tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
authorSteve Capper <steve.capper@arm.com>
Wed, 30 Mar 2022 11:25:43 +0000 (12:25 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 20 Apr 2022 07:34:16 +0000 (09:34 +0200)
commit61dd8bef80c24f8a848d2e4b57e0ded77bf2a1ce
treece105c39be6270a6b482c93897ec9767259f2398
parented2711c696ceb0bad5259bf338044c8a589c798d
tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry

[ Upstream commit 697a1d44af8ba0477ee729e632f4ade37999249a ]

tlb_remove_huge_tlb_entry only considers PMD_SIZE and PUD_SIZE when
updating the mmu_gather structure.

Unfortunately on arm64 there are two additional huge page sizes that
need to be covered: CONT_PTE_SIZE and CONT_PMD_SIZE. Where an end-user
attempts to employ contiguous huge pages, a VM_BUG_ON can be experienced
due to the fact that the tlb structure hasn't been correctly updated by
the relevant tlb_flush_p.._range() call from tlb_remove_huge_tlb_entry.

This patch adds inequality logic to the generic implementation of
tlb_remove_huge_tlb_entry s.t. CONT_PTE_SIZE and CONT_PMD_SIZE are
effectively covered on arm64. Also, as well as ptes, pmds and puds;
p4ds are now considered too.

Reported-by: David Hildenbrand <david@redhat.com>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/linux-mm/811c5c8e-b3a2-85d2-049c-717f17c3a03a@redhat.com/
Signed-off-by: Steve Capper <steve.capper@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220330112543.863-1-steve.capper@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
include/asm-generic/tlb.h