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[2620:137:e000::1:20]) by mx.google.com with ESMTP id x12-20020a05640226cc00b0049e48d13300si1703560edd.459.2023.02.02.19.33.16; Thu, 02 Feb 2023 19:33:40 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20210112 header.b=P2kniv+c; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232287AbjBCDSq (ORCPT + 99 others); Thu, 2 Feb 2023 22:18:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232365AbjBCDSn (ORCPT ); Thu, 2 Feb 2023 22:18:43 -0500 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B24A53B31; Thu, 2 Feb 2023 19:18:42 -0800 (PST) Received: by mail-pj1-x1041.google.com with SMTP id on9-20020a17090b1d0900b002300a96b358so3754304pjb.1; Thu, 02 Feb 2023 19:18:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=z8T4GxvH3ecLMhoa7M3nY3X271thDzk3OTlhfr3JaAo=; b=P2kniv+c+Jjutwu7YxBz3n1H/q/DaWJXjCH5FnGUXyQ3JHM7nd8fNOeFFMuJ68dyB1 srltCs8oOu67F1U31W2arJf/DzqZ5e2IUHm95hod36+Wz8wSnlml/LA2PhvEzJ8LTl77 +ukxMFCprDtQ61Zxnr9+1p0nQlpYoK2AGRfj/577H29pKSRd5ctZNy/32W97GDnPKDVi mHI70Rd53/cwkv3xLrZ2nmlkRBH+9X3xNuFjrzZaEsiqg6kRd748FzIZQFqkK4yGm20K 8evuF1MbB4jANMspENTD39RHQUHJnfdgymHSQqrB11BSTByxFF1yHkURSRP2eRyhHkiy IJmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=z8T4GxvH3ecLMhoa7M3nY3X271thDzk3OTlhfr3JaAo=; b=7rccsrJoJNz+RpoxUanHTttAyJHDSNS2O4x2LRXC6dc7gxaiAefrbtw1YkYcMeZDqt cxjuoqX/SKki9chTErppID72WksHt9T7chZpBpGKMsd2sq2LVXLmR4afS77Iatu5TY/i hUGGg8NDd+eq7Gft6ZaPyW38U464SjmQKFCIXtLoxJn97u4IsFq7QTiy+ta0DJpxRM7k jDkyIcgmzJKC4fOwRsB2KuF/R3p1Doalrw/ObuHvgZDmRFuZit6b8749kaQjnhdJNht1 YwJN/LzYZsMdNtZESFmvPAVlAXKu3X09txstgGUKebqskd9TWTB7t85HW1ELaW5Q2J72 PfrA== X-Gm-Message-State: AO0yUKWPAKSzWs13V9tQVSUCnFU9D/46snEzbG5IHgUPzJviu1j8AEKC t6ujOAOQKB3fEuylVzxIWrU= X-Received: by 2002:a17:902:f2c5:b0:196:8437:1b38 with SMTP id h5-20020a170902f2c500b0019684371b38mr7166029plc.58.1675394321590; Thu, 02 Feb 2023 19:18:41 -0800 (PST) Received: from localhost.localdomain ([203.205.141.16]) by smtp.gmail.com with ESMTPSA id a9-20020a170902ee8900b001899c2a0ae0sm416009pld.40.2023.02.02.19.18.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Feb 2023 19:18:41 -0800 (PST) From: menglong8.dong@gmail.com X-Google-Original-From: imagedong@tencent.com To: andrii.nakryiko@gmail.com, alan.maguire@oracle.com Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Menglong Dong Subject: [PATCH bpf-next 1/2] libbpf: add support to set kprobe/uprobe attach mode Date: Fri, 3 Feb 2023 11:17:41 +0800 Message-Id: <20230203031742.1730761-2-imagedong@tencent.com> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230203031742.1730761-1-imagedong@tencent.com> References: <20230203031742.1730761-1-imagedong@tencent.com> MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1756779218851691126?= X-GMAIL-MSGID: =?utf-8?q?1756779218851691126?= From: Menglong Dong By default, libbpf will attach the kprobe/uprobe eBPF program in the latest mode that supported by kernel. In this patch, we add the support to let users manually attach kprobe/uprobe in legacy or perf mode. There are 3 mode that supported by the kernel to attach kprobe/uprobe: LEGACY: create perf event in legacy way and don't use bpf_link PERF: create perf event with perf_event_open() and don't use bpf_link LINK: create perf event with perf_event_open() and use bpf_link Users now can manually choose the mode with bpf_program__attach_uprobe_opts()/bpf_program__attach_kprobe_opts(). Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com/ Signed-off-by: Menglong Dong --- tools/lib/bpf/libbpf.c | 26 +++++++++++++++++++++++++- tools/lib/bpf/libbpf.h | 19 ++++++++++++++++--- 2 files changed, 41 insertions(+), 4 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index eed5cec6f510..0d20bf1ee301 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9784,7 +9784,7 @@ struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *p link->link.dealloc = &bpf_link_perf_dealloc; link->perf_event_fd = pfd; - if (kernel_supports(prog->obj, FEAT_PERF_LINK)) { + if (kernel_supports(prog->obj, FEAT_PERF_LINK) && !opts->no_link) { DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_opts, .perf_event.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0)); @@ -10148,16 +10148,28 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, struct bpf_link *link; size_t offset; bool retprobe, legacy; + enum probe_mode mode; int pfd, err; if (!OPTS_VALID(opts, bpf_kprobe_opts)) return libbpf_err_ptr(-EINVAL); + mode = OPTS_GET(opts, mode, PROBE_MODE_DEFAULT); retprobe = OPTS_GET(opts, retprobe, false); offset = OPTS_GET(opts, offset, 0); pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); legacy = determine_kprobe_perf_type() < 0; + switch (mode) { + case PROBE_MODE_LEGACY: + legacy = true; + case PROBE_MODE_PERF: + pe_opts.no_link = true; + break; + default: + break; + } + if (!legacy) { pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name, offset, @@ -10817,10 +10829,12 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, int pfd, err; bool retprobe, legacy; const char *func_name; + enum probe_mode mode; if (!OPTS_VALID(opts, bpf_uprobe_opts)) return libbpf_err_ptr(-EINVAL); + mode = OPTS_GET(opts, mode, PROBE_MODE_DEFAULT); retprobe = OPTS_GET(opts, retprobe, false); ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0); pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); @@ -10849,6 +10863,16 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, } legacy = determine_uprobe_perf_type() < 0; + switch (mode) { + case PROBE_MODE_LEGACY: + legacy = true; + case PROBE_MODE_PERF: + pe_opts.no_link = true; + break; + default: + break; + } + if (!legacy) { pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path, func_offset, pid, ref_ctr_off); diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 8777ff21ea1d..7fb474e036a3 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -451,8 +451,10 @@ struct bpf_perf_event_opts { size_t sz; /* custom user-provided value fetchable through bpf_get_attach_cookie() */ __u64 bpf_cookie; + /* don't use bpf_link when attach eBPF pprogram */ + bool no_link; }; -#define bpf_perf_event_opts__last_field bpf_cookie +#define bpf_perf_event_opts__last_field no_link LIBBPF_API struct bpf_link * bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd); @@ -461,6 +463,13 @@ LIBBPF_API struct bpf_link * bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd, const struct bpf_perf_event_opts *opts); +enum probe_mode { + PROBE_MODE_DEFAULT = 0, /* latest supported by kernel */ + PROBE_MODE_LEGACY, + PROBE_MODE_PERF, + PROBE_MODE_LINK, +}; + struct bpf_kprobe_opts { /* size of this struct, for forward/backward compatiblity */ size_t sz; @@ -470,9 +479,11 @@ struct bpf_kprobe_opts { size_t offset; /* kprobe is return probe */ bool retprobe; + /* kprobe attach mode */ + enum probe_mode mode; size_t :0; }; -#define bpf_kprobe_opts__last_field retprobe +#define bpf_kprobe_opts__last_field mode LIBBPF_API struct bpf_link * bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe, @@ -570,9 +581,11 @@ struct bpf_uprobe_opts { * binary_path. */ const char *func_name; + /* uprobe attach mode */ + enum probe_mode mode; size_t :0; }; -#define bpf_uprobe_opts__last_field func_name +#define bpf_uprobe_opts__last_field mode /** * @brief **bpf_program__attach_uprobe()** attaches a BPF program