Re: [PATCH] [TRIVIAL] kasan: Add a prototype of task_struct to avoid warning

[Andrey Ryabinin <aryabinin@virtuozzo.com>]

On 02/13/2017 05:28 PM, Masami Hiramatsu wrote:
> Add a prototype of task_struct to fix below warning on arm64.
> 
>   CC      arch/arm64/kernel/probes/kprobes.o
> In file included from /tmp/linux/arch/arm64/kernel/probes/kprobes.c:19:0:
> /tmp/linux/include/linux/kasan.h:81:53: warning: 'struct task_struct' declared inside parameter list will not be visible outside of this definition or declaration
>  static inline void kasan_unpoison_task_stack(struct task_struct *task) {}
>                                                      ^~~~~~~~~~~


What tree is that?
I can't see how is this possible on upstream or -next. kasan.h includes linux/sched.h so it supposed to know about task_struct.
Also <linux/kasan.h> is the first include in kprobes, so it can't be a header recursion.

BTW, arch/arm64/kernel/probes/kprobes.c no longer needs <linux/kasan.h> since
commit ad05711cec12131e1277ce749a99d08ecf233aa7 ("arm64: Remove stack duplicating code from jprobes")
    

> As same as other types (kmem_cache, page, and vm_struct)
> this adds a prototype of task_struct data structure on
> top of kasan.h.
> 
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
> Cc: Alexander Potapenko <glider@google.com>
> Cc: Dmitry Vyukov <dvyukov@google.com>
> ---
>  include/linux/kasan.h |    1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/linux/kasan.h b/include/linux/kasan.h
> index 820c0ad..c9df9e1 100644
> --- a/include/linux/kasan.h
> +++ b/include/linux/kasan.h
> @@ -7,6 +7,7 @@
>  struct kmem_cache;
>  struct page;
>  struct vm_struct;
> +struct task_struct;
>  
>  #ifdef CONFIG_KASAN
>  
>