mm/vma: const-ify vma_assert_stabilised() and associated functions

Patch series "mm: implement and use vma_has_anon_rmap(), silence KCSAN".

Provide a function to abstract the common task of checking whether a VMA
has an anonymous reverse mapping associated with it.

In the first patch, const-ify vma_assert_stabilised() and related
functions so that vma_has_anon_rmap() can reference a const vma pointer.

In the second patch, introduce vma_has_anon_rmap().

Finally in the third patch, update comments referencing anon_vma to
instead reference the anon rmap to abstract this conceptually to avoid
confusion.

There are still other functions which reference anon_vma directly, those
can be addressed in a follow up.


This patch (of 3):

The vma pointers are not modified in any of these functions so make it
official by const-ify them.

Propagate this throughout the call stack.

No functional change intended.

Link: https://lore.kernel.org/20260917-vma-is-faulted-v3-0-5c22314a72e7@kernel.org
Link: https://lore.kernel.org/20260917-vma-is-faulted-v3-1-5c22314a72e7@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de> 
Reviewed-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>

1 files changed, 6 insertions, 6 deletions

diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
index 28e3696ce9ff..e5553f4a414c 100644
--- a/include/linux/mmap_lock.h
+++ b/include/linux/mmap_lock.h
@@ -273,7 +273,7 @@ static inline void vma_end_read(struct vm_area_struct *vma)
 	vma_refcount_put(vma);
 }
 
-static inline unsigned int __vma_raw_mm_seqnum(struct vm_area_struct *vma)
+static inline unsigned int __vma_raw_mm_seqnum(const struct vm_area_struct *vma)
 {
 	const struct mm_struct *mm = vma->vm_mm;
 
@@ -288,7 +288,7 @@ static inline unsigned int __vma_raw_mm_seqnum(struct vm_area_struct *vma)
  *
  * Returns true if write-locked, otherwise false.
  */
-static inline bool __is_vma_write_locked(struct vm_area_struct *vma)
+static inline bool __is_vma_write_locked(const struct vm_area_struct *vma)
 {
 	/*
 	 * current task is holding mmap_write_lock, both vma->vm_lock_seq and
@@ -344,7 +344,7 @@ int vma_start_write_killable(struct vm_area_struct *vma)
  * vma_assert_write_locked() - assert that @vma holds a VMA write lock.
  * @vma: The VMA to assert.
  */
-static inline void vma_assert_write_locked(struct vm_area_struct *vma)
+static inline void vma_assert_write_locked(const struct vm_area_struct *vma)
 {
 	if (!IS_ENABLED(CONFIG_MMU)) {
 		mmap_assert_write_locked(vma->vm_mm);
@@ -359,7 +359,7 @@ static inline void vma_assert_write_locked(struct vm_area_struct *vma)
  * lock and is not detached.
  * @vma: The VMA to assert.
  */
-static inline void vma_assert_locked(struct vm_area_struct *vma)
+static inline void vma_assert_locked(const struct vm_area_struct *vma)
 {
 	unsigned int refcnt;
 
@@ -410,7 +410,7 @@ static inline void vma_assert_locked(struct vm_area_struct *vma)
  * With lockdep disabled we may sometimes race with other threads acquiring the
  * mmap read lock simultaneous with our VMA read lock.
  */
-static inline void vma_assert_stabilised(struct vm_area_struct *vma)
+static inline void vma_assert_stabilised(const struct vm_area_struct *vma)
 {
 	/*
 	 * If another thread owns an mmap lock, it may go away at any time, and
@@ -445,7 +445,7 @@ static inline void vma_assert_stabilised(struct vm_area_struct *vma)
 	vma_assert_locked(vma);
 }
 
-static inline bool vma_is_attached(struct vm_area_struct *vma)
+static inline bool vma_is_attached(const struct vm_area_struct *vma)
 {
 	return refcount_read(&vma->vm_refcnt);
 }