zx/
vmo.rs

1// Copyright 2017 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5//! Type-safe bindings for Zircon vmo objects.
6
7use crate::{
8    Bti, Koid, Name, NullableHandle, ObjectQuery, Resource, Rights, Status, Topic, ok, sys,
9};
10use bitflags::bitflags;
11use std::mem::MaybeUninit;
12use std::ptr;
13use zerocopy::{FromBytes, Immutable};
14use zx_sys::PadByte;
15
16/// An object representing a Zircon
17/// [virtual memory object](https://fuchsia.dev/fuchsia-src/concepts/objects/vm_object.md).
18///
19/// As essentially a subtype of `NullableHandle`, it can be freely interconverted.
20#[derive(Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
21#[repr(transparent)]
22pub struct Vmo(NullableHandle);
23impl_handle_based!(Vmo);
24
25static_assert_align!(
26    #[doc="Ergonomic equivalent of [sys::zx_info_vmo_t]. Must be ABI-compatible with it."]
27    #[repr(C)]
28    #[derive(Debug, Copy, Clone, Eq, PartialEq, FromBytes, Immutable)]
29    <sys::zx_info_vmo_t> pub struct VmoInfo {
30        pub koid <koid>: Koid,
31        pub name <name>: Name,
32        pub size_bytes <size_bytes>: u64,
33        pub parent_koid <parent_koid>: Koid,
34        pub num_children <num_children>: usize,
35        pub num_mappings <num_mappings>: usize,
36        pub share_count <share_count>: usize,
37        pub flags <flags>: VmoInfoFlags,
38        padding1: [PadByte; 4],
39        pub committed_bytes <committed_bytes>: u64,
40        pub handle_rights <handle_rights>: Rights,
41        cache_policy <cache_policy>: u32,
42        pub metadata_bytes <metadata_bytes>: u64,
43        pub committed_change_events <committed_change_events>: u64,
44        pub populated_bytes <populated_bytes>: u64,
45        pub committed_private_bytes <committed_private_bytes>: u64,
46        pub populated_private_bytes <populated_private_bytes>: u64,
47        pub committed_scaled_bytes <committed_scaled_bytes>: u64,
48        pub populated_scaled_bytes <populated_scaled_bytes>: u64,
49        pub committed_fractional_scaled_bytes <committed_fractional_scaled_bytes>: u64,
50        pub populated_fractional_scaled_bytes <populated_fractional_scaled_bytes>: u64,
51    }
52);
53
54impl VmoInfo {
55    pub fn cache_policy(&self) -> CachePolicy {
56        CachePolicy::from(self.cache_policy)
57    }
58}
59
60impl Default for VmoInfo {
61    fn default() -> VmoInfo {
62        Self::from(sys::zx_info_vmo_t::default())
63    }
64}
65
66impl From<sys::zx_info_vmo_t> for VmoInfo {
67    fn from(info: sys::zx_info_vmo_t) -> VmoInfo {
68        zerocopy::transmute!(info)
69    }
70}
71
72struct VmoInfoQuery;
73unsafe impl ObjectQuery for VmoInfoQuery {
74    const TOPIC: Topic = Topic::VMO;
75    type InfoTy = sys::zx_info_vmo_t;
76}
77
78impl Vmo {
79    /// Create a virtual memory object.
80    ///
81    /// Wraps the
82    /// `zx_vmo_create`
83    /// syscall. See the
84    /// [Shared Memory: Virtual Memory Objects (VMOs)](https://fuchsia.dev/fuchsia-src/concepts/kernel/concepts#shared_memory_virtual_memory_objects_vmos)
85    /// for more information.
86    pub fn create(size: u64) -> Result<Vmo, Status> {
87        Vmo::create_with_opts(VmoOptions::from_bits_truncate(0), size)
88    }
89
90    /// Create a virtual memory object with options.
91    ///
92    /// Wraps the
93    /// `zx_vmo_create`
94    /// syscall, allowing options to be passed.
95    pub fn create_with_opts(opts: VmoOptions, size: u64) -> Result<Vmo, Status> {
96        let mut handle = 0;
97        let status = unsafe { sys::zx_vmo_create(size, opts.bits(), &mut handle) };
98        ok(status)?;
99        unsafe { Ok(Vmo::from(NullableHandle::from_raw(handle))) }
100    }
101
102    /// Create a physically contiguous virtual memory object.
103    ///
104    /// Wraps the
105    /// [`zx_vmo_create_contiguous`](https://fuchsia.dev/fuchsia-src/reference/syscalls/vmo_create_contiguous) syscall.
106    pub fn create_contiguous(bti: &Bti, size: usize, alignment_log2: u32) -> Result<Vmo, Status> {
107        let mut vmo_handle = sys::zx_handle_t::default();
108        let status = unsafe {
109            // SAFETY: regular system call with no unsafe parameters.
