tracing: Fix permissions for the buffer_percent file

commit 4f94559f40ad06d627c0fdfc3319cec778a2845b upstream.

This file defines both read and write operations, yet it is being
created as read-only. This means that it can't be written to without the
CAP_DAC_OVERRIDE capability. Fix the permissions to allow root to write
to it without the need to override DAC perms.

Link: https://lore.kernel.org/linux-trace-kernel/20230503140114.3280002-1-omosnace@redhat.com
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 03329f993978 ("tracing: Add tracefs file buffer_percentage")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 13b324f0082563ca531491ecd609e721b3f3ebb8..a61a96569ef5aec2f10328b8ae9ded7749058351 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9621,7 +9621,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
 
        tr->buffer_percent = 50;
 
-       trace_create_file("buffer_percent", TRACE_MODE_READ, d_tracer,
+       trace_create_file("buffer_percent", TRACE_MODE_WRITE, d_tracer,
                        tr, &buffer_percent_fops);
 
        create_trace_options_dir(tr);