selftests/sgx: Refine the test enclave to have storage

Extend the enclave to have two operations: ENCL_OP_PUT and ENCL_OP_GET.
ENCL_OP_PUT stores value inside the enclave address space and
ENCL_OP_GET reads it. The internal buffer can be later extended to be
variable size, and allow reclaimer tests.

Signed-off-by: Jarkko Sakkinen <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/sgx/defines.h

···
 #include "../../../../arch/x86/include/asm/enclu.h"
 #include "../../../../arch/x86/include/uapi/asm/sgx.h"
 
+enum encl_op_type {
+	ENCL_OP_PUT,
+	ENCL_OP_GET,
+};
+
+struct encl_op {
+	uint64_t type;
+	uint64_t buffer;
+};
+
 #endif /* DEFINES_H */

tools/testing/selftests/sgx/main.c

···
 	encl_delete(&self->encl);
 }
 
-#define ENCL_CALL(in, out, run, clobbered) \
+#define ENCL_CALL(op, run, clobbered) \
 	({ \
 		int ret; \
 		if ((clobbered)) \
-			ret = vdso_sgx_enter_enclave((unsigned long)(in), (unsigned long)(out), 0, \
+			ret = vdso_sgx_enter_enclave((unsigned long)(op), 0, 0, \
 						     EENTER, 0, 0, (run)); \
 		else \
-			ret = sgx_enter_enclave((void *)(in), (void *)(out), 0, EENTER, NULL, NULL, \
+			ret = sgx_enter_enclave((void *)(op), NULL, 0, EENTER, NULL, NULL, \
 						(run)); \
 		ret; \
 	})
···
 
 TEST_F(enclave, unclobbered_vdso)
 {
-	uint64_t result = 0;
+	struct encl_op op;
 
-	EXPECT_EQ(ENCL_CALL(&MAGIC, &result, &self->run, false), 0);
+	op.type = ENCL_OP_PUT;
+	op.buffer = MAGIC;
 
-	EXPECT_EQ(result, MAGIC);
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, false), 0);
+
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.user_data, 0);
+
+	op.type = ENCL_OP_GET;
+	op.buffer = 0;
+
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, false), 0);
+
+	EXPECT_EQ(op.buffer, MAGIC);
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 }
 
 TEST_F(enclave, clobbered_vdso)
 {
-	uint64_t result = 0;
+	struct encl_op op;
 
-	EXPECT_EQ(ENCL_CALL(&MAGIC, &result, &self->run, true), 0);
+	op.type = ENCL_OP_PUT;
+	op.buffer = MAGIC;
 
-	EXPECT_EQ(result, MAGIC);
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.user_data, 0);
+
+	op.type = ENCL_OP_GET;
+	op.buffer = 0;
+
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+
+	EXPECT_EQ(op.buffer, MAGIC);
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 }
···
 
 TEST_F(enclave, clobbered_vdso_and_user_function)
 {
-	uint64_t result = 0;
+	struct encl_op op;
 
 	self->run.user_handler = (__u64)test_handler;
 	self->run.user_data = 0xdeadbeef;
 
-	EXPECT_EQ(ENCL_CALL(&MAGIC, &result, &self->run, true), 0);
+	op.type = ENCL_OP_PUT;
+	op.buffer = MAGIC;
 
-	EXPECT_EQ(result, MAGIC);
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+
+	EXPECT_EEXIT(&self->run);
+	EXPECT_EQ(self->run.user_data, 0);
+
+	op.type = ENCL_OP_GET;
+	op.buffer = 0;
+
+	EXPECT_EQ(ENCL_CALL(&op, &self->run, true), 0);
+
+	EXPECT_EQ(op.buffer, MAGIC);
 	EXPECT_EEXIT(&self->run);
 	EXPECT_EQ(self->run.user_data, 0);
 }

tools/testing/selftests/sgx/test_encl.c

···
 #include <stddef.h>
 #include "defines.h"
 
+static uint8_t encl_buffer[8192] = { 1 };
+
 static void *memcpy(void *dest, const void *src, size_t n)
 {
 	size_t i;
···
 	return dest;
 }
 
-void encl_body(void *rdi, void *rsi)
+void encl_body(void *rdi,  void *rsi)
 {
-	memcpy(rsi, rdi, 8);
+	struct encl_op *op = (struct encl_op *)rdi;
+
+	switch (op->type) {
+	case ENCL_OP_PUT:
+		memcpy(&encl_buffer[0], &op->buffer, 8);
+		break;
+
+	case ENCL_OP_GET:
+		memcpy(&op->buffer, &encl_buffer[0], 8);
+		break;
+
+	default:
+		break;
+	}
 }

tools/testing/selftests/sgx/test_encl.lds

···
 	.text : {
 		*(.text*)
 		*(.rodata*)
+		FILL(0xDEADBEEF);
+		. = ALIGN(4096);
 	} : text
 
-	. = ALIGN(4096);
 	.data : {
 		*(.data*)
 	} : data