[PATCH 2/9] selftests/exec: let binfmt_flag_supported() return a bool

[Christian Brauner <brauner@kernel.org>]

binfmt_flag_supported() returns 0 when the flag is supported and -1
when it is not, so every caller reads backwards:

	if (binfmt_flag_supported('T'))
		SKIP(return, "kernel without the 'T' flag");

Make it return a bool and flip the callers. errno from a failed probe
is still set for callers that check it.

Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---
 tools/testing/selftests/exec/binfmt_misc_bpf.c         | 2 +-
 tools/testing/selftests/exec/binfmt_misc_common.h      | 6 +++---
 tools/testing/selftests/exec/binfmt_misc_transparent.c | 2 +-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/exec/binfmt_misc_bpf.c b/tools/testing/selftests/exec/binfmt_misc_bpf.c
index 069768a66ba0..c6f5e8f34985 100644
--- a/tools/testing/selftests/exec/binfmt_misc_bpf.c
+++ b/tools/testing/selftests/exec/binfmt_misc_bpf.c
@@ -258,7 +258,7 @@ TEST_F(bpf_handler, transparent_dispatch)
 	char src[PATH_MAX], cmd[PATH_MAX + 16];
 
 	/* Probe for transparent-mode support via its static counterpart. */
-	if (binfmt_flag_supported('T'))
+	if (!binfmt_flag_supported('T'))
 		SKIP(return, "kernel without transparent mode");
 
 	ASSERT_EQ(artifact_path(src, sizeof(src), "binfmt_transparent_interp"), 0);
diff --git a/tools/testing/selftests/exec/binfmt_misc_common.h b/tools/testing/selftests/exec/binfmt_misc_common.h
index c6900ded019f..e8d67908dbc4 100644
--- a/tools/testing/selftests/exec/binfmt_misc_common.h
+++ b/tools/testing/selftests/exec/binfmt_misc_common.h
@@ -117,16 +117,16 @@ static inline int artifact_path(char *out, size_t sz, const char *name)
 }
 
 /* Probe kernel support for a registration flag with a throwaway entry. */
-static inline int binfmt_flag_supported(char flag)
+static inline bool binfmt_flag_supported(char flag)
 {
 	char rule[64];
 
 	snprintf(rule, sizeof(rule), ":bm_flag_probe:E::bmprobe::/bin/true:%c",
 		 flag);
 	if (write_reg(rule))
-		return -1;
+		return false;
 	unregister("bm_flag_probe");
-	return 0;
+	return true;
 }
 
 /*
diff --git a/tools/testing/selftests/exec/binfmt_misc_transparent.c b/tools/testing/selftests/exec/binfmt_misc_transparent.c
index d0cb845df1d3..2ebf73de8018 100644
--- a/tools/testing/selftests/exec/binfmt_misc_transparent.c
+++ b/tools/testing/selftests/exec/binfmt_misc_transparent.c
@@ -56,7 +56,7 @@ FIXTURE_SETUP(transparent)
 	ASSERT_EQ(create_target(), 0);
 
 	/* Skip the whole suite on a kernel that does not know 'T'. */
-	if (binfmt_flag_supported('T')) {
+	if (!binfmt_flag_supported('T')) {
 		ASSERT_EQ(errno, EINVAL);
 		SKIP(return, "kernel without the 'T' flag");
 	}

-- 
2.53.0