[PATCH v2 2/4] linux/const.h: move UL() macro to include/linux/const.h
yamada.masahiro at socionext.com
Sat Jan 7 22:27:40 PST 2017
2017-01-06 19:45 GMT+09:00 David Howells <dhowells at redhat.com>:
> Masahiro Yamada <yamada.masahiro at socionext.com> wrote:
>> diff --git a/include/uapi/linux/const.h b/include/uapi/linux/const.h
>> index c872bfd..76fb0f9 100644
>> --- a/include/uapi/linux/const.h
>> +++ b/include/uapi/linux/const.h
>> @@ -1,7 +1,7 @@
>> /* const.h: Macros for dealing with constants. */
>> -#ifndef _LINUX_CONST_H
>> -#define _LINUX_CONST_H
>> +#ifndef _UAPI_LINUX_CONST_H
>> +#define _UAPI_LINUX_CONST_H
> You need to be very careful doing this. Some userspace stuff depends on the
> guard macro names on the kernel header files.
>> /* Some constant macros are used in both assembler and
>> * C code. Therefore we cannot annotate them always with
>> @@ -21,7 +21,10 @@
>> #define _AT(T,X) ((T)(X))
>> +#define _UL(x) (_AC(x, UL))
>> +#define _ULL(x) (_AC(x, ULL))
> How likely is this to collide with existing userspace code somewhere? It
> looks like the sort of thing that could collide with a C library.
Sorry, I do not have enough insight to answer your questions.
If this seems dangerous, please feel free to drop the entire series
because it is not adding any value except some cleanups.
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