From patchwork Thu Oct 10 13:35:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 11183625 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DCC071709 for ; Thu, 10 Oct 2019 13:35:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BFBA92196E for ; Thu, 10 Oct 2019 13:35:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388132AbfJJNfh (ORCPT ); Thu, 10 Oct 2019 09:35:37 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54315 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728393AbfJJNfh (ORCPT ); Thu, 10 Oct 2019 09:35:37 -0400 Received: from [193.96.224.244] (helo=localhost.localdomain) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iIYbO-0001XF-Bj; Thu, 10 Oct 2019 13:35:34 +0000 From: Christian Brauner To: linux-kernel@vger.kernel.org, Oleg Nesterov , Florian Weimer , libc-alpha@sourceware.org Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Shuah Khan , Andrew Morton , Michal Hocko , Elena Reshetova , Thomas Gleixner , Roman Gushchin , Andrea Arcangeli , Al Viro , Aleksa Sarai , "Dmitry V. Levin" , linux-kselftest@vger.kernel.org, Christian Brauner Subject: [PATCH 2/2] tests: test CLONE3_CLEAR_SIGHAND Date: Thu, 10 Oct 2019 15:35:18 +0200 Message-Id: <20191010133518.5420-2-christian.brauner@ubuntu.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010133518.5420-1-christian.brauner@ubuntu.com> References: <20191010133518.5420-1-christian.brauner@ubuntu.com> MIME-Version: 1.0 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Test that CLONE3_CLEAR_SIGHAND resets signal handlers to SIG_DFL for the child process and that CLONE3_CLEAR_SIGHAND and CLONE_SIGHAND are mutually exclusive. Cc: Florian Weimer Cc: libc-alpha@sourceware.org Signed-off-by: Christian Brauner --- MAINTAINERS | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/clone3/.gitignore | 1 + tools/testing/selftests/clone3/Makefile | 7 + .../selftests/clone3/clone3_clear_sighand.c | 171 ++++++++++++++++++ 5 files changed, 181 insertions(+) create mode 100644 tools/testing/selftests/clone3/.gitignore create mode 100644 tools/testing/selftests/clone3/Makefile create mode 100644 tools/testing/selftests/clone3/clone3_clear_sighand.c diff --git a/MAINTAINERS b/MAINTAINERS index 55199ef7fa74..582275d85607 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12828,6 +12828,7 @@ S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git F: samples/pidfd/ F: tools/testing/selftests/pidfd/ +F: tools/testing/selftests/clone3/ K: (?i)pidfd K: (?i)clone3 K: \b(clone_args|kernel_clone_args)\b diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index c3feccb99ff5..6bf7aeb47650 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -4,6 +4,7 @@ TARGETS += bpf TARGETS += breakpoints TARGETS += capabilities TARGETS += cgroup +TARGETS += clone3 TARGETS += cpufreq TARGETS += cpu-hotplug TARGETS += drivers/dma-buf diff --git a/tools/testing/selftests/clone3/.gitignore b/tools/testing/selftests/clone3/.gitignore new file mode 100644 index 000000000000..6c9f98097774 --- /dev/null +++ b/tools/testing/selftests/clone3/.gitignore @@ -0,0 +1 @@ +clone3_clear_sighand diff --git a/tools/testing/selftests/clone3/Makefile b/tools/testing/selftests/clone3/Makefile new file mode 100644 index 000000000000..3ecd56ebc99d --- /dev/null +++ b/tools/testing/selftests/clone3/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0-only +CFLAGS += -g -I../../../../usr/include/ + +TEST_GEN_PROGS := clone3_clear_sighand + +include ../lib.mk + diff --git a/tools/testing/selftests/clone3/clone3_clear_sighand.c b/tools/testing/selftests/clone3/clone3_clear_sighand.c