#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2018 Joe Lawrence <[email protected]>
# Shell functions for the rest of the scripts.
MAX_RETRIES=600
RETRY_INTERVAL=".1" # seconds
KLP_SYSFS_DIR="/sys/kernel/livepatch"
# Kselftest framework requirement - SKIP code is 4
ksft_skip=4
# 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 $ksft_skip
}
# root test
function is_root() {
uid=$(id -u)
if [ $uid -ne 0 ]; then
echo "skip all tests: must be run as root" >&2
exit $ksft_skip
fi
}
# Check if we can compile the modules before loading them
function has_kdir() {
if [ -z "$KDIR" ]; then
KDIR="/lib/modules/$(uname -r)/build"
fi
if [ ! -d "$KDIR" ]; then
echo "skip all tests: KDIR ($KDIR) not available to compile modules."
exit $ksft_skip
fi
}
# die(msg) - game over, man
# msg - dying words
function die() {
log "ERROR: $1"
echo "ERROR: $1" >&2
exit 1
}
function push_config() {
DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \
awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')
FTRACE_ENABLED=$(sysctl --values kernel.ftrace_enabled)
}
function pop_config() {
if [[ -n "$DYNAMIC_DEBUG" ]]; then
echo -n "$DYNAMIC_DEBUG" > /sys/kernel/debug/dynamic_debug/control
fi
if [[ -n "$FTRACE_ENABLED" ]]; then
sysctl kernel.ftrace_enabled="$FTRACE_ENABLED" &> /dev/null
fi
}
function set_dynamic_debug() {
cat <<-EOF > /sys/kernel/debug/dynamic_debug/control
file kernel/livepatch/* +p
func klp_try_switch_task -p
EOF
}
function set_ftrace_enabled() {
local can_fail=0
if [[ "$1" == "--fail" ]] ; then
can_fail=1
shift
fi
local err=$(sysctl -q kernel.ftrace_enabled="$1" 2>&1)
local result=$(sysctl --values kernel.ftrace_enabled)
if [[ "$result" != "$1" ]] ; then
if [[ $can_fail -eq 1 ]] ; then
echo "livepatch: $err" | sed 's#/proc/sys/kernel/#kernel.#' > /dev/kmsg
return
fi
skip "failed to set kernel.ftrace_enabled = $1"
fi
echo "livepatch: kernel.ftrace_enabled = $result" > /dev/kmsg
}
function cleanup() {
pop_config
}
# setup_config - save the current config and set a script exit trap that
# restores the original config. Setup the dynamic debug
# for verbose livepatching output and turn on
# the ftrace_enabled sysctl.
function setup_config() {
is_root
has_kdir
push_config
set_dynamic_debug
set_ftrace_enabled 1
trap cleanup EXIT INT TERM HUP
}
# 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 is_livepatch_mod() {
local mod="$1"
if [[ ! -f "test_modules/$mod.ko" ]]; then
die "Can't find \"test_modules/$mod.ko\", try \"make\""
fi
if [[ $(modinfo "test_modules/$mod.ko" | awk '/^livepatch:/{print $NF}') == "Y" ]]; then
return 0
fi
return 1
}
function __load_mod() {
local mod="$1"; shift
local msg="% insmod test_modules/$mod.ko $*"
log "${msg%% }"
ret=$(insmod "test_modules/$mod.ko" "$@" 2>&1)
if [[ "$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 insmod
function load_mod() {
local mod="$1"; shift
is_livepatch_mod "$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 insmod
function load_lp_nowait() {
local mod="$1"; shift
is_livepatch_mod "$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 insmod
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 insmod
function load_failing_mod() {
local mod="$1"; shift
local msg="% insmod test_modules/$mod.ko $*"
log "${msg%% }"
ret=$(insmod "test_modules/$mod.ko" "$@" 2>&1)
if [[ "$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"
}
function start_test {
local test="$1"
# Dump something unique into the dmesg log, then stash the entry
# in LAST_DMESG. The check_result() function will use it to
# find new kernel messages since the test started.
local last_dmesg_msg="livepatch kselftest timestamp: $(date --rfc-3339=ns)"
log "$last_dmesg_msg"
loop_until 'dmesg | grep -q "$last_dmesg_msg"' ||
die "buffer busy? can't find canary dmesg message: $last_dmesg_msg"
LAST_DMESG=$(dmesg | grep "$last_dmesg_msg")
echo -n "TEST: $test ... "
log "===== TEST: $test ====="
}
# check_result() - verify dmesg output
# TODO - better filter, out of order msgs, etc?
function check_result {
local expect="$*"
local result
# Test results include any new dmesg entry since LAST_DMESG, then:
# - include lines matching keywords
# - exclude lines matching keywords
# - filter out dmesg timestamp prefixes
result=$(dmesg | awk -v last_dmesg="$LAST_DMESG" 'p; $0 == last_dmesg { p=1 }' | \
grep -e 'livepatch:' -e 'test_klp' | \
grep -v '\(tainting\|taints\) kernel' | \
sed 's/^\[[ 0-9.]*\] //')
if [[ "$expect" == "$result" ]] ; then
echo "ok"
elif [[ "$result" == "" ]] ; then
echo -e "not ok\n\nbuffer overrun? can't find canary dmesg entry: $LAST_DMESG\n"
die "livepatch kselftest(s) failed"
else
echo -e "not ok\n\n$(diff -upr --label expected --label result <(echo "$expect") <(echo "$result"))\n"
die "livepatch kselftest(s) failed"
fi
}
# check_sysfs_rights(modname, rel_path, expected_rights) - check sysfs
# path permissions
# modname - livepatch module creating the sysfs interface
# rel_path - relative path of the sysfs interface
# expected_rights - expected access rights
function check_sysfs_rights() {
local mod="$1"; shift
local rel_path="$1"; shift
local expected_rights="$1"; shift
local path="$KLP_SYSFS_DIR/$mod/$rel_path"
local rights=$(/bin/stat --format '%A' "$path")
if test "$rights" != "$expected_rights" ; then
die "Unexpected access rights of $path: $expected_rights vs. $rights"
fi
}
# check_sysfs_value(modname, rel_path, expected_value) - check sysfs value
# modname - livepatch module creating the sysfs interface
# rel_path - relative path of the sysfs interface
# expected_value - expected value read from the file
function check_sysfs_value() {
local mod="$1"; shift
local rel_path="$1"; shift
local expected_value="$1"; shift
local path="$KLP_SYSFS_DIR/$mod/$rel_path"
local value=`cat $path`
if test "$value" != "$expected_value" ; then
die "Unexpected value in $path: $expected_value vs. $value"
fi
}
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