2023-09-22 12:10:38

by Ryan Roberts

[permalink] [raw]
Subject: [PATCH v2 0/2] Fix set_huge_pte_at() panic on arm64

Hi All,

This series fixes a bug in arm64's implementation of set_huge_pte_at(), which
can result in an unprivileged user causing a kernel panic. The problem was
triggered when running the new uffd poison mm selftest for HUGETLB memory. This
test (and the uffd poison feature) was merged for v6.5-rc7.

Ideally, I'd like to get this fix in for v6.6 and I've cc'ed stable (correctly
this time) to get it backported to v6.5, where the issue first showed up.


Description of Bug
------------------

arm64's huge pte implementation supports multiple huge page sizes, some of which
are implemented in the page table with multiple contiguous entries. So
set_huge_pte_at() needs to work out how big the logical pte is, so that it can
also work out how many physical ptes (or pmds) need to be written. It previously
did this by grabbing the folio out of the pte and querying its size.

However, there are cases when the pte being set is actually a swap entry. But
this also used to work fine, because for huge ptes, we only ever saw migration
entries and hwpoison entries. And both of these types of swap entries have a PFN
embedded, so the code would grab that and everything still worked out.

But over time, more calls to set_huge_pte_at() have been added that set swap
entry types that do not embed a PFN. And this causes the code to go bang. The
triggering case is for the uffd poison test, commit 99aa77215ad0 ("selftests/mm:
add uffd unit test for UFFDIO_POISON"), which causes a PTE_MARKER_POISONED swap
entry to be set, coutesey of commit 8a13897fb0da ("mm: userfaultfd: support
UFFDIO_POISON for hugetlbfs") - added in v6.5-rc7. Although review shows that
there are other call sites that set PTE_MARKER_UFFD_WP (which also has no PFN),
these don't trigger on arm64 because arm64 doesn't support UFFD WP.

If CONFIG_DEBUG_VM is enabled, we do at least get a BUG(), but otherwise, it
will dereference a bad pointer in page_folio():

static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
{
VM_BUG_ON(!is_migration_entry(entry) && !is_hwpoison_entry(entry));

return page_folio(pfn_to_page(swp_offset_pfn(entry)));
}


Fix
---

The simplest fix would have been to revert the dodgy cleanup commit 18f3962953e4
("mm: hugetlb: kill set_huge_swap_pte_at()"), but since things have moved on,
this would have required an audit of all the new set_huge_pte_at() call sites to
see if they should be converted to set_huge_swap_pte_at(). As per the original
intent of the change, it would also leave us open to future bugs when people
invariably get it wrong and call the wrong helper.

So instead, I've added a huge page size parameter to set_huge_pte_at(). This
means that the arm64 code has the size in all cases. It's a bigger change, due
to needing to touch the arches that implement the function, but it is entirely
mechanical, so in my view, low risk.

I've compile-tested all touched arches; arm64, parisc, powerpc, riscv, s390,
sparc (and additionally x86_64). I've additionally booted and run mm selftests
against arm64, where I observe the uffd poison test is fixed, and there are no
other regressions.


Patches
-------

patch 1: Convert core mm and arches to pass extra param (no behavioral change)
patch 8: Fix the arm64 bug

Patches based on v6.6-rc2.


Changes since v1 [1]
--------------------

- Pass extra size param instead of converting mm to vma.
- Passing vma was problematic for kernel mapping case without vma
- Squash all interface changes to single patch
- Simplify powerpc so that is doesn't require __set_huge_page_at()
- Added Reviewed-bys


[1] https://lore.kernel.org/linux-arm-kernel/[email protected]/


Thanks,
Ryan

Ryan Roberts (2):
mm: hugetlb: Add huge page size param to set_huge_pte_at()
arm64: hugetlb: Fix set_huge_pte_at() to work with all swap entries

arch/arm64/include/asm/hugetlb.h | 2 +-
arch/arm64/mm/hugetlbpage.c | 23 +++-------
arch/parisc/include/asm/hugetlb.h | 2 +-
arch/parisc/mm/hugetlbpage.c | 2 +-
.../include/asm/nohash/32/hugetlb-8xx.h | 3 +-
arch/powerpc/mm/book3s64/hugetlbpage.c | 5 ++-
arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 3 +-
arch/powerpc/mm/nohash/8xx.c | 3 +-
arch/powerpc/mm/pgtable.c | 3 +-
arch/riscv/include/asm/hugetlb.h | 3 +-
arch/riscv/mm/hugetlbpage.c | 3 +-
arch/s390/include/asm/hugetlb.h | 6 ++-
arch/s390/mm/hugetlbpage.c | 8 +++-
arch/sparc/include/asm/hugetlb.h | 6 ++-
arch/sparc/mm/hugetlbpage.c | 8 +++-
include/asm-generic/hugetlb.h | 2 +-
include/linux/hugetlb.h | 6 ++-
mm/damon/vaddr.c | 3 +-
mm/hugetlb.c | 43 +++++++++++--------
mm/migrate.c | 7 ++-
mm/rmap.c | 23 +++++++---
mm/vmalloc.c | 2 +-
22 files changed, 103 insertions(+), 63 deletions(-)

--
2.25.1


2023-09-22 12:15:18

by Ryan Roberts

[permalink] [raw]
Subject: [PATCH v2 1/2] mm: hugetlb: Add huge page size param to set_huge_pte_at()

In order to fix a bug, arm64 needs to be told the size of the huge page
for which the pte is being set in set_huge_pte_at(). Provide for this by
adding an `unsigned long sz` parameter to the function. This follows the
same pattern as huge_pte_clear().

This commit makes the required interface modifications to the core mm as
well as all arches that implement this function (arm64, parisc, powerpc,
riscv, s390, sparc). The actual arm64 bug will be fixed in a separate
commit.

No behavioral changes intended.

Signed-off-by: Ryan Roberts <[email protected]>
Cc: <[email protected]> # 6.5+
---
arch/arm64/include/asm/hugetlb.h | 2 +-
arch/arm64/mm/hugetlbpage.c | 6 ++-
arch/parisc/include/asm/hugetlb.h | 2 +-
arch/parisc/mm/hugetlbpage.c | 2 +-
.../include/asm/nohash/32/hugetlb-8xx.h | 3 +-
arch/powerpc/mm/book3s64/hugetlbpage.c | 5 ++-
arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 3 +-
arch/powerpc/mm/nohash/8xx.c | 3 +-
arch/powerpc/mm/pgtable.c | 3 +-
arch/riscv/include/asm/hugetlb.h | 3 +-
arch/riscv/mm/hugetlbpage.c | 3 +-
arch/s390/include/asm/hugetlb.h | 6 ++-
arch/s390/mm/hugetlbpage.c | 8 +++-
arch/sparc/include/asm/hugetlb.h | 6 ++-
arch/sparc/mm/hugetlbpage.c | 8 +++-
include/asm-generic/hugetlb.h | 2 +-
include/linux/hugetlb.h | 6 ++-
mm/damon/vaddr.c | 3 +-
mm/hugetlb.c | 43 +++++++++++--------
mm/migrate.c | 7 ++-
mm/rmap.c | 23 +++++++---
mm/vmalloc.c | 2 +-
22 files changed, 100 insertions(+), 49 deletions(-)

diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index f43a38ac1779..2ddc33d93b13 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -28,7 +28,7 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags);
#define arch_make_huge_pte arch_make_huge_pte
#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
extern void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte);
+ pte_t *ptep, pte_t pte, unsigned long sz);
#define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 9c52718ea750..a7f8c8db3425 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -249,7 +249,7 @@ static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
}

void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte)
+ pte_t *ptep, pte_t pte, unsigned long sz)
{
size_t pgsize;
int i;
@@ -571,5 +571,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr
void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
pte_t old_pte, pte_t pte)
{
- set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+ unsigned long psize = huge_page_size(hstate_vma(vma));
+
+ set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
}
diff --git a/arch/parisc/include/asm/hugetlb.h b/arch/parisc/include/asm/hugetlb.h
index f7f078c2872c..72daacc472a0 100644
--- a/arch/parisc/include/asm/hugetlb.h
+++ b/arch/parisc/include/asm/hugetlb.h
@@ -6,7 +6,7 @@

#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte);
+ pte_t *ptep, pte_t pte, unsigned long sz);

#define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
diff --git a/arch/parisc/mm/hugetlbpage.c b/arch/parisc/mm/hugetlbpage.c
index a8a1a7c1e16e..a9f7e21f6656 100644
--- a/arch/parisc/mm/hugetlbpage.c
+++ b/arch/parisc/mm/hugetlbpage.c
@@ -140,7 +140,7 @@ static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
}

void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t entry)
+ pte_t *ptep, pte_t entry, unsigned long sz)
{
__set_huge_pte_at(mm, addr, ptep, entry);
}
diff --git a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
index de092b04ee1a..92df40c6cc6b 100644
--- a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
@@ -46,7 +46,8 @@ static inline int check_and_get_huge_psize(int shift)
}

#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
-void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+ pte_t pte, unsigned long sz);

#define __HAVE_ARCH_HUGE_PTE_CLEAR
static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
diff --git a/arch/powerpc/mm/book3s64/hugetlbpage.c b/arch/powerpc/mm/book3s64/hugetlbpage.c
index 3bc0eb21b2a0..5a2e512e96db 100644
--- a/arch/powerpc/mm/book3s64/hugetlbpage.c
+++ b/arch/powerpc/mm/book3s64/hugetlbpage.c
@@ -143,11 +143,14 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
pte_t *ptep, pte_t old_pte, pte_t pte)
{
+ unsigned long psize;

if (radix_enabled())
return radix__huge_ptep_modify_prot_commit(vma, addr, ptep,
old_pte, pte);
- set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+
+ psize = huge_page_size(hstate_vma(vma));
+ set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
}

void __init hugetlbpage_init_defaultsize(void)
diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
index 17075c78d4bc..35fd2a95be24 100644
--- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
+++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
@@ -47,6 +47,7 @@ void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
pte_t old_pte, pte_t pte)
{
struct mm_struct *mm = vma->vm_mm;
+ unsigned long psize = huge_page_size(hstate_vma(vma));

/*
* POWER9 NMMU must flush the TLB after clearing the PTE before
@@ -58,5 +59,5 @@ void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
atomic_read(&mm->context.copros) > 0)
radix__flush_hugetlb_page(vma, addr);

- set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+ set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
}
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index dbbfe897455d..a642a7929892 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -91,7 +91,8 @@ static int __ref __early_map_kernel_hugepage(unsigned long va, phys_addr_t pa,
if (new && WARN_ON(pte_present(*ptep) && pgprot_val(prot)))
return -EINVAL;

- set_huge_pte_at(&init_mm, va, ptep, pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)));
+ set_huge_pte_at(&init_mm, va, ptep,
+ pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)), psize);

return 0;
}
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 3f86fd217690..3ba9fe411604 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -288,7 +288,8 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
}

#if defined(CONFIG_PPC_8xx)
-void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+ pte_t pte, unsigned long sz)
{
pmd_t *pmd = pmd_off(mm, addr);
pte_basic_t val;
diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
index 34e24f078cc1..4c5b0e929890 100644
--- a/arch/riscv/include/asm/hugetlb.h
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -18,7 +18,8 @@ void huge_pte_clear(struct mm_struct *mm, unsigned long addr,

#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
void set_huge_pte_at(struct mm_struct *mm,
- unsigned long addr, pte_t *ptep, pte_t pte);
+ unsigned long addr, pte_t *ptep, pte_t pte,
+ unsigned long sz);

#define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index 96225a8533ad..e4a2ace92dbe 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -180,7 +180,8 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
void set_huge_pte_at(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep,
- pte_t pte)
+ pte_t pte,
+ unsigned long sz)
{
int i, pte_num;

diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index f07267875a19..deb198a61039 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -16,6 +16,8 @@
#define hugepages_supported() (MACHINE_HAS_EDAT1)

void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned long sz);
+void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte);
pte_t huge_ptep_get(pte_t *ptep);
pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
@@ -65,7 +67,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
int changed = !pte_same(huge_ptep_get(ptep), pte);
if (changed) {
huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
- set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+ __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
}
return changed;
}
@@ -74,7 +76,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
- set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
+ __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
}

static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index c718f2a0de94..297a6d897d5a 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -142,7 +142,7 @@ static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
__storage_key_init_range(paddr, paddr + size - 1);
}

-void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
unsigned long rste;
@@ -163,6 +163,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
set_pte(ptep, __pte(rste));
}

+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned long sz)
+{
+ __set_huge_pte_at(mm, addr, ptep, pte);
+}
+
pte_t huge_ptep_get(pte_t *ptep)
{
return __rste_to_pte(pte_val(*ptep));
diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
index 0a26cca24232..c714ca6a05aa 100644
--- a/arch/sparc/include/asm/hugetlb.h
+++ b/arch/sparc/include/asm/hugetlb.h
@@ -14,6 +14,8 @@ extern struct pud_huge_patch_entry __pud_huge_patch, __pud_huge_patch_end;

#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned long sz);
+void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte);

#define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
@@ -32,7 +34,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
pte_t old_pte = *ptep;
- set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
+ __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
}

#define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
@@ -42,7 +44,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
{
int changed = !pte_same(*ptep, pte);
if (changed) {
- set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+ __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
flush_tlb_page(vma, addr);
}
return changed;
diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index d7018823206c..b432500c13a5 100644
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -328,7 +328,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
return pte_offset_huge(pmd, addr);
}

-void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t entry)
{
unsigned int nptes, orig_shift, shift;
@@ -364,6 +364,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
orig_shift);
}

+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t entry, unsigned long sz)
+{
+ __set_huge_pte_at(mm, addr, ptep, entry);
+}
+
pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index 4da02798a00b..6dcf4d576970 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -76,7 +76,7 @@ static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,

#ifndef __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte)
+ pte_t *ptep, pte_t pte, unsigned long sz)
{
set_pte_at(mm, addr, ptep, pte);
}
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 5b2626063f4f..a30686e649f7 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -984,7 +984,9 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep,
pte_t old_pte, pte_t pte)
{
- set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+ unsigned long psize = huge_page_size(hstate_vma(vma));
+
+ set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
}
#endif

@@ -1173,7 +1175,7 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
}

static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte)
+ pte_t *ptep, pte_t pte, unsigned long sz)
{
}

diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index 4c81a9dbd044..cf8a9fc5c9d1 100644
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -341,13 +341,14 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm,
bool referenced = false;
pte_t entry = huge_ptep_get(pte);
struct folio *folio = pfn_folio(pte_pfn(entry));
+ unsigned long psize = huge_page_size(hstate_vma(vma));

folio_get(folio);

if (pte_young(entry)) {
referenced = true;
entry = pte_mkold(entry);
- set_huge_pte_at(mm, addr, pte, entry);
+ set_huge_pte_at(mm, addr, pte, entry, psize);
}

#ifdef CONFIG_MMU_NOTIFIER
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ba6d39b71cb1..52d26072dfda 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4980,7 +4980,7 @@ static bool is_hugetlb_entry_hwpoisoned(pte_t pte)

static void
hugetlb_install_folio(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr,
- struct folio *new_folio, pte_t old)
+ struct folio *new_folio, pte_t old, unsigned long sz)
{
pte_t newpte = make_huge_pte(vma, &new_folio->page, 1);

@@ -4988,7 +4988,7 @@ hugetlb_install_folio(struct vm_area_struct *vma, pte_t *ptep, unsigned long add
hugepage_add_new_anon_rmap(new_folio, vma, addr);
if (userfaultfd_wp(vma) && huge_pte_uffd_wp(old))
newpte = huge_pte_mkuffd_wp(newpte);
- set_huge_pte_at(vma->vm_mm, addr, ptep, newpte);
+ set_huge_pte_at(vma->vm_mm, addr, ptep, newpte, sz);
hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm);
folio_set_hugetlb_migratable(new_folio);
}
@@ -5065,7 +5065,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) {
if (!userfaultfd_wp(dst_vma))
entry = huge_pte_clear_uffd_wp(entry);
- set_huge_pte_at(dst, addr, dst_pte, entry);
+ set_huge_pte_at(dst, addr, dst_pte, entry, sz);
} else if (unlikely(is_hugetlb_entry_migration(entry))) {
swp_entry_t swp_entry = pte_to_swp_entry(entry);
bool uffd_wp = pte_swp_uffd_wp(entry);
@@ -5080,18 +5080,18 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
entry = swp_entry_to_pte(swp_entry);
if (userfaultfd_wp(src_vma) && uffd_wp)
entry = pte_swp_mkuffd_wp(entry);
- set_huge_pte_at(src, addr, src_pte, entry);
+ set_huge_pte_at(src, addr, src_pte, entry, sz);
}
if (!userfaultfd_wp(dst_vma))
entry = huge_pte_clear_uffd_wp(entry);
- set_huge_pte_at(dst, addr, dst_pte, entry);
+ set_huge_pte_at(dst, addr, dst_pte, entry, sz);
} else if (unlikely(is_pte_marker(entry))) {
pte_marker marker = copy_pte_marker(
pte_to_swp_entry(entry), dst_vma);

if (marker)
set_huge_pte_at(dst, addr, dst_pte,
- make_pte_marker(marker));
+ make_pte_marker(marker), sz);
} else {
entry = huge_ptep_get(src_pte);
pte_folio = page_folio(pte_page(entry));
@@ -5145,7 +5145,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
goto again;
}
hugetlb_install_folio(dst_vma, dst_pte, addr,
- new_folio, src_pte_old);
+ new_folio, src_pte_old, sz);
spin_unlock(src_ptl);
spin_unlock(dst_ptl);
continue;
@@ -5166,7 +5166,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
if (!userfaultfd_wp(dst_vma))
entry = huge_pte_clear_uffd_wp(entry);

- set_huge_pte_at(dst, addr, dst_pte, entry);
+ set_huge_pte_at(dst, addr, dst_pte, entry, sz);
hugetlb_count_add(npages, dst);
}
spin_unlock(src_ptl);
@@ -5184,7 +5184,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
}

static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
- unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte)
+ unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte,
+ unsigned long sz)
{
struct hstate *h = hstate_vma(vma);
struct mm_struct *mm = vma->vm_mm;
@@ -5202,7 +5203,7 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);

pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
- set_huge_pte_at(mm, new_addr, dst_pte, pte);
+ set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);

if (src_ptl != dst_ptl)
spin_unlock(src_ptl);
@@ -5259,7 +5260,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
if (!dst_pte)
break;

