From patchwork Fri Jul 26 16:22:26 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suren Baghdasaryan X-Patchwork-Id: 11061365 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 CEE171398 for ; Fri, 26 Jul 2019 16:22:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BB6DB28B1E for ; Fri, 26 Jul 2019 16:22:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AA3C528B1F; Fri, 26 Jul 2019 16:22:35 +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 2F3AD28ACB for ; Fri, 26 Jul 2019 16:22:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727646AbfGZQWe (ORCPT ); Fri, 26 Jul 2019 12:22:34 -0400 Received: from mail-pl1-f201.google.com ([209.85.214.201]:37103 "EHLO mail-pl1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727924AbfGZQWe (ORCPT ); Fri, 26 Jul 2019 12:22:34 -0400 Received: by mail-pl1-f201.google.com with SMTP id n4so28201601plp.4 for ; Fri, 26 Jul 2019 09:22:34 -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=lPOpgqHnscdwzLGtC0H1Ixwb+B+NAOxyqgNtT/tbhC8=; b=F4aIvxS/xG+ArYWWgs9p5OW3h6Ysy911syFIR4ahzJKxhX5vtAkkF7lgL9AVuhNuKA vGsqO0mxxT0UwIisuM9tG/GSMfBO5M0qB1OOOP1rIhIB13JcZcpU402EpxPrgSt2w9Po 0nhzft0hVquavaHsMph5/v8pUDeXegkxdSX0/bo4wrOmpVq/+EgcrXDvYqw6DrfRg3d3 8tzRhZ/eWISrO4py4GGx1YwBnPyqzsGSdAU7n6/eG6uEGT22aYQ4Wxxw8/FebDyE3Fxp Bnx+OSteztSCR/JMHtQVvrUb784u7YobfmhceKH3H3E0iWJAN5gx1tHqMrbgKM5SlxGG ytAA== 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=lPOpgqHnscdwzLGtC0H1Ixwb+B+NAOxyqgNtT/tbhC8=; b=qzniOYkDeaEPNeu2rRFg7hlibfUIoNTSDu7qlgaKyXGcFE0l/8x99tSjz2rNNgTpBL X8+l4D0ZV8dcm3LRFLNLnPFZjCHTSZsfp/YatIFqfgZJvqoM44TeOUZOLyJ97hjltmI8 /4F1wlTHAdrAHacXsI9PxdDnPqwIc1HO9TNvza1PRdIIz1fmJWniSgOJpz/fUKSYljLu sDDMXU+JXaXspjO0GST4aNQQyOA6hburYZumwuhXy2c35mkRKSkZdMBfSVPWGtK4Wa7f pGQeatj2CsU4mKpSe1bQD5BUD8yGDKtE+RhzUEIHNZolyjsNzKccqLT+pZvBUYJuWDOr yM0A== X-Gm-Message-State: APjAAAUZUw9tuBsDMeTIDd5R4MAOrmAcbfwGCQWKF3vZ6vtemTpgKNxN v3U7+guX3XK2U3x4674g/6n93/pNmN4= X-Google-Smtp-Source: APXvYqweliflgWhX3WB84ijGbSSbRjjNArh+t7qP7CvGNxSJEHL3aYOnPpXzOC/3A0B1KYVKh6Bw5Pien4k= X-Received: by 2002:a63:e213:: with SMTP id q19mr90893338pgh.180.1564158153637; Fri, 26 Jul 2019 09:22:33 -0700 (PDT) Date: Fri, 26 Jul 2019 09:22:26 -0700 In-Reply-To: <20190726162226.252750-1-surenb@google.com> Message-Id: <20190726162226.252750-2-surenb@google.com> Mime-Version: 1.0 References: <20190726162226.252750-1-surenb@google.com> X-Mailer: git-send-email 2.22.0.709.g102302147b-goog Subject: [PATCH v3 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: Joel Fernandes (Google) --- tools/testing/selftests/pidfd/.gitignore | 1 + tools/testing/selftests/pidfd/Makefile | 2 +- .../testing/selftests/pidfd/pidfd_poll_test.c | 117 ++++++++++++++++++ 3 files changed, 119 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..f1b62b91e53e --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_poll_test.c @@ -0,0 +1,117 @@ +// 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 == 0) { + /* 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); + // Wait for child to prevent zombies + if (waitpid(child_pid, NULL, 0) < 0) + ksft_exit_fail_msg("%s - waitpid failed\n", + strerror(errno)); + + } + + ksft_test_result_pass("pidfd poll test: pass\n"); + return ksft_exit_pass(); +}