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Remove now unneeded unsafe block in Heap Allocation post

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The `map_to` method is safe since x86_64 0.8.1.
This commit is contained in:
Philipp Oppermann
2019-12-11 16:50:13 +01:00
parent b65825e99a
commit b0317d0e4a
1 changed files with 2 additions and 2 deletions
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4
blog/content/second-edition/posts/10-heap-allocation/index.md
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@@ -422,7 +422,7 @@ pub fn init_heap(
.allocate_frame() .allocate_frame()
.ok_or(MapToError::FrameAllocationFailed)?; .ok_or(MapToError::FrameAllocationFailed)?;
let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE; let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE;
unsafe { mapper.map_to(page, frame, flags, frame_allocator)?.flush() }; mapper.map_to(page, frame, flags, frame_allocator)?.flush();
} }
Ok(()) Ok(())
@@ -448,7 +448,7 @@ The implementation can be broken down into two parts:
- We set the required `PRESENT` flag and the `WRITABLE` flag for the page. With these flags both read and write accesses are allowed, which makes sense for heap memory. - We set the required `PRESENT` flag and the `WRITABLE` flag for the page. With these flags both read and write accesses are allowed, which makes sense for heap memory.
- We use the unsafe [`Mapper::map_to`] method for creating the mapping in the active page table. The method can fail, therefore we use the [question mark operator] again to forward the error to the caller. On success, the method returns a [`MapperFlush`] instance that we can use to update the [_translation lookaside buffer_] using the [`flush`] method. - We use the [`Mapper::map_to`] method for creating the mapping in the active page table. The method can fail, therefore we use the [question mark operator] again to forward the error to the caller. On success, the method returns a [`MapperFlush`] instance that we can use to update the [_translation lookaside buffer_] using the [`flush`] method.
[`VirtAddr`]: https://docs.rs/x86_64/0.8.1/x86_64/struct.VirtAddr.html [`VirtAddr`]: https://docs.rs/x86_64/0.8.1/x86_64/struct.VirtAddr.html
[`Page`]: https://docs.rs/x86_64/0.8.1/x86_64/structures/paging/page/struct.Page.html [`Page`]: https://docs.rs/x86_64/0.8.1/x86_64/structures/paging/page/struct.Page.html