From patchwork Tue Apr 13 09:16:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= X-Patchwork-Id: 12199737 X-Patchwork-Delegate: bpf@iogearbox.net 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 9D370C433ED for ; Tue, 13 Apr 2021 09:16:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7555E6124B for ; Tue, 13 Apr 2021 09:16:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237414AbhDMJQo (ORCPT ); Tue, 13 Apr 2021 05:16:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:29465 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245592AbhDMJQj (ORCPT ); Tue, 13 Apr 2021 05:16:39 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1618305378; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=0WQ0gS1Z35Vb1nS6NIi8g9cHCL5It5tExitM3okgeQ4=; b=i4yBPnVEweYI+T1OC/Bvqu0qhWp+jCJcairBrQnw+/xgYI7PcyuRf0ulnWxsj70b3Bfdx7 FPEj7L0Y/o1f4xdQqmxwbiaWxzWxDPZ2arw4Oz7fwey6sQ0vAhD6uEeeAyoUm3IPJag4Zi ZiKOoD5oNjvXvxyns9b3nfhE8Cg/wc8= Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-117-oSDW4nezN0SwKIaE04sNtQ-1; Tue, 13 Apr 2021 05:16:16 -0400 X-MC-Unique: oSDW4nezN0SwKIaE04sNtQ-1 Received: by mail-ed1-f70.google.com with SMTP id k20-20020aa7d2d40000b0290382b9d237d6so946884edr.17 for ; Tue, 13 Apr 2021 02:16:16 -0700 (PDT) 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:mime-version :content-transfer-encoding; bh=0WQ0gS1Z35Vb1nS6NIi8g9cHCL5It5tExitM3okgeQ4=; b=Ik5Hk3hM6eo3WZs/eq9a1fBkQGj6oDYPK9hbSChFf65F2QQP0EH/Y8Sqt0Je3j327N dfWV6e+4iCLePYSMiW1MfqbnHXUAE13Oes90KJt1L2XLR2XnEzezpkhZo7IjWpalqAdh MKFjvTxjAyJ/PS6jo2rh1wGv+NOS8OgYnyxjAizfmgEYdLjwJWKIOInnABeWXgEqsA5G uW3acu6y3sMrVxx7ktoTHcl+fWAjSSunD8sFh5xMxjxIY9aX5v8aXTRhZc4/mWtGlykD Cv8XAEFpGwyvhWjuFplEsxbFaY5OBzZzjclUeywu5Hljj2sSgYJ10uzyf1NZucMApSeG D6mQ== X-Gm-Message-State: AOAM533UIb7vWhN2EwK8wLayRCOMR1Xel9zZaSyEbkAtlt80sGaycCaa F0oxrx50DLTRbVp10jYAcsSsqLtwCvLe418N/SYlDTL5VU66Bx3fLCksdMLlItZYhlC5LT31f/w Cr1sn61wz1rKc X-Received: by 2002:a50:eb92:: with SMTP id y18mr25651158edr.230.1618305375698; Tue, 13 Apr 2021 02:16:15 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy2WTTk9TI0R5UtWek42d/MF+SSdn93zgg4UslGBx/SiQnr5Ubifr07U6qmR+qkq6sFQMrx9g== X-Received: by 2002:a50:eb92:: with SMTP id y18mr25651139edr.230.1618305375559; Tue, 13 Apr 2021 02:16:15 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id t7sm3869182ejo.120.2021.04.13.02.16.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Apr 2021 02:16:15 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 691241804E8; Tue, 13 Apr 2021 11:16:14 +0200 (CEST) From: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Alexei Starovoitov , Daniel Borkmann Cc: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , bpf@vger.kernel.org Subject: [PATCH bpf-next v2 1/2] bpf: return target info when a tracing bpf_link is queried Date: Tue, 13 Apr 2021 11:16:06 +0200 Message-Id: <20210413091607.58945-1-toke@redhat.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net There is currently no way to discover the target of a tracing program attachment after the fact. Add this information to bpf_link_info and return it when querying the bpf_link fd. Acked-by: Andrii Nakryiko Signed-off-by: Toke Høiland-Jørgensen --- include/linux/bpf_verifier.h | 9 +++++++++ include/uapi/linux/bpf.h | 2 ++ kernel/bpf/syscall.c | 3 +++ tools/include/uapi/linux/bpf.h | 2 ++ 4 files changed, 16 insertions(+) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 51c2ffa3d901..6023a1367853 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -487,6 +487,15 @@ static inline u64 bpf_trampoline_compute_key(const struct bpf_prog *tgt_prog, return ((u64)btf_obj_id(btf) << 32) | 0x80000000 | btf_id; } +/* unpack the IDs from the key as constructed above */ +static inline void bpf_trampoline_unpack_key(u64 key, u32 *obj_id, u32 *btf_id) +{ + if (obj_id) + *obj_id = key >> 32; + if (btf_id) + *btf_id = key & 0x7FFFFFFF; +} + int bpf_check_attach_target(struct bpf_verifier_log *log, const struct bpf_prog *prog, const struct bpf_prog *tgt_prog, diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 49371eba98ba..397884396671 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5379,6 +5379,8 @@ struct bpf_link_info { } raw_tracepoint; struct { __u32 attach_type; + __u32 target_obj_id; /* prog_id for PROG_EXT, otherwise btf object id */ + __u32 target_btf_id; /* BTF type id inside the object */ } tracing; struct { __u64 cgroup_id; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 6428634da57e..fd495190115e 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2551,6 +2551,9 @@ static int bpf_tracing_link_fill_link_info(const struct bpf_link *link, container_of(link, struct bpf_tracing_link, link); info->tracing.attach_type = tr_link->attach_type; + bpf_trampoline_unpack_key(tr_link->trampoline->key, + &info->tracing.target_obj_id, + &info->tracing.target_btf_id); return 0; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 69902603012c..1a240be873d7 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5373,6 +5373,8 @@ struct bpf_link_info { } raw_tracepoint; struct { __u32 attach_type; + __u32 target_obj_id; /* prog_id for PROG_EXT, otherwise btf object id */ + __u32 target_btf_id; /* BTF type id inside the object */ } tracing; struct { __u64 cgroup_id;