Messages in this thread |  | | Date | Mon, 9 Jul 2001 18:58:32 +0100 (BST) | From | Hugh Dickins <> | Subject | Re: msync() bug |
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On Mon, 9 Jul 2001, Linus Torvalds wrote: > On Mon, 9 Jul 2001, Hugh Dickins wrote: > > > > > > that cannot happen, remap_pte_range only maps invalid pages or reserved > > > pages. > > > > Anyone know why mmap() of /dev/mem behaves in this way - solves the > > problem Andrew raises, but surely that could be solved in a better way? > > Seems strange that mmap() cannot give you what read() and write() can. > > Simple: we MUST NOT muck around with the page counts of random pages.
Of course.
> And if the pages aren't marked Reserved, the page counts _would_ get > corrupted by the VM page handling.
As it stands, yes. But shouldn't there be some kind of VM_ASIFRESERVED vma flag to treat all its pages as if they were reserved, for /dev/mem?
Hugh
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