From: Steve Capper steve.capper@arm.com
[ 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... 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 | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 2c68a545ffa7..71942a1c642d 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -565,10 +565,14 @@ static inline void tlb_flush_p4d_range(struct mmu_gather *tlb, #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \ do { \ unsigned long _sz = huge_page_size(h); \ - if (_sz == PMD_SIZE) \ - tlb_flush_pmd_range(tlb, address, _sz); \ - else if (_sz == PUD_SIZE) \ + if (_sz >= P4D_SIZE) \ + tlb_flush_p4d_range(tlb, address, _sz); \ + else if (_sz >= PUD_SIZE) \ tlb_flush_pud_range(tlb, address, _sz); \ + else if (_sz >= PMD_SIZE) \ + tlb_flush_pmd_range(tlb, address, _sz); \ + else \ + tlb_flush_pte_range(tlb, address, _sz); \ __tlb_remove_tlb_entry(tlb, ptep, address); \ } while (0)