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 04733CCA489 for ; Mon, 27 Jun 2022 19:54:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241324AbiF0TyL (ORCPT ); Mon, 27 Jun 2022 15:54:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241271AbiF0Txv (ORCPT ); Mon, 27 Jun 2022 15:53:51 -0400 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D03E51AF15 for ; Mon, 27 Jun 2022 12:53:47 -0700 (PDT) Received: by mail-pg1-x534.google.com with SMTP id d129so10042444pgc.9 for ; Mon, 27 Jun 2022 12:53:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=ryYp2naL1201DMNfPmSbpexCs+zqiLsBQDBXHc9esFHxBJ8Ep2LLrsgHtxJtosu2+J 1iBYfvQQXv6NYwKQ2qXQCc4mHXYQGPYeeUC3hu2OgPUPjZXH+3Hi6Zqo5SyTeGerBVQA p1Bh5daOuP6Q9UMRPxlj6vxZpUjBpxOPEYhjttl3pP6gtksJnO1wA5G3ERXmm3iOhFrs MlyYmEaZt8I/cdZ0xlE1RQA9V/oE3k4e+iV7r8nrUlXmSvlRImOQktUmXD254MFh7ceV 2zbWTxt+/QD0MTYLBrv8xqePAliI2A59OkEqXOPrksIatTeOcW53aiRz+65e7KopsoX+ 3osw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=A6idtzkdkFjQzB6o+ENVGtuRYZbpdvRefa142pgCepwfOhefDgXwqR55d5ZyT+PJdV uE2HjRGHYSZYSQo2wtBBK1xVAzkD1LdSpenJi+eKEfNyL5GLCjCyXI3DB0yPN4xwIBl0 3VKXqmR57NUBRyJ8nLbWgRtoY5yXmw/wG6ixiETCNYYywN6ewQOvSyLlEmosDZcoNwYX JYvLOcWI4nQLL7eMyv9Dg1WmFeUp/d6NRppqDLvNwpGwc8cgd8cG+C/92YopxZ/rIc08 Cnx5r8CpKvKRTRd11pK7nxUESVNUtFtXTgm1p0wwMRhbtHzBlKDEHDDaG4r4TXIcenfc OcgQ== X-Gm-Message-State: AJIora+XtwBccPXCnpbbavSIeTJDs4YvD8JomrqGtL0Gpa7cmGG0rilU gp4Ql0E8qQLi7g8oHdzhVaVLwg== X-Google-Smtp-Source: AGRyM1ssDeW6Ux1oaY9ixgaaapzXMFszbxcRVeOWaHAYiiaVMZ4HUYtPzqxXzR6I8+fqeJNf8u9hpg== X-Received: by 2002:a63:7a5d:0:b0:40c:fcbe:4799 with SMTP id j29-20020a637a5d000000b0040cfcbe4799mr14428539pgn.297.1656359626928; Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id c16-20020a056a00009000b0051c1b445094sm7821510pfj.7.2022.06.27.12.53.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Date: Mon, 27 Jun 2022 12:53:43 -0700 From: Stephen Hemminger To: "Gustavo A. R. Silva" Cc: Kees Cook , linux-kernel@vger.kernel.org, x86@kernel.org, dm-devel@redhat.com, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-can@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux1394-devel@lists.sourceforge.net, io-uring@vger.kernel.org, lvs-devel@vger.kernel.org, linux-mtd@lists.infradead.org, kasan-dev@googlegroups.com, linux-mmc@vger.kernel.org, nvdimm@lists.linux.dev, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-perf-users@vger.kernel.org, linux-raid@vger.kernel.org, linux-sctp@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, v9fs-developer@lists.sourceforge.net, linux-rdma@vger.kernel.org, alsa-devel@alsa-project.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Message-ID: <20220627125343.44e24c41@hermes.local> In-Reply-To: <20220627180432.GA136081@embeddedor> References: <20220627180432.GA136081@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Mon, 27 Jun 2022 20:04:32 +0200 "Gustavo A. R. Silva" wrote: > There is a regular need in the kernel to provide a way to declare > having a dynamically sized set of trailing elements in a structure. > Kernel code should always use =E2=80=9Cflexible array members=E2=80=9D[1]= for these > cases. The older style of one-element or zero-length arrays should > no longer be used[2]. >=20 > This code was transformed with the help of Coccinelle: > (linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file scr= ipt.cocci --include-headers --dir . > output.patch) >=20 > @@ > identifier S, member, array; > type T1, T2; > @@ >=20 > struct S { > ... > T1 member; > T2 array[ > - 0 > ]; > }; >=20 > -fstrict-flex-arrays=3D3 is coming and we need to land these changes > to prevent issues like these in the short future: >=20 > ../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destinat= ion buffer has size 0, > but the source string has length 2 (including NUL byte) [-Wfortify-source] > strcpy(de3->name, "."); > ^ >=20 > Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If > this breaks anything, we can use a union with a new member name. >=20 > [1] https://en.wikipedia.org/wiki/Flexible_array_member > [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-le= ngth-and-one-element-arrays >=20 > Link: https://github.com/KSPP/linux/issues/78 > Build-tested-by: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%2= 5lkp@intel.com/ > Signed-off-by: Gustavo A. R. Silva Thanks this fixes warning with gcc-12 in iproute2. In function =E2=80=98xfrm_algo_parse=E2=80=99, inlined from =E2=80=98xfrm_state_modify.constprop=E2=80=99 at xfrm_stat= e.c:573:5: