From ade0f0110f138333cc4a86fd27e9d60d62817034 Mon Sep 17 00:00:00 2001 From: WangRunji Date: Sat, 23 Jun 2018 19:11:41 +0800 Subject: [PATCH] Use PageTable interface in OS --- Cargo.toml | 1 + crate/memory/Cargo.toml | 2 +- crate/memory/src/cow.rs | 2 + crate/memory/src/paging/mock_page_table.rs | 7 +- crate/memory/src/paging/mod.rs | 16 +++ src/arch/x86_64/paging/mod.rs | 139 ++++++++++++++++----- src/lib.rs | 1 + src/memory/memory_set.rs | 48 ++++--- src/memory/mod.rs | 8 +- src/memory/stack_allocator.rs | 4 +- 10 files changed, 161 insertions(+), 67 deletions(-) diff --git a/Cargo.toml b/Cargo.toml index a4d9d16..c59b65d 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -36,6 +36,7 @@ uart_16550 = "0.1" lazy_static = { version = "1.0.0", features = ["spin_no_std"] } simple-filesystem = { git = "https://github.com/wangrunji0408/SimpleFileSystem-Rust" } bit-allocator = { path = "crate/bit-allocator" } +ucore-memory = { path = "crate/memory" } [build-dependencies] cc = "1.0" diff --git a/crate/memory/Cargo.toml b/crate/memory/Cargo.toml index c914a0d..dcc9ec1 100644 --- a/crate/memory/Cargo.toml +++ b/crate/memory/Cargo.toml @@ -1,5 +1,5 @@ [package] -name = "memory" +name = "ucore-memory" version = "0.1.0" authors = ["WangRunji "] diff --git a/crate/memory/src/cow.rs b/crate/memory/src/cow.rs index a62d629..b7f4a98 100644 --- a/crate/memory/src/cow.rs +++ b/crate/memory/src/cow.rs @@ -22,6 +22,7 @@ impl CowExt { let entry = self.page_table.map(addr, target); entry.set_writable(false); entry.set_shared(writable); + entry.update(); let frame = target / PAGE_SIZE; match writable { true => self.rc_map.write_increase(&frame), @@ -52,6 +53,7 @@ impl CowExt { if self.rc_map.read_count(&frame) == 0 && self.rc_map.write_count(&frame) == 1 { entry.clear_shared(); entry.set_writable(true); + entry.update(); self.rc_map.write_decrease(&frame); return true; } diff --git a/crate/memory/src/paging/mock_page_table.rs b/crate/memory/src/paging/mock_page_table.rs index 3f10135..78cd33b 100644 --- a/crate/memory/src/paging/mock_page_table.rs +++ b/crate/memory/src/paging/mock_page_table.rs @@ -22,6 +22,7 @@ pub struct MockEntry { } impl Entry for MockEntry { + fn update(&mut self) {} fn accessed(&self) -> bool { self.accessed } fn dirty(&self) -> bool { self.dirty } fn writable(&self) -> bool { self.writable } @@ -42,6 +43,11 @@ impl Entry for MockEntry { self.writable_shared = false; self.readonly_shared = false; } + + fn user(&self) -> bool { unimplemented!() } + fn set_user(&mut self, value: bool) { unimplemented!() } + fn execute(&self) -> bool { unimplemented!() } + fn set_execute(&mut self, value: bool) { unimplemented!() } } type PageFaultHandler = Box; @@ -49,7 +55,6 @@ type PageFaultHandler = Box; impl PageTable for MockPageTable { type Entry = MockEntry; - /// Map a page, return false if no more space fn map(&mut self, addr: VirtAddr, target: PhysAddr) -> &mut Self::Entry { let entry = &mut self.entries[addr / PAGE_SIZE]; assert!