Test for when we're writing to a file from an mmaped area of the file.

2 files changed, 63 insertions, 0 deletions

diff --git a/regress/sys/uvm/mmap_write_self/Makefile b/regress/sys/uvm/mmap_write_self/Makefile
new file mode 100644
index 00000000000..4ad508eccfa
--- /dev/null
+++ b/regress/sys/uvm/mmap_write_self/Makefile
@@ -0,0 +1,5 @@
+#	$OpenBSD: Makefile,v 1.1 2011/07/05 17:48:15 art Exp $
+
+PROG=mmap_write_self
+
+.include <bsd.regress.mk>
diff --git a/regress/sys/uvm/mmap_write_self/mmap_write_self.c b/regress/sys/uvm/mmap_write_self/mmap_write_self.c
new file mode 100644
index 00000000000..417850d072a
--- /dev/null
+++ b/regress/sys/uvm/mmap_write_self/mmap_write_self.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2011 Artur Grabowski <art@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <err.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+
+/*
+ * Test a corner case writing to a file from an mmap region from that file
+ * should fail.
+ */
+int
+main(int argc, char **argv)
+{
+	char name[20] = "/tmp/fluff.XXXXXX";
+	char *buf;
+	size_t ps;
+	int fd;
+
+	ps = getpagesize();
+
+	if ((fd = mkstemp(name)) == -1)
+		err(1, "mkstemp");
+
+	if (unlink(name) == -1)
+		err(1, "unlink");
+
+	buf = mmap(NULL, ps, PROT_READ, MAP_FILE|MAP_SHARED, fd, 0);
+	if (buf == MAP_FAILED)
+		err(1, "mmap");
+
+	if (pwrite(fd, buf, ps, 0) == ps)
+		errx(1, "write to self succeeded");
+
+	if (errno != EFAULT)
+		err(1, "unexpected errno");
+
+	return (0);
+}