Re: [PATCH v1 2/2] firmware: dmi_scan: Pass dmi_entry_point to kexec'ed kernel

From: Jean Delvare
Date: Tue Jan 21 2020 - 04:04:07 EST


On Mon, 20 Jan 2020 23:55:43 +0200, Andy Shevchenko wrote:
> On Mon, Jan 20, 2020 at 11:44 PM Jean Delvare <jdelvare@xxxxxxx> wrote:
> >
> > On Mon, 20 Jan 2020 10:04:04 -0600, Eric W. Biederman wrote:
> > > Second. I looked at your test results and they don't directly make
> > > sense. dmidecode bypasses the kernel completely or it did last time
> > > I looked so I don't know why you would be using that to test if
> > > something in the kernel is working.
> >
> > That must have been long ago. A recent version of dmidecode (>= 3.0)
> > running on a recent kernel
> > (>= d7f96f97c4031fa4ffdb7801f9aae23e96170a6f, v4.2) will read the DMI
> > data from /sys/firmware/dmi/tables, so it is very much relying on the
> > kernel doing the right thing. If not, it will still try to fallback to
> > reading from /dev/mem directly on certain architectures. You can force
> > that old method with --no-sysfs.
> >
> > Hope that helps,
>
> I don't understand how it possible can help for in-kernel code, like
> DMI quirks in a drivers.

OK, just ignore me then, probably I misunderstood the point made by
Eric.

--
Jean Delvare
SUSE L3 Support