- move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte);
+ move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte, sz);
}

if (shared_pmd)
@@ -5337,7 +5338,8 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
if (pte_swp_uffd_wp_any(pte) &&
!(zap_flags & ZAP_FLAG_DROP_MARKER))
set_huge_pte_at(mm, address, ptep,
- make_pte_marker(PTE_MARKER_UFFD_WP));
+ make_pte_marker(PTE_MARKER_UFFD_WP),
+ sz);
else
huge_pte_clear(mm, address, ptep, sz);
spin_unlock(ptl);
@@ -5371,7 +5373,8 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
if (huge_pte_uffd_wp(pte) &&
!(zap_flags & ZAP_FLAG_DROP_MARKER))
set_huge_pte_at(mm, address, ptep,
- make_pte_marker(PTE_MARKER_UFFD_WP));
+ make_pte_marker(PTE_MARKER_UFFD_WP),
+ sz);
hugetlb_count_sub(pages_per_huge_page(h), mm);
page_remove_rmap(page, vma, true);

@@ -5676,7 +5679,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
hugepage_add_new_anon_rmap(new_folio, vma, haddr);
if (huge_pte_uffd_wp(pte))
newpte = huge_pte_mkuffd_wp(newpte);
- set_huge_pte_at(mm, haddr, ptep, newpte);
+ set_huge_pte_at(mm, haddr, ptep, newpte, huge_page_size(h));
folio_set_hugetlb_migratable(new_folio);
/* Make the old page be freed below */
new_folio = old_folio;
@@ -5972,7 +5975,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
*/
if (unlikely(pte_marker_uffd_wp(old_pte)))
new_pte = huge_pte_mkuffd_wp(new_pte);
- set_huge_pte_at(mm, haddr, ptep, new_pte);
+ set_huge_pte_at(mm, haddr, ptep, new_pte, huge_page_size(h));

hugetlb_count_add(pages_per_huge_page(h), mm);
if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
@@ -6261,7 +6264,8 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
}

_dst_pte = make_pte_marker(PTE_MARKER_POISONED);
- set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
+ set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte,
+ huge_page_size(h));

/* No need to invalidate - it was non-present before */
update_mmu_cache(dst_vma, dst_addr, dst_pte);
@@ -6412,7 +6416,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
if (wp_enabled)
_dst_pte = huge_pte_mkuffd_wp(_dst_pte);

- set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
+ set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte, huge_page_size(h));

hugetlb_count_add(pages_per_huge_page(h), dst_mm);

@@ -6598,7 +6602,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
else if (uffd_wp_resolve)
newpte = pte_swp_clear_uffd_wp(newpte);
if (!pte_same(pte, newpte))
- set_huge_pte_at(mm, address, ptep, newpte);
+ set_huge_pte_at(mm, address, ptep, newpte, psize);
} else if (unlikely(is_pte_marker(pte))) {
/* No other markers apply for now. */
WARN_ON_ONCE(!pte_marker_uffd_wp(pte));
@@ -6623,7 +6627,8 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
if (unlikely(uffd_wp))
/* Safe to modify directly (none->non-present). */
set_huge_pte_at(mm, address, ptep,
- make_pte_marker(PTE_MARKER_UFFD_WP));
+ make_pte_marker(PTE_MARKER_UFFD_WP),
+ psize);
}
spin_unlock(ptl);
}
diff --git a/mm/migrate.c b/mm/migrate.c
index b7fa020003f3..2053b54556ca 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -243,7 +243,9 @@ static bool remove_migration_pte(struct folio *folio,

#ifdef CONFIG_HUGETLB_PAGE
if (folio_test_hugetlb(folio)) {
- unsigned int shift = huge_page_shift(hstate_vma(vma));
+ struct hstate *h = hstate_vma(vma);
+ unsigned int shift = huge_page_shift(h);
+ unsigned long psize = huge_page_size(h);

pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
if (folio_test_anon(folio))
@@ -251,7 +253,8 @@ static bool remove_migration_pte(struct folio *folio,
rmap_flags);
else
page_dup_file_rmap(new, true);
- set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
+ set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte,
+ psize);
} else
#endif
{
diff --git a/mm/rmap.c b/mm/rmap.c
index ec7f8e6c9e48..9f795b93cf40 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1480,6 +1480,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
struct mmu_notifier_range range;
enum ttu_flags flags = (enum ttu_flags)(long)arg;
unsigned long pfn;
+ unsigned long hsz = 0;

/*
* When racing against e.g. zap_pte_range() on another cpu,
@@ -1511,6 +1512,9 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
*/
adjust_range_if_pmd_sharing_possible(vma, &range.start,
&range.end);
+
+ /* We need the huge page size for set_huge_pte_at() */
+ hsz = huge_page_size(hstate_vma(vma));
}
mmu_notifier_invalidate_range_start(&range);

@@ -1628,7 +1632,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
if (folio_test_hugetlb(folio)) {
hugetlb_count_sub(folio_nr_pages(folio), mm);
- set_huge_pte_at(mm, address, pvmw.pte, pteval);
+ set_huge_pte_at(mm, address, pvmw.pte, pteval,
+ hsz);
} else {
dec_mm_counter(mm, mm_counter(&folio->page));
set_pte_at(mm, address, pvmw.pte, pteval);
@@ -1820,6 +1825,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
struct mmu_notifier_range range;
enum ttu_flags flags = (enum ttu_flags)(long)arg;
unsigned long pfn;
+ unsigned long hsz = 0;

/*
* When racing against e.g. zap_pte_range() on another cpu,
@@ -1855,6 +1861,9 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
*/
adjust_range_if_pmd_sharing_possible(vma, &range.start,
&range.end);
+
+ /* We need the huge page size for set_huge_pte_at() */
+ hsz = huge_page_size(hstate_vma(vma));
}
mmu_notifier_invalidate_range_start(&range);

@@ -2020,7 +2029,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
if (folio_test_hugetlb(folio)) {
hugetlb_count_sub(folio_nr_pages(folio), mm);
- set_huge_pte_at(mm, address, pvmw.pte, pteval);
+ set_huge_pte_at(mm, address, pvmw.pte, pteval,
+ hsz);
} else {
dec_mm_counter(mm, mm_counter(&folio->page));
set_pte_at(mm, address, pvmw.pte, pteval);
@@ -2044,7 +2054,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,

if (arch_unmap_one(mm, vma, address, pteval) < 0) {
if (folio_test_hugetlb(folio))
- set_huge_pte_at(mm, address, pvmw.pte, pteval);
+ set_huge_pte_at(mm, address, pvmw.pte,
+ pteval, hsz);
else
set_pte_at(mm, address, pvmw.pte, pteval);
ret = false;
@@ -2058,7 +2069,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
if (anon_exclusive &&
page_try_share_anon_rmap(subpage)) {
if (folio_test_hugetlb(folio))
- set_huge_pte_at(mm, address, pvmw.pte, pteval);
+ set_huge_pte_at(mm, address, pvmw.pte,
+ pteval, hsz);
else
set_pte_at(mm, address, pvmw.pte, pteval);
ret = false;
@@ -2090,7 +2102,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
if (pte_uffd_wp(pteval))
swp_pte = pte_swp_mkuffd_wp(swp_pte);
if (folio_test_hugetlb(folio))
- set_huge_pte_at(mm, address, pvmw.pte, swp_pte);
+ set_huge_pte_at(mm, address, pvmw.pte, swp_pte,
+ hsz);
else
set_pte_at(mm, address, pvmw.pte, swp_pte);
trace_set_migration_pte(address, pte_val(swp_pte),
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ef8599d394fd..a3fedb3ee0db 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -111,7 +111,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
pte_t entry = pfn_pte(pfn, prot);

entry = arch_make_huge_pte(entry, ilog2(size), 0);
- set_huge_pte_at(&init_mm, addr, pte, entry);
+ set_huge_pte_at(&init_mm, addr, pte, entry, size);
pfn += PFN_DOWN(size);
continue;
}
--
2.25.1

2023-09-22 12:24:38

by Ryan Roberts

[permalink] [raw]
Subject: [PATCH v2 2/2] arm64: hugetlb: Fix set_huge_pte_at() to work with all swap entries

When called with a swap entry that does not embed a PFN (e.g.
PTE_MARKER_POISONED or PTE_MARKER_UFFD_WP), the previous implementation
of set_huge_pte_at() would either cause a BUG() to fire (if
CONFIG_DEBUG_VM is enabled) or cause a dereference of an invalid address
and subsequent panic.

arm64's huge pte implementation supports multiple huge page sizes, some
of which are implemented in the page table with multiple contiguous
entries. So set_huge_pte_at() needs to work out how big the logical pte
is, so that it can also work out how many physical ptes (or pmds) need
to be written. It previously did this by grabbing the folio out of the
pte and querying its size.

However, there are cases when the pte being set is actually a swap
entry. But this also used to work fine, because for huge ptes, we only
ever saw migration entries and hwpoison entries. And both of these types
of swap entries have a PFN embedded, so the code would grab that and
everything still worked out.

But over time, more calls to set_huge_pte_at() have been added that set
swap entry types that do not embed a PFN. And this causes the code to go
bang. The triggering case is for the uffd poison test, commit
99aa77215ad0 ("selftests/mm: add uffd unit test for UFFDIO_POISON"),
which causes a PTE_MARKER_POISONED swap entry to be set, coutesey of
commit 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for
hugetlbfs") - added in v6.5-rc7. Although review shows that there are
other call sites that set PTE_MARKER_UFFD_WP (which also has no PFN),
these don't trigger on arm64 because arm64 doesn't support UFFD WP.

Arguably, the root cause is really due to commit 18f3962953e4 ("mm:
hugetlb: kill set_huge_swap_pte_at()"), which aimed to simplify the
interface to the core code by removing set_huge_swap_pte_at() (which
took a page size parameter) and replacing it with calls to
set_huge_pte_at() where the size was inferred from the folio, as
descibed above. While that commit didn't break anything at the time, it
did break the interface because it couldn't handle swap entries without
PFNs. And since then new callers have come along which rely on this
working. But given the brokeness is only observable after commit
8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs"),
that one gets the Fixes tag.

Now that we have modified the set_huge_pte_at() interface to pass the
huge page size in the previous patch, we can trivially fix this issue.

Signed-off-by: Ryan Roberts <[email protected]>
Fixes: 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs")
Cc: <[email protected]> # 6.5+
---
arch/arm64/mm/hugetlbpage.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index a7f8c8db3425..13fd592228b1 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -241,13 +241,6 @@ static void clear_flush(struct mm_struct *mm,
flush_tlb_range(&vma, saddr, addr);
}

-static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
-{
- VM_BUG_ON(!is_migration_entry(entry) && !is_hwpoison_entry(entry));
-
- return page_folio(pfn_to_page(swp_offset_pfn(entry)));
-}
-
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte, unsigned long sz)
{
@@ -257,13 +250,10 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
unsigned long pfn, dpfn;
pgprot_t hugeprot;

- if (!pte_present(pte)) {
- struct folio *folio;
-
- folio = hugetlb_swap_entry_to_folio(pte_to_swp_entry(pte));
- ncontig = num_contig_ptes(folio_size(folio), &pgsize);
+ ncontig = num_contig_ptes(sz, &pgsize);

- for (i = 0; i < ncontig; i++, ptep++)
+ if (!pte_present(pte)) {
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
set_pte_at(mm, addr, ptep, pte);
return;
}
@@ -273,7 +263,6 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
return;
}

- ncontig = find_num_contig(mm, addr, ptep, &pgsize);
pfn = pte_pfn(pte);
dpfn = pgsize >> PAGE_SHIFT;
hugeprot = pte_pgprot(pte);
--
2.25.1

2023-09-22 15:24:30

by Ryan Roberts

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] mm: hugetlb: Add huge page size param to set_huge_pte_at()

On 22/09/2023 14:33, Alexandre Ghiti wrote:
> On 22/09/2023 13:58, Ryan Roberts wrote:
>> In order to fix a bug, arm64 needs to be told the size of the huge page
>> for which the pte is being set in set_huge_pte_at(). Provide for this by
>> adding an `unsigned long sz` parameter to the function. This follows the
>> same pattern as huge_pte_clear().
>>
>> This commit makes the required interface modifications to the core mm as
>> well as all arches that implement this function (arm64, parisc, powerpc,
>> riscv, s390, sparc). The actual arm64 bug will be fixed in a separate
>> commit.
>>
>> No behavioral changes intended.
>>
>> Signed-off-by: Ryan Roberts <[email protected]>
>> Cc: <[email protected]> # 6.5+
>> ---
>>   arch/arm64/include/asm/hugetlb.h              |  2 +-
>>   arch/arm64/mm/hugetlbpage.c                   |  6 ++-
>>   arch/parisc/include/asm/hugetlb.h             |  2 +-
>>   arch/parisc/mm/hugetlbpage.c                  |  2 +-
>>   .../include/asm/nohash/32/hugetlb-8xx.h       |  3 +-
>>   arch/powerpc/mm/book3s64/hugetlbpage.c        |  5 ++-
>>   arch/powerpc/mm/book3s64/radix_hugetlbpage.c  |  3 +-
>>   arch/powerpc/mm/nohash/8xx.c                  |  3 +-
>>   arch/powerpc/mm/pgtable.c                     |  3 +-
>>   arch/riscv/include/asm/hugetlb.h              |  3 +-
>>   arch/riscv/mm/hugetlbpage.c                   |  3 +-
>>   arch/s390/include/asm/hugetlb.h               |  6 ++-
>>   arch/s390/mm/hugetlbpage.c                    |  8 +++-
>>   arch/sparc/include/asm/hugetlb.h              |  6 ++-
>>   arch/sparc/mm/hugetlbpage.c                   |  8 +++-
>>   include/asm-generic/hugetlb.h                 |  2 +-
>>   include/linux/hugetlb.h                       |  6 ++-
>>   mm/damon/vaddr.c                              |  3 +-
>>   mm/hugetlb.c                                  | 43 +++++++++++--------
>>   mm/migrate.c                                  |  7 ++-
>>   mm/rmap.c                                     | 23 +++++++---
>>   mm/vmalloc.c                                  |  2 +-
>>   22 files changed, 100 insertions(+), 49 deletions(-)
>>
>> diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
>> index f43a38ac1779..2ddc33d93b13 100644
>> --- a/arch/arm64/include/asm/hugetlb.h
>> +++ b/arch/arm64/include/asm/hugetlb.h
>> @@ -28,7 +28,7 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift,
>> vm_flags_t flags);
>>   #define arch_make_huge_pte arch_make_huge_pte
>>   #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
>>   extern void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> -                pte_t *ptep, pte_t pte);
>> +                pte_t *ptep, pte_t pte, unsigned long sz);
>>   #define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
>>   extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
>>                         unsigned long addr, pte_t *ptep,
>> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
>> index 9c52718ea750..a7f8c8db3425 100644
>> --- a/arch/arm64/mm/hugetlbpage.c
>> +++ b/arch/arm64/mm/hugetlbpage.c
>> @@ -249,7 +249,7 @@ static inline struct folio
>> *hugetlb_swap_entry_to_folio(swp_entry_t entry)
>>   }
>>     void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> -                pte_t *ptep, pte_t pte)
>> +                pte_t *ptep, pte_t pte, unsigned long sz)
>>   {
>>       size_t pgsize;
>>       int i;
>> @@ -571,5 +571,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct
>> *vma, unsigned long addr
>>   void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long
>> addr, pte_t *ptep,
>>                     pte_t old_pte, pte_t pte)
>>   {
>> -    set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
>> +    unsigned long psize = huge_page_size(hstate_vma(vma));
>
>
> Does this sequence "huge_page_size(hstate_vma(vma))" work for a THP backed vma?

No - it only works for hugetlb vmas.

> Or are we sure that THP paths won't call set_huge_pte_at()?

Yes sure; the "huge_pte" stuff is exclusively for hugetlb. THP uses the standard
infrastructure and only applies to PMD.

