From patchwork Mon May 31 15:23:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wander Lairson Costa X-Patchwork-Id: 451685 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS 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 79CA5C47080 for ; Mon, 31 May 2021 15:29:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5964B6128A for ; Mon, 31 May 2021 15:29:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233845AbhEaPap (ORCPT ); Mon, 31 May 2021 11:30:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:51863 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234663AbhEaP1n (ORCPT ); Mon, 31 May 2021 11:27:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622474697; 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; bh=4JcYhWe8fmp3R5gpBfuApjCZLko+hwnxUS+X7YLgb84=; b=a4YZXeRCX8TrZV1OAcJvl93MCvdurbxw8+Ywbqm9zNphYF4/eDLhivQ9vG22P5joczimec +jfopatkeiy2BwiO0pNqaIUwg4zxWFSUbap31EZZXeBRGgiwIW5OFrR2IbIN6cjSjRr2df V94OQk0l+gEl5o3gx0MIpnTFoAkzR2E= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-331-dcUBGinZOB6OVHW4wm3kKQ-1; Mon, 31 May 2021 11:24:54 -0400 X-MC-Unique: dcUBGinZOB6OVHW4wm3kKQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8D6DE8015C6; Mon, 31 May 2021 15:24:52 +0000 (UTC) Received: from wcosta.com (ovpn-116-128.gru2.redhat.com [10.97.116.128]) by smtp.corp.redhat.com (Postfix) with ESMTP id CA3006062C; Mon, 31 May 2021 15:24:42 +0000 (UTC) From: wander@redhat.com Cc: linux-rt-users@vger.kernel.org, bigeasy@linutronix.de, tglx@linutronix.de, rostedt@goodmis.org, Wander Lairson Costa , "David S. Miller" , Jakub Kicinski , Florian Fainelli , Andrew Lunn , Vladimir Oltean , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] netpoll: don't require irqs disabled in rt kernels Date: Mon, 31 May 2021 12:23:23 -0300 Message-Id: <20210531152325.36671-1-wander@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org From: Wander Lairson Costa write_msg(netconsole.c:836) calls netpoll_send_udp after a call to spin_lock_irqsave, which normally disables interrupts; but in PREEMPT_RT this call just locks an rt_mutex without disabling irqs. In this case, netpoll_send_udp is called with interrupts enabled. Signed-off-by: Wander Lairson Costa --- net/core/netpoll.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/core/netpoll.c b/net/core/netpoll.c index c310c7c1cef7..0a6b04714558 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -36,6 +36,7 @@ #include #include #include +#include /* * We maintain a small pool of fully-sized skbs, to make sure the @@ -389,7 +390,8 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len) static atomic_t ip_ident; struct ipv6hdr *ip6h; - WARN_ON_ONCE(!irqs_disabled()); + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) + WARN_ON_ONCE(!irqs_disabled()); udp_len = len + sizeof(*udph); if (np->ipv6)