Re: [PATCH v4 7/9] vsprintf: Factor out %pO handler as kobject_string()

[Sergey Senozhatsky]

On (04/04/18 10:58), Petr Mladek wrote:
>  static noinline_for_stack
> +char *kobject_string(char *buf, char *end, void *ptr,
> +                  struct printf_spec spec, const char *fmt)
> +{
> +     switch (fmt[1]) {
> +     case 'F':
> +             return device_node_string(buf, end, ptr, spec, fmt + 1);
> +     }
> +
> +     WARN_ONCE(1, "Unsupported pointer format specifier: %%pO%c\n", fmt[1]);
> +     return buf;
> +}
> +
> +static noinline_for_stack
>  char *pointer_string(char *buf, char *end, const void *ptr,
>                    struct printf_spec spec)
>  {
> @@ -1982,10 +1995,7 @@ char *pointer(const char *fmt, char *buf, char *end, 
> void *ptr,
>       case 'G':
>               return flags_string(buf, end, ptr, fmt);
>       case 'O':
> -             switch (fmt[1]) {
> -             case 'F':
> -                     return device_node_string(buf, end, ptr, spec, fmt + 1);
> -             }
> +             return kobject_string(buf, end, ptr, spec, fmt);
>       case 'x':
>               return pointer_string(buf, end, ptr, spec);
>       }

So, previously, unsupported 'O' would end up in ptr_to_id()

        case 'O':
                switch (fmt[1]) {
                case 'F':
                        return device_node_string()
                }
        }

        return ptr_to_id();



now we will just return `buf' without doing ptr_to_id()?

        case 'O':
                return kobject_string();  // which does device_node_string()
                                          // for fmt 'O' or return buf
                                          // for unknown fmt.
        }

        return ptr_to_id();


Was this your intention?

        -ss