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    AsHandleRef, Bti, HandleBased, HandleRef, Koid, Name, NullableHandle, ObjectQuery, Property,
9    PropertyQuery, Resource, Rights, Status, Topic, object_get_info_single, object_get_property,
10    object_set_property, ok, sys,
11};
12use bitflags::bitflags;
13use std::mem::MaybeUninit;
14use std::ptr;
15use zerocopy::{FromBytes, Immutable};
16use zx_sys::PadByte;
17
18/// An object representing a Zircon
19/// [virtual memory object](https://fuchsia.dev/fuchsia-src/concepts/objects/vm_object.md).
20///
21/// As essentially a subtype of `NullableHandle`, it can be freely interconverted.
22#[derive(Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
23#[repr(transparent)]
24pub struct Vmo(NullableHandle);
25impl_handle_based!(Vmo);
26
27static_assert_align!(
28    #[doc="Ergonomic equivalent of [sys::zx_info_vmo_t]. Must be ABI-compatible with it."]
29    #[repr(C)]
30    #[derive(Debug, Copy, Clone, Eq, PartialEq, FromBytes, Immutable)]
31    <sys::zx_info_vmo_t> pub struct VmoInfo {
32        pub koid <koid>: Koid,
33        pub name <name>: Name,
34        pub size_bytes <size_bytes>: u64,
35        pub parent_koid <parent_koid>: Koid,
36        pub num_children <num_children>: usize,
37        pub num_mappings <num_mappings>: usize,
38        pub share_count <share_count>: usize,
39        pub flags <flags>: VmoInfoFlags,
40        padding1: [PadByte; 4],
41        pub committed_bytes <committed_bytes>: u64,
42        pub handle_rights <handle_rights>: Rights,
43        cache_policy <cache_policy>: u32,
44        pub metadata_bytes <metadata_bytes>: u64,
45        pub committed_change_events <committed_change_events>: u64,
46        pub populated_bytes <populated_bytes>: u64,
47        pub committed_private_bytes <committed_private_bytes>: u64,
48        pub populated_private_bytes <populated_private_bytes>: u64,
49        pub committed_scaled_bytes <committed_scaled_bytes>: u64,
50        pub populated_scaled_bytes <populated_scaled_bytes>: u64,
51        pub committed_fractional_scaled_bytes <committed_fractional_scaled_bytes>: u64,
52        pub populated_fractional_scaled_bytes <populated_fractional_scaled_bytes>: u64,
53    }
54);
55
56impl VmoInfo {
57    pub fn cache_policy(&self) -> CachePolicy {
58        CachePolicy::from(self.cache_policy)
59    }
60}
61
62impl Default for VmoInfo {
63    fn default() -> VmoInfo {
64        Self::from(sys::zx_info_vmo_t::default())
65    }
66}
67
68impl From<sys::zx_info_vmo_t> for VmoInfo {
69    fn from(info: sys::zx_info_vmo_t) -> VmoInfo {
70        zerocopy::transmute!(info)
71    }
72}
73
74struct VmoInfoQuery;
75unsafe impl ObjectQuery for VmoInfoQuery {
76    const TOPIC: Topic = Topic::VMO;
77    type InfoTy = sys::zx_info_vmo_t;
78}
79
80impl Vmo {
81    /// Create a virtual memory object.
82    ///
83    /// Wraps the
84    /// `zx_vmo_create`
85    /// syscall. See the
86    /// [Shared Memory: Virtual Memory Objects (VMOs)](https://fuchsia.dev/fuchsia-src/concepts/kernel/concepts#shared_memory_virtual_memory_objects_vmos)
87    /// for more information.
88    pub fn create(size: u64) -> Result<Vmo, Status> {
89        Vmo::create_with_opts(VmoOptions::from_bits_truncate(0), size)
90    }
91
92    /// Create a virtual memory object with options.
93    ///
94    /// Wraps the
95    /// `zx_vmo_create`
96    /// syscall, allowing options to be passed.
97    pub fn create_with_opts(opts: VmoOptions, size: u64) -> Result<Vmo, Status> {
98        let mut handle = 0;
99        let status = unsafe { sys::zx_vmo_create(size, opts.bits(), &mut handle) };
100        ok(status)?;
101        unsafe { Ok(Vmo::from(NullableHandle::from_raw(handle))) }
102    }
103
104    /// Create a physically contiguous virtual memory object.
105    ///
106    /// Wraps the
107    /// [`zx_vmo_create_contiguous`](https://fuchsia.dev/fuchsia-src/reference/syscalls/vmo_create_contiguous) syscall.
108    pub fn create_contiguous(bti: &Bti, size: usize, alignment_log2: u32) -> Result<Vmo, Status> {
109        let mut vmo_handle = sys::zx_handle_t::default();
110        let status = unsafe {
111            // SAFETY: regular system call with no unsafe parameters.
