if (!(vma->vm_flags & VM_WRITE))
goto out_unlock_mmap;
- ret = follow_pte(vma->vm_mm, mmio_addr, NULL, &ptep, NULL, &ptl);
+ ret = follow_pte(vma->vm_mm, mmio_addr, &ptep, &ptl);
if (ret)
goto out_unlock_mmap;
if (!(vma->vm_flags & VM_WRITE))
goto out_unlock_mmap;
- ret = follow_pte(vma->vm_mm, mmio_addr, NULL, &ptep, NULL, &ptl);
+ ret = follow_pte(vma->vm_mm, mmio_addr, &ptep, &ptl);
if (ret)
goto out_unlock_mmap;
address = pgoff_address(index, vma);
/*
- * Note because we provide range to follow_pte it will call
+ * follow_invalidate_pte() will use the range to call
* mmu_notifier_invalidate_range_start() on our behalf before
* taking any lock.
*/
- if (follow_pte(vma->vm_mm, address, &range, &ptep, &pmdp, &ptl))
+ if (follow_invalidate_pte(vma->vm_mm, address, &range, &ptep,
+ &pmdp, &ptl))
continue;
/*
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,
}
#endif /* __PAGETABLE_PMD_FOLDED */
-int follow_pte(struct mm_struct *mm, unsigned long address,
- struct mmu_notifier_range *range, pte_t **ptepp, pmd_t **pmdpp,
- spinlock_t **ptlp)
+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)
{
pgd_t *pgd;
p4d_t *p4d;
return -EINVAL;
}
+/**
+ * follow_pte - look up PTE at a user virtual address
+ * @mm: the mm_struct of the target address space
+ * @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;
+ * any further use, if any, must be protected against invalidation
+ * with MMU notifiers.
+ *
+ * Only IO mappings and raw PFN mappings are allowed. The mmap semaphore
+ * should be taken for read.
+ *
+ * KVM uses this function. While it is arguably less bad than ``follow_pfn``,
+ * it is not a good general-purpose API.
+ *
+ * Return: zero on success, -ve otherwise.
+ */
+int follow_pte(struct mm_struct *mm, unsigned long address,
+ pte_t **ptepp, spinlock_t **ptlp)
+{
+ return follow_invalidate_pte(mm, address, NULL, ptepp, NULL, ptlp);
+}
+EXPORT_SYMBOL_GPL(follow_pte);
+
/**
* follow_pfn - look up PFN at a user virtual address
* @vma: memory mapping
*
* Only IO mappings and raw PFN mappings are allowed.
*
+ * This function does not allow the caller to read the permissions
+ * of the PTE. Do not use it.
+ *
* Return: zero and the pfn at @pfn on success, -ve otherwise.
*/
int follow_pfn(struct vm_area_struct *vma, unsigned long address,
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
return ret;
- ret = follow_pte(vma->vm_mm, address, NULL, &ptep, NULL, &ptl);
+ ret = follow_pte(vma->vm_mm, address, &ptep, &ptl);
if (ret)
return ret;
*pfn = pte_pfn(*ptep);
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
goto out;
- if (follow_pte(vma->vm_mm, address, NULL, &ptep, NULL, &ptl))
+ if (follow_pte(vma->vm_mm, address, &ptep, &ptl))
goto out;
pte = *ptep;
spinlock_t *ptl;
int r;
- r = follow_pte(vma->vm_mm, addr, NULL, &ptep, NULL, &ptl);
+ r = follow_pte(vma->vm_mm, addr, &ptep, &ptl);
if (r) {
/*
* get_user_pages fails for VM_IO and VM_PFNMAP vmas and does
if (r)
return r;
- r = follow_pte(vma->vm_mm, addr, NULL, &ptep, NULL, &ptl);
+ r = follow_pte(vma->vm_mm, addr, &ptep, &ptl);
if (r)
return r;
}