110            sys::zx_vmo_create_contiguous(bti.raw_handle(), size, alignment_log2, &mut vmo_handle)
111        };
112        ok(status)?;
113        unsafe {
114            // SAFETY: The syscall docs claim that upon success, vmo_handle will be a valid
115            // handle to a virtual memory object.
116            Ok(Vmo::from(NullableHandle::from_raw(vmo_handle)))
117        }
118    }
119
120    /// Read from a virtual memory object.
121    ///
122    /// Wraps the `zx_vmo_read` syscall.
123    pub fn read(&self, data: &mut [u8], offset: u64) -> Result<(), Status> {
124        unsafe {
125            let status = sys::zx_vmo_read(self.raw_handle(), data.as_mut_ptr(), offset, data.len());
126            ok(status)
127        }
128    }
129
130    /// Provides a very thin wrapper over `zx_vmo_read`.
131    ///
132    /// # Safety
133    ///
134    /// Callers must guarantee that the buffer is valid to write to.
135    pub unsafe fn read_raw<T: FromBytes>(
136        &self,
137        buffer: *mut T,
138        buffer_length: usize,
139        offset: u64,
140    ) -> Result<(), Status> {
141        let status = unsafe {
142            sys::zx_vmo_read(
143                self.raw_handle(),
144                buffer.cast::<u8>(),
145                offset,
146                buffer_length * std::mem::size_of::<T>(),
147            )
148        };
149        ok(status)
150    }
151
152    /// Same as read, but reads into memory that might not be initialized, returning an initialized
153    /// slice of bytes on success.
154    ///
155    /// `Copy` is required to ensure that there are no custom `Drop` implementations. It is
156    /// difficult to correctly run custom drop code after initializing a `MaybeUninit`.
157    pub fn read_uninit<'a, T: Copy + FromBytes>(
158        &self,
159        data: &'a mut [MaybeUninit<T>],
160        offset: u64,
161    ) -> Result<&'a mut [T], Status> {
162        // SAFETY: This system call requires that the pointer and length we pass are valid to write
163        // to, which we guarantee here by getting the pointer and length from a valid slice.
164        unsafe {
165            self.read_raw(
166                // TODO(https://fxbug.dev/42079723) use MaybeUninit::slice_as_mut_ptr when stable
167                data.as_mut_ptr().cast::<T>(),
168                data.len(),
169                offset,
170            )?
171        }
172        // TODO(https://fxbug.dev/42079723) use MaybeUninit::slice_assume_init_mut when stable
173        Ok(
174            // SAFETY: We're converting &mut [MaybeUninit<u8>] back to &mut [u8], which is only
175            // valid to do if all elements of `data` have actually been initialized. Here we
176            // have to trust that the kernel didn't lie when it said it wrote to the entire
177            // buffer, but as long as that assumption is valid them it's safe to assume this
178            // slice is init.
179            unsafe { std::slice::from_raw_parts_mut(data.as_mut_ptr().cast::<T>(), data.len()) },
180        )
181    }
182
183    /// Same as read, but returns a Vec.
184    pub fn read_to_vec<T: Copy + FromBytes>(
185        &self,
186        offset: u64,
187        length: u64,
188    ) -> Result<Vec<T>, Status> {
189        let len = length.try_into().map_err(|_| Status::INVALID_ARGS)?;
190        let mut buffer = Vec::with_capacity(len);
191        self.read_uninit(buffer.spare_capacity_mut(), offset)?;
192        unsafe {
193            // SAFETY: since read_uninit succeeded we know that we can consider the buffer
194            // initialized.
195            buffer.set_len(len);
196        }
197        Ok(buffer)
198    }
199
200    /// Same as read, but returns an array.
201    pub fn read_to_array<T: Copy + FromBytes, const N: usize>(
202        &self,
203        offset: u64,
204    ) -> Result<[T; N], Status> {
205        // TODO(https://fxbug.dev/42079731): replace with MaybeUninit::uninit_array.
206        let array: MaybeUninit<[MaybeUninit<T>; N]> = MaybeUninit::uninit();
207        // SAFETY: We are converting from an uninitialized array to an array
208        // of uninitialized elements which is the same. See
209        // https://doc.rust-lang.org/std/mem/union.MaybeUninit.html#initializing-an-array-element-by-element.
210        let mut array = unsafe { array.assume_init() };
211
212        // SAFETY: T is FromBytes, which means that any bit pattern is valid. Interpreting
213        // [MaybeUninit<T>] as [MaybeUninit<u8>] is safe because T's alignment requirements
214        // are larger than u8.
215        //
216        // TODO(https://fxbug.dev/42079727): Use MaybeUninit::slice_as_bytes_mut once stable.
