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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY, 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 8E735C35DF9 for ; Tue, 25 Feb 2020 08:45:22 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 60F7620CC7 for ; Tue, 25 Feb 2020 08:45:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="n83IrlXf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 60F7620CC7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=qdX6fVt0t1uja/NO/2x3p0+jHuoGoFTJXrJfH66npHk=; b=n83IrlXfpvp0mg HwiF9ePB5S6XwXtgynNVLzjse6VDHqMO9q428B1GirWaO3y+1+OWPNhduyAbTPROA2T4MTFzY0yhF a+usHzOuJr23xjoPVMBJ3CAa5gWrL7hbwT2p9SO7mLuxmUOqanxjWAcvR+FyWNnGjQfmj4vI4phkm AWTyRoDldL/0KDoSIXKQBULxfDzrCTE/AZGP3j7TKMQG/E1yvEKQ8D/6oXAHKrnNgRVcwYcGDMacV HkrPf2QqaeQ3K3uIBhho0+H8rEFX5LUZkix4R8QPvAemG8DCooE2vkW5ukhikmV2gTFs8Q3JIJWM/ 2lh+6Kc0ASmneSR+x/oA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6Vq4-0006JQ-HJ; Tue, 25 Feb 2020 08:45:12 +0000 Received: from mail-lj1-f195.google.com ([209.85.208.195]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6Vpz-0005bv-8z; Tue, 25 Feb 2020 08:45:10 +0000 Received: by mail-lj1-f195.google.com with SMTP id a13so13059556ljm.10; Tue, 25 Feb 2020 00:45:06 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=fiv9myvgkw7xumEgeJGJ5mKNPtyekzHsqGUH5eUSRc4=; b=lf/7MW4Mf6Tg+Om3sjs3DdOf0Lum6SRGuOf6xsZosvpsvg8A9Ao33ZuFs9x+keIFk2 dR2Fc9bOlx2CyUdsKfHFUPHhKvNIhxojmhrm7XZsXRamKiq6hsFoGpKvr3lt6wEEdo30 Ju7Aic4zV6MPRy8Sb7jAhWlLNnadciSVA+1y7M2vYSusfeAyiYJ1cWPGFL5DwTnxjddX MSKzSIt/HQoCZsFs1ERRxz/tFK2F1gSf5VEgurAmfXzihsFXdzSzhuh+8GOkLGZfRWtE sAgv1BzvwP8c1Mn3wbfHTkpZEfOyA/HD6Mi084vpQm3XWiB+7/pBcqyBYWdT2C+TgS00 +J7w== X-Gm-Message-State: APjAAAWjkPbi8+i8d+nAqnyeMkQRVT6th8II1HHLDyWfbiNTK45ttkJv s6NlPzXmXY0XJd+wxx6wYLc= X-Google-Smtp-Source: APXvYqzGgTQlZDTjc/WdsduCx/ZBfzNVw6Bsa4sPCaQ5okT0MJQT0iJdL306dKc+VA7rZExFnSr49w== X-Received: by 2002:a2e:80d1:: with SMTP id r17mr33212112ljg.292.1582620302745; Tue, 25 Feb 2020 00:45:02 -0800 (PST) Received: from xi.terra (c-12aae455.07-184-6d6c6d4.bbcust.telenor.se. [85.228.170.18]) by smtp.gmail.com with ESMTPSA id d24sm7300090lja.82.2020.02.25.00.45.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Feb 2020 00:45:01 -0800 (PST) Received: from johan by xi.terra with local (Exim 4.92.3) (envelope-from ) id 1j6Vpp-0004Ni-IX; Tue, 25 Feb 2020 09:44:57 +0100 Date: Tue, 25 Feb 2020 09:44:57 +0100 From: Johan Hovold To: "Gustavo A. R. Silva" Subject: Re: [PATCH] USB: Replace zero-length array with flexible-array member Message-ID: <20200225084457.GO32540@localhost> References: <20200220132017.GA29262@embeddedor> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200220132017.GA29262@embeddedor> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200225_004507_344658_42E4233D X-CRM114-Status: GOOD ( 14.14 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Felipe Balbi , linux-tegra@vger.kernel.org, Mathias Nyman , Greg Kroah-Hartman , linux-usb@vger.kernel.org, Johan Hovold , Jonathan Hunter , Matthias Brugger , Thierry Reding , Alan Stern , linux-arm-kernel@lists.infradead.org, Minas Harutyunyan , linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Thu, Feb 20, 2020 at 07:20:17AM -0600, Gustavo A. R. Silva wrote: > The current codebase makes use of the zero-length array language > extension to the C90 standard, but the preferred mechanism to declare > variable-length types such as these ones is a flexible array member[1][2], > introduced in C99: > > struct foo { > int stuff; > struct boo array[]; > }; > > By making use of the mechanism above, we will get a compiler warning > in case the flexible array does not occur last in the structure, which > will help us prevent some kind of undefined behavior bugs from being > inadvertently introduced[3] to the codebase from now on. > > Also, notice that, dynamic memory allocations won't be affected by > this change: > > "Flexible array members have incomplete type, and so the sizeof operator > may not be applied. As a quirk of the original implementation of > zero-length arrays, sizeof evaluates to zero."