[RFC bpf-next 03/16] ftrace: Add get/put_direct_func function

[Jiri Olsa]

Move code for managing ftrace_direct_funcs entries
into get_direct_func and put_direct_func functions.
It will be used in following patches, there's no
functional change.

Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
 kernel/trace/ftrace.c | 44 +++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index cb8b7a66c6af..95ef7e2a6a57 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5076,6 +5076,32 @@ static int adjust_direct_size(int new_size, struct 
ftrace_hash **free_hash)
        return 0;
 }
 
+static struct ftrace_direct_func *get_direct_func(unsigned long addr)
+{
+       struct ftrace_direct_func *direct;
+
+       direct = ftrace_find_direct_func(addr);
+       if (!direct) {
+               direct = kmalloc(sizeof(*direct), GFP_KERNEL);
+               if (!direct)
+                       return NULL;
+               direct->addr = addr;
+               direct->count = 0;
+               list_add_rcu(&direct->next, &ftrace_direct_funcs);
+               ftrace_direct_func_count++;
+       }
+
+       return direct;
+}
+
+static void put_direct_func(struct ftrace_direct_func *direct)
+{
+       list_del_rcu(&direct->next);
+       synchronize_rcu_tasks();
+       kfree(direct);
+       ftrace_direct_func_count--;
+}
+
 /**
  * register_ftrace_direct - Call a custom trampoline directly
  * @ip: The address of the nop at the beginning of a function
@@ -5114,17 +5140,10 @@ int register_ftrace_direct(unsigned long ip, unsigned 
long addr)
        if (!entry)
                goto out_unlock;
 
-       direct = ftrace_find_direct_func(addr);
+       direct = get_direct_func(addr);
        if (!direct) {
-               direct = kmalloc(sizeof(*direct), GFP_KERNEL);
-               if (!direct) {
-                       kfree(entry);
-                       goto out_unlock;
-               }
-               direct->addr = addr;
-               direct->count = 0;
-               list_add_rcu(&direct->next, &ftrace_direct_funcs);
-               ftrace_direct_func_count++;
+               kfree(entry);
+               goto out_unlock;
        }
 
        entry->ip = ip;
@@ -5144,13 +5163,10 @@ int register_ftrace_direct(unsigned long ip, unsigned 
long addr)
        if (ret) {
                kfree(entry);
                if (!direct->count) {
-                       list_del_rcu(&direct->next);
-                       synchronize_rcu_tasks();
-                       kfree(direct);
+                       put_direct_func(direct);
                        if (free_hash)
                                free_ftrace_hash(free_hash);
                        free_hash = NULL;
-                       ftrace_direct_func_count--;
                }
        } else {
                direct->count++;
-- 
2.26.2