selftests/bpf: Refactor trace helper func load_kallsyms_local()

Refactor trace helper function load_kallsyms_local() such that
it invokes a common function with a compare function as input.
The common function will be used later for other local functions.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240326041508.1199239-1-yonghong.song@linux.devSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/trace_helpers.c

@@ -61,12 +61,7 @@ void free_kallsyms_local(struct ksyms *ksyms)
 	free(ksyms);
 }
 
-static int ksym_cmp(const void *p1, const void *p2)
-{
-	return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
-}
-
-struct ksyms *load_kallsyms_local(void)
+static struct ksyms *load_kallsyms_local_common(ksym_cmp_t cmp_cb)
 {
 	FILE *f;
 	char func[256], buf[256];
@@ -100,7 +95,7 @@ struct ksyms *load_kallsyms_local(void)
 			goto error;
 	}
 	fclose(f);
-	qsort(ksyms->syms, ksyms->sym_cnt, sizeof(struct ksym), ksym_cmp);
+	qsort(ksyms->syms, ksyms->sym_cnt, sizeof(struct ksym), cmp_cb);
 	return ksyms;
 
 error:
@@ -109,6 +104,16 @@ struct ksyms *load_kallsyms_local(void)
 	return NULL;
 }
 
+static int ksym_cmp(const void *p1, const void *p2)
+{
+	return ((struct ksym *)p1)->addr - ((struct ksym *)p2)->addr;
+}
+
+struct ksyms *load_kallsyms_local(void)
+{
+	return load_kallsyms_local_common(ksym_cmp);
+}
+
 int load_kallsyms(void)
 {
 	pthread_mutex_lock(&ksyms_mutex);

tools/testing/selftests/bpf/trace_helpers.h

@@ -13,6 +13,8 @@ struct ksym {
 };
 struct ksyms;
 
+typedef int (*ksym_cmp_t)(const void *p1, const void *p2);
+
 int load_kallsyms(void);
 struct ksym *ksym_search(long key);
 long ksym_get_addr(const char *name);