Re: stable 4.16.5 hmm build error

From: Arnd Bergmann
Date: Fri Apr 27 2018 - 04:17:50 EST

On Fri, Apr 27, 2018 at 9:30 AM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Apr 27, 2018 at 02:19:24AM +0300, ÐÐÑÐÐÐ ÐÐÑÐÐ wrote:
>> Oh. Yes. Tag v4.16.5 without commit
>> 9d8a463a7016e9e5578a561588a18acef139919c.
>> It's in v4.17-rc1/2.
>> Thank you.
> That patch does not apply to the stable trees. I'm also confused by the
> lack of "real" git commit ids that are being referred to here, that
> commit refers to one that is not valid.
>> 2018-04-27 0:52 GMT+03:00 Randy Dunlap <rdunlap@xxxxxxxxxxxxx>:
>> >
>> >
>> > kernel/fork.o: In function `__mmdrop':
>> > /kernel/build_kernel/linux-4.16.4/kernel/fork.c:600: undefined reference
>> > to `hmm_mm_destroy'
> What .config is creating this? I have not seen any kbuild reports of
> this in the past.

I only got this through randconfig builds on mainline.

>> >
>> > "It is also reproduced in linux-4.16.5"
>> >
>> >
>> > There have been a few attempts to fix this build error. The kernel
>> > mainline
>> > repo seems to have it fixed, but it looks to me like Arnd's latest patch
>> > (9d8a463a7016e: "mm/hmm: fix header file if/else/endif maze, again")
>> > was mis-merged to 4.16.5 stable.
>> >
>> > Please take a look. Do you already have a fixup for this?

JÃrÃme initially created

6b368cd4a44c ("mm/hmm: avoid bloating arch that do not make use of HMM")

which is part of v4.16. He noticed a build error that he fixed up with commit

b28b08de436a ("mm/hmm: fix header file if/else/endif maze")

which you backported as 25df8b83e867 into linux-4.16.y after v4.16.4.
After that originally landed in mainline, I found another build error that
I fixed with commit

9d8a463a7016 ("mm/hmm: fix header file if/else/endif maze, again")

This fixes the issue that Randy is reporting now, please add that into