svn commit: r353416 - head/contrib/llvm/tools/lldb/source/Plugins/Process/FreeBSD
Dimitry Andric
dim at FreeBSD.org
Thu Oct 10 20:33:56 UTC 2019
Author: dim
Date: Thu Oct 10 20:33:55 2019
New Revision: 353416
URL: https://svnweb.freebsd.org/changeset/base/353416
Log:
Pull in r374444 from upstream lldb trunk (by me):
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
PR: 241137
MFC after: 1 month
X-MFC-With: r353358
Modified:
head/contrib/llvm/tools/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
head/contrib/llvm/tools/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h
Modified: head/contrib/llvm/tools/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp
==============================================================================
--- head/contrib/llvm/tools/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp Thu Oct 10 20:30:54 2019 (r353415)
+++ head/contrib/llvm/tools/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.cpp Thu Oct 10 20:33:55 2019 (r353416)
@@ -708,7 +708,7 @@ 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(
@@ -735,20 +735,22 @@ 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);
@@ -773,14 +775,16 @@ ProcessMonitor::ProcessMonitor(ProcessFreeBSD *process
}
// 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(); }
@@ -789,13 +793,15 @@ ProcessMonitor::~ProcessMonitor() { StopMonitor(); }
void ProcessMonitor::StartLaunchOpThread(LaunchArgs *args, Status &error) {
static const char *g_thread_name = "freebsd.op";
- 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) {
@@ -957,14 +963,15 @@ void ProcessMonitor::StartAttachOpThread(AttachArgs *a
lldb_private::Status &error) {
static const char *g_thread_name = "freebsd.op";
- 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) {
@@ -1384,7 +1391,7 @@ bool ProcessMonitor::DupDescriptor(const FileSpec &fil
}
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();
@@ -1422,10 +1429,9 @@ 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: head/contrib/llvm/tools/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h
==============================================================================
--- head/contrib/llvm/tools/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h Thu Oct 10 20:30:54 2019 (r353415)
+++ head/contrib/llvm/tools/lldb/source/Plugins/Process/FreeBSD/ProcessMonitor.h Thu Oct 10 20:33:55 2019 (r353416)
@@ -183,8 +183,8 @@ class ProcessMonitor { (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;
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