This is a note to let you know that I've just added the patch titled
tlb: hugetlb: Add more sizes to tlb_remove_huge_tlb_entry
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tlb-hugetlb-add-more-sizes-to-tlb_remove_huge_tlb_en.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a4dee44f080005228955efde358113f71278a7ab
Author: Steve Capper <steve.capper@xxxxxxx>
Date: Wed Mar 30 12:25:43 2022 +0100
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@xxxxxxxxxx>
Suggested-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Link: https://lore.kernel.org/linux-mm/811c5c8e-b3a2-85d2-049c-717f17c3a03a@xxxxxxxxxx/
Signed-off-by: Steve Capper <steve.capper@xxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220330112543.863-1-steve.capper@xxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 46294ef620ff..268674c1d568 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -547,10 +547,14 @@ 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)
