[lldb-dev] Process::SyncIOHandler(), everyone please try out the following patch

Ryan Brown ribrdb at google.com
Thu May 14 16:59:44 PDT 2015 

I just built lldb with tsan. The tests don't seem to work because python
can't find tsan, but a quick debugging session found a few issues:

WARNING: ThreadSanitizer: data race (pid=64299)
  Write of size 1 at 0x7d4400004bb0 by thread T6:
    #0 lldb_private::IOHandler::SetIsDone(bool)
tools/lldb/include/lldb/Core/IOHandler.h:107
    #1 lldb_private::Process::PushProcessIOHandler()
tools/lldb/source/Target/Process.cpp:5279
    #2
lldb_private::Process::HandlePrivateEvent(std::shared_ptr<lldb_private::Event>&)
tools/lldb/source/Target/Process.cpp:4443
    #3 lldb_private::Process::RunPrivateStateThread()
tools/lldb/source/Target/Process.cpp:4581
    #4 lldb_private::Process::PrivateStateThread(void*)
tools/lldb/source/Target/Process.cpp:4505
    #5 lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81

  Previous write of size 1 at 0x7d4400004bb0 by main thread:
    #0 lldb_private::IOHandler::SetIsDone(bool)
tools/lldb/include/lldb/Core/IOHandler.h:107
    #1 IOHandlerProcessSTDIO::Run()
tools/lldb/source/Target/Process.cpp:5096
    #2 lldb_private::Debugger::ExecuteIOHandlers()
tools/lldb/source/Core/Debugger.cpp:907
    #3 lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool,
lldb_private::CommandInterpreterRunOptions&)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
    #4 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
tools/lldb/source/API/SBDebugger.cpp:980
    #5 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
    #6 main tools/lldb/tools/driver/Driver.cpp:1252

==================
WARNING: ThreadSanitizer: lock-order-inversion (potential deadlock)
(pid=64299)
  Cycle in lock order graph: M31728 (0x7d1000019e58) => M564
(0x7d680001d0f8) => M31728

  Mutex M564 acquired here while holding mutex M31728 in main thread:
    #3 Locker tools/lldb/source/Host/common/Mutex.cpp:114
    #4
lldb_private::ModuleList::FindSymbolsWithNameAndType(lldb_private::ConstString
const&, lldb::SymbolType, lldb_private::SymbolContextList&, bool) const
tools/lldb/source/Core/ModuleList.cpp:565
    #5 JITLoaderGDB::GetSymbolAddress(lldb_private::ModuleList&,
lldb_private::ConstString const&, lldb::SymbolType) const
tools/lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp:432
    #6 JITLoaderGDB::SetJITBreakpoint(lldb_private::ModuleList&)
tools/lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp:109
    #7 JITLoaderGDB::DidLaunch()
tools/lldb/source/Plugins/JITLoader/GDB/JITLoaderGDB.cpp:84
    #8 lldb_private::JITLoaderList::DidLaunch()
tools/lldb/source/Target/JITLoaderList.cpp:60
    #9 lldb_private::Process::Launch(lldb_private::ProcessLaunchInfo&)
tools/lldb/source/Target/Process.cpp:3177
    #10
lldb_private::platform_linux::PlatformLinux::DebugProcess(lldb_private::ProcessLaunchInfo&,
lldb_private::Debugger&, lldb_private::Target*, lldb_private::Error&)
tools/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp:805
    #11 lldb_private::Target::Launch(lldb_private::ProcessLaunchInfo&,
lldb_private::Stream*) tools/lldb/source/Target/Target.cpp:2602
    #12 CommandObjectProcessLaunch::DoExecute(lldb_private::Args&,
lldb_private::CommandReturnObject&)
tools/lldb/source/Commands/CommandObjectProcess.cpp:263
    #13 lldb_private::CommandObjectParsed::Execute(char const*,
lldb_private::CommandReturnObject&)
tools/lldb/source/Interpreter/CommandObject.cpp:1075
    #14 lldb_private::CommandInterpreter::HandleCommand(char const*,
lldb_private::LazyBool, lldb_private::CommandReturnObject&,
lldb_private::ExecutionContext*, bool, bool)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:1812
    #15
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
    #16 non-virtual thunk to
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
    #17 lldb_private::IOHandlerEditline::Run()
tools/lldb/source/Core/IOHandler.cpp:729
    #18 lldb_private::Debugger::ExecuteIOHandlers()
tools/lldb/source/Core/Debugger.cpp:907
    #19 lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool,
lldb_private::CommandInterpreterRunOptions&)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
    #20 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
tools/lldb/source/API/SBDebugger.cpp:980
    #21 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
    #22 main tools/lldb/tools/driver/Driver.cpp:1252

