kernel/tools/testing/selftests/sgx, branch linux-6.2.y

selftests/sgx: Ignore OpenSSL 3.0 deprecated functions warning

2022-08-15T22:50:07Z

OpenSSL 3.0 deprecates some of the functions used in the SGX selftests, causing build errors on new distros. For now ignore the warnings until support for the functions is no longer available and mark FIXME so that it can be clear this should be removed at some point. Signed-off-by: Kristen Carlson Accardi Reviewed-by: Jarkko Sakkinen Signed-off-by: Shuah Khan

selftests/sgx: Page removal stress test

2022-07-07T17:13:05Z

Create enclave with additional heap that consumes all physical SGX memory and then remove it. Depending on the available SGX memory this test could take a significant time to run (several minutes) as it (1) creates the enclave, (2) changes the type of every page to be trimmed, (3) enters the enclave once per page to run EACCEPT, before (4) the pages are finally removed. Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Acked-by: Jarkko Sakkinen Link: https://lkml.kernel.org/r/e7c6aa2ab30cb1c41e52b776958409c06970d168.1652137848.git.reinette.chatre@intel.com

selftests/sgx: Test reclaiming of untouched page

2022-07-07T17:13:05Z

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_TYPES 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 Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Acked-by: Jarkko Sakkinen Link: https://lkml.kernel.org/r/45e1b2a2fcd8c14597d04e40af5d8a9c1c5b017e.1652137848.git.reinette.chatre@intel.com

selftests/sgx: Test invalid access to removed enclave page

2022-07-07T17:13:04Z

Removing a page from an initialized enclave involves three steps: (1) the user requests changing the page type to SGX_PAGE_TYPE_TRIM via the SGX_IOC_ENCLAVE_MODIFY_TYPES 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(). Test two possible invalid accesses during the page removal flow: * Test the behavior when a request to remove the page by changing its type to SGX_PAGE_TYPE_TRIM completes successfully but instead of executing ENCLU[EACCEPT] from within the enclave the enclave attempts to read from the page. Even though the page is accessible from the page table entries its type is SGX_PAGE_TYPE_TRIM and thus not accessible according to SGX. The expected behavior is a page fault with the SGX flag set in the error code. * Test the behavior when the page type is changed successfully and ENCLU[EACCEPT] was run from within the enclave. The final ioctl(), SGX_IOC_ENCLAVE_REMOVE_PAGES, is omitted and replaced with an attempt to access the page. Even though the page is accessible from the page table entries its type is SGX_PAGE_TYPE_TRIM and thus not accessible according to SGX. The expected behavior is a page fault with the SGX flag set in the error code. Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Acked-by: Jarkko Sakkinen Link: https://lkml.kernel.org/r/189a86c25d6d62da7cfdd08ee97abc1a06fcc179.1652137848.git.reinette.chatre@intel.com

selftests/sgx: Test faulty enclave behavior

2022-07-07T17:13:04Z

Removing a page from an initialized enclave involves three steps: first the user requests changing the page type to SGX_PAGE_TYPE_TRIM via an ioctl(), on success the ENCLU[EACCEPT] instruction needs to be run from within the enclave to accept the page removal, finally the user requests page removal to be completed via an ioctl(). Only after acceptance (ENCLU[EACCEPT]) from within the enclave can the kernel remove the page from a running enclave. Test the behavior when the user's request to change the page type succeeds, but the ENCLU[EACCEPT] instruction is not run before the ioctl() requesting page removal is run. This should not be permitted. Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Acked-by: Jarkko Sakkinen Link: https://lkml.kernel.org/r/fa5da30ebac108b7517194c3038b52995602b996.1652137848.git.reinette.chatre@intel.com

