From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751510AbbCTHm5 (ORCPT ); Fri, 20 Mar 2015 03:42:57 -0400 Received: from mail7.hitachi.co.jp ([133.145.228.42]:43851 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751226AbbCTHmy (ORCPT ); Fri, 20 Mar 2015 03:42:54 -0400 Message-ID: <550BCF76.1000809@hitachi.com> Date: Fri, 20 Mar 2015 16:42:46 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: He Kuang CC: acme@kernel.org, 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 References: <20150319135919.GG2983@kernel.org> <1426816616-2394-1-git-send-email-hekuang@huawei.com> In-Reply-To: <1426816616-2394-1-git-send-email-hekuang@huawei.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (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 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