reactos/sdk/lib/crt/except/amd64/ehandler.c
2021-06-05 13:52:42 +02:00

141 lines
4.7 KiB
C

/*
* PROJECT: ReactOS CRT library
* LICENSE: MIT (https://spdx.org/licenses/MIT)
* PURPOSE: C specific exception/unwind handler for AMD64
* COPYRIGHT: Copyright 2018-2021 Timo Kreuzer <timo.kreuzer@reactos.org>
*/
#include <precomp.h>
#include <winnt.h>
_CRTIMP
EXCEPTION_DISPOSITION
__cdecl
__C_specific_handler(
struct _EXCEPTION_RECORD *ExceptionRecord,
void *EstablisherFrame,
struct _CONTEXT *ContextRecord,
struct _DISPATCHER_CONTEXT *DispatcherContext)
{
PSCOPE_TABLE ScopeTable;
ULONG i, BeginAddress, EndAddress, Handler;
ULONG64 ImageBase, JumpTarget, IpOffset, TargetIpOffset;
EXCEPTION_POINTERS ExceptionPointers;
PTERMINATION_HANDLER TerminationHandler;
PEXCEPTION_FILTER ExceptionFilter;
LONG FilterResult;
/* Set up the EXCEPTION_POINTERS */
ExceptionPointers.ExceptionRecord = ExceptionRecord;
ExceptionPointers.ContextRecord = ContextRecord;
/* Get the image base */
ImageBase = (ULONG64)DispatcherContext->ImageBase;
/* Get the image base relative instruction pointers */
IpOffset = DispatcherContext->ControlPc - ImageBase;
TargetIpOffset = DispatcherContext->TargetIp - ImageBase;
/* Get the scope table and current index */
ScopeTable = (PSCOPE_TABLE)DispatcherContext->HandlerData;
/* Loop while we have scope table entries */
while (DispatcherContext->ScopeIndex < ScopeTable->Count)
{
/* Use i as index and update the dispatcher context */
i = DispatcherContext->ScopeIndex++;
/* Get the start and end of the scrope */
BeginAddress = ScopeTable->ScopeRecord[i].BeginAddress;
EndAddress = ScopeTable->ScopeRecord[i].EndAddress;
/* Skip this scope if we are not within the bounds */
if ((IpOffset < BeginAddress) || (IpOffset >= EndAddress))
{
continue;
}
/* Check if this is an unwind */
if (ExceptionRecord->ExceptionFlags & EXCEPTION_UNWIND)
{
/* Check if this is a target unwind */
if (ExceptionRecord->ExceptionFlags & EXCEPTION_TARGET_UNWIND)
{
/* Check if the target is within the scope itself */
if ((TargetIpOffset >= BeginAddress) &&
(TargetIpOffset < EndAddress))
{
return ExceptionContinueSearch;
}
}
/* Check if this is a termination handler / finally function */
if (ScopeTable->ScopeRecord[i].JumpTarget == 0)
{
/* Call the handler */
Handler = ScopeTable->ScopeRecord[i].HandlerAddress;
TerminationHandler = (PTERMINATION_HANDLER)(ImageBase + Handler);
TerminationHandler(TRUE, EstablisherFrame);
}
else if (ScopeTable->ScopeRecord[i].JumpTarget == TargetIpOffset)
{
return ExceptionContinueSearch;
}
}
else
{
/* We are only unterested in exception handlers */
if (ScopeTable->ScopeRecord[i].JumpTarget == 0)
{
continue;
}
/* This is an exception filter, get the handler address */
Handler = ScopeTable->ScopeRecord[i].HandlerAddress;
/* Check for hardcoded EXCEPTION_EXECUTE_HANDLER */
if (Handler == EXCEPTION_EXECUTE_HANDLER)
{
/* This is our result */
FilterResult = EXCEPTION_EXECUTE_HANDLER;
}
else
{
/* Otherwise we need to call the handler */
ExceptionFilter = (PEXCEPTION_FILTER)(ImageBase + Handler);
FilterResult = ExceptionFilter(&ExceptionPointers, EstablisherFrame);
}
if (FilterResult == EXCEPTION_CONTINUE_EXECUTION)
{
return ExceptionContinueExecution;
}
if (FilterResult == EXCEPTION_EXECUTE_HANDLER)
{
JumpTarget = (ImageBase + ScopeTable->ScopeRecord[i].JumpTarget);
/* Unwind to the target address (This does not return) */
RtlUnwindEx(EstablisherFrame,
(PVOID)JumpTarget,
ExceptionRecord,
UlongToPtr(ExceptionRecord->ExceptionCode),
DispatcherContext->ContextRecord,
DispatcherContext->HistoryTable);
/* Should not get here */
__debugbreak();
}
}
}
/* Reached the end of the scope table */
return ExceptionContinueSearch;
}
void __cdecl _local_unwind(void* frame, void* target)
{
RtlUnwind(frame, target, NULL, 0);
}