In X64 update the following to match the C kernel:
- TCB size-bits (11).
- Endpoint size-bits (4).
- Guard bits (58).
- Message registers.
For all architectures, replace magic numbers with defined constants in
specifications, and as far as possible in proofs:
- tcb_bits in abstract spec.
- tcbBlockSizeBits, cteSizeBits, ntfnSizeBits, epSizeBits in Haskell
spec, Haskell and C refinement proofs.
* tcb_context rephrasing to (tcb_context o tcb_arch) and respectively
for set operations
* unfolding of reserved_irq for trivially solving most lemmas
* Changes to the inductive definition of integrity_obj to account for
tcb_arch and tcb_context new location
* Changes to the tcb examples in ExampleSystem to include tcb_arch
* Rephrasing of domain_sep_inv to accommodate the ReservedIRQ case
* Mostly rephrasing of tcb_context to (some form of) (tcb_context o tcb_arch)
* Trivial unfolding of handle_reserved_irq for hoare rules
* Examples in Example_Valid_State.thy were updated
* Nothing remarkable, mostly rephrasing of tcb_context and ReservedIRQ
handling
* Fun fact, some proofs are now shorter
tags: [VER-623][SELFOUR-413]
These changes to the automatons are required by:
SELFOUR-242: invert bitfield scheduler and optimise fast path
Details:
When we enter the kernel, the domain time left (ksDomainTime) is never zero.
If we entered on a timer interrupt, we may decrement it to zero before the
scheduler runs. If we do so, we set the scheduler state to choose_new_thread.
When choosing a new thread, the scheduler switches to a new domain if the
present one is required, and sets the new domain time left from domain_list
(ksDomSchedule).
When entering the kernel on a non-interrupt event, we never touch the domain
time left, which trivially preserves the new constraints.
To prove these, we had to ban a transition from kernel entry to kernel being
preempted when handling an interrupt event in InfoFlow. This is fine, as by
design handling interrupts is not meant to be preempted by interrupts.
To finish the proof of refinement to C, the specification for checkPrio
needed strengthening: the checkPrio spec now takes a machine word
argument. In the spec, priorities are still stored as 8-bit quantities,
however. Once the spec was strenthened, it was possible to remove some
redundant checks and mask operations from the C code.
A thread's maximum controlled priority (MCP) determines the maximum
thread priority or MCP it can assign to another thread (or itself).
Green build except for:
CParserTest (WTF Duplicate fact declaration "dc_20081211.dc_20081211.test_modifies")
AutoCorresSEL4 (waiting on result)
There is still a carefully managed sorry in Schedule_R, waiting on the C
parser FNSPEC+DONT_TRANSLATE fix.
UserOp_IF had its own way of extracting the XN bit from page tables.
This is now unified with the existing functions in ADT_AI, which also
means that the proof for XN bit equality is basically the same as for
pt_rights and pt_lift.
Some of the noninterference results depend on executions at the haskell level starting at a valid initial state. This file demonstrates this condition being realised.
Japheth Lim
Gerwin Klein
Matthew Brecknell
Alejandro Gomez-Londono
Alejandro Gomez-Londono
Miki Tanaka
Rafal Kolanski
Thomas Sewell
Xin,Gao
Gerwin Klein
Matthew Brecknell
Daniel Matichuk
Joel Beeren
deang