I am using Linux 4.13.5 (with Gentoo patches, aka =sys-kernel/gentoo-sources-4.13.5).


The device is:
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Kaveri [Radeon R7 Graphics] (prog-if 00 [VGA controller])
        Subsystem: ASUSTeK Computer Inc. Kaveri [Radeon R7 Graphics]
        Flags: bus master, fast devsel, latency 0, IRQ 49
        Memory at e0000000 (64-bit, prefetchable) [size=256M]
        Memory at f0000000 (64-bit, prefetchable) [size=8M]
        I/O ports at f000 [size=256]
        Memory at feb00000 (32-bit, non-prefetchable) [size=256K]
        Expansion ROM at 000c0000 [disabled] [size=128K]
        Capabilities: [48] Vendor Specific Information: Len=08 <?>
        Capabilities: [50] Power Management version 3
        Capabilities: [58] Express Root Complex Integrated Endpoint, MSI 00
        Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
        Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
        Capabilities: [270] #19
        Capabilities: [2b0] Address Translation Service (ATS)
        Capabilities: [2c0] Page Request Interface (PRI)
        Capabilities: [2d0] Process Address Space ID (PASID)
        Kernel driver in use: amdgpu
        Kernel modules: amdgpu


These versions of LLVM are installed, but the latter is active and the one that is being used by Mesa:

sys-devel/llvm-4.0.1::gentoo was built with the following:
USE="doc gold libffi ncurses -debug -libedit -test" ABI_X86="32 (64) (-x32)" LLVM_TARGETS="AMDGPU BPF NVPTX (X86) -AArch64 -ARM -Hexagon -Lanai -MSP430 -Mips -PowerPC -RISCV -Sparc -SystemZ -XCore"

sys-devel/llvm-5.0.0::gentoo was built with the following:
USE="doc gold libffi ncurses -debug -libedit -test" ABI_X86="32 (64) (-x32)" LLVM_TARGETS="AMDGPU BPF NVPTX (X86) -AArch64 -ARM -Hexagon -Lanai -MSP430 -Mips -PowerPC -Sparc -SystemZ -XCore"

Created attachment 134806 [details]
glxinfo

It just happened again:

Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/lib64/libthread_db.so.1".
[Current thread is 1 (Thread 0x7fc355251d00 (LWP 3241))]

Thread 13 (Thread 0x7fc31350c700 (LWP 30580)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc32df9b7f3 in cnd_wait (mtx=0x144db48, cond=0x144db70) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:159
#2  util_queue_thread_func (input=input@entry=0x13e9bf0) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/util/u_queue.c:158
#3  0x00007fc32df9b717 in impl_thrd_routine (p=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:87
#4  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#5  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 12 (Thread 0x7fc312d0b700 (LWP 3408)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc351dbe634 in ?? () from /usr/lib64/libQt5Script.so.5
#2  0x00007fc351dbe679 in ?? () from /usr/lib64/libQt5Script.so.5
#3  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#4  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 11 (Thread 0x7fc313d0d700 (LWP 3380)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc32df9b7f3 in cnd_wait (mtx=0xf50528, cond=0xf50550) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:159
#2  util_queue_thread_func (input=input@entry=0xe39db0) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/util/u_queue.c:158
#3  0x00007fc32df9b717 in impl_thrd_routine (p=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:87
#4  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#5  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 10 (Thread 0x7fc31450e700 (LWP 3377)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc32df9b7f3 in cnd_wait (mtx=0xdf6b80, cond=0xdf6ba8) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:159
#2  util_queue_thread_func (input=input@entry=0xe45f40) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/util/u_queue.c:158
#3  0x00007fc32df9b717 in impl_thrd_routine (p=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:87
#4  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#5  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 9 (Thread 0x7fc314d0f700 (LWP 3376)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc32df9b7f3 in cnd_wait (mtx=0xdf6b80, cond=0xdf6ba8) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:159
#2  util_queue_thread_func (input=input@entry=0xe45f00) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/util/u_queue.c:158
#3  0x00007fc32df9b717 in impl_thrd_routine (p=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:87
#4  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#5  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 8 (Thread 0x7fc315510700 (LWP 3375)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc32df9b7f3 in cnd_wait (mtx=0xdf6a98, cond=0xdf6ac0) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:159
#2  util_queue_thread_func (input=input@entry=0xe52840) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/util/u_queue.c:158
#3  0x00007fc32df9b717 in impl_thrd_routine (p=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:87
#4  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#5  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 7 (Thread 0x7fc315d11700 (LWP 3374)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc32df9b7f3 in cnd_wait (mtx=0xdf6a98, cond=0xdf6ac0) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:159
#2  util_queue_thread_func (input=input@entry=0xe0a120) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/util/u_queue.c:158
#3  0x00007fc32df9b717 in impl_thrd_routine (p=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:87
#4  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#5  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 6 (Thread 0x7fc316512700 (LWP 3373)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc32df9b7f3 in cnd_wait (mtx=0xdf6a98, cond=0xdf6ac0) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:159
#2  util_queue_thread_func (input=input@entry=0xe45d60) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/util/u_queue.c:158
#3  0x00007fc32df9b717 in impl_thrd_routine (p=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:87
#4  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#5  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 5 (Thread 0x7fc316f19700 (LWP 3372)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc32df9b7f3 in cnd_wait (mtx=0xe45de0, cond=0xe45e08) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:159
#2  util_queue_thread_func (input=input@entry=0xd4c050) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/util/u_queue.c:158
#3  0x00007fc32df9b717 in impl_thrd_routine (p=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:87
#4  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#5  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 4 (Thread 0x7fc31771a700 (LWP 3371)):
#0  0x00007fc34e829466 in pthread_cond_wait () from /lib64/libpthread.so.0
#1  0x00007fc32df9b7f3 in cnd_wait (mtx=0xdf3d38, cond=0xdf3d60) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:159
#2  util_queue_thread_func (input=input@entry=0xd4c390) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/util/u_queue.c:158
#3  0x00007fc32df9b717 in impl_thrd_routine (p=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/include/c11/threads_posix.h:87
#4  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#5  0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 3 (Thread 0x7fc32ffff700 (LWP 3341)):
#0  0x00007fc354d4e5c3 in ppoll () from /lib64/libc.so.6
#1  0x00007fc352c9c419 in ppoll (__ss=<optimized out>, __timeout=<optimized out>, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
#2  qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7fc324000ac8) at kernel/qcore_unix.cpp:81
#3  qt_safe_poll (fds=0x7fc324000ac8, nfds=nfds@entry=1, timeout_ts=timeout_ts@entry=0x0) at kernel/qcore_unix.cpp:102
#4  0x00007fc352c9d663 in QEventDispatcherUNIX::processEvents (this=<optimized out>, flags=...) at kernel/qeventdispatcher_unix.cpp:500
#5  0x00007fc352c5066a in QEventLoop::exec (this=this@entry=0x7fc32fffed50, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#6  0x00007fc352ab43bb in QThread::exec (this=this@entry=0xde0aa0) at thread/qthread.cpp:515
#7  0x00007fc34d6f3675 in QQmlThreadPrivate::run (this=0xde0aa0) at qml/ftw/qqmlthread.cpp:147
#8  0x00007fc352ab85e0 in QThreadPrivate::start (arg=0xde0aa0) at thread/qthread_unix.cpp:368
#9  0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#10 0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 2 (Thread 0x7fc337102700 (LWP 3277)):
#0  0x00007fc354d67b92 in __libc_disable_asynccancel () from /lib64/libc.so.6
#1  0x00007fc354d4e5d6 in ppoll () from /lib64/libc.so.6
#2  0x00007fc352c9c419 in ppoll (__ss=<optimized out>, __timeout=<optimized out>, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
#3  qt_ppoll (timeout_ts=0x0, nfds=1, fds=0x7fc33000ab98) at kernel/qcore_unix.cpp:81
#4  qt_safe_poll (fds=0x7fc33000ab98, nfds=nfds@entry=1, timeout_ts=timeout_ts@entry=0x0) at kernel/qcore_unix.cpp:102
#5  0x00007fc352c9d663 in QEventDispatcherUNIX::processEvents (this=<optimized out>, flags=...) at kernel/qeventdispatcher_unix.cpp:500
#6  0x00007fc352c5066a in QEventLoop::exec (this=this@entry=0x7fc337101d40, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#7  0x00007fc352ab43bb in QThread::exec (this=this@entry=0x7fc3553b4da0 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread.cpp:515
#8  0x00007fc3553406b5 in QDBusConnectionManager::run (this=0x7fc3553b4da0 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at qdbusconnection.cpp:178
#9  0x00007fc352ab85e0 in QThreadPrivate::start (arg=0x7fc3553b4da0 <(anonymous namespace)::Q_QGS__q_manager::innerFunction()::holder>) at thread/qthread_unix.cpp:368
#10 0x00007fc34e822617 in start_thread () from /lib64/libpthread.so.0
#11 0x00007fc354d5960f in clone () from /lib64/libc.so.6

