Messages in this thread | | | Date | Tue, 3 Jul 2018 11:24:29 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH for 4.18] rseq: use __u64 for rseq_cs fields, validate user inputs |
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On Tue, Jul 03, 2018 at 11:17:17AM +0200, Heiko Carstens wrote:
> And to answer also your question: we don't use a regular load, since we > would have to use 'sacf' construct surrounding the load instruction which > would be much slower. > We have something like that implemented for the futex atomic ops, and we > could also implement something like that for this use case > (e.g. get_user_atomic()), if really needed.
/me digs out the s390-PoO PDF and understands.. this is because of the split user/kernel address space stuff.
Fair enough.
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