posix: Add invalid flags test for p{write,read}v2

This patch add an extra test for passing invalid flags and check its
expected failure.  It shows an invalid LO_HI_LONG macro definition for
x86_64 with leads to passing invalid flags on some configurations.

The new tests fails on i686-linux-gnu and potentially on other 32 bits
architecture that uses the compat syscall definition due a kernel bug.
It is intended to be fixed upstream.

Checked on x86_64-linux-gnu

	* misc/tst-preadvwritev2-common.c: New file.
	* misc/tst-preadvwritev2.c (do_test): Add test for invalid flag.
	* misc/tst-preadvwritev64v2.c (do_test): Likewise.

1 files changed, 48 insertions, 0 deletions

diff --git a/misc/tst-preadvwritev2-common.c b/misc/tst-preadvwritev2-common.c
new file mode 100644
index 0000000000..4c53d567b5
--- /dev/null
+++ b/misc/tst-preadvwritev2-common.c
@@ -0,0 +1,48 @@
+/* Common function for preadv2 and pwritev2 tests.
+   Copyright (C) 2017 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 <support/check.h>
+
+static void
+do_test_with_invalid_flags (void)
+{
+  int invalid_flag = 0x1;
+#ifdef RWF_HIPRI
+  invalid_flag <<= 1;
+#endif
+#ifdef RWF_DSYNC
+  invalid_flag <<= 1;
+#endif
+#ifdef RWF_SYNC
+  invalid_flag <<= 1;
+#endif
+
+  char buf[32];
+  const struct iovec vec = { .iov_base = buf, .iov_len = sizeof (buf) };
+  if (preadv2 (temp_fd, &vec, 1, 0, invalid_flag) != -1)
+    FAIL_EXIT1 ("preadv2 did not fail with an invalid flag");
+  if (errno != ENOTSUP)
+    FAIL_EXIT1 ("preadv2 failure did not set errno to ENOTSUP (%d)", errno);
+
+  /* This might fail for compat syscall (32 bits running on 64 bits kernel)
+     due a kernel issue.  */
+  if (pwritev2 (temp_fd, &vec, 1, 0, invalid_flag) != -1)
+    FAIL_EXIT1 ("pwritev2 did not fail with an invalid flag");
+  if (errno != ENOTSUP)
+    FAIL_EXIT1 ("pwritev2 failure did not set errno to ENOTSUP (%d)", errno);
+}