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[PATCH] arm64: fix warning about swapper_pg_dir overflow

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With 4 levels of 16KB pages, we get this warning about the fact that we are
copying a whole page into an array that is declared as having only two pointers
for the top level of the page table:

arch/arm64/mm/mmu.c: In function 'paging_init':
arch/arm64/mm/mmu.c:528:2: error: 'memcpy' writing 16384 bytes into a region of size 16 overflows the destination [-Werror=stringop-overflow=]

This is harmless since we actually reserve a whole page in the definition of the
array that comes from, and just the extern declaration is short. The pgdir
is initialized to zero either way, so copying the actual entries here seems
like the best solution.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm64/mm/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 2131521ddc24..b805c017f789 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -525,7 +525,7 @@ void __init paging_init(void)
 	 * To do this we need to go via a temporary pgd.
 	 */
 	cpu_replace_ttbr1(__va(pgd_phys));
-	memcpy(swapper_pg_dir, pgd, PAGE_SIZE);
+	memcpy(swapper_pg_dir, pgd, PGD_SIZE);
 	cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
 
 	pgd_clear_fixmap();
-- 
2.9.0

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[PATCH] arm64: fix warning about swapper_pg_dir overflow Arnd Bergmann <arnd@arndb.de> - 2017-02-14 22:30 +0100
  Re: [PATCH] arm64: fix warning about swapper_pg_dir overflow Ard Biesheuvel <ard.biesheuvel@linaro.org> - 2017-02-14 22:40 +0100
    Re: [PATCH] arm64: fix warning about swapper_pg_dir overflow Arnd Bergmann <arnd@arndb.de> - 2017-02-14 23:10 +0100
  Re: [PATCH] arm64: fix warning about swapper_pg_dir overflow Will Deacon <will.deacon@arm.com> - 2017-02-15 12:40 +0100

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