Added allocate address to MM_Allocate's OOM fail

[tpg/acess2.git] / Kernel / arch / x86 / mm_virt.c

diff --git a/Kernel/arch/x86/mm_virt.c b/Kernel/arch/x86/mm_virt.c
index 25da743..a022da2 100644 (file)
--- a/Kernel/arch/x86/mm_virt.c
+++ b/Kernel/arch/x86/mm_virt.c
@@ -105,10 +105,18 @@ void MM_PageFault(Uint Addr, Uint ErrorCode, tRegs *Regs)
         && gaPageTable[Addr>>12] & PF_COW )
        {
                tPAddr  paddr;
-               paddr = MM_DuplicatePage( Addr );
-               MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
-               gaPageTable[Addr>>12] &= PF_USER;
-               gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
+               if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 0)
+               {
+                       gaPageTable[Addr>>12] &= ~PF_COW;
+                       gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE;
+               }
+               else
+               {
+                       paddr = MM_DuplicatePage( Addr );
+                       MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF );
+                       gaPageTable[Addr>>12] &= PF_USER;
+                       gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE;
+               }
                INVLPG( Addr & ~0xFFF );
                //LEAVE('-')
                return;
@@ -197,11 +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;
                
@@ -215,13 +230,20 @@ tPAddr MM_Allocate(Uint VAddr)
        }
        
        // Allocate
-       gaPageTable[ VAddr >> 12 ] = MM_AllocPhys() | 3;
+       paddr = MM_AllocPhys();
+       if( paddr == 0 ) {
+               Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)",
+                       VAddr, __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;
 }
 
 /**