cxl/event_trace: parse arrays separately from strings

Arrays are being parsed as strings based on a flag that seems like
it would be the differentiator, ARRAY and STRING, but it is not.

libtraceevent sets the flags for arrays and strings like this:
array:  TEP_FIELD_IS_[ARRAY | STRING]
string: TEP_FIELD_IS_[ARRAY | STRING | DYNAMIC]

Use TEP_FIELD_IS_DYNAMIC to discover the field type, otherwise arrays
get parsed as strings and 'cxl monitor' returns gobbledygook in the
array type fields.

This fixes the "data" field of cxl_generic_events and the "uuid" field
of cxl_poison.

That cxl_poison uuid format can be further improved by using the trace
type (__field_struct uuid_t) in the CXL kernel driver. The parser will
automatically pick up that new type, as illustrated in the "hdr_uuid"
of cxl_generic_media event trace above.

Signed-off-by: Alison Schofield <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Dave Jiang <[email protected]>
Signed-off-by: Vishal Verma <[email protected]>

cxl/event_trace.c

@@ -109,7 +109,13 @@ static int cxl_event_to_json(struct tep_event *event, struct tep_record *record,
 		struct tep_format_field *f = fields[i];
 		int len;
 
-		if (f->flags & TEP_FIELD_IS_STRING) {
+		/*
+		 * libtraceevent differentiates arrays and strings like this:
+		 * array:  TEP_FIELD_IS_[ARRAY | STRING]
+		 * string: TEP_FIELD_IS_[ARRAY | STRING | DYNAMIC]
+		 */
+		if ((f->flags & TEP_FIELD_IS_STRING) &&
+		    ((f->flags & TEP_FIELD_IS_DYNAMIC))) {
 			char *str;
 
 			str = tep_get_field_raw(NULL, event, f->name, record, &len, 0);