Re: [PATCH v2 7/8] mm/zsmalloc: add __init,__exit attribute

From: Minchan Kim
Date: Tue Jul 05 2016 - 22:48:04 EST


On Tue, Jul 05, 2016 at 10:00:28AM +0900, Sergey Senozhatsky wrote:
> Hello Ganesh,
>
> On (07/04/16 17:21), Ganesh Mahendran wrote:
> > > On (07/04/16 14:49), Ganesh Mahendran wrote:
> > > [..]
> > >> -static void zs_unregister_cpu_notifier(void)
> > >> +static void __exit zs_unregister_cpu_notifier(void)
> > >> {
> > >
> > > this __exit symbol is called from `__init zs_init()' and thus is
> > > free to crash.
> >
> > I change code to force the code goto notifier_fail where the
> > zs_unregister_cpu_notifier will be called.
> > I tested with zsmalloc module buildin and built as a module.
>
> sorry, not sure I understand what do you mean by this.

It seems he tested it both builtin and module with simulating to fail
zs_register_cpu_notifier so that finally called zs_unergister_cpu_notifier.
With that, he cannot find any problem.
>

>
> > Please correct me, if I miss something.
>
> you have an __exit section function being called from
> __init section:
>
> static void __exit zs_unregister_cpu_notifier(void)
> {
> }
>
> static int __init zs_init(void)
> {
> zs_unregister_cpu_notifier();
> }
>
> it's no good.

Agree.

I didn't look at linker script how to handle it. Although it works well,
it would be not desirable to mark __exit to the function we already
know it would be called from non-exit functions.