217        let buffer = unsafe {
218            std::slice::from_raw_parts_mut(
219                array.as_mut_ptr().cast::<MaybeUninit<u8>>(),
220                N * std::mem::size_of::<T>(),
221            )
222        };
223
224        self.read_uninit(buffer, offset)?;
225        // SAFETY: This is safe because we have initialized all the elements in
226        // the array (since `read_uninit` returned successfully).
227        //
228        // TODO(https://fxbug.dev/42079725): replace with MaybeUninit::array_assume_init.
229        let buffer = array.map(|a| unsafe { a.assume_init() });
230        Ok(buffer)
231    }
232
233    /// Same as read, but returns a `T`.
234    pub fn read_to_object<T: Copy + FromBytes>(&self, offset: u64) -> Result<T, Status> {
235        let mut object = MaybeUninit::<T>::uninit();
236        // SAFETY: T is FromBytes, which means that any bit pattern is valid. Interpreting
237        // MaybeUninit<T> as [MaybeUninit<u8>] is safe because T's alignment requirements
238        // are larger than, or equal to, u8's.
239        //
240        // TODO(https://fxbug.dev/42079727): Use MaybeUninit::as_bytes_mut once stable.
241        let buffer = unsafe {
242            std::slice::from_raw_parts_mut(
243                object.as_mut_ptr().cast::<MaybeUninit<u8>>(),
244                std::mem::size_of::<T>(),
245            )
246        };
247        self.read_uninit(buffer, offset)?;
248
249        // SAFETY: The call to `read_uninit` succeeded so we know that `object`
250        // has been initialized.
251        let object = unsafe { object.assume_init() };
252        Ok(object)
253    }
254
255    /// Write to a virtual memory object.
256    ///
257    /// Wraps the `zx_vmo_write` syscall.
258    pub fn write(&self, data: &[u8], offset: u64) -> Result<(), Status> {
259        unsafe {
260            let status = sys::zx_vmo_write(self.raw_handle(), data.as_ptr(), offset, data.len());
261            ok(status)
262        }
263    }
264
265    /// Efficiently transfers data from one VMO to another.
266    pub fn transfer_data(
267        &self,
268        options: TransferDataOptions,
269        offset: u64,
270        length: u64,
271        src_vmo: &Vmo,
272        src_offset: u64,
273    ) -> Result<(), Status> {
274        let status = unsafe {
275            sys::zx_vmo_transfer_data(
276                self.raw_handle(),
277                options.bits(),
278                offset,
279                length,
280                src_vmo.raw_handle(),
281                src_offset,
282            )
283        };
284        ok(status)
285    }
286
287    /// Get the size of a virtual memory object.
288    ///
289    /// Wraps the `zx_vmo_get_size` syscall.
290    pub fn get_size(&self) -> Result<u64, Status> {
291        let mut size = 0;
292        let status = unsafe { sys::zx_vmo_get_size(self.raw_handle(), &mut size) };
293        ok(status).map(|()| size)
294    }
295
296    /// Attempt to change the size of a virtual memory object.
297    ///
298    /// Wraps the `zx_vmo_set_size` syscall.
299    pub fn set_size(&self, size: u64) -> Result<(), Status> {
300        let status = unsafe { sys::zx_vmo_set_size(self.raw_handle(), size) };
301        ok(status)
302    }
303
304    /// Get the stream size of a virtual memory object.
305    ///
306    /// Wraps the `zx_vmo_get_stream_size` syscall.
307    pub fn get_stream_size(&self) -> Result<u64, Status> {
308        let mut size = 0;
309        let status = unsafe { sys::zx_vmo_get_stream_size(self.raw_handle(), &mut size) };
310        ok(status).map(|()| size)
311    }
312
313    /// Attempt to set the stream size of a virtual memory object.
314    ///
315    /// Wraps the `zx_vmo_set_stream_size` syscall.
316    pub fn set_stream_size(&self, size: u64) -> Result<(), Status> {
317        let status = unsafe { sys::zx_vmo_set_stream_size(self.raw_handle(), size) };
318        ok(status)
319    }
320
321    /// Attempt to change the cache policy of a virtual memory object.
322    ///
323    /// Wraps the `zx_vmo_set_cache_policy` syscall.
324    pub fn set_cache_policy(&self, cache_policy: CachePolicy) -> Result<(), Status> {
325        let status =
326            unsafe { sys::zx_vmo_set_cache_policy(self.raw_handle(), cache_policy as u32) };
327        ok(status)
328    }
329
330    /// Perform an operation on a range of a virtual memory object.
331    ///
332    /// Wraps the
333    /// [zx_vmo_op_range](https://fuchsia.dev/fuchsia-src/reference/syscalls/vmo_op_range.md)
334    /// syscall.
335    pub fn op_range(&self, op: VmoOp, offset: u64, size: u64) -> Result<(), Status> {
336        let status = unsafe {
337            sys::zx_vmo_op_range(self.raw_handle(), op.into_raw(), offset, size, ptr::null_mut(), 0)
338        };
339        ok(status)
340    }
341
342    /// Wraps the [zx_object_get_info](https://fuchsia.dev/fuchsia-src/reference/syscalls/object_get_info.md)
343    /// syscall for the ZX_INFO_VMO topic.
