From: Steven Rostedt Date: Thu, 7 May 2009 15:49:35 +0000 (-0400) Subject: tracing: append ":*" to internal setting of system events X-Git-Tag: v2.6.31-rc5~1^2~51^2~60 X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;h=d6bf81ef0f7474434c2a049e8bf3c9146a14dd96;p=~andy%2Flinux tracing: append ":*" to internal setting of system events The system enabling of events uses the same code as the set_event file. It passes in the name of the system to the parser and that will enable all the events that has that system as a name. The problem is that it will also enable events with the same name as the system. If you have system name foo, and system name bar, but within the system bar, there exists an event called foo. By setting the system name foo, you will also be enabling the event foo in the system bar. This is not an expected result. The solution is to pass in "foo:*", which will only enable the system foo and not events called foo. [ Impact: prevent accidental enabling of events with same name as a system ] Reported-by: Li Zefan Signed-off-by: Steven Rostedt --- diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 87feb0117ce..8d0fae3af59 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -509,9 +509,11 @@ system_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, return -EINVAL; } - command = kstrdup(system, GFP_KERNEL); + /* +3 for the ":*\0" */ + command = kmalloc(strlen(system)+3, GFP_KERNEL); if (!command) return -ENOMEM; + sprintf(command, "%s:*", system); ret = ftrace_set_clr_event(command, val); if (ret) @@ -1179,7 +1181,7 @@ static __init int event_trace_init(void) &ftrace_show_header_fops); trace_create_file("enable", 0644, d_events, - "*:*", &ftrace_system_enable_fops); + "*", &ftrace_system_enable_fops); for_each_event(call, __start_ftrace_events, __stop_ftrace_events) { /* The linker may leave blanks */