the content of pointer changed when passed to the function - c++

Question

I am using C++ to do my work. The following is the problem I am confulsed.
typedef struct netHandler {
int m_iFd;
poll_event_t* m_pPollEvent;
epoll_event m_Event;
void* m_pConn;
} netHandler_t;
Here is my struct. When the program running. I set a breakpoint in the following place:
connection_t* conn = geneConnection(idenfication, fd, handler);
And before step into this funcition, I record the handler's content.
p *(netHandler_t *) 0x2aaaac000960
$2 = {m_iFd = 9, m_pPollEvent = 0x2aaaac000930, m_Event =
{events = 1, data = {ptr = 0x2aaaac000960, fd = -1409283744, u32 = 2885683552, u64 = 46912518490464}},
m_pConn = 0x60d010}
Then I step into the geneConnection function. The content changed.
p *(netHandler_t *) 0x2aaaac000960
$3 = {m_iFd = 9, m_pPollEvent = 0xac00093000000000, m_Event =
{events = 10922, data = {ptr = 0xac00096000000001, fd = 1, u32 = 1, u64 = 12393916482445115393}},
m_pConn = 0x2aaa}
That's like the struct was shrifted.
connection_t* geneConnection(long iden, int sendfd, netHandler_t* handler);
This is the declare of geneConnection. I don't understand why this happened. When I change this function to inline type. The content of handler would not changed.