[PATCH 1/2] libtraceevent: Do not fail field parsing if field has typecast

[Steven Rostedt <rostedt@xxxxxxxxxxx>]

If a field is expected for a printk format but is typecasted, it could
fail the parsing where the error is a "helpful":

  ARG TYPE NOT FIELD BUT 7

Add a check before each of these to see if it is a typecast, and use the
arg that the typecast is for.

Link: https://lore.kernel.org/all/164182978641.8391.8277203495236105391.stgit@xxxxxxxxxxxxxxxxxxxxxxx/

Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
 src/event-parse.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/event-parse.c b/src/event-parse.c
index 9bd605d74b1f..5f3e2d8a6421 100644
--- a/src/event-parse.c
+++ b/src/event-parse.c
@@ -4834,6 +4834,10 @@ static int print_mac_arg(struct trace_seq *s, const char *format,
 		return 0;
 	}
 
+	/* evaluate if the arg has a type cast */
+	while (arg->type == TEP_PRINT_TYPE)
+		arg = arg->typecast.item;
+
 	if (arg->type != TEP_PRINT_FIELD) {
 		trace_seq_printf(s, "ARG TYPE NOT FIELD BUT %d",
 				 arg->type);
@@ -5042,6 +5046,10 @@ static int print_ipv4_arg(struct trace_seq *s, const char *ptr, char i,
 		return ret;
 	}
 
+	/* evaluate if the arg has a type cast */
+	while (arg->type == TEP_PRINT_TYPE)
+		arg = arg->typecast.item;
+
 	if (arg->type != TEP_PRINT_FIELD) {
 		trace_seq_printf(s, "ARG TYPE NOT FIELD BUT %d", arg->type);
 		return ret;
@@ -5089,6 +5097,10 @@ static int print_ipv6_arg(struct trace_seq *s, const char *ptr, char i,
 		return rc;
 	}
 
+	/* evaluate if the arg has a type cast */
+	while (arg->type == TEP_PRINT_TYPE)
+		arg = arg->typecast.item;
+
 	if (arg->type != TEP_PRINT_FIELD) {
 		trace_seq_printf(s, "ARG TYPE NOT FIELD BUT %d", arg->type);
 		return rc;
@@ -5152,6 +5164,10 @@ static int print_ipsa_arg(struct trace_seq *s, const char *ptr, char i,
 		return rc;
 	}
 
+	/* evaluate if the arg has a type cast */
+	while (arg->type == TEP_PRINT_TYPE)
+		arg = arg->typecast.item;
+
 	if (arg->type != TEP_PRINT_FIELD) {
 		trace_seq_printf(s, "ARG TYPE NOT FIELD BUT %d", arg->type);
 		return rc;
@@ -5267,6 +5283,10 @@ static int print_uuid_arg(struct trace_seq *s, const char *ptr,
 		return ret;
 	}
 
+	/* evaluate if the arg has a type cast */
+	while (arg->type == TEP_PRINT_TYPE)
+		arg = arg->typecast.item;
+
 	if (arg->type != TEP_PRINT_FIELD) {
 		trace_seq_printf(s, "ARG TYPE NOT FIELD BUT %d", arg->type);
 		return ret;
@@ -5440,6 +5460,7 @@ static inline void print_field(struct trace_seq *s, void *data, int size,
 	struct tep_event *event = field->event;
 	struct tep_print_parse *start_parse;
 	struct tep_print_parse *parse;
+	struct tep_print_arg *arg;
 	bool has_0x;
 
 	parse = parse_ptr ? *parse_ptr : event->print_fmt.print_cache;
@@ -5464,9 +5485,13 @@ static inline void print_field(struct trace_seq *s, void *data, int size,
 			goto next;
 		}
 
-		if (!parse->arg ||
-		    parse->arg->type != TEP_PRINT_FIELD ||
-		    parse->arg->field.field != field) {
+		arg = parse->arg;
+
+		while (arg && arg->type == TEP_PRINT_TYPE)
+			arg = arg->typecast.item;
+
+		if (!arg || arg->type != TEP_PRINT_FIELD ||
+		    arg->field.field != field) {
 			has_0x = false;
 			goto next;
 		}
-- 
2.33.0