[ndctl PATCH] cxl/event_trace: parse arrays separately from strings

[alison . schofield]

From: Alison Schofield <alison.schofi...@intel.com>

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.

Before:
{"system":"cxl","event":"cxl_generic_event","timestamp":3469041387470,"memdev":"mem0","host":"cxl_mem.0","log":0,"hdr_uuid":"ba5eba11-abcd-efeb-a55a-a55aa5a55aa5","serial":0,"hdr_flags":8,"hdr_handle":1,"hdr_related_handle":42422,"hdr_timestamp":0,"hdr_length":128,"hdr_maint_op_class":0,"data":"Þ­¾ï"}

After:
{"system":"cxl","event":"cxl_generic_event","timestamp":312851657810,"memdev":"mem0","host":"cxl_mem.0","log":0,"hdr_uuid":"ba5eba11-abcd-efeb-a55a-a55aa5a55aa5","serial":0,"hdr_flags":8,"hdr_handle":1,"hdr_related_handle":42422,"hdr_timestamp":0,"hdr_length":128,"hdr_maint_op_class":0,"data":[222,173,190,239,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]}

Before:
{"system":"cxl","event":"cxl_poison","timestamp":3292418311609,"memdev":"mem1","host":"cxl_mem.1","serial":1,"trace_type":2,"region":"region5","overflow_ts":0,"hpa":1035355557888,"dpa":1073741824,"dpa_length":64,"uuid":"�Fe�c�CI�����2�]","source":0,"flags":0}

After:
{"system":"cxl","event":"cxl_poison","timestamp":94600531271,"memdev":"mem1","host":"cxl_mem.1","serial":1,"trace_type":2,"region":"region5","overflow_ts":0,"hpa":1035355557888,"dpa":1073741824,"dpa_length":64,"uuid":[139,200,184,22,236,103,76,121,157,243,47,110,243,11,158,62],"source":0,"flags":0}

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 <alison.schofi...@intel.com>
---
 cxl/event_trace.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/cxl/event_trace.c b/cxl/event_trace.c
index db8cc85f0b6f..1b5aa09de8b2 100644
--- a/cxl/event_trace.c
+++ b/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);

base-commit: a871e6153b11fe63780b37cdcb1eb347b296095c
-- 
2.37.3