Re: 'kbuild' merge before 4.9-rc1 breaks build and boot

From: Peter Wu
Date: Mon Nov 07 2016 - 16:39:51 EST


On Mon, Nov 07, 2016 at 02:10:12PM -0500, Vince Weaver wrote:
> On Thu, 27 Oct 2016, Peter Wu wrote:
>
> > I can confirm Olivers issue, the current mainline kernel fails to boot
> > on kernels with CONFIG_MODVERSIONS=y. Bisection points to:
> >
> > commit 784d5699eddc55878627da20d3fe0c8542e2f1a2
> > Author: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> > Date: Mon Jan 11 11:04:34 2016 -0500
> > > WARNING: "memset" [sound/usb/snd-usbmidi-lib.ko] has no CRC!
> > > WARNING: "__fentry__" [sound/usb/snd-usbmidi-lib.ko] has no CRC!
> > > WARNING: "memcpy" [sound/usb/snd-usbmidi-lib.ko] has no CRC!
> > > WARNING: "__sw_hweight32" [sound/usb/snd-usbmidi-lib.ko] has no CRC!
>
> Has any progress been made with this problem?
>
> I'm also encountering it on my debian-unstable box on any kernel more
> recent than 4.9-rc1 (up to and including 4.9-rc4). I am glad someone
> managed to isolate it as I was unable to get a clean bisect.
>
> Vince

The original kbuild issue went in via
merge commit 84d69848c97faab0c25aa2667b273404d2e2a64a which notes:

- EXPORT_SYMBOL for asm source by Al Viro.

This does bring a regression, because genksyms no longer generates
checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
working on a patch to fix this.

Plus, we are talking about functions like strcpy(), which rarely
change prototypes.

Adding Nicholas in the cc, hopefully he can give a status update.

Kind regards,
Peter