From 892154c9f11af9480fc6ba0c42f227db4ab789b0 Mon Sep 17 00:00:00 2001
From: Steffen Vogel <steffen.vogel@rwth-aachen.de>
Date: Thu, 14 Nov 2013 13:09:56 +0100
Subject: [PATCH] implemented drop_page_map() (more testing needed)

---
 arch/x86/mm/page64.c | 45 ++++++++++++++++++++++++++++++--------------
 1 file changed, 31 insertions(+), 14 deletions(-)

diff --git a/arch/x86/mm/page64.c b/arch/x86/mm/page64.c
index 3465982f..2d9b1889 100644
--- a/arch/x86/mm/page64.c
+++ b/arch/x86/mm/page64.c
@@ -218,33 +218,50 @@ int create_page_map(task_t* task, int copy)
 
 int drop_page_map(void)
 {
-#if 0
-	page_map_t* pgd = per_core(current_task)->page_map;
-	size_t phy_pgd = virt_to_phys((size_t) pgd);
+#if 1
+	kprintf("TODO: test drop_page_map()\n");
+	return -EINVAL; // TODO
+#else
 	task_t* task = per_core(current_task);
-	uint32_t i;
+	page_map_t* pml4, * pdpt, * pgd, * pgt;
+	size_t phys;
+	uint32_t i, j, k, l;
 
-	if (BUILTIN_EXPECT(pgd == &boot_pgd, 0))
+	pml4 = task->page_map;
+
+	if (BUILTIN_EXPECT(pml4 == &boot_pml4, 0))
 		return -EINVAL;
 
 	spinlock_lock(&task->page_lock);
-	
-	for(i=0; i<1024; i++) {
-		if (pgd->entries[i] & PG_USER) {
-			put_page(pgd->entries[i] & PAGE_MASK);
-			pgd->entries[i] = 0;
+
+	// delete all user pages and tables
+	for(i=0; i<PAGE_MAP_ENTRIES; i++) { // pml4
+		if (pml4->entries[i] & PG_USER) {
+			for(j=0; j<PAGE_MAP_ENTRIES; j++) { // pdpt
+				if (pdpt->entries[j] & PG_USER) {
+					for(k=0; k<PAGE_MAP_ENTRIES; k++) { // pgd
+						if (pgd->entries[k] & PG_USER) {
+							for(l=0; l<PAGE_MAP_ENTRIES; l++) { // pgt
+								if (pgt->entries[l] & PG_USER)
+									put_page(pgt->entries[l] & PAGE_MASK);
+							}
+							// TODO: put pgt
+						}
+					}
+					// TODO: put pgd
+				}
+			}
+			// TODO: put pdpt
 		}
 	}
 
-	// freeing the page directory
-	put_page(phy_pgd);
-
+	put_page(virt_to_phys((size_t) pml4));
 	task->page_map = NULL;
 
 	spinlock_unlock(&task->page_lock);
-#endif
 
 	return 0;
+#endif
 }
 
 size_t virt_to_phys(size_t viraddr)