  Mutex M31728 previously acquired by the same thread here:
    #3 Locker tools/lldb/source/Host/common/Mutex.cpp:114
    #4 lldb_private::JITLoaderList::DidLaunch()
tools/lldb/source/Target/JITLoaderList.cpp:58
    #5 lldb_private::Process::Launch(lldb_private::ProcessLaunchInfo&)
tools/lldb/source/Target/Process.cpp:3177
    #6
lldb_private::platform_linux::PlatformLinux::DebugProcess(lldb_private::ProcessLaunchInfo&,
lldb_private::Debugger&, lldb_private::Target*, lldb_private::Error&)
tools/lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp:805
    #7 lldb_private::Target::Launch(lldb_private::ProcessLaunchInfo&,
lldb_private::Stream*) tools/lldb/source/Target/Target.cpp:2602
    #8 CommandObjectProcessLaunch::DoExecute(lldb_private::Args&,
lldb_private::CommandReturnObject&)
tools/lldb/source/Commands/CommandObjectProcess.cpp:263
    #9 lldb_private::CommandObjectParsed::Execute(char const*,
lldb_private::CommandReturnObject&)
tools/lldb/source/Interpreter/CommandObject.cpp:1075
    #10 lldb_private::CommandInterpreter::HandleCommand(char const*,
lldb_private::LazyBool, lldb_private::CommandReturnObject&,
lldb_private::ExecutionContext*, bool, bool)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:1812
    #11
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
    #12 non-virtual thunk to
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
    #13 lldb_private::IOHandlerEditline::Run()
tools/lldb/source/Core/IOHandler.cpp:729
    #14 lldb_private::Debugger::ExecuteIOHandlers()
tools/lldb/source/Core/Debugger.cpp:907
    #15 lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool,
lldb_private::CommandInterpreterRunOptions&)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
    #16 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
tools/lldb/source/API/SBDebugger.cpp:980
    #17 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
    #18 main tools/lldb/tools/driver/Driver.cpp:1252

