Skip to content

Zig crashes on LoongArch64 #22859

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Closed
xtexx opened this issue Feb 11, 2025 · 7 comments
Closed

Zig crashes on LoongArch64 #22859

xtexx opened this issue Feb 11, 2025 · 7 comments
Labels
arch-loongarch 32-bit and 64-bit LoongArch backend-llvm The LLVM backend outputs an LLVM IR Module. bug Observed behavior contradicts documented or intended behavior regression It worked in a previous version of Zig, but stopped working. upstream An issue with a third party project that Zig uses.
Milestone
0.15.0

Comments

@xtexx
Copy link
Contributor

xtexx commented Feb 11, 2025 •
edited
Loading

Zig Version

0.14.0-dev.3187+d4c85079c

Steps to Reproduce and Observed Behavior

zig init then zig build, got 'zig build' terminated by signal SIGSEGV (Address boundary error)

On earlier versions, zig init build successfully but building the current master zig crashes (SIGBUS or SIGSEGV).
On latest versions, zig init-projects also could not be built.

Expected Behavior

It should build.
@xtexx xtexx added the bug Observed behavior contradicts documented or intended behavior label Feb 11, 2025
@alexrp alexrp added arch-loongarch 32-bit and 64-bit LoongArch compiler-rt regression It worked in a previous version of Zig, but stopped working. labels Feb 12, 2025
@alexrp alexrp added this to the 0.14.0 milestone Feb 12, 2025
@mikdusan
Copy link
Member

a reduction:

