From 2563776b41c3190849c6b011c72b47bff314963d Mon Sep 17 00:00:00 2001 From: Vincenzo Frascino Date: Tue, 6 Aug 2019 11:37:53 +0100 Subject: arm64: mte: Tags-aware copy_{user_,}highpage() implementations When the Memory Tagging Extension is enabled, the tags need to be preserved across page copy (e.g. for copy-on-write, page migration). Introduce MTE-aware copy_{user_,}highpage() functions to copy tags to the destination if the source page has the PG_mte_tagged flag set. copy_user_page() does not need to handle tag copying since, with this patch, it is only called by the DAX code where there is no source page structure (and no source tags). Signed-off-by: Vincenzo Frascino Co-developed-by: Catalin Marinas Signed-off-by: Catalin Marinas Cc: Will Deacon --- arch/arm64/mm/copypage.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) (limited to 'arch/arm64/mm') diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c index 2ee7b73433a5..4a2233fa674e 100644 --- a/arch/arm64/mm/copypage.c +++ b/arch/arm64/mm/copypage.c @@ -6,18 +6,35 @@ * Copyright (C) 2012 ARM Ltd. */ +#include #include #include #include +#include +#include -void __cpu_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr) +void copy_highpage(struct page *to, struct page *from) { - struct page *page = virt_to_page(kto); + struct page *kto = page_address(to); + struct page *kfrom = page_address(from); + copy_page(kto, kfrom); - flush_dcache_page(page); + + if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) { + set_bit(PG_mte_tagged, &to->flags); + mte_copy_page_tags(kto, kfrom); + } +} +EXPORT_SYMBOL(copy_highpage); + +void copy_user_highpage(struct page *to, struct page *from, + unsigned long vaddr, struct vm_area_struct *vma) +{ + copy_highpage(to, from); + flush_dcache_page(to); } -EXPORT_SYMBOL_GPL(__cpu_copy_user_page); +EXPORT_SYMBOL_GPL(copy_user_highpage); void __cpu_clear_user_page(void *kaddr, unsigned long vaddr) { -- cgit v1.2.3