From patchwork Fri Apr 12 03:03:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Poirier X-Patchwork-Id: 1084387 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44gN5L48Nsz9s5c for ; Fri, 12 Apr 2019 13:03:50 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726728AbfDLDDt (ORCPT ); Thu, 11 Apr 2019 23:03:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:60910 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726640AbfDLDDt (ORCPT ); Thu, 11 Apr 2019 23:03:49 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 7506BABC3; Fri, 12 Apr 2019 03:03:47 +0000 (UTC) From: Benjamin Poirier To: Daniel Borkmann Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, David Ahern Subject: [PATCH v2 bpf-next 1/2] bpftool: Use print_entry_error() in case of ENOENT when dumping Date: Fri, 12 Apr 2019 12:03:21 +0900 Message-Id: <20190412030322.15494-1-bpoirier@suse.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190411082700.26888-1-bpoirier@suse.com> References: <20190411082700.26888-1-bpoirier@suse.com> MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-Id: netdev.vger.kernel.org Commit bf598a8f0f77 ("bpftool: Improve handling of ENOENT on map dumps") used print_entry_plain() in case of ENOENT because that function provided the desired formatting. However, that commit actually introduces dead code. Per-cpu maps are zero-filled. When reading them, it's all or nothing. There will never be a case where some cpus have an entry and others don't. The truth is that ENOENT is an error case. So rework print_entry_error() to provide the desired formatting. Note that this commit changes the output format in case of errors other than ENOENT. example before: key: 00 00 00 00 value: No space left on device [...] example after: key: 00 00 00 00 value: No space left on device [...] The ENOENT case is unchanged: key: 00 00 00 00 value: 14 5b 00 00 00 00 00 00 key: 01 00 00 00 value: [...] Signed-off-by: Benjamin Poirier --- tools/bpf/bpftool/map.c | 34 ++++++++++++++-------------------- 1 file changed, 14 insertions(+), 20 deletions(-) diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index e96903078991..71840faaeab5 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -261,20 +261,19 @@ static void print_entry_json(struct bpf_map_info *info, unsigned char *key, } static void print_entry_error(struct bpf_map_info *info, unsigned char *key, - const char *value) + const char *value, bool single_line) { - int value_size = strlen(value); - bool single_line, break_names; + bool break_names; - break_names = info->key_size > 16 || value_size > 16; - single_line = info->key_size + value_size <= 24 && !break_names; + break_names = info->key_size > 16; + single_line = single_line && !break_names; printf("key:%c", break_names ? '\n' : ' '); fprint_hex(stdout, key, info->key_size, " "); printf(single_line ? " " : "\n"); - printf("value:%c%s", break_names ? '\n' : ' ', value); + printf("value:%c%s", single_line ? ' ' : '\n', value); printf("\n"); } @@ -298,11 +297,7 @@ static void print_entry_plain(struct bpf_map_info *info, unsigned char *key, if (info->value_size) { printf("value:%c", break_names ? '\n' : ' '); - if (value) - fprint_hex(stdout, value, info->value_size, - " "); - else - printf(""); + fprint_hex(stdout, value, info->value_size, " "); } printf("\n"); @@ -321,11 +316,8 @@ static void print_entry_plain(struct bpf_map_info *info, unsigned char *key, for (i = 0; i < n; i++) { printf("value (CPU %02d):%c", i, info->value_size > 16 ? '\n' : ' '); - if (value) - fprint_hex(stdout, value + i * step, - info->value_size, " "); - else - printf(""); + fprint_hex(stdout, value + i * step, + info->value_size, " "); printf("\n"); } } @@ -722,11 +714,13 @@ static int dump_map_elem(int fd, void *key, void *value, jsonw_string_field(json_wtr, "error", strerror(lookup_errno)); jsonw_end_object(json_wtr); } else { + const char *msg = NULL; + if (errno == ENOENT) - print_entry_plain(map_info, key, NULL); - else - print_entry_error(map_info, key, - strerror(lookup_errno)); + msg = ""; + + print_entry_error(map_info, key, + msg ? : strerror(lookup_errno), !!msg); } return 0;