Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
new file mode 100644
index 0000000..79b0aff
--- /dev/null
+++ b/tools/testing/selftests/livepatch/functions.sh
@@ -0,0 +1,232 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
+
+# Shell functions for the rest of the scripts.
+
+MAX_RETRIES=600
+RETRY_INTERVAL=".1"	# seconds
+
+# log(msg) - write message to kernel log
+#	msg - insightful words
+function log() {
+	echo "$1" > /dev/kmsg
+}
+
+# skip(msg) - testing can't proceed
+#	msg - explanation
+function skip() {
+	log "SKIP: $1"
+	echo "SKIP: $1" >&2
+	exit 4
+}
+
+# die(msg) - game over, man
+#	msg - dying words
+function die() {
+	log "ERROR: $1"
+	echo "ERROR: $1" >&2
+	exit 1
+}
+
+function push_dynamic_debug() {
+        DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \
+                awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')
+}
+
+function pop_dynamic_debug() {
+	if [[ -n "$DYNAMIC_DEBUG" ]]; then
+		echo -n "$DYNAMIC_DEBUG" > /sys/kernel/debug/dynamic_debug/control
+	fi
+}
+
+# set_dynamic_debug() - save the current dynamic debug config and tweak
+# 			it for the self-tests.  Set a script exit trap
+#			that restores the original config.
+function set_dynamic_debug() {
+        push_dynamic_debug
+        trap pop_dynamic_debug EXIT INT TERM HUP
+        cat <<-EOF > /sys/kernel/debug/dynamic_debug/control
+		file kernel/livepatch/* +p
+		func klp_try_switch_task -p
+		EOF
+}
+
+# loop_until(cmd) - loop a command until it is successful or $MAX_RETRIES,
+#		    sleep $RETRY_INTERVAL between attempts
+#	cmd - command and its arguments to run
+function loop_until() {
+	local cmd="$*"
+	local i=0
+	while true; do
+		eval "$cmd" && return 0
+		[[ $((i++)) -eq $MAX_RETRIES ]] && return 1
+		sleep $RETRY_INTERVAL
+	done
+}
+
+function assert_mod() {
+	local mod="$1"
+
+	modprobe --dry-run "$mod" &>/dev/null
+}
+
+function is_livepatch_mod() {
+	local mod="$1"
+
+	if [[ $(modinfo "$mod" | awk '/^livepatch:/{print $NF}') == "Y" ]]; then
+		return 0
+	fi
+
+	return 1
+}
+
+function __load_mod() {
+	local mod="$1"; shift
+
+	local msg="% modprobe $mod $*"
+	log "${msg%% }"
+	ret=$(modprobe "$mod" "$@" 2>&1)
+	if [[ "$ret" != "" ]]; then
+		die "$ret"
+	fi
+
+	# Wait for module in sysfs ...
+	loop_until '[[ -e "/sys/module/$mod" ]]' ||
+		die "failed to load module $mod"
+}
+
+
+# load_mod(modname, params) - load a kernel module
+#	modname - module name to load
+#	params  - module parameters to pass to modprobe
+function load_mod() {
+	local mod="$1"; shift
+
+	assert_mod "$mod" ||
+		skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
+
+	is_livepatch_mod "$mod" &&
+		die "use load_lp() to load the livepatch module $mod"
+
+	__load_mod "$mod" "$@"
+}
+
+# load_lp_nowait(modname, params) - load a kernel module with a livepatch
+#			but do not wait on until the transition finishes
+#	modname - module name to load
+#	params  - module parameters to pass to modprobe
+function load_lp_nowait() {
+	local mod="$1"; shift
+
+	assert_mod "$mod" ||
+		skip "unable to load module ${mod}, verify CONFIG_TEST_LIVEPATCH=m and run self-tests as root"
+
+	is_livepatch_mod "$mod" ||
+		die "module $mod is not a livepatch"
+
+	__load_mod "$mod" "$@"
+
+	# Wait for livepatch in sysfs ...