Thread 1 (Thread 0x7fc355251d00 (LWP 3241)):
[KCrash Handler]
#6  si_draw_vbo (ctx=0x1413780, info=0x14503f8) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/gallium/drivers/radeonsi/si_state_draw.c:1305
#7  0x00007fc32e0b8863 in tc_call_draw_vbo (pipe=<optimized out>, payload=0x14503f8) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/gallium/auxiliary/util/u_threaded_context.c:1814
#8  0x00007fc32e0b69b0 in tc_batch_execute (thread_index=0, job=0x1450170) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/gallium/auxiliary/util/u_threaded_context.c:94
#9  _tc_sync (tc=0x144d770, func=<optimized out>, info=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/gallium/auxiliary/util/u_threaded_context.c:185
#10 0x00007fc32e0b6e58 in tc_flush (_pipe=<optimized out>, fence=0x7ffe88493950, flags=1) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/gallium/auxiliary/util/u_threaded_context.c:1797
#11 0x00007fc32dee0bfe in st_context_flush (stctxi=0x146cda0, flags=3, fence=0x7ffe88493950) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/mesa/state_tracker/st_manager.c:635
#12 0x00007fc32e01f427 in dri_flush (cPriv=<optimized out>, dPriv=<optimized out>, flags=<optimized out>, reason=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/gallium/state_trackers/dri/dri_drawable.c:550
#13 0x00007fc34bc989ef in loader_dri3_swap_buffers_msc (draw=0x13ea708, target_msc=0, divisor=0, remainder=0, flush_flags=3, force_copy=<optimized out>) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/loader/loader_dri3_helper.c:643
#14 0x00007fc3554345fa in QGLXContext::swapBuffers (this=0x138d910, surface=0x14775d0) at qglxintegration.cpp:545
#15 0x00007fc352fd120d in QOpenGLContext::swapBuffers (this=0x13c1bb0, surface=<optimized out>) at kernel/qopenglcontext.cpp:1107
#16 0x00007fc34dbd312e in QSGGuiThreadRenderLoop::renderWindow (this=0x12092f0, window=<optimized out>) at scenegraph/qsgrenderloop.cpp:445
#17 0x00007fc34dc45796 in QQuickWindow::event (this=this@entry=0x11d0440, e=e@entry=0x7ffe88493f20) at items/qquickwindow.cpp:1587
#18 0x00007fc276db2d0b in PlasmaQuick::Dialog::event (this=0x11d0440, event=0x7ffe88493f20) at /var/tmp/portage/kde-frameworks/plasma-5.39.0/work/plasma-framework-5.39.0/src/plasmaquick/dialog.cpp:1171
#19 0x00007fc35349cf4c in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x11d0440, e=0x7ffe88493f20) at kernel/qapplication.cpp:3722
#20 0x00007fc3534a4620 in QApplication::notify (this=0x7ffe88494610, receiver=0x11d0440, e=0x7ffe88493f20) at kernel/qapplication.cpp:3481
#21 0x00007fc352c51891 in QCoreApplication::notifyInternal2 (receiver=receiver@entry=0x11d0440, event=event@entry=0x7ffe88493f20) at kernel/qcoreapplication.cpp:1018
#22 0x00007fc352fa9986 in QCoreApplication::sendEvent (event=0x7ffe88493f20, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:233
#23 QWindowPrivate::deliverUpdateRequest (this=this@entry=0x11d08b0) at kernel/qwindow.cpp:2302
#24 0x00007fc352fa9e99 in QWindow::event (this=this@entry=0x11d0440, ev=ev@entry=0x7ffe88494390) at kernel/qwindow.cpp:2273
#25 0x00007fc34dc45735 in QQuickWindow::event (this=this@entry=0x11d0440, e=e@entry=0x7ffe88494390) at items/qquickwindow.cpp:1606
#26 0x00007fc276db2d0b in PlasmaQuick::Dialog::event (this=0x11d0440, event=0x7ffe88494390) at /var/tmp/portage/kde-frameworks/plasma-5.39.0/work/plasma-framework-5.39.0/src/plasmaquick/dialog.cpp:1171
#27 0x00007fc35349cf4c in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x11d0440, e=0x7ffe88494390) at kernel/qapplication.cpp:3722
#28 0x00007fc3534a4620 in QApplication::notify (this=0x7ffe88494610, receiver=0x11d0440, e=0x7ffe88494390) at kernel/qapplication.cpp:3481
#29 0x00007fc352c51891 in QCoreApplication::notifyInternal2 (receiver=0x11d0440, event=event@entry=0x7ffe88494390) at kernel/qcoreapplication.cpp:1018
#30 0x00007fc352c9f44b in QCoreApplication::sendEvent (event=0x7ffe88494390, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:233
#31 QTimerInfoList::activateTimers (this=this@entry=0xb4e700) at kernel/qtimerinfo_unix.cpp:643
#32 0x00007fc352c9c844 in QEventDispatcherUNIXPrivate::activateTimers (this=this@entry=0xb4e660) at kernel/qeventdispatcher_unix.cpp:249
#33 0x00007fc352c9d808 in QEventDispatcherUNIX::processEvents (this=<optimized out>, flags=...) at kernel/qeventdispatcher_unix.cpp:514
#34 0x00007fc33da0b135 in QUnixEventDispatcherQPA::processEvents (this=<optimized out>, flags=...) at qunixeventdispatcher.cpp:68
#35 0x00007fc352c5066a in QEventLoop::exec (this=this@entry=0x7ffe88494520, flags=..., flags@entry=...) at kernel/qeventloop.cpp:212
#36 0x00007fc352c588fc in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1291
#37 0x00007fc352f959ec in QGuiApplication::exec () at kernel/qguiapplication.cpp:1679
#38 0x00007fc35349cea5 in QApplication::exec () at kernel/qapplication.cpp:2910
#39 0x00007fc35502408a in kdemain (argc=<optimized out>, argv=0x7ffe884947a8) at /var/tmp/portage/kde-plasma/kwin-5.11.0/work/kwin-5.11.0/main_x11.cpp:466
#40 0x00007fc354c835b1 in __libc_start_main () from /lib64/libc.so.6
#41 0x00000000004006ea in _start ()

I now also have this card plugged into the system:

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Baffin [Radeon RX 560] (rev cf) (prog-if 00 [VGA controller])
        Subsystem: ASUSTeK Computer Inc. Baffin [Radeon RX 560]
        Flags: bus master, fast devsel, latency 0, IRQ 51
        Memory at e0000000 (64-bit, prefetchable) [size=256M]
        Memory at f0000000 (64-bit, prefetchable) [size=2M]
        I/O ports at e000 [size=256]
        Memory at fea00000 (32-bit, non-prefetchable) [size=256K]
        Expansion ROM at fea40000 [disabled] [size=128K]
        Capabilities: [48] Vendor Specific Information: Len=08 <?>
        Capabilities: [50] Power Management version 3
        Capabilities: [58] Express Legacy Endpoint, MSI 00
        Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
        Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
        Capabilities: [150] Advanced Error Reporting
        Capabilities: [200] #15
        Capabilities: [270] #19
        Capabilities: [2b0] Address Translation Service (ATS)
        Capabilities: [2c0] Page Request Interface (PRI)
        Capabilities: [2d0] Process Address Space ID (PASID)
        Capabilities: [320] Latency Tolerance Reporting
        Capabilities: [328] Alternative Routing-ID Interpretation (ARI)
        Capabilities: [370] L1 PM Substates
        Kernel driver in use: amdgpu
        Kernel modules: amdgpu

The monitor is still connected to the other card (comment #1), though.

