There was a discussion (bug #681600) how to disable access to text printed by previous user on the console to prevent sensitive data leak. mingetty should instruct Linux virtual terminal to clear screen including scroll-back buffer. Once Linux will implement it (bug #684261), adapt mingetty to perform the safe clear. Because current behavior is not to clear the screen and there can be demand not to do it always (e.g. to debug broken login shell or to investigate init scripts output on /dev/console), new mingetty positional argument will be added to switch on/off the screen cleaning.
F16 delivers kernel-3.0* that supports \E[3;J to clear screen including scroll-back buffer. F16 uses systemd as init that by default reallocate VT before spawning mingetty, thus the scroll-back buffer is always empty. To test this bug report, one can use following command: # openvt -f -c 10 -s -w -- /bin/bash \ -c 'dmesg; exec /sbin/mingetty --loginprog=/bin/false tty10' This allocates TTY10, switches console there, pollutes buffer with kernel log, and then executes mingetty. Now it's possible to press Shift-PgUp to verify the buffer has gone. I will add new positional argument to mingetty to enable safe console clearing. The clearing will be done by issuing the the new escape sequence followed by the older 2J variant to clean at least current visible area if mingetty run on system not supporting the new 3J sequence.
Se there is already --noclear option defaulting to clear. So adding the new sequence seems to be enough.
Created attachment 504091 [details] Implementation Tested with Linux 3.0-0.rc2.git0.1.fc16.x86_64 on VGA console.