[PATCH 2/2] kselftest/arm64: mte: Skip the hugetlb tests if MTE not supported on such mappings

[Catalin Marinas]

While the kselftest was added at the same time with the kernel support
for MTE on hugetlb mappings, the tests may be run on older kernels. Skip
the tests if PROT_MTE is not supported on MAP_HUGETLB mappings.

Fixes: 27879e8cb6b0 ("selftests: arm64: add hugetlb mte tests")
Cc: Yang Shi <yang at os.amperecomputing.com>
Reported-by: Naresh Kamboju <naresh.kamboju at linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas at arm.com>
---
 .../selftests/arm64/mte/check_hugetlb_options.c       | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tools/testing/selftests/arm64/mte/check_hugetlb_options.c b/tools/testing/selftests/arm64/mte/check_hugetlb_options.c
index 11f812635b51..3bfcd3848432 100644
--- a/tools/testing/selftests/arm64/mte/check_hugetlb_options.c
+++ b/tools/testing/selftests/arm64/mte/check_hugetlb_options.c
@@ -227,6 +227,8 @@ static int check_child_hugetlb_memory_mapping(int mem_type, int mode, int mappin
 int main(int argc, char *argv[])
 {
 	int err;
+	void *map_ptr;
+	unsigned long map_size;
 
 	err = mte_default_setup();
 	if (err)
@@ -243,6 +245,15 @@ int main(int argc, char *argv[])
 		return KSFT_FAIL;
 	}
 
+	/* Check if MTE supports hugetlb mappings */
+	map_size = default_huge_page_size();
+	map_ptr = mmap(NULL, map_size, PROT_READ | PROT_MTE,
+		       MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0);
+	if (map_ptr == MAP_FAILED)
+		ksft_exit_skip("PROT_MTE not supported with MAP_HUGETLB mappings\n");
+	else
+		munmap(map_ptr, map_size);
+
 	/* Set test plan */
 	ksft_set_plan(12);