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 1A3A8C7EE30 for ; Thu, 2 Mar 2023 23:50:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230137AbjCBXus convert rfc822-to-8bit (ORCPT ); Thu, 2 Mar 2023 18:50:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229947AbjCBXur (ORCPT ); Thu, 2 Mar 2023 18:50:47 -0500 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2202931E1A for ; Thu, 2 Mar 2023 15:50:47 -0800 (PST) Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 322N7Bgb022501 for ; Thu, 2 Mar 2023 15:50:47 -0800 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3p2xg6kncd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Thu, 02 Mar 2023 15:50:46 -0800 Received: from twshared37576.17.prn3.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:21d::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.17; Thu, 2 Mar 2023 15:50:46 -0800 Received: by devbig019.vll3.facebook.com (Postfix, from userid 137359) id 178A3291B7F0F; Thu, 2 Mar 2023 15:50:43 -0800 (PST) From: Andrii Nakryiko To: , , CC: , , Tejun Heo Subject: [PATCH bpf-next 12/17] bpf: add support for fixed-size memory pointer returns for kfuncs Date: Thu, 2 Mar 2023 15:50:10 -0800 Message-ID: <20230302235015.2044271-13-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230302235015.2044271-1-andrii@kernel.org> References: <20230302235015.2044271-1-andrii@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-GUID: exlutigjBeive7D-cVZw-zCgCvz_bbaW X-Proofpoint-ORIG-GUID: exlutigjBeive7D-cVZw-zCgCvz_bbaW X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.219,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-03-02_15,2023-03-02_02,2023-02-09_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Support direct fixed-size (and for now, read-only) memory access when kfunc's return type is a pointer to non-struct type. Calculate type size and let BPF program access that many bytes directly. This is crucial for numbers iterator. Signed-off-by: Andrii Nakryiko --- kernel/bpf/verifier.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 641a36204493..0ff9dd9170ef 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -10241,6 +10241,14 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, return -EFAULT; } } else if (!__btf_type_is_struct(ptr_type)) { + if (!meta.r0_size) { + __u32 sz; + + if (!IS_ERR(btf_resolve_size(desc_btf, ptr_type, &sz))) { + meta.r0_size = sz; + meta.r0_rdonly = true; + } + } if (!meta.r0_size) { ptr_type_name = btf_name_by_offset(desc_btf, ptr_type->name_off); -- 2.30.2