Re: [PATCH v20 00/28] Intel SGX1 support
From: Jarkko Sakkinen
Date: Wed Apr 24 2019 - 08:48:57 EST
On 2019-04-23 19:52, Andy Lutomirski wrote:
On Tue, Apr 23, 2019 at 4:56 AM Jarkko Sakkinen
<jarkko.sakkinen@xxxxxxxxxxxxxxx> wrote:
On Wed, Apr 17, 2019 at 01:39:10PM +0300, Jarkko Sakkinen wrote:
> Intel(R) SGX is a set of CPU instructions that can be used by applications
> to set aside private regions of code and data. The code outside the enclave
> is disallowed to access the memory inside the enclave by the CPU access
> control. In a way you can think that SGX provides inverted sandbox. It
> protects the application from a malicious host.
>
> There is a new hardware unit in the processor called Memory Encryption
> Engine (MEE) starting from the Skylake microacrhitecture. BIOS can define
> one or many MEE regions that can hold enclave data by configuring them with
> PRMRR registers.
>
> The MEE automatically encrypts the data leaving the processor package to
> the MEE regions. The data is encrypted using a random key whose life-time
> is exactly one power cycle.
>
> The current implementation requires that the firmware sets
> IA32_SGXLEPUBKEYHASH* MSRs as writable so that ultimately the kernel can
> decide what enclaves it wants run. The implementation does not create
> any bottlenecks to support read-only MSRs later on.
>
> You can tell if your CPU supports SGX by looking into /proc/cpuinfo:
>
> cat /proc/cpuinfo | grep sgx
>
> v20:
> * Fine-tune Kconfig messages and spacing and remove MMU_NOTIFIER
> dependency as MMU notifiers are no longer used in the driver.
> * Use mm_users instead of mm_count as refcount for mm_struct as mm_count
> only protects from deleting mm_struct, not removing its contents.
> * Sanitize EPC when the reclaimer thread starts by doing EREMOVE for all
> of them. They could be in initialized state when the kernel starts
> because it might be spawned by kexec().
> * Documentation overhaul.
> * Use a device /dev/sgx/provision for delivering the provision token
> instead of securityfs.
> * Create a reference to the enclave when already when opening
> /dev/sgx/enclave. The file is then associated with this enclave only.
> mmap() can be done at free at any point and always get a reference to
> the enclave. To summarize the file now represents the enclave.
>
> v19:
> * Took 3-4 months but in some sense this was more like a rewrite of most
> of the corners of the source code. If I've forgotten to deal with some
> feedback, please don't shout me. Make a remark and I will fix it for
> the next version. Hopefully there won't be this big turnovers anymore.
> * Validate SECS attributes properly against CPUID given attributes and
> against allowed attributes. SECS attributes are the ones that are
> enforced whereas SIGSTRUCT attributes tell what is required to run
> the enclave.
> * Add KSS (Key Sharing Support) to the enclave attributes.
> * Deny MAP_PRIVATE as an enclave is always a shared memory entity.
> * Revert back to shmem backing storage so that it can be easily shared
> by multiple processes.
> * Split the recognization of an ENCLS leaf failure by using three
> functions to detect it: encsl_faulted(), encls_returned_code() and
> sgx_failed(). encls_failed() is only caused by a spurious expections that
> should never happen. Thus, it is not defined as an inline function in
> order to easily insert a kprobe to it.
> * Move low-level enclave management routines, page fault handler and page
> reclaiming routines from driver to the core. These cannot be separated
> from each other as they are heavily interdependent. The rationale is that
> the core does not call any code from the driver.
> * Allow the driver to be compiled as a module now that it no code is using
> its routines and it only uses exported symbols. Now the driver is
> essentially just a thin ioctl layer.
> * Reworked the driver to maintain a list of mm_struct's. The VMA callbacks
> add new entries to this list as the process is forked. Each entry has
> its own refcount because they have a different life-cycle as the enclave
> does. In effect @tgid and @mm have been removed from struct sgx_encl
> and we allow forking by removing VM_DONTCOPY from vm flags.
