Bug 125900
| Summary: | [PATCH] CAN-2004-0554: FPU exception handling local DoS | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Robert Scheck <redhat-bugzilla> |
| Component: | kernel | Assignee: | Arjan van de Ven <arjanv> |
| Status: | CLOSED ERRATA | QA Contact: | Brian Brock <bbrock> |
| Severity: | high | Docs Contact: | |
| Priority: | medium | ||
| Version: | 1 | CC: | menscher, pere, trondham |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| URL: | http://reviewed.homelinux.org/news/2004-06-11_kernel_crash/ | ||
| Whiteboard: | |||
| Fixed In Version: | 2.4.22-1.2194.nptl | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2004-06-22 22:33:19 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Attachments: | |||
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Description
Robert Scheck
2004-06-13 16:38:01 UTC
Oh...I forgot to say, that the patches at this website don't apply (signal.c-2.4.2?.patch.txt) to the Red Hat modified kernel and there are kernel oops (http://lkml.org/lkml/2004/6/12/64), but the idea from http://lkml.org/lkml/2004/6/12/81 is working after a 2.4 backport. After applying this patch (I applied it as Patch86x in the spec file), rebuild, install & reboot, I executed the crash code again - it only has a upper cpu usage now, but it doesn't crash the system :) This patch worked for me at i586, i686, athlon. Sorry, I've got no SMP and no x86_64 here (so x86_64 also seems to be generally affected?) to test it there. Created attachment 101097 [details]
linux-2.4.22-fpu.patch
Created attachment 101099 [details]
linux-2.4.22-fpu.patch
Well, I got access to a x86_64 box at work and there, the system crashed also
without a patch. Applying the same patch to the x86_64 solved it for me.
I still don't know, whether that what I'm doing with that patch is maybe good
or bad - but it is working for me currently. If I'm wrong, I'm hoping that you
guys from Red Hat do it better ;-)
Created attachment 101100 [details]
linux-2.4.22-fpu.patch for x86 and x86_64
Sorry, uploaded the wrong x86 (IA32 only) again, so here's the right one ;-)
Created attachment 101125 [details]
Last patch flooding (hopefully), backport (from Linus' official 2.6) for x86 and x86_64
an RPM with this problem fixed went to updates-testing this afternoon. If it looks ok, it'll move to updates-final in the next day or so. This bug is CAN-2004-0554, and the same as bug #125794. Dave, I've got a problem since using 219x: My CPU load isn't lower than 0.5 now (my system is just idling, no CPU intensive processes!), most of the time the "default load" is >= 1.00 - that's still too much for simple idling, where I had with kernel 218x a load from 0.0x up to maximal 0.5. Hotsanic documented this for me very well...so what's up? Could you please have a look to this?! Thank you! FYI: I've got a Intel Celeron 1.0 GHz. theres nothing changed in the kernel that could explain this that I can see. The FPU fix adds a single instruction to context switching, so that path slows down a little, but that should not affect your load average at all. Okay, 2194 is working now on all my computers normally - including the "problem host" above (a reinstall of the kernel solved it for me; don't know what the problem caused). kernel-2.4.22-1.2194.nptl was moved from testing to the stable update repository, but I'm missing an announcement at fedora-announce- list...but I'm closing this bug now, because my issue is solved. |