Skip to content

[MLIR][LLVM] Don't use void return type in MLIR APIs. #4

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.

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

Closed
wants to merge 1 commit into from

Conversation

definelicht
Copy link
Collaborator

In some instances, an LLVM void type is used to model LLVM IR functions with no return type. This is inconsistent with MLIR APIs, which expects a function with no return value to have an empty return type. Handle this special case in LLVMFuncOp to avoid mismatches between the number of return values and return types between caller and callee.

@definelicht definelicht requested review from Dinistro and gysit January 13, 2023 10:35
@definelicht definelicht force-pushed the callable-op-return branch 2 times, most recently from b3c8b8c to 912fc27 Compare January 13, 2023 12:09
Copy link
Collaborator

@Dinistro Dinistro left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM

Copy link
Collaborator

@gysit gysit left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM!

In the LLVM IR dialect, `LLVMVoidType` is used to model the return type
of LLVM IR functions with no return value. This is inconsistent with
MLIR APIs, which expect a function with no return value to have an
empty return type. Handle this special case in `LLVMFuncOp` to avoid
mismatches between the number of return values and return types between
caller and callee.

The parser of `LLVMFuncOp` is adapted to be symmetric with the printer,
and not allow `!llvm.void` to be expressed explicitly as a return type
in the IR, thus avoiding to expose this implementation detail.

Differential Revision: https://reviews.llvm.org/D141676
definelicht pushed a commit that referenced this pull request Jan 17, 2023
When building/testing ASan inside the GCC tree on Solaris while using GNU
`ld` instead of Solaris `ld`, a large number of tests SEGVs on both sparc
and x86 like this:

  Thread 2 received signal SIGSEGV, Segmentation fault.
  [Switching to Thread 1 (LWP 1)]
  0xfe014cfc in __sanitizer::atomic_load<__sanitizer::atomic_uintptr_t>
(a=0xfc602a58, mo=__sanitizer::memory_order_acquire) at
sanitizer_common/sanitizer_atomic_clang_x86.h:46
  46	      v = a->val_dont_use;
  1: x/i $pc
  => 0xfe014cfc
<_ZN11__sanitizer11atomic_loadINS_16atomic_uintptr_tEEENT_4TypeEPVKS2_NS_12memory_orderE+62>:
mov (%eax),%eax
  (gdb) bt
  #0 0xfe014cfc in __sanitizer::atomic_load<__sanitizer::atomic_uintptr_t>
(a=0xfc602a58, mo=__sanitizer::memory_order_acquire) at
sanitizer_common/sanitizer_atomic_clang_x86.h:46
  #1 0xfe0bd1d7 in __sanitizer::DTLS_NextBlock (cur=0xfc602a58) at
sanitizer_common/sanitizer_tls_get_addr.cpp:53
  #2 0xfe0bd319 in __sanitizer::DTLS_Find (id=1) at
sanitizer_common/sanitizer_tls_get_addr.cpp:77
  #3 0xfe0bd466 in __sanitizer::DTLS_on_tls_get_addr (arg_void=0xfeffd068,
res=0xfe602a18, static_tls_begin=0, static_tls_end=0) at
sanitizer_common/sanitizer_tls_get_addr.cpp:116
  #4 0xfe063f81 in __interceptor___tls_get_addr (arg=0xfeffd068) at
sanitizer_common/sanitizer_common_interceptors.inc:5501
  #5 0xfe0a3054 in __sanitizer::CollectStaticTlsBlocks (info=0xfeffd108,
size=40, data=0xfeffd16c) at
sanitizer_common/sanitizer_linux_libcdep.cpp:366
  #6  0xfe6ba9fa in dl_iterate_phdr () from /usr/lib/ld.so.1
  #7 0xfe0a3132 in __sanitizer::GetStaticTlsBoundary (addr=0xfe608020,
size=0xfeffd244, align=0xfeffd1b0) at
sanitizer_common/sanitizer_linux_libcdep.cpp:382
  #8 0xfe0a33f7 in __sanitizer::GetTls (addr=0xfe608020, size=0xfeffd244)
at sanitizer_common/sanitizer_linux_libcdep.cpp:482
  #9 0xfe0a34b1 in __sanitizer::GetThreadStackAndTls (main=true,
stk_addr=0xfe608010, stk_size=0xfeffd240, tls_addr=0xfe608020,
tls_size=0xfeffd244) at sanitizer_common/sanitizer_linux_libcdep.cpp:565

The address being accessed is unmapped.  However, even when the tests
`PASS` with Solaris `ld`, `ASAN_OPTIONS=verbosity=2` shows

  ==6582==__tls_get_addr: Can't guess glibc version

Given that that the code is stricly `glibc`-specific according to
`sanitizer_tls_get_addr.h`, there seems little point in using the
interceptor on non-`glibc` targets.

That's what this patch does.  Tested on `i386-pc-solaris2.11` and
`sparc-sun-solaris2.11` inside the GCC tree.

