From 7e04cc918954f9090952e8d17cb2c3c4a5ad055e Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Mon, 10 May 2021 17:52:06 +0530 Subject: [PATCH] arm64/mm: Validate CONFIG_PGTABLE_LEVELS CONFIG_PGTABLE_LEVELS has been statically defined in (arch/arm64/Kconfig) depending on the page size and requested virtual address range. In order to validate this page table levels selection this adds a BUILD_BUG_ON() as per the existing formula ARM64_HW_PGTABLE_LEVELS(). This would help protect any inadvertent changes to CONFIG_PGTABLE_LEVELS selection. Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual Link: https://lore.kernel.org/r/1620649326-24115-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Will Deacon --- arch/arm64/mm/init.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index e55409caaee3..6e1ca044ca90 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -499,6 +499,13 @@ void __init mem_init(void) BUILD_BUG_ON(TASK_SIZE_32 > DEFAULT_MAP_WINDOW_64); #endif + /* + * Selected page table levels should match when derived from + * scratch using the virtual address range and page size. + */ + BUILD_BUG_ON(ARM64_HW_PGTABLE_LEVELS(CONFIG_ARM64_VA_BITS) != + CONFIG_PGTABLE_LEVELS); + if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) { extern int sysctl_overcommit_memory; /* -- 2.11.0