Re: [PATCH 2/2] tracing/probes: Fix basic print type functions

[Namhyung Kim <namhyung@kernel.org>]

Hi Oleg,

On Wed, 20 Nov 2013 16:22:45 +0100, Oleg Nesterov wrote:
> On 11/18, Namhyung Kim wrote:
>>
>> -DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
>> -DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
>> -DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
>> +DEFINE_BASIC_PRINT_TYPE_FUNC(u8 , "%x", unsigned char)
>> +DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned short)
>> +DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%x", unsigned int)
>> +DEFINE_BASIC_PRINT_TYPE_FUNC(s8,  "%d", signed char)
>> +DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", short)
>> +DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d", int)
>> +#if BITS_PER_LONG == 32
>>  DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
>> -DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
>> -DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
>> -DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
>>  DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
>> +#else /* BITS_PER_LONG == 64 */
>> +DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%lx", unsigned long)
>> +DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%ld", long)
>> +#endif
>
> I must have missed something... Not only I do not understand why
> do we need "#if BITS_PER_LONG", I can't understand why
> DEFINE_BASIC_PRINT_TYPE_FUNC() needs "cast" argument.
>
> IOW, how about the patch below instead?

Looks good to me.

Masami, did you have any issue regarding the casts?

Thanks,
Namhyung

>
> --- x/kernel/trace/trace_probe.c
> +++ x/kernel/trace/trace_probe.c
> @@ -40,23 +40,23 @@ const char *reserved_field_names[] = {
>  #define PRINT_TYPE_FMT_NAME(type)	print_type_format_##type
>  
>  /* Printing  in basic type function template */
> -#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt, cast)			\
> +#define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt)				\
>  static __kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s,	\
>  						const char *name,	\
> -						void *data, void *ent)\
> +						void *data, void *ent)	\
>  {									\
> -	return trace_seq_printf(s, " %s=" fmt, name, (cast)*(type *)data);\
> +	return trace_seq_printf(s, " %s=" fmt, name, *(type *)data);	\
>  }									\
>  static const char PRINT_TYPE_FMT_NAME(type)[] = fmt;
>  
> -DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x", unsigned int)
> -DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x", unsigned int)
> -DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%lx", unsigned long)
> -DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%llx", unsigned long long)
> -DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d", int)
> -DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d", int)
> -DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%ld", long)
> -DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%lld", long long)
> +DEFINE_BASIC_PRINT_TYPE_FUNC(u8, "%x")
> +DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "%x")
> +DEFINE_BASIC_PRINT_TYPE_FUNC(u32, "%x")
> +DEFINE_BASIC_PRINT_TYPE_FUNC(u64, "%Lx")
> +DEFINE_BASIC_PRINT_TYPE_FUNC(s8, "%d")
> +DEFINE_BASIC_PRINT_TYPE_FUNC(s16, "%d")
> +DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d")
> +DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld")
>  
>  static inline void *get_rloc_data(u32 *dl)
>  {