112            sys::zx_vmo_create_contiguous(bti.raw_handle(), size, alignment_log2, &mut vmo_handle)
113        };
114        ok(status)?;
115        unsafe {
116            // SAFETY: The syscall docs claim that upon success, vmo_handle will be a valid
117            // handle to a virtual memory object.
118            Ok(Vmo::from(NullableHandle::from_raw(vmo_handle)))
119        }
120    }
121
122    /// Read from a virtual memory object.
123    ///
124    /// Wraps the `zx_vmo_read` syscall.
125    pub fn read(&self, data: &mut [u8], offset: u64) -> Result<(), Status> {
126        unsafe {
127            let status = sys::zx_vmo_read(self.raw_handle(), data.as_mut_ptr(), offset, data.len());
128            ok(status)
129        }
130    }
131
132    /// Provides a very thin wrapper over `zx_vmo_read`.
133    ///
134    /// # Safety
135    ///
136    /// Callers must guarantee that the buffer is valid to write to.
137    pub unsafe fn read_raw<T: FromBytes>(
138        &self,
139        buffer: *mut T,
140        buffer_length: usize,
141        offset: u64,
142    ) -> Result<(), Status> {
143        let status = unsafe {
144            sys::zx_vmo_read(
145                self.raw_handle(),
146                buffer.cast::<u8>(),
147                offset,
148                buffer_length * std::mem::size_of::<T>(),
149            )
150        };
151        ok(status)
152    }
153
154    /// Same as read, but reads into memory that might not be initialized, returning an initialized
155    /// slice of bytes on success.
156    ///
157    /// `Copy` is required to ensure that there are no custom `Drop` implementations. It is
158    /// difficult to correctly run custom drop code after initializing a `MaybeUninit`.
159    pub fn read_uninit<'a, T: Copy + FromBytes>(
160        &self,
161        data: &'a mut [MaybeUninit<T>],
162        offset: u64,
163    ) -> Result<&'a mut [T], Status> {
164        // SAFETY: This system call requires that the pointer and length we pass are valid to write
165        // to, which we guarantee here by getting the pointer and length from a valid slice.
166        unsafe {
167            self.read_raw(
168                // TODO(https://fxbug.dev/42079723) use MaybeUninit::slice_as_mut_ptr when stable
169                data.as_mut_ptr().cast::<T>(),
170                data.len(),
171                offset,
172            )?
173        }
174        // TODO(https://fxbug.dev/42079723) use MaybeUninit::slice_assume_init_mut when stable
175        Ok(
176            // SAFETY: We're converting &mut [MaybeUninit<u8>] back to &mut [u8], which is only
177            // valid to do if all elements of `data` have actually been initialized. Here we
178            // have to trust that the kernel didn't lie when it said it wrote to the entire
179            // buffer, but as long as that assumption is valid them it's safe to assume this
180            // slice is init.
181            unsafe { std::slice::from_raw_parts_mut(data.as_mut_ptr().cast::<T>(), data.len()) },
182        )
183    }
184
185    /// Same as read, but returns a Vec.
186    pub fn read_to_vec<T: Copy + FromBytes>(
187        &self,
188        offset: u64,
189        length: u64,
190    ) -> Result<Vec<T>, Status> {
191        let len = length.try_into().map_err(|_| Status::INVALID_ARGS)?;
192        let mut buffer = Vec::with_capacity(len);
193        self.read_uninit(buffer.spare_capacity_mut(), offset)?;
194        unsafe {
195            // SAFETY: since read_uninit succeeded we know that we can consider the buffer
196            // initialized.
197            buffer.set_len(len);
198        }
199        Ok(buffer)
200    }
201
202    /// Same as read, but returns an array.
203    pub fn read_to_array<T: Copy + FromBytes, const N: usize>(
204        &self,
205        offset: u64,
206    ) -> Result<[T; N], Status> {
207        // TODO(https://fxbug.dev/42079731): replace with MaybeUninit::uninit_array.
208        let array: MaybeUninit<[MaybeUninit<T>; N]> = MaybeUninit::uninit();
209        // SAFETY: We are converting from an uninitialized array to an array
210        // of uninitialized elements which is the same. See
211        // https://doc.rust-lang.org/std/mem/union.MaybeUninit.html#initializing-an-array-element-by-element.
212        let mut array = unsafe { array.assume_init() };
213
214        // SAFETY: T is FromBytes, which means that any bit pattern is valid. Interpreting
215        // [MaybeUninit<T>] as [MaybeUninit<u8>] is safe because T's alignment requirements
216        // are larger than u8.
217        //
218        // TODO(https://fxbug.dev/42079727): Use MaybeUninit::slice_as_bytes_mut once stable.
219        let buffer = unsafe {
220            std::slice::from_raw_parts_mut(
221                array.as_mut_ptr().cast::<MaybeUninit<u8>>(),
222                N * std::mem::size_of::<T>(),
223            )
224        };
225
226        self.read_uninit(buffer, offset)?;
227        // SAFETY: This is safe because we have initialized all the elements in
228        // the array (since `read_uninit` returned successfully).
