Add support for unwinding during prologue/epilogue #7
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
I don't fully understand the Julia build system, but: how do I apply that during build, and how does it fix the current issue of missing patch file during build? |
|
When building llvm from source in Julia, this repository is what is used by default, with the branch/ref specified by https://github.com/JuliaLang/julia/blob/6026b5ff2a8035fc9d70af30123af9a6e722c585/deps/llvm.version (hence why I opened this pull request to target the branch |
|
@Keno Is there a phabricator change open for this PR? If not can you create one |
|
Note that we we apply this patch directly to libunwind: https://github.com/JuliaPackaging/Yggdrasil/blob/cc0b0caa2df2857cc9c00527732cb79c97ed35a1/L/LLVMLibUnwind/LLVMLibUnwind%4012.0.1/bundled/patches/0001-unwind-prologue-epilogue.patch. I'm not sure we need to rebuild llvm just for that? |
|
I don't understand why we have a separate LLVMLibUnwind to begin with. It should be part of the monobuild. |
|
Don't ask me, I'm merely reporting how it is 😜 |
|
The issue in JuliaLang/julia#44499 is that several patch files (3 IIRC) are missing from the Julia source tree, while being referred to in the Julia build system (julia/deps/unwind.mk) This PR is modifying a header file in libunwind. I'm not seeing it will fix the issue. I'm totally confused. |
|
Yes, I'm also confused. I misread where the patch was being applied, I was convinced it was in Upstreaming the patch, if possible, would solve all issues in the long term though 🙂 |
vchuravy
pushed a commit
that referenced
this pull request
Jan 6, 2023
For the following program,
$ cat t.c
struct t {
int (__attribute__((btf_type_tag("rcu"))) *f)();
int a;
};
int foo(struct t *arg) {
return arg->a;
}
Compiling with 'clang -g -O2 -S t.c' will cause a failure like below:
clang: /home/yhs/work/llvm-project/clang/lib/Sema/SemaType.cpp:6391: void {anonymous}::DeclaratorLocFiller::VisitParenTypeLoc(clang::ParenTypeLoc):
Assertion `Chunk.Kind == DeclaratorChunk::Paren' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
......
#5 0x00007f89e4280ea5 abort (/lib64/libc.so.6+0x21ea5)
#6 0x00007f89e4280d79 _nl_load_domain.cold.0 (/lib64/libc.so.6+0x21d79)
#7 0x00007f89e42a6456 (/lib64/libc.so.6+0x47456)
#8 0x00000000045c2596 GetTypeSourceInfoForDeclarator((anonymous namespace)::TypeProcessingState&, clang::QualType, clang::TypeSourceInfo*) SemaType.cpp:0:0
#9 0x00000000045ccfa5 GetFullTypeForDeclarator((anonymous namespace)::TypeProcessingState&, clang::QualType, clang::TypeSourceInfo*) SemaType.cpp:0:0
......
The reason of the failure is due to the mismatch of TypeLoc and D.getTypeObject().Kind. For example,
the TypeLoc is
BTFTagAttributedType 0x88614e0 'int btf_type_tag(rcu)()' sugar
|-ParenType 0x8861480 'int ()' sugar
| `-FunctionNoProtoType 0x8861450 'int ()' cdecl
| `-BuiltinType 0x87fd500 'int'
while corresponding D.getTypeObject().Kind points to DeclaratorChunk::Paren, and
this will cause later assertion.
To fix the issue, similar to AttributedTypeLoc, let us skip BTFTagAttributedTypeLoc in
GetTypeSourceInfoForDeclarator().
