[LTP] [PATCH v1] Refactoring mmap16.c test using new LTP API

Andrea Cervesato andrea.cervesato@suse.de
Thu Jan 27 16:43:17 CET 2022


Removed TST_CHECKPOINT_INIT and replaced it with the .needs_checkpoints
LTP test feature. Simplified source code.

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.de>
---
 testcases/kernel/syscalls/mmap/mmap16.c | 310 +++++++++---------------
 1 file changed, 121 insertions(+), 189 deletions(-)

diff --git a/testcases/kernel/syscalls/mmap/mmap16.c b/testcases/kernel/syscalls/mmap/mmap16.c
index 0d1fc3e96..1f1e88874 100644
--- a/testcases/kernel/syscalls/mmap/mmap16.c
+++ b/testcases/kernel/syscalls/mmap/mmap16.c
@@ -1,245 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
- *   Copyright (c) 2015 Fujitsu Ltd.
- *   Author: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
- *
- *   This program is free software;  you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- *   the GNU General Public License for more details.
+ * Copyright (c) 2015 Fujitsu Ltd. Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
+ * Copyright (C) 2021 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
  */
 
-/*
- * This is a regression test for commit:
- * http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/
- * commit/?id=90a8020
- * http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/
- * commit/?id=d6320cb
+/*\
+ * [Description]
+ *
+ * This is a regression test for Linux kernel commit:
+ *
+ * commit d6320cbfc92910a3e5f10c42d98c231c98db4f60
+ * Author: Jan Kara <jack@suse.cz>
+ * Date:   Wed Oct 1 21:49:46 2014 -0400
+ * ext4: fix mmap data corruption when blocksize < pagesize
  */
 
 #define _GNU_SOURCE
 
-#include <stdio.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <unistd.h>
-#include <sys/mount.h>
+#include <signal.h>
+#include <time.h>
 #include <sys/mman.h>
+#include <sys/wait.h>
+#include "tst_test.h"
 
-#include "test.h"
-#include "safe_macros.h"
+#define MNTPOINT "mntpoint"
+#define FILE_PARENT "mntpoint/testfilep"
+#define FILE_CHILD "mntpoint/testfilec"
+#define FS_BLOCKSIZE 1024
 
-#define MNTPOINT	"mntpoint"
-#define FS_BLOCKSIZE	1024
-#define SUB_LOOPCOUNT	10
+static int page_size = 1024;
+static int parentfd = -1;
+static int childfd = -1;
 
-static void setup(void);
-static void cleanup(void);
-static void do_child(void);
-static void do_test(void);
+static void do_child(void)
+{
+	int offset;
+	char buf[FS_BLOCKSIZE];
+	char *addr = NULL;
 
-static const char *device;
-static const char *fs_type = "ext4";
-static int mount_flag;
-static int chdir_flag;
-static int parentfd = -1;
+	while ((childfd = SAFE_OPEN(FILE_CHILD, O_RDWR | O_CREAT)) < 0)
+		usleep(100);
 
-static int page_size;
-static int bug_reproduced;
+	memset(buf, 'a', FS_BLOCKSIZE);
+	SAFE_WRITE(1, childfd, buf, FS_BLOCKSIZE);
+
+	/*
+	 * In case mremap() may fail because that memory area can not be
+	 * expanded at current virtual address(MREMAP_MAYMOVE is not set),
+	 * we first do a mmap(page_size * 2) operation to reserve some
+	 * free address space.
+	 */
+	addr = SAFE_MMAP(NULL, page_size * 2, PROT_WRITE | PROT_READ,
+			 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	SAFE_MUNMAP(addr, page_size * 2);
 
-char *TCID = "mmap16";
-int TST_TOTAL = 1;
+	addr = SAFE_MMAP(addr, FS_BLOCKSIZE, PROT_WRITE | PROT_READ, MAP_SHARED,
+			 childfd, 0);
 
-int main(int ac, char **av)
-{
-	int i, lc;
+	addr[0] = 'a';
 
-	tst_parse_opts(ac, av, NULL, NULL);
+	SAFE_FTRUNCATE(childfd, page_size * 2);
 
-	setup();
+	addr = mremap(addr, FS_BLOCKSIZE, 2 * page_size, 0);
+	if (addr == MAP_FAILED)
+		tst_brk(TBROK, "mremap failed unexpectedly");
 
