Re: [ros-dev] [ros-diffs] [dgorbachev] 40008: Return to an old idea of MiMapPageToZeroInHyperSpace(), "fix" bug #4267.

[Timo Kreuzer]

This breaks boot.
http://reactos.org:8010/builders/ReactOS_%28Debug%29/builds/13880/steps/tes…

dgorbachev(a)svn.reactos.org schrieb:
>   Author: dgorbachev
>  Date: Sat Mar 14 04:20:18 2009
>  New Revision: 40008
>
>  URL: http://svn.reactos.org/svn/reactos?rev=40008&view=rev
>  Log:
>  Return to an old idea of MiMapPageToZeroInHyperSpace(), "fix" bug #4267.
>
>  Modified:
>      trunk/reactos/ntoskrnl/mm/hypermap.c
>
>  Modified: trunk/reactos/ntoskrnl/mm/hypermap.c
>  URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/hypermap.c?rev…
>  ==============================================================================
>  --- trunk/reactos/ntoskrnl/mm/hypermap.c [iso-8859-1] (original)
>  +++ trunk/reactos/ntoskrnl/mm/hypermap.c [iso-8859-1] Sat Mar 14 04:20:18 2009
>  @@ -14,8 +14,11 @@
>   
>   /* GLOBALS ********************************************************************/
>   
>  +#define MI_ZEROING_PTES  255
>  +
>   PMMPTE MmFirstReservedMappingPte;
>   PMMPTE MmLastReservedMappingPte;
>  +PMMPTE MmFirstReservedZeroingPte;
>   MMPTE HyperTemplatePte;
>   PEPROCESS HyperProcess;
>   KIRQL HyperIrql;
>  @@ -40,6 +43,8 @@
>       MmFirstReservedMappingPte = MiAddressToPte(MI_MAPPING_RANGE_START);
>       MmLastReservedMappingPte =  MiAddressToPte(MI_MAPPING_RANGE_END);
>       MmFirstReservedMappingPte->u.Hard.PageFrameNumber = MI_HYPERSPACE_PTES;
>  +    MmFirstReservedZeroingPte = MiAddressToPte(MI_ZERO_PTE);
>  +    MmFirstReservedZeroingPte->u.Hard.PageFrameNumber = MI_ZEROING_PTES;
>   }
>   
>   PVOID
>  @@ -134,38 +139,62 @@
>   {
>       MMPTE TempPte;
>       PMMPTE PointerPte;
>  +    PFN_NUMBER Offset;
>       PVOID Address; 
>  -    
>  +
>       //
>       // Never accept page 0
>       //
>       ASSERT(Page != 0);
>  -    
>  +
>       //
>       // Build the PTE
>       //
>       TempPte = HyperTemplatePte;
>       TempPte.u.Hard.PageFrameNumber = Page;
>  -    
>  -    //
>  -    // Get the Zero PTE and its address
>  -    //
>  -    PointerPte = MiAddressToPte(MI_ZERO_PTE);
>  +
>  +    //
>  +    // Pick the first zeroing PTE
>  +    //
>  +    PointerPte = MmFirstReservedZeroingPte;
>  +
>  +    //
>  +    // Now get the first free PTE
>  +    //
>  +    Offset = PFN_FROM_PTE(PointerPte);
>  +    if (!Offset)
>  +    {
>  +        //
>  +        // Reset the PTEs
>  +        //
>  +        Offset = MI_ZEROING_PTES;
>  +        KeFlushProcessTb();
>  +    }
>  +
>  +    //
>  +    // Prepare the next PTE
>  +    //
>  +    PointerPte->u.Hard.PageFrameNumber = Offset - 1;
>  +
>  +    //
>  +    // Write the current PTE
>  +    //
>  +    PointerPte += Offset;
>  +    *PointerPte = TempPte;
>  +
>  +    //
>  +    // Return the address
>  +    //
>       Address = (PVOID)((ULONG_PTR)PointerPte << 10);
>  -    
>  -    //
>  -    // Invalidate the old address
>  -    //
>  -    __invlpg(Address);
>  -    
>  -    //
>  -    // Write the current PTE
>  -    //
>  -    TempPte.u.Hard.PageFrameNumber = Page;
>  -    *PointerPte = TempPte;
>  -    
>  -    //
>  -    // Return the address
>  -    //
>       return Address;
>   }
>  +
>  +VOID
>  +NTAPI
>  +MiUnmapPageInZeroSpace(IN PVOID Address)
>  +{
>  +    //
>  +    // Blow away the mapping
>  +    //
>  +    MiAddressToPte(Address)->u.Long = 0;
>  +}
>
>
>