From 7d436400223bb46e9f88e6bba6f8d867acf0d82c Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 22 Nov 2016 18:32:03 -0500 Subject: [PATCH] tracing: Add error checks to creation of event files The creation of the set_event_pid file was assigned to a variable "entry" but that variable was never used. Ideally, it should be used to check if the file was created and warn if it was not. The files header_page, header_event should also be checked and a warning if they fail to be created. The "enable" file was moved up, as it is a more crucial file to have and a hard failure (return -ENOMEM) should be returned if it is not created. Reported-by: David Binderman Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 03c0a48c3ac4..ba67ede48822 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2843,20 +2843,32 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr) return -ENOMEM; } + entry = trace_create_file("enable", 0644, d_events, + tr, &ftrace_tr_enable_fops); + if (!entry) { + pr_warn("Could not create tracefs 'enable' entry\n"); + return -ENOMEM; + } + + /* There are not as crucial, just warn if they are not created */ + entry = tracefs_create_file("set_event_pid", 0644, parent, tr, &ftrace_set_event_pid_fops); + if (!entry) + pr_warn("Could not create tracefs 'set_event_pid' entry\n"); /* ring buffer internal formats */ - trace_create_file("header_page", 0444, d_events, - ring_buffer_print_page_header, - &ftrace_show_header_fops); + entry = trace_create_file("header_page", 0444, d_events, + ring_buffer_print_page_header, + &ftrace_show_header_fops); + if (!entry) + pr_warn("Could not create tracefs 'header_page' entry\n"); - trace_create_file("header_event", 0444, d_events, - ring_buffer_print_entry_header, - &ftrace_show_header_fops); - - trace_create_file("enable", 0644, d_events, - tr, &ftrace_tr_enable_fops); + entry = trace_create_file("header_event", 0444, d_events, + ring_buffer_print_entry_header, + &ftrace_show_header_fops); + if (!entry) + pr_warn("Could not create tracefs 'header_event' entry\n"); tr->event_dir = d_events;