[PATCH v2 0/4] membarrier fixes

From: Andy Lutomirski
Date: Wed Dec 02 2020 - 10:35:59 EST


Hi all-

This is v2, and this time around everything is tagged for -stable.

Changes from v1:
- patch 1: comment fixes from Mathier
- patch 2: improved comments
- patch 3: split out as a separate patch
- patch 4: now has a proper explanation

Mathieu, I think we have to make sync_core sync the caller. See patch 4.

Andy Lutomirski (4):
x86/membarrier: Get rid of a dubious optimization
membarrier: Add an actual barrier before rseq_preempt()
membarrier: Explicitly sync remote cores when SYNC_CORE is requested
membarrier: Execute SYNC_CORE on the calling thread

arch/x86/include/asm/sync_core.h | 9 ++--
arch/x86/mm/tlb.c | 10 ++++-
kernel/sched/membarrier.c | 75 ++++++++++++++++++++++++--------
3 files changed, 71 insertions(+), 23 deletions(-)

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2.28.0