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[NTOSKRNL]

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- Remove an unneeded (and prone to race) RtlZeroMemory (found by Thomas Faber)
- Fix misuse of PAGE_MASK macro and broken PTE flag comparisons

svn path=/trunk/; revision=54782
This commit is contained in:
Cameron Gutman 2011-12-29 23:48:49 +00:00
parent b604379064
commit f7cb8a56e4
1 changed files with 21 additions and 15 deletions
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36
reactos/ntoskrnl/mm/i386/page.c
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@ -305,7 +305,6 @@ MmGetPageTableForProcess(PEPROCESS Process, PVOID Address, BOOLEAN Create)
MmReleasePageMemoryConsumer(MC_SYSTEM, Pfn);
}
InterlockedExchangePte(PageDir, MmGlobalKernelPageDirectory[PdeOffset]);
RtlZeroMemory(MiPteToAddress(PageDir), PAGE_SIZE);
return (PULONG)MiAddressToPte(Address);
}
InterlockedExchangePte(PageDir, MmGlobalKernelPageDirectory[PdeOffset]);
@ -372,6 +371,7 @@ MmDisableVirtualMapping(PEPROCESS Process, PVOID Address, BOOLEAN* WasDirty, PPF
{
KeBugCheck(MEMORY_MANAGEMENT);
}
/*
* Atomically disable the present bit and get the old value.
*/
@ -380,12 +380,9 @@ MmDisableVirtualMapping(PEPROCESS Process, PVOID Address, BOOLEAN* WasDirty, PPF
Pte = *Pt;
} while (Pte != InterlockedCompareExchangePte(Pt, Pte & ~PA_PRESENT, Pte));
if(Pte & PA_PRESENT)
MiFlushTlb(Pt, Address);
else
MmUnmapPageTable(Pt);
MiFlushTlb(Pt, Address);
WasValid = (PAGE_MASK(Pte) != 0);
WasValid = (Pte & PA_PRESENT);
if (!WasValid)
{
KeBugCheck(MEMORY_MANAGEMENT);
@ -457,7 +454,7 @@ MmDeleteVirtualMapping(PEPROCESS Process, PVOID Address, BOOLEAN FreePage,
*/
Pte = InterlockedExchangePte(Pt, 0);
WasValid = (PAGE_MASK(Pte) != 0);
WasValid = (Pte & PA_PRESENT);
if (WasValid)
{
/* Flush the TLB since we transitioned this PTE
@ -532,7 +529,7 @@ MmDeletePageFileMapping(PEPROCESS Process, PVOID Address,
* are invalid translations, so the processor won't cache them */
MmUnmapPageTable(Pt);
if(!(Pte & 0x800))
if (Pte & PA_PRESENT)
{
KeBugCheck(MEMORY_MANAGEMENT);
}
@ -580,7 +577,6 @@ MmSetCleanPage(PEPROCESS Process, PVOID Address)
}
Pt = MmGetPageTableForProcess(Process, Address, FALSE);
if (Pt == NULL)
{
KeBugCheck(MEMORY_MANAGEMENT);
@ -591,7 +587,11 @@ MmSetCleanPage(PEPROCESS Process, PVOID Address)
Pte = *Pt;
} while (Pte != InterlockedCompareExchangePte(Pt, Pte & ~PA_DIRTY, Pte));
if (Pte & PA_DIRTY)
if (!(Pte & PA_PRESENT))
{
KeBugCheck(MEMORY_MANAGEMENT);
}
else if (Pte & PA_DIRTY)
{
MiFlushTlb(Pt, Address);
}
@ -624,7 +624,12 @@ MmSetDirtyPage(PEPROCESS Process, PVOID Address)
{
Pte = *Pt;
} while (Pte != InterlockedCompareExchangePte(Pt, Pte | PA_DIRTY, Pte));
if (!(Pte & PA_DIRTY))
if (!(Pte & PA_PRESENT))
{
KeBugCheck(MEMORY_MANAGEMENT);
}
else if (!(Pte & PA_DIRTY))
{
MiFlushTlb(Pt, Address);
}
@ -676,7 +681,7 @@ MmIsPageSwapEntry(PEPROCESS Process, PVOID Address)
{
ULONG Entry;
Entry = MmGetPageEntryForProcess(Process, Address);
return !(Entry & PA_PRESENT) && (Entry & 0x800) && Entry != 0;
return !(Entry & PA_PRESENT) && Entry != 0;
}
NTSTATUS
@ -710,7 +715,7 @@ MmCreatePageFileMapping(PEPROCESS Process,
KeBugCheck(MEMORY_MANAGEMENT);
}
Pte = InterlockedExchangePte(Pt, SwapEntry << 1);
if(PAGE_MASK(Pte))
if (Pte != 0)
{
KeBugCheck(MEMORY_MANAGEMENT);
}
@ -814,8 +819,9 @@ MmCreateVirtualMappingUnsafe(PEPROCESS Process,
oldPdeOffset = PdeOffset;
Pte = InterlockedExchangePte(Pt, PFN_TO_PTE(Pages[i]) | Attributes);
/* There should not be anything valid here */
if (PAGE_MASK(Pte) != 0)
if (Pte != 0)
{
DPRINT1("Bad PTE %lx\n", Pte);
KeBugCheck(MEMORY_MANAGEMENT);
@ -928,7 +934,7 @@ MmSetPageProtect(PEPROCESS Process, PVOID Address, ULONG flProtect)
}
Pte = InterlockedExchangePte(Pt, PAGE_MASK(*Pt) | Attributes | (*Pt & (PA_ACCESSED|PA_DIRTY)));
if(!PAGE_MASK(Pte))
if (!(Pte & PA_PRESENT))
{
DPRINT1("Invalid Pte %lx\n", Pte);
KeBugCheck(MEMORY_MANAGEMENT);