l4trace

Extract the fiasco trace buffer running on a target machine using a PCIe screamer device.

Equipment

• M.2 Screamer
• Thunderbold Adapter

Patching Fiasco

The screamer access the tracebuffer memory via Busmastering DMA. You need to set:

CONFIG_IOMMU_PASSTHROUGH=y
CONFIG JDB=y
CONFIG JDB LOGGING=y

To enable Busmastering DMA and place the tracebuffer address at a well-known location, add the provided module (./jdb_scream.cpp) to your kernel.

Building l4trace

Clone submodules

git submodule update --init --recursive

Install dependencies

sudo apt install libusb-1.0-0-dev babeltrace2 libbabeltrace2-dev

Build LeechCore

make all

Optional: Build Babeltrace for development

Optional: Add udev rules to use device as group member of dialout

sudo cp udev.rules /etc/udev/rules.d/99-screamerM2.rules
sudo udevadm control --reload-rules

Run

./l4trace.sh