unsigned int ctrlchar_handle (const unsigned char * buf, int len, struct tty_struct * tty);
param buf Console input buffer. param len Length of valid data in buffer. param tty The tty struct for this console. return CTRLCHAR_NONE, if nothing matched, CTRLCHAR_SYSRQ, if sysrq was encountered otherwise char to be inserted logically or'ed with CTRLCHAR_CTRL