Re: [PATCH v3 1/7] kernel/fork: convert vma assignment to a memcpy

[Suren Baghdasaryan]

On Wed, Jan 25, 2023 at 4:22 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, 25 Jan 2023 15:35:48 -0800 Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote:
>
> > Convert vma assignment in vm_area_dup() to a memcpy() to prevent compiler
> > errors when we add a const modifier to vma->vm_flags.
> >
> > ...
> >
> > --- a/kernel/fork.c
> > +++ b/kernel/fork.c
> > @@ -482,7 +482,7 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig)
> >                * orig->shared.rb may be modified concurrently, but the clone
> >                * will be reinitialized.
> >                */
> > -             *new = data_race(*orig);
> > +             memcpy(new, orig, sizeof(*new));
>
> The data_race() removal is unchangelogged?

True. I'll add a note in the changelog about that. Ideally I would
like to preserve it but I could not find a way to do that.

>
> >               INIT_LIST_HEAD(&new->anon_vma_chain);
> >               dup_anon_vma_name(orig, new);
> >       }
>