Refactor memory module
This commit refactors and reorganises the `memory.rs` module. Now, it consists of two submodules: `memory::ptr` which contains `GuestPtr` and `GuestRef` (and their mutable versions), and `memory::array` which contains `GuestArray` and `GuestArrayRef` (and their mutable versions). This commit also adds basic unit sanity tests for the `memory::ptr` submodule.
This commit is contained in:
Jakub Konka
@@ -1,761 +0,0 @@
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use std::cell::RefCell;
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use std::fmt;
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use std::marker::PhantomData;
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use std::rc::Rc;
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use crate::borrow::{BorrowHandle, GuestBorrows};
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use crate::{GuestError, GuestType, GuestTypeClone, GuestTypeCopy, GuestTypePtr, Region};
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pub struct GuestMemory<'a> {
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ptr: *mut u8,
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len: u32,
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lifetime: PhantomData<&'a ()>,
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borrows: Rc<RefCell<GuestBorrows>>,
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}
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impl<'a> fmt::Debug for GuestMemory<'a> {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(
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f,
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"GuestMemory {{ ptr: {:?}, len: {:?}, borrows: {:?} }}",
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self.ptr, self.len, self.borrows
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)
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}
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}
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impl<'a> GuestMemory<'a> {
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pub fn new(ptr: *mut u8, len: u32) -> GuestMemory<'a> {
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assert_eq!(ptr as usize % 4096, 0, "GuestMemory must be page-aligned");
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GuestMemory {
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ptr,
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len,
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lifetime: PhantomData,
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borrows: Rc::new(RefCell::new(GuestBorrows::new())),
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}
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}
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fn contains(&self, r: Region) -> bool {
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r.start < self.len
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&& r.len < self.len // make sure next clause doesnt underflow
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&& r.start <= (self.len - r.len)
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}
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pub fn ptr<T: GuestType>(&'a self, at: u32) -> Result<GuestPtr<'a, T>, GuestError> {
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let region = Region {
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start: at,
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len: T::size(),
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};
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if !self.contains(region) {
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Err(GuestError::PtrOutOfBounds(region))?;
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}
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if at % T::align() != 0 {
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Err(GuestError::PtrNotAligned(region, T::align()))?;
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}
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Ok(GuestPtr {
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mem: &self,
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region,
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type_: PhantomData,
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})
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}
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pub fn ptr_mut<T: GuestType>(&'a self, at: u32) -> Result<GuestPtrMut<'a, T>, GuestError> {
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let ptr = self.ptr(at)?;
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Ok(GuestPtrMut {
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mem: ptr.mem,
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region: ptr.region,
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type_: ptr.type_,
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})
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}
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}
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#[derive(Clone)]
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pub struct GuestPtr<'a, T> {
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mem: &'a GuestMemory<'a>,
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region: Region,
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type_: PhantomData<T>,
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}
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impl<'a, T: fmt::Debug> fmt::Debug for GuestPtr<'a, T> {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(
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f,
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"GuestPtr {{ mem: {:?}, region: {:?} }}",
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self.mem, self.region
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)
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}
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}
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impl<'a, T: GuestType> GuestPtr<'a, T> {
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pub fn as_raw(&self) -> *const u8 {
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(self.mem.ptr as usize + self.region.start as usize) as *const u8
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}
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pub fn elem(&self, elements: i32) -> Result<GuestPtr<'a, T>, GuestError> {
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self.mem
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.ptr(self.region.start + (elements * self.region.len as i32) as u32)
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}
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pub fn cast<TT: GuestType>(&self, offset: u32) -> Result<GuestPtr<'a, TT>, GuestError> {
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self.mem.ptr(self.region.start + offset)
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}
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pub fn array(&self, num_elems: u32) -> Result<GuestArray<'a, T>, GuestError> {
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let region = self.region.extend((num_elems - 1) * T::size());
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if self.mem.contains(region) {
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let ptr = GuestPtr {
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mem: self.mem,
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region: self.region,
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type_: self.type_,
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};
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Ok(GuestArray { ptr, num_elems })
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} else {
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Err(GuestError::PtrOutOfBounds(region))
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}
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}
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}
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impl<'a, T: GuestTypeCopy> GuestPtr<'a, T> {
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pub fn as_ref(&self) -> Result<GuestRef<'a, T>, GuestError> {
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T::validate(&self)?;
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let handle = {
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let mut borrows = self.mem.borrows.borrow_mut();
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borrows
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.borrow_immut(self.region)
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.ok_or_else(|| GuestError::PtrBorrowed(self.region))?
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};
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Ok(GuestRef {
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mem: self.mem,
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region: self.region,
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handle,
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type_: self.type_,
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})
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}
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}
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impl<'a, T: GuestTypeClone> GuestPtr<'a, T> {
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pub fn clone_from_guest(&self) -> Result<T, GuestError> {
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T::read_from_guest(self)
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}
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}
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impl<'a, T: GuestTypePtr<'a>> GuestPtr<'a, T> {
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pub fn read_ptr_from_guest(&self) -> Result<T, GuestError> {
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T::read_from_guest(self)
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}
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}
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impl<'a, T> GuestType for GuestPtr<'a, T>
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where
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T: GuestType,
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{
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fn size() -> u32 {
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4
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}
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fn align() -> u32 {
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4
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}
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fn name() -> String {
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format!("GuestPtr<{}>", T::name())
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}
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fn validate<'b>(location: &GuestPtr<'b, GuestPtr<'b, T>>) -> Result<(), GuestError> {
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// location is guaranteed to be in GuestMemory and aligned to 4
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let raw_ptr: u32 = unsafe { *(location.as_raw() as *const u32) };
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// GuestMemory can validate that the raw pointer contents are legal for T:
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let _guest_ptr: GuestPtr<T> = location.mem.ptr(raw_ptr)?;
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Ok(())
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}
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}
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// Operations for reading and writing Ptrs to memory:
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impl<'a, T> GuestTypePtr<'a> for GuestPtr<'a, T>
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where
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T: GuestType,
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{
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fn read_from_guest(location: &GuestPtr<'a, Self>) -> Result<Self, GuestError> {
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// location is guaranteed to be in GuestMemory and aligned to 4
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let raw_ptr: u32 = unsafe { *(location.as_raw() as *const u32) };
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// GuestMemory can validate that the raw pointer contents are legal for T:
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let guest_ptr: GuestPtr<'a, T> = location.mem.ptr(raw_ptr)?;
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Ok(guest_ptr)
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}
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fn write_to_guest(&self, location: &GuestPtrMut<'a, Self>) {
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// location is guaranteed to be in GuestMemory and aligned to 4
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unsafe {
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let raw_ptr: *mut u32 = location.as_raw() as *mut u32;
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raw_ptr.write(self.region.start);
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}
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}
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}
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#[derive(Clone)]
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pub struct GuestPtrMut<'a, T> {
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mem: &'a GuestMemory<'a>,
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region: Region,
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type_: PhantomData<T>,
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}
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impl<'a, T: fmt::Debug> fmt::Debug for GuestPtrMut<'a, T> {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(
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f,
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"GuestPtrMut {{ mem: {:?}, region: {:?} }}",
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self.mem, self.region
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)
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}
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}
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impl<'a, T: GuestType> GuestPtrMut<'a, T> {
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pub fn as_immut(&self) -> GuestPtr<'a, T> {
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GuestPtr {
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mem: self.mem,
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region: self.region,
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type_: self.type_,
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}
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}
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pub fn as_raw(&self) -> *const u8 {
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self.as_immut().as_raw()
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}
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pub fn elem(&self, elements: i32) -> Result<GuestPtrMut<'a, T>, GuestError> {
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self.mem
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.ptr_mut(self.region.start + (elements * self.region.len as i32) as u32)
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}
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pub fn cast<TT: GuestType>(&self, offset: u32) -> Result<GuestPtrMut<'a, TT>, GuestError> {
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self.mem.ptr_mut(self.region.start + offset)
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}
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pub fn array_mut(&self, num_elems: u32) -> Result<GuestArrayMut<'a, T>, GuestError> {
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let region = self.region.extend((num_elems - 1) * T::size());
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if self.mem.contains(region) {
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let ptr = GuestPtrMut {
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mem: self.mem,
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region: self.region,
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type_: self.type_,
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};
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Ok(GuestArrayMut { ptr, num_elems })
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} else {
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Err(GuestError::PtrOutOfBounds(region))
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}
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}
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}
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impl<'a, T: GuestTypeCopy> GuestPtrMut<'a, T> {
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pub fn as_ref(&self) -> Result<GuestRef<'a, T>, GuestError> {
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self.as_immut().as_ref()
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}
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pub fn as_ref_mut(&self) -> Result<GuestRefMut<'a, T>, GuestError> {
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T::validate(&self.as_immut())?;
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let handle = {
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let mut borrows = self.mem.borrows.borrow_mut();
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borrows
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.borrow_mut(self.region)
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.ok_or_else(|| GuestError::PtrBorrowed(self.region))?
