From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DDD6527713; Tue, 9 Jul 2024 11:28:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720524495; cv=none; b=A+UF6HZ1oWjkCglIb4FucQVrB6PRDHg599sIHCWpN+XyYvHvqpcfcV8Mi4bn82Lxfl7kL8KtEZoZiRrffkHVzXg65SOj6XCNH8CcNDXn14ln0b1tab3CO9OhGtZYY1NPZ89MA7CFxNPFoSK/GIEB+gR6I25K5AnwOsHpNi1nz9k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720524495; c=relaxed/simple; bh=qDzEabgrIfYeUb0f3wkDuhHj084UM2kYze+tUNQmJJs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=sy0MJJnCw/SH/fo+TfmGkm1nBBOliyKATnWWZDAhUjDOp+jY0oJEAUutFvGqTKHFMb8zv84b4U6NPHA4WapJ5koEmN/DuxngdjPoQGaZgSsoUvcSblX6tqh63yWs/mj8R5RvZoeCrW6xZE4kOzrlMnTwktdvHg6PbE8fmaRFh30= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1Uzg3uKo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1Uzg3uKo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D81DC3277B; Tue, 9 Jul 2024 11:28:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720524494; bh=qDzEabgrIfYeUb0f3wkDuhHj084UM2kYze+tUNQmJJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1Uzg3uKods3TnN5aG6aoqdg1uY/cdh024Ho3npqkpQdl89nbgb+CtKtXlbA919MF3 ZCT73SN2dEkVgikizDqDSXKgnqD48mQJDeMnXXmVOTOe9DB1NoBQtRgHJjnGdnrU1Z 21qSLfoo7lH8oBuc4QDGa3bU4apDCPwDuS8VMraE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christian Brauner , =?UTF-8?q?G=C3=BCnther=20Noack?= , Jakub Kicinski , Kees Cook , Shuah Khan , Will Drewry , Mark Brown , =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Subject: [PATCH 6.9 168/197] selftests/harness: Fix tests timeout and race condition Date: Tue, 9 Jul 2024 13:10:22 +0200 Message-ID: <20240709110715.450858968@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240709110708.903245467@linuxfoundation.org> References: <20240709110708.903245467@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mickaël Salaün commit 130e42806773013e9cf32d211922c935ae2df86c upstream. We cannot use CLONE_VFORK because we also need to wait for the timeout signal. Restore tests timeout by using the original fork() call in __run_test() but also in __TEST_F_IMPL(). Also fix a race condition when waiting for the test child process. Because test metadata are shared between test processes, only the parent process must set the test PID (child). Otherwise, t->pid may be set to zero, leading to inconsistent error cases: # RUN layout1.rule_on_mountpoint ... # rule_on_mountpoint: Test ended in some other way [127] # OK layout1.rule_on_mountpoint ok 20 layout1.rule_on_mountpoint As safeguards, initialize the "status" variable with a valid exit code, and handle unknown test exits as errors. The use of fork() introduces a new race condition in landlock/fs_test.c which seems to be specific to hostfs bind mounts, but I haven't found the root cause and it's difficult to trigger. I'll try to fix it with another patch. Cc: Christian Brauner Cc: Günther Noack Cc: Jakub Kicinski Cc: Kees Cook Cc: Shuah Khan Cc: Will Drewry Cc: stable@vger.kernel.org Closes: https://lore.kernel.org/r/9341d4db-5e21-418c-bf9e-9ae2da7877e1@sirena.org.uk Fixes: a86f18903db9 ("selftests/harness: Fix interleaved scheduling leading to race conditions") Fixes: 24cf65a62266 ("selftests/harness: Share _metadata between forked processes") Link: https://lore.kernel.org/r/20240621180605.834676-1-mic@digikod.net Tested-by: Mark Brown Signed-off-by: Mickaël Salaün Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/kselftest_harness.h | 43 +++++++++++++++------------- 1 file changed, 24 insertions(+), 19 deletions(-) --- a/tools/testing/selftests/kselftest_harness.h +++ b/tools/testing/selftests/kselftest_harness.h @@ -66,8 +66,6 @@ #include #include #include -#include -#include #include "kselftest.h" @@ -82,17 +80,6 @@ # define TH_LOG_ENABLED 1 #endif -/* Wait for the child process to end but without sharing memory mapping. */ -static inline pid_t clone3_vfork(void) -{ - struct clone_args args = { - .flags = CLONE_VFORK, - .exit_signal = SIGCHLD, - }; - - return syscall(__NR_clone3, &args, sizeof(args)); -} - /** * TH_LOG() * @@ -437,7 +424,7 @@ static inline pid_t clone3_vfork(void) } \ if (setjmp(_metadata->env) == 0) { \ /* _metadata and potentially self are shared with all forks. */ \ - child = clone3_vfork(); \ + child = fork(); \ if (child == 0) { \ fixture_name##_setup(_metadata, self, variant->data); \ /* Let setup failure terminate early. */ \ @@ -1016,7 +1003,14 @@ void __wait_for_test(struct __test_metad .sa_flags = SA_SIGINFO, }; struct sigaction saved_action; - int status; + /* + * Sets status so that WIFEXITED(status) returns true and + * WEXITSTATUS(status) returns KSFT_FAIL. This safe default value + * should never be evaluated because of the waitpid(2) check and + * SIGALRM handling. + */ + int status = KSFT_FAIL << 8; + int child; if (sigaction(SIGALRM, &action, &saved_action)) { t->exit_code = KSFT_FAIL; @@ -1028,7 +1022,15 @@ void __wait_for_test(struct __test_metad __active_test = t; t->timed_out = false; alarm(t->timeout); - waitpid(t->pid, &status, 0); + child = waitpid(t->pid, &status, 0); + if (child == -1 && errno != EINTR) { + t->exit_code = KSFT_FAIL; + fprintf(TH_LOG_STREAM, + "# %s: Failed to wait for PID %d (errno: %d)\n", + t->name, t->pid, errno); + return; + } + alarm(0); if (sigaction(SIGALRM, &saved_action, NULL)) { t->exit_code = KSFT_FAIL; @@ -1083,6 +1085,7 @@ void __wait_for_test(struct __test_metad WTERMSIG(status)); } } else { + t->exit_code = KSFT_FAIL; fprintf(TH_LOG_STREAM, "# %s: Test ended in some other way [%u]\n", t->name, @@ -1218,6 +1221,7 @@ void __run_test(struct __fixture_metadat struct __test_xfail *xfail; char test_name[1024]; const char *diagnostic; + int child; /* reset test struct */ t->exit_code = KSFT_PASS; @@ -1236,15 +1240,16 @@ void __run_test(struct __fixture_metadat fflush(stdout); fflush(stderr); - t->pid = clone3_vfork(); - if (t->pid < 0) { + child = fork(); + if (child < 0) { ksft_print_msg("ERROR SPAWNING TEST CHILD\n"); t->exit_code = KSFT_FAIL; - } else if (t->pid == 0) { + } else if (child == 0) { setpgrp(); t->fn(t, variant); _exit(t->exit_code); } else { + t->pid = child; __wait_for_test(t); } ksft_print_msg(" %4s %s\n",