Differential Revision: https://reviews.llvm.org/D141385
Dinistro pushed a commit that referenced this pull request Jan 30, 2023
…ak ordering

`std::sort` requires a comparison operator that obides by strict weak
ordering. `operator<=` on pointer does not and leads to undefined
behaviour. Specifically, when we grow the `scratch_type_systems` vector
slightly larger (and thus take `std::sort` down a slightly different
codepath), we segfault. This happened while working on a patch that
would in fact grow this vector. In such a case ASAN reports:

```
$ ./bin/lldb ./lldb-test-build.noindex/lang/cpp/complete-type-check/TestCppIsTypeComplete.test_builtin_types/a.out -o "script -- lldb.target.FindFirstType(\"void\")"
(lldb) script -- lldb.target.FindFirstType("void")
=================================================================
==59975==ERROR: AddressSanitizer: container-overflow on address 0x000108f6b510 at pc 0x000280177b4c bp 0x00016b7d7430 sp 0x00016b7d7428
READ of size 8 at 0x000108f6b510 thread T0
    #0 0x280177b48 in std::__1::shared_ptr<lldb_private::TypeSystem>::shared_ptr[abi:v15006](std::__1::shared_ptr<lldb_private::TypeSystem> const&)+0xb4 (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0x177b48)
(BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #1 0x280dcc008 in void std::__1::__introsort<std::__1::_ClassicAlgPolicy, lldb_private::Target::GetScratchTypeSystems(bool)::$_3&, std::__1::shared_ptr<lldb_private::TypeSystem>*>(std::__1::shared_ptr<lldb_private::TypeSystem>*, std::__1::shared_
ptr<lldb_private::TypeSystem>*, lldb_private::Target::GetScratchTypeSystems(bool)::$_3&, std::__1::iterator_traits<std::__1::shared_ptr<lldb_private::TypeSystem>*>::difference_type)+0x1050 (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblld
b.17.0.0git.dylib:arm64+0xdcc008) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #2 0x280d88788 in lldb_private::Target::GetScratchTypeSystems(bool)+0x5a4 (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0xd88788) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #3 0x28021f0b4 in lldb::SBTarget::FindFirstType(char const*)+0x624 (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0x21f0b4) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #4 0x2804e9590 in _wrap_SBTarget_FindFirstType(_object*, _object*)+0x26c (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0x4e9590) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #5 0x1062d3ad4 in cfunction_call+0x5c (/opt/homebrew/Cellar/[email protected]/3.11.1/Frameworks/Python.framework/Versions/3.11/Python:arm64+0xcfad4) (BuildId: c9efc4bbb1943f9a9b7cc4e91fce477732000000200000000100000000000d00)

<--- snipped --->

0x000108f6b510 is located 400 bytes inside of 512-byte region [0x000108f6b380,0x000108f6b580)
allocated by thread T0 here:
    #0 0x105209414 in wrap__Znwm+0x74 (/Applications/Xcode2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/clang/14.0.3/lib/darwin/libclang_rt.asan_osx_dynamic.dylib:arm64e+0x51414) (BuildId: 0a44828ceb64337bbfff60b22cd838f0320000
00200000000100000000000b00)
    #1 0x280dca3b4 in std::__1::__split_buffer<std::__1::shared_ptr<lldb_private::TypeSystem>, std::__1::allocator<std::__1::shared_ptr<lldb_private::TypeSystem>>&>::__split_buffer(unsigned long, unsigned long, std::__1::allocator<std::__1::shared_pt
r<lldb_private::TypeSystem>>&)+0x11c (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0xdca3b4) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #2 0x280dc978c in void std::__1::vector<std::__1::shared_ptr<lldb_private::TypeSystem>, std::__1::allocator<std::__1::shared_ptr<lldb_private::TypeSystem>>>::__push_back_slow_path<std::__1::shared_ptr<lldb_private::TypeSystem> const&>(std::__1::s
hared_ptr<lldb_private::TypeSystem> const&)+0x13c (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0xdc978c) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #3 0x280d88dec in std::__1::vector<std::__1::shared_ptr<lldb_private::TypeSystem>, std::__1::allocator<std::__1::shared_ptr<lldb_private::TypeSystem>>>::push_back[abi:v15006](std::__1::shared_ptr<lldb_private::TypeSystem> const&)+0x80 (/Users/mic
haelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0xd88dec) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #4 0x280d8857c in lldb_private::Target::GetScratchTypeSystems(bool)+0x398 (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0xd8857c) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #5 0x28021f0b4 in lldb::SBTarget::FindFirstType(char const*)+0x624 (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0x21f0b4) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #6 0x2804e9590 in _wrap_SBTarget_FindFirstType(_object*, _object*)+0x26c (/Users/michaelbuch/Git/lldb-build-main-no-modules/lib/liblldb.17.0.0git.dylib:arm64+0x4e9590) (BuildId: ea963d2c0d47354fb647f5c5f32b76d932000000200000000100000000000d00)
    #7 0x1062d3ad4 in cfunction_call+0x5c (/opt/homebrew/Cellar/[email protected]/3.11.1/Frameworks/Python.framework/Versions/3.11/Python:arm64+0xcfad4) (BuildId: c9efc4bbb1943f9a9b7cc4e91fce477732000000200000000100000000000d00)
    #8 0x10627fff0 in _PyObject_MakeTpCall+0x7c (/opt/homebrew/Cellar/[email protected]/3.11.1/Frameworks/Python.framework/Versions/3.11/Python:arm64+0x7bff0) (BuildId: c9efc4bbb1943f9a9b7cc4e91fce477732000000200000000100000000000d00)
    #9 0x106378a98 in _PyEval_EvalFrameDefault+0xbcf8 (/opt/homebrew/Cellar/[email protected]/3.11.1/Frameworks/Python.framework/Versions/3.11/Python:arm64+0x174a98) (BuildId: c9efc4bbb1943f9a9b7cc4e91fce477732000000200000000100000000000d00)
```