229        //
230        // TODO(https://fxbug.dev/42079725): replace with MaybeUninit::array_assume_init.
231        let buffer = array.map(|a| unsafe { a.assume_init() });
232        Ok(buffer)
233    }
234
235    /// Same as read, but returns a `T`.
236    pub fn read_to_object<T: Copy + FromBytes>(&self, offset: u64) -> Result<T, Status> {
237        let mut object = MaybeUninit::<T>::uninit();
238        // SAFETY: T is FromBytes, which means that any bit pattern is valid. Interpreting
239        // MaybeUninit<T> as [MaybeUninit<u8>] is safe because T's alignment requirements
240        // are larger than, or equal to, u8's.
241        //
242        // TODO(https://fxbug.dev/42079727): Use MaybeUninit::as_bytes_mut once stable.
243        let buffer = unsafe {
244            std::slice::from_raw_parts_mut(
245                object.as_mut_ptr().cast::<MaybeUninit<u8>>(),
246                std::mem::size_of::<T>(),
247            )
248        };
249        self.read_uninit(buffer, offset)?;
250
251        // SAFETY: The call to `read_uninit` succeeded so we know that `object`
252        // has been initialized.
253        let object = unsafe { object.assume_init() };
254        Ok(object)
255    }
256
257    /// Write to a virtual memory object.
258    ///
259    /// Wraps the `zx_vmo_write` syscall.
260    pub fn write(&self, data: &[u8], offset: u64) -> Result<(), Status> {
261        unsafe {
262            let status = sys::zx_vmo_write(self.raw_handle(), data.as_ptr(), offset, data.len());
263            ok(status)
264        }
265    }
266
267    /// Efficiently transfers data from one VMO to another.
268    pub fn transfer_data(
269        &self,
270        options: TransferDataOptions,
271        offset: u64,
272        length: u64,
273        src_vmo: &Vmo,
274        src_offset: u64,
275    ) -> Result<(), Status> {
276        let status = unsafe {
277            sys::zx_vmo_transfer_data(
278                self.raw_handle(),
279                options.bits(),
280                offset,
281                length,
282                src_vmo.raw_handle(),
283                src_offset,
284            )
285        };
286        ok(status)
287    }
288
289    /// Get the size of a virtual memory object.
290    ///
291    /// Wraps the `zx_vmo_get_size` syscall.
292    pub fn get_size(&self) -> Result<u64, Status> {
293        let mut size = 0;
294        let status = unsafe { sys::zx_vmo_get_size(self.raw_handle(), &mut size) };
295        ok(status).map(|()| size)
296    }
297
298    /// Attempt to change the size of a virtual memory object.
299    ///
300    /// Wraps the `zx_vmo_set_size` syscall.
301    pub fn set_size(&self, size: u64) -> Result<(), Status> {
302        let status = unsafe { sys::zx_vmo_set_size(self.raw_handle(), size) };
303        ok(status)
304    }
305
306    /// Get the stream size of a virtual memory object.
307    ///
308    /// Wraps the `zx_vmo_get_stream_size` syscall.
309    pub fn get_stream_size(&self) -> Result<u64, Status> {
310        let mut size = 0;
311        let status = unsafe { sys::zx_vmo_get_stream_size(self.raw_handle(), &mut size) };
312        ok(status).map(|()| size)
313    }
314
315    /// Attempt to set the stream size of a virtual memory object.
316    ///
317    /// Wraps the `zx_vmo_set_stream_size` syscall.
318    pub fn set_stream_size(&self, size: u64) -> Result<(), Status> {
319        let status = unsafe { sys::zx_vmo_set_stream_size(self.raw_handle(), size) };
320        ok(status)
321    }
322
323    /// Attempt to change the cache policy of a virtual memory object.
324    ///
325    /// Wraps the `zx_vmo_set_cache_policy` syscall.
326    pub fn set_cache_policy(&self, cache_policy: CachePolicy) -> Result<(), Status> {
327        let status =
328            unsafe { sys::zx_vmo_set_cache_policy(self.raw_handle(), cache_policy as u32) };
329        ok(status)
330    }
331
332    /// Perform an operation on a range of a virtual memory object.
333    ///
334    /// Wraps the
335    /// [zx_vmo_op_range](https://fuchsia.dev/fuchsia-src/reference/syscalls/vmo_op_range.md)
336    /// syscall.
337    pub fn op_range(&self, op: VmoOp, offset: u64, size: u64) -> Result<(), Status> {
338        let status = unsafe {
339            sys::zx_vmo_op_range(self.raw_handle(), op.into_raw(), offset, size, ptr::null_mut(), 0)
340        };
341        ok(status)
342    }
343
344    /// Wraps the [zx_object_get_info](https://fuchsia.dev/fuchsia-src/reference/syscalls/object_get_info.md)
345    /// syscall for the ZX_INFO_VMO topic.
