From patchwork Mon Dec 13 21:51:27 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: 12695969 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 E84CFC433F5 for ; Mon, 13 Dec 2021 21:58:14 +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=Djp3QxHPNSuBAcGH+MPtVWLutDMqAIPy2X0ib4BXQlM=; b=Czg3vYevKhrjpV O8mq8ic9HNUArnVJ09g2dn0OvZh7BOGE9m6Gz5UImlmjGvtbn1ckhHbfeFKP5UnamS8oBP4W3bVUi iBkPZnQ2XJeG4KaX3X/aUfEonZORrrKwiz/ld9baL9nwdnPjP6k1G/HaZRK76IhVITr+Y+MV5K0bY HtFe4rwc2NW+aZUHz4sePfeT8rjq8MznyiutyrkpeU99pF27waJApCPIbf2Mh5CI4T/Sfek80amsh zeCEON/WaDiM+brspfMSM6nuKdaG8a2MkAEmHCZEscb2VUBFSqvYWoZ+ZC8uY/PPNNJqYgEsAptkZ LrRFGqA1ca7t8z/QJi/w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mwtJE-00BXJS-Gc; Mon, 13 Dec 2021 21:56:36 +0000 Received: from out2.migadu.com ([2001:41d0:2:aacc::]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mwtFM-00BVPW-KA for linux-arm-kernel@lists.infradead.org; Mon, 13 Dec 2021 21:52:38 +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=1639432355; 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=TniNgsonCV7N4x8CfBP962yTwJ3ZQbzv223ievd0EoQ=; b=qgWBUnSM2HjTQWnNHG+qKWKL4esKiybqeMZ9plWehZNkgmm+ZI3K4eQpAFQawUNEcKB8M7 Bvp0+OgR6omA8Nzhv+ZHwCaNSzgfHuNZ1I9nNuJjYtJZROS3QYE5GGAm7N0IzKF+MtAKzF fCgA/nKiLou/zWxg31elX1Ll+wQYHEk= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Andrew Morton Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, linux-mm@kvack.org, Vincenzo Frascino , Catalin Marinas , Will Deacon , Mark Rutland , linux-arm-kernel@lists.infradead.org, Peter Collingbourne , Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH mm v3 08/38] kasan: only apply __GFP_ZEROTAGS when memory is zeroed Date: Mon, 13 Dec 2021 22:51:27 +0100 Message-Id: <95711511a7f88855ba3ed7dde2f2ad23c7b2b02c.1639432170.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: andrey.konovalov@linux.dev X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211213_135236_888924_77991553 X-CRM114-Status: GOOD ( 10.21 ) 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 __GFP_ZEROTAGS should only be effective if memory is being zeroed. Currently, hardware tag-based KASAN violates this requirement. Fix by including an initialization check along with checking for __GFP_ZEROTAGS. Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko --- mm/kasan/hw_tags.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 0b8225add2e4..c643740b8599 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -199,11 +199,12 @@ void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags) * page_alloc.c. */ bool init = !want_init_on_free() && want_init_on_alloc(flags); + bool init_tags = init && (flags & __GFP_ZEROTAGS); if (flags & __GFP_SKIP_KASAN_POISON) SetPageSkipKASanPoison(page); - if (flags & __GFP_ZEROTAGS) { + if (init_tags) { int i; for (i = 0; i != 1 << order; ++i)