Properly obtain threading debug information in TDE crash handler

Fix potential TDE crash handler lockup uncer certain circumstances
Enhance crashtest program with three threads
(cherry picked from commit c12a32aec0)

drkonqi/backtrace.cpp

@@ -175,8 +175,22 @@ void BackTrace::slotProcessExited(KProcess *proc)
 bool BackTrace::usefulBacktrace()
 {
   // remove crap
-  if( !m_krashconf->removeFromBacktraceRegExp().isEmpty())
+  if( !m_krashconf->removeFromBacktraceRegExp().isEmpty()) {
     m_strBt.replace(TQRegExp( m_krashconf->removeFromBacktraceRegExp()), TQString());
+  }
+
+  // fix threading info output
+  if( !m_krashconf->threadRegExp().isEmpty()) {
+    int pos = -1;
+    TQRegExp threadRegExpression( m_krashconf->threadRegExp());
+    do {
+      threadRegExpression.search(m_strBt);
+      pos = threadRegExpression.pos();
+      if (pos > -1) {
+        m_strBt.insert(threadRegExpression.pos()+1, "==== ");
+      }
+    } while (pos > -1);
+  }
 
   if( m_krashconf->disableChecks())
       return true;
@@ -203,20 +217,32 @@ void BackTrace::processBacktrace()
 {
 	if( !m_krashconf->kcrashRegExp().isEmpty()) {
 		TQRegExp kcrashregexp( m_krashconf->kcrashRegExp());
-		int pos = -1;
-		while ((pos = kcrashregexp.search( m_strBt )) >= 0) {
-			pos = kcrashregexp.search( m_strBt );
+		kcrashregexp.setMinimal(true);
+		int pos = 0;
+		int prevpos = 0;
+		while ((pos = kcrashregexp.search( m_strBt, pos )) >= 0) {
+			if (prevpos == pos) {
+				// Avoid infinite loop
+				// Shouldn't ever get here, but given that this is a crash handler, better safe than sorry!
+				break;
+			}
+			prevpos = pos;
 			if( pos >= 0 ) {
 				int len = kcrashregexp.matchedLength();
 				int nextinfochunkpos = m_strBt.find("====", pos);
 				if (nextinfochunkpos >= 0) {
 					// Trying to delete too much!
-					int chunkpos = pos;
-					TQString limitedstrBt = m_strBt.mid(pos, nextinfochunkpos - pos);
-					pos = kcrashregexp.search( limitedstrBt ) + chunkpos;
-					len = kcrashregexp.matchedLength();
+					int limitedlen = nextinfochunkpos - pos;
+					TQString limitedstrBt = m_strBt.mid(pos, limitedlen);
+					int limitedpos = kcrashregexp.search( limitedstrBt );
+					if (limitedpos >= 0) {
+						len = kcrashregexp.matchedLength();
+					}
+					else {
+						len = 0;
+					}
 				}
-				if (pos >= 0) {
+				if ((pos >= 0) && (len > 0)) {
 					if( m_strBt[ pos ] == '\n' ) {
 						++pos;
 						--len;
@@ -225,6 +251,17 @@ void BackTrace::processBacktrace()
 					m_strBt.insert( pos, TQString::fromLatin1( "[KCrash handler]\n" ));
 				}
 			}
+			if (pos < 0) {
+				// Avoid infinite loop
+				// Shouldn't ever get here, but given that this is a crash handler, better safe than sorry!
+				break;
+			}
+			pos++;
+			if ((uint)pos >= m_strBt.length()) {
+				// Avoid infinite loop
+				// Shouldn't ever get here, but given that this is a crash handler, better safe than sorry!
+				break;
+			}
 		}
 	}
 	if( !m_krashconf->kcrashRegExpSingle().isEmpty()) {
@@ -239,4 +276,14 @@ void BackTrace::processBacktrace()
 			m_strBt.remove( pos, len );
 		}
 	}
+
+	{
+		// Clean up hard to read debug blocks
+		TQRegExp kcrashregexp( "[^\n]\n==== ");
+		kcrashregexp.setMinimal(true);
+		int pos = 0;
+		while ((pos = kcrashregexp.search( m_strBt, pos )) >= 0) {
+			m_strBt.insert(pos+1, "\n");
+		}
+	}
 }

drkonqi/debuggers/gdbrc

@@ -158,10 +158,11 @@ Comment[zu]=Umcoshi wamaphutha osekelwe umbhalo osuka kwi-GNU kwikhonsoli
 Exec=konsole -e gdb -nw %execname %pid
 ExecBatch=gdb -nw -n -batch -x %tempfile %execname %pid
 TryExec=gdb
-BacktraceCommand=echo \\n\necho ==== (gdb) bt ====\\n\nbt\necho \\n\\n\necho ==== (gdb) bt full ====\\n\nbt full\necho\\n\\n\necho ==== (gdb) thread apply all bt ====\\n\nthread apply all bt
+BacktraceCommand=echo \\n\necho ==== (gdb) bt ====\\n\nbt\necho \\n\\n\necho ==== (gdb) bt full ====\\n\nbt full\necho\\n\\n\necho ==== (gdb) info thread ====\\n\ninfo thread\necho\\n\\n\necho ==== (gdb) thread apply all bt ====\\n\nthread apply all bt
 RemoveFromBacktraceRegExp=\(no debugging symbols found\)\.\.\.\\n?
 InvalidStackFrameRegExp=\\n#[0-9]+\\s+0x[0-9A-Fa-f]+ \w* \?\?
 FrameRegExp=\\n#[0-9]+\\s+0x[0-9A-Fa-f]+
 NeededInValidBacktraceRegExp=\\n#5
 KCrashRegExp=\\n#0[ ]*0x[0123456789abcdefABCDEF]+.*<signal handler called>[ ]*\\n
 KCrashRegExpSingle=\\n0x[0123456789abcdefABCDEF][^\\n]*\\n
+ThreadRegExp=\\nThread [0123456789]

drkonqi/krashconf.cpp

@@ -112,6 +112,7 @@ void KrashConfig :: readConfig()
   m_neededInValidBacktraceRegExp = debuggers.readEntry("NeededInValidBacktraceRegExp");
   m_kcrashRegExp = debuggers.readEntry("KCrashRegExp");
   m_kcrashRegExpSingle = debuggers.readEntry("KCrashRegExpSingle");
+  m_threadRegExp = debuggers.readEntry("ThreadRegExp");
 
   KConfig preset(TQString::fromLatin1("presets/%1rc").arg(configname),
                  true, false, "appdata");

drkonqi/krashconf.h

@@ -67,6 +67,7 @@ public:
   TQString neededInValidBacktraceRegExp() const { return m_neededInValidBacktraceRegExp; }
   TQString kcrashRegExp() const { return m_kcrashRegExp; }
   TQString kcrashRegExpSingle() const { return m_kcrashRegExpSingle; }
+  TQString threadRegExp() const { return m_threadRegExp; }
   bool showBacktrace() const { return m_showbacktrace; };
   bool showDebugger() const { return m_showdebugger && !m_debugger.isNull(); };
   bool showBugReport() const { return m_showbugreport; };
@@ -110,6 +111,7 @@ private:
   TQString m_neededInValidBacktraceRegExp;
   TQString m_kcrashRegExp;
   TQString m_kcrashRegExpSingle;
+  TQString m_threadRegExp;
 };
 
 #endif