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=-5.6 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, TRACKER_ID 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 F0370C4321A for ; Tue, 11 Jun 2019 17:41:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7E252063F for ; Tue, 11 Jun 2019 17:41:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406104AbfFKRlj (ORCPT ); Tue, 11 Jun 2019 13:41:39 -0400 Received: from gateway20.websitewelcome.com ([192.185.70.14]:33537 "EHLO gateway20.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406539AbfFKRlj (ORCPT ); Tue, 11 Jun 2019 13:41:39 -0400 Received: from cm12.websitewelcome.com (cm12.websitewelcome.com [100.42.49.8]) by gateway20.websitewelcome.com (Postfix) with ESMTP id 768D3400D0A99 for ; Tue, 11 Jun 2019 11:40:37 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id akmAh6rcSiQerakmAhevVd; Tue, 11 Jun 2019 12:41:38 -0500 X-Authority-Reason: nr=8 Received: from [189.250.75.107] (port=55914 helo=[192.168.1.76]) by gator4166.hostgator.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.92) (envelope-from ) id 1hakm9-001IDy-KE; Tue, 11 Jun 2019 12:41:37 -0500 Subject: Re: [PATCH] bpf: verifier: avoid fall-through warnings From: "Gustavo A. R. Silva" To: Andrii Nakryiko Cc: Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Lawrence Brakmo , Networking , bpf , open list , Kees Cook References: <20190611132811.GA27212@embeddedor> <4acbc6b9-e2aa-02d3-0e99-f641b67a3da3@embeddedor.com> Openpgp: preference=signencrypt Autocrypt: addr=gustavo@embeddedor.com; keydata= mQINBFssHAwBEADIy3ZoPq3z5UpsUknd2v+IQud4TMJnJLTeXgTf4biSDSrXn73JQgsISBwG 2Pm4wnOyEgYUyJd5tRWcIbsURAgei918mck3tugT7AQiTUN3/5aAzqe/4ApDUC+uWNkpNnSV tjOx1hBpla0ifywy4bvFobwSh5/I3qohxDx+c1obd8Bp/B/iaOtnq0inli/8rlvKO9hp6Z4e DXL3PlD0QsLSc27AkwzLEc/D3ZaqBq7ItvT9Pyg0z3Q+2dtLF00f9+663HVC2EUgP25J3xDd 496SIeYDTkEgbJ7WYR0HYm9uirSET3lDqOVh1xPqoy+U9zTtuA9NQHVGk+hPcoazSqEtLGBk YE2mm2wzX5q2uoyptseSNceJ+HE9L+z1KlWW63HhddgtRGhbP8pj42bKaUSrrfDUsicfeJf6 m1iJRu0SXYVlMruGUB1PvZQ3O7TsVfAGCv85pFipdgk8KQnlRFkYhUjLft0u7CL1rDGZWDDr NaNj54q2CX9zuSxBn9XDXvGKyzKEZ4NY1Jfw+TAMPCp4buawuOsjONi2X0DfivFY+ZsjAIcx qQMglPtKk/wBs7q2lvJ+pHpgvLhLZyGqzAvKM1sVtRJ5j+ARKA0w4pYs5a5ufqcfT7dN6TBk LXZeD9xlVic93Ju08JSUx2ozlcfxq+BVNyA+dtv7elXUZ2DrYwARAQABtCxHdXN0YXZvIEEu IFIuIFNpbHZhIDxndXN0YXZvQGVtYmVkZGVkb3IuY29tPokCPQQTAQgAJwUCWywcDAIbIwUJ CWYBgAULCQgHAgYVCAkKCwIEFgIDAQIeAQIXgAAKCRBHBbTLRwbbMZ6tEACk0hmmZ2FWL1Xi