From patchwork Fri Jun 3 14:32:42 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcos Paulo de Souza X-Patchwork-Id: 578576 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 364E8CCA473 for ; Fri, 3 Jun 2022 14:33:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245103AbiFCOdZ (ORCPT ); Fri, 3 Jun 2022 10:33:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244009AbiFCOdY (ORCPT ); Fri, 3 Jun 2022 10:33:24 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 536052ED61; Fri, 3 Jun 2022 07:33:22 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 1069B21A82; Fri, 3 Jun 2022 14:33:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1654266801; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hmD9vrbsq1Z0S4I7dnXkcIHxq9s5TkZQpABzmxA0LHg=; b=fG1gNkmvqIl8mWFH1FVRrMmK3z6Rvn8b6bNYiDpU50t0St/0FpUd7+yrkpoZ5CV8HtfCwI hLl0rxDgPVkZyDuTrYn8HGuRsoS6qHqwTIPYxLfVl0ibcBzD8OnZu87cQIzknFGJyI3fsZ JccPfIsTz525HOP/fLQC+DKoKSNHHEo= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id DEEA613AA2; Fri, 3 Jun 2022 14:33:18 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id mMDEKK4bmmIqGgAAMHmgww (envelope-from ); Fri, 03 Jun 2022 14:33:18 +0000 From: Marcos Paulo de Souza To: live-patching@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: shuah@kernel.org, jpoimboe@redhat.com, mbenes@suse.cz, pmladek@suse.com, Marcos Paulo de Souza Subject: [PATCH 2/2] selftests: livepatch: Test livepatching a heavily called syscall Date: Fri, 3 Jun 2022 11:32:42 -0300 Message-Id: <20220603143242.870-3-mpdesouza@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220603143242.870-1-mpdesouza@suse.com> References: <20220603143242.870-1-mpdesouza@suse.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Syscalls are called a tricky way. Test that it is possible and works. This new test creates one userspace process per online cpu calling getpid continuously and tries to livepatch the getpid function. Signed-off-by: Marcos Paulo de Souza --- tools/testing/selftests/livepatch/Makefile | 12 +++- .../selftests/livepatch/test-syscall.sh | 46 ++++++++++++++ .../test_binaries/test_klp-call_getpid.c | 48 +++++++++++++++ .../selftests/livepatch/test_modules/Makefile | 3 +- .../livepatch/test_modules/test_klp_syscall.c | 60 +++++++++++++++++++ 5 files changed, 165 insertions(+), 4 deletions(-) create mode 100755 tools/testing/selftests/livepatch/test-syscall.sh create mode 100644 tools/testing/selftests/livepatch/test_binaries/test_klp-call_getpid.c create mode 100644 tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile index 5ef492b87bb1..35014197184e 100644 --- a/tools/testing/selftests/livepatch/Makefile +++ b/tools/testing/selftests/livepatch/Makefile @@ -1,10 +1,14 @@ # SPDX-License-Identifier: GPL-2.0 +include ../../../build/Build.include +include ../../../scripts/Makefile.arch +include ../../../scripts/Makefile.include TEST_FILES := settings \ test_modules # We need the test_modules dir in order to make gen_tar and install to work -TEST_GEN_PROGS_EXTENDED := test_modules/test_klp_atomic_replace.ko \ +TEST_GEN_PROGS_EXTENDED := test_binaries/test_klp-call_getpid \ + test_modules/test_klp_atomic_replace.ko \ test_modules/test_klp_callbacks_busy.ko \ test_modules/test_klp_callbacks_demo.ko \ test_modules/test_klp_callbacks_demo2.ko \ @@ -13,7 +17,8 @@ TEST_GEN_PROGS_EXTENDED := test_modules/test_klp_atomic_replace.ko \ test_modules/test_klp_state.ko \ test_modules/test_klp_state2.ko \ test_modules/test_klp_state3.ko \ - test_modules/test_klp_shadow_vars.ko + test_modules/test_klp_shadow_vars.ko \ + test_modules/test_klp_syscall.ko TEST_PROGS_EXTENDED := functions.sh TEST_PROGS := \ @@ -21,7 +26,8 @@ TEST_PROGS := \ test-callbacks.sh \ test-shadow-vars.sh \ test-state.sh \ - test-ftrace.sh + test-ftrace.sh \ + test-syscall.sh # override lib.mk's default rules OVERRIDE_TARGETS := 1 diff --git a/tools/testing/selftests/livepatch/test-syscall.sh b/tools/testing/selftests/livepatch/test-syscall.sh new file mode 100755 index 000000000000..f1d49e6ce2ee --- /dev/null +++ b/tools/testing/selftests/livepatch/test-syscall.sh @@ -0,0 +1,46 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2022 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 + +start_test "patch getpid syscall while being heavily hammered" + +declare -a pids +for i in $(seq 1 $(getconf _NPROCESSORS_ONLN)); do + ./test_klp-call_getpid & + pids[${#pids[*]}]="$!" +done + +load_lp $MOD_SYSCALL +# Success, getpid syscall was livepatched + +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 +livepatch: enabling patch '$MOD_SYSCALL' +livepatch: '$MOD_SYSCALL': initializing patching transition +livepatch: '$MOD_SYSCALL': starting patching transition +livepatch: '$MOD_SYSCALL': completing patching transition +livepatch: '$MOD_SYSCALL': patching complete +% echo 0 > /sys/kernel/livepatch/$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_binaries/test_klp-call_getpid.c b/tools/testing/selftests/livepatch/test_binaries/test_klp-call_getpid.c new file mode 100644 index 000000000000..be9d3110687d --- /dev/null +++ b/tools/testing/selftests/livepatch/test_binaries/test_klp-call_getpid.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2017 SUSE + * Author: Libor Pechacek + */ + +#include +#include +#include +#include +#include + +static int run = 1; +static int sig_int; + +void hup_handler(int signum) +{ + run = 0; +} + +void int_handler(int signum) +{ + run = 0; + sig_int = 1; +} + +int main(int argc, char *argv[]) +{ + pid_t orig_pid, pid; + long count = 0; + + signal(SIGHUP, &hup_handler); + signal(SIGINT, &int_handler); + + orig_pid = syscall(SYS_getpid); + + while(run) { + pid = syscall(SYS_getpid); + if (pid != orig_pid) + return 1; + count++; + } + + if (sig_int) + printf("%d 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 375180bc1b16..288c65ccd080 100644 --- a/tools/testing/selftests/livepatch/test_modules/Makefile +++ b/tools/testing/selftests/livepatch/test_modules/Makefile @@ -15,7 +15,8 @@ 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 %.ko: make -C $(KDIR) M=$(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..e170accfb10c --- /dev/null +++ b/tools/testing/selftests/livepatch/test_modules/test_klp_syscall.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2017-2022 SUSE + * Authors: Libor Pechacek + * Nicolai Stange + * Marcos Paulo de Souza + */ + +#include +#include +#include +#include + +#if defined(__x86_64__) +#define FN_PREFIX __x64_ +#elif defined(__s390x__) +#define FN_PREFIX __s390x_ +#elif defined(__PPC64__) +#define FN_PREFIX __ppc64_ +#else +#error "livepatch not supported" +#endif + +asmlinkage long lp_sys_getpid(void) +{ + 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) +{ + return klp_enable_patch(&patch); +} + +static void livepatch_exit(void) +{ +} + +module_init(livepatch_init); +module_exit(livepatch_exit); +MODULE_LICENSE("GPL"); +MODULE_INFO(livepatch, "Y");