Allocate kernel stack from heap, remove stack allocator, remove guard page.

crate/memory/src/memory_set.rs

@@ -14,7 +14,7 @@ pub trait InactivePageTable {
 
     fn alloc_frame() -> Option<PhysAddr>;
     fn dealloc_frame(target: PhysAddr);
-    fn alloc_stack(size_in_pages: usize) -> Stack;
+    fn alloc_stack() -> Stack;
 }
 
 /// 一片连续内存空间，有相同的访问权限
@@ -139,7 +139,7 @@ impl<T: InactivePageTable> MemorySet<T> {
         MemorySet {
             areas: Vec::<MemoryArea>::new(),
             page_table: T::new(),
-            kstack: T::alloc_stack(7),
+            kstack: T::alloc_stack(),
         }
     }
     /// Used for remap_kernel() where heap alloc is unavailable
@@ -184,7 +184,7 @@ impl<T: InactivePageTable> MemorySet<T> {
         MemorySet {
             areas: self.areas.clone(),
             page_table,
-            kstack: T::alloc_stack(7),
+            kstack: T::alloc_stack(),
         }
     }
     pub fn clear(&mut self) {

crate/riscv

@@ -1 +1 @@
-Subproject commit 48c7d74041c38e4f230df02075ad7519c1bf816d
+Subproject commit 08d4a2e96399cef5985a85a035e1ac222f8d5bef

src/arch/riscv32/memory.rs

@@ -33,6 +33,7 @@ fn init_frame_allocator() {
 }
 
 fn remap_the_kernel() {
+    use consts::{KERNEL_HEAP_OFFSET, KERNEL_HEAP_SIZE};
     let kstack = Stack {
         top: bootstacktop as usize,
         bottom: bootstack as usize + PAGE_SIZE,
@@ -43,6 +44,7 @@ fn remap_the_kernel() {
     ms.push(MemoryArea::new_identity(sdata as usize, edata as usize, MemoryAttr::default(), "data"));
     ms.push(MemoryArea::new_identity(srodata as usize, erodata as usize, MemoryAttr::default().readonly(), "rodata"));
     ms.push(MemoryArea::new_identity(sbss as usize, ebss as usize, MemoryAttr::default(), "bss"));
+    ms.push(MemoryArea::new(KERNEL_HEAP_OFFSET, KERNEL_HEAP_OFFSET + KERNEL_HEAP_SIZE, MemoryAttr::default(), "kernel_heap"));
     unsafe { ms.activate(); }
     info!("kernel remap end");
 }

src/arch/riscv32/paging.rs

@@ -202,8 +202,8 @@ impl InactivePageTable for InactivePageTable0 {
         dealloc_frame(target)
     }
 
-    fn alloc_stack(size_in_pages: usize) -> Stack {
+    fn alloc_stack() -> Stack {
-        alloc_stack(size_in_pages)
+        alloc_stack()
     }
 }
 

src/arch/x86_64/boot/boot.asm

@@ -1,5 +1,6 @@
 global start
 global stack_bottom
+global stack_top
 extern long_mode_start
 
 section .text

src/arch/x86_64/memory.rs

@@ -54,10 +54,10 @@ fn init_frame_allocator(boot_info: &BootInformation) {
 
 fn remap_the_kernel(boot_info: &BootInformation) -> MemorySet {
     extern { fn stack_bottom(); }
-    let stack_bottom = stack_bottom as usize + KERNEL_OFFSET;
+    extern { fn stack_top(); }
     let kstack = Stack {
-        top: stack_bottom + 8 * PAGE_SIZE,
+        top: stack_top as usize + KERNEL_OFFSET,
-        bottom: stack_bottom + 1 * PAGE_SIZE,
+        bottom: stack_bottom as usize + PAGE_SIZE + KERNEL_OFFSET,
     };
 
     let mut memory_set = memory_set_from(boot_info.elf_sections_tag().unwrap(), kstack);
@@ -76,10 +76,6 @@ fn remap_the_kernel(boot_info: &BootInformation) -> MemorySet {
     unsafe { memory_set.activate(); }
     info!("NEW TABLE!!!");
 