l/bPqDGFhzzexrdkXSfTTZjBV3a+4hIOe+jl6Rci/CvRicNW4H9yJHKBrqwwWm9fvKqOBAg9 obq753jydVmLwlXO7xjcfyfcMWyx9QdYLERTeQfDAfRqxir3xMeOiZwgQ6dzX3JjOXs6jHBP cgry90aWbaMpQRRhaAKeAS14EEe9TSIly5JepaHoVdASuxklvOC0VB0OwNblVSR2S5i5hSsh ewbOJtwSlonsYEj4EW1noQNSxnN/vKuvUNegMe+LTtnbbocFQ7dGMsT3kbYNIyIsp42B5eCu JXnyKLih7rSGBtPgJ540CjoPBkw2mCfhj2p5fElRJn1tcX2McsjzLFY5jK9RYFDavez5w3lx JFgFkla6sQHcrxH62gTkb9sUtNfXKucAfjjCMJ0iuQIHRbMYCa9v2YEymc0k0RvYr43GkA3N PJYd/vf9vU7VtZXaY4a/dz1d9dwIpyQARFQpSyvt++R74S78eY/+lX8wEznQdmRQ27kq7BJS R20KI/8knhUNUJR3epJu2YFT/JwHbRYC4BoIqWl+uNvDf+lUlI/D1wP+lCBSGr2LTkQRoU8U 64iK28BmjJh2K3WHmInC1hbUucWT7Swz/+6+FCuHzap/cjuzRN04Z3Fdj084oeUNpP6+b9yW e5YnLxF8ctRAp7K4yVlvA7kCDQRbLBwMARAAsHCE31Ffrm6uig1BQplxMV8WnRBiZqbbsVJB H1AAh8tq2ULl7udfQo1bsPLGGQboJSVN9rckQQNahvHAIK8ZGfU4Qj8+CER+fYPp/MDZj+t0 DbnWSOrG7z9HIZo6PR9z4JZza3Hn/35jFggaqBtuydHwwBANZ7A6DVY+W0COEU4of7CAahQo 5NwYiwS0lGisLTqks5R0Vh+QpvDVfuaF6I8LUgQR/cSgLkR//V1uCEQYzhsoiJ3zc1HSRyOP otJTApqGBq80X0aCVj1LOiOF4rrdvQnj6iIlXQssdb+WhSYHeuJj1wD0ZlC7ds5zovXh+FfF l5qH5RFY/qVn3mNIVxeO987WSF0jh+T5ZlvUNdhedGndRmwFTxq2Li6GNMaolgnpO/CPcFpD jKxY/HBUSmaE9rNdAa1fCd4RsKLlhXda+IWpJZMHlmIKY8dlUybP+2qDzP2lY7kdFgPZRU+e zS/pzC/YTzAvCWM3tDgwoSl17vnZCr8wn2/1rKkcLvTDgiJLPCevqpTb6KFtZosQ02EGMuHQ I6Zk91jbx96nrdsSdBLGH3hbvLvjZm3C+fNlVb9uvWbdznObqcJxSH3SGOZ7kCHuVmXUcqoz ol6ioMHMb+InrHPP16aVDTBTPEGwgxXI38f7SUEn+NpbizWdLNz2hc907DvoPm6HEGCanpcA EQEAAYkCJQQYAQgADwUCWywcDAIbDAUJCWYBgAAKCRBHBbTLRwbbMdsZEACUjmsJx2CAY+QS UMebQRFjKavwXB/xE7fTt2ahuhHT8qQ/lWuRQedg4baInw9nhoPE+VenOzhGeGlsJ0Ys52sd XvUjUocKgUQq6ekOHbcw919nO5L9J2ejMf/VC/quN3r3xijgRtmuuwZjmmi8ct24TpGeoBK4 WrZGh/1hAYw4ieARvKvgjXRstcEqM5thUNkOOIheud/VpY+48QcccPKbngy//zNJWKbRbeVn imua0OpqRXhCrEVm/xomeOvl1WK1BVO7z8DjSdEBGzbV76sPDJb/fw+y+VWrkEiddD/9CSfg fBNOb1p1jVnT2mFgGneIWbU0zdDGhleI9UoQTr0e0b/7TU+Jo6TqwosP9nbk5hXw6uR5k5PF 8ieyHVq3qatJ9K1jPkBr8YWtI5uNwJJjTKIA1jHlj8McROroxMdI6qZ/wZ1ImuylpJuJwCDC ORYf5kW61fcrHEDlIvGc371OOvw6ejF8ksX5+L2zwh43l/pKkSVGFpxtMV6d6J3eqwTafL86 YJWH93PN+ZUh6i6Rd2U/i8jH5WvzR57UeWxE4P8bQc0hNGrUsHQH6bpHV2lbuhDdqo+cM9eh GZEO3+gCDFmKrjspZjkJbB5Gadzvts5fcWGOXEvuT8uQSvl+vEL0g6vczsyPBtqoBLa9SNrS VtSixD1uOgytAP7RWS474w== Message-ID: <07450b27-5c09-2156-e6ee-921fef174c78@embeddedor.com> Date: Tue, 11 Jun 2019 12:41:35 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <4acbc6b9-e2aa-02d3-0e99-f641b67a3da3@embeddedor.