weenix

1 files changed, 28 insertions, 4 deletions

diff --git a/kernel/api/access.c b/kernel/api/access.c
index 0e11b73..9a7bed0 100644
--- a/kernel/api/access.c
+++ b/kernel/api/access.c
@@ -116,8 +116,18 @@ long user_vecdup(argvec_t *uvec, char ***kvecp)
  */
 long addr_perm(proc_t *p, const void *vaddr, int perm)
 {
-    NOT_YET_IMPLEMENTED("VM: addr_perm");
-    return 0;
+    // NOT_YET_IMPLEMENTED("VM: addr_perm");
+
+    // loop through the vmareas in the process's vmmap
+    vmarea_t *vma = vmmap_lookup(p->p_vmmap, ADDR_TO_PN(vaddr));
+
+    // if the vma doesn't exist, return 0
+    if (!vma)
+    {
+        return 0;
+    }
+
+    return !!(perm & vma->vma_prot);
 }
 
 /*
@@ -131,6 +141,20 @@ long addr_perm(proc_t *p, const void *vaddr, int perm)
  */
 long range_perm(proc_t *p, const void *vaddr, size_t len, int perm)
 {
-    NOT_YET_IMPLEMENTED("VM: range_perm");
-    return 0;
+    // NOT_YET_IMPLEMENTED("VM: range_perm");
+
+    // loop through the page numbers in the range
+    size_t vfn = ADDR_TO_PN(vaddr);
+    size_t end_vfn = ADDR_TO_PN(vaddr + len);
+    for (size_t i = vfn; i < end_vfn; i++)
+    {
+        // check the permissions for each page
+        if (!addr_perm(p, PN_TO_ADDR(i), perm))
+        {
+            return 0;
+        }
+    }
+
+    // return 1 if all pages have the correct permissions
+    return 1;
 }