-    // turn the stack bottom into a guard page
-    active_table().unmap(stack_bottom);
-    debug!("guard page at {:x?}", stack_bottom);
-
     memory_set
 }
 

src/arch/x86_64/paging.rs

@@ -1,20 +1,17 @@
-use ucore_memory::PAGE_SIZE;
+use bit_allocator::{BitAlloc, BitAlloc64K};
+// Depends on kernel
+use memory::{active_table, alloc_frame, alloc_stack, dealloc_frame};
+use spin::{Mutex, MutexGuard};
 use ucore_memory::cow::CowExt;
-use ucore_memory::paging::*;
 use ucore_memory::memory_set::*;
-
+use ucore_memory::PAGE_SIZE;
+use ucore_memory::paging::*;
 use x86_64::instructions::tlb;
+use x86_64::PhysAddr;
 use x86_64::registers::control::{Cr3, Cr3Flags};
 use x86_64::structures::paging::{Mapper, PageTable as x86PageTable, PageTableEntry, PageTableFlags as EF, RecursivePageTable};
 use x86_64::structures::paging::{FrameAllocator, FrameDeallocator, Page, PageRange, PhysFrame as Frame, Size4KiB};
 use x86_64::ux::u9;
-use x86_64::PhysAddr;
-
-use bit_allocator::{BitAlloc, BitAlloc64K};
-use spin::{Mutex, MutexGuard};
-
-// Depends on kernel
-use memory::{active_table, alloc_frame, dealloc_frame, alloc_stack};
 
 pub trait PageExt {
     fn of_addr(address: usize) -> Self;
@@ -224,8 +221,8 @@ impl InactivePageTable for InactivePageTable0 {
         dealloc_frame(target)
     }
 
-    fn alloc_stack(size_in_pages: usize) -> Stack {
+    fn alloc_stack() -> Stack {
-        alloc_stack(size_in_pages)
+        alloc_stack()
     }
 }
 

src/consts.rs

@@ -19,10 +19,6 @@ mod riscv {
     pub const KERNEL_PML4: usize = 0x8040_0000 >> 22;
     pub const KERNEL_HEAP_OFFSET: usize = 0x8050_0000;
     pub const KERNEL_HEAP_SIZE: usize = 1 * 1024 * 1024;
-    // 1 MB
-    pub const KERNEL_STACK_OFFSET: usize = KERNEL_HEAP_OFFSET + KERNEL_HEAP_SIZE;
-    pub const KERNEL_STACK_SIZE: usize = 64 * 1024;
-    // 64 KB
     pub const MEMORY_OFFSET: usize = 0x8000_0000;
     pub const MEMORY_END: usize = 0x8080_0000;
 }
@@ -56,9 +52,6 @@ mod x86_64 {
     /// Size of kernel heap
     pub const KERNEL_HEAP_SIZE: usize = 8 * 1024 * 1024; // 8 MB
 
-    pub const KERNEL_STACK_OFFSET: usize = KERNEL_HEAP_OFFSET + KERNEL_HEAP_SIZE;
-    pub const KERNEL_STACK_SIZE: usize = 1 * 1024 * 1024; // 1 MB
-
     pub const MEMORY_OFFSET: usize = 0;
 
     /// Offset to kernel percpu variables

src/memory.rs

@@ -1,22 +1,18 @@
 pub use arch::paging::*;
 use bit_allocator::{BitAlloc, BitAlloc64K};
 use consts::MEMORY_OFFSET;
-use self::stack_allocator::*;
 use spin::{Mutex, MutexGuard};
 use super::HEAP_ALLOCATOR;
 use ucore_memory::{*, paging::PageTable};
-pub use ucore_memory::memory_set::{MemoryArea, MemoryAttr, MemorySet as MemorySet_, Stack};
 #[cfg(target_arch = "x86_64")]
-use ucore_memory::paging::CowExt;
+use ucore_memory::cow::CowExt;
+pub use ucore_memory::memory_set::{MemoryArea, MemoryAttr, MemorySet as MemorySet_, Stack};
 
 pub type MemorySet = MemorySet_<InactivePageTable0>;
 