xfrm_state.c:162:32: warning: writing 1 byte into a region of size 0 [-Wstr= ingop-overflow=3D] 162 | buf[j] =3D val; | ~~~~~~~^~~~~ 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 us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AF97CCCA47E for ; Tue, 28 Jun 2022 06:38:10 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-434-hZ1mUpgcOb6UNS4H79CcYw-1; Tue, 28 Jun 2022 02:38:06 -0400 X-MC-Unique: hZ1mUpgcOb6UNS4H79CcYw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 6C2F6805F4C; Tue, 28 Jun 2022 06:38:03 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (unknown [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id 038901121314; Tue, 28 Jun 2022 06:38:01 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id C5568194704D; Tue, 28 Jun 2022 06:38:00 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id E9FE519466DF for ; Mon, 27 Jun 2022 19:53:50 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id DE09318EA8; Mon, 27 Jun 2022 19:53:50 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast08.extmail.prod.ext.rdu2.redhat.com [10.11.55.24]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D95A418EAF for ; Mon, 27 Jun 2022 19:53:50 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B13B4398CA61 for ; Mon, 27 Jun 2022 19:53:50 +0000 (UTC) Received: from mail-pg1-f174.google.com (mail-pg1-f174.google.com [209.85.215.174]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-591-OAcjOwEWNpO8KFqgtAAvwg-1; Mon, 27 Jun 2022 15:53:48 -0400 X-MC-Unique: OAcjOwEWNpO8KFqgtAAvwg-1 Received: by mail-pg1-f174.google.com with SMTP id s206so1054307pgs.3 for ; Mon, 27 Jun 2022 12:53:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=Ch5JRb8o537gHpy1UZsXiEXA9U4yxjs6nlAb57w9vxxlU0n6MnTOUAC7/Qxqdfjequ ShLRGamrm1xy1ZW9B0q+KbJi6kKg8PyankHwdYdKCwESVl60plWRoiZe3Hb8rt5pZ0wL F1uR2hdmGw9FHviHmGdYh4U9mDtBBLf66CK8NoAdmFId39yBztD2x1JhKYN+8pB8LVIP apqG/zoLEoNP2d8QzsYpy5n8M1SEDfxGxHPnQyfdOFVoPMkLzVxf2CNaOxH0QPHX3Vzf pvEUy6BRhF1/q8RpBrhD1EHfc+3XwE4KT6oBLos6fV6JKq+YQfvZeasoxVt2LQ5ithWf ivSQ== X-Gm-Message-State: AJIora/KMfRix/XcmTe+eEcrXW2ygwv/7He/U3QTriQHxsIPVNnqRYaK P4Ul60JxQWMIb57JudDUVXUaqw== X-Google-Smtp-Source: AGRyM1ssDeW6Ux1oaY9ixgaaapzXMFszbxcRVeOWaHAYiiaVMZ4HUYtPzqxXzR6I8+fqeJNf8u9hpg== X-Received: by 2002:a63:7a5d:0:b0:40c:fcbe:4799 with SMTP id j29-20020a637a5d000000b0040cfcbe4799mr14428539pgn.297.1656359626928; Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id c16-20020a056a00009000b0051c1b445094sm7821510pfj.7.2022.06.27.12.53.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Date: Mon, 27 Jun 2022 12:53:43 -0700 From: Stephen Hemminger To: "Gustavo A. R. Silva" Message-ID: <20220627125343.44e24c41@hermes.local> In-Reply-To: <20220627180432.GA136081@embeddedor> References: <20220627180432.GA136081@embeddedor> MIME-Version: 1.0 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Mailman-Approved-At: Tue, 28 Jun 2022 06:38:00 +0000 Subject: Re: [dm-devel] [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nvdimm@lists.linux.dev, alsa-devel@alsa-project.org, kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-hardening@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-stm32@st-md-mailman.stormreply.com, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org, coreteam@netfilter.org, v9fs-developer@lists.sourceforge.net, Kees Cook , intel-gfx@lists.freedesktop.org, linux-can@vger.kernel.org, linux-raid@vger.kernel.org, linux-m68k@lists.linux-m68k.org, virtualization@lists.linux-foundation.org, io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mips@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-sctp@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 T24gTW9uLCAyNyBKdW4gMjAyMiAyMDowNDozMiArMDIwMAoiR3VzdGF2byBBLiBSLiBTaWx2YSIg PGd1c3Rhdm9hcnNAa2VybmVsLm9yZz4gd3JvdGU6Cgo+IFRoZXJlIGlzIGEgcmVndWxhciBuZWVk IGluIHRoZSBrZXJuZWwgdG8gcHJvdmlkZSBhIHdheSB0byBkZWNsYXJlCj4gaGF2aW5nIGEgZHlu YW1pY2FsbHkgc2l6ZWQgc2V0IG9mIHRyYWlsaW5nIGVsZW1lbnRzIGluIGEgc3RydWN0dXJlLgo+ IEtlcm5lbCBjb2RlIHNob3VsZCBhbHdheXMgdXNlIOKAnGZsZXhpYmxlIGFycmF5IG1lbWJlcnPi gJ1bMV0gZm9yIHRoZXNlCj4gY2FzZXMuIFRoZSBvbGRlciBzdHlsZSBvZiBvbmUtZWxlbWVudCBv ciB6ZXJvLWxlbmd0aCBhcnJheXMgc2hvdWxkCj4gbm8gbG9uZ2VyIGJlIHVzZWRbMl0uCj4gCj4g VGhpcyBjb2RlIHdhcyB0cmFuc2Zvcm1lZCB3aXRoIHRoZSBoZWxwIG9mIENvY2NpbmVsbGU6Cj4g KGxpbnV4LTUuMTktcmMyJCBzcGF0Y2ggLS1qb2JzICQoZ2V0Y29uZiBfTlBST0NFU1NPUlNfT05M TikgLS1zcC1maWxlIHNjcmlwdC5jb2NjaSAtLWluY2x1ZGUtaGVhZGVycyAtLWRpciAuID4gb3V0 cHV0LnBhdGNoKQo+IAo+IEBACj4gaWRlbnRpZmllciBTLCBtZW1iZXIsIGFycmF5Owo+IHR5cGUg