From 32f1a8ba9d9de4a96b7afb1e9fa36b6f552afa99 Mon Sep 17 00:00:00 2001
From: Mathieu Maret <mathieu.maret@gmail.com>
Date: Tue, 13 Nov 2018 14:49:32 +0100
Subject: [PATCH] Fix Paging Mapping

New PT entry should be set unsing the Vaddr, not the Paddr
---
 core/paging.c | 15 ++++++++-------
 tests/test.c  | 10 ++++++----
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/core/paging.c b/core/paging.c
index c326b91..c1b4234 100644
--- a/core/paging.c
+++ b/core/paging.c
@@ -19,7 +19,7 @@
 #define PT_SHIFT 12
 #define PTE_MASK 0x3ff //10bits
 #define PD_SHIFT 22
-#define PD_MIRROR_PAGE_IDX 1023
+#define PD_MIRROR_PAGE_IDX 1023U
 
 struct pde {
 	uint32_t present : 1;
@@ -128,15 +128,15 @@ int pageMap(vaddr_t vaddr, paddr_t paddr, int flags)
 	uint ptEntry = (vaddr >> PT_SHIFT) & PTE_MASK;
 
 	// Thank to mirroring, we can access the PD
-	struct pde *pd = (struct pde *)(PD_MIRROR_PAGE_IDX * (1U << 22) +
-					PD_MIRROR_PAGE_IDX * (1U << 12));
+	struct pde *pd =
+	    (struct pde *)((PD_MIRROR_PAGE_IDX << 22) + (PD_MIRROR_PAGE_IDX << 12));
 
-	struct pte *pt = (struct pte *)(PD_MIRROR_PAGE_IDX * (1U << 22) +
-					pdEntry * (1U << 12));
+	struct pte *pt = (struct pte *)((PD_MIRROR_PAGE_IDX << 22) + (pdEntry << 12));
 
-	if(!pd[pdEntry].present){
+	if (!pd[pdEntry].present) {
 		paddr_t ptPhy = allocPhyPage();
-		memset((void *)ptPhy, 0, PAGE_SIZE);
+		if (ptPhy == (vaddr_t)NULL)
+			return ENOMEM;
 
 		pd[pdEntry].user = (flags & PAGING_MEM_USER) ? 1:0;
 		pd[pdEntry].present = 1;
@@ -144,6 +144,7 @@ int pageMap(vaddr_t vaddr, paddr_t paddr, int flags)
 		pd[pdEntry].pt_addr = (ptPhy >> PT_SHIFT);
 
 		__native_flush_tlb_single((vaddr_t)pt);
+		memset((void *)pt, 0, PAGE_SIZE);
 	}
 
 	// Already mapped ? Remove old mapping
diff --git a/tests/test.c b/tests/test.c
index d7d0871..d99714b 100644
--- a/tests/test.c
+++ b/tests/test.c
@@ -25,7 +25,7 @@ void testPhymem(void)
 		if (page->phy_addr != (ulong)freeCount) {
 			printf("Error page %d modified\n", (ulong)page);
 		}
-		if (unrefPhyPage((ulong)page)) {
+		if (unrefPhyPage((ulong)page) < 0) {
 			printf("Failed to free page %d\n", (ulong)page);
 		}
 		freeCount++;
@@ -50,7 +50,10 @@ static void testPaging(void)
 	int freeCount  = 0;
 
 	while ((page = (struct mem_desc *)allocPhyPage()) != NULL) {
-		pageMap((vaddr_t)page, (paddr_t)page, 0);
+		if (pageMap((vaddr_t)page, (paddr_t)page, PAGING_MEM_WRITE)){
+			printf("Fail to map page %d\n", allocCount);
+			break;
+		}
 		page->phy_addr = allocCount;
 		allocCount++;
 		list_add_tail(allocated_page_list, page);
@@ -61,7 +64,7 @@ static void testPaging(void)
 		if (page->phy_addr != (ulong)freeCount) {
 			printf("Error page %d modified\n", (ulong)page);
 		}
-		if (unrefPhyPage((ulong)page)) {
+		if (unrefPhyPage((ulong)page) < 0) {
 			printf("Failed to free page %d\n", (ulong)page);
 		}
 		pageUnmap((vaddr_t)page);
@@ -73,7 +76,6 @@ static void testPaging(void)
 		printf("Error ! Cannot allocate memory\n");
 	} else {
 		unrefPhyPage((ulong)page);
-		pageUnmap((vaddr_t)page);
 	}
 }