[Lldb-commits] [lldb] r159686 - /lldb/trunk/source/Commands/CommandObjectThread.cpp

[Greg Clayton]

Author: gclayton
Date: Tue Jul  3 15:54:16 2012
New Revision: 159686

URL: http://llvm.org/viewvc/llvm-project?rev=159686&view=rev
Log:
<rdar://problem/11800213>

Fixed a crasher in the "thread continue" code. There were many logic errors in the DoExecute function where thread index IDs were being used where the actual zero based thread index should have been used. This could cause crashes to happen since looking up a thread by index ID, when the zero based index of a thread should be used would return an empty thread shared pointer and cause a NULL deref.


Modified:
    lldb/trunk/source/Commands/CommandObjectThread.cpp

Modified: lldb/trunk/source/Commands/CommandObjectThread.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Commands/CommandObjectThread.cpp?rev=159686&r1=159685&r2=159686&view=diff
==============================================================================
--- lldb/trunk/source/Commands/CommandObjectThread.cpp (original)
+++ lldb/trunk/source/Commands/CommandObjectThread.cpp Tue Jul  3 15:54:16 2012
@@ -646,37 +646,41 @@
         StateType state = process->GetState();
         if ((state == eStateCrashed) || (state == eStateStopped) || (state == eStateSuspended))
         {
+            Mutex::Locker locker (process->GetThreadList().GetMutex());
             const uint32_t num_threads = process->GetThreadList().GetSize();
-            uint32_t idx;
             const size_t argc = command.GetArgumentCount();
             if (argc > 0)
             {
-                std::vector<uint32_t> resume_thread_indexes;
+                std::vector<Thread *> resume_threads;
                 for (uint32_t i=0; i<argc; ++i)
                 {
                     bool success;
                     const int base = 0;
-                    idx = Args::StringToUInt32 (command.GetArgumentAtIndex(i), LLDB_INVALID_INDEX32, base, &success);
-                    if (!success)
+                    uint32_t thread_idx = Args::StringToUInt32 (command.GetArgumentAtIndex(i), LLDB_INVALID_INDEX32, base, &success);
+                    if (success)
                     {
-                        result.AppendErrorWithFormat ("invalid value for thread index: %s.", command.GetArgumentAtIndex(i));
-                        result.SetStatus (eReturnStatusFailed);
-                        return false;
-                    }
-                    else if (process->GetThreadList().FindThreadByIndexID(idx))
-                    {
-                        if (find(resume_thread_indexes.begin(), resume_thread_indexes.end(), idx) == resume_thread_indexes.end())
-                            resume_thread_indexes.push_back(idx);
+                        Thread *thread = process->GetThreadList().FindThreadByIndexID(thread_idx).get();
+                        
+                        if (thread)
+                        {
+                            resume_threads.push_back(thread);
+                        }
+                        else
+                        {
+                            result.AppendErrorWithFormat("invalid thread index %u.\n", thread_idx);
+                            result.SetStatus (eReturnStatusFailed);
+                            return false;
+                        }
                     }
                     else
                     {
-                        result.AppendErrorWithFormat("thread index %u out of range.\n", idx);
+                        result.AppendErrorWithFormat ("invalid thread index argument: \"%s\".\n", command.GetArgumentAtIndex(i));
                         result.SetStatus (eReturnStatusFailed);
                         return false;
                     }
                 }
-
-                if (resume_thread_indexes.empty())
+                
+                if (resume_threads.empty())
                 {
                     result.AppendError ("no valid thread indexes were specified");
                     result.SetStatus (eReturnStatusFailed);
@@ -684,20 +688,20 @@
                 }
                 else
                 {
-                    if (resume_thread_indexes.size() == 1)
+                    if (resume_threads.size() == 1)
                         result.AppendMessageWithFormat ("Resuming thread: ");
                     else
                         result.AppendMessageWithFormat ("Resuming threads: ");
-
-                    for (idx=0; idx<num_threads; ++idx)
+                    
+                    for (uint32_t idx=0; idx<num_threads; ++idx)
                     {
-                        Thread *thread = process->GetThreadList().FindThreadByIndexID(idx).get();
-                        std::vector<uint32_t>::iterator this_thread_pos = find(resume_thread_indexes.begin(), resume_thread_indexes.end(), thread->GetIndexID());
+                        Thread *thread = process->GetThreadList().GetThreadAtIndex(idx).get();
+                        std::vector<Thread *>::iterator this_thread_pos = find(resume_threads.begin(), resume_threads.end(), thread);
                         
-                        if (this_thread_pos != resume_thread_indexes.end())
+                        if (this_thread_pos != resume_threads.end())
                         {
-                            resume_thread_indexes.erase(this_thread_pos);
-                            if (resume_thread_indexes.size() > 0)
+                            resume_threads.erase(this_thread_pos);
+                            if (resume_threads.size() > 0)
                                 result.AppendMessageWithFormat ("%u, ", thread->GetIndexID());
                             else
                                 result.AppendMessageWithFormat ("%u ", thread->GetIndexID());
@@ -722,9 +726,9 @@
                     return false;
                 }
                 // Set the actions that the threads should each take when resuming
-                for (idx=0; idx<num_threads; ++idx)
+                for (uint32_t idx=0; idx<num_threads; ++idx)
                 {
-                    Thread *thread = process->GetThreadList().FindThreadByIndexID(idx).get();
+                    Thread *thread = process->GetThreadList().GetThreadAtIndex(idx).get();
                     if (thread == current_thread)
                     {
                         result.AppendMessageWithFormat ("Resuming thread 0x%4.4llx in process %llu\n", thread->GetID(), process->GetID());
@@ -736,7 +740,7 @@
                     }
                 }
             }
-
+            
             Error error (process->Resume());
             if (error.Success())
             {
@@ -744,7 +748,7 @@
                 if (synchronous_execution)
                 {
                     state = process->WaitForProcessToStop (NULL);
-
+                    
                     result.SetDidChangeProcessState (true);
                     result.AppendMessageWithFormat ("Process %llu %s\n", process->GetID(), StateAsCString (state));
                     result.SetStatus (eReturnStatusSuccessFinishNoResult);