On 20.06.25 20:24, Pedro Falcato wrote:
On Tue, Jun 17, 2025 at 05:43:34PM +0200, David Hildenbrand wrote:
Doing a pte_pfn() etc. of something that is not a present page table
entry is wrong. Let's check in all relevant cases where we want to
upgrade write permissions when inserting pfns/pages whether the entry
is actually present.
It's not expected to have caused real harm in practice, so this is more a
cleanup than a fix for something that would likely trigger in some
weird circumstances.
Couldn't we e.g have a swap entry's "pfn" accidentally match the one we're
inserting? Isn't that a correctness problem?
In theory yes, in practice I think this will not happen.
... especially because the WARN_ON_ONCE() would already trigger in many
other cases before we would find one situation where it doesn't.
That's why I decided against Fixes: and declaring this more a cleanup,
because the starts really would have to align ... :)
Thanks!
--
Cheers,
David / dhildenb
