perf script python: Fix string vs byte array resolving

Jirka reported that python code returns all arrays as strings.  This
makes impossible to get all items for byte array tracepoint field
containing 0x00 value item.

Fixing this by scanning full length of the array and returning it as
PyByteArray object in case non printable byte is found.

Signed-off-by: Jiri Olsa <[email protected]>
Reported-and-Tested-by: Jiri Pirko <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

diff --git a/tools/perf/util/scripting-engines/trace-event-python.c b/tools/perf/util/scripting-engines/trace-event-python.c
index 6ac6b7a33f4238c27b3b5457729644d339543fa6..7bd6da80533eaaa1e549eb7808a4f6b0b0075859 100644 (file)
--- a/tools/perf/util/scripting-engines/trace-event-python.c
+++ b/tools/perf/util/scripting-engines/trace-event-python.c
@@ -386,6 +386,21 @@ exit:
        return pylist;
 }
 
+static int is_printable_array(char *p, unsigned int len)
+{
+       unsigned int i;
+
+       if (!p || !len || p[len - 1] != 0)
+               return 0;
+
+       len--;
+
+       for (i = 0; i < len; i++) {
+               if (!isprint(p[i]) && !isspace(p[i]))
+                       return 0;
+       }
+       return 1;
+}
 
 static void python_process_tracepoint(struct perf_sample *sample,
                                      struct perf_evsel *evsel,
@@ -457,14 +472,26 @@ static void python_process_tracepoint(struct perf_sample *sample,
                pydict_set_item_string_decref(dict, "common_callchain", callchain);
        }
        for (field = event->format.fields; field; field = field->next) {
-               if (field->flags & FIELD_IS_STRING) {
-                       int offset;
+               unsigned int offset, len;
+               unsigned long long val;
+
+               if (field->flags & FIELD_IS_ARRAY) {
+                       offset = field->offset;
+                       len    = field->size;
                        if (field->flags & FIELD_IS_DYNAMIC) {
-                               offset = *(int *)(data + field->offset);
+                               val     = pevent_read_number(scripting_context->pevent,
+                                                            data + offset, len);
+                               offset  = val;
+                               len     = offset >> 16;
                                offset &= 0xffff;
-                       } else
-                               offset = field->offset;
-                       obj = PyString_FromString((char *)data + offset);
+                       }
+                       if (field->flags & FIELD_IS_STRING &&
+                           is_printable_array(data + offset, len)) {
+                               obj = PyString_FromString((char *) data + offset);
+                       } else {
+                               obj = PyByteArray_FromStringAndSize((const char *) data + offset, len);
+                               field->flags &= ~FIELD_IS_STRING;
+                       }
                } else { /* FIELD_IS_NUMERIC */
                        obj = get_field_numeric_entry(event, field, data);
                }