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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24D06C2BB41 for ; Tue, 16 Aug 2022 08:04:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230388AbiHPIEy (ORCPT ); Tue, 16 Aug 2022 04:04:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48488 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230311AbiHPIDj (ORCPT ); Tue, 16 Aug 2022 04:03:39 -0400 Received: from smtp-fw-2101.amazon.com (smtp-fw-2101.amazon.com [72.21.196.25]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 605E85FAE0; Mon, 15 Aug 2022 22:26:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1660627594; x=1692163594; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=pmwCB1rtML/9o8e4ui5GvkioOpZG4mwOUDHFknLWzWw=; b=B/g2HQziSnwT+9603TspJyvI6SaAd/cbfj3sw2vnbA8L+zKvF/QtCEUy lKb61uieX4A8BMLEdiAMEENZ4EKcsfFOxHQbpp2AR3Inaz2RbIKbarKmu yHLLVlp2mqsUH/V1S2YOaxd9Vvhx6DbzZkthzfS1LoUBDFbfCeszUbzZp 0=; X-IronPort-AV: E=Sophos;i="5.93,240,1654560000"; d="scan'208";a="230039760" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-iad-1e-0bfdb89e.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-2101.iad2.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Aug 2022 05:26:33 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-iad-1e-0bfdb89e.us-east-1.amazon.com (Postfix) with ESMTPS id 31347E00CF; Tue, 16 Aug 2022 05:26:30 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Tue, 16 Aug 2022 05:26:30 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.55) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.12; Tue, 16 Aug 2022 05:26:28 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Subject: [PATCH v1 net 09/15] ratelimit: Fix data-races in ___ratelimit(). Date: Mon, 15 Aug 2022 22:23:41 -0700 Message-ID: <20220816052347.70042-10-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220816052347.70042-1-kuniyu@amazon.com> References: <20220816052347.70042-1-kuniyu@amazon.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.160.55] X-ClientProxiedBy: EX13D24UWB003.ant.amazon.com (10.43.161.222) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While reading rs->interval and rs->burst, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima --- lib/ratelimit.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/lib/ratelimit.c b/lib/ratelimit.c index e01a93f46f83..b59a1d3d0cc3 100644 --- a/lib/ratelimit.c +++ b/lib/ratelimit.c @@ -26,10 +26,12 @@ */ int ___ratelimit(struct ratelimit_state *rs, const char *func) { + int interval = READ_ONCE(rs->interval); + int burst = READ_ONCE(rs->burst); unsigned long flags; int ret; - if (!rs->interval) + if (!interval) return 1; /* @@ -44,7 +46,7 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func) if (!rs->begin) rs->begin = jiffies; - if (time_is_before_jiffies(rs->begin + rs->interval)) { + if (time_is_before_jiffies(rs->begin + interval)) { if (rs->missed) { if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE)) { printk_deferred(KERN_WARNING @@ -56,7 +58,7 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func) rs->begin = jiffies; rs->printed = 0; } - if (rs->burst && rs->burst > rs->printed) { + if (burst && burst > rs->printed) { rs->printed++; ret = 1; } else { -- 2.30.2