Thank you for the report!

Can you try with Mesa from git master?

The issue is that in Mesa 17.2.2 (which you have according to glxinfo), si_state_draw.c:1305 corresponds to

   1304                         index_offset -= start_offset;
   1305                 } else if (sctx->b.chip_class <= CIK &&
   1306                            r600_resource(indexbuf)->TC_L2_dirty) {

and it's basically impossible to get a crash there, so I suspect the Gentoo build actually applies some other patches.

Something random you could try is starting KWin with GALLIUM_THREAD=0.

This is the ebuild: https://gitweb.gentoo.org/repo/gentoo.git/tree/media-libs/mesa/mesa-17.2.2.ebuild

Patches would be listed in a PATCHES variable or applied in src_prepare().  The ebuild has only eapply_user there, which would apply patches in /etc/portage/patches/media-libs/mesa (or a version specific directory), which I don't have.  Hence I believe there are no patches applied on my system.

I will extract the sources again and will try to attach GDB, while DrKonqi (KDE's bug-reporting tool) has the process stopped, the next time I reproduce the crash in the coming days.

I will also install using the 9999 / git ebuild and see whether I can reproduce there.

Some more information: It does not immediately happen after login. I also tried to trigger it with maybe more uncommon things like running Steam (and thus Natural Selection 2) with DRI_PRIME=1, but that did not trigger the crash either. I had the crash several times in the past, so I first need to find a way to reproduce it more reliably.

(In reply to Dennis Schridde from comment #7)
> Some more information: It does not immediately happen after login. I also
> tried to trigger it with maybe more uncommon things like running Steam (and
> thus Natural Selection 2) with DRI_PRIME=1, but that did not trigger the
> crash either. I had the crash several times in the past, so I first need to
> find a way to reproduce it more reliably.

That was, because KWin automatically falls back to software rendering, when the OpenGL backend crashes to often.  OpenGL is now enabled again, and I can again perfectly reproduce the crash on every Alt+Tab.

This is what I got from GDB, after extracting the Mesa sources (ebuild ... preprare) and attaching to the process:

