**** Backport of 139424 ****

2009-08-05  Martin Baulig  <martin@ximian.com>

	**** Backport of 139424 ****

	* backend/server/x86_64-arch.c
	(find_code_buffer_slot): Return a different slot each time we're
	called until we iterated over the entire buffer; it looks like
	there's a very weird race condition somewhere in the kernel which
	doesn't always flush the cpu's instruction cache when modifying
	the current instruction and then immediately executing it.
	(x86_arch_child_stopped): Return `STOP_ACTION_INTERNAL_ERROR' if
	we stopped at an unexpected location inside the code buffer.

	* backend/server/i386-arch.c
	(find_code_buffer_slot): No idea whether we need this here as
	well, but it doesn't hurt doing it here as well.

	* backend/server/x86-arch.h
	(ChildStoppedAction): Added `STOP_ACTION_INTERNAL_ERROR'.

	* backend/server/server.h
	(ServerStatusMessageType): Added `MESSAGE_INTERNAL_ERROR'.

	* backend/Inferior.cs
	(Inferior.ChildEventType): Added `INTERNAL_ERROR'.

svn path=/branches/mono-2-4-2/debugger/; revision=139432

ChangeLog

@@ -1,3 +1,29 @@
+2009-08-05  Martin Baulig  <martin@ximian.com>
+
+	**** Backport of 139424 ****
+
+	* backend/server/x86_64-arch.c
+	(find_code_buffer_slot): Return a different slot each time we're
+	called until we iterated over the entire buffer; it looks like
+	there's a very weird race condition somewhere in the kernel which
+	doesn't always flush the cpu's instruction cache when modifying
+	the current instruction and then immediately executing it.
+	(x86_arch_child_stopped): Return `STOP_ACTION_INTERNAL_ERROR' if
+	we stopped at an unexpected location inside the code buffer.
+
+	* backend/server/i386-arch.c
+	(find_code_buffer_slot): No idea whether we need this here as
+	well, but it doesn't hurt doing it here as well.
+
+	* backend/server/x86-arch.h
+	(ChildStoppedAction): Added `STOP_ACTION_INTERNAL_ERROR'.
+
+	* backend/server/server.h
+	(ServerStatusMessageType): Added `MESSAGE_INTERNAL_ERROR'.
+
+	* backend/Inferior.cs
+	(Inferior.ChildEventType): Added `INTERNAL_ERROR'.
+
 2009-08-05  Martin Baulig  <martin@ximian.com>
 
 	**** Backport of 139423 ****

backend/Inferior.cs

@@ -207,6 +207,7 @@ internal enum ChildEventType {
 			CHILD_NOTIFICATION,
 			CHILD_INTERRUPTED,
 			RUNTIME_INVOKE_DONE,
+			INTERNAL_ERROR,
 
 			UNHANDLED_EXCEPTION	= 4001,
 			THROW_EXCEPTION,

backend/SingleSteppingEngine.cs

@@ -389,6 +389,13 @@ public void ProcessEvent (Inferior.ChildEvent cevent)
 					OperationCompleted (new TargetEventArgs (TargetEventType.TargetSignaled, arg));
 				return;
 
+			case Inferior.ChildEventType.INTERNAL_ERROR:
+				frame_changed (inferior.CurrentFrame, null);
+				Report.Error ("{0} got {1} at {2} while executing {2}", this, message,
+					      inferior.CurrentFrame, current_operation);
+				OperationCompleted (new TargetEventArgs (TargetEventType.TargetSignaled, -1));
+				return true;
+
 			case Inferior.ChildEventType.CHILD_EXITED:
 				OperationCompleted (new TargetEventArgs (TargetEventType.TargetExited, arg));
 				return;

backend/server/i386-arch.c

@@ -1153,11 +1153,22 @@ find_code_buffer_slot (MonoRuntimeInfo *runtime)
 {
 	int i;
 
