FAILED: patch "[PATCH] mm: hugetlb: Add huge page size param to" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] mm: hugetlb: Add huge page size param to" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 02410ac72ac3707936c07ede66e94360d0d65319
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025030436-idealize-unsaddle-3c68@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 02410ac72ac3707936c07ede66e94360d0d65319 Mon Sep 17 00:00:00 2001
From: Ryan Roberts <ryan.roberts@arm.com>
Date: Wed, 26 Feb 2025 12:06:51 +0000
Subject: [PATCH] mm: hugetlb: Add huge page size param to
 huge_ptep_get_and_clear()

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

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

Cc: stable@vger.kernel.org
Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> # s390
Link: https://lore.kernel.org/r/20250226120656.2400136-2-ryan.roberts@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index c6dff3e69539..03db9cb21ace 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -42,8 +42,8 @@ extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 				      unsigned long addr, pte_t *ptep,
 				      pte_t pte, int dirty);
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
-extern pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-				     unsigned long addr, pte_t *ptep);
+extern pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+				     pte_t *ptep, unsigned long sz);
 #define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
 extern void huge_ptep_set_wrprotect(struct mm_struct *mm,
 				    unsigned long addr, pte_t *ptep);
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 98a2a0e64e25..06db4649af91 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -396,8 +396,8 @@ void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 		__pte_clear(mm, addr, ptep);
 }
 
-pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-			      unsigned long addr, pte_t *ptep)
+pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, unsigned long sz)
 {
 	int ncontig;
 	size_t pgsize;
@@ -549,6 +549,8 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
 
 pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 {
+	unsigned long psize = huge_page_size(hstate_vma(vma));
+
 	if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) {
 		/*
 		 * Break-before-make (BBM) is required for all user space mappings
@@ -558,7 +560,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr
 		if (pte_user_exec(__ptep_get(ptep)))
 			return huge_ptep_clear_flush(vma, addr, ptep);
 	}
-	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, psize);
 }
 
 void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
diff --git a/arch/loongarch/include/asm/hugetlb.h b/arch/loongarch/include/asm/hugetlb.h
index c8e4057734d0..4dc4b3e04225 100644
--- a/arch/loongarch/include/asm/hugetlb.h
+++ b/arch/loongarch/include/asm/hugetlb.h
@@ -36,7 +36,8 @@ static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-					    unsigned long addr, pte_t *ptep)
+					    unsigned long addr, pte_t *ptep,
+					    unsigned long sz)
 {
 	pte_t clear;
 	pte_t pte = ptep_get(ptep);
@@ -51,8 +52,9 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 					  unsigned long addr, pte_t *ptep)
 {
 	pte_t pte;
+	unsigned long sz = huge_page_size(hstate_vma(vma));
 
-	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, sz);
 	flush_tlb_page(vma, addr);
 	return pte;
 }
diff --git a/arch/mips/include/asm/hugetlb.h b/arch/mips/include/asm/hugetlb.h
index d0a86ce83de9..fbc71ddcf0f6 100644
--- a/arch/mips/include/asm/hugetlb.h
+++ b/arch/mips/include/asm/hugetlb.h
@@ -27,7 +27,8 @@ static inline int prepare_hugepage_range(struct file *file,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-					    unsigned long addr, pte_t *ptep)
+					    unsigned long addr, pte_t *ptep,
+					    unsigned long sz)
 {
 	pte_t clear;
 	pte_t pte = *ptep;
@@ -42,13 +43,14 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 					  unsigned long addr, pte_t *ptep)
 {
 	pte_t pte;
+	unsigned long sz = huge_page_size(hstate_vma(vma));
 
 	/*
 	 * clear the huge pte entry firstly, so that the other smp threads will
 	 * not get old pte entry after finishing flush_tlb_page and before
 	 * setting new huge pte entry
 	 */
-	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, sz);
 	flush_tlb_page(vma, addr);
 	return pte;
 }
diff --git a/arch/parisc/include/asm/hugetlb.h b/arch/parisc/include/asm/hugetlb.h
index 5b3a5429f71b..21e9ace17739 100644
--- a/arch/parisc/include/asm/hugetlb.h
+++ b/arch/parisc/include/asm/hugetlb.h
@@ -10,7 +10,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep);
+			      pte_t *ptep, unsigned long sz);
 
 #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
 static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
diff --git a/arch/parisc/mm/hugetlbpage.c b/arch/parisc/mm/hugetlbpage.c
index e9d18cf25b79..a94fe546d434 100644
--- a/arch/parisc/mm/hugetlbpage.c
+++ b/arch/parisc/mm/hugetlbpage.c
@@ -126,7 +126,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep)
+			      pte_t *ptep, unsigned long sz)
 {
 	pte_t entry;
 
diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index dad2e7980f24..86326587e58d 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -45,7 +45,8 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-					    unsigned long addr, pte_t *ptep)
+					    unsigned long addr, pte_t *ptep,
+					    unsigned long sz)
 {
 	return __pte(pte_update(mm, addr, ptep, ~0UL, 0, 1));
 }
@@ -55,8 +56,9 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 					  unsigned long addr, pte_t *ptep)
 {
 	pte_t pte;
+	unsigned long sz = huge_page_size(hstate_vma(vma));
 
-	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, sz);
 	flush_hugetlb_page(vma, addr);
 	return pte;
 }
diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
index faf3624d8057..446126497768 100644
--- a/arch/riscv/include/asm/hugetlb.h
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -28,7 +28,8 @@ void set_huge_pte_at(struct mm_struct *mm,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-			      unsigned long addr, pte_t *ptep);
+			      unsigned long addr, pte_t *ptep,
+			      unsigned long sz);
 
 #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
 pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index 42314f093922..b4a78a4b35cf 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -293,7 +293,7 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 			      unsigned long addr,
-			      pte_t *ptep)
+			      pte_t *ptep, unsigned long sz)
 {
 	pte_t orig_pte = ptep_get(ptep);
 	int pte_num;
diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index 7c52acaf9f82..663e87220e89 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -25,8 +25,16 @@ void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 #define __HAVE_ARCH_HUGE_PTEP_GET
 pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 
+pte_t __huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+				pte_t *ptep);
+
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
-pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+					    unsigned long addr, pte_t *ptep,
+					    unsigned long sz)
+{
+	return __huge_ptep_get_and_clear(mm, addr, ptep);
+}
 
 static inline void arch_clear_hugetlb_flags(struct folio *folio)
 {
@@ -48,7 +56,7 @@ static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 					  unsigned long address, pte_t *ptep)
 {
-	return huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
+	return __huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
 }
 
