PINK DITAv2: kernel-level finiteness guard (no more null-string crash on inf/NaN)

The aborted hard cutover crash-looped with "Rust kernel returned null string" from
process_intent on the first live trading step. Root cause (reproduced): a non-finite
(inf/NaN) numeric field reaching the kernel — Python json.dumps emits the Infinity/NaN
token, serde_json rejects it at parse, and the FFI returned null. Magnitude is fine;
only finiteness was the problem.

Defense in depth, kernel catches it:
- Rust FFI (lib.rs): dita_kernel_process_intent_json / _on_venue_event_json now return
  a clean INVALID_INTENT KernelResult on parse failure (incl. Infinity/NaN tokens) AND
  on serialize failure (a non-finite produced internally) — never a null string.
- Python bridge (rust_backend.py): ExecutionKernel.process_intent validates intent
  finiteness/bounds (target_size, reference_price, limit_price, leverage, exit_leg_ratios;
  size>=0) BEFORE the FFI and rejects INVALID_INTENT, naming the offending field+value.
- contracts.py: add KernelDiagnosticCode.INVALID_INTENT.
- pink_direct.py: on INVALID_INTENT, log full upstream provenance (snapshot.price,
  capital, leverage, sizes) so the numerical SOURCE can be located on the next live run.
- on_venue_event bridge tolerates the fallback's null slot (uses the live slot).

Verified: kernel recompiled; offline 65 + 7 new guard tests green (no regression);
direct-FFI inf payload -> INVALID_INTENT (no null crash). NOTE: this turns the cutover
crash into a clean rejection — the upstream source of the non-finite (the live run's
inf) still needs locating, now aided by the provenance log.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
Codex
2026-05-31 09:10:13 +02:00
parent 0c15a7698e
commit 9168cf0759
5 changed files with 193 additions and 7 deletions

View File

@@ -1477,6 +1477,31 @@ fn into_c_string(value: &str) -> *mut c_char {
CString::new(value).unwrap().into_raw()
}
/// Build a well-formed INVALID_INTENT KernelResult JSON string. Used when the
/// kernel cannot safely process a request — a payload that fails to parse
/// (e.g. non-finite Infinity/NaN tokens serde rejects) or a result that fails
/// to serialize (a non-finite value produced internally). This keeps the kernel
/// from ever returning a null string on non-finite input/output: it rejects
/// cleanly with a diagnostic instead of panicking.
fn invalid_intent_cstring(reason: &str, detail: &str) -> *mut c_char {
let fallback = serde_json::json!({
"outcome": {
"accepted": false,
"slot_id": 0,
"trade_id": "",
"state": "IDLE",
"diagnostic_code": "INVALID_INTENT",
"severity": "WARNING",
"transitions": [],
"emitted_events": [],
"details": {"reason": reason, "detail": detail}
},
"slot": serde_json::Value::Null,
"snapshot": serde_json::Value::Null
});
into_c_string(&fallback.to_string())
}
fn with_handle_mut<F, R>(handle: *mut KernelHandle, f: F) -> Result<R, String>
where
F: FnOnce(&mut KernelCore) -> Result<R, String>,
@@ -1551,11 +1576,21 @@ pub extern "C" fn dita_kernel_process_intent_json(
};
let control_mode = cstr_to_string(control_mode).unwrap_or_else(|_| "NORMAL".to_string());
let control_verbosity = cstr_to_string(control_verbosity).unwrap_or_else(|_| "QUIET".to_string());
// Reject non-parseable payloads (incl. non-finite Infinity/NaN tokens serde
// refuses) with a clean INVALID_INTENT, never a null string.
let intent: KernelIntent = match serde_json::from_str(&payload) {
Ok(value) => value,
Err(err) => return invalid_intent_cstring("INVALID_INTENT_PARSE", &err.to_string()),
};
match with_handle_mut(handle, |core| {
let intent: KernelIntent = serde_json::from_str(&payload).map_err(|err| err.to_string())?;
Ok(core.process_intent(intent, &control_mode, &control_verbosity))
Ok::<_, String>(core.process_intent(intent, &control_mode, &control_verbosity))
}) {
Ok(result) => serde_json::to_string(&result).ok().map(|s| into_c_string(&s)).unwrap_or(ptr::null_mut()),
// A serialize failure means a non-finite value reached the output; reject
// cleanly rather than returning null.
Ok(result) => match serde_json::to_string(&result) {
Ok(s) => into_c_string(&s),
Err(err) => invalid_intent_cstring("INVALID_INTENT_SERIALIZE", &err.to_string()),
},
Err(_) => ptr::null_mut(),
}
}
@@ -1573,11 +1608,17 @@ pub extern "C" fn dita_kernel_on_venue_event_json(
};
let control_mode = cstr_to_string(control_mode).unwrap_or_else(|_| "NORMAL".to_string());
let control_verbosity = cstr_to_string(control_verbosity).unwrap_or_else(|_| "QUIET".to_string());
let event: VenueEvent = match serde_json::from_str(&payload) {
Ok(value) => value,
Err(err) => return invalid_intent_cstring("INVALID_EVENT_PARSE", &err.to_string()),
};
match with_handle_mut(handle, |core| {
let event: VenueEvent = serde_json::from_str(&payload).map_err(|err| err.to_string())?;
Ok(core.on_venue_event(event, &control_mode, &control_verbosity))
Ok::<_, String>(core.on_venue_event(event, &control_mode, &control_verbosity))
}) {
Ok(result) => serde_json::to_string(&result).ok().map(|s| into_c_string(&s)).unwrap_or(ptr::null_mut()),
Ok(result) => match serde_json::to_string(&result) {
Ok(s) => into_c_string(&s),
Err(err) => invalid_intent_cstring("INVALID_EVENT_SERIALIZE", &err.to_string()),
},
Err(_) => ptr::null_mut(),
}
}

