hurd: Support msync

	* sysdeps/mach/hurd/msync.c: New file.

1 files changed, 93 insertions, 0 deletions

diff --git a/sysdeps/mach/hurd/msync.c b/sysdeps/mach/hurd/msync.c
new file mode 100644
index 0000000000..3e41503ece
--- /dev/null
+++ b/sysdeps/mach/hurd/msync.c
@@ -0,0 +1,93 @@
+/* msync -- Synchronize mapped memory to external storage.  Mach version.
+   Copyright (C) 2002-2018 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 <sys/types.h>
+#include <sys/mman.h>
+#include <errno.h>
+
+#include <hurd/hurd.h>
+
+/* Synchronize the region starting at ADDR and extending LEN bytes with the
+   file it maps.  Filesystem operations on a file being mapped are
+   unpredictable before this is done.  */
+
+int
+msync (void *addr, size_t length, int flags)
+{
+  boolean_t should_flush = flags & MS_INVALIDATE ? 1 : 0;
+  boolean_t should_iosync = flags & MS_ASYNC ? 0 : 1;
+
+  vm_address_t cur = (vm_address_t) addr;
+  vm_address_t target = cur + length;
+
+  vm_size_t len;
+  vm_prot_t prot;
+  vm_prot_t max_prot;
+  vm_inherit_t inherit;
+  boolean_t shared;
+  memory_object_name_t obj;
+  vm_offset_t offset;
+
+  kern_return_t err;
+
+  if (flags & (MS_SYNC | MS_ASYNC) == (MS_SYNC | MS_ASYNC))
+    return __hurd_fail (EINVAL);
+
+  while (cur < target)
+    {
+      vm_address_t begin = cur;
+
+      err = __vm_region (__mach_task_self (),
+			 &begin, &len, &prot, &max_prot, &inherit,
+			 &shared, &obj, &offset)
+
+      if (err != KERN_SUCCESS)
+	return __hurd_fail (err);
+
+      if (begin > cur)
+	/* We were given an address before the first region,
+	   or we found a hole.  */
+	cur = begin;
+
+      if (cur >= target)
+	/* We were given an ending address within a hole. */
+	break;
+
+      if (MACH_PORT_VALID (obj))
+	{
+	  vm_size_t sync_len;
+
+	  if (begin + len > target)
+	    sync_len = target - begin;
+	  else
+	    sync_len = len;
+
+	  err = __vm_object_sync (obj, cur - begin + offset, sync_len,
+				  should_flush, 1, should_iosync);
+	  __mach_port_deallocate (__mach_task_self (), obj);
+
+	  if (err)
+	    return __hurd_fail (err);
+
+	}
+
+      cur = begin + len;
+    }
+
+  return 0;
+}