346    pub fn info(&self) -> Result<VmoInfo, Status> {
347        Ok(VmoInfo::from(object_get_info_single::<VmoInfoQuery>(self.as_handle_ref())?))
348    }
349
350    /// Create a new virtual memory object that clones a range of this one.
351    ///
352    /// Wraps the
353    /// [zx_vmo_create_child](https://fuchsia.dev/fuchsia-src/reference/syscalls/vmo_create_child.md)
354    /// syscall.
355    pub fn create_child(
356        &self,
357        opts: VmoChildOptions,
358        offset: u64,
359        size: u64,
360    ) -> Result<Vmo, Status> {
361        let mut out = 0;
362        let status = unsafe {
363            sys::zx_vmo_create_child(self.raw_handle(), opts.bits(), offset, size, &mut out)
364        };
365        ok(status)?;
366        unsafe { Ok(Vmo::from(NullableHandle::from_raw(out))) }
367    }
368
369    /// Replace a VMO, adding execute rights.
370    ///
371    /// Wraps the
372    /// [zx_vmo_replace_as_executable](https://fuchsia.dev/fuchsia-src/reference/syscalls/vmo_replace_as_executable.md)
373    /// syscall.
374    pub fn replace_as_executable(self, vmex: &Resource) -> Result<Vmo, Status> {
375        let mut out = 0;
376        let status = unsafe {
377            sys::zx_vmo_replace_as_executable(self.raw_handle(), vmex.raw_handle(), &mut out)
378        };
379        // zx_vmo_replace_as_executable always invalidates the passed in handle
380        // so we need to forget 'self' without executing its drop which will attempt
381        // to close the now-invalid handle value.
382        std::mem::forget(self);
383        ok(status)?;
384        unsafe { Ok(Vmo::from(NullableHandle::from_raw(out))) }
385    }
386}
387
388bitflags! {
389    /// Options that may be used when creating a `Vmo`.
390    #[repr(transparent)]
391    #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
392    pub struct VmoOptions: u32 {
393        const RESIZABLE = sys::ZX_VMO_RESIZABLE;
394        const TRAP_DIRTY = sys::ZX_VMO_TRAP_DIRTY;
395        const UNBOUNDED = sys::ZX_VMO_UNBOUNDED;
396    }
397}
398
399/// Flags that may be set when receiving info on a `Vmo`.
400#[repr(transparent)]
401#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, FromBytes, Immutable)]
402pub struct VmoInfoFlags(u32);
403
404bitflags! {
405    impl VmoInfoFlags : u32 {
406        const PAGED = sys::ZX_INFO_VMO_TYPE_PAGED;
407        const RESIZABLE = sys::ZX_INFO_VMO_RESIZABLE;
408        const IS_COW_CLONE = sys::ZX_INFO_VMO_IS_COW_CLONE;
409        const VIA_HANDLE = sys::ZX_INFO_VMO_VIA_HANDLE;
410        const VIA_MAPPING = sys::ZX_INFO_VMO_VIA_MAPPING;
411        const PAGER_BACKED = sys::ZX_INFO_VMO_PAGER_BACKED;
412        const CONTIGUOUS = sys::ZX_INFO_VMO_CONTIGUOUS;
413        const DISCARDABLE = sys::ZX_INFO_VMO_DISCARDABLE;
414        const IMMUTABLE = sys::ZX_INFO_VMO_IMMUTABLE;
415        const VIA_IOB_HANDLE = sys::ZX_INFO_VMO_VIA_IOB_HANDLE;
416    }
417}
418
419impl std::fmt::Debug for VmoInfoFlags {
420    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
421        bitflags::parser::to_writer(self, f)
422    }
423}
424
425bitflags! {
426    /// Options that may be used when creating a `Vmo` child.
427    #[repr(transparent)]
428    #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
429    pub struct VmoChildOptions: u32 {
430        const SNAPSHOT = sys::ZX_VMO_CHILD_SNAPSHOT;
431        const SNAPSHOT_AT_LEAST_ON_WRITE = sys::ZX_VMO_CHILD_SNAPSHOT_AT_LEAST_ON_WRITE;
432        const RESIZABLE = sys::ZX_VMO_CHILD_RESIZABLE;
433        const SLICE = sys::ZX_VMO_CHILD_SLICE;
434        const NO_WRITE = sys::ZX_VMO_CHILD_NO_WRITE;
435        const REFERENCE = sys::ZX_VMO_CHILD_REFERENCE;
436        const SNAPSHOT_MODIFIED = sys::ZX_VMO_CHILD_SNAPSHOT_MODIFIED;
437    }
438}
439
440bitflags! {
441    /// Options that may be used when transferring data between VMOs.
