[RFC PATCH 3/6] testing/pkeys: Add additional test for pkey_alloc()

[ira.weiny at intel.com]

From: Ira Weiny <ira.weiny at intel.com>

When pkeys are not available on the hardware pkey_alloc() has specific
behavior which was previously untested.

Add test for this.

Cc: Dave Hansen <dave.hansen at linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
Signed-off-by: Ira Weiny <ira.weiny at intel.com>
---
 tools/testing/selftests/vm/protection_keys.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index 43e47de19c0d..4b733a75606f 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -1554,6 +1554,16 @@ void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey)
 	do_not_expect_pkey_fault("plain read on recently PROT_EXEC area");
 }
 
+void test_pkey_alloc_on_unsupported_cpu(void)
+{
+	int test_pkey = sys_pkey_alloc(0, 0);
+
+	dprintf1("pkey_alloc: %d (%d %s)\n", test_pkey, errno,
+		 strerror(errno));
+	pkey_assert(test_pkey < 0);
+	pkey_assert(errno == ENOSPC);
+}
+
 void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey)
 {
 	int size = PAGE_SIZE;
@@ -1688,6 +1698,8 @@ int main(int argc, char *argv[])
 
 		printf("running PKEY tests for unsupported CPU/OS\n");
 
+		test_pkey_alloc_on_unsupported_cpu();
+
 		ptr  = mmap(NULL, size, PROT_NONE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
 		assert(ptr != (void *)-1);
 		test_mprotect_pkey_on_unsupported_cpu(ptr, 1);
-- 
2.35.1