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 1A248C43461 for ; Fri, 23 Apr 2021 00:27:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB7FD613FA for ; Fri, 23 Apr 2021 00:27:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240031AbhDWA1n (ORCPT ); Thu, 22 Apr 2021 20:27:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240078AbhDWA1k (ORCPT ); Thu, 22 Apr 2021 20:27:40 -0400 Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4130C06138E; Thu, 22 Apr 2021 17:27:02 -0700 (PDT) Received: by mail-pl1-x631.google.com with SMTP id u15so15836600plf.10; Thu, 22 Apr 2021 17:27:02 -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=AzzvOUyd8TsZNiC1m9Nop4BPUbcupIF2MZCJ1uFtDTE=; b=S3jn+t6zhpcpMRjKBPzfFbe/RYV569zKjq7Oi4pSF6R+1tV/JVlWN1q/ZFvsnDJhn0 WTs8elmZqEcPIDZXXmK4T/BNhcB5O10pDlrEUHNg2IXXgNOuPKGb6NMmDXIU4nsx1B0+ 9zCasOuBRdtJv1JWyGhGnDQsCqfFsrGM/evwWZO/gWytui5pJWMTYTLOtfprqGQ0sP6k MNHt4yPqst1I0/RY2qEb5Wq0qivHTxfpjc/MebXEAEPqSV0JseKhkQthtQ6s87PvuuK2 Ip2q8xwQHYqbN+a7hCiz9qh8Qgk5KZnM9mZ46pzUU+cnzO6+cVzqnK441SR2C09+rMxT TB+Q== 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=AzzvOUyd8TsZNiC1m9Nop4BPUbcupIF2MZCJ1uFtDTE=; b=piTasgump7BLJQPkEibeN5DjJcXQRb1oY87L0KnWHnw/+r070VVDuWRm7f1/GWBCND 0RpTf/GqGQgMreTAMyQn3T+Yg15iQo50/SzypExXmkzwjYob3W/89hkSoD2gVYAVsitN FeUX0pDrZGdnVydn33zjVxHsN3yAo0rVqF5c0pFOU9Oqf7DThsOXiPZYq50UmYvNCTEp LtwboJdwHTTI6U14mZUfm/eN8bO7XEVFfYP4F4vsy6JqfsB4sJ+nPkl6CWmD/PAnpYo3 Ak/J7O9JunixgNY8TbggYZ/y45rYhFipdhiLc5CV0Rj08d9Ug0Ze4wjOiWYG93V0gv/P TR+w== X-Gm-Message-State: AOAM533JimxQ8YP2mMM6eA4e1mu9fnyEgCp7pGN10m7JrjjsXzJkIuG1 20nJgy0k5CVVcvRk9iYhfvQ= X-Google-Smtp-Source: ABdhPJzicS2HSCLgjNvL1swHFT623s5vjayH/fWuSsRLry7T7t8BLeLRVVRLS7cKiYwwZX4sc191jw== X-Received: by 2002:a17:90b:314:: with SMTP id ay20mr2779816pjb.186.1619137622312; Thu, 22 Apr 2021 17:27:02 -0700 (PDT) Received: from ast-mbp.thefacebook.com ([163.114.132.7]) by smtp.gmail.com with ESMTPSA id u12sm6390987pji.45.2021.04.22.17.27.01 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 22 Apr 2021 17:27:01 -0700 (PDT) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, andrii@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v2 bpf-next 10/16] bpf: Add bpf_btf_find_by_name_kind() helper. Date: Thu, 22 Apr 2021 17:26:40 -0700 Message-Id: <20210423002646.35043-11-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.13.5 In-Reply-To: <20210423002646.35043-1-alexei.starovoitov@gmail.com> References: <20210423002646.35043-1-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(u32 btf_fd, char *name, u32 kind, int flags) Description Find given name with given type in BTF pointed to by btf_fd. If btf_fd is zero look for the name in vmlinux BTF and in module's BTFs. Return Returns btf_id and btf_obj_fd in lower and upper 32 bits. Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 8 ++++ kernel/bpf/btf.c | 68 ++++++++++++++++++++++++++++++++++ kernel/bpf/syscall.c | 2 + tools/include/uapi/linux/bpf.h | 8 ++++ 5 files changed, 87 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 0f841bd0cb85..4cf361eb6a80 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1972,6 +1972,7 @@ 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..253f5f031f08 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4748,6 +4748,13 @@ union bpf_attr { * Execute bpf syscall with given arguments. * Return * A syscall result. + * + * long bpf_btf_find_by_name_kind(u32 btf_fd, char *name, u32 kind, int flags) + * Description + * Find given name with given type in BTF pointed to by btf_fd. + * If btf_fd is zero look for the name in vmlinux BTF and 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 +4924,7 @@ 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..446c64171464 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6085,3 +6085,71 @@ struct module *btf_try_get_module(const struct btf *btf) return res; } + +BPF_CALL_4(bpf_btf_find_by_name_kind, int, btf_fd, char *, name, u32, kind, int, flags) +{ + char kname[KSYM_NAME_LEN]; + struct btf *btf; + long ret; + + if (flags) + return -EINVAL; + + ret = strncpy_from_kernel_nofault(kname, name, sizeof(kname)); + if (ret < 0) + return ret; + if (btf_fd) + btf = btf_get_by_fd(btf_fd); + else + btf = bpf_get_btf_vmlinux(); + if (IS_ERR(btf)) + return PTR_ERR(btf); + + ret = btf_find_by_name_kind(btf, kname, kind); + /* ret is never zero, since btf_find_by_name_kind returns + * positive btf_id or negative error. + */ + if (btf_fd) + btf_put(btf); + else 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, kname, 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_ANYTHING, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, + .arg4_type = ARG_ANYTHING, +}; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index a81496c5d09f..638c7acad925 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -4574,6 +4574,8 @@ 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 6c8e178d8ffa..5841adb44de6 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4748,6 +4748,13 @@ union bpf_attr { * Execute bpf syscall with given arguments. * Return * A syscall result. + * + * long bpf_btf_find_by_name_kind(u32 btf_fd, char *name, u32 kind, int flags) + * Description + * Find given name with given type in BTF pointed to by btf_fd. + * If btf_fd is zero look for the name in vmlinux BTF and 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 +4924,7 @@ 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