From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755224AbcESWVo (ORCPT ); Thu, 19 May 2016 18:21:44 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:51241 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754127AbcESWVn (ORCPT ); Thu, 19 May 2016 18:21:43 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , David Ahern , Jiri Olsa , Namhyung Kim , Wang Nan Subject: [PATCH 02/11] perf machine: Do not bail out if not managing to read ref reloc symbol Date: Thu, 19 May 2016 19:21:24 -0300 Message-Id: <1463696493-27528-3-git-send-email-acme@kernel.org> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1463696493-27528-1-git-send-email-acme@kernel.org> References: <1463696493-27528-1-git-send-email-acme@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnaldo Carvalho de Melo This means the user can't access /proc/kallsyms, for instance, because /proc/sys/kernel/kptr_restrict is set to 1. Instead leave the ref_reloc_sym as NULL and code using it will cope. This allows 'perf trace' to work on such systems for !root, the only issue would be when trying to resolve kernel symbols, which happens, for instance, in some libtracevent plugins. A warning for that case will be provided in the next patch in this series. Noticed in Ubuntu 16.04, that comes with kptr_restrict=1. Reported-by: Milian Wolff Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-knpu3z4iyp2dxpdfm798fac4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/machine.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index 7ba9fadb68af..b277984aaa93 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -1135,10 +1135,10 @@ int machine__create_kernel_maps(struct machine *machine) { struct dso *kernel = machine__get_kernel(machine); const char *name; - u64 addr = machine__get_running_kernel_start(machine, &name); + u64 addr; int ret; - if (!addr || kernel == NULL) + if (kernel == NULL) return -1; ret = __machine__create_kernel_maps(machine, kernel); @@ -1160,8 +1160,9 @@ int machine__create_kernel_maps(struct machine *machine) */ map_groups__fixup_end(&machine->kmaps); - if (maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps, name, - addr)) { + addr = machine__get_running_kernel_start(machine, &name); + if (!addr) { + } else if (maps__set_kallsyms_ref_reloc_sym(machine->vmlinux_maps, name, addr)) { machine__destroy_kernel_maps(machine); return -1; } -- 2.5.5