[英]free() causing stack overflow
我正在尝试使用一些通信DLLs
使用Visual Studio C ++开发应用程序。 在其中一个DLL中,我有一个堆栈溢出异常。
我有两个功能,一个接收数据包,另一个函数对数据包执行一些操作。
static EEcpError RxMessage(unsigned char SrcAddr, unsigned char SrcPort, unsigned char DestAddr, unsigned char DestPort, unsigned char* pMessage, unsigned long MessageLength)
{
EEcpError Error = ERROR_MAX;
TEcpChannel* Ch = NULL;
TDevlinkMessage* RxMsg = NULL;
// Check the packet is sent to an existing port
if (DestPort < UC_ECP_CHANNEL_NB)
{
Ch = &tEcpChannel[DestPort];
RxMsg = &Ch->tRxMsgFifo.tDevlinkMessage[Ch->tRxMsgFifo.ucWrIdx];
// Check the packet is not empty
if ((0UL != MessageLength)
&& (NULL != pMessage))
{
if (NULL == RxMsg->pucDataBuffer)
{
// Copy the packet
RxMsg->SrcAddr = SrcAddr;
RxMsg->SrcPort = SrcPort;
RxMsg->DestAddr =DestAddr;
RxMsg->DestPort = DestPort;
RxMsg->ulDataBufferSize = MessageLength;
RxMsg->pucDataBuffer = (unsigned char*)malloc(RxMsg->ulDataBufferSize);
if (NULL != RxMsg->pucDataBuffer)
{
memcpy(RxMsg->pucDataBuffer, pMessage, RxMsg->ulDataBufferSize);
// Prepare for next message
if ((UC_ECP_FIFO_DEPTH - 1) <= Ch->tRxMsgFifo.ucWrIdx)
{
Ch->tRxMsgFifo.ucWrIdx = 0U;
}
else
{
Ch->tRxMsgFifo.ucWrIdx += 1U;
}
// Synchronize the application
if (0 != OS_MbxPost(Ch->hEcpMbx))
{
Error = ERROR_NONE;
}
else
{
Error = ERROR_WINDOWS;
}
}
else
{
Error = ERROR_WINDOWS;
}
}
else
{
// That should never happen. In case it happens, that means the FIFO
// is full. Either the FIFO size should be increased, or the listening thread
// does no more process the messages.
// In that case, the last received message is lost (until the messages are processed, or forever...)
Error = ERROR_FIFO_FULL;
}
}
else
{
Error = ERROR_INVALID_PARAMETER;
}
}
else
{
// Trash the packet, nothing else to do
Error = ERROR_NONE;
}
return Error;
}
static EEcpError ProcessNextRxMsg(unsigned char Port, unsigned char* SrcAddr, unsigned char* SrcPort, unsigned char* DestAddr, unsigned char* Packet, unsigned long* PacketSize)
{
EEcpError Error = ERROR_MAX;
TEcpChannel* Ch = &tEcpChannel[Port];
TDevlinkMessage* RxMsg = &Ch->tRxMsgFifo.tDevlinkMessage[Ch->tRxMsgFifo.ucRdIdx];
if (NULL != RxMsg->pucDataBuffer)
{
*SrcAddr = RxMsg->ucSrcAddr;
*SrcPort = RxMsg->ucSrcPort;
*DestAddr = RxMsg->ucDestAddr;
*PacketSize = RxMsg->ulDataBufferSize;
memcpy(Packet, RxMsg->pucDataBuffer, RxMsg->ulDataBufferSize);
// Cleanup the processed message
free(RxMsg->pucDataBuffer); // <= Exception stack overflow after 40 min
RxMsg->pucDataBuffer = NULL;
RxMsg->ulDataBufferSize = 0UL;
RxMsg->ucSrcAddr = 0U;
RxMsg->ucSrcPort = 0U;
RxMsg->ucDestAddr = 0U;
RxMsg->ucDestPort = 0U;
// Prepare for next message
if ((UC_ECP_FIFO_DEPTH - 1) <= Ch->tRxMsgFifo.ucRdIdx)
{
Ch->tRxMsgFifo.ucRdIdx = 0U;
}
else
{
Ch->tRxMsgFifo.ucRdIdx += 1U;
}
Error =ERROR_NONE;
}
else
{
Error = ERROR_NULL_POINTER;
}
return Error;
}
问题在40分钟后发生,在这段时间内,我收到了很多数据包,并且一切进展顺利。 40分钟后,堆栈溢出异常立即发生。 我不知道怎么了。
有人可以帮我吗?
谢谢。
一些建议:
线
memcpy(Packet, RxMsg->pucDataBuffer, RxMsg->ulDataBufferSize);
有点怀疑,因为它发生在free()
调用崩溃之前。 如何分配Packet
,如何确保此处不会发生缓冲区溢出?
free()
调用中。
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