VDEsIFQyOwo+IEBACj4gCj4gc3RydWN0IFMgewo+ICAgLi4uCj4gICBUMSBtZW1iZXI7Cj4gICBU MiBhcnJheVsKPiAtIDAKPiAgIF07Cj4gfTsKPiAKPiAtZnN0cmljdC1mbGV4LWFycmF5cz0zIGlz IGNvbWluZyBhbmQgd2UgbmVlZCB0byBsYW5kIHRoZXNlIGNoYW5nZXMKPiB0byBwcmV2ZW50IGlz c3VlcyBsaWtlIHRoZXNlIGluIHRoZSBzaG9ydCBmdXR1cmU6Cj4gCj4gLi4vZnMvbWluaXgvZGly LmM6MzM3OjM6IHdhcm5pbmc6ICdzdHJjcHknIHdpbGwgYWx3YXlzIG92ZXJmbG93OyBkZXN0aW5h dGlvbiBidWZmZXIgaGFzIHNpemUgMCwKPiBidXQgdGhlIHNvdXJjZSBzdHJpbmcgaGFzIGxlbmd0 aCAyIChpbmNsdWRpbmcgTlVMIGJ5dGUpIFstV2ZvcnRpZnktc291cmNlXQo+IAkJc3RyY3B5KGRl My0+bmFtZSwgIi4iKTsKPiAJCV4KPiAKPiBTaW5jZSB0aGVzZSBhcmUgYWxsIFswXSB0byBbXSBj aGFuZ2VzLCB0aGUgcmlzayB0byBVQVBJIGlzIG5lYXJseSB6ZXJvLiBJZgo+IHRoaXMgYnJlYWtz IGFueXRoaW5nLCB3ZSBjYW4gdXNlIGEgdW5pb24gd2l0aCBhIG5ldyBtZW1iZXIgbmFtZS4KPiAK PiBbMV0gaHR0cHM6Ly9lbi53aWtpcGVkaWEub3JnL3dpa2kvRmxleGlibGVfYXJyYXlfbWVtYmVy Cj4gWzJdIGh0dHBzOi8vd3d3Lmtlcm5lbC5vcmcvZG9jL2h0bWwvdjUuMTYvcHJvY2Vzcy9kZXBy ZWNhdGVkLmh0bWwjemVyby1sZW5ndGgtYW5kLW9uZS1lbGVtZW50LWFycmF5cwo+IAo+IExpbms6 IGh0dHBzOi8vZ2l0aHViLmNvbS9LU1BQL2xpbnV4L2lzc3Vlcy83OAo+IEJ1aWxkLXRlc3RlZC1i eTogaHR0cHM6Ly9sb3JlLmtlcm5lbC5vcmcvbGttbC82MmI2NzVlYy53S1g2QU9aNmNiRTcxdnRG JTI1bGtwQGludGVsLmNvbS8KPiBTaWduZWQtb2ZmLWJ5OiBHdXN0YXZvIEEuIFIuIFNpbHZhIDxn dXN0YXZvYXJzQGtlcm5lbC5vcmc+CgpUaGFua3MgdGhpcyBmaXhlcyB3YXJuaW5nIHdpdGggZ2Nj LTEyIGluIGlwcm91dGUyLgpJbiBmdW5jdGlvbiDigJh4ZnJtX2FsZ29fcGFyc2XigJksCiAgICBp bmxpbmVkIGZyb20g4oCYeGZybV9zdGF0ZV9tb2RpZnkuY29uc3Rwcm9w4oCZIGF0IHhmcm1fc3Rh dGUuYzo1NzM6NToKeGZybV9zdGF0ZS5jOjE2MjozMjogd2FybmluZzogd3JpdGluZyAxIGJ5dGUg aW50byBhIHJlZ2lvbiBvZiBzaXplIDAgWy1Xc3RyaW5nb3Atb3ZlcmZsb3c9XQogIDE2MiB8ICAg ICAgICAgICAgICAgICAgICAgICAgIGJ1ZltqXSA9IHZhbDsKICAgICAgfCAgICAgICAgICAgICAg ICAgICAgICAgICB+fn5+fn5+Xn5+fn4KCi0tCmRtLWRldmVsIG1haWxpbmcgbGlzdApkbS1kZXZl bEByZWRoYXQuY29tCmh0dHBzOi8vbGlzdG1hbi5yZWRoYXQuY29tL21haWxtYW4vbGlzdGluZm8v ZG0tZGV2ZWwK 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 14F53C433EF for ; Mon, 27 Jun 2022 19:53:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 499B211B47A; Mon, 27 Jun 2022 19:53:49 +0000 (UTC) Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7BA2E11B47A for ; Mon, 27 Jun 2022 19:53:47 +0000 (UTC) Received: by mail-pg1-x52d.google.com with SMTP id 184so10023502pga.12 for ; Mon, 27 Jun 2022 12:53:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=ryYp2naL1201DMNfPmSbpexCs+zqiLsBQDBXHc9esFHxBJ8Ep2LLrsgHtxJtosu2+J 1iBYfvQQXv6NYwKQ2qXQCc4mHXYQGPYeeUC3hu2OgPUPjZXH+3Hi6Zqo5SyTeGerBVQA p1Bh5daOuP6Q9UMRPxlj6vxZpUjBpxOPEYhjttl3pP6gtksJnO1wA5G3ERXmm3iOhFrs MlyYmEaZt8I/cdZ0xlE1RQA9V/oE3k4e+iV7r8nrUlXmSvlRImOQktUmXD254MFh7ceV 2zbWTxt+/QD0MTYLBrv8xqePAliI2A59OkEqXOPrksIatTeOcW53aiRz+65e7KopsoX+ 3osw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=5kpDNrBB6/KGntAzpRxtoTTw+E3Tl2x4VbPvGKGGH0NhGLS7rzskbH0ZMeSPf1yTXZ FurZ2J3ix6Tx+K1Yq3lcpKWgfvPwHYFpjATBsv1MDhMmcDDFVvyWFgsUJI+g++eBpaU5 TAIAmQ4qkxpMW0t/NoGqqydY7nFWvHw2FCquOBbI8KRrE8Nt/DOlTn3mQi1miDAlaX0f 5Qs59tzS+wVkkLLXG2w6fcdboh7bVTAiUY6tsaRtTn3oo8zIxm7jCMacIoveC+/3sP/U VvdNapUaZ+LWedsApvhXSZYabfd0P4aVDfVUMlJXcYPMAC4Rqcax3lsZRkc8pm42PBQD IuOg== X-Gm-Message-State: AJIora+4B99wkJP3CCvfMP/DyKIadI1qh000hFEbzrLzJDzqgs5HvNGb zadzQylUh82Cs8N6ecuNSRffCw== X-Google-Smtp-Source: AGRyM1ssDeW6Ux1oaY9ixgaaapzXMFszbxcRVeOWaHAYiiaVMZ4HUYtPzqxXzR6I8+fqeJNf8u9hpg== X-Received: by 2002:a63:7a5d:0:b0:40c:fcbe:4799 with SMTP id j29-20020a637a5d000000b0040cfcbe4799mr14428539pgn.297.1656359626928; Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id c16-20020a056a00009000b0051c1b445094sm7821510pfj.7.2022.06.27.12.53.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Date: Mon, 27 Jun 2022 12:53:43 -0700 From: Stephen Hemminger To: "Gustavo A. R. Silva" Message-ID: <20220627125343.44e24c41@hermes.local> In-Reply-To: <20220627180432.GA136081@embeddedor> References: <20220627180432.GA136081@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Intel-gfx] [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nvdimm@lists.linux.dev, alsa-devel@alsa-project.org, kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-hardening@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-stm32@st-md-mailman.stormreply.com, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org, coreteam@netfilter.org, v9fs-developer@lists.sourceforge.net, Kees Cook , intel-gfx@lists.freedesktop.org, linux-can@vger.kernel.org, linux-raid@vger.kernel.org, linux-m68k@lists.linux-m68k.org, virtualization@lists.linux-foundation.org, io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mips@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-sctp@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Mon, 