Question

我在C中编写了一个python扩展。在C中有一个用于覆盆子hw开发板的库，所以我正在使用它。所以我将一个函数从C导出到python，在调用结束时，python不再说*** stack smashing detected ***: python3 terminated。

python电话：

print("self.handle="+str(self.handle))
ret=dcc.dcc_send(self.handle, d[0], d[1], d[2], d[3], d[4], d[5])
print("returned: "+str(ret)) # never gets here

C python导出（完成）：

static PyObject* dcc_send(PyObject* self, PyObject* args) {
    unsigned char handle, count, b1, b2, b3, b4, b5;

    if (!PyArg_ParseTuple(args, "iiiiiii", &handle, &count, &b1, &b2, &b3, &b4, &b5))
            return NULL;

    printf("1234-handle: %d\n", handle);

    int ret = -1;
    ret = send_command(handle, count, b1, b2, b3, b4, b5);

    printf("1235-after-send_command-return: %d\n", ret);

    //Py_RETURN_NONE;
    return Py_BuildValue("i", ret);
}

堆栈中的另一个调用：

int send_command(int handle, unsigned char count, unsigned char b1, unsigned char b2, unsigned char b3, unsigned char b4, unsigned char b5) {
    unsigned char message[10];
    message[0] = CMD_START_VAL;
    message[1] = CMD_DCC_MESS;
    message[2] = 0;
    message[3] = 0xF0 | count; //2 byte size
    message[4] = b1;
    message[5] = b2;
    message[6] = b3;
    message[7] = b4;
    message[8] = b5;
    message[9] = CMD_STOP_VAL;
    return write_uart(handle, message,10);
}

堆栈中的最终调用（我没有完全写出来，我只是从lib中取出它并修复了一些内容，就像曾经存在的无效内存访问一样）：

int write_uart(int handle, unsigned char *data,int bytes) {
    #ifdef TEST
    int length = bytes;
    printf("handle: %d\n", handle);
    printf("bytes: %d\ndata: ", length);
    for (int i=0; i<length; ++i)
        printf("%d ", (int) data[i]);
    printf("\n---\n");
    #endif
    int txed;
    int offset=0;
    while (length) {
        txed = write(handle, (unsigned char*)data+offset, length);
        if (txed==-1) {
            fprintf(stderr,"UART WRITE ERRROR!!\n");
            return 0;
        }
        length -= txed;
        offset += txed;
    }
    tcdrain(handle);
    return 1;
}

当我运行它时，我明白了：

self.handle=3
1234-handle: 3
handle: 3
bytes: 10
data: 160 25 0 242 47 130 0 0 0 80
---
1235-after-send_command-return: 1
*** stack smashing detected ***: python3 terminated
Aborted

我做错了什么？感谢

Answer 1

正如苛刻的ossifrage所说，问题在于使用'iiiiiii'作为char类型。然后当函数完成并返回堆栈指针时，它就会关闭，应用程序崩溃了。

python3 stack smashing - 用c扩展的python

1 个答案: