https://git.reactos.org/?p=reactos.git;a=commitdiff;h=c48580135df5ef86732546126830a1ab98f71b29
commit c48580135df5ef86732546126830a1ab98f71b29 Author: Jérôme Gardou <[email protected]> AuthorDate: Tue Apr 6 12:58:02 2021 +0200 Commit: Jérôme Gardou <[email protected]> CommitDate: Thu Apr 8 15:40:37 2021 +0200 [NTOS:MM] Fix a bit page fault handler with regard to COW sections --- ntoskrnl/mm/section.c | 82 ++++++++++++++++++++++++++++++--------------------- 1 file changed, 48 insertions(+), 34 deletions(-) diff --git a/ntoskrnl/mm/section.c b/ntoskrnl/mm/section.c index 0b6b8e80416..e273c3ac10b 100644 --- a/ntoskrnl/mm/section.c +++ b/ntoskrnl/mm/section.c @@ -1697,8 +1697,7 @@ MmNotPresentFaultSectionView(PMMSUPPORT AddressSpace, * Check if this page needs to be mapped COW */ if ((Segment->WriteCopy) && - (Region->Protect == PAGE_READWRITE || - Region->Protect == PAGE_EXECUTE_READWRITE)) + (Region->Protect == PAGE_READWRITE || Region->Protect == PAGE_EXECUTE_READWRITE)) { Attributes = Region->Protect == PAGE_READWRITE ? PAGE_READONLY : PAGE_EXECUTE_READ; } @@ -1883,32 +1882,70 @@ MmAccessFaultSectionView(PMMSUPPORT AddressSpace, PMM_SECTION_SEGMENT Segment; PFN_NUMBER OldPage; PFN_NUMBER NewPage; - NTSTATUS Status; PVOID PAddress; LARGE_INTEGER Offset; PMM_REGION Region; ULONG_PTR Entry; PEPROCESS Process = MmGetAddressSpaceOwner(AddressSpace); + BOOLEAN Cow = FALSE; + ULONG NewProtect; DPRINT("MmAccessFaultSectionView(%p, %p, %p)\n", AddressSpace, MemoryArea, Address); + /* Get the region for this address */ + Region = MmFindRegion((PVOID)MA_GetStartingAddress(MemoryArea), + &MemoryArea->SectionData.RegionListHead, + Address, NULL); + ASSERT(Region != NULL); + if (!(Region->Protect & PAGE_IS_WRITABLE)) + return STATUS_ACCESS_VIOLATION; + /* Make sure we have a page mapping for this address. */ - Status = MmNotPresentFaultSectionView(AddressSpace, MemoryArea, Address, Locked); - if (!NT_SUCCESS(Status)) + if (!MmIsPagePresent(Process, Address)) { - /* This is invalid access ! */ - return Status; + NTSTATUS Status = MmNotPresentFaultSectionView(AddressSpace, MemoryArea, Address, Locked); + if (!NT_SUCCESS(Status)) + { + /* This is invalid access ! */ + return Status; + } } /* * Check if the page has already been set readwrite */ - if (MmGetPageProtect(Process, Address) & PAGE_READWRITE) + if (MmGetPageProtect(Process, Address) & (PAGE_READWRITE | PAGE_EXECUTE_READWRITE)) { DPRINT("Address 0x%p\n", Address); return STATUS_SUCCESS; } + /* Check if we are doing Copy-On-Write */ + Segment = MemoryArea->SectionData.Segment; + Cow = Segment->WriteCopy || (Region->Protect & PAGE_IS_WRITECOPY); + + if (!Cow) + { + /* Simply update page protection and we're done */ + MmSetPageProtect(Process, Address, Region->Protect); + return STATUS_SUCCESS; + } + + /* Calculate the new protection & check if we should update the region */ + NewProtect = Region->Protect; + if (NewProtect & PAGE_IS_WRITECOPY) + { + NewProtect &= ~PAGE_IS_WRITECOPY; + if (Region->Protect & PAGE_IS_EXECUTABLE) + NewProtect |= PAGE_EXECUTE_READWRITE; + else + NewProtect |= PAGE_READWRITE; + MmAlterRegion(AddressSpace, (PVOID)MA_GetStartingAddress(MemoryArea), + &MemoryArea->SectionData.RegionListHead, + Address, PAGE_SIZE, Region->Type, NewProtect, + MmAlterViewAttributes); + } + /* * Find the offset of the page */ @@ -1916,23 +1953,6 @@ MmAccessFaultSectionView(PMMSUPPORT AddressSpace, Offset.QuadPart = (ULONG_PTR)PAddress - MA_GetStartingAddress(MemoryArea) + MemoryArea->SectionData.ViewOffset; - Segment = MemoryArea->SectionData.Segment; - Region = MmFindRegion((PVOID)MA_GetStartingAddress(MemoryArea), - &MemoryArea->SectionData.RegionListHead, - Address, NULL); - ASSERT(Region != NULL); - - /* - * Check if we are doing COW - */ - if (!((Segment->WriteCopy) && - (Region->Protect == PAGE_READWRITE || - Region->Protect == PAGE_EXECUTE_READWRITE))) - { - DPRINT("Address 0x%p\n", Address); - return STATUS_ACCESS_VIOLATION; - } - /* Get the page mapping this section offset. */ MmLockSectionSegment(Segment); Entry = MmGetPageEntrySectionSegment(Segment, &Offset); @@ -1947,15 +1967,14 @@ MmAccessFaultSectionView(PMMSUPPORT AddressSpace, { MmUnlockSectionSegment(Segment); /* This is a private page. We must only change the page protection. */ - MmSetPageProtect(Process, PAddress, Region->Protect); + MmSetPageProtect(Process, PAddress, NewProtect); return STATUS_SUCCESS; } /* * Allocate a page */ - Status = MmRequestPageMemoryConsumer(MC_USER, TRUE, &NewPage); - if (!NT_SUCCESS(Status)) + if (!NT_SUCCESS(MmRequestPageMemoryConsumer(MC_USER, TRUE, &NewPage))) { KeBugCheck(MEMORY_MANAGEMENT); } @@ -1978,15 +1997,10 @@ MmAccessFaultSectionView(PMMSUPPORT AddressSpace, /* * Set the PTE to point to the new page */ - Status = MmCreateVirtualMapping(Process, - PAddress, - Region->Protect, - NewPage); - if (!NT_SUCCESS(Status)) + if (!NT_SUCCESS(MmCreateVirtualMapping(Process, PAddress, NewProtect, NewPage))) { DPRINT1("MmCreateVirtualMapping failed, unable to create virtual mapping, not out of memory\n"); KeBugCheck(MEMORY_MANAGEMENT); - return Status; } if (Process)
