[Crash-utility] "invalid structure member offset: task_struct_parent" on x86_64 rawhide

[Jeff Layton]

On Fri, 04 Apr 2008 10:02:20 -0400
Dave Anderson <anderson at redhat.com> wrote:
> > Jeff Layton wrote:
> >> Looks like we might have gotten bitten by some upstream changes
> >> again...
> >>
> >> When I run crash on a recent rawhide x86_64 kernel, I seem to be
> >> getting this error:
> >>
> >> crash: invalid structure member offset: task_struct_parent
> >>        FILE: task.c  LINE: 2163  FUNCTION: store_context()
> >>
> >> [/usr/bin/crash] error trace: 49150a => 495bb8 => 4963be => 4fc1bc
> >> /usr/bin/nm: /usr/bin/crash: no symbols
> >> /usr/bin/nm: /usr/bin/crash: no symbols
> >> /usr/bin/nm: /usr/bin/crash: no symbols
> >> /usr/bin/nm: /usr/bin/crash: no symbols
> >>
> >> Relevant package versions:
> >>
> >> crash-4.0-6.2.x86_64
> >> kernel-2.6.25-0.185.rc7.git6.fc9.x86_64
> >>
> >> ...machine is a x86_64 FV xen guest. Any thoughts?
> >>
> >> Thanks,
> > 
> > Yep, although the change is not upstream in Linus's tree, Roland's
> > linux-2.6-utrace.patch removes it in Fedora:
> > 
> > @@ -1070,18 +1063,26 @@ struct task_struct {
> >         /*
> >          * pointers to (original) parent process, youngest child, 
> > younger sibling,
> >          * older sibling, respectively.  (p->father can be replaced with
> > -        * p->parent->pid)
> > +        * p->real_parent->pid)
> >          */
> > -       struct task_struct *real_parent; /* real parent process (when 
> > being debugged) */
> > -       struct task_struct *parent;     /* parent process */
> > +       struct task_struct *real_parent; /* real parent process */
> >         /*
> > -        * children/sibling forms the list of my children plus the
> > -        * tasks I'm ptracing.
> > +        * children/sibling forms the list of my natural children
> >          */
> > 
> > AFAICT, task_struct.real_parent can be substituted.  Try the attached
> > patch.  (and then wait to see what else has been broken...)
> > 
> > Dave
> > 
> > 
> > 
> > ------------------------------------------------------------------------
> > 
> > --- task.c.orig	2008-04-04 09:48:38.000000000 -0400
> > +++ task.c	2008-04-04 09:50:13.000000000 -0400
> > @@ -208,6 +208,9 @@
> >          MEMBER_OFFSET_INIT(task_struct_processor, "task_struct", "processor");
> >          MEMBER_OFFSET_INIT(task_struct_p_pptr, "task_struct", "p_pptr");
> >          MEMBER_OFFSET_INIT(task_struct_parent, "task_struct", "parent");
> > +	if (INVALID_MEMBER(task_struct_parent))
> > +        	MEMBER_OFFSET_INIT(task_struct_parent, "task_struct", 
> > +			"real_parent");
> >          MEMBER_OFFSET_INIT(task_struct_has_cpu, "task_struct", "has_cpu");
> >          MEMBER_OFFSET_INIT(task_struct_cpus_runnable,  
> >  		"task_struct", "cpus_runnable");
> 

That worked! I didn't do any extensive testing, but that seems to allow
crash to start and do a "ps".

Many thanks!
-- 
Jeff Layton <jlayton at redhat.com>