From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751414AbdAPWWI (ORCPT ); Mon, 16 Jan 2017 17:22:08 -0500 Received: from mail.kernel.org ([198.145.29.136]:41534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751156AbdAPWWF (ORCPT ); Mon, 16 Jan 2017 17:22:05 -0500 Date: Tue, 17 Jan 2017 07:21:50 +0900 From: Masami Hiramatsu To: Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, Jiri Olsa , Peter Zijlstra , Ingo Molnar , Namhyung Kim Subject: Re: [PATCH perf/core v2 4/4] perf-probe: Find probe events without target module Message-Id: <20170117072150.a6fe58c9f921dadef267022a@kernel.org> In-Reply-To: <20170116184455.GA14872@kernel.org> References: <148411429514.9978.10060675441541429175.stgit@devbox> <148411457651.9978.9001772639862860573.stgit@devbox> <20170116184455.GA14872@kernel.org> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 16 Jan 2017 15:44:55 -0300 Arnaldo Carvalho de Melo wrote: > Em Wed, Jan 11, 2017 at 03:03:06PM +0900, Masami Hiramatsu escreveu: > > Find probe events without -m "module" option. If perf-probe > > failed to find given function in kernel image, it tries to > > find same symbol and module in kallsyms, and retry search > > in the found module. E.g. > > > > # perf probe -D i915_capabilities > > p:probe/i915_capabilities i915:i915_capabilities+0 > > > > Note: without -m option, perf probe can not find inlined > > function since there is no symbol information in kallsyms. > > As this is a new feature, I'll postpone merging it till we get > perf/urgent, with the first three patches in this series, merged into > perf/core, ok? Agreed :-) Thank you! > > - Arnaldo > > > Signed-off-by: Masami Hiramatsu > > Suggested-by: Arnaldo Carvalho de Melo > > --- > > Changes in v2: > > - Fix to remove unneeded zero-return. > > - Remove unneeded debug message. > > --- > > tools/perf/util/probe-event.c | 69 ++++++++++++++++++++++++++++++----------- > > 1 file changed, 51 insertions(+), 18 deletions(-) > > > > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c > > index 6a6f44d..715f330 100644 > > --- a/tools/perf/util/probe-event.c > > +++ b/tools/perf/util/probe-event.c > > @@ -858,11 +858,7 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, > > > > debuginfo__delete(dinfo); > > > > - if (ntevs == 0) { /* No error but failed to find probe point. */ > > - pr_warning("Probe point '%s' not found.\n", > > - synthesize_perf_probe_point(&pev->point)); > > - return -ENOENT; > > - } else if (ntevs < 0) { > > + if (ntevs < 0) { > > /* Error path : ntevs < 0 */ > > pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs); > > if (ntevs == -EBADF) > > @@ -2829,9 +2825,7 @@ static int find_probe_trace_events_from_map(struct perf_probe_event *pev, > > */ > > num_matched_functions = find_probe_functions(map, pp->function, syms); > > if (num_matched_functions == 0) { > > - pr_err("Failed to find symbol %s in %s\n", pp->function, > > - pev->target ? : "kernel"); > > - ret = -ENOENT; > > + ret = 0; > > goto out; > > } else if (num_matched_functions > probe_conf.max_probes) { > > pr_err("Too many functions matched in %s\n", > > @@ -3233,6 +3227,42 @@ static int find_probe_trace_events_from_cache(struct perf_probe_event *pev, > > return ret; > > } > > > > +static int __convert_to_probe_trace_events(struct perf_probe_event *pev, > > + struct probe_trace_event **tevs) > > +{ > > + int ret; > > + > > + /* At first, we need to lookup cache entry */ > > + ret = find_probe_trace_events_from_cache(pev, tevs); > > + if (ret > 0 || pev->sdt) /* SDT can be found only in the cache */ > > + return ret == 0 ? -ENOENT : ret; /* Found in probe cache */ > > + > > + /* Convert perf_probe_event with debuginfo */ > > + ret = try_to_find_probe_trace_events(pev, tevs); > > + if (ret != 0) > > + return ret; /* Found in debuginfo or got an error */ > > + > > + return find_probe_trace_events_from_map(pev, tevs); > > +} > > + > > +static char *find_module_from_kallsyms(const char *symbol_name) > > +{ > > + struct machine *machine = machine__new_kallsyms(); > > + struct symbol *sym; > > + struct map *map; > > + char *module; > > + > > + sym = machine__find_kernel_function_by_name(machine, symbol_name, &map); > > + if (!sym || map->dso->short_name[0] != '[') > > + return NULL; > > + pr_debug("Found %s in %s\n", sym->name, map->dso->short_name); > > + module = strdup(map->dso->short_name + 1); > > + if (module) > > + module[strlen(module) - 1] = '\0'; > > + > > + return module; > > +} > > + > > static int convert_to_probe_trace_events(struct perf_probe_event *pev, > > struct probe_trace_event **tevs) > > { > > @@ -3255,17 +3285,20 @@ static int convert_to_probe_trace_events(struct perf_probe_event *pev, > > if (ret > 0) > > return ret; > > > > - /* At first, we need to lookup cache entry */ > > - ret = find_probe_trace_events_from_cache(pev, tevs); > > - if (ret > 0 || pev->sdt) /* SDT can be found only in the cache */ > > - return ret == 0 ? -ENOENT : ret; /* Found in probe cache */ > > - > > - /* Convert perf_probe_event with debuginfo */ > > - ret = try_to_find_probe_trace_events(pev, tevs); > > - if (ret != 0) > > - return ret; /* Found in debuginfo or got an error */ > > + ret = __convert_to_probe_trace_events(pev, tevs); > > + /* Not found. will retry to check kmodule if possible */ > > + if (ret == 0 && !pev->uprobes && !pev->target) { > > + pev->target = find_module_from_kallsyms(pev->point.function); > > + if (pev->target) > > + ret = __convert_to_probe_trace_events(pev, tevs); > > + } > > > > - return find_probe_trace_events_from_map(pev, tevs); > > + if (ret == 0) { > > + pr_warning("Probe point '%s' not found.\n", > > + synthesize_perf_probe_point(&pev->point)); > > + ret = -ENOENT; > > + } > > + return ret; > > } > > > > int convert_perf_probe_events(struct perf_probe_event *pevs, int npevs) -- Masami Hiramatsu