Bug 288217 – GNOME displays blank screen with mouse cursor after login

• Product: Gentoo Linux
• Status: RESOLVED NEEDINFO

[Description Dmitry 2009-10-08 16:15:33 UTC]

I'm getting blank screen with mouse cursor when logging in via xdm (gdm).

Reproducible: Always

Steps to Reproduce:
1. eclean-dist
2. eclean-pkg
3. emerge --sync
4. emerge -a --depclean
5. emerge -1 linux-headers glibc binutils gcc-config gcc
6. gcc-config 1
7. source /etc/profile
8. emerge -1b glibc binutils gcc portage
9. emerge -bke system
10. emerge -ke world
11. revdep-rebuild
12. dispatch-config
13. reboot
Actual Results:  
GNOME displays blank screen with mouse cursor after login

Expected Results:  
Working GNOME environment

After I had performed full system upgrade I got blank screen with mouse cursor when tried to log in via xdm (gdm). The same thing for the root account. I even did 'emerge -e gnome-light'. It didn't help.

[Comment 1 Dmitry 2009-10-08 16:16:31 UTC]

Created attachment 206452 [details]
printout of 'emerge --info'

[Comment 2 Dmitry 2009-10-08 16:16:49 UTC]

Created attachment 206453 [details]
make.conf

[Comment 3 Dmitry 2009-10-08 16:17:27 UTC]

Created attachment 206454 [details]
printout of 'gnome-session'

[Comment 4 Romain Perier (RETIRED) 2009-10-08 17:34:03 UTC]

- Firstly please read this link http://www.gentoo.org/doc/en/gcc-optimization.xml.
- Then please remerge these packages by using normal CFLAGS.
  -> like following :  CFLAGS="-march=core2 -O2 -pipe"

[Comment 5 Romain Perier (RETIRED) 2009-10-09 12:04:11 UTC]

Please get back us

[Comment 6 Dmitry 2009-10-09 15:12:50 UTC]

(In reply to comment #5)
> Please get back us
> 

Thanks for your attention and information!
I forgot to reassess the CFLAGS after I had switched to the new compiler. Previous one didn't set -mmmx -msse -msse2 -msse3 -mssse3 flags when you stated march=core2 even though these are supported by the hardware! Neither do this version: printout of "gcc <flags go here> -Q --help=target" also shows them disabled. Anyway the system is rebuilding right now with the flags you advised. I'll inform you on the results when it's done.

[Comment 7 Romain Perier (RETIRED) 2009-10-09 15:36:13 UTC]

reopen per comment 6

[Comment 8 Dmitry 2009-10-11 14:53:38 UTC]

(In reply to comment #5)
> Please get back us
> 

Rebuilding with CFLAGS="-O2 -march=core2 -pipe" solved the problem!
Thank you very much for the idea!
So I suggest adding -mmmx -msse -msse2 -msse3 -mssse3 to the CFLAGS and rebuilding again. I guess it was because of -O3. Am I right?

[Comment 9 Gilles Dartiguelongue (RETIRED) 2009-10-11 17:44:01 UTC]

re-opening for the toolchain guys.

[Comment 10 Gilles Dartiguelongue (RETIRED) 2009-10-11 17:44:29 UTC]

@toolchain, another -03 gcc-4.4 bug it seems.

[Comment 11 Ryan Hill (RETIRED) 2009-10-12 07:19:39 UTC]

some of the bugs I've seen w/ -O3 and 4.4 end up being strict-aliasing violations in the code, not an issue with the compiler.  sometimes these are benign until -finline-functions is enabled by -O3, but they are still violations.

compiling gdm with -Wstrict-aliasing=2 reveals:

 * QA Notice: Package has poor programming practices which may compile
 *            fine but exhibit random runtime failures.               
 * gdm-config.c:1042: warning: dereferencing type-punned pointer will break strict-aliasing rules
 * gdm-config.c:1354: warning: dereferencing type-punned pointer will break strict-aliasing rules
 * gdm.c:1500: warning: dereferencing type-punned pointer will break strict-aliasing rules       
 * gdm.c:1500: warning: dereferencing type-punned pointer will break strict-aliasing rules       

 * QA Notice: Package has poor programming practices which may compile
 *            fine but exhibit random runtime failures.               
 * gdm-xdmcp-manager.c:808: warning: dereferencing pointer 'clnt_sa.60' does break strict-aliasing rules
 * gdm-xdmcp-manager.c:2110: warning: dereferencing pointer 'clnt_sa.126' does break strict-aliasing rules
 * gdm-xdmcp-manager.c:2134: warning: dereferencing pointer 'clnt_sa.129' does break strict-aliasing rules
 * gdm-xdmcp-manager.c:2389: warning: dereferencing pointer 'clnt_sa.149' does break strict-aliasing rules
 * gdm-xdmcp-manager.c:1510: warning: dereferencing pointer 'clnt_sa.102' does break strict-aliasing rules

[Comment 12 SpanKY 2009-10-12 15:19:16 UTC]

i.e. try building with -fno-strict-aliasing in your CFLAGS and see if the issue is resolved