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LWN.net Weekly Edition for May 16, 2013
A look at the PyPy 2.0 release
PostgreSQL 9.3 beta: Federated databases and more
LWN.net Weekly Edition for May 9, 2013
(Nearly) full tickless operation in 3.10
Solving the ext3 latency problem
Posted Apr 14, 2009 20:10 UTC (Tue) by drag (subscriber, #31333)
That is they are logged onto the machine and are doing something on them.. programming, editing, web browsing, etc.
So your dealing with computers with multiple monitors with multiple users logged in at once, or LTSP, or people that still sell shell accounts. All of which are fairly rare compared to personal desktops, embedded systems, or most server systems.
Posted Apr 14, 2009 23:24 UTC (Tue) by ktanzer (guest, #6073)
On a more general note, Linux has inherited rich multi-user capabilities from Unix, and I hate to see that atrophy over time. As one example, it is very easy to find information on how to configure popular programs such as Firefox, KDE, OpenOffice, etc. for a single user, but often maddeningly hard to determine how to configure on a system-wide basis. The fact that FF can't run multiple instances from a single profile is not technically a multi-user issue, but also drives me up the wall...
Posted Apr 15, 2009 1:25 UTC (Wed) by drag (subscriber, #31333)
I don't know exactly why, but I have a feeling that multiuser systems will become increasingly important in the future.
Something will come along... like the acceptance of IPv6 and the decline of the "Personal Computer"-ing inflicted client-server relationship and the internet will return to it's P2P roots. (for reasons of scalability, robustness, expense). If something like that were to happen and people realized that having mobile computers could become essentially disposible if they turned into little more then terminals for the 'big' computer at home or clusters at work... Then multiuser systems could become common place again.
Weirder things have happenned.
Posted Apr 15, 2009 4:35 UTC (Wed) by malor (subscriber, #2973)
It would be bad if a bug in the mail server gave access to, say, deleted .htaccess files, or part of a SQL database.
All Unix systems are inherently multiuser, and sabotaging inter-account security features is deliberately cutting away one layer of the net that can catch you if a bug exposes an attack vector.
Posted Apr 15, 2009 5:55 UTC (Wed) by hawk (subscriber, #3195)
Isn't the point that as soon as soon as there are multiple users (no matter if they are logged in using a system account or accessing the system through some other means, eg HTTP, authenticated in some way or even anonymously), there would be a chance that one user's data (or data "belonging to the system") could leak into a file which will be accessible by another user.
So in the case of the the system crashing, a file publicly available on the web, or some logged in user(s), might end up containing anything that has previously been deallocated if that file was being modified, be it by the site administrator, or by a random user on a site where you can for instance upload an image to include in your content.
I would think this definitely falls within the "common usage"-realm for Linux systems and that whoever made the argument may not have really thought it through.
(Or I'm just not understanding in what scenarios something like this could actually happen.)
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