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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 DF4FFC433DF for ; Thu, 25 Jun 2020 22:13:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD44820789 for ; Thu, 25 Jun 2020 22:13:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593123220; bh=0sqmfk2W1VdNCpj7yW0sVFmgI9pHEybqElJ4Rcuk2c8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=np1OJlKewH/C90y/QsTPfY88a9JPOma13N78j90QthuCHaljEtoEju8IUGyjFkUfw eqyQ0RtNyg0Oe8liQFr0ymIQmcBWwZY/gLY2cxkD+Dd/xv6SMQ4v7FcRPBeHjHIJ+k 27JYseaFxs23E6en1GykXZVAP5EOiv5Q6mVA9Xfg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436485AbgFYWNj convert rfc822-to-8bit (ORCPT ); Thu, 25 Jun 2020 18:13:39 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:44404 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2407480AbgFYWNi (ORCPT ); Thu, 25 Jun 2020 18:13:38 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-6-W0LM_0PoNwevIUSnuep6bA-1; Thu, 25 Jun 2020 18:13:33 -0400 X-MC-Unique: W0LM_0PoNwevIUSnuep6bA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5B3E81005512; Thu, 25 Jun 2020 22:13:31 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.192.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id A27C679303; Thu, 25 Jun 2020 22:13:27 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , Martin KaFai Lau , David Miller , John Fastabend , Wenbo Zhang , KP Singh , Andrii Nakryiko , Brendan Gregg , Florent Revest , Al Viro Subject: [PATCH v4 bpf-next 05/14] bpf: Remove btf_id helpers resolving Date: Fri, 26 Jun 2020 00:12:55 +0200 Message-Id: <20200625221304.2817194-6-jolsa@kernel.org> In-Reply-To: <20200625221304.2817194-1-jolsa@kernel.org> References: <20200625221304.2817194-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jolsa@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Now when we moved the helpers btf_id arrays into .BTF_ids section, we can remove the code that resolve those IDs in runtime. Signed-off-by: Jiri Olsa --- kernel/bpf/btf.c | 90 +++++------------------------------------------- 1 file changed, 8 insertions(+), 82 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 4c3007f428b1..4da6b0770ff9 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -4079,96 +4079,22 @@ int btf_struct_access(struct bpf_verifier_log *log, return -EINVAL; } -static int __btf_resolve_helper_id(struct bpf_verifier_log *log, void *fn, - int arg) +int btf_resolve_helper_id(struct bpf_verifier_log *log, + const struct bpf_func_proto *fn, int arg) { - char fnname[KSYM_SYMBOL_LEN + 4] = "btf_"; - const struct btf_param *args; - const struct btf_type *t; - const char *tname, *sym; - u32 btf_id, i; + int id; - if (IS_ERR(btf_vmlinux)) { - bpf_log(log, "btf_vmlinux is malformed\n"); + if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID) return -EINVAL; - } - - sym = kallsyms_lookup((long)fn, NULL, NULL, NULL, fnname + 4); - if (!sym) { - bpf_log(log, "kernel doesn't have kallsyms\n"); - return -EFAULT; - } - for (i = 1; i <= btf_vmlinux->nr_types; i++) { - t = btf_type_by_id(btf_vmlinux, i); - if (BTF_INFO_KIND(t->info) != BTF_KIND_TYPEDEF) - continue; - tname = __btf_name_by_offset(btf_vmlinux, t->name_off); - if (!strcmp(tname, fnname)) - break; - } - if (i > btf_vmlinux->nr_types) { - bpf_log(log, "helper %s type is not found\n", fnname); - return -ENOENT; - } - - t = btf_type_by_id(btf_vmlinux, t->type); - if (!btf_type_is_ptr(t)) - return -EFAULT; - t = btf_type_by_id(btf_vmlinux, t->type); - if (!btf_type_is_func_proto(t)) - return -EFAULT; - - args = (const struct btf_param *)(t + 1); - if (arg >= btf_type_vlen(t)) { - bpf_log(log, "bpf helper %s doesn't have %d-th argument\n", - fnname, arg); + if (WARN_ON_ONCE(!fn->btf_id)) return -EINVAL; - } - t = btf_type_by_id(btf_vmlinux, args[arg].type); - if (!btf_type_is_ptr(t) || !t->type) { - /* anything but the pointer to struct is a helper config bug */ - bpf_log(log, "ARG_PTR_TO_BTF is misconfigured\n"); - return -EFAULT; - } - btf_id = t->type; - t = btf_type_by_id(btf_vmlinux, t->type); - /* skip modifiers */ - while (btf_type_is_modifier(t)) { - btf_id = t->type; - t = btf_type_by_id(btf_vmlinux, t->type); - } - if (!btf_type_is_struct(t)) { - bpf_log(log, "ARG_PTR_TO_BTF is not a struct\n"); - return -EFAULT; - } - bpf_log(log, "helper %s arg%d has btf_id %d struct %s\n", fnname + 4, - arg, btf_id, __btf_name_by_offset(btf_vmlinux, t->name_off)); - return btf_id; -} + id = fn->btf_id[arg]; -int btf_resolve_helper_id(struct bpf_verifier_log *log, - const struct bpf_func_proto *fn, int arg) -{ - int *btf_id = &fn->btf_id[arg]; - int ret; - - if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID) + if (!id || id > btf_vmlinux->nr_types) return -EINVAL; - - ret = READ_ONCE(*btf_id); - if (ret) - return ret; - /* ok to race the search. The result is the same */ - ret = __btf_resolve_helper_id(log, fn->func, arg); - if (!ret) { - /* Function argument cannot be type 'void' */ - bpf_log(log, "BTF resolution bug\n"); - return -EFAULT; - } - WRITE_ONCE(*btf_id, ret); - return ret; + return id; } static int __get_type_size(struct btf *btf, u32 btf_id, -- 2.25.4