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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 7DFD1C43460 for ; Sat, 8 May 2021 03:49:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 62FC261106 for ; Sat, 8 May 2021 03:49:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231160AbhEHDuC (ORCPT ); Fri, 7 May 2021 23:50:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231153AbhEHDuB (ORCPT ); Fri, 7 May 2021 23:50:01 -0400 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B002C061574 for ; Fri, 7 May 2021 20:49:00 -0700 (PDT) Received: by mail-pf1-x42c.google.com with SMTP id a5so2227840pfa.11 for ; Fri, 07 May 2021 20:49:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=y+0bajeKnpUKeB1pFAPp4noxdFqa3DUCLHKzbgOGDnI=; b=goCL3ksFi3/TTS5U3EzFqv6O8XajWUFDx763w9/emlvHTGftAsoYc9d/BodIOZAbjc M02m4QmBk1V3+IZgwll2MfXdZWKViGZ3oZcAzZVkL7ica4aYKPaslBsn/vTpUPAvKOHE nVRePw1c9kvMdZIzGlmAi+szecyTa+1y3neKmc3lGzzi9KLdYynFVu0g8mBaFRDrF3SN JPkRA7zvWaAO1UMKVDTBwQ8JQY2NbB9NT8LzK940gUFV86VtzGlH6kDvaEBxi7jwqtCr jPDn07SoIlwHzseeqnatW/KXP/XaNqf/HL8gAp6lh6G3pzDqBGyEYBtsop9smnPLSICQ hcYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=y+0bajeKnpUKeB1pFAPp4noxdFqa3DUCLHKzbgOGDnI=; b=fN2piEH9wQTHTUdwqQcrVYk49oyIwl6ZcvfigX8DPVBUkPG3nnMSl+FQ+Zzlf7OE8r VYsVxhdA8KjzQxW4tOEh7fERBfTap3di4OFKSaHfWqqGNWDDtkHAdQZzKrm4HuQ6QrTb omyrZIq3RQ6XKqugUXo58K/VKa/aHmZbCN5V0dpdavVaUwion8ILCAWyKqof2pj8zNHy 00aJFJACOhh1Dnb+qT0gPvgKvGpdnTdK6frNgS8iUYIePy1vGzfXDzJHy6GU6DmRtk5G eD0PHU/EUcuPnOOCiEraX5W/v8dTotHlSowHump83rKSIisBERFiVxufowkWrMeaXGTf Z3Fw== X-Gm-Message-State: AOAM533x7FDVtnLwB3w/hwZpnx5Fg+dPpJEHU+vPKf7L7C65fAzrTWqz GTTghdP7j2TgzC7Y4rBSaqhlS1h5hrM= X-Google-Smtp-Source: ABdhPJx1TP301IhcZhbnRtfO48aH9JqaqunxNwWm77sBI8HScoEfeYZ2Sc3NM+5+e3Vf1/iQs4ynjw== X-Received: by 2002:a63:ff66:: with SMTP id s38mr13422863pgk.154.1620445739688; Fri, 07 May 2021 20:48:59 -0700 (PDT) Received: from ast-mbp.thefacebook.com ([163.114.132.1]) by smtp.gmail.com with ESMTPSA id u12sm5784606pfh.122.2021.05.07.20.48.57 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 07 May 2021 20:48:59 -0700 (PDT) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, andrii@kernel.org, john.fastabend@gmail.com, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v4 bpf-next 10/22] bpf: Add bpf_btf_find_by_name_kind() helper. Date: Fri, 7 May 2021 20:48:25 -0700 Message-Id: <20210508034837.64585-11-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20210508034837.64585-1-alexei.starovoitov@gmail.com> References: <20210508034837.64585-1-alexei.starovoitov@gmail.com> Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Alexei Starovoitov Add new helper: long bpf_btf_find_by_name_kind(char *name, int name_sz, u32 kind, int flags) Description Find BTF type with given name and kind in vmlinux BTF or in module's BTFs. Return Returns btf_id and btf_obj_fd in lower and upper 32 bits. It will be used by loader program to find btf_id to attach the program to and to find btf_ids of ksyms. Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 7 ++++ kernel/bpf/btf.c | 62 ++++++++++++++++++++++++++++++++++ kernel/bpf/syscall.c | 2 ++ tools/include/uapi/linux/bpf.h | 7 ++++ 5 files changed, 79 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 7fd53380c981..9dc44ba97584 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1974,6 +1974,7 @@ extern const struct bpf_func_proto bpf_get_socket_ptr_cookie_proto; extern const struct bpf_func_proto bpf_task_storage_get_proto; extern const struct bpf_func_proto bpf_task_storage_delete_proto; extern const struct