#!/usr/bin/env bash
# Copyright 2016 syzkaller project authors. All rights reserved.
# Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
# create-image.sh creates a minimal Debian Linux image suitable for syzkaller.
set -eux
# Create a minimal Debian distribution in a directory.
DIR=chroot
PREINSTALL_PKGS=openssh-server,curl,tar,gcc,libc6-dev,time,strace,sudo,less,psmisc,selinux-utils,policycoreutils,checkpolicy,selinux-policy-default,firmware-atheros,debian-ports-archive-keyring
# If ADD_PACKAGE is not defined as an external environment variable, use our default packages
if [ -z ${ADD_PACKAGE+x} ]; then
ADD_PACKAGE="make,sysbench,git,vim,tmux,usbutils,tcpdump"
fi
# Variables affected by options
ARCH=$(uname -m)
RELEASE=stretch
FEATURE=minimal
SEEK=2047
PERF=false
# Display help function
display_help() {
echo "Usage: $0 [option...] " >&2
echo
echo " -a, --arch Set architecture"
echo " -d, --distribution Set on which debian distribution to create"
echo " -f, --feature Check what packages to install in the image, options are minimal, full"
echo " -s, --seek Image size (MB), default 2048 (2G)"
echo " -h, --help Display help message"
echo " -p, --add-perf Add perf support with this option enabled. Please set envrionment variable \$KERNEL at first"
echo
}
while true; do
if [ $# -eq 0 ];then
echo $#
break
fi
case "$1" in
-h | --help)
display_help
exit 0
;;
-a | --arch)
ARCH=$2
shift 2
;;
-d | --distribution)
RELEASE=$2
shift 2
;;
-f | --feature)
FEATURE=$2
shift 2
;;
-s | --seek)
SEEK=$(($2 - 1))
shift 2
;;
-p | --add-perf)
PERF=true
shift 1
;;
-*)
echo "Error: Unknown option: $1" >&2
exit 1
;;
*) # No more options
break
;;
esac
done
# Handle cases where qemu and Debian use different arch names
case "$ARCH" in
ppc64le)
DEBARCH=ppc64el
;;
aarch64)
DEBARCH=arm64
;;
arm)
DEBARCH=armel
;;
x86_64)
DEBARCH=amd64
;;
*)
DEBARCH=$ARCH
;;
esac
# Foreign architecture
FOREIGN=false
if [ $ARCH != $(uname -m) ]; then
# i386 on an x86_64 host is exempted, as we can run i386 binaries natively
if [ $ARCH != "i386" -o $(uname -m) != "x86_64" ]; then
FOREIGN=true
fi
fi
if [ $FOREIGN = "true" ]; then
# Check for according qemu static binary
if ! which qemu-$ARCH-static; then
echo "Please install qemu static binary for architecture $ARCH (package 'qemu-user-static' on Debian/Ubuntu/Fedora)"
exit 1
fi
# Check for according binfmt entry
if [ ! -r /proc/sys/fs/binfmt_misc/qemu-$ARCH ]; then
echo "binfmt entry /proc/sys/fs/binfmt_misc/qemu-$ARCH does not exist"
exit 1
fi
fi
# Double check KERNEL when PERF is enabled
if [ $PERF = "true" ] && [ -z ${KERNEL+x} ]; then
echo "Please set KERNEL environment variable when PERF is enabled"
exit 1
fi
# If full feature is chosen, install more packages
if [ $FEATURE = "full" ]; then
PREINSTALL_PKGS=$PREINSTALL_PKGS","$ADD_PACKAGE
fi
sudo rm -rf $DIR
sudo mkdir -p $DIR
sudo chmod 0755 $DIR
# 1. debootstrap stage
DEBOOTSTRAP_PARAMS="--arch=$DEBARCH --include=$PREINSTALL_PKGS --components=main,contrib,non-free $RELEASE $DIR"
if [ $FOREIGN = "true" ]; then
DEBOOTSTRAP_PARAMS="--foreign $DEBOOTSTRAP_PARAMS"
fi
# riscv64 is hosted in the debian-ports repository
# debian-ports doesn't include non-free, so we exclude firmware-atheros
if [ $DEBARCH == "riscv64" ]; then
DEBOOTSTRAP_PARAMS="--keyring /usr/share/keyrings/debian-ports-archive-keyring.gpg --exclude firmware-atheros $DEBOOTSTRAP_PARAMS http://deb.debian.org/debian-ports"
fi
sudo debootstrap $DEBOOTSTRAP_PARAMS
# 2. debootstrap stage: only necessary if target != host architecture
if [ $FOREIGN = "true" ]; then
sudo cp $(which qemu-$ARCH-static) $DIR/$(which qemu-$ARCH-static)
sudo chroot $DIR /bin/bash -c "/debootstrap/debootstrap --second-stage"
