Re: [ros-dev] [ros-diffs] [tkreuzer] 64593: [NTOSKRNL] Modify MiCreatePebOrTeb to use MiInsertVadEx instead of doing everything "by hand". No, this does not "change Windows behavior". The TEB creation works exactly as befor...

[Timo Kreuzer]

Already explained in the other mail.
Am 11.10.2014 18:38, schrieb Alex Ionescu:
>   Why do you think PEB creation cannot fail in the first
> place?
>  Best regards,
>  Alex Ionescu
>  On Tue, Oct 7, 2014 at 5:31 PM, <tkreuzer(a)svn.reactos.org
>  <mailto:[e-mail]>> wrote:
>      Author: tkreuzer
>      Date: Wed Oct  8 00:31:49 2014
>      New Revision: 64593
>      URL: http://svn.reactos.org/svn/reactos?rev=64593&view=rev
>      Log:
>      [NTOSKRNL]
>      Modify MiCreatePebOrTeb to use MiInsertVadEx instead of doing
>      everything "by hand". No, this does not "change Windows
> behavior".
>      The TEB creation works exactly as before, and the only difference
>      in the PEB creation is that if the first attempt fails, we will no
>      longer try again from the top of the address space. But since this
>      cannot fail in the first place, at least not due to the VA range
>      not being free, another attempt would be pointless anyway!
>      Modified:
>          trunk/reactos/ntoskrnl/mm/ARM3/procsup.c
>      Modified: trunk/reactos/ntoskrnl/mm/ARM3/procsup.c
>      URL:
> http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/procsup.c…
>      ==============================================================================
>      --- trunk/reactos/ntoskrnl/mm/ARM3/procsup.c    [iso-8859-1]
>      (original)
>      +++ trunk/reactos/ntoskrnl/mm/ARM3/procsup.c    [iso-8859-1] Wed
>      Oct  8 00:31:49 2014
>      @@ -50,14 +50,11 @@
>                        IN ULONG Size,
>                        OUT PULONG_PTR BaseAddress)
>       {
>      -    PETHREAD Thread = PsGetCurrentThread();
>           PMMVAD_LONG Vad;
>           NTSTATUS Status;
>           ULONG_PTR HighestAddress, RandomBase;
>           ULONG AlignedSize;
>           LARGE_INTEGER CurrentTime;
>      -    TABLE_SEARCH_RESULT Result = TableFoundNode;
>      -    PMMADDRESS_NODE Parent;
>           /* Allocate a VAD */
>           Vad = ExAllocatePoolWithTag(NonPagedPool, sizeof(MMVAD_LONG),
>      'ldaV');
>      @@ -70,6 +67,7 @@
>           Vad->u.VadFlags.PrivateMemory = TRUE;
>           Vad->u.VadFlags.Protection = MM_READWRITE;
>           Vad->u.VadFlags.NoChange = TRUE;
>      +    Vad->u1.Parent = NULL;
>           /* Setup the secondary flags to make it a secured, writable,
>      long VAD */
>           Vad->u2.LongFlags2 = 0;
>      @@ -77,10 +75,11 @@
>           Vad->u2.VadFlags2.LongVad = TRUE;
>           Vad->u2.VadFlags2.ReadOnly = FALSE;
>      -    /* Lock the process address space */
>      -    KeAcquireGuardedMutex(&Process->AddressCreationLock);
>      +    Vad->ControlArea = NULL; // For Memory-Area hack
>      +    Vad->FirstPrototypePte = NULL;
>           /* Check if this is a PEB creation */
>      +    ASSERT(sizeof(TEB) != sizeof(PEB));
>           if (Size == sizeof(PEB))
>           {
>               /* Create a random value to select one page in a 64k
>      region */
>      @@ -100,68 +99,27 @@
>               /* Calculate the highest allowed address */
>               HighestAddress = RandomBase + AlignedSize - 1;
>      -
>      -        /* Try to find something below the random upper margin */
>      -        Result =
>      MiFindEmptyAddressRangeDownTree(ROUND_TO_PAGES(Size),
>      -                                                 HighestAddress,
