find_vma_intersection

find_vma_intersection

[Mark Hounschell]

Can someone enlighten me as to what it really means when  a user land
shmat call, in which the virtual address is provided, fails in the
kernel find_vma_intersection function because

  end_addr(of my SHM) is <= vma->vm_start?

static inline struct vm_area_struct * find_vma_intersection(struct
mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
{
        struct vm_area_struct * vma = find_vma(mm,start_addr);

        if (vma && end_addr <= vma->vm_start)
                vma = NULL;
        return vma;
}

Thanks in advance
Mark

Re: find_vma_intersection

[Mark Hounschell]

Mark Hounschell wrote:
> Can someone enlighten me as to what it really means when  a user land
> shmat call, in which the virtual address is provided, fails in the
> kernel find_vma_intersection function because
> 
>   end_addr(of my SHM) is <= vma->vm_start?

Actually because its ! <= vma->vm_start.

> 
> static inline struct vm_area_struct * find_vma_intersection(struct
> mm_struct * mm, unsigned long start_addr, unsigned long end_addr)
> {
>         struct vm_area_struct * vma = find_vma(mm,start_addr);
> 
>         if (vma && end_addr <= vma->vm_start)
>                 vma = NULL;
>         return vma;
> }
> 

Thanks
Mark