Vector35 / Vector35/binaryninja-api

Add support for builtin that sets memory to a pattern.

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Component: Core Effort: Low Impact: Low
Dominant language
C++
Stars
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Forks
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Avg merge
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Merged PRs (30d)
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Description

Version and Platform (required):

  • Binary Ninja Version: 3.6.4764-dev, 1e8f4a9b
  • OS: macos
  • OS Version: 14.2
  • CPU Architecture: arm64

Pseudo C:

    int64_t rcx_3;
    int64_t rdi_2;
    rdi_2 = __memfill_u64(&DriverObject->MajorFunction, sub_14008574c, 0xe0);

HLIL:

  int64_t rcx_3
  int64_t rdi_2
  rdi_2, rcx_3 = __memfill_u64(&DriverObject->MajorFunction, sub_14008574c, 0xe0)

Disassembly:

lea     rax, [rel sub_14008574c]
mov     ecx, 0x1c
lea     rdi, [rbx+0x70]
rep stosq qword [rdi]  {0x0}

Issue is at address 14008a0a2 for this binary:
HEVD.zip

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Reproduce the issue with the attached HEVD.zip at address 14008a0a2, comparing the pseudo C, HLIL, and disassembly shown in the report. Trace how Binary Ninja handles the __memfill_u64 builtin and the rep stosq sequence, then verify that the resulting representation correctly models the memory-pattern operation.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp
Domain
compilers, reverse-engineering
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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