Adapt to changes to AddrSpace in ArceOS (#17)

* feat: adapt to changes to AddrSpace in arceos

* style: format

* fix: add patch to page_table_multiarch

* trigger rerun

* fix: forked aspace does not copy from kernel

Author: Mivik

Cargo.lock

@@ -40,6 +40,8 @@ axns = { git = "https://github.com/oscomp/arceos.git", features = ["thread-local
 
 [patch.crates-io]
 syscalls = { git = "https://github.com/jasonwhite/syscalls.git", rev = "92624de"}
+page_table_multiarch = { git = "https://github.com/Mivik/page_table_multiarch.git", rev = "19ededd" }
+page_table_entry = { git = "https://github.com/Mivik/page_table_multiarch.git", rev = "19ededd" }
 
 [target.'cfg(target_arch = "x86_64")'.dependencies]
 x86 = "0.52"

Cargo.toml

@@ -18,16 +18,38 @@ use alloc::{
     sync::Arc,
     vec::Vec,
 };
+use axerrno::AxResult;
 use axhal::arch::UspaceContext;
+use axmm::{AddrSpace, kernel_aspace};
 use axsync::Mutex;
 use memory_addr::VirtAddr;
 
-fn run_user_app(args: &[String], envs: &[String]) -> Option<i32> {
-    let mut uspace = axmm::new_user_aspace(
+fn new_user_aspace_empty() -> AxResult<AddrSpace> {
+    AddrSpace::new_empty(
         VirtAddr::from_usize(axconfig::plat::USER_SPACE_BASE),
         axconfig::plat::USER_SPACE_SIZE,
     )
-    .expect("Failed to create user address space");
+}
+
+/// If the target architecture requires it, the kernel portion of the address
+/// space will be copied to the user address space.
+fn copy_from_kernel(aspace: &mut AddrSpace) -> AxResult {
+    if !cfg!(target_arch = "aarch64") && !cfg!(target_arch = "loongarch64") {
+        // ARMv8 (aarch64) and LoongArch64 use separate page tables for user space
+        // (aarch64: TTBR0_EL1, LoongArch64: PGDL), so there is no need to copy the
+        // kernel portion to the user page table.
+        aspace.copy_mappings_from(&kernel_aspace().lock())?;
+    }
+    Ok(())
+}
+
+fn run_user_app(args: &[String], envs: &[String]) -> Option<i32> {
+    let mut uspace = new_user_aspace_empty()
+        .and_then(|mut it| {
+            copy_from_kernel(&mut it)?;
+            Ok(it)
+        })
+        .expect("Failed to create user address space");
 
     let path = arceos_posix_api::FilePath::new(&args[0]).expect("Invalid file path");
     axfs::api::set_current_dir(path.parent().unwrap()).expect("Failed to set current dir");

src/main.rs

@@ -11,14 +11,18 @@ use core::{
     cell::UnsafeCell,
     sync::atomic::{AtomicU64, Ordering},
 };
+use memory_addr::VirtAddrRange;
 use spin::Once;
 
-use crate::ctypes::{CloneFlags, TimeStat, WaitStatus};
+use crate::{
+    copy_from_kernel,
+    ctypes::{CloneFlags, TimeStat, WaitStatus},
+};
 use axhal::{
     arch::{TrapFrame, UspaceContext},
     time::{NANOS_PER_MICROS, NANOS_PER_SEC, monotonic_time_nanos},
 };
-use axmm::AddrSpace;
+use axmm::{AddrSpace, kernel_aspace};
 use axns::{AxNamespace, AxNamespaceIf};
 use axsync::Mutex;
 use axtask::{AxTaskRef, TaskExtRef, TaskInner, current};
@@ -100,7 +104,8 @@ impl TaskExt {
 
         let current_task = current();
         let mut current_aspace = current_task.task_ext().aspace.lock();
-        let new_aspace = current_aspace.clone_or_err()?;
+        let mut new_aspace = current_aspace.clone_or_err()?;
+        copy_from_kernel(&mut new_aspace)?;
         new_task
             .ctx_mut()
             .set_page_table_root(new_aspace.page_table_root());
@@ -219,6 +224,18 @@ impl AxNamespaceIf for AxNamespaceImpl {
     }
 }
 
+impl Drop for TaskExt {
+    fn drop(&mut self) {
+        if !cfg!(target_arch = "aarch64") && !cfg!(target_arch = "loongarch64") {
+            // See [`crate::new_user_aspace`]
+            let kernel = kernel_aspace().lock();
+            self.aspace
+                .lock()
+                .clear_mappings(VirtAddrRange::from_start_size(kernel.base(), kernel.size()));
+        }
+    }
+}
+
 axtask::def_task_ext!(TaskExt);
 
 pub fn spawn_user_task(