(!entry.present); diff --git a/crate/memory/src/paging/mod.rs b/crate/memory/src/paging/mod.rs index 03f5f65..720224a 100644 --- a/crate/memory/src/paging/mod.rs +++ b/crate/memory/src/paging/mod.rs @@ -1,6 +1,12 @@ +//! Generic page table interface +//! +//! Implemented for every architecture, used by OS. + use super::*; +#[cfg(test)] pub use self::mock_page_table::MockPageTable; +#[cfg(test)] mod mock_page_table; pub trait PageTable { @@ -13,6 +19,11 @@ pub trait PageTable { } pub trait Entry { + /// IMPORTANT! + /// This must be called after any change to ensure it become effective. + /// Usually this will make a flush to TLB/MMU. + fn update(&mut self); + /// Will be set when accessed fn accessed(&self) -> bool; /// Will be set when written @@ -34,4 +45,9 @@ pub trait Entry { fn readonly_shared(&self) -> bool; fn set_shared(&mut self, writable: bool); fn clear_shared(&mut self); + + fn user(&self) -> bool; + fn set_user(&mut self, value: bool); + fn execute(&self) -> bool; + fn set_execute(&mut self, value: bool); } diff --git a/src/arch/x86_64/paging/mod.rs b/src/arch/x86_64/paging/mod.rs index eb9b65d..38bb5e0 100644 --- a/src/arch/x86_64/paging/mod.rs +++ b/src/arch/x86_64/paging/mod.rs @@ -1,20 +1,11 @@ use memory::*; -//pub use self::cow::*; -use x86_64::structures::paging::*; -use x86_64::registers::control::{Cr3, Cr3Flags}; +pub use ucore_memory::paging::{Entry, PageTable}; use x86_64::instructions::tlb; +use x86_64::registers::control::{Cr3, Cr3Flags}; +use x86_64::structures::paging::{Mapper, PageTable as x86PageTable, PageTableEntry, PageTableFlags as EF, RecursivePageTable}; +pub use x86_64::structures::paging::{FrameAllocator, FrameDeallocator, Page, PageRange, PhysFrame as Frame, Size4KiB}; use x86_64::ux::u9; -pub type Frame = PhysFrame; -pub type EntryFlags = PageTableFlags; -pub type ActivePageTable = RecursivePageTable<'static>; - -pub use x86_64::structures::paging::{Page, PageRange, Mapper, FrameAllocator, FrameDeallocator, Size4KiB, PageTable}; - -//mod cow; - -const ENTRY_COUNT: usize = 512; - pub trait PageExt { fn of_addr(address: VirtAddr) -> Self; fn range_of(begin: VirtAddr, end: VirtAddr) -> PageRange; @@ -40,18 +31,53 @@ impl FrameExt for Frame { } } -pub trait ActiveTableExt { - fn with(&mut self, table: &mut InactivePageTable, f: impl FnOnce(&mut ActivePageTable)); - fn map_to_(&mut self, page: Page, frame: Frame, flags: EntryFlags); +pub struct ActivePageTable(RecursivePageTable<'static>); + +pub struct PageEntry(PageTableEntry); + +impl PageTable for ActivePageTable { + type Entry = PageEntry; + + fn map(&mut self, addr: usize, target: usize) -> &mut PageEntry { + let flags = EF::PRESENT | EF::WRITABLE | EF::NO_EXECUTE; + self.0.map_to(Page::of_addr(addr), Frame::of_addr(target), flags, &mut frame_allocator()) + .unwrap().flush(); + self.get_entry(addr) + } + + fn unmap(&mut self, addr: usize) { + let (frame, flush) = self.0.unmap(Page::of_addr(addr)).unwrap(); + flush.flush(); + } + + fn get_entry(&mut self, addr: usize) -> &mut PageEntry { + let entry_addr = ((addr >> 9) & 0o777_777_777_7770) | 0xffffff80_00000000; + unsafe { &mut *(entry_addr as *mut PageEntry) } + } + + fn read_page(&mut self, addr: usize, data: &mut [u8]) { + use core::slice; + let mem = unsafe { slice::from_raw_parts((addr & !0xfffusize) as *const u8, 4096) }; + data.copy_from_slice(mem); + } + + fn write_page(&mut self, addr: usize, data: &[u8]) { + use core::slice; + let mem = unsafe { slice::from_raw_parts_mut((addr & !0xfffusize) as *mut u8, 4096) }; + mem.copy_from_slice(data); + } } -impl ActiveTableExt for ActivePageTable { - fn with(&mut self, table: &mut InactivePageTable, f: impl FnOnce(&mut ActivePageTable)) { - with_temporary_map(self, &Cr3::read().0, |active_table, p4_table: &mut PageTable| { +impl