344    pub fn info(&self) -> Result<VmoInfo, Status> {
345        Ok(VmoInfo::from(self.0.get_info_single::<VmoInfoQuery>()?))
346    }
347
348    /// Create a new virtual memory object that clones a range of this one.
349    ///
350    /// Wraps the
351    /// [zx_vmo_create_child](https://fuchsia.dev/fuchsia-src/reference/syscalls/vmo_create_child.md)
352    /// syscall.
353    pub fn create_child(
354        &self,
355        opts: VmoChildOptions,
356        offset: u64,
357        size: u64,
358    ) -> Result<Vmo, Status> {
359        let mut out = 0;
360        let status = unsafe {
361            sys::zx_vmo_create_child(self.raw_handle(), opts.bits(), offset, size, &mut out)
362        };
363        ok(status)?;
364        unsafe { Ok(Vmo::from(NullableHandle::from_raw(out))) }
365    }
366
367    /// Replace a VMO, adding execute rights.
368    ///
369    /// Wraps the
370    /// [zx_vmo_replace_as_executable](https://fuchsia.dev/fuchsia-src/reference/syscalls/vmo_replace_as_executable.md)
371    /// syscall.
372    pub fn replace_as_executable(self, vmex: &Resource) -> Result<Vmo, Status> {
373        let mut out = 0;
374        let status = unsafe {
375            sys::zx_vmo_replace_as_executable(self.raw_handle(), vmex.raw_handle(), &mut out)
376        };
377        // zx_vmo_replace_as_executable always invalidates the passed in handle
378        // so we need to forget 'self' without executing its drop which will attempt
379        // to close the now-invalid handle value.
380        std::mem::forget(self);
381        ok(status)?;
382        unsafe { Ok(Vmo::from(NullableHandle::from_raw(out))) }
383    }
384}
385
386bitflags! {
387    /// Options that may be used when creating a `Vmo`.
388    #[repr(transparent)]
389    #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
390    pub struct VmoOptions: u32 {
391        const RESIZABLE = sys::ZX_VMO_RESIZABLE;
392        const TRAP_DIRTY = sys::ZX_VMO_TRAP_DIRTY;
393        const UNBOUNDED = sys::ZX_VMO_UNBOUNDED;
394    }
395}
396
397/// Flags that may be set when receiving info on a `Vmo`.
398#[repr(transparent)]
399#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, FromBytes, Immutable)]
400pub struct VmoInfoFlags(u32);
401
402bitflags! {
403    impl VmoInfoFlags : u32 {
404        const PAGED = sys::ZX_INFO_VMO_TYPE_PAGED;
405        const RESIZABLE = sys::ZX_INFO_VMO_RESIZABLE;
406        const IS_COW_CLONE = sys::ZX_INFO_VMO_IS_COW_CLONE;
407        const VIA_HANDLE = sys::ZX_INFO_VMO_VIA_HANDLE;
408        const VIA_MAPPING = sys::ZX_INFO_VMO_VIA_MAPPING;
409        const PAGER_BACKED = sys::ZX_INFO_VMO_PAGER_BACKED;
410        const CONTIGUOUS = sys::ZX_INFO_VMO_CONTIGUOUS;
411        const DISCARDABLE = sys::ZX_INFO_VMO_DISCARDABLE;
412        const IMMUTABLE = sys::ZX_INFO_VMO_IMMUTABLE;
413        const VIA_IOB_HANDLE = sys::ZX_INFO_VMO_VIA_IOB_HANDLE;
414    }
415}
416
417impl std::fmt::Debug for VmoInfoFlags {
418    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
419        bitflags::parser::to_writer(self, f)
420    }
421}
422
423bitflags! {
424    /// Options that may be used when creating a `Vmo` child.
425    #[repr(transparent)]
426    #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
427    pub struct VmoChildOptions: u32 {
428        const SNAPSHOT = sys::ZX_VMO_CHILD_SNAPSHOT;
429        const SNAPSHOT_AT_LEAST_ON_WRITE = sys::ZX_VMO_CHILD_SNAPSHOT_AT_LEAST_ON_WRITE;
430        const RESIZABLE = sys::ZX_VMO_CHILD_RESIZABLE;
431        const SLICE = sys::ZX_VMO_CHILD_SLICE;
432        const NO_WRITE = sys::ZX_VMO_CHILD_NO_WRITE;
433        const REFERENCE = sys::ZX_VMO_CHILD_REFERENCE;
434        const SNAPSHOT_MODIFIED = sys::ZX_VMO_CHILD_SNAPSHOT_MODIFIED;
435    }
436}
437
438bitflags! {
439    /// Options that may be used when transferring data between VMOs.
