[PATCH 3/5] mm: export zap_page_range_single and list_lru_add/del

Alice Ryhl aliceryhl at google.com
Thu Feb 5 11:04:07 UTC 2026


On Thu, Feb 05, 2026 at 11:59:47AM +0100, David Hildenbrand (arm) wrote:
> On 2/5/26 11:51, Alice Ryhl wrote:
> > These are the functions needed by Binder's shrinker.
> > 
> > Binder uses zap_page_range_single in the shrinker path to remove an
> > unused page from the mmap'd region. Note that pages are only removed
> > from the mmap'd region lazily when shrinker asks for it.
> > 
> > Binder uses list_lru_add/del to keep track of the shrinker lru list, and
> > it can't use _obj because the list head is not stored inline in the page
> > actually being lru freed, so page_to_nid(virt_to_page(item)) on the list
> > head computes the nid of the wrong page.
> > 
> > Signed-off-by: Alice Ryhl <aliceryhl at google.com>
> > ---
> >   mm/list_lru.c | 2 ++
> >   mm/memory.c   | 1 +
> >   2 files changed, 3 insertions(+)
> > 
> > diff --git a/mm/list_lru.c b/mm/list_lru.c
> > index ec48b5dadf519a5296ac14cda035c067f9e448f8..bf95d73c9815548a19db6345f856cee9baad22e3 100644
> > --- a/mm/list_lru.c
> > +++ b/mm/list_lru.c
> > @@ -179,6 +179,7 @@ bool list_lru_add(struct list_lru *lru, struct list_head *item, int nid,
> >   	unlock_list_lru(l, false);
> >   	return false;
> >   }
> > +EXPORT_SYMBOL_GPL(list_lru_add);
> >   bool list_lru_add_obj(struct list_lru *lru, struct list_head *item)
> >   {
> > @@ -216,6 +217,7 @@ bool list_lru_del(struct list_lru *lru, struct list_head *item, int nid,
> >   	unlock_list_lru(l, false);
> >   	return false;
> >   }
> > +EXPORT_SYMBOL_GPL(list_lru_del);
> >   bool list_lru_del_obj(struct list_lru *lru, struct list_head *item)
> >   {
> > diff --git a/mm/memory.c b/mm/memory.c
> > index da360a6eb8a48e29293430d0c577fb4b6ec58099..64083ace239a2caf58e1645dd5d91a41d61492c4 100644
> > --- a/mm/memory.c
> > +++ b/mm/memory.c
> > @@ -2168,6 +2168,7 @@ void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
> >   	zap_page_range_single_batched(&tlb, vma, address, size, details);
> >   	tlb_finish_mmu(&tlb);
> >   }
> > +EXPORT_SYMBOL(zap_page_range_single);
> 
> Why not EXPORT_SYMBOL_GPL?

I just tried to match other symbols in the same file.

Alice



More information about the Linux-security-module-archive mailing list