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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 8666CC2D0A3 for ; Fri, 9 Oct 2020 20:04:07 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E04CD2225B for ; Fri, 9 Oct 2020 20:04:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="jENQ7Fyh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E04CD2225B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UEEqWzEidSAgZ/Eq0Od3nyWm6PPbNO9GMbGBG8GPQYA=; b=jENQ7Fyht2nP1/rjtty0XQaez ykhnRG/0en3DN1ly3uCEQZC2oqN1QzzBaB9ceuoFS1eEDznKyn5oWXQR4EkhI7unRK4J/F9ICKRbs 7Vci/F/npLDl5KV2MuYzVe+/yJeeaCn8lBqC1PvMfLGDTt3KhMoWXQSGGnCAUhzishhX0/Wu/Rsw3 KqDsJoUFduJpc26b8rjAylRcAVwpNcqPY2GJgsYsOF9Xnw7ZaMBV3CLw2j6dQkgYjawpOXJDczZcL 2Ws1hUV3TaowaDhO2dA8YnWdExLl4VFineP/W0nXsV/g42f9A9GoGlPBDQqLaJTJZuJmZZg6uGjjK cdOvF0uWA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kQyav-0006hy-RT; Fri, 09 Oct 2020 20:02:28 +0000 Received: from mga07.intel.com ([134.134.136.100]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kQyUA-0002ns-M8; Fri, 09 Oct 2020 19:55:27 +0000 IronPort-SDR: Muyzc5U86mjl0MgPqdJZj4aVzmrmSxKssWX/kgjcoRJH7QLjIKyDASQnlU/s0zGO9KBDznNL2y MtHDQPXt+CgQ== X-IronPort-AV: E=McAfee;i="6000,8403,9769"; a="229715399" X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="229715399" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 12:54:04 -0700 IronPort-SDR: NEiErKYZfPZGqrWyxIZ0z43ef9+IKjrcXd9NJIRckxXQwdDEMd5poh/dknsqhifod6Ym/UoaZd Mu4h9c7DJvbA== X-IronPort-AV: E=Sophos;i="5.77,355,1596524400"; d="scan'208";a="462301216" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.147]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Oct 2020 12:54:03 -0700 From: ira.weiny@intel.com To: Andrew Morton , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , Peter Zijlstra Subject: [PATCH RFC PKS/PMEM 56/58] dax: Stray access protection for dax_direct_access() Date: Fri, 9 Oct 2020 12:50:31 -0700 Message-Id: <20201009195033.3208459-57-ira.weiny@intel.com> X-Mailer: git-send-email 2.28.0.rc0.12.gb6a658bd00c9 In-Reply-To: <20201009195033.3208459-1-ira.weiny@intel.com> References: <20201009195033.3208459-1-ira.weiny@intel.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201009_155526_925646_F6A691A0 X-CRM114-Status: GOOD ( 13.81 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-aio@kvack.org, linux-efi@vger.kernel.org, kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-mmc@vger.kernel.org, Dave Hansen , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-kselftest@vger.kernel.org, samba-technical@lists.samba.org, Ira Weiny , ceph-devel@vger.kernel.org, drbd-dev@lists.linbit.com, devel@driverdev.osuosl.org, linux-cifs@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-scsi@vger.kernel.org, linux-nvdimm@lists.01.org, linux-rdma@vger.kernel.org, x86@kernel.org, amd-gfx@lists.freedesktop.org, linux-afs@lists.infradead.org, cluster-devel@redhat.com, linux-cachefs@redhat.com, intel-wired-lan@lists.osuosl.org, xen-devel@lists.xenproject.org, linux-ext4@vger.kernel.org, Fenghua Yu , linux-um@lists.infradead.org, intel-gfx@lists.freedesktop.org, ecryptfs@vger.kernel.org, linux-erofs@lists.ozlabs.org, reiserfs-devel@vger.kernel.org, linux-block@vger.kernel.org, linux-bcache@vger.kernel.org, Dan Williams , io-uring@vger.kernel.org, linux-nfs@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, netdev@vger.kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-btrfs@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org From: Ira Weiny dax_direct_access() is a special case of accessing pmem via a page offset and without a struct page. Because the dax driver is well aware of the special protections it has mapped memory with, call dev_access_[en|dis]able() directly instead of the unnecessary overhead of trying to get a page to kmap. Similar to kmap, we leverage existing functions, dax_read_[un]lock(), because they are already required to surround the use of the memory returned from dax_direct_access(). Signed-off-by: Ira Weiny --- drivers/dax/super.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index e84070b55463..0ddb3ee73e36 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -30,6 +30,7 @@ static DEFINE_SPINLOCK(dax_host_lock); int dax_read_lock(void) { + dev_access_enable(false); return srcu_read_lock(&dax_srcu); } EXPORT_SYMBOL_GPL(dax_read_lock); @@ -37,6 +38,7 @@ EXPORT_SYMBOL_GPL(dax_read_lock); void dax_read_unlock(int id) { srcu_read_unlock(&dax_srcu, id); + dev_access_disable(false); } EXPORT_SYMBOL_GPL(dax_read_unlock); -- 2.28.0.rc0.12.gb6a658bd00c9 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/