 #define  __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
@@ -59,7 +67,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 	int changed = !pte_same(huge_ptep_get(vma->vm_mm, addr, ptep), pte);
 
 	if (changed) {
-		huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+		__huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
 		__set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
 	}
 	return changed;
@@ -69,7 +77,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 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);
+	pte_t pte = __huge_ptep_get_and_clear(mm, addr, ptep);
 
 	__set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
 }
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index d9ce199953de..2e568f175cd4 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -188,8 +188,8 @@ pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 	return __rste_to_pte(pte_val(*ptep));
 }
 
-pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-			      unsigned long addr, pte_t *ptep)
+pte_t __huge_ptep_get_and_clear(struct mm_struct *mm,
+				unsigned long addr, pte_t *ptep)
 {
 	pte_t pte = huge_ptep_get(mm, addr, ptep);
 	pmd_t *pmdp = (pmd_t *) ptep;
diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
index c714ca6a05aa..e7a9cdd498dc 100644
--- a/arch/sparc/include/asm/hugetlb.h
+++ b/arch/sparc/include/asm/hugetlb.h
@@ -20,7 +20,7 @@ void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep);
+			      pte_t *ptep, unsigned long sz);
 
 #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
 static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index eee601a0d2cf..80504148d8a5 100644
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -260,7 +260,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 }
 
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep)
+			      pte_t *ptep, unsigned long sz)
 {
 	unsigned int i, nptes, orig_shift, shift;
 	unsigned long size;
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index f42133dae68e..2afc95bf1655 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -90,7 +90,7 @@ static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #ifndef __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-		unsigned long addr, pte_t *ptep)
+		unsigned long addr, pte_t *ptep, unsigned long sz)
 {
 	return ptep_get_and_clear(mm, addr, ptep);
 }
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index ec8c0ccc8f95..bf5f7256bd28 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -1004,7 +1004,9 @@ static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
 static inline pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
 						unsigned long addr, pte_t *ptep)
 {
-	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	unsigned long psize = huge_page_size(hstate_vma(vma));
+
+	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, psize);
 }
 #endif
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 65068671e460..de9d49e521c1 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5447,7 +5447,7 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
 	if (src_ptl != dst_ptl)
 		spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
 
-	pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
+	pte = huge_ptep_get_and_clear(mm, old_addr, src_pte, sz);
 
 	if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
 		huge_pte_clear(mm, new_addr, dst_pte, sz);
@@ -5622,7 +5622,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 			set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
 		}
 
-		pte = huge_ptep_get_and_clear(mm, address, ptep);
+		pte = huge_ptep_get_and_clear(mm, address, ptep, sz);
 		tlb_remove_huge_tlb_entry(h, tlb, ptep, address);
 		if (huge_pte_dirty(pte))
 			set_page_dirty(page);

[PATCH 6.6.y] mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()

[Ryan Roberts]

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

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

Cc: stable@vger.kernel.org
Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> # riscv
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> # s390
Link: https://lore.kernel.org/r/20250226120656.2400136-2-ryan.roberts@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit 02410ac72ac3707936c07ede66e94360d0d65319)
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
 arch/arm64/include/asm/hugetlb.h     |  4 ++--
 arch/arm64/mm/hugetlbpage.c          |  8 +++++---
 arch/loongarch/include/asm/hugetlb.h |  6 ++++--
 arch/mips/include/asm/hugetlb.h      |  6 ++++--
 arch/parisc/include/asm/hugetlb.h    |  2 +-
 arch/parisc/mm/hugetlbpage.c         |  2 +-
 arch/powerpc/include/asm/hugetlb.h   |  6 ++++--
 arch/riscv/include/asm/hugetlb.h     |  3 ++-
 arch/riscv/mm/hugetlbpage.c          |  2 +-
 arch/s390/include/asm/hugetlb.h      | 17 ++++++++++++-----
 arch/s390/mm/hugetlbpage.c           |  4 ++--
 arch/sparc/include/asm/hugetlb.h     |  2 +-
 arch/sparc/mm/hugetlbpage.c          |  2 +-
 include/asm-generic/hugetlb.h        |  2 +-
 include/linux/hugetlb.h              |  4 +++-
 mm/hugetlb.c                         |  4 ++--
 16 files changed, 46 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index 2ddc33d93b13..92a5e0879b11 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -34,8 +34,8 @@ extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 				      unsigned long addr, pte_t *ptep,
 				      pte_t pte, int dirty);
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
-extern pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-				     unsigned long addr, pte_t *ptep);
+extern pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+				     pte_t *ptep, unsigned long sz);
 #define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
 extern void huge_ptep_set_wrprotect(struct mm_struct *mm,
 				    unsigned long addr, pte_t *ptep);
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index a5e1588780b2..f86a09309807 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -403,8 +403,8 @@ void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 		pte_clear(mm, addr, ptep);
 }
 
-pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-			      unsigned long addr, pte_t *ptep)
+pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, unsigned long sz)
 {
 	int ncontig;
 	size_t pgsize;
@@ -556,6 +556,8 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
 
 pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 {
+	unsigned long psize = huge_page_size(hstate_vma(vma));
+
 	if (IS_ENABLED(CONFIG_ARM64_ERRATUM_2645198) &&
 	    cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
 		/*
@@ -566,7 +568,7 @@ pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr
 		if (pte_user_exec(READ_ONCE(*ptep)))
 			return huge_ptep_clear_flush(vma, addr, ptep);
 	}
-	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, psize);
 }
 
 void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
diff --git a/arch/loongarch/include/asm/hugetlb.h b/arch/loongarch/include/asm/hugetlb.h
index 427b487fbfd6..7b88eda0ac7e 100644
--- a/arch/loongarch/include/asm/hugetlb.h
+++ b/arch/loongarch/include/asm/hugetlb.h
@@ -41,7 +41,8 @@ static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-					    unsigned long addr, pte_t *ptep)
+					    unsigned long addr, pte_t *ptep,
+					    unsigned long sz)
 {
 	pte_t clear;
 	pte_t pte = *ptep;
@@ -56,8 +57,9 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 					  unsigned long addr, pte_t *ptep)
 {
 	pte_t pte;
+	unsigned long sz = huge_page_size(hstate_vma(vma));
 
