blob: 1dbce51bb445354513f2e5260897546e2d482db1 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
/***
*sehsupp.c - helper functions for Structured Exception Handling support
*
* Copyright (C) 1993, Microsoft Corporation. All rights reserved.
*
*Purpose:
* Contains _rt_probe_read. Helper for the SEH runtime support
* routines (longjmp in particular). Much of the SEH code is written
* in asm, so these routines are available when probing memory in ways
* that must be guarded with __try/__except in case of access violation.
*
*Revision History:
* 12-05-93 PML Module created.
* 12-22-93 GJF Made #define WIN32_LEAN_AND_MEAN conditional.
* 01-12-94 PML Rewritten - still need helpers, just different ones
*
*******************************************************************************/
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN 1
#endif
#include <windows.h>
/***
*BOOL __stdcall _rt_probe_read4 - Check if a DWORD is readable
*
*Purpose:
* Internal support function called by longjmp. Check if a DWORD is
* readable under a __try/__except.
*
*Entry:
* DWORD * p - Pointer to DWORD to be probed
*
*Exit:
* Success: TRUE - Able to read
* Failure: FALSE - Access violation while reading
*
******************************************************************************/
BOOL __stdcall _rt_probe_read4(
DWORD * ptr)
{
BOOL readable;
__try
{
*(volatile DWORD *)ptr;
readable = TRUE;
}
__except (GetExceptionCode() == EXCEPTION_ACCESS_VIOLATION
? EXCEPTION_EXECUTE_HANDLER
: EXCEPTION_CONTINUE_SEARCH)
{
readable = FALSE;
}
return readable;
}
|
