diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile index 119e2bbebe5d..35418a4790be 100644 --- a/tools/testing/selftests/livepatch/Makefile +++ b/tools/testing/selftests/livepatch/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 +TEST_GEN_FILES := test_klp-call_getpid TEST_GEN_MODS_DIR := test_modules TEST_PROGS_EXTENDED := functions.sh TEST_PROGS := \ @@ -8,7 +9,8 @@ TEST_PROGS := \ test-shadow-vars.sh \ test-state.sh \ test-ftrace.sh \ - test-sysfs.sh + test-sysfs.sh \ + test-syscall.sh TEST_FILES := settings diff --git a/tools/testing/selftests/livepatch/test-syscall.sh b/tools/testing/selftests/livepatch/test-syscall.sh new file mode 100755 index 000000000000..b76a881d4013 --- /dev/null +++ b/tools/testing/selftests/livepatch/test-syscall.sh @@ -0,0 +1,53 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2023 SUSE +# Author: Marcos Paulo de Souza + +. $(dirname $0)/functions.sh + +MOD_SYSCALL=test_klp_syscall + +setup_config + +# - Start _NRPROC processes calling getpid and load a livepatch to patch the +# getpid syscall. Check if all the processes transitioned to the livepatched +# state. + +start_test "patch getpid syscall while being heavily hammered" + +for i in $(seq 1 $(getconf _NPROCESSORS_ONLN)); do + ./test_klp-call_getpid & + pids[$i]="$!" +done + +pid_list=$(echo ${pids[@]} | tr ' ' ',') +load_lp $MOD_SYSCALL klp_pids=$pid_list + +# wait for all tasks to transition to patched state +loop_until 'grep -q '^0$' /sys/kernel/test_klp_syscall/npids' + +pending_pids=$(cat /sys/kernel/test_klp_syscall/npids) +log "$MOD_SYSCALL: Remaining not livepatched processes: $pending_pids" + +for pid in ${pids[@]}; do + kill $pid || true +done + +disable_lp $MOD_SYSCALL +unload_lp $MOD_SYSCALL + +check_result "% insmod test_modules/$MOD_SYSCALL.ko klp_pids=$pid_list +livepatch: enabling patch '$MOD_SYSCALL' +livepatch: '$MOD_SYSCALL': initializing patching transition +livepatch: '$MOD_SYSCALL': starting patching transition +livepatch: '$MOD_SYSCALL': completing patching transition +livepatch: '$MOD_SYSCALL': patching complete +$MOD_SYSCALL: Remaining not livepatched processes: 0 +% echo 0 > /sys/kernel/livepatch/$MOD_SYSCALL/enabled +livepatch: '$MOD_SYSCALL': initializing unpatching transition +livepatch: '$MOD_SYSCALL': starting unpatching transition +livepatch: '$MOD_SYSCALL': completing unpatching transition +livepatch: '$MOD_SYSCALL': unpatching complete +% rmmod $MOD_SYSCALL" + +exit 0 diff --git a/tools/testing/selftests/livepatch/test_klp-call_getpid.c b/tools/testing/selftests/livepatch/test_klp-call_getpid.c new file mode 100644 index 000000000000..ce321a2d7308 --- /dev/null +++ b/tools/testing/selftests/livepatch/test_klp-call_getpid.c @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2023 SUSE + * Authors: Libor Pechacek + * Marcos Paulo de Souza + */ + +#include +#include +#include +#include +#include + +static int stop; +static int sig_int; + +void hup_handler(int signum) +{ + stop = 1; +} + +void int_handler(int signum) +{ + stop = 1; + sig_int = 1; +} + +int main(int argc, char *argv[]) +{ + long count = 0; + + signal(SIGHUP, &hup_handler); + signal(SIGINT, &int_handler); + + while (!stop) { + (void)syscall(SYS_getpid); + count++; + } + + if (sig_int) + printf("%ld iterations done\n", count); + + return 0; +} diff --git a/tools/testing/selftests/livepatch/test_modules/Makefile b/tools/testing/selftests/livepatch/test_modules/Makefile index 6f7c2103d27d..f5e880269bff 100644 --- a/tools/testing/selftests/livepatch/test_modules/Makefile +++ b/tools/testing/selftests/livepatch/test_modules/Makefile @@ -10,7 +10,8 @@ obj-m += test_klp_atomic_replace.o \ test_klp_state.o \ test_klp_state2.o \ test_klp_state3.o \ - test_klp_shadow_vars.o + test_klp_shadow_vars.o \ + test_klp_syscall.o modules: $(Q)$(MAKE) -C $(KDIR) modules KBUILD_EXTMOD=$(TESTMODS_DIR) diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c b/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c new file mode 100644 index 000000000000..dd802783ea84 --- /dev/null +++ b/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c @@ -0,0 +1,116 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2017-2023 SUSE + * Authors: Libor Pechacek + * Nicolai Stange + * Marcos Paulo de Souza + */ + +#include +#include +#include +#include +#include + +#if defined(__x86_64__) +#define FN_PREFIX __x64_ +#elif defined(__s390x__) +#define FN_PREFIX __s390x_ +#elif defined(__aarch64__) +#define FN_PREFIX __arm64_ +#else +/* powerpc does not select ARCH_HAS_SYSCALL_WRAPPER */ +#define FN_PREFIX +#endif + +/* Protects klp_pids */ +static DEFINE_MUTEX(kpid_mutex); + +static unsigned int npids, npids_pending; +static int klp_pids[NR_CPUS]; +module_param_array(klp_pids, int, &npids_pending, 0); +MODULE_PARM_DESC(klp_pids, "Array of pids to be transitioned to livepatched state."); + +static ssize_t npids_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%u\n", npids_pending); +} + +static struct kobj_attribute klp_attr = __ATTR_RO(npids); +static struct kobject *klp_kobj; + +static asmlinkage long lp_sys_getpid(void) +{ + int i; + + mutex_lock(&kpid_mutex); + if (npids_pending > 0) { + for (i = 0; i < npids; i++) { + if (current->pid == klp_pids[i]) { + klp_pids[i] = 0; + npids_pending--; + break; + } + } + } + mutex_unlock(&kpid_mutex); + + return task_tgid_vnr(current); +} + +static struct klp_func vmlinux_funcs[] = { + { + .old_name = __stringify(FN_PREFIX) "sys_getpid", + .new_func = lp_sys_getpid, + }, {} +}; + +static struct klp_object objs[] = { + { + /* name being NULL means vmlinux */ + .funcs = vmlinux_funcs, + }, {} +}; + +static struct klp_patch patch = { + .mod = THIS_MODULE, + .objs = objs, +}; + +static int livepatch_init(void) +{ + int ret; + + klp_kobj = kobject_create_and_add("test_klp_syscall", kernel_kobj); + if (!klp_kobj) + return -ENOMEM; + + ret = sysfs_create_file(klp_kobj, &klp_attr.attr); + if (ret) { + kobject_put(klp_kobj); + return ret; + } + + /* + * Save the number pids to transition to livepatched state before the + * number of pending pids is decremented. + */ + npids = npids_pending; + + return klp_enable_patch(&patch); +} + +static void livepatch_exit(void) +{ + kobject_put(klp_kobj); +} + +module_init(livepatch_init); +module_exit(livepatch_exit); +MODULE_LICENSE("GPL"); +MODULE_INFO(livepatch, "Y"); +MODULE_AUTHOR("Libor Pechacek "); +MODULE_AUTHOR("Nicolai Stange "); +MODULE_AUTHOR("Marcos Paulo de Souza "); +MODULE_DESCRIPTION("Livepatch test: syscall transition");