Fix mipsel page fault handling

kernel/spec.md

@@ -30,6 +30,7 @@
 - fn ack(trap: usize)：确认中断处理
 - fn timer()：处理时钟中断
 - fn wait_for_interrupt()：打开并等待中断
+- fn handle_user_page_fault(thread: &Arc\<Thread\>, addr: usize)：处理用户态的缺页异常
 
 ### interrupt/consts
 

kernel/src/arch/aarch64/interrupt/mod.rs

@@ -2,7 +2,9 @@
 
 pub use self::handler::*;
 use crate::arch::board::timer::is_pending;
+use crate::process::thread::Thread;
 use aarch64::regs::*;
+use alloc::sync::Arc;
 use trapframe::UserContext;
 
 pub mod consts;
@@ -68,3 +70,7 @@ pub fn wait_for_interrupt() {
     aarch64::asm::wfe();
     DAIF.set(daif);
 }
+
+pub fn handle_user_page_fault(thread: &Arc<Thread>, addr: usize) -> bool {
+    thread.vm.lock().handle_page_fault(addr)
+}

kernel/src/arch/mipsel/interrupt/consts.rs

@@ -1,3 +1,5 @@
+use mips::registers::cp0;
+
 pub const IrqMin: usize = 0x20;
 pub const IrqMax: usize = 0x3f;
 pub const Syscall: usize = 0x100;
@@ -5,5 +7,12 @@ pub const Syscall: usize = 0x100;
 pub const Timer: usize = IrqMin + 0;
 
 pub fn is_page_fault(trap: usize) -> bool {
-    false
+    use cp0::cause::Exception as E;
+    let cause = cp0::cause::Cause { bits: trap as u32 };
+    match cause.cause() {
+        E::TLBModification => true,
+        E::TLBLoadMiss => true,
+        E::TLBStoreMiss => true,
+        _ => false,
+    }
 }

kernel/src/arch/mipsel/interrupt/mod.rs

@@ -1,5 +1,7 @@
 use crate::arch::paging::get_root_page_table_ptr;
 use crate::drivers::IRQ_MANAGER;
+use crate::process::thread::Thread;
+use alloc::sync::Arc;
 use log::*;
 use mips::addr::*;
 use mips::interrupts;
@@ -235,6 +237,39 @@ fn reserved_inst(tf: &mut TrapFrame) -> bool {
     false
 }
 
+pub fn handle_user_page_fault(thread: &Arc<Thread>, addr: usize) -> bool {
+    let virt_addr = VirtAddr::new(addr);
+    let root_table = unsafe { &mut *(get_root_page_table_ptr() as *mut MIPSPageTable) };
+    let tlb_result = root_table.lookup(addr);
+    match tlb_result {
+        Ok(tlb_entry) => {
+            trace!(
+                "PhysAddr = {:x}/{:x}",
+                tlb_entry.entry_lo0.get_pfn() << 12,
+                tlb_entry.entry_lo1.get_pfn() << 12
+            );
+
+            let tlb_valid = if virt_addr.page_number() & 1 == 0 {
+                tlb_entry.entry_lo0.valid()
+            } else {
+                tlb_entry.entry_lo1.valid()
+            };
+
+            if !tlb_valid {
+                if !thread.vm.lock().handle_page_fault(addr) {
+                    return false;
+                }
+            }
+
+            tlb_entry.write_random();
+            true
+        }
+        Err(()) => {
+            return thread.vm.lock().handle_page_fault(addr);
+        }
+    }
+}
+
 fn page_fault(tf: &mut TrapFrame) {
     // TODO: set access/dirty bit
     let addr = tf.vaddr;

kernel/src/arch/mipsel/memory.rs

@@ -1,6 +1,7 @@
 use crate::arch::paging::*;
 use crate::consts::{KERNEL_OFFSET, MEMORY_END, MEMORY_OFFSET};
 use crate::memory::{init_heap, FRAME_ALLOCATOR};
+use mips::registers::cp0;
 use rcore_memory::PAGE_SIZE;
 
 /// Initialize the memory management module
@@ -9,13 +10,12 @@ pub fn init() {
     init_frame_allocator();
     init_heap();
 
+    // for debugging
     set_root_page_table_ptr(0xFFFF_FFFF);
     extern "C" {
         fn _root_page_table_buffer();
         fn _root_page_table_ptr();
     }
-
-    println!("_root_page_table_ptr {:x}", _root_page_table_ptr as usize);
 }
 
 pub fn init_other() {
@@ -72,10 +72,11 @@ extern "C" {
 }
 
 pub fn set_page_table(vmtoken: usize) {
-    // TODO
+    if get_root_page_table_ptr() != vmtoken {
+        set_root_page_table_ptr(vmtoken);
+    }
 }
 
 pub fn get_page_fault_addr() -> usize {
-    // TODO
-    0
+    cp0::bad_vaddr::read_u32() as usize
 }

kernel/src/arch/riscv/consts.rs

@@ -15,7 +15,7 @@ pub const MEMORY_OFFSET: usize = 0x8000_0000;
 // TODO: get memory end from device tree
 pub const MEMORY_END: usize = 0x8800_0000;
 