Differential Revision: https://reviews.llvm.org/D142709
gysit pushed a commit that referenced this pull request Mar 8, 2023
There is a fold to create LD1DUPpost from dup(load) that can be postinc. If the
dup is used by a "by element" operation such as fmul or fma then it can be
slightly better to fold the dup into the fmul instead, which produces slightly
fast code.

  ld1r { v1.4s }, [x0], #4
  fmul v0.4s, v1.4s, v0.4s
vs
  ldr s1, [x0], #4
  fmul v0.4s, v0.4s, v1.s[0]

This could also be done with integer operations such as smull/umull too, so
long as the load/dup gets correctly combined into the mul operation. Currently
this just operates on foating point types.

Differential Revision: https://reviews.llvm.org/D145184
gysit pushed a commit that referenced this pull request Mar 23, 2023
This change prevents rare deadlocks observed for specific macOS/iOS GUI
applications which issue many `dlopen()` calls from multiple different
threads at startup and where TSan finds and reports a race during
startup.  Providing a reliable test for this has been deemed infeasible.

Although I've only observed this deadlock on Apple platforms,
conceptually the cause is not confined to Apple code so the fix lives in
platform-independent code.

Deadlock scenario:
```
Thread 2                    | Thread 4
ReportRace()                |
Lock internal TSan mutexes  |
  &ctx->slot_mtx            |
                            | dlopen() interceptor
                            | OnLibraryLoaded()
                            | MemoryMappingLayout::DumpListOfModules()
                            | calls dyld API, which takes internal lock
                            | lock() interceptor
                            | TSan tries to take internal mutexes again
                            |   &ctx->slot_mtx
call into symbolizer        |
MemoryMappingLayout::DumpListOfModules()
calls dyld API, which hangs on trying to take lock
```
Resulting in:
* Thread 2 has internal TSan mutex, blocked on dyld lock
* Thread 4 has dyld lock, blocked on internal TSan mutex

The fix prevents this situation by not intercepting any of the calls
originating from `MemoryMappingLayout::DumpListOfModules()`.