>      -                                                 PAGE_SIZE,
>      -                                                 &Process->VadRoot,
>      -                                                 BaseAddress,
>      -                                                 &Parent);
>      -    }
>      -
>      -    /* Check for success. TableFoundNode means nothing free. */
>      -    if (Result == TableFoundNode)
>      -    {
>      -        /* For TEBs, or if a PEB location couldn't be found, scan
>      the VAD root */
>      -        Result =
>      MiFindEmptyAddressRangeDownTree(ROUND_TO_PAGES(Size),
>      -
>       (ULONG_PTR)MM_HIGHEST_VAD_ADDRESS,
>      -                                                 PAGE_SIZE,
>      -                                                 &Process->VadRoot,
>      -                                                 BaseAddress,
>      -                                                 &Parent);
>      -        /* Bail out, if still nothing free was found */
>      -        if (Result == TableFoundNode)
>      -        {
>      -            KeReleaseGuardedMutex(&Process->AddressCreationLock);
>      -            ExFreePoolWithTag(Vad, 'ldaV');
>      -            return STATUS_NO_MEMORY;
>      -        }
>      -    }
>      -
>      -    /* Validate that it came from the VAD ranges */
>      -    ASSERT(*BaseAddress >= (ULONG_PTR)MI_LOWEST_VAD_ADDRESS);
>      -
>      -    /* Build the rest of the VAD now */
>      -    Vad->StartingVpn = (*BaseAddress) >> PAGE_SHIFT;
>      -    Vad->EndingVpn = ((*BaseAddress) + Size - 1) >> PAGE_SHIFT;
>      -    Vad->u3.Secured.StartVpn = *BaseAddress;
>      -    Vad->u3.Secured.EndVpn = (Vad->EndingVpn << PAGE_SHIFT) |
>      (PAGE_SIZE - 1);
>      -    Vad->u1.Parent = NULL;
>      -
>      -    /* FIXME: Should setup VAD bitmap */
>      -    Status = STATUS_SUCCESS;
>      -
>      -    /* Pretend as if we own the working set */
>      -    MiLockProcessWorkingSetUnsafe(Process, Thread);
>      -
>      -    /* Insert the VAD */
>      -    ASSERT(Vad->EndingVpn >= Vad->StartingVpn);
>      -    Process->VadRoot.NodeHint = Vad;
>      -    Vad->ControlArea = NULL; // For Memory-Area hack
>      -    Vad->FirstPrototypePte = NULL;
>      -    DPRINT("VAD: %p\n", Vad);
>      -    DPRINT("Allocated PEB/TEB at: 0x%p for %16s\n", *BaseAddress,
>      Process->ImageFileName);
>      -    MiInsertNode(&Process->VadRoot, (PVOID)Vad, Parent, Result);
>      -
>      -    /* Release the working set */
>      -    MiUnlockProcessWorkingSetUnsafe(Process, Thread);
>      -
>      -    /* Release the address space lock */
>      -    KeReleaseGuardedMutex(&Process->AddressCreationLock);
>      -
>      -    /* Return the status */
>      -    return Status;
>      +    }
>      +    else
>      +    {
>      +        HighestAddress = (ULONG_PTR)MM_HIGHEST_VAD_ADDRESS;
>      +    }
>      +
>      +    *BaseAddress = 0;
>      +    Status = MiInsertVadEx((PMMVAD)Vad,
>      +                           BaseAddress,
>      +                           BYTES_TO_PAGES(Size),
>      +                           HighestAddress,
>      +                           PAGE_SIZE,
>      +                           MEM_TOP_DOWN);
>      +    if (!NT_SUCCESS(Status))
>      +    {
>      +        ExFreePoolWithTag(Vad, 'ldaV');
>      +        return STATUS_NO_MEMORY;
>      +    }
>      +
>      +    /* Success */
>      +    return STATUS_SUCCESS;
>       }
>       VOID
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