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};
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Ok(GuestRefMut {
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mem: self.mem,
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region: self.region,
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handle,
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type_: self.type_,
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})
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}
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}
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impl<'a, T: GuestTypePtr<'a>> GuestPtrMut<'a, T> {
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pub fn read_ptr_from_guest(&self) -> Result<T, GuestError> {
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T::read_from_guest(&self.as_immut())
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}
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pub fn write_ptr_to_guest(&self, ptr: &T) {
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T::write_to_guest(ptr, &self);
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}
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}
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impl<'a, T: GuestTypeClone> GuestPtrMut<'a, T> {
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pub fn clone_from_guest(&self) -> Result<T, GuestError> {
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T::read_from_guest(&self.as_immut())
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}
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pub fn clone_to_guest(&self, val: &T) {
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T::write_to_guest(val, &self)
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}
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}
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impl<'a, T> GuestType for GuestPtrMut<'a, T>
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where
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T: GuestType,
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{
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fn size() -> u32 {
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4
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}
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fn align() -> u32 {
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4
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}
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fn name() -> String {
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format!("GuestPtrMut<{}>", T::name())
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}
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fn validate<'b>(location: &GuestPtr<'b, GuestPtrMut<'b, T>>) -> Result<(), GuestError> {
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// location is guaranteed to be in GuestMemory and aligned to 4
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let raw_ptr: u32 = unsafe { *(location.as_raw() as *const u32) };
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// GuestMemory can validate that the raw pointer contents are legal for T:
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let _guest_ptr: GuestPtr<T> = location.mem.ptr(raw_ptr)?;
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Ok(())
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}
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}
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// Reading and writing GuestPtrMuts to memory:
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impl<'a, T> GuestTypePtr<'a> for GuestPtrMut<'a, T>
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where
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T: GuestType,
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{
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fn read_from_guest(location: &GuestPtr<'a, Self>) -> Result<Self, GuestError> {
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// location is guaranteed to be in GuestMemory and aligned to 4
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let raw_ptr: u32 = unsafe { *(location.as_raw() as *const u32) };
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// GuestMemory can validate that the raw pointer contents are legal for T:
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let guest_ptr_mut: GuestPtrMut<'a, T> = location.mem.ptr_mut(raw_ptr)?;
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Ok(guest_ptr_mut)
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}
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fn write_to_guest(&self, location: &GuestPtrMut<'a, Self>) {
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// location is guaranteed to be in GuestMemory and aligned to 4
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unsafe {
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let raw_ptr: *mut u32 = location.as_raw() as *mut u32;
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raw_ptr.write(self.region.start);
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}
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}
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}
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pub struct GuestRef<'a, T> {
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mem: &'a GuestMemory<'a>,
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region: Region,
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handle: BorrowHandle,
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type_: PhantomData<T>,
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}
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impl<'a, T: fmt::Debug> fmt::Debug for GuestRef<'a, T> {
|
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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write!(
|
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f,
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"GuestRef {{ mem: {:?}, region: {:?}, handle: {:?} }}",
|
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self.mem, self.region, self.handle
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)
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}
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}
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|
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impl<'a, T> GuestRef<'a, T> {
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pub fn as_ptr(&self) -> GuestPtr<'a, T> {
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GuestPtr {
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mem: self.mem,
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region: self.region,
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type_: self.type_,
|
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}
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}
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}
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|
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impl<'a, T> ::std::ops::Deref for GuestRef<'a, T>
|
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where
|
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T: GuestTypeCopy,
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{
|
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type Target = T;
|
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fn deref(&self) -> &T {
|
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unsafe {
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((self.mem.ptr as usize + self.region.start as usize) as *const T)
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.as_ref()
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||||
.expect("GuestRef implies non-null")
|
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}
|
||||
}
|
||||
}
|
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|
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impl<'a, T> Drop for GuestRef<'a, T> {
|
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fn drop(&mut self) {
|
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let mut borrows = self.mem.borrows.borrow_mut();
|
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borrows.unborrow_immut(self.handle);
|
||||
}
|
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}
|
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|
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pub struct GuestRefMut<'a, T> {
|
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mem: &'a GuestMemory<'a>,
|
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region: Region,
|
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handle: BorrowHandle,
|
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type_: PhantomData<T>,
|
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}
|
||||
|
||||
impl<'a, T: fmt::Debug> fmt::Debug for GuestRefMut<'a, T> {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestRefMut {{ mem: {:?}, region: {:?}, handle: {:?} }}",
|
||||
self.mem, self.region, self.handle
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestRefMut<'a, T> {
|
||||
pub fn as_ptr(&self) -> GuestPtr<'a, T> {
|
||||
GuestPtr {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
type_: self.type_,
|
||||
}
|
||||
}
|
||||
pub fn as_ptr_mut(&self) -> GuestPtrMut<'a, T> {
|
||||
GuestPtrMut {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
type_: self.type_,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> ::std::ops::Deref for GuestRefMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
type Target = T;
|
||||
fn deref(&self) -> &T {
|
||||
unsafe {
|
||||
((self.mem.ptr as usize + self.region.start as usize) as *const T)
|
||||
.as_ref()
|
||||
.expect("GuestRef implies non-null")
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> ::std::ops::DerefMut for GuestRefMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
fn deref_mut(&mut self) -> &mut T {
|
||||
unsafe {
|
||||
((self.mem.ptr as usize + self.region.start as usize) as *mut T)
|
||||
.as_mut()
|
||||
.expect("GuestRef implies non-null")
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> Drop for GuestRefMut<'a, T> {
|
||||
fn drop(&mut self) {
|
||||
let mut borrows = self.mem.borrows.borrow_mut();
|
||||
borrows.unborrow_mut(self.handle);
|
||||
}
|
||||
}
|
||||
|
||||
pub struct GuestArray<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
ptr: GuestPtr<'a, T>,
|
||||
num_elems: u32,
|
||||
}
|
||||
|
||||
impl<'a, T: GuestType + fmt::Debug> fmt::Debug for GuestArray<'a, T> {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestArray {{ ptr: {:?}, num_elems: {:?} }}",
|
||||
self.ptr, self.num_elems
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestArray<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
pub fn as_ref(&self) -> Result<GuestArrayRef<'a, T>, GuestError> {
|
||||
let mut ptr = self.ptr.clone();
|
||||
for _ in 0..self.num_elems {
|
||||
ptr = ptr.elem(1)?;
|
||||
T::validate(&ptr)?;
|
||||
}
|
||||
let region = self.ptr.region.extend((self.num_elems - 1) * T::size());
|
||||
let handle = {
|
||||
let mut borrows = self.ptr.mem.borrows.borrow_mut();
|
||||
borrows
|
||||
.borrow_immut(region)
|
||||
.ok_or_else(|| GuestError::PtrBorrowed(region))?
|
||||
};
|
||||
let ref_ = GuestRef {
|
||||
mem: self.ptr.mem,
|
||||
region,
|
||||
handle,
|
||||
type_: self.ptr.type_,
|
||||
};
|
||||
Ok(GuestArrayRef {
|
||||
ref_,
|
||||
num_elems: self.num_elems,
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
pub struct GuestArrayRef<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
ref_: GuestRef<'a, T>,
|
||||
num_elems: u32,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestArrayRef<'a, T>
|
||||
where
|
||||
T: GuestType + fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestArrayRef {{ ref_: {:?}, num_elems: {:?} }}",
|
||||
self.ref_, self.num_elems
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> ::std::ops::Deref for GuestArrayRef<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
type Target = [T];
|
||||
|
||||
fn deref(&self) -> &Self::Target {
|
||||
unsafe {
|
||||
std::slice::from_raw_parts(
|
||||
self.ref_.as_ptr().as_raw() as *const T,
|
||||
self.num_elems as usize,
|
||||
)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pub struct GuestArrayMut<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
ptr: GuestPtrMut<'a, T>,
|
||||
num_elems: u32,
|
||||
}
|
||||
|
||||
impl<'a, T: GuestType + fmt::Debug> fmt::Debug for GuestArrayMut<'a, T> {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestArrayMut {{ ptr: {:?}, num_elems: {:?} }}",
|
||||
self.ptr, self.num_elems
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestArrayMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
pub fn as_ref(&self) -> Result<GuestArrayRef<'a, T>, GuestError> {
|
||||
let arr = GuestArray {
|
||||
ptr: self.ptr.as_immut(),
|
||||
num_elems: self.num_elems,
|
||||
};
|
||||
arr.as_ref()
|
||||
}
|
||||
|
||||
pub fn as_ref_mut(&self) -> Result<GuestArrayRefMut<'a, T>, GuestError> {
|
||||
let mut ptr = self.ptr.as_immut();
|
||||
for _ in 0..self.num_elems {
|
||||
ptr = ptr.elem(1)?;
|
||||
T::validate(&ptr)?;
|
||||
}
|
||||
let region = self.ptr.region.extend((self.num_elems - 1) * T::size());
|
||||
let handle = {
|
||||
let mut borrows = self.ptr.mem.borrows.borrow_mut();
|
||||
borrows
|
||||
.borrow_mut(region)
|
||||
.ok_or_else(|| GuestError::PtrBorrowed(region))?
|
||||
};
|
||||
let ref_mut = GuestRefMut {
|
||||
mem: self.ptr.mem,
|
||||
region,
|
||||
handle,
|
||||
type_: self.ptr.type_,
|
||||
};
|
||||
Ok(GuestArrayRefMut {
|
||||
ref_mut,
|
||||
num_elems: self.num_elems,
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
pub struct GuestArrayRefMut<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
ref_mut: GuestRefMut<'a, T>,
|
||||
num_elems: u32,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestArrayRefMut<'a, T>
|
||||
where
|
||||
T: GuestType + fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestArrayRefMut {{ ref_mut: {:?}, num_elems: {:?} }}",
|
||||
self.ref_mut, self.num_elems
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> ::std::ops::Deref for GuestArrayRefMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
type Target = [T];
|
||||
|
||||
fn deref(&self) -> &Self::Target {
|
||||
unsafe {
|
||||
std::slice::from_raw_parts(
|
||||
self.ref_mut.as_ptr().as_raw() as *const T,
|
||||
self.num_elems as usize,
|
||||
)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> ::std::ops::DerefMut for GuestArrayRefMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
fn deref_mut(&mut self) -> &mut Self::Target {
|
||||
unsafe {
|
||||
std::slice::from_raw_parts_mut(
|
||||
self.ref_mut.as_ptr_mut().as_raw() as *mut T,
|
||||
self.num_elems as usize,
|
||||
)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
mod test {
|
||||
use super::*;
|
||||
|
||||
#[repr(align(4096))]
|
||||
struct HostMemory {
|
||||
buffer: [u8; 4096],
|
||||
}
|
||||
|
||||
impl HostMemory {
|
||||
pub fn new() -> Self {
|
||||
Self { buffer: [0; 4096] }
|
||||
}
|
||||
pub fn as_mut_ptr(&mut self) -> *mut u8 {
|
||||
self.buffer.as_mut_ptr()
|
||||
}
|
||||
pub fn len(&self) -> usize {
|
||||
self.buffer.len()
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn guest_array_out_of_bounds() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// try extracting an immutable array out of memory bounds
|
||||
let ptr: GuestPtr<i32> = guest_memory.ptr(4092).expect("ptr to last i32 el");
|
||||
let err = ptr.array(2).expect_err("out of bounds ptr error");
|
||||
assert_eq!(err, GuestError::PtrOutOfBounds(Region::new(4092, 8)));
|
||||
// try extracting an mutable array out of memory bounds
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(4092).expect("ptr mut to last i32 el");
|
||||
let err = ptr.array_mut(2).expect_err("out of bounds ptr error");
|
||||
assert_eq!(err, GuestError::PtrOutOfBounds(Region::new(4092, 8)));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn guest_array() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// write a simple array into memory
|
||||
{
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to first el");
|
||||
*el = 1;
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(4).expect("ptr mut to second el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mu to second el");
|
||||
*el = 2;
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(8).expect("ptr mut to third el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to third el");
|
||||
*el = 3;
|
||||
}
|
||||
// extract as array
|
||||
let ptr: GuestPtr<i32> = guest_memory.ptr(0).expect("ptr to first el");
|
||||
let arr = ptr.array(3).expect("convert ptr to array");
|
||||
let as_ref = arr.as_ref().expect("array borrowed immutably");
|
||||
assert_eq!(&*as_ref, &[1, 2, 3]);
|
||||
// borrowing again should be fine
|
||||
let as_ref2 = arr.as_ref().expect("array borrowed immutably again");
|
||||
