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| author | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-05 05:07:11 -0500 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-02-09 07:05:44 -0500 |
| commit | 9fd6dad1261a541b3f5fa7dc5b152222306e6702 (patch) | |
| tree | 07a393402e4e9d938a094731c816ca3b54da8711 /include/linux/mm.h | |
| parent | 897218ff7cf19290ec2d69652ce673d8ed6fedeb (diff) | |
| download | lwn-9fd6dad1261a541b3f5fa7dc5b152222306e6702.tar.gz lwn-9fd6dad1261a541b3f5fa7dc5b152222306e6702.zip | |
mm: provide a saner PTE walking API for modules
Currently, the follow_pfn function is exported for modules but
follow_pte is not. However, follow_pfn is very easy to misuse,
because it does not provide protections (so most of its callers
assume the page is writable!) and because it returns after having
already unlocked the page table lock.
Provide instead a simplified version of follow_pte that does
not have the pmdpp and range arguments. The older version
survives as follow_invalidate_pte() for use by fs/dax.c.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index ecdf8a8cd6ae..24b292fce8e5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1658,9 +1658,11 @@ 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_invalidate_pte(struct mm_struct *mm, unsigned long address, + struct mmu_notifier_range *range, pte_t **ptepp, + pmd_t **pmdpp, spinlock_t **ptlp); int follow_pte(struct mm_struct *mm, unsigned long address, - struct mmu_notifier_range *range, pte_t **ptepp, pmd_t **pmdpp, - spinlock_t **ptlp); + pte_t **ptepp, spinlock_t **ptlp); int follow_pfn(struct vm_area_struct *vma, unsigned long address, unsigned long *pfn); int follow_phys(struct vm_area_struct *vma, unsigned long address, |