#!/bin/bash
#
# kpatch integration test framework
#
# Copyright (C) 2014 Josh Poimboeuf <jpoimboe@redhat.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA,
# 02110-1301, USA.
#
#
# This is a basic integration test framework for kpatch, which tests building,
# loading, and unloading patches, as well as any other related custom tests.
#
# This script looks for test input files in the current directory.  It expects
# certain file naming conventions:
#
# - foo.patch: patch that should build successfully
#
# - bar-FAIL.patch: patch that should fail to build
#
# - foo-LOADED.test: executable which tests whether the foo.patch module is
#   loaded.  It will be used to test that loading/unloading the patch module
#   works as expected.
#
# Any other *.test files will be executed after all the patch modules have been
# built from the *.patch files.  They can be used for more custom tests above
# and beyond the simple loading and unloading tests.

shopt -s nullglob

# shellcheck disable=SC2046
SCRIPTDIR=$(readlink -f $(dirname $(type -p "$0")))
ROOTDIR=$(readlink -f "$SCRIPTDIR/../..")
KPATCH="sudo $ROOTDIR/kpatch/kpatch"
unset CCACHE_HASHDIR
KPATCHBUILD="$ROOTDIR"/kpatch-build/kpatch-build
ERROR=0
LOG=test.log
DYNDEBUG_CONTROL=/sys/kernel/debug/dynamic_debug/control
DYNDEBUG_ENABLED=1
rm -f ./*.log

PATCHDIR="${PATCHDIR:-$PWD}"
declare -a PATCH_LIST
declare -a TEST_LIST

usage() {
	echo "usage: $0 [options] [patch1 ... patchN]" >&2
	echo "		patchN  	Pathnames of patches to test" >&2
	echo "		-h, --help	Show this help message" >&2
	echo "		-c, --cached	Don't rebuild patch modules" >&2
	echo "		-d, --directory	Patch directory" >&2
	echo "		-q, --quick	Test combined patch and -FAIL patches only" >&2
	echo "		--system-kpatch-tools	Use kpatch tools installed in the system" >&2
	echo "		--kpatch-build-opts	Additional options to pass to kpatch-build" >&2
}

options=$(getopt -o hcd:q -l "help,cached,directory,quick,system-kpatch-tools,kpatch-build-opts:" -- "$@") || exit 1

eval set -- "$options"

while [[ $# -gt 0 ]]; do
	case "$1" in
	-h|--help)
		usage
		exit 0
		;;
	-c|--cached)
		SKIPBUILD=1
		;;
	-d|--directory)
		PATCHDIR="$2"
		shift
		;;
	-q|--quick)
		QUICK=1
		;;
	--system-kpatch-tools)
		KPATCH="sudo kpatch"
		KPATCHBUILD="kpatch-build"
		;;
	--kpatch-build-opts)
		KPATCHBUILD_OPTS=$2
		shift
		;;
	*)
		[[ "$1" = "--" ]] && shift && continue
		PATCH_LIST+=("$1")
		;;
	esac
	shift
done

if [[ ${#PATCH_LIST[@]} = 0 ]]; then
	PATCH_LIST=("$PATCHDIR"/*.patch)
	TEST_LIST=("$PATCHDIR"/*.test)
	if [[ ${#PATCH_LIST[@]} = 0 ]]; then
		echo "No patches found!"
		exit 1
	fi
else
	for file in "${PATCH_LIST[@]}"; do
		prefix=${file%%.patch}
		[[ -e "$prefix-FAIL.test" ]]   && TEST_LIST+=("$prefix-FAIL.test")
		[[ -e "$prefix-LOADED.test" ]] && TEST_LIST+=("$prefix-LOADED.test")
	done
fi

error() {
	echo "ERROR: $*" |tee -a $LOG >&2
	ERROR=$((ERROR + 1))
}

log() {
	echo "$@" |tee -a $LOG
}

unload_all() {
	$KPATCH unload --all
}

build_module() {
	file=$1
	prefix=$(basename "${file%%.patch}")
	modname="test-$prefix"
	module="${modname}.ko"

	if [[ $prefix =~ -FAIL ]]; then
		shouldfail=1
	else
		shouldfail=0
	fi

	if [[ $SKIPBUILD -eq 1 ]]; then
		skip=0
		[[ $shouldfail -eq 1 ]] && skip=1
		[[ -e $module ]] && skip=1
		[[ $skip -eq 1 ]] && log "skipping build: $prefix" && return
	fi

	log "build: $prefix"

	# shellcheck disable=SC2086
	# KPATCHBUILD_OPTS may contain several space-separated options,
	# it should remain without quotes.
	if ! $KPATCHBUILD $KPATCHBUILD_OPTS -n "$modname" "$file" >> $LOG 2>&1; then
		if [[ $shouldfail -eq 0 ]]; then
			error "$prefix: build failed"
			cp "$HOME/.kpatch/build.log" "$prefix.log"
		fi
	else
		[[ $shouldfail -eq 1 ]] && error "$prefix: build succeeded when it should have failed"
	fi
}

run_load_test() {
	file=$1
	prefix=$(basename "${file%%.patch}")
	modname="test-$prefix"
	module="${modname}.ko"
	testprog=$(dirname "$1")/"$prefix-LOADED.test"