442    #[repr(transparent)]
443    #[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
444    pub struct TransferDataOptions: u32 {
445    }
446}
447
448/// VM Object opcodes
449#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
450#[repr(transparent)]
451pub struct VmoOp(u32);
452impl VmoOp {
453    pub fn from_raw(raw: u32) -> VmoOp {
454        VmoOp(raw)
455    }
456    pub fn into_raw(self) -> u32 {
457        self.0
458    }
459}
460
461// VM Object Cache Policies.
462#[derive(Debug, Copy, Clone, Eq, PartialEq)]
463#[repr(u32)]
464pub enum CachePolicy {
465    Cached = sys::ZX_CACHE_POLICY_CACHED,
466    UnCached = sys::ZX_CACHE_POLICY_UNCACHED,
467    UnCachedDevice = sys::ZX_CACHE_POLICY_UNCACHED_DEVICE,
468    WriteCombining = sys::ZX_CACHE_POLICY_WRITE_COMBINING,
469    Unknown = u32::MAX,
470}
471
472impl From<u32> for CachePolicy {
473    fn from(v: u32) -> Self {
474        match v {
475            sys::ZX_CACHE_POLICY_CACHED => CachePolicy::Cached,
476            sys::ZX_CACHE_POLICY_UNCACHED => CachePolicy::UnCached,
477            sys::ZX_CACHE_POLICY_UNCACHED_DEVICE => CachePolicy::UnCachedDevice,
478            sys::ZX_CACHE_POLICY_WRITE_COMBINING => CachePolicy::WriteCombining,
479            _ => CachePolicy::Unknown,
480        }
481    }
482}
483
484impl Into<u32> for CachePolicy {
485    fn into(self) -> u32 {
486        match self {
487            CachePolicy::Cached => sys::ZX_CACHE_POLICY_CACHED,
488            CachePolicy::UnCached => sys::ZX_CACHE_POLICY_UNCACHED,
489            CachePolicy::UnCachedDevice => sys::ZX_CACHE_POLICY_UNCACHED_DEVICE,
490            CachePolicy::WriteCombining => sys::ZX_CACHE_POLICY_WRITE_COMBINING,
491            CachePolicy::Unknown => u32::MAX,
492        }
493    }
494}
495
496assoc_values!(VmoOp, [
497    COMMIT =           sys::ZX_VMO_OP_COMMIT;
498    DECOMMIT =         sys::ZX_VMO_OP_DECOMMIT;
499    LOCK =             sys::ZX_VMO_OP_LOCK;
500    UNLOCK =           sys::ZX_VMO_OP_UNLOCK;
501    CACHE_SYNC =       sys::ZX_VMO_OP_CACHE_SYNC;
502    CACHE_INVALIDATE = sys::ZX_VMO_OP_CACHE_INVALIDATE;
503    CACHE_CLEAN =      sys::ZX_VMO_OP_CACHE_CLEAN;
504    CACHE_CLEAN_INVALIDATE = sys::ZX_VMO_OP_CACHE_CLEAN_INVALIDATE;
505    ZERO =             sys::ZX_VMO_OP_ZERO;
506    TRY_LOCK =         sys::ZX_VMO_OP_TRY_LOCK;
507    DONT_NEED =        sys::ZX_VMO_OP_DONT_NEED;
508    ALWAYS_NEED =      sys::ZX_VMO_OP_ALWAYS_NEED;
509    PREFETCH =         sys::ZX_VMO_OP_PREFETCH;
510]);
511
512unsafe_handle_properties!(object: Vmo,
513    props: [
514        {query_ty: VMO_CONTENT_SIZE, tag: VmoContentSizeTag, prop_ty: u64, get:get_content_size, set: set_content_size},
515    ]
516);
517
518#[cfg(test)]
519mod tests {
520    use super::*;
521    use crate::{Iommu, IommuDescStub, ObjectType};
522    use fidl_fuchsia_kernel as fkernel;
523    use fuchsia_component::client::connect_channel_to_protocol;
524    use test_case::test_case;
525    use zerocopy::KnownLayout;
526
527    #[test]
528    fn vmo_create_contiguous() {
529        use zx::{Channel, HandleBased, MonotonicInstant};
530        let (client_end, server_end) = Channel::create();
531        connect_channel_to_protocol::<fkernel::IommuResourceMarker>(server_end).unwrap();
532        let service = fkernel::IommuResourceSynchronousProxy::new(client_end);
533        let resource =
534            service.get(MonotonicInstant::INFINITE).expect("couldn't get iommu resource");
535        // This test and fuchsia-zircon are different crates, so we need
536        // to use from_raw to convert between the zx handle and this test handle.
537        // See https://fxbug.dev/42173139 for details.
