Re: question on memory map cleanup stuff

[Chris Friesen <cfriesen@nortelnetworks.com>]

William Lee Irwin III wrote:
> On Mon, Oct 18, 2004 at 04:57:20PM -0600, Chris Friesen wrote:
> 
>>I've got a small feature that maps a page of kernel memory to userspace via 
>>a syscall, then uses that page for various things.
>>Currently, I'm marking the page reserved, then exporting it via 
>>remap_page_range().  This means that I need to clean up my mapping whenever 
>>the memory map is destroyed (process death, exec(), daemonize, etc.).

> vma->vm_ops->close() often suffices for such without disturbing the core.

I'm running into a problem.

At the time of close(), I need to figure out which page to unreserve and free. 
However, when I call

follow_page(vma->vm_mm, vma->vm_start, 0);

it returns zero. How do I go from vma to page?

Chris