> * Generate a cpu mask in the reclaimer from the cpu mask's of all
> mm_struct's. This will kick out the hardware threads out of the enclave
> from multiple processes. It is not a local variable because it would
> eat too much of the stack space but instead a field in struct
> sgx_encl.
> * Allow forking i.e. remove VM_DONTCOPY. I did not change the API
> because the old API scaled to the workload that Andy described. The
> codebase is now mostly API independent i.e. changing the API is a
> small task. For me the proper trigger to chanage it is a as concrete
> as possible workload that cannot be fulfilled. I hope you understand
> my thinking here. I don't want to change anything w/o proper basis
> but I'm ready to change anything if there is a proper basis. I do
> not have any kind of attachment to any particular type of API.
> * Add Sean's vDSO ENCLS(EENTER) patches and update selftest to use the
> new vDSO.
>
> v18:
> * Update the ioctl-number.txt.
> * Move the driver under arch/x86.
> * Add SGX features (SGX, SGX1, SGX2) to the disabled-features.h.
> * Rename the selftest as test_sgx (previously sgx-selftest).
> * In order to enable process accounting, swap EPC pages and PCMD's to a VMA
> instead of shmem.
> * Allow only to initialize and run enclaves with a subset of
> {DEBUG, MODE64BIT} set.
> * Add SGX_IOC_ENCLAVE_SET_ATTRIBUTE to allow an enclave to have privileged
> attributes e.g. PROVISIONKEY.
>
> v17:
> * Add a simple selftest.
> * Fix a null pointer dereference to section->pages when its
> allocation fails.
> * Add Sean's description of the exception handling to the documentation.
>
> v16:
> * Fixed SOB's in the commits that were a bit corrupted in v15.
> * Implemented exceptio handling properly to detect_sgx().
> * Use GENMASK() to define SGX_CPUID_SUB_LEAF_TYPE_MASK.
> * Updated the documentation to use rst definition lists.
> * Added the missing Documentation/x86/index.rst, which has a link to
> intel_sgx.rst. Now the SGX and uapi documentation is properly generated
> with 'make htmldocs'.
> * While enumerating EPC sections, if an undefined section is found, fail
> the driver initialization instead of continuing the initialization.
> * Issue a warning if there are more than %SGX_MAX_EPC_SECTIONS.
> * Remove copyright notice from arch/x86/include/asm/sgx.h.
> * Migrated from ioremap_cache() to memremap().
>
> v15:
> * Split into more digestable size patches.
> * Lots of small fixes and clean ups.
> * Signal a "plain" SIGSEGV on an EPCM violation.
>
> v14:
> * Change the comment about X86_FEATURE_SGX_LC from âSGX launch
> configurationâ to âSGX launch controlâ.
> * Move the SGX-related CPU feature flags as part of the Linux defined
> virtual leaf 8.
> * Add SGX_ prefix to the constants defining the ENCLS leaf functions.
> * Use GENMASK*() and BIT*() in sgx_arch.h instead of raw hex numbers.
> * Refine the long description for CONFIG_INTEL_SGX_CORE.
> * Do not use pr_*_ratelimited() in the driver. The use of the rate limited
> versions is legacy cruft from the prototyping phase.
> * Detect sleep with SGX_INVALID_EINIT_TOKEN instead of counting power
> cycles.
> * Manually prefix with âsgx:â in the core SGX code instead of redefining
> pr_fmt.
> * Report if IA32_SGXLEPUBKEYHASHx MSRs are not writable in the driver
> instead of core because it is a driver requirement.
> * Change prompt to bool in the entry for CONFIG_INTEL_SGX_CORE because the
> default is ânâ.
> * Rename struct sgx_epc_bank as struct sgx_epc_section in order to match
> the SDM.
> * Allocate struct sgx_epc_page instances one at a time.
