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From: Ryan Roberts <ryan.roberts@arm.com>
To: Andrew Morton <akpm@linux-foundation.org>,
	"Matthew Wilcox (Oracle)" <willy@infradead.org>,
	"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	SeongJae Park <sj@kernel.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, damon@lists.linux.dev
Subject: Re: [PATCH v1 5/5] mm: ptep_deref() conversion
Date: Thu, 11 May 2023 14:14:59 +0100	[thread overview]
Message-ID: <3ebf6962-35f9-546f-3845-81526ff57adc@arm.com> (raw)
In-Reply-To: <20230511125848.78621-6-ryan.roberts@arm.com>

My appologies for the noise: A blank line between Cc and Subject has broken the
subject and grouping in lore.

Please Ignore this, I will resend.


On 11/05/2023 13:58, Ryan Roberts wrote:
> Convert all instances of direct pte_t* dereferencing to instead use
> ptep_deref() helper. By default, the helper does a direct dereference as
> before, but it can (and will) be overridden by the architecture to fully
> encapsulate the contents of the pte. Arch code is deliberately not
> converted, as the arch code knows best.
> 
> Conversion was done using Coccinelle:
> 
> ----
> 
> // $ make coccicheck \
> //          COCCI=ptepderef.cocci \
> //          SPFLAGS="--include-headers" \
> //          MODE=patch
> 
> virtual patch
> 
> @ depends on patch @
> pte_t *v;
> @@
> 
> - *v
> + ptep_deref(v)
> 
> ----
> 
> Then reviewed and hand-edited to avoid multiple unnecessary calls to
> ptep_deref(), instead opting to store the result of a single in a
> variable, where it is correct to do so. This will benefit arch-overrides
> that may be more complex than a simple (optimizable) pointer
> dereference.
> 
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
> ---
>  .../drm/i915/gem/selftests/i915_gem_mman.c    |  8 +-
>  drivers/misc/sgi-gru/grufault.c               |  2 +-
>  drivers/vfio/vfio_iommu_type1.c               |  7 +-
>  drivers/xen/privcmd.c                         |  2 +-
>  fs/proc/task_mmu.c                            | 33 ++++---
>  fs/userfaultfd.c                              |  6 +-
>  include/linux/hugetlb.h                       |  2 +-
>  include/linux/mm_inline.h                     |  2 +-
>  include/linux/pgtable.h                       |  6 +-
>  kernel/events/uprobes.c                       |  2 +-
>  mm/damon/ops-common.c                         |  2 +-
>  mm/damon/paddr.c                              |  2 +-
>  mm/damon/vaddr.c                              | 10 +-
>  mm/filemap.c                                  |  2 +-
>  mm/gup.c                                      | 21 ++--
>  mm/highmem.c                                  | 12 ++-
>  mm/hmm.c                                      |  2 +-
>  mm/huge_memory.c                              |  4 +-
>  mm/hugetlb.c                                  |  2 +-
>  mm/hugetlb_vmemmap.c                          |  6 +-
>  mm/kasan/init.c                               |  9 +-
>  mm/kasan/shadow.c                             | 10 +-
>  mm/khugepaged.c                               | 24 ++---
>  mm/ksm.c                                      | 22 +++--
>  mm/madvise.c                                  |  6 +-
>  mm/mapping_dirty_helpers.c                    |  4 +-
>  mm/memcontrol.c                               |  4 +-
>  mm/memory-failure.c                           |  6 +-
>  mm/memory.c                                   | 99 ++++++++++---------
>  mm/mempolicy.c                                |  6 +-
>  mm/migrate.c                                  | 14 +--
>  mm/migrate_device.c                           | 14 +--
>  mm/mincore.c                                  |  2 +-
>  mm/mlock.c                                    |  6 +-
>  mm/mprotect.c                                 |  8 +-
>  mm/mremap.c                                   |  2 +-
>  mm/page_table_check.c                         |  4 +-
>  mm/page_vma_mapped.c                          | 26 ++---
>  mm/pgtable-generic.c                          |  2 +-
>  mm/rmap.c                                     | 32 +++---
>  mm/sparse-vmemmap.c                           |  8 +-
>  mm/swap_state.c                               |  4 +-
>  mm/swapfile.c                                 | 16 +--
>  mm/userfaultfd.c                              |  4 +-
>  mm/vmalloc.c                                  |  6 +-
>  mm/vmscan.c                                   | 14 +--
>  virt/kvm/kvm_main.c                           |  9 +-
>  47 files changed, 278 insertions(+), 216 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
> index 56279908ed30..d49d08eb55cd 100644
> --- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
> +++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
> @@ -1681,7 +1681,9 @@ static int igt_mmap_gpu(void *arg)
>  
>  static int check_present_pte(pte_t *pte, unsigned long addr, void *data)
>  {
> -	if (!pte_present(*pte) || pte_none(*pte)) {
> +	pte_t ptent = ptep_deref(pte);
> +
> +	if (!pte_present(ptent) || pte_none(ptent)) {
>  		pr_err("missing PTE:%lx\n",
>  		       (addr - (unsigned long)data) >> PAGE_SHIFT);
>  		return -EINVAL;
> @@ -1692,7 +1694,9 @@ static int check_present_pte(pte_t *pte, unsigned long addr, void *data)
>  
>  static int check_absent_pte(pte_t *pte, unsigned long addr, void *data)
>  {
> -	if (pte_present(*pte) && !pte_none(*pte)) {
> +	pte_t ptent = ptep_deref(pte);
> +
> +	if (pte_present(ptent) && !pte_none(ptent)) {
>  		pr_err("present PTE:%lx; expected to be revoked\n",
>  		       (addr - (unsigned long)data) >> PAGE_SHIFT);
>  		return -EINVAL;
> diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
> index b836936e9747..ae141a869638 100644
> --- a/drivers/misc/sgi-gru/grufault.c
> +++ b/drivers/misc/sgi-gru/grufault.c
> @@ -228,7 +228,7 @@ static int atomic_pte_lookup(struct vm_area_struct *vma, unsigned long vaddr,
>  		goto err;
>  #ifdef CONFIG_X86_64
>  	if (unlikely(pmd_large(*pmdp)))
> -		pte = *(pte_t *) pmdp;
> +		pte = ptep_deref((pte_t *)pmdp);
>  	else
>  #endif
>  		pte = *pte_offset_kernel(pmdp, vaddr);
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 3d4dd9420c30..5680542f744f 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -514,6 +514,7 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
>  			    bool write_fault)
>  {
>  	pte_t *ptep;
> +	pte_t pte;
>  	spinlock_t *ptl;
>  	int ret;
>  
> @@ -536,10 +537,12 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
>  			return ret;
>  	}
>  
> -	if (write_fault && !pte_write(*ptep))
> +	pte = ptep_deref(ptep);
> +
> +	if (write_fault && !pte_write(pte))
>  		ret = -EFAULT;
>  	else
> -		*pfn = pte_pfn(*ptep);
> +		*pfn = pte_pfn(pte);
>  
>  	pte_unmap_unlock(ptep, ptl);
>  	return ret;
> diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
> index e2f580e30a86..b53afae05315 100644
> --- a/drivers/xen/privcmd.c
> +++ b/drivers/xen/privcmd.c
> @@ -949,7 +949,7 @@ static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
>   */
>  static int is_mapped_fn(pte_t *pte, unsigned long addr, void *data)
>  {
> -	return pte_none(*pte) ? 0 : -EBUSY;
> +	return pte_none(ptep_deref(pte)) ? 0 : -EBUSY;
>  }
>  
>  static int privcmd_vma_range_is_mapped(
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index 420510f6a545..3ea93edcf194 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -538,13 +538,14 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
>  	bool locked = !!(vma->vm_flags & VM_LOCKED);
>  	struct page *page = NULL;
>  	bool migration = false, young = false, dirty = false;
> +	pte_t ptent = ptep_deref(pte);
>  
> -	if (pte_present(*pte)) {
> -		page = vm_normal_page(vma, addr, *pte);
> -		young = pte_young(*pte);
> -		dirty = pte_dirty(*pte);
> -	} else if (is_swap_pte(*pte)) {
> -		swp_entry_t swpent = pte_to_swp_entry(*pte);
> +	if (pte_present(ptent)) {
> +		page = vm_normal_page(vma, addr, ptent);
> +		young = pte_young(ptent);
> +		dirty = pte_dirty(ptent);
> +	} else if (is_swap_pte(ptent)) {
> +		swp_entry_t swpent = pte_to_swp_entry(ptent);
>  
>  		if (!non_swap_entry(swpent)) {
>  			int mapcount;
> @@ -735,11 +736,12 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
>  	struct mem_size_stats *mss = walk->private;
>  	struct vm_area_struct *vma = walk->vma;
>  	struct page *page = NULL;
> +	pte_t ptent = ptep_deref(pte);
>  
> -	if (pte_present(*pte)) {
> -		page = vm_normal_page(vma, addr, *pte);
> -	} else if (is_swap_pte(*pte)) {
> -		swp_entry_t swpent = pte_to_swp_entry(*pte);
> +	if (pte_present(ptent)) {
> +		page = vm_normal_page(vma, addr, ptent);
> +	} else if (is_swap_pte(ptent)) {
> +		swp_entry_t swpent = pte_to_swp_entry(ptent);
>  
>  		if (is_pfn_swap_entry(swpent))
>  			page = pfn_swap_entry_to_page(swpent);
> @@ -1108,7 +1110,7 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma,
>  	 * Documentation/admin-guide/mm/soft-dirty.rst for full description
>  	 * of how soft-dirty works.
>  	 */
> -	pte_t ptent = *pte;
> +	pte_t ptent = ptep_deref(pte);
>  
>  	if (pte_present(ptent)) {
>  		pte_t old_pte;
> @@ -1196,7 +1198,7 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
>  
>  	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
>  	for (; addr != end; pte++, addr += PAGE_SIZE) {
> -		ptent = *pte;
> +		ptent = ptep_deref(pte);
>  
>  		if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
>  			clear_soft_dirty(vma, addr, pte);
> @@ -1551,7 +1553,7 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end,
>  	for (; addr < end; pte++, addr += PAGE_SIZE) {
>  		pagemap_entry_t pme;
>  
> -		pme = pte_to_pagemap_entry(pm, vma, addr, *pte);
> +		pme = pte_to_pagemap_entry(pm, vma, addr, ptep_deref(pte));
>  		err = add_to_pagemap(addr, &pme, pm);
>  		if (err)
>  			break;
> @@ -1893,10 +1895,11 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
>  #endif
>  	orig_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
>  	do {
> -		struct page *page = can_gather_numa_stats(*pte, vma, addr);
> +		pte_t ptent = ptep_deref(pte);
> +		struct page *page = can_gather_numa_stats(ptent, vma, addr);
>  		if (!page)
>  			continue;
> -		gather_stats(page, md, pte_dirty(*pte), 1);
> +		gather_stats(page, md, pte_dirty(ptent), 1);
>  
>  	} while (pte++, addr += PAGE_SIZE, addr != end);
>  	pte_unmap_unlock(orig_pte, ptl);
> diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
> index 0fd96d6e39ce..901721305483 100644
> --- a/fs/userfaultfd.c
> +++ b/fs/userfaultfd.c
> @@ -335,6 +335,7 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
>  	pud_t *pud;
>  	pmd_t *pmd, _pmd;
>  	pte_t *pte;
> +	pte_t ptent;
>  	bool ret = true;
>  
>  	mmap_assert_locked(mm);
> @@ -381,9 +382,10 @@ static inline bool userfaultfd_must_wait(struct userfaultfd_ctx *ctx,
>  	 * changes under us.  PTE markers should be handled the same as none
>  	 * ptes here.
