diff options
| -rw-r--r-- | kernel/trace/ftrace.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 998d141488a9..d2272fff2f59 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2748,6 +2748,16 @@ static int ftrace_startup(struct ftrace_ops *ops, int command) ftrace_startup_enable(command); + /* + * If ftrace is in an undefined state, we just remove ops from list + * to prevent the NULL pointer, instead of totally rolling it back and + * free trampoline, because those actions could cause further damage. + */ + if (unlikely(ftrace_disabled)) { + __unregister_ftrace_function(ops); + return -ENODEV; + } + ops->flags &= ~FTRACE_OPS_FL_ADDING; return 0; |