[PATCH bpf-next 1/4] selftests/bpf: support for BPF_F_TEST_STATE_FREQ in test_loader

[Eduard Zingerman <eddyz87@xxxxxxxxx>]

Adds a macro __test_state_freq, the macro expands as a btf_decl_tag of a
special form that instructs test_loader that the flag BPF_F_TEST_STATE_FREQ
has to be passed to BPF verifier when program is loaded.

Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
 tools/testing/selftests/bpf/progs/bpf_misc.h |  1 +
 tools/testing/selftests/bpf/test_loader.c    | 10 ++++++++++
 2 files changed, 11 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h
index 4a01ea9113bf..a42363a3fef1 100644
--- a/tools/testing/selftests/bpf/progs/bpf_misc.h
+++ b/tools/testing/selftests/bpf/progs/bpf_misc.h
@@ -6,6 +6,7 @@
 #define __failure		__attribute__((btf_decl_tag("comment:test_expect_failure")))
 #define __success		__attribute__((btf_decl_tag("comment:test_expect_success")))
 #define __log_level(lvl)	__attribute__((btf_decl_tag("comment:test_log_level="#lvl)))
+#define __test_state_freq	__attribute__((btf_decl_tag("comment:test_state_freq")))
 
 #if defined(__TARGET_ARCH_x86)
 #define SYSCALL_WRAPPER 1
diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c
index 679efb3aa785..ac8517a77161 100644
--- a/tools/testing/selftests/bpf/test_loader.c
+++ b/tools/testing/selftests/bpf/test_loader.c
@@ -11,6 +11,7 @@
 
 #define TEST_TAG_EXPECT_FAILURE "comment:test_expect_failure"
 #define TEST_TAG_EXPECT_SUCCESS "comment:test_expect_success"
+#define TEST_TAG_TEST_STATE_FREQ "comment:test_state_freq"
 #define TEST_TAG_EXPECT_MSG_PFX "comment:test_expect_msg="
 #define TEST_TAG_LOG_LEVEL_PFX "comment:test_log_level="
 
@@ -19,6 +20,7 @@ struct test_spec {
 	bool expect_failure;
 	const char *expect_msg;
 	int log_level;
+	bool test_state_freq;
 };
 
 static int tester_init(struct test_loader *tester)
@@ -81,6 +83,8 @@ static int parse_test_spec(struct test_loader *tester,
 			spec->expect_failure = true;
 		} else if (strcmp(s, TEST_TAG_EXPECT_SUCCESS) == 0) {
 			spec->expect_failure = false;
+		} else if (strcmp(s, TEST_TAG_TEST_STATE_FREQ) == 0) {
+			spec->test_state_freq = true;
 		} else if (str_has_pfx(s, TEST_TAG_EXPECT_MSG_PFX)) {
 			spec->expect_msg = s + sizeof(TEST_TAG_EXPECT_MSG_PFX) - 1;
 		} else if (str_has_pfx(s, TEST_TAG_LOG_LEVEL_PFX)) {
@@ -102,6 +106,7 @@ static void prepare_case(struct test_loader *tester,
 			 struct bpf_program *prog)
 {
 	int min_log_level = 0;
+	__u32 flags = 0;
 
 	if (env.verbosity > VERBOSE_NONE)
 		min_log_level = 1;
@@ -120,6 +125,11 @@ static void prepare_case(struct test_loader *tester,
 		bpf_program__set_log_level(prog, spec->log_level);
 
 	tester->log_buf[0] = '\0';
+
+	if (spec->test_state_freq)
+		flags |= BPF_F_TEST_STATE_FREQ;
+
+	bpf_program__set_flags(prog, flags);
 }
 
 static void emit_verifier_log(const char *log_buf, bool force)
-- 
2.38.2