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 <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org>
Link: https://lkml.kernel.org/r/d05b48b00338683a94dcaef9f478540fc3d6d5f9.1652137848.git.reinette.chatre@intel.com
Create a heap for the test enclave, which is allocated from /dev/null,
and left unmeasured. This is beneficial by its own because it verifies
that an enclave built from multiple choices, works properly. If LSM
hooks are added for SGX some day, a multi source enclave has higher
probability to trigger bugs on access control checks.
The immediate need comes from the need to implement page reclaim tests.
In order to trigger the page reclaimer, one can just set the size of
the heap to high enough.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/e070c5f23578c29608051cab879b1d276963a27a.1636997631.git.reinette.chatre@intel.com
For a heap makes sense to leave its contents "unmeasured" in the SGX
enclave build process, meaning that they won't contribute to the
cryptographic signature (a RSA-3072 signed SHA56 hash) of the enclave.
Enclaves are signed blobs where the signature is calculated both from
page data and also from "structural properties" of the pages. For
instance a page offset of *every* page added to the enclave is hashed.
For data, this is optional, not least because hashing a page has a
significant contribution to the enclave load time. Thus, where there is
no reason to hash, do not. The SGX ioctl interface supports this with
SGX_PAGE_MEASURE flag. Only when the flag is *set*, data is measured.
Add seg->measure boolean flag to struct encl_segment. Only when the
flag is set, include the segment data to the signature (represented
by SIGSTRUCT architectural structure).
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/625b6fe28fed76275e9238ec4e15ec3c0d87de81.1636997631.git.reinette.chatre@intel.com
Define source per segment so that enclave pages can be added from different
sources, e.g. anonymous VMA for zero pages. In other words, add 'src' field
to struct encl_segment, and assign it to 'encl->src' for pages inherited
from the enclave binary.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/7850709c3089fe20e4bcecb8295ba87c54cc2b4a.1636997631.git.reinette.chatre@intel.com
Rename symbols for better clarity:
* 'eenter' might be confused for directly calling ENCLU[EENTER]. It does
not. It calls into the VDSO, which actually has the EENTER instruction.
* 'sgx_call_vdso' is *only* used for entering the enclave. It's not some
generic SGX call into the VDSO.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Use a statically generated key for signing the enclave, because
generating keys on the fly can eat the kernel entropy pool. Another
good reason for doing this is predictable builds. The RSA has been
arbitrarily selected. It's contents do not matter.
This also makes the selftest execute a lot quicker instead of the delay
that it had before (because of slow key generation).
[ bp: Disambiguate "static key" which means something else in the
kernel, fix typos. ]
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: linux-kselftest@vger.kernel.org
Link: https://lkml.kernel.org/r/20201118170640.39629-1-jarkko@kernel.org
Add a selftest for SGX. It is a trivial test where a simple enclave
copies one 64-bit word of memory between two memory locations,
but ensures that all SGX hardware and software infrastructure is
functioning.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Cc: linux-kselftest@vger.kernel.org
Link: https://lkml.kernel.org/r/20201112220135.165028-21-jarkko@kernel.org
