From d86564a2f085b79ec046a5cba90188e612352806 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 22 Aug 2018 17:30:15 +0200 Subject: mm/tlb, x86/mm: Support invalidating TLB caches for RCU_TABLE_FREE Jann reported that x86 was missing required TLB invalidates when he hit the !*batch slow path in tlb_remove_table(). This is indeed the case; RCU_TABLE_FREE does not provide TLB (cache) invalidates, the PowerPC-hash where this code originated and the Sparc-hash where this was subsequently used did not need that. ARM which later used this put an explicit TLB invalidate in their __p*_free_tlb() functions, and PowerPC-radix followed that example. But when we hooked up x86 we failed to consider this. Fix this by (optionally) hooking tlb_remove_table() into the TLB invalidate code. NOTE: s390 was also needing something like this and might now be able to use the generic code again. [ Modified to be on top of Nick's cleanups, which simplified this patch now that tlb_flush_mmu_tlbonly() really only flushes the TLB - Linus ] Fixes: 9e52fc2b50de ("x86/mm: Enable RCU based page table freeing (CONFIG_HAVE_RCU_TABLE_FREE=y)") Reported-by: Jann Horn Signed-off-by: Peter Zijlstra (Intel) Acked-by: Rik van Riel Cc: Nicholas Piggin Cc: David Miller Cc: Will Deacon Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- arch/Kconfig | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/Kconfig') diff --git a/arch/Kconfig b/arch/Kconfig index 4426e9687d89..b82f21ff5ae8 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -362,6 +362,9 @@ config HAVE_ARCH_JUMP_LABEL config HAVE_RCU_TABLE_FREE bool +config HAVE_RCU_TABLE_INVALIDATE + bool + config ARCH_HAVE_NMI_SAFE_CMPXCHG bool -- cgit v1.2.3-59-g8ed1b