Stack traces for deadlock between ReportRace() and dlopen() interceptor:
```
thread #2, queue = 'com.apple.root.default-qos'
  frame #0: libsystem_kernel.dylib
  frame #1: libclang_rt.tsan_osx_dynamic.dylib`::wrap_os_unfair_lock_lock_with_options(lock=<unavailable>, options=<unavailable>) at tsan_interceptors_mac.cpp:306:3
  frame #2: dyld`dyld4::RuntimeLocks::withLoadersReadLock(this=0x000000016f21b1e0, work=0x00000001814523c0) block_pointer) at DyldRuntimeState.cpp:227:28
  frame #3: dyld`dyld4::APIs::_dyld_get_image_header(this=0x0000000101012a20, imageIndex=614) at DyldAPIs.cpp:240:11
  frame #4: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::MemoryMappingLayout::CurrentImageHeader(this=<unavailable>) at sanitizer_procmaps_mac.cpp:391:35
  frame #5: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::MemoryMappingLayout::Next(this=0x000000016f2a2800, segment=0x000000016f2a2738) at sanitizer_procmaps_mac.cpp:397:51
  frame #6: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::MemoryMappingLayout::DumpListOfModules(this=0x000000016f2a2800, modules=0x00000001011000a0) at sanitizer_procmaps_mac.cpp:460:10
  frame #7: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::ListOfModules::init(this=0x00000001011000a0) at sanitizer_mac.cpp:610:18
  frame #8: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::Symbolizer::FindModuleForAddress(unsigned long) [inlined] __sanitizer::Symbolizer::RefreshModules(this=0x0000000101100078) at sanitizer_symbolizer_libcdep.cpp:185:12
  frame #9: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::Symbolizer::FindModuleForAddress(this=0x0000000101100078, address=6465454512) at sanitizer_symbolizer_libcdep.cpp:204:5
  frame #10: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::Symbolizer::SymbolizePC(this=0x0000000101100078, addr=6465454512) at sanitizer_symbolizer_libcdep.cpp:88:15
  frame #11: libclang_rt.tsan_osx_dynamic.dylib`__tsan::SymbolizeCode(addr=6465454512) at tsan_symbolize.cpp:106:35
  frame #12: libclang_rt.tsan_osx_dynamic.dylib`__tsan::SymbolizeStack(trace=StackTrace @ 0x0000600002d66d00) at tsan_rtl_report.cpp:112:28
  frame #13: libclang_rt.tsan_osx_dynamic.dylib`__tsan::ScopedReportBase::AddMemoryAccess(this=0x000000016f2a2a90, addr=4381057136, external_tag=<unavailable>, s=<unavailable>, tid=<unavailable>, stack=<unavailable>, mset=0x00000001012fc310) at tsan_rtl_report.cpp:190:16
  frame #14: libclang_rt.tsan_osx_dynamic.dylib`__tsan::ReportRace(thr=0x00000001012fc000, shadow_mem=0x000008020a4340e0, cur=<unavailable>, old=<unavailable>, typ0=1) at tsan_rtl_report.cpp:795:9
  frame #15: libclang_rt.tsan_osx_dynamic.dylib`__tsan::DoReportRace(thr=0x00000001012fc000, shadow_mem=0x000008020a4340e0, cur=Shadow @ x22, old=Shadow @ 0x0000600002d6b4f0, typ=1) at tsan_rtl_access.cpp:166:3
  frame #16: libclang_rt.tsan_osx_dynamic.dylib`::__tsan_read8(void *) at tsan_rtl_access.cpp:220:5
  frame #17: libclang_rt.tsan_osx_dynamic.dylib`::__tsan_read8(void *) [inlined] __tsan::MemoryAccess(thr=0x00000001012fc000, pc=<unavailable>, addr=<unavailable>, size=8, typ=1) at tsan_rtl_access.cpp:442:3
  frame llvm#18: libclang_rt.tsan_osx_dynamic.dylib`::__tsan_read8(addr=<unavailable>) at tsan_interface.inc:34:3
  <call into TSan from from instrumented code>

thread #4, queue = 'com.apple.dock.fullscreen'
  frame #0:  libsystem_kernel.dylib
  frame #1:  libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::FutexWait(p=<unavailable>, cmp=<unavailable>) at sanitizer_mac.cpp:540:3
  frame #2:  libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::Semaphore::Wait(this=<unavailable>) at sanitizer_mutex.cpp:35:7
  frame #3:  libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::Mutex::Lock(this=0x0000000102992a80) at sanitizer_mutex.h:196:18
  frame #4:  libclang_rt.tsan_osx_dynamic.dylib`__tsan::ScopedInterceptor::~ScopedInterceptor() [inlined] __sanitizer::GenericScopedLock<__sanitizer::Mutex>::GenericScopedLock(this=<unavailable>, mu=0x0000000102992a80) at sanitizer_mutex.h:383:10
  frame #5:  libclang_rt.tsan_osx_dynamic.dylib`__tsan::ScopedInterceptor::~ScopedInterceptor() [inlined] __sanitizer::GenericScopedLock<__sanitizer::Mutex>::GenericScopedLock(this=<unavailable>, mu=0x0000000102992a80) at sanitizer_mutex.h:382:77
  frame #6:  libclang_rt.tsan_osx_dynamic.dylib`__tsan::ScopedInterceptor::~ScopedInterceptor() at tsan_rtl.h:708:10
  frame #7:  libclang_rt.tsan_osx_dynamic.dylib`__tsan::ScopedInterceptor::~ScopedInterceptor() [inlined] __tsan::TryTraceFunc(thr=0x000000010f084000, pc=0) at tsan_rtl.h:751:7
  frame #8:  libclang_rt.tsan_osx_dynamic.dylib`__tsan::ScopedInterceptor::~ScopedInterceptor() [inlined] __tsan::FuncExit(thr=0x000000010f084000) at tsan_rtl.h:798:7
  frame #9:  libclang_rt.tsan_osx_dynamic.dylib`__tsan::ScopedInterceptor::~ScopedInterceptor(this=0x000000016f3ba280) at tsan_interceptors_posix.cpp:300:5
  frame #10: libclang_rt.tsan_osx_dynamic.dylib`__tsan::ScopedInterceptor::~ScopedInterceptor(this=<unavailable>) at tsan_interceptors_posix.cpp:293:41
  frame #11: libclang_rt.tsan_osx_dynamic.dylib`::wrap_os_unfair_lock_lock_with_options(lock=0x000000016f21b1e8, options=OS_UNFAIR_LOCK_NONE) at tsan_interceptors_mac.cpp:310:1
  frame #12: dyld`dyld4::RuntimeLocks::withLoadersReadLock(this=0x000000016f21b1e0, work=0x00000001814525d4) block_pointer) at DyldRuntimeState.cpp:227:28
  frame #13: dyld`dyld4::APIs::_dyld_get_image_vmaddr_slide(this=0x0000000101012a20, imageIndex=412) at DyldAPIs.cpp:273:11
  frame #14: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::MemoryMappingLayout::Next(__sanitizer::MemoryMappedSegment*) at sanitizer_procmaps_mac.cpp:286:17
  frame #15: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::MemoryMappingLayout::Next(this=0x000000016f3ba560, segment=0x000000016f3ba498) at sanitizer_procmaps_mac.cpp:432:15
  frame #16: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::MemoryMappingLayout::DumpListOfModules(this=0x000000016f3ba560, modules=0x000000016f3ba618) at sanitizer_procmaps_mac.cpp:460:10
  frame #17: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::ListOfModules::init(this=0x000000016f3ba618) at sanitizer_mac.cpp:610:18
  frame llvm#18: libclang_rt.tsan_osx_dynamic.dylib`__sanitizer::LibIgnore::OnLibraryLoaded(this=0x0000000101f3aa40, name="<some library>") at sanitizer_libignore.cpp:54:11
  frame llvm#19: libclang_rt.tsan_osx_dynamic.dylib`::wrap_dlopen(filename="<some library>", flag=<unavailable>) at sanitizer_common_interceptors.inc:6466:3
  <library code>
```