assert_eq!(&*as_ref2, &*as_ref);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn guest_array_mut() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// set elems of array to zero
|
||||
{
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to first el");
|
||||
*el = 0;
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(4).expect("ptr mut to second el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mu to second el");
|
||||
*el = 0;
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(8).expect("ptr mut to third el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to third el");
|
||||
*el = 0;
|
||||
}
|
||||
// extract as array and verify all is zero
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let arr = ptr.array_mut(3).expect("convert ptr mut to array mut");
|
||||
assert_eq!(&*arr.as_ref().expect("array borrowed immutably"), &[0; 3]);
|
||||
// populate the array and re-verify
|
||||
for el in &mut *arr.as_ref_mut().expect("array borrowed mutably") {
|
||||
*el = 10;
|
||||
}
|
||||
// re-validate
|
||||
assert_eq!(&*arr.as_ref().expect("array borrowed immutably"), &[10; 3]);
|
||||
}
|
||||
|
||||
#[test]
|
||||
#[should_panic(
|
||||
expected = "array borrowed immutably while borrowed mutably: PtrBorrowed(Region { start: 0, len: 12 })"
|
||||
)]
|
||||
fn guest_array_mut_borrow_checker_1() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let arr = GuestArrayMut { ptr, num_elems: 3 };
|
||||
// borrow mutably
|
||||
let _as_mut = arr
|
||||
.as_ref_mut()
|
||||
.expect("array borrowed mutably for the first time");
|
||||
// borrow immutably should be fine
|
||||
let _as_ref = arr
|
||||
.as_ref()
|
||||
.expect("array borrowed immutably while borrowed mutably");
|
||||
}
|
||||
|
||||
#[test]
|
||||
#[should_panic(
|
||||
expected = "array borrowed mutably while borrowed mutably: PtrBorrowed(Region { start: 0, len: 12 })"
|
||||
)]
|
||||
fn guest_array_mut_borrow_checker_2() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let arr = GuestArrayMut { ptr, num_elems: 3 };
|
||||
// borrow mutably
|
||||
let _as_mut = arr
|
||||
.as_ref_mut()
|
||||
.expect("array borrowed mutably for the first time");
|
||||
// try borrowing mutably again
|
||||
let _as_mut2 = arr
|
||||
.as_ref_mut()
|
||||
.expect("array borrowed mutably while borrowed mutably");
|
||||
}
|
||||
}
|
||||
335
crates/memory/src/memory/array.rs
Normal file
335
crates/memory/src/memory/array.rs
Normal file
@@ -0,0 +1,335 @@
|
||||
use super::ptr::{GuestPtr, GuestPtrMut, GuestRef, GuestRefMut};
|
||||
use crate::{GuestError, GuestType, GuestTypeCopy};
|
||||
use std::{
|
||||
fmt,
|
||||
ops::{Deref, DerefMut},
|
||||
};
|
||||
|
||||
pub struct GuestArray<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
pub(super) ptr: GuestPtr<'a, T>,
|
||||
pub(super) num_elems: u32,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestArray<'a, T>
|
||||
where
|
||||
T: GuestType + fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestArray {{ ptr: {:?}, num_elems: {:?} }}",
|
||||
self.ptr, self.num_elems
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestArray<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
pub fn as_ref(&self) -> Result<GuestArrayRef<'a, T>, GuestError> {
|
||||
let mut ptr = self.ptr.clone();
|
||||
for _ in 0..self.num_elems {
|
||||
ptr = ptr.elem(1)?;
|
||||
T::validate(&ptr)?;
|
||||
}
|
||||
let region = self.ptr.region.extend((self.num_elems - 1) * T::size());
|
||||
let handle = {
|
||||
let mut borrows = self.ptr.mem.borrows.borrow_mut();
|
||||
borrows
|
||||
.borrow_immut(region)
|
||||
.ok_or_else(|| GuestError::PtrBorrowed(region))?
|
||||
};
|
||||
let ref_ = GuestRef {
|
||||
mem: self.ptr.mem,
|
||||
region,
|
||||
handle,
|
||||
type_: self.ptr.type_,
|
||||
};
|
||||
Ok(GuestArrayRef {
|
||||
ref_,
|
||||
num_elems: self.num_elems,
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
pub struct GuestArrayRef<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
ref_: GuestRef<'a, T>,
|
||||
num_elems: u32,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestArrayRef<'a, T>
|
||||
where
|
||||
T: GuestType + fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestArrayRef {{ ref_: {:?}, num_elems: {:?} }}",
|
||||
self.ref_, self.num_elems
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> Deref for GuestArrayRef<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
type Target = [T];
|
||||
|
||||
fn deref(&self) -> &Self::Target {
|
||||
unsafe {
|
||||
std::slice::from_raw_parts(
|
||||
self.ref_.as_ptr().as_raw() as *const T,
|
||||
self.num_elems as usize,
|
||||
)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pub struct GuestArrayMut<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
pub(super) ptr: GuestPtrMut<'a, T>,
|
||||
pub(super) num_elems: u32,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestArrayMut<'a, T>
|
||||
where
|
||||
T: GuestType + fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestArrayMut {{ ptr: {:?}, num_elems: {:?} }}",
|
||||
self.ptr, self.num_elems
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestArrayMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
pub fn as_ref(&self) -> Result<GuestArrayRef<'a, T>, GuestError> {
|
||||
let arr = GuestArray {
|
||||
ptr: self.ptr.as_immut(),
|
||||
num_elems: self.num_elems,
|
||||
};
|
||||
arr.as_ref()
|
||||
}
|
||||
|
||||
pub fn as_ref_mut(&self) -> Result<GuestArrayRefMut<'a, T>, GuestError> {
|
||||
let mut ptr = self.ptr.as_immut();
|
||||
for _ in 0..self.num_elems {
|
||||
ptr = ptr.elem(1)?;
|
||||
T::validate(&ptr)?;
|
||||
}
|
||||
let region = self.ptr.region.extend((self.num_elems - 1) * T::size());
|
||||
let handle = {
|
||||
let mut borrows = self.ptr.mem.borrows.borrow_mut();
|
||||
borrows
|
||||
.borrow_mut(region)
|
||||
.ok_or_else(|| GuestError::PtrBorrowed(region))?
