Re: mprotect pgprot handling weirdness

From: Benjamin Herrenschmidt
Date: Tue Apr 06 2010 - 01:32:19 EST


On Tue, 2010-04-06 at 15:09 +1000, Benjamin Herrenschmidt wrote:
> Hi folks !
>
> While looking at untangling a bit some of the mess with vm_flags and
> pgprot (*), I notices a few things I can't quite explain... they may ..
> or may not be bugs, but I though it was worth mentioning:

And another one:

- vma_wants_writenotify():

/* The open routine did something to the protections already? */
if (pgprot_val(vma->vm_page_prot) !=
pgprot_val(vm_get_page_prot(vm_flags)))
return 0;

That's going to blow if any -other- prot bit is used here.

Cheers,
Ben.


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