rdar://106766395

Differential Revision: https://reviews.llvm.org/D146593
definelicht pushed a commit that referenced this pull request May 9, 2023
…callback

The `TypeSystemMap::m_mutex` guards against concurrent modifications
of members of `TypeSystemMap`. In particular, `m_map`.

`TypeSystemMap::ForEach` iterates through the entire `m_map` calling
a user-specified callback for each entry. This is all done while
`m_mutex` is locked. However, there's nothing that guarantees that
the callback itself won't call back into `TypeSystemMap` APIs on the
same thread. This lead to double-locking `m_mutex`, which is undefined
behaviour. We've seen this cause a deadlock in the swift plugin with
following backtrace:

```

int main() {
    std::unique_ptr<int> up = std::make_unique<int>(5);

    volatile int val = *up;
    return val;
}

clang++ -std=c++2a -g -O1 main.cpp

./bin/lldb -o “br se -p return” -o run -o “v *up” -o “expr *up” -b
```

```
frame #4: std::lock_guard<std::mutex>::lock_guard
frame #5: lldb_private::TypeSystemMap::GetTypeSystemForLanguage <<<< Lock #2
frame #6: lldb_private::TypeSystemMap::GetTypeSystemForLanguage
frame #7: lldb_private::Target::GetScratchTypeSystemForLanguage
...
frame llvm#26: lldb_private::SwiftASTContext::LoadLibraryUsingPaths
frame llvm#27: lldb_private::SwiftASTContext::LoadModule
frame llvm#30: swift::ModuleDecl::collectLinkLibraries
frame llvm#31: lldb_private::SwiftASTContext::LoadModule
frame llvm#34: lldb_private::SwiftASTContext::GetCompileUnitImportsImpl
frame llvm#35: lldb_private::SwiftASTContext::PerformCompileUnitImports
frame llvm#36: lldb_private::TypeSystemSwiftTypeRefForExpressions::GetSwiftASTContext
frame llvm#37: lldb_private::TypeSystemSwiftTypeRefForExpressions::GetPersistentExpressionState
frame llvm#38: lldb_private::Target::GetPersistentSymbol
frame llvm#41: lldb_private::TypeSystemMap::ForEach                 <<<< Lock #1
frame llvm#42: lldb_private::Target::GetPersistentSymbol
frame llvm#43: lldb_private::IRExecutionUnit::FindInUserDefinedSymbols
frame llvm#44: lldb_private::IRExecutionUnit::FindSymbol
frame llvm#45: lldb_private::IRExecutionUnit::MemoryManager::GetSymbolAddressAndPresence
frame llvm#46: lldb_private::IRExecutionUnit::MemoryManager::findSymbol
frame llvm#47: non-virtual thunk to lldb_private::IRExecutionUnit::MemoryManager::findSymbol
frame llvm#48: llvm::LinkingSymbolResolver::findSymbol
frame llvm#49: llvm::LegacyJITSymbolResolver::lookup
frame llvm#50: llvm::RuntimeDyldImpl::resolveExternalSymbols
frame llvm#51: llvm::RuntimeDyldImpl::resolveRelocations
frame llvm#52: llvm::MCJIT::finalizeLoadedModules
frame llvm#53: llvm::MCJIT::finalizeObject
frame llvm#54: lldb_private::IRExecutionUnit::ReportAllocations
frame llvm#55: lldb_private::IRExecutionUnit::GetRunnableInfo
frame llvm#56: lldb_private::ClangExpressionParser::PrepareForExecution
frame llvm#57: lldb_private::ClangUserExpression::TryParse
frame llvm#58: lldb_private::ClangUserExpression::Parse
```

Our solution is to simply iterate over a local copy of `m_map`.

