From patchwork Thu Jul 25 00:22:04 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 11057773 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4CE25138D for ; Thu, 25 Jul 2019 00:22:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3B236288E4 for ; Thu, 25 Jul 2019 00:22:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2D3B5288EA; Thu, 25 Jul 2019 00:22:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 97BF5288E4 for ; Thu, 25 Jul 2019 00:22:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728820AbfGYAWM (ORCPT ); Wed, 24 Jul 2019 20:22:12 -0400 Received: from mail-qk1-f201.google.com ([209.85.222.201]:54772 "EHLO mail-qk1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728554AbfGYAWM (ORCPT ); Wed, 24 Jul 2019 20:22:12 -0400 Received: by mail-qk1-f201.google.com with SMTP id b139so40791187qkc.21 for ; Wed, 24 Jul 2019 17:22:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=WoT0JdS5sTZ+KaUnVNgLy4vBDqFwtVz5wRG6YSXVjfE=; b=pHr9hk3tmUqrRWPEMXKO6EjMvXrKDPcNEhjNrRC2YjzvigkcK3FwehQq/WeVohq8EU emUQ8OuW3Op6f/SeAo4w7bzLDNKdHbcVus9x+aZ1D9Z3oPogirZtE1Wmu5IWS40DueWb qQ4+b/OOQSTwJCx7qQn1psTxkqN2BSwGX1HAx0V6QRHOWTRENYmgVZGdD//C3VoKwCbB y+uz0j5AF6r5CSfyVVMJ6HlLDn6gS4uAzJQOOvwmTvqMnBT3F33ubYITV4ad5g71RGY2 tzSnZB3FNGhK1k+koyGGsUu0nf4L3aOrUjAUVq/skcverQ6lPxSferUU8oQDEy1PCnGb 92aA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=WoT0JdS5sTZ+KaUnVNgLy4vBDqFwtVz5wRG6YSXVjfE=; b=D0zZ7X6RTookPv5WzEUkTDuteyJTb8HnhCEdsXe8IAFPB9afR3ZTzJiX6oETriHbeh CoVQputmoIpvxAPIFF93/MTpORNrdWT4ZxqHuu/dsU36F5YrEtyiADWXGrb8HLfAMl23 CAsWeHsNSrTK2T90sS/hJ3jEM49rUnFKrjd52ad+iMWN7ceiHES+Kyj9+ZtTMrnY8ZBD JFQmtLSyzL2HLoJFkQ3zXi8POmw9eBFn5WKEq+rxtWIcYnaohxu5hOFoX3OZGIodccDE YB8FiYWf2titsrRacu+SjwFnBB+g++f2hvbmFZyQrWjmAgvsKT48Gb5th3VfP9NETSR4 zlEg== X-Gm-Message-State: APjAAAVzI8cq+7OtKqUnsvtPVMiKPq+uVI9A9Fqyawuowu3n7lvjD7x5 nfNaHP2rnmljqeHUmDqWrNkuyQM0Cow= X-Google-Smtp-Source: APXvYqyCu86gRhosjk95ByhCLv1y0mU+aviBEYQSxF57aMUceutoRPaIQKhDD1lvj8c94MnUFh1nDcQIbco= X-Received: by 2002:ac8:2971:: with SMTP id z46mr58482727qtz.322.1564014130639; Wed, 24 Jul 2019 17:22:10 -0700 (PDT) Date: Wed, 24 Jul 2019 17:22:04 -0700 In-Reply-To: <20190725002204.185225-1-surenb@google.com> Message-Id: <20190725002204.185225-2-surenb@google.com> Mime-Version: 1.0 References: <20190725002204.185225-1-surenb@google.com> X-Mailer: git-send-email 2.22.0.709.g102302147b-goog Subject: [PATCH v2 2/2] tests: add pidfd poll tests From: Suren Baghdasaryan To: surenb@google.com Cc: christian@brauner.io, arnd@arndb.de, ebiederm@xmission.com, keescook@chromium.org, joel@joelfernandes.org, dancol@google.com, tglx@linutronix.de, jannh@google.com, dhowells@redhat.com, mtk.manpages@gmail.com, luto@kernel.org, akpm@linux-foundation.org, oleg@redhat.com, cyphar@cyphar.com, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, linux-api@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-team@android.com Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This adds testing for polling on pidfd of a process being killed. Test runs 10000 iterations by default to stress test pidfd polling functionality. It accepts an optional command-line parameter to override the number or iterations to run. Specifically, it tests for: - pidfd_open on a child process succeeds - pidfd_send_signal on a child process succeeds - polling on pidfd succeeds and returns exactly one event - returned event is POLLIN - event is received within 3 secs of the process being killed 10000 iterations was chosen because of the race condition being tested which is not consistently