Greg,
I will like to propose backporting "x86/speculation: Use Indirect Branch Prediction Barrier on context switch" from commit 18bf3c3e in upstream to 4.9 and 4.4 stable. The patch has already been ported to 4.14 and 4.15 stable. The patch needs mm context id that Andy added in commit f39681ed. I have lifted the mm context id change from Andy's upstream patch and included it here.
Thanks.
Tim
Tim Chen (2): x86/mm: Give each mm a unique ID x86/speculation: Use Indirect Branch Prediction Barrier in context switch
arch/x86/include/asm/mmu.h | 15 +++++++++++++-- arch/x86/include/asm/mmu_context.h | 5 +++++ arch/x86/include/asm/tlbflush.h | 2 ++ arch/x86/mm/tlb.c | 33 +++++++++++++++++++++++++++++++++ 4 files changed, 53 insertions(+), 2 deletions(-)