ftrace: Add another check for match in register_ftrace_direct()

As an instruction pointer passed into register_ftrace_direct() may just
exist on the ftrace call site, but may not be the start of the call site
itself, register_ftrace_direct() still needs to update test if a direct call
exists on the normalized site, as only one direct call is allowed at any one
time.

Fixes: 763e34e74bb7d ("ftrace: Add register_ftrace_direct()")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 32e4e5f..9fe33eb 100644 (file)
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5030,7 +5030,12 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
                goto out_unlock;
 
        /* Make sure the ip points to the exact record */
-       ip = rec->ip;
+       if (ip != rec->ip) {
+               ip = rec->ip;
+               /* Need to check this ip for a direct. */
+               if (find_rec_direct(ip))
+                       goto out_unlock;
+       }
 
        ret = -ENOMEM;
        if (ftrace_hash_empty(direct_functions) ||