[1] > > This issue was found with the help of Coccinelle. > > [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html > [2] https://github.com/KSPP/linux/issues/21 > [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") > > Signed-off-by: Gustavo A. R. Silva > --- > drivers/usb/atm/usbatm.h | 2 +- > drivers/usb/dwc2/hcd.h | 2 +- > drivers/usb/host/ehci-tegra.c | 2 +- > drivers/usb/host/ehci.h | 4 ++-- > drivers/usb/host/fotg210.h | 2 +- > drivers/usb/host/ohci.h | 4 ++-- > drivers/usb/host/xhci-mtk.h | 2 +- > drivers/usb/host/xhci.h | 4 ++-- > drivers/usb/serial/io_usbvend.h | 4 ++-- > drivers/usb/serial/ti_usb_3410_5052.c | 4 ++-- > include/linux/usb.h | 4 ++-- > include/linux/usb/audio-v2.h | 2 +- > include/linux/usb/audio-v3.h | 2 +- > include/linux/usb/gadget.h | 2 +- > include/linux/usb/hcd.h | 2 +- > include/linux/usbdevice_fs.h | 2 +- > 16 files changed, 22 insertions(+), 22 deletions(-) Looks like your scripts still doesn't catch every instance. A simple grep like git grep -A1 '\[0\];$' drivers/usb/ | grep -B1 '}' found at least three more in drivers/usb/atm/ueagle-atm.c drivers/usb/gadget/function/f_phonet.c drivers/usb/musb/musb_host.c Johan _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johan Hovold Subject: Re: [PATCH] USB: Replace zero-length array with flexible-array member Date: Tue, 25 Feb 2020 09:44:57 +0100 Message-ID: <20200225084457.GO32540@localhost> References: <20200220132017.GA29262@embeddedor> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20200220132017.GA29262@embeddedor> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Gustavo A. R. Silva" Cc: Greg Kroah-Hartman , Minas Harutyunyan , Alan Stern , Thierry Reding , Jonathan Hunter , Mathias Nyman , Matthias Brugger , Johan Hovold , Felipe Balbi , linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-tegra@vger.kernel.org On Thu, Feb 20, 2020 at 07:20:17AM -0600, Gustavo A. R. Silva wrote: > The current codebase makes use of the zero-length array language > extension to the C90 standard, but the preferred mechanism to declare > variable-length types such as these ones is a flexible array member[1][2], > introduced in C99: > > struct foo { > int stuff; > struct boo array[]; > }; > > By making use of the mechanism above, we will get a compiler warning > in case the flexible array does not occur last in the structure, which > will help us prevent some kind of undefined behavior bugs from being > inadvertently introduced[3] to the codebase from now on. > > Also, notice that, dynamic memory allocations won't be affected by > this change: > > "Flexible array members have incomplete type, and so the sizeof operator > may not be applied. As a quirk of the original implementation of > zero-length arrays, sizeof evaluates to zero."