VM Compatibility Analyzer

This tool analyzes Go programs for compatibility with different Virtual Machines (VMs), specifically targeting the Cannon VM. It checks whether the opcodes, syscalls, and other aspects of a Go program are supported by the chosen VM, and flags any compatibility issues.

Overview

VM Compat is a CLI tool designed for checking compatibility of GO programs with different Virtual Machines (VMs), specifically targeting the Cannon VM. It takes a Go source file (typically main.go) as input, generates disassembled code, and parses each instruction to detect syscalls and opcodes. Additionally, it performs syscall analysis using SSA call graphs in Go.

Features

• Static Analysis: Analyzes Go source code without executing it.
• Disassembler Integration: Converts Go code into low-level instructions.
• Opcode and Syscall Detection: Identifies all syscalls and opcodes used in the program.
• SSA Call Graph Analysis: Uses Go's SSA (Static Single Assignment) form to detect syscalls within function call graphs.
• Compatibility Checking: Helps determine whether a given Go program is incompatible with a targeted VM.

How It Works

VM Compat performs static analysis to ensure compatibility with the target VM. Since it does not execute the code, it considers all possible execution paths, detecting any syscalls or opcodes that might be present. This approach is beneficial because it ensures a thorough analysis, even in cases where a particular execution path may never be taken at runtime.

For example, consider the following function:

func demo() {
    if condition1 {
        doSyscall1()
    }
    if condition2 {
        doSyscall2()
    }
}

Even if condition2 is never met during runtime, VM Compat will still detect doSyscall2() as a potential syscall. This ensures that all possible execution paths are analyzed, making the tool effective in identifying compatibility concerns proactively.

Prerequisites

VM Compat requires llvm-objdump to be installed for disassembly. Install it using the following commands:

Linux (Ubuntu/Debian)

sudo apt update && sudo apt install llvm

macOS

brew install llvm

Ensure that llvm-objdump is accessible in your system's PATH. If necessary, update the PATH variable:

export PATH="$(brew --prefix llvm)/bin:$PATH"

Installation

To install VM Compat, clone the repository and build the binary:

git clone https://github.com/your-repo/vm-compat.git
cd vm-compat
make analyser

Usage

General CLI Usage

./bin/analyzer [global options] command [command options]

Commands

• analyze: Checks the program compatibility against the VM profile.
• trace: Generates a stack trace for a given function.
• help, h: Shows a list of commands or help for one command.

Command-Specific Usage

Analyze Command

./bin/analyzer analyze [command options] arg[source path]

Analyze Options

Option	Description	Default
--vm-profile value	Path to the VM profile config file (required).	None
--analysis-type value	Type of analysis to perform. Options: opcode, syscall.	All
--disassembly-output-path	File path to store the disassembled assembly code.	None
--format value	Output format. Options: json, text.	text
--report-output-path value	Output file path for report. Default: stdout.	None
--with-trace	Enable full stack trace output.	false
--help, -h	Show help.	None

Trace Command

./bin/analyzer trace [command options] arg[source path]

Trace Options

Option	Description	Default
--vm-profile value	Path to the VM profile config file (required).	None
--function value	Name of the function to trace. Include package name (e.g., syscall.read). (required)	None
--source-type value	Assembly or go source code.	None
--help, -h	Show help.	None

Example Usage

Running an Analysis

./bin/analyzer  analyze  --with-trace=true --format=text --analysis-type=syscall --disassembly-output-path=sample.asm --vm-profile ./profile/cannon/cannon-64.yaml ./examples/sample.go

Running a Trace

./bin/analyzer trace --vm-profile=./profile/cannon/cannon-64.yaml --function=syscall.read sample.asm

To create vm specific profile, follow this

Example Output

==============================
🔍 Go Compatibility Analysis Report
==============================

🖥 VM Name: Cannon
⚙️ GOOS: linux
🛠 GOARCH: mips64
📅 Timestamp: 2025-02-10 19:40:17 UTC
🔢 Analyzer Version: 1.0.0

------------------------------
🚨 Summary of Issues
------------------------------
 ❗ Critical Issues: 65
⚠️ Warnings: 26
ℹ️ Total Issues: 91

------------------------------
📌 Detailed Issues
------------------------------

1. [CRITICAL] Incompatible Syscall Detected: 5006
   - Sources:
     ->  zsyscall_linux_mips64.go:1677 : (syscall.lstat)
...