Bug 431183
Summary: | utrace: PTRACE_POKEUSR_AREA corrupts ACR0 | ||||||
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Product: | Red Hat Enterprise Linux 5 | Reporter: | Jan Kratochvil <jan.kratochvil> | ||||
Component: | kernel | Assignee: | Anton Arapov <anton> | ||||
Status: | CLOSED ERRATA | QA Contact: | Martin Jenner <mjenner> | ||||
Severity: | medium | Docs Contact: | |||||
Priority: | high | ||||||
Version: | 5.1 | CC: | kernel-mgr, nobody, rlerch, roland | ||||
Target Milestone: | rc | Keywords: | Regression | ||||
Target Release: | --- | ||||||
Hardware: | s390x | ||||||
OS: | Linux | ||||||
URL: | http://sources.redhat.com/cgi-bin/cvsweb.cgi/~checkout~/tests/ptrace-tests/tests/user-area-access.c?cvsroot=systemtap | ||||||
Whiteboard: | |||||||
Fixed In Version: | Doc Type: | Bug Fix | |||||
Doc Text: |
(s390)
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Story Points: | --- | ||||
Clone Of: | Environment: | ||||||
Last Closed: | 2009-01-20 19:42:03 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: | 437932, 448732 | ||||||
Attachments: |
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Description
Jan Kratochvil
2008-02-01 11:33:13 UTC
This bugzilla has Keywords: Regression. Since no regressions are allowed between releases, it is also being proposed as a blocker for this release. Please resolve ASAP. Created attachment 293842 [details]
Fix.
I hope this is an obvious fix but sure the testsuites needs to be rerun with
it.
It is a regression from:
linux-2.6-utrace-s390-regs-fixes.patch
There still remains a regression since RHEL-4 for: biarch-tests/user-area-access as currently the utrace kernels always zeroes on 32-bit s390 the 4 bytes aligned/unused area in between: struct user_regs_struct { ... long unsigned int orig_gpr2; <- HERE are 4 aligned bytes s390_fp_regs fp_regs; ... }; I would rather fix the testcase - or do you rather fix the kernel to be completely backward compatible? It looks to me like the RHEL-4 kernel is actually returning a word of nearby kernel memory, not anything sane. It is a bug and maybe even a security/safety issue that lets you write that word with POKEUSR. It should be an error or ignored to try to write that word. It should probably read back as zero rather than garbage/internal information leak. If anyone cared, you could file a RHEL4 bug for that. So, fix the test case not to expect this to work. I applied the other fix to upstream utrace, and we'll call this bug just about that issue and not the padding word thing. Regression was introduced the patch in 2.6.18-60.el5 built on Fri Dec 14 2007. - [utrace] s390 regs fixes (Roland McGrath ) [325451] in kernel-2.6.18-104.el5 You can download this test kernel from http://people.redhat.com/dzickus/el5 Release note added. If any revisions are required, please set the "requires_release_notes" flag to "?" and edit the "Release Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: (s390) 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-2009-0225.html |