From: Liam R. Howlett <Liam.Howlett@oracle.com>
Date: Fri, 24 Oct 2025 02:59:32 +0000 (-0400)
Subject: mm/userfaultfd: Align poison function definitions for uffd_ops
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=5a43793420facb5d0d7896c379d26d2a6100b248;p=users%2Fjedix%2Flinux-maple.git

mm/userfaultfd: Align poison function definitions for uffd_ops

hugetlb is the most special of memory types, requiring more options for
callers than the rest.  Aligning the function definitions allows for a
uffd ops pointer to be used for memory types.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index d3b9d8adf32d..fee5a904fbd0 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -98,6 +98,9 @@ ssize_t uffd_failed_do_unlock(struct userfaultfd_ctx *ctx,
 		unsigned long src_addr);
 
 struct vm_uffd_ops {
+	int (*poison)(struct vm_area_struct *dst_vma,
+		unsigned long dst_addr, unsigned long increment);
+
 	/* Required features below */
 	ssize_t (*is_dst_valid)(struct vm_area_struct *dst_vma,
 				unsigned long dst_start, unsigned long len);
@@ -227,6 +230,8 @@ static inline unsigned long mfill_size(struct vm_area_struct *vma)
 {
 	return PAGE_SIZE;
 }
+int mfill_atomic_pte_poison(struct vm_area_struct *dst_vma,
+		unsigned long dst_addr, unsigned long increment);
 
 static inline bool vma_can_userfault(struct vm_area_struct *vma,
 				     vm_flags_t vm_flags,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 47eda0866d52..42cb8e5c32ca 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5529,7 +5529,11 @@ static ssize_t hugetlb_failed_do_unlock(struct userfaultfd_ctx *ctx,
 	return copy_folio_from_user(folio,(const void __user *)src_addr, true);
 }
 
+static int hugetlb_mfill_pte_poison(struct vm_area_struct *dst_vma,
+		unsigned long dst_addr, unsigned long increment);
+
 static const struct vm_uffd_ops hugetlb_uffd_ops = {
+	.poison			=	hugetlb_mfill_pte_poison,
 	.is_dst_valid		=	hugetlb_is_dst_valid,
 	.increment		=	hugetlb_mfill_size,
 	.failed_do_unlock	=	hugetlb_failed_do_unlock,
diff --git a/mm/shmem.c b/mm/shmem.c
index 86db6aa3b8e5..c1816a582e48 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -5208,6 +5208,7 @@ static int shmem_error_remove_folio(struct address_space *mapping,
 
 #ifdef CONFIG_USERFAULTFD
 static const struct vm_uffd_ops shmem_uffd_ops = {
+	.poison			=	mfill_atomic_pte_poison,
 	.is_dst_valid		=	shmem_is_dst_valid,
 	.increment		=	mfill_size,
 	.failed_do_unlock	=	uffd_failed_do_unlock,
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index a62c0a05cdfa..fd89aebd86b0 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -433,9 +433,8 @@ out_release:
 }
 
 /* Handles UFFDIO_POISON for all non-hugetlb VMAs. */
-static int mfill_atomic_pte_poison(struct vm_area_struct *dst_vma,
-				   unsigned long dst_addr,
-				   uffd_flags_t flags)
+int mfill_atomic_pte_poison(struct vm_area_struct *dst_vma,
+		unsigned long dst_addr, unsigned long increment)
 {
 	int ret;
 	struct mm_struct *dst_mm = dst_vma->vm_mm;
@@ -508,6 +507,7 @@ static ssize_t uffd_def_is_dst_valid(struct vm_area_struct *dst_vma,
 
 /* Anon vma ops */
 static const struct vm_uffd_ops default_uffd_ops = {
+	.poison			= mfill_atomic_pte_poison,
 	.is_dst_valid		= uffd_def_is_dst_valid,
 	.increment		= mfill_size,
 	.failed_do_unlock	= uffd_failed_do_unlock,