Restrict elements in compound_page_dtors[] array per NR_COMPOUND_DTORS and
explicitly position them according to enum compound_dtor_id. This improves
protection against possible misalignment between compound_page_dtors[] and
enum compound_dtor_id later on.
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
include/linux/mm.h | 2 +-
mm/page_alloc.c | 10 +++++-----
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 688558c57751..d1bd7736a5e5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -856,7 +856,7 @@ enum compound_dtor_id {
#endif
NR_COMPOUND_DTORS,
};
-extern compound_page_dtor * const compound_page_dtors[];
+extern compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS];
static inline void set_compound_page_dtor(struct page *page,
enum compound_dtor_id compound_dtor)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index cef05d3a23f5..2e4c23b34940 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -302,14 +302,14 @@ const char * const migratetype_names[MIGRATE_TYPES] = {
#endif
};
-compound_page_dtor * const compound_page_dtors[] = {
- NULL,
- free_compound_page,
+compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS] = {
+ [NULL_COMPOUND_DTOR] = NULL,
+ [COMPOUND_PAGE_DTOR] = free_compound_page,
#ifdef CONFIG_HUGETLB_PAGE
- free_huge_page,
+ [HUGETLB_PAGE_DTOR] = free_huge_page,
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- free_transhuge_page,
+ [TRANSHUGE_PAGE_DTOR] = free_transhuge_page,
#endif
};
--
2.20.1
