The patch titled
Subject: mm: remove follow_pte()
has been added to the -mm mm-unstable branch. Its filename is
mm-remove-follow_pte.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-remove-follow_pte.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: Peter Xu <peterx@xxxxxxxxxx>
Subject: mm: remove follow_pte()
Date: Mon, 26 Aug 2024 16:43:50 -0400
follow_pte() users have been converted to follow_pfnmap*(). Remove the
API.
Link: https://lkml.kernel.org/r/20240826204353.2228736-17-peterx@xxxxxxxxxx
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Gavin Shan <gshan@xxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Niklas Schnelle <schnelle@xxxxxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Sean Christopherson <seanjc@xxxxxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Zi Yan <ziy@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 2 -
mm/memory.c | 73 -------------------------------------------
2 files changed, 75 deletions(-)
--- a/include/linux/mm.h~mm-remove-follow_pte
+++ a/include/linux/mm.h
@@ -2368,8 +2368,6 @@ void free_pgd_range(struct mmu_gather *t
unsigned long end, unsigned long floor, unsigned long ceiling);
int
copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma);
-int follow_pte(struct vm_area_struct *vma, unsigned long address,
- pte_t **ptepp, spinlock_t **ptlp);
int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
void *buf, int len, int write);
--- a/mm/memory.c~mm-remove-follow_pte
+++ a/mm/memory.c
@@ -6296,79 +6296,6 @@ int __pmd_alloc(struct mm_struct *mm, pu
}
#endif /* __PAGETABLE_PMD_FOLDED */
-/**
- * follow_pte - look up PTE at a user virtual address
- * @vma: the memory mapping
- * @address: user virtual address
- * @ptepp: location to store found PTE
- * @ptlp: location to store the lock for the PTE
- *
- * On a successful return, the pointer to the PTE is stored in @ptepp;
- * the corresponding lock is taken and its location is stored in @ptlp.
- *
- * The contents of the PTE are only stable until @ptlp is released using
- * pte_unmap_unlock(). This function will fail if the PTE is non-present.
- * Present PTEs may include PTEs that map refcounted pages, such as
- * anonymous folios in COW mappings.
- *
- * Callers must be careful when relying on PTE content after
- * pte_unmap_unlock(). Especially if the PTE maps a refcounted page,
- * callers must protect against invalidation with MMU notifiers; otherwise
- * access to the PFN at a later point in time can trigger use-after-free.
- *
- * Only IO mappings and raw PFN mappings are allowed. The mmap semaphore
- * should be taken for read.
- *
- * This function must not be used to modify PTE content.
- *
- * Return: zero on success, -ve otherwise.
- */
-int follow_pte(struct vm_area_struct *vma, unsigned long address,
- pte_t **ptepp, spinlock_t **ptlp)
-{
- struct mm_struct *mm = vma->vm_mm;
- pgd_t *pgd;
- p4d_t *p4d;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *ptep;
-
- mmap_assert_locked(mm);
- if (unlikely(address < vma->vm_start || address >= vma->vm_end))
- goto out;
-
- if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
- goto out;
-
- pgd = pgd_offset(mm, address);
- if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
- goto out;
-
- p4d = p4d_offset(pgd, address);
- if (p4d_none(*p4d) || unlikely(p4d_bad(*p4d)))
- goto out;
-
- pud = pud_offset(p4d, address);
- if (pud_none(*pud) || unlikely(pud_bad(*pud)))
- goto out;
-
- pmd = pmd_offset(pud, address);
- VM_BUG_ON(pmd_trans_huge(*pmd));
-
- ptep = pte_offset_map_lock(mm, pmd, address, ptlp);
- if (!ptep)
- goto out;
- if (!pte_present(ptep_get(ptep)))
- goto unlock;
- *ptepp = ptep;
- return 0;
-unlock:
- pte_unmap_unlock(ptep, *ptlp);
-out:
- return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(follow_pte);
-
static inline void pfnmap_args_setup(struct follow_pfnmap_args *args,
spinlock_t *lock, pte_t *ptep,
pgprot_t pgprot, unsigned long pfn_base,
_
Patches currently in -mm which might be from peterx@xxxxxxxxxx are
mm-dax-dump-start-address-in-fault-handler.patch
mm-mprotect-push-mmu-notifier-to-puds.patch
mm-powerpc-add-missing-pud-helpers.patch
mm-x86-make-pud_leaf-only-care-about-pse-bit.patch
mm-x86-implement-arch_check_zapped_pud.patch
mm-x86-add-missing-pud-helpers.patch
mm-mprotect-fix-dax-pud-handlings.patch
mm-introduce-arch_supports_huge_pfnmap-and-special-bits-to-pmd-pud.patch
mm-drop-is_huge_zero_pud.patch
mm-mark-special-bits-for-huge-pfn-mappings-when-inject.patch
mm-allow-thp-orders-for-pfnmaps.patch
mm-gup-detect-huge-pfnmap-entries-in-gup-fast.patch
mm-pagewalk-check-pfnmap-for-folio_walk_start.patch
mm-fork-accept-huge-pfnmap-entries.patch
mm-always-define-pxx_pgprot.patch
mm-new-follow_pfnmap-api.patch
kvm-use-follow_pfnmap-api.patch
s390-pci_mmio-use-follow_pfnmap-api.patch
mm-x86-pat-use-the-new-follow_pfnmap-api.patch
vfio-use-the-new-follow_pfnmap-api.patch
acrn-use-the-new-follow_pfnmap-api.patch
mm-access_process_vm-use-the-new-follow_pfnmap-api.patch
mm-remove-follow_pte.patch
mm-x86-support-large-pfn-mappings.patch
mm-arm64-support-large-pfn-mappings.patch
