bddisasm/CHANGELOG.md

Changelog

All notable (user-facing) changes to this project will be documented in this file.

The format is based on Keep a Changelog.

[2.1.5] - 2024-05-28

Fixed

• Potential unaligned load, as reported by UBSAN.

[2.1.4] - 2024-03-27

Changed

• Removed no longer needed static assert.

[2.1.3] - 2024-03-04

Changed

• Aligned BDDISASM APX instructions syntax with some of the Intel recomandations (using the suffix notation for NF and ZU indications, using finite set notation for DFV operands).

Disassembly differences

• The ZU indication is appended as a mnemonic sufix, as per recomandations. However, in case of SETcc instructions, BDDISASM will append the ZU indication AFTER the condition code (similar to CMPccXADD and with initial SETcc.ZU specification).
• The DFV (default flags value) operand obeys the finite set notation, but it is placed as the last operand of the instruction.

[2.1.2] - 2024-02-27

Added

• Read access for the rIP operand for the SYSCALL instruction.
• SCS, rCX, rDX operands for the SYSEXIT instruction.

[2.1.1] - 2024-02-26

Added

• Read access for the rIP operand for some CALL instructions.

[2.1.0] - 2024-02-20

Added

• Support in bddisasm for Intel REX2 prefix.
• Support in bddisasm for Intel APX extensions.
• Support in bddisasm for Intel USERMSR extensions.
• Support in bddisasm for prefix activation fields inside INSTRUX - these fields can be consulted to determine whether a particular prefix is present, accepted & active.
• New feature in bdshemu: SHEMU_OPT_DIRECT_MAPPED_SHELL - allows emulation with a smaller IntBuff at the cost of not having WRITE_SELF detections. The shellcode can be provided directly from its original location, without the need to allocate it in a dedicated memory region.
• New feature in bdshemu: SHEMU_OPT_TRACK_LOOPS - loops can now be tracked by bdshemu. SHEMU_OPT_TRACE_LOOPS can be used to log loop information.
• Support in bdshemu for APX instructions (both REX2 and EVEX encoded instructions) - the new SHEMU_OPT_SUPPORT_APX must be set in order to enable APX emulation.

Changed

• Reduced the size of the INSTRUX structure from 856 bytes to 488 bytes (almost -43%!).
• Increased decoding performance from average 300 clocks/instruction to average 235 clocks/instruction (almost +20%!).
• New decode options - do not decode implicit operands - this further increases performance from average 235 clocks/instruction to 200 clocks/instruction (almost +15%!).
• Re-worked the Python scripts - both disasmlib.py and generate_tables.py have been significantly reworked, improving readability, and making them more efficient.
• disasmtool builds on Linux.

Removed

• Support for Cyrix & VIA instructions - only current Intel & AMD instructions remain supported.
• disasmtool_lix has been removed. disasmtool is available on Linux as well.

Breaking changes

Inside INSTRUX

• Removed Iclass field - it was aliased over Instruction field, which must be used from now on.
• Removed OperandsEncodingMap field - one can consult the Encoding field in each operand to determine the encoding.
• Removed ExceptionClass field - only ExceptionType remains, which contains an enum with all the exception types.
• Removed Predicate field - only Condition remains, which was aliased over Predicate.
• Removed HasImm3, Immediate3, Imm3Length and Imm3Offset fields, as they were not used/needed.
• Removed Bhint, SseCondition, SignDisp fields, as they were not used.
• Moved FlagsAccess.RegAccess outside and renamed it to RflAccess, to save more space.
• Switched from char Mnemonic[32] to const char *Mnemonic - this decreases INSTRUX size by almost 32 bytes, and increases perf.

Inside ND_OPERAND

• Removed RawSize - in most cases, Size and RawSize are identical; the only case where they might differ is for Immediate and RelativeOffset operands - in that case, one can consult the RawSize field in Immediate or RelativeOffset.

Inside ND_OPERAND_DECORATOR

• Removed Broadcast field, moved it inside ND_OPDESC_MEMORY.
• Removed HasSae, HasEr - they are per instruction, not per operand, and can be consulted directly inside INSTRUX.
• Moved Msk one level up, inside the ND_OPERAND_DECORATOR structure.

Defines & constants

• Removed ND_PRED_* defines - search & replace them with ND_COND_*.
• Removed ND_HAS_PREDICATE - use ND_HAS_CONDITION instead.
• Removed ND_VEND_GEODE and ND_VEND_CYRIX.