From patchwork Fri Sep 25 21:25:06 2020 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: 11800841 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0E29E6CA for ; Fri, 25 Sep 2020 21:25:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D79BB21741 for ; Fri, 25 Sep 2020 21:25:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Rp9+K/SI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726064AbgIYVZi (ORCPT ); Fri, 25 Sep 2020 17:25:38 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:26299 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729654AbgIYVZN (ORCPT ); Fri, 25 Sep 2020 17:25:13 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601069111; 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: in-reply-to:in-reply-to:references:references; bh=91CR67pYFNd7ytF4vVQShfDIdLJOkMbVvAU7CEP8OPs=; b=Rp9+K/SITDJHJZVgJLmbmF0qjccKBr7zls4+AgW3aufz4dVswfIjErhr2wxFONZM1O4puY nZT/zyANNnYYIRjW+gQyVTACYKxVd1shTC/nUe8uA3Sl6okqemQ8y2qNad17cR7Moe/cta NNKGeXGXs99F8uM8kZjMtYdfTS0LO5E= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-239-1CjCCoz5MJGARf6So8i-DQ-1; Fri, 25 Sep 2020 17:25:09 -0400 X-MC-Unique: 1CjCCoz5MJGARf6So8i-DQ-1 Received: by mail-wm1-f71.google.com with SMTP id c200so126404wmd.5 for ; Fri, 25 Sep 2020 14:25:09 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:date:message-id:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=91CR67pYFNd7ytF4vVQShfDIdLJOkMbVvAU7CEP8OPs=; b=rFGMTYGoOnGuhaGLFunlIoTR3oJC10GXzFU+HOos4LpDf+P86bZXDFnFcR37aws0Uk gn2IYQ6HeHUBYWaYc3kUaiMNpg2GYi3g10X+cZnPFtASaDkoF5sAhVZVkqqDwNpnXjIW iierNRf0SgNvoi1h+GEPoEv3oyy/Gx+GrfNqzoz3Z/yLe0gtDedtov/RnOM9KtTuqlzn j5EZN9ntMguO+4qvP05ZfA70T3q8VFi56KJBmvcn+pGpmd+8YM5WMAhxFK2q8LjjT616 eHVrKE2Jam4XSpL6Q2Og4/eDtMin/jttqB0m6X0TUvgJRKtV6uzUzDyJSOmXb7zPTo7s WjPA== X-Gm-Message-State: AOAM5331oMoLzioc+IfBTGfFGSRNEej9yJ7wKIJMn0CiGUeAdbPd/00o Fd0PPPX/J5Ocw4FkMzgRxMF7+n20eygthEI4jjepaOt0CzsNDXECp2sToetPE0oG/5oq7/RUl7K jorCb7zD9AAhr X-Received: by 2002:adf:eb86:: with SMTP id t6mr6392404wrn.411.1601069108270; Fri, 25 Sep 2020 14:25:08 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx10Sq1i2VD0WofHO07gBXx5LaAkxXUX4/pzfeOIBry/1GwnCODBzTSMH5XzTkVQlzUc4eqtQ== X-Received: by 2002:adf:eb86:: with SMTP id t6mr6392360wrn.411.1601069107809; Fri, 25 Sep 2020 14:25:07 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id h76sm350603wme.10.2020.09.25.14.25.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 25 Sep 2020 14:25:07 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id F3472183C5B; Fri, 25 Sep 2020 23:25:06 +0200 (CEST) Subject: [PATCH bpf-next v9 07/11] libbpf: add support for freplace attachment in bpf_link_create From: =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= To: Alexei Starovoitov Cc: Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , Jiri Olsa , Eelco Chaudron , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org Date: Fri, 25 Sep 2020 23:25:06 +0200 Message-ID: <160106910695.27725.11892692056199700116.stgit@toke.dk> In-Reply-To: <160106909952.27725.8383447127582216829.stgit@toke.dk> References: <160106909952.27725.8383447127582216829.stgit@toke.dk> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: Toke Høiland-Jørgensen This adds support for supplying a target btf ID for the bpf_link_create() operation, and adds a new bpf_program__attach_freplace() high-level API for attaching freplace functions with a target. Acked-by: Andrii Nakryiko Signed-off-by: Toke Høiland-Jørgensen --- tools/lib/bpf/bpf.c | 18 +++++++++++++++--- tools/lib/bpf/bpf.h | 3 ++- tools/lib/bpf/libbpf.c | 44 +++++++++++++++++++++++++++++++++++++++----- tools/lib/bpf/libbpf.h | 3 +++ tools/lib/bpf/libbpf.map | 1 + 5 files changed, 60 insertions(+), 9 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 2baa1308737c..75f627094790 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -586,19 +586,31 @@ int bpf_link_create(int prog_fd, int target_fd, enum bpf_attach_type attach_type, const struct bpf_link_create_opts *opts) { + __u32 target_btf_id, iter_info_len; union bpf_attr attr; if (!OPTS_VALID(opts, bpf_link_create_opts)) return -EINVAL; + iter_info_len = OPTS_GET(opts, iter_info_len, 0); + target_btf_id = OPTS_GET(opts, target_btf_id, 0); + + if (iter_info_len && target_btf_id) + return -EINVAL; + memset(&attr, 0, sizeof(attr)); attr.link_create.prog_fd = prog_fd; attr.link_create.target_fd = target_fd; attr.link_create.attach_type = attach_type; attr.link_create.flags = OPTS_GET(opts, flags, 0); - attr.link_create.iter_info = - ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0)); - attr.link_create.iter_info_len = OPTS_GET(opts, iter_info_len, 0); + + if (iter_info_len) { + attr.link_create.iter_info = + ptr_to_u64(OPTS_GET(opts, iter_info, (void *)0)); + attr.link_create.iter_info_len = iter_info_len; + } else if (target_btf_id) { + attr.link_create.target_btf_id = target_btf_id; + } return sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr)); } diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 8c1ac4b42f90..6b8dbe24adc9 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -174,8 +174,9 @@ struct bpf_link_create_opts { __u32 flags; union bpf_iter_link_info *iter_info; __u32 iter_info_len; + __u32 target_btf_id; }; -#define bpf_link_create_opts__last_field iter_info_len +#define bpf_link_create_opts__last_field target_btf_id LIBBPF_API int bpf_link_create(int prog_fd, int target_fd, enum bpf_attach_type attach_type, diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 32dc444224d8..a4f55f8a460d 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9390,9 +9390,11 @@ static struct bpf_link *attach_iter(const struct bpf_sec_def *sec, } static struct bpf_link * -bpf_program__attach_fd(struct bpf_program *prog, int target_fd, +bpf_program__attach_fd(struct bpf_program *prog, int target_fd, int btf_id, const char *target_name) { + DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts, + .target_btf_id = btf_id); enum bpf_attach_type attach_type; char errmsg[STRERR_BUFSIZE]; struct bpf_link *link; @@ -9410,7 +9412,7 @@ bpf_program__attach_fd(struct bpf_program *prog, int target_fd, link->detach = &bpf_link__detach_fd; attach_type = bpf_program__get_expected_attach_type(prog); - link_fd = bpf_link_create(prog_fd, target_fd, attach_type, NULL); + link_fd = bpf_link_create(prog_fd, target_fd, attach_type, &opts); if (link_fd < 0) { link_fd = -errno; free(link); @@ -9426,19 +9428,51 @@ bpf_program__attach_fd(struct bpf_program *prog, int target_fd, struct bpf_link * bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd) { - return bpf_program__attach_fd(prog, cgroup_fd, "cgroup"); + return bpf_program__attach_fd(prog, cgroup_fd, 0, "cgroup"); } struct bpf_link * bpf_program__attach_netns(struct bpf_program *prog, int netns_fd) { - return bpf_program__attach_fd(prog, netns_fd, "netns"); + return bpf_program__attach_fd(prog, netns_fd, 0, "netns"); } struct bpf_link *bpf_program__attach_xdp(struct bpf_program *prog, int ifindex) { /* target_fd/target_ifindex use the same field in LINK_CREATE */ - return bpf_program__attach_fd(prog, ifindex, "xdp"); + return bpf_program__attach_fd(prog, ifindex, 0, "xdp"); +} + +struct bpf_link *bpf_program__attach_freplace(struct bpf_program *prog, + int target_fd, + const char *attach_func_name) +{ + int btf_id; + + if (!!target_fd != !!attach_func_name) { + pr_warn("prog '%s': supply none or both of target_fd and attach_func_name\n", + prog->name); + return ERR_PTR(-EINVAL); + } + + if (prog->type != BPF_PROG_TYPE_EXT) { + pr_warn("prog '%s': only BPF_PROG_TYPE_EXT can attach as freplace", + prog->name); + return ERR_PTR(-EINVAL); + } + + if (target_fd) { + btf_id = libbpf_find_prog_btf_id(attach_func_name, target_fd); + if (btf_id < 0) + return ERR_PTR(btf_id); + + return bpf_program__attach_fd(prog, target_fd, btf_id, "freplace"); + } else { + /* no target, so use raw_tracepoint_open for compatibility + * with old kernels + */ + return bpf_program__attach_trace(prog); + } } struct bpf_link * diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index a750f67a23f6..6909ee81113a 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -261,6 +261,9 @@ LIBBPF_API struct bpf_link * bpf_program__attach_netns(struct bpf_program *prog, int netns_fd); LIBBPF_API struct bpf_link * bpf_program__attach_xdp(struct bpf_program *prog, int ifindex); +LIBBPF_API struct bpf_link * +bpf_program__attach_freplace(struct bpf_program *prog, + int target_fd, const char *attach_func_name); struct bpf_map; diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 5f054dadf082..b1c537873b23 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -303,6 +303,7 @@ LIBBPF_0.1.0 { LIBBPF_0.2.0 { global: bpf_prog_bind_map; + bpf_program__attach_freplace; bpf_program__section_name; perf_buffer__buffer_cnt; perf_buffer__buffer_fd;