[PATCH for_v29 v2 5/5] selftests/sgx: Add selftest to invoke __vsgx_enter_enclave() from C

[Sean Christopherson <sean.j.christopherson@intel.com>]

Add a selftest to call __vsgx_enter_enclave() from C.

Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 tools/testing/selftests/sgx/main.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index f6bb40f22884..5394b2f6af8e 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -19,7 +19,7 @@
 #include "main.h"
 
 static const uint64_t MAGIC = 0x1122334455667788ULL;
-void *eenter;
+vdso_sgx_enter_enclave_t eenter;
 
 struct vdso_symtab {
 	Elf64_Sym *elf_symtab;
@@ -173,15 +173,27 @@ int main(int argc, char *argv[], char *envp[])
 
 	sgx_call_vdso((void *)&MAGIC, &result, 0, EENTER, NULL, NULL,
 		      (void *)encl.encl_base, &exception, NULL);
-	if (result != MAGIC)
+	if (result != MAGIC) {
+		printf("FAIL: sgx_call_vdso(), expected: 0x%lx, got: 0x%lx\n",
+		       MAGIC, result);
 		goto err;
+	}
+
+	/* Invoke the vDSO directly. */
+	result = 0;
+	eenter((unsigned long)&MAGIC, (unsigned long)&result, 0, EENTER, 0, 0,
+	       (void *)encl.encl_base, &exception, NULL);
+	if (result != MAGIC) {
+		printf("FAIL: eenter(), expected: 0x%lx, got: 0x%lx\n",
+		       MAGIC, result);
+		goto err;
+	}
 
 	printf("SUCCESS\n");
 	encl_delete(&encl);
 	exit(0);
 
 err:
-	printf("FAILURE\n");
 	encl_delete(&encl);
 	exit(1);
 }
-- 
2.24.1