-mod stack_allocator;
-
 lazy_static! {
     pub static ref FRAME_ALLOCATOR: Mutex<BitAlloc64K> = Mutex::new(BitAlloc64K::default());
 }
-pub static STACK_ALLOCATOR: Mutex<Option<StackAllocator>> = Mutex::new(None);
 
 pub fn alloc_frame() -> Option<usize> {
     FRAME_ALLOCATOR.lock().alloc().map(|id| id * PAGE_SIZE + MEMORY_OFFSET)
@@ -26,10 +22,16 @@ pub fn dealloc_frame(target: usize) {
     FRAME_ALLOCATOR.lock().dealloc((target - MEMORY_OFFSET) / PAGE_SIZE);
 }
 
-pub fn alloc_stack(size_in_pages: usize) -> Stack {
+// alloc from heap
-    STACK_ALLOCATOR.lock()
+pub fn alloc_stack() -> Stack {
-        .as_mut().expect("stack allocator is not initialized")
+    use alloc::boxed::Box;
-        .alloc_stack(size_in_pages).expect("no more stack")
+    const STACK_SIZE: usize = 8 * 4096;
+    #[repr(align(4096))]
+    struct StackData([u8; STACK_SIZE]);
+    let data = Box::new(StackData([0; STACK_SIZE]));
+    let bottom = Box::into_raw(data) as usize;
+    let top = bottom + STACK_SIZE;
+    Stack { top, bottom }
 }
 
 #[cfg(target_arch = "x86_64")]
@@ -71,14 +73,9 @@ pub fn page_fault_handler(addr: usize) -> bool {
 }
 
 pub fn init_heap() {
-    use consts::{KERNEL_HEAP_OFFSET, KERNEL_HEAP_SIZE, KERNEL_STACK_OFFSET, KERNEL_STACK_SIZE};
+    use consts::{KERNEL_HEAP_OFFSET, KERNEL_HEAP_SIZE};
-
     unsafe { HEAP_ALLOCATOR.lock().init(KERNEL_HEAP_OFFSET, KERNEL_HEAP_SIZE); }
-
+    info!("heap init end");
-    *STACK_ALLOCATOR.lock() = Some({
-        use ucore_memory::Page;
-        StackAllocator::new(Page::range_of(KERNEL_STACK_OFFSET, KERNEL_STACK_OFFSET + KERNEL_STACK_SIZE))
-    });
 }
 
 //pub mod test {

src/memory/stack_allocator.rs

@@ -1,58 +0,0 @@
-use ucore_memory::*;
-use ucore_memory::paging::PageTable;
-use ucore_memory::memory_set::Stack;
-use memory::{alloc_frame, active_table};
-
-// TODO: use BitAllocator & alloc fixed size stack
-pub struct StackAllocator {
-    range: PageRange,
-}
-
-impl StackAllocator {
-    pub fn new(page_range: PageRange) -> StackAllocator {
-        StackAllocator { range: page_range }
-    }
-}
-
-impl StackAllocator {
-    pub fn alloc_stack(&mut self, size_in_pages: usize) -> Option<Stack> {
-        if size_in_pages == 0 {
-            return None; /* a zero sized stack makes no sense */
-        }
-
-        // clone the range, since we only want to change it on success
-        let mut range = self.range.clone();
-
-        // try to allocate the stack pages and a guard page
-        let guard_page = range.next();
-        let stack_start = range.next();
-        let stack_end = if size_in_pages == 1 {
-            stack_start
-        } else {
-            // choose the (size_in_pages-2)th element, since index
-            // starts at 0 and we already allocated the start page
-            range.nth(size_in_pages - 2)
-        };
-
-        match (guard_page, stack_start, stack_end) {
-            (Some(_), Some(start), Some(end)) => {
-                // success! write back updated range
-                self.range = range;
-
-                // map stack pages to physical frames
-                for page in Page::range_of(start.start_address(), end.start_address() + PAGE_SIZE) {
-                    let frame = alloc_frame().unwrap();
-                    active_table().map(page.start_address(), frame);
-                }
-
-                // create a new stack
-                let top_of_stack = end.start_address() + PAGE_SIZE;
-                Some(Stack {
-                    top: top_of_stack,
-                    bottom: start.start_address(),
-                })
-            }
-            _ => None, /* not enough pages */
-        }
-    }
-}