Messages in this thread | | | Date | Thu, 15 Sep 2005 09:13:02 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: ptrace can't be transparent on readonly MAP_SHARED |
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On Thu, 15 Sep 2005, Andrea Arcangeli wrote:
> On Thu, Sep 15, 2005 at 08:12:59AM -0700, Linus Torvalds wrote: > > have a PROT_READONLY/PROT_NONE area that is visible from the debugger, but > > continues to cause SIGSEGV's if the user process itself tries to access > > it. To me, that's good. > > Continue to cause sigsegv yes, but on the wrong page, when it will read > the page it can contain different data compared to what is on > disk/pagecache.
So? You're not making any sense.
I repeat: we CANNOT AVOID the fact that we will do COW.
That COW is required. No way we can avoid it. It has _nothing_ to do with maybe_mkwrite().
So I don't know why you continually refuse to just admit that fact. Why do you mix up the COW semantics with the maybe_mkwrite() semantics.
If you can't argue against maybe_mkwrite() without involving the COW argument, then stop arguing. They are two totally different thigns.
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