db

A simple x86_64 debugger written with ptrace and Udis86

Building

db depends on Udis86 to provide disassembly. This is an essential feature of any debugger, so the dependency is not optional.

In order to build db, ensure:

• libudis86.{so,a} is available
• Your cc is c99 compliant
• Your libc is POSIX.1-2008 compliant

There is no configure step, and no install target, so simply run:

make

Usage

db accepts only positional arguments: the command-line of the program to be debugged.

Assuming you have placed the db executable somewhere in your PATH, run:

db command

Interface

Prompts begin with (db) , and have limited line-editing support.

Errors are printed before the next prompt.

Commands

All commands in db are identified as a single character mnemonic, followed by any arguments.

db supports the following commands:

commands:
        s             | step single instruction
        d             | dissassemble current instruction
        r <reg>       | read register
        w <reg> <val> | write register
        g <adr>       | get memory
        p <adr> <val> | poke memory
        e             | exit
registers:
        r15
        r14
        r13
        r12
        rbp
        rbx
        r11
        r10
        r9
        r8
        rax
        rcx
        rdx
        rsi
        rdi
        orig_rax
        rip
        cs
        eflags
        rsp
        ss
        fs_base
        gs_base
        ds
        es
        fs
        gs

Values and addresses are expected to be in hexadecimal.

Future Plans

Desired features include:

• Breakpoints
• Visual (TUI) mode
• Arbitrary code execution while single-stepping