From patchwork Mon May 20 13:46:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 10951195 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 AFF4B14C0 for ; Mon, 20 May 2019 13:46:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A13112889C for ; Mon, 20 May 2019 13:46:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 94D8E2888E; Mon, 20 May 2019 13:46:39 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable 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 BF9A02889B for ; Mon, 20 May 2019 13:46:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732390AbfETNqd (ORCPT ); Mon, 20 May 2019 09:46:33 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:34371 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388030AbfETNqd (ORCPT ); Mon, 20 May 2019 09:46:33 -0400 Received: by mail-wr1-f67.google.com with SMTP id f8so8292483wrt.1 for ; Mon, 20 May 2019 06:46:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=brauner.io; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=DwppfX2HVonqBbct6w8ESqqGFkjlHJaSVDGaAUutfIw=; b=VeaBWLfdRE4tAIxQOoa10LigBDx9tX0zYcuKwEi7o2xHW2ycpfLJehgbTNpS8SHJi2 jcXsckEolK5SwcRZA8YxgW2Ai9XqpwR4GpTjiZDhgxPive/lvPiRyiOV+EpUsuIebSq2 QAgcXlS8VaU509k27g8lCydLUqIwZSr3krcWSAdGQJu3pkJXlOAFaQlzNVqo6TB9OllP xkA9Q49FWV2v9hBFJknv0jOn++Vh/MwD13DyYWlAFwJbIZq94A0oBcXj1HFBNRSVy8F2 /EPyD1Mh21EqOlwyCcSL+nw1omOidf5lwE9JJ5P3rmlwi3V1x4s824hyv6ktcu5KOUUi WvFw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=DwppfX2HVonqBbct6w8ESqqGFkjlHJaSVDGaAUutfIw=; b=heWjAJnJa3ZYrizUTTlNN7R5PoznXkkCFK1qL9P63VFrdn39oYjfKUQTxRQbw58D48 dNvgW+tCDqkeANdMwHThI3f3JnkeSMmZ9ev8cWdMR1jubWeV5aXCJTHNpZJsUtr/qYbD sFVNqF/shzSo2MhuQqb9WZCS7qo/m6ClxYUBp6iXf2o0ffRpwHW2AIsVQ7ONqRyH5Nlp FNtpgzNlSaxmURmRyzXcyBzQPjxXU9H7d+fRWLomY3Y/ea+oaLkk2T/mjxfTw1KXJUF0 00Gi6bQYMjz8lGm6XDCS8Xuua6Zh2IXltdzWjwfjZjh60AtnefJ+yOJaC4Fj99oKnSCc tW+g== X-Gm-Message-State: APjAAAXhQYL1a1VAtpttZz5H+nYzRQVip21f5AFllrbZfbKPgcFe+ycp xvs8ZjPgjZypi/ZGKuJD3xE7yg== X-Google-Smtp-Source: APXvYqwcz/PhprR9leZBWHY7wgs5JlaBvvq4bd1Z9DYed6h7w33RIwhTnHfxoF2B7Sq7j400Oo8IUQ== X-Received: by 2002:a5d:4b81:: with SMTP id b1mr21218616wrt.217.1558359990608; Mon, 20 May 2019 06:46:30 -0700 (PDT) Received: from localhost.localdomain ([212.91.227.56]) by smtp.gmail.com with ESMTPSA id k17sm14506592wrm.73.2019.05.20.06.46.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 20 May 2019 06:46:29 -0700 (PDT) From: Christian Brauner To: jannh@google.com, oleg@redhat.com, viro@zeniv.linux.org.uk, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, arnd@arndb.de Cc: akpm@linux-foundation.org, cyphar@cyphar.com, dhowells@redhat.com, ebiederm@xmission.com, elena.reshetova@intel.com, keescook@chromium.org, luto@amacapital.net, luto@kernel.org, tglx@linutronix.de, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, joel@joelfernandes.org, dancol@google.com, serge@hallyn.com, surenb@google.com, kernel-team@android.com, Christian Brauner , "Michael Kerrisk (man-pages)" Subject: [PATCH v2 2/2] tests: add pidfd_open() tests Date: Mon, 20 May 2019 15:46:05 +0200 Message-Id: <20190520134605.29116-2-christian@brauner.io> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190520134605.29116-1-christian@brauner.io> References: <20190520134605.29116-1-christian@brauner.io> MIME-Version: 1.0 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 the new pidfd_open() syscalls. Specifically, we test: - that no invalid flags can be passed to pidfd_open() - that no invalid pid can be passed to pidfd_open() - that