440    #[repr(transparent)]
441    #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
442    pub struct TransferDataOptions: u32 {
443    }
444}
445
446/// VM Object opcodes
447#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
448#[repr(transparent)]
449pub struct VmoOp(u32);
450impl VmoOp {
451    pub fn from_raw(raw: u32) -> VmoOp {
452        VmoOp(raw)
453    }
454    pub fn into_raw(self) -> u32 {
455        self.0
456    }
457}
458
459// VM Object Cache Policies.
460#[derive(Debug, Copy, Clone, Eq, PartialEq)]
461#[repr(u32)]
462pub enum CachePolicy {
463    Cached = sys::ZX_CACHE_POLICY_CACHED,
464    UnCached = sys::ZX_CACHE_POLICY_UNCACHED,
465    UnCachedDevice = sys::ZX_CACHE_POLICY_UNCACHED_DEVICE,
466    WriteCombining = sys::ZX_CACHE_POLICY_WRITE_COMBINING,
467    Unknown = u32::MAX,
468}
469
470impl From<u32> for CachePolicy {
471    fn from(v: u32) -> Self {
472        match v {
473            sys::ZX_CACHE_POLICY_CACHED => CachePolicy::Cached,
474            sys::ZX_CACHE_POLICY_UNCACHED => CachePolicy::UnCached,
475            sys::ZX_CACHE_POLICY_UNCACHED_DEVICE => CachePolicy::UnCachedDevice,
476            sys::ZX_CACHE_POLICY_WRITE_COMBINING => CachePolicy::WriteCombining,
477            _ => CachePolicy::Unknown,
478        }
479    }
480}
481
482impl Into<u32> for CachePolicy {
483    fn into(self) -> u32 {
484        match self {
485            CachePolicy::Cached => sys::ZX_CACHE_POLICY_CACHED,
486            CachePolicy::UnCached => sys::ZX_CACHE_POLICY_UNCACHED,
487            CachePolicy::UnCachedDevice => sys::ZX_CACHE_POLICY_UNCACHED_DEVICE,
488            CachePolicy::WriteCombining => sys::ZX_CACHE_POLICY_WRITE_COMBINING,
489            CachePolicy::Unknown => u32::MAX,
490        }
491    }
492}
493
494assoc_values!(VmoOp, [
495    COMMIT =           sys::ZX_VMO_OP_COMMIT;
496    DECOMMIT =         sys::ZX_VMO_OP_DECOMMIT;
497    LOCK =             sys::ZX_VMO_OP_LOCK;
498    UNLOCK =           sys::ZX_VMO_OP_UNLOCK;
499    CACHE_SYNC =       sys::ZX_VMO_OP_CACHE_SYNC;
500    CACHE_INVALIDATE = sys::ZX_VMO_OP_CACHE_INVALIDATE;
501    CACHE_CLEAN =      sys::ZX_VMO_OP_CACHE_CLEAN;
502    CACHE_CLEAN_INVALIDATE = sys::ZX_VMO_OP_CACHE_CLEAN_INVALIDATE;
503    ZERO =             sys::ZX_VMO_OP_ZERO;
504    TRY_LOCK =         sys::ZX_VMO_OP_TRY_LOCK;
505    DONT_NEED =        sys::ZX_VMO_OP_DONT_NEED;
506    ALWAYS_NEED =      sys::ZX_VMO_OP_ALWAYS_NEED;
507    PREFETCH =         sys::ZX_VMO_OP_PREFETCH;
508]);
509
510unsafe_handle_properties!(object: Vmo,
511    props: [
512        {query_ty: VMO_CONTENT_SIZE, tag: VmoContentSizeTag, prop_ty: u64, get:get_content_size, set: set_content_size},
513    ]
514);
515
516#[cfg(test)]
517mod tests {
518    use super::*;
519    use crate::{Iommu, IommuDescStub, ObjectType};
520    use fidl_fuchsia_kernel as fkernel;
521    use fuchsia_component::client::connect_channel_to_protocol;
522    use test_case::test_case;
523    use zerocopy::KnownLayout;
524
525    #[test]
526    fn vmo_create_contiguous() {
527        use zx::{Channel, MonotonicInstant};
528        let (client_end, server_end) = Channel::create();
529        connect_channel_to_protocol::<fkernel::IommuResourceMarker>(server_end).unwrap();
530        let service = fkernel::IommuResourceSynchronousProxy::new(client_end);
531        let resource =
532            service.get(MonotonicInstant::INFINITE).expect("couldn't get iommu resource");
533        // This test and fuchsia-zircon are different crates, so we need
534        // to use from_raw to convert between the zx handle and this test handle.
535        // See https://fxbug.dev/42173139 for details.
