mm/page_alloc: restrict and formalize compound_page_dtors[] (ae70eddd) · Commits · 戴 / test

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. Signed-off-by:

Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Reviewed-by:

David Hildenbrand <david@redhat.com> Link: http://lkml.kernel.org/r/1589795958-19317-1-git-send-email-anshuman.khandual@arm.com Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mm.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -867,7 +867,7 @@ 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)

mm/page_alloc.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -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
		};

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