a pidfd can be retrieved with pidfd_open() - that the retrieved pidfd references the correct pid Signed-off-by: Christian Brauner Cc: Arnd Bergmann Cc: "Eric W. Biederman" Cc: Kees Cook Cc: Joel Fernandes (Google) Cc: Thomas Gleixner Cc: Jann Horn Cc: David Howells Cc: "Michael Kerrisk (man-pages)" Cc: Andy Lutomirsky Cc: Andrew Morton Cc: Oleg Nesterov Cc: Aleksa Sarai Cc: Linus Torvalds Cc: Al Viro Cc: linux-api@vger.kernel.org --- v1: unchanged v2: - Christian Brauner : - set number of planned tests via ksft_set_plan() --- tools/testing/selftests/pidfd/Makefile | 2 +- tools/testing/selftests/pidfd/pidfd.h | 57 ++++++ .../testing/selftests/pidfd/pidfd_open_test.c | 169 ++++++++++++++++++ tools/testing/selftests/pidfd/pidfd_test.c | 41 +---- 4 files changed, 228 insertions(+), 41 deletions(-) create mode 100644 tools/testing/selftests/pidfd/pidfd.h create mode 100644 tools/testing/selftests/pidfd/pidfd_open_test.c diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile index deaf8073bc06..b36c0be70848 100644 --- a/tools/testing/selftests/pidfd/Makefile +++ b/tools/testing/selftests/pidfd/Makefile @@ -1,6 +1,6 @@ CFLAGS += -g -I../../../../usr/include/ -TEST_GEN_PROGS := pidfd_test +TEST_GEN_PROGS := pidfd_test pidfd_open_test include ../lib.mk diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h new file mode 100644 index 000000000000..8452e910463f --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd.h @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __PIDFD_H +#define __PIDFD_H + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../kselftest.h" + +/* + * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c + * That means, when it wraps around any pid < 300 will be skipped. + * So we need to use a pid > 300 in order to test recycling. + */ +#define PID_RECYCLE 1000 + +/* + * Define a few custom error codes for the child process to clearly indicate + * what is happening. This way we can tell the difference between a system + * error, a test error, etc. + */ +#define PIDFD_PASS 0 +#define PIDFD_FAIL 1 +#define PIDFD_ERROR 2 +#define PIDFD_SKIP 3 +#define PIDFD_XFAIL 4 + +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); +} + + +#endif /* __PIDFD_H */ diff --git a/tools/testing/selftests/pidfd/pidfd_open_test.c b/tools/testing/selftests/pidfd/pidfd_open_test.c new file mode 100644 index 000000000000..0377133dd6dc --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_open_test.c @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pidfd.h" +#include "../kselftest.h" + +static inline int sys_pidfd_open(pid_t pid, unsigned int flags) +{ + return syscall(__NR_pidfd_open, pid, flags); +} + +static int safe_int(const char *numstr, int *converted) +{ + char *err = NULL; + long sli; + + errno = 0; + sli = strtol(numstr, &err, 0); + if (errno == ERANGE && (sli == LONG_MAX || sli == LONG_MIN)) + return -ERANGE; + + if (errno != 0 && sli == 0) + return -EINVAL; + + if (err == numstr || *err != '\0') + return -EINVAL; + + if (sli > INT_MAX || sli < INT_MIN) + return -ERANGE; + + *converted = (int)sli; + return 0; +} + +static int char_left_gc(const char *buffer, size_t len) +{ + size_t i; + + for (i = 0; i < len; i++) { + if (buffer[i] == ' ' || + buffer[i] == '\t') + continue; + + return i; + } + + return 0; +} + +static int char_right_gc(const char *buffer, size_t len) +{ + int i; + + for (i = len - 1; i >= 0; i--) { + if (buffer[i] == ' ' || + buffer[i] == '\t' || + buffer[i] == '\n' || + buffer[i] == '\0') + continue; + + return