536        let resource = unsafe { Resource::from(NullableHandle::from_raw(resource.into_raw())) };
537        let iommu = Iommu::create_stub(&resource, IommuDescStub::default()).unwrap();
538        let bti = Bti::create(&iommu, 0).unwrap();
539
540        let vmo = Vmo::create_contiguous(&bti, 8192, 0).unwrap();
541        let info = vmo.as_handle_ref().basic_info().unwrap();
542        assert_eq!(info.object_type, ObjectType::VMO);
543
544        let vmo_info = vmo.info().unwrap();
545        assert!(vmo_info.flags.contains(VmoInfoFlags::CONTIGUOUS));
546    }
547
548    #[test]
549    fn vmo_get_size() {
550        let size = 16 * 1024 * 1024;
551        let vmo = Vmo::create(size).unwrap();
552        assert_eq!(size, vmo.get_size().unwrap());
553    }
554
555    #[test]
556    fn vmo_set_size() {
557        // Use a multiple of page size to match VMOs page aligned size
558        let start_size = 4096;
559        let vmo = Vmo::create_with_opts(VmoOptions::RESIZABLE, start_size).unwrap();
560        assert_eq!(start_size, vmo.get_size().unwrap());
561
562        // Change the size and make sure the new size is reported
563        let new_size = 8192;
564        assert!(vmo.set_size(new_size).is_ok());
565        assert_eq!(new_size, vmo.get_size().unwrap());
566    }
567
568    #[test]
569    fn vmo_get_info_default() {
570        let size = 4096;
571        let vmo = Vmo::create(size).unwrap();
572        let info = vmo.info().unwrap();
573        assert!(!info.flags.contains(VmoInfoFlags::PAGER_BACKED));
574        assert!(info.flags.contains(VmoInfoFlags::PAGED));
575    }
576
577    #[test]
578    fn vmo_get_child_info() {
579        let size = 4096;
580        let vmo = Vmo::create(size).unwrap();
581        let info = vmo.info().unwrap();
582        assert!(!info.flags.contains(VmoInfoFlags::IS_COW_CLONE));
583
584        let child = vmo.create_child(VmoChildOptions::SNAPSHOT, 0, 512).unwrap();
585        let info = child.info().unwrap();
586        assert!(info.flags.contains(VmoInfoFlags::IS_COW_CLONE));
587
588        let child = vmo.create_child(VmoChildOptions::SNAPSHOT_AT_LEAST_ON_WRITE, 0, 512).unwrap();
589        let info = child.info().unwrap();
590        assert!(info.flags.contains(VmoInfoFlags::IS_COW_CLONE));
591
592        let child = vmo.create_child(VmoChildOptions::SLICE, 0, 512).unwrap();
593        let info = child.info().unwrap();
594        assert!(!info.flags.contains(VmoInfoFlags::IS_COW_CLONE));
595    }
596
597    #[test]
598    fn vmo_set_size_fails_on_non_resizable() {
599        let size = 4096;
600        let vmo = Vmo::create(size).unwrap();
601        assert_eq!(size, vmo.get_size().unwrap());
602
603        let new_size = 8192;
604        assert_eq!(Err(Status::UNAVAILABLE), vmo.set_size(new_size));
605        assert_eq!(size, vmo.get_size().unwrap());
606    }
607
608    #[test_case(0)]
609    #[test_case(1)]
610    fn vmo_read_to_array(read_offset: usize) {
611        const ACTUAL_SIZE: usize = 5;
612        const ACTUAL: [u8; ACTUAL_SIZE] = [1, 2, 3, 4, 5];
613        let vmo = Vmo::create(ACTUAL.len() as u64).unwrap();
614        vmo.write(&ACTUAL, 0).unwrap();
615        let read_len = ACTUAL_SIZE - read_offset;
616        assert_eq!(
617            &vmo.read_to_array::<u8, ACTUAL_SIZE>(read_offset as u64).unwrap()[..read_len],
618            &ACTUAL[read_offset..]
619        );
620    }
621
622    #[test_case(0)]
623    #[test_case(1)]
624    fn vmo_read_to_vec(read_offset: usize) {
625        const ACTUAL_SIZE: usize = 4;
626        const ACTUAL: [u8; ACTUAL_SIZE] = [6, 7, 8, 9];
627        let vmo = Vmo::create(ACTUAL.len() as u64).unwrap();
628        vmo.write(&ACTUAL, 0).unwrap();
629        let read_len = ACTUAL_SIZE - read_offset;
630        assert_eq!(
631            &vmo.read_to_vec::<u8>(read_offset as u64, read_len as u64).unwrap(),
632            &ACTUAL[read_offset..]
