## Why this should be merged
The `vm.PrecompileEnvironment.Call()` method requires careful usage
because of reentrancy vulnerabilities (this is common to all outgoing
`CALL`s in the EVM, not just stateful precompiles). This package
provides a common method of protection, a reentrancy guard.
## How this works
Provides a function that returns `vm.ErrExecutionReverted` if called
twice, by the same contract, in the same transaction, with the same
identifier.
## How this was tested
Unit and integration tests.
## Why this should be merged
Completeness.
## How this works
n/a
## How this was tested
Originally the `DELEGATECALL` test asserted that the `CALLVALUE` was
zero, but this didn't demonstrate that it was inherited (e.g.
`STATICCALL` always receives zero). The value sent to the caller of the
precompile is now non-zero, to precisely demonstrate correct behaviour
of all call types.
## Why this should be merged
Allows direct access to the P-256 verification precompile. Currently the
only alternative is to rely on the planned but not guaranteed address
that Ethereum will use.
## How this works
Embed the non-exported `p256verify` type in an exported struct to allow
its methods to be exposed.
## How this was tested
Run the test suite for `p256verify` on `P256Verify`.
## Why this should be merged
Improved clarity.
## How this works
Semantically equivalent refactor. These values aren't accessible /
needed during execution of a stateful precompile, but are important when
making outgoing calls so were originally only set in the
`PrecompileEnvironment.Call()` implementation. This was confusing and
led to a false-positive bug report.
## How this was tested
Existing tests.
## Why this should be merged
Provides precompiles with unambiguous access to contextual addresses,
without the consumer needing to understand how they change under
different call types.
## How this works
The `libevm.AddressContext` type, which used to carry 3 addresses, now
provides different versions of `Caller` and `Self`. The EVM-semantic
versions are as defined by the rules of the EVM (and available before
this change). The raw versions are the unmodified caller and self.
## How this was tested
Extension of existing UTs to include raw addresses in addition to
existing, EVM-semantic ones.
## Why this should be merged
In case a tx's execution (specifically a registered precompile) should
be invalidated, this allows the EVM to find this error.
## How this works
Adds a setter and getter that can be called from a precompile.
## How this was tested
UT
## Why this should be merged
`goheader` linter apparently hasn't been running but now decided to and
is blocking another PR. It's not worth the time to investigatie why
(probably a version update).
## How this works
Update header comments as required.
## How this was tested
N/A
## Why this should be merged
Adds logging of `libevm` modification of default behaviour.
## How this works
1. Introduces `log.Lazy` functions to allow expensive logging operations
to be computed i.f.f. required by the logging level.
2. Adds `Info` logging for registration of types and `Debug` logging for
all else.
3. Only paths that change behaviour in a potentially unpredictable
manner are logged; of note, RLP / JSON encoding is _not_ considered
unpredictable given that registered extras are logged.
4. The minimal viable package, `set`, was necessary because we don't
want to depend on `avalanchego` and the `hashicorp/go-set` latest
version requires a later version of Go. #153 tracks a swap to the latter
when possible.
The `eth/tracers/internal/tracetest` test flaked at least twice
(unrelated to these changes) so I've marked it as such since it's not
worth a separate PR.
## How this was tested
New unit test on `log.Lazy` + `set` methods. Existing CI for the rest as
it's a refactor.
## Why this should be merged
Aligns precompiled contracts with the pattern used in
`vm.EVMInterpreter` for regular contracts and simplifies gas accounting
by using existing mechanisms. The most notable simplification occurs
when there are multiple error paths that return early and have to
account for consumed gas (any local solution would likely just mirror
this one).
This forms part of a broader, long-term direction of feature parity
between precompiled and bytecode contracts, exposed via
`vm.PrecompileEnvironment`.
The `vm.Contract.Value()` method is also exposed as a natural
accompaniment to this change.
## How this works
The original signature for `vm.PrecompiledStatefulContract` received the
amount of gas available and then returned the amount remaining; this has
been removed in lieu of exposing the existing `vm.Contract.UseGas()`
method via the `vm.PrecompileEnvironment`. A new `legacy` package wraps
the old signature and converts it to a new one so `ava-labs/coreth`
doesn't need to be refactored.
```go
func oldPrecompile(env vm.PrecompileEnvironment, input []byte, gas uint64) ([]byte, uint64, error) {
// ...
if err != nil {
return nil, gas - gasCost, err // pattern susceptible to bugs; should it be `nil, gas, err` ?
