tools/bpf: simplify libbpf API function libbpf_set_print()

Currently, the libbpf API function libbpf_set_print()
takes three function pointer parameters for warning, info
and debug printout respectively.

This patch changes the API to have just one function pointer
parameter and the function pointer has one additional
parameter "debugging level". So if in the future, if
the debug level is increased, the function signature
won't change.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 18 insertions, 2 deletions

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index a08d026ac396..55d05102e7bf 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -10,6 +10,7 @@
 #include <string.h>
 #include <assert.h>
 #include <stdlib.h>
+#include <stdarg.h>
 #include <time.h>
 
 #include <linux/types.h>
@@ -1783,6 +1784,21 @@ static void test_task_fd_query_tp(void)
 				   "sys_enter_read");
 }
 
+static int libbpf_debug_print(enum libbpf_print_level level,
+			      const char *format, ...)
+{
+	va_list args;
+	int ret;
+
+	if (level == LIBBPF_DEBUG)
+		return 0;
+
+	va_start(args, format);
+	ret = vfprintf(stderr, format, args);
+	va_end(args);
+	return ret;
+}
+
 static void test_reference_tracking()
 {
 	const char *file = "./test_sk_lookup_kern.o";
@@ -1809,9 +1825,9 @@ static void test_reference_tracking()
 
 		/* Expect verifier failure if test name has 'fail' */
 		if (strstr(title, "fail") != NULL) {
-			libbpf_set_print(NULL, NULL, NULL);
+			libbpf_set_print(NULL);
 			err = !bpf_program__load(prog, "GPL", 0);
-			libbpf_set_print(printf, printf, NULL);
+			libbpf_set_print(libbpf_debug_print);
 		} else {
 			err = bpf_program__load(prog, "GPL", 0);
 		}