Bug 97887 - llvm segfault in janusvr -render vive
Summary: llvm segfault in janusvr -render vive
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/Gallium/radeonsi (show other bugs)
Version: git
Hardware: Other All
: medium normal
Assignee: Default DRI bug account
QA Contact: Default DRI bug account
Depends on:
Reported: 2016-09-21 11:24 UTC by Christoph Haag
Modified: 2016-10-07 16:07 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

stderr output with R600_DEBUG=vs,tcs,tes,gs,ps,cs (161.21 KB, text/plain)
2016-09-21 11:24 UTC, Christoph Haag
gdb.txt assertion with full backtrace (47.59 KB, text/plain)
2016-09-21 16:04 UTC, Christoph Haag

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Description Christoph Haag 2016-09-21 11:24:38 UTC
Created attachment 126700 [details]
stderr output with R600_DEBUG=vs,tcs,tes,gs,ps,cs

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 480] (rev c7)
mesa git, linux drm-next-4.9-wip, llvm 4.0.0svn_r282018

So I'm trying to start janusvr -render vive with the steamvr-osvr steamvr plugin. Because osvr-rendermanager still doesn't do core profile, I start it with


But llvm segfaults:

Thread 12 "si_shader:1" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffc3568700 (LWP 28734)]
0x00007fffc59ee0c6 in llvm::SSAUpdaterImpl<llvm::SSAUpdater>::BuildBlockList(llvm::BasicBlock*, llvm::SmallVectorImpl<llvm::SSAUpdaterImpl<llvm::SSAUpdater>::BBInfo*>*) () from /usr/lib/libLLVM-4.0svn.so
#0  0x00007fffc59ee0c6 in llvm::SSAUpdaterImpl<llvm::SSAUpdater>::BuildBlockList(llvm::BasicBlock*, llvm::SmallVectorImpl<llvm::SSAUpdaterImpl<llvm::SSAUpdater>::BBInfo*>*) () at /usr/lib/libLLVM-4.0svn.so
#1  0x00007fffc59f2acf in llvm::SSAUpdater::GetValueAtEndOfBlockInternal(llvm::BasicBlock*) () at /usr/lib/libLLVM-4.0svn.so
#2  0x00007fffc59f942a in llvm::SSAUpdater::RewriteUseAfterInsertions(llvm::Use&) () at /usr/lib/libLLVM-4.0svn.so
#3  0x00007fffc5cb7551 in (anonymous namespace)::StructurizeCFG::runOnRegion(llvm::Region*, llvm::RGPassManager&) () at /usr/lib/libLLVM-4.0svn.so
#4  0x00007fffc5f3571c in llvm::RGPassManager::runOnFunction(llvm::Function&) () at /usr/lib/libLLVM-4.0svn.so
#5  0x00007fffc53c03a2 in llvm::FPPassManager::runOnFunction(llvm::Function&) () at /usr/lib/libLLVM-4.0svn.so
#6  0x00007fffc53c0443 in llvm::FPPassManager::runOnModule(llvm::Module&) () at /usr/lib/libLLVM-4.0svn.so
#7  0x00007fffc53c0a54 in llvm::legacy::PassManagerImpl::run(llvm::Module&) () at /usr/lib/libLLVM-4.0svn.so
#8  0x00007fffc61a5d57 in LLVMTargetMachineEmit(LLVMOpaqueTargetMachine*, LLVMOpaqueModule*, llvm::raw_pwrite_stream&, LLVMCodeGenFileType, char**) () at /usr/lib/libLLVM-4.0svn.so
#9  0x00007fffc61a6139 in LLVMTargetMachineEmitToMemoryBuffer () at /usr/lib/libLLVM-4.0svn.so
#10 0x00007fffc889e7c3 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#11 0x00007fffc8814605 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#12 0x00007fffc88161d2 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#13 0x00007fffc8822f73 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#14 0x00007fffc868ec34 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#15 0x00007fffc868e9f6 in  () at /usr/lib/xorg/modules/dri/radeonsi_dri.so
#16 0x00007ffff2636454 in start_thread () at /usr/lib/libpthread.so.0
#17 0x00007ffff1ad67df in clone () at /usr/lib/libc.so.6
Comment 1 Christoph Haag 2016-09-21 16:04:54 UTC
Created attachment 126706 [details]
gdb.txt assertion with full backtrace

With full debugging llvm and mesa I get an assertion instead:

janusvr: /home/chris/build/llvm-svn/src/llvm/include/llvm/Analysis/LoopInfoImpl.h:247: void llvm::LoopBase<N, M>::verifyLoop() const [with BlockT = llvm::BasicBlock; LoopT = llvm::Loop]: Assertion `std::any_of(GraphTraits<BlockT*>::child_begin(BB), GraphTraits<BlockT*>::child_end(BB), [&](BlockT *B){return contains(B);}) && "Loop block has no in-loop successors!"' failed.

backtrace full attached
Comment 2 Nicolai Hähnle 2016-09-28 12:06:07 UTC
I can reproduce this running plain JanusVR, and I'm going to investigate. Looks like there are actually two bugs - the one you originally reported, and another that prevents proper dumping of the affected shader.
Comment 3 Nicolai Hähnle 2016-10-07 16:07:27 UTC
This should be fixed in Mesa master now (commit 6f87d7a14699277be6dd17e9e712841c4057c4df).

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(provided by the Example extension).