Differential Revision: https://reviews.llvm.org/D136807
stahta01
pushed a commit
to stahta01/llvm-project
that referenced
this pull request
Jan 25, 2023
This patch re-introduces the fix in the commit llvm@66b0cebf7f736 by @yrnkrn > In DwarfEHPrepare, after all passes are run, RewindFunction may be a dangling > > pointer to a dead function. To make sure it's valid, doFinalization nullptrs > RewindFunction just like the constructor and so it will be found on next run. > > llvm-svn: 217737 It seems that the fix was not migrated to `DwarfEHPrepareLegacyPass`. This patch also updates `llvm/test/CodeGen/X86/dwarf-eh-prepare.ll` to include `-run-twice` to exercise the cleanup. Without this patch `llvm-lit -v llvm/test/CodeGen/X86/dwarf-eh-prepare.ll` fails with ``` -- Testing: 1 tests, 1 workers -- FAIL: LLVM :: CodeGen/X86/dwarf-eh-prepare.ll (1 of 1) ******************** TEST 'LLVM :: CodeGen/X86/dwarf-eh-prepare.ll' FAILED ******************** Script: -- : 'RUN: at line 1'; /home/arakaki/build/llvm-project/main/bin/opt -mtriple=x86_64-linux-gnu -dwarfehprepare -simplifycfg-require-and-preserve-domtree=1 -run-twice < /home/arakaki/repos/watch/llvm-project/llvm/test/CodeGen/X86/dwarf-eh-prepare.ll -S | /home/arakaki/build/llvm-project/main/bin/FileCheck /home/arakaki/repos/watch/llvm-project/llvm/test/CodeGen/X86/dwarf-eh-prepare.ll -- Exit Code: 2 Command Output (stderr): -- Referencing function in another module! call void @_Unwind_Resume(i8* %ehptr) JuliaLang#1 ; ModuleID = '<stdin>' void (i8*)* @_Unwind_Resume ; ModuleID = '<stdin>' in function simple_cleanup_catch LLVM ERROR: Broken function found, compilation aborted! PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace. Stack dump: 0. Program arguments: /home/arakaki/build/llvm-project/main/bin/opt -mtriple=x86_64-linux-gnu -dwarfehprepare -simplifycfg-require-and-preserve-domtree=1 -run-twice -S 1. Running pass 'Function Pass Manager' on module '<stdin>'. 2. Running pass 'Module Verifier' on function '@simple_cleanup_catch' #0 0x000056121b570a2c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/arakaki/repos/watch/llvm-project/llvm/lib/Support/Unix/Signals.inc:569:0 JuliaLang#1 0x000056121b56eb64 llvm::sys::RunSignalHandlers() /home/arakaki/repos/watch/llvm-project/llvm/lib/Support/Signals.cpp:97:0 JuliaLang#2 0x000056121b56f28e SignalHandler(int) /home/arakaki/repos/watch/llvm-project/llvm/lib/Support/Unix/Signals.inc:397:0 JuliaLang#3 0x00007fc7e9b22980 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x12980) JuliaLang#4 0x00007fc7e87d3fb7 raise /build/glibc-S7xCS9/glibc-2.27/signal/../sysdeps/unix/sysv/linux/raise.c:51:0 JuliaLang#5 0x00007fc7e87d5921 abort /build/glibc-S7xCS9/glibc-2.27/stdlib/abort.c:81:0 JuliaLang#6 0x000056121b4e1386 llvm::raw_svector_ostream::raw_svector_ostream(llvm::SmallVectorImpl<char>&) /home/arakaki/repos/watch/llvm-project/llvm/include/llvm/Support/raw_ostream.h:674:0 JuliaLang#7 0x000056121b4e1386 llvm::report_fatal_error(llvm::Twine const&, bool) /home/arakaki/repos/watch/llvm-project/llvm/lib/Support/ErrorHandling.cpp:114:0 JuliaLang#8 0x000056121b4e1528 (/home/arakaki/build/llvm-project/main/bin/opt+0x29e3528) JuliaLang#9 0x000056121adfd03f llvm::raw_ostream::operator<<(llvm::StringRef) /home/arakaki/repos/watch/llvm-project/llvm/include/llvm/Support/raw_ostream.h:218:0 FileCheck error: '<stdin>' is empty. FileCheck command line: /home/arakaki/build/llvm-project/main/bin/FileCheck /home/arakaki/repos/watch/llvm-project/llvm/test/CodeGen/X86/dwarf-eh-prepare.ll -- ******************** ******************** Failed Tests (1): LLVM :: CodeGen/X86/dwarf-eh-prepare.ll Testing Time: 0.22s Failed: 1 ``` Reviewed By: loladiro Differential Revision: https://reviews.llvm.org/D110979 (cherry picked from commit e8806d7)
