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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 06D04C433E0 for ; Mon, 22 Mar 2021 16:08:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D26896198D for ; Mon, 22 Mar 2021 16:08:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231980AbhCVQIa (ORCPT ); Mon, 22 Mar 2021 12:08:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42596 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230300AbhCVQHr (ORCPT ); Mon, 22 Mar 2021 12:07:47 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3180C061574; Mon, 22 Mar 2021 09:07:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=WnvXnJzljojS8tgnkv0qyX+4X9mX4IsbTi96GynIueY=; b=ArtuoRXw+MQxkBTgpMWQHo9aLO Bqy+gGcBB7EpHPjwSB+HJ5qYLkF0Tf48XE/eZ+hhB0+9yxlcDDMa+c8iaS/fTcHZGnbyUNhP2uPTz tXgNMwbNbKXU3diYnR/Vs1gdk3gtjXD4y7lCdx3jI7fVyXLBP6HMsa/SoxBj9XLPLZp5zkujykaP2 yACZiMrg2uRbPVcwlbmObfZDRLgrLtKNCp6PjH7Sbz1z93aHQCZaGzeuV3pPiscWylmYqA8MOvuCb MjD8e4JWQAVY5b5glxuQ9Cma/iWupffbeA6Ib70uuoaOxOdAy/Bltik7aQuk/kAJmCrE+SSBVn9ih gA9NWfsA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lON4Z-008krr-Bd; Mon, 22 Mar 2021 16:06:48 +0000 Date: Mon, 22 Mar 2021 16:06:31 +0000 From: Matthew Wilcox To: Arnd Bergmann Cc: "Martin K. Petersen" , Arnd Bergmann , Jens Axboe , Chaitanya Kulkarni , Hannes Reinecke , Bodo Stroesser , Guoqing Jiang , linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] target: pscsi: avoid Wempty-body warning Message-ID: <20210322160631.GQ1719932@casper.infradead.org> References: <20210322114441.3479365-1-arnd@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210322114441.3479365-1-arnd@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 22, 2021 at 12:44:34PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann > > Building with 'make W=1' shows a harmless warning for pscsi: > > drivers/target/target_core_pscsi.c: In function 'pscsi_complete_cmd': > drivers/target/target_core_pscsi.c:624:33: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body] > 624 | ; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */ > | ^ > > Rework the coding style as suggested by gcc to avoid the warning. > > Signed-off-by: Arnd Bergmann > --- > drivers/target/target_core_pscsi.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c > index 3cbc074992bc..913b092955f6 100644 > --- a/drivers/target/target_core_pscsi.c > +++ b/drivers/target/target_core_pscsi.c > @@ -620,8 +620,9 @@ static void pscsi_complete_cmd(struct se_cmd *cmd, u8 scsi_status, > unsigned char *buf; > > buf = transport_kmap_data_sg(cmd); > - if (!buf) > - ; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */ > + if (!buf) { > + /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */ > + } But why not just delete the code? buf = transport_kmap_data_sg(cmd); /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */ I mean, this seems like a real warning here. We're not actually handling the failure to allocate 'buf'. It's not marked as __must_check, but watch the code flow: buf = transport_kmap_data_sg(cmd); if (!buf) ; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */ if (cdb[0] == MODE_SENSE_10) { if (!(buf[3] & 0x80)) buf[3] |= 0x80; } else { if (!(buf[2] & 0x80)) buf[2] |= 0x80; } we're about to do a NULL ptr dereference. So this should be handled somehow.