-	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, sz);
 	flush_tlb_page(vma, addr);
 	return pte;
 }
diff --git a/arch/mips/include/asm/hugetlb.h b/arch/mips/include/asm/hugetlb.h
index fd69c8808554..00ee3c036630 100644
--- a/arch/mips/include/asm/hugetlb.h
+++ b/arch/mips/include/asm/hugetlb.h
@@ -32,7 +32,8 @@ static inline int prepare_hugepage_range(struct file *file,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-					    unsigned long addr, pte_t *ptep)
+					    unsigned long addr, pte_t *ptep,
+					    unsigned long sz)
 {
 	pte_t clear;
 	pte_t pte = *ptep;
@@ -47,13 +48,14 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 					  unsigned long addr, pte_t *ptep)
 {
 	pte_t pte;
+	unsigned long sz = huge_page_size(hstate_vma(vma));
 
 	/*
 	 * clear the huge pte entry firstly, so that the other smp threads will
 	 * not get old pte entry after finishing flush_tlb_page and before
 	 * setting new huge pte entry
 	 */
-	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, sz);
 	flush_tlb_page(vma, addr);
 	return pte;
 }
diff --git a/arch/parisc/include/asm/hugetlb.h b/arch/parisc/include/asm/hugetlb.h
index 72daacc472a0..f7a91411dcc9 100644
--- a/arch/parisc/include/asm/hugetlb.h
+++ b/arch/parisc/include/asm/hugetlb.h
@@ -10,7 +10,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep);
+			      pte_t *ptep, unsigned long sz);
 
 /*
  * If the arch doesn't supply something else, assume that hugepage
diff --git a/arch/parisc/mm/hugetlbpage.c b/arch/parisc/mm/hugetlbpage.c
index a9f7e21f6656..9e8da00e55f6 100644
--- a/arch/parisc/mm/hugetlbpage.c
+++ b/arch/parisc/mm/hugetlbpage.c
@@ -147,7 +147,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep)
+			      pte_t *ptep, unsigned long sz)
 {
 	pte_t entry;
 
diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index 8d8f4909ae1a..167c66c4e9ea 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -46,7 +46,8 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-					    unsigned long addr, pte_t *ptep)
+					    unsigned long addr, pte_t *ptep,
+					    unsigned long sz)
 {
 	return __pte(pte_update(mm, addr, ptep, ~0UL, 0, 1));
 }
@@ -56,8 +57,9 @@ static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 					  unsigned long addr, pte_t *ptep)
 {
 	pte_t pte;
+	unsigned long sz = huge_page_size(hstate_vma(vma));
 
-	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	pte = huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, sz);
 	flush_hugetlb_page(vma, addr);
 	return pte;
 }
diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
index 22deb7a2a6ec..0e809026b6e3 100644
--- a/arch/riscv/include/asm/hugetlb.h
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -28,7 +28,8 @@ void set_huge_pte_at(struct mm_struct *mm,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-			      unsigned long addr, pte_t *ptep);
+			      unsigned long addr, pte_t *ptep,
+			      unsigned long sz);
 
 #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
 pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index 5ef2a6891158..c9d70dc310d5 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -293,7 +293,7 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 			      unsigned long addr,
-			      pte_t *ptep)
+			      pte_t *ptep, unsigned long sz)
 {
 	pte_t orig_pte = ptep_get(ptep);
 	int pte_num;
diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index deb198a61039..097b388d4e69 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -20,8 +20,15 @@ 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);
 pte_t huge_ptep_get(pte_t *ptep);
-pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-			      unsigned long addr, pte_t *ptep);
+pte_t __huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
+				pte_t *ptep);
+
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+					    unsigned long addr, pte_t *ptep,
+					    unsigned long sz)
+{
+	return __huge_ptep_get_and_clear(mm, addr, ptep);
+}
 
 /*
  * If the arch doesn't supply something else, assume that hugepage
@@ -57,7 +64,7 @@ static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 					  unsigned long address, pte_t *ptep)
 {
-	return huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
+	return __huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
 }
 
 static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
@@ -66,7 +73,7 @@ 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);
+		__huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
 		__set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
 	}
 	return changed;
@@ -75,7 +82,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 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);
+	pte_t pte = __huge_ptep_get_and_clear(mm, addr, ptep);
 	__set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
 }
 
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index 763469e518ee..5ebd730f1ffb 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -174,8 +174,8 @@ pte_t huge_ptep_get(pte_t *ptep)
 	return __rste_to_pte(pte_val(*ptep));
 }
 
-pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-			      unsigned long addr, pte_t *ptep)
+pte_t __huge_ptep_get_and_clear(struct mm_struct *mm,
+				unsigned long addr, pte_t *ptep)
 {
 	pte_t pte = huge_ptep_get(ptep);
 	pmd_t *pmdp = (pmd_t *) ptep;
diff --git a/arch/sparc/include/asm/hugetlb.h b/arch/sparc/include/asm/hugetlb.h
index c714ca6a05aa..e7a9cdd498dc 100644
--- a/arch/sparc/include/asm/hugetlb.h
+++ b/arch/sparc/include/asm/hugetlb.h
@@ -20,7 +20,7 @@ void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep);
+			      pte_t *ptep, unsigned long sz);
 
 #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
 static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
diff --git a/arch/sparc/mm/hugetlbpage.c b/arch/sparc/mm/hugetlbpage.c
index b432500c13a5..8dad5d0995dc 100644
--- a/arch/sparc/mm/hugetlbpage.c
+++ b/arch/sparc/mm/hugetlbpage.c
@@ -371,7 +371,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 }
 