>  	 */
> -	if (pte_none_mostly(*pte))
> +	ptent = ptep_deref(pte);
> +	if (pte_none_mostly(ptent))
>  		ret = true;
> -	if (!pte_write(*pte) && (reason & VM_UFFD_WP))
> +	if (!pte_write(ptent) && (reason & VM_UFFD_WP))
>  		ret = true;
>  	pte_unmap(pte);
>  
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 6d041aa9f0fe..f75b21739f9d 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -1200,7 +1200,7 @@ static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
>  static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
>  					  unsigned long addr, pte_t *ptep)
>  {
> -	return *ptep;
> +	return ptep_deref(ptep);
>  }
>  
>  static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
> index 0e1d239a882c..8756bf28c362 100644
> --- a/include/linux/mm_inline.h
> +++ b/include/linux/mm_inline.h
> @@ -555,7 +555,7 @@ pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr,
>  	bool arm_uffd_pte = false;
>  
>  	/* The current status of the pte should be "cleared" before calling */
> -	WARN_ON_ONCE(!pte_none(*pte));
> +	WARN_ON_ONCE(!pte_none(ptep_deref(pte)));
>  
>  	/*
>  	 * NOTE: userfaultfd_wp_unpopulated() doesn't need this whole
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index 1161beab2492..c6eb5530a54c 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -216,7 +216,7 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
>  					    unsigned long address,
>  					    pte_t *ptep)
>  {
> -	pte_t pte = *ptep;
> +	pte_t pte = ptep_deref(ptep);
>  	int r = 1;
>  	if (!pte_young(pte))
>  		r = 0;
> @@ -303,7 +303,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
>  				       unsigned long address,
>  				       pte_t *ptep)
>  {
> -	pte_t pte = *ptep;
> +	pte_t pte = ptep_deref(ptep);
>  	pte_clear(mm, address, ptep);
>  	page_table_check_pte_clear(mm, address, pte);
>  	return pte;
> @@ -518,7 +518,7 @@ extern pud_t pudp_huge_clear_flush(struct vm_area_struct *vma,
>  struct mm_struct;
>  static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
>  {
> -	pte_t old_pte = *ptep;
> +	pte_t old_pte = ptep_deref(ptep);
>  	set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
>  }
>  #endif
> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
> index 59887c69d54c..51318c80dc03 100644
> --- a/kernel/events/uprobes.c
> +++ b/kernel/events/uprobes.c
> @@ -192,7 +192,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
>  		inc_mm_counter(mm, MM_ANONPAGES);
>  	}
>  
> -	flush_cache_page(vma, addr, pte_pfn(*pvmw.pte));
> +	flush_cache_page(vma, addr, pte_pfn(ptep_deref(pvmw.pte)));
>  	ptep_clear_flush_notify(vma, addr, pvmw.pte);
>  	if (new_page)
>  		set_pte_at_notify(mm, addr, pvmw.pte,
> diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c
> index acc264b97903..4fce16c01d23 100644
> --- a/mm/damon/ops-common.c
> +++ b/mm/damon/ops-common.c
> @@ -40,7 +40,7 @@ struct folio *damon_get_folio(unsigned long pfn)
>  void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr)
>  {
>  	bool referenced = false;
> -	struct folio *folio = damon_get_folio(pte_pfn(*pte));
> +	struct folio *folio = damon_get_folio(pte_pfn(ptep_deref(pte)));
>  
>  	if (!folio)
>  		return;
> diff --git a/mm/damon/paddr.c b/mm/damon/paddr.c
> index 5b3a3463d078..bc0839548539 100644
> --- a/mm/damon/paddr.c
> +++ b/mm/damon/paddr.c
> @@ -89,7 +89,7 @@ static bool __damon_pa_young(struct folio *folio, struct vm_area_struct *vma,
>  	while (page_vma_mapped_walk(&pvmw)) {
>  		addr = pvmw.address;
>  		if (pvmw.pte) {
> -			*accessed = pte_young(*pvmw.pte) ||
> +			*accessed = pte_young(ptep_deref(pvmw.pte)) ||
>  				!folio_test_idle(folio) ||
>  				mmu_notifier_test_young(vma->vm_mm, addr);
>  		} else {
> diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
> index 37994fb6120c..294a6c08640b 100644
> --- a/mm/damon/vaddr.c
> +++ b/mm/damon/vaddr.c
> @@ -321,7 +321,7 @@ static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr,
>  	if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
>  		return 0;
>  	pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
> -	if (!pte_present(*pte))
> +	if (!pte_present(ptep_deref(pte)))
>  		goto out;
>  	damon_ptep_mkold(pte, walk->vma, addr);
>  out:
> @@ -431,6 +431,7 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr,
>  		unsigned long next, struct mm_walk *walk)
>  {
>  	pte_t *pte;
> +	pte_t ptent;
>  	spinlock_t *ptl;
>  	struct folio *folio;
>  	struct damon_young_walk_private *priv = walk->private;
> @@ -467,12 +468,13 @@ static int damon_young_pmd_entry(pmd_t *pmd, unsigned long addr,
>  	if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
>  		return -EINVAL;
>  	pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
> -	if (!pte_present(*pte))
> +	ptent = ptep_deref(pte);
> +	if (!pte_present(ptent))
>  		goto out;
> -	folio = damon_get_folio(pte_pfn(*pte));
> +	folio = damon_get_folio(pte_pfn(ptent));
>  	if (!folio)
>  		goto out;
> -	if (pte_young(*pte) || !folio_test_idle(folio) ||
> +	if (pte_young(ptent) || !folio_test_idle(folio) ||
>  			mmu_notifier_test_young(walk->mm, addr))
>  		priv->young = true;
>  	*priv->folio_sz = folio_size(folio);
> diff --git a/mm/filemap.c b/mm/filemap.c
> index b4c9bd368b7e..bf1b0bc7bfa2 100644
> --- a/mm/filemap.c
> +++ b/mm/filemap.c
> @@ -3524,7 +3524,7 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf,
>  		 * handled in the specific fault path, and it'll prohibit the
>  		 * fault-around logic.
>  		 */
> -		if (!pte_none(*vmf->pte))
> +		if (!pte_none(ptep_deref(vmf->pte)))
>  			goto unlock;
>  
>  		/* We're about to handle the fault */
> diff --git a/mm/gup.c b/mm/gup.c
> index bbe416236593..c6995f103d5f 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -476,13 +476,14 @@ static int follow_pfn_pte(struct vm_area_struct *vma, unsigned long address,
>  		pte_t *pte, unsigned int flags)
>  {
>  	if (flags & FOLL_TOUCH) {
> -		pte_t entry = *pte;
> +		pte_t orig_entry = ptep_deref(pte);
> +		pte_t entry = orig_entry;
>  
>  		if (flags & FOLL_WRITE)
>  			entry = pte_mkdirty(entry);
>  		entry = pte_mkyoung(entry);
>  
> -		if (!pte_same(*pte, entry)) {
> +		if (!pte_same(orig_entry, entry)) {
>  			set_pte_at(vma->vm_mm, address, pte, entry);
>  			update_mmu_cache(vma, address, pte);
>  		}
> @@ -548,7 +549,7 @@ static struct page *follow_page_pte(struct vm_area_struct *vma,
>  		return no_page_table(vma, flags);
>  
>  	ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
> -	pte = *ptep;
> +	pte = ptep_deref(ptep);
>  	if (!pte_present(pte))
>  		goto no_page;
>  	if (pte_protnone(pte) && !gup_can_follow_protnone(flags))
> @@ -835,6 +836,7 @@ static int get_gate_page(struct mm_struct *mm, unsigned long address,
>  	pud_t *pud;
>  	pmd_t *pmd;
>  	pte_t *pte;
> +	pte_t entry;
>  	int ret = -EFAULT;
>  
>  	/* user gate pages are read-only */
> @@ -857,16 +859,17 @@ static int get_gate_page(struct mm_struct *mm, unsigned long address,
>  		return -EFAULT;
>  	VM_BUG_ON(pmd_trans_huge(*pmd));
>  	pte = pte_offset_map(pmd, address);
> -	if (pte_none(*pte))
> +	entry = ptep_deref(pte);
> +	if (pte_none(entry))
>  		goto unmap;
>  	*vma = get_gate_vma(mm);
>  	if (!page)
>  		goto out;
> -	*page = vm_normal_page(*vma, address, *pte);
> +	*page = vm_normal_page(*vma, address, entry);
>  	if (!*page) {
> -		if ((gup_flags & FOLL_DUMP) || !is_zero_pfn(pte_pfn(*pte)))
> +		if ((gup_flags & FOLL_DUMP) || !is_zero_pfn(pte_pfn(entry)))
>  			goto unmap;
> -		*page = pte_page(*pte);
> +		*page = pte_page(entry);
>  	}
>  	ret = try_grab_page(*page, gup_flags);
>  	if (unlikely(ret))
> @@ -2417,7 +2420,7 @@ static int gup_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
>  		}
>  
>  		if (unlikely(pmd_val(pmd) != pmd_val(*pmdp)) ||
> -		    unlikely(pte_val(pte) != pte_val(*ptep))) {
> +		    unlikely(pte_val(pte) != pte_val(ptep_deref(ptep)))) {
>  			gup_put_folio(folio, 1, flags);
>  			goto pte_unmap;
>  		}
> @@ -2609,7 +2612,7 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
>  	if (!folio)
>  		return 0;
>  
> -	if (unlikely(pte_val(pte) != pte_val(*ptep))) {
> +	if (unlikely(pte_val(pte) != pte_val(ptep_deref(ptep)))) {
>  		gup_put_folio(folio, refs, flags);
>  		return 0;
>  	}
> diff --git a/mm/highmem.c b/mm/highmem.c
> index db251e77f98f..f3be3c91a8a7 100644
> --- a/mm/highmem.c
> +++ b/mm/highmem.c
> @@ -161,7 +161,7 @@ struct page *__kmap_to_page(void *vaddr)
>  	/* kmap() mappings */
>  	if (WARN_ON_ONCE(addr >= PKMAP_ADDR(0) &&
>  			 addr < PKMAP_ADDR(LAST_PKMAP)))
> -		return pte_page(pkmap_page_table[PKMAP_NR(addr)]);
> +		return pte_page(ptep_deref(&pkmap_page_table[PKMAP_NR(addr)]));
>  
>  	/* kmap_local_page() mappings */
>  	if (WARN_ON_ONCE(base >= __fix_to_virt(FIX_KMAP_END) &&
> @@ -191,6 +191,7 @@ static void flush_all_zero_pkmaps(void)
>  
>  	for (i = 0; i < LAST_PKMAP; i++) {
>  		struct page *page;
> +		pte_t ptent;
>  
>  		/*
>  		 * zero means we don't have anything to do,
> @@ -203,7 +204,8 @@ static void flush_all_zero_pkmaps(void)
>  		pkmap_count[i] = 0;
>  
>  		/* sanity check */
> -		BUG_ON(pte_none(pkmap_page_table[i]));
> +		ptent = ptep_deref(&pkmap_page_table[i]);
> +		BUG_ON(pte_none(ptent));
>  
>  		/*
>  		 * Don't need an atomic fetch-and-clear op here;
> @@ -212,7 +214,7 @@ static void flush_all_zero_pkmaps(void)
>  		 * getting the kmap_lock (which is held here).
>  		 * So no dangers, even with speculative execution.