> * Use â__iomem void *â pointers for the mapped EPC memory consistently.
> * Retry once on SGX_INVALID_TOKEN in sgx_einit() instead of counting power
> cycles.
> * Call enclave swapping operations directly from the driver instead of
> calling them .indirectly through struct sgx_epc_page_ops because indirect
> calls are not required yet as the patch set does not contain the KVM
> support.
> * Added special signal SEGV_SGXERR to notify about SGX EPCM violation
> errors.
>
> v13:
> * Always use SGX_CPUID constant instead of a hardcoded value.
> * Simplified and documented the macros and functions for ENCLS leaves.
> * Enable sgx_free_page() to free active enclave pages on demand
> in order to allow sgx_invalidate() to delete enclave pages.
> It no longer performs EREMOVE if a page is in the process of
> being reclaimed.
> * Use PM notifier per enclave so that we don't have to traverse
> the global list of active EPC pages to find enclaves.
> * Removed unused SGX_LE_ROLLBACK constant from uapi/asm/sgx.h
> * Always use ioremap() to map EPC banks as we only support 64-bit kernel.
> * Invalidate IA32_SGXLEPUBKEYHASH cache used by sgx_einit() when going
> to sleep.
>
> v12:
> * Split to more narrow scoped commits in order to ease the review process and
> use co-developed-by tag for co-authors of commits instead of listing them in
> the source files.
> * Removed cruft EXPORT_SYMBOL() declarations and converted to static variables.
> * Removed in-kernel LE i.e. this version of the SGX software stack only
> supports unlocked IA32_SGXLEPUBKEYHASHx MSRs.
> * Refined documentation on launching enclaves, swapping and enclave
> construction.
> * Refined sgx_arch.h to include alignment information for every struct that
> requires it and removed structs that are not needed without an LE.
> * Got rid of SGX_CPUID.
> * SGX detection now prints log messages about firmware configuration issues.
>
> v11:
> * Polished ENCLS wrappers with refined exception handling.
> * ksgxswapd was not stopped (regression in v5) in
> sgx_page_cache_teardown(), which causes a leaked kthread after driver
> deinitialization.
> * Shutdown sgx_le_proxy when going to suspend because its EPC pages will be
> invalidated when resuming, which will cause it not function properly
> anymore.
> * Set EINITTOKEN.VALID to zero for a token that is passed when
> SGXLEPUBKEYHASH matches MRSIGNER as alloc_page() does not give a zero
> page.
> * Fixed the check in sgx_edbgrd() for a TCS page. Allowed to read offsets
> around the flags field, which causes a #GP. Only flags read is readable.
> * On read access memcpy() call inside sgx_vma_access() had src and dest
> parameters in wrong order.
> * The build issue with CONFIG_KASAN is now fixed. Added undefined symbols
> to LE even if âKASAN_SANITIZE := falseâ was set in the makefile.
> * Fixed a regression in the #PF handler. If a page has
> SGX_ENCL_PAGE_RESERVED flag the #PF handler should unconditionally fail.
> It did not, which caused weird races when trying to change other parts of
> swapping code.
> * EPC management has been refactored to a flat LRU cache and moved to
> arch/x86. The swapper thread reads a cluster of EPC pages and swaps all
> of them. It can now swap from multiple enclaves in the same round.
> * For the sake of consistency with SGX_IOC_ENCLAVE_ADD_PAGE, return -EINVAL
> when an enclave is already initialized or dead instead of zero.
>
> v10:
> * Cleaned up anon inode based IPC between the ring-0 and ring-3 parts
> of the driver.
> * Unset the reserved flag from an enclave page if EDBGRD/WR fails
> (regression in v6).
> * Close the anon inode when LE is stopped (regression in v9).
> * Update the documentation with a more detailed description of SGX.
>
> v9:
> * Replaced kernel-LE IPC based on pipes with an anonymous inode.
> The driver does not require anymore new exports.
