Bug 1783957
| Summary: | Implement workaround in assembler for Intel's JCC errata [RHEL 8.2] [rhel-8.1.0.z] | ||
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| Product: | Red Hat Enterprise Linux 8 | Reporter: | RHEL Program Management Team <pgm-rhel-tools> |
| Component: | binutils | Assignee: | Nick Clifton <nickc> |
| binutils sub component: | system-version | QA Contact: | Martin Cermak <mcermak> |
| Status: | CLOSED ERRATA | Docs Contact: | |
| Severity: | high | ||
| Priority: | unspecified | CC: | dbayly, fweimer, law, mcermak, mprchlik, ohudlick, pfrankli, toneata |
| Version: | 8.2 | Keywords: | ZStream |
| Target Milestone: | rc | ||
| Target Release: | 8.0 | ||
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | binutils-2.30-58.el8_1_0.1 | Doc Type: | Bug Fix |
| Doc Text: |
Cause:
A recently discovered problem in some Intel CPUs means that under certain circumstances it is possible for a machine instruction to be executed incorrectly.
Consequence:
A CPU with the flaw could fail to execute programs correctly.
Fix:
The full fix involves updating the microcode of vulnerable CPUs, which can result in a performance degradation. This update enables a workaround in the assembler instead. Recompiling a program with the workaround enabled will render a program immune to the vulnerability, although there will be a size increase and possibly a small performance hit.
Note - the workaround is *not* enabled by default. In order to activate it this gcc command line option must be used:
-Wa,-mbranches-within-32B-boundaries
Result:
Programs rebuilt with the above command line option specified will not be vulnerable to the Intel Jcc flaw.
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Story Points: | --- |
| Clone Of: | 1777002 | Environment: | |
| Last Closed: | 2020-02-04 13:11:48 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: | 1777002 | ||
| Bug Blocks: | |||
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Comment 1
Nick Clifton
2019-12-16 13:18:49 UTC
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:0338 |