View File

@@ -74,6 +74,7 @@ class KernelDiagnosticCode(str, Enum):
OK = "OK"
RATE_LIMITED = "RATE_LIMITED"
INVALID_SLOT_ID = "INVALID_SLOT_ID"
INVALID_INTENT = "INVALID_INTENT"
UNSUPPORTED_INTENT = "UNSUPPORTED_INTENT"
SLOT_BUSY = "SLOT_BUSY"
NO_OPEN_POSITION = "NO_OPEN_POSITION"

View File

@@ -14,6 +14,7 @@ from pathlib import Path
from typing import Any, Dict, Iterable, List, Optional, Sequence
import ctypes
import json
import math
import os
import subprocess
import sys
@@ -281,6 +282,29 @@ def _slot_from_payload(payload: Dict[str, Any]) -> TradeSlot:
)
def _first_invalid_intent_field(intent: KernelIntent) -> Optional[tuple[str, float]]:
"""Return (field, value) for the first non-finite or out-of-bounds numeric
field on an intent, or None if all are sane. Guards the kernel boundary
against inf/NaN that would otherwise crash serde_json serialization."""
scalar_checks = (
("target_size", float(intent.target_size if intent.target_size is not None else 0.0)),
("reference_price", float(intent.reference_price if intent.reference_price is not None else 0.0)),
("leverage", float(intent.leverage if intent.leverage is not None else 0.0)),
("limit_price", float(getattr(intent, "limit_price", 0.0) or 0.0)),
)
for name, value in scalar_checks:
if not math.isfinite(value):
return (name, value)
for idx, ratio in enumerate(intent.exit_leg_ratios or ()): # type: ignore[union-attr]
rv = float(ratio if ratio is not None else 0.0)
if not math.isfinite(rv):
return (f"exit_leg_ratios[{idx}]", rv)
size = float(intent.target_size if intent.target_size is not None else 0.0)
if size < 0.0:
return ("target_size", size)
return None
def _intent_to_payload(intent: KernelIntent) -> Dict[str, Any]:
return {
"timestamp": intent.timestamp.isoformat() if hasattr(intent.timestamp, "isoformat") else str(intent.timestamp),
@@ -561,6 +585,29 @@ class ExecutionKernel:
diagnostic_code=KernelDiagnosticCode.INVALID_SLOT_ID,
details={"reason": "INVALID_SLOT_ID", "slot_id": int(intent.slot_id), "intent_id": intent.intent_id},
)
# Finiteness / sanity guard at the kernel boundary. A non-finite (inf/NaN)
# numeric field would make the Rust core's serde_json serialization return
# a null string (panic). Reject cleanly with INVALID_INTENT instead, naming
# the offending field + value so the upstream numerical source can be located.
bad_field = _first_invalid_intent_field(intent)
if bad_field is not None:
name, value = bad_field
return KernelOutcome(
accepted=False,
slot_id=int(intent.slot_id),
trade_id=intent.trade_id,
state=self._get_slot(int(intent.slot_id)).fsm_state,
diagnostic_code=KernelDiagnosticCode.INVALID_INTENT,
severity=KernelSeverity.WARNING,
details={
"reason": "INVALID_INTENT",
"field": name,
"value": str(value),
"intent_id": intent.intent_id,
"action": intent.action.value,
"asset": intent.asset,
},
)
payload = _intent_to_payload(intent)
result = _get_rust().process_intent(
self._backend,
@@ -648,7 +695,10 @@ class ExecutionKernel:
verbosity=_enum_text(self.control.verbosity),
)
outcome = _outcome_from_payload(result["outcome"])
slot = _slot_from_payload(result["slot"])
# An INVALID_* fallback result carries a null slot; fall back to the
# kernel's current slot so settlement/bookkeeping stays consistent.
slot_payload = result.get("slot")
slot = _slot_from_payload(slot_payload) if slot_payload else self._get_slot(int(outcome.slot_id))
self.state.refresh()
incremental_pnl = slot.realized_pnl - self._last_settled_pnl.get(slot.slot_id, 0.0)
if abs(incremental_pnl) > 1e-12:

