Re: [GIT PULL] kbuild changes for v4.9-rc1

[Nicholas Piggin]

On Thu, 27 Oct 2016 11:10:03 +0300
Kalle Valo <kvalo@xxxxxxxxxxxxxx> wrote:

> (Adding Thorsten because of a serious regression and Steven because he
> tried to fix something in the same commit)
> 
> Nicholas Piggin <npiggin@xxxxxxxxx> writes:
> 
> > On Wed, 19 Oct 2016 16:38:14 +0200
> > Michal Marek <mmarek@xxxxxxxx> wrote:
> >  
> >> Dne 18.10.2016 v 03:34 Nicholas Piggin napsal(a):  
> >> > We should probably just bring all these arch patches through the
> >> > kbuild tree.
> >> > 
> >> > I'm sorry for the breakage: I didn't realize it broke the build with
> >> > some configs, otherwise I would have given Michal a heads up before
> >> > his pull request, and worked to get this stuff in first.    
> >> 
> >> It breaks with some binutils versions only (and only with
> >> CONFIG_MODVERSIONS=y, of course).  
> >
> > Yeah this seems to be the issue, it apparently slipped past all the
> > automated builds. It seems like the existing CRC warnings in the tree
> > only trigger in rare circumstances too, so something could be a bit
> > fragile there.  
> 
> I upgraded from 4.8 to 4.9-rc2 and noticed that kernel modules fail to
> load (log below). After investigating for some time I found this thread
> and apparently this is not still fixed, at least not in Linus' tree.
> 
> Reverting 784d5699eddc5 fixed the issue for me. As I don't see any fix
> available (please correct me if I'm wrong) we should just revert that
> commit until it's properly fixed.

With these two patches together, does it work for you?

http://marc.info/?l=linux-arch&m=147653546809512&w=2
http://marc.info/?l=linux-kernel&m=147669851906489&w=2

It would be helpful if you could test and let us know, because there seems
to be a very tiny number of configs and toolchains that causes problems.

> 
> Also note that there's a related fix from Steven:
> 
> [PATCH] x86: Fix export for mcount and __fentry__
> https://marc.info/?l=linux-kernel&m=147733572502413
> 
> For compiling the kernel I'm using Ubuntu 12.04:
> 
> ii  binutils             2.22-6ubuntu1.4      GNU assembler, linker and binary utilities
> ii  gcc                  4:4.6.3-1ubuntu5     GNU C compiler
> 
> The kernel is running on a separate machine with Ubuntu 14.04.
> 
> [  110.703414] bluetooth: disagrees about version of symbol __get_user_2
> [  110.703416] bluetooth: Unknown symbol __get_user_2 (err -22)
> [  110.703429] bluetooth: disagrees about version of symbol __put_user_2
> [  110.703430] bluetooth: Unknown symbol __put_user_2 (err -22)
> [  110.703579] bluetooth: disagrees about version of symbol __put_user_4
> [  110.703580] bluetooth: Unknown symbol __put_user_4 (err -22)
> [  110.703669] bluetooth: disagrees about version of symbol __put_user_1
> [  110.703670] bluetooth: Unknown symbol __put_user_1 (err -22)
> [  110.703688] bluetooth: disagrees about version of symbol mcount
> [  110.703689] bluetooth: Unknown symbol mcount (err -22)
> 

I haven't seen that one before. Did you definitely make and install new
modules?

Thanks,
Nick