From 35c9e74cff4c798d0a07830d0d483e6ebe70352f Mon Sep 17 00:00:00 2001 From: Joe Lawrence Date: Wed, 16 Oct 2019 13:33:14 +0200 Subject: selftests/livepatch: Make dynamic debug setup and restore generic Livepatch selftests currently save the current dynamic debug config and tweak it for the selftests. The config is restored at the end. Make the infrastructure generic, so that more variables can be saved and restored. Link: http://lkml.kernel.org/r/20191016113316.13415-3-mbenes@suse.cz Signed-off-by: Joe Lawrence Signed-off-by: Miroslav Benes Signed-off-by: Steven Rostedt (VMware) --- tools/testing/selftests/livepatch/functions.sh | 22 +++++++++++++--------- .../testing/selftests/livepatch/test-callbacks.sh | 2 +- .../testing/selftests/livepatch/test-livepatch.sh | 2 +- .../selftests/livepatch/test-shadow-vars.sh | 2 +- 4 files changed, 16 insertions(+), 12 deletions(-) (limited to 'tools/testing/selftests/livepatch') diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh index 79b0affd21fb..b7e5a67ae434 100644 --- a/tools/testing/selftests/livepatch/functions.sh +++ b/tools/testing/selftests/livepatch/functions.sh @@ -29,29 +29,33 @@ function die() { exit 1 } -function push_dynamic_debug() { - DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \ - awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}') +function push_config() { + DYNAMIC_DEBUG=$(grep '^kernel/livepatch' /sys/kernel/debug/dynamic_debug/control | \ + awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}') } -function pop_dynamic_debug() { +function pop_config() { if [[ -n "$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 } +# 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. +function setup_config() { + push_config + set_dynamic_debug + trap pop_config 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 diff --git a/tools/testing/selftests/livepatch/test-callbacks.sh b/tools/testing/selftests/livepatch/test-callbacks.sh index e97a9dcb73c7..a35289b13c9c 100755 --- a/tools/testing/selftests/livepatch/test-callbacks.sh +++ b/tools/testing/selftests/livepatch/test-callbacks.sh @@ -9,7 +9,7 @@ MOD_LIVEPATCH2=test_klp_callbacks_demo2 MOD_TARGET=test_klp_callbacks_mod MOD_TARGET_BUSY=test_klp_callbacks_busy -set_dynamic_debug +setup_config # TEST: target module before livepatch diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh index f05268aea859..493e3df415a1 100755 --- a/tools/testing/selftests/livepatch/test-livepatch.sh +++ b/tools/testing/selftests/livepatch/test-livepatch.sh @@ -7,7 +7,7 @@ MOD_LIVEPATCH=test_klp_livepatch MOD_REPLACE=test_klp_atomic_replace -set_dynamic_debug +setup_config # TEST: basic function patching diff --git a/tools/testing/selftests/livepatch/test-shadow-vars.sh b/tools/testing/selftests/livepatch/test-shadow-vars.sh index 04a37831e204..1aae73299114 100755 --- a/tools/testing/selftests/livepatch/test-shadow-vars.sh +++ b/tools/testing/selftests/livepatch/test-shadow-vars.sh @@ -6,7 +6,7 @@ MOD_TEST=test_klp_shadow_vars -set_dynamic_debug +setup_config # TEST: basic shadow variable API -- cgit v1.2.3-59-g8ed1b From 8c666d2ab5762280cb5ef43df4decb2a25450d54 Mon Sep 17 00:00:00 2001 From: Joe Lawrence Date: Wed, 16 Oct 2019 13:33:15 +0200 Subject: selftests/livepatch: Test interaction with ftrace_enabled Since livepatching depends upon ftrace handlers to implement "patched" code functionality, verify that the ftrace_enabled sysctl value interacts with livepatch registration as expected. At the same time, ensure that ftrace_enabled is set and part of the test environment configuration that is saved and restored when running the selftests. Link: http://lkml.kernel.org/r/20191016113316.13415-4-mbenes@suse.cz Signed-off-by: Joe Lawrence Signed-off-by: Miroslav Benes Signed-off-by: Steven Rostedt (VMware) --- tools/testing/selftests/livepatch/Makefile | 3 +- tools/testing/selftests/livepatch/functions.sh | 14 ++++- tools/testing/selftests/livepatch/test-ftrace.sh | 65 ++++++++++++++++++++++++ 3 files changed, 80 insertions(+), 2 deletions(-) create mode 100755 tools/testing/selftests/livepatch/test-ftrace.sh (limited to 'tools/testing/selftests/livepatch') diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile index fd405402c3ff..1886d9d94b88 100644 --- a/tools/testing/selftests/livepatch/Makefile +++ b/tools/testing/selftests/livepatch/Makefile @@ -4,6 +4,7 @@ TEST_PROGS_EXTENDED := functions.sh TEST_PROGS := \ test-livepatch.sh \ test-callbacks.sh \ - test-shadow-vars.sh + test-shadow-vars.sh \ + test-ftrace.sh include ../lib.mk diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh index b7e5a67ae434..31eb09e38729 100644 --- a/tools/testing/selftests/livepatch/functions.sh +++ b/tools/testing/selftests/livepatch/functions.sh @@ -32,12 +32,16 @@ function die() { 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() { @@ -47,12 +51,20 @@ function set_dynamic_debug() { EOF } +function set_ftrace_enabled() { + local sysctl="$1" + result=$(sysctl kernel.ftrace_enabled="$1" 2>&1 | paste --serial --delimiters=' ') + echo "livepatch: $result" > /dev/kmsg +} + # 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. +# for verbose livepatching output and turn on +# the ftrace_enabled sysctl. function setup_config() { push_config set_dynamic_debug + set_ftrace_enabled 1 trap pop_config EXIT INT TERM HUP } diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh new file mode 100755 index 000000000000..e2a76887f40a --- /dev/null +++ b/tools/testing/selftests/livepatch/test-ftrace.sh @@ -0,0 +1,65 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2019 Joe Lawrence + +. $(dirname $0)/functions.sh + +MOD_LIVEPATCH=test_klp_livepatch + +setup_config + + +# TEST: livepatch interaction with ftrace_enabled sysctl +# - turn ftrace_enabled OFF and verify livepatches can't load +# - turn ftrace_enabled ON and verify livepatch can load +# - verify that ftrace_enabled can't be turned OFF while a livepatch is loaded + +echo -n "TEST: livepatch interaction with ftrace_enabled sysctl ... " +dmesg -C + +set_ftrace_enabled 0 +load_failing_mod $MOD_LIVEPATCH + +set_ftrace_enabled 1 +load_lp $MOD_LIVEPATCH +if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then + echo -e "FAIL\n\n" + die "livepatch kselftest(s) failed" +fi + +set_ftrace_enabled 0 +if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then + echo -e "FAIL\n\n" + die "livepatch kselftest(s) failed" +fi +disable_lp $MOD_LIVEPATCH +unload_lp $MOD_LIVEPATCH + +check_result "livepatch: kernel.ftrace_enabled = 0 +% modprobe $MOD_LIVEPATCH +livepatch: enabling patch '$MOD_LIVEPATCH' +livepatch: '$MOD_LIVEPATCH': initializing patching transition +livepatch: failed to register ftrace handler for function 'cmdline_proc_show' (-16) +livepatch: failed to patch object 'vmlinux' +livepatch: failed to enable patch '$MOD_LIVEPATCH' +livepatch: '$MOD_LIVEPATCH': canceling patching transition, going to unpatch +livepatch: '$MOD_LIVEPATCH': completing unpatching transition +livepatch: '$MOD_LIVEPATCH': unpatching complete +modprobe: ERROR: could not insert '$MOD_LIVEPATCH': Device or resource busy +livepatch: kernel.ftrace_enabled = 1 +% modprobe $MOD_LIVEPATCH +livepatch: enabling patch '$MOD_LIVEPATCH' +livepatch: '$MOD_LIVEPATCH': initializing patching transition +livepatch: '$MOD_LIVEPATCH': starting patching transition +livepatch: '$MOD_LIVEPATCH': completing patching transition +livepatch: '$MOD_LIVEPATCH': patching complete +livepatch: sysctl: setting key \"kernel.ftrace_enabled\": Device or resource busy kernel.ftrace_enabled = 0 +% echo 0 > /sys/kernel/livepatch/$MOD_LIVEPATCH/enabled +livepatch: '$MOD_LIVEPATCH': initializing unpatching transition +livepatch: '$MOD_LIVEPATCH': starting unpatching transition +livepatch: '$MOD_LIVEPATCH': completing unpatching transition +livepatch: '$MOD_LIVEPATCH': unpatching complete +% rmmod $MOD_LIVEPATCH" + + +exit 0 -- cgit v1.2.3-59-g8ed1b