#6  si_draw_vbo (ctx=0x17809c0, info=0x17e2d38) at /var/tmp/portage/media-libs/mesa-17.2.2/work/mesa-17.2.2/src/gallium/drivers/radeonsi/si_state_draw.c:1305
1305                    } else if (sctx->b.chip_class <= CIK &&
(gdb) print sctx
$1 = (struct si_context *) 0x17809c0
(gdb) print *sctx
$2 = {b = {b = {screen = 0x11ef4a0, priv = 0x0, draw = 0x0, stream_uploader = 0x143a290, const_uploader = 0x177eb30, destroy = 0x7fb69cd164c8 <si_destroy_context>, draw_vbo = 0x7fb69cd39a20 <si_draw_vbo>, render_condition = 0x7fb69cdb9c70 <r600_render_condition>, create_query = 0x7fb69cdbab88 <r600_create_query>,
      create_batch_query = 0x7fb69cdb6648 <r600_create_batch_query>, destroy_query = 0x7fb69cdb98f0 <r600_destroy_query>, begin_query = 0x7fb69cdb9900 <r600_begin_query>, end_query = 0x7fb69cdb9910 <r600_end_query>, get_query_result = 0x7fb69cdb9c50 <r600_get_query_result>, get_query_result_resource = 0x7fb69cdb9c60 <r600_get_query_result_resource>,
      set_active_query_state = 0x7fb69cd30a60 <si_set_active_query_state>, create_blend_state = 0x7fb69cd35df0 <si_create_blend_state>, bind_blend_state = 0x7fb69cd306e8 <si_bind_blend_state>, delete_blend_state = 0x7fb69cd32e28 <si_delete_blend_state>, create_sampler_state = 0x7fb69cd325f0 <si_create_sampler_state>,
      bind_sampler_states = 0x7fb69cd0e190 <si_bind_sampler_states>, delete_sampler_state = 0x7fb69cd32350 <si_delete_sampler_state>, create_rasterizer_state = 0x7fb69cd34e60 <si_create_rs_state>, bind_rasterizer_state = 0x7fb69cd32e50 <si_bind_rs_state>, delete_rasterizer_state = 0x7fb69cd32dc0 <si_delete_rs_state>,
      create_depth_stencil_alpha_state = 0x7fb69cd33380 <si_create_dsa_state>, bind_depth_stencil_alpha_state = 0x7fb69cd32468 <si_bind_dsa_state>, delete_depth_stencil_alpha_state = 0x7fb69cd32d90 <si_delete_dsa_state>, create_fs_state = 0x7fb69cd3fad0 <si_create_shader_selector>, bind_fs_state = 0x7fb69cd3be68 <si_bind_ps_shader>,
      delete_fs_state = 0x7fb69cd3e520 <si_delete_shader_selector>, create_vs_state = 0x7fb69cd3fad0 <si_create_shader_selector>, bind_vs_state = 0x7fb69cd3d920 <si_bind_vs_shader>, delete_vs_state = 0x7fb69cd3e520 <si_delete_shader_selector>, create_gs_state = 0x7fb69cd3fad0 <si_create_shader_selector>, bind_gs_state = 0x7fb69cd3dcf0 <si_bind_gs_shader>,
      delete_gs_state = 0x7fb69cd3e520 <si_delete_shader_selector>, create_tcs_state = 0x7fb69cd3fad0 <si_create_shader_selector>, bind_tcs_state = 0x7fb69cd3bf18 <si_bind_tcs_shader>, delete_tcs_state = 0x7fb69cd3e520 <si_delete_shader_selector>, create_tes_state = 0x7fb69cd3fad0 <si_create_shader_selector>,
      bind_tes_state = 0x7fb69cd3dae0 <si_bind_tes_shader>, delete_tes_state = 0x7fb69cd3e520 <si_delete_shader_selector>, create_vertex_elements_state = 0x7fb69cd35e70 <si_create_vertex_elements>, bind_vertex_elements_state = 0x7fb69cd33860 <si_bind_vertex_elements>, delete_vertex_elements_state = 0x7fb69cd32320 <si_delete_vertex_element>,
      set_blend_color = 0x7fb69cd307d0 <si_set_blend_color>, set_stencil_ref = 0x7fb69cd33940 <si_set_stencil_ref>, set_sample_mask = 0x7fb69cd31ed0 <si_set_sample_mask>, set_min_samples = 0x7fb69cd337d0 <si_set_min_samples>, set_clip_state = 0x7fb69cd36998 <si_set_clip_state>, set_constant_buffer = 0x7fb69cd131e0 <si_pipe_set_constant_buffer>,
      set_framebuffer_state = 0x7fb69cd33a48 <si_set_framebuffer_state>, set_polygon_stipple = 0x7fb69cd13210 <si_set_polygon_stipple>, set_scissor_states = 0x7fb69cdc3c70 <r600_set_scissor_states>, set_window_rectangles = 0x0, set_viewport_states = 0x7fb69cdc4278 <r600_set_viewport_states>, set_sampler_views = 0x7fb69cd120e8 <si_set_sampler_views>,
      set_tess_state = 0x7fb69cd368d0 <si_set_tess_state>, set_debug_callback = 0x7fb69cdb7690 <r600_set_debug_callback>, set_shader_buffers = 0x7fb69cd0ee90 <si_set_shader_buffers>, set_shader_images = 0x7fb69cd11600 <si_set_shader_images>, set_vertex_buffers = 0x7fb69cd36758 <si_set_vertex_buffers>,
      create_stream_output_target = 0x7fb69cdbc3b0 <r600_create_so_target>, stream_output_target_destroy = 0x7fb69cdbc4f0 <r600_so_target_destroy>, set_stream_output_targets = 0x7fb69cd0f348 <si_set_streamout_targets>, resource_copy_region = 0x7fb69cd07c30 <si_resource_copy_region>, blit = 0x7fb69cd08db8 <si_blit>, clear = 0x7fb69cd08a38 <si_clear>,
      clear_render_target = 0x7fb69cd087c0 <si_clear_render_target>, clear_depth_stencil = 0x7fb69cd08740 <si_clear_depth_stencil>, clear_texture = 0x7fb69cdbe418 <r600_clear_texture>, clear_buffer = 0x7fb69cd08830 <si_pipe_clear_buffer>, flush = 0x7fb69cdb72f0 <r600_flush_from_st>, create_fence_fd = 0x0, fence_server_sync = 0x0,
      create_sampler_view = 0x7fb69cd37c60 <si_create_sampler_view>, sampler_view_destroy = 0x7fb69cd36700 <si_sampler_view_destroy>, create_surface = 0x7fb69cdc2020 <r600_create_surface>, surface_destroy = 0x7fb69cdbebb0 <r600_surface_destroy>, transfer_map = 0x7fb69cc7dc50 <u_transfer_map_vtbl>,
      transfer_flush_region = 0x7fb69cc7dc60 <u_transfer_flush_region_vtbl>, transfer_unmap = 0x7fb69cc7dc70 <u_transfer_unmap_vtbl>, buffer_subdata = 0x7fb69cdb5358 <r600_buffer_subdata>, texture_subdata = 0x7fb69cc7db60 <u_default_texture_subdata>, texture_barrier = 0x7fb69cd34e18 <si_texture_barrier>, memory_barrier = 0x7fb69cd31f48 <si_memory_barrier>,
      resource_commit = 0x7fb69cdb6eb0 <r600_resource_commit>, create_video_codec = 0x7fb69cd41b68 <si_uvd_create_decoder>, create_video_buffer = 0x7fb69cd41830 <si_video_buffer_create>, create_compute_state = 0x7fb69cd09858 <si_create_compute_state>, bind_compute_state = 0x7fb69cd094a8 <si_bind_compute_state>,
      delete_compute_state = 0x7fb69cd09510 <si_delete_compute_state>, set_compute_resources = 0x7fb69cd094a0 <si_set_compute_resources>, set_global_binding = 0x7fb69cd09ae0 <si_set_global_binding>, launch_grid = 0x7fb69cd09c28 <si_launch_grid>, get_sample_position = 0x7fb69cdb3a70 <cayman_get_sample_position>, get_timestamp = 0x0,
      flush_resource = 0x7fb69cd08960 <si_flush_resource>, invalidate_resource = 0x7fb69cdb5348 <r600_invalidate_resource>, get_device_reset_status = 0x7fb69cd15d70 <si_amdgpu_get_reset_status>, set_device_reset_callback = 0x7fb69cdb76e0 <r600_set_device_reset_callback>, dump_debug_state = 0x7fb69cd0d200 <si_dump_debug_state>,
      emit_string_marker = 0x7fb69cd164b0 <si_emit_string_marker>, generate_mipmap = 0x7fb69cd08620 <si_generate_mipmap>, create_texture_handle = 0x7fb69cd12910 <si_create_texture_handle>, delete_texture_handle = 0x7fb69cd0ed60 <si_delete_texture_handle>, make_texture_handle_resident = 0x7fb69cd12420 <si_make_texture_handle_resident>,
      create_image_handle = 0x7fb69cd11bb0 <si_create_image_handle>, delete_image_handle = 0x7fb69cd0f280 <si_delete_image_handle>, make_image_handle_resident = 0x7fb69cd117c8 <si_make_image_handle_resident>}, screen = 0x11ef4a0, ws = 0x11f12e0, ctx = 0x177eb80, family = CHIP_KAVERI, chip_class = CIK, gfx = {cs = 0x17422b0,
      flush = 0x7fb69cd15a68 <si_context_gfx_flush>}, dma = {cs = 0x1787ba0, flush = 0x7fb69cdb8330 <r600_flush_dma_ring>}, last_gfx_fence = 0xfccf30, last_sdma_fence = 0x180a800, num_gfx_cs_flushes = 20, initial_gfx_cs_size = 4, gpu_reset_counter = 0, last_dirty_tex_counter = 2, last_compressed_colortex_counter = 52, last_num_draw_calls = 0, tc = 0x17db3d0,