zig build-exe hello.zig
  1. maybe a hint to the problem? release zig alternates between SIGSEGV and SIGBUS
  2. debug zig thus far is always SIGSEGV
trace from debug zig 
[4] compiler_rt
Thread 27 "zig" received signal SIGSEGV, Segmentation fault.
[Switching to LWP 4247]
0x000000000e50f81c in compiler_rt.memmove.copyForward () at /home/mike/project/zig-bootstrap/n2/out/host/lib/zig/compiler_rt/memmove.zig:130
warning: 130	/home/mike/project/zig-bootstrap/n2/out/host/lib/zig/compiler_rt/memmove.zig: No such file or directory
(gdb) bt
#0  0x000000000e50f81c in compiler_rt.memmove.copyForward () at /home/mike/project/zig-bootstrap/n2/out/host/lib/zig/compiler_rt/memmove.zig:130
#1  compiler_rt.memmove.copyMove () at /home/mike/project/zig-bootstrap/n2/out/host/lib/zig/compiler_rt/memmove.zig:111
#2  compiler_rt.memmove.memmoveFast (opt_dest=0x7fffd4dd3610 "", opt_src=0x7fffd4dd3618 "@", len=18446744073709551608)
    at /home/mike/project/zig-bootstrap/n2/out/host/lib/zig/compiler_rt/memmove.zig:65
#3  0x0000000005132cb0 in llvm::LoopInfoBase<llvm::BasicBlock, llvm::Loop>::removeBlock(llvm::BasicBlock*) ()
#4  0x000000000531bcc4 in llvm::MergeBlockIntoPredecessor(llvm::BasicBlock*, llvm::DomTreeUpdater*, llvm::LoopInfo*, llvm::MemorySSAUpdater*, llvm::MemoryDependenceResults*, bool, llvm::DominatorTree*) ()
#5  0x000000000564a254 in (anonymous namespace)::LoopRotate::processLoop(llvm::Loop*) ()
#6  0x00000000056478a0 in llvm::LoopRotation(llvm::Loop*, llvm::LoopInfo*, llvm::TargetTransformInfo const*, llvm::AssumptionCache*, llvm::DominatorTree*, llvm::ScalarEvolution*, llvm::MemorySSAUpdater*, llvm::SimplifyQuery const&, bool, unsigned int, bool, bool) ()
#7  0x0000000005646d38 in llvm::LoopRotatePass::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) ()
#8  0x00000000050f601c in llvm::detail::PassModel<llvm::Loop, llvm::LoopRotatePass, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) ()
#9  0x0000000005c5d6a4 in std::__1::optional<llvm::PreservedAnalyses> llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runSinglePass<llvm::Loop, std::__1::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::__1::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&> > > >(llvm::Loop&, std::__1::unique_ptr<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, std::__1::default_delete<llvm::detail::PassConcept<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&> > >&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&, llvm::PassInstrumentation&) ()
#10 0x0000000005c5d400 in llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::runWithoutLoopNestPasses(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) ()
#11 0x0000000005c5cd8c in llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) ()
#12 0x00000000050f1cdc in llvm::detail::PassModel<llvm::Loop, llvm::PassManager<llvm::Loop, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&>::run(llvm::Loop&, llvm::AnalysisManager<llvm::Loop, llvm::LoopStandardAnalysisResults&>&, llvm::LoopStandardAnalysisResults&, llvm::LPMUpdater&) ()
#13 0x0000000005c5e0b4 in llvm::FunctionToLoopPassAdaptor::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) ()
#14 0x00000000050f7abc in llvm::detail::PassModel<llvm::Function, llvm::FunctionToLoopPassAdaptor, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&)
    ()
#15 0x0000000005030bd4 in llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) ()
#16 0x00000000050fe75c in llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) ()
#17 0x00000000056d7b34 in llvm::CGSCCToFunctionPassAdaptor::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) ()
#18 0x00000000050feadc in llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::CGSCCToFunctionPassAdaptor, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) ()
#19 0x00000000056d513c in llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) ()
#20 0x000000000511237c in llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::PassManager<llvm::LazyCallGraph::SCC, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) ()
#21 0x00000000056d6b48 in llvm::DevirtSCCRepeatedPass::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) ()
#22 0x000000000568df1c in llvm::detail::PassModel<llvm::LazyCallGraph::SCC, llvm::DevirtSCCRepeatedPass, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&>::run(llvm::LazyCallGraph::SCC&, llvm::AnalysisManager<llvm::LazyCallGraph::SCC, llvm::LazyCallGraph&>&, llvm::LazyCallGraph&, llvm::CGSCCUpdateResult&) ()
#23 0x00000000056d6150 in llvm::ModuleToPostOrderCGSCCPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) ()
#24 0x000000000510297c in llvm::detail::PassModel<llvm::Module, llvm::ModuleToPostOrderCGSCCPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&)
    ()
#25 0x000000000502f854 in llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) ()
#26 0x0000000005689364 in llvm::ModuleInlinerWrapperPass::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) ()
#27 0x00000000050ff03c in llvm::detail::PassModel<llvm::Module, llvm::ModuleInlinerWrapperPass, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) ()
#28 0x000000000502f854 in llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) ()
--Type <RET> for more, q to quit, c to continue without paging--
#29 0x0000000004d9297c in ZigLLVMTargetMachineEmitToFile (targ_machine_ref=0x7fffd64f0020, module_ref=0x7fffd795cfb0, error_message=0x7fffdee9ec60, options=0x7fffdee9f090) at /home/mike/project/zig-bootstrap/n2/zig/src/zig_llvm.cpp:379
#30 0x000000000b1a7c44 in codegen.llvm.Object.emit (o=0x7fffdde4c250, options=...) at /home/mike/project/zig-bootstrap/n2/zig/src/codegen/llvm.zig:1384
#31 0x000000000b1a09c0 in Compilation.emitLlvmObject (comp=0x7fffdde96f80, arena=..., default_artifact_directory=..., bin_emit_loc=..., llvm_object=0x7fffdde4c250, prog_node=...) at Compilation.zig:2735
#32 0x000000000b8cf7f0 in link.File.emitLlvmObject (base=..., arena=..., llvm_object=0x7fffdde4c250, prog_node=...) at link.zig:1335
#33 0x000000000b62891c in link.Elf.flushModule (self=0x7fffdde9aac0, arena=..., tid=main, prog_node=...) at /home/mike/project/zig-bootstrap/n2/zig/src/link/Elf.zig:819
#34 0x000000000b5f85bc in link.File.flushModule (base=0x7fffdde9ae30, arena=..., tid=main, prog_node=...) at link.zig:842
#35 0x000000000b5f5970 in link.File.linkAsArchiveInner (base=0x7fffdde9ae30, arena=..., tid=main, prog_node=...) at link.zig:1095
#36 0x000000000b3c95c4 in link.File.linkAsArchive (base=0x7fffdde9ae30, arena=..., tid=main, prog_node=...) at link.zig:1077
#37 0x000000000b1a865c in link.File.flush (base=0x7fffdde9ae30, arena=..., tid=main, prog_node=...) at link.zig:826
#38 0x000000000b1a80b8 in Compilation.flush (comp=0x7fffdde96f80, arena=..., default_artifact_directory=..., tid=main, prog_node=...) at Compilation.zig:2438
#39 0x000000000b1ae16c in Compilation.update (comp=0x7fffdde96f80, main_progress_node=...) at Compilation.zig:2375
#40 0x000000000c161980 in Compilation.updateSubCompilation (parent_comp=0x7ffff7f791c0, sub_comp=0x7fffdde96f80, misc_task=compiler_rt, prog_node=...) at Compilation.zig:6448
#41 0x000000000c1644ac in Compilation.buildOutputFromZig (comp=0x7ffff7f791c0, src_basename=..., output_mode=Lib, allow_lto=false, out=0x7ffff7f797f8, misc_task_tag=compiler_rt, prog_node=...) at Compilation.zig:6591
#42 0x000000000bcc3058 in Compilation.buildRt (comp=0x7ffff7f791c0, root_source_name=..., misc_task=compiler_rt, output_mode=Lib, allow_lto=false, out=0x7ffff7f797f8, prog_node=...) at Compilation.zig:4681
#43 0x000000000b83c284 in Thread.WaitGroup.spawnManager__anon_183554.Manager.run (wg_inner=0x7ffff7f79378, args_inner=...) at /home/mike/project/zig-bootstrap/n2/out/host/lib/zig/std/Thread/WaitGroup.zig:66
#44 0x000000000c161850 in Thread.callFn__anon_353682 (args=...) at /home/mike/project/zig-bootstrap/n2/out/host/lib/zig/std/Thread.zig:488
#45 0x000000000bcc2f40 in Thread.PosixThreadImpl.spawn__anon_280580.Instance.entryFn (raw_arg=0x7ffff7fb4860) at /home/mike/project/zig-bootstrap/n2/out/host/lib/zig/std/Thread.zig:757
#46 0x000000000e4e4330 in start (p=0x7fffdeea3680) at /home/mike/project/zig-bootstrap/n2/out/host/lib/zig/libc/musl/src/thread/pthread_create.c:207
#47 0x000000000e4e29e0 in __clone () at /home/mike/project/zig-bootstrap/n2/out/host/lib/zig/libc/musl/src/thread/loongarch64/clone.s:28

