64-bit Linux Question

[Overdose]

Does 64-bit Linux (specifically Ubuntu) have any security advantages over 32-bit? Please mention even the slightest advantage (or disadvantage) that you know of. Thanks in advance.

[TinMan]

Some interesting thoughts were posted so I did some more testing on the 32-bit vs 64-bit issue:
64bit: 3067 frames, 79.0 seconds: 38.8 fps
32bit: 3067 frames, 72.0 seconds: 42.6 fps

There is a notable difference but nothing to really complain about
(38fps is not bad anyway  :wink: )

Than I suddenly remembered these funny settings:

Code Select Expand

vm_cgame 2
vm_game 2
vm_ui 2

These force the game to use the .qvm's and ignore any the .so version (that would be .dll for windows users)

When we set these settings to 0 (to use the dll-version) the picture changes quite a bit:

64bit so
3067 frames, 65.2 seconds: 47.0 fps
32bit so
3067 frames, 69.0 seconds: 44.4 fps

The native version is the clear winner here.

http://tremulous.net/phpBB2/viewtopic.php?t=3442

[Overdose]

That didn't answer my primary question, but it did help with another conundrum I was having.

[TinMan]

I didn't see the word "security", lol.
Nope.

[Taiyo.uk]

Well, most (all?) 32-bit x86 CPUs don't have any method of marking memory areas as holding non-executable data. There is a flag to set memory areas as data only in most 64-bit CPUs. AMD call this the no-execute or NX bit, and Intel call it the execute-disable or XD bit, but they have the same function. The idea is that it makes executing (possibly malicious) code that has been written to data areas more difficault. Whether this actually makes your box more secure overall is another matter though. Since some time in 2004, linux running in 32-bit and 64-bit mode can use the NX bit if it is running on a 64-bit CPU that supports it.

See here: http://en.wikipedia.org/wiki/XD_bit

[Overdose]

Thats pretty neat, but other than that, there aren't any big security advantages that you know of?