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From:   Peter Zijlstra <peterz@infradead.org>
To:     Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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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 02:41:01PM -0400, Mathieu Desnoyers wrote:

> User-space won't ever want to read cpu_id_start and cpu_id from a single
> u64 load, it serves no purpose to do so. So I'm OK with keeping those as
> is and defining a local union for the __put_user() update.

So I think previously we had the sequence number and cpuid in there
together, and in that case it did want to load them both. But since you
made that sequence number dissapear....