I used the following steps to get zig-bootstrap to generate a loongarch64 debug binary:

  1. clone zig-bootstrap master
  2. cd TOP
  3. rm -fr zig
  4. git clone https://github.com/ziglang/zig.git
  5. apply the following quick'n'dirty patch:
diff --git a/build b/build
index fb259b0ff..c9f67f491 100755
--- a/build
+++ b/build
@@ -5,9 +5,10 @@ set -eu

 TARGET="$1" # Example: riscv64-linux-gnu
 MCPU="$2" # Examples: `baseline`, `native`, `generic+v7a`, or `arm1176jzf_s`
+MCMODEL_FLAGS="-mcmodel=medium"

 ROOTDIR="$(pwd)"
-ZIG_VERSION="0.14.0-dev.2257+e6d2e1641"
+ZIG_VERSION="0.14.0-dev.3205+6dc1a4db7"

 TARGET_OS_AND_ABI=${TARGET#*-} # Example: linux-gnu

@@ -98,6 +99,7 @@ $ZIG build-lib \
   --name zstd \
   -target $TARGET \
   -mcpu=$MCPU \
+  $MCMODEL_FLAGS \
   -fstrip -OReleaseFast \
   -lc \
   "$ROOTDIR/zstd/lib/decompress/zstd_ddict.c" \
@@ -197,8 +199,8 @@ $ZIG build \
   --search-prefix "$ROOTDIR/out/$TARGET-$MCPU" \
   -Dflat \
   -Dstatic-llvm \
-  -Doptimize=ReleaseFast \
-  -Dstrip \
+  -Doptimize=Debug \
+  -Dstrip=false \
   -Dtarget="$TARGET" \
   -Dcpu="$MCPU" \
   -Dversion-string="$ZIG_VERSION"
  1. don't forget to update ZIG_VERSION in build script (hint: git --work-tree=zig describe)
  2. ./build loongarch64-linux-musl baseline