>
> Thanks,
>
> Alex
>
>
>> +
>> +    set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
>>   }
>> diff --git a/arch/parisc/include/asm/hugetlb.h
>> b/arch/parisc/include/asm/hugetlb.h
>> index f7f078c2872c..72daacc472a0 100644
>> --- a/arch/parisc/include/asm/hugetlb.h
>> +++ b/arch/parisc/include/asm/hugetlb.h
>> @@ -6,7 +6,7 @@
>>     #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
>>   void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> -             pte_t *ptep, pte_t pte);
>> +             pte_t *ptep, pte_t pte, unsigned long sz);
>>     #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
>>   pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
>> diff --git a/arch/parisc/mm/hugetlbpage.c b/arch/parisc/mm/hugetlbpage.c
>> index a8a1a7c1e16e..a9f7e21f6656 100644
>> --- a/arch/parisc/mm/hugetlbpage.c
>> +++ b/arch/parisc/mm/hugetlbpage.c
>> @@ -140,7 +140,7 @@ static void __set_huge_pte_at(struct mm_struct *mm,
>> unsigned long addr,
>>   }
>>     void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> -             pte_t *ptep, pte_t entry)
>> +             pte_t *ptep, pte_t entry, unsigned long sz)
>>   {
>>       __set_huge_pte_at(mm, addr, ptep, entry);
>>   }
>> diff --git a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
>> b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
>> index de092b04ee1a..92df40c6cc6b 100644
>> --- a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
>> +++ b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
>> @@ -46,7 +46,8 @@ static inline int check_and_get_huge_psize(int shift)
>>   }
>>     #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
>> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
>> pte_t pte);
>> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
>> +             pte_t pte, unsigned long sz);
>>     #define __HAVE_ARCH_HUGE_PTE_CLEAR
>>   static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
>> diff --git a/arch/powerpc/mm/book3s64/hugetlbpage.c
>> b/arch/powerpc/mm/book3s64/hugetlbpage.c
>> index 3bc0eb21b2a0..5a2e512e96db 100644
>> --- a/arch/powerpc/mm/book3s64/hugetlbpage.c
>> +++ b/arch/powerpc/mm/book3s64/hugetlbpage.c
>> @@ -143,11 +143,14 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct
>> *vma,
>>   void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long
>> addr,
>>                     pte_t *ptep, pte_t old_pte, pte_t pte)
>>   {
>> +    unsigned long psize;
>>         if (radix_enabled())
>>           return radix__huge_ptep_modify_prot_commit(vma, addr, ptep,
>>                                  old_pte, pte);
>> -    set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
>> +
>> +    psize = huge_page_size(hstate_vma(vma));
>> +    set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
>>   }
>>     void __init hugetlbpage_init_defaultsize(void)
>> diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
>> b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
>> index 17075c78d4bc..35fd2a95be24 100644
>> --- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
>> +++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
>> @@ -47,6 +47,7 @@ void radix__huge_ptep_modify_prot_commit(struct
>> vm_area_struct *vma,
>>                        pte_t old_pte, pte_t pte)
>>   {
>>       struct mm_struct *mm = vma->vm_mm;
>> +    unsigned long psize = huge_page_size(hstate_vma(vma));
>>         /*
>>        * POWER9 NMMU must flush the TLB after clearing the PTE before
>> @@ -58,5 +59,5 @@ void radix__huge_ptep_modify_prot_commit(struct
>> vm_area_struct *vma,
>>           atomic_read(&mm->context.copros) > 0)
>>           radix__flush_hugetlb_page(vma, addr);
>>   -    set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
>> +    set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
>>   }
>> diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
>> index dbbfe897455d..a642a7929892 100644
>> --- a/arch/powerpc/mm/nohash/8xx.c
>> +++ b/arch/powerpc/mm/nohash/8xx.c
>> @@ -91,7 +91,8 @@ static int __ref __early_map_kernel_hugepage(unsigned long
>> va, phys_addr_t pa,
>>       if (new && WARN_ON(pte_present(*ptep) && pgprot_val(prot)))
>>           return -EINVAL;
>>   -    set_huge_pte_at(&init_mm, va, ptep, pte_mkhuge(pfn_pte(pa >>
>> PAGE_SHIFT, prot)));
>> +    set_huge_pte_at(&init_mm, va, ptep,
>> +            pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)), psize);
>>         return 0;
>>   }
>> diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
>> index 3f86fd217690..3ba9fe411604 100644
>> --- a/arch/powerpc/mm/pgtable.c
>> +++ b/arch/powerpc/mm/pgtable.c
>> @@ -288,7 +288,8 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
>>   }
>>     #if defined(CONFIG_PPC_8xx)
>> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
>> pte_t pte)
>> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
>> +             pte_t pte, unsigned long sz)
>>   {
>>       pmd_t *pmd = pmd_off(mm, addr);
>>       pte_basic_t val;
>> diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
>> index 34e24f078cc1..4c5b0e929890 100644
>> --- a/arch/riscv/include/asm/hugetlb.h
>> +++ b/arch/riscv/include/asm/hugetlb.h
>> @@ -18,7 +18,8 @@ void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
>>     #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
>>   void set_huge_pte_at(struct mm_struct *mm,
>> -             unsigned long addr, pte_t *ptep, pte_t pte);
>> +             unsigned long addr, pte_t *ptep, pte_t pte,
>> +             unsigned long sz);
>>     #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
>>   pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
>> diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
>> index 96225a8533ad..e4a2ace92dbe 100644
>> --- a/arch/riscv/mm/hugetlbpage.c
>> +++ b/arch/riscv/mm/hugetlbpage.c
>> @@ -180,7 +180,8 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift,
>> vm_flags_t flags)
>>   void set_huge_pte_at(struct mm_struct *mm,
>>                unsigned long addr,
>>                pte_t *ptep,
>> -             pte_t pte)
>> +             pte_t pte,
>> +             unsigned long sz)
>>   {
>>       int i, pte_num;
>>   diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
>> index f07267875a19..deb198a61039 100644
>> --- a/arch/s390/include/asm/hugetlb.h
>> +++ b/arch/s390/include/asm/hugetlb.h
>> @@ -16,6 +16,8 @@
>>   #define hugepages_supported()            (MACHINE_HAS_EDAT1)
>>     void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> +             pte_t *ptep, pte_t pte, unsigned long sz);
>> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>>                pte_t *ptep, pte_t pte);
>>   pte_t huge_ptep_get(pte_t *ptep);
>>   pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
>> @@ -65,7 +67,7 @@ static inline int huge_ptep_set_access_flags(struct
>> vm_area_struct *vma,
>>       int changed = !pte_same(huge_ptep_get(ptep), pte);
>>       if (changed) {
>>           huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
>> -        set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
>> +        __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
>>       }
>>       return changed;
>>   }
>> @@ -74,7 +76,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct
>> *mm,
>>                          unsigned long addr, pte_t *ptep)
>>   {
>>       pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
>> -    set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
>> +    __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
>>   }
>>     static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
>> diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
>> index c718f2a0de94..297a6d897d5a 100644
>> --- a/arch/s390/mm/hugetlbpage.c
>> +++ b/arch/s390/mm/hugetlbpage.c
>> @@ -142,7 +142,7 @@ static void clear_huge_pte_skeys(struct mm_struct *mm,
>> unsigned long rste)
>>           __storage_key_init_range(paddr, paddr + size - 1);
>>   }
>>   -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>>                pte_t *ptep, pte_t pte)
>>   {
>>       unsigned long rste;
>> @@ -163,6 +163,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long
>> addr,
>>       set_pte(ptep, __pte(rste));
>>   }
>>   +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> +             pte_t *ptep, pte_t pte, unsigned long sz)
>> +{
>> +    __set_huge_pte_at(mm, addr, ptep, pte);
>> +}
>> +
>>   pte_t huge_ptep_get(pte_t *ptep)
>>   {
>>       return __rste_to_pte(pte_val(*ptep));
>> diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
>> index 0a26cca24232..c714ca6a05aa 100644
>> --- a/arch/sparc/include/asm/hugetlb.h
>> +++ b/arch/sparc/include/asm/hugetlb.h
>> @@ -14,6 +14,8 @@ extern struct pud_huge_patch_entry __pud_huge_patch,
>> __pud_huge_patch_end;
>>     #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
>>   void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> +             pte_t *ptep, pte_t pte, unsigned long sz);
>> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>>                pte_t *ptep, pte_t pte);
>>     #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
>> @@ -32,7 +34,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct
>> *mm,
>>                          unsigned long addr, pte_t *ptep)
>>   {
>>       pte_t old_pte = *ptep;
>> -    set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
>> +    __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
>>   }
>>     #define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
>> @@ -42,7 +44,7 @@ static inline int huge_ptep_set_access_flags(struct
>> vm_area_struct *vma,
>>   {
>>       int changed = !pte_same(*ptep, pte);
>>       if (changed) {
>> -        set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
>> +        __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
>>           flush_tlb_page(vma, addr);
>>       }
>>       return changed;
>> diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
>> index d7018823206c..b432500c13a5 100644
>> --- a/arch/sparc/mm/hugetlbpage.c
>> +++ b/arch/sparc/mm/hugetlbpage.c
>> @@ -328,7 +328,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
>>       return pte_offset_huge(pmd, addr);
>>   }
>>   -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>>                pte_t *ptep, pte_t entry)
>>   {
>>       unsigned int nptes, orig_shift, shift;
>> @@ -364,6 +364,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long
>> addr,
>>                       orig_shift);
>>   }
>>   +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> +             pte_t *ptep, pte_t entry, unsigned long sz)
>> +{
>> +    __set_huge_pte_at(mm, addr, ptep, entry);
>> +}
>> +
>>   pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
>>                     pte_t *ptep)
>>   {
>> diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
>> index 4da02798a00b..6dcf4d576970 100644
>> --- a/include/asm-generic/hugetlb.h
>> +++ b/include/asm-generic/hugetlb.h
>> @@ -76,7 +76,7 @@ static inline void hugetlb_free_pgd_range(struct mmu_gather
>> *tlb,
>>     #ifndef __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
>>   static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> -        pte_t *ptep, pte_t pte)
>> +        pte_t *ptep, pte_t pte, unsigned long sz)
>>   {
>>       set_pte_at(mm, addr, ptep, pte);
>>   }
>> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
>> index 5b2626063f4f..a30686e649f7 100644
>> --- a/include/linux/hugetlb.h
>> +++ b/include/linux/hugetlb.h
>> @@ -984,7 +984,9 @@ static inline void huge_ptep_modify_prot_commit(struct
>> vm_area_struct *vma,
>>                           unsigned long addr, pte_t *ptep,
>>                           pte_t old_pte, pte_t pte)
>>   {
>> -    set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
>> +    unsigned long psize = huge_page_size(hstate_vma(vma));
>> +
>> +    set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
>>   }
>>   #endif
>>   @@ -1173,7 +1175,7 @@ static inline pte_t huge_ptep_clear_flush(struct
>> vm_area_struct *vma,
>>   }
>>     static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> -                   pte_t *ptep, pte_t pte)
>> +                   pte_t *ptep, pte_t pte, unsigned long sz)
>>   {
>>   }
>>   diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
>> index 4c81a9dbd044..cf8a9fc5c9d1 100644
>> --- a/mm/damon/vaddr.c
>> +++ b/mm/damon/vaddr.c
>> @@ -341,13 +341,14 @@ static void damon_hugetlb_mkold(pte_t *pte, struct
>> mm_struct *mm,
>>       bool referenced = false;
>>       pte_t entry = huge_ptep_get(pte);
>>       struct folio *folio = pfn_folio(pte_pfn(entry));
>> +    unsigned long psize = huge_page_size(hstate_vma(vma));
>>         folio_get(folio);
>>         if (pte_young(entry)) {
>>           referenced = true;
>>           entry = pte_mkold(entry);
>> -        set_huge_pte_at(mm, addr, pte, entry);
>> +        set_huge_pte_at(mm, addr, pte, entry, psize);
>>       }
>>     #ifdef CONFIG_MMU_NOTIFIER
>> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
>> index ba6d39b71cb1..52d26072dfda 100644
>> --- a/mm/hugetlb.c
>> +++ b/mm/hugetlb.c
>> @@ -4980,7 +4980,7 @@ static bool is_hugetlb_entry_hwpoisoned(pte_t pte)
>>     static void
>>   hugetlb_install_folio(struct vm_area_struct *vma, pte_t *ptep, unsigned long
>> addr,
>> -              struct folio *new_folio, pte_t old)
>> +              struct folio *new_folio, pte_t old, unsigned long sz)
>>   {
>>       pte_t newpte = make_huge_pte(vma, &new_folio->page, 1);
>>   @@ -4988,7 +4988,7 @@ hugetlb_install_folio(struct vm_area_struct *vma,
>> pte_t *ptep, unsigned long add
>>       hugepage_add_new_anon_rmap(new_folio, vma, addr);
>>       if (userfaultfd_wp(vma) && huge_pte_uffd_wp(old))
>>           newpte = huge_pte_mkuffd_wp(newpte);
>> -    set_huge_pte_at(vma->vm_mm, addr, ptep, newpte);
>> +    set_huge_pte_at(vma->vm_mm, addr, ptep, newpte, sz);
>>       hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm);
>>       folio_set_hugetlb_migratable(new_folio);
>>   }
>> @@ -5065,7 +5065,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst,
>> struct mm_struct *src,
>>           } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) {
>>               if (!userfaultfd_wp(dst_vma))
>>                   entry = huge_pte_clear_uffd_wp(entry);
>> -            set_huge_pte_at(dst, addr, dst_pte, entry);
>> +            set_huge_pte_at(dst, addr, dst_pte, entry, sz);
>>           } else if (unlikely(is_hugetlb_entry_migration(entry))) {
>>               swp_entry_t swp_entry = pte_to_swp_entry(entry);
>>               bool uffd_wp = pte_swp_uffd_wp(entry);
>> @@ -5080,18 +5080,18 @@ int copy_hugetlb_page_range(struct mm_struct *dst,
>> struct mm_struct *src,
>>                   entry = swp_entry_to_pte(swp_entry);
>>                   if (userfaultfd_wp(src_vma) && uffd_wp)
>>                       entry = pte_swp_mkuffd_wp(entry);
>> -                set_huge_pte_at(src, addr, src_pte, entry);
>> +                set_huge_pte_at(src, addr, src_pte, entry, sz);
>>               }
>>               if (!userfaultfd_wp(dst_vma))
>>                   entry = huge_pte_clear_uffd_wp(entry);
>> -            set_huge_pte_at(dst, addr, dst_pte, entry);
>> +            set_huge_pte_at(dst, addr, dst_pte, entry, sz);
>>           } else if (unlikely(is_pte_marker(entry))) {
>>               pte_marker marker = copy_pte_marker(
>>                   pte_to_swp_entry(entry), dst_vma);
>>                 if (marker)
>>                   set_huge_pte_at(dst, addr, dst_pte,
>> -                        make_pte_marker(marker));
>> +                        make_pte_marker(marker), sz);
>>           } else {
>>               entry = huge_ptep_get(src_pte);
>>               pte_folio = page_folio(pte_page(entry));
>> @@ -5145,7 +5145,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst,
>> struct mm_struct *src,
>>                       goto again;
>>                   }
>>                   hugetlb_install_folio(dst_vma, dst_pte, addr,
>> -                              new_folio, src_pte_old);
>> +                              new_folio, src_pte_old, sz);
>>                   spin_unlock(src_ptl);
>>                   spin_unlock(dst_ptl);
>>                   continue;
>> @@ -5166,7 +5166,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst,
>> struct mm_struct *src,
>>               if (!userfaultfd_wp(dst_vma))
>>                   entry = huge_pte_clear_uffd_wp(entry);
>>   -            set_huge_pte_at(dst, addr, dst_pte, entry);
>> +            set_huge_pte_at(dst, addr, dst_pte, entry, sz);
>>               hugetlb_count_add(npages, dst);
>>           }
>>           spin_unlock(src_ptl);
>> @@ -5184,7 +5184,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst,
>> struct mm_struct *src,
>>   }
>>     static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
>> -              unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte)
>> +              unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte,
>> +              unsigned long sz)
>>   {
>>       struct hstate *h = hstate_vma(vma);
>>       struct mm_struct *mm = vma->vm_mm;
>> @@ -5202,7 +5203,7 @@ static void move_huge_pte(struct vm_area_struct *vma,
>> unsigned long old_addr,
>>           spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
>>         pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
>> -    set_huge_pte_at(mm, new_addr, dst_pte, pte);
>> +    set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
>>         if (src_ptl != dst_ptl)
>>           spin_unlock(src_ptl);
>> @@ -5259,7 +5260,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
>>           if (!dst_pte)
>>               break;
>>   -        move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte);
>> +        move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte, sz);
>>       }
>>         if (shared_pmd)
>> @@ -5337,7 +5338,8 @@ static void __unmap_hugepage_range(struct mmu_gather
>> *tlb, struct vm_area_struct
>>               if (pte_swp_uffd_wp_any(pte) &&
>>                   !(zap_flags & ZAP_FLAG_DROP_MARKER))
>>                   set_huge_pte_at(mm, address, ptep,
>> -                        make_pte_marker(PTE_MARKER_UFFD_WP));
>> +                        make_pte_marker(PTE_MARKER_UFFD_WP),
>> +                        sz);
>>               else
>>                   huge_pte_clear(mm, address, ptep, sz);
>>               spin_unlock(ptl);
>> @@ -5371,7 +5373,8 @@ static void __unmap_hugepage_range(struct mmu_gather
>> *tlb, struct vm_area_struct
>>           if (huge_pte_uffd_wp(pte) &&
>>               !(zap_flags & ZAP_FLAG_DROP_MARKER))
>>               set_huge_pte_at(mm, address, ptep,
>> -                    make_pte_marker(PTE_MARKER_UFFD_WP));
>> +                    make_pte_marker(PTE_MARKER_UFFD_WP),
>> +                    sz);
>>           hugetlb_count_sub(pages_per_huge_page(h), mm);
>>           page_remove_rmap(page, vma, true);
>>   @@ -5676,7 +5679,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm,
>> struct vm_area_struct *vma,
>>           hugepage_add_new_anon_rmap(new_folio, vma, haddr);
>>           if (huge_pte_uffd_wp(pte))
>>               newpte = huge_pte_mkuffd_wp(newpte);
>> -        set_huge_pte_at(mm, haddr, ptep, newpte);
>> +        set_huge_pte_at(mm, haddr, ptep, newpte, huge_page_size(h));
>>           folio_set_hugetlb_migratable(new_folio);
>>           /* Make the old page be freed below */
>>           new_folio = old_folio;
>> @@ -5972,7 +5975,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
>>        */
>>       if (unlikely(pte_marker_uffd_wp(old_pte)))
>>           new_pte = huge_pte_mkuffd_wp(new_pte);
>> -    set_huge_pte_at(mm, haddr, ptep, new_pte);
>> +    set_huge_pte_at(mm, haddr, ptep, new_pte, huge_page_size(h));
>>         hugetlb_count_add(pages_per_huge_page(h), mm);
>>       if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
>> @@ -6261,7 +6264,8 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
>>           }
>>             _dst_pte = make_pte_marker(PTE_MARKER_POISONED);
>> -        set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
>> +        set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte,
>> +                huge_page_size(h));
>>             /* No need to invalidate - it was non-present before */
>>           update_mmu_cache(dst_vma, dst_addr, dst_pte);
>> @@ -6412,7 +6416,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
>>       if (wp_enabled)
>>           _dst_pte = huge_pte_mkuffd_wp(_dst_pte);
>>   -    set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
>> +    set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte, huge_page_size(h));
>>         hugetlb_count_add(pages_per_huge_page(h), dst_mm);
>>   @@ -6598,7 +6602,7 @@ long hugetlb_change_protection(struct vm_area_struct
>> *vma,
>>               else if (uffd_wp_resolve)
>>                   newpte = pte_swp_clear_uffd_wp(newpte);
>>               if (!pte_same(pte, newpte))
>> -                set_huge_pte_at(mm, address, ptep, newpte);
>> +                set_huge_pte_at(mm, address, ptep, newpte, psize);
>>           } else if (unlikely(is_pte_marker(pte))) {
>>               /* No other markers apply for now. */
>>               WARN_ON_ONCE(!pte_marker_uffd_wp(pte));
>> @@ -6623,7 +6627,8 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
>>               if (unlikely(uffd_wp))
>>                   /* Safe to modify directly (none->non-present). */
>>                   set_huge_pte_at(mm, address, ptep,
>> -                        make_pte_marker(PTE_MARKER_UFFD_WP));
>> +                        make_pte_marker(PTE_MARKER_UFFD_WP),
>> +                        psize);
>>           }
>>           spin_unlock(ptl);
>>       }
>> diff --git a/mm/migrate.c b/mm/migrate.c
>> index b7fa020003f3..2053b54556ca 100644
>> --- a/mm/migrate.c
>> +++ b/mm/migrate.c
>> @@ -243,7 +243,9 @@ static bool remove_migration_pte(struct folio *folio,
>>     #ifdef CONFIG_HUGETLB_PAGE
>>           if (folio_test_hugetlb(folio)) {
>> -            unsigned int shift = huge_page_shift(hstate_vma(vma));
>> +            struct hstate *h = hstate_vma(vma);
>> +            unsigned int shift = huge_page_shift(h);
>> +            unsigned long psize = huge_page_size(h);
>>                 pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
>>               if (folio_test_anon(folio))
>> @@ -251,7 +253,8 @@ static bool remove_migration_pte(struct folio *folio,
>>                                  rmap_flags);
>>               else
>>                   page_dup_file_rmap(new, true);
>> -            set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
>> +            set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte,
>> +                    psize);
>>           } else
>>   #endif
>>           {
>> diff --git a/mm/rmap.c b/mm/rmap.c
>> index ec7f8e6c9e48..9f795b93cf40 100644
>> --- a/mm/rmap.c
>> +++ b/mm/rmap.c
>> @@ -1480,6 +1480,7 @@ static bool try_to_unmap_one(struct folio *folio, struct
>> vm_area_struct *vma,
>>       struct mmu_notifier_range range;
>>       enum ttu_flags flags = (enum ttu_flags)(long)arg;
>>       unsigned long pfn;
>> +    unsigned long hsz = 0;
>>         /*
>>        * When racing against e.g. zap_pte_range() on another cpu,
>> @@ -1511,6 +1512,9 @@ static bool try_to_unmap_one(struct folio *folio, struct
>> vm_area_struct *vma,
>>            */
>>           adjust_range_if_pmd_sharing_possible(vma, &range.start,
>>                                &range.end);
>> +
>> +        /* We need the huge page size for set_huge_pte_at() */
>> +        hsz = huge_page_size(hstate_vma(vma));
>>       }
>>       mmu_notifier_invalidate_range_start(&range);
>>   @@ -1628,7 +1632,8 @@ static bool try_to_unmap_one(struct folio *folio,
>> struct vm_area_struct *vma,
>>               pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
>>               if (folio_test_hugetlb(folio)) {
>>                   hugetlb_count_sub(folio_nr_pages(folio), mm);
>> -                set_huge_pte_at(mm, address, pvmw.pte, pteval);
>> +                set_huge_pte_at(mm, address, pvmw.pte, pteval,
>> +                        hsz);
>>               } else {
>>                   dec_mm_counter(mm, mm_counter(&folio->page));
>>                   set_pte_at(mm, address, pvmw.pte, pteval);
>> @@ -1820,6 +1825,7 @@ static bool try_to_migrate_one(struct folio *folio,
>> struct vm_area_struct *vma,
>>       struct mmu_notifier_range range;
>>       enum ttu_flags flags = (enum ttu_flags)(long)arg;
>>       unsigned long pfn;
>> +    unsigned long hsz = 0;
>>         /*
>>        * When racing against e.g. zap_pte_range() on another cpu,
>> @@ -1855,6 +1861,9 @@ static bool try_to_migrate_one(struct folio *folio,
>> struct vm_area_struct *vma,
>>            */
>>           adjust_range_if_pmd_sharing_possible(vma, &range.start,
>>                                &range.end);
>> +
>> +        /* We need the huge page size for set_huge_pte_at() */
>> +        hsz = huge_page_size(hstate_vma(vma));
>>       }
>>       mmu_notifier_invalidate_range_start(&range);
>>   @@ -2020,7 +2029,8 @@ static bool try_to_migrate_one(struct folio *folio,
>> struct vm_area_struct *vma,
>>               pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
>>               if (folio_test_hugetlb(folio)) {
>>                   hugetlb_count_sub(folio_nr_pages(folio), mm);
>> -                set_huge_pte_at(mm, address, pvmw.pte, pteval);
>> +                set_huge_pte_at(mm, address, pvmw.pte, pteval,
>> +                        hsz);
>>               } else {
>>                   dec_mm_counter(mm, mm_counter(&folio->page));
>>                   set_pte_at(mm, address, pvmw.pte, pteval);
>> @@ -2044,7 +2054,8 @@ static bool try_to_migrate_one(struct folio *folio,
>> struct vm_area_struct *vma,
>>                 if (arch_unmap_one(mm, vma, address, pteval) < 0) {
>>                   if (folio_test_hugetlb(folio))
>> -                    set_huge_pte_at(mm, address, pvmw.pte, pteval);
>> +                    set_huge_pte_at(mm, address, pvmw.pte,
>> +                            pteval, hsz);
>>                   else
>>                       set_pte_at(mm, address, pvmw.pte, pteval);
>>                   ret = false;
>> @@ -2058,7 +2069,8 @@ static bool try_to_migrate_one(struct folio *folio,
>> struct vm_area_struct *vma,
>>               if (anon_exclusive &&
>>                   page_try_share_anon_rmap(subpage)) {
>>                   if (folio_test_hugetlb(folio))
>> -                    set_huge_pte_at(mm, address, pvmw.pte, pteval);
>> +                    set_huge_pte_at(mm, address, pvmw.pte,
>> +                            pteval, hsz);
>>                   else
>>                       set_pte_at(mm, address, pvmw.pte, pteval);
>>                   ret = false;
>> @@ -2090,7 +2102,8 @@ static bool try_to_migrate_one(struct folio *folio,
>> struct vm_area_struct *vma,
>>               if (pte_uffd_wp(pteval))
>>                   swp_pte = pte_swp_mkuffd_wp(swp_pte);
>>               if (folio_test_hugetlb(folio))
>> -                set_huge_pte_at(mm, address, pvmw.pte, swp_pte);
>> +                set_huge_pte_at(mm, address, pvmw.pte, swp_pte,
>> +                        hsz);
>>               else
>>                   set_pte_at(mm, address, pvmw.pte, swp_pte);
>>               trace_set_migration_pte(address, pte_val(swp_pte),
>> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
>> index ef8599d394fd..a3fedb3ee0db 100644
>> --- a/mm/vmalloc.c
>> +++ b/mm/vmalloc.c
>> @@ -111,7 +111,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
>> unsigned long end,
>>               pte_t entry = pfn_pte(pfn, prot);
>>                 entry = arch_make_huge_pte(entry, ilog2(size), 0);
>> -            set_huge_pte_at(&init_mm, addr, pte, entry);
>> +            set_huge_pte_at(&init_mm, addr, pte, entry, size);
>>               pfn += PFN_DOWN(size);
>>               continue;
>>           }

