From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50C08C433E1 for ; Thu, 16 Jul 2020 21:47:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2035920B80 for ; Thu, 16 Jul 2020 21:47:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594936039; bh=6qPSpYQpyc1fxLPH/mY2eFyRahx17oO0GsEsO1IQxAo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=bvJq0mT4ljD0gMhy1AtI59TT1bWxL1bJQP+ZUJ/qsxzs9wFbj0TmbZJ4zGQS26hR1 7JHwKHPCg7xgKhbKFshzEuPgbMS//GLtfKcSuHblhvVct/h2Ns9DBg7wIFB13JJKnj eUJ8VAF7yZ9rEpLaLikwAMMVliyOMLnpWptIbgA8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726359AbgGPVrR (ORCPT ); Thu, 16 Jul 2020 17:47:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:47940 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726238AbgGPVrR (ORCPT ); Thu, 16 Jul 2020 17:47:17 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4407D208C3; Thu, 16 Jul 2020 21:47:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594936036; bh=6qPSpYQpyc1fxLPH/mY2eFyRahx17oO0GsEsO1IQxAo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=kzw8eztabbEqo9QXEUlwuHdrtsb7ZnwrGvvbLhil84/XI/0ZkZ92uPxM2ibn0gnBN FmjZWPEuV2tIis6HsNXwtwIJI2EvOg1eouvoX4DGMAqyQBlJVdnL+/IuuBmwUraWT2 WR/KfVZncjZ2M2a3BBldj3BlDwE2c3Jm9ObNZxZ0= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 24726403C7; Thu, 16 Jul 2020 18:47:14 -0300 (-03) Date: Thu, 16 Jul 2020 18:47:14 -0300 From: Arnaldo Carvalho de Melo To: Masami Hiramatsu Cc: Arnaldo Carvalho de Melo , Oleg Nesterov , Srikar Dronamraju , linux-kernel@vger.kernel.org, Andi Kleen , Andi Kleen Subject: Re: [PATCH v2 1/4] perf-probe: Avoid setting probes on same address on same event Message-ID: <20200716214714.GA77866@kernel.org> References: <159438665389.62703.13848613271334658629.stgit@devnote2> <159438666401.62703.15196394835032087840.stgit@devnote2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <159438666401.62703.15196394835032087840.stgit@devnote2> X-Url: http://acmel.wordpress.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Jul 10, 2020 at 10:11:04PM +0900, Masami Hiramatsu escreveu: > There is a case that the several same-name symbols points > same address. In that case, perf probe returns an error. > > E.g. > > perf probe -x /lib64/libc-2.30.so -v -a "memcpy arg1=%di" > probe-definition(0): memcpy arg1=%di > symbol:memcpy file:(null) line:0 offset:0 return:0 lazy:(null) > parsing arg: arg1=%di into name:arg1 %di > 1 arguments > symbol:setjmp file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:longjmp file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:longjmp_target file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:lll_lock_wait_private file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt_arena_max file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt_arena_test file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_tunable_tcache_max_bytes file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_tunable_tcache_count file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_tunable_tcache_unsorted_limit file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt_trim_threshold file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt_top_pad file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt_mmap_threshold file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt_mmap_max file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt_perturb file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt_mxfast file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_heap_new file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_arena_reuse_free_list file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_arena_reuse file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_arena_reuse_wait file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_arena_new file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_arena_retry file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_sbrk_less file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_heap_free file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_heap_less file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_tcache_double_free file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_heap_more file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_sbrk_more file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_malloc_retry file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_memalign_retry file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt_free_dyn_thresholds file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_realloc_retry file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_calloc_retry file:(null) line:0 offset:0 return:0 lazy:(null) > symbol:memory_mallopt file:(null) line:0 offset:0 return:0 lazy:(null) > Open Debuginfo file: /usr/lib/debug/usr/lib64/libc-2.30.so.debug > Try to find probe point from debuginfo. > Opening /sys/kernel/debug/tracing//README write=0 > Failed to find the location of the '%di' variable at this address. > Perhaps it has been optimized out. > Use -V with the --range option to show '%di' location range. > An error occurred in debuginfo analysis (-2). > Trying to use symbols. > Opening /sys/kernel/debug/tracing//uprobe_events write=1 > Writing event: p:probe_libc/memcpy /usr/lib64/libc-2.30.so:0x914c0 arg1=%di > Writing event: p:probe_libc/memcpy /usr/lib64/libc-2.30.so:0x914c0 arg1=%di > Failed to write event: File exists > Error: Failed to add events. Reason: File exists (Code: -17) > > You can see the perf tried to write completely same probe definition > twice, which caused an error. > > To fix this issue, check the symbol list and drop duplicated > symbols (which has same symbol name and address) from it. > > With this patch; > > # perf probe -x /lib64/libc-2.30.so -a "memcpy arg1=%di" > Failed to find the location of the '%di' variable at this address. > Perhaps it has been optimized out. > Use -V with the --range option to show '%di' location range. > Added new events: > probe_libc:memcpy (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di) > probe_libc:memcpy (on memcpy in /usr/lib64/libc-2.30.so with arg1=%di) > > You can now use it in all perf tools, such as: > > perf record -e probe_libc:memcpy -aR sleep 1 > > > Reported-by: Andi Kleen > Signed-off-by: Masami Hiramatsu > Reviewed-by: Srikar Dronamraju > --- > Changes in V2 > - Change "find" word to "Found". > --- > tools/perf/util/probe-event.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > index df713a5d1e26..8cd1224e5f4c 100644 > --- a/tools/perf/util/probe-event.c > +++ b/tools/perf/util/probe-event.c > @@ -2968,6 +2968,16 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, > for (j = 0; j < num_matched_functions; j++) { > sym = syms[j]; > > + /* There can be duplicated symbols in the map */ > + for (i = 0; i < j; i++) > + if (sym->start == syms[i]->start) { > + pr_debug("Found duplicated symbol %s @ %lx\n", > + sym->name, sym->start); > + break; > + } Breaks 32-bit builds with: CC /tmp/build/perf/util/demangle-java.o In file included from util/probe-event.c:27: util/probe-event.c: In function 'find_probe_trace_events_from_map': util/probe-event.c:2978:14: error: format '%lx' expects argument of type 'long unsigned int', but argument 5 has type 'u64' {aka 'long long unsigned int'} [-Werror=format=] pr_debug("Found duplicated symbol %s @ %lx\n", ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ util/debug.h:17:21: note: in definition of macro 'pr_fmt' #define pr_fmt(fmt) fmt ^~~ util/probe-event.c:2978:5: note: in expansion of macro 'pr_debug' pr_debug("Found duplicated symbol %s @ %lx\n", ^~~~~~~~ CC /tmp/build/perf/util/demangle-rust.o I'll change this to use PRIx64. - Arnaldo > + if (i != j) > + continue; > + > tev = (*tevs) + ret; > tp = &tev->point; > if (ret == num_matched_functions) { > -- - Arnaldo