Author: Augusto Noronha Date: 2023-08-18T16:53:26-07:00 New Revision: bb90063249707e3ae081bfbd8e3512566abb7df6
URL: https://github.com/llvm/llvm-project/commit/bb90063249707e3ae081bfbd8e3512566abb7df6 DIFF: https://github.com/llvm/llvm-project/commit/bb90063249707e3ae081bfbd8e3512566abb7df6.diff LOG: [lldb] Fix data race in ThreadList ThreadSanitizer reports the following issue: ``` Write of size 8 at 0x00010a70abb0 by thread T3 (mutexes: write M0): #0 lldb_private::ThreadList::Update(lldb_private::ThreadList&) ThreadList.cpp:741 (liblldb.18.0.0git.dylib:arm64+0x5dedf4) (BuildId: 9bced2aafa373580ae9d750d9cf79a8f32000000200000000100000000000e00) #1 lldb_private::Process::UpdateThreadListIfNeeded() Process.cpp:1212 (liblldb.18.0.0git.dylib:arm64+0x53bbec) (BuildId: 9bced2aafa373580ae9d750d9cf79a8f32000000200000000100000000000e00) Previous read of size 8 at 0x00010a70abb0 by main thread (mutexes: write M1): #0 lldb_private::ThreadList::GetMutex() const ThreadList.cpp:785 (liblldb.18.0.0git.dylib:arm64+0x5df138) (BuildId: 9bced2aafa373580ae9d750d9cf79a8f32000000200000000100000000000e00) #1 lldb_private::ThreadList::DidResume() ThreadList.cpp:656 (liblldb.18.0.0git.dylib:arm64+0x5de5c0) (BuildId: 9bced2aafa373580ae9d750d9cf79a8f32000000200000000100000000000e00) #2 lldb_private::Process::PrivateResume() Process.cpp:3130 (liblldb.18.0.0git.dylib:arm64+0x53cd7c) (BuildId: 9bced2aafa373580ae9d750d9cf79a8f32000000200000000100000000000e00) ``` Fix this by only using the mutex in ThreadList and removing the one in process entirely. Differential Revision: https://reviews.llvm.org/D158034 Added: Modified: lldb/include/lldb/Target/Process.h lldb/include/lldb/Target/ThreadCollection.h lldb/include/lldb/Target/ThreadList.h lldb/source/Target/Process.cpp lldb/source/Target/ThreadList.cpp Removed: ################################################################################ diff --git a/lldb/include/lldb/Target/Process.h b/lldb/include/lldb/Target/Process.h index 2186eea7ef5054..2e1bce561526df 100644 --- a/lldb/include/lldb/Target/Process.h +++ b/lldb/include/lldb/Target/Process.h @@ -2970,7 +2970,6 @@ void PruneThreadPlans(); std::string m_exit_string; ///< A textual description of why a process exited. std::mutex m_exit_status_mutex; ///< Mutex so m_exit_status m_exit_string can ///be safely accessed from multiple threads - std::recursive_mutex m_thread_mutex; ThreadList m_thread_list_real; ///< The threads for this process as are known ///to the protocol we are debugging with ThreadList m_thread_list; ///< The threads for this process as the user will diff --git a/lldb/include/lldb/Target/ThreadCollection.h b/lldb/include/lldb/Target/ThreadCollection.h index 29f5103e7eec7c..dc7d8f13eee037 100644 --- a/lldb/include/lldb/Target/ThreadCollection.h +++ b/lldb/include/lldb/Target/ThreadCollection.h @@ -47,7 +47,7 @@ class ThreadCollection { return ThreadIterable(m_threads, GetMutex()); } - virtual std::recursive_mutex &GetMutex() const { return m_mutex; } + std::recursive_mutex &GetMutex() const { return m_mutex; } protected: collection m_threads; diff --git a/lldb/include/lldb/Target/ThreadList.h b/lldb/include/lldb/Target/ThreadList.h index 6af04f8ffc3767..8aaff6e4cba0d4 100644 --- a/lldb/include/lldb/Target/ThreadList.h +++ b/lldb/include/lldb/Target/ThreadList.h @@ -133,8 +133,6 @@ class ThreadList : public ThreadCollection { void SetStopID(uint32_t stop_id); - std::recursive_mutex &GetMutex() const override; - void Update(ThreadList &rhs); protected: diff --git a/lldb/source/Target/Process.cpp b/lldb/source/Target/Process.cpp index fc08cce096103f..4a33d8980c2782 100644 --- a/lldb/source/Target/Process.cpp +++ b/lldb/source/Target/Process.cpp @@ -435,7 +435,7 @@ Process::Process(lldb::TargetSP target_sp, ListenerSP listener_sp, Listener::MakeListener("lldb.process.internal_state_listener")), m_mod_id(), m_process_unique_id(0), m_thread_index_id(0), m_thread_id_to_index_id_map(), m_exit_status(-1), m_exit_string(), - m_exit_status_mutex(), m_thread_mutex(), m_thread_list_real(this), + m_exit_status_mutex(), m_thread_list_real(this), m_thread_list(this), m_thread_plans(*this), m_extended_thread_list(this), m_extended_thread_stop_id(0), m_queue_list(this), m_queue_list_stop_id(0), m_notifications(), m_image_tokens(), @@ -2456,7 +2456,7 @@ Process::WaitForProcessStopPrivate(EventSP &event_sp, } void Process::LoadOperatingSystemPlugin(bool flush) { - std::lock_guard<std::recursive_mutex> guard(m_thread_mutex); + std::lock_guard<std::recursive_mutex> guard(GetThreadList().GetMutex()); if (flush) m_thread_list.Clear(); m_os_up.reset(OperatingSystem::FindPlugin(this, nullptr)); diff --git a/lldb/source/Target/ThreadList.cpp b/lldb/source/Target/ThreadList.cpp index 1ba0c435b993d3..fc6cbd48cf8653 100644 --- a/lldb/source/Target/ThreadList.cpp +++ b/lldb/source/Target/ThreadList.cpp @@ -736,7 +736,8 @@ void ThreadList::Update(ThreadList &rhs) { if (this != &rhs) { // Lock both mutexes to make sure neither side changes anyone on us while // the assignment occurs - std::scoped_lock<std::recursive_mutex, std::recursive_mutex> guard(GetMutex(), rhs.GetMutex()); + std::scoped_lock<std::recursive_mutex, std::recursive_mutex> guard( + GetMutex(), rhs.GetMutex()); m_process = rhs.m_process; m_stop_id = rhs.m_stop_id; @@ -781,10 +782,6 @@ void ThreadList::Flush() { (*pos)->Flush(); } -std::recursive_mutex &ThreadList::GetMutex() const { - return m_process->m_thread_mutex; -} - ThreadList::ExpressionExecutionThreadPusher::ExpressionExecutionThreadPusher( lldb::ThreadSP thread_sp) : m_thread_list(nullptr), m_tid(LLDB_INVALID_THREAD_ID) { _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
