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diff --git a/third_party/rust/fuchsia-zircon/src/vmo.rs b/third_party/rust/fuchsia-zircon/src/vmo.rs
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+// Copyright 2017 The Fuchsia Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+//! Type-safe bindings for Zircon vmo objects.
+
+use {AsHandleRef, Cookied, HandleBased, Handle, HandleRef, Status};
+use {sys, ok};
+use std::{mem, ptr};
+
+/// An object representing a Zircon
+/// [virtual memory object](https://fuchsia.googlesource.com/zircon/+/master/docs/objects/vm_object.md).
+///
+/// As essentially a subtype of `Handle`, it can be freely interconverted.
+#[derive(Debug, Eq, PartialEq)]
+pub struct Vmo(Handle);
+impl_handle_based!(Vmo);
+impl Cookied for Vmo {}
+
+impl Vmo {
+ /// Create a virtual memory object.
+ ///
+ /// Wraps the
+ /// `zx_vmo_create`
+ /// syscall. See the
+ /// [Shared Memory: Virtual Memory Objects (VMOs)](https://fuchsia.googlesource.com/zircon/+/master/docs/concepts.md#Shared-Memory_Virtual-Memory-Objects-VMOs)
+ /// for more information.
+ pub fn create(size: u64) -> Result<Vmo, Status> {
+ let mut handle = 0;
+ let opts = 0;
+ let status = unsafe { sys::zx_vmo_create(size, opts, &mut handle) };
+ ok(status)?;
+ unsafe {
+ Ok(Vmo::from(Handle::from_raw(handle)))
+ }
+ }
+
+ /// Read from a virtual memory object.
+ ///
+ /// Wraps the `zx_vmo_read` syscall.
+ pub fn read(&self, data: &mut [u8], offset: u64) -> Result<usize, Status> {
+ unsafe {
+ let mut actual = 0;
+ let status = sys::zx_vmo_read(self.raw_handle(), data.as_mut_ptr(),
+ offset, data.len(), &mut actual);
+ ok(status).map(|()| actual)
+ }
+ }
+
+ /// Write to a virtual memory object.
+ ///
+ /// Wraps the `zx_vmo_write` syscall.
+ pub fn write(&self, data: &[u8], offset: u64) -> Result<usize, Status> {
+ unsafe {
+ let mut actual = 0;
+ let status = sys::zx_vmo_write(self.raw_handle(), data.as_ptr(),
+ offset, data.len(), &mut actual);
+ ok(status).map(|()| actual)
+ }
+ }
+
+ /// Get the size of a virtual memory object.
+ ///
+ /// Wraps the `zx_vmo_get_size` syscall.
+ pub fn get_size(&self) -> Result<u64, Status> {
+ let mut size = 0;
+ let status = unsafe { sys::zx_vmo_get_size(self.raw_handle(), &mut size) };
+ ok(status).map(|()| size)
+ }
+
+ /// Attempt to change the size of a virtual memory object.
+ ///
+ /// Wraps the `zx_vmo_set_size` syscall.
+ pub fn set_size(&self, size: u64) -> Result<(), Status> {
+ let status = unsafe { sys::zx_vmo_set_size(self.raw_handle(), size) };
+ ok(status)
+ }
+
+ /// Perform an operation on a range of a virtual memory object.
+ ///
+ /// Wraps the
+ /// [zx_vmo_op_range](https://fuchsia.googlesource.com/zircon/+/master/docs/syscalls/vmo_op_range.md)
+ /// syscall.
+ pub fn op_range(&self, op: VmoOp, offset: u64, size: u64) -> Result<(), Status> {
+ let status = unsafe {
+ sys::zx_vmo_op_range(self.raw_handle(), op.into_raw(), offset, size, ptr::null_mut(), 0)
+ };
+ ok(status)
+ }
+
+ /// Look up a list of physical addresses corresponding to the pages held by the VMO from
+ /// `offset` to `offset`+`size`, and store them in `buffer`.