633        );
634    }
635
636    #[test_case(0)]
637    #[test_case(1)]
638    fn vmo_read_to_object(read_offset: usize) {
639        #[repr(C)]
640        #[derive(Copy, Clone, Debug, Eq, KnownLayout, FromBytes, PartialEq)]
641        struct Object {
642            a: u8,
643            b: u8,
644        }
645
646        const ACTUAL_SIZE: usize = std::mem::size_of::<Object>();
647        const ACTUAL: [u8; ACTUAL_SIZE + 1] = [10, 11, 12];
648        let vmo = Vmo::create(ACTUAL.len() as u64).unwrap();
649        vmo.write(&ACTUAL, 0).unwrap();
650        assert_eq!(
651            vmo.read_to_object::<Object>(read_offset as u64).unwrap(),
652            Object { a: ACTUAL[read_offset], b: ACTUAL[1 + read_offset] }
653        );
654    }
655
656    #[test]
657    fn vmo_read_write() {
658        let mut vec1 = vec![0; 16];
659        let vmo = Vmo::create(4096 as u64).unwrap();
660        assert!(vmo.write(b"abcdef", 0).is_ok());
661        assert!(vmo.read(&mut vec1, 0).is_ok());
662        assert_eq!(b"abcdef", &vec1[0..6]);
663        assert!(vmo.write(b"123", 2).is_ok());
664        assert!(vmo.read(&mut vec1, 0).is_ok());
665        assert_eq!(b"ab123f", &vec1[0..6]);
666
667        // Read one byte into the vmo.
668        assert!(vmo.read(&mut vec1, 1).is_ok());
669        assert_eq!(b"b123f", &vec1[0..5]);
670
671        assert_eq!(&vmo.read_to_vec::<u8>(0, 6).expect("read_to_vec failed"), b"ab123f");
672    }
673
674    #[test]
675    fn vmo_child_snapshot() {
676        let size = 4096 * 2;
677        let vmo = Vmo::create(size).unwrap();
678
679        vmo.write(&[1; 4096], 0).unwrap();
680        vmo.write(&[2; 4096], 4096).unwrap();
681
682        let child = vmo.create_child(VmoChildOptions::SNAPSHOT, 0, size).unwrap();
683
684        child.write(&[3; 4096], 0).unwrap();
685
686        vmo.write(&[4; 4096], 0).unwrap();
687        vmo.write(&[5; 4096], 4096).unwrap();
688
689        let mut page = [0; 4096];
690
691        // SNAPSHOT child observes no further changes to parent VMO.
692        child.read(&mut page[..], 0).unwrap();
693        assert_eq!(&page[..], &[3; 4096][..]);
694        child.read(&mut page[..], 4096).unwrap();
695        assert_eq!(&page[..], &[2; 4096][..]);
696    }
697
698    #[test]
699    fn vmo_child_snapshot_at_least_on_write() {
700        let size = 4096 * 2;
701        let vmo = Vmo::create(size).unwrap();
702
703        vmo.write(&[1; 4096], 0).unwrap();
704        vmo.write(&[2; 4096], 4096).unwrap();
705
706        let child = vmo.create_child(VmoChildOptions::SNAPSHOT_AT_LEAST_ON_WRITE, 0, size).unwrap();
707
708        child.write(&[3; 4096], 0).unwrap();
709
710        vmo.write(&[4; 4096], 0).unwrap();
711        vmo.write(&[5; 4096], 4096).unwrap();
712
713        let mut page = [0; 4096];
714
715        // SNAPSHOT_AT_LEAST_ON_WRITE child may observe changes to pages it has not yet written to,
716        // but such behavior is not guaranteed.
717        child.read(&mut page[..], 0).unwrap();
718        assert_eq!(&page[..], &[3; 4096][..]);
719        child.read(&mut page[..], 4096).unwrap();
720        assert!(
721            &page[..] == &[2; 4096][..] || &page[..] == &[5; 4096][..],
722            "expected page of 2 or 5, got {:?}",
723            &page[..]
724        );
725    }
726
727    #[test]
728    fn vmo_child_no_write() {
729        let size = 4096;
730        let vmo = Vmo::create(size).unwrap();
731        vmo.write(&[1; 4096], 0).unwrap();
732
733        let child =
734            vmo.create_child(VmoChildOptions::SLICE | VmoChildOptions::NO_WRITE, 0, size).unwrap();
735        assert_eq!(child.write(&[3; 4096], 0), Err(Status::ACCESS_DENIED));
736    }
737
738    #[test]
739    fn vmo_op_range_unsupported() {
740        let vmo = Vmo::create(12).unwrap();
741        assert_eq!(vmo.op_range(VmoOp::LOCK, 0, 1), Err(Status::NOT_SUPPORTED));
742        assert_eq!(vmo.op_range(VmoOp::UNLOCK, 0, 1), Err(Status::NOT_SUPPORTED));
743    }
744
745    #[test]
746    fn vmo_cache() {
747        let vmo = Vmo::create(12).unwrap();
748
749        // Cache operations should all succeed.
