Bug 492939

Summary:	gcc 4.4 broke ppc64 booting again
Product:	[Fedora] Fedora	Reporter:	Jarod Wilson <jarod>
Component:	gcc	Assignee:	Jakub Jelinek <jakub>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	high
Version:	rawhide	CC:	jakub
Target Milestone:	---
Target Release:	---
Hardware:	ppc64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2009-04-13 13:46:49 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 Jarod Wilson 2009-03-30 20:33:38 UTC

Description of problem:
Somewhere between gcc 4.4.0-0.27.ppc and 4.4.0-0.29.ppc, we stopped getting bootable ppc64 kernels, at least on the YDL PowerStation. Kernel 2.6.29-0.258.rc8.git2.fc11, which was built with gcc 4.4.0-0.26.ppc boots just fine. The F11 beta kernel, 2.6.29-0.258.1.2.rc8.git2.fc11 (or something like that), which was built with gcc 4.4.0-0.29.ppc doesn't boot, nor do any later kernels built in koji. A local rebuild using the older compiler on my PowerStation results in a kernel that boots just fine.

The last thing I get on screen is "returning from prom_init", and the system just hangs there for a few minutes before resetting itself.

Version-Release number of selected component (if applicable):
gcc-4.4.0-0.29.ppc

Comment 1 Jakub Jelinek 2009-03-30 20:49:17 UTC

I guess please first try -0.28, then do a binary search between -0.28 and -0.29 (resp. -0.27 and -0.28) compiled objects to see which file matters.

Comment 2 Jarod Wilson 2009-03-30 21:54:58 UTC

Hrm. I had a build using gcc 4.4.0-0.30.fc11 already under way, and I let that go ahead and finish. The resulting kernel boots fine. Perhaps the '- fix -maltivec conditional vector macro (PR target/39558)' portion of the build 0.30 changelog entry is relevant here? I could keep digging, but I don't have a heck of a lot of spare time to put into this...

Comment 3 Jakub Jelinek 2009-03-30 22:03:47 UTC

None of the changes between -0.29 and -0.30 should affect code generation on ppc/ppc64, all the changes are just about diagnostics or debuginfo, or, as in the case of the vector changes, whether code involving -maltivec vector is parsed or not (but neither of these is a recent regression).

Comment 4 Jarod Wilson 2009-03-30 22:17:22 UTC

Ugh. Seems possibly the blame lies somewhere else then... I have yet to produce a locally-built kernel that didn't boot. Everything out of the build system of late fails to boot (well, haven't tried anything later than 2.6.29-15.fc11). Will poke it some more tomorrow...

Comment 5 Jakub Jelinek 2009-03-31 07:03:09 UTC

Try local mock, if that still fails, try to change one component at a time (gcc, binutils, glibc, ...).

Comment 6 Jarod Wilson 2009-04-02 15:52:50 UTC

Latest kernels out of koji are bootable again, on both my powerstation and on Josh Boyer's G5 (which was also failing similarly).

Comment 7 Jarod Wilson 2009-04-13 13:46:49 UTC

Don't have time to dig into it, and its working now, just going to chalk it up to rawhide being rawhide and close it.