`Scripts/Makefile.rules` used MAKEFILE_LIST to obtain the current
makefile path, but it did so after including some other file, so it got
the included file path instead.
Signed-off-by: borysp <borysp@invisiblethingslab.com>
Change log (most important only):
- unify CPU context structures - now we have only one version -
`PAL_CONTEXT` - which is shared between LibOS and PALs and it should
depend only on the host architecture (not OS),
- syscalls emulation changed:
- dedicated LibOS stack is now used for syscalls emulation,
- removed one indirection level in syscalls table - now it stores
`shim_do_*` functions directly,
- signal handling - completely rewritten:
- all signal queues use proper locking schemes now,
- signals are handled *only* when returning to the user app from LibOS
or PAL,
- nested signals are now possible,
- the app is allowed to jump out of signal handler with the same
sematics as on normal Linux,
- signal altstack is now fully supported,
- syscall restarting is now supported,
- doing a backtrace from the signal handler works properly,
- disallow injecting host-level signals, with one exception, see
`sys.enable_sigterm_injection` manifest option for more details.
The generated-offsets headers have to depend on the code that
defines the relevant data structures. Otherwise, when the data
structures change, the code will get compiled with wrong offsets
and will crash.
This is the next part of the great loader rework, with a lot of breaking changes:
- Complete removal of the "trusted children" thing - now children
processes can be spawned arbitrarily and from arbitrary mountpoint
types, without any additional configuration needed.
- There's a new, required option in the manifest: `libos.entrypoint` - it
specifies the URI to the entry binary in the first process. There's no
need anymore to name the manifest and the first binary identically.
- On SGX, the main binary is not measured in MRENCLAVE anymore - only
PAL, LibOS and the manifest are measured. This is enough to bind
MRENCLAVE to a specific entrypoint user executable if wanted - it
just has to be mounted as a trusted file.
- All Graphene SGX enclaves have now exactly the same MRENCLAVE. This is
a hash of a "Graphene stub", which can "fork" into one of two states
in runtime: initial process or child. The initial process creates a
new "Graphene namespace" with a clean state, it can also be attested
remotely (contrary to child processes). The initial process can spawn
children processes by spawning a Graphene stub and directing it to
start in the child mode. It then attests it locally, and if
successful, establishes an encrypted pipe, "connects" to its own
namespace and treats as trusted (including sending protected files
key).
- Now, there's only one, central manifest describing the initial state
of a Graphene instance which can be spawned from it (previously, each
process required a separate manifest which could have different
configuration - which wasn't actually supported and didn't make sense
design-wise). One downside of central manifests is that all processes
require the same enclave configuration (e.g. size), but that was
already the case so far because of broken checkpointing code. Also,
this is only a temporary problem, which will cease to exist after the
introduction of EDMM.
- `sgx.static_address` was renamed to `sgx.nonpie_binary` and now has to
be inserted manually by users (`sgx_sign` tools doesn't know about the
binaries run inside, which can be even provided or generated in
runtime by the user's workload).
- Caveat: the memory gap for non-PIE executables was removed because it
requires adding a new option to the manifest to be cleanly
implemented. This is left for some future loader rework PR.
Previously, it was possible to use Graphene without the main executable
(e.g. having only preloaded libraries). We aren't aware of anyone using
this weird option, but worse, it led to a very bad UX when the user made
mistakes - e.g. having a typo in the manifest or executable name could
lead to Graphene starting without errors, but doing nothing.
Supporting these options complicates the design of Graphene and loading
logic significantly, providing little useful functionality:
- loader.exec:
- the main user of it were our tests
- worked only for the first process spawned inside Graphene, as it
was a unidirectional manifest->binary mapping, so the child
process didn't know about the corresponding manifest.
- sgx.sigfile:
- probably all existing usages of it were completely redundant
- was resolved relatively to CWD instead of the executable location,
which made it mostly useless
From now on, the correct location of the files is:
- either place the manifest and sigfile next to the binary, with a
matching name, or
- create a symlink to the binary in the folder where manifests are
stored and launch it through this symlink
We don't use it in tests, plus it didn't work on SGX - there was a
warning about autogeneration inserted before the autogenerated shebang.
Also, test_106_manifest_with_shebang didn't actually test the shebang
but ran the binary through the loader, so it was meaningless. We'll need
to fix it and implement again after cleaning up Graphene invocation.
borysp