From patchwork Thu Aug 22 09:13:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= X-Patchwork-Id: 1151391 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="Rps69GMh"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46Df3J4Tpzz9s7T for ; Thu, 22 Aug 2019 19:13:48 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733038AbfHVJNs (ORCPT ); Thu, 22 Aug 2019 05:13:48 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:33623 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733031AbfHVJNs (ORCPT ); Thu, 22 Aug 2019 05:13:48 -0400 Received: by mail-pl1-f193.google.com with SMTP id go14so3098748plb.0; Thu, 22 Aug 2019 02:13:47 -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=mzlRM96REuEosfmv5S1FfhcU+k21Y3nuygBDyIBSw50=; b=Rps69GMhSWVcDbR9c0fC/T58yszbwmfHp6VP9wSWe8S+/IFknD4+xjJlyRF5wfwVeK yso60e8F9ElHDHGziAEsNP3m0C14l0LH2UtM0C2sZDhcO0ZYi4Ig5VzCRFGtJkEcW6T7 wIQWGX9cqw9X6O0Ds+n1AeiqvLZSmVXUmjWS6YbPCf/580SelT9z1iRUWi1YoXYee9jr OEmaj8oIKHhS7dltoOe00V1qKaRRr0l+kSO+LzUQU7SU4dKOe9o5W2r/qM0Wc0bxWH5q rTrqhOKx4BD1H1R5mAl8OwQf0fyUaQA+SQL45tWWHij/jpno0NTCWhfYcJ7YJ1vzwyXh 79iA== 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=mzlRM96REuEosfmv5S1FfhcU+k21Y3nuygBDyIBSw50=; b=Pob/bdQ4dpwzz/cUoj3X/A9IDTle+yS+coQC/5Ob/OvVlN+BeNOqzAWwbbJ/vCMvrK 1R1YGQPJ+5dDpIlW4m9XY3Bp3yycp+Ak0Q5B9Pz9+Lzr9HWEW1gk8M9Slw+SIOqqNlNe Y+qWzp5/ZumKHUrZSaCC3tPrEbW6Xh77V9qwlsXSadBlRfwSWaBLYxfYJQCwbgltZzE5 J75E9jw4kKijhptf2FfRtzXCNqG1GBpHb7xabOfKA8oG59eo1TOnr4ZySAVcj+WDC2e+ 28BRRP38It2O1iVjgF/0Wpms9ObpANbUYHX4hN9L801TuidJeQUE+FNYbwaKvMIH00+Q blQg== X-Gm-Message-State: APjAAAWMfeesYrQM7hyIfxb0x2M9S3oyZcAGtGC93Ef+2upUnRkAzRXr lej3YecnVAswUeEhkvS+SUQ= X-Google-Smtp-Source: APXvYqyAyhGuZwD/a7dtPd3MK5m7Ju3Xe87NjOMlx1X+VZ6YbeyaLtyvdRRWO+llLMWXFwms8uDMDQ== X-Received: by 2002:a17:902:8f95:: with SMTP id z21mr38616146plo.42.1566465227259; Thu, 22 Aug 2019 02:13:47 -0700 (PDT) Received: from btopel-mobl.ger.intel.com ([192.55.54.43]) by smtp.gmail.com with ESMTPSA id w207sm28414754pff.93.2019.08.22.02.13.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Aug 2019 02:13:46 -0700 (PDT) From: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= To: ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org Cc: =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , 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 1/4] xsk: avoid store-tearing when assigning queues Date: Thu, 22 Aug 2019 11:13:03 +0200 Message-Id: <20190822091306.20581-2-bjorn.topel@gmail.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190822091306.20581-1-bjorn.topel@gmail.com> References: <20190822091306.20581-1-bjorn.topel@gmail.com> MIME-Version: 1.0 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. Fixes: 37b076933a8e ("xsk: add missing write- and data-dependency barrier") Signed-off-by: Björn Töpel Acked-by: Jonathan Lemon --- 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 ee4428a892fa..f3351013c2a5 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -409,7 +409,7 @@ 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; }