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=-11.6 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, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 C659BC48BD6 for ; Tue, 25 Jun 2019 19:46:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B330204FD for ; Tue, 25 Jun 2019 19:46:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="o+aJk9f2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727990AbfFYTqF (ORCPT ); Tue, 25 Jun 2019 15:46:05 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:32913 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727384AbfFYTqE (ORCPT ); Tue, 25 Jun 2019 15:46:04 -0400 Received: by mail-pf1-f193.google.com with SMTP id x15so10036006pfq.0; Tue, 25 Jun 2019 12:46:04 -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; bh=CvpGRQIfyA4kHAw6O6Qm/lsMzBb8T0R2UCjutO7iey0=; b=o+aJk9f2CxqvUgKZvbf5ajY+7guRRvKlqLWkhdQ7mXYjuusbCSXWsMdm6Li1wiQL2B rzsNK2NEDBvMcsqbycYMZ/lI0AAXMLnX+ZPMp3xMRtiEraYIv6sI18zlGzACRMtjTsOO 3UnnBDNA1twSyoWr3r9PwGm5IGtp2hYOG+VB8cAOIjIoGs001qOBb3TQAno0pGjDyEx9 f/28iSWq9i05wGwiqD025BC/fovzAVEeCiBzVu3UQ570iS1vnTx3nnAizQeTG2TKf2MS tGHUHl7DyfYkokex0VoE4Ec4LCZK4AQy2hmM/xxcAemMIZ8eq6EXtLwPS90kPmvH4YIg Qq6Q== 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; bh=CvpGRQIfyA4kHAw6O6Qm/lsMzBb8T0R2UCjutO7iey0=; b=lnCL80EUrwetP9u12n9pWBzCo6Rk1BtKsG4qmRvwCOCbeBgXCGRvzp28m19Sluv6lW tEH6bPR6IeRAq/DNCUdjBHHZ8dymJQHSJTnfz+KH8vWgzAVFxGPVgmQkvJ+XArkIoTGH rUXOqt5rrL4WzVe2L4ORBlv00E5EL31ejlwHpHVA7JiXnfDlEkdWbwA9AljcbObr2qy8 cNOsxzAQRyein4C59G6LRw4qs69kzOE1CdYNwqIE2/GlGQjfWShsDa/E6DrJRYYQ6TDg 8CKbdeLWubdrfb27A3JtgEi7kJicgsQDtPvq/SpqIJESHsKQ/mIF/MxMpb6/to04b+zH W5BA== X-Gm-Message-State: APjAAAWYA7j0m2rbnHINEPT4cg8vCPskOM3IIfBlGnNCtMYyiwlywTQy I1fu2YrIt8lHPkHcqAHhvkM= X-Google-Smtp-Source: APXvYqx8sY3iFA0v3H9RPqWYjbhv8UDOaU+yy0WLBP2zSAq6krunuMWOTMLZpAKJ35iE6riRZqKQTg== X-Received: by 2002:a17:90a:2163:: with SMTP id a90mr575441pje.3.1561491964038; Tue, 25 Jun 2019 12:46:04 -0700 (PDT) Received: from [172.20.52.61] ([2620:10d:c090:200::3:e848]) by smtp.gmail.com with ESMTPSA id 133sm17098349pfa.92.2019.06.25.12.46.02 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 25 Jun 2019 12:46:03 -0700 (PDT) From: "Jonathan Lemon" To: "Nathan Chancellor" Cc: "=?utf-8?b?QmrDtnJuIFTDtnBlbA==?=" , "Magnus Karlsson" , "David S. Miller" , "Alexei Starovoitov" , "Daniel Borkmann" , "Jakub Kicinski" , "Jesper Dangaard Brouer" , "John Fastabend" , netdev@vger.kernel.org, bpf@vger.kernel.org, xdp-newbies@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, "Nick Desaulniers" , "Nathan Huckleberry" Subject: Re: [PATCH] xsk: Properly terminate assignment in xskq_produce_flush_desc Date: Tue, 25 Jun 2019 12:46:02 -0700 X-Mailer: MailMate (1.12.5r5635) Message-ID: <34F07894-FDE7-44F8-B7F2-E2003D550AD2@gmail.com> In-Reply-To: <20190625182352.13918-1-natechancellor@gmail.com> References: <20190625182352.13918-1-natechancellor@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; format=flowed Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 25 Jun 2019, at 11:23, Nathan Chancellor wrote: > Clang warns: > > In file included from net/xdp/xsk_queue.c:10: > net/xdp/xsk_queue.h:292:2: warning: expression result unused > [-Wunused-value] > WRITE_ONCE(q->ring->producer, q->prod_tail); > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > include/linux/compiler.h:284:6: note: expanded from macro 'WRITE_ONCE' > __u.__val; \ > ~~~ ^~~~~ > 1 warning generated. > > The q->prod_tail assignment has a comma at the end, not a semi-colon. > Fix that so clang no longer warns and everything works as expected. > > Fixes: c497176cb2e4 ("xsk: add Rx receive functions and poll support") > Link: https://github.com/ClangBuiltLinux/linux/issues/544 > Signed-off-by: Nathan Chancellor Nice find. Acked-by: Jonathan Lemon > --- > net/xdp/xsk_queue.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h > index 88b9ae24658d..cba4a640d5e8 100644 > --- a/net/xdp/xsk_queue.h > +++ b/net/xdp/xsk_queue.h > @@ -288,7 +288,7 @@ static inline void xskq_produce_flush_desc(struct > xsk_queue *q) > /* Order producer and data */ > smp_wmb(); /* B, matches C */ > > - q->prod_tail = q->prod_head, > + q->prod_tail = q->prod_head; > WRITE_ONCE(q->ring->producer, q->prod_tail); > } > > -- > 2.22.0