+ ///
+ /// Wraps the
+ /// [zx_vmo_op_range](https://fuchsia.googlesource.com/zircon/+/master/docs/syscalls/vmo_op_range.md)
+ /// syscall with ZX_VMO_OP_LOOKUP.
+ pub fn lookup(&self, offset: u64, size: u64, buffer: &mut [sys::zx_paddr_t])
+ -> Result<(), Status>
+ {
+ let status = unsafe {
+ sys::zx_vmo_op_range(self.raw_handle(), VmoOp::LOOKUP.into_raw(), offset, size,
+ buffer.as_mut_ptr() as *mut u8, buffer.len() * mem::size_of::<sys::zx_paddr_t>())
+ };
+ ok(status)
+ }
+
+ /// Create a new virtual memory object that clones a range of this one.
+ ///
+ /// Wraps the
+ /// [zx_vmo_clone](https://fuchsia.googlesource.com/zircon/+/master/docs/syscalls/vmo_clone.md)
+ /// syscall.
+ pub fn clone(&self, offset: u64, size: u64) -> Result<Vmo, Status> {
+ let mut out = 0;
+ let opts = sys::ZX_VMO_CLONE_COPY_ON_WRITE;
+ let status = unsafe {
+ sys::zx_vmo_clone(self.raw_handle(), opts, offset, size, &mut out)
+ };
+ ok(status)?;
+ unsafe { Ok(Vmo::from(Handle::from_raw(out))) }
+ }
+}
+
+/// VM Object opcodes
+#[repr(C)]
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub struct VmoOp(u32);
+impl VmoOp {
+ pub fn from_raw(raw: u32) -> VmoOp {
+ VmoOp(raw)
+ }
+ pub fn into_raw(self) -> u32 {
+ self.0
+ }
+}
+
+assoc_consts!(VmoOp, [
+ COMMIT = sys::ZX_VMO_OP_COMMIT;
+ DECOMMIT = sys::ZX_VMO_OP_DECOMMIT;
+ LOCK = sys::ZX_VMO_OP_LOCK;
+ UNLOCK = sys::ZX_VMO_OP_UNLOCK;
+ LOOKUP = sys::ZX_VMO_OP_LOOKUP;
+ CACHE_SYNC = sys::ZX_VMO_OP_CACHE_SYNC;
+ CACHE_INVALIDATE = sys::ZX_VMO_OP_CACHE_INVALIDATE;
+ CACHE_CLEAN = sys::ZX_VMO_OP_CACHE_CLEAN;
+ CACHE_CLEAN_INVALIDATE = sys::ZX_VMO_OP_CACHE_CLEAN_INVALIDATE;
+]);
+
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ #[test]
+ fn vmo_get_size() {
+ let size = 16 * 1024 * 1024;
+ let vmo = Vmo::create(size).unwrap();
+ assert_eq!(size, vmo.get_size().unwrap());
+ }
+
+ #[test]
+ fn vmo_set_size() {
+ let start_size = 12;
+ let vmo = Vmo::create(start_size).unwrap();
+ assert_eq!(start_size, vmo.get_size().unwrap());
+
+ // Change the size and make sure the new size is reported
+ let new_size = 23;
+ assert!(vmo.set_size(new_size).is_ok());
+ assert_eq!(new_size, vmo.get_size().unwrap());
+ }
+
+ #[test]
+ fn vmo_read_write() {
+ let mut vec1 = vec![0; 16];
+ let vmo = Vmo::create(vec1.len() as u64).unwrap();
+ assert_eq!(vmo.write(b"abcdef", 0), Ok(6));
+ assert_eq!(16, vmo.read(&mut vec1, 0).unwrap());
+ assert_eq!(b"abcdef", &vec1[0..6]);
+ assert_eq!(vmo.write(b"123", 2), Ok(3));
+ assert_eq!(16, vmo.read(&mut vec1, 0).unwrap());
+ assert_eq!(b"ab123f", &vec1[0..6]);
+ assert_eq!(15, vmo.read(&mut vec1, 1).unwrap());
+ assert_eq!(b"b123f", &vec1[0..5]);
+ }
+
+ #[test]
+ fn vmo_op_range_unsupported() {
+ let vmo = Vmo::create(12).unwrap();
+ assert_eq!(vmo.op_range(VmoOp::LOCK, 0, 1), Err(Status::NOT_SUPPORTED));
+ assert_eq!(vmo.op_range(VmoOp::UNLOCK, 0, 1), Err(Status::NOT_SUPPORTED));
+ }
+
+ #[test]
+ fn vmo_lookup() {
+ let vmo = Vmo::create(12).unwrap();
+ let mut buffer = vec![0; 2];
+
+ // Lookup will fail as it is not committed yet.
