testsuite: add trap to open() including tests

testsuite/path.c

@@ -1,10 +1,14 @@
 #include <assert.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <dlfcn.h>
 #include <limits.h>
 #include <stdlib.h>
+#include <stdarg.h>
 #include <string.h>
 #include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 
 #include "testsuite.h"
 
@@ -88,3 +92,30 @@ TS_EXPORT FILE *fopen(const char *path, const char *mode)
 
 	return (void *) (long) (*_fopen)(p, mode);
 }
+
+TS_EXPORT int open(const char *path, int flags, ...)
+{
+	const char *p;
+	char buf[PATH_MAX * 2];
+	static int (*_open)(const char *path, int flags, ...);
+
+	if (!get_rootpath(__func__))
+		return -1;
+
+	_open = get_libc_func("open");
+	p = trap_path(path, buf);
+	if (p == NULL)
+		return -1;
+
+	if (flags & O_CREAT) {
+		mode_t mode;
+		va_list ap;
+
+		va_start(ap, flags);
+		mode = va_arg(ap, mode_t);
+		va_end(ap);
+		_open(p, flags, mode);
+	}
+
+	return _open(p, flags);
+}

testsuite/test-testsuite.c

@@ -67,9 +67,46 @@ static const struct test stestsuite_rootfs_fopen = {
 	.need_spawn = true,
 };
 
+static int testsuite_rootfs_open(const struct test *t)
+{
+	char buf[100];
+	int fd, done;
+
+	fd = open("/lib/modules/a", O_RDONLY);
+	if (fd < 0)
+		return EXIT_FAILURE;
+
+	for (done = 0;;) {
+		int r = read(fd, buf + done, sizeof(buf) - 1 - done);
+		if (r == 0)
+			break;
+		if (r == -EWOULDBLOCK || r == -EAGAIN)
+			continue;
+
+		done += r;
+	}
+
+	buf[done] = '\0';
+
+	if (strcmp(buf, "kmod-test-chroot-works\n") != 0)
+		return EXIT_FAILURE;
+
+	return EXIT_SUCCESS;
+}
+static const struct test stestsuite_rootfs_open = {
+	.name = "testsuite_rootfs_open",
+	.description = "test if rootfs works - open()",
+	.func = testsuite_rootfs_open,
+	.config = {
+		[TC_ROOTFS] = TESTSUITE_ROOTFS "test-rootfs/",
+	},
+	.need_spawn = true,
+};
+
 static const struct test *tests[] = {
 	&stestsuite_uname,
 	&stestsuite_rootfs_fopen,
+	&stestsuite_rootfs_open,
 	NULL,
 };