  Mutex M31728 acquired here while holding mutex M564 in thread T6:
    #3 Locker tools/lldb/source/Host/common/Mutex.cpp:114
    #4
lldb_private::JITLoaderList::ModulesDidLoad(lldb_private::ModuleList&)
tools/lldb/source/Target/JITLoaderList.cpp:74
    #5 lldb_private::Process::ModulesDidLoad(lldb_private::ModuleList&)
tools/lldb/source/Target/Process.cpp:6466
    #6 lldb_private::Target::ModulesDidLoad(lldb_private::ModuleList&)
tools/lldb/source/Target/Target.cpp:1286
    #7 lldb_private::Target::ModuleAdded(lldb_private::ModuleList const&,
std::shared_ptr<lldb_private::Module> const&)
tools/lldb/source/Target/Target.cpp:1254
    #8 non-virtual thunk to
lldb_private::Target::ModuleAdded(lldb_private::ModuleList const&,
std::shared_ptr<lldb_private::Module> const&)
tools/lldb/source/Target/Target.cpp:1256
    #9
lldb_private::ModuleList::AppendImpl(std::shared_ptr<lldb_private::Module>
const&, bool) tools/lldb/source/Core/ModuleList.cpp:111
    #10
lldb_private::ModuleList::Append(std::shared_ptr<lldb_private::Module>
const&) tools/lldb/source/Core/ModuleList.cpp:118
    #11 lldb_private::Target::GetSharedModule(lldb_private::ModuleSpec
const&, lldb_private::Error*) tools/lldb/source/Target/Target.cpp:1810
    #12
lldb_private::DynamicLoader::LoadModuleAtAddress(lldb_private::FileSpec
const&, unsigned long, unsigned long)
tools/lldb/source/Core/DynamicLoader.cpp:185
    #13 DynamicLoaderPOSIXDYLD::LoadAllCurrentModules()
tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:530
    #14 DynamicLoaderPOSIXDYLD::EntryBreakpointHit(void*,
lldb_private::StoppointCallbackContext*, unsigned long, unsigned long)
tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:343
    #15
lldb_private::BreakpointOptions::InvokeCallback(lldb_private::StoppointCallbackContext*,
unsigned long, unsigned long)
tools/lldb/source/Breakpoint/BreakpointOptions.cpp:147
    #16
lldb_private::Breakpoint::InvokeCallback(lldb_private::StoppointCallbackContext*,
int) tools/lldb/source/Breakpoint/Breakpoint.cpp:345
    #17
lldb_private::BreakpointLocation::InvokeCallback(lldb_private::StoppointCallbackContext*)
tools/lldb/source/Breakpoint/BreakpointLocation.cpp:222
    #18
lldb_private::BreakpointLocation::ShouldStop(lldb_private::StoppointCallbackContext*)
tools/lldb/source/Breakpoint/BreakpointLocation.cpp:465
    #19
lldb_private::BreakpointLocationCollection::ShouldStop(lldb_private::StoppointCallbackContext*)
tools/lldb/source/Breakpoint/BreakpointLocationCollection.cpp:144
    #20
lldb_private::BreakpointSite::ShouldStop(lldb_private::StoppointCallbackContext*)
tools/lldb/source/Breakpoint/BreakpointSite.cpp:69
    #21
lldb_private::StopInfoBreakpoint::ShouldStopSynchronous(lldb_private::Event*)
tools/lldb/source/Target/StopInfo.cpp:200
    #22 lldb_private::Thread::ShouldStop(lldb_private::Event*)
tools/lldb/source/Target/Thread.cpp:845
    #23 lldb_private::ThreadList::ShouldStop(lldb_private::Event*)
tools/lldb/source/Target/ThreadList.cpp:318
    #24 lldb_private::Process::ShouldBroadcastEvent(lldb_private::Event*)
tools/lldb/source/Target/Process.cpp:4181
    #25
lldb_private::Process::HandlePrivateEvent(std::shared_ptr<lldb_private::Event>&)
tools/lldb/source/Target/Process.cpp:4422
    #26 lldb_private::Process::RunPrivateStateThread()
tools/lldb/source/Target/Process.cpp:4581
    #27 lldb_private::Process::PrivateStateThread(void*)
tools/lldb/source/Target/Process.cpp:4505
    #28 lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81

  Mutex M564 previously acquired by the same thread here:
    #3 Locker tools/lldb/source/Host/common/Mutex.cpp:114
    #4
lldb_private::ModuleList::AppendImpl(std::shared_ptr<lldb_private::Module>
const&, bool) tools/lldb/source/Core/ModuleList.cpp:108
    #5
lldb_private::ModuleList::Append(std::shared_ptr<lldb_private::Module>
const&) tools/lldb/source/Core/ModuleList.cpp:118
    #6 lldb_private::Target::GetSharedModule(lldb_private::ModuleSpec
const&, lldb_private::Error*) tools/lldb/source/Target/Target.cpp:1810
    #7
lldb_private::DynamicLoader::LoadModuleAtAddress(lldb_private::FileSpec
const&, unsigned long, unsigned long)
tools/lldb/source/Core/DynamicLoader.cpp:185
    #8 DynamicLoaderPOSIXDYLD::LoadAllCurrentModules()
tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:530
    #9 DynamicLoaderPOSIXDYLD::EntryBreakpointHit(void*,
lldb_private::StoppointCallbackContext*, unsigned long, unsigned long)
tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp:343
    #10
lldb_private::BreakpointOptions::InvokeCallback(lldb_private::StoppointCallbackContext*,
unsigned long, unsigned long)
tools/lldb/source/Breakpoint/BreakpointOptions.cpp:147
    #11
lldb_private::Breakpoint::InvokeCallback(lldb_private::StoppointCallbackContext*,
int) tools/lldb/source/Breakpoint/Breakpoint.cpp:345
    #12
lldb_private::BreakpointLocation::InvokeCallback(lldb_private::StoppointCallbackContext*)
tools/lldb/source/Breakpoint/BreakpointLocation.cpp:222
    #13
lldb_private::BreakpointLocation::ShouldStop(lldb_private::StoppointCallbackContext*)
tools/lldb/source/Breakpoint/BreakpointLocation.cpp:465
    #14
lldb_private::BreakpointLocationCollection::ShouldStop(lldb_private::StoppointCallbackContext*)
tools/lldb/source/Breakpoint/BreakpointLocationCollection.cpp:144
    #15
lldb_private::BreakpointSite::ShouldStop(lldb_private::StoppointCallbackContext*)
tools/lldb/source/Breakpoint/BreakpointSite.cpp:69
    #16
lldb_private::StopInfoBreakpoint::ShouldStopSynchronous(lldb_private::Event*)
tools/lldb/source/Target/StopInfo.cpp:200
    #17 lldb_private::Thread::ShouldStop(lldb_private::Event*)
tools/lldb/source/Target/Thread.cpp:845
    #18 lldb_private::ThreadList::ShouldStop(lldb_private::Event*)
tools/lldb/source/Target/ThreadList.cpp:318
    #19 lldb_private::Process::ShouldBroadcastEvent(lldb_private::Event*)
tools/lldb/source/Target/Process.cpp:4181
    #20
lldb_private::Process::HandlePrivateEvent(std::shared_ptr<lldb_private::Event>&)
tools/lldb/source/Target/Process.cpp:4422
    #21 lldb_private::Process::RunPrivateStateThread()
tools/lldb/source/Target/Process.cpp:4581
    #22 lldb_private::Process::PrivateStateThread(void*)
tools/lldb/source/Target/Process.cpp:4505
    #23 lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81

