From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: Re: perf trace: Problems initializing symbol libraries! Date: Mon, 16 May 2016 10:15:12 -0300 Message-ID: <20160516131512.GA5475@kernel.org> References: <2323271.hRPH2PSKxc@milian-kdab2> <20160512181044.GK20258@kernel.org> <1849423.FYp0BrzLMo@agathebauer> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail.kernel.org ([198.145.29.136]:32868 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752671AbcEPNPh (ORCPT ); Mon, 16 May 2016 09:15:37 -0400 Content-Disposition: inline In-Reply-To: <1849423.FYp0BrzLMo@agathebauer> Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Milian Wolff Cc: linux-perf-users@vger.kernel.org Em Mon, May 16, 2016 at 01:31:48PM +0200, Milian Wolff escreveu: > On Donnerstag, 12. Mai 2016 15:10:44 CEST Arnaldo Carvalho de Melo wrote: > > Em Thu, May 12, 2016 at 02:05:35PM +0200, Milian Wolff escreveu: > > > I'm getting the following error when trying to run `perf trace` built from > > > acme's perf/core branch on an Ubuntu 16.04 machine: > > > > > > $ perf trace > > > Problems initializing symbol libraries! > > > > > > strace shows this at the end: > > > > > > ... > > > lstat("/proc", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0 > > > lstat("/proc/kallsyms", {st_mode=S_IFREG|0444, st_size=0, ...}) = 0 > > > write(2, "Problems initializing symbol lib"..., 40Problems initializing > > > symbol libraries! > > > ) = 40 > > > exit_group(244) > > > > > > Is something wrong with my /proc/kallsyms? Can someone tell me what the > > > problems are that are being encountered? > > > > Does it work as root? > > It does work as root. Note that on my other machines, I can run these commands > to make it work as a non-root user: > > sudo mount -o remount,mode=755 /sys/kernel/debug > sudo mount -o remount,mode=755 /sys/kernel/debug/tracing > echo "-1" | sudo tee /proc/sys/kernel/perf_event_paranoid > > This does not work on Ubuntu 16.04 anymore. Ok, downloading 16.04 workstation to install on a guinea pig as I can't possibly repro this on a docker image, the issue most likely is with the kernel. > > What is the value of /proc/sys/kernel/kptr_restrict? > > > > This file does not exist. > > > Need to improve that message :-\ > > Yes please :) Will try, as soon as I install u16.04 on bare metal. - Arnaldo