-// FIXME: rv64 `sh` and `ls` will crash if stack top > 0x80000000 ???
+// TODO: rv64 `sh` and `ls` will crash if stack top > 0x80000000 ???
 pub const USER_STACK_OFFSET: usize = 0x40000000 - USER_STACK_SIZE;
 pub const USER_STACK_SIZE: usize = 0x10000;
 

kernel/src/arch/riscv/interrupt/mod.rs

@@ -1,5 +1,7 @@
 use crate::arch::interrupt::consts::SupervisorExternal;
 use crate::drivers::IRQ_MANAGER;
+use crate::process::thread::Thread;
+use alloc::sync::Arc;
 use log::*;
 use riscv::register::*;
 use riscv::register::{scause::Scause, sscratch, stvec};
@@ -113,3 +115,7 @@ pub fn wait_for_interrupt() {
         }
     }
 }
+
+pub fn handle_user_page_fault(thread: &Arc<Thread>, addr: usize) -> bool {
+    thread.vm.lock().handle_page_fault(addr)
+}

kernel/src/arch/riscv/mod.rs

@@ -53,7 +53,7 @@ pub extern "C" fn rust_main(hartid: usize, device_tree_paddr: usize) -> ! {
     }
     memory::init(device_tree_vaddr);
     timer::init();
-    // FIXME: init driver on u540
+    // TODO: init driver on u540
     #[cfg(not(any(feature = "board_u540")))]
     board::init(device_tree_vaddr);
     unsafe {

kernel/src/arch/riscv/syscall.rs

@@ -39,7 +39,7 @@ pub const SYS_MKDIRAT: usize = 34;
 pub const SYS_UNLINKAT: usize = 35;
 pub const SYS_SYMLINKAT: usize = 36;
 pub const SYS_LINKAT: usize = 37;
-pub const SYS_RENAMEAT: usize = 38; // FIXME
+pub const SYS_RENAMEAT: usize = 38;
 pub const SYS_UMOUNT2: usize = 39;
 pub const SYS_MOUNT: usize = 40;
 pub const SYS_PIVOT_ROOT: usize = 41;

kernel/src/arch/x86_64/interrupt/mod.rs

@@ -3,6 +3,8 @@ mod handler;
 
 pub use self::handler::*;
 use crate::memory::phys_to_virt;
+use crate::process::thread::Thread;
+use alloc::sync::Arc;
 use apic::*;
 use trapframe::{TrapFrame, UserContext};
 
@@ -60,3 +62,7 @@ pub fn wait_for_interrupt() {
     x86_64::instructions::interrupts::enable_interrupts_and_hlt();
     x86_64::instructions::interrupts::disable();
 }
+
+pub fn handle_user_page_fault(thread: &Arc<Thread>, addr: usize) -> bool {
+    thread.vm.lock().handle_page_fault(addr)
+}

kernel/src/arch/x86_64/paging.rs

@@ -284,7 +284,7 @@ impl FrameDeallocator<Size4KiB> for FrameAllocatorForX86 {
 
 /// Flush TLB for `vaddr` on all CPU
 fn flush_tlb_all(_vaddr: usize) {
-    // FIXME: too slow, disable now.
+    // TODO: too slow, disable now.
     return;
     // if !super::AP_CAN_INIT.load(Ordering::Relaxed) {
     //     return;

kernel/src/drivers/console/mod.rs

@@ -13,7 +13,7 @@ pub static CONSOLE: Mutex<Option<RCoreConsole>> = Mutex::new(None);
 pub fn init() {
     if cfg!(feature = "consolegraphic") {
         if let Some(fb) = FRAME_BUFFER.write().take() {
-            // FIXME: now take FrameBuffer out of global variable, then move into Console
+            // TODO: now take FrameBuffer out of global variable, then move into Console
             let console = Console::on_frame_buffer(fb.fb_info.xres, fb.fb_info.yres, fb);
             *CONSOLE.lock() = Some(console);
             info!("console: init end");

kernel/src/fs/file.rs

@@ -113,7 +113,7 @@ impl FileHandle {
     pub async fn read_at(&self, offset: usize, buf: &mut [u8]) -> Result<usize> {
         // let options = &self.description.read().options;
         if !self.description.read().options.read {
-            return Err(FsError::InvalidParam); // FIXME: => EBADF
+            return Err(FsError::InvalidParam); // TODO: => EBADF
         }
         if !self.description.read().options.nonblock {
             // block
@@ -150,7 +150,7 @@ impl FileHandle {
 