2023-09-22 16:22:34

by Will Deacon

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] arm64: hugetlb: Fix set_huge_pte_at() to work with all swap entries

On Fri, Sep 22, 2023 at 12:58:04PM +0100, Ryan Roberts wrote:
> When called with a swap entry that does not embed a PFN (e.g.
> PTE_MARKER_POISONED or PTE_MARKER_UFFD_WP), the previous implementation
> of set_huge_pte_at() would either cause a BUG() to fire (if
> CONFIG_DEBUG_VM is enabled) or cause a dereference of an invalid address
> and subsequent panic.
>
> arm64's huge pte implementation supports multiple huge page sizes, some
> of which are implemented in the page table with multiple contiguous
> entries. So set_huge_pte_at() needs to work out how big the logical pte
> is, so that it can also work out how many physical ptes (or pmds) need
> to be written. It previously did this by grabbing the folio out of the
> pte and querying its size.
>
> However, there are cases when the pte being set is actually a swap
> entry. But this also used to work fine, because for huge ptes, we only
> ever saw migration entries and hwpoison entries. And both of these types
> of swap entries have a PFN embedded, so the code would grab that and
> everything still worked out.
>
> But over time, more calls to set_huge_pte_at() have been added that set
> swap entry types that do not embed a PFN. And this causes the code to go
> bang. The triggering case is for the uffd poison test, commit
> 99aa77215ad0 ("selftests/mm: add uffd unit test for UFFDIO_POISON"),
> which causes a PTE_MARKER_POISONED swap entry to be set, coutesey of
> commit 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for
> hugetlbfs") - added in v6.5-rc7. Although review shows that there are
> other call sites that set PTE_MARKER_UFFD_WP (which also has no PFN),
> these don't trigger on arm64 because arm64 doesn't support UFFD WP.
>
> Arguably, the root cause is really due to commit 18f3962953e4 ("mm:
> hugetlb: kill set_huge_swap_pte_at()"), which aimed to simplify the
> interface to the core code by removing set_huge_swap_pte_at() (which
> took a page size parameter) and replacing it with calls to
> set_huge_pte_at() where the size was inferred from the folio, as
> descibed above. While that commit didn't break anything at the time, it
> did break the interface because it couldn't handle swap entries without
> PFNs. And since then new callers have come along which rely on this
> working. But given the brokeness is only observable after commit
> 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs"),
> that one gets the Fixes tag.
>
> Now that we have modified the set_huge_pte_at() interface to pass the
> huge page size in the previous patch, we can trivially fix this issue.
>
> Signed-off-by: Ryan Roberts <[email protected]>
> Fixes: 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs")
> Cc: <[email protected]> # 6.5+
> ---
> arch/arm64/mm/hugetlbpage.c | 17 +++--------------
> 1 file changed, 3 insertions(+), 14 deletions(-)
>
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index a7f8c8db3425..13fd592228b1 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -241,13 +241,6 @@ static void clear_flush(struct mm_struct *mm,
> flush_tlb_range(&vma, saddr, addr);
> }
>
> -static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
> -{
> - VM_BUG_ON(!is_migration_entry(entry) && !is_hwpoison_entry(entry));
> -
> - return page_folio(pfn_to_page(swp_offset_pfn(entry)));
> -}
> -
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte, unsigned long sz)
> {
> @@ -257,13 +250,10 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> unsigned long pfn, dpfn;
> pgprot_t hugeprot;
>
> - if (!pte_present(pte)) {
> - struct folio *folio;
> -
> - folio = hugetlb_swap_entry_to_folio(pte_to_swp_entry(pte));
> - ncontig = num_contig_ptes(folio_size(folio), &pgsize);
> + ncontig = num_contig_ptes(sz, &pgsize);
>
> - for (i = 0; i < ncontig; i++, ptep++)
> + if (!pte_present(pte)) {
> + for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
> set_pte_at(mm, addr, ptep, pte);

Our set_pte_at() doesn't use 'addr' for anything and the old code didn't
even bother to increment it here! I'm fine adding that, but it feels
unrelated to the issue which this patch is actually fixing.

Either way:

Acked-by: Will Deacon <[email protected]>

Will

2023-09-22 16:43:58

by Ryan Roberts

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] arm64: hugetlb: Fix set_huge_pte_at() to work with all swap entries

On 22/09/2023 17:14, Will Deacon wrote:
> On Fri, Sep 22, 2023 at 12:58:04PM +0100, Ryan Roberts wrote:
>> When called with a swap entry that does not embed a PFN (e.g.
>> PTE_MARKER_POISONED or PTE_MARKER_UFFD_WP), the previous implementation
>> of set_huge_pte_at() would either cause a BUG() to fire (if
>> CONFIG_DEBUG_VM is enabled) or cause a dereference of an invalid address
>> and subsequent panic.
>>
>> arm64's huge pte implementation supports multiple huge page sizes, some
>> of which are implemented in the page table with multiple contiguous
>> entries. So set_huge_pte_at() needs to work out how big the logical pte
>> is, so that it can also work out how many physical ptes (or pmds) need
>> to be written. It previously did this by grabbing the folio out of the
>> pte and querying its size.
>>
>> However, there are cases when the pte being set is actually a swap
>> entry. But this also used to work fine, because for huge ptes, we only
>> ever saw migration entries and hwpoison entries. And both of these types
>> of swap entries have a PFN embedded, so the code would grab that and
>> everything still worked out.
>>
>> But over time, more calls to set_huge_pte_at() have been added that set
>> swap entry types that do not embed a PFN. And this causes the code to go
>> bang. The triggering case is for the uffd poison test, commit
>> 99aa77215ad0 ("selftests/mm: add uffd unit test for UFFDIO_POISON"),
>> which causes a PTE_MARKER_POISONED swap entry to be set, coutesey of
>> commit 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for
>> hugetlbfs") - added in v6.5-rc7. Although review shows that there are
>> other call sites that set PTE_MARKER_UFFD_WP (which also has no PFN),
>> these don't trigger on arm64 because arm64 doesn't support UFFD WP.
>>
>> Arguably, the root cause is really due to commit 18f3962953e4 ("mm:
>> hugetlb: kill set_huge_swap_pte_at()"), which aimed to simplify the
>> interface to the core code by removing set_huge_swap_pte_at() (which
>> took a page size parameter) and replacing it with calls to
>> set_huge_pte_at() where the size was inferred from the folio, as
>> descibed above. While that commit didn't break anything at the time, it
>> did break the interface because it couldn't handle swap entries without
>> PFNs. And since then new callers have come along which rely on this
>> working. But given the brokeness is only observable after commit
>> 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs"),
>> that one gets the Fixes tag.
>>
>> Now that we have modified the set_huge_pte_at() interface to pass the
>> huge page size in the previous patch, we can trivially fix this issue.
>>
>> Signed-off-by: Ryan Roberts <[email protected]>
>> Fixes: 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs")
>> Cc: <[email protected]> # 6.5+
>> ---
>> arch/arm64/mm/hugetlbpage.c | 17 +++--------------
>> 1 file changed, 3 insertions(+), 14 deletions(-)
>>
>> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
>> index a7f8c8db3425..13fd592228b1 100644
>> --- a/arch/arm64/mm/hugetlbpage.c
>> +++ b/arch/arm64/mm/hugetlbpage.c
>> @@ -241,13 +241,6 @@ static void clear_flush(struct mm_struct *mm,
>> flush_tlb_range(&vma, saddr, addr);
>> }
>>
>> -static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
>> -{
>> - VM_BUG_ON(!is_migration_entry(entry) && !is_hwpoison_entry(entry));
>> -
>> - return page_folio(pfn_to_page(swp_offset_pfn(entry)));
>> -}
>> -
>> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> pte_t *ptep, pte_t pte, unsigned long sz)
>> {
>> @@ -257,13 +250,10 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>> unsigned long pfn, dpfn;
>> pgprot_t hugeprot;
>>
>> - if (!pte_present(pte)) {
>> - struct folio *folio;
>> -
>> - folio = hugetlb_swap_entry_to_folio(pte_to_swp_entry(pte));
>> - ncontig = num_contig_ptes(folio_size(folio), &pgsize);
>> + ncontig = num_contig_ptes(sz, &pgsize);
>>
>> - for (i = 0; i < ncontig; i++, ptep++)
>> + if (!pte_present(pte)) {
>> + for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
>> set_pte_at(mm, addr, ptep, pte);
>
> Our set_pte_at() doesn't use 'addr' for anything and the old code didn't
> even bother to increment it here! I'm fine adding that, but it feels
> unrelated to the issue which this patch is actually fixing.

True. I agree its not strictly necessary and will presumably be optimized out.
But I'm not sure that having knowledge that the implementation doesn't use it is
a good reason not to call the interface correctly. I'll leave it as I've done it
if that's ok.

>
> Either way:
>
> Acked-by: Will Deacon <[email protected]>

Thanks!

>
> Will

2023-09-22 16:54:16

by Alexandre Ghiti

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] mm: hugetlb: Add huge page size param to set_huge_pte_at()

On 22/09/2023 13:58, Ryan Roberts wrote:
> In order to fix a bug, arm64 needs to be told the size of the huge page
> for which the pte is being set in set_huge_pte_at(). Provide for this by
> adding an `unsigned long sz` parameter to the function. This follows the
> same pattern as huge_pte_clear().
>
> This commit makes the required interface modifications to the core mm as
> well as all arches that implement this function (arm64, parisc, powerpc,
> riscv, s390, sparc). The actual arm64 bug will be fixed in a separate
> commit.
>
> No behavioral changes intended.
>
> Signed-off-by: Ryan Roberts <[email protected]>
> Cc: <[email protected]> # 6.5+
> ---
> arch/arm64/include/asm/hugetlb.h | 2 +-
> arch/arm64/mm/hugetlbpage.c | 6 ++-
> arch/parisc/include/asm/hugetlb.h | 2 +-
> arch/parisc/mm/hugetlbpage.c | 2 +-
> .../include/asm/nohash/32/hugetlb-8xx.h | 3 +-
> arch/powerpc/mm/book3s64/hugetlbpage.c | 5 ++-
> arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 3 +-
> arch/powerpc/mm/nohash/8xx.c | 3 +-
> arch/powerpc/mm/pgtable.c | 3 +-
> arch/riscv/include/asm/hugetlb.h | 3 +-
> arch/riscv/mm/hugetlbpage.c | 3 +-
> arch/s390/include/asm/hugetlb.h | 6 ++-
> arch/s390/mm/hugetlbpage.c | 8 +++-
> arch/sparc/include/asm/hugetlb.h | 6 ++-
> arch/sparc/mm/hugetlbpage.c | 8 +++-
> include/asm-generic/hugetlb.h | 2 +-
> include/linux/hugetlb.h | 6 ++-
> mm/damon/vaddr.c | 3 +-
> mm/hugetlb.c | 43 +++++++++++--------
> mm/migrate.c | 7 ++-
> mm/rmap.c | 23 +++++++---
> mm/vmalloc.c | 2 +-
> 22 files changed, 100 insertions(+), 49 deletions(-)
>
> diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
> index f43a38ac1779..2ddc33d93b13 100644
> --- a/arch/arm64/include/asm/hugetlb.h
> +++ b/arch/arm64/include/asm/hugetlb.h
> @@ -28,7 +28,7 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags);
> #define arch_make_huge_pte arch_make_huge_pte
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> extern void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte);
> + pte_t *ptep, pte_t pte, unsigned long sz);
> #define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
> extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> unsigned long addr, pte_t *ptep,
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 9c52718ea750..a7f8c8db3425 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -249,7 +249,7 @@ static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
> }
>
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte)
> + pte_t *ptep, pte_t pte, unsigned long sz)
> {
> size_t pgsize;
> int i;
> @@ -571,5 +571,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr
> void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
> pte_t old_pte, pte_t pte)
> {
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + unsigned long psize = huge_page_size(hstate_vma(vma));


Does this sequence "huge_page_size(hstate_vma(vma))" work for a THP
backed vma? Or are we sure that THP paths won't call set_huge_pte_at()?

