Re: [PATCH] acpi/ghes: add TAINT_MACHINE_CHECK on GHES panic path

[Rafael J. Wysocki]

On Wed, Jul 2, 2025 at 6:31 PM Luck, Tony <tony.luck@xxxxxxxxx> wrote:
>
> On Wed, Jul 02, 2025 at 08:39:51AM -0700, Breno Leitao wrote:
> > When a GHES (Generic Hardware Error Source) triggers a panic, add the
> > TAINT_MACHINE_CHECK taint flag to the kernel. This explicitly marks the
>
> While it might not strictly be a machine check that caused GHES to
> panic, it seems close enough from the available TAINT options.
>
> So unless someone feels it would be better to create a new TAINT
> flag (TAINT_FATAL_GHES? TAINT_FIRMWARE_REPORTED_FATAL_ERRROR?)
> then this seems OK to me.
>
> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>

Applied as 6.17 material, thanks!

> > kernel as tainted due to a machine check event, improving diagnostics
> > and post-mortem analysis. The taint is set with LOCKDEP_STILL_OK to
> > indicate lockdep remains valid.
> >
> > At large scale deployment, this helps to quickly determin panics that
> > are coming due to hardware failures.
> >
> > Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
> > ---
> >  drivers/acpi/apei/ghes.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> > index f0584ccad4519..3d44f926afe8e 100644
> > --- a/drivers/acpi/apei/ghes.c
> > +++ b/drivers/acpi/apei/ghes.c
> > @@ -1088,6 +1088,8 @@ static void __ghes_panic(struct ghes *ghes,
> >
> >       __ghes_print_estatus(KERN_EMERG, ghes->generic, estatus);
> >
> > +     add_taint(TAINT_MACHINE_CHECK, LOCKDEP_STILL_OK);
> > +
> >       ghes_clear_estatus(ghes, estatus, buf_paddr, fixmap_idx);
> >
> >       if (!panic_timeout)
> >
> > ---
> > base-commit: e96ee511c906c59b7c4e6efd9d9b33917730e000
> > change-id: 20250702-add_tain-902925f3eb96
> >
> > Best regards,
> > --
> > Breno Leitao <leitao@xxxxxxxxxx>
> >