Messages in this thread | | | Date | Tue, 24 Jul 2012 01:08:40 -0700 | From | bforce1729 <> | Subject | Need to know the size of data send from Kernel to USer Ap |
| |
Hi,
I am new to kernel programming so can anyone point me to the right forum/reply for the question below.
I would like to implement a character device and using a node of type character read and write data. However I am not sure of the length of data from kernel which a user app will receive, so I would like to code safely. If the data exceeds the application gets killed. Any idea or API to perform the task of knowing the data length when passing data to and fro from kernel to user level would be appreciated.
Kernel code:
copy_to_user(buff, kernel_msg, strlen(kernel_msg));
User App: fd=open("./my_device",O_RDONLY); ret=read(fd,buff,strlen(buf)); //How can I know the size of buff, which would be sent/filled from kernel???
Regards bforce
| |