    allocator_zeroed_memory = 0x170b740, pool_transfers = {parent = 0x11ef750, pages = 0x175a6c0, free = 0x175bbc0, migrated = 0x0}, pool_transfers_unsync = {parent = 0x11ef750, pages = 0x183b190, free = 0x183bc40, migrated = 0x183bcf0}, vram = 240, gtt = 0, streamout = {begin_atom = {emit = 0x7fb69cdbc5a0 <r600_emit_streamout_begin>, num_dw = 0, id = 2},
      begin_emitted = false, num_dw_for_end = 0, enabled_mask = 0, num_targets = 0, targets = {0x0, 0x0, 0x0, 0x0}, append_bitmask = 0, suspended = false, stride_in_dw = 0x18877ec, enabled_stream_buffers_mask = 0, hw_enabled_mask = 0, enable_atom = {emit = 0x7fb69cdbc180 <r600_emit_streamout_enable>, num_dw = 6, id = 3}, streamout_enabled = false,
      prims_gen_query_enabled = false, num_prims_gen_queries = 0}, scissors = {atom = {emit = 0x7fb69cdc4638 <r600_emit_scissors>, num_dw = 40, id = 14}, dirty_mask = 65534, states = {{minx = 0, miny = 0, maxx = 396, maxy = 1080}, {minx = 0, miny = 0, maxx = 0, maxy = 0} <repeats 15 times>}}, viewports = {atom = {
        emit = 0x7fb69cdc3eb0 <r600_emit_viewport_states>, num_dw = 98, id = 15}, dirty_mask = 65534, depth_range_dirty_mask = 65534, states = {{scale = {198, -540, 0.5}, translate = {198, 540, 0.5}}, {scale = {0, 0, 0}, translate = {0, 0, 0}} <repeats 15 times>}, as_scissor = {{minx = 0, miny = 0, maxx = 396, maxy = 1080}, {minx = 0, miny = 0, maxx = 0,
          maxy = 0} <repeats 15 times>}}, scissor_enabled = false, clip_halfz = false, vs_writes_viewport_index = false, vs_disables_clipping_viewport = false, flags = 0, num_occlusion_queries = 0, num_perfect_occlusion_queries = 0, active_queries = {prev = 0x17811b0, next = 0x17811b0}, num_cs_dw_queries_suspend = 0, num_draw_calls = 257,
    num_prim_restart_calls = 0, num_spill_draw_calls = 0, num_compute_calls = 0, num_spill_compute_calls = 0, num_dma_calls = 139, num_cp_dma_calls = 1, num_vs_flushes = 2, num_ps_flushes = 2, num_cs_flushes = 0, num_cb_cache_flushes = 89, num_db_cache_flushes = 0, num_L2_invalidates = 89, num_L2_writebacks = 0, num_resident_handles = 0,
    num_alloc_tex_transfer_bytes = 2479104, last_tex_ps_draw_ratio = 0, render_cond_atom = {emit = 0x7fb69cdbad08 <r600_emit_query_predication>, num_dw = 0, id = 1}, render_cond = 0x0, render_cond_mode = 0, render_cond_invert = false, render_cond_force_off = false, sample_locations_1x = {{0.5, 0.5}}, sample_locations_2x = {{0.75, 0.75}, {0.25, 0.25}},
    sample_locations_4x = {{0.375, 0.125}, {0.875, 0.375}, {0.125, 0.625}, {0.625, 0.875}}, sample_locations_8x = {{0.5625, 0.3125}, {0.4375, 0.6875}, {0.8125, 0.5625}, {0.3125, 0.1875}, {0.1875, 0.8125}, {0.0625, 0.4375}, {0.6875, 0.9375}, {0.9375, 0.0625}}, sample_locations_16x = {{0.5625, 0.5625}, {0.4375, 0.3125}, {0.3125, 0.625}, {0.75, 0.4375}, {0.1875,
        0.375}, {0.625, 0.8125}, {0.8125, 0.6875}, {0.6875, 0.1875}, {0.375, 0.875}, {0.5, 0.0625}, {0.25, 0.125}, {0.125, 0.75}, {0, 0.5}, {0.9375, 0.25}, {0.875, 0.9375}, {0.0625, 0}}, dcc_stats = {{tex = 0x0, ps_stats = {0x0, 0x0, 0x0}, last_use_timestamp = 0, query_active = false}, {tex = 0x0, ps_stats = {0x0, 0x0, 0x0}, last_use_timestamp = 0,
        query_active = false}, {tex = 0x0, ps_stats = {0x0, 0x0, 0x0}, last_use_timestamp = 0, query_active = false}, {tex = 0x0, ps_stats = {0x0, 0x0, 0x0}, last_use_timestamp = 0, query_active = false}, {tex = 0x0, ps_stats = {0x0, 0x0, 0x0}, last_use_timestamp = 0, query_active = false}}, debug = {async = false, debug_message = 0x0, data = 0x0},
    device_reset_callback = {reset = 0x0, data = 0x0}, query_result_shader = 0x0, dma_copy = 0x7fb69cd04a28 <cik_sdma_copy>, dma_clear_buffer = 0x7fb69cd04860 <cik_sdma_clear_buffer>, clear_buffer = 0x7fb69cd0b380 <si_clear_buffer>, blit_decompress_depth = 0x7fb69cd06870 <si_blit_decompress_depth>, decompress_dcc = 0x7fb69cd07a70 <si_decompress_dcc>,
    invalidate_buffer = 0x7fb69cd10ae0 <si_invalidate_buffer>, rebind_buffer = 0x7fb69cd0fd80 <si_rebind_buffer>, set_occlusion_query_state = 0x7fb69cd30ac0 <si_set_occlusion_query_state>, save_qbo_state = 0x7fb69cd32368 <si_save_qbo_state>, need_gfx_cs_space = 0x7fb69cd32360 <si_need_gfx_cs_space>, set_atom_dirty = 0x7fb69cd15d30 <si_set_atom_dirty>,
    check_vm_faults = 0x7fb69cd0d9a0 <si_check_vm_faults>}, blitter = 0x175bcd0, custom_dsa_flush = 0x1794ae0, custom_blend_resolve = 0x1794e00, custom_blend_fmask_decompress = 0x1795130, custom_blend_eliminate_fastclear = 0x1795460, custom_blend_dcc_decompress = 0x1795790, screen = 0x11ef4a0, tm = 0x1765610, fixed_func_tcs_shader = {cso = 0x0, current = 0x0},
  wait_mem_scratch = 0x0, wait_mem_number = 0, ce_ib = 0x0, ce_preamble_ib = 0x0, ce_ram_saved_buffer = 0x0, ce_suballocator = 0x0, ce_ram_saved_offset = 0, total_ce_ram_allocated = 0, ce_need_synchronization = false, gfx_flush_in_progress = false, compute_is_busy = false, atoms = {s = {prefetch_L2 = 0x1781680, render_cond = 0x1781210,
      streamout_begin = 0x1780e00, streamout_enable = 0x1780e58, framebuffer = 0x1781690, msaa_sample_locs = 0x1781710, db_render_state = 0x1781728, msaa_config = 0x1781738, sample_mask = 0x1781748, cb_render_state = 0x1781760, blend_color = 0x1781778, clip_regs = 0x1781798, clip_state = 0x17817a8, shader_userdata = 0x1781838, scissors = 0x1780e70,
      viewports = 0x1780f08, stencil_ref = 0x1781860, spi_map = 0x1781878, scratch_state = 0x1783390}, array = 0x1781530}, dirty_atoms = 8192, dirty_states = 0, queued = {named = {blend = 0x188ba00, rasterizer = 0x188a710, dsa = 0x183e2e0, poly_offset = 0x0, ls = 0x0, hs = 0x0, es = 0x0, gs = 0x0, vgt_shader_config = 0x1846940, vs = 0x18ca7b0, ps = 0x1893c20},
    array = 0x17815d0}, emitted = {named = {blend = 0x188ba00, rasterizer = 0x188a710, dsa = 0x183e2e0, poly_offset = 0x0, ls = 0x0, hs = 0x0, es = 0x0, gs = 0x0, vgt_shader_config = 0x1846940, vs = 0x18ca7b0, ps = 0x1893c20}, array = 0x1781628}, prefetch_L2 = {emit = 0x7fb69cd0bc50 <cik_emit_prefetch_L2>, num_dw = 0, id = 0}, framebuffer = {atom = {
      emit = 0x7fb69cd312e0 <si_emit_framebuffer_state>, num_dw = 0, id = 4}, state = {width = 396, height = 1080, layers = 0, samples = 0 '\000', nr_cbufs = 1 '\001', cbufs = {0x18c4d80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, zsbuf = 0x1800570}, colorbuf_enabled_4bit = 15, spi_shader_col_format = 4, spi_shader_col_format_alpha = 4,
    spi_shader_col_format_blend = 4, spi_shader_col_format_blend_alpha = 4, nr_samples = 1 '\001', log_samples = 0 '\000', compressed_cb_mask = 0 '\000', color_is_int8 = 0 '\000', color_is_int10 = 0 '\000', dirty_cbufs = 0 '\000', dirty_zsbuf = false, any_dst_linear = false}, msaa_sample_locs = {atom = {emit = 0x7fb69cd33150 <si_emit_msaa_sample_locs>,
      num_dw = 0, id = 5}, nr_samples = 1}, db_render_state = {emit = 0x7fb69cd30ad8 <si_emit_db_render_state>, num_dw = 0, id = 6}, msaa_config = {emit = 0x7fb69cd33090 <si_emit_msaa_config>, num_dw = 0, id = 7}, sample_mask = {atom = {emit = 0x7fb69cd31ef8 <si_emit_sample_mask>, num_dw = 0, id = 8}, sample_mask = 65535}, cb_render_state = {
    emit = 0x7fb69cd301a0 <si_emit_cb_render_state>, num_dw = 0, id = 9}, last_cb_target_mask = 0, blend_color = {atom = {emit = 0x7fb69cd323b0 <si_emit_blend_color>, num_dw = 0, id = 10}, state = {color = {0.192156866, 0.211764708, 0.23137255, 1}}}, clip_regs = {emit = 0x7fb69cd307f8 <si_emit_clip_regs>, num_dw = 0, id = 11}, clip_state = {atom = {
      emit = 0x7fb69cd323f8 <si_emit_clip_state>, num_dw = 0, id = 12}, state = {ucp = {{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 0, 0}}}}, shader_userdata = {atom = {emit = 0x7fb69cd0e790 <si_emit_graphics_shader_userdata>, num_dw = 0, id = 13}, sh_base = {45360, 45104, 45616, 46128, 0, 0}},
  stencil_ref = {atom = {emit = 0x7fb69cd309d8 <si_emit_stencil_ref>, num_dw = 0, id = 16}, state = {ref_value = "\000"}, dsa_part = {valuemask = "\000", writemask = "\000"}}, spi_map = {emit = 0x7fb69cd3df00 <si_emit_spi_map>, num_dw = 0, id = 17}, init_config = 0x1795ac0, init_config_gs_rings = 0x0, init_config_has_vgt_flush = false, vgt_shader_config = {
    0x1846940, 0x0, 0x0, 0x0}, ps_shader = {cso = 0x18884b0, current = 0x18caad0}, gs_shader = {cso = 0x0, current = 0x0}, vs_shader = {cso = 0x18876f0, current = 0x184d260}, tcs_shader = {cso = 0x0, current = 0x0}, tes_shader = {cso = 0x0, current = 0x0}, cs_shader_state = {program = 0x0, emitted_program = 0x0, offset = 0, initialized = false,
    uses_scratch = false}, vertex_elements = 0x188c1a0, sprite_coord_enable = 0, flatshade = false, do_update_shaders = false, vertex_buffers = {list = 0x17949d0, gpu_list = 0x0, dirty_mask = 65535, buffer = 0x1842670, buffer_offset = 61120, element_dw_size = 4 '\004', num_elements = 16 '\020', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000',
    first_active_slot = 0 '\000', num_active_slots = 0 '\000', uses_ce = false, shader_userdata_offset = 24 '\030'}, descriptors = {{list = 0x1794900, gpu_list = 0x7fb67d15cd80, dirty_mask = 0, buffer = 0x1842670, buffer_offset = 60800, element_dw_size = 4 '\004', num_elements = 12 '\f', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000',
      first_active_slot = 0 '\000', num_active_slots = 12 '\f', uses_ce = false, shader_userdata_offset = 0 '\000'}, {list = 0x1780630, gpu_list = 0x7fb67d15ce00, dirty_mask = 0, buffer = 0x1842670, buffer_offset = 60928, element_dw_size = 4 '\004', num_elements = 32 ' ', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000',
      first_active_slot = 16 '\020', num_active_slots = 1 '\001', uses_ce = false, shader_userdata_offset = 8 '\b'}, {list = 0x1790450, gpu_list = 0x0, dirty_mask = 1099511627775, buffer = 0x0, buffer_offset = 0, element_dw_size = 16 '\020', num_elements = 40 '(', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 0 '\000',
      num_active_slots = 0 '\000', uses_ce = false, shader_userdata_offset = 16 '\020'}, {list = 0x1333630, gpu_list = 0x7fb67d15cd50, dirty_mask = 0, buffer = 0x1842670, buffer_offset = 60752, element_dw_size = 4 '\004', num_elements = 32 ' ', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 16 '\020',
      num_active_slots = 1 '\001', uses_ce = false, shader_userdata_offset = 8 '\b'}, {list = 0x1790e60, gpu_list = 0x7fb67d15cd40, dirty_mask = 0, buffer = 0x1842670, buffer_offset = 60736, element_dw_size = 16 '\020', num_elements = 40 '(', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 8 '\b',
      num_active_slots = 1 '\001', uses_ce = false, shader_userdata_offset = 16 '\020'}, {list = 0x1333950, gpu_list = 0x0, dirty_mask = 4294967295, buffer = 0x0, buffer_offset = 0, element_dw_size = 4 '\004', num_elements = 32 ' ', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 0 '\000', num_active_slots = 0 '\000',
      uses_ce = false, shader_userdata_offset = 8 '\b'}, {list = 0x1791870, gpu_list = 0x0, dirty_mask = 1099511627775, buffer = 0x0, buffer_offset = 0, element_dw_size = 16 '\020', num_elements = 40 '(', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 0 '\000', num_active_slots = 0 '\000', uses_ce = false,
      shader_userdata_offset = 16 '\020'}, {list = 0x1792280, gpu_list = 0x0, dirty_mask = 4294967295, buffer = 0x0, buffer_offset = 0, element_dw_size = 4 '\004', num_elements = 32 ' ', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 0 '\000', num_active_slots = 0 '\000', uses_ce = false, shader_userdata_offset = 8 '\b'},
    {list = 0x1792490, gpu_list = 0x0, dirty_mask = 1099511627775, buffer = 0x0, buffer_offset = 0, element_dw_size = 16 '\020', num_elements = 40 '(', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 0 '\000', num_active_slots = 0 '\000', uses_ce = false, shader_userdata_offset = 16 '\020'}, {list = 0x1792fb0,
      gpu_list = 0x0, dirty_mask = 4294967295, buffer = 0x0, buffer_offset = 0, element_dw_size = 4 '\004', num_elements = 32 ' ', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 0 '\000', num_active_slots = 0 '\000', uses_ce = false, shader_userdata_offset = 8 '\b'}, {list = 0x17931c0, gpu_list = 0x0,
      dirty_mask = 1099511627775, buffer = 0x0, buffer_offset = 0, element_dw_size = 16 '\020', num_elements = 40 '(', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 0 '\000', num_active_slots = 0 '\000', uses_ce = false, shader_userdata_offset = 16 '\020'}, {list = 0x1793ce0, gpu_list = 0x0, dirty_mask = 4294967295,
      buffer = 0x0, buffer_offset = 0, element_dw_size = 4 '\004', num_elements = 32 ' ', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 0 '\000', num_active_slots = 0 '\000', uses_ce = false, shader_userdata_offset = 8 '\b'}, {list = 0x1793ef0, gpu_list = 0x0, dirty_mask = 1099511627775, buffer = 0x0, buffer_offset = 0,
---Type <return> to continue, or q <return> to quit---
      element_dw_size = 16 '\020', num_elements = 40 '(', ce_offset = 0, first_ce_slot = 0 '\000', num_ce_slots = 0 '\000', first_active_slot = 0 '\000', num_active_slots = 0 '\000', uses_ce = false, shader_userdata_offset = 16 '\020'}}, descriptors_dirty = 6144, shader_pointers_dirty = 6162, shader_needs_decompress_mask = 0, rw_buffers = {buffers = 0x177ef90,
    shader_usage = RADEON_USAGE_READWRITE, shader_usage_constbuf = RADEON_USAGE_READ, priority = RADEON_PRIO_SHADER_RINGS, priority_constbuf = RADEON_PRIO_CONST_BUFFER, enabled_mask = 3968}, const_and_shader_buffers = {{buffers = 0x1780520, shader_usage = RADEON_USAGE_READWRITE, shader_usage_constbuf = RADEON_USAGE_READ,
      priority = RADEON_PRIO_SHADER_RW_BUFFER, priority_constbuf = RADEON_PRIO_CONST_BUFFER, enabled_mask = 4294901760}, {buffers = 0x1780840, shader_usage = RADEON_USAGE_READWRITE, shader_usage_constbuf = RADEON_USAGE_READ, priority = RADEON_PRIO_SHADER_RW_BUFFER, priority_constbuf = RADEON_PRIO_CONST_BUFFER, enabled_mask = 4294901760}, {buffers = 0x1333840,
      shader_usage = RADEON_USAGE_READWRITE, shader_usage_constbuf = RADEON_USAGE_READ, priority = RADEON_PRIO_SHADER_RW_BUFFER, priority_constbuf = RADEON_PRIO_CONST_BUFFER, enabled_mask = 4294901760}, {buffers = 0x1333b60, shader_usage = RADEON_USAGE_READWRITE, shader_usage_constbuf = RADEON_USAGE_READ, priority = RADEON_PRIO_SHADER_RW_BUFFER,