27 Jun 2022 20:04:32 +0200 "Gustavo A. R. Silva" wrote: > There is a regular need in the kernel to provide a way to declare > having a dynamically sized set of trailing elements in a structure. > Kernel code should always use =E2=80=9Cflexible array members=E2=80=9D[1]= for these > cases. The older style of one-element or zero-length arrays should > no longer be used[2]. >=20 > This code was transformed with the help of Coccinelle: > (linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file scr= ipt.cocci --include-headers --dir . > output.patch) >=20 > @@ > identifier S, member, array; > type T1, T2; > @@ >=20 > struct S { > ... > T1 member; > T2 array[ > - 0 > ]; > }; >=20 > -fstrict-flex-arrays=3D3 is coming and we need to land these changes > to prevent issues like these in the short future: >=20 > ../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destinat= ion buffer has size 0, > but the source string has length 2 (including NUL byte) [-Wfortify-source] > strcpy(de3->name, "."); > ^ >=20 > Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If > this breaks anything, we can use a union with a new member name. >=20 > [1] https://en.wikipedia.org/wiki/Flexible_array_member > [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-le= ngth-and-one-element-arrays >=20 > Link: https://github.com/KSPP/linux/issues/78 > Build-tested-by: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%2= 5lkp@intel.com/ > Signed-off-by: Gustavo A. R. Silva Thanks this fixes warning with gcc-12 in iproute2. In function =E2=80=98xfrm_algo_parse=E2=80=99, inlined from =E2=80=98xfrm_state_modify.constprop=E2=80=99 at xfrm_stat= e.c:573:5: xfrm_state.c:162:32: warning: writing 1 byte into a region of size 0 [-Wstr= ingop-overflow=3D] 162 | buf[j] =3D val; | ~~~~~~~^~~~~ 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 6EF9DC433EF for ; Mon, 27 Jun 2022 19:54:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc: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=LYv2/FdPodWqxZ79ajcsvrPZwrguf4cpaYpucSoYdqs=; b=RGGarW3dTt0BbO kKOmXvIl2zeSEG/PyVFcnANQ4f3LK5sWSVTbhjh1aTAUscrKIMKDfHBlO0UCI0A0t7Xm+FjLGTL0p SF+KL2wSsUPijzQoIEtPwQpaT1Vg0TFuZS38OQoKUQpCbsRpOG46BppTE8o7mfkQB3vtwiNk5ZtwT FaHWD3JH4Aw75DpxaECTeY7DTU14zGQpKk8SPcdjYtP0YRGLUX0yw/6obzuDr/YHMK1pvGOafkfPe 8IzY7X6e0bGsIJ8bcGJsnwmtrKGSm5YhxgyW1EUE/292lsaraJPz2r3CQ2ZdMTJ/V61EywmTO3HS5 54ioTQ64sLNjW7/kBRKA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o5uo7-002fs3-LM; Mon, 27 Jun 2022 19:54:03 +0000 Received: from mail-pg1-x534.google.com ([2607:f8b0:4864:20::534]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o5unv-002fnV-Nf for linux-mtd@lists.infradead.org; Mon, 27 Jun 2022 19:53:53 +0000 Received: by mail-pg1-x534.google.com with SMTP id g4so3151617pgc.1 for ; Mon, 27 Jun 2022 12:53:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=ryYp2naL1201DMNfPmSbpexCs+zqiLsBQDBXHc9esFHxBJ8Ep2LLrsgHtxJtosu2+J 1iBYfvQQXv6NYwKQ2qXQCc4mHXYQGPYeeUC3hu2OgPUPjZXH+3Hi6Zqo5SyTeGerBVQA p1Bh5daOuP6Q9UMRPxlj6vxZpUjBpxOPEYhjttl3pP6gtksJnO1wA5G3ERXmm3iOhFrs MlyYmEaZt8I/cdZ0xlE1RQA9V/oE3k4e+iV7r8nrUlXmSvlRImOQktUmXD254MFh7ceV 2zbWTxt+/QD0MTYLBrv8xqePAliI2A59OkEqXOPrksIatTeOcW53aiRz+65e7KopsoX+ 3osw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=j9XwsEU5mPob7dicnidHfEpd6y+IdPimwFzeKYtpauqBblh9orhTtYFL1ookOtKCEs YwkvdKuP9R+bHa5RSpdglelM2YTNLWTKJ2qzfeHgiG2vi1aZvE4B+ZocQifAeGEKLItH Vpn5Zcrqj4liVhjST8w0Xv49pDSfEy216ijX4HhXGZNL+nPW1WmD9n948DYo3I2mYdlg aQeSFEmNSaoMfvUuGRDaoR47P8hik7XrJEWy8PiONYNbgH+sqGz2KguL+cEgzfwkMG83 Hj7bBanZWvpHBxTJlbjpsBUCQBW6XH7x6l2muC/G/2URyzblM8Ezy7yNnhlIkYuL+ae7 jWDA== X-Gm-Message-State: AJIora8kNc9Ov+bKp7vKUtzHgflRveTD0rZu1+2oBJU0Rboli4HF7u0Q UqToXirhTUFcyGkUVkEeqk2RNA== X-Google-Smtp-Source: AGRyM1ssDeW6Ux1oaY9ixgaaapzXMFszbxcRVeOWaHAYiiaVMZ4HUYtPzqxXzR6I8+fqeJNf8u9hpg== X-Received: by 2002:a63:7a5d:0:b0:40c:fcbe:4799 with SMTP id j29-20020a637a5d000000b0040cfcbe4799mr14428539pgn.297.1656359626928; Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id c16-20020a056a00009000b0051c1b445094sm7821510pfj.7.2022.06.27.12.53.