     pub fn write_at(&self, offset: usize, buf: &[u8]) -> Result<usize> {
         if !self.description.read().options.write {
-            return Err(FsError::InvalidParam); // FIXME: => EBADF
+            return Err(FsError::InvalidParam); // TODO: => EBADF
         }
         let len = self.inode.write_at(offset, buf)?;
         TimeSpec::update(&self.inode);
@@ -169,7 +169,7 @@ impl FileHandle {
 
     pub fn set_len(&mut self, len: u64) -> Result<()> {
         if !self.description.read().options.write {
-            return Err(FsError::InvalidParam); // FIXME: => EBADF
+            return Err(FsError::InvalidParam); // TODO: => EBADF
         }
         self.inode.resize(len as usize)?;
         Ok(())
@@ -194,7 +194,7 @@ impl FileHandle {
     pub fn read_entry(&mut self) -> Result<String> {
         let mut description = self.description.write();
         if !description.options.read {
-            return Err(FsError::InvalidParam); // FIXME: => EBADF
+            return Err(FsError::InvalidParam); // TODO: => EBADF
         }
         let mut offset = &mut description.offset;
         let name = self.inode.get_entry(*offset as usize)?;
@@ -205,7 +205,7 @@ impl FileHandle {
     pub fn read_entry_with_metadata(&mut self) -> Result<(Metadata, String)> {
         let mut description = self.description.write();
         if !description.options.read {
-            return Err(FsError::InvalidParam); // FIXME: => EBADF
+            return Err(FsError::InvalidParam); // TODO: => EBADF
         }
         let mut offset = &mut description.offset;
         let ret = self.inode.get_entry_with_metadata(*offset as usize)?;

kernel/src/net/structs.rs

@@ -527,7 +527,7 @@ impl Socket for UdpSocketState {
         match request {
             // SIOCGARP
             0x8954 => {
-                // FIXME: check addr
+                // TODO: check addr
                 let req = unsafe { &mut *(arg1 as *mut ArpReq) };
                 if let AddressFamily::Internet = AddressFamily::from(req.arp_pa.family) {
                     let name = req.arp_dev.as_ptr();

kernel/src/process/thread.rs

@@ -3,7 +3,7 @@ use super::{
     add_to_process_table, Pid, Process, PROCESSORS,
 };
 use crate::arch::interrupt::consts::{is_page_fault, IrqMax, IrqMin, Syscall, Timer};
-use crate::arch::interrupt::get_trap_num;
+use crate::arch::interrupt::{get_trap_num, handle_user_page_fault};
 use crate::arch::{
     cpu,
     fp::FpState,
@@ -511,7 +511,7 @@ pub fn spawn(thread: Arc<Thread>) {
                     let addr = get_page_fault_addr();
                     debug!("page fault from user @ {:#x}", addr);
 
-                    if !thread.vm.lock().handle_page_fault(addr as usize) {
+                    if !handle_user_page_fault(&thread, addr) {
                         // TODO: SIGSEGV
                         panic!("page fault handle failed");
                     }

kernel/src/signal/mod.rs

@@ -172,7 +172,7 @@ pub fn handle_signal(thread: &Arc<Thread>, tf: &mut UserContext) -> bool {
                 match signal {
                     SIGALRM | SIGHUP | SIGINT => {
                         info!("default action: Term");
-                        // FIXME: exit code ref please?
+                        // TODO: exit code ref please?
                         process.exit(info.signo as usize + 128);
                         return true;
                     }

kernel/src/syscall/mem.rs

@@ -81,7 +81,7 @@ impl Syscall<'_> {
         );
         let _attr = prot.to_attr();
 
-        // FIXME: properly set the attribute of the area
+        // TODO: properly set the attribute of the area
         //        now some mut ptr check is fault
         let vm = self.vm();
         let memory_area = vm
@@ -147,7 +147,7 @@ impl MmapProt {
         if self.contains(MmapProt::EXEC) {
             attr = attr.execute();
         }
-        // FIXME: see sys_mprotect
+        // TODO: see sys_mprotect
         //        if !self.contains(MmapProt::WRITE) { attr = attr.readonly(); }
         attr
     }

kernel/src/syscall/proc.rs

@@ -350,7 +350,7 @@ impl Syscall<'_> {
 
         // perform futex wake 1
         // ref: http://man7.org/linux/man-pages/man2/set_tid_address.2.html
-        // FIXME: do it in all possible ways a thread can exit
+        // TODO: do it in all possible ways a thread can exit
         //        it has memory access so we can't move it to Thread::drop?
         let clear_child_tid = self.thread.inner.lock().clear_child_tid as *mut u32;
         if !clear_child_tid.is_null() {

kernel/src/syscall/user.rs

@@ -38,7 +38,7 @@ impl<T, P: Policy> Debug for UserPtr<T, P> {
     }
 }
 
-// FIXME: this is a workaround for `clear_child_tid`.
+// TODO: this is a workaround for `clear_child_tid`.
 unsafe impl<T, P: Policy> Send for UserPtr<T, P> {}
 unsafe impl<T, P: Policy> Sync for UserPtr<T, P> {}