      priority_constbuf = RADEON_PRIO_CONST_BUFFER, enabled_mask = 4294901760}, {buffers = 0x1792ea0, shader_usage = RADEON_USAGE_READWRITE, shader_usage_constbuf = RADEON_USAGE_READ, priority = RADEON_PRIO_SHADER_RW_BUFFER, priority_constbuf = RADEON_PRIO_CONST_BUFFER, enabled_mask = 4294901760}, {buffers = 0x1793bd0, shader_usage = RADEON_USAGE_READWRITE,
      shader_usage_constbuf = RADEON_USAGE_READ, priority = RADEON_PRIO_SHADER_RW_BUFFER, priority_constbuf = RADEON_PRIO_CONST_BUFFER, enabled_mask = 4294901760}}, samplers = {{views = {views = {0x0 <repeats 32 times>}, sampler_states = {0x0 <repeats 32 times>}, enabled_mask = 0}, needs_depth_decompress_mask = 0, needs_color_decompress_mask = 0}, {views = {
        views = {0x1894d00, 0x0 <repeats 31 times>}, sampler_states = {0x1844110, 0x0 <repeats 31 times>}, enabled_mask = 1}, needs_depth_decompress_mask = 0, needs_color_decompress_mask = 0}, {views = {views = {0x0 <repeats 32 times>}, sampler_states = {0x0 <repeats 32 times>}, enabled_mask = 0}, needs_depth_decompress_mask = 0,
      needs_color_decompress_mask = 0}, {views = {views = {0x0 <repeats 32 times>}, sampler_states = {0x0 <repeats 32 times>}, enabled_mask = 0}, needs_depth_decompress_mask = 0, needs_color_decompress_mask = 0}, {views = {views = {0x0 <repeats 32 times>}, sampler_states = {0x0 <repeats 32 times>}, enabled_mask = 0}, needs_depth_decompress_mask = 0,
      needs_color_decompress_mask = 0}, {views = {views = {0x0 <repeats 32 times>}, sampler_states = {0x0 <repeats 32 times>}, enabled_mask = 0}, needs_depth_decompress_mask = 0, needs_color_decompress_mask = 0}}, images = {{views = {{resource = 0x0, format = PIPE_FORMAT_NONE, access = 0, u = {tex = {first_layer = 0, last_layer = 0, level = 0}, buf = {
              offset = 0, size = 0}}} <repeats 16 times>}, needs_color_decompress_mask = 0, enabled_mask = 0}, {views = {{resource = 0x0, format = PIPE_FORMAT_NONE, access = 0, u = {tex = {first_layer = 0, last_layer = 0, level = 0}, buf = {offset = 0, size = 0}}} <repeats 16 times>}, needs_color_decompress_mask = 0, enabled_mask = 0}, {views = {{
          resource = 0x0, format = PIPE_FORMAT_NONE, access = 0, u = {tex = {first_layer = 0, last_layer = 0, level = 0}, buf = {offset = 0, size = 0}}} <repeats 16 times>}, needs_color_decompress_mask = 0, enabled_mask = 0}, {views = {{resource = 0x0, format = PIPE_FORMAT_NONE, access = 0, u = {tex = {first_layer = 0, last_layer = 0, level = 0}, buf = {
              offset = 0, size = 0}}} <repeats 16 times>}, needs_color_decompress_mask = 0, enabled_mask = 0}, {views = {{resource = 0x0, format = PIPE_FORMAT_NONE, access = 0, u = {tex = {first_layer = 0, last_layer = 0, level = 0}, buf = {offset = 0, size = 0}}} <repeats 16 times>}, needs_color_decompress_mask = 0, enabled_mask = 0}, {views = {{
          resource = 0x0, format = PIPE_FORMAT_NONE, access = 0, u = {tex = {first_layer = 0, last_layer = 0, level = 0}, buf = {offset = 0, size = 0}}} <repeats 16 times>}, needs_color_decompress_mask = 0, enabled_mask = 0}}, null_const_buf = {buffer = 0x1765510, buffer_offset = 0, buffer_size = 16, user_buffer = 0x0}, esgs_ring = 0x0, gsvs_ring = 0x0,
  tf_ring = 0x0, tess_offchip_ring = 0x0, border_color_table = 0x174a6b0, border_color_buffer = 0x177ee90, border_color_map = 0x7fb68401a000, border_color_count = 0, vertex_buffers_dirty = true, vertex_buffer_pointer_dirty = false, vertex_buffer = {{stride = 16, is_user_buffer = false, buffer_offset = 0, buffer = {resource = 0x18773f0, user = 0x18773f0}}, {
      stride = 16, is_user_buffer = false, buffer_offset = 8, buffer = {resource = 0x18773f0, user = 0x18773f0}}, {stride = 4, is_user_buffer = false, buffer_offset = 64, buffer = {resource = 0x18773f0, user = 0x18773f0}}, {stride = 0, is_user_buffer = false, buffer_offset = 0, buffer = {resource = 0x0, user = 0x0}} <repeats 13 times>}, ps_iter_samples = 1,
  smoothing_enabled = false, ps_db_shader_control = 16, dbcb_copy_sample = 0, dbcb_depth_copy_enabled = false, dbcb_stencil_copy_enabled = false, db_flush_depth_inplace = false, db_flush_stencil_inplace = false, db_depth_clear = false, db_depth_disable_expclear = false, db_stencil_clear = false, db_stencil_disable_expclear = false,
  occlusion_queries_disabled = false, generate_mipmap_for_depth = false, gs_tri_strip_adj_fix = false, last_index_size = 2, last_base_vertex = 0, last_start_instance = 0, last_drawid = 0, last_sh_base_reg = 45360, last_primitive_restart_en = 0, last_restart_index = -2147483648, last_gs_out_prim = 2, last_prim = 6, last_multi_vgt_param = 1048703,
  last_rast_prim = -1, last_sc_line_stipple = 4294967295, current_vs_state = 3, last_vs_state = 3, current_rast_prim = PIPE_PRIM_TRIANGLE_STRIP, scratch_state = {emit = 0x7fb69cd3b790 <si_emit_scratch_state>, num_dw = 0, id = 18}, scratch_buffer = 0x0, scratch_waves = 256, spi_tmpring_size = 256, compute_scratch_buffer = 0x0, last_ls = 0x0, last_tcs = 0x0,
  last_num_tcs_input_cp = -1, last_tes_sh_base = -1, last_tess_uses_primid = false, last_num_patches = 0, is_debug = false, last_gfx = {ib = 0x0, num_dw = 0, bo_list = 0x0, bo_count = 0}, last_trace_buf = 0x0, trace_buf = 0x0, trace_id = 0, dmesg_timestamp = 0, apitrace_call_number = 0, need_check_render_feedback = false, decompression_enabled = false,
  ia_multi_vgt_param_key = {u = {prim = 0, uses_instancing = 0, multi_instances_smaller_than_primgroup = 0, primitive_restart = 0, count_from_stream_output = 0, line_stipple_enabled = 0, uses_tess = 0, tess_uses_prim_id = 0, uses_gs = 0, _pad = 0}, index = 0}, ia_multi_vgt_param = {1048576 <repeats 256 times>, 1179648 <repeats 256 times>,
    1048576 <repeats 256 times>, 1179648 <repeats 256 times>, 1048576 <repeats 256 times>, 1179648 <repeats 256 times>, 1835008 <repeats 256 times>, 1966080 <repeats 256 times>, 1048576 <repeats 256 times>, 1179648 <repeats 256 times>, 1048576 <repeats 256 times>, 1179648 <repeats 256 times>, 1048576 <repeats 256 times>, 1179648 <repeats 256 times>,
    1835008 <repeats 256 times>, 1966080 <repeats 256 times>}, bindless_descriptor_slabs = {mutex = {__data = {__lock = 0, __count = 0, __owner = 0, __nusers = 0, __kind = 0, __spins = 0, __elision = 0, __list = {__prev = 0x0, __next = 0x0}}, __size = '\000' <repeats 39 times>, __align = 0}, min_order = 6, num_orders = 1, num_heaps = 1, groups = 0x177c500,
    reclaim = {prev = 0x1787470, next = 0x1787470}, priv = 0x17809c0, can_reclaim = 0x7fb69cd13f30 <si_bindless_descriptor_can_reclaim_slab>, slab_alloc = 0x7fb69cd13f38 <si_bindless_descriptor_slab_alloc>, slab_free = 0x7fb69cd14200 <si_bindless_descriptor_slab_free>}, bindless_descriptors = {mem_ctx = 0x0, data = 0x0, size = 0, capacity = 0},
  bindless_descriptors_dirty = false, tex_handles = 0x1780980, img_handles = 0x17662a0, resident_tex_handles = {mem_ctx = 0x0, data = 0x0, size = 0, capacity = 0}, resident_img_handles = {mem_ctx = 0x0, data = 0x0, size = 0, capacity = 0}, resident_tex_needs_color_decompress = {mem_ctx = 0x0, data = 0x0, size = 0, capacity = 0},
  resident_img_needs_color_decompress = {mem_ctx = 0x0, data = 0x0, size = 0, capacity = 0}, resident_tex_needs_depth_decompress = {mem_ctx = 0x0, data = 0x0, size = 0, capacity = 0}, uses_bindless_samplers = false, uses_bindless_images = false}