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
-			      pte_t *ptep)
+			      pte_t *ptep, unsigned long sz)
 {
 	unsigned int i, nptes, orig_shift, shift;
 	unsigned long size;
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index 6dcf4d576970..2d7ae9b51d1e 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -84,7 +84,7 @@ static inline void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #ifndef __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
-		unsigned long addr, pte_t *ptep)
+		unsigned long addr, pte_t *ptep, unsigned long sz)
 {
 	return ptep_get_and_clear(mm, addr, ptep);
 }
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 0ca93c7574ad..fc2023d07f69 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -1007,7 +1007,9 @@ static inline void hugetlb_count_sub(long l, struct mm_struct *mm)
 static inline pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
 						unsigned long addr, pte_t *ptep)
 {
-	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+	unsigned long psize = huge_page_size(hstate_vma(vma));
+
+	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep, psize);
 }
 #endif
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 21c12519a7ef..faded25b19be 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5236,7 +5236,7 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
 	if (src_ptl != dst_ptl)
 		spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
 
-	pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
+	pte = huge_ptep_get_and_clear(mm, old_addr, src_pte, sz);
 	set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
 
 	if (src_ptl != dst_ptl)
@@ -5399,7 +5399,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 			set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
 		}
 
-		pte = huge_ptep_get_and_clear(mm, address, ptep);
+		pte = huge_ptep_get_and_clear(mm, address, ptep, sz);
 		tlb_remove_huge_tlb_entry(h, tlb, ptep, address);
 		if (huge_pte_dirty(pte))
 			set_page_dirty(page);
-- 
2.43.0

[PATCH 6.6.y] arm64: hugetlb: Fix huge_ptep_get_and_clear() for non-present ptes

[Ryan Roberts]

arm64 supports multiple huge_pte sizes. Some of the sizes are covered by
a single pte entry at a particular level (PMD_SIZE, PUD_SIZE), and some
are covered by multiple ptes at a particular level (CONT_PTE_SIZE,
CONT_PMD_SIZE). So the function has to figure out the size from the
huge_pte pointer. This was previously done by walking the pgtable to
determine the level and by using the PTE_CONT bit to determine the
number of ptes at the level.

But the PTE_CONT bit is only valid when the pte is present. For
non-present pte values (e.g. markers, migration entries), the previous
implementation was therefore erroneously determining the size. There is
at least one known caller in core-mm, move_huge_pte(), which may call
huge_ptep_get_and_clear() for a non-present pte. So we must be robust to
this case. Additionally the "regular" ptep_get_and_clear() is robust to
being called for non-present ptes so it makes sense to follow the
behavior.

Fix this by using the new sz parameter which is now provided to the
function. Additionally when clearing each pte in a contig range, don't
gather the access and dirty bits if the pte is not present.

An alternative approach that would not require API changes would be to
store the PTE_CONT bit in a spare bit in the swap entry pte for the
non-present case. But it felt cleaner to follow other APIs' lead and
just pass in the size.

As an aside, PTE_CONT is bit 52, which corresponds to bit 40 in the swap
entry offset field (layout of non-present pte). Since hugetlb is never
swapped to disk, this field will only be populated for markers, which
always set this bit to 0 and hwpoison swap entries, which set the offset
field to a PFN; So it would only ever be 1 for a 52-bit PVA system where
memory in that high half was poisoned (I think!). So in practice, this
bit would almost always be zero for non-present ptes and we would only
clear the first entry if it was actually a contiguous block. That's
probably a less severe symptom than if it was always interpreted as 1
and cleared out potentially-present neighboring PTEs.

Cc: stable@vger.kernel.org
Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/r/20250226120656.2400136-3-ryan.roberts@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit 49c87f7677746f3c5bd16c81b23700bb6b88bfd4)
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
 arch/arm64/mm/hugetlbpage.c | 53 ++++++++++++++-----------------------
 1 file changed, 20 insertions(+), 33 deletions(-)

diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index f86a09309807..06efc3a1652e 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -121,20 +121,11 @@ static int find_num_contig(struct mm_struct *mm, unsigned long addr,
 
 static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
 {
-	int contig_ptes = 0;
+	int contig_ptes = 1;
 
 	*pgsize = size;
 
 	switch (size) {
-#ifndef __PAGETABLE_PMD_FOLDED
-	case PUD_SIZE:
-		if (pud_sect_supported())
-			contig_ptes = 1;
-		break;
-#endif
-	case PMD_SIZE:
-		contig_ptes = 1;
-		break;
 	case CONT_PMD_SIZE:
 		*pgsize = PMD_SIZE;
 		contig_ptes = CONT_PMDS;
@@ -143,6 +134,8 @@ static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
 		*pgsize = PAGE_SIZE;
 		contig_ptes = CONT_PTES;
 		break;
+	default:
+		WARN_ON(!__hugetlb_valid_size(size));
 	}
 
 	return contig_ptes;
@@ -184,24 +177,23 @@ static pte_t get_clear_contig(struct mm_struct *mm,
 			     unsigned long pgsize,
 			     unsigned long ncontig)
 {
-	pte_t orig_pte = ptep_get(ptep);
-	unsigned long i;
-
-	for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
-		pte_t pte = ptep_get_and_clear(mm, addr, ptep);
-
-		/*
-		 * If HW_AFDBM is enabled, then the HW could turn on
-		 * the dirty or accessed bit for any page in the set,
-		 * so check them all.
-		 */
-		if (pte_dirty(pte))
-			orig_pte = pte_mkdirty(orig_pte);
-
-		if (pte_young(pte))
-			orig_pte = pte_mkyoung(orig_pte);
+	pte_t pte, tmp_pte;
+	bool present;
+
+	pte = ptep_get_and_clear(mm, addr, ptep);
+	present = pte_present(pte);
+	while (--ncontig) {
+		ptep++;
+		addr += pgsize;
+		tmp_pte = ptep_get_and_clear(mm, addr, ptep);
+		if (present) {
+			if (pte_dirty(tmp_pte))
+				pte = pte_mkdirty(pte);
+			if (pte_young(tmp_pte))
+				pte = pte_mkyoung(pte);
+		}
 	}
-	return orig_pte;
+	return pte;
 }
 
 static pte_t get_clear_contig_flush(struct mm_struct *mm,
@@ -408,13 +400,8 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
 {
 	int ncontig;
 	size_t pgsize;
-	pte_t orig_pte = ptep_get(ptep);
-
-	if (!pte_cont(orig_pte))
-		return ptep_get_and_clear(mm, addr, ptep);
-
-	ncontig = find_num_contig(mm, addr, ptep, &pgsize);
 
+	ncontig = num_contig_ptes(sz, &pgsize);
 	return get_clear_contig(mm, addr, ptep, pgsize, ncontig);
 }
 
-- 
2.43.0

Re: [PATCH 6.6.y] arm64: hugetlb: Fix huge_ptep_get_and_clear() for non-present ptes

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
❌ Build failures detected
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: 49c87f7677746f3c5bd16c81b23700bb6b88bfd4

Note: The patch differs from the upstream commit:
---
1:  49c87f7677746 ! 1:  180bfe1de8d8a arm64: hugetlb: Fix huge_ptep_get_and_clear() for non-present ptes
    @@ Commit message
         Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
         Link: https://lore.kernel.org/r/20250226120656.2400136-3-ryan.roberts@arm.com
         Signed-off-by: Will Deacon <will@kernel.org>
    +    (cherry picked from commit 49c87f7677746f3c5bd16c81b23700bb6b88bfd4)
    +    Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
     
      ## arch/arm64/mm/hugetlbpage.c ##
     @@ arch/arm64/mm/hugetlbpage.c: static int find_num_contig(struct mm_struct *mm, unsigned long addr,
    @@ arch/arm64/mm/hugetlbpage.c: static pte_t get_clear_contig(struct mm_struct *mm,
      			     unsigned long pgsize,
      			     unsigned long ncontig)
      {
    --	pte_t orig_pte = __ptep_get(ptep);
    +-	pte_t orig_pte = ptep_get(ptep);
     -	unsigned long i;
     -
     -	for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
    --		pte_t pte = __ptep_get_and_clear(mm, addr, ptep);
    +-		pte_t pte = ptep_get_and_clear(mm, addr, ptep);
     -
     -		/*
     -		 * If HW_AFDBM is enabled, then the HW could turn on
    @@ arch/arm64/mm/hugetlbpage.c: static pte_t get_clear_contig(struct mm_struct *mm,
     +	pte_t pte, tmp_pte;
     +	bool present;
     +
    -+	pte = __ptep_get_and_clear(mm, addr, ptep);
    ++	pte = ptep_get_and_clear(mm, addr, ptep);
     +	present = pte_present(pte);
     +	while (--ncontig) {
     +		ptep++;
     +		addr += pgsize;
    -+		tmp_pte = __ptep_get_and_clear(mm, addr, ptep);
    ++		tmp_pte = ptep_get_and_clear(mm, addr, ptep);
     +		if (present) {
     +			if (pte_dirty(tmp_pte))
     +				pte = pte_mkdirty(pte);
    @@ arch/arm64/mm/hugetlbpage.c: static pte_t get_clear_contig(struct mm_struct *mm,
      }
      
      static pte_t get_clear_contig_flush(struct mm_struct *mm,
    -@@ arch/arm64/mm/hugetlbpage.c: pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
    +@@ arch/arm64/mm/hugetlbpage.c: pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
      {
      	int ncontig;
      	size_t pgsize;
    --	pte_t orig_pte = __ptep_get(ptep);
    +-	pte_t orig_pte = ptep_get(ptep);
     -
     -	if (!pte_cont(orig_pte))
    --		return __ptep_get_and_clear(mm, addr, ptep);
    +-		return ptep_get_and_clear(mm, addr, ptep);
     -
     -	ncontig = find_num_contig(mm, addr, ptep, &pgsize);
      
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Failed    |

Build Errors:
Build error for stable/linux-6.6.y:
    arch/arm64/mm/hugetlbpage.c: In function 'huge_ptep_get_and_clear':
    arch/arm64/mm/hugetlbpage.c:404:35: error: 'sz' undeclared (first use in this function); did you mean 's8'?
      404 |         ncontig = num_contig_ptes(sz, &pgsize);
          |                                   ^~
          |                                   s8
    arch/arm64/mm/hugetlbpage.c:404:35: note: each undeclared identifier is reported only once for each function it appears in
    make[4]: *** [scripts/Makefile.build:243: arch/arm64/mm/hugetlbpage.o] Error 1
    make[4]: Target 'arch/arm64/mm/' not remade because of errors.
    make[3]: *** [scripts/Makefile.build:480: arch/arm64/mm] Error 2
    make[3]: Target 'arch/arm64/' not remade because of errors.
    make[2]: *** [scripts/Makefile.build:480: arch/arm64] Error 2
    make[2]: Target './' not remade because of errors.
    make[1]: *** [/home/sasha/build/linus-next/Makefile:1916: .] Error 2
    make[1]: Target '__all' not remade because of errors.
    make: *** [Makefile:234: __sub-make] Error 2
    make: Target '__all' not remade because of errors.

Re: [PATCH 6.6.y] mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: 02410ac72ac3707936c07ede66e94360d0d65319

Note: The patch differs from the upstream commit:
---
1:  02410ac72ac37 ! 1:  db66591c2390e mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()
    @@ Commit message
         Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> # s390
         Link: https://lore.kernel.org/r/20250226120656.2400136-2-ryan.roberts@arm.com
         Signed-off-by: Will Deacon <will@kernel.org>
    +    (cherry picked from commit 02410ac72ac3707936c07ede66e94360d0d65319)
    +    Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
     
      ## arch/arm64/include/asm/hugetlb.h ##
     @@ arch/arm64/include/asm/hugetlb.h: extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
    @@ arch/arm64/include/asm/hugetlb.h: extern int huge_ptep_set_access_flags(struct v
     
      ## arch/arm64/mm/hugetlbpage.c ##
     @@ arch/arm64/mm/hugetlbpage.c: void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
    - 		__pte_clear(mm, addr, ptep);
    + 		pte_clear(mm, addr, ptep);
      }
      
