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 7BE05134B3 for ; Mon, 26 Jun 2023 18:11:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B96FC433C8; Mon, 26 Jun 2023 18:11:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1687803095; bh=2U52dcWmqtT+N7qp8s667kFTtabBWUvZfK1aeU1/FE8=; h=From:To:Cc:Subject:Date:From; b=elzxVr08Xovc7Dg1NIDcPOJEwiTpTvW8iJxSpC8bvAMtqRAbW3nRD17TFPtBZNiLO 6ITijiI5XIuwMaHoB20aLVj/oQdhZrrRCn+i+LqN4h4RPHoQTp273MzXv2kh9g/xw3 VC4sZyY1sCRz4r6rRi6DlPVNU+ohBOGgiApkJnS72iQ8a7dWgVZuoKFYA4cqWaQpst RVyKrk27vo+rH9LXtBvQp3pc63wSOxpewfgB1ElwAVuPwVDOOjrLhNfk1UVTl84t1s zp/OL48ZW7d9OuvUPM6mChk3Sgapg+64aMs+DhZXn5CWmix/+wRquRTAJJNiHrcBCu J7yY4Nmsvnkgg== From: SeongJae Park To: martin.lau@linux.dev Cc: ast@kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, SeongJae Park , Alexander Egorenkov , Kumar Kartikeya Dwivedi , stable@vger.kernel.org Subject: [PATCH] btf: warn but return no error for NULL btf from __register_btf_kfunc_id_set() Date: Mon, 26 Jun 2023 18:11:20 +0000 Message-Id: <20230626181120.7086-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit __register_btf_kfunc_id_set() assumes .BTF to be part of the module's .ko file if CONFIG_DEBUG_INFO_BTF is enabled. If that's not the case, the function prints an error message and return an error. As a result, such modules cannot be loaded. However, the section could be stripped out during a build process. It would be better to let the modules loaded, because their basic functionalities have no problem[1], though the BTF functionalities will not be supported. Make the function to lower the level of the message from error to warn, and return no error. [1] https://lore.kernel.org/bpf/20220219082037.ow2kbq5brktf4f2u@apollo.legion/ Reported-by: Alexander Egorenkov Link: https://lore.kernel.org/bpf/87y228q66f.fsf@oc8242746057.ibm.com/ Suggested-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/bpf/20220219082037.ow2kbq5brktf4f2u@apollo.legion/ Fixes: dee872e124e8 ("bpf: Populate kfunc BTF ID sets in struct btf") Cc: # 5.17.x Signed-off-by: SeongJae Park --- kernel/bpf/btf.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 6b682b8e4b50..d683f034996f 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -7848,14 +7848,10 @@ static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook, btf = btf_get_module_btf(kset->owner); if (!btf) { - if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) { - pr_err("missing vmlinux BTF, cannot register kfuncs\n"); - return -ENOENT; - } - if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) { - pr_err("missing module BTF, cannot register kfuncs\n"); - return -ENOENT; - } + if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) + pr_warn("missing vmlinux BTF, cannot register kfuncs\n"); + if (kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF_MODULES)) + pr_warn("missing module BTF, cannot register kfuncs\n"); return 0; } if (IS_ERR(btf)) -- 2.25.1