mm: export symbol dependencies of is_zero_pfn() (0b70068e) · Commits · 戴 / test

In order to make the static inline function is_zero_pfn() callable by modules, export its symbol dependencies 'zero_pfn' and (for s390 and mips) 'zero_page_mask'. We need this for KVM, as CONFIG_KVM is a tristate for all supported architectures except ARM and arm64, and testing a pfn whether it refers to the zero page is required to correctly distinguish the zero page from other special RAM ranges that may also have the PG_reserved bit set, but need to be treated as MMIO memory. Signed-off-by:

Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by:

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

Paolo Bonzini <pbonzini@redhat.com>

arch/mips/mm/init.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -53,6 +53,7 @@
		*/
		unsigned long empty_zero_page, zero_page_mask;
		EXPORT_SYMBOL_GPL(empty_zero_page);
		EXPORT_SYMBOL(zero_page_mask);

		/*
		* Not static inline because used by IP27 special magic initialization code

arch/s390/mm/init.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -43,6 +43,7 @@ pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));

		unsigned long empty_zero_page, zero_page_mask;
		EXPORT_SYMBOL(empty_zero_page);
		EXPORT_SYMBOL(zero_page_mask);

		static void __init setup_zero_pages(void)
		{

mm/memory.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -118,6 +118,8 @@ __setup("norandmaps", disable_randmaps);
		unsigned long zero_pfn __read_mostly;
		unsigned long highest_memmap_pfn __read_mostly;

		EXPORT_SYMBOL(zero_pfn);

		/*
		* CONFIG_MMU architectures set up ZERO_PAGE in their paging_init()
		*/

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