[PATCH 1/1] KERNEL: add __attribute__ in c file

[PATCH 1/1] KERNEL: add __attribute__ in c file

[Fabian Frederick]

This patch fixes a sparse warning about noreturn attribute only
featuring in module.h

kernel/module.c:212:6: error: symbol '__module_put_and_exit' redeclared with
different type (originally declared at include/linux/module.h:449)-
different modifiers

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
---
 include/linux/module.h | 4 ++--
 kernel/module.c        | 3 ++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index f520a76..05ab8f3 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -446,8 +446,8 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 					     struct module *, unsigned long),
 				   void *data);
 
-extern void __module_put_and_exit(struct module *mod, long code)
-	__attribute__((noreturn));
+extern void __attribute__((noreturn)) __module_put_and_exit(struct module *mod,
+							    long code);
 #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
 
 #ifdef CONFIG_MODULE_UNLOAD
diff --git a/kernel/module.c b/kernel/module.c
index 079c461..7d78872 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -209,7 +209,8 @@ static inline void add_taint_module(struct module *mod, unsigned flag,
  * A thread that wants to hold a reference to a module only while it
  * is running can call this to safely exit.  nfsd and lockd use this.
  */
-void __module_put_and_exit(struct module *mod, long code)
+void __attribute__((noreturn)) __module_put_and_exit(struct module *mod,
+						     long code)
 {
 	module_put(mod);
 	do_exit(code);
-- 
1.8.4.5

Re: [PATCH 1/1] KERNEL: add __attribute__ in c file

[Andrew Morton]

On Wed, 7 May 2014 22:33:39 +0200 Fabian Frederick <fabf@skynet.be> wrote:

> This patch fixes a sparse warning about noreturn attribute only
> featuring in module.h
> 
> kernel/module.c:212:6: error: symbol '__module_put_and_exit' redeclared with
> different type (originally declared at include/linux/module.h:449)-
> different modifiers
> 
> ...
>
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -446,8 +446,8 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
>  					     struct module *, unsigned long),
>  				   void *data);
>  
> -extern void __module_put_and_exit(struct module *mod, long code)
> -	__attribute__((noreturn));
> +extern void __attribute__((noreturn)) __module_put_and_exit(struct module *mod,
> +							    long code);
>  #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
>  
>  #ifdef CONFIG_MODULE_UNLOAD
> diff --git a/kernel/module.c b/kernel/module.c
> index 079c461..7d78872 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -209,7 +209,8 @@ static inline void add_taint_module(struct module *mod, unsigned flag,
>   * A thread that wants to hold a reference to a module only while it
>   * is running can call this to safely exit.  nfsd and lockd use this.
>   */
> -void __module_put_and_exit(struct module *mod, long code)
> +void __attribute__((noreturn)) __module_put_and_exit(struct module *mod,
> +						     long code)
>  {

Can we use __noreturn here?

Re: [PATCH 1/1] KERNEL: add __attribute__ in c file

[Fabian Frederick]

On Wed, 7 May 2014 15:25:57 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:

> On Wed, 7 May 2014 22:33:39 +0200 Fabian Frederick <fabf@skynet.be> wrote:
> 
> > This patch fixes a sparse warning about noreturn attribute only
> > featuring in module.h
> > 
> > kernel/module.c:212:6: error: symbol '__module_put_and_exit' redeclared with
> > different type (originally declared at include/linux/module.h:449)-
> > different modifiers
> > 
> > ...
> >
> > --- a/include/linux/module.h
> > +++ b/include/linux/module.h
> > @@ -446,8 +446,8 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
> >  					     struct module *, unsigned long),
> >  				   void *data);
> >  
> > -extern void __module_put_and_exit(struct module *mod, long code)
> > -	__attribute__((noreturn));
> > +extern void __attribute__((noreturn)) __module_put_and_exit(struct module *mod,
> > +							    long code);
> >  #define module_put_and_exit(code) __module_put_and_exit(THIS_MODULE, code)
> >  
> >  #ifdef CONFIG_MODULE_UNLOAD
> > diff --git a/kernel/module.c b/kernel/module.c
> > index 079c461..7d78872 100644
> > --- a/kernel/module.c
> > +++ b/kernel/module.c
> > @@ -209,7 +209,8 @@ static inline void add_taint_module(struct module *mod, unsigned flag,
> >   * A thread that wants to hold a reference to a module only while it
> >   * is running can call this to safely exit.  nfsd and lockd use this.
> >   */
> > -void __module_put_and_exit(struct module *mod, long code)
> > +void __attribute__((noreturn)) __module_put_and_exit(struct module *mod,
> > +						     long code)
> >  {
> 
> Can we use __noreturn here?
Well it works(compilation/no more sparse warning) but after looking at some documentation, it looks more like some sparse false positive.

Fabian