Bug 387821

Summary: ptrace: AltiVec PTRACE_GETVRREGS returns invalid VRSAVE
Product: [Fedora] Fedora Reporter: Jan Kratochvil <jan.kratochvil>
Component: kernelAssignee: Roland McGrath <roland>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: low Docs Contact:
Priority: low    
Version: 8CC: jan.kratochvil, roland
Target Milestone: ---   
Target Release: ---   
Hardware: ppc64   
OS: Linux   
Whiteboard:
Fixed In Version: 2.6.23.1-49.fc8 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2007-12-05 00:10:02 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: 367221    
Bug Blocks:    
Attachments:
Description Flags
kernel reportedly-fix by Roland McGrath. none

Description Jan Kratochvil 2007-11-16 22:48:28 UTC 
Description of problem:
PTRACE_GETVRREGS call returns value with an invalid VRSAVE value.

Version-Release number of selected component (if applicable):
kernel-2.6.23.1-49.fc8.ppc64

How reproducible:
Always.

Steps to Reproduce:
1. wget -O powerpc-altivec.c
http://sources.redhat.com/cgi-bin/cvsweb.cgi/~checkout~/tests/ptrace-tests/tests/powerpc-altivec.c?cvsroot=systemtap
2. gcc -o powerpc-altivec powerpc-altivec.c -Wall -ggdb2 -m64 -D_GNU_SOURCE
3. ./powerpc-altivec;echo $?
  
Actual results:
[132] 0xa5a5a5a5
1

Expected results:
0

Additional info:
-m64 in command `2.' can be replacted with -m32 with the same results.

While it should be fixed since kernel-2.6.23.1-47.fc8.ppc64 according to the CVS
logs my tests do not confirm it.
Comment 1 Jan Kratochvil 2007-11-16 22:48:28 UTC 
Created attachment 261921 [details]
kernel reportedly-fix by Roland McGrath.
Comment 3 Roland McGrath 2007-11-19 22:14:18 UTC 
2.6.23.1-49.fc8 is the one I've tested.
Comment 5 Jan Kratochvil 2007-11-19 22:33:12 UTC 
Roland, while I believe your patch is right there is some problem that
  mtspr 256,0x01010101
value does not get mapped into `thread.vrsave'.  It should be a problem outside
of utrace.
Comment 6 Roland McGrath 2007-11-19 23:40:25 UTC 
This flavor of machine simply lacks the Altivec hardware support, though the
ppc64 kernel always supports it when it's there.  I've fixed the test to handle
this.