zdtm: add maps_file_prot

Tests for the bugs fixed by "criu: fix filemap open permissions".
Signed-off-by: Jamie Liu <jamieliu@google.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

test/zdtm.sh

@@ -12,6 +12,7 @@ static/maps00
 static/maps01
 static/maps02
 static/maps04
+static/maps_file_prot
 static/mprotect00
 static/mtime_mmap
 static/sleeping00

test/zdtm/live/static/Makefile

@@ -140,6 +140,7 @@ TST_FILE	=				\
 		file_locks00			\
 		file_locks01			\
 		netns-nf			\
+		maps_file_prot			\
 
 TST_DIR		=				\
 		cwd00				\

test/zdtm/live/static/maps_file_prot.c

+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <linux/limits.h>
+#include "zdtmtst.h"
+
+const char *test_doc	= "Test mappings of same file with different prot";
+const char *test_author	= "Jamie Liu <jamieliu@google.com>";
+
+char *filename;
+TEST_OPTION(filename, string, "file name", 1);
+
+#define die(fmt, arg...) do { err(fmt, ## arg); return 1; } while (0)
+
+int main(int argc, char ** argv)
+{
+	void *ro_map, *rw_map;
+	int fd;
+
+	test_init(argc, argv);
+
+	fd = open(filename, O_RDWR | O_CREAT, 0644);
+	if (fd < 0)
+		die("open failed");
+	if (ftruncate(fd, 2 * PAGE_SIZE))
+		die("ftruncate failed");
+
+	ro_map = mmap(NULL, 2 * PAGE_SIZE, PROT_READ, MAP_SHARED, fd, 0);
+	if (ro_map == MAP_FAILED)
+		die("mmap failed");
+	rw_map = ro_map + PAGE_SIZE;
+	if (mprotect(rw_map, PAGE_SIZE, PROT_READ | PROT_WRITE))
+		die("mprotect failed");
+
+	close(fd);
+
+	test_daemon();
+	test_waitsig();
+
+	/* Check that rw_map is still writeable */
+	*(volatile char *)rw_map = 1;
+
+	if (mprotect(ro_map, PAGE_SIZE, PROT_READ | PROT_WRITE)) {
+		fail("mprotect after restore failed");
+		return 1;
+	}
+
+	pass();
+	return 0;
+}