==================
WARNING: ThreadSanitizer: data race (pid=64299)
  Write of size 1 at 0x7d4400004bb1 by thread T2 (mutexes: write M168):
    #0 lldb_private::IOHandler::Deactivate()
tools/lldb/include/lldb/Core/IOHandler.h:131
    #1
lldb_private::Debugger::PopIOHandler(std::shared_ptr<lldb_private::IOHandler>
const&) tools/lldb/source/Core/Debugger.cpp:1064
    #2 lldb_private::Process::PopProcessIOHandler()
tools/lldb/source/Target/Process.cpp:5291
    #3
lldb_private::Debugger::HandleProcessEvent(std::shared_ptr<lldb_private::Event>
const&) tools/lldb/source/Core/Debugger.cpp:1544
    #4 lldb_private::Debugger::DefaultEventHandler()
tools/lldb/source/Core/Debugger.cpp:1634
    #5 lldb_private::Debugger::EventHandlerThread(void*)
tools/lldb/source/Core/Debugger.cpp:1696
    #6 lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81

  Previous write of size 1 at 0x7d4400004bb1 by main thread:
    #0 lldb_private::IOHandler::Activate()
tools/lldb/include/lldb/Core/IOHandler.h:125
    #1 lldb_private::Debugger::ExecuteIOHandlers()
tools/lldb/source/Core/Debugger.cpp:906
    #2 lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool,
lldb_private::CommandInterpreterRunOptions&)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
    #3 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
tools/lldb/source/API/SBDebugger.cpp:980
    #4 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
    #5 main tools/lldb/tools/driver/Driver.cpp:1252

==================
WARNING: ThreadSanitizer: data race (pid=64299)
  Read of size 8 at 0x7da0000080c0 by thread T2 (mutexes: write M168):
    #0 write <null>:0
    #1 operator() tools/lldb/source/Host/posix/PipePosix.cpp:416
    #2 std::_Function_handler<lldb_private::Error (bool&),
lldb_private::PipePosix::Write(void const*, unsigned long, unsigned
long&)::$_1>::_M_invoke(std::_Any_data const&, bool&)
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/functional:2056
    #3 std::function<lldb_private::Error (bool&)>::operator()(bool&) const
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/functional:2464
    #4 (anonymous namespace)::SelectIO(int, bool,
std::function<lldb_private::Error (bool&)> const&,
std::chrono::duration<long, std::ratio<1l, 1000000l> > const&)
tools/lldb/source/Host/posix/PipePosix.cpp:118
    #5 lldb_private::PipePosix::Write(void const*, unsigned long, unsigned
long&) tools/lldb/source/Host/posix/PipePosix.cpp:411
    #6 IOHandlerProcessSTDIO::Cancel()
tools/lldb/source/Target/Process.cpp:5192
    #7
lldb_private::Debugger::PopIOHandler(std::shared_ptr<lldb_private::IOHandler>
const&) tools/lldb/source/Core/Debugger.cpp:1065
    #8 lldb_private::Process::PopProcessIOHandler()
tools/lldb/source/Target/Process.cpp:5291
    #9
lldb_private::Debugger::HandleProcessEvent(std::shared_ptr<lldb_private::Event>
const&) tools/lldb/source/Core/Debugger.cpp:1544
    #10 lldb_private::Debugger::DefaultEventHandler()
tools/lldb/source/Core/Debugger.cpp:1634
    #11 lldb_private::Debugger::EventHandlerThread(void*)
tools/lldb/source/Core/Debugger.cpp:1696
    #12 lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81

