The following patches implement another interface that allows an admin to restrict permissions inside /proc/<pid> to enhance the privacy of users. Following a suggestion by Albert Calahan this set of patches introduces five sysctls, each one changes the permissions of a certain file in /proc/<pid>.
It works by implementing getattr and permission methods that update the files' permissions (btw. Al Viro suggested doing it this way right from the start..). To "cloak" as much as currently possible: # sysctl -q proc.cmdline=0400 # sysctl -q proc.maps=0400 # sysctl -q proc.stat=0400 # sysctl -q proc.statm=0400 # sysctl -q proc.status=0400 This will set the permissions of /proc/*/cmdline etc. to the given value. The permissions of files in /proc/1 (usually belonging to init) are kept as they are. The idea is to let system processes be freely visible by anyone, just as before. Especially interesting in this regard would be instances of login. I don't know how to easily discriminate between system processes and "normal" processes inside the kernel (apart from pid == 1 and uid == 0 (which is too broad)). Any ideas? It's easy to make more files' permissions configurable, if the need arises. This implementation is a lot bigger than the quick hacks I sent earlier. Is this feature growing too fat? Also I'm unsure about the #ifdef'ery in fs/proc/base.c, I just wanted to be consistent with the surrounding code. :-P Rene - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/