[PATCH] arm: Fix backtrace generation when IPI is masked

[Hillf Danton]

> > Better if dump_stack() is added in a separate patch, given that
> > it is not mentioned in commit message.
> 
> Adding dump_stack() is mentioned in passing ("Some small changes to the
> generic code are required to support this.") but you're right that the
> reason for the change is not explicitly called out.
> 
> I can certainly respin as two patches but perhaps its better just to
> improve the commit message. Something like:
> 
>  > This can be fixed by detecting that the calling context cannot be
>  > preempted and issuing the backtrace directly in this case. Issuing
>  > directly leaves us without any pt_regs to pass to nmi_cpu_backtrace().
>  > Modify the generic code to call dump_stack() when its argument is
>  > NULL.
> 
Looks nice!

thanks
Hillf