  Previous write of size 8 at 0x7da0000080c0 by main thread:
    #0 pipe2 <null>:0
    #1 lldb_private::PipePosix::CreateNew(bool)
tools/lldb/source/Host/posix/PipePosix.cpp:168
    #2 IOHandlerProcessSTDIO::OpenPipes()
tools/lldb/source/Target/Process.cpp:5078
    #3 IOHandlerProcessSTDIO::Run()
tools/lldb/source/Target/Process.cpp:5097
    #4 lldb_private::Debugger::ExecuteIOHandlers()
tools/lldb/source/Core/Debugger.cpp:907
    #5 lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool,
lldb_private::CommandInterpreterRunOptions&)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
    #6 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
tools/lldb/source/API/SBDebugger.cpp:980
    #7 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
    #8 main tools/lldb/tools/driver/Driver.cpp:1252

  Location is file descriptor 12 created by main thread at:
    #0 pipe2 <null>:0
    #1 lldb_private::PipePosix::CreateNew(bool)
tools/lldb/source/Host/posix/PipePosix.cpp:168
    #2 IOHandlerProcessSTDIO::OpenPipes()
tools/lldb/source/Target/Process.cpp:5078
    #3 IOHandlerProcessSTDIO::Run()
tools/lldb/source/Target/Process.cpp:5097
    #4 lldb_private::Debugger::ExecuteIOHandlers()
tools/lldb/source/Core/Debugger.cpp:907
    #5 lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool,
lldb_private::CommandInterpreterRunOptions&)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
    #6 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
tools/lldb/source/API/SBDebugger.cpp:980
    #7 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
    #8 main tools/lldb/tools/driver/Driver.cpp:1252

==================
WARNING: ThreadSanitizer: data race (pid=64299)
  Read of size 8 at 0x7d080001a5c8 by main thread:
    #0 lldb_private::HostNativeThreadBase::GetSystemHandle() const
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:35
    #1 lldb_private::HostThread::EqualsThread(unsigned long) const
tools/lldb/source/Host/common/HostThread.cpp:77
    #2 lldb_private::Process::GetRunLock()
tools/lldb/source/Target/Process.cpp:6373
    #3
lldb_private::ExecutionContextRef::SetTargetPtr(lldb_private::Target*,
bool) tools/lldb/source/Target/ExecutionContext.cpp:723
    #4
lldb_private::CommandInterpreter::UpdateExecutionContext(lldb_private::ExecutionContext*)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:2940
    #5 lldb_private::CommandInterpreter::HandleCommand(char const*,
lldb_private::LazyBool, lldb_private::CommandReturnObject&,
lldb_private::ExecutionContext*, bool, bool)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:1668
    #6
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
    #7 non-virtual thunk to
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
    #8 lldb_private::IOHandlerEditline::Run()
tools/lldb/source/Core/IOHandler.cpp:729
    #9 lldb_private::Debugger::ExecuteIOHandlers()
tools/lldb/source/Core/Debugger.cpp:907
    #10 lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool,
lldb_private::CommandInterpreterRunOptions&)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
    #11 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
tools/lldb/source/API/SBDebugger.cpp:980
    #12 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
    #13 main tools/lldb/tools/driver/Driver.cpp:1252

  Previous write of size 8 at 0x7d080001a5c8 by thread T6:
    #0 memset <null>:0
    #1 lldb_private::HostNativeThreadBase::Reset()
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:54
    #2 lldb_private::HostThread::Reset()
tools/lldb/source/Host/common/HostThread.cpp:41
    #3 lldb_private::Process::RunPrivateStateThread()
tools/lldb/source/Target/Process.cpp:4604
    #4 lldb_private::Process::PrivateStateThread(void*)
tools/lldb/source/Target/Process.cpp:4505
    #5 lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81

