linux-kernel - [PATCH 4.14 17/57] tracing: Do not count ftrace events in top level enable output

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210222121028.439361014@linuxfoundation.org>
Date:   Mon, 22 Feb 2021 13:35:43 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        "Yordan Karadzhov (VMware)" <y.karadz@...il.com>,
        "Steven Rostedt (VMware)" <rostedt@...dmis.org>
Subject: [PATCH 4.14 17/57] tracing: Do not count ftrace events in top level enable output

From: Steven Rostedt (VMware) <rostedt@...dmis.org>

commit 256cfdd6fdf70c6fcf0f7c8ddb0ebd73ce8f3bc9 upstream.

The file /sys/kernel/tracing/events/enable is used to enable all events by
echoing in "1", or disabling all events when echoing in "0". To know if all
events are enabled, disabled, or some are enabled but not all of them,
cating the file should show either "1" (all enabled), "0" (all disabled), or
"X" (some enabled but not all of them). This works the same as the "enable"
files in the individule system directories (like tracing/events/sched/enable).

But when all events are enabled, the top level "enable" file shows "X". The
reason is that its checking the "ftrace" events, which are special events
that only exist for their format files. These include the format for the
function tracer events, that are enabled when the function tracer is
enabled, but not by the "enable" file. The check includes these events,
which will always be disabled, and even though all true events are enabled,
the top level "enable" file will show "X" instead of "1".

To fix this, have the check test the event's flags to see if it has the
"IGNORE_ENABLE" flag set, and if so, not test it.

Cc: stable@...r.kernel.org
Fixes: 553552ce1796c ("tracing: Combine event filter_active and enable into single flags field")
Reported-by: "Yordan Karadzhov (VMware)" <y.karadz@...il.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 kernel/trace/trace_events.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1114,7 +1114,8 @@ system_enable_read(struct file *filp, ch
 	mutex_lock(&event_mutex);
 	list_for_each_entry(file, &tr->events, list) {
 		call = file->event_call;
-		if (!trace_event_name(call) || !call->class || !call->class->reg)
+		if ((call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
+		    !trace_event_name(call) || !call->class || !call->class->reg)
 			continue;

 		if (system && strcmp(call->class->system, system->name) != 0)