[RFC PATCH 4/8] mm: Provide mm_struct and address to huge_ptep_get()

From: Christophe Leroy
Date: Mon Mar 25 2024 - 12:43:37 EST

On powerpc 8xx huge_ptep_get() will need to know whether the given
ptep is a PTE entry or a PMD entry. This cannot be known with the
PMD entry itself because there is no easy way to know it from the
content of the entry.

So huge_ptep_get() will need to know either the size of the page
or get the pmd.

In order to be consistent with huge_ptep_get_and_clear(), give
mm and address to huge_ptep_get().

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/arm64/include/asm/hugetlb.h | 2 +-
fs/hugetlbfs/inode.c | 2 +-
fs/proc/task_mmu.c | 8 +++---
fs/userfaultfd.c | 2 +-
include/asm-generic/hugetlb.h | 2 +-
include/linux/swapops.h | 2 +-
mm/damon/vaddr.c | 6 ++---
mm/gup.c | 2 +-
mm/hmm.c | 2 +-
mm/hugetlb.c | 46 ++++++++++++++++----------------
mm/memory-failure.c | 2 +-
mm/mempolicy.c | 2 +-
mm/migrate.c | 4 +--
mm/mincore.c | 2 +-
mm/userfaultfd.c | 2 +-
15 files changed, 43 insertions(+), 43 deletions(-)

diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index 2ddc33d93b13..1af39a74e791 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -46,7 +46,7 @@ extern pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
extern void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, unsigned long sz);
#define __HAVE_ARCH_HUGE_PTEP_GET
-extern pte_t huge_ptep_get(pte_t *ptep);
+extern pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep);

void __init arm64_hugetlb_cma_reserve(void);

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 6502c7e776d1..ec3ec87d29e7 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -425,7 +425,7 @@ static bool hugetlb_vma_maps_page(struct vm_area_struct *vma,
if (!ptep)
return false;

- pte = huge_ptep_get(ptep);
+ pte = huge_ptep_get(vma->vm_mm, addr, ptep);
if (huge_pte_none(pte) || !pte_present(pte))
return false;

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 23fbab954c20..b14081bcdafe 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1572,7 +1572,7 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
if (vma->vm_flags & VM_SOFTDIRTY)
flags |= PM_SOFT_DIRTY;

- pte = huge_ptep_get(ptep);
+ pte = huge_ptep_get(walk->mm, addr, ptep);
if (pte_present(pte)) {
struct page *page = pte_page(pte);

@@ -2256,7 +2256,7 @@ static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask,
if (~p->arg.flags & PM_SCAN_WP_MATCHING) {
/* Go the short route when not write-protecting pages. */

- pte = huge_ptep_get(ptep);
+ pte = huge_ptep_get(walk->mm, start, ptep);
categories = p->cur_vma_category | pagemap_hugetlb_category(pte);

if (!pagemap_scan_is_interesting_page(categories, p))
@@ -2268,7 +2268,7 @@ static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask,
i_mmap_lock_write(vma->vm_file->f_mapping);
ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep);

- pte = huge_ptep_get(ptep);
+ pte = huge_ptep_get(walk->mm, start, ptep);
categories = p->cur_vma_category | pagemap_hugetlb_category(pte);

if (!pagemap_scan_is_interesting_page(categories, p))
@@ -2663,7 +2663,7 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
unsigned long addr, unsigned long end, struct mm_walk *walk)
{
- pte_t huge_pte = huge_ptep_get(pte);
+ pte_t huge_pte = huge_ptep_get(walk->mm, addr, pte);
struct numa_maps *md;
struct page *page;

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 60dcfafdc11a..177fe1ff14d7 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -256,7 +256,7 @@ static inline bool userfaultfd_huge_must_wait(struct userfaultfd_ctx *ctx,
goto out;

ret = false;
- pte = huge_ptep_get(ptep);
+ pte = huge_ptep_get(vma->vm_mm, vmf->address, ptep);

/*
* Lockless access: we're in a wait_event so it's ok if it
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index 6dcf4d576970..594d5905f615 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -144,7 +144,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
#endif

