linux/tools/testing/selftests/livepatch/test-ftrace.sh

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#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2019 Joe Lawrence <joe.lawrence@redhat.com>
. $(dirname $0)/functions.sh
MOD_LIVEPATCH=test_klp_livepatch
setup_config
# - 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
start_test "livepatch interaction with ftrace_enabled sysctl"
set_ftrace_enabled 0
load_failing_mod $MOD_LIVEPATCH
set_ftrace_enabled 1
load_lp $MOD_LIVEPATCH
if [[ "$(cat /proc/cmdline)" != "$MOD_LIVEPATCH: this has been live patched" ]] ; then
echo -e "FAIL\n\n"
die "livepatch kselftest(s) failed"
fi
livepatch: Skip livepatch tests if ftrace cannot be configured livepatch has a set of selftests that are used to validate the behavior of the livepatching subsystem. One of the testcases in the livepatch testsuite is test-ftrace.sh, which among other things, validates that livepatching gracefully fails when ftrace is disabled. In the event that ftrace cannot be disabled using 'sysctl kernel.ftrace_enabled=0', the test will fail later due to it unexpectedly successfully loading the test_klp_livepatch module. While the livepatch selftests are careful to remove any of the livepatch test modules between testcases to avoid this situation, ftrace may still fail to be disabled if another trace is active on the system that was enabled with FTRACE_OPS_FL_PERMANENT. For example, any active BPF programs that use trampolines will cause this test to fail due to the trampoline being implemented with register_ftrace_direct(). The following is an example of such a trace: tcp_drop (1) R I D tramp: ftrace_regs_caller+0x0/0x58 (call_direct_funcs+0x0/0x30) direct-->bpf_trampoline_6442550536_0+0x0/0x1000 In order to make the test more resilient to system state that is out of its control, this patch updates set_ftrace_enabled() to detect sysctl failures, and skip the testrun when appropriate. Suggested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: David Vernet <void@manifault.com> Acked-by: Miroslav Benes <mbenes@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Acked-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220216161100.3243100-1-void@manifault.com
2022-02-16 08:11:01 -08:00
# Check that ftrace could not get disabled when a livepatch is enabled
set_ftrace_enabled --fail 0
if [[ "$(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
livepatch: Move tests from lib/livepatch to selftests/livepatch The modules are being moved from lib/livepatch to tools/testing/selftests/livepatch/test_modules. This code moving will allow writing more complex tests, like for example an userspace C code that will call a livepatched kernel function. The modules are now built as out-of-tree modules, but being part of the kernel source means they will be maintained. Another advantage of the code moving is to be able to easily change, debug and rebuild the tests by running make on the selftests/livepatch directory, which is not currently possible since the modules on lib/livepatch are build and installed using the "modules" target. The current approach also keeps the ability to execute the tests manually by executing the scripts inside selftests/livepatch directory, as it's currently supported. If the modules are modified, they needed to be rebuilt before running the scripts though. The modules are built before running the selftests when using the kselftest invocations: make kselftest TARGETS=livepatch or make -C tools/testing/selftests/livepatch run_tests Having the modules being built as out-of-modules requires changing the currently used 'modprobe' by 'insmod' and adapt the test scripts that check for the kernel message buffer. Now it is possible to only compile the modules by running: make -C tools/testing/selftests/livepatch/ This way the test modules and other test program can be built in order to be packaged if so desired. As there aren't any modules being built on lib/livepatch, remove the TEST_LIVEPATCH Kconfig and it's references. Note: "make gen_tar" packages the pre-built binaries into the tarball. It means that it will store the test modules pre-built for the kernel running on the build host. Note that these modules need not binary compatible with the kernel built from the same sources. But the same is true for other packaged selftest binaries. The entire kernel sources are needed for rebuilding the selftests on another system. Reviewed-by: Joe Lawrence <joe.lawrence@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-01-12 14:43:51 -03:00
% insmod test_modules/$MOD_LIVEPATCH.ko
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