|
||||
};
|
||||
let ref_mut = GuestRefMut {
|
||||
mem: self.ptr.mem,
|
||||
region,
|
||||
handle,
|
||||
type_: self.ptr.type_,
|
||||
};
|
||||
Ok(GuestArrayRefMut {
|
||||
ref_mut,
|
||||
num_elems: self.num_elems,
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
pub struct GuestArrayRefMut<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
ref_mut: GuestRefMut<'a, T>,
|
||||
num_elems: u32,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestArrayRefMut<'a, T>
|
||||
where
|
||||
T: GuestType + fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestArrayRefMut {{ ref_mut: {:?}, num_elems: {:?} }}",
|
||||
self.ref_mut, self.num_elems
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> Deref for GuestArrayRefMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
type Target = [T];
|
||||
|
||||
fn deref(&self) -> &Self::Target {
|
||||
unsafe {
|
||||
std::slice::from_raw_parts(
|
||||
self.ref_mut.as_ptr().as_raw() as *const T,
|
||||
self.num_elems as usize,
|
||||
)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> DerefMut for GuestArrayRefMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
fn deref_mut(&mut self) -> &mut Self::Target {
|
||||
unsafe {
|
||||
std::slice::from_raw_parts_mut(
|
||||
self.ref_mut.as_ptr_mut().as_raw() as *mut T,
|
||||
self.num_elems as usize,
|
||||
)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
mod test {
|
||||
use super::super::{
|
||||
ptr::{GuestPtr, GuestPtrMut},
|
||||
GuestError, GuestMemory, Region,
|
||||
};
|
||||
|
||||
#[repr(align(4096))]
|
||||
struct HostMemory {
|
||||
buffer: [u8; 4096],
|
||||
}
|
||||
|
||||
impl HostMemory {
|
||||
pub fn new() -> Self {
|
||||
Self { buffer: [0; 4096] }
|
||||
}
|
||||
pub fn as_mut_ptr(&mut self) -> *mut u8 {
|
||||
self.buffer.as_mut_ptr()
|
||||
}
|
||||
pub fn len(&self) -> usize {
|
||||
self.buffer.len()
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn out_of_bounds() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// try extracting an immutable array out of memory bounds
|
||||
let ptr: GuestPtr<i32> = guest_memory.ptr(4092).expect("ptr to last i32 el");
|
||||
let err = ptr.array(2).expect_err("out of bounds ptr error");
|
||||
assert_eq!(err, GuestError::PtrOutOfBounds(Region::new(4092, 8)));
|
||||
// try extracting an mutable array out of memory bounds
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(4092).expect("ptr mut to last i32 el");
|
||||
let err = ptr.array_mut(2).expect_err("out of bounds ptr error");
|
||||
assert_eq!(err, GuestError::PtrOutOfBounds(Region::new(4092, 8)));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn ptr_to_array() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// write a simple array into memory
|
||||
{
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to first el");
|
||||
*el = 1;
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(4).expect("ptr mut to second el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mu to second el");
|
||||
*el = 2;
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(8).expect("ptr mut to third el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to third el");
|
||||
*el = 3;
|
||||
}
|
||||
// extract as array
|
||||
let ptr: GuestPtr<i32> = guest_memory.ptr(0).expect("ptr to first el");
|
||||
let arr = ptr.array(3).expect("convert ptr to array");
|
||||
let as_ref = arr.as_ref().expect("array borrowed immutably");
|
||||
assert_eq!(&*as_ref, &[1, 2, 3]);
|
||||
// borrowing again should be fine
|
||||
let as_ref2 = arr.as_ref().expect("array borrowed immutably again");
|
||||
assert_eq!(&*as_ref2, &*as_ref);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn ptr_mut_to_array_mut() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// set elems of array to zero
|
||||
{
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to first el");
|
||||
*el = 0;
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(4).expect("ptr mut to second el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mu to second el");
|
||||
*el = 0;
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(8).expect("ptr mut to third el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to third el");
|
||||
*el = 0;
|
||||
}
|
||||
// extract as array and verify all is zero
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let arr = ptr.array_mut(3).expect("convert ptr mut to array mut");
|
||||
assert_eq!(&*arr.as_ref().expect("array borrowed immutably"), &[0; 3]);
|
||||
// populate the array and re-verify
|
||||
for el in &mut *arr.as_ref_mut().expect("array borrowed mutably") {
|
||||
*el = 10;
|
||||
}
|
||||
// re-validate
|
||||
assert_eq!(&*arr.as_ref().expect("array borrowed immutably"), &[10; 3]);
|
||||
}
|
||||
|
||||
#[test]
|
||||
#[should_panic(
|
||||
expected = "array borrowed immutably while borrowed mutably: PtrBorrowed(Region { start: 0, len: 12 })"
|
||||
)]
|
||||
fn borrow_mut_then_immut() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let arr = ptr.array_mut(3).expect("convert ptr mut to array mut");
|
||||
// borrow mutably
|
||||
let _as_mut = arr
|
||||
.as_ref_mut()
|
||||
.expect("array borrowed mutably for the first time");
|
||||
// borrow immutably should fail
|
||||
let _as_ref = arr
|
||||
.as_ref()
|
||||
.expect("array borrowed immutably while borrowed mutably");
|
||||
}
|
||||
|
||||
#[test]
|
||||
#[should_panic(
|
||||
expected = "array borrowed mutably while borrowed mutably: PtrBorrowed(Region { start: 0, len: 12 })"
|
||||
)]
|
||||
fn borrow_mut_twice() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
let ptr: GuestPtrMut<i32> = guest_memory.ptr_mut(0).expect("ptr mut to first el");
|
||||
let arr = ptr.array_mut(3).expect("convert ptr mut to array mut");
|
||||
// borrow mutably
|
||||
let _as_mut = arr
|
||||
.as_ref_mut()
|
||||
.expect("array borrowed mutably for the first time");
|
||||
// try borrowing mutably again
|
||||
let _as_mut2 = arr
|
||||
.as_ref_mut()
|
||||
.expect("array borrowed mutably while borrowed mutably");
|
||||
}
|
||||
}
|
||||
70
crates/memory/src/memory/mod.rs
Normal file
70
crates/memory/src/memory/mod.rs
Normal file