reproducible but usually is revealed after less than 2000 iterations. Reveals race fixed by commit b191d6491be6 ("pidfd: fix a poll race when setting exit_state") Signed-off-by: Suren Baghdasaryan Reviewed-by: Christian Brauner --- tools/testing/selftests/pidfd/.gitignore | 1 + tools/testing/selftests/pidfd/Makefile | 2 +- .../testing/selftests/pidfd/pidfd_poll_test.c | 112 ++++++++++++++++++ 3 files changed, 114 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/pidfd/pidfd_poll_test.c diff --git a/tools/testing/selftests/pidfd/.gitignore b/tools/testing/selftests/pidfd/.gitignore index 16d84d117bc0..a67896347d34 100644 --- a/tools/testing/selftests/pidfd/.gitignore +++ b/tools/testing/selftests/pidfd/.gitignore @@ -1,2 +1,3 @@ pidfd_open_test +pidfd_poll_test pidfd_test diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile index 720b2d884b3c..ed58b7108d18 100644 --- a/tools/testing/selftests/pidfd/Makefile +++ b/tools/testing/selftests/pidfd/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only CFLAGS += -g -I../../../../usr/include/ -lpthread -TEST_GEN_PROGS := pidfd_test pidfd_open_test +TEST_GEN_PROGS := pidfd_test pidfd_open_test pidfd_poll_test include ../lib.mk diff --git a/tools/testing/selftests/pidfd/pidfd_poll_test.c b/tools/testing/selftests/pidfd/pidfd_poll_test.c new file mode 100644 index 000000000000..d45c612a0fe5 --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_poll_test.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pidfd.h" +#include "../kselftest.h" + +static bool timeout; + +static void handle_alarm(int sig) +{ + timeout = true; +} + +int main(int argc, char **argv) +{ + struct pollfd fds; + int iter, nevents; + int nr_iterations = 10000; + + fds.events = POLLIN; + + if (argc > 2) + ksft_exit_fail_msg("Unexpected command line argument\n"); + + if (argc == 2) { + nr_iterations = atoi(argv[1]); + if (nr_iterations <= 0) + ksft_exit_fail_msg("invalid input parameter %s\n", + argv[1]); + } + + ksft_print_msg("running pidfd poll test for %d iterations\n", + nr_iterations); + + for (iter = 0; iter < nr_iterations; iter++) { + int pidfd; + int child_pid = fork(); + + if (child_pid < 0) { + if (errno == EAGAIN) { + iter--; + continue; + } + ksft_exit_fail_msg( + "%s - failed to fork a child process\n", + strerror(errno)); + } + + if (!child_pid) { + /* Child process just sleeps for a min and exits */ + sleep(60); + exit(EXIT_SUCCESS); + } + + /* Parent kills the child and waits for its death */ + pidfd = sys_pidfd_open(child_pid, 0); + if (pidfd < 0) + ksft_exit_fail_msg("%s - pidfd_open failed\n", + strerror(errno)); + + /* Setup 3 sec alarm - plenty of time */ + if (signal(SIGALRM, handle_alarm) == SIG_ERR) + ksft_exit_fail_msg("%s - signal failed\n", + strerror(errno)); + alarm(3); + + /* Send SIGKILL to the child */ + if (sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0)) + ksft_exit_fail_msg("%s - pidfd_send_signal failed\n", + strerror(errno)); + + /* Wait for the death notification */ + fds.fd = pidfd; + nevents = poll(&fds, 1, -1); + + /* Check for error conditions */ + if (nevents < 0) + ksft_exit_fail_msg("%s - poll failed\n", + strerror(errno)); + + if (nevents != 1) + ksft_exit_fail_msg("unexpected poll result: %d\n", + nevents); + + if (!(fds.revents & POLLIN)) + ksft_exit_fail_msg( + "unexpected event type received: 0x%x\n", + fds.revents); + + if (timeout) + ksft_exit_fail_msg( + "death notification wait timeout\n"); + + close(pidfd); + } + + ksft_test_result_pass("pidfd poll test: pass\n"); + return ksft_exit_pass(); +}