Re: [RFC PATCH 03/14] ftrace: Fix cleanup in error path of register_ftrace_direct()

[Steven Rostedt]

On Thu, 26 Nov 2020 23:38:40 +0530
"Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxxxxxxx> wrote:

> We need to remove hash entry if register_ftrace_function() fails.
> Consolidate the cleanup to be done after register_ftrace_function() at
> the end.

Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

-- Steve

> 
> Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
> ---
>  kernel/trace/ftrace.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 9c1bba8cc51b03..3844a4a1346a9c 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -5136,8 +5136,6 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
>  	__add_hash_entry(direct_functions, entry);
>  
>  	ret = ftrace_set_filter_ip(&direct_ops, ip, 0, 0);
> -	if (ret)
> -		remove_hash_entry(direct_functions, entry);
>  
>  	if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) {
>  		ret = register_ftrace_function(&direct_ops);
> @@ -5146,6 +5144,7 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
>  	}
>  
>  	if (ret) {
> +		remove_hash_entry(direct_functions, entry);
>  		kfree(entry);
>  		if (!direct->count) {
>  			list_del_rcu(&direct->next);