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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 DFE77C3A5A7 for ; Wed, 4 Sep 2019 11:49:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B7C7020820 for ; Wed, 4 Sep 2019 11:49:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QpckPe4T" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729415AbfIDLtc (ORCPT ); Wed, 4 Sep 2019 07:49:32 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:43115 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725829AbfIDLtc (ORCPT ); Wed, 4 Sep 2019 07:49:32 -0400 Received: by mail-pg1-f195.google.com with SMTP id u72so6930583pgb.10; Wed, 04 Sep 2019 04:49:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Rf5cm9DW3GYmLUhGmmReL+VRthRlK1ZY0sLaJ4jk6OE=; b=QpckPe4Tlgmy8GgSZme52KHTZXB3Vn0gU7/fatjHnpornjVrV5ShUyuUF1Q3SL6nqO guOyMAxl3agY7npQwHxhI7KAuHQ9oCj7arnnScXSF2Jz8U2IrFXC29YLm+0eJL5rJK7u 0GTc/vGnL0VQZ9lb90O5cUjP/fubJpqJboaX69qIH+iDNEcnYoWPEs3D/W7ShZHKwkTg cvGYJOJSKBYF0sNL1Si2KLxwpbqJnfeMOz2kytdZ5xuBAllL7bpfTWDbyNlzFQ62p4xK CDQiMGizlj1Wd/kLfA1JI+rlT2RMgqyWvQYuC/I/675dCb9s053RswWiFj29IcvtPB+R QvUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Rf5cm9DW3GYmLUhGmmReL+VRthRlK1ZY0sLaJ4jk6OE=; b=PVI9d6QWxW2WqmHKi2mvJHYkrvNZGa/eYjNrp34bHPUueZ4QxsD2mu5Y5HJD4y2zxK 5iIwgyAyVFmoSgAmBSiihw5eOvi7JAHalaNChAXSdB7zY2/o8QwgZ6BUTRxeQUOLdJnC wxlgyZsxtPgwTwbv866z8bCTURlgNrjmLyNNVDv6r6LyzS/DGZIQLfgNUSW4sbRlftfp 3QfK0cXmNDXLPXQA8cmcGfVuUI0WTk1ZDtHLDF/uVM/7upzgUBiskIOD3X1nNscjPpO4 8GCbpLP6wepPodcv/nC/8UqoJVrlqIapDx2guBf74g7rHnCkvEYiCaJJUP9Ozw/zndKQ JCWQ== X-Gm-Message-State: APjAAAVHmpxJiLi7RPjvJaOnFFSINq3hjTc6M6RW1W3lr7ba/7IORJ8a L9jDiBR6Riz7qzVnX1iJ5A4= X-Google-Smtp-Source: APXvYqwun13qkIqsxwyOUGIoOqs+AD/fNEIQv/hADdErW6Gp3/ZUOfbbIp7onSS1ULyarcpvYBoyxQ== X-Received: by 2002:a62:75d2:: with SMTP id q201mr10033584pfc.43.1567597771654; Wed, 04 Sep 2019 04:49:31 -0700 (PDT) Received: from btopel-mobl.ger.intel.com (fmdmzpr04-ext.fm.intel.com. [192.55.54.39]) by smtp.gmail.com with ESMTPSA id b126sm48257008pfa.177.2019.09.04.04.49.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Sep 2019 04:49:31 -0700 (PDT) From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= To: ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org Cc: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , magnus.karlsson@intel.com, magnus.karlsson@gmail.com, bpf@vger.kernel.org, jonathan.lemon@gmail.com, syzbot+c82697e3043781e08802@syzkaller.appspotmail.com, hdanton@sina.com, i.maximets@samsung.com Subject: [PATCH bpf-next v3 1/4] xsk: avoid store-tearing when assigning queues Date: Wed, 4 Sep 2019 13:49:10 +0200 Message-Id: <20190904114913.17217-2-bjorn.topel@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190904114913.17217-1-bjorn.topel@gmail.com> References: <20190904114913.17217-1-bjorn.topel@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Björn Töpel Use WRITE_ONCE when doing the store of tx, rx, fq, and cq, to avoid potential store-tearing. These members are read outside of the control mutex in the mmap implementation. Acked-by: Jonathan Lemon Fixes: 37b076933a8e ("xsk: add missing write- and data-dependency barrier") Signed-off-by: Björn Töpel --- net/xdp/xsk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 187fd157fcff..271d8d3fb11e 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -434,7 +434,7 @@ static int xsk_init_queue(u32 entries, struct xsk_queue **queue, /* Make sure queue is ready before it can be seen by others */ smp_wmb(); - *queue = q; + WRITE_ONCE(*queue, q); return 0; } -- 2.20.1