From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 237CFC433ED for ; Fri, 9 Apr 2021 16:52:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA4BA61005 for ; Fri, 9 Apr 2021 16:51:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234224AbhDIQwL (ORCPT ); Fri, 9 Apr 2021 12:52:11 -0400 Received: from ex13-edg-ou-001.vmware.com ([208.91.0.189]:3092 "EHLO EX13-EDG-OU-001.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233038AbhDIQwI (ORCPT ); Fri, 9 Apr 2021 12:52:08 -0400 Received: from sc9-mailhost3.vmware.com (10.113.161.73) by EX13-EDG-OU-001.vmware.com (10.113.208.155) with Microsoft SMTP Server id 15.0.1156.6; Fri, 9 Apr 2021 09:51:48 -0700 Received: from vertex.localdomain (unknown [10.16.119.23]) by sc9-mailhost3.vmware.com (Postfix) with ESMTP id 4078520DB0; Fri, 9 Apr 2021 09:51:52 -0700 (PDT) From: Zack Rusin To: CC: Andrew Morton , =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , Subject: [PATCH v2] mm/mapping_dirty_helpers: Guard hugepage pud's usage Date: Fri, 9 Apr 2021 12:51:51 -0400 Message-ID: <20210409165151.694574-1-zackr@vmware.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Received-SPF: None (EX13-EDG-OU-001.vmware.com: zackr@vmware.com does not designate permitted sender hosts) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mapping dirty helpers have, so far, been only used on X86, but a port of vmwgfx to ARM64 exposed a problem which results in a compilation error on ARM64 systems: mm/mapping_dirty_helpers.c: In function ‘wp_clean_pud_entry’: mm/mapping_dirty_helpers.c:172:32: error: implicit declaration of function ‘pud_dirty’; did you mean ‘pmd_dirty’? [-Werror=implicit-function-declaration] This is due to the fact that mapping_dirty_helpers code assumes that pud_dirty is always defined, which is not the case for architectures that don't define CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD. ARM64 arch is a little inconsistent when it comes to PUD hugepage helpers, e.g. it defines pud_young but not pud_dirty but regardless of that the core kernel code shouldn't assume that any of the PUD hugepage helpers are available unless CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD is defined. This prevents compilation errors whenever one of the drivers is ported to new architectures. Signed-off-by: Zack Rusin Cc: Andrew Morton Cc: Thomas Hellström (Intel) Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org --- mm/mapping_dirty_helpers.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/mapping_dirty_helpers.c b/mm/mapping_dirty_helpers.c index b59054ef2e10..b890854ec761 100644 --- a/mm/mapping_dirty_helpers.c +++ b/mm/mapping_dirty_helpers.c @@ -165,10 +165,12 @@ static int wp_clean_pud_entry(pud_t *pud, unsigned long addr, unsigned long end, return 0; } +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD /* Huge pud */ walk->action = ACTION_CONTINUE; if (pud_trans_huge(pudval) || pud_devmap(pudval)) WARN_ON(pud_write(pudval) || pud_dirty(pudval)); +#endif return 0; } -- 2.27.0