**Testing**

* Confirmed on manual reproducer (would reproduce 100% of the time
  before the patch)

Differential Revision: https://reviews.llvm.org/D149949
Dinistro pushed a commit that referenced this pull request May 29, 2023
…llocator_copy for trivial types

See: llvm#61987

Fix suggested by: @philnik and @var-const

Reviewers: philnik, ldionne, EricWF, var-const

Differential Revision: https://reviews.llvm.org/D147741

Testing:
ninja check-cxx check-clang check-llvm

Benchmark Testcases (BM_CopyConstruct, and BM_Assignment) added.

performance improvement:

Run on (8 X 4800 MHz CPU s)
CPU Caches:
  L1 Data 48 KiB (x4)
  L1 Instruction 32 KiB (x4)
  L2 Unified 1280 KiB (x4)
  L3 Unified 12288 KiB (x1)
Load Average: 1.66, 3.02, 2.43

Comparing build-runtimes-base/libcxx/benchmarks/vector_operations.libcxx.out to build-runtimes/libcxx/benchmarks/vector_operations.libcxx.out
Benchmark                                                   Time             CPU      Time Old      Time New       CPU Old       CPU New
----------------------------------------------------------------------------------------------------------------------------------------
BM_ConstructSize/vector_byte/5140480                     +0.0362         +0.0362        116906        121132        116902        121131
BM_CopyConstruct/vector_int/5140480                      -0.4563         -0.4577       1755224        954241       1755330        951987
BM_Assignment/vector_int/5140480                         -0.0222         -0.0220        990045        968095        989917        968125
BM_ConstructSizeValue/vector_byte/5140480                +0.0308         +0.0307        116970        120567        116977        120573
BM_ConstructIterIter/vector_char/1024                    -0.0831         -0.0831            19            17            19            17
BM_ConstructIterIter/vector_size_t/1024                  +0.0129         +0.0131            88            89            88            89
BM_ConstructIterIter/vector_string/1024                  -0.0064         -0.0018         54455         54109         54208         54112
OVERALL_GEOMEAN                                          -0.0845         -0.0842             0             0             0             0

FYI, the perf improvements for BM_CopyConstruct due to this patch is mostly subsumed by the https://reviews.llvm.org/D149826. However this patch still adds value by converting copy to memmove (the second testcase).

Before the patch:

```
define linkonce_odr dso_local void @_ZNSt3__16vectorIiNS_9allocatorIiEEE18__construct_at_endIPiS5_EEvT_T0_m(ptr noundef nonnull align 8 dereferenceable(24) %0, ptr noundef %1, ptr noundef %2, i64 noundef %3) local_unnamed_addr #4 comdat align 2 {
  %5 = getelementptr inbounds %"class.std::__1::vector", ptr %0, i64 0, i32 1
  %6 = load ptr, ptr %5, align 8, !tbaa !12
  %7 = icmp eq ptr %1, %2
  br i1 %7, label %16, label %8

8:                                                ; preds = %4, %8
  %9 = phi ptr [ %13, %8 ], [ %1, %4 ]
  %10 = phi ptr [ %14, %8 ], [ %6, %4 ]
  %11 = icmp ne ptr %10, null
  tail call void @llvm.assume(i1 %11)
  %12 = load i32, ptr %9, align 4, !tbaa !14
  store i32 %12, ptr %10, align 4, !tbaa !14
  %13 = getelementptr inbounds i32, ptr %9, i64 1
  %14 = getelementptr inbounds i32, ptr %10, i64 1
  %15 = icmp eq ptr %13, %2
  br i1 %15, label %16, label %8, !llvm.loop !16

16:                                               ; preds = %8, %4
  %17 = phi ptr [ %6, %4 ], [ %14, %8 ]
  store ptr %17, ptr %5, align 8, !tbaa !12
  ret void
}
```

After the patch:
```
define linkonce_odr dso_local void @_ZNSt3__16vectorIiNS_9allocatorIiEEE18__construct_at_endIPiS5_EEvT_T0_m(ptr noundef nonnull align 8 dereferenceable(24) %0, ptr noundef %1, ptr noundef %2, i64 noundef %3) local_unnamed_addr #4 comdat align 2 {
  %5 = getelementptr inbounds %"class.std::__1::vector", ptr %0, i64 0, i32 1
  %6 = load ptr, ptr %5, align 8, !tbaa !12
  %7 = ptrtoint ptr %2 to i64
  %8 = ptrtoint ptr %1 to i64
  %9 = sub i64 %7, %8
  %10 = ashr exact i64 %9, 2
  tail call void @llvm.memmove.p0.p0.i64(ptr align 4 %6, ptr align 4 %1, i64 %9, i1 false)
  %11 = getelementptr inbounds i32, ptr %6, i64 %10
  store ptr %11, ptr %5, align 8, !tbaa !12
  ret void
}
```

