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/* msync -- Synchronize mapped memory to external storage. Mach version.
Copyright (C) 2002-2020 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
<https://www.gnu.org/licenses/>. */
#include <sys/types.h>
#include <sys/mman.h>
#include <errno.h>
#include <sysdep-cancel.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;
int cancel_oldtype;
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;
cancel_oldtype = LIBC_CANCEL_ASYNC();
err = __vm_object_sync (obj, cur - begin + offset, sync_len,
should_flush, 1, should_iosync);
LIBC_CANCEL_RESET (cancel_oldtype);
__mach_port_deallocate (__mach_task_self (), obj);
if (err)
return __hurd_fail (err);
}
cur = begin + len;
}
return 0;
}
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