6.6-stable review patch. If anyone has any objections, please let me know.
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From: Alexandre Ghiti alexghiti@rivosinc.com
[ Upstream commit 83d78ac677b9fdd8ea763507c6fe02d6bf415f3a ]
Ryan sent a fix [1] for arm64 that applies to riscv too: in some hugetlb functions, we must not use the pte value to get the size of a mapping because the pte may not be present.
So use the already present size parameter for huge_pte_clear() and the newly introduced size parameter for huge_ptep_get_and_clear(). And make sure to gather A/D bits only on present ptes.
Fixes: 82a1a1f3bfb6 ("riscv: mm: support Svnapot in hugetlb page") Link: https://lore.kernel.org/all/20250217140419.1702389-1-ryan.roberts@arm.com/ [1] Link: https://lore.kernel.org/r/20250317072551.572169-1-alexghiti@rivosinc.com Signed-off-by: Alexandre Ghiti alexghiti@rivosinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/mm/hugetlbpage.c | 76 ++++++++++++++++++++++--------------- 1 file changed, 45 insertions(+), 31 deletions(-)
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c index c9d70dc310d59..57afbc3270a3c 100644 --- a/arch/riscv/mm/hugetlbpage.c +++ b/arch/riscv/mm/hugetlbpage.c @@ -148,22 +148,25 @@ unsigned long hugetlb_mask_last_page(struct hstate *h) static pte_t get_clear_contig(struct mm_struct *mm, unsigned long addr, pte_t *ptep, - unsigned long pte_num) + unsigned long ncontig) { - pte_t orig_pte = ptep_get(ptep); - unsigned long i; - - for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++) { - pte_t pte = ptep_get_and_clear(mm, addr, ptep); - - if (pte_dirty(pte)) - orig_pte = pte_mkdirty(orig_pte); - - if (pte_young(pte)) - orig_pte = pte_mkyoung(orig_pte); + pte_t pte, tmp_pte; + bool present; + + pte = ptep_get_and_clear(mm, addr, ptep); + present = pte_present(pte); + while (--ncontig) { + ptep++; + addr += PAGE_SIZE; + tmp_pte = ptep_get_and_clear(mm, addr, ptep); + if (present) { + if (pte_dirty(tmp_pte)) + pte = pte_mkdirty(pte); + if (pte_young(tmp_pte)) + pte = pte_mkyoung(pte); + } } - - return orig_pte; + return pte; }
static pte_t get_clear_contig_flush(struct mm_struct *mm, @@ -212,6 +215,26 @@ static void clear_flush(struct mm_struct *mm, flush_tlb_range(&vma, saddr, addr); }
+static int num_contig_ptes_from_size(unsigned long sz, size_t *pgsize) +{ + unsigned long hugepage_shift; + + if (sz >= PGDIR_SIZE) + hugepage_shift = PGDIR_SHIFT; + else if (sz >= P4D_SIZE) + hugepage_shift = P4D_SHIFT; + else if (sz >= PUD_SIZE) + hugepage_shift = PUD_SHIFT; + else if (sz >= PMD_SIZE) + hugepage_shift = PMD_SHIFT; + else + hugepage_shift = PAGE_SHIFT; + + *pgsize = 1 << hugepage_shift; + + return sz >> hugepage_shift; +} + /* * When dealing with NAPOT mappings, the privileged specification indicates that * "if an update needs to be made, the OS generally should first mark all of the @@ -226,22 +249,10 @@ void set_huge_pte_at(struct mm_struct *mm, pte_t pte, unsigned long sz) { - unsigned long hugepage_shift, pgsize; + size_t pgsize; int i, pte_num;
- if (sz >= PGDIR_SIZE) - hugepage_shift = PGDIR_SHIFT; - else if (sz >= P4D_SIZE) - hugepage_shift = P4D_SHIFT; - else if (sz >= PUD_SIZE) - hugepage_shift = PUD_SHIFT; - else if (sz >= PMD_SIZE) - hugepage_shift = PMD_SHIFT; - else - hugepage_shift = PAGE_SHIFT; - - pte_num = sz >> hugepage_shift; - pgsize = 1 << hugepage_shift; + pte_num = num_contig_ptes_from_size(sz, &pgsize);
if (!pte_present(pte)) { for (i = 0; i < pte_num; i++, ptep++, addr += pgsize) @@ -295,13 +306,14 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep, unsigned long sz) { + size_t pgsize; pte_t orig_pte = ptep_get(ptep); int pte_num;
if (!pte_napot(orig_pte)) return ptep_get_and_clear(mm, addr, ptep);
- pte_num = napot_pte_num(napot_cont_order(orig_pte)); + pte_num = num_contig_ptes_from_size(sz, &pgsize);
return get_clear_contig(mm, addr, ptep, pte_num); } @@ -351,6 +363,7 @@ void huge_pte_clear(struct mm_struct *mm, pte_t *ptep, unsigned long sz) { + size_t pgsize; pte_t pte = ptep_get(ptep); int i, pte_num;
@@ -359,8 +372,9 @@ void huge_pte_clear(struct mm_struct *mm, return; }
- pte_num = napot_pte_num(napot_cont_order(pte)); - for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++) + pte_num = num_contig_ptes_from_size(sz, &pgsize); + + for (i = 0; i < pte_num; i++, addr += pgsize, ptep++) pte_clear(mm, addr, ptep); }