750        assert_eq!(vmo.op_range(VmoOp::CACHE_SYNC, 0, 12), Ok(()));
751        assert_eq!(vmo.op_range(VmoOp::CACHE_INVALIDATE, 0, 12), Ok(()));
752        assert_eq!(vmo.op_range(VmoOp::CACHE_CLEAN, 0, 12), Ok(()));
753        assert_eq!(vmo.op_range(VmoOp::CACHE_CLEAN_INVALIDATE, 0, 12), Ok(()));
754    }
755
756    #[test]
757    fn vmo_create_child() {
758        let original = Vmo::create(16).unwrap();
759        assert!(original.write(b"one", 0).is_ok());
760
761        // Clone the VMO, and make sure it contains what we expect.
762        let clone =
763            original.create_child(VmoChildOptions::SNAPSHOT_AT_LEAST_ON_WRITE, 0, 16).unwrap();
764        let mut read_buffer = vec![0; 16];
765        assert!(clone.read(&mut read_buffer, 0).is_ok());
766        assert_eq!(&read_buffer[0..3], b"one");
767
768        // Writing to the original will not affect the clone.
769        assert!(original.write(b"two", 0).is_ok());
770        assert!(original.read(&mut read_buffer, 0).is_ok());
771        assert_eq!(&read_buffer[0..3], b"two");
772        assert!(clone.read(&mut read_buffer, 0).is_ok());
773        assert_eq!(&read_buffer[0..3], b"one");
774
775        // However, writing to the clone will not affect the original.
776        assert!(clone.write(b"three", 0).is_ok());
777        assert!(original.read(&mut read_buffer, 0).is_ok());
778        assert_eq!(&read_buffer[0..3], b"two");
779        assert!(clone.read(&mut read_buffer, 0).is_ok());
780        assert_eq!(&read_buffer[0..5], b"three");
781    }
782
783    #[test]
784    fn vmo_replace_as_executeable() {
785        use zx::{Channel, MonotonicInstant};
786
787        let vmo = Vmo::create(16).unwrap();
788
789        let info = vmo.as_handle_ref().basic_info().unwrap();
790        assert!(!info.rights.contains(Rights::EXECUTE));
791
792        let (client_end, server_end) = Channel::create();
793        connect_channel_to_protocol::<fkernel::VmexResourceMarker>(server_end).unwrap();
794        let service = fkernel::VmexResourceSynchronousProxy::new(client_end);
795        let resource = service.get(MonotonicInstant::INFINITE).expect("couldn't get vmex resource");
796        let resource =
797            unsafe { crate::Resource::from(NullableHandle::from_raw(resource.into_raw())) };
798
799        let exec_vmo = vmo.replace_as_executable(&resource).unwrap();
800        let info = exec_vmo.as_handle_ref().basic_info().unwrap();
801        assert!(info.rights.contains(Rights::EXECUTE));
802    }
803
804    #[test]
805    fn vmo_content_size() {
806        let start_size = 1024;
807        let vmo = Vmo::create_with_opts(VmoOptions::RESIZABLE, start_size).unwrap();
808        assert_eq!(vmo.get_content_size().unwrap(), start_size);
809        vmo.set_content_size(&0).unwrap();
810        assert_eq!(vmo.get_content_size().unwrap(), 0);
811
812        // write should not change content size.
813        let content = b"abcdef";
814        assert!(vmo.write(content, 0).is_ok());
815        assert_eq!(vmo.get_content_size().unwrap(), 0);
816    }
817
818    #[test]
819    fn vmo_zero() {
820        let vmo = Vmo::create(16).unwrap();
821        let content = b"0123456789abcdef";
822        assert!(vmo.write(content, 0).is_ok());
823        let mut buf = vec![0u8; 16];
824        assert!(vmo.read(&mut buf[..], 0).is_ok());
825        assert_eq!(&buf[..], content);
826
827        assert!(vmo.op_range(VmoOp::ZERO, 0, 16).is_ok());
828        assert!(vmo.read(&mut buf[..], 0).is_ok());
829        assert_eq!(&buf[..], &[0u8; 16]);
830    }
831
832    #[test]
833    fn vmo_stream_size() {
834        let start_size = 1300;
835        let vmo = Vmo::create_with_opts(VmoOptions::UNBOUNDED, start_size).unwrap();
836        assert_eq!(vmo.get_stream_size().unwrap(), start_size);
837        vmo.set_stream_size(0).unwrap();
838        assert_eq!(vmo.get_stream_size().unwrap(), 0);
839
840        // write should not change content size.
841        let content = b"abcdef";
842        assert!(vmo.write(content, 0).is_ok());
843        assert_eq!(vmo.get_stream_size().unwrap(), 0);
844
845        // stream size can also grow.
846        let mut buf = vec![1; 6];
847        vmo.set_stream_size(6).unwrap();
848        assert!(vmo.read(&mut buf, 0).is_ok());
849        // growing will zero new bytes.
850        assert_eq!(buf, vec![0; 6]);
851    }
852}
zx/vmo.rs

zx/
vmo.rs
