[NativeProcessLinux] Fix removal of temporary breakpoints
Summary:
There was an issue in NPL, where we attempted removal of temporary breakpoints (used to implement
software single stepping), while some threads of the process were running. This is a problem
since we currently always use the main thread's ID in the removal ptrace call. Therefore, if the
main thread was still running, the ptrace call would fail, and the software breakpoint would
remain, causing all kinds of problems. This change removes the breakpoints after all threads have
stopped. This fixes TestExitDuringStep on Android arm and can also potentially help in other
situations, as previously the breakpoint would not get removed if the thread stopped for another
reason.
Test Plan: TestExitDuringStep passes, other tests remain unchanged.
Reviewers: tberghammer
Subscribers: tberghammer, aemerson, lldb-commits
Differential Revision: http://reviews.llvm.org/D9792
llvm-svn: 237448
diff --git a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
index fd88ddf..4cdfd6d 100644
--- a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
+++ b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.cpp
@@ -2601,18 +2601,8 @@
log->Printf("NativeProcessLinux::%s() pid = %" PRIu64 " fixup: %s",
__FUNCTION__, pid, error.AsCString());
- auto it = m_threads_stepping_with_breakpoint.find(pid);
- if (it != m_threads_stepping_with_breakpoint.end())
- {
- Error error = RemoveBreakpoint (it->second);
- if (error.Fail())
- if (log)
- log->Printf("NativeProcessLinux::%s() pid = %" PRIu64 " remove stepping breakpoint: %s",
- __FUNCTION__, pid, error.AsCString());
-
- m_threads_stepping_with_breakpoint.erase(it);
+ if (m_threads_stepping_with_breakpoint.find(pid) != m_threads_stepping_with_breakpoint.end())
std::static_pointer_cast<NativeThreadLinux>(thread_sp)->SetStoppedByTrace();
- }
}
else
if (log)
@@ -3023,7 +3013,6 @@
if (log)
log->Printf ("NativeProcessLinux::%s called: pid %" PRIu64, __FUNCTION__, GetID ());
- bool stepping = false;
bool software_single_step = !SupportHardwareSingleStepping();
Monitor::ScopedOperationLock monitor_lock(*m_monitor_up);
@@ -3109,7 +3098,6 @@
return step_result;
},
false);
- stepping = true;
break;
}
@@ -4081,7 +4069,7 @@
if (m_pending_notification_up)
{
m_pending_notification_up->wait_for_stop_tids.erase(thread_id);
- SignalIfRequirementsSatisfied();
+ SignalIfAllThreadsStopped();
}
return found;
@@ -4331,10 +4319,24 @@
}
void
-NativeProcessLinux::SignalIfRequirementsSatisfied()
+NativeProcessLinux::SignalIfAllThreadsStopped()
{
if (m_pending_notification_up && m_pending_notification_up->wait_for_stop_tids.empty ())
{
+ Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_BREAKPOINTS));
+
+ // Clear any temporary breakpoints we used to implement software single stepping.
+ for (const auto &thread_info: m_threads_stepping_with_breakpoint)
+ {
+ Error error = RemoveBreakpoint (thread_info.second);
+ if (error.Fail())
+ if (log)
+ log->Printf("NativeProcessLinux::%s() pid = %" PRIu64 " remove stepping breakpoint: %s",
+ __FUNCTION__, thread_info.first, error.AsCString());
+ }
+ m_threads_stepping_with_breakpoint.clear();
+
+ // Notify the delegate about the stop
SetCurrentThreadID(m_pending_notification_up->triggering_tid);
SetState(StateType::eStateStopped, true);
m_pending_notification_up.reset();
@@ -4386,7 +4388,7 @@
if (m_pending_notification_up)
{
m_pending_notification_up->wait_for_stop_tids.erase(tid);
- SignalIfRequirementsSatisfied();
+ SignalIfAllThreadsStopped();
}
Error error;
@@ -4423,7 +4425,7 @@
RequestStopOnAllRunningThreads();
- SignalIfRequirementsSatisfied();
+ SignalIfAllThreadsStopped();
}
void
diff --git a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
index f280b36..57c598f 100644
--- a/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
+++ b/lldb/source/Plugins/Process/Linux/NativeProcessLinux.h
@@ -385,8 +385,8 @@
};
typedef std::unique_ptr<PendingNotification> PendingNotificationUP;
- // Fire pending notification if no pending thread stops remain.
- void SignalIfRequirementsSatisfied();
+ // Notify the delegate if all threads have stopped.
+ void SignalIfAllThreadsStopped();
void
RequestStopOnAllRunningThreads();