hooks.c

一个类似与Windows环境下的softice的源代码

/******************************************************************************
 *
 * Copyright (c) 2003 Gerhard W. Gruber
 *
 * PROJECT: pICE
 * $Source: /cvsroot/pice/pice/module/hooks.c,v $
 * $Revision: 1.5 $
 * $Date: 2004/02/17 23:07:36 $
 * $Author: lightweave $
 * $Name:  $
 *
 * $Log: hooks.c,v $
 * Revision 1.5  2004/02/17 23:07:36  lightweave
 *
 * Improved the DEBUG facillity and replaced the configuration handler with a
 * new code which now can read MS Windows INI style files. See CHANGES.txt for
 * more details.
 * Also added a macro which prevents compiling for kernels before 2.4.19.
 *
 * Revision 1.4  2003/06/18 22:00:22  lightweave
 * DEBUG and DEBUG_SERIAL added
 *
 *
 *****************************************************************************/

static char *ident = "$Header: /cvsroot/pice/pice/module/hooks.c,v 1.5 2004/02/17 23:07:36 lightweave Exp $";


/*++

Copyright (c) 1998-2001 Klaus P. Gerlicher

Module Name:

    hooks.c

Abstract:
    
    hooking of interrupts

Environment:

    Kernel mode only

Author:

    Klaus P. Gerlicher

Revision History:

    16-Jul-1998:	created
    15-Nov-2000:    general cleanup of source files

Copyright notice:

  This file may be distributed under the terms of the GNU Public License.

--*/

////////////////////////////////////////////////////
// INCLUDES
////
#include "remods.h"

#include <asm/io.h>

#include "precomp.h"

////////////////////////////////////////////////////
// PROTOTYPES
////

////////////////////////////////////////////////////
// DEFINES
////

////////////////////////////////////////////////////
// GLOBALS
////

// processor flag for interrupt suspension
ULONG g_ulFlags;

////////////////////////////////////////////////////
// PROCEDURES
////

//*************************************************************************
// EnterCritical()
//
//*************************************************************************
void EnterCritical(void) 
{ 
    ENTER_FUNC();

	save_flags(g_ulFlags);
	cli();

    LEAVE_FUNC();
} 
 
//*************************************************************************
// LeaveCritical()
//
//*************************************************************************
void LeaveCritical(void) 
{ 
    ENTER_FUNC();

    restore_flags(g_ulFlags);

    LEAVE_FUNC();
} 

//*************************************************************************
// AtomicSet8Byte()
//
//*************************************************************************
static inline void AtomicSet8Byte(unsigned long long * ptr,
		unsigned int low, unsigned int high)
{
	__asm__ __volatile__ (
		"\n1:\t"
		"movl (%0), %%eax\n\t"
		"movl 4(%0), %%edx\n\t"
		"cmpxchg8b (%0)\n\t"
		"jnz 1b"
		: /* no outputs */
		:	"D"(ptr),
			"b"(low),
			"c"(high)
		:	"ax","dx","memory");
}


//*************************************************************************
// HookInterruptVector()
//
//*************************************************************************
void HookInterruptVector(ULONG dwInt,PVOID NewIntHandler,PVOID* pOldIntHandler)
{
    PIDT	pIdt;
    PULONG	pTempIdt;
    IDT		tempIdtEntry;

    ENTER_FUNC();

    // get linear location of IDT
    pIdt = GetIDTPtr();

    // get pointer to idte for interrupt
    pIdt += dwInt;

    // return old handler's address if requested
    // must do this before setting new handler because INT might
    // be triggered even before we return from here and will jump into
    // nirvana while leaving DebuggerEntry
    if(pOldIntHandler)
    {
       *pOldIntHandler = (PVOID)((pIdt->Offset_31_16<<16) | (pIdt->Offset_15_0&0x0000FFFF));
       DPRINT(PICE_DEBUG, DBT_HOOKS, DBL_INFO, "old INT(%02x) handler = %04x:%p\n", dwInt, pIdt->Selector, *pOldIntHandler);
    }

    // set new handler address
    tempIdtEntry = *pIdt;
    tempIdtEntry.Offset_31_16	=(USHORT)(((ULONG)NewIntHandler)>>16);
    tempIdtEntry.Offset_15_0	=(USHORT)(((ULONG)NewIntHandler)&0x0000FFFF);
#if LINUX_VERSION_CODE < 0x020409
    if(pOldIntHandler)
       tempIdtEntry.DescType = 0x0E; // interrupt gate
    else
       tempIdtEntry.DescType = 0x0F; // trap gate
#endif // LINUX_VERSION_CODE 

    pTempIdt = (PULONG)&tempIdtEntry;

    // now store the 8byte IDT descriptor in one atomic operation
    AtomicSet8Byte((unsigned long long*)pIdt, pTempIdt[0], pTempIdt[1]);

    // flush chip caches
#ifdef CONFIG_SMP
    FlushCacheAndTLBAllCpus();
#else // CONFIG_SMP
    FlushCacheAndTLB();
#endif // CONFIG_SMP

    DPRINT(PICE_DEBUG, DBT_HOOKS, DBL_INFO, "new INT(%02x) handler = %04x:%x\n", dwInt, pIdt->Selector, (pIdt->Offset_31_16<<16)|(pIdt->Offset_15_0&0x0000FFFF));

    LEAVE_FUNC();
}

// EOF