From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E07406FAE; Wed, 1 Nov 2023 08:25:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="H+EfT11F" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE7FEC433C7; Wed, 1 Nov 2023 08:25:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698827146; bh=yFVtjEK6MAAB7vMXEvUnFtsjPel4TJMN6k8Ko8VXdYs=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=H+EfT11FBVdWRjAfeYkOnUaRHnTJepVNb5nikvZ26s+2qtK3y703T79U7MvmnrmF2 ZlcsraE72qoE3Uy6DpNUBlvnWhtZX21/hweezd934PF0SVpcJlo//becBi2Y03TdSq JNIHPs3PP1SF/ua9iAUYzitWUPRcslT3VuHs3KX2U8tTxgzfFcu13Jd4sWSX56Afmq uXsahwZaUXj7YVmpAd5RSS6SPsAuS0opg3CIJQ3D9tvxEgn9MItedOmQskZd7fLoeg 7WaMqGRTfheQriy6+wtkm9I9q28wtTbbBiKNaKR437HxxnejFXD7FXw/bl9vFSXiuU g0XwNSRHsK/9A== Message-ID: <9aad3bb9-daca-405a-93c3-dccea3c0a07a@kernel.org> Date: Wed, 1 Nov 2023 09:25:34 +0100 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH bpf-next] bpf: fix compilation error without CGROUPS Content-Language: en-GB, fr-BE To: Jiri Olsa , Alexei Starovoitov Cc: Yonghong Song , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Chuyi Zhou , Tejun Heo , bpf , LKML , MPTCP Upstream , kernel test robot References: <20231031-bpf-compil-err-css-v1-1-e2244c637835@kernel.org> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Jirka, Alexei, On 01/11/2023 08:25, Jiri Olsa wrote: > On Tue, Oct 31, 2023 at 08:54:56PM -0700, Alexei Starovoitov wrote: >> On Tue, Oct 31, 2023 at 10:05 AM Jiri Olsa wrote: >>> >>> On Tue, Oct 31, 2023 at 04:49:34PM +0100, Matthieu Baerts wrote: >>>> Our MPTCP CI complained [1] -- and KBuild too -- that it was no longer >>>> possible to build the kernel without CONFIG_CGROUPS: >>>> >>>> kernel/bpf/task_iter.c: In function 'bpf_iter_css_task_new': >>>> kernel/bpf/task_iter.c:919:14: error: 'CSS_TASK_ITER_PROCS' undeclared (first use in this function) >>>> 919 | case CSS_TASK_ITER_PROCS | CSS_TASK_ITER_THREADED: >>>> | ^~~~~~~~~~~~~~~~~~~ >>>> kernel/bpf/task_iter.c:919:14: note: each undeclared identifier is reported only once for each function it appears in >>>> kernel/bpf/task_iter.c:919:36: error: 'CSS_TASK_ITER_THREADED' undeclared (first use in this function) >>>> 919 | case CSS_TASK_ITER_PROCS | CSS_TASK_ITER_THREADED: >>>> | ^~~~~~~~~~~~~~~~~~~~~~ >>>> kernel/bpf/task_iter.c:927:60: error: invalid application of 'sizeof' to incomplete type 'struct css_task_iter' >>>> 927 | kit->css_it = bpf_mem_alloc(&bpf_global_ma, sizeof(struct css_task_iter)); >>>> | ^~~~~~ >>>> kernel/bpf/task_iter.c:930:9: error: implicit declaration of function 'css_task_iter_start'; did you mean 'task_seq_start'? [-Werror=implicit-function-declaration] >>>> 930 | css_task_iter_start(css, flags, kit->css_it); >>>> | ^~~~~~~~~~~~~~~~~~~ >>>> | task_seq_start >>>> kernel/bpf/task_iter.c: In function 'bpf_iter_css_task_next': >>>> kernel/bpf/task_iter.c:940:16: error: implicit declaration of function 'css_task_iter_next'; did you mean 'class_dev_iter_next'? [-Werror=implicit-function-declaration] >>>> 940 | return css_task_iter_next(kit->css_it); >>>> | ^~~~~~~~~~~~~~~~~~ >>>> | class_dev_iter_next >>>> kernel/bpf/task_iter.c:940:16: error: returning 'int' from a function with return type 'struct task_struct *' makes pointer from integer without a cast [-Werror=int-conversion] >>>> 940 | return css_task_iter_next(kit->css_it); >>>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>>> kernel/bpf/task_iter.c: In function 'bpf_iter_css_task_destroy': >>>> kernel/bpf/task_iter.c:949:9: error: implicit declaration of function 'css_task_iter_end' [-Werror=implicit-function-declaration] >>>> 949 | css_task_iter_end(kit->css_it); >>>> | ^~~~~~~~~~~~~~~~~ >>>> >>>> This patch simply surrounds with a #ifdef the new code requiring CGroups >>>> support. It seems enough for the compiler and this is similar to >>>> bpf_iter_css_{new,next,destroy}() functions where no other #ifdef have >>>> been added in kernel/bpf/helpers.c and in the selftests. >>>> >>>> Fixes: 9c66dc94b62a ("bpf: Introduce css_task open-coded iterator kfuncs") >>>> Link: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/6665206927 >>>> Reported-by: kernel test robot >>>> Closes: https://lore.kernel.org/oe-kbuild-all/202310260528.aHWgVFqq-lkp@intel.com/ >>>> Signed-off-by: Matthieu Baerts >>> >>> Acked/Tested-by: Jiri Olsa >> >> I believe this patch has the same issue as Arnd's patch: >> https://lore.kernel.org/all/CAADnVQL-zoFPPOVu3nM981gKxRu7Q3G3LTRsKstJEeahpoR1RQ@mail.gmail.com/ @Alexei: Arf, sorry, I didn't find this patch when searching for "9c66dc94b62a" on lore. I don't know why I didn't search for the commit title as usual... >> I'd like to merge the fix asap. Please make it a complete fix. > > ugh, it won't fail the build, it just warns.. I think we should > fail the build in that case, I'll check @Jirka: Thank you for checking that! Please tell me if you want me to send a v2 or if you prefer to do that. I don't mind if you prefer to send your own patches, as long as there is a fix for that at the end :) Note that if a warning is emitted for these new bpf_iter_css_task_*() functions, I guess you will have the same issue with bpf_iter_css_*() and probably others as mentioned in my commit message. Cheers, Matt