This is a note to let you know that I've just added the patch titled
tracing: Do not count ftrace events in top level enable output
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tracing-do-not-count-ftrace-events-in-top-level-enable-output.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 256cfdd6fdf70c6fcf0f7c8ddb0ebd73ce8f3bc9 Mon Sep 17 00:00:00 2001
From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>
Date: Fri, 5 Feb 2021 15:40:04 -0500
Subject: tracing: Do not count ftrace events in top level enable output
From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Fixes: 553552ce1796c ("tracing: Combine event filter_active and enable into single flags field")
Reported-by: "Yordan Karadzhov (VMware)" <y.karadz@xxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -1212,7 +1212,8 @@ 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)
Patches currently in stable-queue which might be from rostedt@xxxxxxxxxxx are
queue-5.10/tracing-do-not-count-ftrace-events-in-top-level-enable-output.patch
queue-5.10/tracing-check-length-before-giving-out-the-filter-buffer.patch