>  		 */
> -		page = pte_page(pkmap_page_table[i]);
> +		page = pte_page(ptent);
>  		pte_clear(&init_mm, PKMAP_ADDR(i), &pkmap_page_table[i]);
>  
>  		set_page_address(page, NULL);
> @@ -511,7 +513,7 @@ static inline bool kmap_high_unmap_local(unsigned long vaddr)
>  {
>  #ifdef ARCH_NEEDS_KMAP_HIGH_GET
>  	if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
> -		kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
> +		kunmap_high(pte_page(ptep_deref(&pkmap_page_table[PKMAP_NR(vaddr)])));
>  		return true;
>  	}
>  #endif
> @@ -548,7 +550,7 @@ void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
>  	idx = arch_kmap_local_map_idx(kmap_local_idx_push(), pfn);
>  	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
>  	kmap_pte = kmap_get_pte(vaddr, idx);
> -	BUG_ON(!pte_none(*kmap_pte));
> +	BUG_ON(!pte_none(ptep_deref(kmap_pte)));
>  	pteval = pfn_pte(pfn, prot);
>  	arch_kmap_local_set_pte(&init_mm, vaddr, kmap_pte, pteval);
>  	arch_kmap_local_post_map(vaddr, pteval);
> diff --git a/mm/hmm.c b/mm/hmm.c
> index 6a151c09de5e..45d867c3fe5b 100644
> --- a/mm/hmm.c
> +++ b/mm/hmm.c
> @@ -228,7 +228,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr,
>  	struct hmm_range *range = hmm_vma_walk->range;
>  	unsigned int required_fault;
>  	unsigned long cpu_flags;
> -	pte_t pte = *ptep;
> +	pte_t pte = ptep_deref(ptep);
>  	uint64_t pfn_req_flags = *hmm_pfn;
>  
>  	if (pte_none_mostly(pte)) {
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 624671aaa60d..ad5653373d35 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2058,7 +2058,7 @@ static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
>  		if (pmd_uffd_wp(old_pmd))
>  			entry = pte_mkuffd_wp(entry);
>  		pte = pte_offset_map(&_pmd, haddr);
> -		VM_BUG_ON(!pte_none(*pte));
> +		VM_BUG_ON(!pte_none(ptep_deref(pte)));
>  		set_pte_at(mm, haddr, pte, entry);
>  		pte_unmap(pte);
>  	}
> @@ -2249,7 +2249,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd,
>  			page_add_anon_rmap(page + i, vma, addr, false);
>  		}
>  		pte = pte_offset_map(&_pmd, addr);
> -		BUG_ON(!pte_none(*pte));
> +		BUG_ON(!pte_none(ptep_deref(pte)));
>  		set_pte_at(mm, addr, pte, entry);
>  		pte_unmap(pte);
>  	}
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index f154019e6b84..c10ece03a63f 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -7254,7 +7254,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
>  				pte = (pte_t *)pmd_alloc(mm, pud, addr);
>  		}
>  	}
> -	BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte));
> +	BUG_ON(pte && pte_present(ptep_deref(pte)) && !pte_huge(ptep_deref(pte)));
>  
>  	return pte;
>  }
> diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c
> index 27f001e0f0a2..79c9afcc8cee 100644
> --- a/mm/hugetlb_vmemmap.c
> +++ b/mm/hugetlb_vmemmap.c
> @@ -105,7 +105,7 @@ static void vmemmap_pte_range(pmd_t *pmd, unsigned long addr,
>  	 * remapping (which is calling @walk->remap_pte).
>  	 */
>  	if (!walk->reuse_page) {
> -		walk->reuse_page = pte_page(*pte);
> +		walk->reuse_page = pte_page(ptep_deref(pte));
>  		/*
>  		 * Because the reuse address is part of the range that we are
>  		 * walking, skip the reuse address range.
> @@ -239,7 +239,7 @@ static void vmemmap_remap_pte(pte_t *pte, unsigned long addr,
>  	 * to the tail pages.
>  	 */
>  	pgprot_t pgprot = PAGE_KERNEL_RO;
> -	struct page *page = pte_page(*pte);
> +	struct page *page = pte_page(ptep_deref(pte));
>  	pte_t entry;
>  
>  	/* Remapping the head page requires r/w */
> @@ -286,7 +286,7 @@ static void vmemmap_restore_pte(pte_t *pte, unsigned long addr,
>  	struct page *page;
>  	void *to;
>  
> -	BUG_ON(pte_page(*pte) != walk->reuse_page);
> +	BUG_ON(pte_page(ptep_deref(pte)) != walk->reuse_page);
>  
>  	page = list_first_entry(walk->vmemmap_pages, struct page, lru);
>  	list_del(&page->lru);
> diff --git a/mm/kasan/init.c b/mm/kasan/init.c
> index cc64ed6858c6..f4d569a39af8 100644
> --- a/mm/kasan/init.c
> +++ b/mm/kasan/init.c
> @@ -286,7 +286,7 @@ static void kasan_free_pte(pte_t *pte_start, pmd_t *pmd)
>  
>  	for (i = 0; i < PTRS_PER_PTE; i++) {
>  		pte = pte_start + i;
> -		if (!pte_none(*pte))
> +		if (!pte_none(ptep_deref(pte)))
>  			return;
>  	}
>  
> @@ -343,16 +343,19 @@ static void kasan_remove_pte_table(pte_t *pte, unsigned long addr,
>  				unsigned long end)
>  {
>  	unsigned long next;
> +	pte_t ptent;
>  
>  	for (; addr < end; addr = next, pte++) {
>  		next = (addr + PAGE_SIZE) & PAGE_MASK;
>  		if (next > end)
>  			next = end;
>  
> -		if (!pte_present(*pte))
> +		ptent = ptep_deref(pte);
> +
> +		if (!pte_present(ptent))
>  			continue;
>  
> -		if (WARN_ON(!kasan_early_shadow_page_entry(*pte)))
> +		if (WARN_ON(!kasan_early_shadow_page_entry(ptent)))
>  			continue;
>  		pte_clear(&init_mm, addr, pte);
>  	}
> diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
> index c8b86f3273b5..b6121185be8f 100644
> --- a/mm/kasan/shadow.c
> +++ b/mm/kasan/shadow.c
> @@ -226,7 +226,7 @@ static bool shadow_mapped(unsigned long addr)
>  	if (pmd_bad(*pmd))
>  		return true;
>  	pte = pte_offset_kernel(pmd, addr);
> -	return !pte_none(*pte);
> +	return !pte_none(ptep_deref(pte));
>  }
>  
>  static int __meminit kasan_mem_notifier(struct notifier_block *nb,
> @@ -317,7 +317,7 @@ static int kasan_populate_vmalloc_pte(pte_t *ptep, unsigned long addr,
>  	unsigned long page;
>  	pte_t pte;
>  
> -	if (likely(!pte_none(*ptep)))
> +	if (likely(!pte_none(ptep_deref(ptep))))
>  		return 0;
>  
>  	page = __get_free_page(GFP_KERNEL);
> @@ -328,7 +328,7 @@ static int kasan_populate_vmalloc_pte(pte_t *ptep, unsigned long addr,
>  	pte = pfn_pte(PFN_DOWN(__pa(page)), PAGE_KERNEL);
>  
>  	spin_lock(&init_mm.page_table_lock);
> -	if (likely(pte_none(*ptep))) {
> +	if (likely(pte_none(ptep_deref(ptep)))) {
>  		set_pte_at(&init_mm, addr, ptep, pte);
>  		page = 0;
>  	}
> @@ -418,11 +418,11 @@ static int kasan_depopulate_vmalloc_pte(pte_t *ptep, unsigned long addr,
>  {
>  	unsigned long page;
>  
> -	page = (unsigned long)__va(pte_pfn(*ptep) << PAGE_SHIFT);
> +	page = (unsigned long)__va(pte_pfn(ptep_deref(ptep)) << PAGE_SHIFT);
>  
>  	spin_lock(&init_mm.page_table_lock);
>  
> -	if (likely(!pte_none(*ptep))) {
> +	if (likely(!pte_none(ptep_deref(ptep)))) {
>  		pte_clear(&init_mm, addr, ptep);
>  		free_page(page);
>  	}
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 6b9d39d65b73..f6c541de63d0 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -513,7 +513,7 @@ static void release_pte_pages(pte_t *pte, pte_t *_pte,
>  	struct folio *folio, *tmp;
>  
>  	while (--_pte >= pte) {
> -		pte_t pteval = *_pte;
> +		pte_t pteval = ptep_deref(_pte);
>  		unsigned long pfn;
>  
>  		if (pte_none(pteval))
> @@ -557,7 +557,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
>  
>  	for (_pte = pte; _pte < pte + HPAGE_PMD_NR;
>  	     _pte++, address += PAGE_SIZE) {
> -		pte_t pteval = *_pte;
> +		pte_t pteval = ptep_deref(_pte);
>  		if (pte_none(pteval) || (pte_present(pteval) &&
>  				is_zero_pfn(pte_pfn(pteval)))) {
>  			++none_or_zero;
> @@ -701,7 +701,7 @@ static void __collapse_huge_page_copy_succeeded(pte_t *pte,
>  
>  	for (_pte = pte; _pte < pte + HPAGE_PMD_NR;
>  	     _pte++, address += PAGE_SIZE) {
> -		pteval = *_pte;
> +		pteval = ptep_deref(_pte);
>  		if (pte_none(pteval) || is_zero_pfn(pte_pfn(pteval))) {
>  			add_mm_counter(vma->vm_mm, MM_ANONPAGES, 1);
>  			if (is_zero_pfn(pte_pfn(pteval))) {
> @@ -799,7 +799,7 @@ static int __collapse_huge_page_copy(pte_t *pte,
>  	 */
>  	for (_pte = pte, _address = address; _pte < pte + HPAGE_PMD_NR;
>  	     _pte++, page++, _address += PAGE_SIZE) {
> -		pteval = *_pte;
> +		pteval = ptep_deref(_pte);
>  		if (pte_none(pteval) || is_zero_pfn(pte_pfn(pteval))) {
>  			clear_user_highpage(page, _address);
>  			continue;
> @@ -1020,7 +1020,7 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm,
>  		};
>  
>  		vmf.pte = pte_offset_map(pmd, address);
> -		vmf.orig_pte = *vmf.pte;
> +		vmf.orig_pte = ptep_deref(vmf.pte);
>  		if (!is_swap_pte(vmf.orig_pte)) {
>  			pte_unmap(vmf.pte);
>  			continue;
> @@ -1260,7 +1260,7 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm,
>  	pte = pte_offset_map_lock(mm, pmd, address, &ptl);
>  	for (_address = address, _pte = pte; _pte < pte + HPAGE_PMD_NR;
>  	     _pte++, _address += PAGE_SIZE) {
> -		pte_t pteval = *_pte;
> +		pte_t pteval = ptep_deref(_pte);
>  		if (is_swap_pte(pteval)) {
>  			++unmapped;
>  			if (!cc->is_khugepaged ||
> @@ -1634,18 +1634,19 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
>  	for (i = 0, addr = haddr, pte = start_pte;
>  	     i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE, pte++) {
>  		struct page *page;
> +		pte_t ptent = ptep_deref(pte);
>  
>  		/* empty pte, skip */
> -		if (pte_none(*pte))
> +		if (pte_none(ptent))
>  			continue;
>  
>  		/* page swapped out, abort */
> -		if (!pte_present(*pte)) {
> +		if (!pte_present(ptent)) {
>  			result = SCAN_PTE_NON_PRESENT;
>  			goto abort;
>  		}
>  
> -		page = vm_normal_page(vma, addr, *pte);
> +		page = vm_normal_page(vma, addr, ptent);
>  		if (WARN_ON_ONCE(page && is_zone_device_page(page)))
>  			page = NULL;
>  		/*
> @@ -1661,10 +1662,11 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
>  	for (i = 0, addr = haddr, pte = start_pte;
>  	     i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE, pte++) {
>  		struct page *page;
> +		pte_t ptent = ptep_deref(pte);
>  
> -		if (pte_none(*pte))
> +		if (pte_none(ptent))
>  			continue;
> -		page = vm_normal_page(vma, addr, *pte);
> +		page = vm_normal_page(vma, addr, ptent);
>  		if (WARN_ON_ONCE(page && is_zone_device_page(page)))
>  			goto abort;
>  		page_remove_rmap(page, vma, false);
> diff --git a/mm/ksm.c b/mm/ksm.c
> index 0156bded3a66..449902e5b2f6 100644
> --- a/mm/ksm.c
> +++ b/mm/ksm.c
> @@ -429,16 +429,18 @@ static int break_ksm_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long nex
>  	struct page *page = NULL;
>  	spinlock_t *ptl;
>  	pte_t *pte;
> +	pte_t ptent;
>  	int ret;
>  
>  	if (pmd_leaf(*pmd) || !pmd_present(*pmd))
>  		return 0;
>  
>  	pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
> -	if (pte_present(*pte)) {
> -		page = vm_normal_page(walk->vma, addr, *pte);
> -	} else if (!pte_none(*pte)) {
> -		swp_entry_t entry = pte_to_swp_entry(*pte);
> +	ptent = ptep_deref(pte);
> +	if (pte_present(ptent)) {
> +		page = vm_normal_page(walk->vma, addr, ptent);
> +	} else if (!pte_none(ptent)) {
> +		swp_entry_t entry = pte_to_swp_entry(ptent);
>  
>  		/*
>  		 * As KSM pages remain KSM pages until freed, no need to wait
> @@ -1086,6 +1088,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
>  	int err = -EFAULT;
>  	struct mmu_notifier_range range;
>  	bool anon_exclusive;
> +	pte_t entry;
>  
>  	pvmw.address = page_address_in_vma(page, vma);
>  	if (pvmw.address == -EFAULT)
> @@ -1103,10 +1106,9 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
>  		goto out_unlock;
>  
>  	anon_exclusive = PageAnonExclusive(page);
> -	if (pte_write(*pvmw.pte) || pte_dirty(*pvmw.pte) ||
> +	entry = ptep_deref(pvmw.pte);
> +	if (pte_write(entry) || pte_dirty(entry) ||
>  	    anon_exclusive || mm_tlb_flush_pending(mm)) {
> -		pte_t entry;
> -
>  		swapped = PageSwapCache(page);
>  		flush_cache_page(vma, pvmw.address, page_to_pfn(page));
>  		/*
> @@ -1148,7 +1150,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
>  
>  		set_pte_at_notify(mm, pvmw.address, pvmw.pte, entry);
>  	}
> -	*orig_pte = *pvmw.pte;
> +	*orig_pte = entry;
>  	err = 0;
>  
>  out_unlock:
> @@ -1204,7 +1206,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
>  	mmu_notifier_invalidate_range_start(&range);
>  
>  	ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
> -	if (!pte_same(*ptep, orig_pte)) {
> +	if (!pte_same(ptep_deref(ptep), orig_pte)) {
>  		pte_unmap_unlock(ptep, ptl);
>  		goto out_mn;
>  	}
> @@ -1231,7 +1233,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
>  		dec_mm_counter(mm, MM_ANONPAGES);
>  	}
>  
> -	flush_cache_page(vma, addr, pte_pfn(*ptep));
> +	flush_cache_page(vma, addr, pte_pfn(ptep_deref(ptep)));
>  	/*
>  	 * No need to notify as we are replacing a read only page with another
>  	 * read only page with the same content.
