Alexey Dobriyan <adobri...@gmail.com> writes: >> The only option I have seen proposed that might qualify as something >> general purpose and simple is a new filesystem that is just the process >> directories of proc. > > While "mount -t pid" and "mount -t sysctl" are decades overdue, I don't > think they cover everything. > > IIRC some gcc versions read /proc/meminfo on every invocation. Now > imagine such program doesn't have a fallback if /proc/ doesn't exist > (how many thousands such programs are there?) So user is going to ask > for /proc with just /proc/meminfo only. At this point it is back to > nearly full /proc.
To avoid falling susceptible to the kinds of checks in fs_fully_visible we can only offer information about objects that root in the user namespace has privilege over. So "mount -t pid" good. A "/proc/meminfo" bad. Which in short means if "mount -t pid" isn't good enough. There really isn't anything the kernel can do. Eric