[1] > > This issue was found with the help of Coccinelle. > > [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html > [2] https://github.com/KSPP/linux/issues/21 > [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") > > Signed-off-by: Gustavo A. R. Silva > --- > drivers/usb/atm/usbatm.h | 2 +- > drivers/usb/dwc2/hcd.h | 2 +- > drivers/usb/host/ehci-tegra.c | 2 +- > drivers/usb/host/ehci.h | 4 ++-- > drivers/usb/host/fotg210.h | 2 +- > drivers/usb/host/ohci.h | 4 ++-- > drivers/usb/host/xhci-mtk.h | 2 +- > drivers/usb/host/xhci.h | 4 ++-- > drivers/usb/serial/io_usbvend.h | 4 ++-- > drivers/usb/serial/ti_usb_3410_5052.c | 4 ++-- > include/linux/usb.h | 4 ++-- > include/linux/usb/audio-v2.h | 2 +- > include/linux/usb/audio-v3.h | 2 +- > include/linux/usb/gadget.h | 2 +- > include/linux/usb/hcd.h | 2 +- > include/linux/usbdevice_fs.h | 2 +- > 16 files changed, 22 insertions(+), 22 deletions(-) Looks like your scripts still doesn't catch every instance. A simple grep like git grep -A1 '\[0\];$' drivers/usb/ | grep -B1 '}' found at least three more in drivers/usb/atm/ueagle-atm.c drivers/usb/gadget/function/f_phonet.c drivers/usb/musb/musb_host.c Johan 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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 73AA0C35DF9 for ; Tue, 25 Feb 2020 08:45:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BE4320CC7 for ; Tue, 25 Feb 2020 08:45:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582620308; bh=6c3IuGsy6ZsjI8u0LwfN1xfHtyxVaHNFDuen1/jojCg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=x1eex/VVaiHuKWLGnlP97WjpS5gGnSj4stVt1DOzAjjOxzNhp6QJwYmvdt/Vy8vli tM/rg5yP/AnVdb7SWTVtjoOPeJ5h44TRsUEQ+d+9SMsUU035eBlNEyPunp7MZ3U3vd OBBEim2O6puaWJ+F4QN7v6KfazIZXtUVDUz9St/o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729838AbgBYIpF (ORCPT ); Tue, 25 Feb 2020 03:45:05 -0500 Received: from mail-lj1-f193.google.com ([209.85.208.193]:45046 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726039AbgBYIpE (ORCPT ); Tue, 25 Feb 2020 03:45:04 -0500 Received: by mail-lj1-f193.google.com with SMTP id q8so13044399ljj.11; Tue, 25 Feb 2020 00:45:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=fiv9myvgkw7xumEgeJGJ5mKNPtyekzHsqGUH5eUSRc4=; b=Q3B/A/3F3ZPIfBBwceYha+7UH8tj6hYiRUwebqZZoCYGcBMCTYnzpBU479Fwu76mHE wPgqLwnbHiUp1Jgm/a3hxmy7E5E4rqseJtGsF7cAgqCA5g0Dlg2uRTeDvG5FwvsXMyiM 1dHglkj+lkKtypvGKJrKcb5/eS4EkftWta0A4EvHC/WnwYr1DSHRUrCL2uiqFH2j7XUV 6KFdCBDRK8+wnoNBQ+zM6EHymTIDjZHe2fqaiDP8NzCX84eRHMBrIsWYNpwzvJoum+Bz SnpTxNCeLB4Req98pSvnF5qlelNnq6Nsidh7II+gJsT8lIkGjrscdeo3fD/55/icHSU3 4ELA== X-Gm-Message-State: APjAAAVcU8GT5u7sB7HmWgcjS2u2QM3LcZ44wevsaraGWA1O+TvTCxBO elFmhKiUCTBpp4u1XJgAirI= X-Google-Smtp-Source: APXvYqzGgTQlZDTjc/WdsduCx/ZBfzNVw6Bsa4sPCaQ5okT0MJQT0iJdL306dKc+VA7rZExFnSr49w== X-Received: by 2002:a2e:80d1:: with SMTP id r17mr33212112ljg.292.1582620302745; Tue, 25 Feb 2020 00:45:02 -0800 (PST) Received: from xi.terra (c-12aae455.07-184-6d6c6d4.bbcust.telenor.se. [85.228.170.18]) by smtp.gmail.com with ESMTPSA id d24sm7300090lja.82.2020.02.25.00.45.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Feb 2020 00:45:01 -0800 (PST) Received: from johan by xi.terra with local (Exim 4.92.3) (envelope-from ) id 1j6Vpp-0004Ni-IX; Tue, 25 Feb 2020 09:44:57 +0100 Date: Tue, 25 Feb 2020 09:44:57 +0100 From: Johan Hovold To: "Gustavo A. R. Silva" Cc: Greg Kroah-Hartman , Minas Harutyunyan , Alan Stern , Thierry Reding , Jonathan Hunter , Mathias Nyman , Matthias Brugger , Johan Hovold , Felipe Balbi , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-tegra@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] USB: Replace zero-length array with flexible-array member Message-ID: <20200225084457.GO32540@localhost> References: <20200220132017.GA29262@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200220132017.GA29262@embeddedor> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Thu, Feb 20, 2020 at 07:20:17AM -0600, Gustavo A. R. Silva wrote: > The current codebase makes use of the zero-length array language > extension