> diff --git a/mm/madvise.c b/mm/madvise.c
> index b5ffbaf616f5..48dab7a309a5 100644
> --- a/mm/madvise.c
> +++ b/mm/madvise.c
> @@ -205,7 +205,7 @@ static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start,
>  		pte_t *ptep;
>  
>  		ptep = pte_offset_map_lock(vma->vm_mm, pmd, index, &ptl);
> -		pte = *ptep;
> +		pte = ptep_deref(ptep);
>  		pte_unmap_unlock(ptep, ptl);
>  
>  		if (!is_swap_pte(pte))
> @@ -430,7 +430,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd,
>  	flush_tlb_batched_pending(mm);
>  	arch_enter_lazy_mmu_mode();
>  	for (; addr < end; pte++, addr += PAGE_SIZE) {
> -		ptent = *pte;
> +		ptent = ptep_deref(pte);
>  
>  		if (pte_none(ptent))
>  			continue;
> @@ -630,7 +630,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
>  	flush_tlb_batched_pending(mm);
>  	arch_enter_lazy_mmu_mode();
>  	for (; addr != end; pte++, addr += PAGE_SIZE) {
> -		ptent = *pte;
> +		ptent = ptep_deref(pte);
>  
>  		if (pte_none(ptent))
>  			continue;
> diff --git a/mm/mapping_dirty_helpers.c b/mm/mapping_dirty_helpers.c
> index e1eb33f49059..f25b743b3322 100644
> --- a/mm/mapping_dirty_helpers.c
> +++ b/mm/mapping_dirty_helpers.c
> @@ -35,7 +35,7 @@ static int wp_pte(pte_t *pte, unsigned long addr, unsigned long end,
>  		  struct mm_walk *walk)
>  {
>  	struct wp_walk *wpwalk = walk->private;
> -	pte_t ptent = *pte;
> +	pte_t ptent = ptep_deref(pte);
>  
>  	if (pte_write(ptent)) {
>  		pte_t old_pte = ptep_modify_prot_start(walk->vma, addr, pte);
> @@ -91,7 +91,7 @@ static int clean_record_pte(pte_t *pte, unsigned long addr,
>  {
>  	struct wp_walk *wpwalk = walk->private;
>  	struct clean_walk *cwalk = to_clean_walk(wpwalk);
> -	pte_t ptent = *pte;
> +	pte_t ptent = ptep_deref(pte);
>  
>  	if (pte_dirty(ptent)) {
>  		pgoff_t pgoff = ((addr - walk->vma->vm_start) >> PAGE_SHIFT) +
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 4b27e245a055..dd7db86ad089 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -6061,7 +6061,7 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
>  		return 0;
>  	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
>  	for (; addr != end; pte++, addr += PAGE_SIZE)
> -		if (get_mctgt_type(vma, addr, *pte, NULL))
> +		if (get_mctgt_type(vma, addr, ptep_deref(pte), NULL))
>  			mc.precharge++;	/* increment precharge temporarily */
>  	pte_unmap_unlock(pte - 1, ptl);
>  	cond_resched();
> @@ -6282,7 +6282,7 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
>  retry:
>  	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
>  	for (; addr != end; addr += PAGE_SIZE) {
> -		pte_t ptent = *(pte++);
> +		pte_t ptent = ptep_deref(pte++);
>  		bool device = false;
>  		swp_entry_t ent;
>  
> diff --git a/mm/memory-failure.c b/mm/memory-failure.c
> index 5b663eca1f29..e81b6cfd5544 100644
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -395,6 +395,7 @@ static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma,
>  	pud_t *pud;
>  	pmd_t *pmd;
>  	pte_t *pte;
> +	pte_t ptent;
>  
>  	VM_BUG_ON_VMA(address == -EFAULT, vma);
>  	pgd = pgd_offset(vma->vm_mm, address);
> @@ -414,7 +415,8 @@ static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma,
>  	if (pmd_devmap(*pmd))
>  		return PMD_SHIFT;
>  	pte = pte_offset_map(pmd, address);
> -	if (pte_present(*pte) && pte_devmap(*pte))
> +	ptent = ptep_deref(pte);
> +	if (pte_present(ptent) && pte_devmap(ptent))
>  		ret = PAGE_SHIFT;
>  	pte_unmap(pte);
>  	return ret;
> @@ -806,7 +808,7 @@ static int hwpoison_pte_range(pmd_t *pmdp, unsigned long addr,
>  	mapped_pte = ptep = pte_offset_map_lock(walk->vma->vm_mm, pmdp,
>  						addr, &ptl);
>  	for (; addr != end; ptep++, addr += PAGE_SIZE) {
> -		ret = check_hwpoisoned_entry(*ptep, addr, PAGE_SHIFT,
> +		ret = check_hwpoisoned_entry(ptep_deref(ptep), addr, PAGE_SHIFT,
>  					     hwp->pfn, &hwp->tk);
>  		if (ret == 1)
>  			break;
> diff --git a/mm/memory.c b/mm/memory.c
> index ed429e20a1bb..e5334fb5615e 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -699,15 +699,17 @@ static void restore_exclusive_pte(struct vm_area_struct *vma,
>  				  struct page *page, unsigned long address,
>  				  pte_t *ptep)
>  {
> +	pte_t orig_pte;
>  	pte_t pte;
>  	swp_entry_t entry;
>  
> +	orig_pte = ptep_deref(ptep);
>  	pte = pte_mkold(mk_pte(page, READ_ONCE(vma->vm_page_prot)));
> -	if (pte_swp_soft_dirty(*ptep))
> +	if (pte_swp_soft_dirty(orig_pte))
>  		pte = pte_mksoft_dirty(pte);
>  
> -	entry = pte_to_swp_entry(*ptep);
> -	if (pte_swp_uffd_wp(*ptep))
> +	entry = pte_to_swp_entry(orig_pte);
> +	if (pte_swp_uffd_wp(orig_pte))
>  		pte = pte_mkuffd_wp(pte);
>  	else if (is_writable_device_exclusive_entry(entry))
>  		pte = maybe_mkwrite(pte_mkdirty(pte), vma);
> @@ -744,7 +746,7 @@ static int
>  try_restore_exclusive_pte(pte_t *src_pte, struct vm_area_struct *vma,
>  			unsigned long addr)
>  {
> -	swp_entry_t entry = pte_to_swp_entry(*src_pte);
> +	swp_entry_t entry = pte_to_swp_entry(ptep_deref(src_pte));
>  	struct page *page = pfn_swap_entry_to_page(entry);
>  
>  	if (trylock_page(page)) {
> @@ -768,9 +770,10 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
>  		struct vm_area_struct *src_vma, unsigned long addr, int *rss)
>  {
>  	unsigned long vm_flags = dst_vma->vm_flags;
> -	pte_t pte = *src_pte;
> +	pte_t orig_pte = ptep_deref(src_pte);
> +	pte_t pte = orig_pte;
>  	struct page *page;
> -	swp_entry_t entry = pte_to_swp_entry(pte);
> +	swp_entry_t entry = pte_to_swp_entry(orig_pte);
>  
>  	if (likely(!non_swap_entry(entry))) {
>  		if (swap_duplicate(entry) < 0)
> @@ -785,8 +788,8 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
>  			spin_unlock(&mmlist_lock);
>  		}
>  		/* Mark the swap entry as shared. */
> -		if (pte_swp_exclusive(*src_pte)) {
> -			pte = pte_swp_clear_exclusive(*src_pte);
> +		if (pte_swp_exclusive(orig_pte)) {
> +			pte = pte_swp_clear_exclusive(orig_pte);
>  			set_pte_at(src_mm, addr, src_pte, pte);
>  		}
>  		rss[MM_SWAPENTS]++;
> @@ -805,9 +808,9 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
>  			entry = make_readable_migration_entry(
>  							swp_offset(entry));
>  			pte = swp_entry_to_pte(entry);
> -			if (pte_swp_soft_dirty(*src_pte))
> +			if (pte_swp_soft_dirty(orig_pte))
>  				pte = pte_swp_mksoft_dirty(pte);
> -			if (pte_swp_uffd_wp(*src_pte))
> +			if (pte_swp_uffd_wp(orig_pte))
>  				pte = pte_swp_mkuffd_wp(pte);
>  			set_pte_at(src_mm, addr, src_pte, pte);
>  		}
> @@ -840,7 +843,7 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
>  			entry = make_readable_device_private_entry(
>  							swp_offset(entry));
>  			pte = swp_entry_to_pte(entry);
> -			if (pte_swp_uffd_wp(*src_pte))
> +			if (pte_swp_uffd_wp(orig_pte))
>  				pte = pte_swp_mkuffd_wp(pte);
>  			set_pte_at(src_mm, addr, src_pte, pte);
>  		}
> @@ -904,7 +907,7 @@ copy_present_page(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma
>  	/* All done, just insert the new page copy in the child */
>  	pte = mk_pte(&new_folio->page, dst_vma->vm_page_prot);
>  	pte = maybe_mkwrite(pte_mkdirty(pte), dst_vma);
> -	if (userfaultfd_pte_wp(dst_vma, *src_pte))
> +	if (userfaultfd_pte_wp(dst_vma, ptep_deref(src_pte)))
>  		/* Uffd-wp needs to be delivered to dest pte as well */
>  		pte = pte_mkuffd_wp(pte);
>  	set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte);
> @@ -922,7 +925,7 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
>  {
>  	struct mm_struct *src_mm = src_vma->vm_mm;
>  	unsigned long vm_flags = src_vma->vm_flags;
> -	pte_t pte = *src_pte;
> +	pte_t pte = ptep_deref(src_pte);
>  	struct page *page;
>  	struct folio *folio;
>  
> @@ -1002,6 +1005,7 @@ copy_pte_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
>  	struct mm_struct *src_mm = src_vma->vm_mm;
>  	pte_t *orig_src_pte, *orig_dst_pte;
>  	pte_t *src_pte, *dst_pte;
> +	pte_t ptent;
>  	spinlock_t *src_ptl, *dst_ptl;
>  	int progress, ret = 0;
>  	int rss[NR_MM_COUNTERS];
> @@ -1035,17 +1039,18 @@ copy_pte_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma,
>  			    spin_needbreak(src_ptl) || spin_needbreak(dst_ptl))
>  				break;
>  		}
> -		if (pte_none(*src_pte)) {
> +		ptent = ptep_deref(src_pte);
> +		if (pte_none(ptent)) {
>  			progress++;
>  			continue;
>  		}
> -		if (unlikely(!pte_present(*src_pte))) {
> +		if (unlikely(!pte_present(ptent))) {
>  			ret = copy_nonpresent_pte(dst_mm, src_mm,
>  						  dst_pte, src_pte,
>  						  dst_vma, src_vma,
>  						  addr, rss);
>  			if (ret == -EIO) {
> -				entry = pte_to_swp_entry(*src_pte);
> +				entry = pte_to_swp_entry(ptep_deref(src_pte));
>  				break;
>  			} else if (ret == -EBUSY) {
>  				break;
> @@ -1395,7 +1400,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
>  	flush_tlb_batched_pending(mm);
>  	arch_enter_lazy_mmu_mode();
>  	do {
> -		pte_t ptent = *pte;
> +		pte_t ptent = ptep_deref(pte);
>  		struct page *page;
>  
>  		if (pte_none(ptent))
> @@ -1821,7 +1826,7 @@ static int validate_page_before_insert(struct page *page)
>  static int insert_page_into_pte_locked(struct vm_area_struct *vma, pte_t *pte,
>  			unsigned long addr, struct page *page, pgprot_t prot)
>  {
> -	if (!pte_none(*pte))
> +	if (!pte_none(ptep_deref(pte)))
>  		return -EBUSY;
>  	/* Ok, finally just insert the thing.. */
>  	get_page(page);
> @@ -2111,7 +2116,8 @@ static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
>  	pte = get_locked_pte(mm, addr, &ptl);
>  	if (!pte)
>  		return VM_FAULT_OOM;
> -	if (!pte_none(*pte)) {
> +	entry = ptep_deref(pte);
> +	if (!pte_none(entry)) {
>  		if (mkwrite) {
>  			/*
>  			 * For read faults on private mappings the PFN passed
> @@ -2123,11 +2129,11 @@ static vm_fault_t insert_pfn(struct vm_area_struct *vma, unsigned long addr,
>  			 * allocation and mapping invalidation so just skip the
>  			 * update.
