perf/scripts: Tuple was set from long in both branches in python_process_event()

This is a fix to the signed/unsigned field handling in the
Python scripting engine, based on a patch from Roel Kluin.

Basically, Python wants to use a PyInt (which is internally a
long) if it can i.e. if the value will fit into that type.  If
not, it stores it into a PyLong, which isn't actually a long,
but an arbitrary-precision integer variable.

The code below is similar to to what Python does internally, and
it seems to work as expected on the x86 and x86_64 sytems I
tested it on.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Roel Kluin <roel.kluin@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: rostedt@goodmis.org
LKML-Reference: <1270184305.6422.10.camel@tropicana>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index 33a414b..6a72f14 100644 (file)
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -208,7 +208,7 @@ static void python_process_event(int cpu, void *data,
                                 int size __unused,
                                 unsigned long long nsecs, char *comm)
 {
-       PyObject *handler, *retval, *context, *t;
+       PyObject *handler, *retval, *context, *t, *obj;
        static char handler_name[256];
        struct format_field *field;
        unsigned long long val;
@@ -256,16 +256,23 @@ static void python_process_event(int cpu, void *data,
                                offset &= 0xffff;
                        } else
                                offset = field->offset;
-                       PyTuple_SetItem(t, n++,
-                               PyString_FromString((char *)data + offset));
+                       obj = PyString_FromString((char *)data + offset);
                } else { /* FIELD_IS_NUMERIC */
                        val = read_size(data + field->offset, field->size);
                        if (field->flags & FIELD_IS_SIGNED) {
-                               PyTuple_SetItem(t, n++, PyInt_FromLong(val));
+                               if ((long long)val >= LONG_MIN &&
+                                   (long long)val <= LONG_MAX)
+                                       obj = PyInt_FromLong(val);
+                               else
+                                       obj = PyLong_FromLongLong(val);
                        } else {
-                               PyTuple_SetItem(t, n++, PyInt_FromLong(val));
+                               if (val <= LONG_MAX)
+                                       obj = PyInt_FromLong(val);
+                               else
+                                       obj = PyLong_FromUnsignedLongLong(val);
                        }
                }
+               PyTuple_SetItem(t, n++, obj);
        }
 
        if (_PyTuple_Resize(&t, n) == -1)