to the C90 standard, but the preferred mechanism to declare > variable-length types such as these ones is a flexible array member[1][2], > introduced in C99: > > struct foo { > int stuff; > struct boo array[]; > }; > > By making use of the mechanism above, we will get a compiler warning > in case the flexible array does not occur last in the structure, which > will help us prevent some kind of undefined behavior bugs from being > inadvertently introduced[3] to the codebase from now on. > > Also, notice that, dynamic memory allocations won't be affected by > this change: > > "Flexible array members have incomplete type, and so the sizeof operator > may not be applied. As a quirk of the original implementation of > zero-length arrays, sizeof evaluates to zero."[1] > > This issue was found with the help of Coccinelle. > > [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html > [2] https://github.com/KSPP/linux/issues/21 > [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") > > Signed-off-by: Gustavo A. R. Silva > --- > drivers/usb/atm/usbatm.h | 2 +- > drivers/usb/dwc2/hcd.h | 2 +- > drivers/usb/host/ehci-tegra.c | 2 +- > drivers/usb/host/ehci.h | 4 ++-- > drivers/usb/host/fotg210.h | 2 +- > drivers/usb/host/ohci.h | 4 ++-- > drivers/usb/host/xhci-mtk.h | 2 +- > drivers/usb/host/xhci.h | 4 ++-- > drivers/usb/serial/io_usbvend.h | 4 ++-- > drivers/usb/serial/ti_usb_3410_5052.c | 4 ++-- > include/linux/usb.h | 4 ++-- > include/linux/usb/audio-v2.h | 2 +- > include/linux/usb/audio-v3.h | 2 +- > include/linux/usb/gadget.h | 2 +- > include/linux/usb/hcd.h | 2 +- > include/linux/usbdevice_fs.h | 2 +- > 16 files changed, 22 insertions(+), 22 deletions(-) Looks like your scripts still doesn't catch every instance. A simple grep like git grep -A1 '\[0\];$' drivers/usb/ | grep -B1 '}' found at least three more in drivers/usb/atm/ueagle-atm.c drivers/usb/gadget/function/f_phonet.c drivers/usb/musb/musb_host.c Johan 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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY, 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 71902C35DF9 for ; Tue, 25 Feb 2020 08:45:14 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4494820CC7 for ; Tue, 25 Feb 2020 08:45:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="I25nXsjn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4494820CC7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=RaW22mw12D3pcMKaCzyNaoT6tFYR1L+fn/P2fH5X2pQ=; b=I25nXsjnHuWAjR VrmDUTLXcF/y+GH8IYs4nR+Pug96SVoBYa9s8N4OqOD0ha6k+d33q76q1izG3Om5uKjGSeI+R/5Vl LvANu8Uqmf9WNCB9tXWu71hlq8fBqFYpfEMSt5ksEYaHlv/zdh6cyyqI8XPxqSlEtxGu1YeBoziYA 63LCDcjJmOb6XLS4C8bKqN545qz22lCXYl3gcB864aS7K2I35Ksxt3D62LLDCk1NzYaXPiHqCmDs8 Dz4HMFx6cLjOaoCe3K4Sw5SXQfyHMI+faXZ3fxixFb54/5F0vhfA3LVSrmjAfWQvcOvZJCvjerddF V1PY8M9iVLZ2Ta8YckRw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6Vq5-0006KB-JL; Tue, 25 Feb 2020 08:45:13 +0000 Received: from mail-lj1-f195.google.com ([209.85.208.195]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6Vpz-0005bv-8z; Tue, 25 Feb 2020 08:45:10 +0000 Received: by mail-lj1-f195.google.com with SMTP id a13so13059556ljm.10; Tue, 25 Feb 2020 00:45:06 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=fiv9myvgkw7xumEgeJGJ5mKNPtyekzHsqGUH5eUSRc4=; b=lf/7MW4Mf6Tg+Om3sjs3DdOf0Lum6SRGuOf6xsZosvpsvg8A9Ao33ZuFs9x+keIFk2 dR2Fc9bOlx2CyUdsKfHFUPHhKvNIhxojmhrm7XZsXRamKiq6hsFoGpKvr3lt6wEEdo30 Ju7Aic4zV6MPRy8Sb7jAhWlLNnadciSVA+1y7M2vYSusfeAyiYJ1cWPGFL5DwTnxjddX MSKzSIt/HQoCZsFs1ERRxz/tFK2F1gSf5VEgurAmfXzihsFXdzSzhuh+8GOkLGZfRWtE sAgv1BzvwP8c1Mn3wbfHTkpZEfOyA/HD6Mi084vpQm3XWiB+7/pBcqyBYWdT2C+TgS00 +J7w== X-Gm-Message-State: APjAAAWjkPbi8+i8d+nAqnyeMkQRVT6th8II1HHLDyWfbiNTK45ttkJv s6NlPzXmXY0XJd+wxx6wYLc= X-Google-Smtp-Source: APXvYqzGgTQlZDTjc/WdsduCx/ZBfzNVw6Bsa4sPCaQ5okT0MJQT0iJdL306dKc+VA7rZExFnSr49w== X-Received: by 2002:a2e:80d1:: with SMTP id r17mr33212112ljg.292.1582620302745; Tue, 25 Feb 2020 00:45:02 -0800 (PST) Received: from xi.terra (c-12aae455.07-184-6d6c6d4.bbcust.telenor.se. [85.228.170.18]) by smtp.gmail.com with ESMTPSA id d24sm7300090lja.82.2020.02.25.00.45.