Re: [PATCH] restore protections after forced fault in get_user_pages

[Ingo Molnar]

* Linus Torvalds <torvalds@xxxxxxxx> wrote:

> > I think this question is orthogonal to my concern about follow_page.
> 
> The follow_page issue should be fixable by just marking the _page_
> dirty inside the ptrace routines. I think we do that anyway (or we'd
> already be buggy wrt perfectly normal writes).

the follow_page() issue could be handled like the 4/4 patch does it: a
repeat-until loop of manual-fault + lookup-pte (we break out of the loop
if the manual fault fails or when the lookup is successful). The race
window is so small that the repeating solution is i think far superior
to artificially dirtying the pte.

	Ingo
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