+ assert_eq!(vmo.lookup(0, 12, &mut buffer), Err(Status::NO_MEMORY));
+
+ // COMMIT and try again.
+ assert_eq!(vmo.op_range(VmoOp::COMMIT, 0, 12), Ok(()));
+ assert_eq!(vmo.lookup(0, 12, &mut buffer), Ok(()));
+ assert_ne!(buffer[0], 0);
+ assert_eq!(buffer[1], 0);
+
+ // If we decommit then lookup should go back to failing.
+ assert_eq!(vmo.op_range(VmoOp::DECOMMIT, 0, 12), Ok(()));
+ assert_eq!(vmo.lookup(0, 12, &mut buffer), Err(Status::NO_MEMORY));
+ }
+
+ #[test]
+ fn vmo_cache() {
+ let vmo = Vmo::create(12).unwrap();
+
+ // Cache operations should all succeed.
+ assert_eq!(vmo.op_range(VmoOp::CACHE_SYNC, 0, 12), Ok(()));
+ assert_eq!(vmo.op_range(VmoOp::CACHE_INVALIDATE, 0, 12), Ok(()));
+ assert_eq!(vmo.op_range(VmoOp::CACHE_CLEAN, 0, 12), Ok(()));
+ assert_eq!(vmo.op_range(VmoOp::CACHE_CLEAN_INVALIDATE, 0, 12), Ok(()));
+ }
+
+ #[test]
+ fn vmo_clone() {
+ let original = Vmo::create(12).unwrap();
+ assert_eq!(original.write(b"one", 0), Ok(3));
+
+ // Clone the VMO, and make sure it contains what we expect.
+ let clone = original.clone(0, 10).unwrap();
+ let mut read_buffer = vec![0; 16];
+ assert_eq!(clone.read(&mut read_buffer, 0), Ok(10));
+ assert_eq!(&read_buffer[0..3], b"one");
+
+ // Writing to the original will affect the clone too, surprisingly.
+ assert_eq!(original.write(b"two", 0), Ok(3));
+ assert_eq!(original.read(&mut read_buffer, 0), Ok(12));
+ assert_eq!(&read_buffer[0..3], b"two");
+ assert_eq!(clone.read(&mut read_buffer, 0), Ok(10));
+ assert_eq!(&read_buffer[0..3], b"two");
+
+ // However, writing to the clone will not affect the original
+ assert_eq!(clone.write(b"three", 0), Ok(5));
+ assert_eq!(original.read(&mut read_buffer, 0), Ok(12));
+ assert_eq!(&read_buffer[0..3], b"two");
+ assert_eq!(clone.read(&mut read_buffer, 0), Ok(10));
+ assert_eq!(&read_buffer[0..5], b"three");
+
+ // And now that the copy-on-write has happened, writing to the original will not affect the
+ // clone. How bizarre.
+ assert_eq!(original.write(b"four", 0), Ok(4));
+ assert_eq!(original.read(&mut read_buffer, 0), Ok(12));
+ assert_eq!(&read_buffer[0..4], b"four");
+ assert_eq!(clone.read(&mut read_buffer, 0), Ok(10));
+ assert_eq!(&read_buffer[0..5], b"three");
+ }
+}
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