Kernel/x86_64 - More bugfixes, I suspect the PMM code is borken

[tpg/acess2.git] / Kernel / arch / x86_64 / mm_virt.c

diff --git a/Kernel/arch/x86_64/mm_virt.c b/Kernel/arch/x86_64/mm_virt.c
index aca3728..511803c 100644 (file)
--- a/Kernel/arch/x86_64/mm_virt.c
+++ b/Kernel/arch/x86_64/mm_virt.c
@@ -100,6 +100,8 @@ void MM_FinishVirtualInit(void)
 void MM_int_ClonePageEnt( Uint64 *Ent, void *NextLevel, tVAddr Addr, int bTable )
 {
        tPAddr  curpage = *Ent & PADDR_MASK; 
+        int    bCopied = 0;
+       
        if( MM_GetRefCount( curpage ) <= 0 ) {
                Log_KernelPanic("MMVirt", "Page %P still marked COW, but unreferenced", curpage);
        }
@@ -107,7 +109,7 @@ void MM_int_ClonePageEnt( Uint64 *Ent, void *NextLevel, tVAddr Addr, int bTable
        {
                *Ent &= ~PF_COW;
                *Ent |= PF_PRESENT|PF_WRITE;
-//             Log_Debug("MMVirt", "COW ent at %p (%p) only %P", Ent, NextLevel, curpage);
+               Log_Debug("MMVirt", "COW ent at %p (%p) only %P", Ent, NextLevel, curpage);
        }
        else
        {
@@ -125,23 +127,28 @@ void MM_int_ClonePageEnt( Uint64 *Ent, void *NextLevel, tVAddr Addr, int bTable
                memcpy( tmp, NextLevel, 0x1000 );
                MM_FreeTemp( (tVAddr)tmp );
                
-//             Log_Debug("MMVirt", "COW ent at %p (%p) from %P to %P", Ent, NextLevel, curpage, paddr);
+               Log_Debug("MMVirt", "COW ent at %p (%p) from %P to %P", Ent, NextLevel, curpage, paddr);
 
                MM_DerefPhys( curpage );
                *Ent &= PF_USER;
                *Ent |= paddr|PF_PRESENT|PF_WRITE;
+               
+               bCopied = 1;
        }
        INVLPG( (tVAddr)NextLevel );
        
-       // Mark COW on pages
+       // Mark COW on contents if it's a PDPT, Dir or Table
        if(bTable) 
        {
                Uint64  *dp = NextLevel;
                 int    i;
                for( i = 0; i < 512; i ++ )
                {
-                       if( !(dp[i] & PF_PRESENT) )     continue;
-                       MM_RefPhys( dp[i] & PADDR_MASK );
+                       if( !(dp[i] & PF_PRESENT) )
+                               continue;
+                       
+                       if( bCopied )
+                               MM_RefPhys( dp[i] & PADDR_MASK );
                        if( dp[i] & PF_WRITE ) {
                                dp[i] &= ~PF_WRITE;
                                dp[i] |= PF_COW;