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This commit purges direct accesses to MD_prof metadata and replaces them with the accessors provided from the utility file wherever possible.

@Dinistro Dinistro requested review from definelicht and gysit January 10, 2023 15:55
@Dinistro Dinistro force-pushed the purge-custom-prof-accessors branch 3 times, most recently from 7c7ce72 to 86a8234 Compare January 10, 2023 16:20
@Dinistro Dinistro force-pushed the purge-custom-prof-accessors branch 2 times, most recently from 24019cc to 072f8a8 Compare January 10, 2023 16:42
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Looks good, this is a good change. Obviously I can't tell if you found every possible location 🙂

@Dinistro Dinistro force-pushed the purge-custom-prof-accessors branch from 072f8a8 to 66efa16 Compare January 11, 2023 10:57
This commit purges direct accesses to MD_prof metadata and replaces them
with the accessors provided from the utility file wherever possible.
This commit can be seen as the first step towards switching the branch weights to 64 bits.
See post here: https://discourse.llvm.org/t/extend-md-prof-branch-weights-metadata-from-32-to-64-bits/67492

Differential Revision: https://reviews.llvm.org/D141393
@Dinistro Dinistro force-pushed the purge-custom-prof-accessors branch from 66efa16 to 374641d Compare January 11, 2023 12:00
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Closing this, as the revision was already opened: https://reviews.llvm.org/D141393

@Dinistro Dinistro closed this Jan 11, 2023
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
definelicht pushed a commit that referenced this pull request Jan 27, 2023
Change https://reviews.llvm.org/D140059 exposed the following crash in
Z3Solver, where bit widths were not checked consistently with that
change. This change makes the check consistent, and fixes the crash.

```
clang: <root>/llvm/include/llvm/ADT/APSInt.h:99:
  int64_t llvm::APSInt::getExtValue() const: Assertion
  `isRepresentableByInt64() && "Too many bits for int64_t"' failed.
...
Stack dump:
0. Program arguments: clang -cc1 -internal-isystem <root>/lib/clang/16/include
  -nostdsysteminc -analyze -analyzer-checker=core,unix.Malloc,debug.ExprInspection
  -analyzer-config crosscheck-with-z3=true -verify reproducer.c

 #0 0x00000000045b3476 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int)
  <root>/llvm/lib/Support/Unix/Signals.inc:567:22
 #1 0x00000000045b3862 PrintStackTraceSignalHandler(void*)
  <root>/llvm/lib/Support/Unix/Signals.inc:641:1
 #2 0x00000000045b14a5 llvm::sys::RunSignalHandlers()
  <root>/llvm/lib/Support/Signals.cpp:104:20
 #3 0x00000000045b2eb4 SignalHandler(int)
  <root>/llvm/lib/Support/Unix/Signals.inc:412:1
 ...
 #9 0x0000000004be2eb3 llvm::APSInt::getExtValue() const
  <root>/llvm/include/llvm/ADT/APSInt.h:99:5
  <root>/llvm/lib/Support/Z3Solver.cpp:740:53
  clang::ASTContext&, clang::ento::SymExpr const*, llvm::APSInt const&, llvm::APSInt const&, bool)
  <root>/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConv.h:552:61
```

Reviewed By: steakhal

Differential Revision: https://reviews.llvm.org/D142627
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
Dinistro pushed a commit that referenced this pull request Feb 6, 2023
… -analyzer-config

I am working on another patch that changes StringMap's hash function,
which changes the iteration order here, and breaks some tests,
specifically:

    clang/test/Analysis/NSString.m
    clang/test/Analysis/shallow-mode.m

with errors like:

    generated arguments do not match in round-trip
    generated arguments #1 in round-trip: <...> "-analyzer-config" "ipa=inlining" "-analyzer-config" "max-nodes=75000" <...>
    generated arguments #2 in round-trip: <...> "-analyzer-config" "max-nodes=75000" "-analyzer-config" "ipa=inlining" <...>

To avoid this, sort the options by key, instead of using the default map
iteration order.

Reviewed By: jansvoboda11, MaskRay

Differential Revision: https://reviews.llvm.org/D142861
gysit pushed a commit that referenced this pull request Mar 8, 2023
For example, if you have a chain of inlined funtions like this:

   1 #include <stdlib.h>
   2 int g1 = 4, g2 = 6;
   3
   4 static inline void bar(int q) {
   5   if (q > 5)
   6     abort();
   7 }
   8
   9 static inline void foo(int q) {
  10   bar(q);
  11 }
  12
  13 int main() {
  14   foo(g1);
  15   foo(g2);
  16   return 0;
  17 }

with optimizations you could end up with a single abort call for the two
inlined instances of foo(). When merging the locations for those inlined
instances you would previously end up with a 0:0 location in main().
Leaving out that inlined chain from the location for the abort call
could make troubleshooting difficult in some cases.

This patch changes DILocation::getMergedLocation() to try to handle such
cases. The function is rewritten to first find a common starting point
for the two locations (same subprogram and inlined-at location), and
then in reverse traverses the inlined-at chain looking for matches in
each subprogram. For each subprogram, the merge function will find the
nearest common scope for the two locations, and matching line and
column (or set them to 0 if not matching).

In the example above, you will for the abort call get a location in
bar() at 6:5, inlined in foo() at 10:3, inlined in main() at 0:0 (since
the two inlined functions are on different lines, but in the same
scope).