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Date: Mon, 27 Jun 2022 12:53:43 -0700 From: Stephen Hemminger To: "Gustavo A. R. Silva" Cc: Kees Cook , linux-kernel@vger.kernel.org, x86@kernel.org, dm-devel@redhat.com, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-can@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux1394-devel@lists.sourceforge.net, io-uring@vger.kernel.org, lvs-devel@vger.kernel.org, linux-mtd@lists.infradead.org, kasan-dev@googlegroups.com, linux-mmc@vger.kernel.org, nvdimm@lists.linux.dev, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-perf-users@vger.kernel.org, linux-raid@vger.kernel.org, linux-sctp@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, v9fs-developer@lists.sourceforge.net, linux-rdma@vger.kernel.org, alsa-devel@alsa-project.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Message-ID: <20220627125343.44e24c41@hermes.local> In-Reply-To: <20220627180432.GA136081@embeddedor> References: <20220627180432.GA136081@embeddedor> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220627_125351_796067_774B4D3F X-CRM114-Status: GOOD ( 15.37 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org T24gTW9uLCAyNyBKdW4gMjAyMiAyMDowNDozMiArMDIwMAoiR3VzdGF2byBBLiBSLiBTaWx2YSIg PGd1c3Rhdm9hcnNAa2VybmVsLm9yZz4gd3JvdGU6Cgo+IFRoZXJlIGlzIGEgcmVndWxhciBuZWVk IGluIHRoZSBrZXJuZWwgdG8gcHJvdmlkZSBhIHdheSB0byBkZWNsYXJlCj4gaGF2aW5nIGEgZHlu YW1pY2FsbHkgc2l6ZWQgc2V0IG9mIHRyYWlsaW5nIGVsZW1lbnRzIGluIGEgc3RydWN0dXJlLgo+ IEtlcm5lbCBjb2RlIHNob3VsZCBhbHdheXMgdXNlIOKAnGZsZXhpYmxlIGFycmF5IG1lbWJlcnPi gJ1bMV0gZm9yIHRoZXNlCj4gY2FzZXMuIFRoZSBvbGRlciBzdHlsZSBvZiBvbmUtZWxlbWVudCBv ciB6ZXJvLWxlbmd0aCBhcnJheXMgc2hvdWxkCj4gbm8gbG9uZ2VyIGJlIHVzZWRbMl0uCj4gCj4g VGhpcyBjb2RlIHdhcyB0cmFuc2Zvcm1lZCB3aXRoIHRoZSBoZWxwIG9mIENvY2NpbmVsbGU6Cj4g KGxpbnV4LTUuMTktcmMyJCBzcGF0Y2ggLS1qb2JzICQoZ2V0Y29uZiBfTlBST0NFU1NPUlNfT05M TikgLS1zcC1maWxlIHNjcmlwdC5jb2NjaSAtLWluY2x1ZGUtaGVhZGVycyAtLWRpciAuID4gb3V0 cHV0LnBhdGNoKQo+IAo+IEBACj4gaWRlbnRpZmllciBTLCBtZW1iZXIsIGFycmF5Owo+IHR5cGUg VDEsIFQyOwo+IEBACj4gCj4gc3RydWN0IFMgewo+ICAgLi4uCj4gICBUMSBtZW1iZXI7Cj4gICBU MiBhcnJheVsKPiAtIDAKPiAgIF07Cj4gfTsKPiAKPiAtZnN0cmljdC1mbGV4LWFycmF5cz0zIGlz IGNvbWluZyBhbmQgd2UgbmVlZCB0byBsYW5kIHRoZXNlIGNoYW5nZXMKPiB0byBwcmV2ZW50IGlz c3VlcyBsaWtlIHRoZXNlIGluIHRoZSBzaG9ydCBmdXR1cmU6Cj4gCj4gLi4vZnMvbWluaXgvZGly LmM6MzM3OjM6IHdhcm5pbmc6ICdzdHJjcHknIHdpbGwgYWx3YXlzIG92ZXJmbG93OyBkZXN0aW5h dGlvbiBidWZmZXIgaGFzIHNpemUgMCwKPiBidXQgdGhlIHNvdXJjZSBzdHJpbmcgaGFzIGxlbmd0 aCAyIChpbmNsdWRpbmcgTlVMIGJ5dGUpIFstV2ZvcnRpZnktc291cmNlXQo+IAkJc3RyY3B5KGRl My0+bmFtZSwgIi4iKTsKPiAJCV4KPiAKPiBTaW5jZSB0aGVzZSBhcmUgYWxsIFswXSB0byBbXSBj aGFuZ2VzLCB0aGUgcmlzayB0byBVQVBJIGlzIG5lYXJseSB6ZXJvLiBJZgo+IHRoaXMgYnJlYWtz IGFueXRoaW5nLCB3ZSBjYW4gdXNlIGEgdW5pb24gd2l0aCBhIG5ldyBtZW1iZXIgbmFtZS4KPiAK PiBbMV0gaHR0cHM6Ly9lbi53aWtpcGVkaWEub3JnL3dpa2kvRmxleGlibGVfYXJyYXlfbWVtYmVy Cj4gWzJdIGh0dHBzOi8vd3d3Lmtlcm5lbC5vcmcvZG9jL2h0bWwvdjUuMTYvcHJvY2Vzcy9kZXBy ZWNhdGVkLmh0bWwjemVyby1sZW5ndGgtYW5kLW9uZS1lbGVtZW50LWFycmF5cwo+IAo+IExpbms6 IGh0dHBzOi8vZ2l0aHViLmNvbS9LU1BQL2xpbnV4L2lzc3Vlcy83OAo+IEJ1aWxkLXRlc3RlZC1i eTogaHR0cHM6Ly9sb3JlLmtlcm5lbC5vcmcvbGttbC82MmI2NzVlYy53S1g2QU9aNmNiRTcxdnRG JTI1bGtwQGludGVsLmNvbS8KPiBTaWduZWQtb2ZmLWJ5OiBHdXN0YXZvIEEuIFIuIFNpbHZhIDxn dXN0YXZvYXJzQGtlcm5lbC5vcmc+CgpUaGFua3MgdGhpcyBmaXhlcyB3YXJuaW5nIHdpdGggZ2Nj LTEyIGluIGlwcm91dGUyLgpJbiBmdW5jdGlvbiDigJh4ZnJtX2FsZ29fcGFyc2XigJksCiAgICBp bmxpbmVkIGZyb20g4oCYeGZybV9zdGF0ZV9tb2RpZnkuY29uc3Rwcm9w4oCZIGF0IHhmcm1fc3Rh dGUuYzo1NzM6NToKeGZybV9zdGF0ZS5jOjE2MjozMjogd2FybmluZzogd3JpdGluZyAxIGJ5dGUg aW50byBhIHJlZ2lvbiBvZiBzaXplIDAgWy1Xc3RyaW5nb3Atb3ZlcmZsb3c9XQogIDE2MiB8ICAg ICAgICAgICAgICAgICAgICAgICAgIGJ1ZltqXSA9IHZhbDsKICAgICAgfCAgICAgICAgICAgICAg ICAgICAgICAgICB+fn5+fn5+Xn5+fn4KCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fXwpMaW51eCBNVEQgZGlzY3Vzc2lvbiBtYWlsaW5nIGxpc3QK aHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1tdGQvCg== From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Date: Mon, 27 Jun 2022 12:53:43 -0700 Message-ID: <20220627125343.44e24c41@hermes.local> References: <20220627180432.GA136081@embeddedor> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=ryYp2naL1201DMNfPmSbpexCs+zqiLsBQDBXHc9esFHxBJ8Ep2LLrsgHtxJtosu2+J 1iBYfvQQXv6NYwKQ2qXQCc4mHXYQGPYeeUC3hu2OgPUPjZXH+3Hi6Zqo5SyTeGerBVQA p1Bh5daOuP6Q9UMRPxlj6vxZpUjBpxOPEYhjttl3pP6gtksJnO1wA5G3ERXmm3iOhFrs MlyYmEaZt8I/cdZ0xlE1RQA9V/oE3k4e+iV7r8nrUlXmSvlRImOQktUmXD254MFh7ceV 2zbWTxt+/QD0MTYLBrv8xqePAliI2A59OkEqXOPrksIatTeOcW53aiRz+65e7KopsoX+ 3osw== In-Reply-To: <20220627180432.GA136081@embeddedor> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Content-Type: text/plain; charset="utf-8" To: "Gustavo A. R. Silva" Cc: nvdimm@lists.linux.dev, alsa-devel@alsa-project.org, kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-hardening@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-stm32@st-md-mailman.stormreply.com, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org, coreteam@netfilter.org, v9fs-developer@lists.sourceforge.net, Kees Cook , intel-gfx@lists.freedesktop.org, linux-can@vger.kernel.org, linux-raid@vger.kernel.org, linux-m68k@lists.linux-m68k.org, virtualization@lists.linux-foundation.org, io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-mmc@vger.kern On Mon, 27 Jun 2022 20:04:32 +0200 "Gustavo A. R. Silva" wrote: > There is a regular need in the kernel to provide a way to declare > having a dynamically sized set of trailing elements in a structure. > Kernel code should always use =E2=80=9Cflexible array members=E2=80=9D[1]= for these > cases. The older style of one-element or zero-length arrays should > no longer be used[2]. >=20 > This code was transformed with the help of Coccinelle: > (linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file scr= ipt.cocci --include-headers --dir . > output.patch) >=20 > @@ > identifier S, member, array; > type T1, T2; > @@ >=20 > struct S { > ... > T1 member; > T2 array[ > - 0 > ]; > }; >=20 > -fstrict-flex-arrays=3D3 is coming and we need to land these changes > to prevent issues like these in the short future: >=20 > ../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destinat= ion buffer has size 0, > but the source string has length 2 (including NUL byte) [-Wfortify-source] > strcpy(de3->name, "."); > ^ >=20 > Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If > this breaks anything, we can use a union with a new member name. >=20 > [1] https://en.wikipedia.org/wiki/Flexible_array_member > [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-le= ngth-and-one-element-arrays >=20 > Link: https://github.com/KSPP/linux/issues/78 > Build-tested-by: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%2= 5lkp@intel.com/ > Signed-off-by: Gustavo A. R. Silva Thanks this fixes warning with gcc-12 in iproute2. In function =E2=80=98xfrm_algo_parse=E2=80=99, inlined from =E2=80=98xfrm_state_modify.constprop=E2=80=99 at xfrm_stat= e.c:573:5: xfrm_state.c:162:32: warning: writing 1 byte into a region of size 0 [-Wstr= ingop-overflow=3D] 162 | buf[j] =3D val; | ~~~~~~~^~~~~ 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id BB127C433EF for ; Mon, 27 Jun 2022 19:54:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:Cc: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=qWcLn8sWBEkzLxKnAaO31oRt2miUiNhQBc7aIxDevno=; b=Bv9ZQJQfxUfsdw qjQBeJCgUz+FaPUyEypkP0Kx7k6LMd+PGlWyDH7aOiSyvX6TLNKzN5+0aeC3rniqcCrwE2S2szJa+ bLIbtzQ58nRgT62Xj+V9Te2FQjNOPRKisWmoz1aYjGFGJ22nuuKHFHpu6rlrHVRspv/2eMUqx3qHt Bp4w+1sgY7y1o2bP72Qk6rbmpSOCf9pQq5vvoIWfum1KRlNEgN2+aXoGbVFt8zT8UsQyT0aqz13CO hZAeeKP93lYpWCLkqzJjCH2obeXGysfPMdOvteXem98+B2HynqLlSSGLJVUA+ulXQwmsvBOd17vQG lVMq+COkZ+mGRBdx9VoQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o5uny-002fpx-Rn; Mon, 27 Jun 2022 19:53:54 +0000 Received: from mail-pg1-x52e.google.com ([2607:f8b0:4864:20::52e]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o5unv-002fnW-M8 for linux-arm-kernel@lists.infradead.org; Mon, 27 Jun 2022 19:53:53 +0000 Received: by mail-pg1-x52e.google.com with SMTP id v126so5888494pgv.11 for ; Mon, 27 Jun 2022 12:53:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=ryYp2naL1201DMNfPmSbpexCs+zqiLsBQDBXHc9esFHxBJ8Ep2LLrsgHtxJtosu2+J 1iBYfvQQXv6NYwKQ2qXQCc4mHXYQGPYeeUC3hu2OgPUPjZXH+3Hi6Zqo5SyTeGerBVQA p1Bh5daOuP6Q9UMRPxlj6vxZpUjBpxOPEYhjttl3pP6gtksJnO1wA5G3ERXmm3iOhFrs MlyYmEaZt8I/cdZ0xlE1RQA9V/oE3k4e+iV7r8nrUlXmSvlRImOQktUmXD254MFh7ceV 2zbWTxt+/QD0MTYLBrv8xqePAliI2A59OkEqXOPrksIatTeOcW53aiRz+65e7KopsoX+ 3osw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=Dq/9joN/thpXSKR52XNdHQDJpzxFuHHObyP0/z1vaV1Zlp9ma6c9qlgMEwxkEtPrrt 55X1AOm8j9nb2U2GyjQsdotbiYh60RPyySJC/0ppOzUzxT1JcyXjE4p5KwhsAdf+uAEI v35Xk2WbDaTdvjchRlrdZ3kxT1RxncfUnylAWo199YzH33WZF8FpFVu5VtDhaB2yEpdj kKCjhQo957Qp8cj4etB9W0wDtzeYTMdjmowws+aJnVV9IPAjN7DpSGKuSrJImCDrjqJx YKaYsKXhOIE8mNsCJKKdwAhls8OHucJ6WZAfakoWdD/DV1mLu6+c9EmekwLM3TpCkRw7 wLDg== X-Gm-Message-State: AJIora8AoJVtdoNdzquQaprEDv0IsoEbW+7rf6jvf3K52LGMdn9x/qQo H4WTzFAF/Yj1ZwKlUGfdQiVlhw== X-Google-Smtp-Source: AGRyM1ssDeW6Ux1oaY9ixgaaapzXMFszbxcRVeOWaHAYiiaVMZ4HUYtPzqxXzR6I8+fqeJNf8u9hpg== X-Received: by 2002:a63:7a5d:0:b0:40c:fcbe:4799 with SMTP id j29-20020a637a5d000000b0040cfcbe4799mr14428539pgn.297.1656359626928; Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id c16-20020a056a00009000b0051c1b445094sm7821510pfj.7.2022.06.27.12.53.