ladybird/Libraries/LibJS/Bytecode
Andreas Kling 0b8fbc03ef LibJS: Add per-field bytecode validation generated from Bytecode.def
Pass 2 of the validator now runs a per-instruction check that walks
each opcode's fields and verifies every reference points somewhere
sensible. Operand indices, label addresses, identifier/string/
property-key/regex table indices, cache indices, and trailing
operand arrays are all bound-checked against the values the C++
side carries on the Executable. Fields whose bound depends on an
enum variant count or other type information not present in
Bytecode.def are left for a follow-up.

The codegen lives in build.rs and reuses the existing layout
machinery from the bytecode_def crate, so each opcode gets a match
arm whose body reads each field at its known byte offset and calls
the right hand-written validate_* helper. Variable-length
instructions cross-check the count field against m_length before
iterating the trailing array, which guards against an attacker
sneaking a count that walks off the end of the instruction.

Note that the encoded operand format is a flat u32 index into the
runtime [registers | locals | constants | arguments] array, since
Operand::offset_index_by zeroes the 3-bit type tag during assembly.
The validator therefore range-checks the flat index rather than
reading the type tag and dispatching per kind.

The argument-count upper bound isn't tracked on Executable yet, so
arguments remain effectively unbounded; tightening that bound is
left for a later commit.

Cache pointer fields are validated only when before_cache_fixup is
true, since after the fixup pass they hold real pointers and must
be left alone. NewFunction and NewClass have plain u32 fields for
shared-function-data and class-blueprint indices; those are
recognized by name in the codegen so the indices still get
range-checked.

The error category enum is renumbered to drop the per-operand-kind
codes, since at the bytecode level we no longer differentiate.
2026-05-03 08:43:19 +02:00
..
AsmInterpreter LibJS: Avoid function envs for lexical-this arrows 2026-04-30 18:44:34 +02:00
BasicBlock.cpp LibJS: Stop worrying about Instruction destructors 2025-11-21 09:46:03 +01:00
BasicBlock.h LibJS: Remove remaining C++ pipeline artifacts 2026-03-19 21:55:10 -05:00
BuiltinAbstractOperationsEnabled.h LibJS: Introduce NativeJavaScriptBackedFunction 2025-11-30 11:54:54 +01:00
Builtins.h LibJS: Add a String.fromCharCode builtin opcode 2026-04-12 19:15:50 +02:00
Bytecode.def LibJS: Add a String.fromCharCode builtin opcode 2026-04-12 19:15:50 +02:00
ClassBlueprint.h LibJS: Add ClassBlueprint data structures 2026-02-11 23:57:41 +01:00
Debug.h LibJS: Move bytecode interpreter state to VM 2026-04-13 18:29:43 +02:00
Executable.cpp LibJS: Preserve source positions in bytecode source maps 2026-04-22 22:34:54 +02:00
Executable.h LibJS: Preserve source positions in bytecode source maps 2026-04-22 22:34:54 +02:00
FormatOperand.h LibJS: Improve bytecode executable dump format 2026-03-20 00:51:23 -05:00
IdentifierTable.cpp LibJS+LibWeb+WebContent: Port JS::PropertyKey to UTF-16 2025-08-05 07:07:15 -04:00
IdentifierTable.h AK: Add SentinelOptional 2026-03-20 12:03:36 +01:00
Instruction.cpp LibJS: Flatten Operand to 32-bit index in bytecode instruction stream 2025-12-09 21:44:13 -06:00
Instruction.h Meta: Reformat QtCreator file-listing script for readability 2026-02-23 13:10:03 +01:00
Interpreter.cpp LibJS: Avoid function envs for lexical-this arrows 2026-04-30 18:44:34 +02:00
Label.cpp Everywhere: Hoist the Libraries folder to the top-level 2024-11-10 12:50:45 +01:00
Label.h LibJS: Revert Enable EXPLICIT_SYMBOL_EXPORT 2025-07-22 11:51:29 -04:00
Operand.h AK: Add SentinelOptional 2026-03-20 12:03:36 +01:00
PropertyAccess.h LibJS: Remove dead C++ bytecode compilation functions 2026-03-19 21:55:10 -05:00
PropertyKeyTable.cpp LibJS: Cache fully-formed PropertyKeys in Executable 2025-12-11 14:34:45 -06:00
PropertyKeyTable.h AK: Add SentinelOptional 2026-03-20 12:03:36 +01:00
PropertyNameIterator.cpp LibJS: Cache stable for-in iteration at bytecode sites 2026-04-10 15:12:53 +02:00
PropertyNameIterator.h LibJS: Cache stable for-in iteration at bytecode sites 2026-04-10 15:12:53 +02:00
PutKind.h LibJS: Consolidate Put bytecode instructions and reduce code bloat 2026-03-04 18:53:12 +01:00
RegexTable.cpp LibRegex: Add ECMAScriptRegex and migrate callers 2026-03-27 17:32:19 +01:00
RegexTable.h LibRegex: Add ECMAScriptRegex and migrate callers 2026-03-27 17:32:19 +01:00
Register.h LibJS: Replace implicit environment stack with explicit registers 2026-02-09 16:35:39 +01:00
StringTable.cpp LibJS+LibWeb: Port interned bytecode strings to UTF-16 2025-08-14 10:27:08 +02:00
StringTable.h LibJS: Add bytecode validator scaffolding driven from Bytecode.def 2026-05-03 08:43:19 +02:00
Validator.cpp LibJS: Add per-field bytecode validation generated from Bytecode.def 2026-05-03 08:43:19 +02:00
Validator.h LibJS: Add bytecode validator scaffolding driven from Bytecode.def 2026-05-03 08:43:19 +02:00