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Pull request overview
This PR adjusts EVM JIT trap handling so that faults at (or near) a null pointer are reported as an internal engine error rather than being misclassified as an EVM out-of-bounds memory access, preventing an engine defect from being surfaced as a consensus-visible halt condition.
Changes:
- Add a dedicated
EVMNullPointerDereferenceerror code for JIT-only null-pointer faults. - Update
Runtime::callEVMInJITModesignal-trap mapping to classify low-address SIGSEGV/SIGBUS asEVMC_INTERNAL_ERRORinstead ofEVMC_INVALID_MEMORY_ACCESS.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| src/runtime/runtime.cpp | Adds low-address (null) fault detection in the EVM JIT trap handler and maps it to an internal EVMC status. |
| src/common/errors.def | Introduces EVMNullPointerDereference to represent JIT null-pointer dereference defects distinctly from EVM execution faults. |
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| /// Size of the unmapped low address range. A faulting address below this is a | ||
| /// null pointer plus a small offset, never a real allocation. | ||
| static constexpr uintptr_t NullPointerPageSize = 4096; | ||
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⚡ Performance Regression Check Results✅ Performance Check Passed (interpreter)Performance Benchmark Results (threshold: 25%)
Summary: 194 benchmarks, 0 regressions ✅ Performance Check Passed (multipass)Performance Benchmark Results (threshold: 25%)
Summary: 194 benchmarks, 0 regressions |
This was referenced Aug 29, 2026
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callEVMInJITMode mapped every SIGSEGV/SIGBUS that was not native stack exhaustion to EVMC_INVALID_MEMORY_ACCESS, a mapping inherited from the guard-page bounds checks of WebAssembly. EVM memory is never bounds-checked by a fault, so in EVM JIT code such a fault is an engine defect, and reporting it as an EVM halt let the embedder accept a wrong result. Report it as EVMC_INTERNAL_ERROR, as other unexpected signals already are. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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1. Does this PR affect any open issues?(Y/N) and add issue references (e.g. "fix #123", "re #123".):
2. What is the scope of this PR (e.g. component or file name):
Runtime::callEVMInJITModeinsrc/runtime/runtime.cpp.3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):
In EVM JIT code, every SIGSEGV/SIGBUS that was not native stack exhaustion was reported as
EVMC_INVALID_MEMORY_ACCESS. The mapping comes from WebAssembly, whose linear memory is bounds-checked by guard pages. EVM memory is a heap buffer expanded explicitly before each access, and EVM exceptions use the illegal-instruction trap, so such a fault can only be an engine defect. Reported as an EVM halt, it was accepted as a valid result: with the stale memory base fixed in #600, the replay of mainnet block 25818502 finished with wrong gas instead of failing.This PR reports these faults as
EVMC_INTERNAL_ERROR, as other unexpected signals already are. Stack exhaustion still maps toEVMC_STACK_OVERFLOW.Change doc:
docs/changes/2026-10-11-evm-jit-fault-internal-error4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):
An embedder now receives
EVMC_INTERNAL_ERRORinstead ofEVMC_INVALID_MEMORY_ACCESSfor a fault in EVM JIT code. No status changes for any condition the EVM defines.5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:
No new tests.
ctest(default and CI multipass arguments) andtools/run_evm_tests.py(multipass, interpreter) pass.6. Release note
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