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author | Peter Zijlstra <peterz@infradead.org> | 2018-08-22 18:30:15 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-23 21:55:58 +0300 |
commit | d86564a2f085b79ec046a5cba90188e612352806 (patch) | |
tree | 18172b419a9ec64fe7e2e569726a1e8db498a67c /net/compat.c | |
parent | a6f572084fbee8b30f91465f4a085d7a90901c57 (diff) | |
download | linux-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 'net/compat.c')
0 files changed, 0 insertions, 0 deletions