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https://github.com/panpaul/tiny_os
synced 2024-09-20 09:45:19 +08:00
fix: allocator: freelist: reserve is not handling overlapped situations
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parent
0bb447ca28
commit
e9751585fe
@ -13,10 +13,10 @@ pub fn align_down(addr: usize, align: usize) -> usize {
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addr & !(align - 1)
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}
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#[derive(Copy, Clone, Default, PartialOrd, PartialEq)]
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#[derive(Copy, Clone, Default, Eq, Ord, PartialOrd, PartialEq)]
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pub struct PhysAddr(pub usize);
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#[derive(Copy, Clone, Default, PartialOrd, PartialEq)]
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#[derive(Copy, Clone, Default, Eq, Ord, PartialOrd, PartialEq)]
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pub struct VirtAddr(pub usize);
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pub trait AddressOps {
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@ -227,6 +227,12 @@ impl<T> From<*mut T> for PhysAddr {
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}
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}
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impl<T> From<*const T> for PhysAddr {
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fn from(addr: *const T) -> Self {
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PhysAddr(addr as usize)
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}
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}
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impl From<PhysAddr> for usize {
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fn from(addr: PhysAddr) -> Self {
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addr.0
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@ -263,6 +269,12 @@ impl<T> From<*mut T> for VirtAddr {
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}
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}
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impl<T> From<*const T> for VirtAddr {
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fn from(addr: *const T) -> Self {
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VirtAddr(addr as usize)
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}
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}
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impl From<VirtAddr> for usize {
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fn from(addr: VirtAddr) -> Self {
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addr.0
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@ -3,6 +3,8 @@
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use crate::utils::then::Then;
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use crate::vspace::addr::{AddressOps, PhysAddr};
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use core::alloc::{GlobalAlloc, Layout};
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use core::cmp::{max, min};
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use core::fmt::Debug;
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use spin::Mutex;
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struct ListNode {
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@ -42,12 +44,21 @@ impl ListNode {
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}
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}
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struct FreeList {
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impl Debug for ListNode {
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fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
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f.debug_struct("ListNode")
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.field("begin", &self.start_addr())
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.field("end", &self.end_addr())
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.finish()
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}
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}
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pub struct FreeList {
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head: ListNode,
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}
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impl FreeList {
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const fn new() -> Self {
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pub const fn new() -> Self {
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Self {
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head: ListNode::new(0),
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}
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@ -78,7 +89,7 @@ impl FreeList {
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(size, layout.align())
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}
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unsafe fn alloc(&mut self, layout: Layout) -> *mut u8 {
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pub unsafe fn alloc(&mut self, layout: Layout) -> *mut u8 {
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let (size, align) = Self::align_layout(layout);
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if let Some((region, alloc_start)) = self.alloc_node(|region| region.fit(size, align)) {
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@ -93,7 +104,7 @@ impl FreeList {
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}
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}
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unsafe fn dealloc(&mut self, start: PhysAddr, size: usize) {
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pub unsafe fn dealloc(&mut self, start: PhysAddr, size: usize) {
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assert_eq!(start.align_up(core::mem::align_of::<ListNode>()), start);
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assert!(size >= core::mem::size_of::<ListNode>());
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@ -105,32 +116,37 @@ impl FreeList {
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}
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pub fn reserve(&mut self, start: PhysAddr, size: usize) {
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if let Some((region, _)) =
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self.alloc_node(|region| (region.start_addr() <= start).and(|| region.fit(size, 1), ()))
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{
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/* layout
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* region: | before | [start +: size] | after |
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* ^ ^ ^ ^ region.end_addr()
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* | | alloc_start |
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* | | alloc_end
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* | region.start_addr()
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*/
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if let Some((region, _)) = self.alloc_node(|region| {
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let left = max(region.start_addr(), start);
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let right = min(region.end_addr(), start + size);
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(left < right).some(|| (), ())
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}) {
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let region_start = region.start_addr();
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let region_end = region.end_addr();
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let before_size = (start - region_start).as_usize();
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if before_size > 0 {
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unsafe { self.dealloc(region_start, before_size) }
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}
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let after_size = (region_end - (start + size)).as_usize();
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if after_size > 0 {
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unsafe { self.dealloc(start + size, after_size) }
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}
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let before_size = (start - region_start).as_usize();
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if before_size > 0 {
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unsafe { self.dealloc(region_start, before_size) }
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}
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}
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}
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}
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impl Debug for FreeList {
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fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
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let mut current = &self.head;
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while let Some(ref region) = current.next {
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write!(f, "{:?} -> ", region)?;
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current = region;
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}
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write!(f, "None")
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}
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}
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pub struct FreeListAllocator {
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list: Mutex<FreeList>,
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