From patchwork Sat May 8 00:50:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 432992 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 F345CC43460 for ; Sat, 8 May 2021 00:50:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCFA46135F for ; Sat, 8 May 2021 00:50:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230185AbhEHAvQ (ORCPT ); Fri, 7 May 2021 20:51:16 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:58654 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229488AbhEHAvP (ORCPT ); Fri, 7 May 2021 20:51:15 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 1480btCP012794 for ; Fri, 7 May 2021 17:50:15 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : content-type : content-transfer-encoding : mime-version; s=facebook; bh=/6dBoZ4Ptb1cVlTcUL9MBk10I9K2L40jILV4exYzOfg=; b=E5H2du6x3ktQSar0F9/zgdfl2n6u1zqQfBE3qTuSg1zakFtDILI9srVGjZyNMDO1m5Bk VozYJalnnzQAJD78QB4jQq1XWuV89lLn5JBs4OgixnuDCMS+fy/bFbGdqVYCM1F2RZoU kTn15iS+Oh7evvnytsogr5RYOmI3FMdmAGY= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 38css568yf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 07 May 2021 17:50:15 -0700 Received: from intmgw002.06.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 7 May 2021 17:50:13 -0700 Received: by devbig005.ftw2.facebook.com (Postfix, from userid 6611) id 484AA29428F7; Fri, 7 May 2021 17:50:11 -0700 (PDT) From: Martin KaFai Lau To: CC: Alexei Starovoitov , Daniel Borkmann , , , =?utf-8?q?Michal_Such=C3=A1nek?= , Jiri Slaby , Jiri Olsa Subject: [PATCH bpf] bpf: Limit static tcp-cc functions in the .BTF_ids list to x86 Date: Fri, 7 May 2021 17:50:11 -0700 Message-ID: <20210508005011.3863757-1-kafai@fb.com> X-Mailer: git-send-email 2.30.2 X-FB-Internal: Safe X-Proofpoint-GUID: QdmpJ4pVLILrkJAWhn9JVG-7j4s265Ye X-Proofpoint-ORIG-GUID: QdmpJ4pVLILrkJAWhn9JVG-7j4s265Ye X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391, 18.0.761 definitions=2021-05-07_10:2021-05-06,2021-05-07 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 mlxscore=0 spamscore=0 malwarescore=0 lowpriorityscore=0 impostorscore=0 priorityscore=1501 mlxlogscore=632 phishscore=0 clxscore=1015 suspectscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2105080001 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org During the discussion in [0]. It was pointed out that static functions in ppc64 is prefixed with ".". For example, the 'readelf -s vmlinux.ppc': 89326: c000000001383280 24 NOTYPE LOCAL DEFAULT 31 cubictcp_init 89327: c000000000c97c50 168 FUNC LOCAL DEFAULT 2 .cubictcp_init The one with FUNC type is ".cubictcp_init" instead of "cubictcp_init". The "." seems to be done by arch/powerpc/include/asm/ppc_asm.h. This caused the pahole cannot generate the BTF for these tcp-cc kernel functions because pahole only captures the FUNC type and "cubictcp_init" is not. It then failed the kernel compilation in ppc64. This behavior is only reported in ppc64 so far. I tried arm64, s390, and sparc64 and did not observe this "." prefix and NOTYPE behavior. Since the kfunc call is only supported in the x86_64 and x86_32 jit, this patch limits those tcp-cc functions to x86 only to avoid unnecessary compilation issue in other ARCHs. In the future, we can examine if it is better to change all those functions from static to extern. [0]: https://lore.kernel.org/bpf/4e051459-8532-7b61-c815-f3435767f8a0@kernel.org/ Fixes: e78aea8b2170 ("bpf: tcp: Put some tcp cong functions in allowlist for bpf-tcp-cc") Cc: Michal Suchánek Cc: Jiri Slaby Cc: Jiri Olsa Signed-off-by: Martin KaFai Lau --- net/ipv4/bpf_tcp_ca.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c index dff4f0eb96b0..9e41eff4a685 100644 --- a/net/ipv4/bpf_tcp_ca.c +++ b/net/ipv4/bpf_tcp_ca.c @@ -185,6 +185,7 @@ BTF_ID(func, tcp_reno_cong_avoid) BTF_ID(func, tcp_reno_undo_cwnd) BTF_ID(func, tcp_slow_start) BTF_ID(func, tcp_cong_avoid_ai) +#ifdef CONFIG_X86 #ifdef CONFIG_DYNAMIC_FTRACE #if IS_BUILTIN(CONFIG_TCP_CONG_CUBIC) BTF_ID(func, cubictcp_init) @@ -213,6 +214,7 @@ BTF_ID(func, bbr_min_tso_segs) BTF_ID(func, bbr_set_state) #endif #endif /* CONFIG_DYNAMIC_FTRACE */ +#endif /* CONFIG_X86 */ BTF_SET_END(bpf_tcp_ca_kfunc_ids) static bool bpf_tcp_ca_check_kfunc_call(u32 kfunc_btf_id)