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 b4fd222..a022da2 100644 (file)
--- a/Kernel/arch/x86/mm_virt.c
+++ b/Kernel/arch/x86/mm_virt.c
@@ -28,8 +28,6 @@
 #define        TEMP_MAP_ADDR   0xFEFF0000      // Allows 16 "temp" pages
 #define        NUM_TEMP_PAGES  16
 
-#define        USE_COW 1
-
 #define        PF_PRESENT      0x1
 #define        PF_WRITE        0x2
 #define        PF_USER         0x4
@@ -99,7 +97,7 @@ void MM_InstallVirtual()
  */
 void MM_PageFault(Uint Addr, Uint ErrorCode, tRegs *Regs)
 {
-       ENTER("xAddr bErrorCode", Addr, ErrorCode);
+       //ENTER("xAddr bErrorCode", Addr, ErrorCode);
        
        // -- Check for COW --
        if( gaPageDir  [Addr>>22] & PF_PRESENT
@@ -107,12 +105,20 @@ 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('-');
+               //LEAVE('-')
                return;
        }
        
@@ -136,7 +142,6 @@ void MM_PageFault(Uint Addr, Uint ErrorCode, tRegs *Regs)
        MM_DumpTables(0, -1);   
        
        Panic("Page Fault at 0x%x\n", Regs->eip);
-       LEAVE('-');
 }
 
 /**
@@ -200,11 +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;
                
@@ -213,18 +225,25 @@ tPAddr MM_Allocate(Uint VAddr)
        }
        // Check if the page is already allocated
        else if( gaPageTable[ VAddr >> 12 ] != 0 ) {
-               Warning("MM_Allocate - Allocating to used address");
+               Warning("MM_Allocate - Allocating to used address (%p)", VAddr);
                return gaPageTable[ VAddr >> 12 ] & ~0xFFF;
        }
        
        // 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;
 }
 
 /**
@@ -393,7 +412,6 @@ Uint MM_Clone()
                                continue;
                        }
                        
-                       #if USE_COW
                        // Refrence old page
                        MM_RefPhys( gaPageTable[i*1024+j] & ~0xFFF );
                        // Add to new table
@@ -403,10 +421,6 @@ Uint MM_Clone()
                        }
                        else
                                gaTmpTable[i*1024+j] = gaPageTable[i*1024+j];
-                       LOG("gaTmpTable[0x%x] = 0x%x", i*1024+j, gaTmpTable[i*1024+j]);
-                       #else
-                       gaTmpTable[i*1024+j] = MM_DuplicatePage( (i*1024+j)<<12 ) | (gaPageTable[i*1024+j]&7);
-                       #endif
                }
        }
        
@@ -524,6 +538,19 @@ void MM_SetFlags(Uint VAddr, Uint Flags, Uint Mask)
                if( Flags & MM_PFLAG_KERNEL )   *ent &= ~PF_USER;
                else    *ent |= PF_USER;
        }
+       
+       // Copy-On-Write
+       if( Mask & MM_PFLAG_COW )
+       {
+               if( Flags & MM_PFLAG_COW ) {
+                       *ent &= ~PF_WRITE;
+                       *ent |= PF_COW;
+               }
+               else {
+                       *ent &= ~PF_COW;
+                       *ent |= PF_WRITE;
+               }
+       }
 }
 
 /**