Bug 494876
| Summary: | [RHEL5.4]: Explicitly zero CR[1] in getvcpucontext | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 5 | Reporter: | Chris Lalancette <clalance> |
| Component: | kernel-xen | Assignee: | Miroslav Rezanina <mrezanin> |
| Status: | CLOSED ERRATA | QA Contact: | Red Hat Kernel QE team <kernel-qe> |
| Severity: | medium | Docs Contact: | |
| Priority: | low | ||
| Version: | 5.3 | CC: | dzickus, mjenner, syeghiay, xen-maint |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2009-09-02 09:00:27 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: | |||
| Bug Depends On: | |||
| Bug Blocks: | 492570 | ||
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Description
Chris Lalancette
2009-04-08 14:07:57 UTC
Assigned for triage. Miroslav, we have to figure out whether this is actually needed or not. At a quick glance, I couldn't figure it out. If we don't need it, I'd want to know why we don't need it while upstream does, especially since supporting pv-ops guests is a high priority for us going forward. Chris Lalancette I'd recommended copy this patch as it guarantees that guest won't received undefined value that can cause guest to behave unstable. If we want to be sure that each calling getvcpucontext hypercall returns concrete value. Miroslav,
OK, a couple of things. First, the patch that actually was committed into the upstream tree is slightly different than the one posted to the mailing list. This happens often in the Xen world, you'll get used to it :). That being said, we like to stay as close as possible to what is in the upstream; it makes future porting work easier.
The second thing is that I still don't understand how or why this patch is needed. Maybe I'm just missing something, but doing a "grep -rI ctrlreg *" in the pv-ops source tree, I *only* see ctrlreg[3] being used, not ctrlreg[1]. Now, it's entirely possible that I'm missing something, and it's copied around as part of a larger data structure. But before committing the patch to the tree, I would like to understand better where and how this is used. Maybe you can point out what I'm missing to make this patch useful. Or, if need be, we can always email Ian Campbell (the original patch author) to see why exactly he posted the patch in the first place.
Chris Lalancette
*** Bug 499598 has been marked as a duplicate of this bug. *** in kernel-2.6.18-146.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5 Please do NOT transition this bugzilla state to VERIFIED until our QE team has sent specific instructions indicating when to do so. However feel free to provide a comment indicating that this fix has been verified. An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2009-1243.html |