Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E401BC433F5 for ; Tue, 30 Nov 2021 22:05:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230153AbhK3WJD (ORCPT ); Tue, 30 Nov 2021 17:09:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344480AbhK3WI5 (ORCPT ); Tue, 30 Nov 2021 17:08:57 -0500 Received: from out2.migadu.com (out2.migadu.com [IPv6:2001:41d0:2:aacc::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E0ECAC06175B for ; Tue, 30 Nov 2021 14:05:34 -0800 (PST) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1638309933; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QgrHb09Vj6aJ0+9nbQZNm9kk14SqendbAdApMN1ty98=; b=kKuuQS7/dsa+tGRFwUmdluLYwH181K80+n9qftIO6/pGTMzmQQf0P2nkonmZrMoKqotGhC 2gQtyPERQxs3yUsHIEeHisTO4bsyHx2NpZwdslj0iQ+hkkJxsH6bB5oFHsleWBfHpWH05r LRw4k8NLXCsQjuzaov4w7A1b2oPTagQ= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Vincenzo Frascino , Catalin Marinas , Peter Collingbourne Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Andrew Morton , linux-mm@kvack.org, Will Deacon , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH 13/31] kasan, page_alloc: simplify kasan_unpoison_pages call site Date: Tue, 30 Nov 2021 23:05:30 +0100 Message-Id: <4e23fb3399fbc2bd59effeb89946a75c3c75b6a2.1638308023.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrey Konovalov Simplify the checks around kasan_unpoison_pages() call in post_alloc_hook(). The logical condition for calling this function is: - If a software KASAN mode is enabled, we need to mark shadow memory. - Otherwise, HW_TAGS KASAN is enabled, and it only makes sense to set tags if they haven't already been cleared by tag_clear_highpage(), which is indicated by init_tags. This patch concludes the simplifications for post_alloc_hook(). Signed-off-by: Andrey Konovalov --- mm/page_alloc.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ba950889f5ea..4eb341351124 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2420,15 +2420,18 @@ inline void post_alloc_hook(struct page *page, unsigned int order, /* Note that memory is already initialized by the loop above. */ init = false; } - if (kasan_has_integrated_init()) { - if (!init_tags) { - kasan_unpoison_pages(page, order, init); + /* + * If either a software KASAN mode is enabled, or, + * in the case of hardware tag-based KASAN, + * if memory tags have not been cleared via tag_clear_highpage(). + */ + if (!IS_ENABLED(CONFIG_KASAN_HW_TAGS) || !init_tags) { + /* Mark shadow memory or set memory tags. */ + kasan_unpoison_pages(page, order, init); - /* Note that memory is already initialized by KASAN. */ + /* Note that memory is already initialized by KASAN. */ + if (kasan_has_integrated_init()) init = false; - } - } else { - kasan_unpoison_pages(page, order, init); } /* If memory is still not initialized, do it now. */ if (init) -- 2.25.1