View File

@@ -427,6 +427,27 @@ class PinkDirectRuntime:
kernel_intent = _decision_to_kernel_intent(decision, intent, slot_id=0)
outcome = self.kernel.process_intent(kernel_intent)
# Locate the source of any non-finite intent the kernel rejected:
# log the full upstream provenance (snapshot price, account capital,
# leverage, sizing) so a numerical error can be traced to its origin
# rather than silently rejected.
if outcome.diagnostic_code == KernelDiagnosticCode.INVALID_INTENT:
self.logger.error(
"INVALID_INTENT rejected by kernel: %s | provenance: "
"snapshot.price=%r capital=%r open_positions=%r leverage=%r "
"target_size=%r reference_price=%r limit_price=%r action=%s asset=%s",
dict(outcome.details or {}),
getattr(snapshot, "price", None),
context.capital,
context.open_positions,
getattr(kernel_intent, "leverage", None),
getattr(kernel_intent, "target_size", None),
getattr(kernel_intent, "reference_price", None),
getattr(kernel_intent, "limit_price", None),
decision.action.value,
intent.asset,
)
# Read authoritative final state from kernel.
final_slot = self.kernel.slot(0)
slot_dict = final_slot.to_dict()

View File

@@ -0,0 +1,73 @@
"""Kernel-level finiteness guard: non-finite (inf/NaN) intents must be rejected
with INVALID_INTENT, never crash the kernel ("Rust kernel returned null string").
Two layers (defense in depth):
- Python bridge (ExecutionKernel.process_intent): rejects non-finite/insane fields
before the FFI call, naming the offending field for source-location.
- Rust kernel (FFI): a payload that fails to parse (incl. the Infinity/NaN tokens
serde rejects) or a result that fails to serialize returns a clean INVALID_INTENT
outcome instead of a null string.
"""
from __future__ import annotations
from datetime import datetime, timezone
import pytest
from prod.clean_arch.dita_v2 import (
ExecutionKernel, InMemoryControlPlane, KernelCommandType, KernelControlSnapshot,
KernelMode, KernelVerbosity, MemoryKernelJournal, MockVenueAdapter, MockVenueScenario,
TradeSide,
)
from prod.clean_arch.dita_v2.contracts import KernelDiagnosticCode, KernelIntent
from prod.clean_arch.dita_v2.rust_backend import _get_rust, _intent_to_payload
def _kernel():
return ExecutionKernel(
control_plane=InMemoryControlPlane(
KernelControlSnapshot(mode=KernelMode.DEBUG, verbosity=KernelVerbosity.TRACE)
),
venue=MockVenueAdapter(MockVenueScenario(emit_fill_on_submit=True, partial_fill_ratio=1.0)),
journal=MemoryKernelJournal(),
)
def _intent(size, price, lev=3.0):
return KernelIntent(
timestamp=datetime.now(timezone.utc), intent_id="i", trade_id="T", slot_id=0,
asset="BTCUSDT", side=TradeSide.SHORT, action=KernelCommandType.ENTER,
reference_price=price, target_size=size, leverage=lev, exit_leg_ratios=(1.0,), reason="X",
)
@pytest.mark.parametrize("size,price,lev,field", [
(float("inf"), 100.0, 3.0, "target_size"),
(float("nan"), 100.0, 3.0, "target_size"),
(0.1, float("inf"), 3.0, "reference_price"),
(0.1, 100.0, float("nan"), "leverage"),
(-0.1, 100.0, 3.0, "target_size"),
])
def test_bridge_rejects_nonfinite_intent(size, price, lev, field):
out = _kernel().process_intent(_intent(size, price, lev))
assert out.accepted is False
assert out.diagnostic_code == KernelDiagnosticCode.INVALID_INTENT
assert out.details.get("field") == field
def test_finite_intent_still_accepted():
out = _kernel().process_intent(_intent(0.15, 100000.0))
assert out.accepted is True
assert out.diagnostic_code == KernelDiagnosticCode.OK
def test_rust_kernel_rejects_nonfinite_payload_without_null_crash():
# Bypass the Python bridge guard: hand a non-finite payload straight to the
# Rust FFI (json.dumps emits the Infinity token serde rejects). The kernel
# must return a clean INVALID_INTENT outcome, not a null string.
k = _kernel()
payload = _intent_to_payload(_intent(float("inf"), 100.0))
res = _get_rust().process_intent(k._backend, payload, mode="NORMAL", verbosity="QUIET")
assert res["outcome"]["diagnostic_code"] == "INVALID_INTENT"
assert res["outcome"]["accepted"] is False