Re: [PATCH v3] err.h: allow IS_ERR_VALUE to handle properly more types

[Andrzej Hajda]

On 02/04/2016 01:40 PM, Arnd Bergmann wrote:
> On Wednesday 03 February 2016 14:15:28 Andrzej Hajda wrote:
>> diff --git a/include/linux/err.h b/include/linux/err.h
>> index 56762ab..b7d4a9f 100644
>> --- a/include/linux/err.h
>> +++ b/include/linux/err.h
>> @@ -18,7 +18,9 @@
>>  
>>  #ifndef __ASSEMBLY__
>>  
>> -#define IS_ERR_VALUE(x) unlikely((x) >= (unsigned long)-MAX_ERRNO)
>> +#define IS_ERR_VALUE(x) ((typeof(x))(-1) <= 0 \
>> +                               ? unlikely((x) <= -1) \
>> +                               : unlikely((x) >= (typeof(x))-MAX_ERRNO))
>>  
>>  static inline void * __must_check ERR_PTR(long error)
>>  {
>>
> This has caused a warning to reappear that I had fixed before:
>
> fs/gfs2/dir.c: In function 'get_first_leaf':
> fs/gfs2/dir.c:802:9: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]
>    error = get_leaf(dip, leaf_no, bh_out);
>          ^
> fs/gfs2/dir.c: In function 'dir_split_leaf':
> fs/gfs2/dir.c:1021:8: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   error = get_leaf(dip, leaf_no, &obh);

What gcc/arch/build options do you use? I cannot reproduce it in my
environment.

Regards
Andrzej