modpost Module.symver handling is broken in 5.6.0-rc7

modpost Module.symver handling is broken in 5.6.0-rc7

[David Laight]

Something is currently broken in modpost.
I'm guessing it is down to the recent patch that moved the
namespace back to the end of the line.

I'm building 2 'out of tree' modules that have a symbol dependency.
When I build the 2nd module I get ERROR "symbol" undefined message.

If I flip the order of the fields in Module.symver to the older order
and link with modpost from 5.4.0-rc7 (which I happen to have lurking)
it all works fine.

Note that I'm using a named namespace, not the default one
that is the full path of the module.

I'll dig in a little further.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: modpost Module.symver handling is broken in 5.6.0-rc7

[Jessica Yu]

+++ David Laight [26/03/20 16:25 +0000]:
>Something is currently broken in modpost.
>I'm guessing it is down to the recent patch that moved the
>namespace back to the end of the line.
>
>I'm building 2 'out of tree' modules that have a symbol dependency.
>When I build the 2nd module I get ERROR "symbol" undefined message.
>
>If I flip the order of the fields in Module.symver to the older order
>and link with modpost from 5.4.0-rc7 (which I happen to have lurking)
>it all works fine.
>
>Note that I'm using a named namespace, not the default one
>that is the full path of the module.
>
>I'll dig in a little further.

[ Adding more people to CC ]

Hi David,

Could you provide some more details about how I can reproduce the
issue? As I understand it, you have two out-of-tree modules, and one
has a symbol dependency on the second? Pasting the modpost error
messages helps too.

Thanks,

Jessica

RE: modpost Module.symver handling is broken in 5.6.0-rc7

[David Laight]

From: Jessica Yu
> Sent: 26 March 2020 16:51
> +++ David Laight [26/03/20 16:25 +0000]:
> >Something is currently broken in modpost.
> >I'm guessing it is down to the recent patch that moved the
> >namespace back to the end of the line.
> >
> >I'm building 2 'out of tree' modules that have a symbol dependency.
> >When I build the 2nd module I get ERROR "symbol" undefined message.
> >
> >If I flip the order of the fields in Module.symver to the older order
> >and link with modpost from 5.4.0-rc7 (which I happen to have lurking)
> >it all works fine.
> >
> >Note that I'm using a named namespace, not the default one
> >that is the full path of the module.
> >
> >I'll dig in a little further.
> 
> [ Adding more people to CC ]
> 
> Hi David,
> 
> Could you provide some more details about how I can reproduce the
> issue? As I understand it, you have two out-of-tree modules, and one
> has a symbol dependency on the second? Pasting the modpost error
> messages helps too.

Ok, I've found out what broke it.
Was actually the removal of the code that parsed Module.symvers
from the current directory (which happened for 5.5.0-rc0).

Took some digging and printfs in modpost to find what wasn't happening.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: modpost Module.symver handling is broken in 5.6.0-rc7

[Jessica Yu]

+++ David Laight [26/03/20 17:06 +0000]:
>From: Jessica Yu
>> Sent: 26 March 2020 16:51
>> +++ David Laight [26/03/20 16:25 +0000]:
>> >Something is currently broken in modpost.
>> >I'm guessing it is down to the recent patch that moved the
>> >namespace back to the end of the line.
>> >
>> >I'm building 2 'out of tree' modules that have a symbol dependency.
>> >When I build the 2nd module I get ERROR "symbol" undefined message.
>> >
>> >If I flip the order of the fields in Module.symver to the older order
>> >and link with modpost from 5.4.0-rc7 (which I happen to have lurking)
>> >it all works fine.
>> >
>> >Note that I'm using a named namespace, not the default one
>> >that is the full path of the module.
>> >
>> >I'll dig in a little further.
>>
>> [ Adding more people to CC ]
>>
>> Hi David,
>>
>> Could you provide some more details about how I can reproduce the
>> issue? As I understand it, you have two out-of-tree modules, and one
>> has a symbol dependency on the second? Pasting the modpost error
>> messages helps too.
>
>Ok, I've found out what broke it.
>Was actually the removal of the code that parsed Module.symvers
>from the current directory (which happened for 5.5.0-rc0).
>
>Took some digging and printfs in modpost to find what wasn't happening.
>
>	David

Hi David,

I'm a bit confused - just to confirm, is there a legitimate bug
upstream or was it just a hiccup related to your setup?

Thanks!

Jessica

RE: modpost Module.symver handling is broken in 5.6.0-rc7

[David Laight]

From: Jessica Yu
> Sent: 26 March 2020 17:15
...
> I'm a bit confused - just to confirm, is there a legitimate bug
> upstream or was it just a hiccup related to your setup?

An upstream change broke our build scripts in a very confusing way.

I think KBUILD_EXTRA_SYMBOLS was added in 2.6.26.
Since we no longer need to build on anything older than 2.6.32
I can use that instead of copying the Module.symvers from the
other build directory and relying on the build scripts passing
-I Module.symver to modpost.

I just need to find a suitable system to check it on.
All made more difficult by working from home....

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)