>
> v8:
> * Check that public key MSRs match the LE public key hash in the
> driver initialization when the MSRs are read-only.
> * Fix the race in VA slot allocation by checking the fullness
> immediately after succeesful allocation.
> * Fix the race in hash mrsigner calculation between the launch
> enclave and user enclaves by having a separate lock for hash
> calculation.
>
> v7:
> * Fixed offset calculation in sgx_edbgr/wr(). Address was masked with PAGE_MASK
> when it should have been masked with ~PAGE_MASK.
> * Fixed a memory leak in sgx_ioc_enclave_create().
> * Simplified swapping code by using a pointer array for a cluster
> instead of a linked list.
> * Squeezed struct sgx_encl_page to 32 bytes.
> * Fixed deferencing of an RSA key on OpenSSL 1.1.0.
> * Modified TC's CMAC to use kernel AES-NI. Restructured the code
> a bit in order to better align with kernel conventions.
>
> v6:
> * Fixed semaphore underrun when accessing /dev/sgx from the launch enclave.
> * In sgx_encl_create() s/IS_ERR(secs)/IS_ERR(encl)/.
> * Removed virtualization chapter from the documentation.
> * Changed the default filename for the signing key as signing_key.pem.
> * Reworked EPC management in a way that instead of a linked list of
> struct sgx_epc_page instances there is an array of integers that
> encodes address and bank of an EPC page (the same data as 'pa' field
> earlier). The locking has been moved to the EPC bank level instead
> of a global lock.
> * Relaxed locking requirements for EPC management. EPC pages can be
> released back to the EPC bank concurrently.
> * Cleaned up ptrace() code.
> * Refined commit messages for new architectural constants.
> * Sorted includes in every source file.
> * Sorted local variable declarations according to the line length in
> every function.
> * Style fixes based on Darren's comments to sgx_le.c.
>
> v5:
> * Described IPC between the Launch Enclave and kernel in the commit messages.
> * Fixed all relevant checkpatch.pl issues that I have forgot fix in earlier
> versions except those that exist in the imported TinyCrypt code.
> * Fixed spelling mistakes in the documentation.
> * Forgot to check the return value of sgx_drv_subsys_init().
> * Encapsulated properly page cache init and teardown.
> * Collect epc pages to a temp list in sgx_add_epc_bank
> * Removed SGX_ENCLAVE_INIT_ARCH constant.
>
> v4:
> * Tied life-cycle of the sgx_le_proxy process to /dev/sgx.
> * Removed __exit annotation from sgx_drv_subsys_exit().
> * Fixed a leak of a backing page in sgx_process_add_page_req() in the
> case when vm_insert_pfn() fails.
> * Removed unused symbol exports for sgx_page_cache.c.
> * Updated sgx_alloc_page() to require encl parameter and documented the
> behavior (Sean Christopherson).
> * Refactored a more lean API for sgx_encl_find() and documented the behavior.
> * Moved #PF handler to sgx_fault.c.
> * Replaced subsys_system_register() with plain bus_register().
> * Retry EINIT 2nd time only if MSRs are not locked.
>
> v3:
> * Check that FEATURE_CONTROL_LOCKED and FEATURE_CONTROL_SGX_ENABLE are set.
> * Return -ERESTARTSYS in __sgx_encl_add_page() when sgx_alloc_page() fails.
> * Use unused bits in epc_page->pa to store the bank number.
> * Removed #ifdef for WQ_NONREENTRANT.
> * If mmu_notifier_register() fails with -EINTR, return -ERESTARTSYS.
> * Added --remove-section=.got.plt to objcopy flags in order to prevent a
> dummy .got.plt, which will cause an inconsistent size for the LE.
> * Documented sgx_encl_* functions.
> * Added remark about AES implementation used inside the LE.
> * Removed redundant sgx_sys_exit() from le/main.c.
> * Fixed struct sgx_secinfo alignment from 128 to 64 bytes.