==================
WARNING: ThreadSanitizer: data race (pid=64299)
  Write of size 4 at 0x7d680001c8e8 by main thread:
    #0 lldb_private::Terminal::SetFileDescriptor(int)
tools/lldb/include/lldb/Host/Terminal.h:46
    #1 lldb_private::TerminalState::Save(int, bool)
tools/lldb/source/Host/common/Terminal.cpp:144
    #2 lldb_private::Debugger::SaveInputTerminalState()
tools/lldb/source/Core/Debugger.cpp:825
    #3 lldb::SBDebugger::SaveInputTerminalState()
tools/lldb/source/API/SBDebugger.cpp:395
    #4 sigtstp_handler(int) tools/lldb/tools/driver/Driver.cpp:1203
    #5 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool, int,
my_siginfo_t*, void*) tsan_interceptors.o:0
    #6 std::string::_Rep::_M_dispose(std::allocator<char> const&)
/build/buildd/gcc-4.8-4.8.2/build/x86_64-linux-gnu/libstdc++-v3/include/bits/basic_string.h:538
    #7
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
    #8 non-virtual thunk to
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
    #9 lldb_private::IOHandlerEditline::Run()
tools/lldb/source/Core/IOHandler.cpp:729
    #10 lldb_private::Debugger::ExecuteIOHandlers()
tools/lldb/source/Core/Debugger.cpp:907
    #11 lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool,
lldb_private::CommandInterpreterRunOptions&)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
    #12 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
tools/lldb/source/API/SBDebugger.cpp:980
    #13 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
    #14 main tools/lldb/tools/driver/Driver.cpp:1252

  Previous write of size 4 at 0x7d680001c8e8 by thread T2 (mutexes: write
M159):
    #0 lldb_private::Terminal::SetFileDescriptor(int)
tools/lldb/include/lldb/Host/Terminal.h:46
    #1 lldb_private::TerminalState::Save(int, bool)
tools/lldb/source/Host/common/Terminal.cpp:144
    #2 lldb_private::Debugger::SaveInputTerminalState()
tools/lldb/source/Core/Debugger.cpp:825
    #3 lldb::SBDebugger::SaveInputTerminalState()
tools/lldb/source/API/SBDebugger.cpp:395
    #4 sigtstp_handler(int) tools/lldb/tools/driver/Driver.cpp:1203
    #5 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool, int,
my_siginfo_t*, void*) tsan_interceptors.o:0
    #6 lldb_private::Condition::Wait(lldb_private::Mutex&,
lldb_private::TimeValue const*, bool*)
tools/lldb/source/Host/common/Condition.cpp:85
    #7 lldb_private::Predicate<bool>::WaitForValueEqualTo(bool,
lldb_private::TimeValue const*, bool*)
tools/lldb/include/lldb/Host/Predicate.h:339
    #8
lldb_private::Listener::WaitForEventsInternal(lldb_private::TimeValue
const*, lldb_private::Broadcaster*, lldb_private::ConstString const*,
unsigned int, unsigned int, std::shared_ptr<lldb_private::Event>&)
tools/lldb/source/Core/Listener.cpp:442
    #9 lldb_private::Listener::WaitForEvent(lldb_private::TimeValue const*,
std::shared_ptr<lldb_private::Event>&)
tools/lldb/source/Core/Listener.cpp:492
    #10 lldb_private::Debugger::DefaultEventHandler()
tools/lldb/source/Core/Debugger.cpp:1623
    #11 lldb_private::Debugger::EventHandlerThread(void*)
tools/lldb/source/Core/Debugger.cpp:1696
    #12 lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81

