On Mon, Sep 17, 2007 at 08:55:49AM +0200, Brice Goglin wrote: > > > On arm platforms where physical RAM doesn't start at physical address > > > zero, opening /dev/mem and reading from it causes a kernel oops. This > > > is arguably a kernel bug, but it's still not a very good idea to just > > > start randomly poking around in /dev/mem in search of entropy, which is > > > what xdm does if it can't get entropy elsewhere. > > > > > > (When the kernel is fixed, blindly reading from /dev/mem will simply > > > just fail with EFAULT instead of oopsing. If that will cause xdm to > > > fail, it should really just fail right away if /dev/random doesn't work.) > > > > xdm seems to try /dev/urandom first nowadays (before /dev/random and then > > /dev/mem). I don't whether arm systems have a /dev/urandom, but it seems > > more likely than having a /dev/random. > > > > I don't know which version of xdm you were running when you reported this > > problem (Xorg 6.8.2 was the latest release on 2005/10/28). But it was at > > the same time that the urandom support has been added upstream (in Xorg > > 6.9.99.902 on 2005/10/29). > > > > So please test with a more recent xdm and report back whether it helps. > > Ping?
I'm not sure what to reply to this. The problem is not that xdm doesn't check /dev/urandom first, the problem is that it reads from /dev/mem _at all_. It is possible that checking /dev/urandom first masks the problem in most configurations, but it doesn't solve it (if you don't have /dev/random and /dev/urandom in your filesystem for whatever reason, you still oops.) -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
