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Return the UnusedPhysFrame on MapToError::PageAlreadyMapped #118

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Merged
merged 1 commit into from
Jan 22, 2020
Merged

Return the UnusedPhysFrame on MapToError::PageAlreadyMapped #118

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38 changes: 28 additions & 10 deletions src/structures/paging/mapper/mapped_page_table.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,7 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {
frame: UnusedPhysFrame<Size1GiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size1GiB>, MapToError>
) -> Result<MapperFlush<Size1GiB>, MapToError<Size1GiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand All @@ -52,7 +52,7 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {
.create_next_table(&mut p4[page.p4_index()], allocator)?;

if !p3[page.p3_index()].is_unused() {
return Err(MapToError::PageAlreadyMapped);
return Err(MapToError::PageAlreadyMapped(frame));
}
p3[page.p3_index()].set_addr(frame.start_address(), flags | PageTableFlags::HUGE_PAGE);

Expand All @@ -67,7 +67,7 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {
frame: UnusedPhysFrame<Size2MiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size2MiB>, MapToError>
) -> Result<MapperFlush<Size2MiB>, MapToError<Size2MiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand All @@ -80,7 +80,7 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {
.create_next_table(&mut p3[page.p3_index()], allocator)?;

if !p2[page.p2_index()].is_unused() {
return Err(MapToError::PageAlreadyMapped);
return Err(MapToError::PageAlreadyMapped(frame));
}
p2[page.p2_index()].set_addr(frame.start_address(), flags | PageTableFlags::HUGE_PAGE);

Expand All @@ -95,7 +95,7 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {
frame: UnusedPhysFrame<Size4KiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size4KiB>, MapToError>
) -> Result<MapperFlush<Size4KiB>, MapToError<Size4KiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand All @@ -111,7 +111,7 @@ impl<'a, P: PhysToVirt> MappedPageTable<'a, P> {
.create_next_table(&mut p2[page.p2_index()], allocator)?;

if !p1[page.p1_index()].is_unused() {
return Err(MapToError::PageAlreadyMapped);
return Err(MapToError::PageAlreadyMapped(frame));
}
p1[page.p1_index()].set_frame(frame.frame(), flags);

Expand All @@ -126,7 +126,7 @@ impl<'a, P: PhysToVirt> Mapper<Size1GiB> for MappedPageTable<'a, P> {
frame: UnusedPhysFrame<Size1GiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size1GiB>, MapToError>
) -> Result<MapperFlush<Size1GiB>, MapToError<Size1GiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down Expand Up @@ -199,7 +199,7 @@ impl<'a, P: PhysToVirt> Mapper<Size2MiB> for MappedPageTable<'a, P> {
frame: UnusedPhysFrame<Size2MiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size2MiB>, MapToError>
) -> Result<MapperFlush<Size2MiB>, MapToError<Size2MiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down Expand Up @@ -280,7 +280,7 @@ impl<'a, P: PhysToVirt> Mapper<Size4KiB> for MappedPageTable<'a, P> {
frame: UnusedPhysFrame<Size4KiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size4KiB>, MapToError>
) -> Result<MapperFlush<Size4KiB>, MapToError<Size4KiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down Expand Up @@ -499,7 +499,25 @@ enum PageTableCreateError {
FrameAllocationFailed,
}

impl From<PageTableCreateError> for MapToError {
impl From<PageTableCreateError> for MapToError<Size4KiB> {
fn from(err: PageTableCreateError) -> Self {
match err {
PageTableCreateError::MappedToHugePage => MapToError::ParentEntryHugePage,
PageTableCreateError::FrameAllocationFailed => MapToError::FrameAllocationFailed,
}
}
}

impl From<PageTableCreateError> for MapToError<Size2MiB> {
fn from(err: PageTableCreateError) -> Self {
match err {
PageTableCreateError::MappedToHugePage => MapToError::ParentEntryHugePage,
PageTableCreateError::FrameAllocationFailed => MapToError::FrameAllocationFailed,
}
}
}

impl From<PageTableCreateError> for MapToError<Size1GiB> {
fn from(err: PageTableCreateError) -> Self {
match err {
PageTableCreateError::MappedToHugePage => MapToError::ParentEntryHugePage,
Expand Down
8 changes: 4 additions & 4 deletions src/structures/paging/mapper/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -88,7 +88,7 @@ pub trait Mapper<S: PageSize> {
frame: UnusedPhysFrame<S>,
flags: PageTableFlags,
frame_allocator: &mut A,
) -> Result<MapperFlush<S>, MapToError>
) -> Result<MapperFlush<S>, MapToError<S>>
where
Self: Sized,
A: FrameAllocator<Size4KiB>;
Expand Down Expand Up @@ -117,7 +117,7 @@ pub trait Mapper<S: PageSize> {
frame: UnusedPhysFrame<S>,
flags: PageTableFlags,
frame_allocator: &mut A,
) -> Result<MapperFlush<S>, MapToError>
) -> Result<MapperFlush<S>, MapToError<S>>
where
Self: Sized,
A: FrameAllocator<Size4KiB>,
Expand Down Expand Up @@ -156,15 +156,15 @@ impl<S: PageSize> MapperFlush<S> {

/// This error is returned from `map_to` and similar methods.
#[derive(Debug)]
pub enum MapToError {
pub enum MapToError<S: PageSize> {
/// An additional frame was needed for the mapping process, but the frame allocator
/// returned `None`.
FrameAllocationFailed,
/// An upper level page table entry has the `HUGE_PAGE` flag set, which means that the
/// given page is part of an already mapped huge page.
ParentEntryHugePage,
/// The given page is already mapped to a physical frame.
PageAlreadyMapped,
PageAlreadyMapped(UnusedPhysFrame<S>),
}