 	/*
-	 * If child process was killed by SIGBUS, indeed that can not guarantee
-	 * this bug must have been fixed, If we're luckily enough, virtual
-	 * memory subsystem happen to decide that it is time to write dirty
-	 * pages, it will make mapped pages write-protect, so ->page_mkwrite()
-	 * still will be called, child process will be killed by SIGBUS, but
-	 * it's not because of above fixing patches. So here we run this test
-	 * 10 times, if once, child process exits normally, we can sure that
-	 * this bug is not fixed.
+	 * Let parent process consume FS free blocks as many as possible, then
+	 * there'll be no free blocks allocated for this new file mmaping for
+	 * offset starting at 1024, 2048, or 3072. If this above kernel bug
+	 * has been fixed, usually child process will killed by SIGBUS signal,
+	 * if not, the data 'A', 'B', 'C' will be silently discarded later when
+	 * kernel writepage is called, that means data corruption.
 	 */
-	for (lc = 0; TEST_LOOPING(lc); lc++) {
-		tst_count = 0;
+	TST_CHECKPOINT_WAKE_AND_WAIT(0);
 
-		for (i = 0; i < SUB_LOOPCOUNT; i++)
-			do_test();
-	}
-
-	if (bug_reproduced)
-		tst_resm(TFAIL, "Bug is reproduced!");
-	else
-		tst_resm(TPASS, "Bug is not reproduced!");
+	for (offset = FS_BLOCKSIZE; offset < page_size; offset += FS_BLOCKSIZE)
+		addr[offset] = 'a';
 
-	cleanup();
-	tst_exit();
+	SAFE_MUNMAP(addr, 2 * page_size);
+	SAFE_CLOSE(childfd);
 }
 
-static void do_test(void)
+static void run(void)
 {
 	int ret, status;
 	pid_t child;
 	char buf[FS_BLOCKSIZE];
+	int bug_reproduced = 0;
 
-	SAFE_TOUCH(cleanup, "testfilep", 0644, NULL);
-	SAFE_TOUCH(cleanup, "testfilec", 0644, NULL);
-
-	child = tst_fork();
-	switch (child) {
-	case -1:
-		tst_brkm(TBROK | TERRNO, cleanup, "fork failed");
-	case 0:
+	child = SAFE_FORK();
+	if (!child) {
 		do_child();
-	default:
-		parentfd = SAFE_OPEN(cleanup, "testfilep", O_RDWR);
-		memset(buf, 'a', FS_BLOCKSIZE);
-
-		TST_SAFE_CHECKPOINT_WAIT(cleanup, 0);
-		while (1) {
-			ret = write(parentfd, buf, FS_BLOCKSIZE);
-			if (ret < 0) {
-				if (errno == ENOSPC) {
-					break;
-				} else {
-					tst_brkm(TBROK | TERRNO, cleanup,
-						 "write failed unexpectedly");
-				}
-			}
+		return;
+	}
+
+	while ((parentfd = SAFE_OPEN(FILE_PARENT, O_RDWR | O_CREAT)) < 0)
+		usleep(100);
+
+	memset(buf, 'a', FS_BLOCKSIZE);
+
+	TST_CHECKPOINT_WAIT(0);
+
+	while (1) {
+		ret = write(parentfd, buf, FS_BLOCKSIZE);
+		if (ret < 0) {
+			if (errno == ENOSPC)
+				break;
+
+			tst_brk(TBROK, "write failed unexpectedly");
 		}
-		SAFE_CLOSE(cleanup, parentfd);
-		TST_SAFE_CHECKPOINT_WAKE(cleanup, 0);
 	}
 
-	wait(&status);
+	SAFE_CLOSE(parentfd);
+
+	TST_CHECKPOINT_WAKE(0);
+
+	SAFE_WAITPID(child, &status, 0);
 	if (WIFEXITED(status) && WEXITSTATUS(status) == 1) {
 		bug_reproduced = 1;
 	} else {
 		/*
 		 * If child process was killed by SIGBUS, bug is not reproduced.
 		 */
-		if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGBUS) {
-			tst_brkm(TBROK | TERRNO, cleanup,
-				 "child process terminate unexpectedly");
-		}
+		if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGBUS)
+			tst_brk(TBROK, "child process terminate unexpectedly");
 	}
 
-	SAFE_UNLINK(cleanup, "testfilep");
-	SAFE_UNLINK(cleanup, "testfilec");
+	SAFE_UNLINK(FILE_PARENT);
+	SAFE_UNLINK(FILE_CHILD);
+
+	if (bug_reproduced)
+		tst_res(TFAIL, "bug is reproduced");
+	else
+		tst_res(TPASS, "bug is not reproduced");
 }
 
 static void setup(void)
 {
 	const char *fs_opts[3] = {"-b", "1024", NULL};
-	const char *extra_opts[] = {"10240", NULL};
-
-	tst_sig(FORK, DEF_HANDLER, NULL);
-	tst_require_root();
-
-	TEST_PAUSE;
-	tst_tmpdir();
-
-	TST_CHECKPOINT_INIT(tst_rmdir);
+	const char *extra_opts[2] = {"10240", NULL};
 
 	page_size = getpagesize();
 
