bhushan created this revision.
bhushan added a reviewer: clayborg.
bhushan added subscribers: lldb-commits, jaydeep, sagar, mohit.bhakkad,
nitesh.jain.
bhushan set the repository for this revision to rL LLVM.
This patch fixes couple of issues described below:
1. A thread tries to lock a mutex which is already locked. This happens in
ProcessGDBRemote.cpp
ProcessGDBRemote::RefreshStateAfterStop ()
- locks m_last_stop_packet_mutex
- access packet stack to get the stop info and
- call SetThreadStopInfo(stop_info)
- calls UpdateThreadIDList() to get the thread list if the
response is old style 'S' packet which does not provide the thread information.
This causes a problem because UpdateThreadIDList() again
tries to aquire a lock on m_last_stop_packet_mutex (which is already locked).
This patch fixes this issue by changing the Type of m_last_stop_packet_mutex to
eMutexTypeRecursive so that the same thread can enter the mutex recursively.
2. The old style 'S' packet isn't handled correctly.
This patch fixes this issue by updating a thread list before the stop packet is
parsed so that it can get a valid thread id and allows to set the stop info
correctly.
Repository:
rL LLVM
http://reviews.llvm.org/D11449
Files:
source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
Index: source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
===================================================================
--- source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -371,7 +371,7 @@
m_flags (0),
m_gdb_comm (),
m_debugserver_pid (LLDB_INVALID_PROCESS_ID),
- m_last_stop_packet_mutex (Mutex::eMutexTypeNormal),
+ m_last_stop_packet_mutex (Mutex::eMutexTypeRecursive),
m_register_info (),
m_async_broadcaster (NULL, "lldb.process.gdb-remote.async-broadcaster"),
m_async_thread_state_mutex(Mutex::eMutexTypeRecursive),
@@ -2485,6 +2485,15 @@
}
}
+ if (tid == LLDB_INVALID_THREAD_ID)
+ {
+ // A thread id may be invalid if the response is old style 'S'
packet which does not provide the
+ // thread information. So update the thread list and choose
the first one.
+ UpdateThreadIDList ();
+
+ tid = m_thread_ids.front ();
+ }
+
ThreadSP thread_sp = SetThreadStopInfo (tid,
expedited_register_map,
signo,
@@ -2499,19 +2508,6 @@
queue_kind,
queue_serial);
- // If the response is old style 'S' packet which does not provide
us with thread information
- // then update the thread list and choose the first one.
- if (!thread_sp)
- {
- UpdateThreadIDList ();
-
- if (!m_thread_ids.empty ())
- {
- Mutex::Locker locker (m_thread_list_real.GetMutex ());
- thread_sp = m_thread_list_real.FindThreadByProtocolID
(m_thread_ids.front (), false);
- }
- }
-
return eStateStopped;
}
break;
Index: source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
===================================================================
--- source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -371,7 +371,7 @@
m_flags (0),
m_gdb_comm (),
m_debugserver_pid (LLDB_INVALID_PROCESS_ID),
- m_last_stop_packet_mutex (Mutex::eMutexTypeNormal),
+ m_last_stop_packet_mutex (Mutex::eMutexTypeRecursive),
m_register_info (),
m_async_broadcaster (NULL, "lldb.process.gdb-remote.async-broadcaster"),
m_async_thread_state_mutex(Mutex::eMutexTypeRecursive),
@@ -2485,6 +2485,15 @@
}
}
+ if (tid == LLDB_INVALID_THREAD_ID)
+ {
+ // A thread id may be invalid if the response is old style 'S' packet which does not provide the
+ // thread information. So update the thread list and choose the first one.
+ UpdateThreadIDList ();
+
+ tid = m_thread_ids.front ();
+ }
+
ThreadSP thread_sp = SetThreadStopInfo (tid,
expedited_register_map,
signo,
@@ -2499,19 +2508,6 @@
queue_kind,
queue_serial);
- // If the response is old style 'S' packet which does not provide us with thread information
- // then update the thread list and choose the first one.
- if (!thread_sp)
- {
- UpdateThreadIDList ();
-
- if (!m_thread_ids.empty ())
- {
- Mutex::Locker locker (m_thread_list_real.GetMutex ());
- thread_sp = m_thread_list_real.FindThreadByProtocolID (m_thread_ids.front (), false);
- }
- }
-
return eStateStopped;
}
break;
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