538        let resource = unsafe { Resource::from(NullableHandle::from_raw(resource.into_raw())) };
539        let iommu = Iommu::create_stub(&resource, IommuDescStub::default()).unwrap();
540        let bti = Bti::create(&iommu, 0).unwrap();
541
542        let vmo = Vmo::create_contiguous(&bti, 8192, 0).unwrap();
543        let info = vmo.as_handle_ref().basic_info().unwrap();
544        assert_eq!(info.object_type, ObjectType::VMO);
545
546        let vmo_info = vmo.info().unwrap();
547        assert!(vmo_info.flags.contains(VmoInfoFlags::CONTIGUOUS));
548    }
549
550    #[test]
551    fn vmo_get_size() {
552        let size = 16 * 1024 * 1024;
553        let vmo = Vmo::create(size).unwrap();
554        assert_eq!(size, vmo.get_size().unwrap());
555    }
556
557    #[test]
558    fn vmo_set_size() {
559        // Use a multiple of page size to match VMOs page aligned size
560        let start_size = 4096;
561        let vmo = Vmo::create_with_opts(VmoOptions::RESIZABLE, start_size).unwrap();
562        assert_eq!(start_size, vmo.get_size().unwrap());
563
564        // Change the size and make sure the new size is reported
565        let new_size = 8192;
566        assert!(vmo.set_size(new_size).is_ok());
567        assert_eq!(new_size, vmo.get_size().unwrap());
568    }
569
570    #[test]
571    fn vmo_get_info_default() {
572        let size = 4096;
573        let vmo = Vmo::create(size).unwrap();
574        let info = vmo.info().unwrap();
575        assert!(!info.flags.contains(VmoInfoFlags::PAGER_BACKED));
576        assert!(info.flags.contains(VmoInfoFlags::PAGED));
577    }
578
579    #[test]
580    fn vmo_get_child_info() {
581        let size = 4096;
582        let vmo = Vmo::create(size).unwrap();
583        let info = vmo.info().unwrap();
584        assert!(!info.flags.contains(VmoInfoFlags::IS_COW_CLONE));
585
586        let child = vmo.create_child(VmoChildOptions::SNAPSHOT, 0, 512).unwrap();
587        let info = child.info().unwrap();
588        assert!(info.flags.contains(VmoInfoFlags::IS_COW_CLONE));
589
590        let child = vmo.create_child(VmoChildOptions::SNAPSHOT_AT_LEAST_ON_WRITE, 0, 512).unwrap();
591        let info = child.info().unwrap();
592        assert!(info.flags.contains(VmoInfoFlags::IS_COW_CLONE));
593
594        let child = vmo.create_child(VmoChildOptions::SLICE, 0, 512).unwrap();
595        let info = child.info().unwrap();
596        assert!(!info.flags.contains(VmoInfoFlags::IS_COW_CLONE));
597    }
598
599    #[test]
600    fn vmo_set_size_fails_on_non_resizable() {
601        let size = 4096;
602        let vmo = Vmo::create(size).unwrap();
603        assert_eq!(size, vmo.get_size().unwrap());
604
605        let new_size = 8192;
606        assert_eq!(Err(Status::UNAVAILABLE), vmo.set_size(new_size));
607        assert_eq!(size, vmo.get_size().unwrap());
608    }
609
610    #[test_case(0)]
611    #[test_case(1)]
612    fn vmo_read_to_array(read_offset: usize) {
613        const ACTUAL_SIZE: usize = 5;
614        const ACTUAL: [u8; ACTUAL_SIZE] = [1, 2, 3, 4, 5];
615        let vmo = Vmo::create(ACTUAL.len() as u64).unwrap();
616        vmo.write(&ACTUAL, 0).unwrap();
617        let read_len = ACTUAL_SIZE - read_offset;
618        assert_eq!(
619            &vmo.read_to_array::<u8, ACTUAL_SIZE>(read_offset as u64).unwrap()[..read_len],
620            &ACTUAL[read_offset..]
621        );
622    }
623
624    #[test_case(0)]
625    #[test_case(1)]
626    fn vmo_read_to_vec(read_offset: usize) {
627        const ACTUAL_SIZE: usize = 4;
628        const ACTUAL: [u8; ACTUAL_SIZE] = [6, 7, 8, 9];
629        let vmo = Vmo::create(ACTUAL.len() as u64).unwrap();
630        vmo.write(&ACTUAL, 0).unwrap();
631        let read_len = ACTUAL_SIZE - read_offset;
632        assert_eq!(
633            &vmo.read_to_vec::<u8>(read_offset as u64, read_len as u64).unwrap(),
634            &ACTUAL[read_offset..]
