From patchwork Sat Jul 11 21:53:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 1327404 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B43Zl6BcXz9sRK for ; Sun, 12 Jul 2020 07:53:51 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728178AbgGKVxu convert rfc822-to-8bit (ORCPT ); Sat, 11 Jul 2020 17:53:50 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:53174 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728055AbgGKVxr (ORCPT ); Sat, 11 Jul 2020 17:53:47 -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-440-UMkMTqfOMFu274MuJD3IgA-1; Sat, 11 Jul 2020 17:53:42 -0400 X-MC-Unique: UMkMTqfOMFu274MuJD3IgA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A5EBC106B242; Sat, 11 Jul 2020 21:53:41 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.192.15]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3E82B60BEC; Sat, 11 Jul 2020 21:53:40 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH v7 bpf-next 5/9] bpf: Remove btf_id helpers resolving Date: Sat, 11 Jul 2020 23:53:25 +0200 Message-Id: <20200711215329.41165-6-jolsa@kernel.org> In-Reply-To: <20200711215329.41165-1-jolsa@kernel.org> References: <20200711215329.41165-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org 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. Acked-by: Andrii Nakryiko Tested-by: Andrii Nakryiko Signed-off-by: Jiri Olsa --- kernel/bpf/btf.c | 89 +++--------------------------------------------- 1 file changed, 5 insertions(+), 84 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 4c3007f428b1..71140b73ae3c 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -4079,96 +4079,17 @@ 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) -{ - 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; - - if (IS_ERR(btf_vmlinux)) { - bpf_log(log, "btf_vmlinux is malformed\n"); - 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); - 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; -} - 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; + int id; if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID) 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; + id = fn->btf_id[arg]; + if (!id || id > btf_vmlinux->nr_types) + return -EINVAL; + return id; } static int __get_type_size(struct btf *btf, u32 btf_id,