@@ -0,0 +1,70 @@
|
||||
mod array;
|
||||
mod ptr;
|
||||
|
||||
pub use array::*;
|
||||
pub use ptr::*;
|
||||
|
||||
use crate::{borrow::GuestBorrows, GuestError, GuestType, Region};
|
||||
use std::{cell::RefCell, fmt, marker::PhantomData, rc::Rc};
|
||||
|
||||
pub struct GuestMemory<'a> {
|
||||
ptr: *mut u8,
|
||||
len: u32,
|
||||
lifetime: PhantomData<&'a ()>,
|
||||
borrows: Rc<RefCell<GuestBorrows>>,
|
||||
}
|
||||
|
||||
impl<'a> fmt::Debug for GuestMemory<'a> {
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestMemory {{ ptr: {:?}, len: {:?}, borrows: {:?} }}",
|
||||
self.ptr, self.len, self.borrows
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a> GuestMemory<'a> {
|
||||
pub fn new(ptr: *mut u8, len: u32) -> Self {
|
||||
assert_eq!(ptr as usize % 4096, 0, "GuestMemory must be page-aligned");
|
||||
Self {
|
||||
ptr,
|
||||
len,
|
||||
lifetime: PhantomData,
|
||||
borrows: Rc::new(RefCell::new(GuestBorrows::new())),
|
||||
}
|
||||
}
|
||||
|
||||
fn contains(&self, r: Region) -> bool {
|
||||
r.start < self.len
|
||||
&& r.len < self.len // make sure next clause doesnt underflow
|
||||
&& r.start <= (self.len - r.len)
|
||||
}
|
||||
|
||||
pub fn ptr<T: GuestType>(&'a self, at: u32) -> Result<GuestPtr<'a, T>, GuestError> {
|
||||
let region = Region {
|
||||
start: at,
|
||||
len: T::size(),
|
||||
};
|
||||
if !self.contains(region) {
|
||||
Err(GuestError::PtrOutOfBounds(region))?;
|
||||
}
|
||||
if at % T::align() != 0 {
|
||||
Err(GuestError::PtrNotAligned(region, T::align()))?;
|
||||
}
|
||||
Ok(GuestPtr {
|
||||
mem: &self,
|
||||
region,
|
||||
type_: PhantomData,
|
||||
})
|
||||
}
|
||||
|
||||
pub fn ptr_mut<T: GuestType>(&'a self, at: u32) -> Result<GuestPtrMut<'a, T>, GuestError> {
|
||||
let ptr = self.ptr(at)?;
|
||||
Ok(GuestPtrMut {
|
||||
mem: ptr.mem,
|
||||
region: ptr.region,
|
||||
type_: ptr.type_,
|
||||
})
|
||||
}
|
||||
}
|
||||
564
crates/memory/src/memory/ptr.rs
Normal file
564
crates/memory/src/memory/ptr.rs
Normal file
@@ -0,0 +1,564 @@
|
||||
use super::{
|
||||
array::{GuestArray, GuestArrayMut},
|
||||
GuestMemory,
|
||||
};
|
||||
use crate::{
|
||||
borrow::BorrowHandle, GuestError, GuestType, GuestTypeClone, GuestTypeCopy, GuestTypePtr,
|
||||
Region,
|
||||
};
|
||||
use std::{
|
||||
fmt,
|
||||
marker::PhantomData,
|
||||
ops::{Deref, DerefMut},
|
||||
};
|
||||
|
||||
#[derive(Clone)]
|
||||
pub struct GuestPtr<'a, T> {
|
||||
pub(super) mem: &'a GuestMemory<'a>,
|
||||
pub(super) region: Region,
|
||||
pub(super) type_: PhantomData<T>,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestPtr<'a, T>
|
||||
where
|
||||
T: fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestPtr {{ mem: {:?}, region: {:?} }}",
|
||||
self.mem, self.region
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T: GuestType> GuestPtr<'a, T> {
|
||||
pub fn as_raw(&self) -> *const u8 {
|
||||
(self.mem.ptr as usize + self.region.start as usize) as *const u8
|
||||
}
|
||||
|
||||
pub fn elem(&self, elements: i32) -> Result<Self, GuestError> {
|
||||
self.mem
|
||||
.ptr(self.region.start + (elements * self.region.len as i32) as u32)
|
||||
}
|
||||
|
||||
pub fn cast<CastTo: GuestType>(&self, offset: u32) -> Result<GuestPtr<'a, CastTo>, GuestError> {
|
||||
self.mem.ptr(self.region.start + offset)
|
||||
}
|
||||
|
||||
pub fn array(&self, num_elems: u32) -> Result<GuestArray<'a, T>, GuestError> {
|
||||
let region = self.region.extend((num_elems - 1) * T::size());
|
||||
if self.mem.contains(region) {
|
||||
let ptr = GuestPtr {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
type_: self.type_,
|
||||
};
|
||||
Ok(GuestArray { ptr, num_elems })
|
||||
} else {
|
||||
Err(GuestError::PtrOutOfBounds(region))
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestPtr<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
pub fn as_ref(&self) -> Result<GuestRef<'a, T>, GuestError> {
|
||||
T::validate(&self)?;
|
||||
let handle = {
|
||||
let mut borrows = self.mem.borrows.borrow_mut();
|
||||
borrows
|
||||
.borrow_immut(self.region)
|
||||
.ok_or_else(|| GuestError::PtrBorrowed(self.region))?
|
||||
};
|
||||
Ok(GuestRef {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
handle,
|
||||
type_: self.type_,
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestPtr<'a, T>
|
||||
where
|
||||
T: GuestTypeClone,
|
||||
{
|
||||
pub fn clone_from_guest(&self) -> Result<T, GuestError> {
|
||||
T::read_from_guest(self)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestPtr<'a, T>
|
||||
where
|
||||
T: GuestTypePtr<'a>,
|
||||
{
|
||||
pub fn read_ptr_from_guest(&self) -> Result<T, GuestError> {
|
||||
T::read_from_guest(self)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestType for GuestPtr<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
fn size() -> u32 {
|
||||
4
|
||||
}
|
||||
|
||||
fn align() -> u32 {
|
||||
4
|
||||
}
|
||||
|
||||
fn name() -> String {
|
||||
format!("GuestPtr<{}>", T::name())
|
||||
}
|
||||
|
||||
fn validate<'b>(location: &GuestPtr<'b, GuestPtr<'b, T>>) -> Result<(), GuestError> {
|
||||
// location is guaranteed to be in GuestMemory and aligned to 4
|
||||
let raw_ptr: u32 = unsafe { *(location.as_raw() as *const u32) };
|
||||
// GuestMemory can validate that the raw pointer contents are legal for T:
|
||||
let _guest_ptr: GuestPtr<T> = location.mem.ptr(raw_ptr)?;
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
|
||||
// Operations for reading and writing Ptrs to memory:
|
||||
impl<'a, T> GuestTypePtr<'a> for GuestPtr<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
fn read_from_guest(location: &GuestPtr<'a, Self>) -> Result<Self, GuestError> {
|
||||
// location is guaranteed to be in GuestMemory and aligned to 4
|
||||
let raw_ptr: u32 = unsafe { *(location.as_raw() as *const u32) };
|
||||
// GuestMemory can validate that the raw pointer contents are legal for T:
|
||||
let guest_ptr: GuestPtr<'a, T> = location.mem.ptr(raw_ptr)?;
|
||||
Ok(guest_ptr)
|
||||
}
|
||||
|
||||
fn write_to_guest(&self, location: &GuestPtrMut<'a, Self>) {
|
||||
// location is guaranteed to be in GuestMemory and aligned to 4
