Re: Possible rdma-core header conflict

[Yigal Korman <yigal@plexistor.com>]

On Thu, Aug 24, 2017 at 1:50 PM, Leon Romanovsky <leon@kernel.org> wrote:
> On Tue, Aug 22, 2017 at 09:47:04AM +0300, Leon Romanovsky wrote:
>> On Tue, Aug 22, 2017 at 09:08:56AM +0300, Yigal Korman wrote:
>> > On Mon, Aug 21, 2017 at 6:57 PM, Jason Gunthorpe
>> > <jgunthorpe@obsidianresearch.com> wrote:
>> > > On Mon, Aug 21, 2017 at 03:03:10PM +0300, Leon Romanovsky wrote:
>> > >> On Mon, Aug 21, 2017 at 12:24:14PM +0300, Yigal Korman wrote:
>> > >> > Hi,
>> > >> > Has anyone noticed that installing rdma-core (or older
>> > >> > librdmacm-devel) package and then installing kernel headers manually
>> > >> > (make headers_install) removes the librdmacm headers?
>> > >> > I actually see it in the make output:
>> > >> >
>> > >> > make INSTALL_HDR_PATH=/usr headers_install
>> > >> >   CHK     include/generated/uapi/linux/version.h
>> > >> >   REMOVE  rdma_cma_abi.h rdma_verbs.h rdma_cma.h rsocket.h
>> > >> >
>> > >> > Am I doing something wrong?
>> > >> > Sounds like the kernel rdma headers and librdmacm headers shouldn't
>> > >> > sit in the same directory...
>> > >>
>> > >> It looks like this behavior (removal of header files) was from the beginning of git era.
>> > >> ➜  linux-rdma git:(rdma-next) ✗ git co -b tmp v2.6.34.8
>> > >> ➜  linux-rdma git:(tmp) ✗ cp ~/src/rdma-core/librdmacm/rdma_verbs.h /tmp/h/include/rdma/ && make INSTALL_HDR_PATH=/tmp/h headers_install | grep REMOVE
>> > >>   REMOVE  rdma_verbs.h
>> > >
>> > > The user space files have also been sharing the directory with the
>> > > kernel files since the start.. Not sure why, but I don't think we can
>> > > change it now.
>> > >
>> > > Maybe someone can patch the kernel to exempt rdma/ from the removal
>> > > process?
>> >
>> > Yeah, that would be a good possible fix for this.
>> > I had a quick look at the kernel headers install scripts and didn't
>> > see any mechanism for this, but I might've missed it.
>>
>> It is in scripts/Makefile.headersinst
>> The change should be in the ...
>>  66 # Work out what needs to be removed
>>  67 oldheaders    := $(patsubst $(installdir)/%,%,$(wildcard $(installdir)/*.h))
>>  68 unwanted      := $(filter-out $(all-files),$(oldheaders))
>>
>> And we should filter out very specific headers, because it is a good thing
>> to remove all other files to ensure that older headers are removed.
>
> Yesterday, I took a look on various distributions in order to understand
> why we didn't see this issue earlier.
>
> Some distros install kernel headers into separate folder and not
> into /usr/include, so rdmacm header files are not overwritten.
>
> And some distros install kernel headers into different from /usr
> directory, prepare all files in advance and copy them to /usr after
> that without deleting the old files.
>
> So, it looks like there is no need to fix anything, because installation
> of header files with "make INSTALL_HDR_PATH=/usr headers_install" is an
> easy thing to do for the development but is not right thing from the distro
> point of view.
>
> If there is distro which deletes rdmacm headers, it should be fixed there and
> not in the kernel.

Thanks Leon!

So for development workflow, I guess that the trivial thing to do is
to make sure to first install the kernel headers and then install
rdmacm headers.

Y

>
> Thanks
>>
>> > I'm adding linux-kbuild mailing list here, maybe someone there can help?
>> >
>> > Thanks
>> >
>> > >
>> > > Jason
>
>