#ifndef __HAVE_ARCH_HUGE_PTEP_GET
-static inline pte_t huge_ptep_get(pte_t *ptep)
+static inline pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
return ptep_get(ptep);
}
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 48b700ba1d18..b9a9f5003bf5 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -334,7 +334,7 @@ static inline bool is_migration_entry_dirty(swp_entry_t entry)

extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
unsigned long address);
-extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte);
+extern void migration_entry_wait_huge(struct vm_area_struct *vma, unsigned long addr, pte_t *pte);
#else /* CONFIG_MIGRATION */
static inline swp_entry_t make_readable_migration_entry(pgoff_t offset)
{
diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index 381559e4a1fa..58829baf8b5d 100644
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -339,7 +339,7 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long addr)
{
bool referenced = false;
- pte_t entry = huge_ptep_get(pte);
+ pte_t entry = huge_ptep_get(mm, addr, pte);
struct folio *folio = pfn_folio(pte_pfn(entry));
unsigned long psize = huge_page_size(hstate_vma(vma));

@@ -373,7 +373,7 @@ static int damon_mkold_hugetlb_entry(pte_t *pte, unsigned long hmask,
pte_t entry;

ptl = huge_pte_lock(h, walk->mm, pte);
- entry = huge_ptep_get(pte);
+ entry = huge_ptep_get(walk->mm, addr, pte);
if (!pte_present(entry))
goto out;

@@ -509,7 +509,7 @@ static int damon_young_hugetlb_entry(pte_t *pte, unsigned long hmask,
pte_t entry;

ptl = huge_pte_lock(h, walk->mm, pte);
- entry = huge_ptep_get(pte);
+ entry = huge_ptep_get(walk->mm, addr, pte);
if (!pte_present(entry))
goto out;

diff --git a/mm/gup.c b/mm/gup.c
index df83182ec72d..ae3f27fc9cc5 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2800,7 +2800,7 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr,
if (pte_end < end)
end = pte_end;

- pte = huge_ptep_get(ptep);
+ pte = huge_ptep_get(NULL, addr, ptep);

if (!pte_access_permitted(pte, flags & FOLL_WRITE))
return 0;
diff --git a/mm/hmm.c b/mm/hmm.c
index 277ddcab4947..91a0b57fcb2e 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -485,7 +485,7 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask,
pte_t entry;

ptl = huge_pte_lock(hstate_vma(vma), walk->mm, pte);
- entry = huge_ptep_get(pte);
+ entry = huge_ptep_get(walk->mm, addr, pte);

i = (start - range->start) >> PAGE_SHIFT;
pfn_req_flags = range->hmm_pfns[i];
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 23ef240ba48a..cfe1cf2f30dc 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5334,7 +5334,7 @@ static void set_huge_ptep_writable(struct vm_area_struct *vma,
{
pte_t entry;

- entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep)));
+ entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(vma->vm_mm, address, ptep)));
if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1))
update_mmu_cache(vma, address, ptep);
}
@@ -5442,7 +5442,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
dst_ptl = huge_pte_lock(h, dst, dst_pte);
src_ptl = huge_pte_lockptr(h, src, src_pte);
spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
- entry = huge_ptep_get(src_pte);
+ entry = huge_ptep_get(src_vma->vm_mm, addr, src_pte);
again:
if (huge_pte_none(entry)) {
/*
@@ -5480,7 +5480,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
set_huge_pte_at(dst, addr, dst_pte,
make_pte_marker(marker), sz);
} else {
- entry = huge_ptep_get(src_pte);
+ entry = huge_ptep_get(src_vma->vm_mm, addr, src_pte);
pte_folio = page_folio(pte_page(entry));
folio_get(pte_folio);

@@ -5522,7 +5522,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
dst_ptl = huge_pte_lock(h, dst, dst_pte);
src_ptl = huge_pte_lockptr(h, src, src_pte);
spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
- entry = huge_ptep_get(src_pte);
+ entry = huge_ptep_get(src_vma->vm_mm, addr, src_pte);
if (!pte_same(src_pte_old, entry)) {
restore_reserve_on_error(h, dst_vma, addr,
new_folio);
@@ -5632,7 +5632,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
new_addr |= last_addr_mask;
continue;
}
- if (huge_pte_none(huge_ptep_get(src_pte)))
+ if (huge_pte_none(huge_ptep_get(mm, old_addr, src_pte)))
continue;

if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) {
@@ -5705,7 +5705,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
continue;
}