Thanks,

Alex


> +
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
> diff --git a/arch/parisc/include/asm/hugetlb.h b/arch/parisc/include/asm/hugetlb.h
> index f7f078c2872c..72daacc472a0 100644
> --- a/arch/parisc/include/asm/hugetlb.h
> +++ b/arch/parisc/include/asm/hugetlb.h
> @@ -6,7 +6,7 @@
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte);
> + pte_t *ptep, pte_t pte, unsigned long sz);
>
> #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
> diff --git a/arch/parisc/mm/hugetlbpage.c b/arch/parisc/mm/hugetlbpage.c
> index a8a1a7c1e16e..a9f7e21f6656 100644
> --- a/arch/parisc/mm/hugetlbpage.c
> +++ b/arch/parisc/mm/hugetlbpage.c
> @@ -140,7 +140,7 @@ static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> }
>
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t entry)
> + pte_t *ptep, pte_t entry, unsigned long sz)
> {
> __set_huge_pte_at(mm, addr, ptep, entry);
> }
> diff --git a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
> index de092b04ee1a..92df40c6cc6b 100644
> --- a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
> +++ b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
> @@ -46,7 +46,8 @@ static inline int check_and_get_huge_psize(int shift)
> }
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
> + pte_t pte, unsigned long sz);
>
> #define __HAVE_ARCH_HUGE_PTE_CLEAR
> static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
> diff --git a/arch/powerpc/mm/book3s64/hugetlbpage.c b/arch/powerpc/mm/book3s64/hugetlbpage.c
> index 3bc0eb21b2a0..5a2e512e96db 100644
> --- a/arch/powerpc/mm/book3s64/hugetlbpage.c
> +++ b/arch/powerpc/mm/book3s64/hugetlbpage.c
> @@ -143,11 +143,14 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
> void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
> pte_t *ptep, pte_t old_pte, pte_t pte)
> {
> + unsigned long psize;
>
> if (radix_enabled())
> return radix__huge_ptep_modify_prot_commit(vma, addr, ptep,
> old_pte, pte);
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> +
> + psize = huge_page_size(hstate_vma(vma));
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
>
> void __init hugetlbpage_init_defaultsize(void)
> diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> index 17075c78d4bc..35fd2a95be24 100644
> --- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> +++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> @@ -47,6 +47,7 @@ void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> pte_t old_pte, pte_t pte)
> {
> struct mm_struct *mm = vma->vm_mm;
> + unsigned long psize = huge_page_size(hstate_vma(vma));
>
> /*
> * POWER9 NMMU must flush the TLB after clearing the PTE before
> @@ -58,5 +59,5 @@ void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> atomic_read(&mm->context.copros) > 0)
> radix__flush_hugetlb_page(vma, addr);
>
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
> diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
> index dbbfe897455d..a642a7929892 100644
> --- a/arch/powerpc/mm/nohash/8xx.c
> +++ b/arch/powerpc/mm/nohash/8xx.c
> @@ -91,7 +91,8 @@ static int __ref __early_map_kernel_hugepage(unsigned long va, phys_addr_t pa,
> if (new && WARN_ON(pte_present(*ptep) && pgprot_val(prot)))
> return -EINVAL;
>
> - set_huge_pte_at(&init_mm, va, ptep, pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)));
> + set_huge_pte_at(&init_mm, va, ptep,
> + pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)), psize);
>
> return 0;
> }
> diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
> index 3f86fd217690..3ba9fe411604 100644
> --- a/arch/powerpc/mm/pgtable.c
> +++ b/arch/powerpc/mm/pgtable.c
> @@ -288,7 +288,8 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> }
>
> #if defined(CONFIG_PPC_8xx)
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
> + pte_t pte, unsigned long sz)
> {
> pmd_t *pmd = pmd_off(mm, addr);
> pte_basic_t val;
> diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
> index 34e24f078cc1..4c5b0e929890 100644
> --- a/arch/riscv/include/asm/hugetlb.h
> +++ b/arch/riscv/include/asm/hugetlb.h
> @@ -18,7 +18,8 @@ void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> void set_huge_pte_at(struct mm_struct *mm,
> - unsigned long addr, pte_t *ptep, pte_t pte);
> + unsigned long addr, pte_t *ptep, pte_t pte,
> + unsigned long sz);
>
> #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
> diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
> index 96225a8533ad..e4a2ace92dbe 100644
> --- a/arch/riscv/mm/hugetlbpage.c
> +++ b/arch/riscv/mm/hugetlbpage.c
> @@ -180,7 +180,8 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
> void set_huge_pte_at(struct mm_struct *mm,
> unsigned long addr,
> pte_t *ptep,
> - pte_t pte)
> + pte_t pte,
> + unsigned long sz)
> {
> int i, pte_num;
>
> diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
> index f07267875a19..deb198a61039 100644
> --- a/arch/s390/include/asm/hugetlb.h
> +++ b/arch/s390/include/asm/hugetlb.h
> @@ -16,6 +16,8 @@
> #define hugepages_supported() (MACHINE_HAS_EDAT1)
>
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned long sz);
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte);
> pte_t huge_ptep_get(pte_t *ptep);
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
> @@ -65,7 +67,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> int changed = !pte_same(huge_ptep_get(ptep), pte);
> if (changed) {
> huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> }
> return changed;
> }
> @@ -74,7 +76,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
> unsigned long addr, pte_t *ptep)
> {
> pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
> - set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
> + __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
> }
>
> static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
> diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
> index c718f2a0de94..297a6d897d5a 100644
> --- a/arch/s390/mm/hugetlbpage.c
> +++ b/arch/s390/mm/hugetlbpage.c
> @@ -142,7 +142,7 @@ static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
> __storage_key_init_range(paddr, paddr + size - 1);
> }
>
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte)
> {
> unsigned long rste;
> @@ -163,6 +163,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> set_pte(ptep, __pte(rste));
> }
>
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned long sz)
> +{
> + __set_huge_pte_at(mm, addr, ptep, pte);
> +}
> +
> pte_t huge_ptep_get(pte_t *ptep)
> {
> return __rste_to_pte(pte_val(*ptep));
> diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
> index 0a26cca24232..c714ca6a05aa 100644
> --- a/arch/sparc/include/asm/hugetlb.h
> +++ b/arch/sparc/include/asm/hugetlb.h
> @@ -14,6 +14,8 @@ extern struct pud_huge_patch_entry __pud_huge_patch, __pud_huge_patch_end;
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned long sz);
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte);
>
> #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
> @@ -32,7 +34,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
> unsigned long addr, pte_t *ptep)
> {
> pte_t old_pte = *ptep;
> - set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
> + __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
> }
>
> #define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
> @@ -42,7 +44,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> {
> int changed = !pte_same(*ptep, pte);
> if (changed) {
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> flush_tlb_page(vma, addr);
> }
> return changed;
> diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
> index d7018823206c..b432500c13a5 100644
> --- a/arch/sparc/mm/hugetlbpage.c
> +++ b/arch/sparc/mm/hugetlbpage.c
> @@ -328,7 +328,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
> return pte_offset_huge(pmd, addr);
> }
>
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t entry)
> {
> unsigned int nptes, orig_shift, shift;
> @@ -364,6 +364,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> orig_shift);
> }
>
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t entry, unsigned long sz)
> +{
> + __set_huge_pte_at(mm, addr, ptep, entry);
> +}
> +
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep)
> {
> diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
> index 4da02798a00b..6dcf4d576970 100644
> --- a/include/asm-generic/hugetlb.h
> +++ b/include/asm-generic/hugetlb.h
> @@ -76,7 +76,7 @@ static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
>
> #ifndef __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte)
> + pte_t *ptep, pte_t pte, unsigned long sz)
> {
> set_pte_at(mm, addr, ptep, pte);
> }
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 5b2626063f4f..a30686e649f7 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -984,7 +984,9 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> unsigned long addr, pte_t *ptep,
> pte_t old_pte, pte_t pte)
> {
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + unsigned long psize = huge_page_size(hstate_vma(vma));
> +
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
> #endif
>
> @@ -1173,7 +1175,7 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
> }
>
> static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte)
> + pte_t *ptep, pte_t pte, unsigned long sz)
> {
> }
>
> diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
> index 4c81a9dbd044..cf8a9fc5c9d1 100644
> --- a/mm/damon/vaddr.c
> +++ b/mm/damon/vaddr.c
> @@ -341,13 +341,14 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm,
> bool referenced = false;
> pte_t entry = huge_ptep_get(pte);
> struct folio *folio = pfn_folio(pte_pfn(entry));
> + unsigned long psize = huge_page_size(hstate_vma(vma));
>
> folio_get(folio);
>
> if (pte_young(entry)) {
> referenced = true;
> entry = pte_mkold(entry);
> - set_huge_pte_at(mm, addr, pte, entry);
> + set_huge_pte_at(mm, addr, pte, entry, psize);
> }
>
> #ifdef CONFIG_MMU_NOTIFIER
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index ba6d39b71cb1..52d26072dfda 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -4980,7 +4980,7 @@ static bool is_hugetlb_entry_hwpoisoned(pte_t pte)
>
> static void
> hugetlb_install_folio(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr,
> - struct folio *new_folio, pte_t old)
> + struct folio *new_folio, pte_t old, unsigned long sz)
> {
> pte_t newpte = make_huge_pte(vma, &new_folio->page, 1);
>
> @@ -4988,7 +4988,7 @@ hugetlb_install_folio(struct vm_area_struct *vma, pte_t *ptep, unsigned long add
> hugepage_add_new_anon_rmap(new_folio, vma, addr);
> if (userfaultfd_wp(vma) && huge_pte_uffd_wp(old))
> newpte = huge_pte_mkuffd_wp(newpte);
> - set_huge_pte_at(vma->vm_mm, addr, ptep, newpte);
> + set_huge_pte_at(vma->vm_mm, addr, ptep, newpte, sz);
> hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm);
> folio_set_hugetlb_migratable(new_folio);
> }
> @@ -5065,7 +5065,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) {
> if (!userfaultfd_wp(dst_vma))
> entry = huge_pte_clear_uffd_wp(entry);
> - set_huge_pte_at(dst, addr, dst_pte, entry);
> + set_huge_pte_at(dst, addr, dst_pte, entry, sz);
> } else if (unlikely(is_hugetlb_entry_migration(entry))) {
> swp_entry_t swp_entry = pte_to_swp_entry(entry);
> bool uffd_wp = pte_swp_uffd_wp(entry);
> @@ -5080,18 +5080,18 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> entry = swp_entry_to_pte(swp_entry);
> if (userfaultfd_wp(src_vma) && uffd_wp)
> entry = pte_swp_mkuffd_wp(entry);
> - set_huge_pte_at(src, addr, src_pte, entry);
> + set_huge_pte_at(src, addr, src_pte, entry, sz);
> }
> if (!userfaultfd_wp(dst_vma))
> entry = huge_pte_clear_uffd_wp(entry);
> - set_huge_pte_at(dst, addr, dst_pte, entry);
> + set_huge_pte_at(dst, addr, dst_pte, entry, sz);
> } else if (unlikely(is_pte_marker(entry))) {
> pte_marker marker = copy_pte_marker(
> pte_to_swp_entry(entry), dst_vma);
>
> if (marker)
> set_huge_pte_at(dst, addr, dst_pte,
> - make_pte_marker(marker));
> + make_pte_marker(marker), sz);
> } else {
> entry = huge_ptep_get(src_pte);
> pte_folio = page_folio(pte_page(entry));
> @@ -5145,7 +5145,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> goto again;
> }
> hugetlb_install_folio(dst_vma, dst_pte, addr,
> - new_folio, src_pte_old);
> + new_folio, src_pte_old, sz);
> spin_unlock(src_ptl);
> spin_unlock(dst_ptl);
> continue;
> @@ -5166,7 +5166,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> if (!userfaultfd_wp(dst_vma))
> entry = huge_pte_clear_uffd_wp(entry);
>
> - set_huge_pte_at(dst, addr, dst_pte, entry);
> + set_huge_pte_at(dst, addr, dst_pte, entry, sz);
> hugetlb_count_add(npages, dst);
> }
> spin_unlock(src_ptl);
> @@ -5184,7 +5184,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> }
>
> static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
> - unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte)
> + unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte,
> + unsigned long sz)
> {
> struct hstate *h = hstate_vma(vma);
> struct mm_struct *mm = vma->vm_mm;
> @@ -5202,7 +5203,7 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
> spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
>
> pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
> - set_huge_pte_at(mm, new_addr, dst_pte, pte);
> + set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
>
> if (src_ptl != dst_ptl)
> spin_unlock(src_ptl);
> @@ -5259,7 +5260,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
> if (!dst_pte)
> break;
>
> - move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte);
> + move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte, sz);
> }
>
> if (shared_pmd)
> @@ -5337,7 +5338,8 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
> if (pte_swp_uffd_wp_any(pte) &&
> !(zap_flags & ZAP_FLAG_DROP_MARKER))
> set_huge_pte_at(mm, address, ptep,
> - make_pte_marker(PTE_MARKER_UFFD_WP));
> + make_pte_marker(PTE_MARKER_UFFD_WP),
> + sz);
> else
> huge_pte_clear(mm, address, ptep, sz);
> spin_unlock(ptl);
> @@ -5371,7 +5373,8 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
> if (huge_pte_uffd_wp(pte) &&
> !(zap_flags & ZAP_FLAG_DROP_MARKER))
> set_huge_pte_at(mm, address, ptep,
> - make_pte_marker(PTE_MARKER_UFFD_WP));
> + make_pte_marker(PTE_MARKER_UFFD_WP),
> + sz);
> hugetlb_count_sub(pages_per_huge_page(h), mm);
> page_remove_rmap(page, vma, true);
>
> @@ -5676,7 +5679,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
> hugepage_add_new_anon_rmap(new_folio, vma, haddr);
> if (huge_pte_uffd_wp(pte))
> newpte = huge_pte_mkuffd_wp(newpte);
> - set_huge_pte_at(mm, haddr, ptep, newpte);
> + set_huge_pte_at(mm, haddr, ptep, newpte, huge_page_size(h));
> folio_set_hugetlb_migratable(new_folio);
> /* Make the old page be freed below */
> new_folio = old_folio;
> @@ -5972,7 +5975,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
> */
> if (unlikely(pte_marker_uffd_wp(old_pte)))
> new_pte = huge_pte_mkuffd_wp(new_pte);
> - set_huge_pte_at(mm, haddr, ptep, new_pte);
> + set_huge_pte_at(mm, haddr, ptep, new_pte, huge_page_size(h));
>
> hugetlb_count_add(pages_per_huge_page(h), mm);
> if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
> @@ -6261,7 +6264,8 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
> }
>
> _dst_pte = make_pte_marker(PTE_MARKER_POISONED);
> - set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
> + set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte,
> + huge_page_size(h));
>
> /* No need to invalidate - it was non-present before */
> update_mmu_cache(dst_vma, dst_addr, dst_pte);
> @@ -6412,7 +6416,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
> if (wp_enabled)
> _dst_pte = huge_pte_mkuffd_wp(_dst_pte);
>
> - set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
> + set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte, huge_page_size(h));
>
> hugetlb_count_add(pages_per_huge_page(h), dst_mm);
>
> @@ -6598,7 +6602,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
> else if (uffd_wp_resolve)
> newpte = pte_swp_clear_uffd_wp(newpte);
> if (!pte_same(pte, newpte))
> - set_huge_pte_at(mm, address, ptep, newpte);
> + set_huge_pte_at(mm, address, ptep, newpte, psize);
> } else if (unlikely(is_pte_marker(pte))) {
> /* No other markers apply for now. */
> WARN_ON_ONCE(!pte_marker_uffd_wp(pte));
> @@ -6623,7 +6627,8 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
> if (unlikely(uffd_wp))
> /* Safe to modify directly (none->non-present). */
> set_huge_pte_at(mm, address, ptep,
> - make_pte_marker(PTE_MARKER_UFFD_WP));
> + make_pte_marker(PTE_MARKER_UFFD_WP),
> + psize);
> }
> spin_unlock(ptl);
> }
> diff --git a/mm/migrate.c b/mm/migrate.c
> index b7fa020003f3..2053b54556ca 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -243,7 +243,9 @@ static bool remove_migration_pte(struct folio *folio,
>
> #ifdef CONFIG_HUGETLB_PAGE
> if (folio_test_hugetlb(folio)) {
> - unsigned int shift = huge_page_shift(hstate_vma(vma));
> + struct hstate *h = hstate_vma(vma);
> + unsigned int shift = huge_page_shift(h);
> + unsigned long psize = huge_page_size(h);
>
> pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
> if (folio_test_anon(folio))
> @@ -251,7 +253,8 @@ static bool remove_migration_pte(struct folio *folio,
> rmap_flags);
> else
> page_dup_file_rmap(new, true);
> - set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
> + set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte,
> + psize);
> } else
> #endif
> {
> diff --git a/mm/rmap.c b/mm/rmap.c
> index ec7f8e6c9e48..9f795b93cf40 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -1480,6 +1480,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> struct mmu_notifier_range range;
> enum ttu_flags flags = (enum ttu_flags)(long)arg;
> unsigned long pfn;
> + unsigned long hsz = 0;
>
> /*
> * When racing against e.g. zap_pte_range() on another cpu,
> @@ -1511,6 +1512,9 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> */
> adjust_range_if_pmd_sharing_possible(vma, &range.start,
> &range.end);
> +
> + /* We need the huge page size for set_huge_pte_at() */
> + hsz = huge_page_size(hstate_vma(vma));
> }
> mmu_notifier_invalidate_range_start(&range);
>
> @@ -1628,7 +1632,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
> if (folio_test_hugetlb(folio)) {
> hugetlb_count_sub(folio_nr_pages(folio), mm);
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte, pteval,
> + hsz);
> } else {
> dec_mm_counter(mm, mm_counter(&folio->page));
> set_pte_at(mm, address, pvmw.pte, pteval);
> @@ -1820,6 +1825,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> struct mmu_notifier_range range;
> enum ttu_flags flags = (enum ttu_flags)(long)arg;
> unsigned long pfn;
> + unsigned long hsz = 0;
>
> /*
> * When racing against e.g. zap_pte_range() on another cpu,
> @@ -1855,6 +1861,9 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> */
> adjust_range_if_pmd_sharing_possible(vma, &range.start,
> &range.end);
> +
> + /* We need the huge page size for set_huge_pte_at() */
> + hsz = huge_page_size(hstate_vma(vma));
> }
> mmu_notifier_invalidate_range_start(&range);
>
> @@ -2020,7 +2029,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
> if (folio_test_hugetlb(folio)) {
> hugetlb_count_sub(folio_nr_pages(folio), mm);
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte, pteval,
> + hsz);
> } else {
> dec_mm_counter(mm, mm_counter(&folio->page));
> set_pte_at(mm, address, pvmw.pte, pteval);
> @@ -2044,7 +2054,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
>
> if (arch_unmap_one(mm, vma, address, pteval) < 0) {
> if (folio_test_hugetlb(folio))
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte,
> + pteval, hsz);
> else
> set_pte_at(mm, address, pvmw.pte, pteval);
> ret = false;
> @@ -2058,7 +2069,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> if (anon_exclusive &&
> page_try_share_anon_rmap(subpage)) {
> if (folio_test_hugetlb(folio))
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte,
> + pteval, hsz);
> else
> set_pte_at(mm, address, pvmw.pte, pteval);
> ret = false;
> @@ -2090,7 +2102,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> if (pte_uffd_wp(pteval))
> swp_pte = pte_swp_mkuffd_wp(swp_pte);
> if (folio_test_hugetlb(folio))
> - set_huge_pte_at(mm, address, pvmw.pte, swp_pte);
> + set_huge_pte_at(mm, address, pvmw.pte, swp_pte,
> + hsz);
> else
> set_pte_at(mm, address, pvmw.pte, swp_pte);
> trace_set_migration_pte(address, pte_val(swp_pte),
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index ef8599d394fd..a3fedb3ee0db 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -111,7 +111,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
> pte_t entry = pfn_pte(pfn, prot);
>
> entry = arch_make_huge_pte(entry, ilog2(size), 0);
> - set_huge_pte_at(&init_mm, addr, pte, entry);
> + set_huge_pte_at(&init_mm, addr, pte, entry, size);
> pfn += PFN_DOWN(size);
> continue;
> }

2023-09-22 21:15:45

by Axel Rasmussen

[permalink] [raw]
Subject: Re: [PATCH v2 2/2] arm64: hugetlb: Fix set_huge_pte_at() to work with all swap entries

Looks correct to me - thanks for the fix!

