From patchwork Tue Nov 30 22:05:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 12694231 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E0512C433EF for ; Tue, 30 Nov 2021 22:09:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=t7vj88GkYm+INZiqvJ7c/aRFxKrimAe9WImdKKLlXvA=; b=eGyGdAx8LyW/K+ HsQ57byy/kWWNMFEeFHl2+W1WqxavD5zA7uOll3worqMSnMtvVlJn8qsPYza98h3tNcMW8fuTMZZ5 Hlaa4KvZTE6EV/QdF+Kto2gfXpzhCURl3y2WsRQenQap+5UOcBAPJLUtpRBXiiv7SJT4dkWGOc6XF XNll5EpJzEwFiatcAoha5rvIgaq1mAlTmkNvWcS1imQjjYzqklbA8lbsL152P6bTX+YpmTTDpl6b8 XfGn4sUcz+JVqZtRJhDRNBqDSnOyHG+4G3J0wUQN/WSueGZ5ecRqkXpGvs1Z/dSraD/oCb0xXvR42 clf0AD/nw/jLiTfPuF9w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1msBH9-006uKm-TJ; Tue, 30 Nov 2021 22:07:01 +0000 Received: from out2.migadu.com ([188.165.223.204]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1msBFm-006tqc-96 for linux-arm-kernel@lists.infradead.org; Tue, 30 Nov 2021 22:05:35 +0000 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 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211130_140534_516307_720042D1 X-CRM114-Status: GOOD ( 13.59 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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)