Re: Calculating kernel logical address ..

Manfred Spraul
2002-09-09T21:14:43Z

Andrew Morton wrote:
> Nobody seems to have come forth to implement a thought-out scatter/gather,
> map-user-pages library infrastructure so I'd be a bit reluctant to
> break stuff without offering a replacement.
>

We'd need one.

get_user_pages() is broken if a kernel module access the virtual address
of the page and the cpu caches are not coherent:
Most of the flush functions need the vma pointer, but it's impossible to
guarantee that it still exists when the get_user_pages() user calls
page_cache_release().

--
Manfred