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path: root/sys/compat/cloudabi/cloudabi_vdso.c
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Diffstat (limited to 'sys/compat/cloudabi/cloudabi_vdso.c')
-rw-r--r--sys/compat/cloudabi/cloudabi_vdso.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/sys/compat/cloudabi/cloudabi_vdso.c b/sys/compat/cloudabi/cloudabi_vdso.c
new file mode 100644
index 000000000000..27c3d365af83
--- /dev/null
+++ b/sys/compat/cloudabi/cloudabi_vdso.c
@@ -0,0 +1,88 @@
+/*-
+ * 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);
+}