/// An error indicating that an `unmap` call failed.
Expand Down
6 changes: 3 additions & 3 deletions src/structures/paging/mapper/offset_page_table.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -55,7 +55,7 @@ impl<'a> Mapper<Size1GiB> for OffsetPageTable<'a> {
frame: UnusedPhysFrame<Size1GiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size1GiB>, MapToError>
) -> Result<MapperFlush<Size1GiB>, MapToError<Size1GiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down Expand Up @@ -89,7 +89,7 @@ impl<'a> Mapper<Size2MiB> for OffsetPageTable<'a> {
frame: UnusedPhysFrame<Size2MiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size2MiB>, MapToError>
) -> Result<MapperFlush<Size2MiB>, MapToError<Size2MiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down Expand Up @@ -123,7 +123,7 @@ impl<'a> Mapper<Size4KiB> for OffsetPageTable<'a> {
frame: UnusedPhysFrame<Size4KiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size4KiB>, MapToError>
) -> Result<MapperFlush<Size4KiB>, MapToError<Size4KiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down
26 changes: 13 additions & 13 deletions src/structures/paging/mapper/recursive_page_table.rs
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Expand Up @@ -85,22 +85,22 @@ impl<'a> RecursivePageTable<'a> {
/// Returns `MapToError::FrameAllocationFailed` if the entry is unused and the allocator
/// returned `None`. Returns `MapToError::ParentEntryHugePage` if the `HUGE_PAGE` flag is set
/// in the passed entry.
unsafe fn create_next_table<'b, A>(
unsafe fn create_next_table<'b, A, S: PageSize>(
entry: &'b mut PageTableEntry,
next_table_page: Page,
allocator: &mut A,
) -> Result<&'b mut PageTable, MapToError>
) -> Result<&'b mut PageTable, MapToError<S>>
where
A: FrameAllocator<Size4KiB>,
{
/// This inner function is used to limit the scope of `unsafe`.
///
/// This is a safe function, so we need to use `unsafe` blocks when we do something unsafe.
fn inner<'b, A>(
fn inner<'b, A, S: PageSize>(
entry: &'b mut PageTableEntry,
next_table_page: Page,
allocator: &mut A,
) -> Result<&'b mut PageTable, MapToError>
) -> Result<&'b mut PageTable, MapToError<S>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down Expand Up @@ -141,7 +141,7 @@ impl<'a> RecursivePageTable<'a> {
frame: UnusedPhysFrame<Size1GiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size1GiB>, MapToError>
) -> Result<MapperFlush<Size1GiB>, MapToError<Size1GiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand All @@ -152,7 +152,7 @@ impl<'a> RecursivePageTable<'a> {
let p3 = unsafe { Self::create_next_table(&mut p4[page.p4_index()], p3_page, allocator)? };

if !p3[page.p3_index()].is_unused() {
return Err(MapToError::PageAlreadyMapped);
return Err(MapToError::PageAlreadyMapped(frame));
}
p3[page.p3_index()].set_addr(frame.start_address(), flags | Flags::HUGE_PAGE);

Expand All @@ -167,7 +167,7 @@ impl<'a> RecursivePageTable<'a> {
frame: UnusedPhysFrame<Size2MiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size2MiB>, MapToError>
) -> Result<MapperFlush<Size2MiB>, MapToError<Size2MiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand All @@ -181,7 +181,7 @@ impl<'a> RecursivePageTable<'a> {
let p2 = unsafe { Self::create_next_table(&mut p3[page.p3_index()], p2_page, allocator)? };

if !p2[page.p2_index()].is_unused() {
return Err(MapToError::PageAlreadyMapped);
return Err(MapToError::PageAlreadyMapped(frame));
}
p2[page.p2_index()].set_addr(frame.start_address(), flags | Flags::HUGE_PAGE);

Expand All @@ -196,7 +196,7 @@ impl<'a> RecursivePageTable<'a> {
frame: UnusedPhysFrame<Size4KiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size4KiB>, MapToError>
) -> Result<MapperFlush<Size4KiB>, MapToError<Size4KiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand All @@ -212,7 +212,7 @@ impl<'a> RecursivePageTable<'a> {
let p1 = unsafe { Self::create_next_table(&mut p2[page.p2_index()], p1_page, allocator)? };

if !p1[page.p1_index()].is_unused() {
return Err(MapToError::PageAlreadyMapped);
return Err(MapToError::PageAlreadyMapped(frame));
}
p1[page.p1_index()].set_frame(frame.frame(), flags);

Expand All @@ -227,7 +227,7 @@ impl<'a> Mapper<Size1GiB> for RecursivePageTable<'a> {
frame: UnusedPhysFrame<Size1GiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size1GiB>, MapToError>
) -> Result<MapperFlush<Size1GiB>, MapToError<Size1GiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down Expand Up @@ -312,7 +312,7 @@ impl<'a> Mapper<Size2MiB> for RecursivePageTable<'a> {
frame: UnusedPhysFrame<Size2MiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size2MiB>, MapToError>
) -> Result<MapperFlush<Size2MiB>, MapToError<Size2MiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down Expand Up @@ -417,7 +417,7 @@ impl<'a> Mapper<Size4KiB> for RecursivePageTable<'a> {
frame: UnusedPhysFrame<Size4KiB>,
flags: PageTableFlags,
allocator: &mut A,
) -> Result<MapperFlush<Size4KiB>, MapToError>
) -> Result<MapperFlush<Size4KiB>, MapToError<Size4KiB>>
where
A: FrameAllocator<Size4KiB>,
{
Expand Down