==================
WARNING: ThreadSanitizer: data race (pid=64299)
  Write of size 4 at 0x7d680001c8ec by main thread:
    #0 lldb_private::TerminalState::Save(int, bool)
tools/lldb/source/Host/common/Terminal.cpp:148
    #1 lldb_private::Debugger::SaveInputTerminalState()
tools/lldb/source/Core/Debugger.cpp:825
    #2 lldb::SBDebugger::SaveInputTerminalState()
tools/lldb/source/API/SBDebugger.cpp:395
    #3 sigtstp_handler(int) tools/lldb/tools/driver/Driver.cpp:1203
    #4 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool, int,
my_siginfo_t*, void*) tsan_interceptors.o:0
    #5 std::string::_Rep::_M_dispose(std::allocator<char> const&)
/build/buildd/gcc-4.8-4.8.2/build/x86_64-linux-gnu/libstdc++-v3/include/bits/basic_string.h:538
    #6
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:2997
    #7 non-virtual thunk to
lldb_private::CommandInterpreter::IOHandlerInputComplete(lldb_private::IOHandler&,
std::string&) tools/lldb/source/Interpreter/CommandInterpreter.cpp:3076
    #8 lldb_private::IOHandlerEditline::Run()
tools/lldb/source/Core/IOHandler.cpp:729
    #9 lldb_private::Debugger::ExecuteIOHandlers()
tools/lldb/source/Core/Debugger.cpp:907
    #10 lldb_private::CommandInterpreter::RunCommandInterpreter(bool, bool,
lldb_private::CommandInterpreterRunOptions&)
tools/lldb/source/Interpreter/CommandInterpreter.cpp:3234
    #11 lldb::SBDebugger::RunCommandInterpreter(bool, bool)
tools/lldb/source/API/SBDebugger.cpp:980
    #12 Driver::MainLoop() tools/lldb/tools/driver/Driver.cpp:1152
    #13 main tools/lldb/tools/driver/Driver.cpp:1252

  Previous write of size 4 at 0x7d680001c8ec by thread T2 (mutexes: write
M159):
    #0 lldb_private::TerminalState::Save(int, bool)
tools/lldb/source/Host/common/Terminal.cpp:148
    #1 lldb_private::Debugger::SaveInputTerminalState()
tools/lldb/source/Core/Debugger.cpp:825
    #2 lldb::SBDebugger::SaveInputTerminalState()
tools/lldb/source/API/SBDebugger.cpp:395
    #3 sigtstp_handler(int) tools/lldb/tools/driver/Driver.cpp:1203
    #4 __tsan::CallUserSignalHandler(__tsan::ThreadState*, bool, bool, int,
my_siginfo_t*, void*) tsan_interceptors.o:0
    #5 lldb_private::Condition::Wait(lldb_private::Mutex&,
lldb_private::TimeValue const*, bool*)
tools/lldb/source/Host/common/Condition.cpp:85
    #6 lldb_private::Predicate<bool>::WaitForValueEqualTo(bool,
lldb_private::TimeValue const*, bool*)
tools/lldb/include/lldb/Host/Predicate.h:339
    #7
lldb_private::Listener::WaitForEventsInternal(lldb_private::TimeValue
const*, lldb_private::Broadcaster*, lldb_private::ConstString const*,
unsigned int, unsigned int, std::shared_ptr<lldb_private::Event>&)
tools/lldb/source/Core/Listener.cpp:442
    #8 lldb_private::Listener::WaitForEvent(lldb_private::TimeValue const*,
std::shared_ptr<lldb_private::Event>&)
tools/lldb/source/Core/Listener.cpp:492
    #9 lldb_private::Debugger::DefaultEventHandler()
tools/lldb/source/Core/Debugger.cpp:1623
    #10 lldb_private::Debugger::EventHandlerThread(void*)
tools/lldb/source/Core/Debugger.cpp:1696
    #11 lldb_private::HostNativeThreadBase::ThreadCreateTrampoline(void*)
tools/lldb/source/Host/common/HostNativeThreadBase.cpp:81


-- Ryan Brown

On Mon, May 11, 2015 at 8:20 AM, Ed Maste <emaste at freebsd.org> wrote:

> On 11 May 2015 at 10:21, Pavel Labath <labath at google.com> wrote:
> >
> > BTW, I've noticed that PushIOHandler does not lock
> > m_input_reader_stack.GetMutex(), unlike PopIOHandler, and all other
> > functions which deal with handlers. Is that intentional? I think it
> > should lock the mutex as well.
>
> A slight tangent here, but there's a lot of dubious thread behaviour
> like this. One example I've run into is PR22611 - I see that if we set
> a prompt that fits in libc++'s short string optimization (that is, no
> more than 22 characters) it works fine, but as soon as the prompt is
> 23 characters long we end up pointing at uninitialized memory;
> presumably the race window is much larger in that case.
>
> Unfortunately TSan isn't fully functional on FreeBSD at the moment, so
> it's not that easy for me to find other cases like this with a
> systematic approach. I recall there was an effort to run LLDB under
> TSan on Linux some time ago, and that found a number of issues. Is
> anyone on the Linux side interested in picking that up again?
> _______________________________________________
> lldb-dev mailing list
> lldb-dev at cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/lldb-dev
>
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