     -pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
    @@ arch/arm64/mm/hugetlbpage.c: bool __init arch_hugetlb_valid_size(unsigned long s
      {
     +	unsigned long psize = huge_page_size(hstate_vma(vma));
     +
    - 	if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) {
    + 	if (IS_ENABLED(CONFIG_ARM64_ERRATUM_2645198) &&
    + 	    cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
      		/*
    - 		 * Break-before-make (BBM) is required for all user space mappings
     @@ arch/arm64/mm/hugetlbpage.c: pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr
    - 		if (pte_user_exec(__ptep_get(ptep)))
    + 		if (pte_user_exec(READ_ONCE(*ptep)))
      			return huge_ptep_clear_flush(vma, addr, ptep);
      	}
     -	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
    @@ arch/loongarch/include/asm/hugetlb.h: static inline void huge_pte_clear(struct m
     +					    unsigned long sz)
      {
      	pte_t clear;
    - 	pte_t pte = ptep_get(ptep);
    + 	pte_t pte = *ptep;
     @@ arch/loongarch/include/asm/hugetlb.h: static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
      					  unsigned long addr, pte_t *ptep)
      {
    @@ arch/parisc/include/asm/hugetlb.h: void set_huge_pte_at(struct mm_struct *mm, un
     -			      pte_t *ptep);
     +			      pte_t *ptep, unsigned long sz);
      
    - #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
    - static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
    + /*
    +  * If the arch doesn't supply something else, assume that hugepage
     
      ## arch/parisc/mm/hugetlbpage.c ##
     @@ arch/parisc/mm/hugetlbpage.c: void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
    @@ arch/parisc/mm/hugetlbpage.c: void set_huge_pte_at(struct mm_struct *mm, unsigne
      
     
      ## arch/powerpc/include/asm/hugetlb.h ##
    -@@ arch/powerpc/include/asm/hugetlb.h: void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
    +@@ arch/powerpc/include/asm/hugetlb.h: void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
      
      #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
      static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
    @@ arch/riscv/mm/hugetlbpage.c: int huge_ptep_set_access_flags(struct vm_area_struc
      	int pte_num;
     
      ## arch/s390/include/asm/hugetlb.h ##
    -@@ arch/s390/include/asm/hugetlb.h: void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
    - #define __HAVE_ARCH_HUGE_PTEP_GET
    - pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
    - 
    +@@ arch/s390/include/asm/hugetlb.h: 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);
    + pte_t huge_ptep_get(pte_t *ptep);
    +-pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
    +-			      unsigned long addr, pte_t *ptep);
     +pte_t __huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
     +				pte_t *ptep);
     +
    - #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
    --pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
     +static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
     +					    unsigned long addr, pte_t *ptep,
     +					    unsigned long sz)
    @@ arch/s390/include/asm/hugetlb.h: void __set_huge_pte_at(struct mm_struct *mm, un
     +	return __huge_ptep_get_and_clear(mm, addr, ptep);
     +}
      
    - static inline void arch_clear_hugetlb_flags(struct folio *folio)
    - {
    + /*
    +  * If the arch doesn't supply something else, assume that hugepage
     @@ arch/s390/include/asm/hugetlb.h: static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
      static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
      					  unsigned long address, pte_t *ptep)
    @@ arch/s390/include/asm/hugetlb.h: static inline void huge_pte_clear(struct mm_str
     +	return __huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
      }
      
    - #define  __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
    + static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
     @@ arch/s390/include/asm/hugetlb.h: static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
    - 	int changed = !pte_same(huge_ptep_get(vma->vm_mm, addr, ptep), pte);
    - 
    + {
    + 	int changed = !pte_same(huge_ptep_get(ptep), pte);
      	if (changed) {
     -		huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
     +		__huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
    @@ arch/s390/include/asm/hugetlb.h: static inline int huge_ptep_set_access_flags(st
      {
     -	pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
     +	pte_t pte = __huge_ptep_get_and_clear(mm, addr, ptep);
    - 
      	__set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
      }
    + 
     
      ## arch/s390/mm/hugetlbpage.c ##
    -@@ arch/s390/mm/hugetlbpage.c: pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
    +@@ arch/s390/mm/hugetlbpage.c: pte_t huge_ptep_get(pte_t *ptep)
      	return __rste_to_pte(pte_val(*ptep));
      }
      
    @@ arch/s390/mm/hugetlbpage.c: pte_t huge_ptep_get(struct mm_struct *mm, unsigned l
     +pte_t __huge_ptep_get_and_clear(struct mm_struct *mm,
     +				unsigned long addr, pte_t *ptep)
      {
    - 	pte_t pte = huge_ptep_get(mm, addr, ptep);
    + 	pte_t pte = huge_ptep_get(ptep);
      	pmd_t *pmdp = (pmd_t *) ptep;
     
      ## arch/sparc/include/asm/hugetlb.h ##
    @@ mm/hugetlb.c: static void move_huge_pte(struct vm_area_struct *vma, unsigned lon
      
     -	pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
     +	pte = huge_ptep_get_and_clear(mm, old_addr, src_pte, sz);
    + 	set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
      
    - 	if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
    - 		huge_pte_clear(mm, new_addr, dst_pte, sz);
    + 	if (src_ptl != dst_ptl)
     @@ mm/hugetlb.c: void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
      			set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
      		}
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |

Re: [PATCH 6.6.y] mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()

[Ryan Roberts]

On 06/03/2025 19:11, Sasha Levin wrote:
> [ Sasha's backport helper bot ]
> 
> Hi,
> 
> Summary of potential issues:
> ⚠️ Found matching upstream commit but patch is missing proper reference to it

Hi,

I'm not sure what the issue is here? I've added the line:

(cherry picked from commit 02410ac72ac3707936c07ede66e94360d0d65319)

to the commit log. Is that not the correct/sufficient thing to do?

