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

zx/
vmo.rs