> * Validate miscselect in sgx_encl_create().
> * Fixed SSA frame size calculation to take the misc region into account.
> * Implemented consistent exception handling to __encls() and __encls_ret().
> * Implemented a proper device model in order to allow sysfs attributes
> and in-kernel API.
> * Cleaned up various "find enclave" implementations to the unified
> sgx_encl_find().
> * Validate that vm_pgoff is zero.
> * Discard backing pages with shmem_truncate_range() after EADD.
> * Added missing EEXTEND operations to LE signing and launch.
> * Fixed SSA size for GPRS region from 168 to 184 bytes.
> * Fixed the checks for TCS flags. Now DBGOPTIN is allowed.
> * Check that TCS addresses are in ELRANGE and not just page aligned.
> * Require kernel to be compiled with X64_64 and CPU_SUP_INTEL.
> * Fixed an incorrect value for SGX_ATTR_DEBUG from 0x01 to 0x02.
>
> v2:
> * get_rand_uint32() changed the value of the pointer instead of value
> where it is pointing at.
> * Launch enclave incorrectly used sigstruct attributes-field instead of
> enclave attributes-field.
> * Removed unused struct sgx_add_page_req from sgx_ioctl.c
> * Removed unused sgx_has_sgx2.
> * Updated arch/x86/include/asm/sgx.h so that it provides stub
> implementations when sgx in not enabled.
> * Removed cruft rdmsr-calls from sgx_set_pubkeyhash_msrs().
> * return -ENOMEM in sgx_alloc_page() when VA pages consume too much space
> * removed unused global sgx_nr_pids
> * moved sgx_encl_release to sgx_encl.c
> * return -ERESTARTSYS instead of -EINTR in sgx_encl_init()
>
> Jarkko Sakkinen (11):
> x86/sgx: Add ENCLS architectural error codes
> x86/sgx: Add SGX1 and SGX2 architectural data structures
> x86/sgx: Add wrappers for ENCLS leaf functions
> x86/sgx: Add functions to allocate and free EPC pages
> x86/sgx: Add the Linux SGX Enclave Driver
> x86/sgx: Add provisioning
> x86/sgx: Add swapping code to the core and SGX driver
> x86/sgx: ptrace() support for the SGX driver
> selftests/x86: Add a selftest for SGX
> x86/sgx: Update MAINTAINERS
> docs: x86/sgx: Document the enclave API
>
> Kai Huang (2):
> x86/cpufeatures: Add Intel-defined SGX feature bit
> x86/cpufeatures: Add Intel-defined SGX_LC feature bit
>
> Sean Christopherson (15):
> x86/cpufeatures: Add SGX sub-features (as Linux-defined bits)
> x86/msr: Add IA32_FEATURE_CONTROL.SGX_ENABLE definition
> x86/msr: Add SGX Launch Control MSR definitions
> x86/mm: x86/sgx: Add new 'PF_SGX' page fault error code bit
> x86/mm: x86/sgx: Signal SIGSEGV for userspace #PFs w/ PF_SGX
> x86/cpu/intel: Detect SGX support and update caps appropriately
> x86/sgx: Enumerate and track EPC sections
> x86/sgx: Add sgx_einit() for initializing enclaves
> x86/vdso: Add support for exception fixup in vDSO functions
> x86/fault: Add helper function to sanitize error code
> x86/fault: Attempt to fixup unhandled #PF in vDSO before signaling
> x86/traps: Attempt to fixup exceptions in vDSO before signaling
> x86/vdso: Add __vdso_sgx_enter_enclave() to wrap SGX enclave
> transitions
> docs: x86/sgx: Add Architecture documentation
