The patch titled
Subject: fixup: mm/memory: pass PTE to copy_present_pte()
has been added to the -mm mm-unstable branch. Its filename is
mm-memory-pass-pte-to-copy_present_pte-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory-pass-pte-to-copy_present_pte-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: fixup: mm/memory: pass PTE to copy_present_pte()
Date: Wed, 14 Feb 2024 23:40:22 +0100
For device-exclusive nonswp entries (is_device_exclusive_entry()),
copy_nonpresent_pte() can turn the PTEs into actual present PTEs while
holding the page table lock.
We hae to re-read the PTE after that operation, such that we won't be
working on the stale non-present PTE, assuming it would be present.
This fixes the hmm "exclusive_cow" selftest.
./run_vmtests.sh -t hmm
# # RUN hmm.hmm_device_private.exclusive_cow ...
# # OK hmm.hmm_device_private.exclusive_cow
# ok 23 hmm.hmm_device_private.exclusive_cow
Link: https://lkml.kernel.org/r/13f296b8-e882-47fd-b939-c2141dc28717@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Dinh Nguyen <dinguyen@xxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Russell King (Oracle) <linux@xxxxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/memory.c~mm-memory-pass-pte-to-copy_present_pte-fix
+++ a/mm/memory.c
@@ -1093,6 +1093,8 @@ again:
progress += 8;
continue;
}
+ ptent = ptep_get(src_pte);
+ VM_WARN_ON_ONCE(!pte_present(ptent));
/*
* Device exclusive entry restored, continue by copying
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
arm-pgtable-define-pfn_pte_shift.patch
nios2-pgtable-define-pfn_pte_shift.patch
powerpc-pgtable-define-pfn_pte_shift.patch
riscv-pgtable-define-pfn_pte_shift.patch
s390-pgtable-define-pfn_pte_shift.patch
sparc-pgtable-define-pfn_pte_shift.patch
mm-pgtable-make-pte_next_pfn-independent-of-set_ptes.patch
arm-mm-use-pte_next_pfn-in-set_ptes.patch
powerpc-mm-use-pte_next_pfn-in-set_ptes.patch
mm-memory-factor-out-copying-the-actual-pte-in-copy_present_pte.patch
mm-memory-pass-pte-to-copy_present_pte.patch
mm-memory-pass-pte-to-copy_present_pte-fix.patch
mm-memory-optimize-fork-with-pte-mapped-thp.patch
mm-memory-ignore-dirty-accessed-soft-dirty-bits-in-folio_pte_batch.patch
mm-memory-ignore-writable-bit-in-folio_pte_batch.patch
mm-memory-factor-out-zapping-of-present-pte-into-zap_present_pte.patch
mm-memory-handle-page-case-in-zap_present_pte-separately.patch
mm-memory-further-separate-anon-and-pagecache-folio-handling-in-zap_present_pte.patch
mm-memory-factor-out-zapping-folio-pte-into-zap_present_folio_pte.patch
mm-mmu_gather-pass-delay_rmap-instead-of-encoded-page-to-__tlb_remove_page_size.patch
mm-mmu_gather-define-encoded_page_flag_delay_rmap.patch
mm-mmu_gather-add-tlb_remove_tlb_entries.patch
mm-mmu_gather-add-__tlb_remove_folio_pages.patch
mm-mmu_gather-improve-cond_resched-handling-with-large-folios-and-expensive-page-freeing.patch
mm-memory-optimize-unmap-zap-with-pte-mapped-thp.patch