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 25 Feb 2020 00:45:01 -0800 (PST) Received: from johan by xi.terra with local (Exim 4.92.3) (envelope-from ) id 1j6Vpp-0004Ni-IX; Tue, 25 Feb 2020 09:44:57 +0100 Date: Tue, 25 Feb 2020 09:44:57 +0100 From: Johan Hovold To: "Gustavo A. R. Silva" Subject: Re: [PATCH] USB: Replace zero-length array with flexible-array member Message-ID: <20200225084457.GO32540@localhost> References: <20200220132017.GA29262@embeddedor> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200220132017.GA29262@embeddedor> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200225_004507_344658_42E4233D X-CRM114-Status: GOOD ( 14.14 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Felipe Balbi , linux-tegra@vger.kernel.org, Mathias Nyman , Greg Kroah-Hartman , linux-usb@vger.kernel.org, Johan Hovold , Jonathan Hunter , Matthias Brugger , Thierry Reding , Alan Stern , linux-arm-kernel@lists.infradead.org, Minas Harutyunyan , linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Feb 20, 2020 at 07:20:17AM -0600, Gustavo A. R. Silva wrote: > The current codebase makes use of the zero-length array language > extension to the C90 standard, but the preferred mechanism to declare > variable-length types such as these ones is a flexible array member[1][2], > introduced in C99: > > struct foo { > int stuff; > struct boo array[]; > }; > > By making use of the mechanism above, we will get a compiler warning > in case the flexible array does not occur last in the structure, which > will help us prevent some kind of undefined behavior bugs from being > inadvertently introduced[3] to the codebase from now on. > > Also, notice that, dynamic memory allocations won't be affected by > this change: > > "Flexible array members have incomplete type, and so the sizeof operator > may not be applied. As a quirk of the original implementation of > zero-length arrays, sizeof evaluates to zero."[1] > > This issue was found with the help of Coccinelle. > > [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html > [2] https://github.com/KSPP/linux/issues/21 > [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") > > Signed-off-by: Gustavo A. R. Silva > --- > drivers/usb/atm/usbatm.h | 2 +- > drivers/usb/dwc2/hcd.h | 2 +- > drivers/usb/host/ehci-tegra.c | 2 +- > drivers/usb/host/ehci.h | 4 ++-- > drivers/usb/host/fotg210.h | 2 +- > drivers/usb/host/ohci.h | 4 ++-- > drivers/usb/host/xhci-mtk.h | 2 +- > drivers/usb/host/xhci.h | 4 ++-- > drivers/usb/serial/io_usbvend.h | 4 ++-- > drivers/usb/serial/ti_usb_3410_5052.c | 4 ++-- > include/linux/usb.h | 4 ++-- > include/linux/usb/audio-v2.h | 2 +- > include/linux/usb/audio-v3.h | 2 +- > include/linux/usb/gadget.h | 2 +- > include/linux/usb/hcd.h | 2 +- > include/linux/usbdevice_fs.h | 2 +- > 16 files changed, 22 insertions(+), 22 deletions(-) Looks like your scripts still doesn't catch every instance. A simple grep like git grep -A1 '\[0\];$' drivers/usb/ | grep -B1 '}' found at least three more in drivers/usb/atm/ueagle-atm.c drivers/usb/gadget/function/f_phonet.c drivers/usb/musb/musb_host.c Johan _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel