Re: [PATCH 1/3] usercopy: Handle vm_map_ram() areas

[Uladzislau Rezki <urezki@gmail.com>]

> vmalloc does not allocate a vm_struct for vm_map_ram() areas.  That causes
> us to deny usercopies from those areas.  This affects XFS which uses
> vm_map_ram() for its directories.
> 
> Fix this by calling find_vmap_area() instead of find_vm_area().
> 
> Fixes: 0aef499f3172 ("mm/usercopy: Detect vmalloc overruns")
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  include/linux/vmalloc.h | 1 +
>  mm/usercopy.c           | 8 +++++---
>  mm/vmalloc.c            | 2 +-
>  3 files changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> index b159c2789961..096d48aa3437 100644
> --- a/include/linux/vmalloc.h
> +++ b/include/linux/vmalloc.h
> @@ -215,6 +215,7 @@ extern struct vm_struct *__get_vm_area_caller(unsigned long size,
>  void free_vm_area(struct vm_struct *area);
>  extern struct vm_struct *remove_vm_area(const void *addr);
>  extern struct vm_struct *find_vm_area(const void *addr);
> +struct vmap_area *find_vmap_area(unsigned long addr);
Make it "extern" since it becomes globally visible?

--
Uladzislau Rezki