LLDB

Some useful LLDB scripts for my macOS debugging

Installation

git clone git@github.com:kohnakagawa/LLDB.git $HOME/lldb
echo "command script import $HOME/lldb/commands/lldbinit.py" >> $HOME/.lldbinit
mkdir -p $HOME/Documents/Resources/
git clone https://github.com/DerekSelander/LLDB.git $HOME/Documents/Resources/LLDB
echo "command script import $HOME/Documents/Resources/LLDB/lldb_commands/dslldb.py" >> $HOME/.lldbinit
rm $HOME/Documents/Resources/LLDB/lldb_commands/generate_new_script.py

Defined commands

brt_set_bps

Summary

Sets breakpoints at all indirect branch instructions (call/jmp) in the main module of the target program. This command is specifically designed for x86_64 processes and currently only supports the main module.

Usage

(lldb) brt_set_bps

Details

• Identifies all indirect branch instructions in the __TEXT.__text section
• Creates breakpoints at each identified instruction
• When a breakpoint is hit, it records:
  • Current module name
  • Function name
  • Values of all 64-bit general purpose registers
  • Destination address of the branch
• Collected data can be saved to a JSON file using the brt_save command

Requirements

This tool uses the radare2 tool to identify indirect branch instructions, so you need to install it first.

brew install radare2

brt_save

Summary

Saves the collected branch trace data to a JSON file in the /tmp directory. The saved JSON file can be loaded through my Binja Missing Link Plugin.

Usage

(lldb) brt_save

swtt_set_bps

Summary

Sets breakpoints on swift_allocObject and swift_initStackObject to obtain type metadata. Collected type metadata can be saved to a JSON file using the swtt_save command.

Usage

(lldb) swtt_set_bps

swtt_save

Summary

Saves the collected type metadata to a JSON file in the /tmp directory. The saved JSON file can be loaded through our Binja Swift Analyzer Plugin.

Usage

(lldb) swtt_save

sdump

Summary

Prints the contents of a Swift object.

Usage

(lldb) sdump <object address>

p_boxed_array, po_boxed_array, dump_boxed_array

Summary

Prints the contents of an existential container.

Usage

(lldb) p_boxed_array <object address>
(lldb) po_boxed_array <object address>
(lldb) dump_boxed_array <object address>

xpr_yara_dump

Summary

Dumps what YaraMatcher object is initialized with what YARA rule string. This command works only for XProtectRemediator binaries (version 145).

Usage

(lldb) xpr_yara_dump

Author

Koh M. Nakagawa (@tsunek0h)

License

Apache version 2.0