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

Kalle Valo
2016-10-27T13:54:56Z

Nicholas Piggin <npiggin@gmail.com> writes:

> On Thu, 27 Oct 2016 11:10:03 +0300
> Kalle Valo <kvalo@codeaurora.org> wrote:
>
>> (Adding Thorsten because of a serious regression and Steven because he
>> tried to fix something in the same commit)
>>
>> Nicholas Piggin <npiggin@gmail.com> writes:
>>
>> > On Wed, 19 Oct 2016 16:38:14 +0200
>> > Michal Marek <mmarek@suse.com> 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.

With these two patches (on top of ath-201610251249 from ath.git, in
practice 4.9-rc2 + latest wireless patches) module loading works again.
If you want you can add my Tested-by:

Tested-by: Kalle Valo <kvalo@codeaurora.org>

Can we get these patches to Linus' tree soon? It's annoying to revert
784d5699eddc5 everytime I update my tree.

>> 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?

I'm pretty sure modules are correctly installed as I have used the same
procedure for years: on my workstation I do 'make bindeb-pkg', copy the
.deb to the test laptop and install the deb there. Also once I revert
784d5699eddc5 it starts immeadiately working.

--
Kalle Valo