> docs: x86/sgx: Document kernel internals
>
> Documentation/index.rst | 1 +
> Documentation/ioctl/ioctl-number.txt | 1 +
> Documentation/x86/index.rst | 10 +
> Documentation/x86/sgx/1.Architecture.rst | 431 +++++++++
> Documentation/x86/sgx/2.Kernel-internals.rst | 56 ++
> Documentation/x86/sgx/3.API.rst | 27 +
> Documentation/x86/sgx/index.rst | 18 +
> MAINTAINERS | 12 +
> arch/x86/Kconfig | 27 +
> arch/x86/entry/vdso/Makefile | 6 +-
> arch/x86/entry/vdso/extable.c | 37 +
> arch/x86/entry/vdso/extable.h | 29 +
> arch/x86/entry/vdso/vdso-layout.lds.S | 9 +-
> arch/x86/entry/vdso/vdso.lds.S | 1 +
> arch/x86/entry/vdso/vdso2c.h | 58 +-
> arch/x86/entry/vdso/vsgx_enter_enclave.S | 101 +++
> arch/x86/include/asm/cpufeatures.h | 24 +-
> arch/x86/include/asm/disabled-features.h | 14 +-
> arch/x86/include/asm/msr-index.h | 8 +
> arch/x86/include/asm/traps.h | 1 +
> arch/x86/include/asm/vdso.h | 5 +
> arch/x86/include/uapi/asm/sgx.h | 86 ++
> arch/x86/include/uapi/asm/sgx_errno.h | 91 ++
> arch/x86/kernel/cpu/Makefile | 1 +
> arch/x86/kernel/cpu/intel.c | 39 +
> arch/x86/kernel/cpu/scattered.c | 2 +
> arch/x86/kernel/cpu/sgx/Makefile | 2 +
> arch/x86/kernel/cpu/sgx/arch.h | 424 +++++++++
> arch/x86/kernel/cpu/sgx/driver/Makefile | 3 +
> arch/x86/kernel/cpu/sgx/driver/driver.h | 38 +
> arch/x86/kernel/cpu/sgx/driver/ioctl.c | 850 ++++++++++++++++++
> arch/x86/kernel/cpu/sgx/driver/main.c | 368 ++++++++
> arch/x86/kernel/cpu/sgx/encl.c | 709 +++++++++++++++
> arch/x86/kernel/cpu/sgx/encl.h | 136 +++
> arch/x86/kernel/cpu/sgx/encls.c | 22 +
> arch/x86/kernel/cpu/sgx/encls.h | 244 +++++
> arch/x86/kernel/cpu/sgx/main.c | 360 ++++++++
> arch/x86/kernel/cpu/sgx/reclaim.c | 482 ++++++++++
> arch/x86/kernel/cpu/sgx/sgx.h | 90 ++
> arch/x86/kernel/traps.c | 14 +
> arch/x86/mm/fault.c | 44 +-
> tools/arch/x86/include/asm/cpufeatures.h | 21 +-
> tools/testing/selftests/x86/Makefile | 10 +
> tools/testing/selftests/x86/sgx/Makefile | 48 +
> tools/testing/selftests/x86/sgx/defines.h | 39 +
> tools/testing/selftests/x86/sgx/encl.c | 20 +
> tools/testing/selftests/x86/sgx/encl.lds | 33 +
> .../selftests/x86/sgx/encl_bootstrap.S | 94 ++
> tools/testing/selftests/x86/sgx/encl_piggy.S | 18 +
> tools/testing/selftests/x86/sgx/encl_piggy.h | 14 +
> tools/testing/selftests/x86/sgx/main.c | 279 ++++++
> tools/testing/selftests/x86/sgx/sgx_call.S | 15 +
> tools/testing/selftests/x86/sgx/sgxsign.c | 508 +++++++++++
> .../testing/selftests/x86/sgx/signing_key.pem | 39 +
> 54 files changed, 5987 insertions(+), 32 deletions(-)
> create mode 100644 Documentation/x86/index.rst
> create mode 100644 Documentation/x86/sgx/1.Architecture.rst
> create mode 100644 Documentation/x86/sgx/2.Kernel-internals.rst
> create mode 100644 Documentation/x86/sgx/3.API.rst
> create mode 100644 Documentation/x86/sgx/index.rst
> create mode 100644 arch/x86/entry/vdso/extable.c
> create mode 100644 arch/x86/entry/vdso/extable.h
> create mode 100644 arch/x86/entry/vdso/vsgx_enter_enclave.S
> create mode 100644 arch/x86/include/uapi/asm/sgx.h
> create mode 100644 arch/x86/include/uapi/asm/sgx_errno.h
