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authorMatthew Wilcox (Oracle) <willy@infradead.org>2021-07-12 18:32:07 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-12 21:30:56 +0300
commit79789db03fdd77510cfb35cb4b3bd52b6c50c901 (patch)
tree44e6aba4c3735b180392437ef0d71f08a47337ee /include
parentefdb6720b44b2f016d2a04b2c84e577e57ed84bd (diff)
downloadlinux-79789db03fdd77510cfb35cb4b3bd52b6c50c901.tar.xz
mm: Make copy_huge_page() always available
Rewrite copy_huge_page() and move it into mm/util.c so it's always available. Fixes an exposure of uninitialised memory on configurations with HUGETLB and UFFD enabled and MIGRATION disabled. Fixes: 8cc5fcbb5be8 ("mm, hugetlb: fix racy resv_huge_pages underflow on UFFDIO_COPY") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/migrate.h5
-rw-r--r--include/linux/mm.h1
2 files changed, 1 insertions, 5 deletions
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 9b7b7cd3bae9..23dadf7aeba8 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -51,7 +51,6 @@ extern int migrate_huge_page_move_mapping(struct address_space *mapping,
struct page *newpage, struct page *page);
extern int migrate_page_move_mapping(struct address_space *mapping,
struct page *newpage, struct page *page, int extra_count);
-extern void copy_huge_page(struct page *dst, struct page *src);
#else
static inline void putback_movable_pages(struct list_head *l) {}
@@ -77,10 +76,6 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping,
{
return -ENOSYS;
}
-
-static inline void copy_huge_page(struct page *dst, struct page *src)
-{
-}
#endif /* CONFIG_MIGRATION */
#ifdef CONFIG_COMPACTION
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 57453dba41b9..7ca22e6e694a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -906,6 +906,7 @@ void __put_page(struct page *page);
void put_pages_list(struct list_head *pages);
void split_page(struct page *page, unsigned int order);
+void copy_huge_page(struct page *dst, struct page *src);
/*
* Compound pages have a destructor function. Provide a