On 6/16/21 11:08 AM, Mathieu Desnoyers wrote: > ----- On Jun 15, 2021, at 11:21 PM, Andy Lutomirski luto@xxxxxxxxxx wrote: > >> membarrier reads cpu_rq(remote cpu)->curr->mm without locking. Use >> READ_ONCE() and WRITE_ONCE() to remove the data races. > > I notice that kernel/exit.c:exit_mm() also has: > > current->mm = NULL; > > I suspect you may want to add a WRITE_ONCE() there as well ? Good catch. I was thinking that exit_mm() couldn't execute concurrently with membarrier(), but that's wrong. --Andy