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Date: Mon, 27 Jun 2022 12:53:43 -0700 From: Stephen Hemminger To: "Gustavo A. R. Silva" Cc: Kees Cook , linux-kernel@vger.kernel.org, x86@kernel.org, dm-devel@redhat.com, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-can@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux1394-devel@lists.sourceforge.net, io-uring@vger.kernel.org, lvs-devel@vger.kernel.org, linux-mtd@lists.infradead.org, kasan-dev@googlegroups.com, linux-mmc@vger.kernel.org, nvdimm@lists.linux.dev, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-perf-users@vger.kernel.org, linux-raid@vger.kernel.org, linux-sctp@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, v9fs-developer@lists.sourceforge.net, linux-rdma@vger.kernel.org, alsa-devel@alsa-project.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Message-ID: <20220627125343.44e24c41@hermes.local> In-Reply-To: <20220627180432.GA136081@embeddedor> References: <20220627180432.GA136081@embeddedor> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220627_125351_748541_ED55D917 X-CRM114-Status: GOOD ( 15.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gTW9uLCAyNyBKdW4gMjAyMiAyMDowNDozMiArMDIwMAoiR3VzdGF2byBBLiBSLiBTaWx2YSIg PGd1c3Rhdm9hcnNAa2VybmVsLm9yZz4gd3JvdGU6Cgo+IFRoZXJlIGlzIGEgcmVndWxhciBuZWVk IGluIHRoZSBrZXJuZWwgdG8gcHJvdmlkZSBhIHdheSB0byBkZWNsYXJlCj4gaGF2aW5nIGEgZHlu YW1pY2FsbHkgc2l6ZWQgc2V0IG9mIHRyYWlsaW5nIGVsZW1lbnRzIGluIGEgc3RydWN0dXJlLgo+ IEtlcm5lbCBjb2RlIHNob3VsZCBhbHdheXMgdXNlIOKAnGZsZXhpYmxlIGFycmF5IG1lbWJlcnPi gJ1bMV0gZm9yIHRoZXNlCj4gY2FzZXMuIFRoZSBvbGRlciBzdHlsZSBvZiBvbmUtZWxlbWVudCBv ciB6ZXJvLWxlbmd0aCBhcnJheXMgc2hvdWxkCj4gbm8gbG9uZ2VyIGJlIHVzZWRbMl0uCj4gCj4g VGhpcyBjb2RlIHdhcyB0cmFuc2Zvcm1lZCB3aXRoIHRoZSBoZWxwIG9mIENvY2NpbmVsbGU6Cj4g KGxpbnV4LTUuMTktcmMyJCBzcGF0Y2ggLS1qb2JzICQoZ2V0Y29uZiBfTlBST0NFU1NPUlNfT05M TikgLS1zcC1maWxlIHNjcmlwdC5jb2NjaSAtLWluY2x1ZGUtaGVhZGVycyAtLWRpciAuID4gb3V0 cHV0LnBhdGNoKQo+IAo+IEBACj4gaWRlbnRpZmllciBTLCBtZW1iZXIsIGFycmF5Owo+IHR5cGUg VDEsIFQyOwo+IEBACj4gCj4gc3RydWN0IFMgewo+ICAgLi4uCj4gICBUMSBtZW1iZXI7Cj4gICBU MiBhcnJheVsKPiAtIDAKPiAgIF07Cj4gfTsKPiAKPiAtZnN0cmljdC1mbGV4LWFycmF5cz0zIGlz IGNvbWluZyBhbmQgd2UgbmVlZCB0byBsYW5kIHRoZXNlIGNoYW5nZXMKPiB0byBwcmV2ZW50IGlz c3VlcyBsaWtlIHRoZXNlIGluIHRoZSBzaG9ydCBmdXR1cmU6Cj4gCj4gLi4vZnMvbWluaXgvZGly LmM6MzM3OjM6IHdhcm5pbmc6ICdzdHJjcHknIHdpbGwgYWx3YXlzIG92ZXJmbG93OyBkZXN0aW5h dGlvbiBidWZmZXIgaGFzIHNpemUgMCwKPiBidXQgdGhlIHNvdXJjZSBzdHJpbmcgaGFzIGxlbmd0 aCAyIChpbmNsdWRpbmcgTlVMIGJ5dGUpIFstV2ZvcnRpZnktc291cmNlXQo+IAkJc3RyY3B5KGRl My0+bmFtZSwgIi4iKTsKPiAJCV4KPiAKPiBTaW5jZSB0aGVzZSBhcmUgYWxsIFswXSB0byBbXSBj aGFuZ2VzLCB0aGUgcmlzayB0byBVQVBJIGlzIG5lYXJseSB6ZXJvLiBJZgo+IHRoaXMgYnJlYWtz IGFueXRoaW5nLCB3ZSBjYW4gdXNlIGEgdW5pb24gd2l0aCBhIG5ldyBtZW1iZXIgbmFtZS4KPiAK PiBbMV0gaHR0cHM6Ly9lbi53aWtpcGVkaWEub3JnL3dpa2kvRmxleGlibGVfYXJyYXlfbWVtYmVy Cj4gWzJdIGh0dHBzOi8vd3d3Lmtlcm5lbC5vcmcvZG9jL2h0bWwvdjUuMTYvcHJvY2Vzcy9kZXBy ZWNhdGVkLmh0bWwjemVyby1sZW5ndGgtYW5kLW9uZS1lbGVtZW50LWFycmF5cwo+IAo+IExpbms6 IGh0dHBzOi8vZ2l0aHViLmNvbS9LU1BQL2xpbnV4L2lzc3Vlcy83OAo+IEJ1aWxkLXRlc3RlZC1i eTogaHR0cHM6Ly9sb3JlLmtlcm5lbC5vcmcvbGttbC82MmI2NzVlYy53S1g2QU9aNmNiRTcxdnRG JTI1bGtwQGludGVsLmNvbS8KPiBTaWduZWQtb2ZmLWJ5OiBHdXN0YXZvIEEuIFIuIFNpbHZhIDxn dXN0YXZvYXJzQGtlcm5lbC5vcmc+CgpUaGFua3MgdGhpcyBmaXhlcyB3YXJuaW5nIHdpdGggZ2Nj LTEyIGluIGlwcm91dGUyLgpJbiBmdW5jdGlvbiDigJh4ZnJtX2FsZ29fcGFyc2XigJksCiAgICBp bmxpbmVkIGZyb20g4oCYeGZybV9zdGF0ZV9tb2RpZnkuY29uc3Rwcm9w4oCZIGF0IHhmcm1fc3Rh dGUuYzo1NzM6NToKeGZybV9zdGF0ZS5jOjE2MjozMjogd2FybmluZzogd3JpdGluZyAxIGJ5dGUg aW50byBhIHJlZ2lvbiBvZiBzaXplIDAgWy1Xc3RyaW5nb3Atb3ZlcmZsb3c9XQogIDE2MiB8ICAg ICAgICAgICAgICAgICAgICAgICAgIGJ1ZltqXSA9IHZhbDsKICAgICAgfCAgICAgICAgICAgICAg ICAgICAgICAgICB+fn5+fn5+Xn5+fn4KCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fCmxpbnV4LWFybS1rZXJuZWwgbWFpbGluZyBsaXN0CmxpbnV4LWFybS1r ZXJuZWxAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWls bWFuL2xpc3RpbmZvL2xpbnV4LWFybS1rZXJuZWwK 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 423F7C43334 for ; Tue, 28 Jun 2022 06:03:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 65AC0113D2F; Tue, 28 Jun 2022 06:03:28 +0000 (UTC) Received: from mail-pg1-x52b.google.com (mail-pg1-x52b.google.com [IPv6:2607:f8b0:4864:20::52b]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7BA7F11B47B for ; Mon, 27 Jun 2022 19:53:47 +0000 (UTC) Received: by