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

[Rolf Eike Beer <eb@emlix.com>]

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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
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