Thanks,
Ryan

> 
> Found matching upstream commit: 02410ac72ac3707936c07ede66e94360d0d65319
> 
> Note: The patch differs from the upstream commit:
> ---
> 1:  02410ac72ac37 ! 1:  db66591c2390e mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()
>     @@ Commit message
>          Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> # s390
>          Link: https://lore.kernel.org/r/20250226120656.2400136-2-ryan.roberts@arm.com
>          Signed-off-by: Will Deacon <will@kernel.org>
>     +    (cherry picked from commit 02410ac72ac3707936c07ede66e94360d0d65319)
>     +    Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
>      
>       ## arch/arm64/include/asm/hugetlb.h ##
>      @@ arch/arm64/include/asm/hugetlb.h: extern int huge_ptep_set_access_flags(struct vm_area_struct *vma,
>     @@ arch/arm64/include/asm/hugetlb.h: extern int huge_ptep_set_access_flags(struct v
>      
>       ## arch/arm64/mm/hugetlbpage.c ##
>      @@ arch/arm64/mm/hugetlbpage.c: void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
>     - 		__pte_clear(mm, addr, ptep);
>     + 		pte_clear(mm, addr, ptep);
>       }
>       
>      -pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
>     @@ arch/arm64/mm/hugetlbpage.c: bool __init arch_hugetlb_valid_size(unsigned long s
>       {
>      +	unsigned long psize = huge_page_size(hstate_vma(vma));
>      +
>     - 	if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) {
>     + 	if (IS_ENABLED(CONFIG_ARM64_ERRATUM_2645198) &&
>     + 	    cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
>       		/*
>     - 		 * Break-before-make (BBM) is required for all user space mappings
>      @@ arch/arm64/mm/hugetlbpage.c: pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr
>     - 		if (pte_user_exec(__ptep_get(ptep)))
>     + 		if (pte_user_exec(READ_ONCE(*ptep)))
>       			return huge_ptep_clear_flush(vma, addr, ptep);
>       	}
>      -	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
>     @@ arch/loongarch/include/asm/hugetlb.h: static inline void huge_pte_clear(struct m
>      +					    unsigned long sz)
>       {
>       	pte_t clear;
>     - 	pte_t pte = ptep_get(ptep);
>     + 	pte_t pte = *ptep;
>      @@ arch/loongarch/include/asm/hugetlb.h: static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
>       					  unsigned long addr, pte_t *ptep)
>       {
>     @@ arch/parisc/include/asm/hugetlb.h: void set_huge_pte_at(struct mm_struct *mm, un
>      -			      pte_t *ptep);
>      +			      pte_t *ptep, unsigned long sz);
>       
>     - #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
>     - static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
>     + /*
>     +  * If the arch doesn't supply something else, assume that hugepage
>      
>       ## arch/parisc/mm/hugetlbpage.c ##
>      @@ arch/parisc/mm/hugetlbpage.c: void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>     @@ arch/parisc/mm/hugetlbpage.c: void set_huge_pte_at(struct mm_struct *mm, unsigne
>       
>      
>       ## arch/powerpc/include/asm/hugetlb.h ##
>     -@@ arch/powerpc/include/asm/hugetlb.h: void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
>     +@@ arch/powerpc/include/asm/hugetlb.h: void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
>       
>       #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
>       static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
>     @@ arch/riscv/mm/hugetlbpage.c: int huge_ptep_set_access_flags(struct vm_area_struc
>       	int pte_num;
>      
>       ## arch/s390/include/asm/hugetlb.h ##
>     -@@ arch/s390/include/asm/hugetlb.h: void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>     - #define __HAVE_ARCH_HUGE_PTEP_GET
>     - pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
>     - 
>     +@@ arch/s390/include/asm/hugetlb.h: 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);
>     + pte_t huge_ptep_get(pte_t *ptep);
>     +-pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
>     +-			      unsigned long addr, pte_t *ptep);
>      +pte_t __huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
>      +				pte_t *ptep);
>      +
>     - #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
>     --pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
>      +static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
>      +					    unsigned long addr, pte_t *ptep,
>      +					    unsigned long sz)
>     @@ arch/s390/include/asm/hugetlb.h: void __set_huge_pte_at(struct mm_struct *mm, un
>      +	return __huge_ptep_get_and_clear(mm, addr, ptep);
>      +}
>       
>     - static inline void arch_clear_hugetlb_flags(struct folio *folio)
>     - {
>     + /*
>     +  * If the arch doesn't supply something else, assume that hugepage
>      @@ arch/s390/include/asm/hugetlb.h: static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
>       static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
>       					  unsigned long address, pte_t *ptep)
>     @@ arch/s390/include/asm/hugetlb.h: static inline void huge_pte_clear(struct mm_str
>      +	return __huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
>       }
>       
>     - #define  __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
>     + static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
>      @@ arch/s390/include/asm/hugetlb.h: static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
>     - 	int changed = !pte_same(huge_ptep_get(vma->vm_mm, addr, ptep), pte);
>     - 
>     + {
>     + 	int changed = !pte_same(huge_ptep_get(ptep), pte);
>       	if (changed) {
>      -		huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
>      +		__huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
>     @@ arch/s390/include/asm/hugetlb.h: static inline int huge_ptep_set_access_flags(st
>       {
>      -	pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
>      +	pte_t pte = __huge_ptep_get_and_clear(mm, addr, ptep);
>     - 
>       	__set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
>       }
>     + 
>      
>       ## arch/s390/mm/hugetlbpage.c ##
>     -@@ arch/s390/mm/hugetlbpage.c: pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
>     +@@ arch/s390/mm/hugetlbpage.c: pte_t huge_ptep_get(pte_t *ptep)
>       	return __rste_to_pte(pte_val(*ptep));
>       }
>       
>     @@ arch/s390/mm/hugetlbpage.c: pte_t huge_ptep_get(struct mm_struct *mm, unsigned l
>      +pte_t __huge_ptep_get_and_clear(struct mm_struct *mm,
>      +				unsigned long addr, pte_t *ptep)
>       {
>     - 	pte_t pte = huge_ptep_get(mm, addr, ptep);
>     + 	pte_t pte = huge_ptep_get(ptep);
>       	pmd_t *pmdp = (pmd_t *) ptep;
>      
>       ## arch/sparc/include/asm/hugetlb.h ##
>     @@ mm/hugetlb.c: static void move_huge_pte(struct vm_area_struct *vma, unsigned lon
>       
>      -	pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
>      +	pte = huge_ptep_get_and_clear(mm, old_addr, src_pte, sz);
>     + 	set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
>       
>     - 	if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
>     - 		huge_pte_clear(mm, new_addr, dst_pte, sz);
>     + 	if (src_ptl != dst_ptl)
>      @@ mm/hugetlb.c: void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
>       			set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
>       		}
> ---
> 
> Results of testing on various branches:
> 
> | Branch                    | Patch Apply | Build Test |
> |---------------------------|-------------|------------|
> | stable/linux-6.6.y        |  Success    |  Success   |