>  			 */
> -			if (pte_pfn(*pte) != pfn_t_to_pfn(pfn)) {
> -				WARN_ON_ONCE(!is_zero_pfn(pte_pfn(*pte)));
> +			if (pte_pfn(entry) != pfn_t_to_pfn(pfn)) {
> +				WARN_ON_ONCE(!is_zero_pfn(pte_pfn(entry)));
>  				goto out_unlock;
>  			}
> -			entry = pte_mkyoung(*pte);
> +			entry = pte_mkyoung(entry);
>  			entry = maybe_mkwrite(pte_mkdirty(entry), vma);
>  			if (ptep_set_access_flags(vma, addr, pte, entry, 1))
>  				update_mmu_cache(vma, addr, pte);
> @@ -2339,7 +2345,7 @@ static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd,
>  		return -ENOMEM;
>  	arch_enter_lazy_mmu_mode();
>  	do {
> -		BUG_ON(!pte_none(*pte));
> +		BUG_ON(!pte_none(ptep_deref(pte)));
>  		if (!pfn_modify_allowed(pfn, prot)) {
>  			err = -EACCES;
>  			break;
> @@ -2580,7 +2586,7 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
>  
>  	if (fn) {
>  		do {
> -			if (create || !pte_none(*pte)) {
> +			if (create || !pte_none(ptep_deref(pte))) {
>  				err = fn(pte++, addr, data);
>  				if (err)
>  					break;
> @@ -2783,7 +2789,7 @@ static inline int pte_unmap_same(struct vm_fault *vmf)
>  	if (sizeof(pte_t) > sizeof(unsigned long)) {
>  		spinlock_t *ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd);
>  		spin_lock(ptl);
> -		same = pte_same(*vmf->pte, vmf->orig_pte);
> +		same = pte_same(ptep_deref(vmf->pte), vmf->orig_pte);
>  		spin_unlock(ptl);
>  	}
>  #endif
> @@ -2835,7 +2841,7 @@ static inline int __wp_page_copy_user(struct page *dst, struct page *src,
>  
>  		vmf->pte = pte_offset_map_lock(mm, vmf->pmd, addr, &vmf->ptl);
>  		locked = true;
> -		if (!likely(pte_same(*vmf->pte, vmf->orig_pte))) {
> +		if (!likely(pte_same(ptep_deref(vmf->pte), vmf->orig_pte))) {
>  			/*
>  			 * Other thread has already handled the fault
>  			 * and update local tlb only
> @@ -2863,7 +2869,7 @@ static inline int __wp_page_copy_user(struct page *dst, struct page *src,
>  		/* Re-validate under PTL if the page is still mapped */
>  		vmf->pte = pte_offset_map_lock(mm, vmf->pmd, addr, &vmf->ptl);
>  		locked = true;
> -		if (!likely(pte_same(*vmf->pte, vmf->orig_pte))) {
> +		if (!likely(pte_same(ptep_deref(vmf->pte), vmf->orig_pte))) {
>  			/* The PTE changed under us, update local tlb */
>  			update_mmu_tlb(vma, addr, vmf->pte);
>  			ret = -EAGAIN;
> @@ -3234,7 +3240,7 @@ vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf)
>  	 * We might have raced with another page fault while we released the
>  	 * pte_offset_map_lock.
>  	 */
> -	if (!pte_same(*vmf->pte, vmf->orig_pte)) {
> +	if (!pte_same(ptep_deref(vmf->pte), vmf->orig_pte)) {
>  		update_mmu_tlb(vmf->vma, vmf->address, vmf->pte);
>  		pte_unmap_unlock(vmf->pte, vmf->ptl);
>  		return VM_FAULT_NOPAGE;
> @@ -3329,7 +3335,7 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf)
>  	struct folio *folio = NULL;
>  
>  	if (likely(!unshare)) {
> -		if (userfaultfd_pte_wp(vma, *vmf->pte)) {
> +		if (userfaultfd_pte_wp(vma, ptep_deref(vmf->pte))) {
>  			pte_unmap_unlock(vmf->pte, vmf->ptl);
>  			return handle_userfault(vmf, VM_UFFD_WP);
>  		}
> @@ -3591,7 +3597,7 @@ static vm_fault_t remove_device_exclusive_entry(struct vm_fault *vmf)
>  
>  	vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,
>  				&vmf->ptl);
> -	if (likely(pte_same(*vmf->pte, vmf->orig_pte)))
> +	if (likely(pte_same(ptep_deref(vmf->pte), vmf->orig_pte)))
>  		restore_exclusive_pte(vma, vmf->page, vmf->address, vmf->pte);
>  
>  	pte_unmap_unlock(vmf->pte, vmf->ptl);
> @@ -3633,7 +3639,7 @@ static vm_fault_t pte_marker_clear(struct vm_fault *vmf)
>  	 * quickly from a PTE_MARKER_UFFD_WP into PTE_MARKER_SWAPIN_ERROR.
>  	 * So is_pte_marker() check is not enough to safely drop the pte.
>  	 */
> -	if (pte_same(vmf->orig_pte, *vmf->pte))
> +	if (pte_same(vmf->orig_pte, ptep_deref(vmf->pte)))
>  		pte_clear(vmf->vma->vm_mm, vmf->address, vmf->pte);
>  	pte_unmap_unlock(vmf->pte, vmf->ptl);
>  	return 0;
> @@ -3728,7 +3734,8 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
>  			vmf->page = pfn_swap_entry_to_page(entry);
>  			vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,
>  					vmf->address, &vmf->ptl);
> -			if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte)))
> +			if (unlikely(!pte_same(ptep_deref(vmf->pte),
> +							vmf->orig_pte)))
>  				goto unlock;
>  
>  			/*
> @@ -3805,7 +3812,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
>  			 */
>  			vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd,
>  					vmf->address, &vmf->ptl);
> -			if (likely(pte_same(*vmf->pte, vmf->orig_pte)))
> +			if (likely(pte_same(ptep_deref(vmf->pte), vmf->orig_pte)))
>  				ret = VM_FAULT_OOM;
>  			goto unlock;
>  		}
> @@ -3875,7 +3882,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
>  	 */
>  	vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address,
>  			&vmf->ptl);
> -	if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte)))
> +	if (unlikely(!pte_same(ptep_deref(vmf->pte), vmf->orig_pte)))
>  		goto out_nomap;
>  
>  	if (unlikely(!folio_test_uptodate(folio))) {
> @@ -4323,9 +4330,9 @@ void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
>  static bool vmf_pte_changed(struct vm_fault *vmf)
>  {
>  	if (vmf->flags & FAULT_FLAG_ORIG_PTE_VALID)
> -		return !pte_same(*vmf->pte, vmf->orig_pte);
> +		return !pte_same(ptep_deref(vmf->pte), vmf->orig_pte);
>  
> -	return !pte_none(*vmf->pte);
> +	return !pte_none(ptep_deref(vmf->pte));
>  }
>  
>  /**
> @@ -4646,7 +4653,7 @@ static vm_fault_t do_fault(struct vm_fault *vmf)
>  			 * we don't have concurrent modification by hardware
>  			 * followed by an update.
>  			 */
> -			if (unlikely(pte_none(*vmf->pte)))
> +			if (unlikely(pte_none(ptep_deref(vmf->pte))))
>  				ret = VM_FAULT_SIGBUS;
>  			else
>  				ret = VM_FAULT_NOPAGE;
> @@ -4703,7 +4710,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
>  	 */
>  	vmf->ptl = pte_lockptr(vma->vm_mm, vmf->pmd);
>  	spin_lock(vmf->ptl);
> -	if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) {
> +	if (unlikely(!pte_same(ptep_deref(vmf->pte), vmf->orig_pte))) {
>  		pte_unmap_unlock(vmf->pte, vmf->ptl);
>  		goto out;
>  	}
> @@ -4774,7 +4781,7 @@ static vm_fault_t do_numa_page(struct vm_fault *vmf)
>  		flags |= TNF_MIGRATE_FAIL;
>  		vmf->pte = pte_offset_map(vmf->pmd, vmf->address);
>  		spin_lock(vmf->ptl);
> -		if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) {
> +		if (unlikely(!pte_same(ptep_deref(vmf->pte), vmf->orig_pte))) {
>  			pte_unmap_unlock(vmf->pte, vmf->ptl);
>  			goto out;
>  		}
> @@ -4923,7 +4930,7 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
>  		 * So now it's safe to run pte_offset_map().