635        );
636    }
637
638    #[test_case(0)]
639    #[test_case(1)]
640    fn vmo_read_to_object(read_offset: usize) {
641        #[repr(C)]
642        #[derive(Copy, Clone, Debug, Eq, KnownLayout, FromBytes, PartialEq)]
643        struct Object {
644            a: u8,
645            b: u8,
646        }
647
648        const ACTUAL_SIZE: usize = std::mem::size_of::<Object>();
649        const ACTUAL: [u8; ACTUAL_SIZE + 1] = [10, 11, 12];
650        let vmo = Vmo::create(ACTUAL.len() as u64).unwrap();
651        vmo.write(&ACTUAL, 0).unwrap();
652        assert_eq!(
653            vmo.read_to_object::<Object>(read_offset as u64).unwrap(),
654            Object { a: ACTUAL[read_offset], b: ACTUAL[1 + read_offset] }
655        );
656    }
657
658    #[test]
659    fn vmo_read_write() {
660        let mut vec1 = vec![0; 16];
661        let vmo = Vmo::create(4096 as u64).unwrap();
662        assert!(vmo.write(b"abcdef", 0).is_ok());
663        assert!(vmo.read(&mut vec1, 0).is_ok());
664        assert_eq!(b"abcdef", &vec1[0..6]);
665        assert!(vmo.write(b"123", 2).is_ok());
666        assert!(vmo.read(&mut vec1, 0).is_ok());
667        assert_eq!(b"ab123f", &vec1[0..6]);
668
669        // Read one byte into the vmo.
670        assert!(vmo.read(&mut vec1, 1).is_ok());
671        assert_eq!(b"b123f", &vec1[0..5]);
672
673        assert_eq!(&vmo.read_to_vec::<u8>(0, 6).expect("read_to_vec failed"), b"ab123f");
674    }
675
676    #[test]
677    fn vmo_child_snapshot() {
678        let size = 4096 * 2;
679        let vmo = Vmo::create(size).unwrap();
680
681        vmo.write(&[1; 4096], 0).unwrap();
682        vmo.write(&[2; 4096], 4096).unwrap();
683
684        let child = vmo.create_child(VmoChildOptions::SNAPSHOT, 0, size).unwrap();
685
686        child.write(&[3; 4096], 0).unwrap();
687
688        vmo.write(&[4; 4096], 0).unwrap();
689        vmo.write(&[5; 4096], 4096).unwrap();
690
691        let mut page = [0; 4096];
692
693        // SNAPSHOT child observes no further changes to parent VMO.
694        child.read(&mut page[..], 0).unwrap();
695        assert_eq!(&page[..], &[3; 4096][..]);
696        child.read(&mut page[..], 4096).unwrap();
697        assert_eq!(&page[..], &[2; 4096][..]);
698    }
699
700    #[test]
701    fn vmo_child_snapshot_at_least_on_write() {
702        let size = 4096 * 2;
703        let vmo = Vmo::create(size).unwrap();
704
705        vmo.write(&[1; 4096], 0).unwrap();
706        vmo.write(&[2; 4096], 4096).unwrap();
707
708        let child = vmo.create_child(VmoChildOptions::SNAPSHOT_AT_LEAST_ON_WRITE, 0, size).unwrap();
709
710        child.write(&[3; 4096], 0).unwrap();
711
712        vmo.write(&[4; 4096], 0).unwrap();
713        vmo.write(&[5; 4096], 4096).unwrap();
714
715        let mut page = [0; 4096];
716
717        // SNAPSHOT_AT_LEAST_ON_WRITE child may observe changes to pages it has not yet written to,
718        // but such behavior is not guaranteed.
719        child.read(&mut page[..], 0).unwrap();
720        assert_eq!(&page[..], &[3; 4096][..]);
721        child.read(&mut page[..], 4096).unwrap();
722        assert!(
723            &page[..] == &[2; 4096][..] || &page[..] == &[5; 4096][..],
724            "expected page of 2 or 5, got {:?}",
725            &page[..]
726        );
727    }
728
729    #[test]
730    fn vmo_child_no_write() {
731        let size = 4096;
732        let vmo = Vmo::create(size).unwrap();
733        vmo.write(&[1; 4096], 0).unwrap();
734
735        let child =
736            vmo.create_child(VmoChildOptions::SLICE | VmoChildOptions::NO_WRITE, 0, size).unwrap();
737        assert_eq!(child.write(&[3; 4096], 0), Err(Status::ACCESS_DENIED));
738    }
739
740    #[test]
741    fn vmo_op_range_unsupported() {
742        let vmo = Vmo::create(12).unwrap();
743        assert_eq!(vmo.op_range(VmoOp::LOCK, 0, 1), Err(Status::NOT_SUPPORTED));
744        assert_eq!(vmo.op_range(VmoOp::UNLOCK, 0, 1), Err(Status::NOT_SUPPORTED));
745    }
746
747    #[test]
748    fn vmo_cache() {
749        let vmo = Vmo::create(12).unwrap();
750
751        // Cache operations should all succeed.
