Bug 1258223
| Summary: | [i686] BUG: unable to handle kernel paging request at ... in add_nops | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Richard W.M. Jones <rjones> |
| Component: | kernel | Assignee: | Kernel Maintainer List <kernel-maint> |
| Status: | CLOSED RAWHIDE | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | rawhide | CC: | cebbert.lkml, gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda, mchehab |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2015-09-08 16:11:01 UTC | Type: | Bug |
| 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: | 910269 | ||
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Description
Richard W.M. Jones
2015-08-30 11:51:34 UTC
OK, I did reproduce it! It took a long time though. My set up is: 32 bit i686 Fedora Rawhide VM running on AMD hardware *Inside* this VM, I'm running: $ while libguestfs-test-tool >/tmp/log 2>&1; do echo -n .; done .................................................................................................................................................................................................................................................................................................................................................................................................................. and boom it fails after ~ 400 iterations with the same backtrace as above. I don't have any convenient 32 bit baremetal machine to test this on. 0: 8d 90 90 83 04 24 lea 0x24048390(%eax),%edx 6: 80 fc 0f cmp $0xf,%ah 9: a8 0f test $0xf,%al >> b: a0 06 1e 50 55 mov 0x55501e06,%al 10: 57 push %edi 11: 56 push %esi Interrupt 0x30 occurred while the alternatives code was replacing the initial 0x90,0x90,0x90 NOPs (from the ASM_CLAC macro) with the optimized version, 0x8d,0x76,0x00. Only the first byte has been replaced so far, and it makes a mess out of the insn decoding. Reported on lkml: http://marc.info/?l=linux-kernel&m=144098871818266&w=4 Seems to be a generally accepted solution upstream, which I have extensively tested and it works for me. https://marc.info/?l=linux-kernel&m=144127697521764&w=4 Added in Fedora git. It will be in the 4.3.0-0.rc0.git8.1 build (whenever that happens). Thanks for chasing this down everyone. |