[PATCH v3 03/16] mm: document vm_operations_struct->open the same as close()

Lorenzo Stoakes (Oracle)
2026-03-19T18:23:58Z

Describe when the operation is invoked and the context in which it is
invoked, matching the description already added for vm_op->close().

While we're here, update all outdated references to an 'area' field for
VMAs to the more consistent 'vma'.

Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
---
include/linux/mm.h | 15 ++++++++++-----
tools/testing/vma/include/dup.h | 15 ++++++++++-----
2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1e63b3a44a47..da94edb287cd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -766,15 +766,20 @@ struct vm_uffd_ops;
* to the functions called when a no-page or a wp-page exception occurs.
*/
struct vm_operations_struct {
- void (*open)(struct vm_area_struct * area);
+ /**
+ * @open: Called when a VMA is remapped, split or forked. Not called
+ * upon first mapping a VMA.
+ * Context: User context. May sleep. Caller holds mmap_lock.
+ */
+ void (*open)(struct vm_area_struct *vma);
/**
* @close: Called when the VMA is being removed from the MM.
* Context: User context. May sleep. Caller holds mmap_lock.
*/
- void (*close)(struct vm_area_struct * area);
+ void (*close)(struct vm_area_struct *vma);
/* Called any time before splitting to check if it's allowed */
- int (*may_split)(struct vm_area_struct *area, unsigned long addr);
- int (*mremap)(struct vm_area_struct *area);
+ int (*may_split)(struct vm_area_struct *vma, unsigned long addr);
+ int (*mremap)(struct vm_area_struct *vma);
/*
* Called by mprotect() to make driver-specific permission
* checks before mprotect() is finalised. The VMA must not
@@ -786,7 +791,7 @@ struct vm_operations_struct {
vm_fault_t (*huge_fault)(struct vm_fault *vmf, unsigned int order);
vm_fault_t (*map_pages)(struct vm_fault *vmf,
pgoff_t start_pgoff, pgoff_t end_pgoff);
- unsigned long (*pagesize)(struct vm_area_struct * area);
+ unsigned long (*pagesize)(struct vm_area_struct *vma);

/* notification that a previously read-only page is about to become
* writable, if an error is returned it will cause a SIGBUS */
diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h
index 9eada1e0949c..8ae525ed1738 100644
--- a/tools/testing/vma/include/dup.h
+++ b/tools/testing/vma/include/dup.h
@@ -632,15 +632,20 @@ struct vm_area_struct {
} __randomize_layout;

struct vm_operations_struct {
- void (*open)(struct vm_area_struct * area);
+ /**
+ * @open: Called when a VMA is remapped, split or forked. Not called
+ * upon first mapping a VMA.
+ * Context: User context. May sleep. Caller holds mmap_lock.
+ */
+ void (*open)(struct vm_area_struct *vma);
/**
* @close: Called when the VMA is being removed from the MM.
* Context: User context. May sleep. Caller holds mmap_lock.
*/
- void (*close)(struct vm_area_struct * area);
+ void (*close)(struct vm_area_struct *vma);
/* Called any time before splitting to check if it's allowed */
- int (*may_split)(struct vm_area_struct *area, unsigned long addr);
- int (*mremap)(struct vm_area_struct *area);
+ int (*may_split)(struct vm_area_struct *vma, unsigned long addr);
+ int (*mremap)(struct vm_area_struct *vma);
/*
* Called by mprotect() to make driver-specific permission
* checks before mprotect() is finalised. The VMA must not
@@ -652,7 +657,7 @@ struct vm_operations_struct {
vm_fault_t (*huge_fault)(struct vm_fault *vmf, unsigned int order);
vm_fault_t (*map_pages)(struct vm_fault *vmf,
pgoff_t start_pgoff, pgoff_t end_pgoff);
- unsigned long (*pagesize)(struct vm_area_struct * area);
+ unsigned long (*pagesize)(struct vm_area_struct *vma);

/* notification that a previously read-only page is about to become
* writable, if an error is returned it will cause a SIGBUS */
--
2.53.0