>  		 */
>  		vmf->pte = pte_offset_map(vmf->pmd, vmf->address);
> -		vmf->orig_pte = *vmf->pte;
> +		vmf->orig_pte = ptep_deref(vmf->pte);
>  		vmf->flags |= FAULT_FLAG_ORIG_PTE_VALID;
>  
>  		/*
> @@ -4953,7 +4960,7 @@ static vm_fault_t handle_pte_fault(struct vm_fault *vmf)
>  	vmf->ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd);
>  	spin_lock(vmf->ptl);
>  	entry = vmf->orig_pte;
> -	if (unlikely(!pte_same(*vmf->pte, entry))) {
> +	if (unlikely(!pte_same(ptep_deref(vmf->pte), entry))) {
>  		update_mmu_tlb(vmf->vma, vmf->address, vmf->pte);
>  		goto unlock;
>  	}
> @@ -5441,7 +5448,7 @@ int follow_pte(struct mm_struct *mm, unsigned long address,
>  		goto out;
>  
>  	ptep = pte_offset_map_lock(mm, pmd, address, ptlp);
> -	if (!pte_present(*ptep))
> +	if (!pte_present(ptep_deref(ptep)))
>  		goto unlock;
>  	*ptepp = ptep;
>  	return 0;
> @@ -5478,7 +5485,7 @@ int follow_pfn(struct vm_area_struct *vma, unsigned long address,
>  	ret = follow_pte(vma->vm_mm, address, &ptep, &ptl);
>  	if (ret)
>  		return ret;
> -	*pfn = pte_pfn(*ptep);
> +	*pfn = pte_pfn(ptep_deref(ptep));
>  	pte_unmap_unlock(ptep, ptl);
>  	return 0;
>  }
> @@ -5498,7 +5505,7 @@ int follow_phys(struct vm_area_struct *vma,
>  
>  	if (follow_pte(vma->vm_mm, address, &ptep, &ptl))
>  		goto out;
> -	pte = *ptep;
> +	pte = ptep_deref(ptep);
>  
>  	if ((flags & FOLL_WRITE) && !pte_write(pte))
>  		goto unlock;
> @@ -5542,7 +5549,7 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
>  retry:
>  	if (follow_pte(vma->vm_mm, addr, &ptep, &ptl))
>  		return -EINVAL;
> -	pte = *ptep;
> +	pte = ptep_deref(ptep);
>  	pte_unmap_unlock(ptep, ptl);
>  
>  	prot = pgprot_val(pte_pgprot(pte));
> @@ -5558,7 +5565,7 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
>  	if (follow_pte(vma->vm_mm, addr, &ptep, &ptl))
>  		goto out_unmap;
>  
> -	if (!pte_same(pte, *ptep)) {
> +	if (!pte_same(pte, ptep_deref(ptep))) {
>  		pte_unmap_unlock(ptep, ptl);
>  		iounmap(maddr);
>  
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 1756389a0609..45faf3a574da 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -508,6 +508,7 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
>  	unsigned long flags = qp->flags;
>  	bool has_unmovable = false;
>  	pte_t *pte, *mapped_pte;
> +	pte_t ptent;
>  	spinlock_t *ptl;
>  
>  	ptl = pmd_trans_huge_lock(pmd, vma);
> @@ -519,9 +520,10 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
>  
>  	mapped_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
>  	for (; addr != end; pte++, addr += PAGE_SIZE) {
> -		if (!pte_present(*pte))
> +		ptent = ptep_deref(pte);
> +		if (!pte_present(ptent))
>  			continue;
> -		folio = vm_normal_folio(vma, addr, *pte);
> +		folio = vm_normal_folio(vma, addr, ptent);
>  		if (!folio || folio_is_zone_device(folio))
>  			continue;
>  		/*
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 01cac26a3127..6cdcf5fc7980 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -188,6 +188,7 @@ static bool remove_migration_pte(struct folio *folio,
>  
>  	while (page_vma_mapped_walk(&pvmw)) {
>  		rmap_t rmap_flags = RMAP_NONE;
> +		pte_t old_pte;
>  		pte_t pte;
>  		swp_entry_t entry;
>  		struct page *new;
> @@ -210,17 +211,18 @@ static bool remove_migration_pte(struct folio *folio,
>  
>  		folio_get(folio);
>  		pte = mk_pte(new, READ_ONCE(vma->vm_page_prot));
> -		if (pte_swp_soft_dirty(*pvmw.pte))
> +		old_pte = ptep_deref(pvmw.pte);
> +		if (pte_swp_soft_dirty(old_pte))
>  			pte = pte_mksoft_dirty(pte);
>  
> -		entry = pte_to_swp_entry(*pvmw.pte);
> +		entry = pte_to_swp_entry(old_pte);
>  		if (!is_migration_entry_young(entry))
>  			pte = pte_mkold(pte);
>  		if (folio_test_dirty(folio) && is_migration_entry_dirty(entry))
>  			pte = pte_mkdirty(pte);
>  		if (is_writable_migration_entry(entry))
>  			pte = pte_mkwrite(pte);
> -		else if (pte_swp_uffd_wp(*pvmw.pte))
> +		else if (pte_swp_uffd_wp(old_pte))
>  			pte = pte_mkuffd_wp(pte);
>  
>  		if (folio_test_anon(folio) && !is_readable_migration_entry(entry))
> @@ -234,9 +236,9 @@ static bool remove_migration_pte(struct folio *folio,
>  				entry = make_readable_device_private_entry(
>  							page_to_pfn(new));
>  			pte = swp_entry_to_pte(entry);
> -			if (pte_swp_soft_dirty(*pvmw.pte))
> +			if (pte_swp_soft_dirty(old_pte))
>  				pte = pte_swp_mksoft_dirty(pte);
> -			if (pte_swp_uffd_wp(*pvmw.pte))
> +			if (pte_swp_uffd_wp(old_pte))
>  				pte = pte_swp_mkuffd_wp(pte);
>  		}
>  
> @@ -303,7 +305,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
>  	swp_entry_t entry;
>  
>  	spin_lock(ptl);
> -	pte = *ptep;
> +	pte = ptep_deref(ptep);
>  	if (!is_swap_pte(pte))
>  		goto out;
>  
> diff --git a/mm/migrate_device.c b/mm/migrate_device.c
> index d30c9de60b0d..b5e2e73ec0ad 100644
> --- a/mm/migrate_device.c
> +++ b/mm/migrate_device.c
> @@ -118,7 +118,7 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
>  		swp_entry_t entry;
>  		pte_t pte;
>  
> -		pte = *ptep;
> +		pte = ptep_deref(ptep);
>  
>  		if (pte_none(pte)) {
>  			if (vma_is_anonymous(vma)) {
> @@ -201,7 +201,7 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp,
>  			bool anon_exclusive;
>  			pte_t swp_pte;
>  
> -			flush_cache_page(vma, addr, pte_pfn(*ptep));
> +			flush_cache_page(vma, addr, pte_pfn(pte));
>  			anon_exclusive = PageAnon(page) && PageAnonExclusive(page);
>  			if (anon_exclusive) {
>  				pte = ptep_clear_flush(vma, addr, ptep);
> @@ -580,6 +580,7 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
>  	pud_t *pudp;
>  	pmd_t *pmdp;
>  	pte_t *ptep;
> +	pte_t orig_pte;
>  
>  	/* Only allow populating anonymous memory */
>  	if (!vma_is_anonymous(vma))
> @@ -650,17 +651,18 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
>  	}
>  
>  	ptep = pte_offset_map_lock(mm, pmdp, addr, &ptl);
> +	orig_pte = ptep_deref(ptep);
>  
>  	if (check_stable_address_space(mm))
>  		goto unlock_abort;
>  
> -	if (pte_present(*ptep)) {
> -		unsigned long pfn = pte_pfn(*ptep);
> +	if (pte_present(orig_pte)) {
> +		unsigned long pfn = pte_pfn(orig_pte);
>  
>  		if (!is_zero_pfn(pfn))
>  			goto unlock_abort;
>  		flush = true;
> -	} else if (!pte_none(*ptep))
> +	} else if (!pte_none(orig_pte))
>  		goto unlock_abort;
>  
>  	/*
> @@ -677,7 +679,7 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
>  	get_page(page);
>  
>  	if (flush) {
> -		flush_cache_page(vma, addr, pte_pfn(*ptep));
> +		flush_cache_page(vma, addr, pte_pfn(orig_pte));
>  		ptep_clear_flush_notify(vma, addr, ptep);
>  		set_pte_at_notify(mm, addr, ptep, entry);
>  		update_mmu_cache(vma, addr, ptep);
> diff --git a/mm/mincore.c b/mm/mincore.c
> index 2d5be013a25a..29ae8681918e 100644
> --- a/mm/mincore.c
> +++ b/mm/mincore.c
> @@ -120,7 +120,7 @@ static int mincore_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
>  
>  	ptep = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
>  	for (; addr != end; ptep++, addr += PAGE_SIZE) {
> -		pte_t pte = *ptep;
> +		pte_t pte = ptep_deref(ptep);
>  
>  		/* We need to do cache lookup too for pte markers */
>  		if (pte_none_mostly(pte))
> diff --git a/mm/mlock.c b/mm/mlock.c
> index 40b43f8740df..f2b73a9f14e8 100644
> --- a/mm/mlock.c
> +++ b/mm/mlock.c
> @@ -312,6 +312,7 @@ static int mlock_pte_range(pmd_t *pmd, unsigned long addr,
>  	struct vm_area_struct *vma = walk->vma;
>  	spinlock_t *ptl;
>  	pte_t *start_pte, *pte;
> +	pte_t ptent;
>  	struct folio *folio;
>  
>  	ptl = pmd_trans_huge_lock(pmd, vma);
> @@ -330,9 +331,10 @@ static int mlock_pte_range(pmd_t *pmd, unsigned long addr,
>  
>  	start_pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
>  	for (pte = start_pte; addr != end; pte++, addr += PAGE_SIZE) {
> -		if (!pte_present(*pte))
> +		ptent = ptep_deref(pte);
> +		if (!pte_present(ptent))
>  			continue;
> -		folio = vm_normal_folio(vma, addr, *pte);
> +		folio = vm_normal_folio(vma, addr, ptent);
>  		if (!folio || folio_is_zone_device(folio))
>  			continue;
>  		if (folio_test_large(folio))
> diff --git a/mm/mprotect.c b/mm/mprotect.c
> index 92d3d3ca390a..0cce93f3a82b 100644
> --- a/mm/mprotect.c
> +++ b/mm/mprotect.c
> @@ -118,7 +118,7 @@ static long change_pte_range(struct mmu_gather *tlb,
>  	flush_tlb_batched_pending(vma->vm_mm);
>  	arch_enter_lazy_mmu_mode();
>  	do {
> -		oldpte = *pte;
> +		oldpte = ptep_deref(pte);
>  		if (pte_present(oldpte)) {
>  			pte_t ptent;
>  
> @@ -589,7 +589,8 @@ long change_protection(struct mmu_gather *tlb,
>  static int prot_none_pte_entry(pte_t *pte, unsigned long addr,
>  			       unsigned long next, struct mm_walk *walk)
>  {
> -	return pfn_modify_allowed(pte_pfn(*pte), *(pgprot_t *)(walk->private)) ?
> +	return pfn_modify_allowed(pte_pfn(ptep_deref(pte)),
> +				  *(pgprot_t *)(walk->private)) ?
>  		0 : -EACCES;
>  }
>  
> @@ -597,7 +598,8 @@ static int prot_none_hugetlb_entry(pte_t *pte, unsigned long hmask,
>  				   unsigned long addr, unsigned long next,
>  				   struct mm_walk *walk)
>  {
> -	return pfn_modify_allowed(pte_pfn(*pte), *(pgprot_t *)(walk->private)) ?
> +	return pfn_modify_allowed(pte_pfn(ptep_deref(pte)),
> +				  *(pgprot_t *)(walk->private)) ?
