On Mon, May 08, 2017 at 08:09:16AM +0000, Tiwei Bie wrote:
> Don't zero the pages during mmap in contigmem. Instead, zero the
> pages after mmap in primary process. Otherwise, the multi-process
> support will be broken, as the pages will be zeroed when secondary
> processes map the memory.
>
> Fixes: 82f931805506 ("contigmem: zero all pages during mmap")
> Cc: [email protected]
>
> Signed-off-by: Tiwei Bie <[email protected]>
> ---
I agree there is a problem here, but I'm not sure about the solution to
it. I still think that the kernel should zero the pages before they get
given to userspace. Is there any way to keep that working e.g
* have them zeroed on mmap only when they are not already mmaped into
another process?
* have them zeroed on init, and again on unmap by the last process to
have them mapped?
/Bruce