ActivePageTable { + pub unsafe fn new() -> Self { + ActivePageTable(RecursivePageTable::new(&mut *(0xffffffff_fffff000 as *mut _)).unwrap()) + } + pub fn with(&mut self, table: &mut InactivePageTable, f: impl FnOnce(&mut ActivePageTable)) { + with_temporary_map(self, &Cr3::read().0, |active_table, p4_table: &mut x86PageTable| { let backup = p4_table[0o777].clone(); // overwrite recursive mapping - p4_table[0o777].set_frame(table.p4_frame.clone(), EntryFlags::PRESENT | EntryFlags::WRITABLE); + p4_table[0o777].set_frame(table.p4_frame.clone(), EF::PRESENT | EF::WRITABLE); tlb::flush_all(); // execute f in the new context @@ -62,20 +88,55 @@ impl ActiveTableExt for ActivePageTable { tlb::flush_all(); }); } - fn map_to_(&mut self, page: Page, frame: PhysFrame, flags: EntryFlags) { - self.map_to(page, frame, flags, &mut frame_allocator()).unwrap().flush(); + pub fn map_to(&mut self, page: Page, frame: Frame) -> &mut PageEntry { + self.map(page.start_address().as_u64() as usize, frame.start_address().as_u64() as usize) + } +} - // Set user bit for p1-p4 entry - // It's a workaround since x86_64 PageTable do not set user bit. - if flags.contains(EntryFlags::USER_ACCESSIBLE) { - let mut addr = page.start_address().as_u64(); - for _ in 0..4 { +impl Entry for PageEntry { + fn update(&mut self) { + use x86_64::{VirtAddr, instructions::tlb::flush}; + let addr = VirtAddr::new_unchecked((self as *const _ as u64) << 9); + flush(addr); + } + fn accessed(&self) -> bool { self.0.flags().contains(EF::ACCESSED) } + fn dirty(&self) -> bool { self.0.flags().contains(EF::DIRTY) } + fn writable(&self) -> bool { self.0.flags().contains(EF::WRITABLE) } + fn present(&self) -> bool { self.0.flags().contains(EF::PRESENT) } + fn clear_accessed(&mut self) { self.as_flags().remove(EF::ACCESSED); } + fn clear_dirty(&mut self) { self.as_flags().remove(EF::DIRTY); } + fn set_writable(&mut self, value: bool) { self.as_flags().set(EF::WRITABLE, value); } + fn set_present(&mut self, value: bool) { self.as_flags().set(EF::PRESENT, value); } + fn target(&self) -> usize { self.0.addr().as_u64() as usize } + fn writable_shared(&self) -> bool { self.0.flags().contains(EF::BIT_10) } + fn readonly_shared(&self) -> bool { self.0.flags().contains(EF::BIT_9) } + fn set_shared(&mut self, writable: bool) { + let flags = self.as_flags(); + flags.set(EF::BIT_10, writable); + flags.set(EF::BIT_9, !writable); + } + fn clear_shared(&mut self) { self.as_flags().remove(EF::BIT_9 | EF::BIT_10); } + fn user(&self) -> bool { self.0.flags().contains(EF::USER_ACCESSIBLE) } + fn set_user(&mut self, value: bool) { + self.as_flags().set(EF::USER_ACCESSIBLE, value); + if value { + let mut addr = self as *const _ as usize; + for _ in 0..3 { + // Upper level entry addr = ((addr >> 9) & 0o777_777_777_7770) | 0xffffff80_00000000; // set USER_ACCESSIBLE - unsafe { (*(addr as *mut EntryFlags)).insert(EntryFlags::USER_ACCESSIBLE) }; + unsafe { (*(addr as *mut EF)).insert(EF::USER_ACCESSIBLE) }; } } } + fn execute(&self) -> bool { !self.0.flags().contains(EF::NO_EXECUTE) } + fn set_execute(&mut self, value: bool) { self.as_flags().set(EF::NO_EXECUTE, !value); } +} + +impl PageEntry { + fn as_flags(&mut self) -> &mut EF { + unsafe { &mut *(self as *mut _ as *mut EF) } + } } #[derive(Debug)] @@ -85,13 +146,23 @@ pub struct InactivePageTable { impl InactivePageTable { pub fn new(frame: Frame, active_table: &mut ActivePageTable) -> InactivePageTable { - with_temporary_map(active_table, &frame, |_, table: &mut PageTable| { + with_temporary_map(active_table, &frame, |_, table: &mut x86PageTable| { table.zero(); // set up recursive mapping for the table - table[511].set_frame(frame.clone(), EntryFlags::PRESENT | EntryFlags::WRITABLE); + table[511].set_frame(frame.clone(), EF::PRESENT | EF::WRITABLE); }); InactivePageTable { p4_frame: frame } } + pub fn map_kernel(&mut self, active_table: &mut ActivePageTable) { + let mut table = unsafe { &mut *(0xffffffff_fffff000 as *mut x86PageTable) }; + let e510 = table[510].clone(); + let e509 = table[509].clone(); + + active_table.with(self, |pt: &mut ActivePageTable| { + table[510] = e510; + table[509] = e509; + }); + } pub fn switch(&self) { let old_frame = Cr3::read().0; let new_frame = self.p4_frame.clone(); @@ -112,15 +183,15 @@ impl Drop for InactivePageTable { } } -fn with_temporary_map(active_table: &mut ActivePageTable, frame: &Frame, f: impl FnOnce(&mut ActivePageTable, &mut PageTable)) { +fn with_temporary_map(active_table: &mut ActivePageTable, frame: &Frame, f: impl FnOnce(&mut ActivePageTable, &mut x86PageTable)) { // Create a temporary page let page = Page::of_addr(0xcafebabe); - assert!(active_table.translate_page(page).is_none(), "temporary page is already mapped"); + assert!(active_table.0.translate_page(page).is_none(), "temporary page is already mapped"); // Map it to table - active_table.map_to_(page, frame.clone(), EntryFlags::PRESENT | EntryFlags::WRITABLE); + active_table.map_to(page, frame.clone()); // Call f let table = unsafe { &mut *page.start_address().as_mut_ptr() }; f(active_table, table); // Unmap the page - active_table.unmap(page).unwrap().1.flush(); + active_table.unmap(0xcafebabe); } \ No newline at end of file diff --git a/src/lib.rs b/src/lib.rs index ed52957..7ad73b4 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -36,6 +36,7 @@ extern crate simple_filesystem; extern crate spin; extern crate syscall as redox_syscall; extern crate uart_16550; +extern crate ucore_memory; extern crate volatile; #[macro_use] extern crate x86_64; diff --git a/src/memory/memory_set.rs b/src/memory/memory_set.rs index d0ee1d4..7cba816 100644 --- a/src/memory/memory_set.rs +++ b/src/memory/memory_set.rs @@ -67,54 +67,61 @@ impl MemoryArea { Some(phys_start) => { for page in Page::range_of(self.start_addr, self.end_addr) { let frame = Frame::of_addr(phys_start.get() + page.start_address().as_u64() as usize - self.start_addr); - pt.map_to_(page, frame, self.flags.0); + self.flags.apply(pt.map_to(page, frame)); } } None => { for page in Page::range_of(self.start_addr, self.end_addr) { let frame = alloc_frame(); - pt.map_to_(page, frame, self.flags.0); + self.flags.apply(pt.map_to(page, frame)); } } } } fn unmap(&self, pt: &mut ActivePageTable) { for page in Page::range_of(self.start_addr, self.end_addr) { - let (frame, flush) = pt.unmap(page).unwrap(); - flush.flush(); + let addr = page.start_address().as_u64() as usize; if self.phys_start_addr.is_none() { + let frame = Frame::of_addr(pt.get_entry(addr).target()); dealloc_frame(frame); } + pt.unmap(addr); } } } -#[derive(Debug, Copy, Clone, Eq, PartialEq)] -pub struct MemoryAttr(EntryFlags); - -impl Default for MemoryAttr { - fn default() -> Self { - MemoryAttr(EntryFlags::PRESENT | EntryFlags::NO_EXECUTE | EntryFlags::WRITABLE) - } +#[derive(Debug, Copy, Clone, Eq, PartialEq, Default)] +pub struct MemoryAttr { + user: bool, + readonly: bool, + execute: bool, + hide: bool, } impl MemoryAttr { pub fn user(mut self) -> Self { - self.0 |= EntryFlags::USER_ACCESSIBLE; + self.user = true; self } pub fn readonly(mut self) -> Self { - self.0.remove(EntryFlags::WRITABLE); + self.readonly = true; self } pub fn execute(mut self) -> Self { - self.0.remove(EntryFlags::NO_EXECUTE); + self.execute = true; self } pub fn hide(mut self) -> Self { - self.0.remove(EntryFlags::PRESENT); + self.hide = true; self } + fn apply(&self, entry: &mut impl Entry) { + if self.user { entry.set_user(true); } + if self.readonly { entry.set_writable(false); } + if self.execute { entry.set_execute(true); } + if self.hide { entry.set_present(false); } + if self.user || self.readonly || self.execute || self.hide { entry.update(); } + } } /// 内存空间集合，包含若干段连续空间 @@ -226,15 +233,6 @@ fn new_page_table_with_kernel() -> InactivePageTable { let frame = alloc_frame(); let mut active_table = active_table(); let mut page_table = InactivePageTable::new(frame, &mut active_table); - - use consts::{KERNEL_HEAP_PML4, KERNEL_PML4}; - let mut table = unsafe { &mut *(0xffffffff_fffff000 as *mut PageTable) }; - let e510 = table[KERNEL_PML4].clone(); - let e509 = table[KERNEL_HEAP_PML4].clone(); - - active_table.with(&mut page_table, |pt: &mut ActivePageTable| { - table[KERNEL_PML4] = e510; - table[KERNEL_HEAP_PML4] = e509; - }); + page_table.map_kernel(&mut active_table); page_table } diff --git a/src/memory/mod.rs b/src/memory/mod.rs index 2da473c..03e548c 100644 --- a/src/memory/mod.rs +++ b/src/memory/mod.rs @@ -8,6 +8,7 @@ pub use self::memory_set::*; pub use self::stack_allocator::*; use spin::{Mutex, MutexGuard}; use super::HEAP_ALLOCATOR; +use ucore_memory::paging::PageTable; mod memory_set; mod stack_allocator; @@ -42,7 +43,7 @@ fn alloc_stack(size_in_pages: usize) -> Stack { fn active_table() -> MutexGuard<'static, ActivePageTable> { lazy_static! { static ref ACTIVE_TABLE: Mutex = Mutex::new(unsafe { - ActivePageTable::new(&mut *(0xffffffff_fffff000 as *mut _)).unwrap() + ActivePageTable::new() }); } ACTIVE_TABLE.lock() @@ -153,11 +154,10 @@ fn get_init_kstack_and_set_guard_page() -> Stack { extern { fn stack_bottom(); } let stack_bottom = PhysAddr::new(stack_bottom as u64).to_kernel_virtual(); - let stack_bottom_page = Page::of_addr(stack_bottom); // turn the stack bottom into a guard page - active_table().unmap(stack_bottom_page); - debug!("guard page at {:?}", stack_bottom_page.start_address()); + active_table().unmap(stack_bottom); + debug!("guard page at {:?}", stack_bottom); Stack::new(stack_bottom + 8 * PAGE_SIZE, stack_bottom + 1 * PAGE_SIZE) } diff --git a/src/memory/stack_allocator.rs b/src/memory/stack_allocator.rs index 4b7358f..bdb313e 100644 --- a/src/memory/stack_allocator.rs +++ b/src/memory/stack_allocator.rs @@ -1,5 +1,5 @@ -use super::*; use memory::PAGE_SIZE; +use super::*; // TODO: use BitAllocator & alloc fixed size stack pub struct StackAllocator { @@ -41,7 +41,7 @@ impl StackAllocator { // map stack pages to physical frames for page in Page::range_inclusive(start, end) { let frame = alloc_frame(); - active_table.map_to_(page, frame, EntryFlags::PRESENT | EntryFlags::WRITABLE); + active_table.map_to(page, frame); } // create a new stack