This is due to the optimized version of uninitialized_allocator_copy function.
Dinistro pushed a commit that referenced this pull request May 29, 2023
…est unittest

Need to finalize the DIBuilder to avoid leak sanitizer errors
like this:

Direct leak of 48 byte(s) in 1 object(s) allocated from:
    #0 0x55c99ea1761d in operator new(unsigned long)
    #1 0x55c9a518ae49 in operator new
    #2 0x55c9a518ae49 in llvm::MDTuple::getImpl(...)
    #3 0x55c9a4f1b1ec in getTemporary
    #4 0x55c9a4f1b1ec in llvm::DIBuilder::createFunction(...)
definelicht pushed a commit that referenced this pull request Dec 13, 2023
… on (llvm#74207)

lld string tail merging interacts badly with ASAN on Windows, as is
reported in llvm#62078.
A similar error was found when building LLVM with
`-DLLVM_USE_SANITIZER=Address`:
```console
[2/2] Building GenVT.inc...
FAILED: include/llvm/CodeGen/GenVT.inc C:/Dev/llvm-project/Build_asan/include/llvm/CodeGen/GenVT.inc
cmd.exe /C "cd /D C:\Dev\llvm-project\Build_asan && C:\Dev\llvm-project\Build_asan\bin\llvm-min-tblgen.exe -gen-vt -I C:/Dev/llvm-project/llvm/include/llvm/CodeGen -IC:/Dev/llvm-project/Build_asan/include -IC:/Dev/llvm-project/llvm/include C:/Dev/llvm-project/llvm/include/llvm/CodeGen/ValueTypes.td --write-if-changed -o include/llvm/CodeGen/GenVT.inc -d include/llvm/CodeGen/GenVT.inc.d"       
=================================================================
==31944==ERROR: AddressSanitizer: global-buffer-overflow on address 0x7ff6cff80d20 at pc 0x7ff6cfcc7378 bp 0x00e8bcb8e990 sp 0x00e8bcb8e9d8
READ of size 1 at 0x7ff6cff80d20 thread T0
    #0 0x7ff6cfcc7377 in strlen (C:\Dev\llvm-project\Build_asan\bin\llvm-min-tblgen.exe+0x1400a7377)
    #1 0x7ff6cfde50c2 in operator delete(void *, unsigned __int64) (C:\Dev\llvm-project\Build_asan\bin\llvm-min-tblgen.exe+0x1401c50c2)
    #2 0x7ff6cfdd75ef in operator delete(void *, unsigned __int64) (C:\Dev\llvm-project\Build_asan\bin\llvm-min-tblgen.exe+0x1401b75ef)
    #3 0x7ff6cfde59f9 in operator delete(void *, unsigned __int64) (C:\Dev\llvm-project\Build_asan\bin\llvm-min-tblgen.exe+0x1401c59f9)
    #4 0x7ff6cff03f6c in operator delete(void *, unsigned __int64) (C:\Dev\llvm-project\Build_asan\bin\llvm-min-tblgen.exe+0x1402e3f6c)
    #5 0x7ff6cfefbcbc in operator delete(void *, unsigned __int64) (C:\Dev\llvm-project\Build_asan\bin\llvm-min-tblgen.exe+0x1402dbcbc)
    #6 0x7ffb7f247343  (C:\WINDOWS\System32\KERNEL32.DLL+0x180017343)
    #7 0x7ffb800826b0  (C:\WINDOWS\SYSTEM32\ntdll.dll+0x1800526b0)

0x7ff6cff80d20 is located 31 bytes after global variable '"#error \"ArgKind is not defined\"\n"...' defined in 'C:\Dev\llvm-project\llvm\utils\TableGen\IntrinsicEmitter.cpp' (0x7ff6cff80ce0) of size 33
  '"#error \"ArgKind is not defined\"\n"...' is ascii string '#error "ArgKind is not defined"
'
0x7ff6cff80d20 is located 0 bytes inside of global variable '""' defined in 'C:\Dev\llvm-project\llvm\utils\TableGen\IntrinsicEmitter.cpp' (0x7ff6cff80d20) of size 1
  '""' is ascii string ''
SUMMARY: AddressSanitizer: global-buffer-overflow (C:\Dev\llvm-project\Build_asan\bin\llvm-min-tblgen.exe+0x1400a7377) in strlen
Shadow bytes around the buggy address:
  0x7ff6cff80a80: 01 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 01 f9 f9 f9
  0x7ff6cff80b00: f9 f9 f9 f9 00 00 00 00 00 00 00 00 01 f9 f9 f9
  0x7ff6cff80b80: f9 f9 f9 f9 00 00 00 00 01 f9 f9 f9 f9 f9 f9 f9
  0x7ff6cff80c00: 00 00 00 00 01 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
  0x7ff6cff80c80: 00 00 00 00 01 f9 f9 f9 f9 f9 f9 f9 00 00 00 00
=>0x7ff6cff80d00: 01 f9 f9 f9[f9]f9 f9 f9 00 00 00 00 00 00 00 00
  0x7ff6cff80d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7ff6cff80e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7ff6cff80e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7ff6cff80f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7ff6cff80f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==31944==ABORTING
```
This is reproducible with the 17.0.3 release:
```console
$ clang-cl --version
clang version 17.0.3
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: C:\Program Files\LLVM\bin
$ cmake -S llvm -B Build -G Ninja -DLLVM_USE_SANITIZER=Address -DCMAKE_C_COMPILER=clang-cl -DCMAKE_CXX_COMPILER=clang-cl -DCMAKE_MSVC_RUNTIME_LIBRARY=MultiThreaded -DCMAKE_BUILD_TYPE=Release
$ cd Build
$ ninja all
```
definelicht pushed a commit that referenced this pull request Jan 5, 2024
This has been flaky for a while, for example
https://lab.llvm.org/buildbot/#/builders/96/builds/50350

```
Command Output (stdout):
--
lldb version 18.0.0git (https://github.com/llvm/llvm-project.git revision 3974d89)
  clang revision 3974d89
  llvm revision 3974d89
"can't evaluate expressions when the process is running."
```

```
  PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
   #0 0x0000ffffa46191a0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x529a1a0)
   #1 0x0000ffffa4617144 llvm::sys::RunSignalHandlers() (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x5298144)
   #2 0x0000ffffa46198d0 SignalHandler(int) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x529a8d0)
   #3 0x0000ffffab25b7dc (linux-vdso.so.1+0x7dc)
   #4 0x0000ffffab13d050 /build/glibc-Q8DG8B/glibc-2.31/string/../sysdeps/aarch64/multiarch/memcpy_advsimd.S:92:0
   #5 0x0000ffffa446f420 lldb_private::process_gdb_remote::GDBRemoteRegisterContext::PrivateSetRegisterValue(unsigned int, llvm::ArrayRef<unsigned char>) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x50f0420)
   #6 0x0000ffffa446f7b8 lldb_private::process_gdb_remote::GDBRemoteRegisterContext::GetPrimordialRegister(lldb_private::RegisterInfo const*, lldb_private::process_gdb_remote::GDBRemoteCommunicationClient&) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x50f07b8)
   #7 0x0000ffffa446f308 lldb_private::process_gdb_remote::GDBRemoteRegisterContext::ReadRegisterBytes(lldb_private::RegisterInfo const*) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x50f0308)
   #8 0x0000ffffa446ec1c lldb_private::process_gdb_remote::GDBRemoteRegisterContext::ReadRegister(lldb_private::RegisterInfo const*, lldb_private::RegisterValue&) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x50efc1c)
   #9 0x0000ffffa412eaa4 lldb_private::RegisterContext::ReadRegisterAsUnsigned(lldb_private::RegisterInfo const*, unsigned long) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x4dafaa4)
  #10 0x0000ffffa420861c ReadLinuxProcessAddressMask(std::shared_ptr<lldb_private::Process>, llvm::StringRef) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x4e8961c)
  #11 0x0000ffffa4208430 ABISysV_arm64::FixCodeAddress(unsigned long) (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lib/python3.8/site-packages/lldb/_lldb.cpython-38-aarch64-linux-gnu.so+0x4e89430)
```

