memtest86+ test #7 false positives (random number sequence error)
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Memtest86+ |
Fix Released
|
Undecided
|
|||
Release Notes for Ubuntu |
Invalid
|
Undecided
|
Unassigned | ||
memtest86+ (Ubuntu) |
Fix Released
|
Medium
|
Chris J Arges | ||
Quantal |
Fix Released
|
Medium
|
Chris J Arges | ||
Raring |
Fix Released
|
Medium
|
Chris J Arges | ||
memtest86+ (openSUSE) |
Fix Released
|
Medium
|
Bug Description
Trying to check the memory at newly bought notebook I found a bug in the memtest86+ version 4.20 in ubuntu 12.10, in ubuntu 12.04 it is ok. The bug is reported at least in Fedora and Opensuse. It is assumed that the bug is caused by the gcc-4.7.
It is easily reproducible - select the test #7 in memtest or just wait till it - starting from the 129Mb it will report a lot of errors. I have checked it on three different systems , two of them I use on a daily basis and would note if RAM is really bad.
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SRU Justification
[Impact]
Users of memtest86+ will get false positives of memory failures. This will cause users to suspect hardware and require unnecessary testing/headaches.
[Test Case]
Boot Ubuntu in Quantal/Raring. At GRUB select memtest86+. Wait until the 7th test. It will fail at the 7th test.
[Regression Potential]
The fix is just adding another register to clobber in the inline assembly routine. Because this affects newer GCC versions, older releases aren't affected. Thus, if there are compiler changes we should re-test.
tags: | added: memtest86+ |
tags: |
added: number random sequence removed: memtest86+ |
tags: |
added: random-number-sequence removed: number random sequence |
summary: |
- memtest86 test #7 fails (random pattern error) + memtest86 test #7 fails (random number sequence error) |
Changed in memtest86+ (Ubuntu): | |
status: | Confirmed → In Progress |
status: | In Progress → Confirmed |
Changed in memtest86+ (openSUSE): | |
importance: | Unknown → Medium |
status: | Unknown → Fix Released |
tags: | added: quantal |
summary: |
- memtest86 test #7 fails (random number sequence error) + memtest86 test #7 false positives (random number sequence error) |
Changed in memtest86+ (Ubuntu): | |
assignee: | nobody → Chris J Arges (christopherarges) |
importance: | Undecided → Medium |
Changed in memtest86+ (Ubuntu Quantal): | |
assignee: | nobody → Chris J Arges (christopherarges) |
importance: | Undecided → Medium |
status: | New → In Progress |
Changed in memtest86+ (Ubuntu Raring): | |
status: | Confirmed → In Progress |
description: | updated |
summary: |
- memtest86 test #7 false positives (random number sequence error) + memtest86+ test #7 false positives (random number sequence error) |
Changed in ubuntu-release-notes: | |
status: | New → Incomplete |
Changed in ubuntu-release-notes: | |
status: | Incomplete → Invalid |
Changed in memtest86+: | |
importance: | Unknown → Undecided |
status: | Unknown → Fix Released |
Description of problem:
Trying to run the latest memtest86+ on various hardware, even in qemu, the seventh test (Random number sequence) fails and reports errors for each address from 129 MiB on.
Version-Release number of selected component (if applicable):
memtest86+ 4.20 from Fedora 17 Alpha DVD
How reproducible:
always
Steps to Reproduce: 17-Alpha- x86_64. DVD.iso
1. qemu-kvm -m 1024 -cdrom Fedora-
2. choose Troubleshooting => Run memory test
Actual results:
see the attached screenshot
Expected results:
no errors
Additional info:
Initially, I've run this on Intel SandyBridge hardware - Pentium B950 with some Samsung memories, and it failed this way, leading me to unjustified warranty claim ...
After that, I've verified the same memtest behaviour on T510 with Core i7 M620, and on some older desktop with Core i5 - real hardware, proven by months of service => seeing the same all the time I've tried in qemu and it fails too.