selftests/sgx: Test complete changing of page type flow

2022-07-07T17:13:04Z

Support for changing an enclave page's type enables an initialized enclave to be expanded with support for more threads by changing the type of a regular enclave page to that of a Thread Control Structure (TCS). Additionally, being able to change a TCS or regular enclave page's type to be trimmed (SGX_PAGE_TYPE_TRIM) initiates the removal of the page from the enclave. Test changing page type to TCS as well as page removal flows in two phases: In the first phase support for a new thread is dynamically added to an initialized enclave and in the second phase the pages associated with the new thread are removed from the enclave. As an additional sanity check after the second phase the page used as a TCS page during the first phase is added back as a regular page and ensured that it can be written to (which is not possible if it was a TCS page). Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Acked-by: Jarkko Sakkinen Link: https://lkml.kernel.org/r/d05b48b00338683a94dcaef9f478540fc3d6d5f9.1652137848.git.reinette.chatre@intel.com

selftests/sgx: Introduce TCS initialization enclave operation

2022-07-07T17:13:04Z

The Thread Control Structure (TCS) contains meta-data used by the hardware to save and restore thread specific information when entering/exiting the enclave. A TCS can be added to an initialized enclave by first adding a new regular enclave page, initializing the content of the new page from within the enclave, and then changing that page's type to a TCS. Support the initialization of a TCS from within the enclave. The variable information needed that should be provided from outside the enclave is the address of the TCS, address of the State Save Area (SSA), and the entry point that the thread should use to enter the enclave. With this information provided all needed fields of a TCS can be initialized. Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Acked-by: Jarkko Sakkinen Link: https://lkml.kernel.org/r/bad6052056188bde753a54313da1ac8f1e29088a.1652137848.git.reinette.chatre@intel.com

selftests/sgx: Introduce dynamic entry point

2022-07-07T17:13:04Z

The test enclave (test_encl.elf) is built with two initialized Thread Control Structures (TCS) included in the binary. Both TCS are initialized with the same entry point, encl_entry, that correctly computes the absolute address of the stack based on the stack of each TCS that is also built into the binary. A new TCS can be added dynamically to the enclave and requires to be initialized with an entry point used to enter the enclave. Since the existing entry point, encl_entry, assumes that the TCS and its stack exists at particular offsets within the binary it is not able to handle a dynamically added TCS and its stack. Introduce a new entry point, encl_dyn_entry, that initializes the absolute address of that thread's stack to the address immediately preceding the TCS itself. It is now possible to dynamically add a contiguous memory region to the enclave with the new stack preceding the new TCS. With the new TCS initialized with encl_dyn_entry as entry point the absolute address of the stack is computed correctly on entry. Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Acked-by: Jarkko Sakkinen Link: https://lkml.kernel.org/r/93e9c420dedf5f773ba6965c18245bc7d62aca83.1652137848.git.reinette.chatre@intel.com

selftests/sgx: Test two different SGX2 EAUG flows

2022-07-07T17:13:04Z

Enclave pages can be added to an initialized enclave when an address belonging to the enclave but without a backing page is accessed from within the enclave. Accessing memory without a backing enclave page from within an enclave can be in different ways: 1) Pre-emptively run ENCLU[EACCEPT]. Since the addition of a page always needs to be accepted by the enclave via ENCLU[EACCEPT] this flow is efficient since the first execution of ENCLU[EACCEPT] triggers the addition of the page and when execution returns to the same instruction the second execution would be successful as an acceptance of the page. 2) A direct read or write. The flow where a direct read or write triggers the page addition execution cannot resume from the instruction (read/write) that triggered the fault but instead the enclave needs to be entered at a different entry point to run needed ENCLU[EACCEPT] before execution can return to the original entry point and the read/write instruction that faulted. Add tests for both flows. Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Acked-by: Jarkko Sakkinen Link: https://lkml.kernel.org/r/0c321e0e32790ac1de742ce5017a331e6d902ac1.1652137848.git.reinette.chatre@intel.com

selftests/sgx: Add test for TCS page permission changes

2022-07-07T17:13:04Z

Kernel should not allow permission changes on TCS pages. Add test to confirm this behavior. Signed-off-by: Reinette Chatre Signed-off-by: Dave Hansen Acked-by: Jarkko Sakkinen Link: https://lkml.kernel.org/r/0121ad1b21befb94519072e2c18b89aa5dca00d4.1652137848.git.reinette.chatre@intel.com