Reviewed-by: Axel Rasmussen <[email protected]>

On Fri, Sep 22, 2023 at 9:41 AM Ryan Roberts <[email protected]> wrote:
>
> On 22/09/2023 17:14, Will Deacon wrote:
> > On Fri, Sep 22, 2023 at 12:58:04PM +0100, Ryan Roberts wrote:
> >> When called with a swap entry that does not embed a PFN (e.g.
> >> PTE_MARKER_POISONED or PTE_MARKER_UFFD_WP), the previous implementation
> >> of set_huge_pte_at() would either cause a BUG() to fire (if
> >> CONFIG_DEBUG_VM is enabled) or cause a dereference of an invalid address
> >> and subsequent panic.
> >>
> >> arm64's huge pte implementation supports multiple huge page sizes, some
> >> of which are implemented in the page table with multiple contiguous
> >> entries. So set_huge_pte_at() needs to work out how big the logical pte
> >> is, so that it can also work out how many physical ptes (or pmds) need
> >> to be written. It previously did this by grabbing the folio out of the
> >> pte and querying its size.
> >>
> >> However, there are cases when the pte being set is actually a swap
> >> entry. But this also used to work fine, because for huge ptes, we only
> >> ever saw migration entries and hwpoison entries. And both of these types
> >> of swap entries have a PFN embedded, so the code would grab that and
> >> everything still worked out.
> >>
> >> But over time, more calls to set_huge_pte_at() have been added that set
> >> swap entry types that do not embed a PFN. And this causes the code to go
> >> bang. The triggering case is for the uffd poison test, commit
> >> 99aa77215ad0 ("selftests/mm: add uffd unit test for UFFDIO_POISON"),
> >> which causes a PTE_MARKER_POISONED swap entry to be set, coutesey of
> >> commit 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for
> >> hugetlbfs") - added in v6.5-rc7. Although review shows that there are
> >> other call sites that set PTE_MARKER_UFFD_WP (which also has no PFN),
> >> these don't trigger on arm64 because arm64 doesn't support UFFD WP.
> >>
> >> Arguably, the root cause is really due to commit 18f3962953e4 ("mm:
> >> hugetlb: kill set_huge_swap_pte_at()"), which aimed to simplify the
> >> interface to the core code by removing set_huge_swap_pte_at() (which
> >> took a page size parameter) and replacing it with calls to
> >> set_huge_pte_at() where the size was inferred from the folio, as
> >> descibed above. While that commit didn't break anything at the time, it
> >> did break the interface because it couldn't handle swap entries without
> >> PFNs. And since then new callers have come along which rely on this
> >> working. But given the brokeness is only observable after commit
> >> 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs"),
> >> that one gets the Fixes tag.
> >>
> >> Now that we have modified the set_huge_pte_at() interface to pass the
> >> huge page size in the previous patch, we can trivially fix this issue.
> >>
> >> Signed-off-by: Ryan Roberts <[email protected]>
> >> Fixes: 8a13897fb0da ("mm: userfaultfd: support UFFDIO_POISON for hugetlbfs")
> >> Cc: <[email protected]> # 6.5+
> >> ---
> >> arch/arm64/mm/hugetlbpage.c | 17 +++--------------
> >> 1 file changed, 3 insertions(+), 14 deletions(-)
> >>
> >> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> >> index a7f8c8db3425..13fd592228b1 100644
> >> --- a/arch/arm64/mm/hugetlbpage.c
> >> +++ b/arch/arm64/mm/hugetlbpage.c
> >> @@ -241,13 +241,6 @@ static void clear_flush(struct mm_struct *mm,
> >> flush_tlb_range(&vma, saddr, addr);
> >> }
> >>
> >> -static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
> >> -{
> >> - VM_BUG_ON(!is_migration_entry(entry) && !is_hwpoison_entry(entry));
> >> -
> >> - return page_folio(pfn_to_page(swp_offset_pfn(entry)));
> >> -}
> >> -
> >> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> >> pte_t *ptep, pte_t pte, unsigned long sz)
> >> {
> >> @@ -257,13 +250,10 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> >> unsigned long pfn, dpfn;
> >> pgprot_t hugeprot;
> >>
> >> - if (!pte_present(pte)) {
> >> - struct folio *folio;
> >> -
> >> - folio = hugetlb_swap_entry_to_folio(pte_to_swp_entry(pte));
> >> - ncontig = num_contig_ptes(folio_size(folio), &pgsize);
> >> + ncontig = num_contig_ptes(sz, &pgsize);
> >>
> >> - for (i = 0; i < ncontig; i++, ptep++)
> >> + if (!pte_present(pte)) {
> >> + for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
> >> set_pte_at(mm, addr, ptep, pte);
> >
> > Our set_pte_at() doesn't use 'addr' for anything and the old code didn't
> > even bother to increment it here! I'm fine adding that, but it feels
> > unrelated to the issue which this patch is actually fixing.
>
> True. I agree its not strictly necessary and will presumably be optimized out.
> But I'm not sure that having knowledge that the implementation doesn't use it is
> a good reason not to call the interface correctly. I'll leave it as I've done it
> if that's ok.
>
> >
> > Either way:
> >
> > Acked-by: Will Deacon <[email protected]>
>
> Thanks!
>
> >
> > Will
>

2023-09-29 10:43:57

by Christophe Leroy

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] mm: hugetlb: Add huge page size param to set_huge_pte_at()



Le 22/09/2023 à 13:58, Ryan Roberts a écrit :
> In order to fix a bug, arm64 needs to be told the size of the huge page
> for which the pte is being set in set_huge_pte_at(). Provide for this by
> adding an `unsigned long sz` parameter to the function. This follows the
> same pattern as huge_pte_clear().
>
> This commit makes the required interface modifications to the core mm as
> well as all arches that implement this function (arm64, parisc, powerpc,
> riscv, s390, sparc). The actual arm64 bug will be fixed in a separate
> commit.
>
> No behavioral changes intended.
>
> Signed-off-by: Ryan Roberts <[email protected]>
> Cc: <[email protected]> # 6.5+