Judging by the backtrace something is trying to read the pointer authentication address/code mask
registers. This explains why I've not seen this issue locally, as the buildbot runs on Graviton
3 with has the pointer authentication extension.

I will try to reproduce, fix and re-enable the test.
definelicht pushed a commit that referenced this pull request Jan 18, 2024
…vm#75394)

Calling one of pthread join/detach interceptor on an already
joined/detached thread causes asserts such as:

AddressSanitizer: CHECK failed: sanitizer_thread_arg_retval.cpp:56
"((t)) != (0)" (0x0, 0x0) (tid=1236094)
#0 0x555555634f8b in __asan::CheckUnwind()
compiler-rt/lib/asan/asan_rtl.cpp:69:3
#1 0x55555564e06e in __sanitizer::CheckFailed(char const*, int, char
const*, unsigned long long, unsigned long long)
compiler-rt/lib/sanitizer_common/sanitizer_termination.cpp:86:24
#2 0x5555556491df in __sanitizer::ThreadArgRetval::BeforeJoin(unsigned
long) const
compiler-rt/lib/sanitizer_common/sanitizer_thread_arg_retval.cpp:56:3
#3 0x5555556198ed in Join<___interceptor_pthread_tryjoin_np(void*,
void**)::<lambda()> >
compiler-rt/lib/asan/../sanitizer_common/sanitizer_thread_arg_retval.h:74:26
#4 0x5555556198ed in pthread_tryjoin_np
compiler-rt/lib/asan/asan_interceptors.cpp:311:29

The assert are replaced by error codes.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

Successfully merging this pull request may close these issues.

3 participants