|
||||
unsafe {
|
||||
let raw_ptr: *mut u32 = location.as_raw() as *mut u32;
|
||||
raw_ptr.write(self.region.start);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Clone)]
|
||||
pub struct GuestPtrMut<'a, T> {
|
||||
pub(super) mem: &'a GuestMemory<'a>,
|
||||
pub(super) region: Region,
|
||||
pub(super) type_: PhantomData<T>,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestPtrMut<'a, T>
|
||||
where
|
||||
T: fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestPtrMut {{ mem: {:?}, region: {:?} }}",
|
||||
self.mem, self.region
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestPtrMut<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
pub fn as_immut(&self) -> GuestPtr<'a, T> {
|
||||
GuestPtr {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
type_: self.type_,
|
||||
}
|
||||
}
|
||||
|
||||
pub fn as_raw(&self) -> *const u8 {
|
||||
self.as_immut().as_raw()
|
||||
}
|
||||
|
||||
pub fn elem(&self, elements: i32) -> Result<Self, GuestError> {
|
||||
self.mem
|
||||
.ptr_mut(self.region.start + (elements * self.region.len as i32) as u32)
|
||||
}
|
||||
|
||||
pub fn cast<CastTo: GuestType>(
|
||||
&self,
|
||||
offset: u32,
|
||||
) -> Result<GuestPtrMut<'a, CastTo>, GuestError> {
|
||||
self.mem.ptr_mut(self.region.start + offset)
|
||||
}
|
||||
|
||||
pub fn array_mut(&self, num_elems: u32) -> Result<GuestArrayMut<'a, T>, GuestError> {
|
||||
let region = self.region.extend((num_elems - 1) * T::size());
|
||||
if self.mem.contains(region) {
|
||||
let ptr = GuestPtrMut {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
type_: self.type_,
|
||||
};
|
||||
Ok(GuestArrayMut { ptr, num_elems })
|
||||
} else {
|
||||
Err(GuestError::PtrOutOfBounds(region))
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestPtrMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
pub fn as_ref(&self) -> Result<GuestRef<'a, T>, GuestError> {
|
||||
self.as_immut().as_ref()
|
||||
}
|
||||
|
||||
pub fn as_ref_mut(&self) -> Result<GuestRefMut<'a, T>, GuestError> {
|
||||
T::validate(&self.as_immut())?;
|
||||
let handle = {
|
||||
let mut borrows = self.mem.borrows.borrow_mut();
|
||||
borrows
|
||||
.borrow_mut(self.region)
|
||||
.ok_or_else(|| GuestError::PtrBorrowed(self.region))?
|
||||
};
|
||||
Ok(GuestRefMut {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
handle,
|
||||
type_: self.type_,
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestPtrMut<'a, T>
|
||||
where
|
||||
T: GuestTypePtr<'a>,
|
||||
{
|
||||
pub fn read_ptr_from_guest(&self) -> Result<T, GuestError> {
|
||||
T::read_from_guest(&self.as_immut())
|
||||
}
|
||||
|
||||
pub fn write_ptr_to_guest(&self, ptr: &T) {
|
||||
T::write_to_guest(ptr, &self);
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestPtrMut<'a, T>
|
||||
where
|
||||
T: GuestTypeClone,
|
||||
{
|
||||
pub fn clone_from_guest(&self) -> Result<T, GuestError> {
|
||||
T::read_from_guest(&self.as_immut())
|
||||
}
|
||||
|
||||
pub fn clone_to_guest(&self, val: &T) {
|
||||
T::write_to_guest(val, &self)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestType for GuestPtrMut<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
fn size() -> u32 {
|
||||
4
|
||||
}
|
||||
|
||||
fn align() -> u32 {
|
||||
4
|
||||
}
|
||||
|
||||
fn name() -> String {
|
||||
format!("GuestPtrMut<{}>", T::name())
|
||||
}
|
||||
|
||||
fn validate<'b>(location: &GuestPtr<'b, GuestPtrMut<'b, T>>) -> Result<(), GuestError> {
|
||||
// location is guaranteed to be in GuestMemory and aligned to 4
|
||||
let raw_ptr: u32 = unsafe { *(location.as_raw() as *const u32) };
|
||||
// GuestMemory can validate that the raw pointer contents are legal for T:
|
||||
let _guest_ptr: GuestPtr<T> = location.mem.ptr(raw_ptr)?;
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
|
||||
// Reading and writing GuestPtrMuts to memory:
|
||||
impl<'a, T> GuestTypePtr<'a> for GuestPtrMut<'a, T>
|
||||
where
|
||||
T: GuestType,
|
||||
{
|
||||
fn read_from_guest(location: &GuestPtr<'a, Self>) -> Result<Self, GuestError> {
|
||||
// location is guaranteed to be in GuestMemory and aligned to 4
|
||||
let raw_ptr: u32 = unsafe { *(location.as_raw() as *const u32) };
|
||||
// GuestMemory can validate that the raw pointer contents are legal for T:
|
||||
let guest_ptr_mut: GuestPtrMut<'a, T> = location.mem.ptr_mut(raw_ptr)?;
|
||||
Ok(guest_ptr_mut)
|
||||
}
|
||||
|
||||
fn write_to_guest(&self, location: &GuestPtrMut<'a, Self>) {
|
||||
// location is guaranteed to be in GuestMemory and aligned to 4
|
||||
unsafe {
|
||||
let raw_ptr: *mut u32 = location.as_raw() as *mut u32;
|
||||
raw_ptr.write(self.region.start);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pub struct GuestRef<'a, T> {
|
||||
pub(super) mem: &'a GuestMemory<'a>,
|
||||
pub(super) region: Region,
|
||||
pub(super) handle: BorrowHandle,
|
||||
pub(super) type_: PhantomData<T>,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestRef<'a, T>
|
||||
where
|
||||
T: fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestRef {{ mem: {:?}, region: {:?}, handle: {:?} }}",
|
||||
self.mem, self.region, self.handle
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestRef<'a, T> {
|
||||
pub fn as_ptr(&self) -> GuestPtr<'a, T> {
|
||||
GuestPtr {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
type_: self.type_,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> Deref for GuestRef<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
type Target = T;
|
||||
|
||||
fn deref(&self) -> &Self::Target {
|
||||
unsafe {
|
||||
((self.mem.ptr as usize + self.region.start as usize) as *const T)
|
||||
.as_ref()
|
||||
.expect("GuestRef implies non-null")
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> Drop for GuestRef<'a, T> {
|
||||
fn drop(&mut self) {
|
||||
let mut borrows = self.mem.borrows.borrow_mut();
|
||||
borrows.unborrow_immut(self.handle);
|
||||
}
|
||||
}
|
||||
|
||||
pub struct GuestRefMut<'a, T> {
|
||||
pub(super) mem: &'a GuestMemory<'a>,
|
||||
pub(super) region: Region,
|
||||
pub(super) handle: BorrowHandle,
|
||||
pub(super) type_: PhantomData<T>,
|
||||
}
|
||||
