[Crash-utility] [PATCH] x86_64: fix "bt" command on 5.12-rc1 and later kernels

[HAGIO KAZUHITO(萩尾 一仁)]

-----Original Message-----
> 在 2021年03月02日 12:38, HAGIO KAZUHITO(萩尾　一仁) 写道:
> > Fix "bt" command on Linux 5.12-rc1 and later kernels that contains
> > kernel commit 951c2a51ae75 ("x86/irq/64: Adjust the per CPU irq stack
> > pointer by 8").  Without the patch, the "bt" command and some options
> > that read irq stack fails with the error message "bt: read of stack
> > at <address> failed".
> >
> > Signed-off-by: Kazuhito Hagio <k-hagio-ab at nec.com>
> > ---
> >  x86_64.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/x86_64.c b/x86_64.c
> > index 23a40a04bbc4..f5b2f7b5f040 100644
> > --- a/x86_64.c
> > +++ b/x86_64.c
> > @@ -1326,6 +1326,8 @@ x86_64_per_cpu_init(void)
> >  		    	    KVADDR, &hardirq_stack_ptr, sizeof(void *),
> >  		    	    "hardirq_stack_ptr (per_cpu)", QUIET|RETURN_ON_ERROR))
> >  				continue;
> > +			if (hardirq_stack_ptr != PAGEBASE(hardirq_stack_ptr))
> > +				hardirq_stack_ptr += 8;
> >  			ms->stkinfo.ibase[i] = hardirq_stack_ptr - ms->stkinfo.isize;
> >  		} else if (irq_sp)
> >  			ms->stkinfo.ibase[i] = irq_sp->value + kt->__per_cpu_offset[i];
> >
> 
> Looks good. Acked-by: Lianbo Jiang <lijiang at redhat.com>

Thanks for the review, applied.
https://github.com/crash-utility/crash/commit/720279fc141100893ba6da6ab18e52776ecf7424

Kazu