>  		0 : -EACCES;
>  }
>  
> diff --git a/mm/mremap.c b/mm/mremap.c
> index b11ce6c92099..0b9d7b88da53 100644
> --- a/mm/mremap.c
> +++ b/mm/mremap.c
> @@ -179,7 +179,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
>  
>  	for (; old_addr < old_end; old_pte++, old_addr += PAGE_SIZE,
>  				   new_pte++, new_addr += PAGE_SIZE) {
> -		if (pte_none(*old_pte))
> +		if (pte_none(ptep_deref(old_pte)))
>  			continue;
>  
>  		pte = ptep_get_and_clear(mm, old_addr, old_pte);
> diff --git a/mm/page_table_check.c b/mm/page_table_check.c
> index 25d8610c0042..33b601581e5b 100644
> --- a/mm/page_table_check.c
> +++ b/mm/page_table_check.c
> @@ -190,7 +190,7 @@ void __page_table_check_pte_set(struct mm_struct *mm, unsigned long addr,
>  	if (&init_mm == mm)
>  		return;
>  
> -	__page_table_check_pte_clear(mm, addr, *ptep);
> +	__page_table_check_pte_clear(mm, addr, ptep_deref(ptep));
>  	if (pte_user_accessible_page(pte)) {
>  		page_table_check_set(mm, addr, pte_pfn(pte),
>  				     PAGE_SIZE >> PAGE_SHIFT,
> @@ -241,7 +241,7 @@ void __page_table_check_pte_clear_range(struct mm_struct *mm,
>  		unsigned long i;
>  
>  		for (i = 0; i < PTRS_PER_PTE; i++) {
> -			__page_table_check_pte_clear(mm, addr, *ptep);
> +			__page_table_check_pte_clear(mm, addr, ptep_deref(ptep));
>  			addr += PAGE_SIZE;
>  			ptep++;
>  		}
> diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
> index 4e448cfbc6ef..df791c39a588 100644
> --- a/mm/page_vma_mapped.c
> +++ b/mm/page_vma_mapped.c
> @@ -15,10 +15,13 @@ static inline bool not_found(struct page_vma_mapped_walk *pvmw)
>  
>  static bool map_pte(struct page_vma_mapped_walk *pvmw)
>  {
> +	pte_t ptent;
> +
>  	pvmw->pte = pte_offset_map(pvmw->pmd, pvmw->address);
>  	if (!(pvmw->flags & PVMW_SYNC)) {
> +		ptent = ptep_deref(pvmw->pte);
>  		if (pvmw->flags & PVMW_MIGRATION) {
> -			if (!is_swap_pte(*pvmw->pte))
> +			if (!is_swap_pte(ptent))
>  				return false;
>  		} else {
>  			/*
> @@ -36,15 +39,15 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw)
>  			 * For more details on device private memory see HMM
>  			 * (include/linux/hmm.h or mm/hmm.c).
>  			 */
> -			if (is_swap_pte(*pvmw->pte)) {
> +			if (is_swap_pte(ptent)) {
>  				swp_entry_t entry;
>  
>  				/* Handle un-addressable ZONE_DEVICE memory */
> -				entry = pte_to_swp_entry(*pvmw->pte);
> +				entry = pte_to_swp_entry(ptent);
>  				if (!is_device_private_entry(entry) &&
>  				    !is_device_exclusive_entry(entry))
>  					return false;
> -			} else if (!pte_present(*pvmw->pte))
> +			} else if (!pte_present(ptent))
>  				return false;
>  		}
>  	}
> @@ -75,33 +78,34 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw)
>  static bool check_pte(struct page_vma_mapped_walk *pvmw)
>  {
>  	unsigned long pfn;
> +	pte_t ptent = ptep_deref(pvmw->pte);
>  
>  	if (pvmw->flags & PVMW_MIGRATION) {
>  		swp_entry_t entry;
> -		if (!is_swap_pte(*pvmw->pte))
> +		if (!is_swap_pte(ptent))
>  			return false;
> -		entry = pte_to_swp_entry(*pvmw->pte);
> +		entry = pte_to_swp_entry(ptent);
>  
>  		if (!is_migration_entry(entry) &&
>  		    !is_device_exclusive_entry(entry))
>  			return false;
>  
>  		pfn = swp_offset_pfn(entry);
> -	} else if (is_swap_pte(*pvmw->pte)) {
> +	} else if (is_swap_pte(ptent)) {
>  		swp_entry_t entry;
>  
>  		/* Handle un-addressable ZONE_DEVICE memory */
> -		entry = pte_to_swp_entry(*pvmw->pte);
> +		entry = pte_to_swp_entry(ptent);
>  		if (!is_device_private_entry(entry) &&
>  		    !is_device_exclusive_entry(entry))
>  			return false;
>  
>  		pfn = swp_offset_pfn(entry);
>  	} else {
> -		if (!pte_present(*pvmw->pte))
> +		if (!pte_present(ptent))
>  			return false;
>  
> -		pfn = pte_pfn(*pvmw->pte);
> +		pfn = pte_pfn(ptent);
>  	}
>  
>  	return (pfn - pvmw->pfn) < pvmw->nr_pages;
> @@ -279,7 +283,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
>  				pvmw->ptl = pte_lockptr(mm, pvmw->pmd);
>  				spin_lock(pvmw->ptl);
>  			}
> -		} while (pte_none(*pvmw->pte));
> +		} while (pte_none(ptep_deref(pvmw->pte)));
>  
>  		if (!pvmw->ptl) {
>  			pvmw->ptl = pte_lockptr(mm, pvmw->pmd);
> diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
> index d2fc52bffafc..59a426444be0 100644
> --- a/mm/pgtable-generic.c
> +++ b/mm/pgtable-generic.c
> @@ -66,7 +66,7 @@ int ptep_set_access_flags(struct vm_area_struct *vma,
>  			  unsigned long address, pte_t *ptep,
>  			  pte_t entry, int dirty)
>  {
> -	int changed = !pte_same(*ptep, entry);
> +	int changed = !pte_same(ptep_deref(ptep), entry);
>  	if (changed) {
>  		set_pte_at(vma->vm_mm, address, ptep, entry);
>  		flush_tlb_fix_spurious_fault(vma, address, ptep);
> diff --git a/mm/rmap.c b/mm/rmap.c
> index 19392e090bec..403a8310d34a 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -826,7 +826,8 @@ static bool folio_referenced_one(struct folio *folio,
>  		}
>  
>  		if (pvmw.pte) {
> -			if (lru_gen_enabled() && pte_young(*pvmw.pte)) {
> +			if (lru_gen_enabled() &&
> +			    pte_young(ptep_deref(pvmw.pte))) {
>  				lru_gen_look_around(&pvmw);
>  				referenced++;
>  			}
> @@ -956,13 +957,13 @@ static int page_vma_mkclean_one(struct page_vma_mapped_walk *pvmw)
>  
>  		address = pvmw->address;
>  		if (pvmw->pte) {
> -			pte_t entry;
>  			pte_t *pte = pvmw->pte;
> +			pte_t entry = ptep_deref(pte);
>  
> -			if (!pte_dirty(*pte) && !pte_write(*pte))
> +			if (!pte_dirty(entry) && !pte_write(entry))
>  				continue;
>  
> -			flush_cache_page(vma, address, pte_pfn(*pte));
> +			flush_cache_page(vma, address, pte_pfn(entry));
>  			entry = ptep_clear_flush(vma, address, pte);
>  			entry = pte_wrprotect(entry);
>  			entry = pte_mkclean(entry);
> @@ -1458,6 +1459,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
>  	bool anon_exclusive, ret = true;
>  	struct mmu_notifier_range range;
>  	enum ttu_flags flags = (enum ttu_flags)(long)arg;
> +	unsigned long pfn;
>  
>  	/*
>  	 * When racing against e.g. zap_pte_range() on another cpu,
> @@ -1508,8 +1510,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
>  			break;
>  		}
>  
> -		subpage = folio_page(folio,
> -					pte_pfn(*pvmw.pte) - folio_pfn(folio));
> +		pfn = pte_pfn(ptep_deref(pvmw.pte));
> +		subpage = folio_page(folio, pfn - folio_pfn(folio));
>  		address = pvmw.address;
>  		anon_exclusive = folio_test_anon(folio) &&
>  				 PageAnonExclusive(subpage);
> @@ -1571,7 +1573,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
>  			}
>  			pteval = huge_ptep_clear_flush(vma, address, pvmw.pte);
>  		} else {
> -			flush_cache_page(vma, address, pte_pfn(*pvmw.pte));
> +			flush_cache_page(vma, address, pfn);
>  			/* Nuke the page table entry. */
>  			if (should_defer_flush(mm, flags)) {
>  				/*
> @@ -1818,6 +1820,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
>  	bool anon_exclusive, ret = true;
>  	struct mmu_notifier_range range;
>  	enum ttu_flags flags = (enum ttu_flags)(long)arg;
> +	unsigned long pfn;
>  
>  	/*
>  	 * When racing against e.g. zap_pte_range() on another cpu,
> @@ -1877,6 +1880,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
>  		/* Unexpected PMD-mapped THP? */
>  		VM_BUG_ON_FOLIO(!pvmw.pte, folio);
>  
> +		pfn = pte_pfn(ptep_deref(pvmw.pte));
> +
>  		if (folio_is_zone_device(folio)) {
>  			/*
>  			 * Our PTE is a non-present device exclusive entry and
> @@ -1891,8 +1896,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
>  			VM_BUG_ON_FOLIO(folio_nr_pages(folio) > 1, folio);
>  			subpage = &folio->page;
>  		} else {
> -			subpage = folio_page(folio,
> -					pte_pfn(*pvmw.pte) - folio_pfn(folio));
> +			subpage = folio_page(folio, pfn - folio_pfn(folio));
>  		}
>  		address = pvmw.address;
>  		anon_exclusive = folio_test_anon(folio) &&
> @@ -1952,7 +1956,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
>  			/* Nuke the hugetlb page table entry */
>  			pteval = huge_ptep_clear_flush(vma, address, pvmw.pte);
>  		} else {
> -			flush_cache_page(vma, address, pte_pfn(*pvmw.pte));
> +			flush_cache_page(vma, address, pfn);
>  			/* Nuke the page table entry. */
>  			if (should_defer_flush(mm, flags)) {
>  				/*
> @@ -2187,6 +2191,7 @@ static bool page_make_device_exclusive_one(struct folio *folio,
>  	struct mmu_notifier_range range;
>  	swp_entry_t entry;
>  	pte_t swp_pte;
> +	pte_t ptent;
>  
>  	mmu_notifier_range_init_owner(&range, MMU_NOTIFY_EXCLUSIVE, 0,
>  				      vma->vm_mm, address, min(vma->vm_end,
> @@ -2198,18 +2203,19 @@ static bool page_make_device_exclusive_one(struct folio *folio,
>  		/* Unexpected PMD-mapped THP? */
>  		VM_BUG_ON_FOLIO(!pvmw.pte, folio);
>  
> -		if (!pte_present(*pvmw.pte)) {
> +		ptent = ptep_deref(pvmw.pte);
> +		if (!pte_present(ptent)) {
>  			ret = false;
>  			page_vma_mapped_walk_done(&pvmw);
>  			break;
>  		}
>  
>  		subpage = folio_page(folio,
> -				pte_pfn(*pvmw.pte) - folio_pfn(folio));
> +				pte_pfn(ptent) - folio_pfn(folio));
>  		address = pvmw.address;
>  
>  		/* Nuke the page table entry. */
> -		flush_cache_page(vma, address, pte_pfn(*pvmw.pte));
> +		flush_cache_page(vma, address, pte_pfn(ptent));
>  		pteval = ptep_clear_flush(vma, address, pvmw.pte);
>  
>  		/* Set the dirty flag on the folio now the pte is gone. */
> diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
> index 10d73a0dfcec..4a33bcab355b 100644
> --- a/mm/sparse-vmemmap.c
> +++ b/mm/sparse-vmemmap.c
> @@ -133,7 +133,7 @@ static void * __meminit altmap_alloc_block_buf(unsigned long size,
>  void __meminit vmemmap_verify(pte_t *pte, int node,
>  				unsigned long start, unsigned long end)
>  {
> -	unsigned long pfn = pte_pfn(*pte);
> +	unsigned long pfn = pte_pfn(ptep_deref(pte));
>  	int actual_node = early_pfn_to_nid(pfn);
>  
>  	if (node_distance(actual_node, node) > LOCAL_DISTANCE)
> @@ -146,7 +146,7 @@ pte_t * __meminit vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
>  				       struct page *reuse)
>  {
>  	pte_t *pte = pte_offset_kernel(pmd, addr);
> -	if (pte_none(*pte)) {
> +	if (pte_none(ptep_deref(pte))) {
>  		pte_t entry;
>  		void *p;
>  
> @@ -414,7 +414,7 @@ static int __meminit vmemmap_populate_compound_pages(unsigned long start_pfn,
>  		 * with just tail struct pages.
