Test p{read,write}64 with offset > 4GB

Test p{read,write}64 with offset > 4GB.  Since it is not an error for a
successful pread/pwrite call to transfer fewer bytes than requested, we
should check if the return value is -1.   No need to close and unlink
temporary file, which is handled by test-skeleton.c.

	[BZ #20350]
	* posix/tst-preadwrite.c: Renamed to ...
	* posix/tst-preadwrite-common.c: This.
	(PREAD): Removed.
	(PWRITE): Likewise.
	(STRINGIFY): Likewise.
	(STRINGIFY2): Likewise.
	(do_prepare): Make it static and remove function arguments.
	(do_test): Likewise.
	(PREPARE): Updated.
	(TEST_FUNCTION): New.
	(name): Make it static.
	(fd): Likewise.
	(do_prepare): Use create_temp_file.
	(do_test): Renamed to ...
	(do_test_with_offset): This.  Make it static and accept offset.
	Properly check return value of PWRITE and PREAD.  Return bytes
	read.  Don't close fd nor unlink name.
	* posix/tst-preadwrite.c: Rewrite.
	* posix/tst-preadwrite64.c: Likewise.

1 files changed, 85 insertions, 0 deletions

diff --git a/posix/tst-preadwrite-common.c b/posix/tst-preadwrite-common.c
new file mode 100644
index 0000000..533fb93
--- /dev/null
+++ b/posix/tst-preadwrite-common.c
@@ -0,0 +1,85 @@
+/* Common definitions for pread and pwrite.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <error.h>
+#include <string.h>
+#include <unistd.h>
+
+static void do_prepare (void);
+#define PREPARE(argc, argv)	do_prepare ()
+static int do_test (void);
+#define TEST_FUNCTION		do_test ()
+
+/* We might need a bit longer timeout.  */
+#define TIMEOUT 20 /* sec */
+
+/* This defines the `main' function and some more.  */
+#include <test-skeleton.c>
+
+/* These are for the temporary file we generate.  */
+static char *name;
+static int fd;
+
+static void
+do_prepare (void)
+{
+  fd = create_temp_file ("tst-preadwrite.", &name);
+  if (fd == -1)
+    error (EXIT_FAILURE, errno, "cannot create temporary file");
+}
+
+
+static ssize_t
+do_test_with_offset (off_t offset)
+{
+  char buf[1000];
+  char res[1000];
+  int i;
+  ssize_t ret;
+
+  memset (buf, '\0', sizeof (buf));
+  memset (res, '\xff', sizeof (res));
+
+  if (write (fd, buf, sizeof (buf)) != sizeof (buf))
+    error (EXIT_FAILURE, errno, "during write");
+
+  for (i = 100; i < 200; ++i)
+    buf[i] = i;
+  ret = pwrite (fd, buf + 100, 100, offset + 100);
+  if (ret == -1)
+    error (EXIT_FAILURE, errno, "during pwrite");
+
+  for (i = 450; i < 600; ++i)
+    buf[i] = i;
+  ret = pwrite (fd, buf + 450, 150, offset + 450);
+  if (ret == -1)
+    error (EXIT_FAILURE, errno, "during pwrite");
+
+  ret = pread (fd, res, sizeof (buf) - 50, offset + 50);
+  if (ret == -1)
+    error (EXIT_FAILURE, errno, "during pread");
+
+  if (memcmp (buf + 50, res, ret) != 0)
+    {
+      printf ("error: read of pread != write of pwrite\n");
+      return -1;
+    }
+
+  return ret;
+}