[PATCH] tracing/user_events: Fix the order of the fields in the trace output

From: sunliming
Date: Thu May 25 2023 - 01:40:44 EST

Commit 4bec284cc0b9 ("tracing/user_events: Use print_format_fields() for
trace output") use print_event_fields() as safe and gives user readable
output. However, due to the insertion of the struct ftrace_event_field
structure into the field linked list from the header, the trace output
oder of fields of user events is reversed. Fix the problem by insertint
to the tail of field linked list.

Signed-off-by: sunliming <sunliming@xxxxxxxxxx>
kernel/trace/trace_events_user.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c
index aacd22c1e9f8..e9e2ec3c7613 100644
--- a/kernel/trace/trace_events_user.c
+++ b/kernel/trace/trace_events_user.c
@@ -972,7 +972,7 @@ static int user_event_add_field(struct user_event *user, const char *type,
if (filter_type == FILTER_OTHER)
field->filter_type = filter_assign_type(type);

- list_add(&field->link, &user->fields);
+ list_add_tail(&field->link, &user->fields);

* Min size from user writes that are required, this does not include