+	loop_until '[[ -e "/sys/kernel/livepatch/$mod" ]]' ||
+		die "failed to load module $mod (sysfs)"
+}
+
+# load_lp(modname, params) - load a kernel module with a livepatch
+#	modname - module name to load
+#	params  - module parameters to pass to modprobe
+function load_lp() {
+	local mod="$1"; shift
+
+	load_lp_nowait "$mod" "$@"
+
+	# Wait until the transition finishes ...
+	loop_until 'grep -q '^0$' /sys/kernel/livepatch/$mod/transition' ||
+		die "failed to complete transition"
+}
+
+# load_failing_mod(modname, params) - load a kernel module, expect to fail
+#	modname - module name to load
+#	params  - module parameters to pass to modprobe
+function load_failing_mod() {
+	local mod="$1"; shift
+
+	local msg="% modprobe $mod $*"
+	log "${msg%% }"
+	ret=$(modprobe "$mod" "$@" 2>&1)
+	if [[ "$ret" == "" ]]; then
+		die "$mod unexpectedly loaded"
+	fi
+	log "$ret"
+}
+
+# unload_mod(modname) - unload a kernel module
+#	modname - module name to unload
+function unload_mod() {
+	local mod="$1"
+
+	# Wait for module reference count to clear ...
+	loop_until '[[ $(cat "/sys/module/$mod/refcnt") == "0" ]]' ||
+		die "failed to unload module $mod (refcnt)"
+
+	log "% rmmod $mod"
+	ret=$(rmmod "$mod" 2>&1)
+	if [[ "$ret" != "" ]]; then
+		die "$ret"
+	fi
+
+	# Wait for module in sysfs ...
+	loop_until '[[ ! -e "/sys/module/$mod" ]]' ||
+		die "failed to unload module $mod (/sys/module)"
+}
+
+# unload_lp(modname) - unload a kernel module with a livepatch
+#	modname - module name to unload
+function unload_lp() {
+	unload_mod "$1"
+}
+
+# disable_lp(modname) - disable a livepatch
+#	modname - module name to unload
+function disable_lp() {
+	local mod="$1"
+
+	log "% echo 0 > /sys/kernel/livepatch/$mod/enabled"
+	echo 0 > /sys/kernel/livepatch/"$mod"/enabled
+
+	# Wait until the transition finishes and the livepatch gets
+	# removed from sysfs...
+	loop_until '[[ ! -e "/sys/kernel/livepatch/$mod" ]]' ||
+		die "failed to disable livepatch $mod"
+}
+
+# set_pre_patch_ret(modname, pre_patch_ret)
+#	modname - module name to set
+#	pre_patch_ret - new pre_patch_ret value
+function set_pre_patch_ret {
+	local mod="$1"; shift
+	local ret="$1"
+
+	log "% echo $ret > /sys/module/$mod/parameters/pre_patch_ret"
+	echo "$ret" > /sys/module/"$mod"/parameters/pre_patch_ret
+
+	# Wait for sysfs value to hold ...
+	loop_until '[[ $(cat "/sys/module/$mod/parameters/pre_patch_ret") == "$ret" ]]' ||
+		die "failed to set pre_patch_ret parameter for $mod module"
+}
+
+# check_result() - verify dmesg output
+#	TODO - better filter, out of order msgs, etc?
+function check_result {
+	local expect="$*"
+	local result
+
+	result=$(dmesg | grep -v 'tainting' | grep -e 'livepatch:' -e 'test_klp' | sed 's/^\[[ 0-9.]*\] //')
+
+	if [[ "$expect" == "$result" ]] ; then
+		echo "ok"
+	else
+		echo -e "not ok\n\n$(diff -upr --label expected --label result <(echo "$expect") <(echo "$result"))\n"
+		die "livepatch kselftest(s) failed"
+	fi
+}