Re: [PATCH 1/2] nmi: Export CPU backtrace APIs for loadable modules

From: Doug Anderson

Date: Thu Jul 30 2026 - 21:54:38 EST


Hi,

On Thu, Jul 30, 2026 at 3:00 PM Mayank Rungta via B4 Relay
<devnull+mrungta.google.com@xxxxxxxxxx> wrote:
>
> From: Mayank Rungta <mrungta@xxxxxxxxxx>
>
> Currently, CPU backtrace functions cannot be called from loadable
> modules because the underlying helper arch_trigger_cpumask_backtrace()
> is not exported.
>
> Instead of exporting arch_trigger_cpumask_backtrace() individually
> across every supported architecture, introduce and export a common
> helper, cpumask_backtrace(), in lib/nmi_backtrace.c. Update the four
> inline CPU backtrace macros in include/linux/nmi.h to route through this
> centralized helper.
>
> Signed-off-by: Mayank Rungta <mrungta@xxxxxxxxxx>
> ---
> include/linux/nmi.h | 10 ++++++----
> lib/nmi_backtrace.c | 7 +++++++
> 2 files changed, 13 insertions(+), 4 deletions(-)

Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>