I have not seen anything in the DWARF standard that would disallow
inlining a non-zero location at 0:0 in the inlined-at function, and both
LLDB and GDB seem to accept these locations (with D142552 needed for
LLDB to handle cases where the file, line and column number are all 0).
One incompatibility with GDB is that it seems to ignore 0-line locations
in some cases, but I am not aware of any specific issue that this patch
produces related to that.

With x86-64 LLDB (trunk) you previously got:

  frame #0: 0x00007ffff7a44930 libc.so.6`abort
  frame #1: 0x00005555555546ec a.out`main at merge.c:0

and will now get:

  frame #0: 0x[...] libc.so.6`abort
  frame #1: 0x[...] a.out`main [inlined] bar(q=<unavailable>) at merge.c:6:5
  frame #2: 0x[...] a.out`main [inlined] foo(q=<unavailable>) at merge.c:10:3
  frame #3: 0x[...] a.out`main at merge.c:0

and with x86-64 GDB (11.1) you will get:

  (gdb) bt
  #0  0x00007ffff7a44930 in abort () from /lib64/libc.so.6
  #1  0x00005555555546ec in bar (q=<optimized out>) at merge.c:6
  #2  foo (q=<optimized out>) at merge.c:10
  #3  0x00005555555546ec in main ()

Reviewed By: aprantl, dblaikie

Differential Revision: https://reviews.llvm.org/D142556
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
…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(...)
Dinistro pushed a commit that referenced this pull request May 29, 2023
The motivation for this change is a workload generated by the XLA compiler
targeting nvidia GPUs.

This kernel has a few hundred i8 loads and stores.  Merging is critical for
performance.

The current LSV doesn't merge these well because it only considers instructions
within a block of 64 loads+stores.  This limit is necessary to contain the
O(n^2) behavior of the pass.  I'm hesitant to increase the limit, because this
pass is already one of the slowest parts of compiling an XLA program.

So we rewrite basically the whole thing to use a new algorithm.  Before, we
compared every load/store to every other to see if they're consecutive.  The
insight (from tra@) is that this is redundant.  If we know the offset from PtrA
to PtrB, then we don't need to compare PtrC to both of them in order to tell
whether C may be adjacent to A or B.

So that's what we do.  When scanning a basic block, we maintain a list of
chains, where we know the offset from every element in the chain to the first
element in the chain.  Each instruction gets compared only to the leaders of
all the chains.

In the worst case, this is still O(n^2), because all chains might be of length
1.  To prevent compile time blowup, we only consider the 64 most recently used
chains.  Thus we do no more comparisons than before, but we have the potential
to make much longer chains.

This rewrite affects many tests.  The changes to tests fall into two
categories.

1. The old code had what appears to be a bug when deciding whether a misaligned
   vectorized load is fast.  Suppose TTI reports that load <i32 x 4> align 4
   has relative speed 1, and suppose that load i32 align 4 has relative speed
   32.

   The intent of the code seems to be that we prefer the scalar load, because
   it's faster.  But the old code would choose the vectorized load.
   accessIsMisaligned would set RelativeSpeed to 0 for the scalar load (and not
   even call into TTI to get the relative speed), because the scalar load is
   aligned.

   After this patch, we will prefer the scalar load if it's faster.

2. This patch changes the logic for how we vectorize.  Usually this results in
   vectorizing more.

Explanation of changes to tests:

 - AMDGPU/adjust-alloca-alignment.ll: #1
 - AMDGPU/flat_atomic.ll: #2, we vectorize more.
 - AMDGPU/int_sideeffect.ll: #2, there are two possible locations for the call to @foo, and the pass is brittle to this.  Before, we'd vectorize in case 1 and not case 2.  Now we vectorize in case 2 and not case 1.  So we just move the call.
 - AMDGPU/adjust-alloca-alignment.ll: #2, we vectorize more
 - AMDGPU/insertion-point.ll: #2 we vectorize more
 - AMDGPU/merge-stores-private.ll: #1 (undoes changes from git rev 86f9117, which appear to have hit the bug from #1)
 - AMDGPU/multiple_tails.ll: #1
 - AMDGPU/vect-ptr-ptr-size-mismatch.ll: Fix alignment (I think related to #1 above).
 - AMDGPU CodeGen: I have difficulty commenting on these changes, but many of them look like #2, we vectorize more.
 - NVPTX/4x2xhalf.ll: Fix alignment (I think related to #1 above).
 - NVPTX/vectorize_i8.ll: We don't generate <3 x i8> vectors on NVPTX because they're not legal (and eventually get split)
 - X86/correct-order.ll: #2, we vectorize more, probably because of changes to the chain-splitting logic.
 - X86/subchain-interleaved.ll: #2, we vectorize more
 - X86/vector-scalar.ll: #2, we can now vectorize scalar float + <1 x float>
 - X86/vectorize-i8-nested-add-inseltpoison.ll: Deleted the nuw test because it was nonsensical.  It was doing `add nuw %v0, -1`, but this is equivalent to `add nuw %v0, 0xffff'ffff`, which is equivalent to asserting that %v0 == 0.
 - X86/vectorize-i8-nested-add.ll: Same as nested-add-inseltpoison.ll

Differential Revision: https://reviews.llvm.org/D149893
definelicht pushed a commit that referenced this pull request Jul 26, 2023
ParmVarDecl of BlockDecl is unnecessarily dumped twice.
Remove this duplication as other FunctionDecls.

Fixes llvm#64005 (#2)

Differential Revision: https://reviews.llvm.org/D155985
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.
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