From: Donglin Peng <[email protected]>
Use BTF to print symbolic names for enum-type function arguments,
improving trace readability.
Before:
count_memcg_events(memcg=0xffff..., idx=20, count=0x1) {
After:
count_memcg_events(memcg=0xffff..., idx=20 [PGFAULT], count=0x1) {
Cc: Steven Rostedt <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: [email protected]
Signed-off-by: Donglin Peng <[email protected]>
---
kernel/trace/trace_output.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index cc2d3306bb60..c395f768c3b8 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -695,12 +695,13 @@ void print_function_args(struct trace_seq *s, unsigned
long *args,
{
const struct btf_param *param;
const struct btf_type *t;
+ const struct btf_enum *enump;
const char *param_name;
char name[KSYM_NAME_LEN];
unsigned long arg;
struct btf *btf;
s32 tid, nr = 0;
- int a, p, x;
+ int a, p, x, i;
u16 encode;
trace_seq_printf(s, "(");
@@ -754,6 +755,14 @@ void print_function_args(struct trace_seq *s, unsigned
long *args,
break;
case BTF_KIND_ENUM:
trace_seq_printf(s, "%ld", arg);
+ for_each_enum(i, t, enump) {
+ if (arg == enump->val) {
+ trace_seq_printf(s, " [%s]",
+ btf_name_by_offset(btf,
+ enump->name_off));
+ break;
+ }
+ }
break;
default:
/* This does not handle complex arguments */
--
2.34.1
