| Summary: | user-space probes wrongly reject repnz;ret instructions | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Frank Ch. Eigler <fche> |
| Component: | systemtap | Assignee: | Frank Ch. Eigler <fche> |
| Status: | CLOSED ERRATA | QA Contact: | qe-baseos-tools-bugs |
| Severity: | medium | Docs Contact: | |
| Priority: | low | ||
| Version: | 6.1 | CC: | mjw, pmuller |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | x86_64 | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | systemtap-1.4-2.el6 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2011-05-19 13:54:50 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
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/RHBA-2011-0651.html |
GCC sometimes emits the code sequence "repnz;ret" to end a function. systemtap's uprobes module rejects that as an unknown instruction sequence, but this is unnecessary. We have a patch in hand to let such instructions be treated just like "rep;ret" = "ret". This should let stap run even with such optimized gcc code, without risk. commit 9ee518c4d6c36770aa5da534ae85754962bfe305 Author: Roland McGrath <roland> Date: Wed Jan 19 11:23:43 2011 -0800 PR12419: fix x86 uprobes decoding of "repnz ret"