60 lines
1.5 KiB
C
60 lines
1.5 KiB
C
/***
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*sehsupp.c - helper functions for Structured Exception Handling support
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*
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* Copyright (C) 1993-2001, Microsoft Corporation. All rights reserved.
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*
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*Purpose:
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* Contains _rt_probe_read. Helper for the SEH runtime support
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* routines (longjmp in particular). Much of the SEH code is written
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* in asm, so these routines are available when probing memory in ways
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* that must be guarded with __try/__except in case of access violation.
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*
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*Revision History:
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* 12-05-93 PML Module created.
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* 12-22-93 GJF Made #define WIN32_LEAN_AND_MEAN conditional.
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* 01-12-94 PML Rewritten - still need helpers, just different ones
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*
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*******************************************************************************/
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#ifndef WIN32_LEAN_AND_MEAN
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#define WIN32_LEAN_AND_MEAN 1
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#endif
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#include <windows.h>
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/***
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*BOOL __stdcall _rt_probe_read4 - Check if a DWORD is readable
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*
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*Purpose:
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* Internal support function called by longjmp. Check if a DWORD is
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* readable under a __try/__except.
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*
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*Entry:
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* DWORD * p - Pointer to DWORD to be probed
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*
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*Exit:
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* Success: TRUE - Able to read
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* Failure: FALSE - Access violation while reading
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*
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******************************************************************************/
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BOOL __stdcall _rt_probe_read4(
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DWORD * ptr)
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{
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BOOL readable;
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__try
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{
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*(volatile DWORD *)ptr;
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readable = TRUE;
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}
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__except (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION
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? EXCEPTION_EXECUTE_HANDLER
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: EXCEPTION_CONTINUE_SEARCH)
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{
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readable = FALSE;
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}
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return readable;
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}
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