From: Reinette Chatre reinette.chatre@intel.com

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_ENCLAVE_MODIFY_TYPE 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_ENCLAVE_REMOVE_PAGES 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@intel.com Signed-off-by: Reinette Chatre reinette.chatre@intel.com --- tools/testing/selftests/sgx/main.c | 82 ++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+)

diff --git a/tools/testing/selftests/sgx/main.c b/tools/testing/selftests/sgx/main.c index d132e7d32454..c691a4864db8 100644 --- a/tools/testing/selftests/sgx/main.c +++ b/tools/testing/selftests/sgx/main.c @@ -1816,4 +1816,86 @@ 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 sgx_enclave_remove_pages remove_ioc; + struct encl_op_eaccept eaccept_op; + struct sgx_enclave_modt modt_ioc; + struct sgx_secinfo secinfo; + unsigned long data_start; + int ret, errno_save; + + ASSERT_TRUE(setup_test_encl(ENCL_HEAP_SIZE_DEFAULT, &self->encl, _metadata)); + + /* + * Hardware (SGX2) and kernel support is needed for this test. Start + * with check that test has a chance of succeeding. + */ + memset(&modt_ioc, 0, sizeof(modt_ioc)); + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPE, &modt_ioc); + + if (ret == -1) { + if (errno == ENOTTY) + SKIP(return, "Kernel does not support SGX_IOC_ENCLAVE_MODIFY_TYPE ioctl()"); + else if (errno == ENODEV) + SKIP(return, "System does not support SGX2"); + } + + /* + * Invalid parameters were provided during sanity check, + * expect command to fail. + */ + EXPECT_EQ(ret, -1); + + /* SGX2 is supported by kernel and hardware, test can proceed. */ + 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)); + memset(&secinfo, 0, sizeof(secinfo)); + + secinfo.flags = SGX_PAGE_TYPE_TRIM << 8; + modt_ioc.offset = encl_get_data_offset(&self->encl) + PAGE_SIZE; + modt_ioc.length = PAGE_SIZE; + modt_ioc.secinfo = (unsigned long)&secinfo; + ret = ioctl(self->encl.fd, SGX_IOC_ENCLAVE_MODIFY_TYPE, &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_ENCLAVE_REMOVE_PAGES, &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