration const&) const (this=0x7f63d17f8c10, __args#0=...) at /usr/include/c++/12/bits/std_function.h:591
#27 0x00007f656dc9d785 in KMSCurrentConfiguration::with_current_configuration_do(const std::function<void(const mir::graphics::gbm::KMSDisplayConfiguration&)> &) (this=0x5604ed860df0, exec=...) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/display.cpp:337
#28 0x00007f656dc8cf6f in mir::graphics::gbm::Cursor::for_each_used_output(std::function<void (mir::graphics::gbm::KMSOutput&, mir::graphics::DisplayConfigurationOutput const&)> const&) (this=0x5604ed9bccf0, f=...) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/cursor.cpp:336
#29 0x00007f656dc8d692 in mir::graphics::gbm::Cursor::place_cursor_at_locked(std::lock_guard<std::mutex> const&, mir::geometry::generic::Point<int>, mir::graphics::gbm::Cursor::ForceCursorState) (this=0x5604ed9bccf0, lg=..., position=..., force_state=mir::graphics::gbm::Cursor::ForceState) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/cursor.cpp:371
#30 0x00007f656dc8d022 in mir::graphics::gbm::Cursor::place_cursor_at(mir::geometry::generic::Point<int>, mir::graphics::gbm::Cursor::ForceCursorState) (this=0x5604ed9bccf0, position=..., force_state=mir::graphics::gbm::Cursor::ForceState) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/cursor.cpp:355
#31 0x00007f656dc8ccd4 in mir::graphics::gbm::Cursor::resume() (this=0x5604ed9bccf0) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/cursor.cpp:323
#32 0x00007f656dc9d164 in mir::graphics::gbm::Display::configure(mir::graphics::DisplayConfiguration const&) (this=0x5604ed6384e0, conf=...) at /home/michal/dev/MirServer/mir/src/platforms/gbm-kms/server/kms/display.cpp:263
#33 0x00007f6570122341 in mir::scene::MediatingDisplayChanger::apply_config(std::shared_ptr<mir::graphics::DisplayConfiguration> const&) (this=0x5604ee19cee0, conf=std::shared_ptr<mir::graphics::DisplayConfiguration> (use count 1, weak count 0) = {...}) at /home/michal/dev/MirServer/mir/src/server/scene/mediating_display_changer.cpp:397
#34 0x00007f6570123038 in mir::scene::MediatingDisplayChanger::set_power_mode(MirPowerMode) (this=0x5604ee19cee0, new_power_mode=mir_power_mode_off) at /home/michal/dev/MirServer/mir/src/server/scene/mediating_display_changer.cpp:533
#35 0x00007f65703313b2 in (anonymous namespace)::PowerModeSetter::idle() (this=0x5604ee1df320) at /home/michal/dev/MirServer/mir/src/server/shell/basic_idle_handler.cpp:142
#36 0x00007f65701767eb in std::__invoke_impl<void, void (mir::scene::IdleStateObserver::* const&)(), mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::WeakObserver::LockedObserver&>(std::__invoke_memfun_deref, void (mir::scene::IdleStateObserver::* const&)(), mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::WeakObserver::LockedObserver&) (__f=@0x7f63b0000cc0: &virtual mir::scene::IdleStateObserver::idle(), __t=...) at /usr/include/c++/12/bits/invoke.h:74
#37 0x00007f6570174f30 in std::__invoke<void (mir::scene::IdleStateObserver::* const&)(), mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::WeakObserver::LockedObserver&>(void (mir::scene::IdleStateObserver::* const&)(), mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::WeakObserver::LockedObserver&) (__fn=@0x7f63b0000cc0: &virtual mir::scene::IdleStateObserver::idle()) at /usr/include/c++/12/bits/invoke.h:96
#38 0x00007f6570173178 in std::_Mem_fn_base<void (mir::scene::IdleStateObserver::*)(), true>::operator()<mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::WeakObserver::LockedObserver&>(mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::WeakObserver::LockedObserver&) const (this=0x7f63b0000cc0) at /usr/include/c++/12/functional:167
#39 0x00007f657017157f in mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::for_each_observer<void (mir::scene::IdleStateObserver::*)()>(void (mir::scene::IdleStateObserver::*)())::{lambda()#1}::operator()() (__closure=0x7f63b0000cc0) at /home/michal/dev/MirServer/mir/src/include/server/mir/observer_multiplexer.h:243
#40 0x00007f6570177d96 in std::__invoke_impl<void, mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::for_each_observer<void (mir::scene::IdleStateObserver::*)()>(void (mir::scene::IdleStateObserver::*)())::{lambda()#1}&>(std::__invoke_other, mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::for_each_observer<void (mir::scene::IdleStateObserver::*)()>(void (mir::scene::IdleStateObserver::*)())::{lambda()#1}&) (__f=...) at /usr/include/c++/12/bits/invoke.h:61
#41 0x00007f6570176a72 in std::__invoke_r<void, mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::for_each_observer<void (mir::scene::IdleStateObserver::*)()>(void (mir::scene::IdleStateObserver::*)())::{lambda()#1}&>(mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::for_each_observer<void (mir::scene::IdleStateObserver::*)()>(void (mir::scene::IdleStateObserver::*)())::{lambda()#1}&) (__fn=...) at /usr/include/c++/12/bits/invoke.h:111
#42 0x00007f6570175111 in std::_Function_handler<void (), mir::ObserverMultiplexer<mir::scene::IdleStateObserver>::for_each_observer<void (mir::scene::IdleStateObserver::*)()>(void (mir::scene::IdleStateObserver::*)())::{lambda()#1}>::_M_invoke(std::_Any_data const&) (__functor=...) at /usr/include/c++/12/bits/std_function.h:290
