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mm: remove follow_pte()

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follow_pte() users have been converted to follow_pfnmap*().  Remove the
API.

Link: https://lkml.kernel.org/r/20240826204353.2228736-17-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Peter Xu 2024-08-26 16:43:50 -04:00 committed by Andrew Morton
parent b17269a51c
commit b0a1c0d0ed
2 changed files with 0 additions and 75 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/linux/mm.h
View File

@ -2368,8 +2368,6 @@ void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
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);

73
mm/memory.c
View File

@ -6099,79 +6099,6 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
}
#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,