Re: [PATCH] vma->shared list_head initializations

[Andrew Morton]

Zach Brown wrote:
> 
> more list_head debugging carnage.
> 

yup

> --- linux-2.5.39/fs/exec.c.fmuta        Sat Sep 28 19:50:20 2002
> +++ linux-2.5.39/fs/exec.c      Sat Sep 28 19:51:08 2002
> @@ -400,6 +400,7 @@
>                 mpnt->vm_ops = NULL;
>                 mpnt->vm_pgoff = 0;
>                 mpnt->vm_file = NULL;
> +               INIT_LIST_HEAD(&mpnt->shared);
>                 mpnt->vm_private_data = (void *) 0;
>                 insert_vm_struct(mm, mpnt);
>                 mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;

Fair enough, short-term.  But what your patch is really saying
is "this code stinks".

We need to lose all those open-coded accesses to vm_area_cachep,
give that cache a constructor and possibly write some helper
functions.  To lose all this fragile "did I remember to
initialise everything and has anyone added any more fields
since I wrote that code" gunk.

<looks hopefully at Christoph>