> create mode 100644 arch/x86/kernel/cpu/sgx/Makefile
> create mode 100644 arch/x86/kernel/cpu/sgx/arch.h
> create mode 100644 arch/x86/kernel/cpu/sgx/driver/Makefile
> create mode 100644 arch/x86/kernel/cpu/sgx/driver/driver.h
> create mode 100644 arch/x86/kernel/cpu/sgx/driver/ioctl.c
> create mode 100644 arch/x86/kernel/cpu/sgx/driver/main.c
> create mode 100644 arch/x86/kernel/cpu/sgx/encl.c
> create mode 100644 arch/x86/kernel/cpu/sgx/encl.h
> create mode 100644 arch/x86/kernel/cpu/sgx/encls.c
> create mode 100644 arch/x86/kernel/cpu/sgx/encls.h
> create mode 100644 arch/x86/kernel/cpu/sgx/main.c
> create mode 100644 arch/x86/kernel/cpu/sgx/reclaim.c
> create mode 100644 arch/x86/kernel/cpu/sgx/sgx.h
> create mode 100644 tools/testing/selftests/x86/sgx/Makefile
> create mode 100644 tools/testing/selftests/x86/sgx/defines.h
> create mode 100644 tools/testing/selftests/x86/sgx/encl.c
> create mode 100644 tools/testing/selftests/x86/sgx/encl.lds
> create mode 100644 tools/testing/selftests/x86/sgx/encl_bootstrap.S
> create mode 100644 tools/testing/selftests/x86/sgx/encl_piggy.S
> create mode 100644 tools/testing/selftests/x86/sgx/encl_piggy.h
> create mode 100644 tools/testing/selftests/x86/sgx/main.c
> create mode 100644 tools/testing/selftests/x86/sgx/sgx_call.S
> create mode 100644 tools/testing/selftests/x86/sgx/sgxsign.c
> create mode 100644 tools/testing/selftests/x86/sgx/signing_key.pem
>
> --
> 2.19.1
>
I'm on leave for this week and next week's Monday if you wonder why
I'm
so passive in the discussion. Looking at the things next week's Tue.
Just a quick comment about Andy's proposal. Probably pretty DSO like
ELF blob could work with an addition of a section called ".tcs" for
entry points. They need to be recognized so that the loader can add
them as TCS pages.
Hmm.
There's a decent argument for specifically supporting whatever format
Windows uses. There's also an argument for allowing one or more
enclaves to be bundled in a regular ELF DSO. FWIW, there's no
fundamental reason we can't support more than one type of enclave
format.
It would also be better to contain sigstruct so that EINIT can
be performed. I wonder if we could use dlopen() as call path
for this? That would also provide all the DAC/MAC/whatever
security checks.
I can start to PoC this next week once I get back to work (back
on next Tue). I haven't studied Windows format much but I'd
*guess* it is a COFF DLL?
For me easier path to get something done would to do ELF DSO
first. As you said they both could be done, which means that
Windows COFF could be upstreamed later on.
If this approach works, it'd mean that no ioctl's would be
required except SGX_ENCLAVE_SET_ATTRIBUTE.
PS. This quote from LWN got a bit into my feelings:
"After 20 revisions of the patch set over three years, the
authors of this work (which was posted by Jarkko Sakkinen)
might well be forgiven for thinking that it must be about
ready for merging."
I seriously do not make any pre-conclusions ever for any patch
that I post when it should be merged, no matter how big or
small :-) For me this is just work...
/Jarkko