DataBreakPoint

http://msinilo.pl/blog/?p=571

http://www.codeproject.com/KB/debug/hardwarebreakpoint.aspx

查冲内存的 错误时候，可以通过程序来控制哪里有data breakpoint，那里没有，什么时间有，和write，read格式，比vc里面设给力10倍。

每个thread只能有4个data break point这个还比较郁闷（vc2005里面，vs2010里没试过）

把下载的代码copy一份这里吧，方便快速查找和索引

 

#include "core/Debug.h"
#include "core/Config.h"
#include "core/win32/Windows.h"
namespace
{
int FindBreakpointIndexForAddress(const void* address, CONTEXT& ctx, DWORD** retDebugReg)
{
	int dataIndex(-1);
	*retDebugReg = 0;
	if (ctx.Dr0 == (size_t)address)
	{
		dataIndex = 0;
		*retDebugReg = &ctx.Dr0;
	}
	else if (ctx.Dr1 == (size_t)address)
	{
		dataIndex = 1;
		*retDebugReg = &ctx.Dr1;
	}
	else if (ctx.Dr2 == (size_t)address)
	{
		dataIndex = 2;
		*retDebugReg = &ctx.Dr2;
	}
	else if (ctx.Dr3 == (size_t)address)
	{
		dataIndex = 3;
		*retDebugReg = &ctx.Dr3;
	}
	return dataIndex;
}
int FindFreeBreakpointIndex(CONTEXT& ctx, DWORD** retDebugReg)
{
	return FindBreakpointIndexForAddress(NULL, ctx, retDebugReg);
}
// Indexed with DataBreakpoint::Enum
const rde::uint32 s_triggerMasks[] =
{
	0xFFFFFFFF, // NONE
	1,			// WRITE
	3,			// READWRITE
	0,			// EXECUTE
};
// Indexed with DataBreakpoint::SizeEnum
const rde::uint32 s_sizeMasks[] =
{
	0, 1, 3, 2,
};
} // <anonymous> namespace
namespace rde
{
bool SetDataBreakpoint(const void* address, DataBreakpoint::Enum accessType, DataBreakpoint::SizeEnum dataSize)
{
	CONTEXT threadContext;
	threadContext.ContextFlags = CONTEXT_DEBUG_REGISTERS;
	const HANDLE currentThread = ::GetCurrentThread();
	if (!::GetThreadContext(currentThread, &threadContext))
		return false;
	DWORD* dataDebugReg(0);
	int dataIndex = FindBreakpointIndexForAddress(address, threadContext, &dataDebugReg);
	bool success(false);
	// Clear data breakpoint
	if (accessType == DataBreakpoint::NONE)
	{
		if (dataIndex >= 0)
		{
			threadContext.Dr7 &= ~(3 << (dataIndex * 2));
			*dataDebugReg = 0;	// clear address
			success = true;
		}
	}
	else	// set/change data breakpoint
	{
		if (dataIndex < 0)
			dataIndex = FindFreeBreakpointIndex(threadContext, &dataDebugReg);
		if (dataIndex >= 0)
		{
			// Enable breakpoint.
			threadContext.Dr7 &= ~(3 << (dataIndex * 2));
			threadContext.Dr7 |= 3 << (dataIndex * 2);	// local & global
			// Set trigger mode.
			// (starts at bit 16, 2 bits per entry).
			const uint32 triggerMask = s_triggerMasks[accessType];
			threadContext.Dr7 &= ~(3 << ((dataIndex * 2) + 16)); // clear old mask
			threadContext.Dr7 |= triggerMask << ((dataIndex * 2) + 16);
			// Set data size
			// (starts at bit 24, 2 bits per entry).
			threadContext.Dr7 &= ~(3 << ((dataIndex * 2) + 24)); // clear old mask
			const uint32 sizeMask = s_sizeMasks[dataSize];
			threadContext.Dr7 |= sizeMask << ((dataIndex * 2) + 24);
			*dataDebugReg = (DWORD)((size_t)address);
			
			success = true;
		}
	}
	if (success)
	{
		success = (::SetThreadContext(currentThread, &threadContext) != 0);
	}
	return success;
}
} // rde

 

原文链接： http://blog.csdn.net/ccanan/article/details/6018931