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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30B5DECAAD5 for ; Tue, 6 Sep 2022 15:54:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238379AbiIFPyh (ORCPT ); Tue, 6 Sep 2022 11:54:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44832 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233915AbiIFPyL (ORCPT ); Tue, 6 Sep 2022 11:54:11 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C7C92DA9A; Tue, 6 Sep 2022 08:11:39 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 79285B8191A; Tue, 6 Sep 2022 15:11:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 443B5C433D7; Tue, 6 Sep 2022 15:11:36 +0000 (UTC) Date: Tue, 6 Sep 2022 11:12:14 -0400 From: Steven Rostedt To: Jianlin Lv Cc: corbet@lwn.net, mingo@redhat.com, jianlv@ebay.com, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Masami Hiramatsu , Tom Zanussi Subject: Re: [PATCH v2] tracing/kprobes: Add method to display private kprobes in tracefs Message-ID: <20220906111214.0dd113cd@gandalf.local.home> In-Reply-To: <20220725062334.1778-1-iecedge@gmail.com> References: <20220725062334.1778-1-iecedge@gmail.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Adding Masami and Tom ] On Mon, 25 Jul 2022 06:23:34 +0000 Jianlin Lv wrote: > The private kprobes are not added to the global list dyn_event_list, > so there is a missing interface to show probe hit and probe miss. > This patch adds a profiling interface to check the number of hits or > misses for private kprobes. Masami, what do you think of this patch? -- Steve > > Signed-off-by: Jianlin Lv > --- > v2: update commit message > --- > Documentation/trace/kprobetrace.rst | 6 +++- > kernel/trace/trace_dynevent.c | 20 +++++++++++ > kernel/trace/trace_dynevent.h | 37 ++++++++++++++++++++ > kernel/trace/trace_kprobe.c | 54 +++++++++++++++++++++++++++++ > 4 files changed, 116 insertions(+), 1 deletion(-) > > diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst > index b175d88f31eb..8815d64dd8a6 100644 > --- a/Documentation/trace/kprobetrace.rst > +++ b/Documentation/trace/kprobetrace.rst > @@ -146,7 +146,11 @@ trigger: > Event Profiling > --------------- > You can check the total number of probe hits and probe miss-hits via > -/sys/kernel/debug/tracing/kprobe_profile. > +/sys/kernel/debug/tracing/kprobe_profile or > +/sys/kernel/debug/tracing/kprobe_local_profile. > +All kprobe events created by kprobe_events will be added to the global > +list, you can get their profiling via kprobe_profile; kprobe_local_profile > +shows profiling for private kprobe events created by perf_kprobe pmu. > The first column is event name, the second is the number of probe hits, > the third is the number of probe miss-hits. > > diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c > index 076b447a1b88..70ec99cd9c53 100644 > --- a/kernel/trace/trace_dynevent.c > +++ b/kernel/trace/trace_dynevent.c > @@ -181,6 +181,26 @@ static const struct seq_operations dyn_event_seq_op = { > .show = dyn_event_seq_show > }; > > +#ifdef CONFIG_KPROBE_EVENTS > +LIST_HEAD(local_event_list); > + > +void *local_event_seq_start(struct seq_file *m, loff_t *pos) > +{ > + mutex_lock(&event_mutex); > + return seq_list_start(&local_event_list, *pos); > +} > + > +void *local_event_seq_next(struct seq_file *m, void *v, loff_t *pos) > +{ > + return seq_list_next(v, &local_event_list, pos); > +} > + > +void local_event_seq_stop(struct seq_file *m, void *v) > +{ > + mutex_unlock(&event_mutex); > +} > +#endif /* CONFIG_KPROBE_EVENTS */ > + > /* > * dyn_events_release_all - Release all specific events > * @type: the dyn_event_operations * which filters releasing events > diff --git a/kernel/trace/trace_dynevent.h b/kernel/trace/trace_dynevent.h > index 936477a111d3..e30193470295 100644 > --- a/kernel/trace/trace_dynevent.h > +++ b/kernel/trace/trace_dynevent.h > @@ -101,6 +101,43 @@ void dyn_event_seq_stop(struct seq_file *m, void *v); > int dyn_events_release_all(struct dyn_event_operations *type); > int dyn_event_release(const char *raw_command, struct dyn_event_operations *type); > > +#ifdef CONFIG_KPROBE_EVENTS > +extern struct list_head local_event_list; > + > +static inline > +int local_event_init(struct dyn_event *ev, struct dyn_event_operations *ops) > +{ > + if (!ev || !ops) > + return -EINVAL; > + > + INIT_LIST_HEAD(&ev->list); > + ev->ops = ops; > + return 0; > +} > + > +static inline int local_event_add(struct dyn_event *ev) > +{ > + lockdep_assert_held(&event_mutex); > + > + if (!ev || !ev->ops) > + return -EINVAL; > + > + list_add_tail(&ev->list, &local_event_list); > + return 0; > +} > + > +static inline void local_event_remove(struct dyn_event *ev) > +{ > + lockdep_assert_held(&event_mutex); > + list_del_init(&ev->list); > +} > + > +void *local_event_seq_start(struct seq_file *m, loff_t *pos); > +void *local_event_seq_next(struct seq_file *m, void *v, loff_t *pos); > +void local_event_seq_stop(struct seq_file *m, void *v); > + > +#endif /* CONFIG_KPROBE_EVENTS */ > + > /* > * for_each_dyn_event - iterate over the dyn_event list > * @pos: the struct dyn_event * to use as a loop cursor > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index a245ea673715..76f500b17b46 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -1213,6 +1213,52 @@ static const struct file_operations kprobe_profile_ops = { > .release = seq_release, > }; > > +#ifdef CONFIG_KPROBE_EVENTS > +/* kprobe Local profile */ > +static int local_probes_profile_seq_show(struct seq_file *m, void *v) > +{ > + struct dyn_event *ev = v; > + struct trace_kprobe *tk; > + > + if (!is_trace_kprobe(ev)) > + return 0; > + > + tk = to_trace_kprobe(ev); > + seq_printf(m, " %-44s %15lu %15lu\n", > + trace_probe_name(&tk->tp), > + trace_kprobe_nhit(tk), > + tk->rp.kp.nmissed); > + > + return 0; > +} > + > +static const struct seq_operations local_profile_seq_op = { > + .start = local_event_seq_start, > + .next = local_event_seq_next, > + .stop = local_event_seq_stop, > + .show = local_probes_profile_seq_show > +}; > + > +static int local_profile_open(struct inode *inode, struct file *file) > +{ > + int ret; > + > + ret = security_locked_down(LOCKDOWN_TRACEFS); > + if (ret) > + return ret; > + > + return seq_open(file, &local_profile_seq_op); > +} > + > +static const struct file_operations kprobe_local_profile_ops = { > + .owner = THIS_MODULE, > + .open = local_profile_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = seq_release, > +}; > +#endif /* CONFIG_KPROBE_EVENTS */ > + > /* Kprobe specific fetch functions */ > > /* Return the length of string -- including null terminal byte */ > @@ -1830,6 +1876,7 @@ create_local_trace_kprobe(char *func, void *addr, unsigned long offs, > if (ret < 0) > goto error; > > + local_event_add(&tk->devent); > return trace_probe_event_call(&tk->tp); > error: > free_trace_kprobe(tk); > @@ -1849,6 +1896,7 @@ void destroy_local_trace_kprobe(struct trace_event_call *event_call) > return; > } > > + local_event_remove(&tk->devent); > __unregister_trace_kprobe(tk); > > free_trace_kprobe(tk); > @@ -1929,6 +1977,12 @@ static __init int init_kprobe_trace(void) > trace_create_file("kprobe_profile", TRACE_MODE_READ, > NULL, NULL, &kprobe_profile_ops); > > +#ifdef CONFIG_KPROBE_EVENTS > + /* kprobe Local profile */ > + tracefs_create_file("kprobe_local_profile", TRACE_MODE_READ, > + NULL, NULL, &kprobe_local_profile_ops); > +#endif /* CONFIG_KPROBE_EVENTS */ > + > setup_boot_kprobe_events(); > > return 0;