Messages in this thread | | | Date | Fri, 28 Aug 2020 13:15:25 +0200 | From | peterz@infradea ... | Subject | Re: [PATCH 1/4] mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race |
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On Fri, Aug 28, 2020 at 08:00:19PM +1000, Nicholas Piggin wrote:
> Closing this race only requires interrupts to be disabled while ->mm > and ->active_mm are being switched, but the TLB problem requires also > holding interrupts off over activate_mm. Unfortunately not all archs > can do that yet, e.g., arm defers the switch if irqs are disabled and > expects finish_arch_post_lock_switch() to be called to complete the > flush; um takes a blocking lock in activate_mm().
ARM at least has activate_mm() := switch_mm(), so it could be made to work.
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