Reviewed-by: Christophe Leroy <[email protected]> # powerpc 8xx

> ---
> arch/arm64/include/asm/hugetlb.h | 2 +-
> arch/arm64/mm/hugetlbpage.c | 6 ++-
> arch/parisc/include/asm/hugetlb.h | 2 +-
> arch/parisc/mm/hugetlbpage.c | 2 +-
> .../include/asm/nohash/32/hugetlb-8xx.h | 3 +-
> arch/powerpc/mm/book3s64/hugetlbpage.c | 5 ++-
> arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 3 +-
> arch/powerpc/mm/nohash/8xx.c | 3 +-
> arch/powerpc/mm/pgtable.c | 3 +-
> arch/riscv/include/asm/hugetlb.h | 3 +-
> arch/riscv/mm/hugetlbpage.c | 3 +-
> arch/s390/include/asm/hugetlb.h | 6 ++-
> arch/s390/mm/hugetlbpage.c | 8 +++-
> arch/sparc/include/asm/hugetlb.h | 6 ++-
> arch/sparc/mm/hugetlbpage.c | 8 +++-
> include/asm-generic/hugetlb.h | 2 +-
> include/linux/hugetlb.h | 6 ++-
> mm/damon/vaddr.c | 3 +-
> mm/hugetlb.c | 43 +++++++++++--------
> mm/migrate.c | 7 ++-
> mm/rmap.c | 23 +++++++---
> mm/vmalloc.c | 2 +-
> 22 files changed, 100 insertions(+), 49 deletions(-)
>
> diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
> index f43a38ac1779..2ddc33d93b13 100644
> --- a/arch/arm64/include/asm/hugetlb.h
> +++ b/arch/arm64/include/asm/hugetlb.h
> @@ -28,7 +28,7 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags);
> #define arch_make_huge_pte arch_make_huge_pte
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> extern void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte);
> + pte_t *ptep, pte_t pte, unsigned long sz);
> #define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
> extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> unsigned long addr, pte_t *ptep,
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 9c52718ea750..a7f8c8db3425 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -249,7 +249,7 @@ static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
> }
>
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte)
> + pte_t *ptep, pte_t pte, unsigned long sz)
> {
> size_t pgsize;
> int i;
> @@ -571,5 +571,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr
> void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
> pte_t old_pte, pte_t pte)
> {
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + unsigned long psize = huge_page_size(hstate_vma(vma));
> +
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
> diff --git a/arch/parisc/include/asm/hugetlb.h b/arch/parisc/include/asm/hugetlb.h
> index f7f078c2872c..72daacc472a0 100644
> --- a/arch/parisc/include/asm/hugetlb.h
> +++ b/arch/parisc/include/asm/hugetlb.h
> @@ -6,7 +6,7 @@
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte);
> + pte_t *ptep, pte_t pte, unsigned long sz);
>
> #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
> diff --git a/arch/parisc/mm/hugetlbpage.c b/arch/parisc/mm/hugetlbpage.c
> index a8a1a7c1e16e..a9f7e21f6656 100644
> --- a/arch/parisc/mm/hugetlbpage.c
> +++ b/arch/parisc/mm/hugetlbpage.c
> @@ -140,7 +140,7 @@ static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> }
>
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t entry)
> + pte_t *ptep, pte_t entry, unsigned long sz)
> {
> __set_huge_pte_at(mm, addr, ptep, entry);
> }
> diff --git a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
> index de092b04ee1a..92df40c6cc6b 100644
> --- a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
> +++ b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
> @@ -46,7 +46,8 @@ static inline int check_and_get_huge_psize(int shift)
> }
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
> + pte_t pte, unsigned long sz);
>
> #define __HAVE_ARCH_HUGE_PTE_CLEAR
> static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
> diff --git a/arch/powerpc/mm/book3s64/hugetlbpage.c b/arch/powerpc/mm/book3s64/hugetlbpage.c
> index 3bc0eb21b2a0..5a2e512e96db 100644
> --- a/arch/powerpc/mm/book3s64/hugetlbpage.c
> +++ b/arch/powerpc/mm/book3s64/hugetlbpage.c
> @@ -143,11 +143,14 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
> void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
> pte_t *ptep, pte_t old_pte, pte_t pte)
> {
> + unsigned long psize;
>
> if (radix_enabled())
> return radix__huge_ptep_modify_prot_commit(vma, addr, ptep,
> old_pte, pte);
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> +
> + psize = huge_page_size(hstate_vma(vma));
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
>
> void __init hugetlbpage_init_defaultsize(void)
> diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> index 17075c78d4bc..35fd2a95be24 100644
> --- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> +++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> @@ -47,6 +47,7 @@ void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> pte_t old_pte, pte_t pte)
> {
> struct mm_struct *mm = vma->vm_mm;
> + unsigned long psize = huge_page_size(hstate_vma(vma));
>
> /*
> * POWER9 NMMU must flush the TLB after clearing the PTE before
> @@ -58,5 +59,5 @@ void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> atomic_read(&mm->context.copros) > 0)
> radix__flush_hugetlb_page(vma, addr);
>
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
> diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
> index dbbfe897455d..a642a7929892 100644
> --- a/arch/powerpc/mm/nohash/8xx.c
> +++ b/arch/powerpc/mm/nohash/8xx.c
> @@ -91,7 +91,8 @@ static int __ref __early_map_kernel_hugepage(unsigned long va, phys_addr_t pa,
> if (new && WARN_ON(pte_present(*ptep) && pgprot_val(prot)))
> return -EINVAL;
>
> - set_huge_pte_at(&init_mm, va, ptep, pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)));
> + set_huge_pte_at(&init_mm, va, ptep,
> + pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)), psize);
>
> return 0;
> }
> diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
> index 3f86fd217690..3ba9fe411604 100644
> --- a/arch/powerpc/mm/pgtable.c
> +++ b/arch/powerpc/mm/pgtable.c
> @@ -288,7 +288,8 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> }
>
> #if defined(CONFIG_PPC_8xx)
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
> + pte_t pte, unsigned long sz)
> {
> pmd_t *pmd = pmd_off(mm, addr);
> pte_basic_t val;
> diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
> index 34e24f078cc1..4c5b0e929890 100644
> --- a/arch/riscv/include/asm/hugetlb.h
> +++ b/arch/riscv/include/asm/hugetlb.h
> @@ -18,7 +18,8 @@ void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> void set_huge_pte_at(struct mm_struct *mm,
> - unsigned long addr, pte_t *ptep, pte_t pte);
> + unsigned long addr, pte_t *ptep, pte_t pte,
> + unsigned long sz);
>
> #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
> diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
> index 96225a8533ad..e4a2ace92dbe 100644
> --- a/arch/riscv/mm/hugetlbpage.c
> +++ b/arch/riscv/mm/hugetlbpage.c
> @@ -180,7 +180,8 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
> void set_huge_pte_at(struct mm_struct *mm,
> unsigned long addr,
> pte_t *ptep,
> - pte_t pte)
> + pte_t pte,
> + unsigned long sz)
> {
> int i, pte_num;
>
> diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
> index f07267875a19..deb198a61039 100644
> --- a/arch/s390/include/asm/hugetlb.h
> +++ b/arch/s390/include/asm/hugetlb.h
> @@ -16,6 +16,8 @@
> #define hugepages_supported() (MACHINE_HAS_EDAT1)
>
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned long sz);
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte);
> pte_t huge_ptep_get(pte_t *ptep);
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
> @@ -65,7 +67,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> int changed = !pte_same(huge_ptep_get(ptep), pte);
> if (changed) {
> huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> }
> return changed;
> }
> @@ -74,7 +76,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
> unsigned long addr, pte_t *ptep)
> {
> pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
> - set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
> + __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
> }
>
> static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
> diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
> index c718f2a0de94..297a6d897d5a 100644
> --- a/arch/s390/mm/hugetlbpage.c
> +++ b/arch/s390/mm/hugetlbpage.c
> @@ -142,7 +142,7 @@ static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
> __storage_key_init_range(paddr, paddr + size - 1);
> }
>
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte)
> {
> unsigned long rste;
> @@ -163,6 +163,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> set_pte(ptep, __pte(rste));
> }
>
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned long sz)
> +{
> + __set_huge_pte_at(mm, addr, ptep, pte);
> +}
> +
> pte_t huge_ptep_get(pte_t *ptep)
> {
> return __rste_to_pte(pte_val(*ptep));
> diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
> index 0a26cca24232..c714ca6a05aa 100644
> --- a/arch/sparc/include/asm/hugetlb.h
> +++ b/arch/sparc/include/asm/hugetlb.h
> @@ -14,6 +14,8 @@ extern struct pud_huge_patch_entry __pud_huge_patch, __pud_huge_patch_end;
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned long sz);
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte);
>
> #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
> @@ -32,7 +34,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
> unsigned long addr, pte_t *ptep)
> {
> pte_t old_pte = *ptep;
> - set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
> + __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
> }
>
> #define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
> @@ -42,7 +44,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> {
> int changed = !pte_same(*ptep, pte);
> if (changed) {
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> flush_tlb_page(vma, addr);
> }
> return changed;
> diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
> index d7018823206c..b432500c13a5 100644
> --- a/arch/sparc/mm/hugetlbpage.c
> +++ b/arch/sparc/mm/hugetlbpage.c
> @@ -328,7 +328,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
> return pte_offset_huge(pmd, addr);
> }
>
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t entry)
> {
> unsigned int nptes, orig_shift, shift;
> @@ -364,6 +364,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> orig_shift);
> }
>
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t entry, unsigned long sz)
> +{
> + __set_huge_pte_at(mm, addr, ptep, entry);
> +}
> +
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep)
> {
> diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
> index 4da02798a00b..6dcf4d576970 100644
> --- a/include/asm-generic/hugetlb.h
> +++ b/include/asm-generic/hugetlb.h
> @@ -76,7 +76,7 @@ static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
>
> #ifndef __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte)
> + pte_t *ptep, pte_t pte, unsigned long sz)
> {
> set_pte_at(mm, addr, ptep, pte);
> }
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 5b2626063f4f..a30686e649f7 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -984,7 +984,9 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> unsigned long addr, pte_t *ptep,
> pte_t old_pte, pte_t pte)
> {
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + unsigned long psize = huge_page_size(hstate_vma(vma));
> +
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
> #endif
>
> @@ -1173,7 +1175,7 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
> }
>
> static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte)
> + pte_t *ptep, pte_t pte, unsigned long sz)
> {
> }
>
> diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
> index 4c81a9dbd044..cf8a9fc5c9d1 100644
> --- a/mm/damon/vaddr.c
> +++ b/mm/damon/vaddr.c
> @@ -341,13 +341,14 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm,
> bool referenced = false;
> pte_t entry = huge_ptep_get(pte);
> struct folio *folio = pfn_folio(pte_pfn(entry));
> + unsigned long psize = huge_page_size(hstate_vma(vma));
>
> folio_get(folio);
>
> if (pte_young(entry)) {
> referenced = true;
> entry = pte_mkold(entry);
> - set_huge_pte_at(mm, addr, pte, entry);
> + set_huge_pte_at(mm, addr, pte, entry, psize);
> }
>
> #ifdef CONFIG_MMU_NOTIFIER
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index ba6d39b71cb1..52d26072dfda 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -4980,7 +4980,7 @@ static bool is_hugetlb_entry_hwpoisoned(pte_t pte)
>
> static void
> hugetlb_install_folio(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr,
> - struct folio *new_folio, pte_t old)
> + struct folio *new_folio, pte_t old, unsigned long sz)
> {
> pte_t newpte = make_huge_pte(vma, &new_folio->page, 1);
>
> @@ -4988,7 +4988,7 @@ hugetlb_install_folio(struct vm_area_struct *vma, pte_t *ptep, unsigned long add
> hugepage_add_new_anon_rmap(new_folio, vma, addr);
> if (userfaultfd_wp(vma) && huge_pte_uffd_wp(old))
> newpte = huge_pte_mkuffd_wp(newpte);
> - set_huge_pte_at(vma->vm_mm, addr, ptep, newpte);
> + set_huge_pte_at(vma->vm_mm, addr, ptep, newpte, sz);
> hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm);
> folio_set_hugetlb_migratable(new_folio);
> }
> @@ -5065,7 +5065,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) {
> if (!userfaultfd_wp(dst_vma))
> entry = huge_pte_clear_uffd_wp(entry);
> - set_huge_pte_at(dst, addr, dst_pte, entry);
> + set_huge_pte_at(dst, addr, dst_pte, entry, sz);
> } else if (unlikely(is_hugetlb_entry_migration(entry))) {
> swp_entry_t swp_entry = pte_to_swp_entry(entry);
> bool uffd_wp = pte_swp_uffd_wp(entry);
> @@ -5080,18 +5080,18 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> entry = swp_entry_to_pte(swp_entry);
> if (userfaultfd_wp(src_vma) && uffd_wp)
> entry = pte_swp_mkuffd_wp(entry);
> - set_huge_pte_at(src, addr, src_pte, entry);
> + set_huge_pte_at(src, addr, src_pte, entry, sz);
> }
> if (!userfaultfd_wp(dst_vma))
> entry = huge_pte_clear_uffd_wp(entry);
> - set_huge_pte_at(dst, addr, dst_pte, entry);
> + set_huge_pte_at(dst, addr, dst_pte, entry, sz);
> } else if (unlikely(is_pte_marker(entry))) {
> pte_marker marker = copy_pte_marker(
> pte_to_swp_entry(entry), dst_vma);
>
> if (marker)
> set_huge_pte_at(dst, addr, dst_pte,
> - make_pte_marker(marker));
> + make_pte_marker(marker), sz);
> } else {
> entry = huge_ptep_get(src_pte);
> pte_folio = page_folio(pte_page(entry));
> @@ -5145,7 +5145,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> goto again;
> }
> hugetlb_install_folio(dst_vma, dst_pte, addr,
> - new_folio, src_pte_old);
> + new_folio, src_pte_old, sz);
> spin_unlock(src_ptl);
> spin_unlock(dst_ptl);
> continue;
> @@ -5166,7 +5166,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> if (!userfaultfd_wp(dst_vma))
> entry = huge_pte_clear_uffd_wp(entry);
>
> - set_huge_pte_at(dst, addr, dst_pte, entry);
> + set_huge_pte_at(dst, addr, dst_pte, entry, sz);
> hugetlb_count_add(npages, dst);
> }
> spin_unlock(src_ptl);
> @@ -5184,7 +5184,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> }
>
> static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
> - unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte)
> + unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte,
> + unsigned long sz)
> {
> struct hstate *h = hstate_vma(vma);
> struct mm_struct *mm = vma->vm_mm;
> @@ -5202,7 +5203,7 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
> spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
>
> pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
> - set_huge_pte_at(mm, new_addr, dst_pte, pte);
> + set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
>
> if (src_ptl != dst_ptl)
> spin_unlock(src_ptl);
> @@ -5259,7 +5260,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
> if (!dst_pte)
> break;
>
> - move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte);
> + move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte, sz);
> }
>
> if (shared_pmd)
> @@ -5337,7 +5338,8 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
> if (pte_swp_uffd_wp_any(pte) &&
> !(zap_flags & ZAP_FLAG_DROP_MARKER))
> set_huge_pte_at(mm, address, ptep,
> - make_pte_marker(PTE_MARKER_UFFD_WP));
> + make_pte_marker(PTE_MARKER_UFFD_WP),
> + sz);
> else
> huge_pte_clear(mm, address, ptep, sz);
> spin_unlock(ptl);
> @@ -5371,7 +5373,8 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
> if (huge_pte_uffd_wp(pte) &&
> !(zap_flags & ZAP_FLAG_DROP_MARKER))
> set_huge_pte_at(mm, address, ptep,
> - make_pte_marker(PTE_MARKER_UFFD_WP));
> + make_pte_marker(PTE_MARKER_UFFD_WP),
> + sz);
> hugetlb_count_sub(pages_per_huge_page(h), mm);
> page_remove_rmap(page, vma, true);
>
> @@ -5676,7 +5679,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
> hugepage_add_new_anon_rmap(new_folio, vma, haddr);
> if (huge_pte_uffd_wp(pte))
> newpte = huge_pte_mkuffd_wp(newpte);
> - set_huge_pte_at(mm, haddr, ptep, newpte);
> + set_huge_pte_at(mm, haddr, ptep, newpte, huge_page_size(h));
> folio_set_hugetlb_migratable(new_folio);
> /* Make the old page be freed below */
> new_folio = old_folio;
> @@ -5972,7 +5975,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
> */
> if (unlikely(pte_marker_uffd_wp(old_pte)))
> new_pte = huge_pte_mkuffd_wp(new_pte);
> - set_huge_pte_at(mm, haddr, ptep, new_pte);
> + set_huge_pte_at(mm, haddr, ptep, new_pte, huge_page_size(h));
>
> hugetlb_count_add(pages_per_huge_page(h), mm);
> if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
> @@ -6261,7 +6264,8 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
> }
>
> _dst_pte = make_pte_marker(PTE_MARKER_POISONED);
> - set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
> + set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte,
> + huge_page_size(h));
>
> /* No need to invalidate - it was non-present before */
> update_mmu_cache(dst_vma, dst_addr, dst_pte);
> @@ -6412,7 +6416,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
> if (wp_enabled)
> _dst_pte = huge_pte_mkuffd_wp(_dst_pte);
>
> - set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
> + set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte, huge_page_size(h));
>
> hugetlb_count_add(pages_per_huge_page(h), dst_mm);
>
> @@ -6598,7 +6602,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
> else if (uffd_wp_resolve)
> newpte = pte_swp_clear_uffd_wp(newpte);
> if (!pte_same(pte, newpte))
> - set_huge_pte_at(mm, address, ptep, newpte);
> + set_huge_pte_at(mm, address, ptep, newpte, psize);
> } else if (unlikely(is_pte_marker(pte))) {
> /* No other markers apply for now. */
> WARN_ON_ONCE(!pte_marker_uffd_wp(pte));
> @@ -6623,7 +6627,8 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
> if (unlikely(uffd_wp))
> /* Safe to modify directly (none->non-present). */
> set_huge_pte_at(mm, address, ptep,
> - make_pte_marker(PTE_MARKER_UFFD_WP));
> + make_pte_marker(PTE_MARKER_UFFD_WP),
> + psize);
> }
> spin_unlock(ptl);
> }
> diff --git a/mm/migrate.c b/mm/migrate.c
> index b7fa020003f3..2053b54556ca 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -243,7 +243,9 @@ static bool remove_migration_pte(struct folio *folio,
>
> #ifdef CONFIG_HUGETLB_PAGE
> if (folio_test_hugetlb(folio)) {
> - unsigned int shift = huge_page_shift(hstate_vma(vma));
> + struct hstate *h = hstate_vma(vma);
> + unsigned int shift = huge_page_shift(h);
> + unsigned long psize = huge_page_size(h);
>
> pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
> if (folio_test_anon(folio))
> @@ -251,7 +253,8 @@ static bool remove_migration_pte(struct folio *folio,
> rmap_flags);
> else
> page_dup_file_rmap(new, true);
> - set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
> + set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte,
> + psize);
> } else
> #endif
> {
> diff --git a/mm/rmap.c b/mm/rmap.c
> index ec7f8e6c9e48..9f795b93cf40 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -1480,6 +1480,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> struct mmu_notifier_range range;
> enum ttu_flags flags = (enum ttu_flags)(long)arg;
> unsigned long pfn;
> + unsigned long hsz = 0;
>
> /*
> * When racing against e.g. zap_pte_range() on another cpu,
> @@ -1511,6 +1512,9 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> */
> adjust_range_if_pmd_sharing_possible(vma, &range.start,
> &range.end);
> +
> + /* We need the huge page size for set_huge_pte_at() */
> + hsz = huge_page_size(hstate_vma(vma));
> }
> mmu_notifier_invalidate_range_start(&range);
>
> @@ -1628,7 +1632,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
> if (folio_test_hugetlb(folio)) {
> hugetlb_count_sub(folio_nr_pages(folio), mm);
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte, pteval,
> + hsz);
> } else {
> dec_mm_counter(mm, mm_counter(&folio->page));
> set_pte_at(mm, address, pvmw.pte, pteval);
> @@ -1820,6 +1825,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> struct mmu_notifier_range range;
> enum ttu_flags flags = (enum ttu_flags)(long)arg;
> unsigned long pfn;
> + unsigned long hsz = 0;
>
> /*
> * When racing against e.g. zap_pte_range() on another cpu,
> @@ -1855,6 +1861,9 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> */
> adjust_range_if_pmd_sharing_possible(vma, &range.start,
> &range.end);
> +
> + /* We need the huge page size for set_huge_pte_at() */
> + hsz = huge_page_size(hstate_vma(vma));
> }
> mmu_notifier_invalidate_range_start(&range);
>
> @@ -2020,7 +2029,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
> if (folio_test_hugetlb(folio)) {
> hugetlb_count_sub(folio_nr_pages(folio), mm);
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte, pteval,
> + hsz);
> } else {
> dec_mm_counter(mm, mm_counter(&folio->page));
> set_pte_at(mm, address, pvmw.pte, pteval);
> @@ -2044,7 +2054,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
>
> if (arch_unmap_one(mm, vma, address, pteval) < 0) {
> if (folio_test_hugetlb(folio))
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte,
> + pteval, hsz);
> else
> set_pte_at(mm, address, pvmw.pte, pteval);
> ret = false;
> @@ -2058,7 +2069,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> if (anon_exclusive &&
> page_try_share_anon_rmap(subpage)) {
> if (folio_test_hugetlb(folio))
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte,
> + pteval, hsz);
> else
> set_pte_at(mm, address, pvmw.pte, pteval);
> ret = false;
> @@ -2090,7 +2102,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> if (pte_uffd_wp(pteval))
> swp_pte = pte_swp_mkuffd_wp(swp_pte);
> if (folio_test_hugetlb(folio))
> - set_huge_pte_at(mm, address, pvmw.pte, swp_pte);
> + set_huge_pte_at(mm, address, pvmw.pte, swp_pte,
> + hsz);
> else
> set_pte_at(mm, address, pvmw.pte, swp_pte);
> trace_set_migration_pte(address, pte_val(swp_pte),
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index ef8599d394fd..a3fedb3ee0db 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -111,7 +111,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
> pte_t entry = pfn_pte(pfn, prot);
>
> entry = arch_make_huge_pte(entry, ilog2(size), 0);
> - set_huge_pte_at(&init_mm, addr, pte, entry);
> + set_huge_pte_at(&init_mm, addr, pte, entry, size);
> pfn += PFN_DOWN(size);
> continue;
> }

2023-09-30 07:19:27

by Lorenzo Stoakes

[permalink] [raw]
Subject: Re: [PATCH v2 1/2] mm: hugetlb: Add huge page size param to set_huge_pte_at()

