foo

core/mem/pmap.c

@@ -17,6 +17,16 @@ errno_t pmap_new_kernel(struct pmap* pt, enum alloc_flags flags) {
     if (status)
         return status;
 
+    pte_t* root = HHDM_PTR(addr);
+    const size_t num_entries = (size_t)1 << arch_mem_level_bits();
+    for (size_t i = num_entries / 2; i < num_entries; i++) {
+        phys_t dir;
+        status = mem_phys_alloc(1, flags, &dir);
+        if (status)
+            return status;
+        root[i] = pte_build(dir, PTE_DIR, CACHE_ANY);
+    }
+
     struct pmap result = {
         .root = addr,
         .lock = (struct spinlock){0},
@@ -71,7 +81,7 @@ static pte_t* get_pte(struct pmap* pt, uintptr_t vaddr, bool is_user, bool check
 
         if (pte_is_present(pte)) {
             // Get the next level.
-            *pte = pte_build(pte_address(pte), level_flags, CACHE_ANY);
+            *pte |= pte_build(0, level_flags, CACHE_ANY);
             current_head = HHDM_PTR(pte_address(pte));
         } else {
             // If the current level isn't present, we can skip the rest.