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.250.75.107 X-Source-L: No X-Exim-ID: 1hakm9-001IDy-KE X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: ([192.168.1.76]) [189.250.75.107]:55914 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 21 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/11/19 12:27 PM, Gustavo A. R. Silva wrote: > > > On 6/11/19 12:22 PM, Andrii Nakryiko wrote: >> On Tue, Jun 11, 2019 at 7:05 AM Gustavo A. R. Silva >> wrote: >>> >>> In preparation to enabling -Wimplicit-fallthrough, this patch silences >>> the following warning: >> >> Your patch doesn't apply cleanly to neither bpf nor bpf-next tree. >> Could you please rebase and re-submit? Please also include which tree >> (probably bpf-next) you are designating this patch to in subject >> prefix. >> > > This patch applies cleanly to linux-next (tag next-20190611). > It seems that this commit hasn't been merged into bpf/bpf-next yet: 983695fa676568fc0fe5ddd995c7267aabc24632 -- Gustavo >>> >>> kernel/bpf/verifier.c: In function ‘check_return_code’: >>> kernel/bpf/verifier.c:5509:6: warning: this statement may fall through [-Wimplicit-fallthrough=] >>> if (env->prog->expected_attach_type == BPF_CGROUP_UDP4_RECVMSG || >>> ^ >>> kernel/bpf/verifier.c:5512:2: note: here >>> case BPF_PROG_TYPE_CGROUP_SKB: >>> ^~~~ >>> >>> Warning level 3 was used: -Wimplicit-fallthrough=3 >>> >>> Notice that it's much clearer to explicitly add breaks in each case >>> (that actually contains some code), rather than letting the code to >>> fall through. >>> >>> This patch is part of the ongoing efforts to enable >>> -Wimplicit-fallthrough. >>> >>> Signed-off-by: Gustavo A. R. Silva >>> --- >>> kernel/bpf/verifier.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c >>> index 1e9d10b32984..e9fc28991548 100644 >>> --- a/kernel/bpf/verifier.c >>> +++ b/kernel/bpf/verifier.c >>> @@ -5509,11 +5509,13 @@ static int check_return_code(struct bpf_verifier_env *env) >>> if (env->prog->expected_attach_type == BPF_CGROUP_UDP4_RECVMSG || >>> env->prog->expected_attach_type == BPF_CGROUP_UDP6_RECVMSG) >>> range = tnum_range(1, 1); >>> + break; >>> case BPF_PROG_TYPE_CGROUP_SKB: >>> if (env->prog->expected_attach_type == BPF_CGROUP_INET_EGRESS) { >>> range = tnum_range(0, 3); >>> enforce_attach_type_range = tnum_range(2, 3); >>> } >>> + break; >>> case BPF_PROG_TYPE_CGROUP_SOCK: >>> case BPF_PROG_TYPE_SOCK_OPS: >>> case BPF_PROG_TYPE_CGROUP_DEVICE: >>> -- >>> 2.21.0 >>>