Revert "selftests/bpf: extend changes_pkt_data with cases w/o subprograms"

This reverts commit 04789af756a4a43e72986185f66f148e65b32fed which is
commit 04789af756a4a43e72986185f66f148e65b32fed upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I454badded1d44b44beded5b1382c581caf57fc03
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

tools/testing/selftests/bpf/prog_tests/changes_pkt_data.c

@@ -10,14 +10,10 @@ static void print_verifier_log(const char *log)
 		fprintf(stdout, "VERIFIER LOG:\n=============\n%s=============\n", log);
 }
 
-static void test_aux(const char *main_prog_name,
+static void test_aux(const char *main_prog_name, const char *freplace_prog_name, bool expect_load)
-		     const char *to_be_replaced,
-		     const char *replacement,
-		     bool expect_load)
 {
 	struct changes_pkt_data_freplace *freplace = NULL;
 	struct bpf_program *freplace_prog = NULL;
-	struct bpf_program *main_prog = NULL;
 	LIBBPF_OPTS(bpf_object_open_opts, opts);
 	struct changes_pkt_data *main = NULL;
 	char log[16*1024];
@@ -30,10 +26,6 @@ static void test_aux(const char *main_prog_name,
 	main = changes_pkt_data__open_opts(&opts);
 	if (!ASSERT_OK_PTR(main, "changes_pkt_data__open"))
 		goto out;
-	main_prog = bpf_object__find_program_by_name(main->obj, main_prog_name);
-	if (!ASSERT_OK_PTR(main_prog, "main_prog"))
-		goto out;
-	bpf_program__set_autoload(main_prog, true);
 	err = changes_pkt_data__load(main);
 	print_verifier_log(log);
 	if (!ASSERT_OK(err, "changes_pkt_data__load"))
@@ -41,14 +33,14 @@ static void test_aux(const char *main_prog_name,
 	freplace = changes_pkt_data_freplace__open_opts(&opts);
 	if (!ASSERT_OK_PTR(freplace, "changes_pkt_data_freplace__open"))
 		goto out;
-	freplace_prog = bpf_object__find_program_by_name(freplace->obj, replacement);
+	freplace_prog = bpf_object__find_program_by_name(freplace->obj, freplace_prog_name);
 	if (!ASSERT_OK_PTR(freplace_prog, "freplace_prog"))
 		goto out;
 	bpf_program__set_autoload(freplace_prog, true);
 	bpf_program__set_autoattach(freplace_prog, true);
 	bpf_program__set_attach_target(freplace_prog,
-				       bpf_program__fd(main_prog),
+				       bpf_program__fd(main->progs.dummy),
-				       to_be_replaced);
+				       main_prog_name);
 	err = changes_pkt_data_freplace__load(freplace);
 	print_verifier_log(log);
 	if (expect_load) {
@@ -70,38 +62,15 @@ out:
  * that either do or do not. It is only ok to freplace subprograms
  * that do not change packet data with those that do not as well.
  * The below tests check outcomes for each combination of such freplace.
- * Also test a case when main subprogram itself is replaced and is a single
- * subprogram in a program.
  */
 void test_changes_pkt_data_freplace(void)
 {
-	struct {
+	if (test__start_subtest("changes_with_changes"))
-		const char *main;
+		test_aux("changes_pkt_data", "changes_pkt_data", true);
-		const char *to_be_replaced;
+	if (test__start_subtest("changes_with_doesnt_change"))
-		bool changes;
+		test_aux("changes_pkt_data", "does_not_change_pkt_data", true);
-	} mains[] = {
+	if (test__start_subtest("doesnt_change_with_changes"))
-		{ "main_with_subprogs",   "changes_pkt_data",         true },
+		test_aux("does_not_change_pkt_data", "changes_pkt_data", false);
-		{ "main_with_subprogs",   "does_not_change_pkt_data", false },
+	if (test__start_subtest("doesnt_change_with_doesnt_change"))
-		{ "main_changes",         "main_changes",             true },
+		test_aux("does_not_change_pkt_data", "does_not_change_pkt_data", true);
-		{ "main_does_not_change", "main_does_not_change",     false },
-	};
-	struct {
-		const char *func;
-		bool changes;
-	} replacements[] = {
-		{ "changes_pkt_data",         true },
-		{ "does_not_change_pkt_data", false }
-	};
-	char buf[64];
-
-	for (int i = 0; i < ARRAY_SIZE(mains); ++i) {
-		for (int j = 0; j < ARRAY_SIZE(replacements); ++j) {
-			snprintf(buf, sizeof(buf), "%s_with_%s",
-				 mains[i].to_be_replaced, replacements[j].func);
-			if (!test__start_subtest(buf))
-				continue;
-			test_aux(mains[i].main, mains[i].to_be_replaced, replacements[j].func,
-				 mains[i].changes || !replacements[j].changes);
-		}
-	}
 }

tools/testing/selftests/bpf/progs/changes_pkt_data.c

@@ -4,35 +4,22 @@
 #include <bpf/bpf_helpers.h>
 
 __noinline
-long changes_pkt_data(struct __sk_buff *sk)
+long changes_pkt_data(struct __sk_buff *sk, __u32 len)
 {
-	return bpf_skb_pull_data(sk, 0);
+	return bpf_skb_pull_data(sk, len);
 }
 
 __noinline __weak
-long does_not_change_pkt_data(struct __sk_buff *sk)
+long does_not_change_pkt_data(struct __sk_buff *sk, __u32 len)
 {
 	return 0;
 }
 
-SEC("?tc")
+SEC("tc")
-int main_with_subprogs(struct __sk_buff *sk)
+int dummy(struct __sk_buff *sk)
-{
-	changes_pkt_data(sk);
-	does_not_change_pkt_data(sk);
-	return 0;
-}
-
-SEC("?tc")
-int main_changes(struct __sk_buff *sk)
-{
-	bpf_skb_pull_data(sk, 0);
-	return 0;
-}
-
-SEC("?tc")
-int main_does_not_change(struct __sk_buff *sk)
 {
+	changes_pkt_data(sk, 0);
+	does_not_change_pkt_data(sk, 0);
 	return 0;
 }
 

tools/testing/selftests/bpf/progs/changes_pkt_data_freplace.c

@@ -4,13 +4,13 @@
 #include <bpf/bpf_helpers.h>
 
 SEC("?freplace")
-long changes_pkt_data(struct __sk_buff *sk)
+long changes_pkt_data(struct __sk_buff *sk, __u32 len)
 {
-	return bpf_skb_pull_data(sk, 0);
+	return bpf_skb_pull_data(sk, len);
 }
 
 SEC("?freplace")
-long does_not_change_pkt_data(struct __sk_buff *sk)
+long does_not_change_pkt_data(struct __sk_buff *sk, __u32 len)
 {
 	return 0;
 }