> On May 24, 2022, at 7:45 AM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> On Thu, 12 May 2022 15:08:08 -0700
> Song Liu <song@xxxxxxxxxx> wrote:
>
>> --- a/kernel/trace/ftrace.c
>> +++ b/kernel/trace/ftrace.c
>> @@ -4465,7 +4465,7 @@ int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
>> * @ip: The instruction pointer address to remove the data from
>> *
>> * Returns the data if it is found, otherwise NULL.
>> - * Note, if the data pointer is used as the data itself, (see
>> + * Note, if the data pointer is used as the data itself, (see
>> * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
>> * if the data pointer was set to zero.
>> */
>> @@ -5200,8 +5200,10 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
>>
>> if (!ret && !(direct_ops.flags & FTRACE_OPS_FL_ENABLED)) {
>> ret = register_ftrace_function(&direct_ops);
>> - if (ret)
>> + if (ret) {
>> ftrace_set_filter_ip(&direct_ops, ip, 1, 0);
>> + remove_hash_entry(direct_functions, entry);
>> + }
>> }
>>
>> if (ret) {
>
> Perhaps something like this is more robust?
Yeah, this does look better. Do I need to send v2 with this version?
Thanks,
Song
>
> -- Steve
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 4f1d2f5e7263..cd38ad490174 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -5195,8 +5195,6 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
> goto out_unlock;
>
> 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);
> @@ -5205,6 +5203,7 @@ 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);
>