#43 0x00007f656fe38b4a in std::function<void ()>::operator()() const (this=0x7f63d17f9100) at /usr/include/c++/12/bits/std_function.h:591
#44 0x00007f656fe5871d in (anonymous namespace)::LinearisingAdaptor::work_loop() (this=0x7f656fe9d260 <(anonymous namespace)::adaptor>) at /home/michal/dev/MirServer/mir/src/common/linearising_executor.cpp:66
#45 0x00007f656fe5856f in operator()() const (__closure=0x7f63c4067280) at /home/michal/dev/MirServer/mir/src/common/linearising_executor.cpp:50
#46 0x00007f656fe58aec in std::__invoke_impl<void, (anonymous namespace)::LinearisingAdaptor::spawn(std::function<void()>&&)::<lambda()>&>(std::__invoke_other, struct {...} &) (__f=...) at /usr/include/c++/12/bits/invoke.h:61
#47 0x00007f656fe589d3 in std::__invoke_r<void, (anonymous namespace)::LinearisingAdaptor::spawn(std::function<void()>&&)::<lambda()>&>(struct {...} &) (__fn=...) at /usr/include/c++/12/bits/invoke.h:111
#48 0x00007f656fe588c1 in std::_Function_handler<void(), (anonymous namespace)::LinearisingAdaptor::spawn(std::function<void()>&&)::<lambda()> >::_M_invoke(const std::_Any_data &) (__functor=...) at /usr/include/c++/12/bits/std_function.h:290
#49 0x00007f656fe38b4a in std::function<void ()>::operator()() const (this=0x7f63c4067280) at /usr/include/c++/12/bits/std_function.h:591
#50 0x00007f656fe5097f in operator()() (__closure=0x7f63c4067260) at /home/michal/dev/MirServer/mir/src/common/thread_pool_executor.cpp:266
#51 0x00007f656fe52fd4 in std::__invoke_impl<void, (anonymous namespace)::ThreadPool::spawn(std::function<void()>&&)::<lambda()>&>(std::__invoke_other, struct {...} &) (__f=...) at /usr/include/c++/12/bits/invoke.h:61
#52 0x00007f656fe52723 in std::__invoke_r<void, (anonymous namespace)::ThreadPool::spawn(std::function<void()>&&)::<lambda()>&>(struct {...} &) (__fn=...) at /usr/include/c++/12/bits/invoke.h:111
#53 0x00007f656fe51e98 in std::_Function_handler<void(), (anonymous namespace)::ThreadPool::spawn(std::function<void()>&&)::<lambda()> >::_M_invoke(const std::_Any_data &) (__functor=...) at /usr/include/c++/12/bits/std_function.h:290
#54 0x00007f656fe38b4a in std::function<void ()>::operator()() const (this=0x7f63d17f92c0) at /usr/include/c++/12/bits/std_function.h:591
#55 0x00007f656fe50529 in (anonymous namespace)::Worker::work_loop((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&) (me=0x7f63c4052850, shutdown_channel=...) at /home/michal/dev/MirServer/mir/src/common/thread_pool_executor.cpp:184
#56 0x00007f656fe54069 in std::__invoke_impl<void, void (*)((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&), (anonymous namespace)::Worker*, std::promise<std::atomic<bool>*> >(std::__invoke_other, void (*&&)((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&)) (__f=@0x7f63c40215a8: 0x7f656fe5044d <(anonymous namespace)::Worker::work_loop((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&)>) at /usr/include/c++/12/bits/invoke.h:61
#57 0x00007f656fe53fdf in std::__invoke<void (*)((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&), (anonymous namespace)::Worker*, std::promise<std::atomic<bool>*> >(void (*&&)((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&)) (__fn=@0x7f63c40215a8: 0x7f656fe5044d <(anonymous namespace)::Worker::work_loop((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&)>) at /usr/include/c++/12/bits/invoke.h:96
#58 0x00007f656fe53ef7 in std::thread::_Invoker<std::tuple<void (*)((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&), (anonymous namespace)::Worker*, std::promise<std::atomic<bool>*> > >::_M_invoke<0, 1, 2>(std::_Index_tuple<0, 1, 2>) (this=0x7f63c4021588) at /usr/include/c++/12/bits/std_thread.h:252
#59 0x00007f656fe53e7a in std::thread::_Invoker<std::tuple<void (*)((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&), (anonymous namespace)::Worker*, std::promise<std::atomic<bool>*> > >::operator()() (this=0x7f63c4021588) at /usr/include/c++/12/bits/std_thread.h:259
#60 0x00007f656fe53e24 in std::thread::_State_impl<std::thread::_Invoker<std::tuple<void (*)((anonymous namespace)::Worker*, std::promise<std::atomic<bool>*>&&), (anonymous namespace)::Worker*, std::promise<std::atomic<bool>*> > > >::_M_run() (this=0x7f63c4021580) at /usr/include/c++/12/bits/std_thread.h:210
#61 0x00007f65709643a3 in  () at /lib/x86_64-linux-gnu/libstdc++.so.6
#62 0x00007f65706f32a2 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
#63 0x00007f6570782260 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

[AlanGriffiths]

Is this another case of connector being stale?

Apart from "shutdown" the system was quiet? Or where there apps active?

[Saviq]

Is this another case of connector being stale?

This was with #2684, so shouldn't be.

Apart from "shutdown" the system was quiet? Or where there apps active?

Yeah there were apps, I Ctrl+Alt+Backspaced to refresh to #2689.

[AlanGriffiths]

This was with #2684, so shouldn't be.

That refreshed connector on one codepath through ensure_crtc(). This path isn't calling ensure_crtc() anywhere I've seen

[Saviq]

Fixed by #2691