Re: [PATCH 6.6.y] arm64: hugetlb: Fix huge_ptep_get_and_clear() for non-present ptes

[Ryan Roberts]

On 06/03/2025 19:11, Sasha Levin wrote:
> [ Sasha's backport helper bot ]
> 
> Hi,
> 
> Summary of potential issues:
> ❌ Build failures detected

I think this is becuase you didn't include the dependent patch? See below.

> ⚠️ Found matching upstream commit but patch is missing proper reference to it

Same question as the other patch, I thought adding:

(cherry picked from commit 49c87f7677746f3c5bd16c81b23700bb6b88bfd4)

to the commit log was sufficient?

> 
> Found matching upstream commit: 49c87f7677746f3c5bd16c81b23700bb6b88bfd4
> 
> Note: The patch differs from the upstream commit:
> ---
> 1:  49c87f7677746 ! 1:  180bfe1de8d8a arm64: hugetlb: Fix huge_ptep_get_and_clear() for non-present ptes
>     @@ Commit message
>          Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
>          Link: https://lore.kernel.org/r/20250226120656.2400136-3-ryan.roberts@arm.com
>          Signed-off-by: Will Deacon <will@kernel.org>
>     +    (cherry picked from commit 49c87f7677746f3c5bd16c81b23700bb6b88bfd4)
>     +    Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
>      
>       ## arch/arm64/mm/hugetlbpage.c ##
>      @@ arch/arm64/mm/hugetlbpage.c: static int find_num_contig(struct mm_struct *mm, unsigned long addr,
>     @@ arch/arm64/mm/hugetlbpage.c: static pte_t get_clear_contig(struct mm_struct *mm,
>       			     unsigned long pgsize,
>       			     unsigned long ncontig)
>       {
>     --	pte_t orig_pte = __ptep_get(ptep);
>     +-	pte_t orig_pte = ptep_get(ptep);
>      -	unsigned long i;
>      -
>      -	for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
>     --		pte_t pte = __ptep_get_and_clear(mm, addr, ptep);
>     +-		pte_t pte = ptep_get_and_clear(mm, addr, ptep);
>      -
>      -		/*
>      -		 * If HW_AFDBM is enabled, then the HW could turn on
>     @@ arch/arm64/mm/hugetlbpage.c: static pte_t get_clear_contig(struct mm_struct *mm,
>      +	pte_t pte, tmp_pte;
>      +	bool present;
>      +
>     -+	pte = __ptep_get_and_clear(mm, addr, ptep);
>     ++	pte = ptep_get_and_clear(mm, addr, ptep);
>      +	present = pte_present(pte);
>      +	while (--ncontig) {
>      +		ptep++;
>      +		addr += pgsize;
>     -+		tmp_pte = __ptep_get_and_clear(mm, addr, ptep);
>     ++		tmp_pte = ptep_get_and_clear(mm, addr, ptep);
>      +		if (present) {
>      +			if (pte_dirty(tmp_pte))
>      +				pte = pte_mkdirty(pte);
>     @@ arch/arm64/mm/hugetlbpage.c: static pte_t get_clear_contig(struct mm_struct *mm,
>       }
>       
>       static pte_t get_clear_contig_flush(struct mm_struct *mm,
>     -@@ arch/arm64/mm/hugetlbpage.c: pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
>     +@@ arch/arm64/mm/hugetlbpage.c: pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
>       {
>       	int ncontig;
>       	size_t pgsize;
>     --	pte_t orig_pte = __ptep_get(ptep);
>     +-	pte_t orig_pte = ptep_get(ptep);
>      -
>      -	if (!pte_cont(orig_pte))
>     --		return __ptep_get_and_clear(mm, addr, ptep);
>     +-		return ptep_get_and_clear(mm, addr, ptep);
>      -
>      -	ncontig = find_num_contig(mm, addr, ptep, &pgsize);
>       
> ---
> 
> Results of testing on various branches:
> 
> | Branch                    | Patch Apply | Build Test |
> |---------------------------|-------------|------------|
> | stable/linux-6.6.y        |  Success    |  Failed    |
> 
> Build Errors:
> Build error for stable/linux-6.6.y:
>     arch/arm64/mm/hugetlbpage.c: In function 'huge_ptep_get_and_clear':
>     arch/arm64/mm/hugetlbpage.c:404:35: error: 'sz' undeclared (first use in this function); did you mean 's8'?
>       404 |         ncontig = num_contig_ptes(sz, &pgsize);
>           |                                   ^~
>           |                                   s8

The previous patch (see 20250306144716.71199-1-ryan.roberts@arm.com) adds the sz
parameter to the function. I think you built this without that patch present? I
sent them out as a pair for that reason.

Should I be doing anything in the commit log or email body to mark up the
dependency?

Thanks,
Ryan



>     arch/arm64/mm/hugetlbpage.c:404:35: note: each undeclared identifier is reported only once for each function it appears in
>     make[4]: *** [scripts/Makefile.build:243: arch/arm64/mm/hugetlbpage.o] Error 1
>     make[4]: Target 'arch/arm64/mm/' not remade because of errors.
>     make[3]: *** [scripts/Makefile.build:480: arch/arm64/mm] Error 2
>     make[3]: Target 'arch/arm64/' not remade because of errors.
>     make[2]: *** [scripts/Makefile.build:480: arch/arm64] Error 2
>     make[2]: Target './' not remade because of errors.
>     make[1]: *** [/home/sasha/build/linus-next/Makefile:1916: .] Error 2
>     make[1]: Target '__all' not remade because of errors.
>     make: *** [Makefile:234: __sub-make] Error 2
>     make: Target '__all' not remade because of errors.