i + 1; + } + + return 0; +} + +static char *trim_whitespace_in_place(char *buffer) +{ + buffer += char_left_gc(buffer, strlen(buffer)); + buffer[char_right_gc(buffer, strlen(buffer))] = '\0'; + return buffer; +} + +static pid_t get_pid_from_fdinfo_file(int pidfd, const char *key, size_t keylen) +{ + int ret; + char path[512]; + FILE *f; + size_t n = 0; + pid_t result = -1; + char *line = NULL; + + snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", pidfd); + + f = fopen(path, "re"); + if (!f) + return -1; + + while (getline(&line, &n, f) != -1) { + char *numstr; + + if (strncmp(line, key, keylen)) + continue; + + numstr = trim_whitespace_in_place(line + 4); + ret = safe_int(numstr, &result); + if (ret < 0) + goto out; + + break; + } + +out: + free(line); + fclose(f); + return result; +} + +int main(int argc, char **argv) +{ + int pidfd = -1, ret = 1; + pid_t pid; + + ksft_set_plan(3); + + pidfd = sys_pidfd_open(-1, 0); + if (pidfd >= 0) { + ksft_print_msg( + "%s - succeeded to open pidfd for invalid pid -1\n", + strerror(errno)); + goto on_error; + } + ksft_test_result_pass("do not allow invalid pid test: passed\n"); + + pidfd = sys_pidfd_open(getpid(), 1); + if (pidfd >= 0) { + ksft_print_msg( + "%s - succeeded to open pidfd with invalid flag value specified\n", + strerror(errno)); + goto on_error; + } + ksft_test_result_pass("do not allow invalid flag test: passed\n"); + + pidfd = sys_pidfd_open(getpid(), 0); + if (pidfd < 0) { + ksft_print_msg("%s - failed to open pidfd\n", strerror(errno)); + goto on_error; + } + ksft_test_result_pass("open a new pidfd test: passed\n"); + + pid = get_pid_from_fdinfo_file(pidfd, "Pid:", sizeof("Pid:") - 1); + ksft_print_msg("pidfd %d refers to process with pid %d\n", pidfd, pid); + + ret = 0; + +on_error: + if (pidfd >= 0) + close(pidfd); + + return !ret ? ksft_exit_pass() : ksft_exit_fail(); +} diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c index 5bae1792e3d6..a03387052aa7 100644 --- a/tools/testing/selftests/pidfd/pidfd_test.c +++ b/tools/testing/selftests/pidfd/pidfd_test.c @@ -14,6 +14,7 @@ #include #include +#include "pidfd.h" #include "../kselftest.h" static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, @@ -62,28 +63,6 @@ static int test_pidfd_send_signal_simple_success(void) return 0; } -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 (ret != pid) - goto again; - - if (!WIFEXITED(status)) - return -1; - - return WEXITSTATUS(status); -} - static int test_pidfd_send_signal_exited_fail(void) { int pidfd, ret, saved_errno; @@ -128,13 +107,6 @@ static int test_pidfd_send_signal_exited_fail(void) return 0; } -/* - * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c - * That means, when it wraps around any pid < 300 will be skipped. - * So we need to use a pid > 300 in order to test recycling. - */ -#define PID_RECYCLE 1000 - /* * Maximum number of cycles we allow. This is equivalent to PID_MAX_DEFAULT. * If users set a higher limit or we have cycled PIDFD_MAX_DEFAULT number of @@ -143,17 +115,6 @@ static int test_pidfd_send_signal_exited_fail(void) */ #define PIDFD_MAX_DEFAULT 0x8000 -/* - * Define a few custom error codes for the child process to clearly indicate - * what is happening. This way we can tell the difference between a system - * error, a test error, etc. - */ -#define PIDFD_PASS 0 -#define PIDFD_FAIL 1 -#define PIDFD_ERROR 2 -#define PIDFD_SKIP 3 -#define PIDFD_XFAIL 4 - static int test_pidfd_send_signal_recycled_pid_fail(void) { int i, ret;