This will now allow sorrying of proofs in refine to aid parallelism as
we proceed.
Note: the invariants are in no way complete and the aim should be to
update them as required - allowing people to start working on refine
proofs without the high initial cost of fixing/writing all of the
invariants.
Other platforms such as arm-hyp will need to look into additional TCB state
such as VCPU in sanitiseRegister. This commit provides the scaffolding for
that.
- replace ARM-specific constants and types with aliases which can be
instantiated separately for each architecture.
- expand lib with lemmas used in X64 proofs.
- simplify some proofs.
Also-by: Matthew Brecknell <Matthew.Brecknell@data61.csiro.au>
The things that usually go wrong:
- wp fall through: add +, e.g.
apply (wp select_wp) -> apply (wp select_wp)+
- precondition: you can remove most hoare_pre, but wpc still needs it, and
sometimes the wp instance relies on being able to fit a rule to the
current non-schematic precondition. In that case, use "including no_pre"
to switch off the automatic hoare_pre application.
- very rarely there is a schematic postcondition that interferes with the
new trivial cleanup rules, because the rest of the script assumes some
specific state afterwards (shouldn't happen in a reasonable proof, but
not all proofs are reasonable..). In that case, (wp_once ...)+ should
emulate the old behaviour precisely.
SUPREMUM changed from a definition to an abbreviation.
A number of proofs that previously used blast, fastforce or auto to
solve goals involving UNION, now either fail or loop. This commit
includes various ad-hoc workarounds.
* Changes to StateRelation.thy, most notably the addition of
arch_tcb_relation and arch_fault_map to acount for the new
arch_tcb and arch_fault types
* On ADT_H ArchFault_Map and ArchTcbMap were added to account for
(yet again) the new arch_tcb and arch_fault types
* Also irq_state_map and IRQStateMap were extended to support the new
IRQReserved
* Everything else was mostly unfolding stuff and
(tcb_arch -> tcb_context) rearrangement
tags: [VER-623][SELFOUR-413]
This reverts:
- a67b443ca5
"SELFOUR-242: update goal number based indentation in Fastpath_C"
- f704cf0404
"SELFOUR-242: invert bitfield scheduler and optimise fast path"
Verification confirmed functional correctness and refinement of the
system in this case. However, guarantees on thread scheduling and
fairness are not modeled in the current verification. Once this issue is
addressed, SELFOUR-242 will be re-examined.
* Reverse the level 2 of the bitmap scheduler to move the highest priority
threads' level 2 entries into the same cache line as the level 1.
* Use the bitfield scheduler to make the fast path a more common occurrence.
* Change possibleSwitchTo to not invoke scheduler when the fast path would not
invoke it either (using implicit assumptions about the current thread being
the highest priority schedulable thread)
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.
Figured out how to pass the necessary assumptions about the region
being zeroed through the createNewObjects loop and resolve at
invokeUntyped_Retype. Still WIP.
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).
Also includes fixes to specs and invariants, and initial progress
towards C refinement.
A thread's maximum controlled priority (MCP) determines the maximum
thread priority or MCP it can assign to another thread (or itself).
Substantial adjustments to crunch. Main user changes are:
- 'lift' and 'unfold' mechanisms replaced by more general 'rule'.
- some more 'ignores' standardised.
- crunch has a more principled overall design:
+ discover crunch rule
* provided or by definition extraction
+ recurse according to rule
+ prove goal based on rule, recursive discoveries, standard tactic
* wp/simp adjustments tweak tactic
* commit 'ecbb860532b4c576fc4726a805802f16bcf5302c': (29 commits)
autocorres-crefine: specialise corres_no_failI for compatibility with Refine
Add license tags for autocorres-crefine files
crefine: refactor AutoCorresTest a bit
autocorres-crefine: remove local debugging imports
Fix InfoFlowC to accommodate corres_underlying changes.
Fix DRefine to accommodate corres_underlying changes.
autocorres-crefine: experiment with manually translating a function (clzl).
autocorres-crefine: experiment with translating bitfield_gen specs.
autocorres-crefine: start a test case for function calls.
autocorres-crefine: update example proofs to work with no_c_termination, which does not require proving termination for the C spec.
autocorres: add user option "no_c_termination" for previous patch.
Making termination proof optional for AutoCorres.
WIP: autocorres: hacky proof of concept for incremental translation.
autocorres: add some missing WordAbstract rules.
autocorres-crefine: fix some comments in work theory.
autocorres-crefine: prove modifies and (simple) terminates specs.
autocorres-crefine: experiment with generating modifies proofs
autocorres-crefine: run autocorres in kernel_all_substitute locale
autocorres-crefine: update another corres_UL that snuck in before rebasing.
autocorres-crefine: working ccorres for handleYield (modulo some white lies).
...
inj_on_image_set_diff: resolved the injection map lemma application issue in CSpace1_R.thy, CSpace_R.thy
Pair_fst_snd_eq chaged to prod_eq_iff in TcbAcc_R.thy, Schedule_R.thy, Retype_R.thy
TrueI removed in Schedule_R.thy
not_leE changed to not_le_imp_less in Retype_R.thy
Some generalisation is done in finaliseSlot_invs'' to avoid
duplicating it in Orphanage and PageTableDuplicates.
Finally cleanup in haskell translation.
The very last twist of this: the proof that resolveAddressBits can
be seen as functional needs to change, a lot, because it's now
sensitive to gsCNodes. Still working on that.
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.
Added word_log2 and word_clz (inline for now, will migrate them out to
lib later).
Proved most important properties of word_log2 and some basic
count leading zeros properties (word_clz). The former were painful.
Thanks to Thomas, we have a nice tactic for dealing with complicated
obj_at' predicates in conclusion: normalise_obj_at'
This commit should at least remove merge conflict markers, and the idea
is that at least refine, crefine, drefine, and infoflow (with sorrys)
build. Subsequent commits may be required to fix build issues that I
have not picked up.
Joel Beeren
Matthew Brecknell
Daniel Matichuk
Gerwin Klein
Miki Tanaka
Daniel Matichuk
Rafal Kolanski
Gerwin Klein
Alejandro Gomez-Londono
Xin,Gao
Ramana Kumar
Thomas Sewell
Matthew Brecknell
Japheth Lim
Sophie Taylor
David Greenaway
Toby Murray