@mikdusan
Copy link
Member 

$ git bisect bad
f278038923c33ddf710f0328a07ce18613a94130 is the first bad commit
commit f278038923c33ddf710f0328a07ce18613a94130 (HEAD)
Author:     David Rubin <daviru007@icloud.com>
AuthorDate: Sat Nov 30 16:08:26 2024 -0800
Commit:     Andrew Kelley <andrew@ziglang.org>
CommitDate: Fri Jan 17 12:34:15 2025 -0800

    replace `compiler_rt` memcpy with a better version

 lib/compiler_rt.zig         |   1 -
 lib/compiler_rt/memcpy.zig  | 143 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 lib/compiler_rt/memmove.zig |  25 ----------------
 3 files changed, 130 insertions(+), 39 deletions(-)
 delete mode 100644 lib/compiler_rt/memmove.zig

@xtexx
Copy link
Contributor Author

xtexx commented Feb 16, 2025

For record, @mikdusan reported on zulip that applying #22606 resolves this for Debug zig but release zig still crashes.

However, both Debug and ReleaseSafe zig worked for me. I have successfully compiled Debug zig from the ReleaseSafe LoongArch64 zig.

@xtexx
Copy link
Contributor Author

xtexx commented Feb 16, 2025 •
edited
Loading

#22606 crashes in ReleaseFast. Debug, ReleaseSmall, ReleaseSafe not crash.

ReleaseFast crashes on another place:

#0  fifo.LinearFifo(InternPool.FileIndex,.{ .Dynamic = {} }).readItem (self=0x7fffe75675f8) at /buildroots/xtex/zig-bootstrap/zig/lib/std/fifo.zig:210
#1  Compilation.performAllTheWorkInner (comp=0x7fffe75671e0, main_progress_node=...) at Compilation.zig:3786
#2  0x000000000a5bc2f8 in Compilation.performAllTheWork (comp=0x7fffe75671e0) at Compilation.zig:3645
#3  Compilation.update (comp=0x7fffe75671e0, main_progress_node=...) at Compilation.zig:2259
#4  0x000000000a5e480c in main.updateModule (comp=0x7fffe75671e0, color=<optimized out>, prog_node=<error reading variable: Cannot access memory at address 0x81>) at main.zig:4500
#5  0x000000000a6823f0 in main.cmdBuild (arena=...) at main.zig:5322
#6  0x000000000a554a60 in main.mainArgs (arena=...) at main.zig:293
#7  main.main () at main.zig:212
#8  start.callMain () at /buildroots/xtex/zig-bootstrap/zig/lib/std/start.zig:656
#9  start.callMainWithArgs () at /buildroots/xtex/zig-bootstrap/zig/lib/std/start.zig:616
#10 start.main (c_argc=<optimized out>, c_argv=<optimized out>, c_envp=<optimized out>) at /buildroots/xtex/zig-bootstrap/zig/lib/std/start.zig:631

@xtexx
Copy link
Contributor Author

xtexx commented Feb 16, 2025 •
edited
Loading

There seems to be some race conditions (or miscomp?). By repeating starting Zig, it sometimes worked well!

@alexrp
Copy link
Member

alexrp commented Feb 23, 2025

All analysis on this so far indicates that we're hitting multiple LLVM bugs. The plan is to ship 0.14.0 with this regression and hope that the situation has improved in LLVM 20.

@alexrp alexrp modified the milestones: 0.14.0, 0.15.0 Feb 23, 2025
@alexrp alexrp added upstream An issue with a third party project that Zig uses. backend-llvm The LLVM backend outputs an LLVM IR Module. labels Feb 23, 2025
@alexrp alexrp mentioned this issue Feb 23, 2025
Closed
14 tasks
This was referenced Mar 5, 2025
Closed
Closed
This was referenced Mar 14, 2025
Merged
Open
@xtexx
Copy link
Contributor Author

xtexx commented Apr 5, 2025

#22780 seems to have fixed this and the latest dev version is working.

@xtexx xtexx closed this as completed Apr 5, 2025
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees
No one assigned
Labels
arch-loongarch 32-bit and 64-bit LoongArch backend-llvm The LLVM backend outputs an LLVM IR Module. bug Observed behavior contradicts documented or intended behavior regression It worked in a previous version of Zig, but stopped working. upstream An issue with a third party project that Zig uses.
Projects
None yet
Milestone
0.15.0
Development

No branches or pull requests
3 participants
@alexrp @xtexx @mikdusan