-	device = tst_acquire_device(cleanup);
-	if (!device)
-		tst_brkm(TCONF, cleanup, "Failed to obtain block device");
-	tst_mkfs(cleanup, device, fs_type, fs_opts, extra_opts);
-
-	SAFE_MKDIR(cleanup, MNTPOINT, 0755);
-	/*
-	 * Disable ext4 delalloc feature, so block will be allocated
-	 * as soon as possible
-	 */
-	SAFE_MOUNT(cleanup, device, MNTPOINT, fs_type, 0, "nodelalloc");
-	mount_flag = 1;
-
-	SAFE_CHDIR(cleanup, MNTPOINT);
-	chdir_flag = 1;
-
+	SAFE_MKDIR(MNTPOINT, 0777);
+	SAFE_MKFS(tst_device->dev, tst_device->fs_type, fs_opts, extra_opts);
+	SAFE_MOUNT(tst_device->dev, MNTPOINT, tst_device->fs_type, 0, 0);
 }
 
-static void do_child(void)
+static void cleanup(void)
 {
-	int fd, offset;
-	char buf[FS_BLOCKSIZE];
-	char *addr = NULL;
-
-	/*
-	 * We have changed SIGBUS' handler in parent process by calling
-	 * tst_sig(FORK, DEF_HANDLER, NULL), so here just restore it.
-	 */
-	if (signal(SIGBUS, SIG_DFL) == SIG_ERR)
-		tst_brkm(TBROK | TERRNO, NULL, "signal(SIGBUS) failed");
-
-	memset(buf, 'a', FS_BLOCKSIZE);
-	fd = SAFE_OPEN(NULL, "testfilec", O_RDWR);
-	SAFE_WRITE(NULL, 1, fd, buf, FS_BLOCKSIZE);
-
-	/*
-	 * In case mremap() may fail because that memory area can not be
-	 * expanded at current virtual address(MREMAP_MAYMOVE is not set),
-	 * we first do a mmap(page_size * 2) operation to reserve some
-	 * free address space.
-	 */
-	addr = SAFE_MMAP(NULL, NULL, page_size * 2, PROT_WRITE | PROT_READ,
-			 MAP_PRIVATE_EXCEPT_UCLINUX | MAP_ANONYMOUS, -1, 0);
-	SAFE_MUNMAP(NULL, addr, page_size * 2);
-
-	addr = SAFE_MMAP(NULL, addr, FS_BLOCKSIZE, PROT_WRITE | PROT_READ,
-			 MAP_SHARED, fd, 0);
-
-	addr[0] = 'a';
-
-	SAFE_FTRUNCATE(NULL, fd, page_size * 2);
-	addr = mremap(addr, FS_BLOCKSIZE, 2 * page_size, 0);
-	if (addr == MAP_FAILED)
-		tst_brkm(TBROK | TERRNO, NULL, "mremap failed unexpectedly");
-
-	/*
-	 * Let parent process consume FS free blocks as many as possible, then
-	 * there'll be no free blocks allocated for this new file mmaping for
-	 * offset starting at 1024, 2048, or 3072. If this above kernel bug
-	 * has been fixed, usually child process will killed by SIGBUS signal,
-	 * if not, the data 'A', 'B', 'C' will be silently discarded later when
-	 * kernel writepage is called, that means data corruption.
-	 */
-	TST_SAFE_CHECKPOINT_WAKE(NULL, 0);
-	TST_SAFE_CHECKPOINT_WAIT2(NULL, 0, 60*1000);
+	if (childfd >= 0)
+		SAFE_CLOSE(childfd);
 
-	for (offset = FS_BLOCKSIZE; offset < page_size; offset += FS_BLOCKSIZE)
-		addr[offset] = 'a';
+	if (parentfd >= 0)
+		SAFE_CLOSE(parentfd);
 
-	SAFE_MUNMAP(NULL, addr, 2 * page_size);
-	SAFE_CLOSE(NULL, fd);
-	exit(TFAIL);
+	if (tst_is_mounted(MNTPOINT))
+		SAFE_UMOUNT(MNTPOINT);
 }
 
-static void cleanup(void)
-{
-	if (parentfd >= 0)
-		close(parentfd);
-	if (chdir_flag && chdir(".."))
-		tst_resm(TWARN | TERRNO, "chdir('..') failed");
-	if (mount_flag && tst_umount(MNTPOINT) < 0)
-		tst_resm(TWARN | TERRNO, "umount device:%s failed", device);
-	if (device)
-		tst_release_device(device);
-	tst_rmdir();
-}
+static struct tst_test test = {
+	.test_all = run,
+	.setup = setup,
+	.cleanup = cleanup,
+	.dev_fs_type = "ext4",
+	.forks_child = 1,
+	.needs_root = 1,
+	.needs_device = 1,
+	.needs_checkpoints = 1,
+	.needs_tmpdir = 1,
+	.needs_cmds = (const char *const []) {
+		"mkfs.ext4",
+		NULL,
+	},
+};
-- 
2.34.1



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