}
// ...
return output, gas - gasCost, nil
}
func newPrecompile(env vm.PrecompileEnvironment, input []byte) ([]byte, error) {
// The original `gas` argument is still available as `env.Gas()`
// ...
if !env.UseGas(gasCost) { // an explicit point at which gas is consumed
return nil, vm.ErrOutOfGas
}
// ...
if err != nil {
return nil, err
}
// ...
return output, nil
}
```
## How this was tested
Existing unit test modified to use the `legacy` adaptor.
---------
Signed-off-by: Arran Schlosberg <519948+ARR4N@users.noreply.github.com>
Co-authored-by: Quentin McGaw <quentin.mcgaw@gmail.com>
## Why this should be merged
Fixes tracing when a stateful precompile calls another contract that
itself accesses storage.
## How this works
The pre-state tracer from `eth/tracers/native` doesn't implement
`CaptureEnter()` (entry of a new context), instead relying on
`CaptureState()` (per-opcode tracing) to detect that a new contract has
been entered. In doing so, it [maintains an
invariant](cb7eb89341/eth/tracers/native/prestate.go (L160))
that is expected when `CaptureState(vm.SLOAD, ...)` is called—breaking
the invariant results in a panic due to a nil map.
The fix involves (a) maintaining the invariant as part of
`CaptureEnter()` (previously a no-op); and (b) calling said method
inside `vm.PrecompileEnvironment.Call()`. The latter has the added
benefit of properly handling all tracing involving an outbound call from
precompiles.
## How this was tested
New integration test demonstrates that the tracer can log the retrieved
storage value.
---------
Co-authored-by: Darioush Jalali <darioush.jalali@avalabs.org>
* fix: `vm.WithUNSAFECallerAddressProxying` under `DELEGATECALL`
* test: `vm.WithUNSAFECallerAddressProxying()` effect on outgoing caller addr
* chore: mark `eth/tracers/js` test flaky
* feat: `vm.PrecompileEnvironment.IncomingCallType()`
* chore: minor documentation edit
* doc: `PrecompileEnvironment` example for determining actual caller
* chore: placate the linter
* chore: `golangci-lint` CI workflow
* fix: make `golangci-lint` happy
* chore: bump `actions/{checkout,setup-go}` versions
* chore: overhaul `.golanci.yml` config
* fix: all linter issues
* chore: exclude non-libevm linters + change deprecated option
* fix: add overflow check in example
* fix: try again; different local version?
* chore: this is trying my patience
* chore: enable `gci` and fix ordering
* chore: mark `ethclient/gethclient` test as flaky
* chore: mark `eth/catalyst` test as flaky
* feat: pseudo-generic extra payloads in `params.ChainConfig` and `params.Rules`
* feat: `params.ExtraPayloadGetter` for end-user type safety
* refactor: payloads only available through `params.ExtraPayloadGetter`
* chore: make `libevm/examples/extraparams` a `params` testable example
* doc: `libevm/pseudo` package comments and improved readability
* doc: `params.*Extra*` comments and improved readability
* doc: `params.ExtraPayloadGetter` comments and improved readability
* doc: `params/config.libevm_test.go` comments and improved readability
* refactor: simplify `params.ChainConfig.UnmarshalJSON()`
* refactor: abstract new/nil-pointer creation into `pseudo.Constructor`s
* feat: precompile override via `params.Extras` hooks
* doc: flesh out `PrecompileOverride()` in example
* doc: complete commentary and improve readability
* refactor: `ChainConfig.Hooks()` + `Rules` equivalent
* chore: rename precompiles test file in keeping with geth equivalent
* feat: stateful precompiles + allowlist hooks
The allowlist hooks are included in this commit because they allow for the same functionality as stateful precompiles in `ava-labs/coreth` and `ava-labs/subnet-evm`.
* fix: `StateTransition.canExecuteTransaction()` used `msg.From` instead of `To`
* test: `params.RulesHooks.CanCreateContract` integration
* test: `params.RulesHooks.CanExecuteTransaction` integration
* test: `vm.NewStatefulPrecompile()` integration
* refactor: simplify test of `CanCreateContract`
* refactor: abstract generation of random `Address`/`Hash` values
* doc: full documentation + readability refactoring/renaming
* fix: remove circular dependency in tests