Created attachment 136121 [details]
modinfo radeon for my version

Output for modinfo modinfo

Created attachment 136122 [details]
crashlog for kwin

Added another crashlog

FYI Mesa 17.2.x is EOL, so it might be better to check if 17.3.3 and master still have the issue.

GDB output near to current master (at 8d1f1ce412, later does not compile on my system at the moment):



Thread 17 "gallium_drv:0" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f67d592f700 (LWP 7986)]
si_emit_draw_packets (sctx=sctx@entry=0x2c94390, info=info@entry=0x2ce22e8, indexbuf=<optimized out>, index_size=index_size@entry=2, index_offset=<optimized out>) at /home/roman/dev/mesa/src/mesa/src/gallium/drivers/radeonsi/si_state_draw.c:718
718                     index_max_size = (indexbuf->width0 - index_offset) /



(gdb) bt
#0  si_emit_draw_packets (sctx=sctx@entry=0x2c94390, info=info@entry=0x2ce22e8, indexbuf=<optimized out>, index_size=index_size@entry=2, index_offset=<optimized out>) at /home/roman/dev/mesa/src/mesa/src/gallium/drivers/radeonsi/si_state_draw.c:718
#1  0x00007f67d4a2467d in si_draw_vbo (ctx=0x2c94390, info=0x2ce22e8) at /home/roman/dev/mesa/src/mesa/src/gallium/drivers/radeonsi/si_state_draw.c:1481
#2  0x00007f67d492f871 in tc_call_draw_vbo (pipe=<optimized out>, payload=0x2ce22e8) at /home/roman/dev/mesa/src/mesa/src/gallium/auxiliary/util/u_threaded_context.c:2012
#3  0x00007f67d492bff7 in tc_batch_execute (job=job@entry=0x2ce18f0, thread_index=thread_index@entry=0) at /home/roman/dev/mesa/src/mesa/src/gallium/auxiliary/util/u_threaded_context.c:96
#4  0x00007f67d47b529f in util_queue_thread_func (input=input@entry=0x2ad6d30) at /home/roman/dev/mesa/src/mesa/src/util/u_queue.c:271
#5  0x00007f67d47b4e27 in impl_thrd_routine (p=<optimized out>) at /home/roman/dev/mesa/src/mesa/include/c11/threads_posix.h:87
#6  0x00007f68839146ba in start_thread (arg=0x7f67d592f700) at pthread_create.c:333
#7  0x00007f688ad0c41d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109



(gdb) bt full
#0  si_emit_draw_packets (sctx=sctx@entry=0x2c94390, info=info@entry=0x2ce22e8, indexbuf=<optimized out>, index_size=index_size@entry=2, index_offset=<optimized out>) at /home/roman/dev/mesa/src/mesa/src/gallium/drivers/radeonsi/si_state_draw.c:718
        indirect = 0x0
        cs = 0x2ca3a90
        sh_base_reg = 45360
        render_cond_bit = false
        index_max_size = 0
        index_va = 0
        __PRETTY_FUNCTION__ = "si_emit_draw_packets"
#1  0x00007f67d4a2467d in si_draw_vbo (ctx=0x2c94390, info=0x2ce22e8) at /home/roman/dev/mesa/src/mesa/src/gallium/drivers/radeonsi/si_state_draw.c:1481
        sctx = 0x2c94390
        rs = <optimized out>
        indexbuf = 0x0
        dirty_tex_counter = <optimized out>
        rast_prim = <optimized out>
        index_size = 2
        index_offset = 0
        __PRETTY_FUNCTION__ = "si_draw_vbo"
#2  0x00007f67d492f871 in tc_call_draw_vbo (pipe=<optimized out>, payload=0x2ce22e8) at /home/roman/dev/mesa/src/mesa/src/gallium/auxiliary/util/u_threaded_context.c:2012
        info = 0x2ce22e8
#3  0x00007f67d492bff7 in tc_batch_execute (job=job@entry=0x2ce18f0, thread_index=thread_index@entry=0) at /home/roman/dev/mesa/src/mesa/src/gallium/auxiliary/util/u_threaded_context.c:96
        iter = 0x2ce22e0
        batch = 0x2ce18f0
        pipe = 0x2c94390
        last = 0x2ce24e0
#4  0x00007f67d47b529f in util_queue_thread_func (input=input@entry=0x2ad6d30) at /home/roman/dev/mesa/src/mesa/src/util/u_queue.c:271
        job = {job = 0x2ce18f0, fence = 0x2ce1908, execute = 0x7f67d492bfb0 <tc_batch_execute>, cleanup = 0x0}
        queue = 0x2cde788
        thread_index = <optimized out>
        __PRETTY_FUNCTION__ = "util_queue_thread_func"
#5  0x00007f67d47b4e27 in impl_thrd_routine (p=<optimized out>) at /home/roman/dev/mesa/src/mesa/include/c11/threads_posix.h:87
        pack = {func = 0x7f67d47b5060 <util_queue_thread_func>, arg = 0x2ad6d30}
#6  0x00007f68839146ba in start_thread (arg=0x7f67d592f700) at pthread_create.c:333
        __res = <optimized out>
        pd = 0x7f67d592f700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140083941537536, 7002528104003647912, 0, 140728410686399, 8388608, 39522672, -6925884145858791000, -6918376651715135064}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, 
              canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#7  0x00007f688ad0c41d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109
No locals.

I have a RFC with a potential fix on the mailing list:
https://lists.freedesktop.org/archives/mesa-dev/2018-March/187675.html

Can you get a backtrace with GALLIUM_THREAD=0 ? I'd like to know where indexbuf == NULL is coming from.

I can't reproduce the issue currently. What is weird, since it didn't work for months.

Maybe it's working now again because I deleted the $HOME/.cache content?

Could someone with the same problem do the same to see if it works afterwards as well for him again?

*** Bug 105611 has been marked as a duplicate of this bug. ***

Possible fix:
https://patchwork.freedesktop.org/patch/211876/

*** Bug 106153 has been marked as a duplicate of this bug. ***

Got already commited in master branch:
https://cgit.freedesktop.org/mesa/mesa/commit/src/mesa/state_tracker/st_draw.c?id=f75421751782222e724510c7918edfe09ba33c7a

But not yet in 17.3 or 18.0 branch.

*** Bug 106327 has been marked as a duplicate of this bug. ***

(In reply to Marek Olšák from comment #18)
> Possible fix:
> https://patchwork.freedesktop.org/patch/211876/

My bug has been disappeared.  I use Fedora  and there ara 2 different X11 drivers.
The xorg-x11-drv-ati and xorg-x11-drv-amdgpu. I deleted the amdgpu x11 driver, and install the ati x11 driver. According to lsmod my system still use the amdgpu module.

The xorg ati driver is for the radeon kernel module.
The xorg amdgpu driver is for the amdgpu kernel module.

If the xorg driver is missing for the respective kernel module, the X server will use the generic xorg modesetting driver instead. The behavior might be the same because the modesetting driver has similar capabilities as the hw-specific drivers.

(In reply to Marek Olšák from comment #23)
> The xorg ati driver is for the radeon kernel module.
> The xorg amdgpu driver is for the amdgpu kernel module.
> 
> If the xorg driver is missing for the respective kernel module, the X server
> will use the generic xorg modesetting driver instead. The behavior might be
> the same because the modesetting driver has similar capabilities as the
> hw-specific drivers.

My mistake...I  took an other look on the system, and the KDE scale method was set to smooth (The default is accurate). This is reproducable 
System > compositor > scale method > accurate = crash
System > compositor > scale method > smooth or crisp = Can Alt + Tab without crash.
So you are right, the different X11 driver doesn't solve the problem.

Since a patch that fixes this landed and 17.x is out of support I'm marking this fixed.