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authorPeter Zijlstra <peterz@infradead.org>2018-08-22 18:30:15 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-08-23 21:55:58 +0300
commitd86564a2f085b79ec046a5cba90188e612352806 (patch)
tree18172b419a9ec64fe7e2e569726a1e8db498a67c /arch
parenta6f572084fbee8b30f91465f4a085d7a90901c57 (diff)
downloadlinux-d86564a2f085b79ec046a5cba90188e612352806.tar.xz
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 <jannh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rik van Riel <riel@surriel.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: David Miller <davem@davemloft.net> Cc: Will Deacon <will.deacon@arm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/Kconfig3
-rw-r--r--arch/x86/Kconfig1
2 files changed, 4 insertions, 0 deletions
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
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 512003f16889..b9d37815176f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -181,6 +181,7 @@ config X86
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
select HAVE_RCU_TABLE_FREE
+ select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE
select HAVE_REGS_AND_STACK_ACCESS_API
select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR