From patchwork Mon Dec 20 21:58:23 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: 12696913 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 62FCCC433F5 for ; Mon, 20 Dec 2021 22:03:19 +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=C2NjDaaEH20ysT zTT2Y0nzR0oM3fsT6zRtDj2/X0Zcmg+VWws1GCWf9gN4cuojRp2RdJX9Gb2iTzVSL79lOaXYL6ZTM 8dUFd6aTN21h/p1Lu2fqqUghuH0+VrmnlpYmjeYrlFlfxHTg26haM3bvBDq5aGRHSSAdwiH72/G5/ nL8er6OjeVLPFQOwRJ+uO8mE9Og2mFib7nLkk6a8aofMt3wbUQIRoAio0qyLSN3GSQeFEdXI7+Xlm Um6IeEc45mtLiL6WHPkB2HaebZDeJOnKwy3v8qJhsZJ9sTj5Xnm/QT+tmHJfK6dh0b8wRRe8t8TVA IsNQpJNwEosyTkJ1Uyjw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mzQj9-004cLu-6B; Mon, 20 Dec 2021 22:01:51 +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 1mzQgf-004av9-KU for linux-arm-kernel@lists.infradead.org; Mon, 20 Dec 2021 21:59:19 +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=1640037556; 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=it34flvfcLOdcrRHxhWxGMiieuoHPAysd1PyKFeZzsg9OFhItE1PZdD8m920HC1c9CFCWe Ft1EqF4lSlACrLPzEjGxBYnf3451QMngiL+YUwh4fal2CpV/Tk3rCjBg95r6Z/kcIjp2hI MOE81wP1KiEYeNSmiTkoluN5dCcJOHk= 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 v4 08/39] kasan: only apply __GFP_ZEROTAGS when memory is zeroed Date: Mon, 20 Dec 2021 22:58:23 +0100 Message-Id: <705af53a07d789b2f139ff91fb7a18343e980989.1640036051.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-20211220_135917_859268_D8B91C82 X-CRM114-Status: GOOD ( 10.23 ) 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)