Move handling of kernel page table entry copying to RMM

This way it can ensure those page table entries never get unmapped,
ensuring they are kept in sync between all processes.

src/context/memory.rs

@@ -14,7 +14,7 @@ use syscall::{error::*, flag::MapFlags, GrantFlags, MunmapFlags};
 
 use crate::{
     arch::paging::PAGE_SIZE,
-    context::{arch::setup_new_utable, file::LockedFileDescription},
+    context::file::LockedFileDescription,
     cpu_set::LogicalCpuSet,
     memory::{
         deallocate_frame, get_page_info, init_frame, the_zeroed_frame, AddRefError, Enomem, Frame,
@@ -566,9 +566,14 @@ impl AddrSpace {
     }
 
     pub fn new() -> Result<Self> {
+        let utable = unsafe {
+            PageMapper::create(TableKind::User, crate::memory::TheFrameAllocator)
+                .ok_or(Error::new(ENOMEM))?
+        };
+
         Ok(Self {
             grants: UserGrants::new(),
-            table: setup_new_utable()?,
+            table: Table { utable },
             mmap_min: MMAP_MIN_DEFAULT,
             used_by: LogicalCpuSet::empty(),
         })
@@ -1822,11 +1827,9 @@ impl Grant {
         for src_page in self.span().pages() {
             let dst_page = dst_base.next_by(src_page.offset_from(self.base));
 
-            let unmap_parents = true;
-
             // TODO: Validate flags?
             let Some((phys, _flags, flush)) =
-                (unsafe { src_mapper.unmap_phys(src_page.start_address(), unmap_parents) })
+                (unsafe { src_mapper.unmap_phys(src_page.start_address()) })
             else {
                 continue;
             };
@@ -1953,7 +1956,7 @@ impl Grant {
             for i in 0..self.info.page_count {
                 unsafe {
                     let (phys, _, flush) = mapper
-                        .unmap_phys(self.base.next_by(i).start_address(), true)
+                        .unmap_phys(self.base.next_by(i).start_address())
                         .expect("all physborrowed grants must be fully Present in the page tables");
                     flush.ignore();
 
@@ -1969,8 +1972,7 @@ impl Grant {
         } else {
             for page in self.span().pages() {
                 // Lazy mappings do not need to be unmapped.
-                let Some((phys, _, flush)) =
-                    (unsafe { mapper.unmap_phys(page.start_address(), true) })
+                let Some((phys, _, flush)) = (unsafe { mapper.unmap_phys(page.start_address()) })
                 else {
                     continue;
                 };