new file mode 100644 index 000000000000..0e38c06dd6eb --- /dev/null +++ b/tools/testing/selftests/clone3/clone3_clear_sighand.c @@ -0,0 +1,171 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../kselftest.h" + +#ifndef CLONE3_CLEAR_SIGHAND +#define CLONE3_CLEAR_SIGHAND 0x100000000ULL +#endif + +#ifndef __NR_clone3 +#define __NR_clone3 -1 +struct clone_args { + __aligned_u64 flags; + __aligned_u64 pidfd; + __aligned_u64 child_tid; + __aligned_u64 parent_tid; + __aligned_u64 exit_signal; + __aligned_u64 stack; + __aligned_u64 stack_size; + __aligned_u64 tls; +}; +#endif + +static pid_t sys_clone3(struct clone_args *args, size_t size) +{ + return syscall(__NR_clone3, args, size); +} + +static void test_clone3_supported(void) +{ + pid_t pid; + struct clone_args args = {}; + + if (__NR_clone3 < 0) + ksft_exit_skip("clone3() syscall is not supported\n"); + + /* Set to something that will always cause EINVAL. */ + args.exit_signal = -1; + pid = sys_clone3(&args, sizeof(args)); + if (!pid) + exit(EXIT_SUCCESS); + + if (pid > 0) { + wait(NULL); + ksft_exit_fail_msg( + "Managed to create child process with invalid exit_signal\n"); + } + + if (errno == ENOSYS) + ksft_exit_skip("clone3() syscall is not supported\n"); + + ksft_print_msg("clone3() syscall supported\n"); +} + +static void nop_handler(int signo) +{ +} + +static int wait_for_pid(pid_t pid) +{ + int status, ret; + +again: + ret = waitpid(pid, &status, 0); + if (ret == -1) { + if (errno == EINTR) + goto again; + + return -1; + } + + if (!WIFEXITED(status)) + return -1; + + return WEXITSTATUS(status); +} + +static void test_clone3_clear_sighand(void) +{ + int ret; + pid_t pid; + struct clone_args args = {}; + struct sigaction new_action, old_action; + + new_action.sa_handler = nop_handler; + ret = sigemptyset(&new_action.sa_mask); + if (ret < 0) + ksft_exit_fail_msg("%s - sigemptyset() failed\n", + strerror(errno)); + + new_action.sa_flags = 0; + + ret = sigaction(SIGUSR1, &new_action, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s - sigaction(SIGUSR1, &new_action, NULL) failed\n", + strerror(errno)); + + ret = sigaction(SIGUSR2, &new_action, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s - sigaction(SIGUSR2, &new_action, NULL) failed\n", + strerror(errno)); + + /* + * Check that CLONE3_CLEAR_SIGHAND and CLONE_SIGHAND are mutually + * exclusive. + */ + args.flags |= CLONE3_CLEAR_SIGHAND | CLONE_SIGHAND; + args.exit_signal = SIGCHLD; + pid = sys_clone3(&args, sizeof(args)); + if (pid > 0) + ksft_exit_fail_msg( + "clone3(CLONE3_CLEAR_SIGHAND | CLONE_SIGHAND) succeeded\n"); + + /* Check that CLONE3_CLEAR_SIGHAND works. */ + args.flags = CLONE3_CLEAR_SIGHAND; + pid = sys_clone3(&args, sizeof(args)); + if (pid < 0) + ksft_exit_fail_msg("%s - clone3(CLONE3_CLEAR_SIGHAND) failed\n", strerror(errno)); + + if (pid == 0) { + struct sigaction query_action; + + ret = sigaction(SIGUSR1, NULL, &query_action); + if (ret < 0) + exit(EXIT_FAILURE); + + if (query_action.sa_handler != SIG_DFL) + exit(EXIT_FAILURE); + + ret = sigaction(SIGUSR2, NULL, &query_action); + if (ret < 0) + exit(EXIT_FAILURE); + + if (query_action.sa_handler != SIG_DFL) + exit(EXIT_FAILURE); + + exit(EXIT_SUCCESS); + } + + ret = wait_for_pid(pid); + if (ret) + ksft_exit_fail_msg( + "Failed to clear signal handler for child process\n"); + + ksft_test_result_pass("Cleared signal handlers for child process\n"); +} + +int main(int argc, char **argv) +{ + ksft_print_header(); + ksft_set_plan(1); + + test_clone3_supported(); + test_clone3_clear_sighand(); + + return ksft_exit_pass(); +}