Bug 450501

Summary:	User Mode Linux (UML) broken on Fedora 9 (and now F8, too)
Product:	[Fedora] Fedora	Reporter:	Ronald Wahl <ronald.wahl>
Component:	kernel	Assignee:	Roland McGrath <roland>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	low
Version:	8	CC:	chkr, kernel-maint
Target Milestone:	---
Target Release:	---
Hardware:	i386
OS:	Linux
Whiteboard:
Fixed In Version:	2.6.25.6-27.fc8	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2008-06-20 19:05:06 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:

Description Ronald Wahl 2008-06-09 09:11:55 UTC

+++ This bug was initially created as a clone of Bug #449909 +++

Description of problem:

User Mode Linux (UML) kernels do not start on Fedora 9 anymore.

Version-Release number of selected component (if applicable):

kernel-2.6.25.4-10.fc8

How reproducible:

Always

Steps to Reproduce:
1. Download UML kernel from http://user-mode-linux.sourceforge.net/ (no
filesystem required)
2. Uncompress the kernel (bunzip2 ...)
3. Make it executable (chmod 755 ...)
4. Start the UML kernel
  
Actual results:

$ ./linux-2.6.24-rc7 
Core dump limits :
        soft - 0
        hard - NONE
Checking that ptrace can change system call numbers...OK
Checking syscall emulation patch for ptrace...OK
Checking advanced syscall emulation patch for ptrace...check_ptrace : expected
SIGTRAP or (SIGTRAP | 0x80), got status = 256

Expected results:

Kernel should not give the error and start

Additional info:

UML mailing list suggests to report this here as it seems to be a ptrace bug in
Fedora 9. See: http://marc.info/?l=user-mode-linux-user&m=121207568609301&w=2

I have not yet found a way to get UML kernels to work and so I cannot really
make use of Fedora 9 because I develop software that requires UML.

Beginning with kernel 2.6.25.4-10.fc8 the bug appears in Fedora 8, too, which
makes things even worse. I start to get the impression that I work with rawhide
and not a release version... ;-/

Comment 1 Christian Krause 2008-06-11 13:36:13 UTC

I've rebuilt the kernel package kernel-2.6.25.4-10.fc8.i686.rpm without the
utrace patch (linux-2.6-utrace.patch) and starting UML instances just worked
fine again. ;-)

Sure, there isn't a solution yet, but at least the problem is identified...

@Roland McGrath: How we could procede with this issue? Is there any chance that
this patch gets removed from the official kernel package? Or is it necessary to
find the real root cause within the patch? Any help to solve the problem is
appreciated...

Comment 2 Chuck Ebbert 2008-06-12 20:33:58 UTC

Dixed in 2.6.25.6-26

Comment 3 Fedora Update System 2008-06-17 17:24:07 UTC

kernel-2.6.25.6-27.fc8 has been submitted as an update for Fedora 8

Comment 4 Fedora Update System 2008-06-20 19:04:48 UTC

kernel-2.6.25.6-27.fc8 has been pushed to the Fedora 8 stable repository.  If problems still persist, please make note of it in this bug report.