Removing a page from an initialized enclave involves three steps: (1) the
user requests changing the page type to PT_TRIM via the SGX_IOC_PAGE_MODT
ioctl, (2) on success the ENCLU[EACCEPT] instruction is run from within
the enclave to accept the page removal, (3) the user initiates the actual
removal of the page via the SGX_IOC_PAGE_REMOVE ioctl.
Remove a page that has never been accessed. This means that when the first
ioctl requesting page removal arrives, there will be no page table entry,
yet a valid page table entry needs to exist for the ENCLU[EACCEPT] function
to succeed. In this test it is verified that a page table entry can still
be installed for a page that is in the process of being removed.
Suggested-by: Haitao Huang <haitao.huang@xxxxxxxxx>
Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
---
tools/testing/selftests/sgx/main.c | 58 ++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)
diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c
index 3bee8fa557fd..618f5ff0601b 100644
--- a/tools/testing/selftests/sgx/main.c
+++ b/tools/testing/selftests/sgx/main.c
@@ -1849,4 +1849,62 @@ TEST_F(enclave, remove_added_page_invalid_access_after_eaccept)
EXPECT_EQ(self->run.exception_addr, data_start);
}
+TEST_F(enclave, remove_untouched_page)
+{
+ struct encl_op_eaccept eaccept_op;
+ struct sgx_page_remove remove_ioc;
+ struct sgx_page_modt modt_ioc;
+ unsigned long data_start;
+ int ret, errno_save;
+
+ ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata));
+
+ memset(&self->run, 0, sizeof(self->run));
+ self->run.tcs = self->encl.encl_base;
+
+ data_start = self->encl.encl_base +
+ encl_get_data_offset(&self->encl) + PAGE_SIZE;
+
+ memset(&modt_ioc, 0, sizeof(modt_ioc));
+
+ modt_ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE;
+ modt_ioc.length = PAGE_SIZE;
+ modt_ioc.type = SGX_PAGE_TYPE_TRIM;
+ ret = ioctl(self->encl.fd, SGX_IOC_PAGE_MODT, &modt_ioc);
+ errno_save = ret == -1 ? errno : 0;
+
+ EXPECT_EQ(ret, 0);
+ EXPECT_EQ(errno_save, 0);
+ EXPECT_EQ(modt_ioc.result, 0);
+ EXPECT_EQ(modt_ioc.count, 4096);
+
+ /*
+ * Enter enclave via TCS #1 and approve page removal by sending
+ * EACCEPT for removed page.
+ */
+
+ eaccept_op.epc_addr = data_start;
+ eaccept_op.flags = SGX_SECINFO_TRIM | SGX_SECINFO_MODIFIED;
+ eaccept_op.ret = 0;
+ eaccept_op.header.type = ENCL_OP_EACCEPT;
+
+ EXPECT_EQ(ENCL_CALL(&eaccept_op, &self->run, true), 0);
+ EXPECT_EEXIT(&self->run);
+ EXPECT_EQ(self->run.exception_vector, 0);
+ EXPECT_EQ(self->run.exception_error_code, 0);
+ EXPECT_EQ(self->run.exception_addr, 0);
+ EXPECT_EQ(eaccept_op.ret, 0);
+
+ memset(&remove_ioc, 0, sizeof(remove_ioc));
+
+ remove_ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE;
+ remove_ioc.length = PAGE_SIZE;
+ ret = ioctl(self->encl.fd, SGX_IOC_PAGE_REMOVE, &remove_ioc);
+ errno_save = ret == -1 ? errno : 0;
+
+ EXPECT_EQ(ret, 0);
+ EXPECT_EQ(errno_save, 0);
+ EXPECT_EQ(remove_ioc.count, 4096);
+}
+
TEST_HARNESS_MAIN
--
2.25.1
