[Vm-dev] Nativeboost & memory protection

[Igor Stasenko]

On 7 February 2013 05:39,  <btc at openinworld.com> wrote:
>
>
> I have been wondering for a while about the implications with Nativeboost for a misbehaving C-library to corrupt the Smalltalk image.  Just now I came across http://stackoverflow.com/questions/9056427/kernel-mode-and-memory-protection, where I read:
>
> "Each process has its own page table, and each page in the page table can be restricted by setting a maximum CPL (Current Privilege Level).  Changing your CPL is a relatively fast operation"
>
> I don't know much about this but I am curious...   Could the VM be made to normally run at CPL 2 and when allocating calling out to foreign function switch to CPL 3 - without too much overhead?
>

there's many interesting things which can be done if running VM at
higher privilege level.
I seen there is a paper where people use a memory read protection (and
handle it properly),
to implement efficient read-barrier for GC

> cheers -ben
>

-- 
Best regards,
Igor Stasenko.