From 9521538a2533451531292eaef4b1a380772831c7 Mon Sep 17 00:00:00 2001
From: John Hodge <tpg@portege.thepowersgang.com>
Date: Tue, 22 Sep 2009 20:36:59 +0800
Subject: [PATCH] Added out of memory handling to MM_Allocate

---
 Kernel/arch/x86/mm_phys.c |  2 +-
 Kernel/arch/x86/mm_virt.c | 19 ++++++++++++++++---
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/Kernel/arch/x86/mm_phys.c b/Kernel/arch/x86/mm_phys.c
index 72f5dc9a..a6656e50 100644
--- a/Kernel/arch/x86/mm_phys.c
+++ b/Kernel/arch/x86/mm_phys.c
@@ -96,7 +96,7 @@ tPAddr MM_AllocPhys()
 	for(a=0;gaSuperBitmap[a]==-1&&a<num;a++);
 	if(a == num) {
 		RELEASE( &giPhysAlloc );
-		Warning("MM_AllocPhys - OUT OF MEMORY (Called by %p)",  __builtin_return_address(0));
+		Warning("MM_AllocPhys - OUT OF MEMORY (Called by %p)", __builtin_return_address(0));
 		return 0;
 	}
 	for(b=0;gaSuperBitmap[a]&(1<<b);b++);
diff --git a/Kernel/arch/x86/mm_virt.c b/Kernel/arch/x86/mm_virt.c
index 8fe1b4aa..3f23d35c 100644
--- a/Kernel/arch/x86/mm_virt.c
+++ b/Kernel/arch/x86/mm_virt.c
@@ -205,11 +205,18 @@ void MM_DumpTables(tVAddr Start, tVAddr End)
  */
 tPAddr MM_Allocate(Uint VAddr)
 {
+	tPAddr	paddr;
 	// Check if the directory is mapped
 	if( gaPageDir[ VAddr >> 22 ] == 0 )
 	{
 		// Allocate directory
-		gaPageDir[ VAddr >> 22 ] = MM_AllocPhys() | 3;
+		paddr = MM_AllocPhys();
+		if( paddr == 0 ) {
+			Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
+			return 0;
+		}
+		// Map
+		gaPageDir[ VAddr >> 22 ] = paddr | 3;
 		// Mark as user
 		if(VAddr < MM_USER_MAX)	gaPageDir[ VAddr >> 22 ] |= PF_USER;
 		
@@ -223,13 +230,19 @@ tPAddr MM_Allocate(Uint VAddr)
 	}
 	
 	// Allocate
-	gaPageTable[ VAddr >> 12 ] = MM_AllocPhys() | 3;
+	paddr = MM_AllocPhys();
+	if( paddr == 0 ) {
+		Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0));
+		return 0;
+	}
+	// Map
+	gaPageTable[ VAddr >> 12 ] = paddr | 3;
 	// Mark as user
 	if(VAddr < MM_USER_MAX)	gaPageTable[ VAddr >> 12 ] |= PF_USER;
 	// Invalidate Cache for address
 	INVLPG( VAddr & ~0xFFF );
 	
-	return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
+	return paddr;
 }
 
 /**
-- 
2.20.1