Author: dim Date: Thu Oct 10 13:26:59 2019 New Revision: 374444 URL: http://llvm.org/viewvc/llvm-project?rev=374444&view=rev Log: Fix process launch failure on FreeBSD after r365761
Summary: After rLLDB365761, and with `LLVM_ENABLE_ABI_BREAKING_CHECKS` enabled, launching any process on FreeBSD crashes lldb with: ``` Expected<T> must be checked before access or destruction. Expected<T> value was in success state. (Note: Expected<T> values in success mode must still be checked prior to being destroyed). ``` This is because `m_operation_thread` and `m_monitor_thread` were wrapped in `llvm::Expected<>`, but this requires the objects to be correctly initialized before accessing them. To fix the crashes, use `llvm::Optional<>` for the members (as indicated by labath), and use local variables to store the return values of `LaunchThread` and `StartMonitoringChildProcess`. Then, only assign to the member variables after checking if the return values indicated success. Reviewers: devnexen, emaste, MaskRay, mgorny Reviewed By: devnexen Subscribers: jfb, labath, krytarowski, lldb-commits Differential Revision: https://reviews.llvm.org/D68723 Modified: lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.h Modified: lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp?rev=374444&r1=374443&r2=374444&view=diff ============================================================================== --- lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp (original) +++ lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp Thu Oct 10 13:26:59 2019 @@ -703,7 +703,7 @@ ProcessMonitor::ProcessMonitor( const lldb_private::ProcessLaunchInfo & /* launch_info */, lldb_private::Status &error) : m_process(static_cast<ProcessFreeBSD *>(process)), - m_operation_thread(nullptr), m_monitor_thread(nullptr), m_pid(LLDB_INVALID_PROCESS_ID), m_terminal_fd(-1), m_operation(0) { + m_operation_thread(), m_monitor_thread(), m_pid(LLDB_INVALID_PROCESS_ID), m_terminal_fd(-1), m_operation(0) { using namespace std::placeholders; std::unique_ptr<LaunchArgs> args( @@ -730,20 +730,22 @@ ProcessMonitor::ProcessMonitor( } // Finally, start monitoring the child process for change in state. - m_monitor_thread = Host::StartMonitoringChildProcess( + llvm::Expected<lldb_private::HostThread> monitor_thread = + Host::StartMonitoringChildProcess( std::bind(&ProcessMonitor::MonitorCallback, this, _1, _2, _3, _4), GetPID(), true); - if (!m_monitor_thread->IsJoinable()) { + if (!monitor_thread || !monitor_thread->IsJoinable()) { error.SetErrorToGenericError(); error.SetErrorString("Process launch failed."); return; } + m_monitor_thread = *monitor_thread; } ProcessMonitor::ProcessMonitor(ProcessFreeBSD *process, lldb::pid_t pid, lldb_private::Status &error) : m_process(static_cast<ProcessFreeBSD *>(process)), - m_operation_thread(nullptr), m_monitor_thread(nullptr), m_pid(pid), m_terminal_fd(-1), m_operation(0) { + m_operation_thread(), m_monitor_thread(), m_pid(pid), m_terminal_fd(-1), m_operation(0) { using namespace std::placeholders; sem_init(&m_operation_pending, 0, 0); @@ -768,14 +770,16 @@ ProcessMonitor::ProcessMonitor(ProcessFr } // Finally, start monitoring the child process for change in state. - m_monitor_thread = Host::StartMonitoringChildProcess( + llvm::Expected<lldb_private::HostThread> monitor_thread = + Host::StartMonitoringChildProcess( std::bind(&ProcessMonitor::MonitorCallback, this, _1, _2, _3, _4), GetPID(), true); - if (!m_monitor_thread->IsJoinable()) { + if (!monitor_thread || !monitor_thread->IsJoinable()) { error.SetErrorToGenericError(); error.SetErrorString("Process attach failed."); return; } + m_monitor_thread = *monitor_thread; } ProcessMonitor::~ProcessMonitor() { StopMonitor(); } @@ -784,13 +788,15 @@ ProcessMonitor::~ProcessMonitor() { Stop void ProcessMonitor::StartLaunchOpThread(LaunchArgs *args, Status &error) { static const char *g_thread_name = "lldb.process.freebsd.operation"; - if (m_operation_thread->IsJoinable()) + if (m_operation_thread && m_operation_thread->IsJoinable()) return; - m_operation_thread = - ThreadLauncher::LaunchThread(g_thread_name, LaunchOpThread, args); - if (!m_operation_thread) - error = m_operation_thread.takeError(); + llvm::Expected<lldb_private::HostThread> operation_thread = + ThreadLauncher::LaunchThread(g_thread_name, LaunchOpThread, args); + if (operation_thread) + m_operation_thread = *operation_thread; + else + error = operation_thread.takeError(); } void *ProcessMonitor::LaunchOpThread(void *arg) { @@ -952,14 +958,15 @@ void ProcessMonitor::StartAttachOpThread lldb_private::Status &error) { static const char *g_thread_name = "lldb.process.freebsd.operation"; - if (m_operation_thread->IsJoinable()) + if (m_operation_thread && m_operation_thread->IsJoinable()) return; - m_operation_thread = - ThreadLauncher::LaunchThread(g_thread_name, AttachOpThread, args); - - if (!m_operation_thread) - error = m_operation_thread.takeError(); + llvm::Expected<lldb_private::HostThread> operation_thread = + ThreadLauncher::LaunchThread(g_thread_name, AttachOpThread, args); + if (operation_thread) + m_operation_thread = *operation_thread; + else + error = operation_thread.takeError(); } void *ProcessMonitor::AttachOpThread(void *arg) { @@ -1374,7 +1381,7 @@ bool ProcessMonitor::DupDescriptor(const } void ProcessMonitor::StopMonitoringChildProcess() { - if (m_monitor_thread->IsJoinable()) { + if (m_monitor_thread && m_monitor_thread->IsJoinable()) { m_monitor_thread->Cancel(); m_monitor_thread->Join(nullptr); m_monitor_thread->Reset(); @@ -1412,10 +1419,9 @@ void ProcessMonitor::StopMonitor() { bool ProcessMonitor::WaitForInitialTIDStop(lldb::tid_t tid) { return true; } void ProcessMonitor::StopOpThread() { - if (!m_operation_thread->IsJoinable()) - return; - - m_operation_thread->Cancel(); - m_operation_thread->Join(nullptr); - m_operation_thread->Reset(); + if (m_operation_thread && m_operation_thread->IsJoinable()) { + m_operation_thread->Cancel(); + m_operation_thread->Join(nullptr); + m_operation_thread->Reset(); + } } Modified: lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.h URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.h?rev=374444&r1=374443&r2=374444&view=diff ============================================================================== --- lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.h (original) +++ lldb/trunk/source/Plugins/Process/FreeBSD/ProcessMonitor.h Thu Oct 10 13:26:59 2019 @@ -183,8 +183,8 @@ public: private: ProcessFreeBSD *m_process; - llvm::Expected<lldb_private::HostThread> m_operation_thread; - llvm::Expected<lldb_private::HostThread> m_monitor_thread; + llvm::Optional<lldb_private::HostThread> m_operation_thread; + llvm::Optional<lldb_private::HostThread> m_monitor_thread; lldb::pid_t m_pid; int m_terminal_fd; _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
