Re: Linux 4.9.180 build fails with gcc 9 and 'cleanup_module' specifies less restrictive attribute than its target …

Rolf Eike Beer
2019-06-12T07:19:24Z

[-- Attachment #1: Type: text/plain, Size: 2316 bytes --]

Am Donnerstag, 6. Juni 2019, 20:59:00 CEST schrieb Greg KH:
> On Thu, Jun 06, 2019 at 08:25:28PM +0200, Miguel Ojeda wrote:
> > On Thu, Jun 6, 2019 at 5:29 PM Greg KH <greg@kroah.com> wrote:
> > > And if you want this, you should look at how the backports to 4.14.y
> > > worked, they did not include a3f8a30f3f00 ("Compiler Attributes: use
> > > feature checks instead of version checks"), as that gets really messy...
> >
> > I am confused -- I interpreted Rolf's message as reporting that he
> > already successfully built 4.9 by applying a6e60d84989f
> > ("include/linux/module.h: copy __init/__exit attrs to
> > init/cleanup_module") and manually fixing it up. But maybe I am
> > completely wrong... :-)
>
> "manually fixing it up" means "hacked it to pieces" to me, I have no
> idea what the end result really was :)
>
> If someone wants to send me some patches I can actually apply, that
> would be best...

Hi all,

the patch I actually used was this:

diff --git a/include/linux/module.h b/include/linux/module.h
index 8fa38d3e7538..f5bc4c046461 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -129,13 +129,13 @@ extern void cleanup_module(void);
#define module_init(initfn) \
static inline initcall_t __maybe_unused __inittest(void) \
{ return initfn; } \
- int init_module(void) __attribute__((alias(#initfn)));
+ int init_module(void) __attribute__((__copy__(initfn))) __attribute__((alias(#initfn)));

/* This is only required if you want to be unloadable. */
#define module_exit(exitfn) \
static inline exitcall_t __maybe_unused __exittest(void) \
{ return exitfn; } \
- void cleanup_module(void) __attribute__((alias(#exitfn)));
+ void cleanup_module(void) __attribute__((__copy__(exitfn))) __attribute__((alias(#exitfn)));

#endif

So the final question is: do we want 4.9.x to be buildable with gcc 9.x? If
yes then we can probably get this patches into shape.

Eike
--
Rolf Eike Beer, emlix GmbH, http://www.emlix.com
Fon +49 551 30664-0, Fax +49 551 30664-11
Gothaer Platz 3, 37083 Göttingen, Germany
Sitz der Gesellschaft: Göttingen, Amtsgericht Göttingen HR B 3160
Geschäftsführung: Heike Jordan, Dr. Uwe Kracke – Ust-IdNr.: DE 205 198 055

emlix - smart embedded open source

[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 313 bytes --]