From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752348AbbCTNvB (ORCPT ); Fri, 20 Mar 2015 09:51:01 -0400 Received: from mail.kernel.org ([198.145.29.136]:47445 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752135AbbCTNu4 (ORCPT ); Fri, 20 Mar 2015 09:50:56 -0400 Date: Fri, 20 Mar 2015 10:50:50 -0300 From: Arnaldo Carvalho de Melo To: Masami Hiramatsu Cc: He Kuang , a.p.zijlstra@chello.nl, mingo@redhat.com, namhyung@kernel.org, wangnan0@huawei.com, linux-kernel@vger.kernel.org Subject: Re: [PATCHv2] perf probe: Fix failure to add multiple probes without debuginfo Message-ID: <20150320135050.GF16485@kernel.org> References: <20150319135919.GG2983@kernel.org> <1426816616-2394-1-git-send-email-hekuang@huawei.com> <550BCF76.1000809@hitachi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <550BCF76.1000809@hitachi.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Mar 20, 2015 at 04:42:46PM +0900, Masami Hiramatsu escreveu: > (2015/03/20 10:56), He Kuang wrote: > > Perf tries to find probe function addresses from map when debuginfo > > could not be found. > > > > To the first added function, the value of ref_reloc_sym was set in > > maps__set_kallsyms_ref_reloc_sym() and can be obtained from > > host_machine->kmaps->maps. After that, new maps are added to > > host_machine->kmaps->maps in dso__load_kcore(), all these new added maps > > do not have a valid ref_reloc_sym. > > > > When adding a second function, get_target_map() may get a map without > > valid ref_reloc_sym, and raise the error "Relocated base symbol is not > > found". > > > > Fix this by using kernel_get_ref_reloc_sym() to get ref_reloc_sym. > > > > This problem can be reproduced as following: > > > > $ perf probe --add='sys_write' --add='sys_open' > > Relocated base symbol is not found! > > Error: Failed to add events. > > > > After this patch: > > > > $ perf probe --add='sys_write' --add='sys_open' > > Added new event: > > probe:sys_write (on sys_write) > > > > You can now use it in all perf tools, such as: > > > > perf record -e probe:sys_write -aR sleep 1 > > > > Added new event: > > probe:sys_open (on sys_open) > > > > You can now use it in all perf tools, such as: > > > > perf record -e probe:sys_open -aR sleep 1 > > > > OK, I've checked that this solve the problem :) > > Acked-by: Masami Hiramatsu Ok, next time, please consider sending a Tested-by: tag instead, if what you did was to apply the patch, check that it fixes the problem, that provides a stronger patch endorsement. - Arnaldo > > Thank you! > > > Signed-off-by: He Kuang > > --- > > tools/perf/util/probe-event.c | 4 +--- > > 1 file changed, 1 insertion(+), 3 deletions(-) > > > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > > index c5e1338..c1ccd6a 100644 > > --- a/tools/perf/util/probe-event.c > > +++ b/tools/perf/util/probe-event.c > > @@ -2507,7 +2507,6 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, > > int max_tevs, const char *target) > > { > > struct map *map = NULL; > > - struct kmap *kmap = NULL; > > struct ref_reloc_sym *reloc_sym = NULL; > > struct symbol *sym; > > struct probe_trace_event *tev; > > @@ -2540,8 +2539,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, > > } > > > > if (!pev->uprobes && !pp->retprobe) { > > - kmap = map__kmap(map); > > - reloc_sym = kmap->ref_reloc_sym; > > + reloc_sym = kernel_get_ref_reloc_sym(); > > if (!reloc_sym) { > > pr_warning("Relocated base symbol is not found!\n"); > > ret = -EINVAL; > > > > > -- > Masami HIRAMATSU > Software Platform Research Dept. Linux Technology Research Center > Hitachi, Ltd., Yokohama Research Laboratory > E-mail: masami.hiramatsu.pt@hitachi.com >