From patchwork Fri Feb 21 07:38:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 231016 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 13F14C35643 for ; Fri, 21 Feb 2020 07:51:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF6EC20801 for ; Fri, 21 Feb 2020 07:51:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582271498; bh=MMvYnTh/h4R2QL5OTCI5uAa2vYTgJROedZx4TjC11Sw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hbwFsbsHU9A0ENdchvOnGvbBlepuPFYVvWyByq+QBliGjBfO/I3SFSwNZ18VxXK61 p0KoVx5cmVIHP9jnHEUqRNRqSxgRlFLF7Gfy9i2XFHvym1OgC2oqXMKFqF8QIwOX4k ZmbmZ/o9X6sa1P098T6+4Zj9fwft+KdB5IOLJaxI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729780AbgBUHvi (ORCPT ); Fri, 21 Feb 2020 02:51:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:48966 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729764AbgBUHve (ORCPT ); Fri, 21 Feb 2020 02:51:34 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3CCD420578; Fri, 21 Feb 2020 07:51:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582271493; bh=MMvYnTh/h4R2QL5OTCI5uAa2vYTgJROedZx4TjC11Sw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sjp7jtY+utdkALWE+Kf9aOrGuEa81Chyj+Sp9sFjwR4EDzlZ0KbBB6AJk4xRTrt1V ubqQY/EwDRYRgd/MjLx4cAFZENrmVGzfWVH/mSPDUw8Z4HNItk1no1qXI2NInDvmfc jtYlgm4SndczUhUAivdYnMZz+4n1HocULZZi73V4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hechao Li , Daniel Borkmann , Sasha Levin Subject: [PATCH 5.5 186/399] bpf: Print error message for bpftool cgroup show Date: Fri, 21 Feb 2020 08:38:31 +0100 Message-Id: <20200221072420.894981197@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200221072402.315346745@linuxfoundation.org> References: <20200221072402.315346745@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Hechao Li [ Upstream commit 1162f844030ac1ac7321b5e8f6c9badc7a11428f ] Currently, when bpftool cgroup show has an error, no error message is printed. This is confusing because the user may think the result is empty. Before the change: $ bpftool cgroup show /sys/fs/cgroup ID AttachType AttachFlags Name $ echo $? 255 After the change: $ ./bpftool cgroup show /sys/fs/cgroup Error: can't query bpf programs attached to /sys/fs/cgroup: Operation not permitted v2: Rename check_query_cgroup_progs to cgroup_has_attached_progs Signed-off-by: Hechao Li Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20191224011742.3714301-1-hechaol@fb.com Signed-off-by: Sasha Levin --- tools/bpf/bpftool/cgroup.c | 56 ++++++++++++++++++++++++++------------ 1 file changed, 39 insertions(+), 17 deletions(-) diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c index 1ef45e55039e1..2f017caa678dc 100644 --- a/tools/bpf/bpftool/cgroup.c +++ b/tools/bpf/bpftool/cgroup.c @@ -117,6 +117,25 @@ static int count_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type) return prog_cnt; } +static int cgroup_has_attached_progs(int cgroup_fd) +{ + enum bpf_attach_type type; + bool no_prog = true; + + for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) { + int count = count_attached_bpf_progs(cgroup_fd, type); + + if (count < 0 && errno != EINVAL) + return -1; + + if (count > 0) { + no_prog = false; + break; + } + } + + return no_prog ? 0 : 1; +} static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type, int level) { @@ -161,6 +180,7 @@ static int show_attached_bpf_progs(int cgroup_fd, enum bpf_attach_type type, static int do_show(int argc, char **argv) { enum bpf_attach_type type; + int has_attached_progs; const char *path; int cgroup_fd; int ret = -1; @@ -192,6 +212,16 @@ static int do_show(int argc, char **argv) goto exit; } + has_attached_progs = cgroup_has_attached_progs(cgroup_fd); + if (has_attached_progs < 0) { + p_err("can't query bpf programs attached to %s: %s", + path, strerror(errno)); + goto exit_cgroup; + } else if (!has_attached_progs) { + ret = 0; + goto exit_cgroup; + } + if (json_output) jsonw_start_array(json_wtr); else @@ -212,6 +242,7 @@ static int do_show(int argc, char **argv) if (json_output) jsonw_end_array(json_wtr); +exit_cgroup: close(cgroup_fd); exit: return ret; @@ -228,7 +259,7 @@ static int do_show_tree_fn(const char *fpath, const struct stat *sb, int typeflag, struct FTW *ftw) { enum bpf_attach_type type; - bool skip = true; + int has_attached_progs; int cgroup_fd; if (typeflag != FTW_D) @@ -240,22 +271,13 @@ static int do_show_tree_fn(const char *fpath, const struct stat *sb, return SHOW_TREE_FN_ERR; } - for (type = 0; type < __MAX_BPF_ATTACH_TYPE; type++) { - int count = count_attached_bpf_progs(cgroup_fd, type); - - if (count < 0 && errno != EINVAL) { - p_err("can't query bpf programs attached to %s: %s", - fpath, strerror(errno)); - close(cgroup_fd); - return SHOW_TREE_FN_ERR; - } - if (count > 0) { - skip = false; - break; - } - } - - if (skip) { + has_attached_progs = cgroup_has_attached_progs(cgroup_fd); + if (has_attached_progs < 0) { + p_err("can't query bpf programs attached to %s: %s", + fpath, strerror(errno)); + close(cgroup_fd); + return SHOW_TREE_FN_ERR; + } else if (!has_attached_progs) { close(cgroup_fd); return 0; }