[SRU][Bionic][Cosmic][PATCH 1/1] powerpc/livepatch: Implement reliable stack tracing for the consistency model

[Khaled Elmously]

On 2018-06-07 15:03:25 , Joseph Salisbury wrote:
> On 06/07/2018 01:37 PM, Khaled Elmously wrote:
> > On 2018-06-05 11:52:15 , Joseph Salisbury wrote:
> >> On 06/04/2018 10:11 PM, Michael Ellerman wrote:
> >>> Joseph Salisbury <joseph.salisbury at canonical.com> writes:
> >>>> diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
> >>>> index d534ed901538..26a50603177c 100644
> >>>> --- a/arch/powerpc/kernel/stacktrace.c
> >>>> +++ b/arch/powerpc/kernel/stacktrace.c
> >>>> @@ -76,3 +81,115 @@ save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
> >>>>  	save_context_stack(trace, regs->gpr[1], current, 0);
> >>>>  }
> >>>>  EXPORT_SYMBOL_GPL(save_stack_trace_regs);
> >>>> +
> >>>> +#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE
> >>>> +int
> >>>> +save_stack_trace_tsk_reliable(struct task_struct *tsk,
> >>>> +				struct stack_trace *trace)
> >>>> +{
> >>> ...
> >>>> +		/*
> >>>> +		 * Mark stacktraces with kretprobed functions on them
> >>>> +		 * as unreliable.
> >>>> +		 */
> >>>> +		if (ip == (unsigned long)kretprobe_trampoline)
> >>>> +			return 1;
> >>> You may also want:
> >>>
> >>> 5e3f0d15ae5f ("powerpc/livepatch: Fix build error with kprobes disabled.")
> >>>
> >>> cheers
> >> Thanks for the feedback, Michael.  Would it be possible for you to post
> >> this comment to the bug?  That way we can get feedback from the original
> >> bug reporter and IBM.
> >>
> >>
> >> Thanks,
> >>
> >>
> >> Joe
> > Joe, I did not apply this patch as it is not clear to me if a V2 is on the way or if it needs more work. Please advise.
> >
> > Thanks
> >
> > Khalid
> I don't plan on sending a V2.  IBM tested what is in this SRU request
> and it was confirmed to fix the bug for them.  I would say apply what is
> in this request.
> 
> Michael, it's probably best to open a new bug if you believe additional
> commits are needed.

Cool, thanks

> 
> >
> >>
> >>
> >> -- 
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> >> kernel-team at lists.ubuntu.com
> >> https://lists.ubuntu.com/mailman/listinfo/kernel-team
> 
>