>  		 */
>  		return vmemmap_populate_range(start, end, node, NULL,
> -					      pte_page(*pte));
> +					      pte_page(ptep_deref(pte)));
>  	}
>  
>  	size = min(end - start, pgmap_vmemmap_nr(pgmap) * sizeof(struct page));
> @@ -438,7 +438,7 @@ static int __meminit vmemmap_populate_compound_pages(unsigned long start_pfn,
>  		 */
>  		next += PAGE_SIZE;
>  		rc = vmemmap_populate_range(next, last, node, NULL,
> -					    pte_page(*pte));
> +					    pte_page(ptep_deref(pte)));
>  		if (rc)
>  			return -ENOMEM;
>  	}
> diff --git a/mm/swap_state.c b/mm/swap_state.c
> index b76a65ac28b3..c6d533691986 100644
> --- a/mm/swap_state.c
> +++ b/mm/swap_state.c
> @@ -759,7 +759,7 @@ static void swap_ra_info(struct vm_fault *vmf,
>  #else
>  	tpte = ra_info->ptes;
>  	for (pfn = start; pfn != end; pfn++)
> -		*tpte++ = *pte++;
> +		*tpte++ = ptep_deref(pte++);
>  #endif
>  	pte_unmap(orig_pte);
>  }
> @@ -800,7 +800,7 @@ static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask,
>  	blk_start_plug(&plug);
>  	for (i = 0, pte = ra_info.ptes; i < ra_info.nr_pte;
>  	     i++, pte++) {
> -		pentry = *pte;
> +		pentry = ptep_deref(pte);
>  		if (!is_swap_pte(pentry))
>  			continue;
>  		entry = pte_to_swp_entry(pentry);
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 274bbf797480..7ecab09eb0bd 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1762,7 +1762,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
>  	struct page *page = folio_file_page(folio, swp_offset(entry));
>  	struct page *swapcache;
>  	spinlock_t *ptl;
> -	pte_t *pte, new_pte;
> +	pte_t *pte, new_pte, old_pte;
>  	bool hwposioned = false;
>  	int ret = 1;
>  
> @@ -1774,7 +1774,8 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
>  		hwposioned = true;
>  
>  	pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
> -	if (unlikely(!pte_same_as_swp(*pte, swp_entry_to_pte(entry)))) {
> +	old_pte = ptep_deref(pte);
> +	if (unlikely(!pte_same_as_swp(old_pte, swp_entry_to_pte(entry)))) {
>  		ret = 0;
>  		goto out;
>  	}
> @@ -1810,7 +1811,7 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
>  		 * call and have the page locked.
>  		 */
>  		VM_BUG_ON_PAGE(PageWriteback(page), page);
> -		if (pte_swp_exclusive(*pte))
> +		if (pte_swp_exclusive(old_pte))
>  			rmap_flags |= RMAP_EXCLUSIVE;
>  
>  		page_add_anon_rmap(page, vma, addr, rmap_flags);
> @@ -1819,9 +1820,9 @@ static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd,
>  		lru_cache_add_inactive_or_unevictable(page, vma);
>  	}
>  	new_pte = pte_mkold(mk_pte(page, vma->vm_page_prot));
> -	if (pte_swp_soft_dirty(*pte))
> +	if (pte_swp_soft_dirty(old_pte))
>  		new_pte = pte_mksoft_dirty(new_pte);
> -	if (pte_swp_uffd_wp(*pte))
> +	if (pte_swp_uffd_wp(old_pte))
>  		new_pte = pte_mkuffd_wp(new_pte);
>  setpte:
>  	set_pte_at(vma->vm_mm, addr, pte, new_pte);
> @@ -1850,11 +1851,12 @@ static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
>  		struct folio *folio;
>  		unsigned long offset;
>  		unsigned char swp_count;
> +		pte_t ptent = ptep_deref(pte);
>  
> -		if (!is_swap_pte(*pte))
> +		if (!is_swap_pte(ptent))
>  			continue;
>  
> -		entry = pte_to_swp_entry(*pte);
> +		entry = pte_to_swp_entry(ptent);
>  		if (swp_type(entry) != type)
>  			continue;
>  
> diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
> index e97a0b4889fc..f83532e87e43 100644
> --- a/mm/userfaultfd.c
> +++ b/mm/userfaultfd.c
> @@ -94,7 +94,7 @@ int mfill_atomic_install_pte(pmd_t *dst_pmd,
>  	 * registered, we firstly wr-protect a none pte which has no page cache
>  	 * page backing it, then access the page.
>  	 */
> -	if (!pte_none_mostly(*dst_pte))
> +	if (!pte_none_mostly(ptep_deref(dst_pte)))
>  		goto out_unlock;
>  
>  	folio = page_folio(page);
> @@ -223,7 +223,7 @@ static int mfill_atomic_pte_zeropage(pmd_t *dst_pmd,
>  			goto out_unlock;
>  	}
>  	ret = -EEXIST;
> -	if (!pte_none(*dst_pte))
> +	if (!pte_none(ptep_deref(dst_pte)))
>  		goto out_unlock;
>  	set_pte_at(dst_vma->vm_mm, dst_addr, dst_pte, _dst_pte);
>  	/* No need to invalidate - it was non-present before */
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index d8d2fe797c55..3e807e4eb836 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -103,7 +103,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
>  	if (!pte)
>  		return -ENOMEM;
>  	do {
> -		BUG_ON(!pte_none(*pte));
> +		BUG_ON(!pte_none(ptep_deref(pte)));
>  
>  #ifdef CONFIG_HUGETLB_PAGE
>  		size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
> @@ -472,7 +472,7 @@ static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
>  	do {
>  		struct page *page = pages[*nr];
>  
> -		if (WARN_ON(!pte_none(*pte)))
> +		if (WARN_ON(!pte_none(ptep_deref(pte))))
>  			return -EBUSY;
>  		if (WARN_ON(!page))
>  			return -ENOMEM;
> @@ -704,7 +704,7 @@ struct page *vmalloc_to_page(const void *vmalloc_addr)
>  		return NULL;
>  
>  	ptep = pte_offset_map(pmd, addr);
> -	pte = *ptep;
> +	pte = ptep_deref(ptep);
>  	if (pte_present(pte))
>  		page = pte_page(pte);
>  	pte_unmap(ptep);
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index d257916f39e5..081b0791d1b4 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -4005,15 +4005,16 @@ static bool walk_pte_range(pmd_t *pmd, unsigned long start, unsigned long end,
>  	for (i = pte_index(start), addr = start; addr != end; i++, addr += PAGE_SIZE) {
>  		unsigned long pfn;
>  		struct folio *folio;
> +		pte_t ptent = ptep_deref(pte + i);
>  
>  		total++;
>  		walk->mm_stats[MM_LEAF_TOTAL]++;
>  
> -		pfn = get_pte_pfn(pte[i], args->vma, addr);
> +		pfn = get_pte_pfn(ptent, args->vma, addr);
>  		if (pfn == -1)
>  			continue;
>  
> -		if (!pte_young(pte[i])) {
> +		if (!pte_young(ptent)) {
>  			walk->mm_stats[MM_LEAF_OLD]++;
>  			continue;
>  		}
> @@ -4028,7 +4029,7 @@ static bool walk_pte_range(pmd_t *pmd, unsigned long start, unsigned long end,
>  		young++;
>  		walk->mm_stats[MM_LEAF_YOUNG]++;
>  
> -		if (pte_dirty(pte[i]) && !folio_test_dirty(folio) &&
> +		if (pte_dirty(ptent) && !folio_test_dirty(folio) &&
>  		    !(folio_test_anon(folio) && folio_test_swapbacked(folio) &&
>  		      !folio_test_swapcache(folio)))
>  			folio_mark_dirty(folio);
> @@ -4673,12 +4674,13 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
>  
>  	for (i = 0, addr = start; addr != end; i++, addr += PAGE_SIZE) {
>  		unsigned long pfn;
> +		pte_t ptent = ptep_deref(pte + i);
>  
> -		pfn = get_pte_pfn(pte[i], pvmw->vma, addr);
> +		pfn = get_pte_pfn(ptent, pvmw->vma, addr);
>  		if (pfn == -1)
>  			continue;
>  
> -		if (!pte_young(pte[i]))
> +		if (!pte_young(ptent))
>  			continue;
>  
>  		folio = get_pfn_folio(pfn, memcg, pgdat, !walk || walk->can_swap);
> @@ -4690,7 +4692,7 @@ void lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
>  
>  		young++;
>  
> -		if (pte_dirty(pte[i]) && !folio_test_dirty(folio) &&
> +		if (pte_dirty(ptent) && !folio_test_dirty(folio) &&
>  		    !(folio_test_anon(folio) && folio_test_swapbacked(folio) &&
>  		      !folio_test_swapcache(folio)))
>  			folio_mark_dirty(folio);
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index cb5c13eee193..0d981c381b51 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2578,6 +2578,7 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma,
>  {
>  	kvm_pfn_t pfn;
>  	pte_t *ptep;
> +	pte_t pte;
>  	spinlock_t *ptl;
>  	int r;
>  
> @@ -2601,14 +2602,16 @@ static int hva_to_pfn_remapped(struct vm_area_struct *vma,
>  			return r;
>  	}
>  
> -	if (write_fault && !pte_write(*ptep)) {
> +	pte = ptep_deref(ptep);
> +
> +	if (write_fault && !pte_write(pte)) {
>  		pfn = KVM_PFN_ERR_RO_FAULT;
>  		goto out;
>  	}
>  
>  	if (writable)
> -		*writable = pte_write(*ptep);
> -	pfn = pte_pfn(*ptep);
> +		*writable = pte_write(pte);
> +	pfn = pte_pfn(pte);
>  
>  	/*
>  	 * Get a reference here because callers of *hva_to_pfn* and


  reply	other threads:[~2023-05-11 13:15 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-11 12:58 Ryan Roberts
2023-05-11 12:58 ` [PATCH v1 1/5] mm: vmalloc must set pte via arch code Ryan Roberts
2023-05-11 13:14   ` Ryan Roberts
2023-05-11 12:58 ` [PATCH v1 2/5] mm: damon must atomically clear young on ptes and pmds Ryan Roberts
2023-05-11 13:14   ` Ryan Roberts
2023-05-11 12:58 ` [PATCH v1 3/5] mm: Fix failure to unmap pte on highmem systems Ryan Roberts
2023-05-11 13:14   ` Ryan Roberts
2023-05-11 12:58 ` [PATCH v1 4/5] mm: Add new ptep_deref() helper to fully encapsulate pte_t Ryan Roberts
2023-05-11 13:14   ` Ryan Roberts
2023-05-11 12:58 ` [PATCH v1 5/5] mm: ptep_deref() conversion Ryan Roberts
2023-05-11 13:14   ` Ryan Roberts [this message]
2023-05-12 10:34   ` kernel test robot
2023-05-11 13:13 ` Ryan Roberts

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