Kernel/MMU: Don't return non present pages unless creation is desired

`get_page` is a horrible multipurpose function and at this point I am
unsure what behavior I expect and have expected it to produce. Refactor
should probably be done soon.

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/arch/i386/mmu.c b/kernel/arch/i386/mmu.c
index c38d834..a59eccf 100644
--- a/kernel/arch/i386/mmu.c
+++ b/kernel/arch/i386/mmu.c
@@ -127,6 +127,9 @@ Page *get_page(void *ptr, PageDirectory *directory, int create_new_page,
     }
   }
   Page *p = &directory->tables[table_index]->pages[address % 1024];
+  if (!p->present && !create_new_page) {
+    return 0;
+  }
   if (create_new_page) {
     p->present = 0;
     p->user = set_user;