From nobody Sat Feb 7 14:52:43 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1EDB235D5E8 for ; Tue, 27 Jan 2026 15:06:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769526367; cv=none; b=nLeyKIDZQcfdiXp982RoOc91NsdfunH6cEpxXFKmNr4bL/q+1Y4F4gDUZ5O6KiDLu9MbbMMiRju1gu0IH81+rNtdWqcbHTCHiSREEqPDIevhP513iV+hn2IJrSmMiOjtut3AeS0XgIs1urBBiRwGXl2J+Td7xRClLiNyvz4wSSU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769526367; c=relaxed/simple; bh=nywsedjg+r1aPax6Erd7Q/470qmMSyOdyB+yMNJ4UVM=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=cnMlKMsvB+15VC/KpqFGq4XHP8+SyWl9+7uZrgh28CK1z0oW0ZoTDQvrN1j+xpBb3vp/ZPc0YMciilqWNyfMi1qr7nBm+4C8T8W6zTVUxNW5F4GfTFc/+G3nNht1+qTjw58rtjGTpwidfRfPiiMqxeG5aDJXJ2SkF1KWuQ4iHa4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sRaSmP37; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="sRaSmP37" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92F11C116C6; Tue, 27 Jan 2026 15:06:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769526366; bh=nywsedjg+r1aPax6Erd7Q/470qmMSyOdyB+yMNJ4UVM=; h=Date:From:To:Cc:Subject:References:From; b=sRaSmP37RkOPfgBazu6UpoDAq2KxJjElWDmZ5xSl8F1HVvBUZooMLn3TsKs9T4s4I kMoTYj+fc/fVWB9hejfbQDafzfVFG8MOuzo5jHgUOZnBwMjKDDtYeednk2gZZQtQP5 eCqr8Du2RabtTmdHRJ6MQ7X9duanrnd2A4DLrGYh0VoAv93O0cDvTHdE3m+b0HBoIe y4yOc6q6mjiTvX/YR7nBCDTBybl+HWOSWvMLrIbPdazZb1RolZmex/NCdtD29+iyVd pF4EuvFiHFJFHTt0RfTIgOkhS4LO/8jC/v054z7sErgaW+dUqeTqRpjjD4BT3j6aYz /rqEoMH+9K2dA== Received: from rostedt by gandalf with local (Exim 4.99.1) (envelope-from ) id 1vkkdw-00000000Ld2-1qh7; Tue, 27 Jan 2026 10:06:12 -0500 Message-ID: <20260127150612.296956158@kernel.org> User-Agent: quilt/0.68 Date: Tue, 27 Jan 2026 10:06:01 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Aaron Tomlin Subject: [for-next][PATCH 06/15] tracing: Add show_event_triggers to expose active event triggers References: <20260127150555.840066272@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Aaron Tomlin To audit active event triggers, userspace currently must traverse the events/ directory and read each individual trigger file. This is cumbersome for system-wide auditing or debugging. Introduce "show_event_triggers" at the trace root directory. This file displays all events that currently have one or more triggers applied, alongside the trigger configuration, in a consolidated system:event [tab] trigger format. The implementation leverages the existing trace_event_file iterators and uses the trigger's own print() operation to ensure output consistency with the per-event trigger files. Link: https://patch.msgid.link/20260105142939.2655342-3-atomlin@atomlin.com Signed-off-by: Aaron Tomlin Signed-off-by: Steven Rostedt (Google) --- Documentation/trace/ftrace.rst | 8 +++++ kernel/trace/trace_events.c | 64 ++++++++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+) diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 4ce01e726b09..b9efb148a5c2 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -692,6 +692,14 @@ of ftrace. Here is a list of some of the key files: =20 See events.rst for more information. =20 + show_event_triggers: + + A list of events that have triggers. This shows the + system/event pair along with the trigger that is attached to + the event. + + See events.rst for more information. + available_events: =20 A list of events that can be enabled in tracing. diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 6cbd36508368..36936697fa2a 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1688,6 +1688,38 @@ static int t_show_filters(struct seq_file *m, void *= v) return 0; } =20 +/** + * t_show_triggers - seq_file callback to display active event triggers + * @m: The seq_file interface for formatted output + * @v: The current trace_event_file being iterated + * + * Iterates through the trigger list of the current event file and prints + * each active trigger's configuration using its associated print + * operation. + */ +static int t_show_triggers(struct seq_file *m, void *v) +{ + struct trace_event_file *file =3D v; + struct trace_event_call *call =3D file->event_call; + struct event_trigger_data *data; + + /* + * The event_mutex is held by t_start(), protecting the + * file->triggers list traversal. + */ + if (list_empty(&file->triggers)) + return 0; + + list_for_each_entry_rcu(data, &file->triggers, list) { + seq_printf(m, "%s:%s\t", call->class->system, + trace_event_name(call)); + + data->cmd_ops->print(m, data); + } + + return 0; +} + #ifdef CONFIG_MODULES static int s_show(struct seq_file *m, void *v) { @@ -2516,6 +2548,7 @@ ftrace_event_npid_write(struct file *filp, const char= __user *ubuf, static int ftrace_event_avail_open(struct inode *inode, struct file *file); static int ftrace_event_set_open(struct inode *inode, struct file *file); static int ftrace_event_show_filters_open(struct inode *inode, struct file= *file); +static int ftrace_event_show_triggers_open(struct inode *inode, struct fil= e *file); static int ftrace_event_set_pid_open(struct inode *inode, struct file *fil= e); static int ftrace_event_set_npid_open(struct inode *inode, struct file *fi= le); static int ftrace_event_release(struct inode *inode, struct file *file); @@ -2541,6 +2574,13 @@ static const struct seq_operations show_show_event_f= ilters_seq_ops =3D { .stop =3D t_stop, }; =20 +static const struct seq_operations show_show_event_triggers_seq_ops =3D { + .start =3D t_start, + .next =3D t_next, + .show =3D t_show_triggers, + .stop =3D t_stop, +}; + static const struct seq_operations show_set_pid_seq_ops =3D { .start =3D p_start, .next =3D p_next, @@ -2577,6 +2617,13 @@ static const struct file_operations ftrace_show_even= t_filters_fops =3D { .release =3D seq_release, }; =20 +static const struct file_operations ftrace_show_event_triggers_fops =3D { + .open =3D ftrace_event_show_triggers_open, + .read =3D seq_read, + .llseek =3D seq_lseek, + .release =3D seq_release, +}; + static const struct file_operations ftrace_set_event_pid_fops =3D { .open =3D ftrace_event_set_pid_open, .read =3D seq_read, @@ -2735,6 +2782,20 @@ ftrace_event_show_filters_open(struct inode *inode, = struct file *file) return ftrace_event_open(inode, file, &show_show_event_filters_seq_ops); } =20 +/** + * ftrace_event_show_triggers_open - open interface for show_event_triggers + * @inode: The inode of the file + * @file: The file being opened + * + * Connects the show_event_triggers file to the sequence operations + * required to iterate over and display active event triggers. + */ +static int +ftrace_event_show_triggers_open(struct inode *inode, struct file *file) +{ + return ftrace_event_open(inode, file, &show_show_event_triggers_seq_ops); +} + static int ftrace_event_set_pid_open(struct inode *inode, struct file *file) { @@ -4458,6 +4519,9 @@ create_event_toplevel_files(struct dentry *parent, st= ruct trace_array *tr) trace_create_file("show_event_filters", TRACE_MODE_READ, parent, tr, &ftrace_show_event_filters_fops); =20 + trace_create_file("show_event_triggers", TRACE_MODE_READ, parent, tr, + &ftrace_show_event_triggers_fops); + nr_entries =3D ARRAY_SIZE(events_entries); =20 e_events =3D eventfs_create_events_dir("events", parent, events_entries, --=20 2.51.0