livepatch: Move tests from lib/livepatch to selftests/livepatch The modules are being moved from lib/livepatch to tools/testing/selftests/livepatch/test_modules. This code moving will allow writing more complex tests, like for example an userspace C code that will call a livepatched kernel function. The modules are now built as out-of-tree modules, but being part of the kernel source means they will be maintained. Another advantage of the code moving is to be able to easily change, debug and rebuild the tests by running make on the selftests/livepatch directory, which is not currently possible since the modules on lib/livepatch are build and installed using the "modules" target. The current approach also keeps the ability to execute the tests manually by executing the scripts inside selftests/livepatch directory, as it's currently supported. If the modules are modified, they needed to be rebuilt before running the scripts though. The modules are built before running the selftests when using the kselftest invocations: make kselftest TARGETS=livepatch or make -C tools/testing/selftests/livepatch run_tests Having the modules being built as out-of-modules requires changing the currently used 'modprobe' by 'insmod' and adapt the test scripts that check for the kernel message buffer. Now it is possible to only compile the modules by running: make -C tools/testing/selftests/livepatch/ This way the test modules and other test program can be built in order to be packaged if so desired. As there aren't any modules being built on lib/livepatch, remove the TEST_LIVEPATCH Kconfig and it's references. Note: "make gen_tar" packages the pre-built binaries into the tarball. It means that it will store the test modules pre-built for the kernel running on the build host. Note that these modules need not binary compatible with the kernel built from the same sources. But the same is true for other packaged selftest binaries. The entire kernel sources are needed for rebuilding the selftests on another system. Reviewed-by: Joe Lawrence <joe.lawrence@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-01-12 14:43:51 -03:00
insmod: ERROR: could not insert module test_modules/$MOD_LIVEPATCH.ko: Device or resource busy
livepatch: kernel.ftrace_enabled = 1
livepatch: Move tests from lib/livepatch to selftests/livepatch The modules are being moved from lib/livepatch to tools/testing/selftests/livepatch/test_modules. This code moving will allow writing more complex tests, like for example an userspace C code that will call a livepatched kernel function. The modules are now built as out-of-tree modules, but being part of the kernel source means they will be maintained. Another advantage of the code moving is to be able to easily change, debug and rebuild the tests by running make on the selftests/livepatch directory, which is not currently possible since the modules on lib/livepatch are build and installed using the "modules" target. The current approach also keeps the ability to execute the tests manually by executing the scripts inside selftests/livepatch directory, as it's currently supported. If the modules are modified, they needed to be rebuilt before running the scripts though. The modules are built before running the selftests when using the kselftest invocations: make kselftest TARGETS=livepatch or make -C tools/testing/selftests/livepatch run_tests Having the modules being built as out-of-modules requires changing the currently used 'modprobe' by 'insmod' and adapt the test scripts that check for the kernel message buffer. Now it is possible to only compile the modules by running: make -C tools/testing/selftests/livepatch/ This way the test modules and other test program can be built in order to be packaged if so desired. As there aren't any modules being built on lib/livepatch, remove the TEST_LIVEPATCH Kconfig and it's references. Note: "make gen_tar" packages the pre-built binaries into the tarball. It means that it will store the test modules pre-built for the kernel running on the build host. Note that these modules need not binary compatible with the kernel built from the same sources. But the same is true for other packaged selftest binaries. The entire kernel sources are needed for rebuilding the selftests on another system. Reviewed-by: Joe Lawrence <joe.lawrence@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-01-12 14:43:51 -03:00
% insmod test_modules/$MOD_LIVEPATCH.ko
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
% echo 0 > $SYSFS_KLP_DIR/$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"
# - verify livepatch can load
# - check if traces have a patched function
# - reset trace and unload livepatch
start_test "trace livepatched function and check that the live patch remains in effect"
FUNCTION_NAME="livepatch_cmdline_proc_show"
load_lp $MOD_LIVEPATCH
trace_function "$FUNCTION_NAME"
if [[ "$(cat /proc/cmdline)" == "$MOD_LIVEPATCH: this has been live patched" ]] ; then
log "livepatch: ok"
fi
check_traced_functions "$FUNCTION_NAME"
disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH
check_result "% insmod test_modules/$MOD_LIVEPATCH.ko
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: ok
% echo 0 > $SYSFS_KLP_DIR/$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