From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFDA7C43387 for ; Sun, 30 Dec 2018 21:02:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90C0B2070C for ; Sun, 30 Dec 2018 21:02:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726812AbeL3VCt (ORCPT ); Sun, 30 Dec 2018 16:02:49 -0500 Received: from mail.hallyn.com ([178.63.66.53]:42588 "EHLO mail.hallyn.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726007AbeL3VCt (ORCPT ); Sun, 30 Dec 2018 16:02:49 -0500 Received: by mail.hallyn.com (Postfix, from userid 1001) id 0F9B5D55; Sun, 30 Dec 2018 15:02:45 -0600 (CST) Date: Sun, 30 Dec 2018 15:02:45 -0600 From: "Serge E. Hallyn" To: Christian Brauner Cc: linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, luto@kernel.org, arnd@arndb.de, serge@hallyn.com, keescook@chromium.org, akpm@linux-foundation.org, jannh@google.com, oleg@redhat.com, cyphar@cyphar.com, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, dancol@google.com, timmurray@google.com, fweimer@redhat.com, tglx@linutronix.de, x86@kernel.org, ebiederm@xmission.com Subject: Re: [PATCH v6 2/2] selftests: add tests for pidfd_send_signal() Message-ID: <20181230210245.GA30252@mail.hallyn.com> References: <20181229222756.30027-1-christian@brauner.io> <20181229222756.30027-2-christian@brauner.io> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181229222756.30027-2-christian@brauner.io> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 29, 2018 at 11:27:56PM +0100, Christian Brauner wrote: > As suggested by Andrew Morton in [1] add selftests for the new > sys_pidfd_send_signal() syscall. > This tests whether we can send a signal to an existing process and whether > sending a signal to a process that has already exited fails with ESRCH. > > [1]: https://lore.kernel.org/lkml/20181228152012.dbf0508c2508138efc5f2bbe@linux-foundation.org/ > > Cc: Arnd Bergmann > Cc: "Eric W. Biederman" > Cc: Kees Cook > Cc: Serge Hallyn Acked-by: Serge Hallyn Not saying you need to do this, but it would be neat if you could test sending to a pid which has been recycled :) > Cc: Jann Horn > Cc: Andy Lutomirsky > Cc: Andrew Morton > Cc: Oleg Nesterov > Cc: Aleksa Sarai > Cc: Al Viro > Cc: Florian Weimer > Signed-off-by: Christian Brauner > --- > /* Changelog */ > v6: > - patch introduced > v5..v0: > - patch not present > --- > tools/testing/selftests/Makefile | 1 + > tools/testing/selftests/pidfd/Makefile | 6 + > tools/testing/selftests/pidfd/pidfd_test.c | 130 +++++++++++++++++++++ > 3 files changed, 137 insertions(+) > create mode 100644 tools/testing/selftests/pidfd/Makefile > create mode 100644 tools/testing/selftests/pidfd/pidfd_test.c > > diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile > index 24b9934fb269..63b0d8a0ebf7 100644 > --- a/tools/testing/selftests/Makefile > +++ b/tools/testing/selftests/Makefile > @@ -27,6 +27,7 @@ TARGETS += net > TARGETS += netfilter > TARGETS += networking/timestamping > TARGETS += nsfs > +TARGETS += pidfd > TARGETS += powerpc > TARGETS += proc > TARGETS += pstore > diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile > new file mode 100644 > index 000000000000..deaf8073bc06 > --- /dev/null > +++ b/tools/testing/selftests/pidfd/Makefile > @@ -0,0 +1,6 @@ > +CFLAGS += -g -I../../../../usr/include/ > + > +TEST_GEN_PROGS := pidfd_test > + > +include ../lib.mk > + > diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c > new file mode 100644 > index 000000000000..edcd59979b10 > --- /dev/null > +++ b/tools/testing/selftests/pidfd/pidfd_test.c > @@ -0,0 +1,130 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#define _GNU_SOURCE > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "../kselftest.h" > + > +static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, > + unsigned int flags) > +{ > + return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); > +} > + > +static int signal_received; > + > +static void do_exit_success(int sig) > +{ > + signal_received = 1; > +} > + > +/* > + * Straightforward test to see whether pidfd_send_signal() works is to send > + * a signal to ourselves. > + */ > +static int test_pidfd_send_signal_simple_success(void) > +{ > + int pidfd, ret; > + const char *test_name = "pidfd_send_signal send SIGUSR1"; > + > + pidfd = open("/proc/self", O_DIRECTORY | O_CLOEXEC); > + if (pidfd < 0) > + ksft_exit_fail_msg( > + "%s test: Failed to open process file descriptor\n", > + test_name); > + > + signal(SIGUSR1, do_exit_success); > + > + ret = sys_pidfd_send_signal(pidfd, SIGUSR1, NULL, 0); > + close(pidfd); > + if (ret < 0) > + ksft_exit_fail_msg("%s test: Failed to send signal\n", > + test_name); > + > + if (signal_received != 1) > + ksft_exit_fail_msg("%s test: Failed to receive signal\n", > + test_name); > + > + signal_received = 0; > + ksft_test_result_pass("%s test: Sent signal\n", test_name); > + return 0; > +} > + > +static void wait_for_pid(pid_t pid) > +{ > + int status, ret; > + > +again: > + ret = waitpid(pid, &status, 0); > + if (ret == -1) { > + if (errno == EINTR) > + goto again; > + > + return; > + } > + > + if (ret != pid) > + goto again; > +} > + > +static int test_pidfd_send_signal_exited_fail(void) > +{ > + int pidfd, ret, saved_errno; > + char buf[256]; > + pid_t pid; > + const char *test_name = "pidfd_send_signal signal exited process"; > + > + pid = fork(); > + if (pid < 0) > + ksft_exit_fail_msg("%s test: Failed to create new process\n", > + test_name); > + > + if (pid == 0) > + _exit(EXIT_SUCCESS); > + > + snprintf(buf, sizeof(buf), "/proc/%d", pid); > + > + pidfd = open(buf, O_DIRECTORY | O_CLOEXEC); > + > + wait_for_pid(pid); > + > + if (pidfd < 0) > + ksft_exit_fail_msg( > + "%s test: Failed to open process file descriptor\n", > + test_name); > + > + ret = sys_pidfd_send_signal(pidfd, 0, NULL, 0); > + saved_errno = errno; > + close(pidfd); > + if (ret == 0) > + ksft_exit_fail_msg( > + "%s test: Managed to send signal to process even though it should have failed\n", > + test_name); > + > + if (saved_errno != ESRCH) > + ksft_exit_fail_msg( > + "%s test: Expected to receive ESRCH as errno value but received %d instead\n", > + test_name, saved_errno); > + > + ksft_test_result_pass("%s test: Failed to send signal as expected\n", > + test_name); > + return 0; > +} > + > +int main(int argc, char **argv) > +{ > + ksft_print_header(); > + > + test_pidfd_send_signal_simple_success(); > + test_pidfd_send_signal_exited_fail(); > + > + return ksft_exit_pass(); > +} > -- > 2.19.1