[RFC v4 4/8] mm/rmap: Export essential functions for rmap_run

[SeongJae Park <sjpark@amazon.com>]

From: SeongJae Park <sjpark@amazon.de>

This commit exports the three essential functions for ramp walk,
'page_lock_anon_vma_read()', 'rmap_walk()', and 'page_rmapping()', to
GPL modules.  Those will be used by DAMON for the physical memory
address based access monitoring in the following commit.

Signed-off-by: SeongJae Park <sjpark@amazon.de>
---
 mm/rmap.c | 2 ++
 mm/util.c | 1 +
 2 files changed, 3 insertions(+)

diff --git a/mm/rmap.c b/mm/rmap.c
index f79a206b271a..20ac37b27a7d 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -579,6 +579,7 @@ struct anon_vma *page_lock_anon_vma_read(struct page *page)
 	rcu_read_unlock();
 	return anon_vma;
 }
+EXPORT_SYMBOL_GPL(page_lock_anon_vma_read);
 
 void page_unlock_anon_vma_read(struct anon_vma *anon_vma)
 {
@@ -1934,6 +1935,7 @@ void rmap_walk(struct page *page, struct rmap_walk_control *rwc)
 	else
 		rmap_walk_file(page, rwc, false);
 }
+EXPORT_SYMBOL_GPL(rmap_walk);
 
 /* Like rmap_walk, but caller holds relevant rmap lock */
 void rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc)
diff --git a/mm/util.c b/mm/util.c
index 988d11e6c17c..1df32546fe28 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -620,6 +620,7 @@ void *page_rmapping(struct page *page)
 	page = compound_head(page);
 	return __page_rmapping(page);
 }
+EXPORT_SYMBOL_GPL(page_rmapping);
 
 /*
  * Return true if this page is mapped into pagetables.
-- 
2.17.1