- pte = huge_ptep_get(ptep);
+ pte = huge_ptep_get(mm, address, ptep);
if (huge_pte_none(pte)) {
spin_unlock(ptl);
continue;
@@ -5942,7 +5942,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_fault *vmf)
{
const bool unshare = flags & FAULT_FLAG_UNSHARE;
- pte_t pte = huge_ptep_get(ptep);
+ pte_t pte = huge_ptep_get(mm, address, ptep);
struct hstate *h = hstate_vma(vma);
struct folio *old_folio;
struct folio *new_folio;
@@ -6055,7 +6055,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
spin_lock(ptl);
ptep = hugetlb_walk(vma, haddr, huge_page_size(h));
if (likely(ptep &&
- pte_same(huge_ptep_get(ptep), pte)))
+ pte_same(huge_ptep_get(mm, haddr, ptep), pte)))
goto retry_avoidcopy;
/*
* race occurs while re-acquiring page table
@@ -6093,7 +6093,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
*/
spin_lock(ptl);
ptep = hugetlb_walk(vma, haddr, huge_page_size(h));
- if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) {
+ if (likely(ptep && pte_same(huge_ptep_get(mm, haddr, ptep), pte))) {
pte_t newpte = make_huge_pte(vma, &new_folio->page, !unshare);

/* Break COW or unshare */
@@ -6193,14 +6193,14 @@ static inline vm_fault_t hugetlb_handle_userfault(struct vm_fault *vmf,
* Recheck pte with pgtable lock. Returns true if pte didn't change, or
* false if pte changed or is changing.
*/
-static bool hugetlb_pte_stable(struct hstate *h, struct mm_struct *mm,
+static bool hugetlb_pte_stable(struct hstate *h, struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t old_pte)
{
spinlock_t *ptl;
bool same;

ptl = huge_pte_lock(h, mm, ptep);
- same = pte_same(huge_ptep_get(ptep), old_pte);
+ same = pte_same(huge_ptep_get(mm, addr, ptep), old_pte);
spin_unlock(ptl);

return same;
@@ -6265,7 +6265,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
* never happen on the page after UFFDIO_COPY has
* correctly installed the page and returned.
*/
- if (!hugetlb_pte_stable(h, mm, ptep, old_pte)) {
+ if (!hugetlb_pte_stable(h, mm, haddr, ptep, old_pte)) {
ret = 0;
goto out;
}
@@ -6288,7 +6288,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
* here. Before returning error, get ptl and make
* sure there really is no pte entry.
*/
- if (hugetlb_pte_stable(h, mm, ptep, old_pte))
+ if (hugetlb_pte_stable(h, mm, haddr, ptep, old_pte))
ret = vmf_error(PTR_ERR(folio));
else
ret = 0;
@@ -6338,7 +6338,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
folio_unlock(folio);
folio_put(folio);
/* See comment in userfaultfd_missing() block above */
- if (!hugetlb_pte_stable(h, mm, ptep, old_pte)) {
+ if (!hugetlb_pte_stable(h, mm, haddr, ptep, old_pte)) {
ret = 0;
goto out;
}
@@ -6365,7 +6365,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
ptl = huge_pte_lock(h, mm, ptep);
ret = 0;
/* If pte changed from under us, retry */
- if (!pte_same(huge_ptep_get(ptep), old_pte))
+ if (!pte_same(huge_ptep_get(mm, address, ptep), old_pte))
goto backout;

if (anon_rmap)
@@ -6488,7 +6488,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
return VM_FAULT_OOM;
}

- entry = huge_ptep_get(ptep);
+ entry = huge_ptep_get(mm, address, ptep);
if (huge_pte_none_mostly(entry)) {
if (is_pte_marker(entry)) {
pte_marker marker =
@@ -6529,7 +6529,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
* be released there.
*/
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
- migration_entry_wait_huge(vma, ptep);
+ migration_entry_wait_huge(vma, haddr, ptep);
return 0;
} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
ret = VM_FAULT_HWPOISON_LARGE |
@@ -6562,11 +6562,11 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
ptl = huge_pte_lock(h, mm, ptep);