On Fri, Sep 22, 2023 at 12:58:03PM +0100, Ryan Roberts wrote:
> In order to fix a bug, arm64 needs to be told the size of the huge page
> for which the pte is being set in set_huge_pte_at(). Provide for this by
> adding an `unsigned long sz` parameter to the function. This follows the
> same pattern as huge_pte_clear().
>
> This commit makes the required interface modifications to the core mm as
> well as all arches that implement this function (arm64, parisc, powerpc,
> riscv, s390, sparc). The actual arm64 bug will be fixed in a separate
> commit.
>
> No behavioral changes intended.
>
> Signed-off-by: Ryan Roberts <[email protected]>
> Cc: <[email protected]> # 6.5+
> ---
> arch/arm64/include/asm/hugetlb.h | 2 +-
> arch/arm64/mm/hugetlbpage.c | 6 ++-
> arch/parisc/include/asm/hugetlb.h | 2 +-
> arch/parisc/mm/hugetlbpage.c | 2 +-
> .../include/asm/nohash/32/hugetlb-8xx.h | 3 +-
> arch/powerpc/mm/book3s64/hugetlbpage.c | 5 ++-
> arch/powerpc/mm/book3s64/radix_hugetlbpage.c | 3 +-
> arch/powerpc/mm/nohash/8xx.c | 3 +-
> arch/powerpc/mm/pgtable.c | 3 +-
> arch/riscv/include/asm/hugetlb.h | 3 +-
> arch/riscv/mm/hugetlbpage.c | 3 +-
> arch/s390/include/asm/hugetlb.h | 6 ++-
> arch/s390/mm/hugetlbpage.c | 8 +++-
> arch/sparc/include/asm/hugetlb.h | 6 ++-
> arch/sparc/mm/hugetlbpage.c | 8 +++-
> include/asm-generic/hugetlb.h | 2 +-
> include/linux/hugetlb.h | 6 ++-
> mm/damon/vaddr.c | 3 +-
> mm/hugetlb.c | 43 +++++++++++--------
> mm/migrate.c | 7 ++-
> mm/rmap.c | 23 +++++++---
> mm/vmalloc.c | 2 +-
> 22 files changed, 100 insertions(+), 49 deletions(-)
>
> diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
> index f43a38ac1779..2ddc33d93b13 100644
> --- a/arch/arm64/include/asm/hugetlb.h
> +++ b/arch/arm64/include/asm/hugetlb.h
> @@ -28,7 +28,7 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags);
> #define arch_make_huge_pte arch_make_huge_pte
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> extern void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte);
> + pte_t *ptep, pte_t pte, unsigned long sz);
> #define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
> extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> unsigned long addr, pte_t *ptep,
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 9c52718ea750..a7f8c8db3425 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -249,7 +249,7 @@ static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
> }
>
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte)
> + pte_t *ptep, pte_t pte, unsigned long sz)
> {
> size_t pgsize;
> int i;
> @@ -571,5 +571,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr
> void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
> pte_t old_pte, pte_t pte)
> {
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + unsigned long psize = huge_page_size(hstate_vma(vma));
> +
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
> diff --git a/arch/parisc/include/asm/hugetlb.h b/arch/parisc/include/asm/hugetlb.h
> index f7f078c2872c..72daacc472a0 100644
> --- a/arch/parisc/include/asm/hugetlb.h
> +++ b/arch/parisc/include/asm/hugetlb.h
> @@ -6,7 +6,7 @@
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte);
> + pte_t *ptep, pte_t pte, unsigned long sz);
>
> #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
> diff --git a/arch/parisc/mm/hugetlbpage.c b/arch/parisc/mm/hugetlbpage.c
> index a8a1a7c1e16e..a9f7e21f6656 100644
> --- a/arch/parisc/mm/hugetlbpage.c
> +++ b/arch/parisc/mm/hugetlbpage.c
> @@ -140,7 +140,7 @@ static void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> }
>
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t entry)
> + pte_t *ptep, pte_t entry, unsigned long sz)
> {
> __set_huge_pte_at(mm, addr, ptep, entry);
> }
> diff --git a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
> index de092b04ee1a..92df40c6cc6b 100644
> --- a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
> +++ b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
> @@ -46,7 +46,8 @@ static inline int check_and_get_huge_psize(int shift)
> }
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
> + pte_t pte, unsigned long sz);
>
> #define __HAVE_ARCH_HUGE_PTE_CLEAR
> static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
> diff --git a/arch/powerpc/mm/book3s64/hugetlbpage.c b/arch/powerpc/mm/book3s64/hugetlbpage.c
> index 3bc0eb21b2a0..5a2e512e96db 100644
> --- a/arch/powerpc/mm/book3s64/hugetlbpage.c
> +++ b/arch/powerpc/mm/book3s64/hugetlbpage.c
> @@ -143,11 +143,14 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
> void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
> pte_t *ptep, pte_t old_pte, pte_t pte)
> {
> + unsigned long psize;
>
> if (radix_enabled())
> return radix__huge_ptep_modify_prot_commit(vma, addr, ptep,
> old_pte, pte);
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> +
> + psize = huge_page_size(hstate_vma(vma));
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
>
> void __init hugetlbpage_init_defaultsize(void)
> diff --git a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> index 17075c78d4bc..35fd2a95be24 100644
> --- a/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> +++ b/arch/powerpc/mm/book3s64/radix_hugetlbpage.c
> @@ -47,6 +47,7 @@ void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> pte_t old_pte, pte_t pte)
> {
> struct mm_struct *mm = vma->vm_mm;
> + unsigned long psize = huge_page_size(hstate_vma(vma));
>
> /*
> * POWER9 NMMU must flush the TLB after clearing the PTE before
> @@ -58,5 +59,5 @@ void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> atomic_read(&mm->context.copros) > 0)
> radix__flush_hugetlb_page(vma, addr);
>
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
> diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
> index dbbfe897455d..a642a7929892 100644
> --- a/arch/powerpc/mm/nohash/8xx.c
> +++ b/arch/powerpc/mm/nohash/8xx.c
> @@ -91,7 +91,8 @@ static int __ref __early_map_kernel_hugepage(unsigned long va, phys_addr_t pa,
> if (new && WARN_ON(pte_present(*ptep) && pgprot_val(prot)))
> return -EINVAL;
>
> - set_huge_pte_at(&init_mm, va, ptep, pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)));
> + set_huge_pte_at(&init_mm, va, ptep,
> + pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)), psize);
>
> return 0;
> }
> diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
> index 3f86fd217690..3ba9fe411604 100644
> --- a/arch/powerpc/mm/pgtable.c
> +++ b/arch/powerpc/mm/pgtable.c
> @@ -288,7 +288,8 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> }
>
> #if defined(CONFIG_PPC_8xx)
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
> + pte_t pte, unsigned long sz)
> {
> pmd_t *pmd = pmd_off(mm, addr);
> pte_basic_t val;
> diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
> index 34e24f078cc1..4c5b0e929890 100644
> --- a/arch/riscv/include/asm/hugetlb.h
> +++ b/arch/riscv/include/asm/hugetlb.h
> @@ -18,7 +18,8 @@ void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> void set_huge_pte_at(struct mm_struct *mm,
> - unsigned long addr, pte_t *ptep, pte_t pte);
> + unsigned long addr, pte_t *ptep, pte_t pte,
> + unsigned long sz);
>
> #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
> diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
> index 96225a8533ad..e4a2ace92dbe 100644
> --- a/arch/riscv/mm/hugetlbpage.c
> +++ b/arch/riscv/mm/hugetlbpage.c
> @@ -180,7 +180,8 @@ pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
> void set_huge_pte_at(struct mm_struct *mm,
> unsigned long addr,
> pte_t *ptep,
> - pte_t pte)
> + pte_t pte,
> + unsigned long sz)
> {
> int i, pte_num;
>
> diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
> index f07267875a19..deb198a61039 100644
> --- a/arch/s390/include/asm/hugetlb.h
> +++ b/arch/s390/include/asm/hugetlb.h
> @@ -16,6 +16,8 @@
> #define hugepages_supported() (MACHINE_HAS_EDAT1)
>
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned long sz);
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte);
> pte_t huge_ptep_get(pte_t *ptep);
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
> @@ -65,7 +67,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> int changed = !pte_same(huge_ptep_get(ptep), pte);
> if (changed) {
> huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> }
> return changed;
> }
> @@ -74,7 +76,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
> unsigned long addr, pte_t *ptep)
> {
> pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
> - set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
> + __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
> }
>
> static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
> diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
> index c718f2a0de94..297a6d897d5a 100644
> --- a/arch/s390/mm/hugetlbpage.c
> +++ b/arch/s390/mm/hugetlbpage.c
> @@ -142,7 +142,7 @@ static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste)
> __storage_key_init_range(paddr, paddr + size - 1);
> }
>
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte)
> {
> unsigned long rste;
> @@ -163,6 +163,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> set_pte(ptep, __pte(rste));
> }
>
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned long sz)
> +{
> + __set_huge_pte_at(mm, addr, ptep, pte);
> +}
> +
> pte_t huge_ptep_get(pte_t *ptep)
> {
> return __rste_to_pte(pte_val(*ptep));
> diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
> index 0a26cca24232..c714ca6a05aa 100644
> --- a/arch/sparc/include/asm/hugetlb.h
> +++ b/arch/sparc/include/asm/hugetlb.h
> @@ -14,6 +14,8 @@ extern struct pud_huge_patch_entry __pud_huge_patch, __pud_huge_patch_end;
>
> #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t pte, unsigned long sz);
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte);
>
> #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
> @@ -32,7 +34,7 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
> unsigned long addr, pte_t *ptep)
> {
> pte_t old_pte = *ptep;
> - set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
> + __set_huge_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
> }
>
> #define __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
> @@ -42,7 +44,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
> {
> int changed = !pte_same(*ptep, pte);
> if (changed) {
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + __set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> flush_tlb_page(vma, addr);
> }
> return changed;
> diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
> index d7018823206c..b432500c13a5 100644
> --- a/arch/sparc/mm/hugetlbpage.c
> +++ b/arch/sparc/mm/hugetlbpage.c
> @@ -328,7 +328,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm,
> return pte_offset_huge(pmd, addr);
> }
>
> -void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> +void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t entry)
> {
> unsigned int nptes, orig_shift, shift;
> @@ -364,6 +364,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> orig_shift);
> }
>
> +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> + pte_t *ptep, pte_t entry, unsigned long sz)
> +{
> + __set_huge_pte_at(mm, addr, ptep, entry);
> +}
> +
> pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep)
> {
> diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
> index 4da02798a00b..6dcf4d576970 100644
> --- a/include/asm-generic/hugetlb.h
> +++ b/include/asm-generic/hugetlb.h
> @@ -76,7 +76,7 @@ static inline void hugetlb_free_pgd_range(struct mmu_gather *tlb,
>
> #ifndef __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
> static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte)
> + pte_t *ptep, pte_t pte, unsigned long sz)
> {
> set_pte_at(mm, addr, ptep, pte);
> }
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 5b2626063f4f..a30686e649f7 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -984,7 +984,9 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
> unsigned long addr, pte_t *ptep,
> pte_t old_pte, pte_t pte)
> {
> - set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
> + unsigned long psize = huge_page_size(hstate_vma(vma));
> +
> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
> }
> #endif
>
> @@ -1173,7 +1175,7 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
> }
>
> static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
> - pte_t *ptep, pte_t pte)
> + pte_t *ptep, pte_t pte, unsigned long sz)
> {
> }
>
> diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
> index 4c81a9dbd044..cf8a9fc5c9d1 100644
> --- a/mm/damon/vaddr.c
> +++ b/mm/damon/vaddr.c
> @@ -341,13 +341,14 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm,
> bool referenced = false;
> pte_t entry = huge_ptep_get(pte);
> struct folio *folio = pfn_folio(pte_pfn(entry));
> + unsigned long psize = huge_page_size(hstate_vma(vma));
>
> folio_get(folio);
>
> if (pte_young(entry)) {
> referenced = true;
> entry = pte_mkold(entry);
> - set_huge_pte_at(mm, addr, pte, entry);
> + set_huge_pte_at(mm, addr, pte, entry, psize);
> }
>
> #ifdef CONFIG_MMU_NOTIFIER
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index ba6d39b71cb1..52d26072dfda 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -4980,7 +4980,7 @@ static bool is_hugetlb_entry_hwpoisoned(pte_t pte)
>
> static void
> hugetlb_install_folio(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr,
> - struct folio *new_folio, pte_t old)
> + struct folio *new_folio, pte_t old, unsigned long sz)
> {
> pte_t newpte = make_huge_pte(vma, &new_folio->page, 1);
>
> @@ -4988,7 +4988,7 @@ hugetlb_install_folio(struct vm_area_struct *vma, pte_t *ptep, unsigned long add
> hugepage_add_new_anon_rmap(new_folio, vma, addr);
> if (userfaultfd_wp(vma) && huge_pte_uffd_wp(old))
> newpte = huge_pte_mkuffd_wp(newpte);
> - set_huge_pte_at(vma->vm_mm, addr, ptep, newpte);
> + set_huge_pte_at(vma->vm_mm, addr, ptep, newpte, sz);
> hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm);
> folio_set_hugetlb_migratable(new_folio);
> }
> @@ -5065,7 +5065,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry))) {
> if (!userfaultfd_wp(dst_vma))
> entry = huge_pte_clear_uffd_wp(entry);
> - set_huge_pte_at(dst, addr, dst_pte, entry);
> + set_huge_pte_at(dst, addr, dst_pte, entry, sz);
> } else if (unlikely(is_hugetlb_entry_migration(entry))) {
> swp_entry_t swp_entry = pte_to_swp_entry(entry);
> bool uffd_wp = pte_swp_uffd_wp(entry);
> @@ -5080,18 +5080,18 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> entry = swp_entry_to_pte(swp_entry);
> if (userfaultfd_wp(src_vma) && uffd_wp)
> entry = pte_swp_mkuffd_wp(entry);
> - set_huge_pte_at(src, addr, src_pte, entry);
> + set_huge_pte_at(src, addr, src_pte, entry, sz);
> }
> if (!userfaultfd_wp(dst_vma))
> entry = huge_pte_clear_uffd_wp(entry);
> - set_huge_pte_at(dst, addr, dst_pte, entry);
> + set_huge_pte_at(dst, addr, dst_pte, entry, sz);
> } else if (unlikely(is_pte_marker(entry))) {
> pte_marker marker = copy_pte_marker(
> pte_to_swp_entry(entry), dst_vma);
>
> if (marker)
> set_huge_pte_at(dst, addr, dst_pte,
> - make_pte_marker(marker));
> + make_pte_marker(marker), sz);
> } else {
> entry = huge_ptep_get(src_pte);
> pte_folio = page_folio(pte_page(entry));
> @@ -5145,7 +5145,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> goto again;
> }
> hugetlb_install_folio(dst_vma, dst_pte, addr,
> - new_folio, src_pte_old);
> + new_folio, src_pte_old, sz);
> spin_unlock(src_ptl);
> spin_unlock(dst_ptl);
> continue;
> @@ -5166,7 +5166,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> if (!userfaultfd_wp(dst_vma))
> entry = huge_pte_clear_uffd_wp(entry);
>
> - set_huge_pte_at(dst, addr, dst_pte, entry);
> + set_huge_pte_at(dst, addr, dst_pte, entry, sz);
> hugetlb_count_add(npages, dst);
> }
> spin_unlock(src_ptl);
> @@ -5184,7 +5184,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
> }
>
> static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
> - unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte)
> + unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte,
> + unsigned long sz)
> {
> struct hstate *h = hstate_vma(vma);
> struct mm_struct *mm = vma->vm_mm;
> @@ -5202,7 +5203,7 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
> spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
>
> pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
> - set_huge_pte_at(mm, new_addr, dst_pte, pte);
> + set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
>
> if (src_ptl != dst_ptl)
> spin_unlock(src_ptl);
> @@ -5259,7 +5260,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
> if (!dst_pte)
> break;
>
> - move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte);
> + move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte, sz);
> }
>
> if (shared_pmd)
> @@ -5337,7 +5338,8 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
> if (pte_swp_uffd_wp_any(pte) &&
> !(zap_flags & ZAP_FLAG_DROP_MARKER))
> set_huge_pte_at(mm, address, ptep,
> - make_pte_marker(PTE_MARKER_UFFD_WP));
> + make_pte_marker(PTE_MARKER_UFFD_WP),
> + sz);
> else
> huge_pte_clear(mm, address, ptep, sz);
> spin_unlock(ptl);
> @@ -5371,7 +5373,8 @@ static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct
> if (huge_pte_uffd_wp(pte) &&
> !(zap_flags & ZAP_FLAG_DROP_MARKER))
> set_huge_pte_at(mm, address, ptep,
> - make_pte_marker(PTE_MARKER_UFFD_WP));
> + make_pte_marker(PTE_MARKER_UFFD_WP),
> + sz);
> hugetlb_count_sub(pages_per_huge_page(h), mm);
> page_remove_rmap(page, vma, true);
>
> @@ -5676,7 +5679,7 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
> hugepage_add_new_anon_rmap(new_folio, vma, haddr);
> if (huge_pte_uffd_wp(pte))
> newpte = huge_pte_mkuffd_wp(newpte);
> - set_huge_pte_at(mm, haddr, ptep, newpte);
> + set_huge_pte_at(mm, haddr, ptep, newpte, huge_page_size(h));
> folio_set_hugetlb_migratable(new_folio);
> /* Make the old page be freed below */
> new_folio = old_folio;
> @@ -5972,7 +5975,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
> */
> if (unlikely(pte_marker_uffd_wp(old_pte)))
> new_pte = huge_pte_mkuffd_wp(new_pte);
> - set_huge_pte_at(mm, haddr, ptep, new_pte);
> + set_huge_pte_at(mm, haddr, ptep, new_pte, huge_page_size(h));
>
> hugetlb_count_add(pages_per_huge_page(h), mm);
> if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
> @@ -6261,7 +6264,8 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
> }
>
> _dst_pte = make_pte_marker(PTE_MARKER_POISONED);
> - set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
> + set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte,
> + huge_page_size(h));
>
> /* No need to invalidate - it was non-present before */
> update_mmu_cache(dst_vma, dst_addr, dst_pte);
> @@ -6412,7 +6416,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
> if (wp_enabled)
> _dst_pte = huge_pte_mkuffd_wp(_dst_pte);
>
> - set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
> + set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte, huge_page_size(h));
>
> hugetlb_count_add(pages_per_huge_page(h), dst_mm);
>
> @@ -6598,7 +6602,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
> else if (uffd_wp_resolve)
> newpte = pte_swp_clear_uffd_wp(newpte);
> if (!pte_same(pte, newpte))
> - set_huge_pte_at(mm, address, ptep, newpte);
> + set_huge_pte_at(mm, address, ptep, newpte, psize);
> } else if (unlikely(is_pte_marker(pte))) {
> /* No other markers apply for now. */
> WARN_ON_ONCE(!pte_marker_uffd_wp(pte));
> @@ -6623,7 +6627,8 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
> if (unlikely(uffd_wp))
> /* Safe to modify directly (none->non-present). */
> set_huge_pte_at(mm, address, ptep,
> - make_pte_marker(PTE_MARKER_UFFD_WP));
> + make_pte_marker(PTE_MARKER_UFFD_WP),
> + psize);
> }
> spin_unlock(ptl);
> }
> diff --git a/mm/migrate.c b/mm/migrate.c
> index b7fa020003f3..2053b54556ca 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -243,7 +243,9 @@ static bool remove_migration_pte(struct folio *folio,
>
> #ifdef CONFIG_HUGETLB_PAGE
> if (folio_test_hugetlb(folio)) {
> - unsigned int shift = huge_page_shift(hstate_vma(vma));
> + struct hstate *h = hstate_vma(vma);
> + unsigned int shift = huge_page_shift(h);
> + unsigned long psize = huge_page_size(h);
>
> pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
> if (folio_test_anon(folio))
> @@ -251,7 +253,8 @@ static bool remove_migration_pte(struct folio *folio,
> rmap_flags);
> else
> page_dup_file_rmap(new, true);
> - set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte);
> + set_huge_pte_at(vma->vm_mm, pvmw.address, pvmw.pte, pte,
> + psize);
> } else
> #endif
> {
> diff --git a/mm/rmap.c b/mm/rmap.c
> index ec7f8e6c9e48..9f795b93cf40 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -1480,6 +1480,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> struct mmu_notifier_range range;
> enum ttu_flags flags = (enum ttu_flags)(long)arg;
> unsigned long pfn;
> + unsigned long hsz = 0;
>
> /*
> * When racing against e.g. zap_pte_range() on another cpu,
> @@ -1511,6 +1512,9 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> */
> adjust_range_if_pmd_sharing_possible(vma, &range.start,
> &range.end);
> +
> + /* We need the huge page size for set_huge_pte_at() */
> + hsz = huge_page_size(hstate_vma(vma));
> }
> mmu_notifier_invalidate_range_start(&range);
>
> @@ -1628,7 +1632,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
> if (folio_test_hugetlb(folio)) {
> hugetlb_count_sub(folio_nr_pages(folio), mm);
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte, pteval,
> + hsz);
> } else {
> dec_mm_counter(mm, mm_counter(&folio->page));
> set_pte_at(mm, address, pvmw.pte, pteval);
> @@ -1820,6 +1825,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> struct mmu_notifier_range range;
> enum ttu_flags flags = (enum ttu_flags)(long)arg;
> unsigned long pfn;
> + unsigned long hsz = 0;
>
> /*
> * When racing against e.g. zap_pte_range() on another cpu,
> @@ -1855,6 +1861,9 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> */
> adjust_range_if_pmd_sharing_possible(vma, &range.start,
> &range.end);
> +
> + /* We need the huge page size for set_huge_pte_at() */
> + hsz = huge_page_size(hstate_vma(vma));
> }
> mmu_notifier_invalidate_range_start(&range);
>
> @@ -2020,7 +2029,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> pteval = swp_entry_to_pte(make_hwpoison_entry(subpage));
> if (folio_test_hugetlb(folio)) {
> hugetlb_count_sub(folio_nr_pages(folio), mm);
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte, pteval,
> + hsz);
> } else {
> dec_mm_counter(mm, mm_counter(&folio->page));
> set_pte_at(mm, address, pvmw.pte, pteval);
> @@ -2044,7 +2054,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
>
> if (arch_unmap_one(mm, vma, address, pteval) < 0) {
> if (folio_test_hugetlb(folio))
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte,
> + pteval, hsz);
> else
> set_pte_at(mm, address, pvmw.pte, pteval);
> ret = false;
> @@ -2058,7 +2069,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> if (anon_exclusive &&
> page_try_share_anon_rmap(subpage)) {
> if (folio_test_hugetlb(folio))
> - set_huge_pte_at(mm, address, pvmw.pte, pteval);
> + set_huge_pte_at(mm, address, pvmw.pte,
> + pteval, hsz);
> else
> set_pte_at(mm, address, pvmw.pte, pteval);
> ret = false;
> @@ -2090,7 +2102,8 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
> if (pte_uffd_wp(pteval))
> swp_pte = pte_swp_mkuffd_wp(swp_pte);
> if (folio_test_hugetlb(folio))
> - set_huge_pte_at(mm, address, pvmw.pte, swp_pte);
> + set_huge_pte_at(mm, address, pvmw.pte, swp_pte,
> + hsz);
> else
> set_pte_at(mm, address, pvmw.pte, swp_pte);
> trace_set_migration_pte(address, pte_val(swp_pte),
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index ef8599d394fd..a3fedb3ee0db 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -111,7 +111,7 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
> pte_t entry = pfn_pte(pfn, prot);
>
> entry = arch_make_huge_pte(entry, ilog2(size), 0);
> - set_huge_pte_at(&init_mm, addr, pte, entry);
> + set_huge_pte_at(&init_mm, addr, pte, entry, size);
> pfn += PFN_DOWN(size);
> continue;
> }
> --
> 2.25.1
>

Looks good to me, vmalloc-wise.

Reviewed-by: Lorenzo Stoakes <[email protected]> (for vmalloc change)