Messages in this thread | | | Date | Wed, 10 Aug 2016 09:50:44 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH v7 1/7] Restartable sequences system call |
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On Tue, Aug 09, 2016 at 10:41:47PM +0000, Mathieu Desnoyers wrote: > #ifdef __LP64__ > > static bool rseq_update_cpu_id_event_counter(struct task_struct *t) > { > union rseq_cpu_event u; > > u.e.cpu_id = raw_smp_processor_id(); > u.e.event_counter = ++t->rseq_event_counter; > if (__put_user(u.v, &t->rseq->u.v)) > return false; > trace_rseq_inc(t->rseq_event_counter); > return true; > } > > #else /* #ifdef __LP64__ */ > > static bool rseq_update_cpu_id_event_counter(struct task_struct *t) > { > if (__put_user(raw_smp_processor_id(), &t->rseq->u.e.cpu_id)) > return false; > if (__put_user(++t->rseq_event_counter, &t->rseq->u.e.event_counter)) > return false; > trace_rseq_inc(t->rseq_event_counter); > return true; > } > > #endif /* #else #ifdef __LP64__ */
I don't think you need to guard it (and CONFIG_64BIT is the 'right' kernel symbol for that), 32bit should have u64 __put_user() only implemented as 2 u32 stores.
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