mail-pg1-x52b.google.com with SMTP id e63so10057274pgc.5 for ; Mon, 27 Jun 2022 12:53:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=ryYp2naL1201DMNfPmSbpexCs+zqiLsBQDBXHc9esFHxBJ8Ep2LLrsgHtxJtosu2+J 1iBYfvQQXv6NYwKQ2qXQCc4mHXYQGPYeeUC3hu2OgPUPjZXH+3Hi6Zqo5SyTeGerBVQA p1Bh5daOuP6Q9UMRPxlj6vxZpUjBpxOPEYhjttl3pP6gtksJnO1wA5G3ERXmm3iOhFrs MlyYmEaZt8I/cdZ0xlE1RQA9V/oE3k4e+iV7r8nrUlXmSvlRImOQktUmXD254MFh7ceV 2zbWTxt+/QD0MTYLBrv8xqePAliI2A59OkEqXOPrksIatTeOcW53aiRz+65e7KopsoX+ 3osw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=k/l4LcE4w+6LYrCo6/Ek+44r04gbnpHm9yyPA0qKR6A=; b=rBGqHipy+s3HcgtEjuLBajQfcQYJC+k3mWGJZIibF0M6TvZQ4sxJTLct8rLmdvEhSS rCYvgTJGZullrBzeVE82qAotqbpVz2rRdSLYFsdK9ybE3JInqLBY7Kv05x6PlJBCS69b DRtG7zf+hbVjEwoyW5vD6CGvJDnUAL1kNjdX7Ot+xiRkJBD//n7fP1CECgM1I+SS7SsS utM129F/WiVGrSoBkb5/uDl88OY1hzkOUjGguslXOhOnOmZsYJySYF/iD/IqNklBPsWu tQEn8LemYtrV7S3mOiIaieEQ4yeheJFTj3fQcZ/YA0+eAltUI/txyC2LqN8jOWsLuVfU Diyg== X-Gm-Message-State: AJIora9jC7QrdNUkHpzXmLQUWAXyi4vDeqkLDTAoQExhPvljZzq+v3Ye PfBIfNAAV4mYqoqJKXrkxP4HPQ== X-Google-Smtp-Source: AGRyM1ssDeW6Ux1oaY9ixgaaapzXMFszbxcRVeOWaHAYiiaVMZ4HUYtPzqxXzR6I8+fqeJNf8u9hpg== X-Received: by 2002:a63:7a5d:0:b0:40c:fcbe:4799 with SMTP id j29-20020a637a5d000000b0040cfcbe4799mr14428539pgn.297.1656359626928; Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id c16-20020a056a00009000b0051c1b445094sm7821510pfj.7.2022.06.27.12.53.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jun 2022 12:53:46 -0700 (PDT) Date: Mon, 27 Jun 2022 12:53:43 -0700 From: Stephen Hemminger To: "Gustavo A. R. Silva" Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Message-ID: <20220627125343.44e24c41@hermes.local> In-Reply-To: <20220627180432.GA136081@embeddedor> References: <20220627180432.GA136081@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Mailman-Approved-At: Tue, 28 Jun 2022 06:03:27 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nvdimm@lists.linux.dev, alsa-devel@alsa-project.org, kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-hardening@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-stm32@st-md-mailman.stormreply.com, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-rdma@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org, coreteam@netfilter.org, v9fs-developer@lists.sourceforge.net, Kees Cook , intel-gfx@lists.freedesktop.org, linux-can@vger.kernel.org, linux-raid@vger.kernel.org, linux-m68k@lists.linux-m68k.org, virtualization@lists.linux-foundation.org, io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mips@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-sctp@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, 27 Jun 2022 20:04:32 +0200 "Gustavo A. R. Silva" wrote: > There is a regular need in the kernel to provide a way to declare > having a dynamically sized set of trailing elements in a structure. > Kernel code should always use =E2=80=9Cflexible array members=E2=80=9D[1]= for these > cases. The older style of one-element or zero-length arrays should > no longer be used[2]. >=20 > This code was transformed with the help of Coccinelle: > (linux-5.19-rc2$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file scr= ipt.cocci --include-headers --dir . > output.patch) >=20 > @@ > identifier S, member, array; > type T1, T2; > @@ >=20 > struct S { > ... > T1 member; > T2 array[ > - 0 > ]; > }; >=20 > -fstrict-flex-arrays=3D3 is coming and we need to land these changes > to prevent issues like these in the short future: >=20 > ../fs/minix/dir.c:337:3: warning: 'strcpy' will always overflow; destinat= ion buffer has size 0, > but the source string has length 2 (including NUL byte) [-Wfortify-source] > strcpy(de3->name, "."); > ^ >=20 > Since these are all [0] to [] changes, the risk to UAPI is nearly zero. If > this breaks anything, we can use a union with a new member name. >=20 > [1] https://en.wikipedia.org/wiki/Flexible_array_member > [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-le= ngth-and-one-element-arrays >=20 > Link: https://github.com/KSPP/linux/issues/78 > Build-tested-by: https://lore.kernel.org/lkml/62b675ec.wKX6AOZ6cbE71vtF%2= 5lkp@intel.com/ > Signed-off-by: Gustavo A. R. Silva Thanks this fixes warning with gcc-12 in iproute2. In function =E2=80=98xfrm_algo_parse=E2=80=99, inlined from =E2=80=98xfrm_state_modify.constprop=E2=80=99 at xfrm_stat= e.c:573:5: xfrm_state.c:162:32: warning: writing 1 byte into a region of size 0 [-Wstr= ingop-overflow=3D] 162 | buf[j] =3D val; | ~~~~~~~^~~~~