[PATCH v3 3/4] libtraceevent: Have BTF find functions with extra characters

From: "Steven Rostedt (Google)" <[email protected]>

Sometimes the symbol of a function has extra characters followed by a '.'.
In this case, the BTF lookup may not find the function. If the function is
not found and the function name contains a '.', try stripping off the
extra characters and try again. That way, instead of:

  __mutex_unlock_slowpath.isra.0(ffffffffb5cd4e40, 8, 1, 1, ffffffffb43e0fe4, ffffed1024699f88)

It can produce:

  __mutex_unlock_slowpath.isra.0(lock=0xffffffffb5cd4e40, ip=0x8)

Signed-off-by: Steven Rostedt (Google) <[email protected]>
---
 src/trace-btf.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/trace-btf.c b/src/trace-btf.c
index 12dc49447027..742cffd35edc 100644
--- a/src/trace-btf.c
+++ b/src/trace-btf.c
@@ -357,11 +357,23 @@ int tep_btf_print_args(struct tep_handle *tep, struct trace_seq *s, void *args,
 	unsigned long long arg;
 	unsigned int encode;
 	const char *param_name;
+	const char *fp;
 	int a, p, x, nr;
 
 	if (size != 4 && size != 8)
 		return -1;
 
+	if (!type && (fp = strchr(func, '.'))) {
+		char *f;
+		/* func name has extra characters */
+		f = strdup(func);
+		if (f) {
+			f[fp - func] = '\0';
+			type = tep_btf_find_func(btf, f);
+			free(f);
+		}
+	}
+
 	if (!type) {
 		for (int i = 0; i < nmem; i++) {
 			assign_arg(&arg, args, size, i);
-- 
2.51.0