Enable handle tracing in Canary, Dev, and all debug builds of Chrome (Windows only).

sandbox/win/src/handle_closer_agent.cc

Index: sandbox/win/src/handle_closer_agent.cc
diff --git a/sandbox/win/src/handle_closer_agent.cc b/sandbox/win/src/handle_closer_agent.cc
index be262e8d158c192407c89f78387ff8f87df0e8b3..b7e872c7112bbd9bde8367651e5c79f2c1bc89e3 100644
--- a/sandbox/win/src/handle_closer_agent.cc
+++ b/sandbox/win/src/handle_closer_agent.cc
@@ -10,6 +10,12 @@
 
 namespace {
 
+int QueryObjectTypeInformationFilter(EXCEPTION_POINTERS* exception_pointers,
+                                     NTSTATUS* exception_code) {
+  *exception_code = exception_pointers->ExceptionRecord->ExceptionCode;
+  return EXCEPTION_EXECUTE_HANDLER;

[rvargas (doing something else), 2012/10/03 03:01:16]

I'm a little concerned here about the actual handling of the exception, given
that not all exceptions are created equal. Should't we at least filter
breakpoints?

+}
+
 // Returns type infomation for an NT object. This routine is expected to be
 // called for invalid handles so it catches STATUS_INVALID_HANDLE exceptions
 // that can be generated when handle tracing is enabled.
@@ -20,14 +26,13 @@ NTSTATUS QueryObjectTypeInformation(HANDLE handle,
   if (!QueryObject)
     ResolveNTFunctionPtr("NtQueryObject", &QueryObject);
 
-  NTSTATUS status = STATUS_UNSUCCESSFUL;
+  NTSTATUS exception_code = STATUS_UNSUCCESSFUL;

[rvargas (doing something else), 2012/10/03 03:01:16]

I would prefer setting exeption_code, but I don't think I fully understand your
concern.

If NtQueryOpen is patched, and there's an exception in that code, what changes?
(I mean, we are not assigning the value)... if it is being patched? If it is
executing the assignment? I don't see it. Stack corruption? let it crash :)

   __try {
-    status = QueryObject(handle, ObjectTypeInformation, buffer, *size, size);
-  } __except(GetExceptionCode() == STATUS_INVALID_HANDLE ?
-                 EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH) {
-    status = STATUS_INVALID_HANDLE;
+    return QueryObject(handle, ObjectTypeInformation, buffer, *size, size);
+  } __except(QueryObjectTypeInformationFilter(GetExceptionInformation(),
+                                              &exception_code)) {

[cpu_(ooo_6.6-7.5), 2012/10/02 19:21:37]

can't you call GetExceptionCode() from the body of the __except and not need
block 12-17 ?

[alexeypa (please no reviews), 2012/10/02 19:23:22]

GetExceptionCode() can only be called from the filter expression. It is not a
real function. Calling it from any other place will result in compiler error.

+    return exception_code;
   }
-  return status;
 }
 
 }  // namespace