fi
# Set some defaults and enable promtless ssh to the machine for root.
sudo sed -i '/^root/ { s/:x:/::/ }' $DIR/etc/passwd
echo 'T0:23:respawn:/sbin/getty -L ttyS0 115200 vt100' | sudo tee -a $DIR/etc/inittab
printf '\nauto eth0\niface eth0 inet dhcp\n' | sudo tee -a $DIR/etc/network/interfaces
echo '/dev/root / ext4 defaults 0 0' | sudo tee -a $DIR/etc/fstab
echo 'debugfs /sys/kernel/debug debugfs defaults 0 0' | sudo tee -a $DIR/etc/fstab
echo 'securityfs /sys/kernel/security securityfs defaults 0 0' | sudo tee -a $DIR/etc/fstab
echo 'configfs /sys/kernel/config/ configfs defaults 0 0' | sudo tee -a $DIR/etc/fstab
echo 'binfmt_misc /proc/sys/fs/binfmt_misc binfmt_misc defaults 0 0' | sudo tee -a $DIR/etc/fstab
echo -en "127.0.0.1\tlocalhost\n" | sudo tee $DIR/etc/hosts
echo "nameserver 8.8.8.8" | sudo tee -a $DIR/etc/resolve.conf
echo "syzkaller" | sudo tee $DIR/etc/hostname
ssh-keygen -f $RELEASE.id_rsa -t rsa -N ''
sudo mkdir -p $DIR/root/.ssh/
cat $RELEASE.id_rsa.pub | sudo tee $DIR/root/.ssh/authorized_keys
# Add perf support
if [ $PERF = "true" ]; then
cp -r $KERNEL $DIR/tmp/
BASENAME=$(basename $KERNEL)
sudo chroot $DIR /bin/bash -c "apt-get update; apt-get install -y flex bison python-dev libelf-dev libunwind8-dev libaudit-dev libslang2-dev libperl-dev binutils-dev liblzma-dev libnuma-dev"
sudo chroot $DIR /bin/bash -c "cd /tmp/$BASENAME/tools/perf/; make"
sudo chroot $DIR /bin/bash -c "cp /tmp/$BASENAME/tools/perf/perf /usr/bin/"
rm -r $DIR/tmp/$BASENAME
fi
# Add udev rules for custom drivers.
# Create a /dev/vim2m symlink for the device managed by the vim2m driver
echo 'ATTR{name}=="vim2m", SYMLINK+="vim2m"' | sudo tee -a $DIR/etc/udev/rules.d/50-udev-default.rules
# Build a disk image
dd if=/dev/zero of=$RELEASE.img bs=1M seek=$SEEK count=1
sudo mkfs.ext4 -F $RELEASE.img
sudo mkdir -p /mnt/$DIR
sudo mount -o loop $RELEASE.img /mnt/$DIR
sudo cp -a $DIR/. /mnt/$DIR/.
sudo umount /mnt/$DIR
|