+	for (i = runtime->executable_code_last_slot + 1; i < runtime->executable_code_total_chunks; i++) {
+		if (runtime->executable_code_bitfield [i])
+			continue;
+
+		runtime->executable_code_bitfield [i] = 1;
+		runtime->executable_code_last_slot = i;
+		return i;
+	}
+
+	runtime->executable_code_last_slot = 0;
 	for (i = 0; i < runtime->executable_code_total_chunks; i++) {
 		if (runtime->executable_code_bitfield [i])
 			continue;
 
 		runtime->executable_code_bitfield [i] = 1;
+		runtime->executable_code_last_slot = i;
 		return i;
 	}
 

backend/server/server.h

@@ -54,7 +54,8 @@ typedef enum {
 	MESSAGE_CHILD_CALLED_EXIT,
 	MESSAGE_CHILD_NOTIFICATION,
 	MESSAGE_CHILD_INTERRUPTED,
-	MESSAGE_RUNTIME_INVOKE_DONE
+	MESSAGE_RUNTIME_INVOKE_DONE,
+	MESSAGE_INTERNAL_ERROR
 } ServerStatusMessageType;
 
 typedef struct {
@@ -94,6 +95,7 @@ typedef struct
 	/* Private */
 	guint8 *breakpoint_table_bitfield;
 	guint8 *executable_code_bitfield;
+	guint32 executable_code_last_slot;
 } MonoRuntimeInfo;
 
 /* This is an opaque data structure which the backend may use to store stuff. */

backend/server/x86-arch.h

@@ -12,7 +12,8 @@ typedef enum {
 	STOP_ACTION_CALLBACK,
 	STOP_ACTION_CALLBACK_COMPLETED,
 	STOP_ACTION_NOTIFICATION,
-	STOP_ACTION_RTI_DONE
+	STOP_ACTION_RTI_DONE,
+	STOP_ACTION_INTERNAL_ERROR
 } ChildStoppedAction;
 
 typedef enum {

backend/server/x86-ptrace.c

@@ -347,6 +347,9 @@ server_ptrace_dispatch_event (ServerHandle *handle, guint32 status, guint64 *arg
 			*data1 = retval;
 			*data2 = retval2;
 			return MESSAGE_RUNTIME_INVOKE_DONE;
+
+		case STOP_ACTION_INTERNAL_ERROR:
+			return MESSAGE_INTERNAL_ERROR;
 		}
 
 		g_assert_not_reached ();

backend/server/x86_64-arch.c

@@ -294,7 +294,7 @@ x86_arch_child_stopped (ServerHandle *handle, int stopsig,
 		if (cbuffer->code_address + cbuffer->insn_size != INFERIOR_REG_RIP (arch->current_regs)) {
 			char buffer [1024];
 
-			g_warning (G_STRLOC ": %Lx,%d - %Lx - %Lx",
+			g_warning (G_STRLOC ": %d - %Lx,%d - %Lx - %Lx", cbuffer->slot,
 				   cbuffer->code_address, cbuffer->insn_size,
 				   cbuffer->code_address + cbuffer->insn_size,
 				   INFERIOR_REG_RIP (arch->current_regs));
@@ -304,7 +304,7 @@ x86_arch_child_stopped (ServerHandle *handle, int stopsig,
 				   buffer [0], buffer [1], buffer [2], buffer [3], buffer [4],
 				   buffer [5], buffer [6], buffer [7]);
 
-			return STOP_ACTION_STOPPED;
+			return STOP_ACTION_INTERNAL_ERROR;
 		}
 
 		INFERIOR_REG_RIP (arch->current_regs) = cbuffer->original_rip;
@@ -1202,11 +1202,22 @@ find_code_buffer_slot (MonoRuntimeInfo *runtime)
 {
 	int i;
 
+	for (i = runtime->executable_code_last_slot + 1; i < runtime->executable_code_total_chunks; i++) {
+		if (runtime->executable_code_bitfield [i])
+			continue;
+
+		runtime->executable_code_bitfield [i] = 1;
+		runtime->executable_code_last_slot = i;
+		return i;
+	}
+
+	runtime->executable_code_last_slot = 0;
 	for (i = 0; i < runtime->executable_code_total_chunks; i++) {
 		if (runtime->executable_code_bitfield [i])
 			continue;
 
 		runtime->executable_code_bitfield [i] = 1;
+		runtime->executable_code_last_slot = i;
 		return i;
 	}