/* Check for a racing update before calling hugetlb_wp() */
- if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
+ if (unlikely(!pte_same(entry, huge_ptep_get(mm, address, ptep))))
goto out_ptl;

/* Handle userfault-wp first, before trying to lock more pages */
- if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) &&
+ if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(mm, address, ptep)) &&
(flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) {
if (!userfaultfd_wp_async(vma)) {
spin_unlock(ptl);
@@ -6689,7 +6689,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
ptl = huge_pte_lock(h, dst_mm, dst_pte);

/* Don't overwrite any existing PTEs (even markers) */
- if (!huge_pte_none(huge_ptep_get(dst_pte))) {
+ if (!huge_pte_none(huge_ptep_get(mm, dst_addr, dst_pte))) {
spin_unlock(ptl);
return -EEXIST;
}
@@ -6826,7 +6826,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
* page backing it, then access the page.
*/
ret = -EEXIST;
- if (!huge_pte_none_mostly(huge_ptep_get(dst_pte)))
+ if (!huge_pte_none_mostly(huge_ptep_get(mm, dst_addr, dst_pte)))
goto out_release_unlock;

if (folio_in_pagecache)
@@ -6901,7 +6901,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
goto out_unlock;

ptl = huge_pte_lock(h, mm, pte);
- entry = huge_ptep_get(pte);
+ entry = huge_ptep_get(mm, address, pte);
if (pte_present(entry)) {
page = pte_page(entry);

@@ -7018,7 +7018,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
address |= last_addr_mask;
continue;
}
- pte = huge_ptep_get(ptep);
+ pte = huge_ptep_get(mm, address, ptep);
if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) {
/* Nothing to do. */
} else if (unlikely(is_hugetlb_entry_migration(pte))) {
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 9349948f1abf..7c65340b1adb 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -820,7 +820,7 @@ static int hwpoison_hugetlb_range(pte_t *ptep, unsigned long hmask,
struct mm_walk *walk)
{
struct hwpoison_walk *hwp = walk->private;
- pte_t pte = huge_ptep_get(ptep);
+ pte_t pte = huge_ptep_get(walk->mm, addr, ptep);
struct hstate *h = hstate_vma(walk->vma);

return check_hwpoisoned_entry(pte, addr, huge_page_shift(h),
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 0fe77738d971..50a79700f496 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -624,7 +624,7 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
pte_t entry;

ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
- entry = huge_ptep_get(pte);
+ entry = huge_ptep_get(walk->mm, addr, pte);
if (!pte_present(entry)) {
if (unlikely(is_hugetlb_entry_migration(entry)))
qp->nr_failed++;
diff --git a/mm/migrate.c b/mm/migrate.c
index 73a052a382f1..87f7aedb8ee2 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -338,14 +338,14 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
*
* This function will release the vma lock before returning.
*/
-void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *ptep)
+void migration_entry_wait_huge(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
{
spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), vma->vm_mm, ptep);
pte_t pte;

hugetlb_vma_assert_locked(vma);
spin_lock(ptl);
- pte = huge_ptep_get(ptep);
+ pte = huge_ptep_get(vma->vm_mm, addr, ptep);

if (unlikely(!is_hugetlb_entry_migration(pte))) {
spin_unlock(ptl);
diff --git a/mm/mincore.c b/mm/mincore.c
index dad3622cc963..b5735a4aaa7d 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -33,7 +33,7 @@ static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr,
* Hugepages under user process are always in RAM and never
* swapped out, but theoretically it needs to be checked.
*/
- present = pte && !huge_pte_none_mostly(huge_ptep_get(pte));
+ present = pte && !huge_pte_none_mostly(huge_ptep_get(walk->mm, addr, pte));
for (; addr != end; vec++, addr += PAGE_SIZE)
*vec = present;
walk->private = vec;
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 9baf507ce193..2b2ce329552e 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -555,7 +555,7 @@ static __always_inline ssize_t mfill_atomic_hugetlb(
}

if (!uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE) &&
- !huge_pte_none_mostly(huge_ptep_get(dst_pte))) {
+ !huge_pte_none_mostly(huge_ptep_get(dst_mm, dst_addr, dst_pte))) {
err = -EEXIST;
hugetlb_vma_unlock_read(dst_vma);
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
--
2.43.0