From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752493AbdGZOU1 (ORCPT ); Wed, 26 Jul 2017 10:20:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:49032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752454AbdGZOUX (ORCPT ); Wed, 26 Jul 2017 10:20:23 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2677822CB6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=acme@kernel.org From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Krister Johansen , Alexander Shishkin , Brendan Gregg , Peter Zijlstra , Thomas-Mich Richter , Arnaldo Carvalho de Melo Subject: [PATCH 29/40] perf top: Support lookup of symbols in other mount namespaces. Date: Wed, 26 Jul 2017 11:17:19 -0300 Message-Id: <20170726141730.30750-30-acme@kernel.org> X-Mailer: git-send-email 2.9.4 In-Reply-To: <20170726141730.30750-1-acme@kernel.org> References: <20170726141730.30750-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Krister Johansen The perf top command needs to unshare its fs from the helper threads in order to successfully setns(2) during its symbol lookup. It also needs to impelement a force flag to ignore ownership of perf-.map files. Signed-off-by: Krister Johansen Cc: Alexander Shishkin Cc: Brendan Gregg Cc: Peter Zijlstra Cc: Thomas-Mich Richter Link: http://lkml.kernel.org/r/1499305693-1599-6-git-send-email-kjlx@templeofstupid.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-top.txt | 4 ++++ tools/perf/builtin-top.c | 15 +++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt index e71d63843f45..d864ea6fd367 100644 --- a/tools/perf/Documentation/perf-top.txt +++ b/tools/perf/Documentation/perf-top.txt @@ -237,6 +237,10 @@ Default is to monitor all CPUS. --hierarchy:: Enable hierarchy output. +--force:: + Don't do ownership validation. + + INTERACTIVE PROMPTING KEYS -------------------------- diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index e5a8f249077f..ee954bde7e3e 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -587,6 +587,13 @@ static void *display_thread_tui(void *arg) .refresh = top->delay_secs, }; + /* In order to read symbols from other namespaces perf to needs to call + * setns(2). This isn't permitted if the struct_fs has multiple users. + * unshare(2) the fs so that we may continue to setns into namespaces + * that we're observing. + */ + unshare(CLONE_FS); + perf_top__sort_new_samples(top); /* @@ -628,6 +635,13 @@ static void *display_thread(void *arg) struct perf_top *top = arg; int delay_msecs, c; + /* In order to read symbols from other namespaces perf to needs to call + * setns(2). This isn't permitted if the struct_fs has multiple users. + * unshare(2) the fs so that we may continue to setns into namespaces + * that we're observing. + */ + unshare(CLONE_FS); + display_setup_sig(); pthread__unblock_sigwinch(); repeat: @@ -1206,6 +1220,7 @@ int cmd_top(int argc, const char **argv) "Show raw trace event output (do not use print fmt or plugins)"), OPT_BOOLEAN(0, "hierarchy", &symbol_conf.report_hierarchy, "Show entries in a hierarchy"), + OPT_BOOLEAN(0, "force", &symbol_conf.force, "don't complain, do it"), OPT_END() }; const char * const top_usage[] = { -- 2.9.4