From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759487AbdEOGVI (ORCPT ); Mon, 15 May 2017 02:21:08 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:34736 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758942AbdEOGVG (ORCPT ); Mon, 15 May 2017 02:21:06 -0400 From: js1304@gmail.com X-Google-Original-From: iamjoonsoo.kim@lge.com To: Andrew Morton Cc: "Kirill A . Shutemov" , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@lge.com, Joonsoo Kim Subject: [PATCH] mm/kasan: use kasan_zero_pud for p4d table Date: Mon, 15 May 2017 15:20:55 +0900 Message-Id: <1494829255-23946-1-git-send-email-iamjoonsoo.kim@lge.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joonsoo Kim There is missing optimization in zero_p4d_populate() that can save some memory when mapping zero shadow. Implement it like as others. Signed-off-by: Joonsoo Kim --- mm/kasan/kasan_init.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/mm/kasan/kasan_init.c b/mm/kasan/kasan_init.c index b96a5f7..554e4c0 100644 --- a/mm/kasan/kasan_init.c +++ b/mm/kasan/kasan_init.c @@ -118,6 +118,18 @@ static void __init zero_p4d_populate(pgd_t *pgd, unsigned long addr, do { next = p4d_addr_end(addr, end); + if (IS_ALIGNED(addr, P4D_SIZE) && end - addr >= P4D_SIZE) { + pud_t *pud; + pmd_t *pmd; + + p4d_populate(&init_mm, p4d, lm_alias(kasan_zero_pud)); + pud = pud_offset(p4d, addr); + pud_populate(&init_mm, pud, lm_alias(kasan_zero_pmd)); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, + lm_alias(kasan_zero_pte)); + continue; + } if (p4d_none(*p4d)) { p4d_populate(&init_mm, p4d, -- 2.7.4