Messages in this thread | | | Date | Tue, 17 Apr 2007 18:21:26 +0100 | From | Alan Cox <> | Subject | Re: [AppArmor 31/41] Fix __d_path() for lazy unmounts and make it unambiguous; exclude unreachable mount points from /proc/mounts |
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> For /proc/mounts, one could argue that the admin might want to see everything, > but then that's not actually true even today because /proc/mounts doesn't > show lazyily unmounted stuff or mounts from other namespaces, so that > everything is quite relative.
The current state is not good either
> The getcwd() case is even stronger as the "see everything" argument makes even > less sense there. I really can't see why the kernel should return processes > fake pathnames. The process is explicitly asking for the current pathname to > the working directory, it doesn't want to know what the pathname was at some > previous point in time.
Can you prove no existing application on the planet relies on the existing behaviour ? Actually more limited but sane as a test would be "Can you prove that the glibc behaviour visible to applications does not change"
> Actually, no. We could live fine with leaving getcwd() and /proc/mounts as > ambiguous / weird / broken as they are right now. All it would take would be > to reambiguate the result of the unambiguous __d_path(), which is really > easy. Everything that cares about real pathnames would use the unambiguous > version while the legacy interfaces would use the ambiguous version. But that > really wouldn't make sense.
I disagree - firstly because of not breaking stuff, and secondly because it separates two discussions - merging AppArmor being one of them , and the correct behaviour for getcwd & /proc/mounts being the other.
> > Ok, providing the "real" root sees them all it isn't so bad, but to > > assume you can filter based upon what the task can see is dodgy as an > > assumption. > > Why?
Because the viewing apparatus on the other side of the monitor is not operating in current directories/contexts.
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