752        assert_eq!(vmo.op_range(VmoOp::CACHE_SYNC, 0, 12), Ok(()));
753        assert_eq!(vmo.op_range(VmoOp::CACHE_INVALIDATE, 0, 12), Ok(()));
754        assert_eq!(vmo.op_range(VmoOp::CACHE_CLEAN, 0, 12), Ok(()));
755        assert_eq!(vmo.op_range(VmoOp::CACHE_CLEAN_INVALIDATE, 0, 12), Ok(()));
756    }
757
758    #[test]
759    fn vmo_create_child() {
760        let original = Vmo::create(16).unwrap();
761        assert!(original.write(b"one", 0).is_ok());
762
763        // Clone the VMO, and make sure it contains what we expect.
764        let clone =
765            original.create_child(VmoChildOptions::SNAPSHOT_AT_LEAST_ON_WRITE, 0, 16).unwrap();
766        let mut read_buffer = vec![0; 16];
767        assert!(clone.read(&mut read_buffer, 0).is_ok());
768        assert_eq!(&read_buffer[0..3], b"one");
769
770        // Writing to the original will not affect the clone.
771        assert!(original.write(b"two", 0).is_ok());
772        assert!(original.read(&mut read_buffer, 0).is_ok());
773        assert_eq!(&read_buffer[0..3], b"two");
774        assert!(clone.read(&mut read_buffer, 0).is_ok());
775        assert_eq!(&read_buffer[0..3], b"one");
776
777        // However, writing to the clone will not affect the original.
778        assert!(clone.write(b"three", 0).is_ok());
779        assert!(original.read(&mut read_buffer, 0).is_ok());
780        assert_eq!(&read_buffer[0..3], b"two");
781        assert!(clone.read(&mut read_buffer, 0).is_ok());
782        assert_eq!(&read_buffer[0..5], b"three");
783    }
784
785    #[test]
786    fn vmo_replace_as_executeable() {
787        use zx::{Channel, HandleBased, MonotonicInstant};
788
789        let vmo = Vmo::create(16).unwrap();
790
791        let info = vmo.as_handle_ref().basic_info().unwrap();
792        assert!(!info.rights.contains(Rights::EXECUTE));
793
794        let (client_end, server_end) = Channel::create();
795        connect_channel_to_protocol::<fkernel::VmexResourceMarker>(server_end).unwrap();
796        let service = fkernel::VmexResourceSynchronousProxy::new(client_end);
797        let resource = service.get(MonotonicInstant::INFINITE).expect("couldn't get vmex resource");
798        let resource =
799            unsafe { crate::Resource::from(NullableHandle::from_raw(resource.into_raw())) };
800
801        let exec_vmo = vmo.replace_as_executable(&resource).unwrap();
802        let info = exec_vmo.as_handle_ref().basic_info().unwrap();
803        assert!(info.rights.contains(Rights::EXECUTE));
804    }
805
806    #[test]
807    fn vmo_content_size() {
808        let start_size = 1024;
809        let vmo = Vmo::create_with_opts(VmoOptions::RESIZABLE, start_size).unwrap();
810        assert_eq!(vmo.get_content_size().unwrap(), start_size);
811        vmo.set_content_size(&0).unwrap();
812        assert_eq!(vmo.get_content_size().unwrap(), 0);
813
814        // write should not change content size.
815        let content = b"abcdef";
816        assert!(vmo.write(content, 0).is_ok());
817        assert_eq!(vmo.get_content_size().unwrap(), 0);
818    }
819
820    #[test]
821    fn vmo_zero() {
822        let vmo = Vmo::create(16).unwrap();
823        let content = b"0123456789abcdef";
824        assert!(vmo.write(content, 0).is_ok());
825        let mut buf = vec![0u8; 16];
826        assert!(vmo.read(&mut buf[..], 0).is_ok());
827        assert_eq!(&buf[..], content);
828
829        assert!(vmo.op_range(VmoOp::ZERO, 0, 16).is_ok());
830        assert!(vmo.read(&mut buf[..], 0).is_ok());
831        assert_eq!(&buf[..], &[0u8; 16]);
832    }
833
834    #[test]
835    fn vmo_stream_size() {
836        let start_size = 1300;
837        let vmo = Vmo::create_with_opts(VmoOptions::UNBOUNDED, start_size).unwrap();
838        assert_eq!(vmo.get_stream_size().unwrap(), start_size);
839        vmo.set_stream_size(0).unwrap();
840        assert_eq!(vmo.get_stream_size().unwrap(), 0);
841
842        // write should not change content size.
843        let content = b"abcdef";
844        assert!(vmo.write(content, 0).is_ok());
845        assert_eq!(vmo.get_stream_size().unwrap(), 0);
846
847        // stream size can also grow.
848        let mut buf = vec![1; 6];
849        vmo.set_stream_size(6).unwrap();
850        assert!(vmo.read(&mut buf, 0).is_ok());
851        // growing will zero new bytes.
852        assert_eq!(buf, vec![0; 6]);
853    }
854}
zx/vmo.rs

zx/
vmo.rs