bpf_func_proto bpf_for_each_map_elem_proto; +extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index de58a714ed36..3cc07351c1cf 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4748,6 +4748,12 @@ union bpf_attr { * Execute bpf syscall with given arguments. * Return * A syscall result. + * + * long bpf_btf_find_by_name_kind(char *name, int name_sz, u32 kind, int flags) + * Description + * Find BTF type with given name and kind in vmlinux BTF or in module's BTFs. + * Return + * Returns btf_id and btf_obj_fd in lower and upper 32 bits. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -4917,6 +4923,7 @@ union bpf_attr { FN(for_each_map_elem), \ FN(snprintf), \ FN(sys_bpf), \ + FN(btf_find_by_name_kind), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index fbf6c06a9d62..85716327c375 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6085,3 +6085,65 @@ struct module *btf_try_get_module(const struct btf *btf) return res; } + +BPF_CALL_4(bpf_btf_find_by_name_kind, char *, name, int, name_sz, u32, kind, int, flags) +{ + struct btf *btf; + long ret; + + if (flags) + return -EINVAL; + + if (name_sz <= 1 || name[name_sz - 1]) + return -EINVAL; + + btf = bpf_get_btf_vmlinux(); + if (IS_ERR(btf)) + return PTR_ERR(btf); + + ret = btf_find_by_name_kind(btf, name, kind); + /* ret is never zero, since btf_find_by_name_kind returns + * positive btf_id or negative error. + */ + if (ret < 0) { + struct btf *mod_btf; + int id; + + /* If name is not found in vmlinux's BTF then search in module's BTFs */ + spin_lock_bh(&btf_idr_lock); + idr_for_each_entry(&btf_idr, mod_btf, id) { + if (!btf_is_module(mod_btf)) + continue; + /* linear search could be slow hence unlock/lock + * the IDR to avoiding holding it for too long + */ + btf_get(mod_btf); + spin_unlock_bh(&btf_idr_lock); + ret = btf_find_by_name_kind(mod_btf, name, kind); + if (ret > 0) { + int btf_obj_fd; + + btf_obj_fd = __btf_new_fd(mod_btf); + if (btf_obj_fd < 0) { + btf_put(mod_btf); + return btf_obj_fd; + } + return ret | (((u64)btf_obj_fd) << 32); + } + spin_lock_bh(&btf_idr_lock); + btf_put(mod_btf); + } + spin_unlock_bh(&btf_idr_lock); + } + return ret; +} + +const struct bpf_func_proto bpf_btf_find_by_name_kind_proto = { + .func = bpf_btf_find_by_name_kind, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_MEM, + .arg2_type = ARG_CONST_SIZE, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, +}; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index da7dc2406470..f93ff2ebf96d 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4584,6 +4584,8 @@ syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) switch (func_id) { case BPF_FUNC_sys_bpf: return &bpf_sys_bpf_proto; + case BPF_FUNC_btf_find_by_name_kind: + return &bpf_btf_find_by_name_kind_proto; default: return tracing_prog_func_proto(func_id, prog); } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index de58a714ed36..3cc07351c1cf 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4748,6 +4748,12 @@ union bpf_attr { * Execute bpf syscall with given arguments. * Return * A syscall result. + * + * long bpf_btf_find_by_name_kind(char *name, int name_sz, u32 kind, int flags) + * Description + * Find BTF type with given name and kind in vmlinux BTF or in module's BTFs. + * Return + * Returns btf_id and btf_obj_fd in lower and upper 32 bits. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -4917,6 +4923,7 @@ union bpf_attr { FN(for_each_map_elem), \ FN(snprintf), \ FN(sys_bpf), \ + FN(btf_find_by_name_kind), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper -- 2.30.2