stahta01
pushed a commit
to stahta01/llvm-project
that referenced
this pull request
Feb 9, 2023
We experienced some deadlocks when we used multiple threads for logging using `scan-builds` intercept-build tool when we used multiple threads by e.g. logging `make -j16` ``` (gdb) bt #0 0x00007f2bb3aff110 in __lll_lock_wait () from /lib/x86_64-linux-gnu/libpthread.so.0 JuliaLang#1 0x00007f2bb3af70a3 in pthread_mutex_lock () from /lib/x86_64-linux-gnu/libpthread.so.0 JuliaLang#2 0x00007f2bb3d152e4 in ?? () JuliaLang#3 0x00007ffcc5f0cc80 in ?? () JuliaLang#4 0x00007f2bb3d2bf5b in ?? () from /lib64/ld-linux-x86-64.so.2 JuliaLang#5 0x00007f2bb3b5da27 in ?? () from /lib/x86_64-linux-gnu/libc.so.6 JuliaLang#6 0x00007f2bb3b5dbe0 in exit () from /lib/x86_64-linux-gnu/libc.so.6 JuliaLang#7 0x00007f2bb3d144ee in ?? () JuliaLang#8 0x746e692f706d742f in ?? () JuliaLang#9 0x692d747065637265 in ?? () JuliaLang#10 0x2f653631326b3034 in ?? () JuliaLang#11 0x646d632e35353532 in ?? () JuliaLang#12 0x0000000000000000 in ?? () ``` I think the gcc's exit call caused the injected `libear.so` to be unloaded by the `ld`, which in turn called the `void on_unload() __attribute__((destructor))`. That tried to acquire an already locked mutex which was left locked in the `bear_report_call()` call, that probably encountered some error and returned early when it forgot to unlock the mutex. All of these are speculation since from the backtrace I could not verify if frames 2 and 3 are in fact corresponding to the `libear.so` module. But I think it's a fairly safe bet. So, hereby I'm releasing the held mutex on *all paths*, even if some failure happens. PS: I would use lock_guards, but it's C. Reviewed-by: NoQ Differential Revision: https://reviews.llvm.org/D118439 (cherry picked from commit d919d02)
vtjnash
pushed a commit
that referenced
this pull request
Feb 11, 2025
…ible (llvm#123752) This patch adds a new option `-aarch64-enable-zpr-predicate-spills` (which is disabled by default), this option replaces predicate spills with vector spills in streaming[-compatible] functions. For example: ``` str p8, [sp, #7, mul vl] // 2-byte Folded Spill // ... ldr p8, [sp, #7, mul vl] // 2-byte Folded Reload ``` Becomes: ``` mov z0.b, p8/z, #1 str z0, [sp] // 16-byte Folded Spill // ... ldr z0, [sp] // 16-byte Folded Reload ptrue p4.b cmpne p8.b, p4/z, z0.b, #0 ``` This is done to avoid streaming memory hazards between FPR/vector and predicate spills, which currently occupy the same stack area even when the `-aarch64-stack-hazard-size` flag is set. This is implemented with two new pseudos SPILL_PPR_TO_ZPR_SLOT_PSEUDO and FILL_PPR_FROM_ZPR_SLOT_PSEUDO. The expansion of these pseudos handles scavenging the required registers (z0 in the above example) and, in the worst case spilling a register to an emergency stack slot in the expansion. The condition flags are also preserved around the `cmpne` in case they are live at the expansion point.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Ref: JuliaLang/julia#44499. CC: @Keno @vchuravy @fxcoudert