From mboxrd@z Thu Jan 1 00:00:00 1970 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=-15.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,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 A1AC7C32753 for ; Wed, 14 Aug 2019 18:44:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6EAEB2064A for ; Wed, 14 Aug 2019 18:44:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565808283; bh=PmQkUTXNDpQDQMp/sDyeIwxyXuij3/hzlkYfi9zN5vM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1NSK3eNxjzvbPKE+P4rxri4u01Kc0+J2hU7iLHYQtC8iPX2h9InNF500T0iXXEllJ 9sFUSz6fY48fNxwWLlSjwQwKSx9SSEoZqemcL5obXKh8obakwgj/6UDu3UvTNNYWeG KwFw779D4QhHRb3qyV2kbsuP9tghsrPm671YqhRk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729313AbfHNSom (ORCPT ); Wed, 14 Aug 2019 14:44:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:54580 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728265AbfHNSom (ORCPT ); Wed, 14 Aug 2019 14:44:42 -0400 Received: from quaco.ghostprotocols.net (unknown [177.195.212.110]) (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 4B8CF2084F; Wed, 14 Aug 2019 18:44:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565808281; bh=PmQkUTXNDpQDQMp/sDyeIwxyXuij3/hzlkYfi9zN5vM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=x3YiUgwyj5AKUTXO38KvYTTQq8WNljSdzXJI+fgCDR1nhiydri9RnD0CBnqwUijPX 2vj9vXdoP0E61lf9ZGOzPcWbNYWU+fo1/ENaYCuA33InoobCy5qlWqpSiTuKopUvbK nNeEM+FktIv5m7SyfOkRVwiH4Dq22bkolsNSN2o0= From: Arnaldo Carvalho de Melo To: Ingo Molnar , Thomas Gleixner Cc: Jiri Olsa , Namhyung Kim , Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , Alexander Shishkin , Alexey Budankov , Igor Lubashev , James Morris , Mathieu Poirier , Peter Zijlstra , Suzuki Poulouse Subject: [PATCH 17/28] perf ftrace: Improve error message about capability to use ftrace Date: Wed, 14 Aug 2019 15:40:40 -0300 Message-Id: <20190814184051.3125-18-acme@kernel.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190814184051.3125-1-acme@kernel.org> References: <20190814184051.3125-1-acme@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnaldo Carvalho de Melo If we link against libcap, then we can state that CAP_SYS_ADMIN is needed, if not, fallback to telling the user it needs to be root, as was before linking against libcap. Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexey Budankov Cc: Igor Lubashev Cc: James Morris Cc: Jiri Olsa Cc: Mathieu Poirier Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Suzuki Poulouse Link: https://lkml.kernel.org/n/tip-hhnbjdo8r67054of9zm2kxtl@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-ftrace.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 01a5bb58eb04..1367bb5046a7 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -284,7 +284,13 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) }; if (!perf_cap__capable(CAP_SYS_ADMIN)) { - pr_err("ftrace only works for root!\n"); + pr_err("ftrace only works for %s!\n", +#ifdef HAVE_LIBCAP_SUPPORT + "users with the SYS_ADMIN capability" +#else + "root" +#endif + ); return -1; } -- 2.21.0