[PATCH v2 2/2] arm64: Add dump_backtrace() in show_regs
Will Deacon
will.deacon at arm.com
Thu May 25 03:58:32 PDT 2017
On Wed, May 24, 2017 at 11:09:49AM +0100, Mark Rutland wrote:
> On Tue, May 09, 2017 at 09:53:37AM +0800, Kefeng Wang wrote:
> > Generic code expects show_regs() to dump the stack, but arm64's
> > show_regs() does not. This makes it hard to debug softlockups and
> > other issues that result in show_regs() being called.
> >
> > This patch updates arm64's show_regs() to dump the stack, as common
> > code expects.
> >
> > Acked-by: Mark Rutland <mark.rutland at arm.com>
> > Signed-off-by: Kefeng Wang <wangkefeng.wang at huawei.com>
[...]
> diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
> index 0805b44..f452fcc 100644
> --- a/arch/arm64/kernel/traps.c
> +++ b/arch/arm64/kernel/traps.c
> @@ -728,8 +728,6 @@ static int bug_handler(struct pt_regs *regs, unsigned int esr)
> break;
>
> case BUG_TRAP_TYPE_WARN:
> - /* Ideally, report_bug() should backtrace for us... but no. */
> - dump_backtrace(regs, NULL);
> break;
>
> default:
>
> ... since report_bug() will call show_regs(), and dump the stack itself
> now.
>
> With that change, these patches will also fix *_ONCE() traps spewing
> backtraces every time they're invoked, which was a side-effect of
> commit:
>
> 19d436268dde9538 ("debug: Add _ONCE() logic to report_bug()")
>
> Would you mind folding that into a v3?
I've queued this locally, so I can just fold that in too. No need to repost.
I'll push what I have at -rc3.
Cheers,
Will
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