	[[ $prefix =~ -FAIL ]] && return

	if [[ ! -e $module ]]; then
		log "can't find $module, skipping"
		return
	fi

	if [[ -e $testprog ]]; then
		log "load test: $prefix"
	else
		log "load test: $prefix (no test prog)"
	fi


	if [[ -e $testprog ]] && $testprog >> $LOG 2>&1; then
		error "$prefix: $testprog succeeded before kpatch load"
		return
	fi

	if ! $KPATCH load "$module" >> $LOG 2>&1; then
		error "$prefix: kpatch load failed"
		return
	fi

	if [[ -e $testprog ]] && ! $testprog >> $LOG 2>&1; then
		error "$prefix: $testprog failed after kpatch load"
	fi

	if ! $KPATCH unload "$module" >> $LOG 2>&1; then
		error "$prefix: kpatch unload failed"
		return
	fi

	if [[ -e $testprog ]] && $testprog >> $LOG 2>&1; then
		error "$prefix: $testprog succeeded after kpatch unload"
		return
	fi
}

run_custom_test() {
	testprog=$1
	prefix=$(basename "${testprog%%.test}")

	[[ $testprog = *-LOADED.test ]] && return

	log "custom test: $prefix"

	if ! $testprog >> $LOG 2>&1; then
		error "$prefix: test failed"
	fi
}

build_combined_module() {

	if [[ $SKIPBUILD -eq 1 ]] && [[ -e test-COMBINED.ko ]]; then
		log "skipping build: combined"
		return
	fi

	declare -a COMBINED_LIST
	for file in "${PATCH_LIST[@]}"; do
		[[ $file =~ -FAIL ]] && log "combine: skipping $file" && continue
		COMBINED_LIST+=("$file")
	done
	if [[ ${#COMBINED_LIST[@]} -le 1 ]]; then
		log "skipping build: combined (only ${#PATCH_LIST[@]} patch(es))"
		return
	fi

	log "build: combined module"

	# shellcheck disable=SC2086
	if ! $KPATCHBUILD $KPATCHBUILD_OPTS -n test-COMBINED "${COMBINED_LIST[@]}" >> $LOG 2>&1; then
		error "combined build failed"
		cp "$HOME/.kpatch/build.log" combined.log
	fi
}

run_combined_test() {
	if [[ ! -e test-COMBINED.ko ]]; then
		log "can't find test-COMBINED.ko, skipping"
		return
	fi

	log "load test: combined module"

	unload_all

	for testprog in "${TEST_LIST[@]}"; do
		[[ $testprog != *-LOADED.test ]] && continue
		if $testprog >> $LOG 2>&1; then
			error "combined: $testprog succeeded before kpatch load"
			return
		fi
	done

	if ! $KPATCH load test-COMBINED.ko >> $LOG 2>&1; then
		error "combined: kpatch load failed"
		return
	fi

	for testprog in "${TEST_LIST[@]}"; do
		[[ $testprog != *-LOADED.test ]] && continue
		[ -e "${testprog/-LOADED.test/.patch.disabled}" ] && continue
		if ! $testprog >> $LOG 2>&1; then
			error "combined: $testprog failed after kpatch load"
		fi
	done

	if ! $KPATCH unload test-COMBINED.ko >> $LOG 2>&1; then
		error "combined: kpatch unload failed"
		return
	fi

	for testprog in "${TEST_LIST[@]}"; do
		[[ $testprog != *-LOADED.test ]] && continue
		if $testprog >> $LOG 2>&1; then
			error "combined: $testprog succeeded after kpatch unload"
			return
		fi
	done

}

# save existing dmesg so we can detect new content
save_dmesg() {
	SAVED_DMESG="$(dmesg | tail -n1)"
}

# new dmesg entries since our saved entry
new_dmesg() {
	if ! dmesg | awk -v last="$SAVED_DMESG" 'p; $0 == last{p=1} END {exit !p}'; then
		error "dmesg overflow, try increasing kernel log buffer size"
	fi
}

# shellcheck disable=SC1091
source /etc/os-release
if [[ "${ID}" == "rhel" && "${VERSION_ID%%.*}" == "7" && "${VERSION_ID##*.}" -le "6" ]]; then
	DYNDEBUG_ENABLED=0
	echo "Dynamic debug is not supported on '${PRETTY_NAME}', disabling."
fi

for file in "${PATCH_LIST[@]}"; do
	if [[ $QUICK != 1 || "$file" =~ -FAIL ]]; then
		build_module "$file"
	fi
done

build_combined_module

unload_all

save_dmesg

if [ "${DYNDEBUG_ENABLED}" == "1" ]; then
	prev_dyndebug=$(grep klp_try_switch_task "${DYNDEBUG_CONTROL}" | awk '{print $3;}')
	echo "func klp_try_switch_task +p" >"${DYNDEBUG_CONTROL}" 2>/dev/null
fi

if [[ $QUICK != 1 ]]; then
	for file in "${PATCH_LIST[@]}"; do
		run_load_test "$file"
	done
fi

run_combined_test

if [[ $QUICK != 1 ]]; then
	for testprog in "${TEST_LIST[@]}"; do
		if [[ ! $testprog =~ -FAIL ]]; then
			unload_all
			run_custom_test "$testprog"
		fi
	done
fi


unload_all

if [ "${DYNDEBUG_ENABLED}" == "1" ]; then
	echo "func klp_try_switch_task ${prev_dyndebug}" >"${DYNDEBUG_CONTROL}" 2>/dev/null
fi

if new_dmesg | grep -q "Call Trace"; then
	new_dmesg > dmesg.log
	error "kernel error detected in printk buffer"
fi

if [[ $ERROR -gt 0 ]]; then
	log "$ERROR errors encountered"
	echo "see test.log for more information"
else
	log "SUCCESS"
fi

exit $ERROR