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/*-
* Copyright (c) 2016 Nuxi, https://nuxi.nl/
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/lock.h>
#include <sys/sysent.h>
#include <sys/rwlock.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <compat/cloudabi/cloudabi_util.h>
void
cloudabi_vdso_init(struct sysentvec *sv, char *begin, char *end)
{
vm_page_t m;
vm_object_t obj;
vm_offset_t addr;
size_t i, pages, pages_length, vdso_length;
/* Determine the number of pages needed to store the vDSO. */
vdso_length = end - begin;
pages = howmany(vdso_length, PAGE_SIZE);
pages_length = pages * PAGE_SIZE;
/* Allocate a VM object and fill it with the vDSO. */
obj = vm_pager_allocate(OBJT_PHYS, 0, pages_length,
VM_PROT_DEFAULT, 0, NULL);
addr = kva_alloc(PAGE_SIZE);
for (i = 0; i < pages; ++i) {
VM_OBJECT_WLOCK(obj);
m = vm_page_grab(obj, i, VM_ALLOC_NOBUSY | VM_ALLOC_ZERO);
m->valid = VM_PAGE_BITS_ALL;
VM_OBJECT_WUNLOCK(obj);
pmap_qenter(addr, &m, 1);
memcpy((void *)addr, begin + i * PAGE_SIZE,
MIN(vdso_length - i * PAGE_SIZE, PAGE_SIZE));
pmap_qremove(addr, 1);
}
kva_free(addr, PAGE_SIZE);
/*
* Place the vDSO at the top of the address space. The user
* stack can start right below it.
*/
sv->sv_shared_page_base = sv->sv_maxuser - pages_length;
sv->sv_shared_page_len = pages_length;
sv->sv_shared_page_obj = obj;
sv->sv_usrstack = sv->sv_shared_page_base;
}
void
cloudabi_vdso_destroy(struct sysentvec *sv)
{
vm_object_deallocate(sv->sv_shared_page_obj);
}
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