https://git.reactos.org/?p=reactos.git;a=commitdiff;h=cb74d9e24ed16d3d52e1a4cff3ff3fde6bcd9bd1
commit cb74d9e24ed16d3d52e1a4cff3ff3fde6bcd9bd1 Author: Timo Kreuzer <[email protected]> AuthorDate: Tue Dec 27 17:43:10 2022 +0200 Commit: Timo Kreuzer <[email protected]> CommitDate: Fri Apr 14 11:56:08 2023 +0300 [NTOS/CC] Fix broken usage of _SEH2_FINALLY Finally handlers are - unlike except blocks - not part of the function they are in, but separate functions, which are called during unwind. PSEH implements them on GCC using nested functions. While "return" from a finally handler is allowed with native SEH, it's handled by the compiler through an extra unwinding operation using _local_unwind, WHICH IS NOT SUPPORTED BY PSEH! With PSEH, returning from a finally handler does not return from the function, instead it will only return from [...] Also use _SEH_VOLATILE to make sure the variable assignment is not optimized away by the compiler and add zero out the result parameters on error. --- ntoskrnl/cc/pin.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff --git a/ntoskrnl/cc/pin.c b/ntoskrnl/cc/pin.c index 3d80befb660..dcd1d5483a5 100644 --- a/ntoskrnl/cc/pin.c +++ b/ntoskrnl/cc/pin.c @@ -221,7 +221,7 @@ CcpPinData( KIRQL OldIrql; ULONG VacbOffset; NTSTATUS Status; - BOOLEAN Result; + _SEH2_VOLATILE BOOLEAN Result; VacbOffset = (ULONG)(FileOffset->QuadPart % VACB_MAPPING_GRANULARITY); @@ -302,15 +302,19 @@ CcpPinData( CCTRACE(CC_API_DEBUG, "FileObject=%p FileOffset=%p Length=%lu Flags=0x%lx -> FALSE\n", SharedCacheMap->FileObject, FileOffset, Length, Flags); CcUnpinData(&NewBcb->PFCB); - return FALSE; + *Bcb = NULL; + *Buffer = NULL; } } _SEH2_END; - *Bcb = &NewBcb->PFCB; - *Buffer = (PVOID)((ULONG_PTR)NewBcb->Vacb->BaseAddress + VacbOffset); + if (Result) + { + *Bcb = &NewBcb->PFCB; + *Buffer = (PVOID)((ULONG_PTR)NewBcb->Vacb->BaseAddress + VacbOffset); + } - return TRUE; + return Result; } /* @@ -332,7 +336,7 @@ CcMapData ( PROS_SHARED_CACHE_MAP SharedCacheMap; ULONG VacbOffset; NTSTATUS Status; - BOOLEAN Result; + _SEH2_VOLATILE BOOLEAN Result; CCTRACE(CC_API_DEBUG, "CcMapData(FileObject 0x%p, FileOffset 0x%I64x, Length %lu, Flags 0x%lx," " pBcb 0x%p, pBuffer 0x%p)\n", FileObject, FileOffset->QuadPart, @@ -406,13 +410,17 @@ CcMapData ( if (!Result) { CcpDereferenceBcb(SharedCacheMap, iBcb); - return FALSE; + *pBcb = NULL; + *pBuffer = NULL; } } _SEH2_END; - *pBcb = &iBcb->PFCB; - *pBuffer = (PVOID)((ULONG_PTR)iBcb->Vacb->BaseAddress + VacbOffset); + if (Result) + { + *pBcb = &iBcb->PFCB; + *pBuffer = (PVOID)((ULONG_PTR)iBcb->Vacb->BaseAddress + VacbOffset); + } CCTRACE(CC_API_DEBUG, "FileObject=%p FileOffset=%p Length=%lu Flags=0x%lx -> TRUE Bcb=%p, Buffer %p\n", FileObject, FileOffset, Length, Flags, *pBcb, *pBuffer);