|
||||
impl<'a, T> fmt::Debug for GuestRefMut<'a, T>
|
||||
where
|
||||
T: fmt::Debug,
|
||||
{
|
||||
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
write!(
|
||||
f,
|
||||
"GuestRefMut {{ mem: {:?}, region: {:?}, handle: {:?} }}",
|
||||
self.mem, self.region, self.handle
|
||||
)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> GuestRefMut<'a, T> {
|
||||
pub fn as_ptr(&self) -> GuestPtr<'a, T> {
|
||||
GuestPtr {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
type_: self.type_,
|
||||
}
|
||||
}
|
||||
pub fn as_ptr_mut(&self) -> GuestPtrMut<'a, T> {
|
||||
GuestPtrMut {
|
||||
mem: self.mem,
|
||||
region: self.region,
|
||||
type_: self.type_,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> ::std::ops::Deref for GuestRefMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
type Target = T;
|
||||
|
||||
fn deref(&self) -> &Self::Target {
|
||||
unsafe {
|
||||
((self.mem.ptr as usize + self.region.start as usize) as *const T)
|
||||
.as_ref()
|
||||
.expect("GuestRef implies non-null")
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> DerefMut for GuestRefMut<'a, T>
|
||||
where
|
||||
T: GuestTypeCopy,
|
||||
{
|
||||
fn deref_mut(&mut self) -> &mut Self::Target {
|
||||
unsafe {
|
||||
((self.mem.ptr as usize + self.region.start as usize) as *mut T)
|
||||
.as_mut()
|
||||
.expect("GuestRef implies non-null")
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, T> Drop for GuestRefMut<'a, T> {
|
||||
fn drop(&mut self) {
|
||||
let mut borrows = self.mem.borrows.borrow_mut();
|
||||
borrows.unborrow_mut(self.handle);
|
||||
}
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
mod test {
|
||||
use super::{
|
||||
super::{GuestError, GuestMemory, Region},
|
||||
{GuestPtr, GuestPtrMut},
|
||||
};
|
||||
|
||||
#[repr(align(4096))]
|
||||
struct HostMemory {
|
||||
buffer: [u8; 4096],
|
||||
}
|
||||
|
||||
impl HostMemory {
|
||||
pub fn new() -> Self {
|
||||
Self { buffer: [0; 4096] }
|
||||
}
|
||||
pub fn as_mut_ptr(&mut self) -> *mut u8 {
|
||||
self.buffer.as_mut_ptr()
|
||||
}
|
||||
pub fn len(&self) -> usize {
|
||||
self.buffer.len()
|
||||
}
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn out_of_bounds() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// try extracting an immutable ptr out of memory bounds
|
||||
let err = guest_memory
|
||||
.ptr::<GuestPtr<i32>>(4096)
|
||||
.expect_err("out of bounds ptr error");
|
||||
assert_eq!(err, GuestError::PtrOutOfBounds(Region::new(4096, 4)));
|
||||
// try extracting an mutable ptr out of memory bounds
|
||||
let err = guest_memory
|
||||
.ptr_mut::<GuestPtrMut<i32>>(4096)
|
||||
.expect_err("out of bounds ptr error");
|
||||
assert_eq!(err, GuestError::PtrOutOfBounds(Region::new(4096, 4)));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn not_aligned() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// try extracting a misaligned immutable ptr
|
||||
let err = guest_memory
|
||||
.ptr::<GuestPtr<i32>>(2)
|
||||
.expect_err("ptr misaligned");
|
||||
assert_eq!(err, GuestError::PtrNotAligned(Region::new(2, 4), 4));
|
||||
// try extracting a misaligned mutable ptr
|
||||
let err = guest_memory
|
||||
.ptr_mut::<GuestPtrMut<i32>>(2)
|
||||
.expect_err("ptr mut misaligned");
|
||||
assert_eq!(err, GuestError::PtrNotAligned(Region::new(2, 4), 4));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn ptr_from_memory() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// write something to memory
|
||||
{
|
||||
let ptr: GuestPtrMut<i64> = guest_memory.ptr_mut(8).expect("ptr mut to the el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to the el");
|
||||
*el = 100;
|
||||
}
|
||||
// extract as ref
|
||||
let ptr: GuestPtr<i64> = guest_memory.ptr(8).expect("ptr to the el");
|
||||
let as_ref = ptr.as_ref().expect("el borrowed immutably");
|
||||
assert_eq!(*as_ref, 100);
|
||||
// borrowing again should be fine
|
||||
let as_ref2 = ptr.as_ref().expect("el borrowed immutably again");
|
||||
assert_eq!(*as_ref2, *as_ref);
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn ptr_mut_from_memory() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
// set elems of array to zero
|
||||
{
|
||||
let ptr: GuestPtrMut<i64> = guest_memory.ptr_mut(8).expect("ptr mut to the el");
|
||||
let mut el = ptr.as_ref_mut().expect("ref mut to the el");
|
||||
*el = 100;
|
||||
}
|
||||
// extract as ref
|
||||
let ptr: GuestPtrMut<i64> = guest_memory.ptr_mut(8).expect("ptr mut to the el");
|
||||
assert_eq!(*ptr.as_ref().expect("el borrowed immutably"), 100);
|
||||
// overwrite the memory and re-verify
|
||||
*ptr.as_ref_mut().expect("el borrowed mutably") = 2000;
|
||||
// re-validate
|
||||
assert_eq!(*ptr.as_ref().expect("el borrowed immutably"), 2000);
|
||||
}
|
||||
|
||||
#[test]
|
||||
#[should_panic(
|
||||
expected = "el borrowed immutably while borrowed mutably: PtrBorrowed(Region { start: 0, len: 2 })"
|
||||
)]
|
||||
fn borrow_mut_then_immut() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
let ptr: GuestPtrMut<i16> = guest_memory.ptr_mut(0).expect("ptr mut to the el");
|
||||
// borrow mutably
|
||||
let _as_mut = ptr
|
||||
.as_ref_mut()
|
||||
.expect("el borrowed mutably for the first time");
|
||||
// borrow immutably should fail
|
||||
let _as_ref = ptr
|
||||
.as_ref()
|
||||
.expect("el borrowed immutably while borrowed mutably");
|
||||
}
|
||||
|
||||
#[test]
|
||||
#[should_panic(
|
||||
expected = "el borrowed mutably while borrowed mutably: PtrBorrowed(Region { start: 0, len: 2 })"
|
||||
)]
|
||||
fn borrow_mut_twice() {
|
||||
let mut host_memory = HostMemory::new();
|
||||
let guest_memory = GuestMemory::new(host_memory.as_mut_ptr(), host_memory.len() as u32);
|
||||
let ptr: GuestPtrMut<i16> = guest_memory.ptr_mut(0).expect("ptr mut to the el");
|
||||
// borrow mutably
|
||||
let _as_mut = ptr
|
||||
.as_ref_mut()
|
||||
.expect("el borrowed mutably for the first time");
|
||||
// try borrowing mutably again
|
||||
let _as_mut2 = ptr
|
||||
.as_ref_mut()
|
||||
.expect("el borrowed mutably while borrowed mutably");
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user