klogd(8) looks for System.map at startup so that it can map locations to symbols. According to the man page, the paths searched are: /boot/System.map /System.map /usr/src/linux/System.map (I have not checked the source to verify the paths or the search order.) If the user mounts /boot for whatever reason, then changes runlevel or otherwise restarts klogd, klogd will open /boot/System.map. This file remains open while klogd is running, preventing the user from umounting /boot until klogd is stopped. Since Gentoo recommends against automounting /boot, we might want to consider patching klogd so that it ignores /boot/System.map by default. I copy /usr/src/linux/System.map to /System.map when I build a new kernel, since klogd doesn't seem to look on /usr/src/linux for System.map when it starts.
this doesn't seem to be a potential issue that warrants any sort of change.
