1 files changed, 109 insertions, 0 deletions
diff --git a/usr/src/test/os-tests/tests/writev.c b/usr/src/test/os-tests/tests/writev.c
new file mode 100644
index 0000000000..e4f4bf0a66
--- /dev/null
+++ b/usr/src/test/os-tests/tests/writev.c
@@ -0,0 +1,109 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright 2020 Joyent, Inc.
+ */
+
+/*
+ * Some simple testing of the read/writev() family: specifically we're checking
+ * IOV_MAX == 1024, and that a large-file compiled 32-bit binary can correctly
+ * access certain offsets.
+ */
+
+#include <sys/uio.h>
+#include <strings.h>
+#include <limits.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <err.h>
+
+#define	ONE_GIG ((off_t)1024 * 1024 * 1024)
+
+#define	DATA_LEN (sizeof ("data"))
+
+char path[] = "/var/tmp/writev_test.XXXXXX";
+
+static void
+cleanup(void)
+{
+	(void) unlink(path);
+}
+
+int
+main(int argc, char *argv[])
+{
+	char data[(IOV_MAX + 1) * DATA_LEN] = "";
+	struct iovec iov[IOV_MAX + 1];
+
+	if (IOV_MAX != 1024)
+		errx(EXIT_FAILURE, "IOV_MAX != 1024");
+
+	int fd = mkstemp(path);
+
+	if (fd == -1)
+		err(EXIT_FAILURE, "failed to create file");
+
+	(void) atexit(cleanup);
+
+	int ret = ftruncate(fd, ONE_GIG * 8);
+
+	if (ret != 0)
+		err(EXIT_FAILURE, "failed to truncate file");
+
+	for (int i = 0; i < IOV_MAX + 1; i++) {
+		(void) strcpy(data + i * DATA_LEN, "data");
+		iov[i].iov_base = data + i * 5;
+		iov[i].iov_len = DATA_LEN;
+	}
+
+	ssize_t written = writev(fd, iov, IOV_MAX + 1);
+
+	if (written != -1 || errno != EINVAL)
+		errx(EXIT_FAILURE, "writev(IOV_MAX + 1) didn't fail properly");
+
+	written = writev(fd, iov, IOV_MAX);
+
+	if (written == -1)
+		err(EXIT_FAILURE, "writev failed");
+
+	bzero(data, sizeof (data));
+
+	ssize_t read = preadv(fd, iov, IOV_MAX, 0);
+
+	if (read != DATA_LEN * IOV_MAX)
+		err(EXIT_FAILURE, "preadv failed");
+
+	for (int i = 0; i < IOV_MAX; i++) {
+		if (strcmp(data + i * DATA_LEN, "data") != 0)
+			errx(EXIT_FAILURE, "bad read at 0x%lx", i * DATA_LEN);
+	}
+
+	/*
+	 * Now test various "interesting" offsets.
+	 */
+
+	for (off_t off = 0; off < ONE_GIG * 8; off += ONE_GIG) {
+		if ((written = pwritev(fd, iov, 1, off)) != DATA_LEN)
+			err(EXIT_FAILURE, "pwritev(0x%lx) failed", off);
+	}
+
+	for (off_t off = 0; off < ONE_GIG * 8; off += ONE_GIG) {
+		if ((read = preadv(fd, iov, 1, off)) != DATA_LEN)
+			err(EXIT_FAILURE, "preadv(0x%lx) failed", off);
+		if (strcmp(data, "data") != 0)
+			errx(EXIT_FAILURE, "bad read at 0x%lx", off);
+	}
+
+	return (EXIT_SUCCESS);
+}