From patchwork Wed Jun 29 15:18:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuang Wang X-Patchwork-Id: 12900294 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64BFACCA47C for ; Wed, 29 Jun 2022 15:19:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233926AbiF2PTo (ORCPT ); Wed, 29 Jun 2022 11:19:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233884AbiF2PTl (ORCPT ); Wed, 29 Jun 2022 11:19:41 -0400 Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F3DFA252BE; Wed, 29 Jun 2022 08:19:40 -0700 (PDT) Received: by mail-pj1-x1033.google.com with SMTP id b12-20020a17090a6acc00b001ec2b181c98so19768510pjm.4; Wed, 29 Jun 2022 08:19:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=NCR65AgEN7e8ge6gFaeYgLnI/aL4mIVTifuImi+nxuU=; b=qMfCbq33d4ryv+VK2N01vtFa72jjYz0nYz2EAE3ETlJJxWeYplC5Yv/k7ZMwfNXdam 6O0SP3ZF5j0U6qzqCsqJjnFpJTbUUYn7IYHZlIi5A00e4GfeCdCLXdeU8kGpF5dTMpWX 2D3POY0dLQ5PrdNZqt369mxc+U/VV4j0MIKyvs2LV1OFFRsQ2tKILcfrGtMIzkahkHu0 4+laIdJd2IfgCgVA7a/9kmpu48Ixmz3hRhPZP2W6kyr0EDR+3Nrviv/q/TNTpR5hT2ca bulkofz0F49kSujm4DeWEWVYMWKfdpGr3KWANwT2cGprEMBh4y8yLQYbs5DEHyOY/U+4 eCJg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=NCR65AgEN7e8ge6gFaeYgLnI/aL4mIVTifuImi+nxuU=; b=7SAAIjVJ+RT0dC6x8Z3BUuXIEgzn/OZ/GhlO2evEsbSCAW0BZ+18VqksElQ44Rx582 A/GHySEK+NjOeGF2YWHFSUWnGkMvw/JrpqaXGpJgtXFWlo5Na375ibeGcEmEMVDVDRGH 0oBjASTFCuct+hDEKb/VueiXh82OCyJfMML1TBLC8kp24+WW6zehgjwj+KkKTaqAKd2J ssWLYxIFcyTywQsy9Amt6esboDW0lFLByE44bEigbyx8PRLxAphY8fEgBt6MDAMC5mIN eLSHtupfDzp9RCy3UBV/J+HQLdTDUpHhfwiUE5a0q//Ljf63tPONg6AVfUXD/32Fs+Nw 6Rng== X-Gm-Message-State: AJIora8iNkbJxGPs0vpInq0tel7co7e4JJ1HLc2M6uDWsCFudF+quM/z T94Rmu/hgznPIl3eABfAM8Xk5/cytOPx7A== X-Google-Smtp-Source: AGRyM1ua3RPK72bxy2NoNyrj6KWzRCCDDeOXPITO7g4kSTv2G1YxGM4YumrKM4dtu5lXu2gNN/Dd1w== X-Received: by 2002:a17:90a:31c1:b0:1ec:729f:36b7 with SMTP id j1-20020a17090a31c100b001ec729f36b7mr6179995pjf.123.1656515980491; Wed, 29 Jun 2022 08:19:40 -0700 (PDT) Received: from localhost.localdomain ([47.242.114.172]) by smtp.gmail.com with ESMTPSA id x20-20020a170902b41400b001676dac529asm11522657plr.146.2022.06.29.08.19.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Jun 2022 08:19:39 -0700 (PDT) From: Chuang Wang Cc: Chuang Wang , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 3/3] libbpf: cleanup the legacy uprobe_event on failed add/attach_event() Date: Wed, 29 Jun 2022 23:18:47 +0800 Message-Id: <20220629151848.65587-4-nashuiliang@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220629151848.65587-1-nashuiliang@gmail.com> References: <20220629151848.65587-1-nashuiliang@gmail.com> MIME-Version: 1.0 To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net A potential scenario, when an error is returned after add_uprobe_event_legacy() in perf_event_uprobe_open_legacy(), or bpf_program__attach_perf_event_opts() in bpf_program__attach_uprobe_opts() returns an error, the uprobe_event that was previously created is not cleaned. So, with this patch, when an error is returned, fix this by adding remove_uprobe_event_legacy() Signed-off-by: Chuang Wang --- tools/lib/bpf/libbpf.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 159b69d8b941..5aa6033a0284 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -10240,9 +10240,10 @@ static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe, } type = determine_uprobe_perf_type_legacy(probe_name, retprobe); if (type < 0) { + err = type; pr_warn("failed to determine legacy uprobe event id for %s:0x%zx: %d\n", - binary_path, offset, type); - return type; + binary_path, offset, err); + goto err_clean_legacy; } memset(&attr, 0, sizeof(attr)); @@ -10257,9 +10258,14 @@ static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe, if (pfd < 0) { err = -errno; pr_warn("legacy uprobe perf_event_open() failed: %d\n", err); - return err; + goto err_clean_legacy; } return pfd; + +err_clean_legacy: + /* Clear the newly added legacy uprobe_event */ + remove_uprobe_event_legacy(probe_name, retprobe); + return err; } /* Return next ELF section of sh_type after scn, or first of that type if scn is NULL. */ @@ -10593,7 +10599,7 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, prog->name, retprobe ? "uretprobe" : "uprobe", binary_path, func_offset, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); - goto err_out; + goto err_clean_legacy; } if (legacy) { struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link); @@ -10603,10 +10609,14 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, perf_link->legacy_is_retprobe = retprobe; } return link; + +err_clean_legacy: + if (legacy) + remove_uprobe_event_legacy(legacy_probe, retprobe); + err_out: free(legacy_probe); return libbpf_err_ptr(err); - } /* Format of u[ret]probe section definition supporting auto-attach: